diff options
| author | Jan Kara <jack@suse.cz> | 2020-04-01 21:04:40 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-04-02 09:35:26 -0700 |
| commit | 5c72feee3e45b40a3c96c7145ec422899d0e8964 (patch) | |
| tree | 91843a458e7055013b79897a9de59f6bab44e02e /mm/page-writeback.c | |
| parent | 5f2d5026be67691af26327ab722db4dacaacf399 (diff) | |
mm/filemap.c: don't bother dropping mmap_sem for zero size readahead
When handling a page fault, we drop mmap_sem to start async readahead so
that we don't block on IO submission with mmap_sem held. However there's
no point to drop mmap_sem in case readahead is disabled. Handle that case
to avoid pointless dropping of mmap_sem and retrying the fault. This was
actually reported to block mlockall(MCL_CURRENT) indefinitely.
Fixes: 6b4c9f446981 ("filemap: drop the mmap_sem for all blocking operations")
Reported-by: Minchan Kim <minchan@kernel.org>
Reported-by: Robert Stupp <snazy@gmx.de>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Minchan Kim <minchan@kernel.org>
Link: http://lkml.kernel.org/r/20200212101356.30759-1-jack@suse.cz
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/page-writeback.c')
0 files changed, 0 insertions, 0 deletions