4 files changed, 41 insertions, 46 deletions

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index fa45e3cae40..1ad0f47ac85 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -1702,7 +1702,7 @@ static int btrfs_congested_fn(void *congested_data, int bdi_bits)
 		if (!device->bdev)
 			continue;
 		bdi = blk_get_backing_dev_info(device->bdev);
-		if (bdi && bdi_congested(bdi, bdi_bits)) {
+		if (bdi_congested(bdi, bdi_bits)) {
 			ret = 1;
 			break;
 		}
diff --git a/fs/btrfs/hash.c b/fs/btrfs/hash.c
index 64f15bb30a8..aae520b2aee 100644
--- a/fs/btrfs/hash.c
+++ b/fs/btrfs/hash.c
@@ -31,18 +31,16 @@ void btrfs_hash_exit(void)
 
 u32 btrfs_crc32c(u32 crc, const void *address, unsigned int length)
 {
-	struct {
-		struct shash_desc shash;
-		char ctx[crypto_shash_descsize(tfm)];
-	} desc;
+	SHASH_DESC_ON_STACK(shash, tfm);
+	u32 *ctx = (u32 *)shash_desc_ctx(shash);
 	int err;
 
-	desc.shash.tfm = tfm;
-	desc.shash.flags = 0;
-	*(u32 *)desc.ctx = crc;
+	shash->tfm = tfm;
+	shash->flags = 0;
+	*ctx = crc;
 
-	err = crypto_shash_update(&desc.shash, address, length);
+	err = crypto_shash_update(shash, address, length);
 	BUG_ON(err);
 
-	return *(u32 *)desc.ctx;
+	return *ctx;
 }
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index fc9c0439caa..d23362f4464 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -5261,42 +5261,6 @@ struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry)
 			iput(inode);
 			inode = ERR_PTR(ret);
 		}
-		/*
-		 * If orphan cleanup did remove any orphans, it means the tree
-		 * was modified and therefore the commit root is not the same as
-		 * the current root anymore. This is a problem, because send
-		 * uses the commit root and therefore can see inode items that
-		 * don't exist in the current root anymore, and for example make
-		 * calls to btrfs_iget, which will do tree lookups based on the
-		 * current root and not on the commit root. Those lookups will
-		 * fail, returning a -ESTALE error, and making send fail with
-		 * that error. So make sure a send does not see any orphans we
-		 * have just removed, and that it will see the same inodes
-		 * regardless of whether a transaction commit happened before
-		 * it started (meaning that the commit root will be the same as
-		 * the current root) or not.
-		 */
-		if (sub_root->node != sub_root->commit_root) {
-			u64 sub_flags = btrfs_root_flags(&sub_root->root_item);
-
-			if (sub_flags & BTRFS_ROOT_SUBVOL_RDONLY) {
-				struct extent_buffer *eb;
-
-				/*
-				 * Assert we can't have races between dentry
-				 * lookup called through the snapshot creation
-				 * ioctl and the VFS.
-				 */
-				ASSERT(mutex_is_locked(&dir->i_mutex));
-
-				down_write(&root->fs_info->commit_root_sem);
-				eb = sub_root->commit_root;
-				sub_root->commit_root =
-					btrfs_root_node(sub_root);
-				up_write(&root->fs_info->commit_root_sem);
-				free_extent_buffer(eb);
-			}
-		}
 	}
 
 	return inode;
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 0fe1aa047f1..8d2b76e29d3 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -713,6 +713,39 @@ static int create_snapshot(struct btrfs_root *root, struct inode *dir,
 	if (ret)
 		goto fail;
 
+	ret = btrfs_orphan_cleanup(pending_snapshot->snap);
+	if (ret)
+		goto fail;
+
+	/*
+	 * If orphan cleanup did remove any orphans, it means the tree was
+	 * modified and therefore the commit root is not the same as the
+	 * current root anymore. This is a problem, because send uses the
+	 * commit root and therefore can see inode items that don't exist
+	 * in the current root anymore, and for example make calls to
+	 * btrfs_iget, which will do tree lookups based on the current root
+	 * and not on the commit root. Those lookups will fail, returning a
+	 * -ESTALE error, and making send fail with that error. So make sure
+	 * a send does not see any orphans we have just removed, and that it
+	 * will see the same inodes regardless of whether a transaction
+	 * commit happened before it started (meaning that the commit root
+	 * will be the same as the current root) or not.
+	 */
+	if (readonly && pending_snapshot->snap->node !=
+	    pending_snapshot->snap->commit_root) {
+		trans = btrfs_join_transaction(pending_snapshot->snap);
+		if (IS_ERR(trans) && PTR_ERR(trans) != -ENOENT) {
+			ret = PTR_ERR(trans);
+			goto fail;
+		}
+		if (!IS_ERR(trans)) {
+			ret = btrfs_commit_transaction(trans,
+						       pending_snapshot->snap);
+			if (ret)
+				goto fail;
+		}
+	}
+
 	inode = btrfs_lookup_dentry(dentry->d_parent->d_inode, dentry);
 	if (IS_ERR(inode)) {
 		ret = PTR_ERR(inode);