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authorLinus Torvalds <torvalds@linux-foundation.org>2016-12-14 20:01:00 +0100
committerLinus Torvalds <torvalds@linux-foundation.org>2016-12-14 20:01:00 +0100
commit775a2e29c3bbcf853432f47d3caa9ff8808807ad (patch)
tree614a7481b68dc9b0b628f392ab9bbdc53bbfe447 /drivers/md/dm-bufio.c
parentMerge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/shl... (diff)
parentdm flakey: introduce "error_writes" feature (diff)
downloadlinux-775a2e29c3bbcf853432f47d3caa9ff8808807ad.tar.xz
linux-775a2e29c3bbcf853432f47d3caa9ff8808807ad.zip
Merge tag 'dm-4.10-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm
Pull device mapper updates from Mike Snitzer: - various fixes and improvements to request-based DM and DM multipath - some locking improvements in DM bufio - add Kconfig option to disable the DM block manager's extra locking which mainly serves as a developer tool - a few bug fixes to DM's persistent-data - a couple changes to prepare for multipage biovec support in the block layer - various improvements and cleanups in the DM core, DM cache, DM raid and DM crypt - add ability to have DM crypt use keys from the kernel key retention service - add a new "error_writes" feature to the DM flakey target, reads are left unchanged in this mode * tag 'dm-4.10-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: (40 commits) dm flakey: introduce "error_writes" feature dm cache policy smq: use hash_32() instead of hash_32_generic() dm crypt: reject key strings containing whitespace chars dm space map: always set ev if sm_ll_mutate() succeeds dm space map metadata: skip useless memcpy in metadata_ll_init_index() dm space map metadata: fix 'struct sm_metadata' leak on failed create Documentation: dm raid: define data_offset status field dm raid: fix discard support regression dm raid: don't allow "write behind" with raid4/5/6 dm mpath: use hw_handler_params if attached hw_handler is same as requested dm crypt: add ability to use keys from the kernel key retention service dm array: remove a dead assignment in populate_ablock_with_values() dm ioctl: use offsetof() instead of open-coding it dm rq: simplify use_blk_mq initialization dm: use blk_set_queue_dying() in __dm_destroy() dm bufio: drop the lock when doing GFP_NOIO allocation dm bufio: don't take the lock in dm_bufio_shrink_count dm bufio: avoid sleeping while holding the dm_bufio lock dm table: simplify dm_table_determine_type() dm table: an 'all_blk_mq' table must be loaded for a blk-mq DM device ...
Diffstat (limited to 'drivers/md/dm-bufio.c')
-rw-r--r--drivers/md/dm-bufio.c28
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]);
}
/*