diff options
Diffstat (limited to 'block/blk-lib.c')
| -rw-r--r-- | block/blk-lib.c | 23 |
1 files changed, 17 insertions, 6 deletions
diff --git a/block/blk-lib.c b/block/blk-lib.c index 9f735efa6c94..4c9f20a689f7 100644 --- a/block/blk-lib.c +++ b/block/blk-lib.c @@ -111,13 +111,20 @@ static sector_t bio_write_zeroes_limit(struct block_device *bdev) (UINT_MAX >> SECTOR_SHIFT) & ~bs_mask); } +/* + * There is no reliable way for the SCSI subsystem to determine whether a + * device supports a WRITE SAME operation without actually performing a write + * to media. As a result, write_zeroes is enabled by default and will be + * disabled if a zeroing operation subsequently fails. This means that this + * queue limit is likely to change at runtime. + */ static void __blkdev_issue_write_zeroes(struct block_device *bdev, sector_t sector, sector_t nr_sects, gfp_t gfp_mask, - struct bio **biop, unsigned flags) + struct bio **biop, unsigned flags, sector_t limit) { + while (nr_sects) { - unsigned int len = min_t(sector_t, nr_sects, - bio_write_zeroes_limit(bdev)); + unsigned int len = min(nr_sects, limit); struct bio *bio; if ((flags & BLKDEV_ZERO_KILLABLE) && @@ -141,12 +148,14 @@ static void __blkdev_issue_write_zeroes(struct block_device *bdev, static int blkdev_issue_write_zeroes(struct block_device *bdev, sector_t sector, sector_t nr_sects, gfp_t gfp, unsigned flags) { + sector_t limit = bio_write_zeroes_limit(bdev); struct bio *bio = NULL; struct blk_plug plug; int ret = 0; blk_start_plug(&plug); - __blkdev_issue_write_zeroes(bdev, sector, nr_sects, gfp, &bio, flags); + __blkdev_issue_write_zeroes(bdev, sector, nr_sects, gfp, &bio, + flags, limit); if (bio) { if ((flags & BLKDEV_ZERO_KILLABLE) && fatal_signal_pending(current)) { @@ -265,12 +274,14 @@ int __blkdev_issue_zeroout(struct block_device *bdev, sector_t sector, sector_t nr_sects, gfp_t gfp_mask, struct bio **biop, unsigned flags) { + sector_t limit = bio_write_zeroes_limit(bdev); + if (bdev_read_only(bdev)) return -EPERM; - if (bdev_write_zeroes_sectors(bdev)) { + if (limit) { __blkdev_issue_write_zeroes(bdev, sector, nr_sects, - gfp_mask, biop, flags); + gfp_mask, biop, flags, limit); } else { if (flags & BLKDEV_ZERO_NOFALLBACK) return -EOPNOTSUPP; |