kernel/git/stable/linux.git/drivers/md/dm-table.c, branch linux-4.6.y

dm snapshot: disallow the COW and origin devices from being identical

2016-03-10T22:12:09+00:00

Otherwise loading a "snapshot" table using the same device for the origin and COW devices, e.g.: echo "0 20971520 snapshot 253:3 253:3 P 8" | dmsetup create snap will trigger: BUG: unable to handle kernel NULL pointer dereference at 0000000000000098 [ 1958.979934] IP: [] dm_exception_store_set_chunk_size+0x7a/0x110 [dm_snapshot] [ 1958.989655] PGD 0 [ 1958.991903] Oops: 0000 [#1] SMP ... [ 1959.059647] CPU: 9 PID: 3556 Comm: dmsetup Tainted: G IO 4.5.0-rc5.snitm+ #150 ... [ 1959.083517] task: ffff8800b9660c80 ti: ffff88032a954000 task.ti: ffff88032a954000 [ 1959.091865] RIP: 0010:[] [] dm_exception_store_set_chunk_size+0x7a/0x110 [dm_snapshot] [ 1959.104295] RSP: 0018:ffff88032a957b30 EFLAGS: 00010246 [ 1959.110219] RAX: 0000000000000000 RBX: 0000000000000008 RCX: 0000000000000001 [ 1959.118180] RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff880329334a00 [ 1959.126141] RBP: ffff88032a957b50 R08: 0000000000000000 R09: 0000000000000001 [ 1959.134102] R10: 000000000000000a R11: f000000000000000 R12: ffff880330884d80 [ 1959.142061] R13: 0000000000000008 R14: ffffc90001c13088 R15: ffff880330884d80 [ 1959.150021] FS: 00007f8926ba3840(0000) GS:ffff880333440000(0000) knlGS:0000000000000000 [ 1959.159047] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 1959.165456] CR2: 0000000000000098 CR3: 000000032f48b000 CR4: 00000000000006e0 [ 1959.173415] Stack: [ 1959.175656] ffffc90001c13040 ffff880329334a00 ffff880330884ed0 ffff88032a957bdc [ 1959.183946] ffff88032a957bb8 ffffffffa040f225 ffff880329334a30 ffff880300000000 [ 1959.192233] ffffffffa04133e0 ffff880329334b30 0000000830884d58 00000000569c58cf [ 1959.200521] Call Trace: [ 1959.203248] [] dm_exception_store_create+0x1d5/0x240 [dm_snapshot] [ 1959.211986] [] snapshot_ctr+0x140/0x630 [dm_snapshot] [ 1959.219469] [] ? dm_split_args+0x64/0x150 [dm_mod] [ 1959.226656] [] dm_table_add_target+0x177/0x440 [dm_mod] [ 1959.234328] [] table_load+0x143/0x370 [dm_mod] [ 1959.241129] [] ? retrieve_status+0x1b0/0x1b0 [dm_mod] [ 1959.248607] [] ctl_ioctl+0x255/0x4d0 [dm_mod] [ 1959.255307] [] ? memzero_explicit+0x12/0x20 [ 1959.261816] [] dm_ctl_ioctl+0x13/0x20 [dm_mod] [ 1959.268615] [] do_vfs_ioctl+0xa6/0x5c0 [ 1959.274637] [] ? __audit_syscall_entry+0xaf/0x100 [ 1959.281726] [] ? do_audit_syscall_entry+0x66/0x70 [ 1959.288814] [] SyS_ioctl+0x79/0x90 [ 1959.294450] [] entry_SYSCALL_64_fastpath+0x12/0x71 ... [ 1959.323277] RIP [] dm_exception_store_set_chunk_size+0x7a/0x110 [dm_snapshot] [ 1959.333090] RSP [ 1959.336978] CR2: 0000000000000098 [ 1959.344121] ---[ end trace b049991ccad1169e ]--- Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1195899 Cc: stable@vger.kernel.org Signed-off-by: Ding Xiang Signed-off-by: Mike Snitzer

dm: rename target's per_bio_data_size to per_io_data_size

2016-02-23T03:34:37+00:00

Request-based DM will also make use of per_bio_data_size. Signed-off-by: Mike Snitzer

dm: optimize dm_mq_queue_rq()

2016-02-22T16:06:22+00:00

DM multipath is the only dm-mq target. But that aside, request-based DM only supports tables with a single target that is immutable. Leverage this fact in dm_mq_queue_rq() by using the 'immutable_target' stored in the mapped_device when the table was made active. This saves the need to even take the read-side of the SRCU via dm_{get,put}_live_table. If the active DM table does not have an immutable target (e.g. "error" target was swapped in) then fallback to the slow-path where the target is looked up from the live table. Signed-off-by: Mike Snitzer

dm: set DM_TARGET_WILDCARD feature on "error" target

2016-02-22T16:06:21+00:00

The DM_TARGET_WILDCARD feature indicates that the "error" target may replace any target; even immutable targets. This feature will be useful to preserve the ability to replace the "multipath" target even once it is formally converted over to having the DM_TARGET_IMMUTABLE feature. Also, implicit in the DM_TARGET_WILDCARD feature flag being set is that .map, .map_rq, .clone_and_map_rq and .release_clone_rq are all defined in the target_type. Signed-off-by: Mike Snitzer

block: Inline blk_integrity in struct gendisk

2015-10-21T20:42:42+00:00

Up until now the_integrity profile has been dynamically allocated and attached to struct gendisk after the disk has been made active. This causes problems because NVMe devices need to register the profile prior to the partition table being read due to a mandatory metadata buffer requirement. In addition, DM goes through hoops to deal with preallocating, but not initializing integrity profiles. Since the integrity profile is small (4 bytes + a pointer), Christoph suggested moving it to struct gendisk proper. This requires several changes: - Moving the blk_integrity definition to genhd.h. - Inlining blk_integrity in struct gendisk. - Removing the dynamic allocation code. - Adding helper functions which allow gendisk to set up and tear down the integrity sysfs dir when a disk is added/deleted. - Adding a blk_integrity_revalidate() callback for updating the stable pages bdi setting. - The calls that depend on whether a device has an integrity profile or not now key off of the bi->profile pointer. - Simplifying the integrity support routines in DM (Mike Snitzer). Signed-off-by: Martin K. Petersen Reported-by: Christoph Hellwig Reviewed-by: Sagi Grimberg Signed-off-by: Mike Snitzer Cc: Dan Williams Signed-off-by: Dan Williams Signed-off-by: Jens Axboe

block: Replace SG_GAPS with new queue limits mask

2015-08-19T21:26:02+00:00

The SG_GAPS queue flag caused checks for bio vector alignment against PAGE_SIZE, but the device may have different constraints. This patch adds a queue limits so a driver with such constraints can set to allow requests that would have been unnecessarily split. The new gaps check takes the request_queue as a parameter to simplify the logic around invoking this function. This new limit makes the queue flag redundant, so removing it and all usage. Device-mappers will inherit the correct settings through blk_stack_limits(). Signed-off-by: Keith Busch Reviewed-by: Martin K. Petersen Reviewed-by: Christoph Hellwig Signed-off-by: Jens Axboe

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

Revert "block, dm: don't copy bios for request clones"

2015-06-26T14:11:58+00:00

This reverts commit 5f1b670d0bef508a5554d92525f5f6d00d640b38. Justification for revert as reported in this dm-devel post: https://www.redhat.com/archives/dm-devel/2015-June/msg00160.html this change should not be pushed to mainline yet. Firstly, Christoph has a newer version of the patch that fixes silent data corruption problem: https://www.redhat.com/archives/dm-devel/2015-May/msg00229.html And the new version still depends on LLDDs to always complete requests to the end when error happens, while block API doesn't enforce such a requirement. If the assumption is ever broken, the inconsistency between request and bio (e.g. rq->__sector and rq->bio) will cause silent data corruption: https://www.redhat.com/archives/dm-devel/2015-June/msg00022.html Reported-by: Junichi Nomura Signed-off-by: Mike Snitzer

Revert "dm: do not allocate any mempools for blk-mq request-based DM"

2015-06-26T14:11:07+00:00

This reverts commit cbc4e3c1350beb47beab8f34ad9be3d34a20c705. Reported-by: Junichi Nomura Signed-off-by: Mike Snitzer

dm: do not allocate any mempools for blk-mq request-based DM

2015-05-29T18:18:57+00:00

Do not allocate the io_pool mempool for blk-mq request-based DM (DM_TYPE_MQ_REQUEST_BASED) in dm_alloc_rq_mempools(). Also refine __bind_mempools() to have more precise awareness of which mempools each type of DM device uses -- avoids mempool churn when reloading DM tables (particularly for DM_TYPE_REQUEST_BASED). Signed-off-by: Mike Snitzer