Patch "btrfs: handle errors returned from unpin_extent_cache()" has been added to the 6.8-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    btrfs: handle errors returned from unpin_extent_cache()

to the 6.8-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     btrfs-handle-errors-returned-from-unpin_extent_cache.patch
and it can be found in the queue-6.8 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit d9312298af52d17a358abd45247fb29f0418a8c0
Author: David Sterba <dsterba@xxxxxxxx>
Date:   Fri Jan 12 18:31:40 2024 +0100

    btrfs: handle errors returned from unpin_extent_cache()
    
    [ Upstream commit c03c89f821e51325d0e592cf625cf5e0a26fa3a7 ]
    
    We've had numerous attempts to let function unpin_extent_cache() return
    void as it only returns 0. There are still error cases to handle so do
    that, in addition to the verbose messages. The only caller
    btrfs_finish_one_ordered() will now abort the transaction, previously it
    let it continue which could lead to further problems.
    
    Signed-off-by: David Sterba <dsterba@xxxxxxxx>
    Stable-dep-of: 4dc1d69c2b10 ("btrfs: fix warning messages not printing interval at unpin_extent_range()")
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/fs/btrfs/extent_map.c b/fs/btrfs/extent_map.c
index b61099bf97a82..f170e7122e747 100644
--- a/fs/btrfs/extent_map.c
+++ b/fs/btrfs/extent_map.c
@@ -291,6 +291,10 @@ static void try_merge_map(struct extent_map_tree *tree, struct extent_map *em)
  * Called after an extent has been written to disk properly.  Set the generation
  * to the generation that actually added the file item to the inode so we know
  * we need to sync this extent when we call fsync().
+ *
+ * Returns: 0	     on success
+ * 	    -ENOENT  when the extent is not found in the tree
+ * 	    -EUCLEAN if the found extent does not match the expected start
  */
 int unpin_extent_cache(struct btrfs_inode *inode, u64 start, u64 len, u64 gen)
 {
@@ -308,14 +312,18 @@ int unpin_extent_cache(struct btrfs_inode *inode, u64 start, u64 len, u64 gen)
 "no extent map found for inode %llu (root %lld) when unpinning extent range [%llu, %llu), generation %llu",
 			   btrfs_ino(inode), btrfs_root_id(inode->root),
 			   start, len, gen);
+		ret = -ENOENT;
 		goto out;
 	}
 
-	if (WARN_ON(em->start != start))
+	if (WARN_ON(em->start != start)) {
 		btrfs_warn(fs_info,
 "found extent map for inode %llu (root %lld) with unexpected start offset %llu when unpinning extent range [%llu, %llu), generation %llu",
 			   btrfs_ino(inode), btrfs_root_id(inode->root),
 			   em->start, start, len, gen);
+		ret = -EUCLEAN;
+		goto out;
+	}
 
 	em->generation = gen;
 	em->flags &= ~EXTENT_FLAG_PINNED;
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 8151ad5f4650b..5ceb995709b56 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -3127,8 +3127,13 @@ int btrfs_finish_one_ordered(struct btrfs_ordered_extent *ordered_extent)
 						ordered_extent->disk_num_bytes);
 		}
 	}
-	unpin_extent_cache(inode, ordered_extent->file_offset,
-			   ordered_extent->num_bytes, trans->transid);
+	if (ret < 0) {
+		btrfs_abort_transaction(trans, ret);
+		goto out;
+	}
+
+	ret = unpin_extent_cache(inode, ordered_extent->file_offset,
+				 ordered_extent->num_bytes, trans->transid);
 	if (ret < 0) {
 		btrfs_abort_transaction(trans, ret);
 		goto out;