* [Qemu-devel] [PULL for-2.5 1/7] docs: update bitmaps.md
2015-11-17 11:17 [Qemu-devel] [PULL for-2.5 0/7] Block patches Stefan Hajnoczi
@ 2015-11-17 11:17 ` Stefan Hajnoczi
2015-11-17 11:17 ` [Qemu-devel] [PULL for-2.5 2/7] tests: Ignore recent test binaries Stefan Hajnoczi
` (6 subsequent siblings)
7 siblings, 0 replies; 9+ messages in thread
From: Stefan Hajnoczi @ 2015-11-17 11:17 UTC (permalink / raw)
To: qemu-devel; +Cc: Peter Maydell, John Snow, Stefan Hajnoczi
From: John Snow <jsnow@redhat.com>
Include new error handling scenarios for 2.5.
Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 1447196417-26081-1-git-send-email-jsnow@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
docs/bitmaps.md | 157 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 157 insertions(+)
diff --git a/docs/bitmaps.md b/docs/bitmaps.md
index 9fd8ea6..a2e8d51 100644
--- a/docs/bitmaps.md
+++ b/docs/bitmaps.md
@@ -19,12 +19,20 @@ which is included at the end of this document.
* A dirty bitmap's name is unique to the node, but bitmaps attached to different
nodes can share the same name.
+* Dirty bitmaps created for internal use by QEMU may be anonymous and have no
+ name, but any user-created bitmaps may not be. There can be any number of
+ anonymous bitmaps per node.
+
+* The name of a user-created bitmap must not be empty ("").
+
## Bitmap Modes
* A Bitmap can be "frozen," which means that it is currently in-use by a backup
operation and cannot be deleted, renamed, written to, reset,
etc.
+* The normal operating mode for a bitmap is "active."
+
## Basic QMP Usage
### Supported Commands ###
@@ -319,6 +327,155 @@ full backup as a backing image.
"event": "BLOCK_JOB_COMPLETED" }
```
+### Partial Transactional Failures
+
+* Sometimes, a transaction will succeed in launching and return success,
+ but then later the backup jobs themselves may fail. It is possible that
+ a management application may have to deal with a partial backup failure
+ after a successful transaction.
+
+* If multiple backup jobs are specified in a single transaction, when one of
+ them fails, it will not interact with the other backup jobs in any way.
+
+* The job(s) that succeeded will clear the dirty bitmap associated with the
+ operation, but the job(s) that failed will not. It is not "safe" to delete
+ any incremental backups that were created successfully in this scenario,
+ even though others failed.
+
+#### Example
+
+* QMP example highlighting two backup jobs:
+
+ ```json
+ { "execute": "transaction",
+ "arguments": {
+ "actions": [
+ { "type": "drive-backup",
+ "data": { "device": "drive0", "bitmap": "bitmap0",
+ "format": "qcow2", "mode": "existing",
+ "sync": "incremental", "target": "d0-incr-1.qcow2" } },
+ { "type": "drive-backup",
+ "data": { "device": "drive1", "bitmap": "bitmap1",
+ "format": "qcow2", "mode": "existing",
+ "sync": "incremental", "target": "d1-incr-1.qcow2" } },
+ ]
+ }
+ }
+ ```
+
+* QMP example response, highlighting one success and one failure:
+ * Acknowledgement that the Transaction was accepted and jobs were launched:
+ ```json
+ { "return": {} }
+ ```
+
+ * Later, QEMU sends notice that the first job was completed:
+ ```json
+ { "timestamp": { "seconds": 1447192343, "microseconds": 615698 },
+ "data": { "device": "drive0", "type": "backup",
+ "speed": 0, "len": 67108864, "offset": 67108864 },
+ "event": "BLOCK_JOB_COMPLETED"
+ }
+ ```
+
+ * Later yet, QEMU sends notice that the second job has failed:
+ ```json
+ { "timestamp": { "seconds": 1447192399, "microseconds": 683015 },
+ "data": { "device": "drive1", "action": "report",
+ "operation": "read" },
+ "event": "BLOCK_JOB_ERROR" }
+ ```
+
+ ```json
+ { "timestamp": { "seconds": 1447192399, "microseconds": 685853 },
+ "data": { "speed": 0, "offset": 0, "len": 67108864,
+ "error": "Input/output error",
+ "device": "drive1", "type": "backup" },
+ "event": "BLOCK_JOB_COMPLETED" }
+
+* In the above example, "d0-incr-1.qcow2" is valid and must be kept,
+ but "d1-incr-1.qcow2" is invalid and should be deleted. If a VM-wide
+ incremental backup of all drives at a point-in-time is to be made,
+ new backups for both drives will need to be made, taking into account
+ that a new incremental backup for drive0 needs to be based on top of
+ "d0-incr-1.qcow2."
+
+### Grouped Completion Mode
+
+* While jobs launched by transactions normally complete or fail on their own,
+ it is possible to instruct them to complete or fail together as a group.
+
+* QMP transactions take an optional properties structure that can affect
+ the semantics of the transaction.
+
+* The "completion-mode" transaction property can be either "individual"
+ which is the default, legacy behavior described above, or "grouped,"
+ a new behavior detailed below.
+
+* Delayed Completion: In grouped completion mode, no jobs will report
+ success until all jobs are ready to report success.
+
+* Grouped failure: If any job fails in grouped completion mode, all remaining
+ jobs will be cancelled. Any incremental backups will restore their dirty
+ bitmap objects as if no backup command was ever issued.
+
+ * Regardless of if QEMU reports a particular incremental backup job as
+ CANCELLED or as an ERROR, the in-memory bitmap will be restored.
+
+#### Example
+
+* Here's the same example scenario from above with the new property:
+
+ ```json
+ { "execute": "transaction",
+ "arguments": {
+ "actions": [
+ { "type": "drive-backup",
+ "data": { "device": "drive0", "bitmap": "bitmap0",
+ "format": "qcow2", "mode": "existing",
+ "sync": "incremental", "target": "d0-incr-1.qcow2" } },
+ { "type": "drive-backup",
+ "data": { "device": "drive1", "bitmap": "bitmap1",
+ "format": "qcow2", "mode": "existing",
+ "sync": "incremental", "target": "d1-incr-1.qcow2" } },
+ ],
+ "properties": {
+ "completion-mode": "grouped"
+ }
+ }
+ }
+ ```
+
+* QMP example response, highlighting a failure for drive2:
+ * Acknowledgement that the Transaction was accepted and jobs were launched:
+ ```json
+ { "return": {} }
+ ```
+
+ * Later, QEMU sends notice that the second job has errored out,
+ but that the first job was also cancelled:
+ ```json
+ { "timestamp": { "seconds": 1447193702, "microseconds": 632377 },
+ "data": { "device": "drive1", "action": "report",
+ "operation": "read" },
+ "event": "BLOCK_JOB_ERROR" }
+ ```
+
+ ```json
+ { "timestamp": { "seconds": 1447193702, "microseconds": 640074 },
+ "data": { "speed": 0, "offset": 0, "len": 67108864,
+ "error": "Input/output error",
+ "device": "drive1", "type": "backup" },
+ "event": "BLOCK_JOB_COMPLETED" }
+ ```
+
+ ```json
+ { "timestamp": { "seconds": 1447193702, "microseconds": 640163 },
+ "data": { "device": "drive0", "type": "backup", "speed": 0,
+ "len": 67108864, "offset": 16777216 },
+ "event": "BLOCK_JOB_CANCELLED" }
+ ```
+
<!--
The FreeBSD Documentation License
--
2.5.0
^ permalink raw reply related [flat|nested] 9+ messages in thread* [Qemu-devel] [PULL for-2.5 2/7] tests: Ignore recent test binaries
2015-11-17 11:17 [Qemu-devel] [PULL for-2.5 0/7] Block patches Stefan Hajnoczi
2015-11-17 11:17 ` [Qemu-devel] [PULL for-2.5 1/7] docs: update bitmaps.md Stefan Hajnoczi
@ 2015-11-17 11:17 ` Stefan Hajnoczi
2015-11-17 11:17 ` [Qemu-devel] [PULL for-2.5 3/7] tpm: avoid clang shifting negative signed warning Stefan Hajnoczi
` (5 subsequent siblings)
7 siblings, 0 replies; 9+ messages in thread
From: Stefan Hajnoczi @ 2015-11-17 11:17 UTC (permalink / raw)
To: qemu-devel; +Cc: Peter Maydell, Stefan Hajnoczi
From: Eric Blake <eblake@redhat.com>
Commits 6c6f312d and bd797fc1 added new tests (test-blockjob-txn
and test-timed-average, respectively), but did not mark them for
exclusion in .gitignore.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Message-id: 1447386423-13160-1-git-send-email-eblake@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
tests/.gitignore | 2 ++
1 file changed, 2 insertions(+)
diff --git a/tests/.gitignore b/tests/.gitignore
index e96f569..1e55722 100644
--- a/tests/.gitignore
+++ b/tests/.gitignore
@@ -9,6 +9,7 @@ check-qom-proplist
rcutorture
test-aio
test-bitops
+test-blockjob-txn
test-coroutine
test-crypto-cipher
test-crypto-hash
@@ -45,6 +46,7 @@ test-string-input-visitor
test-string-output-visitor
test-thread-pool
test-throttle
+test-timed-average
test-visitor-serialization
test-vmstate
test-write-threshold
--
2.5.0
^ permalink raw reply related [flat|nested] 9+ messages in thread* [Qemu-devel] [PULL for-2.5 3/7] tpm: avoid clang shifting negative signed warning
2015-11-17 11:17 [Qemu-devel] [PULL for-2.5 0/7] Block patches Stefan Hajnoczi
2015-11-17 11:17 ` [Qemu-devel] [PULL for-2.5 1/7] docs: update bitmaps.md Stefan Hajnoczi
2015-11-17 11:17 ` [Qemu-devel] [PULL for-2.5 2/7] tests: Ignore recent test binaries Stefan Hajnoczi
@ 2015-11-17 11:17 ` Stefan Hajnoczi
2015-11-17 11:17 ` [Qemu-devel] [PULL for-2.5 4/7] disas/arm: " Stefan Hajnoczi
` (4 subsequent siblings)
7 siblings, 0 replies; 9+ messages in thread
From: Stefan Hajnoczi @ 2015-11-17 11:17 UTC (permalink / raw)
To: qemu-devel; +Cc: Peter Maydell, Stefan Hajnoczi
clang 3.7.0 on x86_64 warns about the following:
hw/tpm/tpm_tis.c:1000:36: warning: shifting a negative signed value is undefined [-Wshift-negative-value]
tis->loc[c].iface_id = TPM_TIS_IFACE_ID_SUPPORTED_FLAGS1_3;
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
hw/tpm/tpm_tis.c:144:10: note: expanded from macro 'TPM_TIS_IFACE_ID_SUPPORTED_FLAGS1_3'
(~0 << 4)/* all of it is don't care */)
~~ ^
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
hw/tpm/tpm_tis.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/hw/tpm/tpm_tis.c b/hw/tpm/tpm_tis.c
index 0806b5f..ff073d5 100644
--- a/hw/tpm/tpm_tis.c
+++ b/hw/tpm/tpm_tis.c
@@ -141,7 +141,7 @@
#define TPM_TIS_IFACE_ID_SUPPORTED_FLAGS1_3 \
(TPM_TIS_IFACE_ID_INTERFACE_TIS1_3 | \
- (~0 << 4)/* all of it is don't care */)
+ (~0u << 4)/* all of it is don't care */)
/* if backend was a TPM 2.0: */
#define TPM_TIS_IFACE_ID_SUPPORTED_FLAGS2_0 \
--
2.5.0
^ permalink raw reply related [flat|nested] 9+ messages in thread* [Qemu-devel] [PULL for-2.5 4/7] disas/arm: avoid clang shifting negative signed warning
2015-11-17 11:17 [Qemu-devel] [PULL for-2.5 0/7] Block patches Stefan Hajnoczi
` (2 preceding siblings ...)
2015-11-17 11:17 ` [Qemu-devel] [PULL for-2.5 3/7] tpm: avoid clang shifting negative signed warning Stefan Hajnoczi
@ 2015-11-17 11:17 ` Stefan Hajnoczi
2015-11-17 11:17 ` [Qemu-devel] [PULL for-2.5 5/7] aio-epoll: Fix use-after-free of node Stefan Hajnoczi
` (3 subsequent siblings)
7 siblings, 0 replies; 9+ messages in thread
From: Stefan Hajnoczi @ 2015-11-17 11:17 UTC (permalink / raw)
To: qemu-devel; +Cc: Peter Maydell, Stefan Hajnoczi
clang 3.7.0 on x86_64 warns about the following:
disas/arm.c:1782:17: warning: shifting a negative signed value is undefined [-Wshift-negative-value]
imm |= (-1 << 7);
~~ ^
Note that this patch preserves the tab indent in this source file
because the surrounding code still uses tabs.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
disas/arm.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/disas/arm.c b/disas/arm.c
index 6165246..7a7354b 100644
--- a/disas/arm.c
+++ b/disas/arm.c
@@ -1779,7 +1779,7 @@ print_insn_coprocessor (bfd_vma pc, struct disassemble_info *info, long given,
/* Is ``imm'' a negative number? */
if (imm & 0x40)
- imm |= (-1 << 7);
+ imm |= (~0u << 7);
func (stream, "%d", imm);
}
--
2.5.0
^ permalink raw reply related [flat|nested] 9+ messages in thread* [Qemu-devel] [PULL for-2.5 5/7] aio-epoll: Fix use-after-free of node
2015-11-17 11:17 [Qemu-devel] [PULL for-2.5 0/7] Block patches Stefan Hajnoczi
` (3 preceding siblings ...)
2015-11-17 11:17 ` [Qemu-devel] [PULL for-2.5 4/7] disas/arm: " Stefan Hajnoczi
@ 2015-11-17 11:17 ` Stefan Hajnoczi
2015-11-17 11:17 ` [Qemu-devel] [PULL for-2.5 6/7] block: make 'stats-interval' an array of ints instead of a string Stefan Hajnoczi
` (2 subsequent siblings)
7 siblings, 0 replies; 9+ messages in thread
From: Stefan Hajnoczi @ 2015-11-17 11:17 UTC (permalink / raw)
To: qemu-devel; +Cc: Peter Maydell, Fam Zheng, Stefan Hajnoczi
From: Fam Zheng <famz@redhat.com>
aio_epoll_update needs the fields in node, so delay the free.
Reported-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
Message-id: 1447655534-13974-1-git-send-email-famz@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
aio-posix.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/aio-posix.c b/aio-posix.c
index 06148a9..482b316 100644
--- a/aio-posix.c
+++ b/aio-posix.c
@@ -210,6 +210,7 @@ void aio_set_fd_handler(AioContext *ctx,
{
AioHandler *node;
bool is_new = false;
+ bool deleted = false;
node = find_aio_handler(ctx, fd);
@@ -228,7 +229,7 @@ void aio_set_fd_handler(AioContext *ctx,
* releasing the walking_handlers lock.
*/
QLIST_REMOVE(node, node);
- g_free(node);
+ deleted = true;
}
}
} else {
@@ -253,6 +254,9 @@ void aio_set_fd_handler(AioContext *ctx,
aio_epoll_update(ctx, node, is_new);
aio_notify(ctx);
+ if (deleted) {
+ g_free(node);
+ }
}
void aio_set_event_notifier(AioContext *ctx,
--
2.5.0
^ permalink raw reply related [flat|nested] 9+ messages in thread* [Qemu-devel] [PULL for-2.5 6/7] block: make 'stats-interval' an array of ints instead of a string
2015-11-17 11:17 [Qemu-devel] [PULL for-2.5 0/7] Block patches Stefan Hajnoczi
` (4 preceding siblings ...)
2015-11-17 11:17 ` [Qemu-devel] [PULL for-2.5 5/7] aio-epoll: Fix use-after-free of node Stefan Hajnoczi
@ 2015-11-17 11:17 ` Stefan Hajnoczi
2015-11-17 11:17 ` [Qemu-devel] [PULL for-2.5 7/7] virtio-blk: Fix double completion for werror=stop Stefan Hajnoczi
2015-11-17 12:33 ` [Qemu-devel] [PULL for-2.5 0/7] Block patches Peter Maydell
7 siblings, 0 replies; 9+ messages in thread
From: Stefan Hajnoczi @ 2015-11-17 11:17 UTC (permalink / raw)
To: qemu-devel; +Cc: Peter Maydell, Alberto Garcia, Stefan Hajnoczi
From: Alberto Garcia <berto@igalia.com>
This is the natural JSON representation and prevents us from having to
decode the list manually.
Signed-off-by: Alberto Garcia <berto@igalia.com>
Message-id: 0e3da8fa206f4ab534ae3ce6086e75fe84f1557e.1447665472.git.berto@igalia.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
blockdev.c | 91 +++++++++++++++++++++++++++++++-------------------
qapi/block-core.json | 7 ++--
tests/qemu-iotests/136 | 2 +-
3 files changed, 61 insertions(+), 39 deletions(-)
diff --git a/blockdev.c b/blockdev.c
index fc85128..917ae06 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -300,6 +300,45 @@ static int parse_block_error_action(const char *buf, bool is_read, Error **errp)
}
}
+static bool parse_stats_intervals(BlockAcctStats *stats, QList *intervals,
+ Error **errp)
+{
+ const QListEntry *entry;
+ for (entry = qlist_first(intervals); entry; entry = qlist_next(entry)) {
+ switch (qobject_type(entry->value)) {
+
+ case QTYPE_QSTRING: {
+ unsigned long long length;
+ const char *str = qstring_get_str(qobject_to_qstring(entry->value));
+ if (parse_uint_full(str, &length, 10) == 0 &&
+ length > 0 && length <= UINT_MAX) {
+ block_acct_add_interval(stats, (unsigned) length);
+ } else {
+ error_setg(errp, "Invalid interval length: %s", str);
+ return false;
+ }
+ break;
+ }
+
+ case QTYPE_QINT: {
+ int64_t length = qint_get_int(qobject_to_qint(entry->value));
+ if (length > 0 && length <= UINT_MAX) {
+ block_acct_add_interval(stats, (unsigned) length);
+ } else {
+ error_setg(errp, "Invalid interval length: %" PRId64, length);
+ return false;
+ }
+ break;
+ }
+
+ default:
+ error_setg(errp, "The specification of stats-intervals is invalid");
+ return false;
+ }
+ }
+ return true;
+}
+
static bool check_throttle_config(ThrottleConfig *cfg, Error **errp)
{
if (throttle_conflicting(cfg)) {
@@ -442,13 +481,14 @@ static BlockBackend *blockdev_init(const char *file, QDict *bs_opts,
int bdrv_flags = 0;
int on_read_error, on_write_error;
bool account_invalid, account_failed;
- const char *stats_intervals;
BlockBackend *blk;
BlockDriverState *bs;
ThrottleConfig cfg;
int snapshot = 0;
Error *error = NULL;
QemuOpts *opts;
+ QDict *interval_dict = NULL;
+ QList *interval_list = NULL;
const char *id;
bool has_driver_specific_opts;
BlockdevDetectZeroesOptions detect_zeroes =
@@ -482,7 +522,14 @@ static BlockBackend *blockdev_init(const char *file, QDict *bs_opts,
account_invalid = qemu_opt_get_bool(opts, "stats-account-invalid", true);
account_failed = qemu_opt_get_bool(opts, "stats-account-failed", true);
- stats_intervals = qemu_opt_get(opts, "stats-intervals");
+ qdict_extract_subqdict(bs_opts, &interval_dict, "stats-intervals.");
+ qdict_array_split(interval_dict, &interval_list);
+
+ if (qdict_size(interval_dict) != 0) {
+ error_setg(errp, "Invalid option stats-intervals.%s",
+ qdict_first(interval_dict)->key);
+ goto early_err;
+ }
extract_common_blockdev_options(opts, &bdrv_flags, &throttling_group, &cfg,
&detect_zeroes, &error);
@@ -583,33 +630,10 @@ static BlockBackend *blockdev_init(const char *file, QDict *bs_opts,
block_acct_init(blk_get_stats(blk), account_invalid, account_failed);
- if (stats_intervals) {
- char **intervals = g_strsplit(stats_intervals, ":", 0);
- unsigned i;
-
- if (*stats_intervals == '\0') {
- error_setg(&error, "stats-intervals can't have an empty value");
- }
-
- for (i = 0; !error && intervals[i] != NULL; i++) {
- unsigned long long val;
- if (parse_uint_full(intervals[i], &val, 10) == 0 &&
- val > 0 && val <= UINT_MAX) {
- block_acct_add_interval(blk_get_stats(blk), val);
- } else {
- error_setg(&error, "Invalid interval length: '%s'",
- intervals[i]);
- }
- }
-
- g_strfreev(intervals);
-
- if (error) {
- error_propagate(errp, error);
- blk_unref(blk);
- blk = NULL;
- goto err_no_bs_opts;
- }
+ if (!parse_stats_intervals(blk_get_stats(blk), interval_list, errp)) {
+ blk_unref(blk);
+ blk = NULL;
+ goto err_no_bs_opts;
}
}
@@ -617,10 +641,14 @@ static BlockBackend *blockdev_init(const char *file, QDict *bs_opts,
err_no_bs_opts:
qemu_opts_del(opts);
+ QDECREF(interval_dict);
+ QDECREF(interval_list);
return blk;
early_err:
qemu_opts_del(opts);
+ QDECREF(interval_dict);
+ QDECREF(interval_list);
err_no_opts:
QDECREF(bs_opts);
return NULL;
@@ -3948,11 +3976,6 @@ QemuOptsList qemu_common_drive_opts = {
.type = QEMU_OPT_BOOL,
.help = "whether to account for failed I/O operations "
"in the statistics",
- },{
- .name = "stats-intervals",
- .type = QEMU_OPT_STRING,
- .help = "colon-separated list of intervals "
- "for collecting I/O statistics, in seconds",
},
{ /* end of list */ }
},
diff --git a/qapi/block-core.json b/qapi/block-core.json
index f97c250..a07b13f 100644
--- a/qapi/block-core.json
+++ b/qapi/block-core.json
@@ -1531,9 +1531,8 @@
# @stats-account-failed: #optional whether to include failed
# operations when computing latency and last
# access statistics (default: true) (Since 2.5)
-# @stats-intervals: #optional colon-separated list of intervals for
-# collecting I/O statistics, in seconds (default: none)
-# (Since 2.5)
+# @stats-intervals: #optional list of intervals for collecting I/O
+# statistics, in seconds (default: none) (Since 2.5)
# @detect-zeroes: #optional detect and optimize zero writes (Since 2.1)
# (default: off)
#
@@ -1551,7 +1550,7 @@
'*read-only': 'bool',
'*stats-account-invalid': 'bool',
'*stats-account-failed': 'bool',
- '*stats-intervals': 'str',
+ '*stats-intervals': ['int'],
'*detect-zeroes': 'BlockdevDetectZeroesOptions' } }
##
diff --git a/tests/qemu-iotests/136 b/tests/qemu-iotests/136
index f574d83..e8c6937 100644
--- a/tests/qemu-iotests/136
+++ b/tests/qemu-iotests/136
@@ -69,7 +69,7 @@ sector = "%d"
def setUp(self):
drive_args = []
- drive_args.append("stats-intervals=%d" % interval_length)
+ drive_args.append("stats-intervals.0=%d" % interval_length)
drive_args.append("stats-account-invalid=%s" %
(self.account_invalid and "on" or "off"))
drive_args.append("stats-account-failed=%s" %
--
2.5.0
^ permalink raw reply related [flat|nested] 9+ messages in thread* [Qemu-devel] [PULL for-2.5 7/7] virtio-blk: Fix double completion for werror=stop
2015-11-17 11:17 [Qemu-devel] [PULL for-2.5 0/7] Block patches Stefan Hajnoczi
` (5 preceding siblings ...)
2015-11-17 11:17 ` [Qemu-devel] [PULL for-2.5 6/7] block: make 'stats-interval' an array of ints instead of a string Stefan Hajnoczi
@ 2015-11-17 11:17 ` Stefan Hajnoczi
2015-11-17 12:33 ` [Qemu-devel] [PULL for-2.5 0/7] Block patches Peter Maydell
7 siblings, 0 replies; 9+ messages in thread
From: Stefan Hajnoczi @ 2015-11-17 11:17 UTC (permalink / raw)
To: qemu-devel; +Cc: Peter Maydell, Fam Zheng, Stefan Hajnoczi
From: Fam Zheng <famz@redhat.com>
When a request R is absorbed by request M, it is appended to the
"mr_next" queue led by M, and is completed together with the completion
of M, in virtio_blk_rw_complete.
During DMA restart in virtio_blk_dma_restart_bh, requests in s->rq are
parsed and submitted again, possibly with a stale req->mr_next. It could
be a problem if the request merging in virtio_blk_handle_request hasn't
refreshed every mr_next pointer, in which case, virtio_blk_rw_complete
could walk through unexpected requests following the stale pointers.
Fix this by unsetting the pointer in virtio_blk_rw_complete. It is safe
because this req is either completed and freed right away, or it will be
restarted and parsed from scratch out of the vq later.
Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
hw/block/virtio-blk.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/hw/block/virtio-blk.c b/hw/block/virtio-blk.c
index e70fccf..848f3fe 100644
--- a/hw/block/virtio-blk.c
+++ b/hw/block/virtio-blk.c
@@ -112,6 +112,10 @@ static void virtio_blk_rw_complete(void *opaque, int ret)
* happen on the other side of the migration).
*/
if (virtio_blk_handle_rw_error(req, -ret, is_read)) {
+ /* Break the link in case the next request is added to the
+ * restart queue and is going to be parsed from the ring again.
+ */
+ req->mr_next = NULL;
continue;
}
}
--
2.5.0
^ permalink raw reply related [flat|nested] 9+ messages in thread* Re: [Qemu-devel] [PULL for-2.5 0/7] Block patches
2015-11-17 11:17 [Qemu-devel] [PULL for-2.5 0/7] Block patches Stefan Hajnoczi
` (6 preceding siblings ...)
2015-11-17 11:17 ` [Qemu-devel] [PULL for-2.5 7/7] virtio-blk: Fix double completion for werror=stop Stefan Hajnoczi
@ 2015-11-17 12:33 ` Peter Maydell
7 siblings, 0 replies; 9+ messages in thread
From: Peter Maydell @ 2015-11-17 12:33 UTC (permalink / raw)
To: Stefan Hajnoczi; +Cc: QEMU Developers
On 17 November 2015 at 11:17, Stefan Hajnoczi <stefanha@redhat.com> wrote:
> Bug fixes plus clang warning fixes that have no tree.
>
> The following changes since commit c257779e2a586043a1480bb7e96fb6bcd0129634:
>
> Merge remote-tracking branch 'remotes/otubo/tags/pull-seccomp-20151116' into staging (2015-11-16 12:09:47 +0000)
>
> are available in the git repository at:
>
> git://github.com/stefanha/qemu.git tags/block-pull-request
>
> for you to fetch changes up to 10f5a72f70862d299ddbdf226d6dc71fa4ae34dd:
>
> virtio-blk: Fix double completion for werror=stop (2015-11-17 18:35:57 +0800)
>
> ----------------------------------------------------------------
>
Applied, thanks.
-- PMM
^ permalink raw reply [flat|nested] 9+ messages in thread