dm bufio: remove redundant __GFP_NOWARN

GFP_NOWAIT already includes __GFP_NOWARN, so let's remove the redundant
__GFP_NOWARN.  Also update comments to clarify the flag semantics.

Signed-off-by: Qianfeng Rong <rongqianfeng@vivo.com>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>

diff --git a/drivers/md/dm-bufio.c b/drivers/md/dm-bufio.c
index ff7595caf44039811611cc4a0155c4c10c599085..ad0507726abdd754e1b39ef99d5711e768f39e35 100644 (file)
--- a/drivers/md/dm-bufio.c
+++ b/drivers/md/dm-bufio.c
@@ -1337,7 +1337,7 @@ static void use_bio(struct dm_buffer *b, enum req_op op, sector_t sector,
        char *ptr;
        unsigned int len;
 
-       bio = bio_kmalloc(1, GFP_NOWAIT | __GFP_NORETRY | __GFP_NOWARN);
+       bio = bio_kmalloc(1, GFP_NOWAIT);
        if (!bio) {
                use_dmio(b, op, sector, n_sectors, offset, ioprio);
                return;
@@ -1601,18 +1601,18 @@ static struct dm_buffer *__alloc_buffer_wait_no_callback(struct dm_bufio_client
         * 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_NOWAIT: don't wait; if we need to sleep we'll release our
-        *                  mutex and wait ourselves.
+        *      GFP_NOWAIT: don't wait and don't print a warning in case of
+        *                  failure; 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
         *
         * For debugging, if we set the cache size to 1, no new buffers will
         * be allocated.
         */
        while (1) {
                if (dm_bufio_cache_size_latch != 1) {
-                       b = alloc_buffer(c, GFP_NOWAIT | __GFP_NORETRY | __GFP_NOMEMALLOC | __GFP_NOWARN);
+                       b = alloc_buffer(c, GFP_NOWAIT | __GFP_NORETRY | __GFP_NOMEMALLOC);
                        if (b)
                                return b;
                }