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[PULL 16/27] block: push error reporting into bdrv_all_*_snapshot functi
From: |
Dr. David Alan Gilbert (git) |
Subject: |
[PULL 16/27] block: push error reporting into bdrv_all_*_snapshot functions |
Date: |
Thu, 4 Feb 2021 16:39:48 +0000 |
From: Daniel P. Berrangé <berrange@redhat.com>
The bdrv_all_*_snapshot functions return a BlockDriverState pointer
for the invalid backend, which the callers then use to report an
error message. In some cases multiple callers are reporting the
same error message, but with slightly different text. In the future
there will be more error scenarios for some of these methods, which
will benefit from fine grained error message reporting. So it is
helpful to push error reporting down a level.
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
[PMD: Initialize variables]
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20210204124834.774401-2-berrange@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
---
block/monitor/block-hmp-cmds.c | 7 ++--
block/snapshot.c | 77 +++++++++++++++++-----------------
include/block/snapshot.h | 14 +++----
migration/savevm.c | 39 +++++------------
monitor/hmp-cmds.c | 7 +---
replay/replay-debugging.c | 4 +-
tests/qemu-iotests/267.out | 10 ++---
7 files changed, 68 insertions(+), 90 deletions(-)
diff --git a/block/monitor/block-hmp-cmds.c b/block/monitor/block-hmp-cmds.c
index afd75ab628..9532d085ea 100644
--- a/block/monitor/block-hmp-cmds.c
+++ b/block/monitor/block-hmp-cmds.c
@@ -900,10 +900,11 @@ void hmp_info_snapshots(Monitor *mon, const QDict *qdict)
ImageEntry *image_entry, *next_ie;
SnapshotEntry *snapshot_entry;
+ Error *err = NULL;
- bs = bdrv_all_find_vmstate_bs();
+ bs = bdrv_all_find_vmstate_bs(&err);
if (!bs) {
- monitor_printf(mon, "No available block device supports snapshots\n");
+ error_report_err(err);
return;
}
aio_context = bdrv_get_aio_context(bs);
@@ -953,7 +954,7 @@ void hmp_info_snapshots(Monitor *mon, const QDict *qdict)
total = 0;
for (i = 0; i < nb_sns; i++) {
SnapshotEntry *next_sn;
- if (bdrv_all_find_snapshot(sn_tab[i].name, &bs1) == 0) {
+ if (bdrv_all_find_snapshot(sn_tab[i].name, NULL) == 0) {
global_snapshots[total] = i;
total++;
QTAILQ_FOREACH(image_entry, &image_list, next) {
diff --git a/block/snapshot.c b/block/snapshot.c
index a2bf3a54eb..482e3fc7b7 100644
--- a/block/snapshot.c
+++ b/block/snapshot.c
@@ -462,14 +462,14 @@ static bool
bdrv_all_snapshots_includes_bs(BlockDriverState *bs)
* These functions will properly handle dataplane (take aio_context_acquire
* when appropriate for appropriate block drivers) */
-bool bdrv_all_can_snapshot(BlockDriverState **first_bad_bs)
+bool bdrv_all_can_snapshot(Error **errp)
{
- bool ok = true;
BlockDriverState *bs;
BdrvNextIterator it;
for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) {
AioContext *ctx = bdrv_get_aio_context(bs);
+ bool ok = true;
aio_context_acquire(ctx);
if (bdrv_all_snapshots_includes_bs(bs)) {
@@ -477,26 +477,25 @@ bool bdrv_all_can_snapshot(BlockDriverState
**first_bad_bs)
}
aio_context_release(ctx);
if (!ok) {
+ error_setg(errp, "Device '%s' is writable but does not support "
+ "snapshots", bdrv_get_device_or_node_name(bs));
bdrv_next_cleanup(&it);
- goto fail;
+ return false;
}
}
-fail:
- *first_bad_bs = bs;
- return ok;
+ return true;
}
-int bdrv_all_delete_snapshot(const char *name, BlockDriverState **first_bad_bs,
- Error **errp)
+int bdrv_all_delete_snapshot(const char *name, Error **errp)
{
- int ret = 0;
BlockDriverState *bs;
BdrvNextIterator it;
QEMUSnapshotInfo sn1, *snapshot = &sn1;
for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) {
AioContext *ctx = bdrv_get_aio_context(bs);
+ int ret = 0;
aio_context_acquire(ctx);
if (bdrv_all_snapshots_includes_bs(bs) &&
@@ -507,26 +506,25 @@ int bdrv_all_delete_snapshot(const char *name,
BlockDriverState **first_bad_bs,
}
aio_context_release(ctx);
if (ret < 0) {
+ error_prepend(errp, "Could not delete snapshot '%s' on '%s': ",
+ name, bdrv_get_device_or_node_name(bs));
bdrv_next_cleanup(&it);
- goto fail;
+ return -1;
}
}
-fail:
- *first_bad_bs = bs;
- return ret;
+ return 0;
}
-int bdrv_all_goto_snapshot(const char *name, BlockDriverState **first_bad_bs,
- Error **errp)
+int bdrv_all_goto_snapshot(const char *name, Error **errp)
{
- int ret = 0;
BlockDriverState *bs;
BdrvNextIterator it;
for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) {
AioContext *ctx = bdrv_get_aio_context(bs);
+ int ret = 0;
aio_context_acquire(ctx);
if (bdrv_all_snapshots_includes_bs(bs)) {
@@ -534,75 +532,75 @@ int bdrv_all_goto_snapshot(const char *name,
BlockDriverState **first_bad_bs,
}
aio_context_release(ctx);
if (ret < 0) {
+ error_prepend(errp, "Could not load snapshot '%s' on '%s': ",
+ name, bdrv_get_device_or_node_name(bs));
bdrv_next_cleanup(&it);
- goto fail;
+ return -1;
}
}
-fail:
- *first_bad_bs = bs;
- return ret;
+ return 0;
}
-int bdrv_all_find_snapshot(const char *name, BlockDriverState **first_bad_bs)
+int bdrv_all_find_snapshot(const char *name, Error **errp)
{
QEMUSnapshotInfo sn;
- int err = 0;
BlockDriverState *bs;
BdrvNextIterator it;
for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) {
AioContext *ctx = bdrv_get_aio_context(bs);
+ int ret = 0;
aio_context_acquire(ctx);
if (bdrv_all_snapshots_includes_bs(bs)) {
- err = bdrv_snapshot_find(bs, &sn, name);
+ ret = bdrv_snapshot_find(bs, &sn, name);
}
aio_context_release(ctx);
- if (err < 0) {
+ if (ret < 0) {
+ error_setg(errp, "Could not find snapshot '%s' on '%s'",
+ name, bdrv_get_device_or_node_name(bs));
bdrv_next_cleanup(&it);
- goto fail;
+ return -1;
}
}
-fail:
- *first_bad_bs = bs;
- return err;
+ return 0;
}
int bdrv_all_create_snapshot(QEMUSnapshotInfo *sn,
BlockDriverState *vm_state_bs,
uint64_t vm_state_size,
- BlockDriverState **first_bad_bs)
+ Error **errp)
{
- int err = 0;
BlockDriverState *bs;
BdrvNextIterator it;
for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) {
AioContext *ctx = bdrv_get_aio_context(bs);
+ int ret = 0;
aio_context_acquire(ctx);
if (bs == vm_state_bs) {
sn->vm_state_size = vm_state_size;
- err = bdrv_snapshot_create(bs, sn);
+ ret = bdrv_snapshot_create(bs, sn);
} else if (bdrv_all_snapshots_includes_bs(bs)) {
sn->vm_state_size = 0;
- err = bdrv_snapshot_create(bs, sn);
+ ret = bdrv_snapshot_create(bs, sn);
}
aio_context_release(ctx);
- if (err < 0) {
+ if (ret < 0) {
+ error_setg(errp, "Could not create snapshot '%s' on '%s'",
+ sn->name, bdrv_get_device_or_node_name(bs));
bdrv_next_cleanup(&it);
- goto fail;
+ return -1;
}
}
-fail:
- *first_bad_bs = bs;
- return err;
+ return 0;
}
-BlockDriverState *bdrv_all_find_vmstate_bs(void)
+BlockDriverState *bdrv_all_find_vmstate_bs(Error **errp)
{
BlockDriverState *bs;
BdrvNextIterator it;
@@ -620,5 +618,8 @@ BlockDriverState *bdrv_all_find_vmstate_bs(void)
break;
}
}
+ if (!bs) {
+ error_setg(errp, "No block device supports snapshots");
+ }
return bs;
}
diff --git a/include/block/snapshot.h b/include/block/snapshot.h
index b0fe42993d..5cb2b696ad 100644
--- a/include/block/snapshot.h
+++ b/include/block/snapshot.h
@@ -77,17 +77,15 @@ int bdrv_snapshot_load_tmp_by_id_or_name(BlockDriverState
*bs,
* These functions will properly handle dataplane (take aio_context_acquire
* when appropriate for appropriate block drivers */
-bool bdrv_all_can_snapshot(BlockDriverState **first_bad_bs);
-int bdrv_all_delete_snapshot(const char *name, BlockDriverState **first_bsd_bs,
- Error **errp);
-int bdrv_all_goto_snapshot(const char *name, BlockDriverState **first_bad_bs,
- Error **errp);
-int bdrv_all_find_snapshot(const char *name, BlockDriverState **first_bad_bs);
+bool bdrv_all_can_snapshot(Error **errp);
+int bdrv_all_delete_snapshot(const char *name, Error **errp);
+int bdrv_all_goto_snapshot(const char *name, Error **errp);
+int bdrv_all_find_snapshot(const char *name, Error **errp);
int bdrv_all_create_snapshot(QEMUSnapshotInfo *sn,
BlockDriverState *vm_state_bs,
uint64_t vm_state_size,
- BlockDriverState **first_bad_bs);
+ Error **errp);
-BlockDriverState *bdrv_all_find_vmstate_bs(void);
+BlockDriverState *bdrv_all_find_vmstate_bs(Error **errp);
#endif
diff --git a/migration/savevm.c b/migration/savevm.c
index 1178c6ca90..948e82c9ed 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -2766,7 +2766,7 @@ int qemu_load_device_state(QEMUFile *f)
int save_snapshot(const char *name, Error **errp)
{
- BlockDriverState *bs, *bs1;
+ BlockDriverState *bs;
QEMUSnapshotInfo sn1, *sn = &sn1;
int ret = -1, ret2;
QEMUFile *f;
@@ -2786,25 +2786,19 @@ int save_snapshot(const char *name, Error **errp)
return ret;
}
- if (!bdrv_all_can_snapshot(&bs)) {
- error_setg(errp, "Device '%s' is writable but does not support "
- "snapshots", bdrv_get_device_or_node_name(bs));
+ if (!bdrv_all_can_snapshot(errp)) {
return ret;
}
/* Delete old snapshots of the same name */
if (name) {
- ret = bdrv_all_delete_snapshot(name, &bs1, errp);
- if (ret < 0) {
- error_prepend(errp, "Error while deleting snapshot on device "
- "'%s': ", bdrv_get_device_or_node_name(bs1));
+ if (bdrv_all_delete_snapshot(name, errp) < 0) {
return ret;
}
}
- bs = bdrv_all_find_vmstate_bs();
+ bs = bdrv_all_find_vmstate_bs(errp);
if (bs == NULL) {
- error_setg(errp, "No block device can accept snapshots");
return ret;
}
aio_context = bdrv_get_aio_context(bs);
@@ -2868,11 +2862,9 @@ int save_snapshot(const char *name, Error **errp)
aio_context_release(aio_context);
aio_context = NULL;
- ret = bdrv_all_create_snapshot(sn, bs, vm_state_size, &bs);
+ ret = bdrv_all_create_snapshot(sn, bs, vm_state_size, errp);
if (ret < 0) {
- error_setg(errp, "Error while creating snapshot on '%s'",
- bdrv_get_device_or_node_name(bs));
- bdrv_all_delete_snapshot(sn->name, &bs, NULL);
+ bdrv_all_delete_snapshot(sn->name, NULL);
goto the_end;
}
@@ -2975,30 +2967,23 @@ void qmp_xen_load_devices_state(const char *filename,
Error **errp)
int load_snapshot(const char *name, Error **errp)
{
- BlockDriverState *bs, *bs_vm_state;
+ BlockDriverState *bs_vm_state;
QEMUSnapshotInfo sn;
QEMUFile *f;
int ret;
AioContext *aio_context;
MigrationIncomingState *mis = migration_incoming_get_current();
- if (!bdrv_all_can_snapshot(&bs)) {
- error_setg(errp,
- "Device '%s' is writable but does not support snapshots",
- bdrv_get_device_or_node_name(bs));
+ if (!bdrv_all_can_snapshot(errp)) {
return -ENOTSUP;
}
- ret = bdrv_all_find_snapshot(name, &bs);
+ ret = bdrv_all_find_snapshot(name, errp);
if (ret < 0) {
- error_setg(errp,
- "Device '%s' does not have the requested snapshot '%s'",
- bdrv_get_device_or_node_name(bs), name);
return ret;
}
- bs_vm_state = bdrv_all_find_vmstate_bs();
+ bs_vm_state = bdrv_all_find_vmstate_bs(errp);
if (!bs_vm_state) {
- error_setg(errp, "No block device supports snapshots");
return -ENOTSUP;
}
aio_context = bdrv_get_aio_context(bs_vm_state);
@@ -3024,10 +3009,8 @@ int load_snapshot(const char *name, Error **errp)
/* Flush all IO requests so they don't interfere with the new state. */
bdrv_drain_all_begin();
- ret = bdrv_all_goto_snapshot(name, &bs, errp);
+ ret = bdrv_all_goto_snapshot(name, errp);
if (ret < 0) {
- error_prepend(errp, "Could not load snapshot '%s' on '%s': ",
- name, bdrv_get_device_or_node_name(bs));
goto err_drain;
}
diff --git a/monitor/hmp-cmds.c b/monitor/hmp-cmds.c
index 992ecf6f04..2b954763e4 100644
--- a/monitor/hmp-cmds.c
+++ b/monitor/hmp-cmds.c
@@ -1155,15 +1155,10 @@ void hmp_savevm(Monitor *mon, const QDict *qdict)
void hmp_delvm(Monitor *mon, const QDict *qdict)
{
- BlockDriverState *bs;
Error *err = NULL;
const char *name = qdict_get_str(qdict, "name");
- if (bdrv_all_delete_snapshot(name, &bs, &err) < 0) {
- error_prepend(&err,
- "deleting snapshot on device '%s': ",
- bdrv_get_device_name(bs));
- }
+ bdrv_all_delete_snapshot(name, &err);
hmp_handle_error(mon, err);
}
diff --git a/replay/replay-debugging.c b/replay/replay-debugging.c
index 5ec574724a..3a9b609e62 100644
--- a/replay/replay-debugging.c
+++ b/replay/replay-debugging.c
@@ -148,7 +148,7 @@ static char *replay_find_nearest_snapshot(int64_t icount,
*snapshot_icount = -1;
- bs = bdrv_all_find_vmstate_bs();
+ bs = bdrv_all_find_vmstate_bs(NULL);
if (!bs) {
goto fail;
}
@@ -159,7 +159,7 @@ static char *replay_find_nearest_snapshot(int64_t icount,
aio_context_release(aio_context);
for (i = 0; i < nb_sns; i++) {
- if (bdrv_all_find_snapshot(sn_tab[i].name, &bs) == 0) {
+ if (bdrv_all_find_snapshot(sn_tab[i].name, NULL) == 0) {
if (sn_tab[i].icount != -1ULL
&& sn_tab[i].icount <= icount
&& (!nearest || nearest->icount < sn_tab[i].icount)) {
diff --git a/tests/qemu-iotests/267.out b/tests/qemu-iotests/267.out
index 27471ffae8..6149029b25 100644
--- a/tests/qemu-iotests/267.out
+++ b/tests/qemu-iotests/267.out
@@ -6,9 +6,9 @@ Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=134217728
Testing:
QEMU X.Y.Z monitor - type 'help' for more information
(qemu) savevm snap0
-Error: No block device can accept snapshots
+Error: No block device supports snapshots
(qemu) info snapshots
-No available block device supports snapshots
+No block device supports snapshots
(qemu) loadvm snap0
Error: No block device supports snapshots
(qemu) quit
@@ -22,7 +22,7 @@ QEMU X.Y.Z monitor - type 'help' for more information
(qemu) savevm snap0
Error: Device 'none0' is writable but does not support snapshots
(qemu) info snapshots
-No available block device supports snapshots
+No block device supports snapshots
(qemu) loadvm snap0
Error: Device 'none0' is writable but does not support snapshots
(qemu) quit
@@ -58,7 +58,7 @@ QEMU X.Y.Z monitor - type 'help' for more information
(qemu) savevm snap0
Error: Device 'virtio0' is writable but does not support snapshots
(qemu) info snapshots
-No available block device supports snapshots
+No block device supports snapshots
(qemu) loadvm snap0
Error: Device 'virtio0' is writable but does not support snapshots
(qemu) quit
@@ -83,7 +83,7 @@ QEMU X.Y.Z monitor - type 'help' for more information
(qemu) savevm snap0
Error: Device 'file' is writable but does not support snapshots
(qemu) info snapshots
-No available block device supports snapshots
+No block device supports snapshots
(qemu) loadvm snap0
Error: Device 'file' is writable but does not support snapshots
(qemu) quit
--
2.29.2
- [PULL 06/27] migration: introduce UFFD-WP low-level interface helpers, (continued)
- [PULL 06/27] migration: introduce UFFD-WP low-level interface helpers, Dr. David Alan Gilbert (git), 2021/02/04
- [PULL 07/27] migration: support UFFD write fault processing in ram_save_iterate(), Dr. David Alan Gilbert (git), 2021/02/04
- [PULL 08/27] migration: implementation of background snapshot thread, Dr. David Alan Gilbert (git), 2021/02/04
- [PULL 09/27] migration: introduce 'userfaultfd-wrlat.py' script, Dr. David Alan Gilbert (git), 2021/02/04
- [PULL 10/27] migration: Fix migrate-set-parameters argument validation, Dr. David Alan Gilbert (git), 2021/02/04
- [PULL 11/27] migration: Clean up signed vs. unsigned XBZRLE cache-size, Dr. David Alan Gilbert (git), 2021/02/04
- [PULL 12/27] migration: Fix cache_init()'s "Failed to allocate" error messages, Dr. David Alan Gilbert (git), 2021/02/04
- [PULL 13/27] migration: Fix a few absurdly defective error messages, Dr. David Alan Gilbert (git), 2021/02/04
- [PULL 14/27] migration: Add blocker information, Dr. David Alan Gilbert (git), 2021/02/04
- [PULL 15/27] migration: Display the migration blockers, Dr. David Alan Gilbert (git), 2021/02/04
- [PULL 16/27] block: push error reporting into bdrv_all_*_snapshot functions,
Dr. David Alan Gilbert (git) <=
- [PULL 17/27] migration: Make save_snapshot() return bool, not 0/-1, Dr. David Alan Gilbert (git), 2021/02/04
- [PULL 18/27] migration: stop returning errno from load_snapshot(), Dr. David Alan Gilbert (git), 2021/02/04
- [PULL 19/27] block: add ability to specify list of blockdevs during snapshot, Dr. David Alan Gilbert (git), 2021/02/04
- [PULL 20/27] block: allow specifying name of block device for vmstate storage, Dr. David Alan Gilbert (git), 2021/02/04
- [PULL 22/27] migration: control whether snapshots are ovewritten, Dr. David Alan Gilbert (git), 2021/02/04
- [PULL 23/27] migration: wire up support for snapshot device selection, Dr. David Alan Gilbert (git), 2021/02/04
- [PULL 21/27] block: rename and alter bdrv_all_find_snapshot semantics, Dr. David Alan Gilbert (git), 2021/02/04
- [PULL 25/27] iotests: add support for capturing and matching QMP events, Dr. David Alan Gilbert (git), 2021/02/04
- [PULL 26/27] iotests: fix loading of common.config from tests/ subdir, Dr. David Alan Gilbert (git), 2021/02/04
- [PULL 24/27] migration: introduce a delete_snapshot wrapper, Dr. David Alan Gilbert (git), 2021/02/04