From da4ee4c0d56200042cb86f8ccd2777009bd82df3 Mon Sep 17 00:00:00 2001

From: Sergio Lopez Pascual <slp@redhat.com>

Date: Fri, 7 Feb 2020 11:27:44 +0000

Subject: [PATCH 11/18] blockdev: honor bdrv_try_set_aio_context() context

 requirements

RH-Author: Sergio Lopez Pascual <slp@redhat.com>

Message-id: <20200207112749.25073-5-slp@redhat.com>

Patchwork-id: 93758

O-Subject: [RHEL-AV-8.2.0 qemu-kvm PATCH v2 4/9] blockdev: honor bdrv_try_set_aio_context() context requirements

Bugzilla: 1745606 1746217 1773517 1779036 1782111 1782175 1783965

RH-Acked-by: Stefano Garzarella <sgarzare@redhat.com>

RH-Acked-by: Paolo Bonzini <pbonzini@redhat.com>

RH-Acked-by: Max Reitz <mreitz@redhat.com>

RH-Acked-by: Stefan Hajnoczi <stefanha@redhat.com>

bdrv_try_set_aio_context() requires that the old context is held, and

the new context is not held. Fix all the occurrences where it's not

done this way.

Suggested-by: Max Reitz <mreitz@redhat.com>

Signed-off-by: Sergio Lopez <slp@redhat.com>

Signed-off-by: Kevin Wolf <kwolf@redhat.com>

(cherry picked from commit 3ea67e08832775a28d0bd2795f01bc77e7ea1512)

Signed-off-by: Sergio Lopez <slp@redhat.com>

Signed-off-by: Danilo C. L. de Paula <ddepaula@redhat.com>

---

 blockdev.c | 68 ++++++++++++++++++++++++++++++++++++++++++++++++++++++--------

 1 file changed, 60 insertions(+), 8 deletions(-)

diff --git a/blockdev.c b/blockdev.c

index 152a0f7..1dacbc2 100644

--- a/blockdev.c

+++ b/blockdev.c

@@ -1535,6 +1535,7 @@ static void external_snapshot_prepare(BlkActionState *common,

                              DO_UPCAST(ExternalSnapshotState, common, common);

     TransactionAction *action = common->action;

     AioContext *aio_context;

+    AioContext *old_context;

     int ret;

     /* 'blockdev-snapshot' and 'blockdev-snapshot-sync' have similar

@@ -1675,7 +1676,16 @@ static void external_snapshot_prepare(BlkActionState *common,

         goto out;

     }

+    /* Honor bdrv_try_set_aio_context() context acquisition requirements. */

+    old_context = bdrv_get_aio_context(state->new_bs);

+    aio_context_release(aio_context);

+    aio_context_acquire(old_context);

+

     ret = bdrv_try_set_aio_context(state->new_bs, aio_context, errp);

+

+    aio_context_release(old_context);

+    aio_context_acquire(aio_context);

+

     if (ret < 0) {

         goto out;

     }

@@ -1775,11 +1785,13 @@ static void drive_backup_prepare(BlkActionState *common, Error **errp)

     BlockDriverState *target_bs;

     BlockDriverState *source = NULL;

     AioContext *aio_context;

+    AioContext *old_context;

     QDict *options;

     Error *local_err = NULL;

     int flags;

     int64_t size;

     bool set_backing_hd = false;

+    int ret;

     assert(common->action->type == TRANSACTION_ACTION_KIND_DRIVE_BACKUP);

     backup = common->action->u.drive_backup.data;

@@ -1868,6 +1880,21 @@ static void drive_backup_prepare(BlkActionState *common, Error **errp)

         goto out;

     }

+    /* Honor bdrv_try_set_aio_context() context acquisition requirements. */

+    old_context = bdrv_get_aio_context(target_bs);

+    aio_context_release(aio_context);

+    aio_context_acquire(old_context);

+

+    ret = bdrv_try_set_aio_context(target_bs, aio_context, errp);

+    if (ret < 0) {

+        bdrv_unref(target_bs);

+        aio_context_release(old_context);

+        return;

+    }

+

+    aio_context_release(old_context);

+    aio_context_acquire(aio_context);

+

     if (set_backing_hd) {

         bdrv_set_backing_hd(target_bs, source, &local_err);

         if (local_err) {

@@ -1947,6 +1974,8 @@ static void blockdev_backup_prepare(BlkActionState *common, Error **errp)

     BlockDriverState *bs;

     BlockDriverState *target_bs;

     AioContext *aio_context;

+    AioContext *old_context;

+    int ret;

     assert(common->action->type == TRANSACTION_ACTION_KIND_BLOCKDEV_BACKUP);

     backup = common->action->u.blockdev_backup.data;

@@ -1961,7 +1990,18 @@ static void blockdev_backup_prepare(BlkActionState *common, Error **errp)

         return;

     }

+    /* Honor bdrv_try_set_aio_context() context acquisition requirements. */

     aio_context = bdrv_get_aio_context(bs);

+    old_context = bdrv_get_aio_context(target_bs);

+    aio_context_acquire(old_context);

+

+    ret = bdrv_try_set_aio_context(target_bs, aio_context, errp);

+    if (ret < 0) {

+        aio_context_release(old_context);

+        return;

+    }

+

+    aio_context_release(old_context);

     aio_context_acquire(aio_context);

     state->bs = bs;

@@ -3562,7 +3602,6 @@ static BlockJob *do_backup_common(BackupCommon *backup,

     BlockJob *job = NULL;

     BdrvDirtyBitmap *bmap = NULL;

     int job_flags = JOB_DEFAULT;

-    int ret;

     if (!backup->has_speed) {

         backup->speed = 0;

@@ -3586,11 +3625,6 @@ static BlockJob *do_backup_common(BackupCommon *backup,

         backup->compress = false;

     }

-    ret = bdrv_try_set_aio_context(target_bs, aio_context, errp);

-    if (ret < 0) {

-        return NULL;

-    }

-

     if ((backup->sync == MIRROR_SYNC_MODE_BITMAP) ||

         (backup->sync == MIRROR_SYNC_MODE_INCREMENTAL)) {

         /* done before desugaring 'incremental' to print the right message */

@@ -3825,6 +3859,7 @@ void qmp_drive_mirror(DriveMirror *arg, Error **errp)

     BlockDriverState *bs;

     BlockDriverState *source, *target_bs;

     AioContext *aio_context;

+    AioContext *old_context;

     BlockMirrorBackingMode backing_mode;

     Error *local_err = NULL;

     QDict *options = NULL;

@@ -3937,12 +3972,22 @@ void qmp_drive_mirror(DriveMirror *arg, Error **errp)

                    (arg->mode == NEW_IMAGE_MODE_EXISTING ||

                     !bdrv_has_zero_init(target_bs)));

+

+    /* Honor bdrv_try_set_aio_context() context acquisition requirements. */

+    old_context = bdrv_get_aio_context(target_bs);

+    aio_context_release(aio_context);

+    aio_context_acquire(old_context);

+

     ret = bdrv_try_set_aio_context(target_bs, aio_context, errp);

     if (ret < 0) {

         bdrv_unref(target_bs);

-        goto out;

+        aio_context_release(old_context);

+        return;

     }

+    aio_context_release(old_context);

+    aio_context_acquire(aio_context);

+

     blockdev_mirror_common(arg->has_job_id ? arg->job_id : NULL, bs, target_bs,

                            arg->has_replaces, arg->replaces, arg->sync,

                            backing_mode, zero_target,

@@ -3984,6 +4029,7 @@ void qmp_blockdev_mirror(bool has_job_id, const char *job_id,

     BlockDriverState *bs;

     BlockDriverState *target_bs;

     AioContext *aio_context;

+    AioContext *old_context;

     BlockMirrorBackingMode backing_mode = MIRROR_LEAVE_BACKING_CHAIN;

     Error *local_err = NULL;

     bool zero_target;

@@ -4001,10 +4047,16 @@ void qmp_blockdev_mirror(bool has_job_id, const char *job_id,

     zero_target = (sync == MIRROR_SYNC_MODE_FULL);

+    /* Honor bdrv_try_set_aio_context() context acquisition requirements. */

+    old_context = bdrv_get_aio_context(target_bs);

     aio_context = bdrv_get_aio_context(bs);

-    aio_context_acquire(aio_context);

+    aio_context_acquire(old_context);

     ret = bdrv_try_set_aio_context(target_bs, aio_context, errp);

+

+    aio_context_release(old_context);

+    aio_context_acquire(aio_context);

+

     if (ret < 0) {

         goto out;

     }

-- 

1.8.3.1