diff options
| author | Mikulas Patocka <mpatocka@redhat.com> | 2016-11-23 17:04:00 -0500 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-07-11 16:03:51 +0200 |
| commit | 3ce44cad02d3987d71ee69eed1e3b9e59559417c (patch) | |
| tree | 359d6e7080aa56449fcc5307bc86539f7c251f33 /drivers | |
| parent | 7396cb30cbfb379fb9fe715f348f2effe8eb52b7 (diff) | |
dm bufio: drop the lock when doing GFP_NOIO allocation
commit 41c73a49df31151f4ff868f28fe4f129f113fa2c upstream.
If the first allocation attempt using GFP_NOWAIT fails, drop the lock
and retry using GFP_NOIO allocation (lock is dropped because the
allocation can take some time).
Note that we won't do GFP_NOIO allocation when we loop for the second
time, because the lock shouldn't be dropped between __wait_for_free_buffer
and __get_unclaimed_buffer.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/md/dm-bufio.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/drivers/md/dm-bufio.c b/drivers/md/dm-bufio.c index d566c32e222a..767b5c049736 100644 --- a/drivers/md/dm-bufio.c +++ b/drivers/md/dm-bufio.c @@ -813,6 +813,7 @@ enum new_flag { static struct dm_buffer *__alloc_buffer_wait_no_callback(struct dm_bufio_client *c, enum new_flag nf) { struct dm_buffer *b; + bool tried_noio_alloc = false; /* * dm-bufio is resistant to allocation failures (it just keeps @@ -837,6 +838,15 @@ static struct dm_buffer *__alloc_buffer_wait_no_callback(struct dm_bufio_client if (nf == NF_PREFETCH) return NULL; + if (dm_bufio_cache_size_latch != 1 && !tried_noio_alloc) { + dm_bufio_unlock(c); + b = alloc_buffer(c, GFP_NOIO | __GFP_NORETRY | __GFP_NOMEMALLOC | __GFP_NOWARN); + dm_bufio_lock(c); + if (b) + return b; + tried_noio_alloc = true; + } + if (!list_empty(&c->reserved_buffers)) { b = list_entry(c->reserved_buffers.next, struct dm_buffer, lru_list); |