4.9-stable review patch. If anyone has any objections, please let me know.
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[ Upstream commit af097f5d199e2aa3ab3ef777f0716e487b8f7b08 ]
Don't build discards bigger than what the user asked for, if the user decided to limit the size by writing to 'discard_max_bytes'.
Reviewed-by: Darrick J. Wong darrick.wong@oracle.com Reviewed-by: Omar Sandoval osandov@fb.com Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Sasha Levin sashal@kernel.org --- block/blk-lib.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-)
diff --git a/block/blk-lib.c b/block/blk-lib.c index 46fe9248410d..d8b89c58af3d 100644 --- a/block/blk-lib.c +++ b/block/blk-lib.c @@ -63,10 +63,16 @@ int __blkdev_issue_discard(struct block_device *bdev, sector_t sector, unsigned int req_sects; sector_t end_sect, tmp;
- /* Make sure bi_size doesn't overflow */ - req_sects = min_t(sector_t, nr_sects, UINT_MAX >> 9); + /* + * Issue in chunks of the user defined max discard setting, + * ensuring that bi_size doesn't overflow + */ + req_sects = min_t(sector_t, nr_sects, + q->limits.max_discard_sectors); + if (req_sects > UINT_MAX >> 9) + req_sects = UINT_MAX >> 9;
- /** + /* * If splitting a request, and the next starting sector would be * misaligned, stop the discard at the previous aligned sector. */