block: use int to store blk_stack_limits() return value

[ Upstream commit b0b4518c992eb5f316c6e40ff186cbb7a5009518 ]

Change the 'ret' variable in blk_stack_limits() from unsigned int to int,
as it needs to store negative value -1.

Storing the negative error codes in unsigned type, or performing equality
comparisons (e.g., ret == -1), doesn't cause an issue at runtime [1] but
can be confusing.  Additionally, assigning negative error codes to unsigned
type may trigger a GCC warning when the -Wsign-conversion flag is enabled.

No effect on runtime.

Link: https://lore.kernel.org/all/x3wogjf6vgpkisdhg3abzrx7v7zktmdnfmqeih5kosszmagqfs@oh3qxrgzkikf/
Signed-off-by: Qianfeng Rong <rongqianfeng@vivo.com>
Reviewed-by: John Garry <john.g.garry@oracle.com>
Fixes: fe0b393f2c0a ("block: Correct handling of bottom device misaligment")
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20250902130930.68317-1-rongqianfeng@vivo.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/block/blk-settings.c b/block/blk-settings.c
index 305b47a38429e7af540200796fca484ec0046cf5..741c4085b9e4530885e6436151b20fccfece226b 100644 (file)
--- a/block/blk-settings.c
+++ b/block/blk-settings.c
@@ -547,7 +547,8 @@ static unsigned int blk_round_down_sectors(unsigned int sectors, unsigned int lb
 int blk_stack_limits(struct queue_limits *t, struct queue_limits *b,
                     sector_t start)
 {
-       unsigned int top, bottom, alignment, ret = 0;
+       unsigned int top, bottom, alignment;
+       int ret = 0;
 
        t->max_sectors = min_not_zero(t->max_sectors, b->max_sectors);
        t->max_hw_sectors = min_not_zero(t->max_hw_sectors, b->max_hw_sectors);