Merge remote-tracking branch 'remotes/kevin/tags/for-upstream' into staging

Block layer fixes for 2.9.0-rc1

# gpg: Signature made Fri 17 Mar 2017 12:06:04 GMT
# gpg:                using RSA key 0x7F09B272C88F2FD6
# gpg: Good signature from "Kevin Wolf <kwolf@redhat.com>"
# Primary key fingerprint: DC3D EB15 9A9A F95D 3D74  56FE 7F09 B272 C88F 2FD6

* remotes/kevin/tags/for-upstream:
  block: quiesce AioContext when detaching from it
  thread-pool: add missing qemu_bh_cancel in completion function
  block: Propagate error in bdrv_open_backing_file
  blockdev: fix bitmap clear undo
  block: Always call bdrv_child_check_perm first
  file-posix: Don't leak fd in hdev_get_max_segments
  replication: clarify permissions
  file-posix: clean up max_segments buffer termination

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

7 files changed, 48 insertions, 13 deletions

diff --git a/block.c b/block.c
index cb5737073f..6e906ec53c 100644
--- a/block.c
+++ b/block.c
@@ -1393,6 +1393,11 @@ static int bdrv_fill_options(QDict **options, const char *filename,
     return 0;
 }
 
+static int bdrv_child_check_perm(BdrvChild *c, uint64_t perm, uint64_t shared,
+                                 GSList *ignore_children, Error **errp);
+static void bdrv_child_abort_perm_update(BdrvChild *c);
+static void bdrv_child_set_perm(BdrvChild *c, uint64_t perm, uint64_t shared);
+
 /*
  * Check whether permissions on this node can be changed in a way that
  * @cumulative_perms and @cumulative_shared_perms are the new cumulative
@@ -1615,8 +1620,8 @@ static int bdrv_check_update_perm(BlockDriverState *bs, uint64_t new_used_perm,
 
 /* Needs to be followed by a call to either bdrv_child_set_perm() or
  * bdrv_child_abort_perm_update(). */
-int bdrv_child_check_perm(BdrvChild *c, uint64_t perm, uint64_t shared,
-                          GSList *ignore_children, Error **errp)
+static int bdrv_child_check_perm(BdrvChild *c, uint64_t perm, uint64_t shared,
+                                 GSList *ignore_children, Error **errp)
 {
     int ret;
 
@@ -1627,7 +1632,7 @@ int bdrv_child_check_perm(BdrvChild *c, uint64_t perm, uint64_t shared,
     return ret;
 }
 
-void bdrv_child_set_perm(BdrvChild *c, uint64_t perm, uint64_t shared)
+static void bdrv_child_set_perm(BdrvChild *c, uint64_t perm, uint64_t shared)
 {
     uint64_t cumulative_perms, cumulative_shared_perms;
 
@@ -1639,7 +1644,7 @@ void bdrv_child_set_perm(BdrvChild *c, uint64_t perm, uint64_t shared)
     bdrv_set_perm(c->bs, cumulative_perms, cumulative_shared_perms);
 }
 
-void bdrv_child_abort_perm_update(BdrvChild *c)
+static void bdrv_child_abort_perm_update(BdrvChild *c)
 {
     bdrv_abort_perm_update(c->bs);
 }
@@ -2025,6 +2030,7 @@ int bdrv_open_backing_file(BlockDriverState *bs, QDict *parent_options,
     bdrv_set_backing_hd(bs, backing_hd, &local_err);
     bdrv_unref(backing_hd);
     if (local_err) {
+        error_propagate(errp, local_err);
         ret = -EINVAL;
         goto free_exit;
     }
@@ -4344,8 +4350,15 @@ void bdrv_attach_aio_context(BlockDriverState *bs,
 
 void bdrv_set_aio_context(BlockDriverState *bs, AioContext *new_context)
 {
+    AioContext *ctx;
+
     bdrv_drain(bs); /* ensure there are no in-flight requests */
 
+    ctx = bdrv_get_aio_context(bs);
+    while (aio_poll(ctx, false)) {
+        /* wait for all bottom halves to execute */
+    }
+
     bdrv_detach_aio_context(bs);
 
     /* This function executes in the old AioContext so acquire the new one in
diff --git a/block/file-posix.c b/block/file-posix.c
index c4c06637ef..53febd3767 100644
--- a/block/file-posix.c
+++ b/block/file-posix.c
@@ -686,7 +686,7 @@ static int hdev_get_max_segments(const struct stat *st)
         goto out;
     }
     do {
-        ret = read(fd, buf, sizeof(buf));
+        ret = read(fd, buf, sizeof(buf) - 1);
     } while (ret == -1 && errno == EINTR);
     if (ret < 0) {
         ret = -errno;
@@ -703,6 +703,9 @@ static int hdev_get_max_segments(const struct stat *st)
     }
 
 out:
+    if (fd != -1) {
+        close(fd);
+    }
     g_free(sysfspath);
     return ret;
 #else
diff --git a/block/mirror.c b/block/mirror.c
index 4f3a5cb310..ca4baa510a 100644
--- a/block/mirror.c
+++ b/block/mirror.c
@@ -574,7 +574,8 @@ static void mirror_exit(BlockJob *job, void *opaque)
      * valid. Also give up permissions on mirror_top_bs->backing, which might
      * block the removal. */
     block_job_remove_all_bdrv(job);
-    bdrv_child_set_perm(mirror_top_bs->backing, 0, BLK_PERM_ALL);
+    bdrv_child_try_set_perm(mirror_top_bs->backing, 0, BLK_PERM_ALL,
+                            &error_abort);
     bdrv_replace_node(mirror_top_bs, backing_bs(mirror_top_bs), &error_abort);
 
     /* We just changed the BDS the job BB refers to (with either or both of the
@@ -1245,7 +1246,8 @@ fail:
         block_job_unref(&s->common);
     }
 
-    bdrv_child_set_perm(mirror_top_bs->backing, 0, BLK_PERM_ALL);
+    bdrv_child_try_set_perm(mirror_top_bs->backing, 0, BLK_PERM_ALL,
+                            &error_abort);
     bdrv_replace_node(mirror_top_bs, backing_bs(mirror_top_bs), &error_abort);
 }
 
diff --git a/block/replication.c b/block/replication.c
index 22f170fd33..bf3c395eb4 100644
--- a/block/replication.c
+++ b/block/replication.c
@@ -155,6 +155,18 @@ static void replication_close(BlockDriverState *bs)
     replication_remove(s->rs);
 }
 
+static void replication_child_perm(BlockDriverState *bs, BdrvChild *c,
+                                   const BdrvChildRole *role,
+                                   uint64_t perm, uint64_t shared,
+                                   uint64_t *nperm, uint64_t *nshared)
+{
+    *nperm = *nshared = BLK_PERM_CONSISTENT_READ \
+                        | BLK_PERM_WRITE \
+                        | BLK_PERM_WRITE_UNCHANGED;
+
+    return;
+}
+
 static int64_t replication_getlength(BlockDriverState *bs)
 {
     return bdrv_getlength(bs->file->bs);
@@ -660,7 +672,7 @@ BlockDriver bdrv_replication = {
 
     .bdrv_open                  = replication_open,
     .bdrv_close                 = replication_close,
-    .bdrv_child_perm            = bdrv_filter_default_perms,
+    .bdrv_child_perm            = replication_child_perm,
 
     .bdrv_getlength             = replication_getlength,
     .bdrv_co_readv              = replication_co_readv,
diff --git a/blockdev.c b/blockdev.c
index f1f49bd3ca..c5b2c2c209 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -2047,7 +2047,9 @@ static void block_dirty_bitmap_clear_abort(BlkActionState *common)
     BlockDirtyBitmapState *state = DO_UPCAST(BlockDirtyBitmapState,
                                              common, common);
 
-    bdrv_undo_clear_dirty_bitmap(state->bitmap, state->backup);
+    if (state->backup) {
+        bdrv_undo_clear_dirty_bitmap(state->bitmap, state->backup);
+    }
 }
 
 static void block_dirty_bitmap_clear_commit(BlkActionState *common)
diff --git a/include/block/block_int.h b/include/block/block_int.h
index 6c699ac9c3..59400bd848 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -889,10 +889,6 @@ BdrvChild *bdrv_root_attach_child(BlockDriverState *child_bs,
                                   void *opaque, Error **errp);
 void bdrv_root_unref_child(BdrvChild *child);
 
-int bdrv_child_check_perm(BdrvChild *c, uint64_t perm, uint64_t shared,
-                          GSList *ignore_children, Error **errp);
-void bdrv_child_set_perm(BdrvChild *c, uint64_t perm, uint64_t shared);
-void bdrv_child_abort_perm_update(BdrvChild *c);
 int bdrv_child_try_set_perm(BdrvChild *c, uint64_t perm, uint64_t shared,
                             Error **errp);
 
diff --git a/util/thread-pool.c b/util/thread-pool.c
index ce6cd30193..610646d131 100644
--- a/util/thread-pool.c
+++ b/util/thread-pool.c
@@ -188,6 +188,13 @@ restart:
             aio_context_release(pool->ctx);
             elem->common.cb(elem->common.opaque, elem->ret);
             aio_context_acquire(pool->ctx);
+
+            /* We can safely cancel the completion_bh here regardless of someone
+             * else having scheduled it meanwhile because we reenter the
+             * completion function anyway (goto restart).
+             */
+            qemu_bh_cancel(pool->completion_bh);
+
             qemu_aio_unref(elem);
             goto restart;
         } else {