linux/drivers/block
Martin K. Petersen d93ba7a5a9 block: Add discard flag to blkdev_issue_zeroout() function
blkdev_issue_discard() will zero a given block range. This is done by
way of explicit writing, thus provisioning or allocating the blocks on
disk.

There are use cases where the desired behavior is to zero the blocks but
unprovision them if possible. The blocks must deterministically contain
zeroes when they are subsequently read back.

This patch adds a flag to blkdev_issue_zeroout() that provides this
variant. If the discard flag is set and a block device guarantees
discard_zeroes_data we will use REQ_DISCARD to clear the block range. If
the device does not support discard_zeroes_data or if the discard
request fails we will fall back to first REQ_WRITE_SAME and then a
regular REQ_WRITE.

Also update the callers of blkdev_issue_zero() to reflect the new flag
and make sb_issue_zeroout() prefer the discard approach.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-01-21 10:41:46 -07:00
..
aoe block: remove artifical max_hw_sectors cap 2014-10-21 14:02:54 -06:00
drbd block: Add discard flag to blkdev_issue_zeroout() function 2015-01-21 10:41:46 -07:00
mtip32xx blk-mq: add a 'list' parameter to ->queue_rq() 2014-10-29 11:14:52 -06:00
paride Merge branch 'for-3.18/core' of git://git.kernel.dk/linux-block 2014-10-18 11:53:51 -07:00
rsxx block/rsxx: use generic io stats accounting functions to simplify io stat accounting 2014-11-24 08:05:18 -07:00
xen-blkback Merge branch 'for-3.18/drivers' of git://git.kernel.dk/linux-block 2014-10-18 12:12:45 -07:00
zram zram: use DEVICE_ATTR_[RW|RO|WO] to define zram sys device attribute 2014-12-13 12:42:50 -08:00
amiflop.c block: drop owner assignment from platform_drivers 2014-10-20 16:20:18 +02:00
ataflop.c
brd.c block: Change direct_access calling convention 2015-01-13 21:58:11 -07:00
cciss_cmd.h
cciss_scsi.c
cciss_scsi.h
cciss.c
cciss.h
cpqarray.c
cpqarray.h
cryptoloop.c
DAC960.c
DAC960.h
floppy.c
hd.c block: hd: remove deprecated IRQF_DISABLED 2014-10-01 08:16:07 -06:00
ida_cmd.h
ida_ioctl.h
Kconfig
loop.c
loop.h
Makefile
mg_disk.c block: drop owner assignment from platform_drivers 2014-10-20 16:20:18 +02:00
nbd.c block: disable entropy contributions for nonrot devices 2014-10-04 10:55:32 -06:00
null_blk.c block: fix checking return value of blk_mq_init_queue 2015-01-02 10:32:02 -07:00
nvme-core.c block: fix checking return value of blk_mq_init_queue 2015-01-02 10:32:02 -07:00
nvme-scsi.c Merge branch 'for-3.19/drivers' of git://git.kernel.dk/linux-block 2014-12-13 14:22:26 -08:00
osdblk.c
pktcdvd.c block,scsi: fixup blk_get_request dead queue scenarios 2014-08-28 10:03:46 -06:00
ps3disk.c
ps3vram.c
rbd_types.h
rbd.c rbd: don't treat CEPH_OSD_OP_DELETE as extent op 2014-12-17 20:09:51 +03:00
skd_main.c block: disable entropy contributions for nonrot devices 2014-10-04 10:55:32 -06:00
skd_s1120.h
smart1,2.h
sunvdc.c sunvdc: reconnect ldc after vds service domain restarts 2014-12-11 18:52:45 -08:00
swim3.c
swim_asm.S
swim.c block: drop owner assignment from platform_drivers 2014-10-20 16:20:18 +02:00
sx8.c block,scsi: fixup blk_get_request dead queue scenarios 2014-08-28 10:03:46 -06:00
umem.c
umem.h
virtio_blk.c block: fix checking return value of blk_mq_init_queue 2015-01-02 10:32:02 -07:00
xen-blkfront.c xen/blkfront: remove redundant flush_op 2014-12-10 12:20:18 -05:00
xsysace.c
z2ram.c