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authorColy Li2020-02-01 22:42:34 +0800
committerJens Axboe2020-02-01 07:55:39 -0700
commitd1c3cc34f5a78b38d2b809b289d912c3560545df (patch)
tree5b1df3da7b81c9745e5647015d990d6354f716a6 /drivers/md
parent038ba8cc1bffc51250add4a9b9249d4331576d8f (diff)
bcache: fix incorrect data type usage in btree_flush_write()
Dan Carpenter points out that from commit 2aa8c529387c ("bcache: avoid unnecessary btree nodes flushing in btree_flush_write()"), there is a incorrect data type usage which leads to the following static checker warning: drivers/md/bcache/journal.c:444 btree_flush_write() warn: 'ref_nr' unsigned <= 0 drivers/md/bcache/journal.c 422 static void btree_flush_write(struct cache_set *c) 423 { 424 struct btree *b, *t, *btree_nodes[BTREE_FLUSH_NR]; 425 unsigned int i, nr, ref_nr; ^^^^^^ 426 atomic_t *fifo_front_p, *now_fifo_front_p; 427 size_t mask; 428 429 if (c->journal.btree_flushing) 430 return; 431 432 spin_lock(&c->journal.flush_write_lock); 433 if (c->journal.btree_flushing) { 434 spin_unlock(&c->journal.flush_write_lock); 435 return; 436 } 437 c->journal.btree_flushing = true; 438 spin_unlock(&c->journal.flush_write_lock); 439 440 /* get the oldest journal entry and check its refcount */ 441 spin_lock(&c->journal.lock); 442 fifo_front_p = &fifo_front(&c->journal.pin); 443 ref_nr = atomic_read(fifo_front_p); 444 if (ref_nr <= 0) { ^^^^^^^^^^^ Unsigned can't be less than zero. 445 /* 446 * do nothing if no btree node references 447 * the oldest journal entry 448 */ 449 spin_unlock(&c->journal.lock); 450 goto out; 451 } 452 spin_unlock(&c->journal.lock); As the warning information indicates, local varaible ref_nr in unsigned int type is wrong, which does not matche atomic_read() and the "<= 0" checking. This patch fixes the above error by defining local variable ref_nr as int type. Fixes: 2aa8c529387c ("bcache: avoid unnecessary btree nodes flushing in btree_flush_write()") Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Coly Li <colyli@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'drivers/md')
-rw-r--r--drivers/md/bcache/journal.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/md/bcache/journal.c b/drivers/md/bcache/journal.c
index 33ddc5269e8d..6730820780b0 100644
--- a/drivers/md/bcache/journal.c
+++ b/drivers/md/bcache/journal.c
@@ -422,7 +422,8 @@ err:
static void btree_flush_write(struct cache_set *c)
{
struct btree *b, *t, *btree_nodes[BTREE_FLUSH_NR];
- unsigned int i, nr, ref_nr;
+ unsigned int i, nr;
+ int ref_nr;
atomic_t *fifo_front_p, *now_fifo_front_p;
size_t mask;