kernel/linux.git/drivers/md/md.c, branch v3.0.95

md: protect against crash upon fsync on ro array

2013-03-20T19:58:52+00:00

commit bbfa57c0f2243a7c31fd248d22e9861a2802cad5 upstream. If an fsync occurs on a read-only array, we need to send a completion for the IO and may not increment the active IO count. Otherwise, we hit a bug trace and can't stop the MD array anymore. By advice of Christoph Hellwig we return success upon a flush request but we return -EROFS for other writes. We detect flush requests by checking if the bio has zero sectors. Signed-off-by: Sebastian Riemer Cc: Christoph Hellwig Cc: Ben Hutchings Cc: NeilBrown Reported-by: Ben Hutchings Acked-by: Paul Menzel Signed-off-by: Greg Kroah-Hartman

md: Don't truncate size at 4TB for RAID0 and Linear

2012-10-02T16:47:25+00:00

commit 667a5313ecd7308d79629c0738b0db588b0b0a4e upstream. commit 27a7b260f71439c40546b43588448faac01adb93 md: Fix handling for devices from 2TB to 4TB in 0.90 metadata. changed 0.90 metadata handling to truncated size to 4TB as that is all that 0.90 can record. However for RAID0 and Linear, 0.90 doesn't need to record the size, so this truncation is not needed and causes working arrays to become too small. So avoid the truncation for RAID0 and Linear This bug was introduced in 3.1 and is suitable for any stable kernels from then onwards. As the offending commit was tagged for 'stable', any stable kernel that it was applied to should also get this patch. That includes at least 2.6.32, 2.6.33 and 3.0. (Thanks to Ben Hutchings for providing that list). Signed-off-by: Neil Brown Signed-off-by: Greg Kroah-Hartman

md: using GFP_NOIO to allocate bio for flush request

2012-06-01T07:12:56+00:00

commit b5e1b8cee7ad58a15d2fa79bcd7946acb592602d upstream. A flush request is usually issued in transaction commit code path, so using GFP_KERNEL to allocate memory for flush request bio falls into the classic deadlock issue. This is suitable for any -stable kernel to which it applies as it avoids a possible deadlock. Signed-off-by: Shaohua Li Signed-off-by: NeilBrown Signed-off-by: Greg Kroah-Hartman

MD: Add del_timer_sync to mddev_suspend (fix nasty panic)

2012-05-21T16:40:03+00:00

commit 0d9f4f135eb6dea06bdcb7065b1e4ff78274a5e9 upstream. Use del_timer_sync to remove timer before mddev_suspend finishes. We don't want a timer going off after an mddev_suspend is called. This is especially true with device-mapper, since it can call the destructor function immediately following a suspend. This results in the removal (kfree) of the structures upon which the timer depends - resulting in a very ugly panic. Therefore, we add a del_timer_sync to mddev_suspend to prevent this. Signed-off-by: NeilBrown Signed-off-by: Greg Kroah-Hartman

md: Avoid waking up a thread after it has been freed.

2011-10-16T21:14:53+00:00

commit 01f96c0a9922cd9919baf9d16febdf7016177a12 upstream. Two related problems: 1/ some error paths call "md_unregister_thread(mddev->thread)" without subsequently clearing ->thread. A subsequent call to mddev_unlock will try to wake the thread, and crash. 2/ Most calls to md_wakeup_thread are protected against the thread disappeared either by: - holding the ->mutex - having an active request, so something else must be keeping the array active. However mddev_unlock calls md_wakeup_thread after dropping the mutex and without any certainty of an active request, so the ->thread could theoretically disappear. So we need a spinlock to provide some protections. So change md_unregister_thread to take a pointer to the thread pointer, and ensure that it always does the required locking, and clears the pointer properly. Reported-by: "Moshe Melnikov" Signed-off-by: NeilBrown Signed-off-by: Greg Kroah-Hartman

md: Fix handling for devices from 2TB to 4TB in 0.90 metadata.

2011-10-03T18:40:14+00:00

commit 27a7b260f71439c40546b43588448faac01adb93 upstream. 0.90 metadata uses an unsigned 32bit number to count the number of kilobytes used from each device. This should allow up to 4TB per device. However we multiply this by 2 (to get sectors) before casting to a larger type, so sizes above 2TB get truncated. Also we allow rdev->sectors to be larger than 4TB, so it is possible for the array to be resized larger than the metadata can handle. So make sure rdev->sectors never exceeds 4TB when 0.90 metadata is in used. Also the sanity check at the end of super_90_load should include level 1 as it used ->size too. (RAID0 and Linear don't use ->size at all). Reported-by: Pim Zandbergen Signed-off-by: NeilBrown Signed-off-by: Greg Kroah-Hartman

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

2011-06-28T06:59:42+00:00

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. Cc: stable@kernel.org Reported-by: Jim Paradis Signed-off-by: NeilBrown

md: check ->hot_remove_disk when removing disk

2011-06-09T01:42:54+00:00

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 Cc: stable@kernel.org Signed-off-by: NeilBrown

md: Using poll /proc/mdstat can monitor the events of adding a spare disks

2011-06-09T01:42:48+00:00

Signed-off-by: majianpeng Signed-off-by: NeilBrown

MD: add sync_super to mddev_t struct

2011-06-08T05:11:31+00:00

Add the 'sync_super' function pointer to MD array structure (struct mddev_s) If device-mapper (dm-raid.c) is to define its own on-disk superblock and be able to load it, there must still be a way for MD to initiate superblock updates. The simplest way to make this happen is to provide a pointer in the MD array structure that can be set by device-mapper (or other module) with a function to do this. If the function has been set, it will be used; otherwise, the method with be looked up via 'super_types' as usual. Signed-off-by: Jonathan Brassow Signed-off-by: NeilBrown