kernel/git/stable/linux-stable.git/drivers/md/md.c, branch linux-2.6.35.y

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

2011-08-01T20:54:58+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 Signed-off-by: Andi Kleen

md: check ->hot_remove_disk when removing disk

2011-08-01T20:54:56+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 Signed-off-by: Andi Kleen

md: Fix - again - partition detection when array becomes active

2011-03-31T18:58:54+00:00

[ upstream commit f0b4f7e2f29af678bd9af43422c537dcb6008603 ] Revert b821eaa572fd737faaf6928ba046e571526c36c6 and f3b99be19ded511a1bf05a148276239d9f13eefa When I wrote the first of these I had a wrong idea about the lifetime of 'struct block_device'. It can disappear at any time that the block device is not open if it falls out of the inode cache. So relying on the 'size' recorded with it to detect when the device size has changed and so we need to revalidate, is wrong. Rather, we really do need the 'changed' attribute stored directly in the mddev and set/tested as appropriate. Without this patch, a sequence of: mknod / open / close / unlink (which can cause a block_device to be created and then destroyed) will result in a rescan of the partition table and consequence removal and addition of partitions. Several of these in a row can get udev racing to create and unlink and other code can get confused. With the patch, the rescan is only performed when needed and so there are no races. This is suitable for any stable kernel from 2.6.35. Reported-by: "Wojcik, Krzysztof" Signed-off-by: NeilBrown Signed-off-by: Andi Kleen Cc: stable@kernel.org

md: correctly handle probe of an 'mdp' device.

2011-03-31T18:58:13+00:00

commit 8f5f02c460b7ca74ce55ce126ce0c1e58a3f923d upstream. 'mdp' devices are md devices with preallocated device numbers for partitions. As such it is possible to mknod and open a partition before opening the whole device. this causes md_probe() to be called with a device number of a partition, which in-turn calls mddev_find with such a number. However mddev_find expects the number of a 'whole device' and does the wrong thing with partition numbers. So add code to mddev_find to remove the 'partition' part of a device number and just work with the 'whole device'. This patch addresses https://bugzilla.kernel.org/show_bug.cgi?id=28652 Reported-by: hkmaly@bigfoot.com Signed-off-by: NeilBrown Signed-off-by: Greg Kroah-Hartman Signed-off-by: Andi Kleen

md: fix regression with re-adding devices to arrays with no metadata

2011-03-31T18:57:53+00:00

commit bf572541ab44240163eaa2d486b06f306a31d45a upstream. Commit 1a855a0606 (2.6.37-rc4) fixed a problem where devices were re-added when they shouldn't be but caused a regression in a less common case that means sometimes devices cannot be re-added when they should be. In particular, when re-adding a device to an array without metadata we should always access the device, but after the above commit we didn't. This patch sets the In_sync flag in that case so that the re-add succeeds. This patch is suitable for any -stable kernel to which 1a855a0606 was applied. Signed-off-by: NeilBrown Signed-off-by: Greg Kroah-Hartman Signed-off-by: Andi Kleen

block: Deprecate QUEUE_FLAG_CLUSTER and use queue_limits instead

2011-02-06T19:03:52+00:00

commit e692cb668fdd5a712c6ed2a2d6f2a36ee83997b4 upstream. When stacking devices, a request_queue is not always available. This forced us to have a no_cluster flag in the queue_limits that could be used as a carrier until the request_queue had been set up for a metadevice. There were several problems with that approach. First of all it was up to the stacking device to remember to set queue flag after stacking had completed. Also, the queue flag and the queue limits had to be kept in sync at all times. We got that wrong, which could lead to us issuing commands that went beyond the max scatterlist limit set by the driver. The proper fix is to avoid having two flags for tracking the same thing. We deprecate QUEUE_FLAG_CLUSTER and use the queue limit directly in the block layer merging functions. The queue_limit 'no_cluster' is turned into 'cluster' to avoid double negatives and to ease stacking. Clustering defaults to being enabled as before. The queue flag logic is removed from the stacking function, and explicitly setting the cluster flag is no longer necessary in DM and MD. Reported-by: Ed Lin Signed-off-by: Martin K. Petersen Acked-by: Mike Snitzer Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman Signed-off-by: Andi Kleen

md: protect against NULL reference when waiting to start a raid10.

2011-02-06T19:03:42+00:00

commit 589a594be1fb8815b3f18e517be696c48664f728 upstream. When we fail to start a raid10 for some reason, we call md_unregister_thread to kill the thread that was created. Unfortunately md_thread() will then make one call into the handler (raid10d) even though md_wakeup_thread has not been called. This is not safe and as md_unregister_thread is called after mddev->private has been set to NULL, it will definitely cause a NULL dereference. So fix this at both ends: - md_thread should only call the handler if THREAD_WAKEUP has been set. - raid10 should call md_unregister_thread before setting things to NULL just like all the other raid modules do. This is applicable to 2.6.35 and later. Reported-by: "Citizen" Signed-off-by: NeilBrown Signed-off-by: Greg Kroah-Hartman Signed-off-by: Andi Kleen

md: fix bug with re-adding of partially recovered device.

2011-02-06T19:03:42+00:00

commit 1a855a0606653d2d82506281e2c686bacb4b2f45 upstream. With v0.90 metadata, a hot-spare does not become a full member of the array until recovery is complete. So if we re-add such a device to the array, we know that all of it is as up-to-date as the event count would suggest, and so it a bitmap-based recovery is possible. However with v1.x metadata, the hot-spare immediately becomes a full member of the array, but it record how much of the device has been recovered. If the array is stopped and re-assembled recovery starts from this point. When such a device is hot-added to an array we currently lose the 'how much is recovered' information and incorrectly included it as a full in-sync member (after bitmap-based fixup). This is wrong and unsafe and could corrupt data. So be more careful about setting saved_raid_disk - which is what guides the re-adding of devices back into an array. The new code matches the code in slot_store which does a similar thing, which is encouraging. This is suitable for any -stable kernel. Reported-by: "Dailey, Nate" Signed-off-by: NeilBrown Signed-off-by: Greg Kroah-Hartman Signed-off-by: Andi Kleen

md: fix return value of rdev_size_change()

2010-12-14T22:40:08+00:00

commit c26a44ed1e552aaa1d4ceb71842002d235fe98d7 upstream. When trying to grow an array by enlarging component devices, rdev_size_store() expects the return value of rdev_size_change() to be in sectors, but the actual value is returned in KBs. This functionality was broken by commit dd8ac336c13fd8afdb082ebacb1cddd5cf727889 so this patch is suitable for any kernel since 2.6.30. Signed-off-by: Justin Maggard Signed-off-by: NeilBrown Signed-off-by: Greg Kroah-Hartman Signed-off-by: Andi Kleen

md: fix another deadlock with removing sysfs attributes.

2010-08-13T20:30:48+00:00

commit bb4f1e9d0e2ef93de8e36ca0f5f26625fcd70b7d upstream. Move the deletion of sysfs attributes from reconfig_mutex to open_mutex didn't really help as a process can try to take open_mutex while holding reconfig_mutex, so the same deadlock can happen, just requiring one more process to be involved in the chain. I looks like I cannot easily use locking to wait for the sysfs deletion to complete, so don't. The only things that we cannot do while the deletions are still pending is other things which can change the sysfs namespace: run, takeover, stop. Each of these can fail with -EBUSY. So set a flag while doing a sysfs deletion, and fail run, takeover, stop if that flag is set. This is suitable for 2.6.35.x Signed-off-by: NeilBrown Signed-off-by: Greg Kroah-Hartman