[PATCH 1/3] btrfs: fix inode rwsem regression

Goldwyn Rodrigues
2019-09-11T16:45:29Z

From: Goldwyn Rodrigues <rgoldwyn@suse.com>

This is similar to 942491c9e6d6 ("xfs: fix AIM7 regression")
Apparently our current rwsem code doesn't like doing the trylock, then
lock for real scheme. So change our read/write methods to just do the
trylock for the RWF_NOWAIT case.

Fixes: edf064e7c6fe ("btrfs: nowait aio support")
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
---
fs/btrfs/file.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index 58a18ed11546..651b2b1f4219 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -1893,9 +1893,10 @@ static ssize_t btrfs_file_write_iter(struct kiocb *iocb,
(iocb->ki_flags & IOCB_NOWAIT))
return -EOPNOTSUPP;

- if (!inode_trylock(inode)) {
- if (iocb->ki_flags & IOCB_NOWAIT)
+ if (iocb->ki_flags & IOCB_NOWAIT) {
+ if (!inode_trylock(inode))
return -EAGAIN;
+ } else {
inode_lock(inode);
}

--
2.16.4