diff options
Diffstat (limited to 'drivers/md/dm-bufio.c')
| -rw-r--r-- | drivers/md/dm-bufio.c | 28 |
1 files changed, 15 insertions, 13 deletions
diff --git a/drivers/md/dm-bufio.c b/drivers/md/dm-bufio.c index 262e75365cc0..84d2f0e4c754 100644 --- a/drivers/md/dm-bufio.c +++ b/drivers/md/dm-bufio.c @@ -820,12 +820,14 @@ 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 * one buffer reserved in cases all the allocations fail). * So set flags to not try too hard: - * GFP_NOIO: don't recurse into the I/O layer + * GFP_NOWAIT: don't wait; if we need to sleep we'll release our + * mutex and wait ourselves. * __GFP_NORETRY: don't retry and rather return failure * __GFP_NOMEMALLOC: don't use emergency reserves * __GFP_NOWARN: don't print a warning in case of failure @@ -835,7 +837,7 @@ static struct dm_buffer *__alloc_buffer_wait_no_callback(struct dm_bufio_client */ while (1) { if (dm_bufio_cache_size_latch != 1) { - b = alloc_buffer(c, GFP_NOIO | __GFP_NORETRY | __GFP_NOMEMALLOC | __GFP_NOWARN); + b = alloc_buffer(c, GFP_NOWAIT | __GFP_NORETRY | __GFP_NOMEMALLOC | __GFP_NOWARN); if (b) return b; } @@ -843,6 +845,15 @@ 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); @@ -1585,18 +1596,9 @@ dm_bufio_shrink_scan(struct shrinker *shrink, struct shrink_control *sc) static unsigned long dm_bufio_shrink_count(struct shrinker *shrink, struct shrink_control *sc) { - struct dm_bufio_client *c; - unsigned long count; - - c = container_of(shrink, struct dm_bufio_client, shrinker); - if (sc->gfp_mask & __GFP_FS) - dm_bufio_lock(c); - else if (!dm_bufio_trylock(c)) - return 0; + struct dm_bufio_client *c = container_of(shrink, struct dm_bufio_client, shrinker); - count = c->n_buffers[LIST_CLEAN] + c->n_buffers[LIST_DIRTY]; - dm_bufio_unlock(c); - return count; + return ACCESS_ONCE(c->n_buffers[LIST_CLEAN]) + ACCESS_ONCE(c->n_buffers[LIST_DIRTY]); } /* |