Patch "btrfs: finish ordered extent cleaning if no progress is found" has been added to the 4.13-stable tree

[<gregkh@linuxfoundation.org>]

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

    btrfs: finish ordered extent cleaning if no progress is found

to the 4.13-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-finish-ordered-extent-cleaning-if-no-progress-is-found.patch
and it can be found in the queue-4.13 subdirectory.

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


>From 67c003f90fd68062d92a7ffade36f9b2a9098bd8 Mon Sep 17 00:00:00 2001
From: Naohiro Aota <naohiro.aota@wdc.com>
Date: Fri, 1 Sep 2017 17:59:07 +0900
Subject: btrfs: finish ordered extent cleaning if no progress is found

From: Naohiro Aota <naohiro.aota@wdc.com>

commit 67c003f90fd68062d92a7ffade36f9b2a9098bd8 upstream.

__endio_write_update_ordered() repeats the search until it reaches the end
of the specified range. This works well with direct IO path, because before
the function is called, it's ensured that there are ordered extents filling
whole the range. It's not the case, however, when it's called from
run_delalloc_range(): it is possible to have error in the midle of the loop
in e.g. run_delalloc_nocow(), so that there exisits the range not covered
by any ordered extents. By cleaning such "uncomplete" range,
__endio_write_update_ordered() stucks at offset where there're no ordered
extents.

Since the ordered extents are created from head to tail, we can stop the
search if there are no offset progress.

Fixes: 524272607e88 ("btrfs: Handle delalloc error correctly to avoid ordered extent hang")
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Reviewed-by: Qu Wenruo <quwenruo.btrfs@gmx.com>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 fs/btrfs/inode.c |    8 ++++++++
 1 file changed, 8 insertions(+)

--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -8309,6 +8309,7 @@ static void __endio_write_update_ordered
 	btrfs_work_func_t func;
 	u64 ordered_offset = offset;
 	u64 ordered_bytes = bytes;
+	u64 last_offset;
 	int ret;
 
 	if (btrfs_is_free_space_inode(BTRFS_I(inode))) {
@@ -8320,6 +8321,7 @@ static void __endio_write_update_ordered
 	}
 
 again:
+	last_offset = ordered_offset;
 	ret = btrfs_dec_test_first_ordered_pending(inode, &ordered,
 						   &ordered_offset,
 						   ordered_bytes,
@@ -8331,6 +8333,12 @@ again:
 	btrfs_queue_work(wq, &ordered->work);
 out_test:
 	/*
+	 * If btrfs_dec_test_ordered_pending does not find any ordered extent
+	 * in the range, we can exit.
+	 */
+	if (ordered_offset == last_offset)
+		return;
+	/*
 	 * our bio might span multiple ordered extents.  If we haven't
 	 * completed the accounting for the whole dio, go back and try again
 	 */


Patches currently in stable-queue which might be from naohiro.aota@wdc.com are

queue-4.13/btrfs-propagate-error-to-btrfs_cmp_data_prepare-caller.patch
queue-4.13/btrfs-fix-null-pointer-dereference-from-free_reloc_roots.patch
queue-4.13/btrfs-clear-ordered-flag-on-cleaning-up-ordered-extents.patch
queue-4.13/btrfs-finish-ordered-extent-cleaning-if-no-progress-is-found.patch