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[Qemu-devel] [PATCH v7 05/20] iscsi: Switch cluster_sectors to byte-base
From: |
Eric Blake |
Subject: |
[Qemu-devel] [PATCH v7 05/20] iscsi: Switch cluster_sectors to byte-based |
Date: |
Fri, 5 Jan 2018 16:57:38 -0600 |
We are gradually converting to byte-based interfaces, as they are
easier to reason about than sector-based. Convert all uses of
the cluster size in sectors, along with adding assertions that we
are not dividing by zero.
Improve some comment grammar while in the area.
Signed-off-by: Eric Blake <address@hidden>
Acked-by: Paolo Bonzini <address@hidden>
Reviewed-by: Fam Zheng <address@hidden>
---
v2-v7: no change
---
block/iscsi.c | 56 +++++++++++++++++++++++++++++++++++---------------------
1 file changed, 35 insertions(+), 21 deletions(-)
diff --git a/block/iscsi.c b/block/iscsi.c
index 5c0a9e55b6..7b03da54ee 100644
--- a/block/iscsi.c
+++ b/block/iscsi.c
@@ -84,7 +84,7 @@ typedef struct IscsiLun {
unsigned long *allocmap;
unsigned long *allocmap_valid;
long allocmap_size;
- int cluster_sectors;
+ int cluster_size;
bool use_16_for_rw;
bool write_protected;
bool lbpme;
@@ -428,9 +428,10 @@ static int iscsi_allocmap_init(IscsiLun *iscsilun, int
open_flags)
{
iscsi_allocmap_free(iscsilun);
+ assert(iscsilun->cluster_size);
iscsilun->allocmap_size =
- DIV_ROUND_UP(sector_lun2qemu(iscsilun->num_blocks, iscsilun),
- iscsilun->cluster_sectors);
+ DIV_ROUND_UP(iscsilun->num_blocks * iscsilun->block_size,
+ iscsilun->cluster_size);
iscsilun->allocmap = bitmap_try_new(iscsilun->allocmap_size);
if (!iscsilun->allocmap) {
@@ -438,7 +439,7 @@ static int iscsi_allocmap_init(IscsiLun *iscsilun, int
open_flags)
}
if (open_flags & BDRV_O_NOCACHE) {
- /* in case that cache.direct = on all allocmap entries are
+ /* when cache.direct = on all allocmap entries are
* treated as invalid to force a relookup of the block
* status on every read request */
return 0;
@@ -459,17 +460,19 @@ iscsi_allocmap_update(IscsiLun *iscsilun, int64_t
sector_num,
int nb_sectors, bool allocated, bool valid)
{
int64_t cl_num_expanded, nb_cls_expanded, cl_num_shrunk, nb_cls_shrunk;
+ int cluster_sectors = iscsilun->cluster_size >> BDRV_SECTOR_BITS;
if (iscsilun->allocmap == NULL) {
return;
}
/* expand to entirely contain all affected clusters */
- cl_num_expanded = sector_num / iscsilun->cluster_sectors;
+ assert(cluster_sectors);
+ cl_num_expanded = sector_num / cluster_sectors;
nb_cls_expanded = DIV_ROUND_UP(sector_num + nb_sectors,
- iscsilun->cluster_sectors) -
cl_num_expanded;
+ cluster_sectors) - cl_num_expanded;
/* shrink to touch only completely contained clusters */
- cl_num_shrunk = DIV_ROUND_UP(sector_num, iscsilun->cluster_sectors);
- nb_cls_shrunk = (sector_num + nb_sectors) / iscsilun->cluster_sectors
+ cl_num_shrunk = DIV_ROUND_UP(sector_num, cluster_sectors);
+ nb_cls_shrunk = (sector_num + nb_sectors) / cluster_sectors
- cl_num_shrunk;
if (allocated) {
bitmap_set(iscsilun->allocmap, cl_num_expanded, nb_cls_expanded);
@@ -533,9 +536,12 @@ iscsi_allocmap_is_allocated(IscsiLun *iscsilun, int64_t
sector_num,
if (iscsilun->allocmap == NULL) {
return true;
}
- size = DIV_ROUND_UP(sector_num + nb_sectors, iscsilun->cluster_sectors);
+ assert(iscsilun->cluster_size);
+ size = DIV_ROUND_UP(sector_num + nb_sectors,
+ iscsilun->cluster_size >> BDRV_SECTOR_BITS);
return !(find_next_bit(iscsilun->allocmap, size,
- sector_num / iscsilun->cluster_sectors) == size);
+ sector_num * BDRV_SECTOR_SIZE /
+ iscsilun->cluster_size) == size);
}
static inline bool iscsi_allocmap_is_valid(IscsiLun *iscsilun,
@@ -545,9 +551,12 @@ static inline bool iscsi_allocmap_is_valid(IscsiLun
*iscsilun,
if (iscsilun->allocmap_valid == NULL) {
return false;
}
- size = DIV_ROUND_UP(sector_num + nb_sectors, iscsilun->cluster_sectors);
+ assert(iscsilun->cluster_size);
+ size = DIV_ROUND_UP(sector_num + nb_sectors,
+ iscsilun->cluster_size >> BDRV_SECTOR_BITS);
return (find_next_zero_bit(iscsilun->allocmap_valid, size,
- sector_num / iscsilun->cluster_sectors) ==
size);
+ sector_num * BDRV_SECTOR_SIZE /
+ iscsilun->cluster_size) == size);
}
static int coroutine_fn
@@ -790,16 +799,21 @@ static int coroutine_fn iscsi_co_readv(BlockDriverState
*bs,
BlockDriverState *file;
/* check the block status from the beginning of the cluster
* containing the start sector */
- int64_t ret = iscsi_co_get_block_status(bs,
- sector_num - sector_num % iscsilun->cluster_sectors,
- BDRV_REQUEST_MAX_SECTORS, &pnum, &file);
+ int cluster_sectors = iscsilun->cluster_size >> BDRV_SECTOR_BITS;
+ int head;
+ int64_t ret;
+
+ assert(cluster_sectors);
+ head = sector_num % cluster_sectors;
+ ret = iscsi_co_get_block_status(bs, sector_num - head,
+ BDRV_REQUEST_MAX_SECTORS, &pnum,
+ &file);
if (ret < 0) {
return ret;
}
/* if the whole request falls into an unallocated area we can avoid
- * to read and directly return zeroes instead */
- if (ret & BDRV_BLOCK_ZERO &&
- pnum >= nb_sectors + sector_num % iscsilun->cluster_sectors) {
+ * reading and directly return zeroes instead */
+ if (ret & BDRV_BLOCK_ZERO && pnum >= nb_sectors + head) {
qemu_iovec_memset(iov, 0, 0x00, iov->size);
return 0;
}
@@ -1951,8 +1965,8 @@ static int iscsi_open(BlockDriverState *bs, QDict
*options, int flags,
* reasonable size */
if (iscsilun->bl.opt_unmap_gran * iscsilun->block_size >= 4 * 1024 &&
iscsilun->bl.opt_unmap_gran * iscsilun->block_size <= 16 * 1024 *
1024) {
- iscsilun->cluster_sectors = (iscsilun->bl.opt_unmap_gran *
- iscsilun->block_size) >> BDRV_SECTOR_BITS;
+ iscsilun->cluster_size = iscsilun->bl.opt_unmap_gran *
+ iscsilun->block_size;
if (iscsilun->lbprz) {
ret = iscsi_allocmap_init(iscsilun, bs->open_flags);
}
@@ -2158,7 +2172,7 @@ static int iscsi_get_info(BlockDriverState *bs,
BlockDriverInfo *bdi)
IscsiLun *iscsilun = bs->opaque;
bdi->unallocated_blocks_are_zero = iscsilun->lbprz;
bdi->can_write_zeroes_with_unmap = iscsilun->lbprz && iscsilun->lbp.lbpws;
- bdi->cluster_size = iscsilun->cluster_sectors * BDRV_SECTOR_SIZE;
+ bdi->cluster_size = iscsilun->cluster_size;
return 0;
}
--
2.14.3
- [Qemu-devel] [PATCH v7 00/20] add byte-based block_status driver callbacks, Eric Blake, 2018/01/05
- [Qemu-devel] [PATCH v7 01/20] block: Add .bdrv_co_block_status() callback, Eric Blake, 2018/01/05
- [Qemu-devel] [PATCH v7 03/20] file-posix: Switch to .bdrv_co_block_status(), Eric Blake, 2018/01/05
- [Qemu-devel] [PATCH v7 02/20] block: Switch passthrough drivers to .bdrv_co_block_status(), Eric Blake, 2018/01/05
- [Qemu-devel] [PATCH v7 04/20] gluster: Switch to .bdrv_co_block_status(), Eric Blake, 2018/01/05
- [Qemu-devel] [PATCH v7 05/20] iscsi: Switch cluster_sectors to byte-based,
Eric Blake <=
- [Qemu-devel] [PATCH v7 06/20] iscsi: Switch iscsi_allocmap_update() to byte-based, Eric Blake, 2018/01/05
- [Qemu-devel] [PATCH v7 07/20] iscsi: Switch to .bdrv_co_block_status(), Eric Blake, 2018/01/05
- [Qemu-devel] [PATCH v7 09/20] parallels: Switch to .bdrv_co_block_status(), Eric Blake, 2018/01/05
- [Qemu-devel] [PATCH v7 08/20] null: Switch to .bdrv_co_block_status(), Eric Blake, 2018/01/05
- [Qemu-devel] [PATCH v7 10/20] qcow: Switch to .bdrv_co_block_status(), Eric Blake, 2018/01/05
- [Qemu-devel] [PATCH v7 11/20] qcow2: Switch to .bdrv_co_block_status(), Eric Blake, 2018/01/05
- [Qemu-devel] [PATCH v7 13/20] raw: Switch to .bdrv_co_block_status(), Eric Blake, 2018/01/05