evie/android_kernel_oneplus_msm8998
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

dm bufio: drop the lock when doing GFP_NOIO allocation

Browse source 
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>
This commit is contained in:
Mikulas Patocka 2016-11-23 17:04:00 -05:00 • committed by Greg Kroah-Hartman
parent 7396cb30cb
commit 3ce44cad02
1 changed files with 10 additions and 0 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

10
drivers/md/dm-bufio.c
View file

@ -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) static struct dm_buffer *__alloc_buffer_wait_no_callback(struct dm_bufio_client *c, enum new_flag nf)
{ {
struct dm_buffer *b; struct dm_buffer *b;
bool tried_noio_alloc = false;
/* /*
* dm-bufio is resistant to allocation failures (it just keeps * 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) if (nf == NF_PREFETCH)
return NULL; 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)) { if (!list_empty(&c->reserved_buffers)) {
b = list_entry(c->reserved_buffers.next, b = list_entry(c->reserved_buffers.next,
struct dm_buffer, lru_list); struct dm_buffer, lru_list);