[PATCH 6.4 611/800] gfs2: Fix duplicate should_fault_in_pages() call

Greg Kroah-Hartman
2023-07-16T20:21:27Z

From: Bob Peterson <rpeterso@redhat.com>

[ Upstream commit c8ed1b35931245087968fd95b2ec3dfc50f77769 ]

In gfs2_file_buffered_write(), we currently jump from the second call of
function should_fault_in_pages() to above the first call, so
should_fault_in_pages() is getting called twice in a row, causing it to
accidentally fall back to single-page writes rather than trying the more
efficient multi-page writes first.

Fix that by moving the retry label to the correct place, behind the
first call to should_fault_in_pages().

Fixes: e1fa9ea85ce8 ("gfs2: Stop using glock holder auto-demotion for now")
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/gfs2/file.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/gfs2/file.c b/fs/gfs2/file.c
index cb62c8f07d1e7..21335d1b67bf2 100644
--- a/fs/gfs2/file.c
+++ b/fs/gfs2/file.c
@@ -1030,8 +1030,8 @@ static ssize_t gfs2_file_buffered_write(struct kiocb *iocb,
}

gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, gh);
-retry:
if (should_fault_in_pages(from, iocb, &prev_count, &window_size)) {
+retry:
window_size -= fault_in_iov_iter_readable(from, window_size);
if (!window_size) {
ret = -EFAULT;
--
2.39.2