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| author |   Coly Li <colyli@suse.de> | 2020-02-01 22:42:34 +0800 |
|---|---|---|
| committer |   Jens Axboe <axboe@kernel.dk> | 2020-02-01 07:55:39 -0700 |
| commit | d1c3cc34f5a78b38d2b809b289d912c3560545df (patch) | |
| tree | 5b1df3da7b81c9745e5647015d990d6354f716a6 /drivers/md | |
| parent | bcache: add readahead cache policy options via sysfs interface (diff) | |
| download | linux-dev-d1c3cc34f5a78b38d2b809b289d912c3560545df.tar.xz linux-dev-d1c3cc34f5a78b38d2b809b289d912c3560545df.zip | |
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.c | 3 |
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; |