BMC/Intel-BMC/linux.git/drivers/md/dm-cache-target.c, branch dev-4.3

Merge tag 'dm-4.3-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

2015-09-02T23:35:26+00:00

Pull device mapper update from Mike Snitzer: - a couple small cleanups in dm-cache, dm-verity, persistent-data's dm-btree, and DM core. - a 4.1-stable fix for dm-cache that fixes the leaking of deferred bio prison cells - a 4.2-stable fix that adds feature reporting for the dm-stats features added in 4.2 - improve DM-snapshot to not invalidate the on-disk snapshot if snapshot device write overflow occurs; but a write overflow triggered through the origin device will still invalidate the snapshot. - optimize DM-thinp's async discard submission a bit now that late bio splitting has been included in block core. - switch DM-cache's SMQ policy lock from using a mutex to a spinlock; improves performance on very low latency devices (eg. NVMe SSD). - document DM RAID 4/5/6's discard support [ I did not pull the slab changes, which weren't appropriate for this tree, and weren't obviously the right thing to do anyway. At the very least they need some discussion and explanation before getting merged. Because not pulling the actual tagged commit but doing a partial pull instead, this merge commit thus also obviously is missing the git signature from the original tag ] * tag 'dm-4.3-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: dm cache: fix use after freeing migrations dm cache: small cleanups related to deferred prison cell cleanup dm cache: fix leaking of deferred bio prison cells dm raid: document RAID 4/5/6 discard support dm stats: report precise_timestamps and histogram in @stats_list output dm thin: optimize async discard submission dm snapshot: don't invalidate on-disk image on snapshot write overflow dm: remove unlikely() before IS_ERR() dm: do not override error code returned from dm_get_device() dm: test return value for DM_MAPIO_SUBMITTED dm verity: remove unused mempool dm cache: move wake_waker() from free_migrations() to where it is needed dm btree remove: remove unused function get_nr_entries() dm btree: remove unused "dm_block_t root" parameter in btree_split_sibling() dm cache policy smq: change the mutex to a spinlock

Merge branch 'for-4.3/core' of git://git.kernel.dk/linux-block

2015-09-02T20:10:25+00:00

Pull core block updates from Jens Axboe: "This first core part of the block IO changes contains: - Cleanup of the bio IO error signaling from Christoph. We used to rely on the uptodate bit and passing around of an error, now we store the error in the bio itself. - Improvement of the above from myself, by shrinking the bio size down again to fit in two cachelines on x86-64. - Revert of the max_hw_sectors cap removal from a revision again, from Jeff Moyer. This caused performance regressions in various tests. Reinstate the limit, bump it to a more reasonable size instead. - Make /sys/block//queue/discard_max_bytes writeable, by me. Most devices have huge trim limits, which can cause nasty latencies when deleting files. Enable the admin to configure the size down. We will look into having a more sane default instead of UINT_MAX sectors. - Improvement of the SGP gaps logic from Keith Busch. - Enable the block core to handle arbitrarily sized bios, which enables a nice simplification of bio_add_page() (which is an IO hot path). From Kent. - Improvements to the partition io stats accounting, making it faster. From Ming Lei. - Also from Ming Lei, a basic fixup for overflow of the sysfs pending file in blk-mq, as well as a fix for a blk-mq timeout race condition. - Ming Lin has been carrying Kents above mentioned patches forward for a while, and testing them. Ming also did a few fixes around that. - Sasha Levin found and fixed a use-after-free problem introduced by the bio->bi_error changes from Christoph. - Small blk cgroup cleanup from Viresh Kumar" * 'for-4.3/core' of git://git.kernel.dk/linux-block: (26 commits) blk: Fix bio_io_vec index when checking bvec gaps block: Replace SG_GAPS with new queue limits mask block: bump BLK_DEF_MAX_SECTORS to 2560 Revert "block: remove artifical max_hw_sectors cap" blk-mq: fix race between timeout and freeing request blk-mq: fix buffer overflow when reading sysfs file of 'pending' Documentation: update notes in biovecs about arbitrarily sized bios block: remove bio_get_nr_vecs() fs: use helper bio_add_page() instead of open coding on bi_io_vec block: kill merge_bvec_fn() completely md/raid5: get rid of bio_fits_rdev() md/raid5: split bio for chunk_aligned_read block: remove split code in blkdev_issue_{discard,write_same} btrfs: remove bio splitting and merge_bvec_fn() calls bcache: remove driver private bio splitting code block: simplify bio_add_page() block: make generic_make_request handle arbitrarily sized bios blk-cgroup: Drop unlikely before IS_ERR(_OR_NULL) block: don't access bio->bi_error after bio_put() block: shrink struct bio down to 2 cache lines again ...

dm cache: fix use after freeing migrations

2015-09-01T12:56:14+00:00

Both free_io_migration() and issue_discard() dereference a migration that was just freed. Fix those by saving off the migrations's cache object before freeing the migration. Also cleanup needless mg->cache dereferences now that the cache object is available directly. Fixes: e44b6a5a3c ("dm cache: move wake_waker() from free_migrations() to where it is needed") Signed-off-by: Joe Thornber Signed-off-by: Mike Snitzer

dm cache: small cleanups related to deferred prison cell cleanup

2015-08-31T19:50:28+00:00

Eliminate __cell_release() since it only had one caller that always released the cell holder. Switch cell_error_with_code() to using free_prison_cell() for the sake of consistency. Signed-off-by: Mike Snitzer

dm cache: fix leaking of deferred bio prison cells

2015-08-31T19:08:14+00:00

There were two cases where dm_cell_visit_release() was being called, which removes the cell from the prison's rbtree, but the callers didn't also return the cell to the mempool. Fix this by having them call free_prison_cell(). This leak manifested as the 'kmalloc-96' slab growing until OOM. Fixes: 651f5fa2a3 ("dm cache: defer whole cells") Signed-off-by: Joe Thornber Signed-off-by: Mike Snitzer Cc: stable@vger.kernel.org # 4.1+

block: kill merge_bvec_fn() completely

2015-08-13T18:31:57+00:00

As generic_make_request() is now able to handle arbitrarily sized bios, it's no longer necessary for each individual block driver to define its own ->merge_bvec_fn() callback. Remove every invocation completely. Cc: Jens Axboe Cc: Lars Ellenberg Cc: drbd-user@lists.linbit.com Cc: Jiri Kosina Cc: Yehuda Sadeh Cc: Sage Weil Cc: Alex Elder Cc: ceph-devel@vger.kernel.org Cc: Alasdair Kergon Cc: Mike Snitzer Cc: dm-devel@redhat.com Cc: Neil Brown Cc: linux-raid@vger.kernel.org Cc: Christoph Hellwig Cc: "Martin K. Petersen" Acked-by: NeilBrown (for the 'md' bits) Acked-by: Mike Snitzer Signed-off-by: Kent Overstreet [dpark: also remove ->merge_bvec_fn() in dm-thin as well as dm-era-target, and resolve merge conflicts] Signed-off-by: Dongsu Park Signed-off-by: Ming Lin Signed-off-by: Jens Axboe

dm cache: move wake_waker() from free_migrations() to where it is needed

2015-08-12T15:32:20+00:00

This stops spurious wake ups from calls to prealloc_free_structs(). Signed-off-by: Joe Thornber Signed-off-by: Mike Snitzer

dm cache: fix device destroy hang due to improper prealloc_used accounting

2015-07-29T18:32:09+00:00

Commit 665022d72f9 ("dm cache: avoid calls to prealloc_free_structs() if possible") introduced a regression that caused the removal of a DM cache device to hang in cache_postsuspend()'s call to wait_for_migrations() with the following stack trace: [] schedule+0x37/0x80 [] cache_postsuspend+0xbb/0x470 [dm_cache] [] ? prepare_to_wait_event+0xf0/0xf0 [] dm_table_postsuspend_targets+0x47/0x60 [dm_mod] [] __dm_destroy+0x215/0x250 [dm_mod] [] dm_destroy+0x13/0x20 [dm_mod] [] dev_remove+0x10d/0x170 [dm_mod] [] ? dev_suspend+0x240/0x240 [dm_mod] [] ctl_ioctl+0x255/0x4d0 [dm_mod] [] ? SYSC_semtimedop+0x280/0xe10 [] dm_ctl_ioctl+0x13/0x20 [dm_mod] [] do_vfs_ioctl+0x2d2/0x4b0 [] ? __audit_syscall_entry+0xaf/0x100 [] ? do_audit_syscall_entry+0x66/0x70 [] SyS_ioctl+0x79/0x90 [] ? syscall_trace_leave+0xb8/0x110 [] entry_SYSCALL_64_fastpath+0x12/0x71 Fix this by accounting for the call to prealloc_data_structs() immediately _before_ the call as opposed to after. This is needed because it is possible to break out of the control loop after the call to prealloc_data_structs() but before prealloc_used was set to true. Signed-off-by: Mike Snitzer

Revert "dm cache: do not wake_worker() in free_migration()"

2015-07-29T18:32:08+00:00

This reverts commit 386cb7cdeeef97e0bf082a8d6bbfc07a2ccce07b. Taking the wake_worker() out of free_migration() will slow writeback dramatically, and hence adaptability. Say we have 10k blocks that need writing back, but are only able to issue 5 concurrently due to the migration bandwidth: it's imperative that we wake_worker() immediately after migration completion; waiting for the next 1 second wake up (via do_waker) means it'll take a long time to write that all back. Reported-by: Joe Thornber Signed-off-by: Mike Snitzer

block: add a bi_error field to struct bio

2015-07-29T14:55:15+00:00

Currently we have two different ways to signal an I/O error on a BIO: (1) by clearing the BIO_UPTODATE flag (2) by returning a Linux errno value to the bi_end_io callback The first one has the drawback of only communicating a single possible error (-EIO), and the second one has the drawback of not beeing persistent when bios are queued up, and are not passed along from child to parent bio in the ever more popular chaining scenario. Having both mechanisms available has the additional drawback of utterly confusing driver authors and introducing bugs where various I/O submitters only deal with one of them, and the others have to add boilerplate code to deal with both kinds of error returns. So add a new bi_error field to store an errno value directly in struct bio and remove the existing mechanisms to clean all this up. Signed-off-by: Christoph Hellwig Reviewed-by: Hannes Reinecke Reviewed-by: NeilBrown Signed-off-by: Jens Axboe