kernel/git/stable/linux-stable.git/drivers/md/md.c, branch linux-2.6.39.y

md: avoid endless recovery loop when waiting for fail device to complete.

2011-07-09T06:15:29+00:00

commit 4274215d24633df7302069e51426659d4759c5ed upstream. If a device fails in a way that causes pending request to take a while to complete, md will not be able to immediately remove it from the array in remove_and_add_spares. It will then incorrectly look like a spare device and md will try to recover it even though it is failed. This leads to a recovery process starting and instantly aborting over and over again. We should check if the device is faulty before considering it to be a spare. This will avoid trying to start a recovery that cannot proceed. This bug was introduced in 2.6.26 so that patch is suitable for any kernel since then. Reported-by: Jim Paradis Signed-off-by: NeilBrown Signed-off-by: Greg Kroah-Hartman

md: check ->hot_remove_disk when removing disk

2011-06-23T22:05:40+00:00

commit 01393f3d5836b7d62e925e6f4658a7eb22b83a11 upstream. Check pers->hot_remove_disk instead of pers->hot_add_disk in slot_store() during disk removal. The linear personality only has ->hot_add_disk and no ->hot_remove_disk, so that removing disk in the array resulted to following kernel bug: $ sudo mdadm --create /dev/md0 --level=linear --raid-devices=4 /dev/loop[0-3] $ echo none | sudo tee /sys/block/md0/md/dev-loop2/slot BUG: unable to handle kernel NULL pointer dereference at (null) IP: [< (null)>] (null) PGD c9f5d067 PUD 8575a067 PMD 0 Oops: 0010 [#1] SMP CPU 2 Modules linked in: linear loop bridge stp llc kvm_intel kvm asus_atk0110 sr_mod cdrom sg Pid: 10450, comm: tee Not tainted 3.0.0-rc1-leonard+ #173 System manufacturer System Product Name/P5G41TD-M PRO RIP: 0010:[<0000000000000000>] [< (null)>] (null) RSP: 0018:ffff880085757df0 EFLAGS: 00010282 RAX: ffffffffa00168e0 RBX: ffff8800d1431800 RCX: 000000000000006e RDX: 0000000000000001 RSI: 0000000000000002 RDI: ffff88008543c000 RBP: ffff880085757e48 R08: 0000000000000002 R09: 000000000000000a R10: 0000000000000000 R11: ffff88008543c2e0 R12: 00000000ffffffff R13: ffff8800b4641000 R14: 0000000000000005 R15: 0000000000000000 FS: 00007fe8c9e05700(0000) GS:ffff88011fa00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: 0000000000000000 CR3: 00000000b4502000 CR4: 00000000000406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Process tee (pid: 10450, threadinfo ffff880085756000, task ffff8800c9f08000) Stack: ffffffff8138496a ffff8800b4641000 ffff88008543c268 0000000000000000 ffff8800b4641000 ffff88008543c000 ffff8800d1431868 ffffffff81a78a90 ffff8800b4641000 ffff88008543c000 ffff8800d1431800 ffff880085757e98 Call Trace: [] ? slot_store+0xaa/0x265 [] rdev_attr_store+0x89/0xa8 [] sysfs_write_file+0x108/0x144 [] vfs_write+0xb1/0x10d [] ? trace_hardirqs_on_caller+0x111/0x135 [] sys_write+0x4d/0x77 [] system_call_fastpath+0x16/0x1b Code: Bad RIP value. RIP [< (null)>] (null) RSP CR2: 0000000000000000 ---[ end trace ba5fc64319a826fb ]--- Signed-off-by: Namhyung Kim Signed-off-by: NeilBrown Signed-off-by: Greg Kroah-Hartman

md: Fix race when creating a new md device.

2011-06-03T00:32:12+00:00

commit b0140891a8cea36469f58d23859e599b1122bd37 upstream. There is a race when creating an md device by opening /dev/mdXX. If two processes do this at much the same time they will follow the call path __blkdev_get -> get_gendisk -> kobj_lookup The first will call -> md_probe -> md_alloc -> add_disk -> blk_register_region and the race happens when the second gets to kobj_lookup after add_disk has called blk_register_region but before it returns to md_alloc. In the case the second will not call md_probe (as the probe is already done) but will get a handle on the gendisk, return to __blkdev_get which will then call md_open (via the ->open) pointer. As mddev->gendisk hasn't been set yet, md_open will think something is wrong an return with ERESTARTSYS. This can loop endlessly while the first thread makes no progress through add_disk. Nothing is blocking it, but due to scheduler behaviour it doesn't get a turn. So this is essentially a live-lock. We fix this by simply moving the assignment to mddev->gendisk before the call the add_disk() so md_open doesn't get confused. Also move blk_queue_flush earlier because add_disk should be as late as possible. To make sure that md_open doesn't complete until md_alloc has done all that is needed, we take mddev->open_mutex during the last part of md_alloc. md_open will wait for this. This can cause a lock-up on boot so Cc:ing for stable. For 2.6.36 and earlier a different patch will be needed as the 'blk_queue_flush' call isn't there. Signed-off-by: NeilBrown Reported-by: Thomas Jarosch Tested-by: Thomas Jarosch Signed-off-by: Greg Kroah-Hartman

md: Cleanup after raid45->raid0 takeover

2011-04-20T05:39:53+00:00

Problem: After raid4->raid0 takeover operation, another takeover operation (e.g raid0->raid10) results "kernel oops". Root cause: Variables 'degraded' in mddev structure is not cleared on raid45->raid0 takeover. This patch reset this variable. Signed-off-by: Krzysztof Wojcik Signed-off-by: NeilBrown

md: provide generic support for handling unplug callbacks.

2011-04-18T08:25:42+00:00

When an md device adds a request to a queue, it can call mddev_check_plugged. If this succeeds then we know that the md thread will be woken up shortly, and ->plug_cnt will be non-zero until then, so some processing can be delayed. If it fails, then no unplug callback is expected and the make_request function needs to do whatever is required to make the request happen. Signed-off-by: NeilBrown

md - remove old plugging code.

2011-04-18T08:25:42+00:00

md has some plugging infrastructure for RAID5 to use because the normal plugging infrastructure required a 'request_queue', and when called from dm, RAID5 doesn't have one of those available. This relied on the ->unplug_fn callback which doesn't exist any more. So remove all of that code, both in md and raid5. Subsequent patches with restore the plugging functionality. Signed-off-by: NeilBrown

Fix common misspellings

2011-03-31T14:26:23+00:00

Fixes generated by 'codespell' and manually reviewed. Signed-off-by: Lucas De Marchi

md: Fix integrity registration error when no devices are capable

2011-03-29T00:53:29+00:00

We incorrectly returned -EINVAL when none of the devices in the array had an integrity profile. This in turn prevented mdadm from starting the metadevice. Fix this so we only return errors on mismatched profiles and memory allocation failures. Reported-by: Giacomo Catenazzi Reported-by: Thomas Gleixner Signed-off-by: Martin K. Petersen Signed-off-by: Linus Torvalds

Merge branch 'for-2.6.39/core' of git://git.kernel.dk/linux-2.6-block

2011-03-24T17:16:26+00:00

* 'for-2.6.39/core' of git://git.kernel.dk/linux-2.6-block: (65 commits) Documentation/iostats.txt: bit-size reference etc. cfq-iosched: removing unnecessary think time checking cfq-iosched: Don't clear queue stats when preempt. blk-throttle: Reset group slice when limits are changed blk-cgroup: Only give unaccounted_time under debug cfq-iosched: Don't set active queue in preempt block: fix non-atomic access to genhd inflight structures block: attempt to merge with existing requests on plug flush block: NULL dereference on error path in __blkdev_get() cfq-iosched: Don't update group weights when on service tree fs: assign sb->s_bdi to default_backing_dev_info if the bdi is going away block: Require subsystems to explicitly allocate bio_set integrity mempool jbd2: finish conversion from WRITE_SYNC_PLUG to WRITE_SYNC and explicit plugging jbd: finish conversion from WRITE_SYNC_PLUG to WRITE_SYNC and explicit plugging fs: make fsync_buffers_list() plug mm: make generic_writepages() use plugging blk-cgroup: Add unaccounted time to timeslice_used. block: fixup plugging stubs for !CONFIG_BLOCK block: remove obsolete comments for blkdev_issue_zeroout. blktrace: Use rq->cmd_flags directly in blk_add_trace_rq. ... Fix up conflicts in fs/{aio.c,super.c}

block: Require subsystems to explicitly allocate bio_set integrity mempool

2011-03-17T10:11:05+00:00

MD and DM create a new bio_set for every metadevice. Each bio_set has an integrity mempool attached regardless of whether the metadevice is capable of passing integrity metadata. This is a waste of memory. Instead we defer the allocation decision to MD and DM since we know at metadevice creation time whether integrity passthrough is needed or not. Automatic integrity mempool allocation can then be removed from bioset_create() and we make an explicit integrity allocation for the fs_bio_set. Signed-off-by: Martin K. Petersen Reported-by: Zdenek Kabelac Acked-by: Mike Snitzer Signed-off-by: Jens Axboe