user/sven/linux.git/drivers/md/dm-snap.c, branch v3.0

dm kcopyd: return client directly and not through a pointer

2011-05-29T12:03:13Z

Return client directly from dm_kcopyd_client_create, not through a parameter, making it consistent with dm_io_client_create. Signed-off-by: Mikulas Patocka Signed-off-by: Alasdair G Kergon

dm kcopyd: reserve fewer pages

2011-05-29T12:03:11Z

Reserve just the minimum of pages needed to process one job. Because we allocate pages from page allocator, we don't need to reserve a large number of pages. The maximum job size is SUB_JOB_SIZE and we calculate the number of reserved pages based on this. Signed-off-by: Mikulas Patocka Signed-off-by: Alasdair G Kergon

dm: fix opening log and cow devices for read only tables

2011-03-24T13:52:14Z

If a table is read-only, also open any log and cow devices it uses read-only. Previously, even read-only devices were opened read-write internally. After patch 75f1dc0d076d1c1168f2115f1941ea627d38bd5a block: check bdev_read_only() from blkdev_get() was applied, loading such tables began to fail. The patch was reverted by e51900f7d38cbcfb481d84567fd92540e7e1d23a block: revert block_dev read-only check but this patch fixes this part of the code to work with the original patch. Signed-off-by: Milan Broz Signed-off-by: Alasdair G Kergon

dm snapshot: avoid storing private suspended state

2011-01-13T19:59:59Z

Use dm_suspended() rather than having each snapshot target maintain a private 'suspended' flag in struct dm_snapshot. Signed-off-by: Mike Snitzer Signed-off-by: Alasdair G Kergon

dm snapshot: remove unused dm_snapshot queued_bios_work

2011-01-13T19:59:56Z

dm_snapshot->queued_bios_work isn't used. Remove ->queued_bios[_work] from dm_snapshot structure, the flush_queued_bios work function and ksnapd workqueue. The DM snapshot changes that were going to use the ksnapd workqueue were either superseded (fix for origin write races) or never completed (deallocation of invalid snapshot's memory via workqueue). Signed-off-by: Tejun Heo Signed-off-by: Mike Snitzer Signed-off-by: Alasdair G Kergon

Merge branch 'for-2.6.37/barrier' of git://git.kernel.dk/linux-2.6-block

2010-10-23T00:07:18Z

* 'for-2.6.37/barrier' of git://git.kernel.dk/linux-2.6-block: (46 commits) xen-blkfront: disable barrier/flush write support Added blk-lib.c and blk-barrier.c was renamed to blk-flush.c block: remove BLKDEV_IFL_WAIT aic7xxx_old: removed unused 'req' variable block: remove the BH_Eopnotsupp flag block: remove the BLKDEV_IFL_BARRIER flag block: remove the WRITE_BARRIER flag swap: do not send discards as barriers fat: do not send discards as barriers ext4: do not send discards as barriers jbd2: replace barriers with explicit flush / FUA usage jbd2: Modify ASYNC_COMMIT code to not rely on queue draining on barrier jbd: replace barriers with explicit flush / FUA usage nilfs2: replace barriers with explicit flush / FUA usage reiserfs: replace barriers with explicit flush / FUA usage gfs2: replace barriers with explicit flush / FUA usage btrfs: replace barriers with explicit flush / FUA usage xfs: replace barriers with explicit flush / FUA usage block: pass gfp_mask and flags to sb_issue_discard dm: convey that all flushes are processed as empty ...

Consolidate min_not_zero

2010-09-10T18:07:38Z

We have several users of min_not_zero, each of them using their own definition. Move the define to kernel.h. Signed-off-by: Martin K. Petersen Signed-off-by: Jens Axboe

dm: implement REQ_FLUSH/FUA support for bio-based dm

2010-09-10T10:35:38Z

This patch converts bio-based dm to support REQ_FLUSH/FUA instead of now deprecated REQ_HARDBARRIER. * -EOPNOTSUPP handling logic dropped. * Preflush is handled as before but postflush is dropped and replaced with passing down REQ_FUA to member request_queues. This replaces one array wide cache flush w/ member specific FUA writes. * __split_and_process_bio() now calls __clone_and_map_flush() directly for flushes and guarantees all FLUSH bio's going to targets are zero ` length. * It's now guaranteed that all FLUSH bio's which are passed onto dm targets are zero length. bio_empty_barrier() tests are replaced with REQ_FLUSH tests. * Empty WRITE_BARRIERs are replaced with WRITE_FLUSHes. * Dropped unlikely() around REQ_FLUSH tests. Flushes are not unlikely enough to be marked with unlikely(). * Block layer now filters out REQ_FLUSH/FUA bio's if the request_queue doesn't support cache flushing. Advertise REQ_FLUSH | REQ_FUA capability. * Request based dm isn't converted yet. dm_init_request_based_queue() resets flush support to 0 for now. To avoid disturbing request based dm code, dm->flush_error is added for bio based dm while requested based dm continues to use dm->barrier_error. Lightly tested linear, stripe, raid1, snap and crypt targets. Please proceed with caution as I'm not familiar with the code base. Signed-off-by: Tejun Heo Cc: dm-devel@redhat.com Cc: Christoph Hellwig Signed-off-by: Jens Axboe

dm: rename map_info flush_request to target_request_nr

2010-08-12T03:14:04Z

'target_request_nr' is a more generic name that reflects the fact that it will be used for both flush and discard support. Signed-off-by: Mike Snitzer Signed-off-by: Alasdair G Kergon

dm snapshot: implement merge

2010-08-12T03:14:02Z

Implement merge method for the snapshot origin to improve read performance. Without merge method, dm asks the upper layers to submit smallest possible bios --- one page. Submitting such small bios impacts performance negatively when reading or writing the origin device. Without this patch, CPU consumption when reading the origin on lvm on md-raid0 was 6 to 12%, with this patch, it drops to 1 to 4%. Note: in my testing, it actually degraded performance in some settings, I traced it to Maxtor disks having problems with > 512-sector requests. Reducing the number of sectors to /sys/block/sd*/queue/max_sectors_kb to 256 fixed the read performance. I think we don't have to care about weird disks that actually degrade performance because of large requests being sent to them. Signed-off-by: Mikulas Patocka Signed-off-by: Alasdair G Kergon