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[Qemu-devel] [PULL 76/76] block: move I/O request processing to block/io
|
From: |
Kevin Wolf |
|
Subject: |
[Qemu-devel] [PULL 76/76] block: move I/O request processing to block/io.c |
|
Date: |
Tue, 28 Apr 2015 17:00:58 +0200 |
From: Stefan Hajnoczi <address@hidden>
The block.c file has grown to over 6000 lines. It is time to split this
file so there are fewer conflicts and the code is easier to maintain.
Extract I/O request processing code:
* Read
* Write
* Zero writes and making the image empty
* Flush
* Discard
* ioctl
* Tracked requests and queuing
* Throttling and copy-on-read
* Block status and allocated functions
* Refreshing block limits
* Reading/writing vmstate
* qemu_blockalign() and friends
The patch simply moves code from block.c into block/io.c.
Signed-off-by: Stefan Hajnoczi <address@hidden>
Signed-off-by: Kevin Wolf <address@hidden>
---
block.c | 3394 +++++++--------------------------------------------
block/Makefile.objs | 2 +-
block/io.c | 2540 ++++++++++++++++++++++++++++++++++++++
3 files changed, 2982 insertions(+), 2954 deletions(-)
create mode 100644 block/io.c
diff --git a/block.c b/block.c
index 954d783..7904098 100644
--- a/block.c
+++ b/block.c
@@ -30,7 +30,6 @@
#include "qapi/qmp/qjson.h"
#include "sysemu/block-backend.h"
#include "sysemu/sysemu.h"
-#include "sysemu/qtest.h"
#include "qemu/notify.h"
#include "block/coroutine.h"
#include "block/qapi.h"
@@ -71,36 +70,6 @@ struct BdrvDirtyBitmap {
#define NOT_DONE 0x7fffffff /* used while emulated sync operation in progress
*/
-static BlockAIOCB *bdrv_aio_readv_em(BlockDriverState *bs,
- int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
- BlockCompletionFunc *cb, void *opaque);
-static BlockAIOCB *bdrv_aio_writev_em(BlockDriverState *bs,
- int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
- BlockCompletionFunc *cb, void *opaque);
-static int coroutine_fn bdrv_co_readv_em(BlockDriverState *bs,
- int64_t sector_num, int nb_sectors,
- QEMUIOVector *iov);
-static int coroutine_fn bdrv_co_writev_em(BlockDriverState *bs,
- int64_t sector_num, int nb_sectors,
- QEMUIOVector *iov);
-static int coroutine_fn bdrv_co_do_preadv(BlockDriverState *bs,
- int64_t offset, unsigned int bytes, QEMUIOVector *qiov,
- BdrvRequestFlags flags);
-static int coroutine_fn bdrv_co_do_pwritev(BlockDriverState *bs,
- int64_t offset, unsigned int bytes, QEMUIOVector *qiov,
- BdrvRequestFlags flags);
-static BlockAIOCB *bdrv_co_aio_rw_vector(BlockDriverState *bs,
- int64_t sector_num,
- QEMUIOVector *qiov,
- int nb_sectors,
- BdrvRequestFlags flags,
- BlockCompletionFunc *cb,
- void *opaque,
- bool is_write);
-static void coroutine_fn bdrv_co_do_rw(void *opaque);
-static int coroutine_fn bdrv_co_do_write_zeroes(BlockDriverState *bs,
- int64_t sector_num, int nb_sectors, BdrvRequestFlags flags);
-
static QTAILQ_HEAD(, BlockDriverState) bdrv_states =
QTAILQ_HEAD_INITIALIZER(bdrv_states);
@@ -134,110 +103,6 @@ int is_windows_drive(const char *filename)
}
#endif
-/* throttling disk I/O limits */
-void bdrv_set_io_limits(BlockDriverState *bs,
- ThrottleConfig *cfg)
-{
- int i;
-
- throttle_config(&bs->throttle_state, cfg);
-
- for (i = 0; i < 2; i++) {
- qemu_co_enter_next(&bs->throttled_reqs[i]);
- }
-}
-
-/* this function drain all the throttled IOs */
-static bool bdrv_start_throttled_reqs(BlockDriverState *bs)
-{
- bool drained = false;
- bool enabled = bs->io_limits_enabled;
- int i;
-
- bs->io_limits_enabled = false;
-
- for (i = 0; i < 2; i++) {
- while (qemu_co_enter_next(&bs->throttled_reqs[i])) {
- drained = true;
- }
- }
-
- bs->io_limits_enabled = enabled;
-
- return drained;
-}
-
-void bdrv_io_limits_disable(BlockDriverState *bs)
-{
- bs->io_limits_enabled = false;
-
- bdrv_start_throttled_reqs(bs);
-
- throttle_destroy(&bs->throttle_state);
-}
-
-static void bdrv_throttle_read_timer_cb(void *opaque)
-{
- BlockDriverState *bs = opaque;
- qemu_co_enter_next(&bs->throttled_reqs[0]);
-}
-
-static void bdrv_throttle_write_timer_cb(void *opaque)
-{
- BlockDriverState *bs = opaque;
- qemu_co_enter_next(&bs->throttled_reqs[1]);
-}
-
-/* should be called before bdrv_set_io_limits if a limit is set */
-void bdrv_io_limits_enable(BlockDriverState *bs)
-{
- int clock_type = QEMU_CLOCK_REALTIME;
-
- if (qtest_enabled()) {
- /* For testing block IO throttling only */
- clock_type = QEMU_CLOCK_VIRTUAL;
- }
- assert(!bs->io_limits_enabled);
- throttle_init(&bs->throttle_state,
- bdrv_get_aio_context(bs),
- clock_type,
- bdrv_throttle_read_timer_cb,
- bdrv_throttle_write_timer_cb,
- bs);
- bs->io_limits_enabled = true;
-}
-
-/* This function makes an IO wait if needed
- *
- * @nb_sectors: the number of sectors of the IO
- * @is_write: is the IO a write
- */
-static void bdrv_io_limits_intercept(BlockDriverState *bs,
- unsigned int bytes,
- bool is_write)
-{
- /* does this io must wait */
- bool must_wait = throttle_schedule_timer(&bs->throttle_state, is_write);
-
- /* if must wait or any request of this type throttled queue the IO */
- if (must_wait ||
- !qemu_co_queue_empty(&bs->throttled_reqs[is_write])) {
- qemu_co_queue_wait(&bs->throttled_reqs[is_write]);
- }
-
- /* the IO will be executed, do the accounting */
- throttle_account(&bs->throttle_state, is_write, bytes);
-
-
- /* if the next request must wait -> do nothing */
- if (throttle_schedule_timer(&bs->throttle_state, is_write)) {
- return;
- }
-
- /* else queue next request for execution */
- qemu_co_queue_next(&bs->throttled_reqs[is_write]);
-}
-
size_t bdrv_opt_mem_align(BlockDriverState *bs)
{
if (!bs || !bs->drv) {
@@ -349,24 +214,6 @@ void bdrv_get_full_backing_filename(BlockDriverState *bs,
char *dest, size_t sz,
dest, sz, errp);
}
-void bdrv_setup_io_funcs(BlockDriver *bdrv)
-{
- /* Block drivers without coroutine functions need emulation */
- if (!bdrv->bdrv_co_readv) {
- bdrv->bdrv_co_readv = bdrv_co_readv_em;
- bdrv->bdrv_co_writev = bdrv_co_writev_em;
-
- /* bdrv_co_readv_em()/brdv_co_writev_em() work in terms of aio, so if
- * the block driver lacks aio we need to emulate that too.
- */
- if (!bdrv->bdrv_aio_readv) {
- /* add AIO emulation layer */
- bdrv->bdrv_aio_readv = bdrv_aio_readv_em;
- bdrv->bdrv_aio_writev = bdrv_aio_writev_em;
- }
- }
-}
-
void bdrv_register(BlockDriver *bdrv)
{
bdrv_setup_io_funcs(bdrv);
@@ -541,54 +388,6 @@ int bdrv_create_file(const char *filename, QemuOpts *opts,
Error **errp)
return ret;
}
-void bdrv_refresh_limits(BlockDriverState *bs, Error **errp)
-{
- BlockDriver *drv = bs->drv;
- Error *local_err = NULL;
-
- memset(&bs->bl, 0, sizeof(bs->bl));
-
- if (!drv) {
- return;
- }
-
- /* Take some limits from the children as a default */
- if (bs->file) {
- bdrv_refresh_limits(bs->file, &local_err);
- if (local_err) {
- error_propagate(errp, local_err);
- return;
- }
- bs->bl.opt_transfer_length = bs->file->bl.opt_transfer_length;
- bs->bl.max_transfer_length = bs->file->bl.max_transfer_length;
- bs->bl.opt_mem_alignment = bs->file->bl.opt_mem_alignment;
- } else {
- bs->bl.opt_mem_alignment = 512;
- }
-
- if (bs->backing_hd) {
- bdrv_refresh_limits(bs->backing_hd, &local_err);
- if (local_err) {
- error_propagate(errp, local_err);
- return;
- }
- bs->bl.opt_transfer_length =
- MAX(bs->bl.opt_transfer_length,
- bs->backing_hd->bl.opt_transfer_length);
- bs->bl.max_transfer_length =
- MIN_NON_ZERO(bs->bl.max_transfer_length,
- bs->backing_hd->bl.max_transfer_length);
- bs->bl.opt_mem_alignment =
- MAX(bs->bl.opt_mem_alignment,
- bs->backing_hd->bl.opt_mem_alignment);
- }
-
- /* Then let the driver override it */
- if (drv->bdrv_refresh_limits) {
- drv->bdrv_refresh_limits(bs, errp);
- }
-}
-
/**
* Try to get @bs's logical and physical block size.
* On success, store them in @bsz struct and return 0.
@@ -862,22 +661,6 @@ int bdrv_parse_cache_flags(const char *mode, int *flags)
return 0;
}
-/**
- * The copy-on-read flag is actually a reference count so multiple users may
- * use the feature without worrying about clobbering its previous state.
- * Copy-on-read stays enabled until all users have called to disable it.
- */
-void bdrv_enable_copy_on_read(BlockDriverState *bs)
-{
- bs->copy_on_read++;
-}
-
-void bdrv_disable_copy_on_read(BlockDriverState *bs)
-{
- assert(bs->copy_on_read > 0);
- bs->copy_on_read--;
-}
-
/*
* Returns the flags that a temporary snapshot should get, based on the
* originally requested flags (the originally requested image will have flags
@@ -1987,108 +1770,6 @@ void bdrv_close_all(void)
}
}
-/* Check if any requests are in-flight (including throttled requests) */
-static bool bdrv_requests_pending(BlockDriverState *bs)
-{
- if (!QLIST_EMPTY(&bs->tracked_requests)) {
- return true;
- }
- if (!qemu_co_queue_empty(&bs->throttled_reqs[0])) {
- return true;
- }
- if (!qemu_co_queue_empty(&bs->throttled_reqs[1])) {
- return true;
- }
- if (bs->file && bdrv_requests_pending(bs->file)) {
- return true;
- }
- if (bs->backing_hd && bdrv_requests_pending(bs->backing_hd)) {
- return true;
- }
- return false;
-}
-
-static bool bdrv_drain_one(BlockDriverState *bs)
-{
- bool bs_busy;
-
- bdrv_flush_io_queue(bs);
- bdrv_start_throttled_reqs(bs);
- bs_busy = bdrv_requests_pending(bs);
- bs_busy |= aio_poll(bdrv_get_aio_context(bs), bs_busy);
- return bs_busy;
-}
-
-/*
- * Wait for pending requests to complete on a single BlockDriverState subtree
- *
- * See the warning in bdrv_drain_all(). This function can only be called if
- * you are sure nothing can generate I/O because you have op blockers
- * installed.
- *
- * Note that unlike bdrv_drain_all(), the caller must hold the BlockDriverState
- * AioContext.
- */
-void bdrv_drain(BlockDriverState *bs)
-{
- while (bdrv_drain_one(bs)) {
- /* Keep iterating */
- }
-}
-
-/*
- * Wait for pending requests to complete across all BlockDriverStates
- *
- * This function does not flush data to disk, use bdrv_flush_all() for that
- * after calling this function.
- *
- * Note that completion of an asynchronous I/O operation can trigger any
- * number of other I/O operations on other devices---for example a coroutine
- * can be arbitrarily complex and a constant flow of I/O can come until the
- * coroutine is complete. Because of this, it is not possible to have a
- * function to drain a single device's I/O queue.
- */
-void bdrv_drain_all(void)
-{
- /* Always run first iteration so any pending completion BHs run */
- bool busy = true;
- BlockDriverState *bs = NULL;
-
- while ((bs = bdrv_next(bs))) {
- AioContext *aio_context = bdrv_get_aio_context(bs);
-
- aio_context_acquire(aio_context);
- if (bs->job) {
- block_job_pause(bs->job);
- }
- aio_context_release(aio_context);
- }
-
- while (busy) {
- busy = false;
- bs = NULL;
-
- while ((bs = bdrv_next(bs))) {
- AioContext *aio_context = bdrv_get_aio_context(bs);
-
- aio_context_acquire(aio_context);
- busy |= bdrv_drain_one(bs);
- aio_context_release(aio_context);
- }
- }
-
- bs = NULL;
- while ((bs = bdrv_next(bs))) {
- AioContext *aio_context = bdrv_get_aio_context(bs);
-
- aio_context_acquire(aio_context);
- if (bs->job) {
- block_job_resume(bs->job);
- }
- aio_context_release(aio_context);
- }
-}
-
/* make a BlockDriverState anonymous by removing from bdrv_state and
* graph_bdrv_state list.
Also, NULL terminate the device_name to prevent double remove */
@@ -2410,152 +2091,6 @@ int bdrv_commit_all(void)
return 0;
}
-/**
- * Remove an active request from the tracked requests list
- *
- * This function should be called when a tracked request is completing.
- */
-static void tracked_request_end(BdrvTrackedRequest *req)
-{
- if (req->serialising) {
- req->bs->serialising_in_flight--;
- }
-
- QLIST_REMOVE(req, list);
- qemu_co_queue_restart_all(&req->wait_queue);
-}
-
-/**
- * Add an active request to the tracked requests list
- */
-static void tracked_request_begin(BdrvTrackedRequest *req,
- BlockDriverState *bs,
- int64_t offset,
- unsigned int bytes, bool is_write)
-{
- *req = (BdrvTrackedRequest){
- .bs = bs,
- .offset = offset,
- .bytes = bytes,
- .is_write = is_write,
- .co = qemu_coroutine_self(),
- .serialising = false,
- .overlap_offset = offset,
- .overlap_bytes = bytes,
- };
-
- qemu_co_queue_init(&req->wait_queue);
-
- QLIST_INSERT_HEAD(&bs->tracked_requests, req, list);
-}
-
-static void mark_request_serialising(BdrvTrackedRequest *req, uint64_t align)
-{
- int64_t overlap_offset = req->offset & ~(align - 1);
- unsigned int overlap_bytes = ROUND_UP(req->offset + req->bytes, align)
- - overlap_offset;
-
- if (!req->serialising) {
- req->bs->serialising_in_flight++;
- req->serialising = true;
- }
-
- req->overlap_offset = MIN(req->overlap_offset, overlap_offset);
- req->overlap_bytes = MAX(req->overlap_bytes, overlap_bytes);
-}
-
-/**
- * Round a region to cluster boundaries
- */
-void bdrv_round_to_clusters(BlockDriverState *bs,
- int64_t sector_num, int nb_sectors,
- int64_t *cluster_sector_num,
- int *cluster_nb_sectors)
-{
- BlockDriverInfo bdi;
-
- if (bdrv_get_info(bs, &bdi) < 0 || bdi.cluster_size == 0) {
- *cluster_sector_num = sector_num;
- *cluster_nb_sectors = nb_sectors;
- } else {
- int64_t c = bdi.cluster_size / BDRV_SECTOR_SIZE;
- *cluster_sector_num = QEMU_ALIGN_DOWN(sector_num, c);
- *cluster_nb_sectors = QEMU_ALIGN_UP(sector_num - *cluster_sector_num +
- nb_sectors, c);
- }
-}
-
-static int bdrv_get_cluster_size(BlockDriverState *bs)
-{
- BlockDriverInfo bdi;
- int ret;
-
- ret = bdrv_get_info(bs, &bdi);
- if (ret < 0 || bdi.cluster_size == 0) {
- return bs->request_alignment;
- } else {
- return bdi.cluster_size;
- }
-}
-
-static bool tracked_request_overlaps(BdrvTrackedRequest *req,
- int64_t offset, unsigned int bytes)
-{
- /* aaaa bbbb */
- if (offset >= req->overlap_offset + req->overlap_bytes) {
- return false;
- }
- /* bbbb aaaa */
- if (req->overlap_offset >= offset + bytes) {
- return false;
- }
- return true;
-}
-
-static bool coroutine_fn wait_serialising_requests(BdrvTrackedRequest *self)
-{
- BlockDriverState *bs = self->bs;
- BdrvTrackedRequest *req;
- bool retry;
- bool waited = false;
-
- if (!bs->serialising_in_flight) {
- return false;
- }
-
- do {
- retry = false;
- QLIST_FOREACH(req, &bs->tracked_requests, list) {
- if (req == self || (!req->serialising && !self->serialising)) {
- continue;
- }
- if (tracked_request_overlaps(req, self->overlap_offset,
- self->overlap_bytes))
- {
- /* Hitting this means there was a reentrant request, for
- * example, a block driver issuing nested requests. This must
- * never happen since it means deadlock.
- */
- assert(qemu_coroutine_self() != req->co);
-
- /* If the request is already (indirectly) waiting for us, or
- * will wait for us as soon as it wakes up, then just go on
- * (instead of producing a deadlock in the former case). */
- if (!req->waiting_for) {
- self->waiting_for = req;
- qemu_co_queue_wait(&req->wait_queue);
- self->waiting_for = NULL;
- retry = true;
- waited = true;
- break;
- }
- }
- }
- } while (retry);
-
- return waited;
-}
-
/*
* Return values:
* 0 - success
@@ -2724,1127 +2259,254 @@ exit:
return ret;
}
-
-static int bdrv_check_byte_request(BlockDriverState *bs, int64_t offset,
- size_t size)
+/**
+ * Truncate file to 'offset' bytes (needed only for file protocols)
+ */
+int bdrv_truncate(BlockDriverState *bs, int64_t offset)
{
- if (size > BDRV_REQUEST_MAX_SECTORS << BDRV_SECTOR_BITS) {
- return -EIO;
- }
-
- if (!bdrv_is_inserted(bs)) {
+ BlockDriver *drv = bs->drv;
+ int ret;
+ if (!drv)
return -ENOMEDIUM;
- }
+ if (!drv->bdrv_truncate)
+ return -ENOTSUP;
+ if (bs->read_only)
+ return -EACCES;
- if (offset < 0) {
- return -EIO;
+ ret = drv->bdrv_truncate(bs, offset);
+ if (ret == 0) {
+ ret = refresh_total_sectors(bs, offset >> BDRV_SECTOR_BITS);
+ bdrv_dirty_bitmap_truncate(bs);
+ if (bs->blk) {
+ blk_dev_resize_cb(bs->blk);
+ }
}
-
- return 0;
+ return ret;
}
-static int bdrv_check_request(BlockDriverState *bs, int64_t sector_num,
- int nb_sectors)
+/**
+ * Length of a allocated file in bytes. Sparse files are counted by actual
+ * allocated space. Return < 0 if error or unknown.
+ */
+int64_t bdrv_get_allocated_file_size(BlockDriverState *bs)
{
- if (nb_sectors < 0 || nb_sectors > BDRV_REQUEST_MAX_SECTORS) {
- return -EIO;
+ BlockDriver *drv = bs->drv;
+ if (!drv) {
+ return -ENOMEDIUM;
}
-
- return bdrv_check_byte_request(bs, sector_num * BDRV_SECTOR_SIZE,
- nb_sectors * BDRV_SECTOR_SIZE);
-}
-
-typedef struct RwCo {
- BlockDriverState *bs;
- int64_t offset;
- QEMUIOVector *qiov;
- bool is_write;
- int ret;
- BdrvRequestFlags flags;
-} RwCo;
-
-static void coroutine_fn bdrv_rw_co_entry(void *opaque)
-{
- RwCo *rwco = opaque;
-
- if (!rwco->is_write) {
- rwco->ret = bdrv_co_do_preadv(rwco->bs, rwco->offset,
- rwco->qiov->size, rwco->qiov,
- rwco->flags);
- } else {
- rwco->ret = bdrv_co_do_pwritev(rwco->bs, rwco->offset,
- rwco->qiov->size, rwco->qiov,
- rwco->flags);
+ if (drv->bdrv_get_allocated_file_size) {
+ return drv->bdrv_get_allocated_file_size(bs);
+ }
+ if (bs->file) {
+ return bdrv_get_allocated_file_size(bs->file);
}
+ return -ENOTSUP;
}
-/*
- * Process a vectored synchronous request using coroutines
+/**
+ * Return number of sectors on success, -errno on error.
*/
-static int bdrv_prwv_co(BlockDriverState *bs, int64_t offset,
- QEMUIOVector *qiov, bool is_write,
- BdrvRequestFlags flags)
+int64_t bdrv_nb_sectors(BlockDriverState *bs)
{
- Coroutine *co;
- RwCo rwco = {
- .bs = bs,
- .offset = offset,
- .qiov = qiov,
- .is_write = is_write,
- .ret = NOT_DONE,
- .flags = flags,
- };
-
- /**
- * In sync call context, when the vcpu is blocked, this throttling timer
- * will not fire; so the I/O throttling function has to be disabled here
- * if it has been enabled.
- */
- if (bs->io_limits_enabled) {
- fprintf(stderr, "Disabling I/O throttling on '%s' due "
- "to synchronous I/O.\n", bdrv_get_device_name(bs));
- bdrv_io_limits_disable(bs);
- }
+ BlockDriver *drv = bs->drv;
- if (qemu_in_coroutine()) {
- /* Fast-path if already in coroutine context */
- bdrv_rw_co_entry(&rwco);
- } else {
- AioContext *aio_context = bdrv_get_aio_context(bs);
+ if (!drv)
+ return -ENOMEDIUM;
- co = qemu_coroutine_create(bdrv_rw_co_entry);
- qemu_coroutine_enter(co, &rwco);
- while (rwco.ret == NOT_DONE) {
- aio_poll(aio_context, true);
+ if (drv->has_variable_length) {
+ int ret = refresh_total_sectors(bs, bs->total_sectors);
+ if (ret < 0) {
+ return ret;
}
}
- return rwco.ret;
+ return bs->total_sectors;
}
-/*
- * Process a synchronous request using coroutines
+/**
+ * Return length in bytes on success, -errno on error.
+ * The length is always a multiple of BDRV_SECTOR_SIZE.
*/
-static int bdrv_rw_co(BlockDriverState *bs, int64_t sector_num, uint8_t *buf,
- int nb_sectors, bool is_write, BdrvRequestFlags flags)
+int64_t bdrv_getlength(BlockDriverState *bs)
{
- QEMUIOVector qiov;
- struct iovec iov = {
- .iov_base = (void *)buf,
- .iov_len = nb_sectors * BDRV_SECTOR_SIZE,
- };
-
- if (nb_sectors < 0 || nb_sectors > BDRV_REQUEST_MAX_SECTORS) {
- return -EINVAL;
- }
-
- qemu_iovec_init_external(&qiov, &iov, 1);
- return bdrv_prwv_co(bs, sector_num << BDRV_SECTOR_BITS,
- &qiov, is_write, flags);
-}
+ int64_t ret = bdrv_nb_sectors(bs);
-/* return < 0 if error. See bdrv_write() for the return codes */
-int bdrv_read(BlockDriverState *bs, int64_t sector_num,
- uint8_t *buf, int nb_sectors)
-{
- return bdrv_rw_co(bs, sector_num, buf, nb_sectors, false, 0);
+ return ret < 0 ? ret : ret * BDRV_SECTOR_SIZE;
}
-/* Just like bdrv_read(), but with I/O throttling temporarily disabled */
-int bdrv_read_unthrottled(BlockDriverState *bs, int64_t sector_num,
- uint8_t *buf, int nb_sectors)
+/* return 0 as number of sectors if no device present or error */
+void bdrv_get_geometry(BlockDriverState *bs, uint64_t *nb_sectors_ptr)
{
- bool enabled;
- int ret;
+ int64_t nb_sectors = bdrv_nb_sectors(bs);
- enabled = bs->io_limits_enabled;
- bs->io_limits_enabled = false;
- ret = bdrv_read(bs, sector_num, buf, nb_sectors);
- bs->io_limits_enabled = enabled;
- return ret;
+ *nb_sectors_ptr = nb_sectors < 0 ? 0 : nb_sectors;
}
-/* Return < 0 if error. Important errors are:
- -EIO generic I/O error (may happen for all errors)
- -ENOMEDIUM No media inserted.
- -EINVAL Invalid sector number or nb_sectors
- -EACCES Trying to write a read-only device
-*/
-int bdrv_write(BlockDriverState *bs, int64_t sector_num,
- const uint8_t *buf, int nb_sectors)
+void bdrv_set_on_error(BlockDriverState *bs, BlockdevOnError on_read_error,
+ BlockdevOnError on_write_error)
{
- return bdrv_rw_co(bs, sector_num, (uint8_t *)buf, nb_sectors, true, 0);
+ bs->on_read_error = on_read_error;
+ bs->on_write_error = on_write_error;
}
-int bdrv_write_zeroes(BlockDriverState *bs, int64_t sector_num,
- int nb_sectors, BdrvRequestFlags flags)
+BlockdevOnError bdrv_get_on_error(BlockDriverState *bs, bool is_read)
{
- return bdrv_rw_co(bs, sector_num, NULL, nb_sectors, true,
- BDRV_REQ_ZERO_WRITE | flags);
+ return is_read ? bs->on_read_error : bs->on_write_error;
}
-/*
- * Completely zero out a block device with the help of bdrv_write_zeroes.
- * The operation is sped up by checking the block status and only writing
- * zeroes to the device if they currently do not return zeroes. Optional
- * flags are passed through to bdrv_write_zeroes (e.g. BDRV_REQ_MAY_UNMAP).
- *
- * Returns < 0 on error, 0 on success. For error codes see bdrv_write().
- */
-int bdrv_make_zero(BlockDriverState *bs, BdrvRequestFlags flags)
+BlockErrorAction bdrv_get_error_action(BlockDriverState *bs, bool is_read, int
error)
{
- int64_t target_sectors, ret, nb_sectors, sector_num = 0;
- int n;
-
- target_sectors = bdrv_nb_sectors(bs);
- if (target_sectors < 0) {
- return target_sectors;
- }
+ BlockdevOnError on_err = is_read ? bs->on_read_error : bs->on_write_error;
- for (;;) {
- nb_sectors = MIN(target_sectors - sector_num,
BDRV_REQUEST_MAX_SECTORS);
- if (nb_sectors <= 0) {
- return 0;
- }
- ret = bdrv_get_block_status(bs, sector_num, nb_sectors, &n);
- if (ret < 0) {
- error_report("error getting block status at sector %" PRId64 ":
%s",
- sector_num, strerror(-ret));
- return ret;
- }
- if (ret & BDRV_BLOCK_ZERO) {
- sector_num += n;
- continue;
- }
- ret = bdrv_write_zeroes(bs, sector_num, n, flags);
- if (ret < 0) {
- error_report("error writing zeroes at sector %" PRId64 ": %s",
- sector_num, strerror(-ret));
- return ret;
- }
- sector_num += n;
+ switch (on_err) {
+ case BLOCKDEV_ON_ERROR_ENOSPC:
+ return (error == ENOSPC) ?
+ BLOCK_ERROR_ACTION_STOP : BLOCK_ERROR_ACTION_REPORT;
+ case BLOCKDEV_ON_ERROR_STOP:
+ return BLOCK_ERROR_ACTION_STOP;
+ case BLOCKDEV_ON_ERROR_REPORT:
+ return BLOCK_ERROR_ACTION_REPORT;
+ case BLOCKDEV_ON_ERROR_IGNORE:
+ return BLOCK_ERROR_ACTION_IGNORE;
+ default:
+ abort();
}
}
-int bdrv_pread(BlockDriverState *bs, int64_t offset, void *buf, int bytes)
+static void send_qmp_error_event(BlockDriverState *bs,
+ BlockErrorAction action,
+ bool is_read, int error)
{
- QEMUIOVector qiov;
- struct iovec iov = {
- .iov_base = (void *)buf,
- .iov_len = bytes,
- };
- int ret;
-
- if (bytes < 0) {
- return -EINVAL;
- }
-
- qemu_iovec_init_external(&qiov, &iov, 1);
- ret = bdrv_prwv_co(bs, offset, &qiov, false, 0);
- if (ret < 0) {
- return ret;
- }
+ IoOperationType optype;
- return bytes;
+ optype = is_read ? IO_OPERATION_TYPE_READ : IO_OPERATION_TYPE_WRITE;
+ qapi_event_send_block_io_error(bdrv_get_device_name(bs), optype, action,
+ bdrv_iostatus_is_enabled(bs),
+ error == ENOSPC, strerror(error),
+ &error_abort);
}
-int bdrv_pwritev(BlockDriverState *bs, int64_t offset, QEMUIOVector *qiov)
+/* This is done by device models because, while the block layer knows
+ * about the error, it does not know whether an operation comes from
+ * the device or the block layer (from a job, for example).
+ */
+void bdrv_error_action(BlockDriverState *bs, BlockErrorAction action,
+ bool is_read, int error)
{
- int ret;
+ assert(error >= 0);
- ret = bdrv_prwv_co(bs, offset, qiov, true, 0);
- if (ret < 0) {
- return ret;
- }
+ if (action == BLOCK_ERROR_ACTION_STOP) {
+ /* First set the iostatus, so that "info block" returns an iostatus
+ * that matches the events raised so far (an additional error iostatus
+ * is fine, but not a lost one).
+ */
+ bdrv_iostatus_set_err(bs, error);
- return qiov->size;
+ /* Then raise the request to stop the VM and the event.
+ * qemu_system_vmstop_request_prepare has two effects. First,
+ * it ensures that the STOP event always comes after the
+ * BLOCK_IO_ERROR event. Second, it ensures that even if management
+ * can observe the STOP event and do a "cont" before the STOP
+ * event is issued, the VM will not stop. In this case, vm_start()
+ * also ensures that the STOP/RESUME pair of events is emitted.
+ */
+ qemu_system_vmstop_request_prepare();
+ send_qmp_error_event(bs, action, is_read, error);
+ qemu_system_vmstop_request(RUN_STATE_IO_ERROR);
+ } else {
+ send_qmp_error_event(bs, action, is_read, error);
+ }
}
-int bdrv_pwrite(BlockDriverState *bs, int64_t offset,
- const void *buf, int bytes)
+int bdrv_is_read_only(BlockDriverState *bs)
{
- QEMUIOVector qiov;
- struct iovec iov = {
- .iov_base = (void *) buf,
- .iov_len = bytes,
- };
-
- if (bytes < 0) {
- return -EINVAL;
- }
-
- qemu_iovec_init_external(&qiov, &iov, 1);
- return bdrv_pwritev(bs, offset, &qiov);
+ return bs->read_only;
}
-/*
- * Writes to the file and ensures that no writes are reordered across this
- * request (acts as a barrier)
- *
- * Returns 0 on success, -errno in error cases.
- */
-int bdrv_pwrite_sync(BlockDriverState *bs, int64_t offset,
- const void *buf, int count)
+int bdrv_is_sg(BlockDriverState *bs)
{
- int ret;
-
- ret = bdrv_pwrite(bs, offset, buf, count);
- if (ret < 0) {
- return ret;
- }
-
- /* No flush needed for cache modes that already do it */
- if (bs->enable_write_cache) {
- bdrv_flush(bs);
- }
-
- return 0;
+ return bs->sg;
}
-static int coroutine_fn bdrv_co_do_copy_on_readv(BlockDriverState *bs,
- int64_t sector_num, int nb_sectors, QEMUIOVector *qiov)
+int bdrv_enable_write_cache(BlockDriverState *bs)
{
- /* Perform I/O through a temporary buffer so that users who scribble over
- * their read buffer while the operation is in progress do not end up
- * modifying the image file. This is critical for zero-copy guest I/O
- * where anything might happen inside guest memory.
- */
- void *bounce_buffer;
-
- BlockDriver *drv = bs->drv;
- struct iovec iov;
- QEMUIOVector bounce_qiov;
- int64_t cluster_sector_num;
- int cluster_nb_sectors;
- size_t skip_bytes;
- int ret;
-
- /* Cover entire cluster so no additional backing file I/O is required when
- * allocating cluster in the image file.
- */
- bdrv_round_to_clusters(bs, sector_num, nb_sectors,
- &cluster_sector_num, &cluster_nb_sectors);
-
- trace_bdrv_co_do_copy_on_readv(bs, sector_num, nb_sectors,
- cluster_sector_num, cluster_nb_sectors);
-
- iov.iov_len = cluster_nb_sectors * BDRV_SECTOR_SIZE;
- iov.iov_base = bounce_buffer = qemu_try_blockalign(bs, iov.iov_len);
- if (bounce_buffer == NULL) {
- ret = -ENOMEM;
- goto err;
- }
-
- qemu_iovec_init_external(&bounce_qiov, &iov, 1);
-
- ret = drv->bdrv_co_readv(bs, cluster_sector_num, cluster_nb_sectors,
- &bounce_qiov);
- if (ret < 0) {
- goto err;
- }
-
- if (drv->bdrv_co_write_zeroes &&
- buffer_is_zero(bounce_buffer, iov.iov_len)) {
- ret = bdrv_co_do_write_zeroes(bs, cluster_sector_num,
- cluster_nb_sectors, 0);
- } else {
- /* This does not change the data on the disk, it is not necessary
- * to flush even in cache=writethrough mode.
- */
- ret = drv->bdrv_co_writev(bs, cluster_sector_num, cluster_nb_sectors,
- &bounce_qiov);
- }
-
- if (ret < 0) {
- /* It might be okay to ignore write errors for guest requests. If this
- * is a deliberate copy-on-read then we don't want to ignore the error.
- * Simply report it in all cases.
- */
- goto err;
- }
-
- skip_bytes = (sector_num - cluster_sector_num) * BDRV_SECTOR_SIZE;
- qemu_iovec_from_buf(qiov, 0, bounce_buffer + skip_bytes,
- nb_sectors * BDRV_SECTOR_SIZE);
-
-err:
- qemu_vfree(bounce_buffer);
- return ret;
+ return bs->enable_write_cache;
}
-/*
- * Forwards an already correctly aligned request to the BlockDriver. This
- * handles copy on read and zeroing after EOF; any other features must be
- * implemented by the caller.
- */
-static int coroutine_fn bdrv_aligned_preadv(BlockDriverState *bs,
- BdrvTrackedRequest *req, int64_t offset, unsigned int bytes,
- int64_t align, QEMUIOVector *qiov, int flags)
+void bdrv_set_enable_write_cache(BlockDriverState *bs, bool wce)
{
- BlockDriver *drv = bs->drv;
- int ret;
-
- int64_t sector_num = offset >> BDRV_SECTOR_BITS;
- unsigned int nb_sectors = bytes >> BDRV_SECTOR_BITS;
-
- assert((offset & (BDRV_SECTOR_SIZE - 1)) == 0);
- assert((bytes & (BDRV_SECTOR_SIZE - 1)) == 0);
- assert(!qiov || bytes == qiov->size);
-
- /* Handle Copy on Read and associated serialisation */
- if (flags & BDRV_REQ_COPY_ON_READ) {
- /* If we touch the same cluster it counts as an overlap. This
- * guarantees that allocating writes will be serialized and not race
- * with each other for the same cluster. For example, in copy-on-read
- * it ensures that the CoR read and write operations are atomic and
- * guest writes cannot interleave between them. */
- mark_request_serialising(req, bdrv_get_cluster_size(bs));
- }
-
- wait_serialising_requests(req);
-
- if (flags & BDRV_REQ_COPY_ON_READ) {
- int pnum;
-
- ret = bdrv_is_allocated(bs, sector_num, nb_sectors, &pnum);
- if (ret < 0) {
- goto out;
- }
-
- if (!ret || pnum != nb_sectors) {
- ret = bdrv_co_do_copy_on_readv(bs, sector_num, nb_sectors, qiov);
- goto out;
- }
- }
+ bs->enable_write_cache = wce;
- /* Forward the request to the BlockDriver */
- if (!bs->zero_beyond_eof) {
- ret = drv->bdrv_co_readv(bs, sector_num, nb_sectors, qiov);
+ /* so a reopen() will preserve wce */
+ if (wce) {
+ bs->open_flags |= BDRV_O_CACHE_WB;
} else {
- /* Read zeros after EOF */
- int64_t total_sectors, max_nb_sectors;
-
- total_sectors = bdrv_nb_sectors(bs);
- if (total_sectors < 0) {
- ret = total_sectors;
- goto out;
- }
-
- max_nb_sectors = ROUND_UP(MAX(0, total_sectors - sector_num),
- align >> BDRV_SECTOR_BITS);
- if (nb_sectors < max_nb_sectors) {
- ret = drv->bdrv_co_readv(bs, sector_num, nb_sectors, qiov);
- } else if (max_nb_sectors > 0) {
- QEMUIOVector local_qiov;
-
- qemu_iovec_init(&local_qiov, qiov->niov);
- qemu_iovec_concat(&local_qiov, qiov, 0,
- max_nb_sectors * BDRV_SECTOR_SIZE);
-
- ret = drv->bdrv_co_readv(bs, sector_num, max_nb_sectors,
- &local_qiov);
-
- qemu_iovec_destroy(&local_qiov);
- } else {
- ret = 0;
- }
-
- /* Reading beyond end of file is supposed to produce zeroes */
- if (ret == 0 && total_sectors < sector_num + nb_sectors) {
- uint64_t offset = MAX(0, total_sectors - sector_num);
- uint64_t bytes = (sector_num + nb_sectors - offset) *
- BDRV_SECTOR_SIZE;
- qemu_iovec_memset(qiov, offset * BDRV_SECTOR_SIZE, 0, bytes);
- }
+ bs->open_flags &= ~BDRV_O_CACHE_WB;
}
-
-out:
- return ret;
}
-static inline uint64_t bdrv_get_align(BlockDriverState *bs)
+int bdrv_is_encrypted(BlockDriverState *bs)
{
- /* TODO Lift BDRV_SECTOR_SIZE restriction in BlockDriver interface */
- return MAX(BDRV_SECTOR_SIZE, bs->request_alignment);
+ if (bs->backing_hd && bs->backing_hd->encrypted)
+ return 1;
+ return bs->encrypted;
}
-static inline bool bdrv_req_is_aligned(BlockDriverState *bs,
- int64_t offset, size_t bytes)
+int bdrv_key_required(BlockDriverState *bs)
{
- int64_t align = bdrv_get_align(bs);
- return !(offset & (align - 1) || (bytes & (align - 1)));
+ BlockDriverState *backing_hd = bs->backing_hd;
+
+ if (backing_hd && backing_hd->encrypted && !backing_hd->valid_key)
+ return 1;
+ return (bs->encrypted && !bs->valid_key);
}
-/*
- * Handle a read request in coroutine context
- */
-static int coroutine_fn bdrv_co_do_preadv(BlockDriverState *bs,
- int64_t offset, unsigned int bytes, QEMUIOVector *qiov,
- BdrvRequestFlags flags)
+int bdrv_set_key(BlockDriverState *bs, const char *key)
{
- BlockDriver *drv = bs->drv;
- BdrvTrackedRequest req;
-
- uint64_t align = bdrv_get_align(bs);
- uint8_t *head_buf = NULL;
- uint8_t *tail_buf = NULL;
- QEMUIOVector local_qiov;
- bool use_local_qiov = false;
int ret;
-
- if (!drv) {
+ if (bs->backing_hd && bs->backing_hd->encrypted) {
+ ret = bdrv_set_key(bs->backing_hd, key);
+ if (ret < 0)
+ return ret;
+ if (!bs->encrypted)
+ return 0;
+ }
+ if (!bs->encrypted) {
+ return -EINVAL;
+ } else if (!bs->drv || !bs->drv->bdrv_set_key) {
return -ENOMEDIUM;
}
-
- ret = bdrv_check_byte_request(bs, offset, bytes);
+ ret = bs->drv->bdrv_set_key(bs, key);
if (ret < 0) {
- return ret;
- }
-
- if (bs->copy_on_read) {
- flags |= BDRV_REQ_COPY_ON_READ;
- }
-
- /* throttling disk I/O */
- if (bs->io_limits_enabled) {
- bdrv_io_limits_intercept(bs, bytes, false);
+ bs->valid_key = 0;
+ } else if (!bs->valid_key) {
+ bs->valid_key = 1;
+ if (bs->blk) {
+ /* call the change callback now, we skipped it on open */
+ blk_dev_change_media_cb(bs->blk, true);
+ }
}
-
- /* Align read if necessary by padding qiov */
- if (offset & (align - 1)) {
- head_buf = qemu_blockalign(bs, align);
- qemu_iovec_init(&local_qiov, qiov->niov + 2);
- qemu_iovec_add(&local_qiov, head_buf, offset & (align - 1));
- qemu_iovec_concat(&local_qiov, qiov, 0, qiov->size);
- use_local_qiov = true;
-
- bytes += offset & (align - 1);
- offset = offset & ~(align - 1);
- }
-
- if ((offset + bytes) & (align - 1)) {
- if (!use_local_qiov) {
- qemu_iovec_init(&local_qiov, qiov->niov + 1);
- qemu_iovec_concat(&local_qiov, qiov, 0, qiov->size);
- use_local_qiov = true;
- }
- tail_buf = qemu_blockalign(bs, align);
- qemu_iovec_add(&local_qiov, tail_buf,
- align - ((offset + bytes) & (align - 1)));
-
- bytes = ROUND_UP(bytes, align);
- }
-
- tracked_request_begin(&req, bs, offset, bytes, false);
- ret = bdrv_aligned_preadv(bs, &req, offset, bytes, align,
- use_local_qiov ? &local_qiov : qiov,
- flags);
- tracked_request_end(&req);
-
- if (use_local_qiov) {
- qemu_iovec_destroy(&local_qiov);
- qemu_vfree(head_buf);
- qemu_vfree(tail_buf);
- }
-
- return ret;
-}
-
-static int coroutine_fn bdrv_co_do_readv(BlockDriverState *bs,
- int64_t sector_num, int nb_sectors, QEMUIOVector *qiov,
- BdrvRequestFlags flags)
-{
- if (nb_sectors < 0 || nb_sectors > BDRV_REQUEST_MAX_SECTORS) {
- return -EINVAL;
- }
-
- return bdrv_co_do_preadv(bs, sector_num << BDRV_SECTOR_BITS,
- nb_sectors << BDRV_SECTOR_BITS, qiov, flags);
-}
-
-int coroutine_fn bdrv_co_readv(BlockDriverState *bs, int64_t sector_num,
- int nb_sectors, QEMUIOVector *qiov)
-{
- trace_bdrv_co_readv(bs, sector_num, nb_sectors);
-
- return bdrv_co_do_readv(bs, sector_num, nb_sectors, qiov, 0);
-}
-
-int coroutine_fn bdrv_co_copy_on_readv(BlockDriverState *bs,
- int64_t sector_num, int nb_sectors, QEMUIOVector *qiov)
-{
- trace_bdrv_co_copy_on_readv(bs, sector_num, nb_sectors);
-
- return bdrv_co_do_readv(bs, sector_num, nb_sectors, qiov,
- BDRV_REQ_COPY_ON_READ);
-}
-
-#define MAX_WRITE_ZEROES_BOUNCE_BUFFER 32768
-
-static int coroutine_fn bdrv_co_do_write_zeroes(BlockDriverState *bs,
- int64_t sector_num, int nb_sectors, BdrvRequestFlags flags)
-{
- BlockDriver *drv = bs->drv;
- QEMUIOVector qiov;
- struct iovec iov = {0};
- int ret = 0;
-
- int max_write_zeroes = MIN_NON_ZERO(bs->bl.max_write_zeroes,
- BDRV_REQUEST_MAX_SECTORS);
-
- while (nb_sectors > 0 && !ret) {
- int num = nb_sectors;
-
- /* Align request. Block drivers can expect the "bulk" of the request
- * to be aligned.
- */
- if (bs->bl.write_zeroes_alignment
- && num > bs->bl.write_zeroes_alignment) {
- if (sector_num % bs->bl.write_zeroes_alignment != 0) {
- /* Make a small request up to the first aligned sector. */
- num = bs->bl.write_zeroes_alignment;
- num -= sector_num % bs->bl.write_zeroes_alignment;
- } else if ((sector_num + num) % bs->bl.write_zeroes_alignment !=
0) {
- /* Shorten the request to the last aligned sector. num cannot
- * underflow because num > bs->bl.write_zeroes_alignment.
- */
- num -= (sector_num + num) % bs->bl.write_zeroes_alignment;
- }
- }
-
- /* limit request size */
- if (num > max_write_zeroes) {
- num = max_write_zeroes;
- }
-
- ret = -ENOTSUP;
- /* First try the efficient write zeroes operation */
- if (drv->bdrv_co_write_zeroes) {
- ret = drv->bdrv_co_write_zeroes(bs, sector_num, num, flags);
- }
-
- if (ret == -ENOTSUP) {
- /* Fall back to bounce buffer if write zeroes is unsupported */
- int max_xfer_len = MIN_NON_ZERO(bs->bl.max_transfer_length,
- MAX_WRITE_ZEROES_BOUNCE_BUFFER);
- num = MIN(num, max_xfer_len);
- iov.iov_len = num * BDRV_SECTOR_SIZE;
- if (iov.iov_base == NULL) {
- iov.iov_base = qemu_try_blockalign(bs, num * BDRV_SECTOR_SIZE);
- if (iov.iov_base == NULL) {
- ret = -ENOMEM;
- goto fail;
- }
- memset(iov.iov_base, 0, num * BDRV_SECTOR_SIZE);
- }
- qemu_iovec_init_external(&qiov, &iov, 1);
-
- ret = drv->bdrv_co_writev(bs, sector_num, num, &qiov);
-
- /* Keep bounce buffer around if it is big enough for all
- * all future requests.
- */
- if (num < max_xfer_len) {
- qemu_vfree(iov.iov_base);
- iov.iov_base = NULL;
- }
- }
-
- sector_num += num;
- nb_sectors -= num;
- }
-
-fail:
- qemu_vfree(iov.iov_base);
- return ret;
-}
+ return ret;
+}
/*
- * Forwards an already correctly aligned write request to the BlockDriver.
+ * Provide an encryption key for @bs.
+ * If @key is non-null:
+ * If @bs is not encrypted, fail.
+ * Else if the key is invalid, fail.
+ * Else set @bs's key to @key, replacing the existing key, if any.
+ * If @key is null:
+ * If @bs is encrypted and still lacks a key, fail.
+ * Else do nothing.
+ * On failure, store an error object through @errp if non-null.
*/
-static int coroutine_fn bdrv_aligned_pwritev(BlockDriverState *bs,
- BdrvTrackedRequest *req, int64_t offset, unsigned int bytes,
- QEMUIOVector *qiov, int flags)
+void bdrv_add_key(BlockDriverState *bs, const char *key, Error **errp)
{
- BlockDriver *drv = bs->drv;
- bool waited;
- int ret;
-
- int64_t sector_num = offset >> BDRV_SECTOR_BITS;
- unsigned int nb_sectors = bytes >> BDRV_SECTOR_BITS;
-
- assert((offset & (BDRV_SECTOR_SIZE - 1)) == 0);
- assert((bytes & (BDRV_SECTOR_SIZE - 1)) == 0);
- assert(!qiov || bytes == qiov->size);
-
- waited = wait_serialising_requests(req);
- assert(!waited || !req->serialising);
- assert(req->overlap_offset <= offset);
- assert(offset + bytes <= req->overlap_offset + req->overlap_bytes);
-
- ret = notifier_with_return_list_notify(&bs->before_write_notifiers, req);
-
- if (!ret && bs->detect_zeroes != BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF &&
- !(flags & BDRV_REQ_ZERO_WRITE) && drv->bdrv_co_write_zeroes &&
- qemu_iovec_is_zero(qiov)) {
- flags |= BDRV_REQ_ZERO_WRITE;
- if (bs->detect_zeroes == BLOCKDEV_DETECT_ZEROES_OPTIONS_UNMAP) {
- flags |= BDRV_REQ_MAY_UNMAP;
- }
- }
-
- if (ret < 0) {
- /* Do nothing, write notifier decided to fail this request */
- } else if (flags & BDRV_REQ_ZERO_WRITE) {
- BLKDBG_EVENT(bs, BLKDBG_PWRITEV_ZERO);
- ret = bdrv_co_do_write_zeroes(bs, sector_num, nb_sectors, flags);
- } else {
- BLKDBG_EVENT(bs, BLKDBG_PWRITEV);
- ret = drv->bdrv_co_writev(bs, sector_num, nb_sectors, qiov);
- }
- BLKDBG_EVENT(bs, BLKDBG_PWRITEV_DONE);
-
- if (ret == 0 && !bs->enable_write_cache) {
- ret = bdrv_co_flush(bs);
- }
-
- bdrv_set_dirty(bs, sector_num, nb_sectors);
-
- block_acct_highest_sector(&bs->stats, sector_num, nb_sectors);
-
- if (ret >= 0) {
- bs->total_sectors = MAX(bs->total_sectors, sector_num + nb_sectors);
- }
-
- return ret;
-}
-
-/*
- * Handle a write request in coroutine context
- */
-static int coroutine_fn bdrv_co_do_pwritev(BlockDriverState *bs,
- int64_t offset, unsigned int bytes, QEMUIOVector *qiov,
- BdrvRequestFlags flags)
-{
- BdrvTrackedRequest req;
- uint64_t align = bdrv_get_align(bs);
- uint8_t *head_buf = NULL;
- uint8_t *tail_buf = NULL;
- QEMUIOVector local_qiov;
- bool use_local_qiov = false;
- int ret;
-
- if (!bs->drv) {
- return -ENOMEDIUM;
- }
- if (bs->read_only) {
- return -EACCES;
- }
-
- ret = bdrv_check_byte_request(bs, offset, bytes);
- if (ret < 0) {
- return ret;
- }
-
- /* throttling disk I/O */
- if (bs->io_limits_enabled) {
- bdrv_io_limits_intercept(bs, bytes, true);
- }
-
- /*
- * Align write if necessary by performing a read-modify-write cycle.
- * Pad qiov with the read parts and be sure to have a tracked request not
- * only for bdrv_aligned_pwritev, but also for the reads of the RMW cycle.
- */
- tracked_request_begin(&req, bs, offset, bytes, true);
-
- if (offset & (align - 1)) {
- QEMUIOVector head_qiov;
- struct iovec head_iov;
-
- mark_request_serialising(&req, align);
- wait_serialising_requests(&req);
-
- head_buf = qemu_blockalign(bs, align);
- head_iov = (struct iovec) {
- .iov_base = head_buf,
- .iov_len = align,
- };
- qemu_iovec_init_external(&head_qiov, &head_iov, 1);
-
- BLKDBG_EVENT(bs, BLKDBG_PWRITEV_RMW_HEAD);
- ret = bdrv_aligned_preadv(bs, &req, offset & ~(align - 1), align,
- align, &head_qiov, 0);
- if (ret < 0) {
- goto fail;
- }
- BLKDBG_EVENT(bs, BLKDBG_PWRITEV_RMW_AFTER_HEAD);
-
- qemu_iovec_init(&local_qiov, qiov->niov + 2);
- qemu_iovec_add(&local_qiov, head_buf, offset & (align - 1));
- qemu_iovec_concat(&local_qiov, qiov, 0, qiov->size);
- use_local_qiov = true;
-
- bytes += offset & (align - 1);
- offset = offset & ~(align - 1);
- }
-
- if ((offset + bytes) & (align - 1)) {
- QEMUIOVector tail_qiov;
- struct iovec tail_iov;
- size_t tail_bytes;
- bool waited;
-
- mark_request_serialising(&req, align);
- waited = wait_serialising_requests(&req);
- assert(!waited || !use_local_qiov);
-
- tail_buf = qemu_blockalign(bs, align);
- tail_iov = (struct iovec) {
- .iov_base = tail_buf,
- .iov_len = align,
- };
- qemu_iovec_init_external(&tail_qiov, &tail_iov, 1);
-
- BLKDBG_EVENT(bs, BLKDBG_PWRITEV_RMW_TAIL);
- ret = bdrv_aligned_preadv(bs, &req, (offset + bytes) & ~(align - 1),
align,
- align, &tail_qiov, 0);
- if (ret < 0) {
- goto fail;
- }
- BLKDBG_EVENT(bs, BLKDBG_PWRITEV_RMW_AFTER_TAIL);
-
- if (!use_local_qiov) {
- qemu_iovec_init(&local_qiov, qiov->niov + 1);
- qemu_iovec_concat(&local_qiov, qiov, 0, qiov->size);
- use_local_qiov = true;
- }
-
- tail_bytes = (offset + bytes) & (align - 1);
- qemu_iovec_add(&local_qiov, tail_buf + tail_bytes, align - tail_bytes);
-
- bytes = ROUND_UP(bytes, align);
- }
-
- if (use_local_qiov) {
- /* Local buffer may have non-zero data. */
- flags &= ~BDRV_REQ_ZERO_WRITE;
- }
- ret = bdrv_aligned_pwritev(bs, &req, offset, bytes,
- use_local_qiov ? &local_qiov : qiov,
- flags);
-
-fail:
- tracked_request_end(&req);
-
- if (use_local_qiov) {
- qemu_iovec_destroy(&local_qiov);
- }
- qemu_vfree(head_buf);
- qemu_vfree(tail_buf);
-
- return ret;
-}
-
-static int coroutine_fn bdrv_co_do_writev(BlockDriverState *bs,
- int64_t sector_num, int nb_sectors, QEMUIOVector *qiov,
- BdrvRequestFlags flags)
-{
- if (nb_sectors < 0 || nb_sectors > BDRV_REQUEST_MAX_SECTORS) {
- return -EINVAL;
- }
-
- return bdrv_co_do_pwritev(bs, sector_num << BDRV_SECTOR_BITS,
- nb_sectors << BDRV_SECTOR_BITS, qiov, flags);
-}
-
-int coroutine_fn bdrv_co_writev(BlockDriverState *bs, int64_t sector_num,
- int nb_sectors, QEMUIOVector *qiov)
-{
- trace_bdrv_co_writev(bs, sector_num, nb_sectors);
-
- return bdrv_co_do_writev(bs, sector_num, nb_sectors, qiov, 0);
-}
-
-int coroutine_fn bdrv_co_write_zeroes(BlockDriverState *bs,
- int64_t sector_num, int nb_sectors,
- BdrvRequestFlags flags)
-{
- int ret;
-
- trace_bdrv_co_write_zeroes(bs, sector_num, nb_sectors, flags);
-
- if (!(bs->open_flags & BDRV_O_UNMAP)) {
- flags &= ~BDRV_REQ_MAY_UNMAP;
- }
- if (bdrv_req_is_aligned(bs, sector_num << BDRV_SECTOR_BITS,
- nb_sectors << BDRV_SECTOR_BITS)) {
- ret = bdrv_co_do_writev(bs, sector_num, nb_sectors, NULL,
- BDRV_REQ_ZERO_WRITE | flags);
- } else {
- uint8_t *buf;
- QEMUIOVector local_qiov;
- size_t bytes = nb_sectors << BDRV_SECTOR_BITS;
-
- buf = qemu_memalign(bdrv_opt_mem_align(bs), bytes);
- memset(buf, 0, bytes);
- qemu_iovec_init(&local_qiov, 1);
- qemu_iovec_add(&local_qiov, buf, bytes);
-
- ret = bdrv_co_do_writev(bs, sector_num, nb_sectors, &local_qiov,
- BDRV_REQ_ZERO_WRITE | flags);
- qemu_vfree(buf);
- }
- return ret;
-}
-
-/**
- * Truncate file to 'offset' bytes (needed only for file protocols)
- */
-int bdrv_truncate(BlockDriverState *bs, int64_t offset)
-{
- BlockDriver *drv = bs->drv;
- int ret;
- if (!drv)
- return -ENOMEDIUM;
- if (!drv->bdrv_truncate)
- return -ENOTSUP;
- if (bs->read_only)
- return -EACCES;
-
- ret = drv->bdrv_truncate(bs, offset);
- if (ret == 0) {
- ret = refresh_total_sectors(bs, offset >> BDRV_SECTOR_BITS);
- bdrv_dirty_bitmap_truncate(bs);
- if (bs->blk) {
- blk_dev_resize_cb(bs->blk);
- }
- }
- return ret;
-}
-
-/**
- * Length of a allocated file in bytes. Sparse files are counted by actual
- * allocated space. Return < 0 if error or unknown.
- */
-int64_t bdrv_get_allocated_file_size(BlockDriverState *bs)
-{
- BlockDriver *drv = bs->drv;
- if (!drv) {
- return -ENOMEDIUM;
- }
- if (drv->bdrv_get_allocated_file_size) {
- return drv->bdrv_get_allocated_file_size(bs);
- }
- if (bs->file) {
- return bdrv_get_allocated_file_size(bs->file);
- }
- return -ENOTSUP;
-}
-
-/**
- * Return number of sectors on success, -errno on error.
- */
-int64_t bdrv_nb_sectors(BlockDriverState *bs)
-{
- BlockDriver *drv = bs->drv;
-
- if (!drv)
- return -ENOMEDIUM;
-
- if (drv->has_variable_length) {
- int ret = refresh_total_sectors(bs, bs->total_sectors);
- if (ret < 0) {
- return ret;
- }
- }
- return bs->total_sectors;
-}
-
-/**
- * Return length in bytes on success, -errno on error.
- * The length is always a multiple of BDRV_SECTOR_SIZE.
- */
-int64_t bdrv_getlength(BlockDriverState *bs)
-{
- int64_t ret = bdrv_nb_sectors(bs);
-
- return ret < 0 ? ret : ret * BDRV_SECTOR_SIZE;
-}
-
-/* return 0 as number of sectors if no device present or error */
-void bdrv_get_geometry(BlockDriverState *bs, uint64_t *nb_sectors_ptr)
-{
- int64_t nb_sectors = bdrv_nb_sectors(bs);
-
- *nb_sectors_ptr = nb_sectors < 0 ? 0 : nb_sectors;
-}
-
-void bdrv_set_on_error(BlockDriverState *bs, BlockdevOnError on_read_error,
- BlockdevOnError on_write_error)
-{
- bs->on_read_error = on_read_error;
- bs->on_write_error = on_write_error;
-}
-
-BlockdevOnError bdrv_get_on_error(BlockDriverState *bs, bool is_read)
-{
- return is_read ? bs->on_read_error : bs->on_write_error;
-}
-
-BlockErrorAction bdrv_get_error_action(BlockDriverState *bs, bool is_read, int
error)
-{
- BlockdevOnError on_err = is_read ? bs->on_read_error : bs->on_write_error;
-
- switch (on_err) {
- case BLOCKDEV_ON_ERROR_ENOSPC:
- return (error == ENOSPC) ?
- BLOCK_ERROR_ACTION_STOP : BLOCK_ERROR_ACTION_REPORT;
- case BLOCKDEV_ON_ERROR_STOP:
- return BLOCK_ERROR_ACTION_STOP;
- case BLOCKDEV_ON_ERROR_REPORT:
- return BLOCK_ERROR_ACTION_REPORT;
- case BLOCKDEV_ON_ERROR_IGNORE:
- return BLOCK_ERROR_ACTION_IGNORE;
- default:
- abort();
- }
-}
-
-static void send_qmp_error_event(BlockDriverState *bs,
- BlockErrorAction action,
- bool is_read, int error)
-{
- IoOperationType optype;
-
- optype = is_read ? IO_OPERATION_TYPE_READ : IO_OPERATION_TYPE_WRITE;
- qapi_event_send_block_io_error(bdrv_get_device_name(bs), optype, action,
- bdrv_iostatus_is_enabled(bs),
- error == ENOSPC, strerror(error),
- &error_abort);
-}
-
-/* This is done by device models because, while the block layer knows
- * about the error, it does not know whether an operation comes from
- * the device or the block layer (from a job, for example).
- */
-void bdrv_error_action(BlockDriverState *bs, BlockErrorAction action,
- bool is_read, int error)
-{
- assert(error >= 0);
-
- if (action == BLOCK_ERROR_ACTION_STOP) {
- /* First set the iostatus, so that "info block" returns an iostatus
- * that matches the events raised so far (an additional error iostatus
- * is fine, but not a lost one).
- */
- bdrv_iostatus_set_err(bs, error);
-
- /* Then raise the request to stop the VM and the event.
- * qemu_system_vmstop_request_prepare has two effects. First,
- * it ensures that the STOP event always comes after the
- * BLOCK_IO_ERROR event. Second, it ensures that even if management
- * can observe the STOP event and do a "cont" before the STOP
- * event is issued, the VM will not stop. In this case, vm_start()
- * also ensures that the STOP/RESUME pair of events is emitted.
- */
- qemu_system_vmstop_request_prepare();
- send_qmp_error_event(bs, action, is_read, error);
- qemu_system_vmstop_request(RUN_STATE_IO_ERROR);
- } else {
- send_qmp_error_event(bs, action, is_read, error);
- }
-}
-
-int bdrv_is_read_only(BlockDriverState *bs)
-{
- return bs->read_only;
-}
-
-int bdrv_is_sg(BlockDriverState *bs)
-{
- return bs->sg;
-}
-
-int bdrv_enable_write_cache(BlockDriverState *bs)
-{
- return bs->enable_write_cache;
-}
-
-void bdrv_set_enable_write_cache(BlockDriverState *bs, bool wce)
-{
- bs->enable_write_cache = wce;
-
- /* so a reopen() will preserve wce */
- if (wce) {
- bs->open_flags |= BDRV_O_CACHE_WB;
- } else {
- bs->open_flags &= ~BDRV_O_CACHE_WB;
- }
-}
-
-int bdrv_is_encrypted(BlockDriverState *bs)
-{
- if (bs->backing_hd && bs->backing_hd->encrypted)
- return 1;
- return bs->encrypted;
-}
-
-int bdrv_key_required(BlockDriverState *bs)
-{
- BlockDriverState *backing_hd = bs->backing_hd;
-
- if (backing_hd && backing_hd->encrypted && !backing_hd->valid_key)
- return 1;
- return (bs->encrypted && !bs->valid_key);
-}
-
-int bdrv_set_key(BlockDriverState *bs, const char *key)
-{
- int ret;
- if (bs->backing_hd && bs->backing_hd->encrypted) {
- ret = bdrv_set_key(bs->backing_hd, key);
- if (ret < 0)
- return ret;
- if (!bs->encrypted)
- return 0;
- }
- if (!bs->encrypted) {
- return -EINVAL;
- } else if (!bs->drv || !bs->drv->bdrv_set_key) {
- return -ENOMEDIUM;
- }
- ret = bs->drv->bdrv_set_key(bs, key);
- if (ret < 0) {
- bs->valid_key = 0;
- } else if (!bs->valid_key) {
- bs->valid_key = 1;
- if (bs->blk) {
- /* call the change callback now, we skipped it on open */
- blk_dev_change_media_cb(bs->blk, true);
- }
- }
- return ret;
-}
-
-/*
- * Provide an encryption key for @bs.
- * If @key is non-null:
- * If @bs is not encrypted, fail.
- * Else if the key is invalid, fail.
- * Else set @bs's key to @key, replacing the existing key, if any.
- * If @key is null:
- * If @bs is encrypted and still lacks a key, fail.
- * Else do nothing.
- * On failure, store an error object through @errp if non-null.
- */
-void bdrv_add_key(BlockDriverState *bs, const char *key, Error **errp)
-{
- if (key) {
- if (!bdrv_is_encrypted(bs)) {
- error_setg(errp, "Node '%s' is not encrypted",
- bdrv_get_device_or_node_name(bs));
- } else if (bdrv_set_key(bs, key) < 0) {
- error_set(errp, QERR_INVALID_PASSWORD);
+ if (key) {
+ if (!bdrv_is_encrypted(bs)) {
+ error_setg(errp, "Node '%s' is not encrypted",
+ bdrv_get_device_or_node_name(bs));
+ } else if (bdrv_set_key(bs, key) < 0) {
+ error_set(errp, QERR_INVALID_PASSWORD);
}
} else {
if (bdrv_key_required(bs)) {
@@ -3856,1334 +2518,409 @@ void bdrv_add_key(BlockDriverState *bs, const char
*key, Error **errp)
}
}
-const char *bdrv_get_format_name(BlockDriverState *bs)
-{
- return bs->drv ? bs->drv->format_name : NULL;
-}
-
-static int qsort_strcmp(const void *a, const void *b)
-{
- return strcmp(a, b);
-}
-
-void bdrv_iterate_format(void (*it)(void *opaque, const char *name),
- void *opaque)
-{
- BlockDriver *drv;
- int count = 0;
- int i;
- const char **formats = NULL;
-
- QLIST_FOREACH(drv, &bdrv_drivers, list) {
- if (drv->format_name) {
- bool found = false;
- int i = count;
- while (formats && i && !found) {
- found = !strcmp(formats[--i], drv->format_name);
- }
-
- if (!found) {
- formats = g_renew(const char *, formats, count + 1);
- formats[count++] = drv->format_name;
- }
- }
- }
-
- qsort(formats, count, sizeof(formats[0]), qsort_strcmp);
-
- for (i = 0; i < count; i++) {
- it(opaque, formats[i]);
- }
-
- g_free(formats);
-}
-
-/* This function is to find a node in the bs graph */
-BlockDriverState *bdrv_find_node(const char *node_name)
-{
- BlockDriverState *bs;
-
- assert(node_name);
-
- QTAILQ_FOREACH(bs, &graph_bdrv_states, node_list) {
- if (!strcmp(node_name, bs->node_name)) {
- return bs;
- }
- }
- return NULL;
-}
-
-/* Put this QMP function here so it can access the static graph_bdrv_states. */
-BlockDeviceInfoList *bdrv_named_nodes_list(Error **errp)
-{
- BlockDeviceInfoList *list, *entry;
- BlockDriverState *bs;
-
- list = NULL;
- QTAILQ_FOREACH(bs, &graph_bdrv_states, node_list) {
- BlockDeviceInfo *info = bdrv_block_device_info(bs, errp);
- if (!info) {
- qapi_free_BlockDeviceInfoList(list);
- return NULL;
- }
- entry = g_malloc0(sizeof(*entry));
- entry->value = info;
- entry->next = list;
- list = entry;
- }
-
- return list;
-}
-
-BlockDriverState *bdrv_lookup_bs(const char *device,
- const char *node_name,
- Error **errp)
-{
- BlockBackend *blk;
- BlockDriverState *bs;
-
- if (device) {
- blk = blk_by_name(device);
-
- if (blk) {
- return blk_bs(blk);
- }
- }
-
- if (node_name) {
- bs = bdrv_find_node(node_name);
-
- if (bs) {
- return bs;
- }
- }
-
- error_setg(errp, "Cannot find device=%s nor node_name=%s",
- device ? device : "",
- node_name ? node_name : "");
- return NULL;
-}
-
-/* If 'base' is in the same chain as 'top', return true. Otherwise,
- * return false. If either argument is NULL, return false. */
-bool bdrv_chain_contains(BlockDriverState *top, BlockDriverState *base)
-{
- while (top && top != base) {
- top = top->backing_hd;
- }
-
- return top != NULL;
-}
-
-BlockDriverState *bdrv_next_node(BlockDriverState *bs)
-{
- if (!bs) {
- return QTAILQ_FIRST(&graph_bdrv_states);
- }
- return QTAILQ_NEXT(bs, node_list);
-}
-
-BlockDriverState *bdrv_next(BlockDriverState *bs)
-{
- if (!bs) {
- return QTAILQ_FIRST(&bdrv_states);
- }
- return QTAILQ_NEXT(bs, device_list);
-}
-
-const char *bdrv_get_node_name(const BlockDriverState *bs)
-{
- return bs->node_name;
-}
-
-/* TODO check what callers really want: bs->node_name or blk_name() */
-const char *bdrv_get_device_name(const BlockDriverState *bs)
-{
- return bs->blk ? blk_name(bs->blk) : "";
-}
-
-/* This can be used to identify nodes that might not have a device
- * name associated. Since node and device names live in the same
- * namespace, the result is unambiguous. The exception is if both are
- * absent, then this returns an empty (non-null) string. */
-const char *bdrv_get_device_or_node_name(const BlockDriverState *bs)
-{
- return bs->blk ? blk_name(bs->blk) : bs->node_name;
-}
-
-int bdrv_get_flags(BlockDriverState *bs)
-{
- return bs->open_flags;
-}
-
-int bdrv_flush_all(void)
-{
- BlockDriverState *bs = NULL;
- int result = 0;
-
- while ((bs = bdrv_next(bs))) {
- AioContext *aio_context = bdrv_get_aio_context(bs);
- int ret;
-
- aio_context_acquire(aio_context);
- ret = bdrv_flush(bs);
- if (ret < 0 && !result) {
- result = ret;
- }
- aio_context_release(aio_context);
- }
-
- return result;
-}
-
-int bdrv_has_zero_init_1(BlockDriverState *bs)
-{
- return 1;
-}
-
-int bdrv_has_zero_init(BlockDriverState *bs)
-{
- assert(bs->drv);
-
- /* If BS is a copy on write image, it is initialized to
- the contents of the base image, which may not be zeroes. */
- if (bs->backing_hd) {
- return 0;
- }
- if (bs->drv->bdrv_has_zero_init) {
- return bs->drv->bdrv_has_zero_init(bs);
- }
-
- /* safe default */
- return 0;
-}
-
-bool bdrv_unallocated_blocks_are_zero(BlockDriverState *bs)
-{
- BlockDriverInfo bdi;
-
- if (bs->backing_hd) {
- return false;
- }
-
- if (bdrv_get_info(bs, &bdi) == 0) {
- return bdi.unallocated_blocks_are_zero;
- }
-
- return false;
-}
-
-bool bdrv_can_write_zeroes_with_unmap(BlockDriverState *bs)
-{
- BlockDriverInfo bdi;
-
- if (bs->backing_hd || !(bs->open_flags & BDRV_O_UNMAP)) {
- return false;
- }
-
- if (bdrv_get_info(bs, &bdi) == 0) {
- return bdi.can_write_zeroes_with_unmap;
- }
-
- return false;
-}
-
-typedef struct BdrvCoGetBlockStatusData {
- BlockDriverState *bs;
- BlockDriverState *base;
- int64_t sector_num;
- int nb_sectors;
- int *pnum;
- int64_t ret;
- bool done;
-} BdrvCoGetBlockStatusData;
-
-/*
- * Returns the allocation status of the specified sectors.
- * Drivers not implementing the functionality are assumed to not support
- * backing files, hence all their sectors are reported as allocated.
- *
- * If 'sector_num' is beyond the end of the disk image the return value is 0
- * and 'pnum' is set to 0.
- *
- * 'pnum' is set to the number of sectors (including and immediately following
- * the specified sector) that are known to be in the same
- * allocated/unallocated state.
- *
- * 'nb_sectors' is the max value 'pnum' should be set to. If nb_sectors goes
- * beyond the end of the disk image it will be clamped.
- */
-static int64_t coroutine_fn bdrv_co_get_block_status(BlockDriverState *bs,
- int64_t sector_num,
- int nb_sectors, int *pnum)
-{
- int64_t total_sectors;
- int64_t n;
- int64_t ret, ret2;
-
- total_sectors = bdrv_nb_sectors(bs);
- if (total_sectors < 0) {
- return total_sectors;
- }
-
- if (sector_num >= total_sectors) {
- *pnum = 0;
- return 0;
- }
-
- n = total_sectors - sector_num;
- if (n < nb_sectors) {
- nb_sectors = n;
- }
-
- if (!bs->drv->bdrv_co_get_block_status) {
- *pnum = nb_sectors;
- ret = BDRV_BLOCK_DATA | BDRV_BLOCK_ALLOCATED;
- if (bs->drv->protocol_name) {
- ret |= BDRV_BLOCK_OFFSET_VALID | (sector_num * BDRV_SECTOR_SIZE);
- }
- return ret;
- }
-
- ret = bs->drv->bdrv_co_get_block_status(bs, sector_num, nb_sectors, pnum);
- if (ret < 0) {
- *pnum = 0;
- return ret;
- }
-
- if (ret & BDRV_BLOCK_RAW) {
- assert(ret & BDRV_BLOCK_OFFSET_VALID);
- return bdrv_get_block_status(bs->file, ret >> BDRV_SECTOR_BITS,
- *pnum, pnum);
- }
-
- if (ret & (BDRV_BLOCK_DATA | BDRV_BLOCK_ZERO)) {
- ret |= BDRV_BLOCK_ALLOCATED;
- }
-
- if (!(ret & BDRV_BLOCK_DATA) && !(ret & BDRV_BLOCK_ZERO)) {
- if (bdrv_unallocated_blocks_are_zero(bs)) {
- ret |= BDRV_BLOCK_ZERO;
- } else if (bs->backing_hd) {
- BlockDriverState *bs2 = bs->backing_hd;
- int64_t nb_sectors2 = bdrv_nb_sectors(bs2);
- if (nb_sectors2 >= 0 && sector_num >= nb_sectors2) {
- ret |= BDRV_BLOCK_ZERO;
- }
- }
- }
-
- if (bs->file &&
- (ret & BDRV_BLOCK_DATA) && !(ret & BDRV_BLOCK_ZERO) &&
- (ret & BDRV_BLOCK_OFFSET_VALID)) {
- int file_pnum;
-
- ret2 = bdrv_co_get_block_status(bs->file, ret >> BDRV_SECTOR_BITS,
- *pnum, &file_pnum);
- if (ret2 >= 0) {
- /* Ignore errors. This is just providing extra information, it
- * is useful but not necessary.
- */
- if (!file_pnum) {
- /* !file_pnum indicates an offset at or beyond the EOF; it is
- * perfectly valid for the format block driver to point to such
- * offsets, so catch it and mark everything as zero */
- ret |= BDRV_BLOCK_ZERO;
- } else {
- /* Limit request to the range reported by the protocol driver
*/
- *pnum = file_pnum;
- ret |= (ret2 & BDRV_BLOCK_ZERO);
- }
- }
- }
-
- return ret;
-}
-
-/* Coroutine wrapper for bdrv_get_block_status() */
-static void coroutine_fn bdrv_get_block_status_co_entry(void *opaque)
-{
- BdrvCoGetBlockStatusData *data = opaque;
- BlockDriverState *bs = data->bs;
-
- data->ret = bdrv_co_get_block_status(bs, data->sector_num,
data->nb_sectors,
- data->pnum);
- data->done = true;
-}
-
-/*
- * Synchronous wrapper around bdrv_co_get_block_status().
- *
- * See bdrv_co_get_block_status() for details.
- */
-int64_t bdrv_get_block_status(BlockDriverState *bs, int64_t sector_num,
- int nb_sectors, int *pnum)
-{
- Coroutine *co;
- BdrvCoGetBlockStatusData data = {
- .bs = bs,
- .sector_num = sector_num,
- .nb_sectors = nb_sectors,
- .pnum = pnum,
- .done = false,
- };
-
- if (qemu_in_coroutine()) {
- /* Fast-path if already in coroutine context */
- bdrv_get_block_status_co_entry(&data);
- } else {
- AioContext *aio_context = bdrv_get_aio_context(bs);
-
- co = qemu_coroutine_create(bdrv_get_block_status_co_entry);
- qemu_coroutine_enter(co, &data);
- while (!data.done) {
- aio_poll(aio_context, true);
- }
- }
- return data.ret;
-}
-
-int coroutine_fn bdrv_is_allocated(BlockDriverState *bs, int64_t sector_num,
- int nb_sectors, int *pnum)
-{
- int64_t ret = bdrv_get_block_status(bs, sector_num, nb_sectors, pnum);
- if (ret < 0) {
- return ret;
- }
- return !!(ret & BDRV_BLOCK_ALLOCATED);
-}
-
-/*
- * Given an image chain: ... -> [BASE] -> [INTER1] -> [INTER2] -> [TOP]
- *
- * Return true if the given sector is allocated in any image between
- * BASE and TOP (inclusive). BASE can be NULL to check if the given
- * sector is allocated in any image of the chain. Return false otherwise.
- *
- * 'pnum' is set to the number of sectors (including and immediately following
- * the specified sector) that are known to be in the same
- * allocated/unallocated state.
- *
- */
-int bdrv_is_allocated_above(BlockDriverState *top,
- BlockDriverState *base,
- int64_t sector_num,
- int nb_sectors, int *pnum)
-{
- BlockDriverState *intermediate;
- int ret, n = nb_sectors;
-
- intermediate = top;
- while (intermediate && intermediate != base) {
- int pnum_inter;
- ret = bdrv_is_allocated(intermediate, sector_num, nb_sectors,
- &pnum_inter);
- if (ret < 0) {
- return ret;
- } else if (ret) {
- *pnum = pnum_inter;
- return 1;
- }
-
- /*
- * [sector_num, nb_sectors] is unallocated on top but intermediate
- * might have
- *
- * [sector_num+x, nr_sectors] allocated.
- */
- if (n > pnum_inter &&
- (intermediate == top ||
- sector_num + pnum_inter < intermediate->total_sectors)) {
- n = pnum_inter;
- }
-
- intermediate = intermediate->backing_hd;
- }
-
- *pnum = n;
- return 0;
-}
-
-const char *bdrv_get_encrypted_filename(BlockDriverState *bs)
-{
- if (bs->backing_hd && bs->backing_hd->encrypted)
- return bs->backing_file;
- else if (bs->encrypted)
- return bs->filename;
- else
- return NULL;
-}
-
-void bdrv_get_backing_filename(BlockDriverState *bs,
- char *filename, int filename_size)
-{
- pstrcpy(filename, filename_size, bs->backing_file);
-}
-
-int bdrv_write_compressed(BlockDriverState *bs, int64_t sector_num,
- const uint8_t *buf, int nb_sectors)
-{
- BlockDriver *drv = bs->drv;
- int ret;
-
- if (!drv) {
- return -ENOMEDIUM;
- }
- if (!drv->bdrv_write_compressed) {
- return -ENOTSUP;
- }
- ret = bdrv_check_request(bs, sector_num, nb_sectors);
- if (ret < 0) {
- return ret;
- }
-
- assert(QLIST_EMPTY(&bs->dirty_bitmaps));
-
- return drv->bdrv_write_compressed(bs, sector_num, buf, nb_sectors);
-}
-
-int bdrv_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
-{
- BlockDriver *drv = bs->drv;
- if (!drv)
- return -ENOMEDIUM;
- if (!drv->bdrv_get_info)
- return -ENOTSUP;
- memset(bdi, 0, sizeof(*bdi));
- return drv->bdrv_get_info(bs, bdi);
-}
-
-ImageInfoSpecific *bdrv_get_specific_info(BlockDriverState *bs)
-{
- BlockDriver *drv = bs->drv;
- if (drv && drv->bdrv_get_specific_info) {
- return drv->bdrv_get_specific_info(bs);
- }
- return NULL;
-}
-
-int bdrv_save_vmstate(BlockDriverState *bs, const uint8_t *buf,
- int64_t pos, int size)
-{
- QEMUIOVector qiov;
- struct iovec iov = {
- .iov_base = (void *) buf,
- .iov_len = size,
- };
-
- qemu_iovec_init_external(&qiov, &iov, 1);
- return bdrv_writev_vmstate(bs, &qiov, pos);
-}
-
-int bdrv_writev_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos)
-{
- BlockDriver *drv = bs->drv;
-
- if (!drv) {
- return -ENOMEDIUM;
- } else if (drv->bdrv_save_vmstate) {
- return drv->bdrv_save_vmstate(bs, qiov, pos);
- } else if (bs->file) {
- return bdrv_writev_vmstate(bs->file, qiov, pos);
- }
-
- return -ENOTSUP;
-}
-
-int bdrv_load_vmstate(BlockDriverState *bs, uint8_t *buf,
- int64_t pos, int size)
-{
- BlockDriver *drv = bs->drv;
- if (!drv)
- return -ENOMEDIUM;
- if (drv->bdrv_load_vmstate)
- return drv->bdrv_load_vmstate(bs, buf, pos, size);
- if (bs->file)
- return bdrv_load_vmstate(bs->file, buf, pos, size);
- return -ENOTSUP;
-}
-
-void bdrv_debug_event(BlockDriverState *bs, BlkDebugEvent event)
-{
- if (!bs || !bs->drv || !bs->drv->bdrv_debug_event) {
- return;
- }
-
- bs->drv->bdrv_debug_event(bs, event);
-}
-
-int bdrv_debug_breakpoint(BlockDriverState *bs, const char *event,
- const char *tag)
-{
- while (bs && bs->drv && !bs->drv->bdrv_debug_breakpoint) {
- bs = bs->file;
- }
-
- if (bs && bs->drv && bs->drv->bdrv_debug_breakpoint) {
- return bs->drv->bdrv_debug_breakpoint(bs, event, tag);
- }
-
- return -ENOTSUP;
-}
-
-int bdrv_debug_remove_breakpoint(BlockDriverState *bs, const char *tag)
-{
- while (bs && bs->drv && !bs->drv->bdrv_debug_remove_breakpoint) {
- bs = bs->file;
- }
-
- if (bs && bs->drv && bs->drv->bdrv_debug_remove_breakpoint) {
- return bs->drv->bdrv_debug_remove_breakpoint(bs, tag);
- }
-
- return -ENOTSUP;
-}
-
-int bdrv_debug_resume(BlockDriverState *bs, const char *tag)
-{
- while (bs && (!bs->drv || !bs->drv->bdrv_debug_resume)) {
- bs = bs->file;
- }
-
- if (bs && bs->drv && bs->drv->bdrv_debug_resume) {
- return bs->drv->bdrv_debug_resume(bs, tag);
- }
-
- return -ENOTSUP;
-}
-
-bool bdrv_debug_is_suspended(BlockDriverState *bs, const char *tag)
-{
- while (bs && bs->drv && !bs->drv->bdrv_debug_is_suspended) {
- bs = bs->file;
- }
-
- if (bs && bs->drv && bs->drv->bdrv_debug_is_suspended) {
- return bs->drv->bdrv_debug_is_suspended(bs, tag);
- }
-
- return false;
-}
-
-int bdrv_is_snapshot(BlockDriverState *bs)
-{
- return !!(bs->open_flags & BDRV_O_SNAPSHOT);
-}
-
-/* backing_file can either be relative, or absolute, or a protocol. If it is
- * relative, it must be relative to the chain. So, passing in bs->filename
- * from a BDS as backing_file should not be done, as that may be relative to
- * the CWD rather than the chain. */
-BlockDriverState *bdrv_find_backing_image(BlockDriverState *bs,
- const char *backing_file)
-{
- char *filename_full = NULL;
- char *backing_file_full = NULL;
- char *filename_tmp = NULL;
- int is_protocol = 0;
- BlockDriverState *curr_bs = NULL;
- BlockDriverState *retval = NULL;
-
- if (!bs || !bs->drv || !backing_file) {
- return NULL;
- }
-
- filename_full = g_malloc(PATH_MAX);
- backing_file_full = g_malloc(PATH_MAX);
- filename_tmp = g_malloc(PATH_MAX);
-
- is_protocol = path_has_protocol(backing_file);
-
- for (curr_bs = bs; curr_bs->backing_hd; curr_bs = curr_bs->backing_hd) {
-
- /* If either of the filename paths is actually a protocol, then
- * compare unmodified paths; otherwise make paths relative */
- if (is_protocol || path_has_protocol(curr_bs->backing_file)) {
- if (strcmp(backing_file, curr_bs->backing_file) == 0) {
- retval = curr_bs->backing_hd;
- break;
- }
- } else {
- /* If not an absolute filename path, make it relative to the
current
- * image's filename path */
- path_combine(filename_tmp, PATH_MAX, curr_bs->filename,
- backing_file);
-
- /* We are going to compare absolute pathnames */
- if (!realpath(filename_tmp, filename_full)) {
- continue;
- }
-
- /* We need to make sure the backing filename we are comparing
against
- * is relative to the current image filename (or absolute) */
- path_combine(filename_tmp, PATH_MAX, curr_bs->filename,
- curr_bs->backing_file);
-
- if (!realpath(filename_tmp, backing_file_full)) {
- continue;
- }
-
- if (strcmp(backing_file_full, filename_full) == 0) {
- retval = curr_bs->backing_hd;
- break;
- }
- }
- }
-
- g_free(filename_full);
- g_free(backing_file_full);
- g_free(filename_tmp);
- return retval;
-}
-
-int bdrv_get_backing_file_depth(BlockDriverState *bs)
-{
- if (!bs->drv) {
- return 0;
- }
-
- if (!bs->backing_hd) {
- return 0;
- }
-
- return 1 + bdrv_get_backing_file_depth(bs->backing_hd);
-}
-
-/**************************************************************/
-/* async I/Os */
-
-BlockAIOCB *bdrv_aio_readv(BlockDriverState *bs, int64_t sector_num,
- QEMUIOVector *qiov, int nb_sectors,
- BlockCompletionFunc *cb, void *opaque)
-{
- trace_bdrv_aio_readv(bs, sector_num, nb_sectors, opaque);
-
- return bdrv_co_aio_rw_vector(bs, sector_num, qiov, nb_sectors, 0,
- cb, opaque, false);
-}
-
-BlockAIOCB *bdrv_aio_writev(BlockDriverState *bs, int64_t sector_num,
- QEMUIOVector *qiov, int nb_sectors,
- BlockCompletionFunc *cb, void *opaque)
-{
- trace_bdrv_aio_writev(bs, sector_num, nb_sectors, opaque);
-
- return bdrv_co_aio_rw_vector(bs, sector_num, qiov, nb_sectors, 0,
- cb, opaque, true);
-}
-
-BlockAIOCB *bdrv_aio_write_zeroes(BlockDriverState *bs,
- int64_t sector_num, int nb_sectors, BdrvRequestFlags flags,
- BlockCompletionFunc *cb, void *opaque)
-{
- trace_bdrv_aio_write_zeroes(bs, sector_num, nb_sectors, flags, opaque);
-
- return bdrv_co_aio_rw_vector(bs, sector_num, NULL, nb_sectors,
- BDRV_REQ_ZERO_WRITE | flags,
- cb, opaque, true);
-}
-
-
-typedef struct MultiwriteCB {
- int error;
- int num_requests;
- int num_callbacks;
- struct {
- BlockCompletionFunc *cb;
- void *opaque;
- QEMUIOVector *free_qiov;
- } callbacks[];
-} MultiwriteCB;
-
-static void multiwrite_user_cb(MultiwriteCB *mcb)
-{
- int i;
-
- for (i = 0; i < mcb->num_callbacks; i++) {
- mcb->callbacks[i].cb(mcb->callbacks[i].opaque, mcb->error);
- if (mcb->callbacks[i].free_qiov) {
- qemu_iovec_destroy(mcb->callbacks[i].free_qiov);
- }
- g_free(mcb->callbacks[i].free_qiov);
- }
-}
-
-static void multiwrite_cb(void *opaque, int ret)
+const char *bdrv_get_format_name(BlockDriverState *bs)
{
- MultiwriteCB *mcb = opaque;
-
- trace_multiwrite_cb(mcb, ret);
-
- if (ret < 0 && !mcb->error) {
- mcb->error = ret;
- }
-
- mcb->num_requests--;
- if (mcb->num_requests == 0) {
- multiwrite_user_cb(mcb);
- g_free(mcb);
- }
+ return bs->drv ? bs->drv->format_name : NULL;
}
-static int multiwrite_req_compare(const void *a, const void *b)
+static int qsort_strcmp(const void *a, const void *b)
{
- const BlockRequest *req1 = a, *req2 = b;
-
- /*
- * Note that we can't simply subtract req2->sector from req1->sector
- * here as that could overflow the return value.
- */
- if (req1->sector > req2->sector) {
- return 1;
- } else if (req1->sector < req2->sector) {
- return -1;
- } else {
- return 0;
- }
+ return strcmp(a, b);
}
-/*
- * Takes a bunch of requests and tries to merge them. Returns the number of
- * requests that remain after merging.
- */
-static int multiwrite_merge(BlockDriverState *bs, BlockRequest *reqs,
- int num_reqs, MultiwriteCB *mcb)
+void bdrv_iterate_format(void (*it)(void *opaque, const char *name),
+ void *opaque)
{
- int i, outidx;
-
- // Sort requests by start sector
- qsort(reqs, num_reqs, sizeof(*reqs), &multiwrite_req_compare);
-
- // Check if adjacent requests touch the same clusters. If so, combine them,
- // filling up gaps with zero sectors.
- outidx = 0;
- for (i = 1; i < num_reqs; i++) {
- int merge = 0;
- int64_t oldreq_last = reqs[outidx].sector + reqs[outidx].nb_sectors;
-
- // Handle exactly sequential writes and overlapping writes.
- if (reqs[i].sector <= oldreq_last) {
- merge = 1;
- }
+ BlockDriver *drv;
+ int count = 0;
+ int i;
+ const char **formats = NULL;
- if (reqs[outidx].qiov->niov + reqs[i].qiov->niov + 1 > IOV_MAX) {
- merge = 0;
- }
+ QLIST_FOREACH(drv, &bdrv_drivers, list) {
+ if (drv->format_name) {
+ bool found = false;
+ int i = count;
+ while (formats && i && !found) {
+ found = !strcmp(formats[--i], drv->format_name);
+ }
- if (bs->bl.max_transfer_length && reqs[outidx].nb_sectors +
- reqs[i].nb_sectors > bs->bl.max_transfer_length) {
- merge = 0;
+ if (!found) {
+ formats = g_renew(const char *, formats, count + 1);
+ formats[count++] = drv->format_name;
+ }
}
+ }
- if (merge) {
- size_t size;
- QEMUIOVector *qiov = g_malloc0(sizeof(*qiov));
- qemu_iovec_init(qiov,
- reqs[outidx].qiov->niov + reqs[i].qiov->niov + 1);
-
- // Add the first request to the merged one. If the requests are
- // overlapping, drop the last sectors of the first request.
- size = (reqs[i].sector - reqs[outidx].sector) << 9;
- qemu_iovec_concat(qiov, reqs[outidx].qiov, 0, size);
+ qsort(formats, count, sizeof(formats[0]), qsort_strcmp);
- // We should need to add any zeros between the two requests
- assert (reqs[i].sector <= oldreq_last);
+ for (i = 0; i < count; i++) {
+ it(opaque, formats[i]);
+ }
- // Add the second request
- qemu_iovec_concat(qiov, reqs[i].qiov, 0, reqs[i].qiov->size);
+ g_free(formats);
+}
- // Add tail of first request, if necessary
- if (qiov->size < reqs[outidx].qiov->size) {
- qemu_iovec_concat(qiov, reqs[outidx].qiov, qiov->size,
- reqs[outidx].qiov->size - qiov->size);
- }
+/* This function is to find a node in the bs graph */
+BlockDriverState *bdrv_find_node(const char *node_name)
+{
+ BlockDriverState *bs;
- reqs[outidx].nb_sectors = qiov->size >> 9;
- reqs[outidx].qiov = qiov;
+ assert(node_name);
- mcb->callbacks[i].free_qiov = reqs[outidx].qiov;
- } else {
- outidx++;
- reqs[outidx].sector = reqs[i].sector;
- reqs[outidx].nb_sectors = reqs[i].nb_sectors;
- reqs[outidx].qiov = reqs[i].qiov;
+ QTAILQ_FOREACH(bs, &graph_bdrv_states, node_list) {
+ if (!strcmp(node_name, bs->node_name)) {
+ return bs;
}
}
-
- block_acct_merge_done(&bs->stats, BLOCK_ACCT_WRITE, num_reqs - outidx - 1);
-
- return outidx + 1;
+ return NULL;
}
-/*
- * Submit multiple AIO write requests at once.
- *
- * On success, the function returns 0 and all requests in the reqs array have
- * been submitted. In error case this function returns -1, and any of the
- * requests may or may not be submitted yet. In particular, this means that the
- * callback will be called for some of the requests, for others it won't. The
- * caller must check the error field of the BlockRequest to wait for the right
- * callbacks (if error != 0, no callback will be called).
- *
- * The implementation may modify the contents of the reqs array, e.g. to merge
- * requests. However, the fields opaque and error are left unmodified as they
- * are used to signal failure for a single request to the caller.
- */
-int bdrv_aio_multiwrite(BlockDriverState *bs, BlockRequest *reqs, int num_reqs)
+/* Put this QMP function here so it can access the static graph_bdrv_states. */
+BlockDeviceInfoList *bdrv_named_nodes_list(Error **errp)
{
- MultiwriteCB *mcb;
- int i;
+ BlockDeviceInfoList *list, *entry;
+ BlockDriverState *bs;
- /* don't submit writes if we don't have a medium */
- if (bs->drv == NULL) {
- for (i = 0; i < num_reqs; i++) {
- reqs[i].error = -ENOMEDIUM;
+ list = NULL;
+ QTAILQ_FOREACH(bs, &graph_bdrv_states, node_list) {
+ BlockDeviceInfo *info = bdrv_block_device_info(bs, errp);
+ if (!info) {
+ qapi_free_BlockDeviceInfoList(list);
+ return NULL;
}
- return -1;
+ entry = g_malloc0(sizeof(*entry));
+ entry->value = info;
+ entry->next = list;
+ list = entry;
}
- if (num_reqs == 0) {
- return 0;
- }
+ return list;
+}
- // Create MultiwriteCB structure
- mcb = g_malloc0(sizeof(*mcb) + num_reqs * sizeof(*mcb->callbacks));
- mcb->num_requests = 0;
- mcb->num_callbacks = num_reqs;
+BlockDriverState *bdrv_lookup_bs(const char *device,
+ const char *node_name,
+ Error **errp)
+{
+ BlockBackend *blk;
+ BlockDriverState *bs;
- for (i = 0; i < num_reqs; i++) {
- mcb->callbacks[i].cb = reqs[i].cb;
- mcb->callbacks[i].opaque = reqs[i].opaque;
- }
+ if (device) {
+ blk = blk_by_name(device);
- // Check for mergable requests
- num_reqs = multiwrite_merge(bs, reqs, num_reqs, mcb);
+ if (blk) {
+ return blk_bs(blk);
+ }
+ }
- trace_bdrv_aio_multiwrite(mcb, mcb->num_callbacks, num_reqs);
+ if (node_name) {
+ bs = bdrv_find_node(node_name);
- /* Run the aio requests. */
- mcb->num_requests = num_reqs;
- for (i = 0; i < num_reqs; i++) {
- bdrv_co_aio_rw_vector(bs, reqs[i].sector, reqs[i].qiov,
- reqs[i].nb_sectors, reqs[i].flags,
- multiwrite_cb, mcb,
- true);
+ if (bs) {
+ return bs;
+ }
}
- return 0;
+ error_setg(errp, "Cannot find device=%s nor node_name=%s",
+ device ? device : "",
+ node_name ? node_name : "");
+ return NULL;
}
-void bdrv_aio_cancel(BlockAIOCB *acb)
+/* If 'base' is in the same chain as 'top', return true. Otherwise,
+ * return false. If either argument is NULL, return false. */
+bool bdrv_chain_contains(BlockDriverState *top, BlockDriverState *base)
{
- qemu_aio_ref(acb);
- bdrv_aio_cancel_async(acb);
- while (acb->refcnt > 1) {
- if (acb->aiocb_info->get_aio_context) {
- aio_poll(acb->aiocb_info->get_aio_context(acb), true);
- } else if (acb->bs) {
- aio_poll(bdrv_get_aio_context(acb->bs), true);
- } else {
- abort();
- }
+ while (top && top != base) {
+ top = top->backing_hd;
}
- qemu_aio_unref(acb);
+
+ return top != NULL;
}
-/* Async version of aio cancel. The caller is not blocked if the acb implements
- * cancel_async, otherwise we do nothing and let the request normally complete.
- * In either case the completion callback must be called. */
-void bdrv_aio_cancel_async(BlockAIOCB *acb)
+BlockDriverState *bdrv_next_node(BlockDriverState *bs)
{
- if (acb->aiocb_info->cancel_async) {
- acb->aiocb_info->cancel_async(acb);
+ if (!bs) {
+ return QTAILQ_FIRST(&graph_bdrv_states);
}
+ return QTAILQ_NEXT(bs, node_list);
}
-/**************************************************************/
-/* async block device emulation */
-
-typedef struct BlockAIOCBSync {
- BlockAIOCB common;
- QEMUBH *bh;
- int ret;
- /* vector translation state */
- QEMUIOVector *qiov;
- uint8_t *bounce;
- int is_write;
-} BlockAIOCBSync;
-
-static const AIOCBInfo bdrv_em_aiocb_info = {
- .aiocb_size = sizeof(BlockAIOCBSync),
-};
-
-static void bdrv_aio_bh_cb(void *opaque)
+BlockDriverState *bdrv_next(BlockDriverState *bs)
{
- BlockAIOCBSync *acb = opaque;
-
- if (!acb->is_write && acb->ret >= 0) {
- qemu_iovec_from_buf(acb->qiov, 0, acb->bounce, acb->qiov->size);
+ if (!bs) {
+ return QTAILQ_FIRST(&bdrv_states);
}
- qemu_vfree(acb->bounce);
- acb->common.cb(acb->common.opaque, acb->ret);
- qemu_bh_delete(acb->bh);
- acb->bh = NULL;
- qemu_aio_unref(acb);
+ return QTAILQ_NEXT(bs, device_list);
}
-static BlockAIOCB *bdrv_aio_rw_vector(BlockDriverState *bs,
- int64_t sector_num,
- QEMUIOVector *qiov,
- int nb_sectors,
- BlockCompletionFunc *cb,
- void *opaque,
- int is_write)
-
+const char *bdrv_get_node_name(const BlockDriverState *bs)
{
- BlockAIOCBSync *acb;
-
- acb = qemu_aio_get(&bdrv_em_aiocb_info, bs, cb, opaque);
- acb->is_write = is_write;
- acb->qiov = qiov;
- acb->bounce = qemu_try_blockalign(bs, qiov->size);
- acb->bh = aio_bh_new(bdrv_get_aio_context(bs), bdrv_aio_bh_cb, acb);
-
- if (acb->bounce == NULL) {
- acb->ret = -ENOMEM;
- } else if (is_write) {
- qemu_iovec_to_buf(acb->qiov, 0, acb->bounce, qiov->size);
- acb->ret = bs->drv->bdrv_write(bs, sector_num, acb->bounce,
nb_sectors);
- } else {
- acb->ret = bs->drv->bdrv_read(bs, sector_num, acb->bounce, nb_sectors);
- }
-
- qemu_bh_schedule(acb->bh);
-
- return &acb->common;
+ return bs->node_name;
}
-static BlockAIOCB *bdrv_aio_readv_em(BlockDriverState *bs,
- int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
- BlockCompletionFunc *cb, void *opaque)
+/* TODO check what callers really want: bs->node_name or blk_name() */
+const char *bdrv_get_device_name(const BlockDriverState *bs)
{
- return bdrv_aio_rw_vector(bs, sector_num, qiov, nb_sectors, cb, opaque, 0);
+ return bs->blk ? blk_name(bs->blk) : "";
}
-static BlockAIOCB *bdrv_aio_writev_em(BlockDriverState *bs,
- int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
- BlockCompletionFunc *cb, void *opaque)
+/* This can be used to identify nodes that might not have a device
+ * name associated. Since node and device names live in the same
+ * namespace, the result is unambiguous. The exception is if both are
+ * absent, then this returns an empty (non-null) string. */
+const char *bdrv_get_device_or_node_name(const BlockDriverState *bs)
{
- return bdrv_aio_rw_vector(bs, sector_num, qiov, nb_sectors, cb, opaque, 1);
+ return bs->blk ? blk_name(bs->blk) : bs->node_name;
}
-
-typedef struct BlockAIOCBCoroutine {
- BlockAIOCB common;
- BlockRequest req;
- bool is_write;
- bool need_bh;
- bool *done;
- QEMUBH* bh;
-} BlockAIOCBCoroutine;
-
-static const AIOCBInfo bdrv_em_co_aiocb_info = {
- .aiocb_size = sizeof(BlockAIOCBCoroutine),
-};
-
-static void bdrv_co_complete(BlockAIOCBCoroutine *acb)
+int bdrv_get_flags(BlockDriverState *bs)
{
- if (!acb->need_bh) {
- acb->common.cb(acb->common.opaque, acb->req.error);
- qemu_aio_unref(acb);
- }
+ return bs->open_flags;
}
-static void bdrv_co_em_bh(void *opaque)
+int bdrv_has_zero_init_1(BlockDriverState *bs)
{
- BlockAIOCBCoroutine *acb = opaque;
-
- assert(!acb->need_bh);
- qemu_bh_delete(acb->bh);
- bdrv_co_complete(acb);
+ return 1;
}
-static void bdrv_co_maybe_schedule_bh(BlockAIOCBCoroutine *acb)
+int bdrv_has_zero_init(BlockDriverState *bs)
{
- acb->need_bh = false;
- if (acb->req.error != -EINPROGRESS) {
- BlockDriverState *bs = acb->common.bs;
+ assert(bs->drv);
- acb->bh = aio_bh_new(bdrv_get_aio_context(bs), bdrv_co_em_bh, acb);
- qemu_bh_schedule(acb->bh);
+ /* If BS is a copy on write image, it is initialized to
+ the contents of the base image, which may not be zeroes. */
+ if (bs->backing_hd) {
+ return 0;
+ }
+ if (bs->drv->bdrv_has_zero_init) {
+ return bs->drv->bdrv_has_zero_init(bs);
}
+
+ /* safe default */
+ return 0;
}
-/* Invoke bdrv_co_do_readv/bdrv_co_do_writev */
-static void coroutine_fn bdrv_co_do_rw(void *opaque)
+bool bdrv_unallocated_blocks_are_zero(BlockDriverState *bs)
{
- BlockAIOCBCoroutine *acb = opaque;
- BlockDriverState *bs = acb->common.bs;
+ BlockDriverInfo bdi;
- if (!acb->is_write) {
- acb->req.error = bdrv_co_do_readv(bs, acb->req.sector,
- acb->req.nb_sectors, acb->req.qiov, acb->req.flags);
- } else {
- acb->req.error = bdrv_co_do_writev(bs, acb->req.sector,
- acb->req.nb_sectors, acb->req.qiov, acb->req.flags);
+ if (bs->backing_hd) {
+ return false;
+ }
+
+ if (bdrv_get_info(bs, &bdi) == 0) {
+ return bdi.unallocated_blocks_are_zero;
}
- bdrv_co_complete(acb);
+ return false;
}
-static BlockAIOCB *bdrv_co_aio_rw_vector(BlockDriverState *bs,
- int64_t sector_num,
- QEMUIOVector *qiov,
- int nb_sectors,
- BdrvRequestFlags flags,
- BlockCompletionFunc *cb,
- void *opaque,
- bool is_write)
+bool bdrv_can_write_zeroes_with_unmap(BlockDriverState *bs)
{
- Coroutine *co;
- BlockAIOCBCoroutine *acb;
+ BlockDriverInfo bdi;
- acb = qemu_aio_get(&bdrv_em_co_aiocb_info, bs, cb, opaque);
- acb->need_bh = true;
- acb->req.error = -EINPROGRESS;
- acb->req.sector = sector_num;
- acb->req.nb_sectors = nb_sectors;
- acb->req.qiov = qiov;
- acb->req.flags = flags;
- acb->is_write = is_write;
+ if (bs->backing_hd || !(bs->open_flags & BDRV_O_UNMAP)) {
+ return false;
+ }
- co = qemu_coroutine_create(bdrv_co_do_rw);
- qemu_coroutine_enter(co, acb);
+ if (bdrv_get_info(bs, &bdi) == 0) {
+ return bdi.can_write_zeroes_with_unmap;
+ }
- bdrv_co_maybe_schedule_bh(acb);
- return &acb->common;
+ return false;
}
-static void coroutine_fn bdrv_aio_flush_co_entry(void *opaque)
+const char *bdrv_get_encrypted_filename(BlockDriverState *bs)
{
- BlockAIOCBCoroutine *acb = opaque;
- BlockDriverState *bs = acb->common.bs;
-
- acb->req.error = bdrv_co_flush(bs);
- bdrv_co_complete(acb);
+ if (bs->backing_hd && bs->backing_hd->encrypted)
+ return bs->backing_file;
+ else if (bs->encrypted)
+ return bs->filename;
+ else
+ return NULL;
}
-BlockAIOCB *bdrv_aio_flush(BlockDriverState *bs,
- BlockCompletionFunc *cb, void *opaque)
+void bdrv_get_backing_filename(BlockDriverState *bs,
+ char *filename, int filename_size)
{
- trace_bdrv_aio_flush(bs, opaque);
-
- Coroutine *co;
- BlockAIOCBCoroutine *acb;
-
- acb = qemu_aio_get(&bdrv_em_co_aiocb_info, bs, cb, opaque);
- acb->need_bh = true;
- acb->req.error = -EINPROGRESS;
+ pstrcpy(filename, filename_size, bs->backing_file);
+}
- co = qemu_coroutine_create(bdrv_aio_flush_co_entry);
- qemu_coroutine_enter(co, acb);
+int bdrv_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
+{
+ BlockDriver *drv = bs->drv;
+ if (!drv)
+ return -ENOMEDIUM;
+ if (!drv->bdrv_get_info)
+ return -ENOTSUP;
+ memset(bdi, 0, sizeof(*bdi));
+ return drv->bdrv_get_info(bs, bdi);
+}
- bdrv_co_maybe_schedule_bh(acb);
- return &acb->common;
+ImageInfoSpecific *bdrv_get_specific_info(BlockDriverState *bs)
+{
+ BlockDriver *drv = bs->drv;
+ if (drv && drv->bdrv_get_specific_info) {
+ return drv->bdrv_get_specific_info(bs);
+ }
+ return NULL;
}
-static void coroutine_fn bdrv_aio_discard_co_entry(void *opaque)
+void bdrv_debug_event(BlockDriverState *bs, BlkDebugEvent event)
{
- BlockAIOCBCoroutine *acb = opaque;
- BlockDriverState *bs = acb->common.bs;
+ if (!bs || !bs->drv || !bs->drv->bdrv_debug_event) {
+ return;
+ }
- acb->req.error = bdrv_co_discard(bs, acb->req.sector, acb->req.nb_sectors);
- bdrv_co_complete(acb);
+ bs->drv->bdrv_debug_event(bs, event);
}
-BlockAIOCB *bdrv_aio_discard(BlockDriverState *bs,
- int64_t sector_num, int nb_sectors,
- BlockCompletionFunc *cb, void *opaque)
+int bdrv_debug_breakpoint(BlockDriverState *bs, const char *event,
+ const char *tag)
{
- Coroutine *co;
- BlockAIOCBCoroutine *acb;
-
- trace_bdrv_aio_discard(bs, sector_num, nb_sectors, opaque);
+ while (bs && bs->drv && !bs->drv->bdrv_debug_breakpoint) {
+ bs = bs->file;
+ }
- acb = qemu_aio_get(&bdrv_em_co_aiocb_info, bs, cb, opaque);
- acb->need_bh = true;
- acb->req.error = -EINPROGRESS;
- acb->req.sector = sector_num;
- acb->req.nb_sectors = nb_sectors;
- co = qemu_coroutine_create(bdrv_aio_discard_co_entry);
- qemu_coroutine_enter(co, acb);
+ if (bs && bs->drv && bs->drv->bdrv_debug_breakpoint) {
+ return bs->drv->bdrv_debug_breakpoint(bs, event, tag);
+ }
- bdrv_co_maybe_schedule_bh(acb);
- return &acb->common;
+ return -ENOTSUP;
}
-void bdrv_init(void)
+int bdrv_debug_remove_breakpoint(BlockDriverState *bs, const char *tag)
{
- module_call_init(MODULE_INIT_BLOCK);
-}
+ while (bs && bs->drv && !bs->drv->bdrv_debug_remove_breakpoint) {
+ bs = bs->file;
+ }
-void bdrv_init_with_whitelist(void)
-{
- use_bdrv_whitelist = 1;
- bdrv_init();
+ if (bs && bs->drv && bs->drv->bdrv_debug_remove_breakpoint) {
+ return bs->drv->bdrv_debug_remove_breakpoint(bs, tag);
+ }
+
+ return -ENOTSUP;
}
-void *qemu_aio_get(const AIOCBInfo *aiocb_info, BlockDriverState *bs,
- BlockCompletionFunc *cb, void *opaque)
+int bdrv_debug_resume(BlockDriverState *bs, const char *tag)
{
- BlockAIOCB *acb;
+ while (bs && (!bs->drv || !bs->drv->bdrv_debug_resume)) {
+ bs = bs->file;
+ }
- acb = g_slice_alloc(aiocb_info->aiocb_size);
- acb->aiocb_info = aiocb_info;
- acb->bs = bs;
- acb->cb = cb;
- acb->opaque = opaque;
- acb->refcnt = 1;
- return acb;
-}
+ if (bs && bs->drv && bs->drv->bdrv_debug_resume) {
+ return bs->drv->bdrv_debug_resume(bs, tag);
+ }
-void qemu_aio_ref(void *p)
-{
- BlockAIOCB *acb = p;
- acb->refcnt++;
+ return -ENOTSUP;
}
-void qemu_aio_unref(void *p)
+bool bdrv_debug_is_suspended(BlockDriverState *bs, const char *tag)
{
- BlockAIOCB *acb = p;
- assert(acb->refcnt > 0);
- if (--acb->refcnt == 0) {
- g_slice_free1(acb->aiocb_info->aiocb_size, acb);
+ while (bs && bs->drv && !bs->drv->bdrv_debug_is_suspended) {
+ bs = bs->file;
}
-}
-/**************************************************************/
-/* Coroutine block device emulation */
+ if (bs && bs->drv && bs->drv->bdrv_debug_is_suspended) {
+ return bs->drv->bdrv_debug_is_suspended(bs, tag);
+ }
-typedef struct CoroutineIOCompletion {
- Coroutine *coroutine;
- int ret;
-} CoroutineIOCompletion;
+ return false;
+}
-static void bdrv_co_io_em_complete(void *opaque, int ret)
+int bdrv_is_snapshot(BlockDriverState *bs)
{
- CoroutineIOCompletion *co = opaque;
-
- co->ret = ret;
- qemu_coroutine_enter(co->coroutine, NULL);
+ return !!(bs->open_flags & BDRV_O_SNAPSHOT);
}
-static int coroutine_fn bdrv_co_io_em(BlockDriverState *bs, int64_t sector_num,
- int nb_sectors, QEMUIOVector *iov,
- bool is_write)
+/* backing_file can either be relative, or absolute, or a protocol. If it is
+ * relative, it must be relative to the chain. So, passing in bs->filename
+ * from a BDS as backing_file should not be done, as that may be relative to
+ * the CWD rather than the chain. */
+BlockDriverState *bdrv_find_backing_image(BlockDriverState *bs,
+ const char *backing_file)
{
- CoroutineIOCompletion co = {
- .coroutine = qemu_coroutine_self(),
- };
- BlockAIOCB *acb;
+ char *filename_full = NULL;
+ char *backing_file_full = NULL;
+ char *filename_tmp = NULL;
+ int is_protocol = 0;
+ BlockDriverState *curr_bs = NULL;
+ BlockDriverState *retval = NULL;
- if (is_write) {
- acb = bs->drv->bdrv_aio_writev(bs, sector_num, iov, nb_sectors,
- bdrv_co_io_em_complete, &co);
- } else {
- acb = bs->drv->bdrv_aio_readv(bs, sector_num, iov, nb_sectors,
- bdrv_co_io_em_complete, &co);
+ if (!bs || !bs->drv || !backing_file) {
+ return NULL;
}
- trace_bdrv_co_io_em(bs, sector_num, nb_sectors, is_write, acb);
- if (!acb) {
- return -EIO;
- }
- qemu_coroutine_yield();
+ filename_full = g_malloc(PATH_MAX);
+ backing_file_full = g_malloc(PATH_MAX);
+ filename_tmp = g_malloc(PATH_MAX);
- return co.ret;
-}
+ is_protocol = path_has_protocol(backing_file);
-static int coroutine_fn bdrv_co_readv_em(BlockDriverState *bs,
- int64_t sector_num, int nb_sectors,
- QEMUIOVector *iov)
-{
- return bdrv_co_io_em(bs, sector_num, nb_sectors, iov, false);
-}
+ for (curr_bs = bs; curr_bs->backing_hd; curr_bs = curr_bs->backing_hd) {
-static int coroutine_fn bdrv_co_writev_em(BlockDriverState *bs,
- int64_t sector_num, int nb_sectors,
- QEMUIOVector *iov)
-{
- return bdrv_co_io_em(bs, sector_num, nb_sectors, iov, true);
-}
+ /* If either of the filename paths is actually a protocol, then
+ * compare unmodified paths; otherwise make paths relative */
+ if (is_protocol || path_has_protocol(curr_bs->backing_file)) {
+ if (strcmp(backing_file, curr_bs->backing_file) == 0) {
+ retval = curr_bs->backing_hd;
+ break;
+ }
+ } else {
+ /* If not an absolute filename path, make it relative to the
current
+ * image's filename path */
+ path_combine(filename_tmp, PATH_MAX, curr_bs->filename,
+ backing_file);
-static void coroutine_fn bdrv_flush_co_entry(void *opaque)
-{
- RwCo *rwco = opaque;
+ /* We are going to compare absolute pathnames */
+ if (!realpath(filename_tmp, filename_full)) {
+ continue;
+ }
- rwco->ret = bdrv_co_flush(rwco->bs);
-}
+ /* We need to make sure the backing filename we are comparing
against
+ * is relative to the current image filename (or absolute) */
+ path_combine(filename_tmp, PATH_MAX, curr_bs->filename,
+ curr_bs->backing_file);
-int coroutine_fn bdrv_co_flush(BlockDriverState *bs)
-{
- int ret;
+ if (!realpath(filename_tmp, backing_file_full)) {
+ continue;
+ }
- if (!bs || !bdrv_is_inserted(bs) || bdrv_is_read_only(bs)) {
- return 0;
+ if (strcmp(backing_file_full, filename_full) == 0) {
+ retval = curr_bs->backing_hd;
+ break;
+ }
+ }
}
- /* Write back cached data to the OS even with cache=unsafe */
- BLKDBG_EVENT(bs->file, BLKDBG_FLUSH_TO_OS);
- if (bs->drv->bdrv_co_flush_to_os) {
- ret = bs->drv->bdrv_co_flush_to_os(bs);
- if (ret < 0) {
- return ret;
- }
+ g_free(filename_full);
+ g_free(backing_file_full);
+ g_free(filename_tmp);
+ return retval;
+}
+
+int bdrv_get_backing_file_depth(BlockDriverState *bs)
+{
+ if (!bs->drv) {
+ return 0;
}
- /* But don't actually force it to the disk with cache=unsafe */
- if (bs->open_flags & BDRV_O_NO_FLUSH) {
- goto flush_parent;
+ if (!bs->backing_hd) {
+ return 0;
}
- BLKDBG_EVENT(bs->file, BLKDBG_FLUSH_TO_DISK);
- if (bs->drv->bdrv_co_flush_to_disk) {
- ret = bs->drv->bdrv_co_flush_to_disk(bs);
- } else if (bs->drv->bdrv_aio_flush) {
- BlockAIOCB *acb;
- CoroutineIOCompletion co = {
- .coroutine = qemu_coroutine_self(),
- };
+ return 1 + bdrv_get_backing_file_depth(bs->backing_hd);
+}
- acb = bs->drv->bdrv_aio_flush(bs, bdrv_co_io_em_complete, &co);
- if (acb == NULL) {
- ret = -EIO;
- } else {
- qemu_coroutine_yield();
- ret = co.ret;
- }
- } else {
- /*
- * Some block drivers always operate in either writethrough or unsafe
- * mode and don't support bdrv_flush therefore. Usually qemu doesn't
- * know how the server works (because the behaviour is hardcoded or
- * depends on server-side configuration), so we can't ensure that
- * everything is safe on disk. Returning an error doesn't work because
- * that would break guests even if the server operates in writethrough
- * mode.
- *
- * Let's hope the user knows what he's doing.
- */
- ret = 0;
- }
- if (ret < 0) {
- return ret;
- }
+void bdrv_init(void)
+{
+ module_call_init(MODULE_INIT_BLOCK);
+}
- /* Now flush the underlying protocol. It will also have BDRV_O_NO_FLUSH
- * in the case of cache=unsafe, so there are no useless flushes.
- */
-flush_parent:
- return bdrv_co_flush(bs->file);
+void bdrv_init_with_whitelist(void)
+{
+ use_bdrv_whitelist = 1;
+ bdrv_init();
}
void bdrv_invalidate_cache(BlockDriverState *bs, Error **errp)
@@ -5235,143 +2972,6 @@ void bdrv_invalidate_cache_all(Error **errp)
}
}
-int bdrv_flush(BlockDriverState *bs)
-{
- Coroutine *co;
- RwCo rwco = {
- .bs = bs,
- .ret = NOT_DONE,
- };
-
- if (qemu_in_coroutine()) {
- /* Fast-path if already in coroutine context */
- bdrv_flush_co_entry(&rwco);
- } else {
- AioContext *aio_context = bdrv_get_aio_context(bs);
-
- co = qemu_coroutine_create(bdrv_flush_co_entry);
- qemu_coroutine_enter(co, &rwco);
- while (rwco.ret == NOT_DONE) {
- aio_poll(aio_context, true);
- }
- }
-
- return rwco.ret;
-}
-
-typedef struct DiscardCo {
- BlockDriverState *bs;
- int64_t sector_num;
- int nb_sectors;
- int ret;
-} DiscardCo;
-static void coroutine_fn bdrv_discard_co_entry(void *opaque)
-{
- DiscardCo *rwco = opaque;
-
- rwco->ret = bdrv_co_discard(rwco->bs, rwco->sector_num, rwco->nb_sectors);
-}
-
-int coroutine_fn bdrv_co_discard(BlockDriverState *bs, int64_t sector_num,
- int nb_sectors)
-{
- int max_discard, ret;
-
- if (!bs->drv) {
- return -ENOMEDIUM;
- }
-
- ret = bdrv_check_request(bs, sector_num, nb_sectors);
- if (ret < 0) {
- return ret;
- } else if (bs->read_only) {
- return -EROFS;
- }
-
- bdrv_reset_dirty(bs, sector_num, nb_sectors);
-
- /* Do nothing if disabled. */
- if (!(bs->open_flags & BDRV_O_UNMAP)) {
- return 0;
- }
-
- if (!bs->drv->bdrv_co_discard && !bs->drv->bdrv_aio_discard) {
- return 0;
- }
-
- max_discard = MIN_NON_ZERO(bs->bl.max_discard, BDRV_REQUEST_MAX_SECTORS);
- while (nb_sectors > 0) {
- int ret;
- int num = nb_sectors;
-
- /* align request */
- if (bs->bl.discard_alignment &&
- num >= bs->bl.discard_alignment &&
- sector_num % bs->bl.discard_alignment) {
- if (num > bs->bl.discard_alignment) {
- num = bs->bl.discard_alignment;
- }
- num -= sector_num % bs->bl.discard_alignment;
- }
-
- /* limit request size */
- if (num > max_discard) {
- num = max_discard;
- }
-
- if (bs->drv->bdrv_co_discard) {
- ret = bs->drv->bdrv_co_discard(bs, sector_num, num);
- } else {
- BlockAIOCB *acb;
- CoroutineIOCompletion co = {
- .coroutine = qemu_coroutine_self(),
- };
-
- acb = bs->drv->bdrv_aio_discard(bs, sector_num, nb_sectors,
- bdrv_co_io_em_complete, &co);
- if (acb == NULL) {
- return -EIO;
- } else {
- qemu_coroutine_yield();
- ret = co.ret;
- }
- }
- if (ret && ret != -ENOTSUP) {
- return ret;
- }
-
- sector_num += num;
- nb_sectors -= num;
- }
- return 0;
-}
-
-int bdrv_discard(BlockDriverState *bs, int64_t sector_num, int nb_sectors)
-{
- Coroutine *co;
- DiscardCo rwco = {
- .bs = bs,
- .sector_num = sector_num,
- .nb_sectors = nb_sectors,
- .ret = NOT_DONE,
- };
-
- if (qemu_in_coroutine()) {
- /* Fast-path if already in coroutine context */
- bdrv_discard_co_entry(&rwco);
- } else {
- AioContext *aio_context = bdrv_get_aio_context(bs);
-
- co = qemu_coroutine_create(bdrv_discard_co_entry);
- qemu_coroutine_enter(co, &rwco);
- while (rwco.ret == NOT_DONE) {
- aio_poll(aio_context, true);
- }
- }
-
- return rwco.ret;
-}
-
/**************************************************************/
/* removable device support */
@@ -5437,87 +3037,11 @@ void bdrv_lock_medium(BlockDriverState *bs, bool locked)
}
}
-/* needed for generic scsi interface */
-
-int bdrv_ioctl(BlockDriverState *bs, unsigned long int req, void *buf)
-{
- BlockDriver *drv = bs->drv;
-
- if (drv && drv->bdrv_ioctl)
- return drv->bdrv_ioctl(bs, req, buf);
- return -ENOTSUP;
-}
-
-BlockAIOCB *bdrv_aio_ioctl(BlockDriverState *bs,
- unsigned long int req, void *buf,
- BlockCompletionFunc *cb, void *opaque)
-{
- BlockDriver *drv = bs->drv;
-
- if (drv && drv->bdrv_aio_ioctl)
- return drv->bdrv_aio_ioctl(bs, req, buf, cb, opaque);
- return NULL;
-}
-
void bdrv_set_guest_block_size(BlockDriverState *bs, int align)
{
bs->guest_block_size = align;
}
-void *qemu_blockalign(BlockDriverState *bs, size_t size)
-{
- return qemu_memalign(bdrv_opt_mem_align(bs), size);
-}
-
-void *qemu_blockalign0(BlockDriverState *bs, size_t size)
-{
- return memset(qemu_blockalign(bs, size), 0, size);
-}
-
-void *qemu_try_blockalign(BlockDriverState *bs, size_t size)
-{
- size_t align = bdrv_opt_mem_align(bs);
-
- /* Ensure that NULL is never returned on success */
- assert(align > 0);
- if (size == 0) {
- size = align;
- }
-
- return qemu_try_memalign(align, size);
-}
-
-void *qemu_try_blockalign0(BlockDriverState *bs, size_t size)
-{
- void *mem = qemu_try_blockalign(bs, size);
-
- if (mem) {
- memset(mem, 0, size);
- }
-
- return mem;
-}
-
-/*
- * Check if all memory in this vector is sector aligned.
- */
-bool bdrv_qiov_is_aligned(BlockDriverState *bs, QEMUIOVector *qiov)
-{
- int i;
- size_t alignment = bdrv_opt_mem_align(bs);
-
- for (i = 0; i < qiov->niov; i++) {
- if ((uintptr_t) qiov->iov[i].iov_base % alignment) {
- return false;
- }
- if (qiov->iov[i].iov_len % alignment) {
- return false;
- }
- }
-
- return true;
-}
-
BdrvDirtyBitmap *bdrv_find_dirty_bitmap(BlockDriverState *bs, const char *name)
{
BdrvDirtyBitmap *bm;
@@ -6239,12 +3763,6 @@ void bdrv_remove_aio_context_notifier(BlockDriverState
*bs,
abort();
}
-void bdrv_add_before_write_notifier(BlockDriverState *bs,
- NotifierWithReturn *notifier)
-{
- notifier_with_return_list_add(&bs->before_write_notifiers, notifier);
-}
-
int bdrv_amend_options(BlockDriverState *bs, QemuOpts *opts,
BlockDriverAmendStatusCB *status_cb)
{
@@ -6345,36 +3863,6 @@ out:
return to_replace_bs;
}
-void bdrv_io_plug(BlockDriverState *bs)
-{
- BlockDriver *drv = bs->drv;
- if (drv && drv->bdrv_io_plug) {
- drv->bdrv_io_plug(bs);
- } else if (bs->file) {
- bdrv_io_plug(bs->file);
- }
-}
-
-void bdrv_io_unplug(BlockDriverState *bs)
-{
- BlockDriver *drv = bs->drv;
- if (drv && drv->bdrv_io_unplug) {
- drv->bdrv_io_unplug(bs);
- } else if (bs->file) {
- bdrv_io_unplug(bs->file);
- }
-}
-
-void bdrv_flush_io_queue(BlockDriverState *bs)
-{
- BlockDriver *drv = bs->drv;
- if (drv && drv->bdrv_flush_io_queue) {
- drv->bdrv_flush_io_queue(bs);
- } else if (bs->file) {
- bdrv_flush_io_queue(bs->file);
- }
-}
-
static bool append_open_options(QDict *d, BlockDriverState *bs)
{
const QDictEntry *entry;
diff --git a/block/Makefile.objs b/block/Makefile.objs
index 179e71d..0d8c2a4 100644
--- a/block/Makefile.objs
+++ b/block/Makefile.objs
@@ -9,7 +9,7 @@ block-obj-y += block-backend.o snapshot.o qapi.o
block-obj-$(CONFIG_WIN32) += raw-win32.o win32-aio.o
block-obj-$(CONFIG_POSIX) += raw-posix.o
block-obj-$(CONFIG_LINUX_AIO) += linux-aio.o
-block-obj-y += null.o mirror.o
+block-obj-y += null.o mirror.o io.o
block-obj-y += nbd.o nbd-client.o sheepdog.o
block-obj-$(CONFIG_LIBISCSI) += iscsi.o
diff --git a/block/io.c b/block/io.c
new file mode 100644
index 0000000..1ce62c4
--- /dev/null
+++ b/block/io.c
@@ -0,0 +1,2540 @@
+/*
+ * Block layer I/O functions
+ *
+ * Copyright (c) 2003 Fabrice Bellard
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to
deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "trace.h"
+#include "sysemu/qtest.h"
+#include "block/blockjob.h"
+#include "block/block_int.h"
+
+#define NOT_DONE 0x7fffffff /* used while emulated sync operation in progress
*/
+
+static BlockAIOCB *bdrv_aio_readv_em(BlockDriverState *bs,
+ int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
+ BlockCompletionFunc *cb, void *opaque);
+static BlockAIOCB *bdrv_aio_writev_em(BlockDriverState *bs,
+ int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
+ BlockCompletionFunc *cb, void *opaque);
+static int coroutine_fn bdrv_co_readv_em(BlockDriverState *bs,
+ int64_t sector_num, int nb_sectors,
+ QEMUIOVector *iov);
+static int coroutine_fn bdrv_co_writev_em(BlockDriverState *bs,
+ int64_t sector_num, int nb_sectors,
+ QEMUIOVector *iov);
+static int coroutine_fn bdrv_co_do_preadv(BlockDriverState *bs,
+ int64_t offset, unsigned int bytes, QEMUIOVector *qiov,
+ BdrvRequestFlags flags);
+static int coroutine_fn bdrv_co_do_pwritev(BlockDriverState *bs,
+ int64_t offset, unsigned int bytes, QEMUIOVector *qiov,
+ BdrvRequestFlags flags);
+static BlockAIOCB *bdrv_co_aio_rw_vector(BlockDriverState *bs,
+ int64_t sector_num,
+ QEMUIOVector *qiov,
+ int nb_sectors,
+ BdrvRequestFlags flags,
+ BlockCompletionFunc *cb,
+ void *opaque,
+ bool is_write);
+static void coroutine_fn bdrv_co_do_rw(void *opaque);
+static int coroutine_fn bdrv_co_do_write_zeroes(BlockDriverState *bs,
+ int64_t sector_num, int nb_sectors, BdrvRequestFlags flags);
+
+/* throttling disk I/O limits */
+void bdrv_set_io_limits(BlockDriverState *bs,
+ ThrottleConfig *cfg)
+{
+ int i;
+
+ throttle_config(&bs->throttle_state, cfg);
+
+ for (i = 0; i < 2; i++) {
+ qemu_co_enter_next(&bs->throttled_reqs[i]);
+ }
+}
+
+/* this function drain all the throttled IOs */
+static bool bdrv_start_throttled_reqs(BlockDriverState *bs)
+{
+ bool drained = false;
+ bool enabled = bs->io_limits_enabled;
+ int i;
+
+ bs->io_limits_enabled = false;
+
+ for (i = 0; i < 2; i++) {
+ while (qemu_co_enter_next(&bs->throttled_reqs[i])) {
+ drained = true;
+ }
+ }
+
+ bs->io_limits_enabled = enabled;
+
+ return drained;
+}
+
+void bdrv_io_limits_disable(BlockDriverState *bs)
+{
+ bs->io_limits_enabled = false;
+
+ bdrv_start_throttled_reqs(bs);
+
+ throttle_destroy(&bs->throttle_state);
+}
+
+static void bdrv_throttle_read_timer_cb(void *opaque)
+{
+ BlockDriverState *bs = opaque;
+ qemu_co_enter_next(&bs->throttled_reqs[0]);
+}
+
+static void bdrv_throttle_write_timer_cb(void *opaque)
+{
+ BlockDriverState *bs = opaque;
+ qemu_co_enter_next(&bs->throttled_reqs[1]);
+}
+
+/* should be called before bdrv_set_io_limits if a limit is set */
+void bdrv_io_limits_enable(BlockDriverState *bs)
+{
+ int clock_type = QEMU_CLOCK_REALTIME;
+
+ if (qtest_enabled()) {
+ /* For testing block IO throttling only */
+ clock_type = QEMU_CLOCK_VIRTUAL;
+ }
+ assert(!bs->io_limits_enabled);
+ throttle_init(&bs->throttle_state,
+ bdrv_get_aio_context(bs),
+ clock_type,
+ bdrv_throttle_read_timer_cb,
+ bdrv_throttle_write_timer_cb,
+ bs);
+ bs->io_limits_enabled = true;
+}
+
+/* This function makes an IO wait if needed
+ *
+ * @nb_sectors: the number of sectors of the IO
+ * @is_write: is the IO a write
+ */
+static void bdrv_io_limits_intercept(BlockDriverState *bs,
+ unsigned int bytes,
+ bool is_write)
+{
+ /* does this io must wait */
+ bool must_wait = throttle_schedule_timer(&bs->throttle_state, is_write);
+
+ /* if must wait or any request of this type throttled queue the IO */
+ if (must_wait ||
+ !qemu_co_queue_empty(&bs->throttled_reqs[is_write])) {
+ qemu_co_queue_wait(&bs->throttled_reqs[is_write]);
+ }
+
+ /* the IO will be executed, do the accounting */
+ throttle_account(&bs->throttle_state, is_write, bytes);
+
+
+ /* if the next request must wait -> do nothing */
+ if (throttle_schedule_timer(&bs->throttle_state, is_write)) {
+ return;
+ }
+
+ /* else queue next request for execution */
+ qemu_co_queue_next(&bs->throttled_reqs[is_write]);
+}
+
+void bdrv_setup_io_funcs(BlockDriver *bdrv)
+{
+ /* Block drivers without coroutine functions need emulation */
+ if (!bdrv->bdrv_co_readv) {
+ bdrv->bdrv_co_readv = bdrv_co_readv_em;
+ bdrv->bdrv_co_writev = bdrv_co_writev_em;
+
+ /* bdrv_co_readv_em()/brdv_co_writev_em() work in terms of aio, so if
+ * the block driver lacks aio we need to emulate that too.
+ */
+ if (!bdrv->bdrv_aio_readv) {
+ /* add AIO emulation layer */
+ bdrv->bdrv_aio_readv = bdrv_aio_readv_em;
+ bdrv->bdrv_aio_writev = bdrv_aio_writev_em;
+ }
+ }
+}
+
+void bdrv_refresh_limits(BlockDriverState *bs, Error **errp)
+{
+ BlockDriver *drv = bs->drv;
+ Error *local_err = NULL;
+
+ memset(&bs->bl, 0, sizeof(bs->bl));
+
+ if (!drv) {
+ return;
+ }
+
+ /* Take some limits from the children as a default */
+ if (bs->file) {
+ bdrv_refresh_limits(bs->file, &local_err);
+ if (local_err) {
+ error_propagate(errp, local_err);
+ return;
+ }
+ bs->bl.opt_transfer_length = bs->file->bl.opt_transfer_length;
+ bs->bl.max_transfer_length = bs->file->bl.max_transfer_length;
+ bs->bl.opt_mem_alignment = bs->file->bl.opt_mem_alignment;
+ } else {
+ bs->bl.opt_mem_alignment = 512;
+ }
+
+ if (bs->backing_hd) {
+ bdrv_refresh_limits(bs->backing_hd, &local_err);
+ if (local_err) {
+ error_propagate(errp, local_err);
+ return;
+ }
+ bs->bl.opt_transfer_length =
+ MAX(bs->bl.opt_transfer_length,
+ bs->backing_hd->bl.opt_transfer_length);
+ bs->bl.max_transfer_length =
+ MIN_NON_ZERO(bs->bl.max_transfer_length,
+ bs->backing_hd->bl.max_transfer_length);
+ bs->bl.opt_mem_alignment =
+ MAX(bs->bl.opt_mem_alignment,
+ bs->backing_hd->bl.opt_mem_alignment);
+ }
+
+ /* Then let the driver override it */
+ if (drv->bdrv_refresh_limits) {
+ drv->bdrv_refresh_limits(bs, errp);
+ }
+}
+
+/**
+ * The copy-on-read flag is actually a reference count so multiple users may
+ * use the feature without worrying about clobbering its previous state.
+ * Copy-on-read stays enabled until all users have called to disable it.
+ */
+void bdrv_enable_copy_on_read(BlockDriverState *bs)
+{
+ bs->copy_on_read++;
+}
+
+void bdrv_disable_copy_on_read(BlockDriverState *bs)
+{
+ assert(bs->copy_on_read > 0);
+ bs->copy_on_read--;
+}
+
+/* Check if any requests are in-flight (including throttled requests) */
+static bool bdrv_requests_pending(BlockDriverState *bs)
+{
+ if (!QLIST_EMPTY(&bs->tracked_requests)) {
+ return true;
+ }
+ if (!qemu_co_queue_empty(&bs->throttled_reqs[0])) {
+ return true;
+ }
+ if (!qemu_co_queue_empty(&bs->throttled_reqs[1])) {
+ return true;
+ }
+ if (bs->file && bdrv_requests_pending(bs->file)) {
+ return true;
+ }
+ if (bs->backing_hd && bdrv_requests_pending(bs->backing_hd)) {
+ return true;
+ }
+ return false;
+}
+
+static bool bdrv_drain_one(BlockDriverState *bs)
+{
+ bool bs_busy;
+
+ bdrv_flush_io_queue(bs);
+ bdrv_start_throttled_reqs(bs);
+ bs_busy = bdrv_requests_pending(bs);
+ bs_busy |= aio_poll(bdrv_get_aio_context(bs), bs_busy);
+ return bs_busy;
+}
+
+/*
+ * Wait for pending requests to complete on a single BlockDriverState subtree
+ *
+ * See the warning in bdrv_drain_all(). This function can only be called if
+ * you are sure nothing can generate I/O because you have op blockers
+ * installed.
+ *
+ * Note that unlike bdrv_drain_all(), the caller must hold the BlockDriverState
+ * AioContext.
+ */
+void bdrv_drain(BlockDriverState *bs)
+{
+ while (bdrv_drain_one(bs)) {
+ /* Keep iterating */
+ }
+}
+
+/*
+ * Wait for pending requests to complete across all BlockDriverStates
+ *
+ * This function does not flush data to disk, use bdrv_flush_all() for that
+ * after calling this function.
+ *
+ * Note that completion of an asynchronous I/O operation can trigger any
+ * number of other I/O operations on other devices---for example a coroutine
+ * can be arbitrarily complex and a constant flow of I/O can come until the
+ * coroutine is complete. Because of this, it is not possible to have a
+ * function to drain a single device's I/O queue.
+ */
+void bdrv_drain_all(void)
+{
+ /* Always run first iteration so any pending completion BHs run */
+ bool busy = true;
+ BlockDriverState *bs = NULL;
+
+ while ((bs = bdrv_next(bs))) {
+ AioContext *aio_context = bdrv_get_aio_context(bs);
+
+ aio_context_acquire(aio_context);
+ if (bs->job) {
+ block_job_pause(bs->job);
+ }
+ aio_context_release(aio_context);
+ }
+
+ while (busy) {
+ busy = false;
+ bs = NULL;
+
+ while ((bs = bdrv_next(bs))) {
+ AioContext *aio_context = bdrv_get_aio_context(bs);
+
+ aio_context_acquire(aio_context);
+ busy |= bdrv_drain_one(bs);
+ aio_context_release(aio_context);
+ }
+ }
+
+ bs = NULL;
+ while ((bs = bdrv_next(bs))) {
+ AioContext *aio_context = bdrv_get_aio_context(bs);
+
+ aio_context_acquire(aio_context);
+ if (bs->job) {
+ block_job_resume(bs->job);
+ }
+ aio_context_release(aio_context);
+ }
+}
+
+/**
+ * Remove an active request from the tracked requests list
+ *
+ * This function should be called when a tracked request is completing.
+ */
+static void tracked_request_end(BdrvTrackedRequest *req)
+{
+ if (req->serialising) {
+ req->bs->serialising_in_flight--;
+ }
+
+ QLIST_REMOVE(req, list);
+ qemu_co_queue_restart_all(&req->wait_queue);
+}
+
+/**
+ * Add an active request to the tracked requests list
+ */
+static void tracked_request_begin(BdrvTrackedRequest *req,
+ BlockDriverState *bs,
+ int64_t offset,
+ unsigned int bytes, bool is_write)
+{
+ *req = (BdrvTrackedRequest){
+ .bs = bs,
+ .offset = offset,
+ .bytes = bytes,
+ .is_write = is_write,
+ .co = qemu_coroutine_self(),
+ .serialising = false,
+ .overlap_offset = offset,
+ .overlap_bytes = bytes,
+ };
+
+ qemu_co_queue_init(&req->wait_queue);
+
+ QLIST_INSERT_HEAD(&bs->tracked_requests, req, list);
+}
+
+static void mark_request_serialising(BdrvTrackedRequest *req, uint64_t align)
+{
+ int64_t overlap_offset = req->offset & ~(align - 1);
+ unsigned int overlap_bytes = ROUND_UP(req->offset + req->bytes, align)
+ - overlap_offset;
+
+ if (!req->serialising) {
+ req->bs->serialising_in_flight++;
+ req->serialising = true;
+ }
+
+ req->overlap_offset = MIN(req->overlap_offset, overlap_offset);
+ req->overlap_bytes = MAX(req->overlap_bytes, overlap_bytes);
+}
+
+/**
+ * Round a region to cluster boundaries
+ */
+void bdrv_round_to_clusters(BlockDriverState *bs,
+ int64_t sector_num, int nb_sectors,
+ int64_t *cluster_sector_num,
+ int *cluster_nb_sectors)
+{
+ BlockDriverInfo bdi;
+
+ if (bdrv_get_info(bs, &bdi) < 0 || bdi.cluster_size == 0) {
+ *cluster_sector_num = sector_num;
+ *cluster_nb_sectors = nb_sectors;
+ } else {
+ int64_t c = bdi.cluster_size / BDRV_SECTOR_SIZE;
+ *cluster_sector_num = QEMU_ALIGN_DOWN(sector_num, c);
+ *cluster_nb_sectors = QEMU_ALIGN_UP(sector_num - *cluster_sector_num +
+ nb_sectors, c);
+ }
+}
+
+static int bdrv_get_cluster_size(BlockDriverState *bs)
+{
+ BlockDriverInfo bdi;
+ int ret;
+
+ ret = bdrv_get_info(bs, &bdi);
+ if (ret < 0 || bdi.cluster_size == 0) {
+ return bs->request_alignment;
+ } else {
+ return bdi.cluster_size;
+ }
+}
+
+static bool tracked_request_overlaps(BdrvTrackedRequest *req,
+ int64_t offset, unsigned int bytes)
+{
+ /* aaaa bbbb */
+ if (offset >= req->overlap_offset + req->overlap_bytes) {
+ return false;
+ }
+ /* bbbb aaaa */
+ if (req->overlap_offset >= offset + bytes) {
+ return false;
+ }
+ return true;
+}
+
+static bool coroutine_fn wait_serialising_requests(BdrvTrackedRequest *self)
+{
+ BlockDriverState *bs = self->bs;
+ BdrvTrackedRequest *req;
+ bool retry;
+ bool waited = false;
+
+ if (!bs->serialising_in_flight) {
+ return false;
+ }
+
+ do {
+ retry = false;
+ QLIST_FOREACH(req, &bs->tracked_requests, list) {
+ if (req == self || (!req->serialising && !self->serialising)) {
+ continue;
+ }
+ if (tracked_request_overlaps(req, self->overlap_offset,
+ self->overlap_bytes))
+ {
+ /* Hitting this means there was a reentrant request, for
+ * example, a block driver issuing nested requests. This must
+ * never happen since it means deadlock.
+ */
+ assert(qemu_coroutine_self() != req->co);
+
+ /* If the request is already (indirectly) waiting for us, or
+ * will wait for us as soon as it wakes up, then just go on
+ * (instead of producing a deadlock in the former case). */
+ if (!req->waiting_for) {
+ self->waiting_for = req;
+ qemu_co_queue_wait(&req->wait_queue);
+ self->waiting_for = NULL;
+ retry = true;
+ waited = true;
+ break;
+ }
+ }
+ }
+ } while (retry);
+
+ return waited;
+}
+
+static int bdrv_check_byte_request(BlockDriverState *bs, int64_t offset,
+ size_t size)
+{
+ if (size > BDRV_REQUEST_MAX_SECTORS << BDRV_SECTOR_BITS) {
+ return -EIO;
+ }
+
+ if (!bdrv_is_inserted(bs)) {
+ return -ENOMEDIUM;
+ }
+
+ if (offset < 0) {
+ return -EIO;
+ }
+
+ return 0;
+}
+
+static int bdrv_check_request(BlockDriverState *bs, int64_t sector_num,
+ int nb_sectors)
+{
+ if (nb_sectors < 0 || nb_sectors > BDRV_REQUEST_MAX_SECTORS) {
+ return -EIO;
+ }
+
+ return bdrv_check_byte_request(bs, sector_num * BDRV_SECTOR_SIZE,
+ nb_sectors * BDRV_SECTOR_SIZE);
+}
+
+typedef struct RwCo {
+ BlockDriverState *bs;
+ int64_t offset;
+ QEMUIOVector *qiov;
+ bool is_write;
+ int ret;
+ BdrvRequestFlags flags;
+} RwCo;
+
+static void coroutine_fn bdrv_rw_co_entry(void *opaque)
+{
+ RwCo *rwco = opaque;
+
+ if (!rwco->is_write) {
+ rwco->ret = bdrv_co_do_preadv(rwco->bs, rwco->offset,
+ rwco->qiov->size, rwco->qiov,
+ rwco->flags);
+ } else {
+ rwco->ret = bdrv_co_do_pwritev(rwco->bs, rwco->offset,
+ rwco->qiov->size, rwco->qiov,
+ rwco->flags);
+ }
+}
+
+/*
+ * Process a vectored synchronous request using coroutines
+ */
+static int bdrv_prwv_co(BlockDriverState *bs, int64_t offset,
+ QEMUIOVector *qiov, bool is_write,
+ BdrvRequestFlags flags)
+{
+ Coroutine *co;
+ RwCo rwco = {
+ .bs = bs,
+ .offset = offset,
+ .qiov = qiov,
+ .is_write = is_write,
+ .ret = NOT_DONE,
+ .flags = flags,
+ };
+
+ /**
+ * In sync call context, when the vcpu is blocked, this throttling timer
+ * will not fire; so the I/O throttling function has to be disabled here
+ * if it has been enabled.
+ */
+ if (bs->io_limits_enabled) {
+ fprintf(stderr, "Disabling I/O throttling on '%s' due "
+ "to synchronous I/O.\n", bdrv_get_device_name(bs));
+ bdrv_io_limits_disable(bs);
+ }
+
+ if (qemu_in_coroutine()) {
+ /* Fast-path if already in coroutine context */
+ bdrv_rw_co_entry(&rwco);
+ } else {
+ AioContext *aio_context = bdrv_get_aio_context(bs);
+
+ co = qemu_coroutine_create(bdrv_rw_co_entry);
+ qemu_coroutine_enter(co, &rwco);
+ while (rwco.ret == NOT_DONE) {
+ aio_poll(aio_context, true);
+ }
+ }
+ return rwco.ret;
+}
+
+/*
+ * Process a synchronous request using coroutines
+ */
+static int bdrv_rw_co(BlockDriverState *bs, int64_t sector_num, uint8_t *buf,
+ int nb_sectors, bool is_write, BdrvRequestFlags flags)
+{
+ QEMUIOVector qiov;
+ struct iovec iov = {
+ .iov_base = (void *)buf,
+ .iov_len = nb_sectors * BDRV_SECTOR_SIZE,
+ };
+
+ if (nb_sectors < 0 || nb_sectors > BDRV_REQUEST_MAX_SECTORS) {
+ return -EINVAL;
+ }
+
+ qemu_iovec_init_external(&qiov, &iov, 1);
+ return bdrv_prwv_co(bs, sector_num << BDRV_SECTOR_BITS,
+ &qiov, is_write, flags);
+}
+
+/* return < 0 if error. See bdrv_write() for the return codes */
+int bdrv_read(BlockDriverState *bs, int64_t sector_num,
+ uint8_t *buf, int nb_sectors)
+{
+ return bdrv_rw_co(bs, sector_num, buf, nb_sectors, false, 0);
+}
+
+/* Just like bdrv_read(), but with I/O throttling temporarily disabled */
+int bdrv_read_unthrottled(BlockDriverState *bs, int64_t sector_num,
+ uint8_t *buf, int nb_sectors)
+{
+ bool enabled;
+ int ret;
+
+ enabled = bs->io_limits_enabled;
+ bs->io_limits_enabled = false;
+ ret = bdrv_read(bs, sector_num, buf, nb_sectors);
+ bs->io_limits_enabled = enabled;
+ return ret;
+}
+
+/* Return < 0 if error. Important errors are:
+ -EIO generic I/O error (may happen for all errors)
+ -ENOMEDIUM No media inserted.
+ -EINVAL Invalid sector number or nb_sectors
+ -EACCES Trying to write a read-only device
+*/
+int bdrv_write(BlockDriverState *bs, int64_t sector_num,
+ const uint8_t *buf, int nb_sectors)
+{
+ return bdrv_rw_co(bs, sector_num, (uint8_t *)buf, nb_sectors, true, 0);
+}
+
+int bdrv_write_zeroes(BlockDriverState *bs, int64_t sector_num,
+ int nb_sectors, BdrvRequestFlags flags)
+{
+ return bdrv_rw_co(bs, sector_num, NULL, nb_sectors, true,
+ BDRV_REQ_ZERO_WRITE | flags);
+}
+
+/*
+ * Completely zero out a block device with the help of bdrv_write_zeroes.
+ * The operation is sped up by checking the block status and only writing
+ * zeroes to the device if they currently do not return zeroes. Optional
+ * flags are passed through to bdrv_write_zeroes (e.g. BDRV_REQ_MAY_UNMAP).
+ *
+ * Returns < 0 on error, 0 on success. For error codes see bdrv_write().
+ */
+int bdrv_make_zero(BlockDriverState *bs, BdrvRequestFlags flags)
+{
+ int64_t target_sectors, ret, nb_sectors, sector_num = 0;
+ int n;
+
+ target_sectors = bdrv_nb_sectors(bs);
+ if (target_sectors < 0) {
+ return target_sectors;
+ }
+
+ for (;;) {
+ nb_sectors = MIN(target_sectors - sector_num,
BDRV_REQUEST_MAX_SECTORS);
+ if (nb_sectors <= 0) {
+ return 0;
+ }
+ ret = bdrv_get_block_status(bs, sector_num, nb_sectors, &n);
+ if (ret < 0) {
+ error_report("error getting block status at sector %" PRId64 ":
%s",
+ sector_num, strerror(-ret));
+ return ret;
+ }
+ if (ret & BDRV_BLOCK_ZERO) {
+ sector_num += n;
+ continue;
+ }
+ ret = bdrv_write_zeroes(bs, sector_num, n, flags);
+ if (ret < 0) {
+ error_report("error writing zeroes at sector %" PRId64 ": %s",
+ sector_num, strerror(-ret));
+ return ret;
+ }
+ sector_num += n;
+ }
+}
+
+int bdrv_pread(BlockDriverState *bs, int64_t offset, void *buf, int bytes)
+{
+ QEMUIOVector qiov;
+ struct iovec iov = {
+ .iov_base = (void *)buf,
+ .iov_len = bytes,
+ };
+ int ret;
+
+ if (bytes < 0) {
+ return -EINVAL;
+ }
+
+ qemu_iovec_init_external(&qiov, &iov, 1);
+ ret = bdrv_prwv_co(bs, offset, &qiov, false, 0);
+ if (ret < 0) {
+ return ret;
+ }
+
+ return bytes;
+}
+
+int bdrv_pwritev(BlockDriverState *bs, int64_t offset, QEMUIOVector *qiov)
+{
+ int ret;
+
+ ret = bdrv_prwv_co(bs, offset, qiov, true, 0);
+ if (ret < 0) {
+ return ret;
+ }
+
+ return qiov->size;
+}
+
+int bdrv_pwrite(BlockDriverState *bs, int64_t offset,
+ const void *buf, int bytes)
+{
+ QEMUIOVector qiov;
+ struct iovec iov = {
+ .iov_base = (void *) buf,
+ .iov_len = bytes,
+ };
+
+ if (bytes < 0) {
+ return -EINVAL;
+ }
+
+ qemu_iovec_init_external(&qiov, &iov, 1);
+ return bdrv_pwritev(bs, offset, &qiov);
+}
+
+/*
+ * Writes to the file and ensures that no writes are reordered across this
+ * request (acts as a barrier)
+ *
+ * Returns 0 on success, -errno in error cases.
+ */
+int bdrv_pwrite_sync(BlockDriverState *bs, int64_t offset,
+ const void *buf, int count)
+{
+ int ret;
+
+ ret = bdrv_pwrite(bs, offset, buf, count);
+ if (ret < 0) {
+ return ret;
+ }
+
+ /* No flush needed for cache modes that already do it */
+ if (bs->enable_write_cache) {
+ bdrv_flush(bs);
+ }
+
+ return 0;
+}
+
+static int coroutine_fn bdrv_co_do_copy_on_readv(BlockDriverState *bs,
+ int64_t sector_num, int nb_sectors, QEMUIOVector *qiov)
+{
+ /* Perform I/O through a temporary buffer so that users who scribble over
+ * their read buffer while the operation is in progress do not end up
+ * modifying the image file. This is critical for zero-copy guest I/O
+ * where anything might happen inside guest memory.
+ */
+ void *bounce_buffer;
+
+ BlockDriver *drv = bs->drv;
+ struct iovec iov;
+ QEMUIOVector bounce_qiov;
+ int64_t cluster_sector_num;
+ int cluster_nb_sectors;
+ size_t skip_bytes;
+ int ret;
+
+ /* Cover entire cluster so no additional backing file I/O is required when
+ * allocating cluster in the image file.
+ */
+ bdrv_round_to_clusters(bs, sector_num, nb_sectors,
+ &cluster_sector_num, &cluster_nb_sectors);
+
+ trace_bdrv_co_do_copy_on_readv(bs, sector_num, nb_sectors,
+ cluster_sector_num, cluster_nb_sectors);
+
+ iov.iov_len = cluster_nb_sectors * BDRV_SECTOR_SIZE;
+ iov.iov_base = bounce_buffer = qemu_try_blockalign(bs, iov.iov_len);
+ if (bounce_buffer == NULL) {
+ ret = -ENOMEM;
+ goto err;
+ }
+
+ qemu_iovec_init_external(&bounce_qiov, &iov, 1);
+
+ ret = drv->bdrv_co_readv(bs, cluster_sector_num, cluster_nb_sectors,
+ &bounce_qiov);
+ if (ret < 0) {
+ goto err;
+ }
+
+ if (drv->bdrv_co_write_zeroes &&
+ buffer_is_zero(bounce_buffer, iov.iov_len)) {
+ ret = bdrv_co_do_write_zeroes(bs, cluster_sector_num,
+ cluster_nb_sectors, 0);
+ } else {
+ /* This does not change the data on the disk, it is not necessary
+ * to flush even in cache=writethrough mode.
+ */
+ ret = drv->bdrv_co_writev(bs, cluster_sector_num, cluster_nb_sectors,
+ &bounce_qiov);
+ }
+
+ if (ret < 0) {
+ /* It might be okay to ignore write errors for guest requests. If this
+ * is a deliberate copy-on-read then we don't want to ignore the error.
+ * Simply report it in all cases.
+ */
+ goto err;
+ }
+
+ skip_bytes = (sector_num - cluster_sector_num) * BDRV_SECTOR_SIZE;
+ qemu_iovec_from_buf(qiov, 0, bounce_buffer + skip_bytes,
+ nb_sectors * BDRV_SECTOR_SIZE);
+
+err:
+ qemu_vfree(bounce_buffer);
+ return ret;
+}
+
+/*
+ * Forwards an already correctly aligned request to the BlockDriver. This
+ * handles copy on read and zeroing after EOF; any other features must be
+ * implemented by the caller.
+ */
+static int coroutine_fn bdrv_aligned_preadv(BlockDriverState *bs,
+ BdrvTrackedRequest *req, int64_t offset, unsigned int bytes,
+ int64_t align, QEMUIOVector *qiov, int flags)
+{
+ BlockDriver *drv = bs->drv;
+ int ret;
+
+ int64_t sector_num = offset >> BDRV_SECTOR_BITS;
+ unsigned int nb_sectors = bytes >> BDRV_SECTOR_BITS;
+
+ assert((offset & (BDRV_SECTOR_SIZE - 1)) == 0);
+ assert((bytes & (BDRV_SECTOR_SIZE - 1)) == 0);
+ assert(!qiov || bytes == qiov->size);
+
+ /* Handle Copy on Read and associated serialisation */
+ if (flags & BDRV_REQ_COPY_ON_READ) {
+ /* If we touch the same cluster it counts as an overlap. This
+ * guarantees that allocating writes will be serialized and not race
+ * with each other for the same cluster. For example, in copy-on-read
+ * it ensures that the CoR read and write operations are atomic and
+ * guest writes cannot interleave between them. */
+ mark_request_serialising(req, bdrv_get_cluster_size(bs));
+ }
+
+ wait_serialising_requests(req);
+
+ if (flags & BDRV_REQ_COPY_ON_READ) {
+ int pnum;
+
+ ret = bdrv_is_allocated(bs, sector_num, nb_sectors, &pnum);
+ if (ret < 0) {
+ goto out;
+ }
+
+ if (!ret || pnum != nb_sectors) {
+ ret = bdrv_co_do_copy_on_readv(bs, sector_num, nb_sectors, qiov);
+ goto out;
+ }
+ }
+
+ /* Forward the request to the BlockDriver */
+ if (!bs->zero_beyond_eof) {
+ ret = drv->bdrv_co_readv(bs, sector_num, nb_sectors, qiov);
+ } else {
+ /* Read zeros after EOF */
+ int64_t total_sectors, max_nb_sectors;
+
+ total_sectors = bdrv_nb_sectors(bs);
+ if (total_sectors < 0) {
+ ret = total_sectors;
+ goto out;
+ }
+
+ max_nb_sectors = ROUND_UP(MAX(0, total_sectors - sector_num),
+ align >> BDRV_SECTOR_BITS);
+ if (nb_sectors < max_nb_sectors) {
+ ret = drv->bdrv_co_readv(bs, sector_num, nb_sectors, qiov);
+ } else if (max_nb_sectors > 0) {
+ QEMUIOVector local_qiov;
+
+ qemu_iovec_init(&local_qiov, qiov->niov);
+ qemu_iovec_concat(&local_qiov, qiov, 0,
+ max_nb_sectors * BDRV_SECTOR_SIZE);
+
+ ret = drv->bdrv_co_readv(bs, sector_num, max_nb_sectors,
+ &local_qiov);
+
+ qemu_iovec_destroy(&local_qiov);
+ } else {
+ ret = 0;
+ }
+
+ /* Reading beyond end of file is supposed to produce zeroes */
+ if (ret == 0 && total_sectors < sector_num + nb_sectors) {
+ uint64_t offset = MAX(0, total_sectors - sector_num);
+ uint64_t bytes = (sector_num + nb_sectors - offset) *
+ BDRV_SECTOR_SIZE;
+ qemu_iovec_memset(qiov, offset * BDRV_SECTOR_SIZE, 0, bytes);
+ }
+ }
+
+out:
+ return ret;
+}
+
+static inline uint64_t bdrv_get_align(BlockDriverState *bs)
+{
+ /* TODO Lift BDRV_SECTOR_SIZE restriction in BlockDriver interface */
+ return MAX(BDRV_SECTOR_SIZE, bs->request_alignment);
+}
+
+static inline bool bdrv_req_is_aligned(BlockDriverState *bs,
+ int64_t offset, size_t bytes)
+{
+ int64_t align = bdrv_get_align(bs);
+ return !(offset & (align - 1) || (bytes & (align - 1)));
+}
+
+/*
+ * Handle a read request in coroutine context
+ */
+static int coroutine_fn bdrv_co_do_preadv(BlockDriverState *bs,
+ int64_t offset, unsigned int bytes, QEMUIOVector *qiov,
+ BdrvRequestFlags flags)
+{
+ BlockDriver *drv = bs->drv;
+ BdrvTrackedRequest req;
+
+ uint64_t align = bdrv_get_align(bs);
+ uint8_t *head_buf = NULL;
+ uint8_t *tail_buf = NULL;
+ QEMUIOVector local_qiov;
+ bool use_local_qiov = false;
+ int ret;
+
+ if (!drv) {
+ return -ENOMEDIUM;
+ }
+
+ ret = bdrv_check_byte_request(bs, offset, bytes);
+ if (ret < 0) {
+ return ret;
+ }
+
+ if (bs->copy_on_read) {
+ flags |= BDRV_REQ_COPY_ON_READ;
+ }
+
+ /* throttling disk I/O */
+ if (bs->io_limits_enabled) {
+ bdrv_io_limits_intercept(bs, bytes, false);
+ }
+
+ /* Align read if necessary by padding qiov */
+ if (offset & (align - 1)) {
+ head_buf = qemu_blockalign(bs, align);
+ qemu_iovec_init(&local_qiov, qiov->niov + 2);
+ qemu_iovec_add(&local_qiov, head_buf, offset & (align - 1));
+ qemu_iovec_concat(&local_qiov, qiov, 0, qiov->size);
+ use_local_qiov = true;
+
+ bytes += offset & (align - 1);
+ offset = offset & ~(align - 1);
+ }
+
+ if ((offset + bytes) & (align - 1)) {
+ if (!use_local_qiov) {
+ qemu_iovec_init(&local_qiov, qiov->niov + 1);
+ qemu_iovec_concat(&local_qiov, qiov, 0, qiov->size);
+ use_local_qiov = true;
+ }
+ tail_buf = qemu_blockalign(bs, align);
+ qemu_iovec_add(&local_qiov, tail_buf,
+ align - ((offset + bytes) & (align - 1)));
+
+ bytes = ROUND_UP(bytes, align);
+ }
+
+ tracked_request_begin(&req, bs, offset, bytes, false);
+ ret = bdrv_aligned_preadv(bs, &req, offset, bytes, align,
+ use_local_qiov ? &local_qiov : qiov,
+ flags);
+ tracked_request_end(&req);
+
+ if (use_local_qiov) {
+ qemu_iovec_destroy(&local_qiov);
+ qemu_vfree(head_buf);
+ qemu_vfree(tail_buf);
+ }
+
+ return ret;
+}
+
+static int coroutine_fn bdrv_co_do_readv(BlockDriverState *bs,
+ int64_t sector_num, int nb_sectors, QEMUIOVector *qiov,
+ BdrvRequestFlags flags)
+{
+ if (nb_sectors < 0 || nb_sectors > BDRV_REQUEST_MAX_SECTORS) {
+ return -EINVAL;
+ }
+
+ return bdrv_co_do_preadv(bs, sector_num << BDRV_SECTOR_BITS,
+ nb_sectors << BDRV_SECTOR_BITS, qiov, flags);
+}
+
+int coroutine_fn bdrv_co_readv(BlockDriverState *bs, int64_t sector_num,
+ int nb_sectors, QEMUIOVector *qiov)
+{
+ trace_bdrv_co_readv(bs, sector_num, nb_sectors);
+
+ return bdrv_co_do_readv(bs, sector_num, nb_sectors, qiov, 0);
+}
+
+int coroutine_fn bdrv_co_copy_on_readv(BlockDriverState *bs,
+ int64_t sector_num, int nb_sectors, QEMUIOVector *qiov)
+{
+ trace_bdrv_co_copy_on_readv(bs, sector_num, nb_sectors);
+
+ return bdrv_co_do_readv(bs, sector_num, nb_sectors, qiov,
+ BDRV_REQ_COPY_ON_READ);
+}
+
+#define MAX_WRITE_ZEROES_BOUNCE_BUFFER 32768
+
+static int coroutine_fn bdrv_co_do_write_zeroes(BlockDriverState *bs,
+ int64_t sector_num, int nb_sectors, BdrvRequestFlags flags)
+{
+ BlockDriver *drv = bs->drv;
+ QEMUIOVector qiov;
+ struct iovec iov = {0};
+ int ret = 0;
+
+ int max_write_zeroes = MIN_NON_ZERO(bs->bl.max_write_zeroes,
+ BDRV_REQUEST_MAX_SECTORS);
+
+ while (nb_sectors > 0 && !ret) {
+ int num = nb_sectors;
+
+ /* Align request. Block drivers can expect the "bulk" of the request
+ * to be aligned.
+ */
+ if (bs->bl.write_zeroes_alignment
+ && num > bs->bl.write_zeroes_alignment) {
+ if (sector_num % bs->bl.write_zeroes_alignment != 0) {
+ /* Make a small request up to the first aligned sector. */
+ num = bs->bl.write_zeroes_alignment;
+ num -= sector_num % bs->bl.write_zeroes_alignment;
+ } else if ((sector_num + num) % bs->bl.write_zeroes_alignment !=
0) {
+ /* Shorten the request to the last aligned sector. num cannot
+ * underflow because num > bs->bl.write_zeroes_alignment.
+ */
+ num -= (sector_num + num) % bs->bl.write_zeroes_alignment;
+ }
+ }
+
+ /* limit request size */
+ if (num > max_write_zeroes) {
+ num = max_write_zeroes;
+ }
+
+ ret = -ENOTSUP;
+ /* First try the efficient write zeroes operation */
+ if (drv->bdrv_co_write_zeroes) {
+ ret = drv->bdrv_co_write_zeroes(bs, sector_num, num, flags);
+ }
+
+ if (ret == -ENOTSUP) {
+ /* Fall back to bounce buffer if write zeroes is unsupported */
+ int max_xfer_len = MIN_NON_ZERO(bs->bl.max_transfer_length,
+ MAX_WRITE_ZEROES_BOUNCE_BUFFER);
+ num = MIN(num, max_xfer_len);
+ iov.iov_len = num * BDRV_SECTOR_SIZE;
+ if (iov.iov_base == NULL) {
+ iov.iov_base = qemu_try_blockalign(bs, num * BDRV_SECTOR_SIZE);
+ if (iov.iov_base == NULL) {
+ ret = -ENOMEM;
+ goto fail;
+ }
+ memset(iov.iov_base, 0, num * BDRV_SECTOR_SIZE);
+ }
+ qemu_iovec_init_external(&qiov, &iov, 1);
+
+ ret = drv->bdrv_co_writev(bs, sector_num, num, &qiov);
+
+ /* Keep bounce buffer around if it is big enough for all
+ * all future requests.
+ */
+ if (num < max_xfer_len) {
+ qemu_vfree(iov.iov_base);
+ iov.iov_base = NULL;
+ }
+ }
+
+ sector_num += num;
+ nb_sectors -= num;
+ }
+
+fail:
+ qemu_vfree(iov.iov_base);
+ return ret;
+}
+
+/*
+ * Forwards an already correctly aligned write request to the BlockDriver.
+ */
+static int coroutine_fn bdrv_aligned_pwritev(BlockDriverState *bs,
+ BdrvTrackedRequest *req, int64_t offset, unsigned int bytes,
+ QEMUIOVector *qiov, int flags)
+{
+ BlockDriver *drv = bs->drv;
+ bool waited;
+ int ret;
+
+ int64_t sector_num = offset >> BDRV_SECTOR_BITS;
+ unsigned int nb_sectors = bytes >> BDRV_SECTOR_BITS;
+
+ assert((offset & (BDRV_SECTOR_SIZE - 1)) == 0);
+ assert((bytes & (BDRV_SECTOR_SIZE - 1)) == 0);
+ assert(!qiov || bytes == qiov->size);
+
+ waited = wait_serialising_requests(req);
+ assert(!waited || !req->serialising);
+ assert(req->overlap_offset <= offset);
+ assert(offset + bytes <= req->overlap_offset + req->overlap_bytes);
+
+ ret = notifier_with_return_list_notify(&bs->before_write_notifiers, req);
+
+ if (!ret && bs->detect_zeroes != BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF &&
+ !(flags & BDRV_REQ_ZERO_WRITE) && drv->bdrv_co_write_zeroes &&
+ qemu_iovec_is_zero(qiov)) {
+ flags |= BDRV_REQ_ZERO_WRITE;
+ if (bs->detect_zeroes == BLOCKDEV_DETECT_ZEROES_OPTIONS_UNMAP) {
+ flags |= BDRV_REQ_MAY_UNMAP;
+ }
+ }
+
+ if (ret < 0) {
+ /* Do nothing, write notifier decided to fail this request */
+ } else if (flags & BDRV_REQ_ZERO_WRITE) {
+ BLKDBG_EVENT(bs, BLKDBG_PWRITEV_ZERO);
+ ret = bdrv_co_do_write_zeroes(bs, sector_num, nb_sectors, flags);
+ } else {
+ BLKDBG_EVENT(bs, BLKDBG_PWRITEV);
+ ret = drv->bdrv_co_writev(bs, sector_num, nb_sectors, qiov);
+ }
+ BLKDBG_EVENT(bs, BLKDBG_PWRITEV_DONE);
+
+ if (ret == 0 && !bs->enable_write_cache) {
+ ret = bdrv_co_flush(bs);
+ }
+
+ bdrv_set_dirty(bs, sector_num, nb_sectors);
+
+ block_acct_highest_sector(&bs->stats, sector_num, nb_sectors);
+
+ if (ret >= 0) {
+ bs->total_sectors = MAX(bs->total_sectors, sector_num + nb_sectors);
+ }
+
+ return ret;
+}
+
+/*
+ * Handle a write request in coroutine context
+ */
+static int coroutine_fn bdrv_co_do_pwritev(BlockDriverState *bs,
+ int64_t offset, unsigned int bytes, QEMUIOVector *qiov,
+ BdrvRequestFlags flags)
+{
+ BdrvTrackedRequest req;
+ uint64_t align = bdrv_get_align(bs);
+ uint8_t *head_buf = NULL;
+ uint8_t *tail_buf = NULL;
+ QEMUIOVector local_qiov;
+ bool use_local_qiov = false;
+ int ret;
+
+ if (!bs->drv) {
+ return -ENOMEDIUM;
+ }
+ if (bs->read_only) {
+ return -EACCES;
+ }
+
+ ret = bdrv_check_byte_request(bs, offset, bytes);
+ if (ret < 0) {
+ return ret;
+ }
+
+ /* throttling disk I/O */
+ if (bs->io_limits_enabled) {
+ bdrv_io_limits_intercept(bs, bytes, true);
+ }
+
+ /*
+ * Align write if necessary by performing a read-modify-write cycle.
+ * Pad qiov with the read parts and be sure to have a tracked request not
+ * only for bdrv_aligned_pwritev, but also for the reads of the RMW cycle.
+ */
+ tracked_request_begin(&req, bs, offset, bytes, true);
+
+ if (offset & (align - 1)) {
+ QEMUIOVector head_qiov;
+ struct iovec head_iov;
+
+ mark_request_serialising(&req, align);
+ wait_serialising_requests(&req);
+
+ head_buf = qemu_blockalign(bs, align);
+ head_iov = (struct iovec) {
+ .iov_base = head_buf,
+ .iov_len = align,
+ };
+ qemu_iovec_init_external(&head_qiov, &head_iov, 1);
+
+ BLKDBG_EVENT(bs, BLKDBG_PWRITEV_RMW_HEAD);
+ ret = bdrv_aligned_preadv(bs, &req, offset & ~(align - 1), align,
+ align, &head_qiov, 0);
+ if (ret < 0) {
+ goto fail;
+ }
+ BLKDBG_EVENT(bs, BLKDBG_PWRITEV_RMW_AFTER_HEAD);
+
+ qemu_iovec_init(&local_qiov, qiov->niov + 2);
+ qemu_iovec_add(&local_qiov, head_buf, offset & (align - 1));
+ qemu_iovec_concat(&local_qiov, qiov, 0, qiov->size);
+ use_local_qiov = true;
+
+ bytes += offset & (align - 1);
+ offset = offset & ~(align - 1);
+ }
+
+ if ((offset + bytes) & (align - 1)) {
+ QEMUIOVector tail_qiov;
+ struct iovec tail_iov;
+ size_t tail_bytes;
+ bool waited;
+
+ mark_request_serialising(&req, align);
+ waited = wait_serialising_requests(&req);
+ assert(!waited || !use_local_qiov);
+
+ tail_buf = qemu_blockalign(bs, align);
+ tail_iov = (struct iovec) {
+ .iov_base = tail_buf,
+ .iov_len = align,
+ };
+ qemu_iovec_init_external(&tail_qiov, &tail_iov, 1);
+
+ BLKDBG_EVENT(bs, BLKDBG_PWRITEV_RMW_TAIL);
+ ret = bdrv_aligned_preadv(bs, &req, (offset + bytes) & ~(align - 1),
align,
+ align, &tail_qiov, 0);
+ if (ret < 0) {
+ goto fail;
+ }
+ BLKDBG_EVENT(bs, BLKDBG_PWRITEV_RMW_AFTER_TAIL);
+
+ if (!use_local_qiov) {
+ qemu_iovec_init(&local_qiov, qiov->niov + 1);
+ qemu_iovec_concat(&local_qiov, qiov, 0, qiov->size);
+ use_local_qiov = true;
+ }
+
+ tail_bytes = (offset + bytes) & (align - 1);
+ qemu_iovec_add(&local_qiov, tail_buf + tail_bytes, align - tail_bytes);
+
+ bytes = ROUND_UP(bytes, align);
+ }
+
+ if (use_local_qiov) {
+ /* Local buffer may have non-zero data. */
+ flags &= ~BDRV_REQ_ZERO_WRITE;
+ }
+ ret = bdrv_aligned_pwritev(bs, &req, offset, bytes,
+ use_local_qiov ? &local_qiov : qiov,
+ flags);
+
+fail:
+ tracked_request_end(&req);
+
+ if (use_local_qiov) {
+ qemu_iovec_destroy(&local_qiov);
+ }
+ qemu_vfree(head_buf);
+ qemu_vfree(tail_buf);
+
+ return ret;
+}
+
+static int coroutine_fn bdrv_co_do_writev(BlockDriverState *bs,
+ int64_t sector_num, int nb_sectors, QEMUIOVector *qiov,
+ BdrvRequestFlags flags)
+{
+ if (nb_sectors < 0 || nb_sectors > BDRV_REQUEST_MAX_SECTORS) {
+ return -EINVAL;
+ }
+
+ return bdrv_co_do_pwritev(bs, sector_num << BDRV_SECTOR_BITS,
+ nb_sectors << BDRV_SECTOR_BITS, qiov, flags);
+}
+
+int coroutine_fn bdrv_co_writev(BlockDriverState *bs, int64_t sector_num,
+ int nb_sectors, QEMUIOVector *qiov)
+{
+ trace_bdrv_co_writev(bs, sector_num, nb_sectors);
+
+ return bdrv_co_do_writev(bs, sector_num, nb_sectors, qiov, 0);
+}
+
+int coroutine_fn bdrv_co_write_zeroes(BlockDriverState *bs,
+ int64_t sector_num, int nb_sectors,
+ BdrvRequestFlags flags)
+{
+ int ret;
+
+ trace_bdrv_co_write_zeroes(bs, sector_num, nb_sectors, flags);
+
+ if (!(bs->open_flags & BDRV_O_UNMAP)) {
+ flags &= ~BDRV_REQ_MAY_UNMAP;
+ }
+ if (bdrv_req_is_aligned(bs, sector_num << BDRV_SECTOR_BITS,
+ nb_sectors << BDRV_SECTOR_BITS)) {
+ ret = bdrv_co_do_writev(bs, sector_num, nb_sectors, NULL,
+ BDRV_REQ_ZERO_WRITE | flags);
+ } else {
+ uint8_t *buf;
+ QEMUIOVector local_qiov;
+ size_t bytes = nb_sectors << BDRV_SECTOR_BITS;
+
+ buf = qemu_memalign(bdrv_opt_mem_align(bs), bytes);
+ memset(buf, 0, bytes);
+ qemu_iovec_init(&local_qiov, 1);
+ qemu_iovec_add(&local_qiov, buf, bytes);
+
+ ret = bdrv_co_do_writev(bs, sector_num, nb_sectors, &local_qiov,
+ BDRV_REQ_ZERO_WRITE | flags);
+ qemu_vfree(buf);
+ }
+ return ret;
+}
+
+int bdrv_flush_all(void)
+{
+ BlockDriverState *bs = NULL;
+ int result = 0;
+
+ while ((bs = bdrv_next(bs))) {
+ AioContext *aio_context = bdrv_get_aio_context(bs);
+ int ret;
+
+ aio_context_acquire(aio_context);
+ ret = bdrv_flush(bs);
+ if (ret < 0 && !result) {
+ result = ret;
+ }
+ aio_context_release(aio_context);
+ }
+
+ return result;
+}
+
+typedef struct BdrvCoGetBlockStatusData {
+ BlockDriverState *bs;
+ BlockDriverState *base;
+ int64_t sector_num;
+ int nb_sectors;
+ int *pnum;
+ int64_t ret;
+ bool done;
+} BdrvCoGetBlockStatusData;
+
+/*
+ * Returns the allocation status of the specified sectors.
+ * Drivers not implementing the functionality are assumed to not support
+ * backing files, hence all their sectors are reported as allocated.
+ *
+ * If 'sector_num' is beyond the end of the disk image the return value is 0
+ * and 'pnum' is set to 0.
+ *
+ * 'pnum' is set to the number of sectors (including and immediately following
+ * the specified sector) that are known to be in the same
+ * allocated/unallocated state.
+ *
+ * 'nb_sectors' is the max value 'pnum' should be set to. If nb_sectors goes
+ * beyond the end of the disk image it will be clamped.
+ */
+static int64_t coroutine_fn bdrv_co_get_block_status(BlockDriverState *bs,
+ int64_t sector_num,
+ int nb_sectors, int *pnum)
+{
+ int64_t total_sectors;
+ int64_t n;
+ int64_t ret, ret2;
+
+ total_sectors = bdrv_nb_sectors(bs);
+ if (total_sectors < 0) {
+ return total_sectors;
+ }
+
+ if (sector_num >= total_sectors) {
+ *pnum = 0;
+ return 0;
+ }
+
+ n = total_sectors - sector_num;
+ if (n < nb_sectors) {
+ nb_sectors = n;
+ }
+
+ if (!bs->drv->bdrv_co_get_block_status) {
+ *pnum = nb_sectors;
+ ret = BDRV_BLOCK_DATA | BDRV_BLOCK_ALLOCATED;
+ if (bs->drv->protocol_name) {
+ ret |= BDRV_BLOCK_OFFSET_VALID | (sector_num * BDRV_SECTOR_SIZE);
+ }
+ return ret;
+ }
+
+ ret = bs->drv->bdrv_co_get_block_status(bs, sector_num, nb_sectors, pnum);
+ if (ret < 0) {
+ *pnum = 0;
+ return ret;
+ }
+
+ if (ret & BDRV_BLOCK_RAW) {
+ assert(ret & BDRV_BLOCK_OFFSET_VALID);
+ return bdrv_get_block_status(bs->file, ret >> BDRV_SECTOR_BITS,
+ *pnum, pnum);
+ }
+
+ if (ret & (BDRV_BLOCK_DATA | BDRV_BLOCK_ZERO)) {
+ ret |= BDRV_BLOCK_ALLOCATED;
+ }
+
+ if (!(ret & BDRV_BLOCK_DATA) && !(ret & BDRV_BLOCK_ZERO)) {
+ if (bdrv_unallocated_blocks_are_zero(bs)) {
+ ret |= BDRV_BLOCK_ZERO;
+ } else if (bs->backing_hd) {
+ BlockDriverState *bs2 = bs->backing_hd;
+ int64_t nb_sectors2 = bdrv_nb_sectors(bs2);
+ if (nb_sectors2 >= 0 && sector_num >= nb_sectors2) {
+ ret |= BDRV_BLOCK_ZERO;
+ }
+ }
+ }
+
+ if (bs->file &&
+ (ret & BDRV_BLOCK_DATA) && !(ret & BDRV_BLOCK_ZERO) &&
+ (ret & BDRV_BLOCK_OFFSET_VALID)) {
+ int file_pnum;
+
+ ret2 = bdrv_co_get_block_status(bs->file, ret >> BDRV_SECTOR_BITS,
+ *pnum, &file_pnum);
+ if (ret2 >= 0) {
+ /* Ignore errors. This is just providing extra information, it
+ * is useful but not necessary.
+ */
+ if (!file_pnum) {
+ /* !file_pnum indicates an offset at or beyond the EOF; it is
+ * perfectly valid for the format block driver to point to such
+ * offsets, so catch it and mark everything as zero */
+ ret |= BDRV_BLOCK_ZERO;
+ } else {
+ /* Limit request to the range reported by the protocol driver
*/
+ *pnum = file_pnum;
+ ret |= (ret2 & BDRV_BLOCK_ZERO);
+ }
+ }
+ }
+
+ return ret;
+}
+
+/* Coroutine wrapper for bdrv_get_block_status() */
+static void coroutine_fn bdrv_get_block_status_co_entry(void *opaque)
+{
+ BdrvCoGetBlockStatusData *data = opaque;
+ BlockDriverState *bs = data->bs;
+
+ data->ret = bdrv_co_get_block_status(bs, data->sector_num,
data->nb_sectors,
+ data->pnum);
+ data->done = true;
+}
+
+/*
+ * Synchronous wrapper around bdrv_co_get_block_status().
+ *
+ * See bdrv_co_get_block_status() for details.
+ */
+int64_t bdrv_get_block_status(BlockDriverState *bs, int64_t sector_num,
+ int nb_sectors, int *pnum)
+{
+ Coroutine *co;
+ BdrvCoGetBlockStatusData data = {
+ .bs = bs,
+ .sector_num = sector_num,
+ .nb_sectors = nb_sectors,
+ .pnum = pnum,
+ .done = false,
+ };
+
+ if (qemu_in_coroutine()) {
+ /* Fast-path if already in coroutine context */
+ bdrv_get_block_status_co_entry(&data);
+ } else {
+ AioContext *aio_context = bdrv_get_aio_context(bs);
+
+ co = qemu_coroutine_create(bdrv_get_block_status_co_entry);
+ qemu_coroutine_enter(co, &data);
+ while (!data.done) {
+ aio_poll(aio_context, true);
+ }
+ }
+ return data.ret;
+}
+
+int coroutine_fn bdrv_is_allocated(BlockDriverState *bs, int64_t sector_num,
+ int nb_sectors, int *pnum)
+{
+ int64_t ret = bdrv_get_block_status(bs, sector_num, nb_sectors, pnum);
+ if (ret < 0) {
+ return ret;
+ }
+ return !!(ret & BDRV_BLOCK_ALLOCATED);
+}
+
+/*
+ * Given an image chain: ... -> [BASE] -> [INTER1] -> [INTER2] -> [TOP]
+ *
+ * Return true if the given sector is allocated in any image between
+ * BASE and TOP (inclusive). BASE can be NULL to check if the given
+ * sector is allocated in any image of the chain. Return false otherwise.
+ *
+ * 'pnum' is set to the number of sectors (including and immediately following
+ * the specified sector) that are known to be in the same
+ * allocated/unallocated state.
+ *
+ */
+int bdrv_is_allocated_above(BlockDriverState *top,
+ BlockDriverState *base,
+ int64_t sector_num,
+ int nb_sectors, int *pnum)
+{
+ BlockDriverState *intermediate;
+ int ret, n = nb_sectors;
+
+ intermediate = top;
+ while (intermediate && intermediate != base) {
+ int pnum_inter;
+ ret = bdrv_is_allocated(intermediate, sector_num, nb_sectors,
+ &pnum_inter);
+ if (ret < 0) {
+ return ret;
+ } else if (ret) {
+ *pnum = pnum_inter;
+ return 1;
+ }
+
+ /*
+ * [sector_num, nb_sectors] is unallocated on top but intermediate
+ * might have
+ *
+ * [sector_num+x, nr_sectors] allocated.
+ */
+ if (n > pnum_inter &&
+ (intermediate == top ||
+ sector_num + pnum_inter < intermediate->total_sectors)) {
+ n = pnum_inter;
+ }
+
+ intermediate = intermediate->backing_hd;
+ }
+
+ *pnum = n;
+ return 0;
+}
+
+int bdrv_write_compressed(BlockDriverState *bs, int64_t sector_num,
+ const uint8_t *buf, int nb_sectors)
+{
+ BlockDriver *drv = bs->drv;
+ int ret;
+
+ if (!drv) {
+ return -ENOMEDIUM;
+ }
+ if (!drv->bdrv_write_compressed) {
+ return -ENOTSUP;
+ }
+ ret = bdrv_check_request(bs, sector_num, nb_sectors);
+ if (ret < 0) {
+ return ret;
+ }
+
+ assert(QLIST_EMPTY(&bs->dirty_bitmaps));
+
+ return drv->bdrv_write_compressed(bs, sector_num, buf, nb_sectors);
+}
+
+int bdrv_save_vmstate(BlockDriverState *bs, const uint8_t *buf,
+ int64_t pos, int size)
+{
+ QEMUIOVector qiov;
+ struct iovec iov = {
+ .iov_base = (void *) buf,
+ .iov_len = size,
+ };
+
+ qemu_iovec_init_external(&qiov, &iov, 1);
+ return bdrv_writev_vmstate(bs, &qiov, pos);
+}
+
+int bdrv_writev_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos)
+{
+ BlockDriver *drv = bs->drv;
+
+ if (!drv) {
+ return -ENOMEDIUM;
+ } else if (drv->bdrv_save_vmstate) {
+ return drv->bdrv_save_vmstate(bs, qiov, pos);
+ } else if (bs->file) {
+ return bdrv_writev_vmstate(bs->file, qiov, pos);
+ }
+
+ return -ENOTSUP;
+}
+
+int bdrv_load_vmstate(BlockDriverState *bs, uint8_t *buf,
+ int64_t pos, int size)
+{
+ BlockDriver *drv = bs->drv;
+ if (!drv)
+ return -ENOMEDIUM;
+ if (drv->bdrv_load_vmstate)
+ return drv->bdrv_load_vmstate(bs, buf, pos, size);
+ if (bs->file)
+ return bdrv_load_vmstate(bs->file, buf, pos, size);
+ return -ENOTSUP;
+}
+
+/**************************************************************/
+/* async I/Os */
+
+BlockAIOCB *bdrv_aio_readv(BlockDriverState *bs, int64_t sector_num,
+ QEMUIOVector *qiov, int nb_sectors,
+ BlockCompletionFunc *cb, void *opaque)
+{
+ trace_bdrv_aio_readv(bs, sector_num, nb_sectors, opaque);
+
+ return bdrv_co_aio_rw_vector(bs, sector_num, qiov, nb_sectors, 0,
+ cb, opaque, false);
+}
+
+BlockAIOCB *bdrv_aio_writev(BlockDriverState *bs, int64_t sector_num,
+ QEMUIOVector *qiov, int nb_sectors,
+ BlockCompletionFunc *cb, void *opaque)
+{
+ trace_bdrv_aio_writev(bs, sector_num, nb_sectors, opaque);
+
+ return bdrv_co_aio_rw_vector(bs, sector_num, qiov, nb_sectors, 0,
+ cb, opaque, true);
+}
+
+BlockAIOCB *bdrv_aio_write_zeroes(BlockDriverState *bs,
+ int64_t sector_num, int nb_sectors, BdrvRequestFlags flags,
+ BlockCompletionFunc *cb, void *opaque)
+{
+ trace_bdrv_aio_write_zeroes(bs, sector_num, nb_sectors, flags, opaque);
+
+ return bdrv_co_aio_rw_vector(bs, sector_num, NULL, nb_sectors,
+ BDRV_REQ_ZERO_WRITE | flags,
+ cb, opaque, true);
+}
+
+
+typedef struct MultiwriteCB {
+ int error;
+ int num_requests;
+ int num_callbacks;
+ struct {
+ BlockCompletionFunc *cb;
+ void *opaque;
+ QEMUIOVector *free_qiov;
+ } callbacks[];
+} MultiwriteCB;
+
+static void multiwrite_user_cb(MultiwriteCB *mcb)
+{
+ int i;
+
+ for (i = 0; i < mcb->num_callbacks; i++) {
+ mcb->callbacks[i].cb(mcb->callbacks[i].opaque, mcb->error);
+ if (mcb->callbacks[i].free_qiov) {
+ qemu_iovec_destroy(mcb->callbacks[i].free_qiov);
+ }
+ g_free(mcb->callbacks[i].free_qiov);
+ }
+}
+
+static void multiwrite_cb(void *opaque, int ret)
+{
+ MultiwriteCB *mcb = opaque;
+
+ trace_multiwrite_cb(mcb, ret);
+
+ if (ret < 0 && !mcb->error) {
+ mcb->error = ret;
+ }
+
+ mcb->num_requests--;
+ if (mcb->num_requests == 0) {
+ multiwrite_user_cb(mcb);
+ g_free(mcb);
+ }
+}
+
+static int multiwrite_req_compare(const void *a, const void *b)
+{
+ const BlockRequest *req1 = a, *req2 = b;
+
+ /*
+ * Note that we can't simply subtract req2->sector from req1->sector
+ * here as that could overflow the return value.
+ */
+ if (req1->sector > req2->sector) {
+ return 1;
+ } else if (req1->sector < req2->sector) {
+ return -1;
+ } else {
+ return 0;
+ }
+}
+
+/*
+ * Takes a bunch of requests and tries to merge them. Returns the number of
+ * requests that remain after merging.
+ */
+static int multiwrite_merge(BlockDriverState *bs, BlockRequest *reqs,
+ int num_reqs, MultiwriteCB *mcb)
+{
+ int i, outidx;
+
+ // Sort requests by start sector
+ qsort(reqs, num_reqs, sizeof(*reqs), &multiwrite_req_compare);
+
+ // Check if adjacent requests touch the same clusters. If so, combine them,
+ // filling up gaps with zero sectors.
+ outidx = 0;
+ for (i = 1; i < num_reqs; i++) {
+ int merge = 0;
+ int64_t oldreq_last = reqs[outidx].sector + reqs[outidx].nb_sectors;
+
+ // Handle exactly sequential writes and overlapping writes.
+ if (reqs[i].sector <= oldreq_last) {
+ merge = 1;
+ }
+
+ if (reqs[outidx].qiov->niov + reqs[i].qiov->niov + 1 > IOV_MAX) {
+ merge = 0;
+ }
+
+ if (bs->bl.max_transfer_length && reqs[outidx].nb_sectors +
+ reqs[i].nb_sectors > bs->bl.max_transfer_length) {
+ merge = 0;
+ }
+
+ if (merge) {
+ size_t size;
+ QEMUIOVector *qiov = g_malloc0(sizeof(*qiov));
+ qemu_iovec_init(qiov,
+ reqs[outidx].qiov->niov + reqs[i].qiov->niov + 1);
+
+ // Add the first request to the merged one. If the requests are
+ // overlapping, drop the last sectors of the first request.
+ size = (reqs[i].sector - reqs[outidx].sector) << 9;
+ qemu_iovec_concat(qiov, reqs[outidx].qiov, 0, size);
+
+ // We should need to add any zeros between the two requests
+ assert (reqs[i].sector <= oldreq_last);
+
+ // Add the second request
+ qemu_iovec_concat(qiov, reqs[i].qiov, 0, reqs[i].qiov->size);
+
+ // Add tail of first request, if necessary
+ if (qiov->size < reqs[outidx].qiov->size) {
+ qemu_iovec_concat(qiov, reqs[outidx].qiov, qiov->size,
+ reqs[outidx].qiov->size - qiov->size);
+ }
+
+ reqs[outidx].nb_sectors = qiov->size >> 9;
+ reqs[outidx].qiov = qiov;
+
+ mcb->callbacks[i].free_qiov = reqs[outidx].qiov;
+ } else {
+ outidx++;
+ reqs[outidx].sector = reqs[i].sector;
+ reqs[outidx].nb_sectors = reqs[i].nb_sectors;
+ reqs[outidx].qiov = reqs[i].qiov;
+ }
+ }
+
+ block_acct_merge_done(&bs->stats, BLOCK_ACCT_WRITE, num_reqs - outidx - 1);
+
+ return outidx + 1;
+}
+
+/*
+ * Submit multiple AIO write requests at once.
+ *
+ * On success, the function returns 0 and all requests in the reqs array have
+ * been submitted. In error case this function returns -1, and any of the
+ * requests may or may not be submitted yet. In particular, this means that the
+ * callback will be called for some of the requests, for others it won't. The
+ * caller must check the error field of the BlockRequest to wait for the right
+ * callbacks (if error != 0, no callback will be called).
+ *
+ * The implementation may modify the contents of the reqs array, e.g. to merge
+ * requests. However, the fields opaque and error are left unmodified as they
+ * are used to signal failure for a single request to the caller.
+ */
+int bdrv_aio_multiwrite(BlockDriverState *bs, BlockRequest *reqs, int num_reqs)
+{
+ MultiwriteCB *mcb;
+ int i;
+
+ /* don't submit writes if we don't have a medium */
+ if (bs->drv == NULL) {
+ for (i = 0; i < num_reqs; i++) {
+ reqs[i].error = -ENOMEDIUM;
+ }
+ return -1;
+ }
+
+ if (num_reqs == 0) {
+ return 0;
+ }
+
+ // Create MultiwriteCB structure
+ mcb = g_malloc0(sizeof(*mcb) + num_reqs * sizeof(*mcb->callbacks));
+ mcb->num_requests = 0;
+ mcb->num_callbacks = num_reqs;
+
+ for (i = 0; i < num_reqs; i++) {
+ mcb->callbacks[i].cb = reqs[i].cb;
+ mcb->callbacks[i].opaque = reqs[i].opaque;
+ }
+
+ // Check for mergable requests
+ num_reqs = multiwrite_merge(bs, reqs, num_reqs, mcb);
+
+ trace_bdrv_aio_multiwrite(mcb, mcb->num_callbacks, num_reqs);
+
+ /* Run the aio requests. */
+ mcb->num_requests = num_reqs;
+ for (i = 0; i < num_reqs; i++) {
+ bdrv_co_aio_rw_vector(bs, reqs[i].sector, reqs[i].qiov,
+ reqs[i].nb_sectors, reqs[i].flags,
+ multiwrite_cb, mcb,
+ true);
+ }
+
+ return 0;
+}
+
+void bdrv_aio_cancel(BlockAIOCB *acb)
+{
+ qemu_aio_ref(acb);
+ bdrv_aio_cancel_async(acb);
+ while (acb->refcnt > 1) {
+ if (acb->aiocb_info->get_aio_context) {
+ aio_poll(acb->aiocb_info->get_aio_context(acb), true);
+ } else if (acb->bs) {
+ aio_poll(bdrv_get_aio_context(acb->bs), true);
+ } else {
+ abort();
+ }
+ }
+ qemu_aio_unref(acb);
+}
+
+/* Async version of aio cancel. The caller is not blocked if the acb implements
+ * cancel_async, otherwise we do nothing and let the request normally complete.
+ * In either case the completion callback must be called. */
+void bdrv_aio_cancel_async(BlockAIOCB *acb)
+{
+ if (acb->aiocb_info->cancel_async) {
+ acb->aiocb_info->cancel_async(acb);
+ }
+}
+
+/**************************************************************/
+/* async block device emulation */
+
+typedef struct BlockAIOCBSync {
+ BlockAIOCB common;
+ QEMUBH *bh;
+ int ret;
+ /* vector translation state */
+ QEMUIOVector *qiov;
+ uint8_t *bounce;
+ int is_write;
+} BlockAIOCBSync;
+
+static const AIOCBInfo bdrv_em_aiocb_info = {
+ .aiocb_size = sizeof(BlockAIOCBSync),
+};
+
+static void bdrv_aio_bh_cb(void *opaque)
+{
+ BlockAIOCBSync *acb = opaque;
+
+ if (!acb->is_write && acb->ret >= 0) {
+ qemu_iovec_from_buf(acb->qiov, 0, acb->bounce, acb->qiov->size);
+ }
+ qemu_vfree(acb->bounce);
+ acb->common.cb(acb->common.opaque, acb->ret);
+ qemu_bh_delete(acb->bh);
+ acb->bh = NULL;
+ qemu_aio_unref(acb);
+}
+
+static BlockAIOCB *bdrv_aio_rw_vector(BlockDriverState *bs,
+ int64_t sector_num,
+ QEMUIOVector *qiov,
+ int nb_sectors,
+ BlockCompletionFunc *cb,
+ void *opaque,
+ int is_write)
+
+{
+ BlockAIOCBSync *acb;
+
+ acb = qemu_aio_get(&bdrv_em_aiocb_info, bs, cb, opaque);
+ acb->is_write = is_write;
+ acb->qiov = qiov;
+ acb->bounce = qemu_try_blockalign(bs, qiov->size);
+ acb->bh = aio_bh_new(bdrv_get_aio_context(bs), bdrv_aio_bh_cb, acb);
+
+ if (acb->bounce == NULL) {
+ acb->ret = -ENOMEM;
+ } else if (is_write) {
+ qemu_iovec_to_buf(acb->qiov, 0, acb->bounce, qiov->size);
+ acb->ret = bs->drv->bdrv_write(bs, sector_num, acb->bounce,
nb_sectors);
+ } else {
+ acb->ret = bs->drv->bdrv_read(bs, sector_num, acb->bounce, nb_sectors);
+ }
+
+ qemu_bh_schedule(acb->bh);
+
+ return &acb->common;
+}
+
+static BlockAIOCB *bdrv_aio_readv_em(BlockDriverState *bs,
+ int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
+ BlockCompletionFunc *cb, void *opaque)
+{
+ return bdrv_aio_rw_vector(bs, sector_num, qiov, nb_sectors, cb, opaque, 0);
+}
+
+static BlockAIOCB *bdrv_aio_writev_em(BlockDriverState *bs,
+ int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
+ BlockCompletionFunc *cb, void *opaque)
+{
+ return bdrv_aio_rw_vector(bs, sector_num, qiov, nb_sectors, cb, opaque, 1);
+}
+
+
+typedef struct BlockAIOCBCoroutine {
+ BlockAIOCB common;
+ BlockRequest req;
+ bool is_write;
+ bool need_bh;
+ bool *done;
+ QEMUBH* bh;
+} BlockAIOCBCoroutine;
+
+static const AIOCBInfo bdrv_em_co_aiocb_info = {
+ .aiocb_size = sizeof(BlockAIOCBCoroutine),
+};
+
+static void bdrv_co_complete(BlockAIOCBCoroutine *acb)
+{
+ if (!acb->need_bh) {
+ acb->common.cb(acb->common.opaque, acb->req.error);
+ qemu_aio_unref(acb);
+ }
+}
+
+static void bdrv_co_em_bh(void *opaque)
+{
+ BlockAIOCBCoroutine *acb = opaque;
+
+ assert(!acb->need_bh);
+ qemu_bh_delete(acb->bh);
+ bdrv_co_complete(acb);
+}
+
+static void bdrv_co_maybe_schedule_bh(BlockAIOCBCoroutine *acb)
+{
+ acb->need_bh = false;
+ if (acb->req.error != -EINPROGRESS) {
+ BlockDriverState *bs = acb->common.bs;
+
+ acb->bh = aio_bh_new(bdrv_get_aio_context(bs), bdrv_co_em_bh, acb);
+ qemu_bh_schedule(acb->bh);
+ }
+}
+
+/* Invoke bdrv_co_do_readv/bdrv_co_do_writev */
+static void coroutine_fn bdrv_co_do_rw(void *opaque)
+{
+ BlockAIOCBCoroutine *acb = opaque;
+ BlockDriverState *bs = acb->common.bs;
+
+ if (!acb->is_write) {
+ acb->req.error = bdrv_co_do_readv(bs, acb->req.sector,
+ acb->req.nb_sectors, acb->req.qiov, acb->req.flags);
+ } else {
+ acb->req.error = bdrv_co_do_writev(bs, acb->req.sector,
+ acb->req.nb_sectors, acb->req.qiov, acb->req.flags);
+ }
+
+ bdrv_co_complete(acb);
+}
+
+static BlockAIOCB *bdrv_co_aio_rw_vector(BlockDriverState *bs,
+ int64_t sector_num,
+ QEMUIOVector *qiov,
+ int nb_sectors,
+ BdrvRequestFlags flags,
+ BlockCompletionFunc *cb,
+ void *opaque,
+ bool is_write)
+{
+ Coroutine *co;
+ BlockAIOCBCoroutine *acb;
+
+ acb = qemu_aio_get(&bdrv_em_co_aiocb_info, bs, cb, opaque);
+ acb->need_bh = true;
+ acb->req.error = -EINPROGRESS;
+ acb->req.sector = sector_num;
+ acb->req.nb_sectors = nb_sectors;
+ acb->req.qiov = qiov;
+ acb->req.flags = flags;
+ acb->is_write = is_write;
+
+ co = qemu_coroutine_create(bdrv_co_do_rw);
+ qemu_coroutine_enter(co, acb);
+
+ bdrv_co_maybe_schedule_bh(acb);
+ return &acb->common;
+}
+
+static void coroutine_fn bdrv_aio_flush_co_entry(void *opaque)
+{
+ BlockAIOCBCoroutine *acb = opaque;
+ BlockDriverState *bs = acb->common.bs;
+
+ acb->req.error = bdrv_co_flush(bs);
+ bdrv_co_complete(acb);
+}
+
+BlockAIOCB *bdrv_aio_flush(BlockDriverState *bs,
+ BlockCompletionFunc *cb, void *opaque)
+{
+ trace_bdrv_aio_flush(bs, opaque);
+
+ Coroutine *co;
+ BlockAIOCBCoroutine *acb;
+
+ acb = qemu_aio_get(&bdrv_em_co_aiocb_info, bs, cb, opaque);
+ acb->need_bh = true;
+ acb->req.error = -EINPROGRESS;
+
+ co = qemu_coroutine_create(bdrv_aio_flush_co_entry);
+ qemu_coroutine_enter(co, acb);
+
+ bdrv_co_maybe_schedule_bh(acb);
+ return &acb->common;
+}
+
+static void coroutine_fn bdrv_aio_discard_co_entry(void *opaque)
+{
+ BlockAIOCBCoroutine *acb = opaque;
+ BlockDriverState *bs = acb->common.bs;
+
+ acb->req.error = bdrv_co_discard(bs, acb->req.sector, acb->req.nb_sectors);
+ bdrv_co_complete(acb);
+}
+
+BlockAIOCB *bdrv_aio_discard(BlockDriverState *bs,
+ int64_t sector_num, int nb_sectors,
+ BlockCompletionFunc *cb, void *opaque)
+{
+ Coroutine *co;
+ BlockAIOCBCoroutine *acb;
+
+ trace_bdrv_aio_discard(bs, sector_num, nb_sectors, opaque);
+
+ acb = qemu_aio_get(&bdrv_em_co_aiocb_info, bs, cb, opaque);
+ acb->need_bh = true;
+ acb->req.error = -EINPROGRESS;
+ acb->req.sector = sector_num;
+ acb->req.nb_sectors = nb_sectors;
+ co = qemu_coroutine_create(bdrv_aio_discard_co_entry);
+ qemu_coroutine_enter(co, acb);
+
+ bdrv_co_maybe_schedule_bh(acb);
+ return &acb->common;
+}
+
+void *qemu_aio_get(const AIOCBInfo *aiocb_info, BlockDriverState *bs,
+ BlockCompletionFunc *cb, void *opaque)
+{
+ BlockAIOCB *acb;
+
+ acb = g_slice_alloc(aiocb_info->aiocb_size);
+ acb->aiocb_info = aiocb_info;
+ acb->bs = bs;
+ acb->cb = cb;
+ acb->opaque = opaque;
+ acb->refcnt = 1;
+ return acb;
+}
+
+void qemu_aio_ref(void *p)
+{
+ BlockAIOCB *acb = p;
+ acb->refcnt++;
+}
+
+void qemu_aio_unref(void *p)
+{
+ BlockAIOCB *acb = p;
+ assert(acb->refcnt > 0);
+ if (--acb->refcnt == 0) {
+ g_slice_free1(acb->aiocb_info->aiocb_size, acb);
+ }
+}
+
+/**************************************************************/
+/* Coroutine block device emulation */
+
+typedef struct CoroutineIOCompletion {
+ Coroutine *coroutine;
+ int ret;
+} CoroutineIOCompletion;
+
+static void bdrv_co_io_em_complete(void *opaque, int ret)
+{
+ CoroutineIOCompletion *co = opaque;
+
+ co->ret = ret;
+ qemu_coroutine_enter(co->coroutine, NULL);
+}
+
+static int coroutine_fn bdrv_co_io_em(BlockDriverState *bs, int64_t sector_num,
+ int nb_sectors, QEMUIOVector *iov,
+ bool is_write)
+{
+ CoroutineIOCompletion co = {
+ .coroutine = qemu_coroutine_self(),
+ };
+ BlockAIOCB *acb;
+
+ if (is_write) {
+ acb = bs->drv->bdrv_aio_writev(bs, sector_num, iov, nb_sectors,
+ bdrv_co_io_em_complete, &co);
+ } else {
+ acb = bs->drv->bdrv_aio_readv(bs, sector_num, iov, nb_sectors,
+ bdrv_co_io_em_complete, &co);
+ }
+
+ trace_bdrv_co_io_em(bs, sector_num, nb_sectors, is_write, acb);
+ if (!acb) {
+ return -EIO;
+ }
+ qemu_coroutine_yield();
+
+ return co.ret;
+}
+
+static int coroutine_fn bdrv_co_readv_em(BlockDriverState *bs,
+ int64_t sector_num, int nb_sectors,
+ QEMUIOVector *iov)
+{
+ return bdrv_co_io_em(bs, sector_num, nb_sectors, iov, false);
+}
+
+static int coroutine_fn bdrv_co_writev_em(BlockDriverState *bs,
+ int64_t sector_num, int nb_sectors,
+ QEMUIOVector *iov)
+{
+ return bdrv_co_io_em(bs, sector_num, nb_sectors, iov, true);
+}
+
+static void coroutine_fn bdrv_flush_co_entry(void *opaque)
+{
+ RwCo *rwco = opaque;
+
+ rwco->ret = bdrv_co_flush(rwco->bs);
+}
+
+int coroutine_fn bdrv_co_flush(BlockDriverState *bs)
+{
+ int ret;
+
+ if (!bs || !bdrv_is_inserted(bs) || bdrv_is_read_only(bs)) {
+ return 0;
+ }
+
+ /* Write back cached data to the OS even with cache=unsafe */
+ BLKDBG_EVENT(bs->file, BLKDBG_FLUSH_TO_OS);
+ if (bs->drv->bdrv_co_flush_to_os) {
+ ret = bs->drv->bdrv_co_flush_to_os(bs);
+ if (ret < 0) {
+ return ret;
+ }
+ }
+
+ /* But don't actually force it to the disk with cache=unsafe */
+ if (bs->open_flags & BDRV_O_NO_FLUSH) {
+ goto flush_parent;
+ }
+
+ BLKDBG_EVENT(bs->file, BLKDBG_FLUSH_TO_DISK);
+ if (bs->drv->bdrv_co_flush_to_disk) {
+ ret = bs->drv->bdrv_co_flush_to_disk(bs);
+ } else if (bs->drv->bdrv_aio_flush) {
+ BlockAIOCB *acb;
+ CoroutineIOCompletion co = {
+ .coroutine = qemu_coroutine_self(),
+ };
+
+ acb = bs->drv->bdrv_aio_flush(bs, bdrv_co_io_em_complete, &co);
+ if (acb == NULL) {
+ ret = -EIO;
+ } else {
+ qemu_coroutine_yield();
+ ret = co.ret;
+ }
+ } else {
+ /*
+ * Some block drivers always operate in either writethrough or unsafe
+ * mode and don't support bdrv_flush therefore. Usually qemu doesn't
+ * know how the server works (because the behaviour is hardcoded or
+ * depends on server-side configuration), so we can't ensure that
+ * everything is safe on disk. Returning an error doesn't work because
+ * that would break guests even if the server operates in writethrough
+ * mode.
+ *
+ * Let's hope the user knows what he's doing.
+ */
+ ret = 0;
+ }
+ if (ret < 0) {
+ return ret;
+ }
+
+ /* Now flush the underlying protocol. It will also have BDRV_O_NO_FLUSH
+ * in the case of cache=unsafe, so there are no useless flushes.
+ */
+flush_parent:
+ return bdrv_co_flush(bs->file);
+}
+
+int bdrv_flush(BlockDriverState *bs)
+{
+ Coroutine *co;
+ RwCo rwco = {
+ .bs = bs,
+ .ret = NOT_DONE,
+ };
+
+ if (qemu_in_coroutine()) {
+ /* Fast-path if already in coroutine context */
+ bdrv_flush_co_entry(&rwco);
+ } else {
+ AioContext *aio_context = bdrv_get_aio_context(bs);
+
+ co = qemu_coroutine_create(bdrv_flush_co_entry);
+ qemu_coroutine_enter(co, &rwco);
+ while (rwco.ret == NOT_DONE) {
+ aio_poll(aio_context, true);
+ }
+ }
+
+ return rwco.ret;
+}
+
+typedef struct DiscardCo {
+ BlockDriverState *bs;
+ int64_t sector_num;
+ int nb_sectors;
+ int ret;
+} DiscardCo;
+static void coroutine_fn bdrv_discard_co_entry(void *opaque)
+{
+ DiscardCo *rwco = opaque;
+
+ rwco->ret = bdrv_co_discard(rwco->bs, rwco->sector_num, rwco->nb_sectors);
+}
+
+int coroutine_fn bdrv_co_discard(BlockDriverState *bs, int64_t sector_num,
+ int nb_sectors)
+{
+ int max_discard, ret;
+
+ if (!bs->drv) {
+ return -ENOMEDIUM;
+ }
+
+ ret = bdrv_check_request(bs, sector_num, nb_sectors);
+ if (ret < 0) {
+ return ret;
+ } else if (bs->read_only) {
+ return -EROFS;
+ }
+
+ bdrv_reset_dirty(bs, sector_num, nb_sectors);
+
+ /* Do nothing if disabled. */
+ if (!(bs->open_flags & BDRV_O_UNMAP)) {
+ return 0;
+ }
+
+ if (!bs->drv->bdrv_co_discard && !bs->drv->bdrv_aio_discard) {
+ return 0;
+ }
+
+ max_discard = MIN_NON_ZERO(bs->bl.max_discard, BDRV_REQUEST_MAX_SECTORS);
+ while (nb_sectors > 0) {
+ int ret;
+ int num = nb_sectors;
+
+ /* align request */
+ if (bs->bl.discard_alignment &&
+ num >= bs->bl.discard_alignment &&
+ sector_num % bs->bl.discard_alignment) {
+ if (num > bs->bl.discard_alignment) {
+ num = bs->bl.discard_alignment;
+ }
+ num -= sector_num % bs->bl.discard_alignment;
+ }
+
+ /* limit request size */
+ if (num > max_discard) {
+ num = max_discard;
+ }
+
+ if (bs->drv->bdrv_co_discard) {
+ ret = bs->drv->bdrv_co_discard(bs, sector_num, num);
+ } else {
+ BlockAIOCB *acb;
+ CoroutineIOCompletion co = {
+ .coroutine = qemu_coroutine_self(),
+ };
+
+ acb = bs->drv->bdrv_aio_discard(bs, sector_num, nb_sectors,
+ bdrv_co_io_em_complete, &co);
+ if (acb == NULL) {
+ return -EIO;
+ } else {
+ qemu_coroutine_yield();
+ ret = co.ret;
+ }
+ }
+ if (ret && ret != -ENOTSUP) {
+ return ret;
+ }
+
+ sector_num += num;
+ nb_sectors -= num;
+ }
+ return 0;
+}
+
+int bdrv_discard(BlockDriverState *bs, int64_t sector_num, int nb_sectors)
+{
+ Coroutine *co;
+ DiscardCo rwco = {
+ .bs = bs,
+ .sector_num = sector_num,
+ .nb_sectors = nb_sectors,
+ .ret = NOT_DONE,
+ };
+
+ if (qemu_in_coroutine()) {
+ /* Fast-path if already in coroutine context */
+ bdrv_discard_co_entry(&rwco);
+ } else {
+ AioContext *aio_context = bdrv_get_aio_context(bs);
+
+ co = qemu_coroutine_create(bdrv_discard_co_entry);
+ qemu_coroutine_enter(co, &rwco);
+ while (rwco.ret == NOT_DONE) {
+ aio_poll(aio_context, true);
+ }
+ }
+
+ return rwco.ret;
+}
+
+/* needed for generic scsi interface */
+
+int bdrv_ioctl(BlockDriverState *bs, unsigned long int req, void *buf)
+{
+ BlockDriver *drv = bs->drv;
+
+ if (drv && drv->bdrv_ioctl)
+ return drv->bdrv_ioctl(bs, req, buf);
+ return -ENOTSUP;
+}
+
+BlockAIOCB *bdrv_aio_ioctl(BlockDriverState *bs,
+ unsigned long int req, void *buf,
+ BlockCompletionFunc *cb, void *opaque)
+{
+ BlockDriver *drv = bs->drv;
+
+ if (drv && drv->bdrv_aio_ioctl)
+ return drv->bdrv_aio_ioctl(bs, req, buf, cb, opaque);
+ return NULL;
+}
+
+void *qemu_blockalign(BlockDriverState *bs, size_t size)
+{
+ return qemu_memalign(bdrv_opt_mem_align(bs), size);
+}
+
+void *qemu_blockalign0(BlockDriverState *bs, size_t size)
+{
+ return memset(qemu_blockalign(bs, size), 0, size);
+}
+
+void *qemu_try_blockalign(BlockDriverState *bs, size_t size)
+{
+ size_t align = bdrv_opt_mem_align(bs);
+
+ /* Ensure that NULL is never returned on success */
+ assert(align > 0);
+ if (size == 0) {
+ size = align;
+ }
+
+ return qemu_try_memalign(align, size);
+}
+
+void *qemu_try_blockalign0(BlockDriverState *bs, size_t size)
+{
+ void *mem = qemu_try_blockalign(bs, size);
+
+ if (mem) {
+ memset(mem, 0, size);
+ }
+
+ return mem;
+}
+
+/*
+ * Check if all memory in this vector is sector aligned.
+ */
+bool bdrv_qiov_is_aligned(BlockDriverState *bs, QEMUIOVector *qiov)
+{
+ int i;
+ size_t alignment = bdrv_opt_mem_align(bs);
+
+ for (i = 0; i < qiov->niov; i++) {
+ if ((uintptr_t) qiov->iov[i].iov_base % alignment) {
+ return false;
+ }
+ if (qiov->iov[i].iov_len % alignment) {
+ return false;
+ }
+ }
+
+ return true;
+}
+
+void bdrv_add_before_write_notifier(BlockDriverState *bs,
+ NotifierWithReturn *notifier)
+{
+ notifier_with_return_list_add(&bs->before_write_notifiers, notifier);
+}
+
+void bdrv_io_plug(BlockDriverState *bs)
+{
+ BlockDriver *drv = bs->drv;
+ if (drv && drv->bdrv_io_plug) {
+ drv->bdrv_io_plug(bs);
+ } else if (bs->file) {
+ bdrv_io_plug(bs->file);
+ }
+}
+
+void bdrv_io_unplug(BlockDriverState *bs)
+{
+ BlockDriver *drv = bs->drv;
+ if (drv && drv->bdrv_io_unplug) {
+ drv->bdrv_io_unplug(bs);
+ } else if (bs->file) {
+ bdrv_io_unplug(bs->file);
+ }
+}
+
+void bdrv_flush_io_queue(BlockDriverState *bs)
+{
+ BlockDriver *drv = bs->drv;
+ if (drv && drv->bdrv_flush_io_queue) {
+ drv->bdrv_flush_io_queue(bs);
+ } else if (bs->file) {
+ bdrv_flush_io_queue(bs->file);
+ }
+}
--
1.8.3.1
- [Qemu-devel] [PULL 65/76] iotests: add invalid input incremental backup tests, (continued)
- [Qemu-devel] [PULL 65/76] iotests: add invalid input incremental backup tests, Kevin Wolf, 2015/04/28
- [Qemu-devel] [PULL 68/76] iotests: add incremental backup failure recovery test, Kevin Wolf, 2015/04/28
- [Qemu-devel] [PULL 69/76] iotests: add incremental backup granularity tests, Kevin Wolf, 2015/04/28
- [Qemu-devel] [PULL 71/76] block/dmg: make it modular, Kevin Wolf, 2015/04/28
- [Qemu-devel] [PULL 70/76] block/mirror: Always call block_job_sleep_ns(), Kevin Wolf, 2015/04/28
- [Qemu-devel] [PULL 73/76] block: replace bdrv_states iteration with bdrv_next(), Kevin Wolf, 2015/04/28
- [Qemu-devel] [PULL 67/76] iotests: add simple incremental backup case, Kevin Wolf, 2015/04/28
- [Qemu-devel] [PULL 72/76] vmdk: Widen before shifting 32 bit header field, Kevin Wolf, 2015/04/28
- [Qemu-devel] [PULL 74/76] block: add bdrv_set_dirty()/bdrv_reset_dirty() to block_int.h, Kevin Wolf, 2015/04/28
- [Qemu-devel] [PULL 75/76] block: extract bdrv_setup_io_funcs(), Kevin Wolf, 2015/04/28
- [Qemu-devel] [PULL 76/76] block: move I/O request processing to block/io.c,
Kevin Wolf <=
- [Qemu-devel] [PULL 66/76] iotests: add QMP event waiting queue, Kevin Wolf, 2015/04/28
- Re: [Qemu-devel] [PULL 00/76] Block patches, Peter Maydell, 2015/04/28