kernel/linux.git/drivers/md/md.c, branch v4.14.85

MD: fix invalid stored role for a disk - try2

2018-11-13T19:15:18+00:00

commit 9e753ba9b9b405e3902d9f08aec5f2ea58a0c317 upstream. Commit d595567dc4f0 (MD: fix invalid stored role for a disk) broke linear hotadd. Let's only fix the role for disks in raid1/10. Based on Guoqing's original patch. Reported-by: kernel test robot Cc: Gioh Kim Cc: Guoqing Jiang Signed-off-by: Shaohua Li Signed-off-by: Greg Kroah-Hartman

MD: fix invalid stored role for a disk

2018-11-13T19:14:58+00:00

[ Upstream commit d595567dc4f0c1d90685ec1e2e296e2cad2643ac ] If we change the number of array's device after device is removed from array, then add the device back to array, we can see that device is added as active role instead of spare which we expected. Please see the below link for details: https://marc.info/?l=linux-raid&m=153736982015076&w=2 This is caused by that we prefer to use device's previous role which is recorded by saved_raid_disk, but we should respect the new number of conf->raid_disks since it could be changed after device is removed. Reported-by: Gioh Kim Tested-by: Gioh Kim Acked-by: Guoqing Jiang Signed-off-by: Shaohua Li Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

md: fix NULL dereference of mddev->pers in remove_and_add_spares()

2018-08-03T05:50:33+00:00

[ Upstream commit c42a0e2675721e1444f56e6132a07b7b1ec169ac ] We met NULL pointer BUG as follow: [ 151.760358] BUG: unable to handle kernel NULL pointer dereference at 0000000000000060 [ 151.761340] PGD 80000001011eb067 P4D 80000001011eb067 PUD 1011ea067 PMD 0 [ 151.762039] Oops: 0000 [#1] SMP PTI [ 151.762406] Modules linked in: [ 151.762723] CPU: 2 PID: 3561 Comm: mdadm-test Kdump: loaded Not tainted 4.17.0-rc1+ #238 [ 151.763542] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1.fc26 04/01/2014 [ 151.764432] RIP: 0010:remove_and_add_spares.part.56+0x13c/0x3a0 [ 151.765061] RSP: 0018:ffffc90001d7fcd8 EFLAGS: 00010246 [ 151.765590] RAX: 0000000000000000 RBX: ffff88013601d600 RCX: 0000000000000000 [ 151.766306] RDX: 0000000000000000 RSI: ffff88013601d600 RDI: ffff880136187000 [ 151.767014] RBP: ffff880136187018 R08: 0000000000000003 R09: 0000000000000051 [ 151.767728] R10: ffffc90001d7fed8 R11: 0000000000000000 R12: ffff88013601d600 [ 151.768447] R13: ffff8801298b1300 R14: ffff880136187000 R15: 0000000000000000 [ 151.769160] FS: 00007f2624276700(0000) GS:ffff88013ae80000(0000) knlGS:0000000000000000 [ 151.769971] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 151.770554] CR2: 0000000000000060 CR3: 0000000111aac000 CR4: 00000000000006e0 [ 151.771272] Call Trace: [ 151.771542] md_ioctl+0x1df2/0x1e10 [ 151.771906] ? __switch_to+0x129/0x440 [ 151.772295] ? __schedule+0x244/0x850 [ 151.772672] blkdev_ioctl+0x4bd/0x970 [ 151.773048] block_ioctl+0x39/0x40 [ 151.773402] do_vfs_ioctl+0xa4/0x610 [ 151.773770] ? dput.part.23+0x87/0x100 [ 151.774151] ksys_ioctl+0x70/0x80 [ 151.774493] __x64_sys_ioctl+0x16/0x20 [ 151.774877] do_syscall_64+0x5b/0x180 [ 151.775258] entry_SYSCALL_64_after_hwframe+0x44/0xa9 For raid6, when two disk of the array are offline, two spare disks can be added into the array. Before spare disks recovery completing, system reboot and mdadm thinks it is ok to restart the degraded array by md_ioctl(). Since disks in raid6 is not only_parity(), raid5_run() will abort, when there is no PPL feature or not setting 'start_dirty_degraded' parameter. Therefore, mddev->pers is NULL. But, mddev->raid_disks has been set and it will not be cleared when raid5_run abort. md_ioctl() can execute cmd 'HOT_REMOVE_DISK' to remove a disk by mdadm, which will cause NULL pointer dereference in remove_and_add_spares() finally. Signed-off-by: Yufen Yu Signed-off-by: Shaohua Li Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

md: remove special meaning of ->quiesce(.., 2)

2018-07-08T13:30:50+00:00

commit b03e0ccb5ab9df3efbe51c87843a1ffbecbafa1f upstream. The '2' argument means "wake up anything that is waiting". This is an inelegant part of the design and was added to help support management of suspend_lo/suspend_hi setting. Now that suspend_lo/hi is managed in mddev_suspend/resume, that need is gone. These is still a couple of places where we call 'quiesce' with an argument of '2', but they can safely be changed to call ->quiesce(.., 1); ->quiesce(.., 0) which achieve the same result at the small cost of pausing IO briefly. This removes a small "optimization" from suspend_{hi,lo}_store, but it isn't clear that optimization served a useful purpose. The code now is a lot clearer. Suggested-by: Shaohua Li Signed-off-by: NeilBrown Signed-off-by: Shaohua Li Signed-off-by: Jack Wang Signed-off-by: Greg Kroah-Hartman

md: allow metadata update while suspending.

2018-07-08T13:30:50+00:00

commit 35bfc52187f6df8779d0f1cebdb52b7f797baf4e upstream. There are various deadlocks that can occur when a thread holds reconfig_mutex and calls ->quiesce(mddev, 1). As some write request block waiting for metadata to be updated (e.g. to record device failure), and as the md thread updates the metadata while the reconfig mutex is held, holding the mutex can stop write requests completing, and this prevents ->quiesce(mddev, 1) from completing. ->quiesce() is now usually called from mddev_suspend(), and it is always called with reconfig_mutex held. So at this time it is safe for the thread to update metadata without explicitly taking the lock. So add 2 new flags, one which says the unlocked updates is allowed, and one which ways it is happening. Then allow it while the quiesce completes, and then wait for it to finish. Reported-and-tested-by: Xiao Ni Signed-off-by: NeilBrown Signed-off-by: Shaohua Li Signed-off-by: Jack Wang Signed-off-by: Greg Kroah-Hartman

md: use mddev_suspend/resume instead of ->quiesce()

2018-07-08T13:30:50+00:00

commit 9e1cc0a54556a6c63dc0cfb7cd7d60d43337bba6 upstream. mddev_suspend() is a more general interface than calling ->quiesce() and is so more extensible. A future patch will make use of this. Signed-off-by: NeilBrown Signed-off-by: Shaohua Li Signed-off-by: Jack Wang Signed-off-by: Greg Kroah-Hartman

md: move suspend_hi/lo handling into core md code

2018-07-08T13:30:50+00:00

commit b3143b9a38d5039bcd1f2d1c94039651bfba8043 upstream. responding to ->suspend_lo and ->suspend_hi is similar to responding to ->suspended. It is best to wait in the common core code without incrementing ->active_io. This allows mddev_suspend()/mddev_resume() to work while requests are waiting for suspend_lo/hi to change. This is will be important after a subsequent patch which uses mddev_suspend() to synchronize updating for suspend_lo/hi. So move the code for testing suspend_lo/hi out of raid1.c and raid5.c, and place it in md.c Signed-off-by: NeilBrown Signed-off-by: Shaohua Li Signed-off-by: Jack Wang Signed-off-by: Greg Kroah-Hartman

md: don't call bitmap_create() while array is quiesced.

2018-07-08T13:30:50+00:00

commit 52a0d49de3d592a3118e13f35985e3d99eaf43df upstream. bitmap_create() allocates memory with GFP_KERNEL and so can wait for IO. If called while the array is quiesced, it could wait indefinitely for write out to the array - deadlock. So call bitmap_create() before quiescing the array. Signed-off-by: NeilBrown Signed-off-by: Shaohua Li Signed-off-by: Jack Wang Signed-off-by: Greg Kroah-Hartman

md: always hold reconfig_mutex when calling mddev_suspend()

2018-07-08T13:30:49+00:00

commit 4d5324f760aacaefeb721b172aa14bf66045c332 upstream. Most often mddev_suspend() is called with reconfig_mutex held. Make this a requirement in preparation a subsequent patch. Also require reconfig_mutex to be held for mddev_resume(), partly for symmetry and partly to guarantee no races with incr/decr of mddev->suspend. Taking the mutex in r5c_disable_writeback_async() is a little tricky as this is called from a work queue via log->disable_writeback_work, and flush_work() is called on that while holding ->reconfig_mutex. If the work item hasn't run before flush_work() is called, the work function will not be able to get the mutex. So we use mddev_trylock() inside the wait_event() call, and have that abort when conf->log is set to NULL, which happens before flush_work() is called. We wait in mddev->sb_wait and ensure this is woken when any of the conditions change. This requires waking mddev->sb_wait in mddev_unlock(). This is only like to trigger extra wake_ups of threads that needn't be woken when metadata is being written, and that doesn't happen often enough that the cost would be noticeable. Signed-off-by: NeilBrown Signed-off-by: Shaohua Li Signed-off-by: Jack Wang Signed-off-by: Greg Kroah-Hartman

md: fix two problems with setting the "re-add" device state.

2018-07-03T09:24:59+00:00

commit 011abdc9df559ec75779bb7c53a744c69b2a94c6 upstream. If "re-add" is written to the "state" file for a device which is faulty, this has an effect similar to removing and re-adding the device. It should take up the same slot in the array that it previously had, and an accelerated (e.g. bitmap-based) rebuild should happen. The slot that "it previously had" is determined by rdev->saved_raid_disk. However this is not set when a device fails (only when a device is added), and it is cleared when resync completes. This means that "re-add" will normally work once, but may not work a second time. This patch includes two fixes. 1/ when a device fails, record the ->raid_disk value in ->saved_raid_disk before clearing ->raid_disk 2/ when "re-add" is written to a device for which ->saved_raid_disk is not set, fail. I think this is suitable for stable as it can cause re-adding a device to be forced to do a full resync which takes a lot longer and so puts data at more risk. Cc: (v4.1) Fixes: 97f6cd39da22 ("md-cluster: re-add capabilities") Signed-off-by: NeilBrown Reviewed-by: Goldwyn Rodrigues Signed-off-by: Shaohua Li Signed-off-by: Greg Kroah-Hartman