| Message ID | 20190510215212.8413-1-jsnow@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | blockdev: fix missed target unref for drive-backup | expand |
Am 10.05.2019 um 23:52 hat John Snow geschrieben: > If the bitmap can't be used for whatever reason, we skip putting down > the reference. Fix that. > > In practice, this means that if you attempt to gracefully exit QEMU > after a backup command being rejected, bdrv_close_all will fail and > tell you some unpleasant things via assert(). > > Reported-by: aihua liang <aliang@redhat.com> > Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1703916 > Signed-off-by: John Snow <jsnow@redhat.com> > --- > blockdev.c | 12 +++++------- > 1 file changed, 5 insertions(+), 7 deletions(-) > > diff --git a/blockdev.c b/blockdev.c > index 79fbac8450..278ecdd122 100644 > --- a/blockdev.c > +++ b/blockdev.c > @@ -3525,8 +3525,7 @@ static BlockJob *do_drive_backup(DriveBackup *backup, JobTxn *txn, > if (set_backing_hd) { > bdrv_set_backing_hd(target_bs, source, &local_err); > if (local_err) { > - bdrv_unref(target_bs); > - goto out; > + goto unref; > } > } > > @@ -3534,11 +3533,10 @@ static BlockJob *do_drive_backup(DriveBackup *backup, JobTxn *txn, > bmap = bdrv_find_dirty_bitmap(bs, backup->bitmap); > if (!bmap) { > error_setg(errp, "Bitmap '%s' could not be found", backup->bitmap); > - bdrv_unref(target_bs); > - goto out; > + goto unref; > } > if (bdrv_dirty_bitmap_check(bmap, BDRV_BITMAP_DEFAULT, errp)) { > - goto out; > + goto unref; > } > } > if (!backup->auto_finalize) { > @@ -3552,12 +3550,12 @@ static BlockJob *do_drive_backup(DriveBackup *backup, JobTxn *txn, > backup->sync, bmap, backup->compress, > backup->on_source_error, backup->on_target_error, > job_flags, NULL, NULL, txn, &local_err); > - bdrv_unref(target_bs); > if (local_err != NULL) { > error_propagate(errp, local_err); > - goto out; Please leave a 'goto unref' here so we can later add more code without modifying unrelated error paths (or, more likely, forgetting to modify them). > } > > +unref: > + bdrv_unref(target_bs); > out: > aio_context_release(aio_context); > return job; With this fixed: Reviewed-by: Kevin Wolf <kwolf@redhat.com>
On 5/13/19 7:13 AM, Kevin Wolf wrote: > Am 10.05.2019 um 23:52 hat John Snow geschrieben: >> If the bitmap can't be used for whatever reason, we skip putting down >> the reference. Fix that. >> >> In practice, this means that if you attempt to gracefully exit QEMU >> after a backup command being rejected, bdrv_close_all will fail and >> tell you some unpleasant things via assert(). >> >> Reported-by: aihua liang <aliang@redhat.com> >> Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1703916 >> Signed-off-by: John Snow <jsnow@redhat.com> >> --- >> blockdev.c | 12 +++++------- >> 1 file changed, 5 insertions(+), 7 deletions(-) >> >> diff --git a/blockdev.c b/blockdev.c >> index 79fbac8450..278ecdd122 100644 >> --- a/blockdev.c >> +++ b/blockdev.c >> @@ -3525,8 +3525,7 @@ static BlockJob *do_drive_backup(DriveBackup *backup, JobTxn *txn, >> if (set_backing_hd) { >> bdrv_set_backing_hd(target_bs, source, &local_err); >> if (local_err) { >> - bdrv_unref(target_bs); >> - goto out; >> + goto unref; >> } >> } >> >> @@ -3534,11 +3533,10 @@ static BlockJob *do_drive_backup(DriveBackup *backup, JobTxn *txn, >> bmap = bdrv_find_dirty_bitmap(bs, backup->bitmap); >> if (!bmap) { >> error_setg(errp, "Bitmap '%s' could not be found", backup->bitmap); >> - bdrv_unref(target_bs); >> - goto out; >> + goto unref; >> } >> if (bdrv_dirty_bitmap_check(bmap, BDRV_BITMAP_DEFAULT, errp)) { >> - goto out; >> + goto unref; >> } >> } >> if (!backup->auto_finalize) { >> @@ -3552,12 +3550,12 @@ static BlockJob *do_drive_backup(DriveBackup *backup, JobTxn *txn, >> backup->sync, bmap, backup->compress, >> backup->on_source_error, backup->on_target_error, >> job_flags, NULL, NULL, txn, &local_err); >> - bdrv_unref(target_bs); >> if (local_err != NULL) { >> error_propagate(errp, local_err); >> - goto out; > > Please leave a 'goto unref' here so we can later add more code without > modifying unrelated error paths (or, more likely, forgetting to modify > them). > Oh, that makes sense. >> } >> >> +unref: >> + bdrv_unref(target_bs); >> out: >> aio_context_release(aio_context); >> return job; > > With this fixed: > Reviewed-by: Kevin Wolf <kwolf@redhat.com> > Thanks!
diff --git a/blockdev.c b/blockdev.c index 79fbac8450..278ecdd122 100644 --- a/blockdev.c +++ b/blockdev.c @@ -3525,8 +3525,7 @@ static BlockJob *do_drive_backup(DriveBackup *backup, JobTxn *txn, if (set_backing_hd) { bdrv_set_backing_hd(target_bs, source, &local_err); if (local_err) { - bdrv_unref(target_bs); - goto out; + goto unref; } } @@ -3534,11 +3533,10 @@ static BlockJob *do_drive_backup(DriveBackup *backup, JobTxn *txn, bmap = bdrv_find_dirty_bitmap(bs, backup->bitmap); if (!bmap) { error_setg(errp, "Bitmap '%s' could not be found", backup->bitmap); - bdrv_unref(target_bs); - goto out; + goto unref; } if (bdrv_dirty_bitmap_check(bmap, BDRV_BITMAP_DEFAULT, errp)) { - goto out; + goto unref; } } if (!backup->auto_finalize) { @@ -3552,12 +3550,12 @@ static BlockJob *do_drive_backup(DriveBackup *backup, JobTxn *txn, backup->sync, bmap, backup->compress, backup->on_source_error, backup->on_target_error, job_flags, NULL, NULL, txn, &local_err); - bdrv_unref(target_bs); if (local_err != NULL) { error_propagate(errp, local_err); - goto out; } +unref: + bdrv_unref(target_bs); out: aio_context_release(aio_context); return job;
If the bitmap can't be used for whatever reason, we skip putting down the reference. Fix that. In practice, this means that if you attempt to gracefully exit QEMU after a backup command being rejected, bdrv_close_all will fail and tell you some unpleasant things via assert(). Reported-by: aihua liang <aliang@redhat.com> Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1703916 Signed-off-by: John Snow <jsnow@redhat.com> --- blockdev.c | 12 +++++------- 1 file changed, 5 insertions(+), 7 deletions(-)