dm bufio: fix some cases where the code sleeps with spinlock held

[linux-2.6-microblaze.git] / drivers / md / dm-bufio.c

diff --git a/drivers/md/dm-bufio.c b/drivers/md/dm-bufio.c
index bef8c6e..7999152 100644 (file)
--- a/drivers/md/dm-bufio.c
+++ b/drivers/md/dm-bufio.c
@@ -815,6 +815,10 @@ static struct dm_buffer *__get_unclaimed_buffer(struct dm_bufio_client *c)
                BUG_ON(test_bit(B_WRITING, &b->state));
                BUG_ON(test_bit(B_DIRTY, &b->state));
 
+               if (static_branch_unlikely(&no_sleep_enabled) && c->no_sleep &&
+                   unlikely(test_bit(B_READING, &b->state)))
+                       continue;
+
                if (!b->hold_count) {
                        __make_buffer_clean(b);
                        __unlink_buffer(b);
@@ -823,6 +827,9 @@ static struct dm_buffer *__get_unclaimed_buffer(struct dm_bufio_client *c)
                cond_resched();
        }
 
+       if (static_branch_unlikely(&no_sleep_enabled) && c->no_sleep)
+               return NULL;
+
        list_for_each_entry_reverse(b, &c->lru[LIST_DIRTY], lru_list) {
                BUG_ON(test_bit(B_READING, &b->state));
 
@@ -1632,7 +1639,8 @@ static void drop_buffers(struct dm_bufio_client *c)
  */
 static bool __try_evict_buffer(struct dm_buffer *b, gfp_t gfp)
 {
-       if (!(gfp & __GFP_FS)) {
+       if (!(gfp & __GFP_FS) ||
+           (static_branch_unlikely(&no_sleep_enabled) && b->c->no_sleep)) {
                if (test_bit(B_READING, &b->state) ||
                    test_bit(B_WRITING, &b->state) ||
                    test_bit(B_DIRTY, &b->state))