| Message ID | 1525709615-14395-2-git-send-email-axboe@kernel.dk (mailing list archive) |
|---|---|
| State | Not Applicable, archived |
| Headers | show |
On Mon, May 07, 2018 at 10:13:32AM -0600, Jens Axboe wrote: > 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'. > > Signed-off-by: Jens Axboe <axboe@kernel.dk> Seems fine to me, Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> --D > --- > block/blk-lib.c | 7 ++++--- > 1 file changed, 4 insertions(+), 3 deletions(-) > > diff --git a/block/blk-lib.c b/block/blk-lib.c > index a676084d4740..7417d617091b 100644 > --- a/block/blk-lib.c > +++ b/block/blk-lib.c > @@ -62,10 +62,11 @@ 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 */ > + req_sects = min_t(sector_t, nr_sects, > + q->limits.max_discard_sectors); > > - /** > + /* > * If splitting a request, and the next starting sector would be > * misaligned, stop the discard at the previous aligned sector. > */ > -- > 2.7.4 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-xfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-xfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Mon, May 07, 2018 at 10:13:32AM -0600, Jens Axboe wrote: > 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'. > > Signed-off-by: Jens Axboe <axboe@kernel.dk> > --- > block/blk-lib.c | 7 ++++--- > 1 file changed, 4 insertions(+), 3 deletions(-) > > diff --git a/block/blk-lib.c b/block/blk-lib.c > index a676084d4740..7417d617091b 100644 > --- a/block/blk-lib.c > +++ b/block/blk-lib.c > @@ -62,10 +62,11 @@ 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 */ > + req_sects = min_t(sector_t, nr_sects, > + q->limits.max_discard_sectors); > Some drivers, including nvme, do blk_queue_max_discard_sectors(q, UINT_MAX) That means q->limits.max_discard_sectors can be UINT_MAX, and bio->bi_iter.bi_size = req_sects << 9; will overflow. We should probably cap max_discard_sectors at UINT_MAX >> 9 in a prep patch. -- To unsubscribe from this list: send the line "unsubscribe linux-xfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 5/8/18 2:43 PM, Omar Sandoval wrote: > On Mon, May 07, 2018 at 10:13:32AM -0600, Jens Axboe wrote: >> 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'. >> >> Signed-off-by: Jens Axboe <axboe@kernel.dk> >> --- >> block/blk-lib.c | 7 ++++--- >> 1 file changed, 4 insertions(+), 3 deletions(-) >> >> diff --git a/block/blk-lib.c b/block/blk-lib.c >> index a676084d4740..7417d617091b 100644 >> --- a/block/blk-lib.c >> +++ b/block/blk-lib.c >> @@ -62,10 +62,11 @@ 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 */ >> + req_sects = min_t(sector_t, nr_sects, >> + q->limits.max_discard_sectors); >> > > Some drivers, including nvme, do > > blk_queue_max_discard_sectors(q, UINT_MAX) > > That means q->limits.max_discard_sectors can be UINT_MAX, and > > bio->bi_iter.bi_size = req_sects << 9; > > will overflow. We should probably cap max_discard_sectors at > UINT_MAX >> 9 in a prep patch. Probably better to just keep the local overflow check, I'll do that. Thanks for spotting it!
diff --git a/block/blk-lib.c b/block/blk-lib.c index a676084d4740..7417d617091b 100644 --- a/block/blk-lib.c +++ b/block/blk-lib.c @@ -62,10 +62,11 @@ 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 */ + req_sects = min_t(sector_t, nr_sects, + q->limits.max_discard_sectors); - /** + /* * If splitting a request, and the next starting sector would be * misaligned, stop the discard at the previous aligned sector. */
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'. Signed-off-by: Jens Axboe <axboe@kernel.dk> --- block/blk-lib.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-)