user/sven/linux.git/drivers/md/md.c, branch v3.0

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

2011-06-28T06:59:42Z

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

2011-06-09T01:42:54Z

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

2011-06-09T01:42:48Z

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

MD: add sync_super to mddev_t struct

2011-06-08T05:11:31Z

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

MD: move thread wakeups into resume

2011-06-08T05:11:31Z

Move personality and sync/recovery thread starting outside md_run. Moving the wakeup's of the personality and sync/recovery threads out of md_run and into do_md_run and mddev_resume solves two issues: 1) It allows bitmap_load to be called before the sync_thread is run and 2) when MD personalities are used by device-mapper (dm-raid.c), the start-up of the array is better alligned with device-mapper primatives (CTR/resume/suspend/DTR). I/O - in this case, recovery operations - should not happen until after a resume has taken place. Signed-off-by: Jonathan Brassow Signed-off-by: NeilBrown

MD: possible typo

2011-06-08T05:11:31Z

Make message a bit clearer by s/blocks/k/ I chose 'k' vs 'kiB' or 'kB' because it is what is used earlier in the message. 'k' may be a bit ambigous, but I think it's better than "blocks" which normally means 512, but means 1024 in MD. Signed-off-by: Jonathan Brassow Signed-off-by: NeilBrown

MD: no sync IO while suspended

2011-06-08T05:10:08Z

Disallow resync I/O while the RAID array is suspended. Recovery, resync, and metadata I/O should not be allowed while a device is suspended. Signed-off-by: Jonathan Brassow Signed-off-by: NeilBrown

MD: no integrity register if no gendisk

2011-06-08T05:10:08Z

Don't attempt md_integrity_register if there is no gendisk struct available. When MD arrays are built via device-mapper, the gendisk structure is not available via mddev. Signed-off-by: Jonathan Brassow Signed-off-by: NeilBrown

md: allow resync_start to be set while an array is active.

2011-05-11T05:52:21Z

The sysfs attribute 'resync_start' (known internally as recovery_cp), records where a resync is up to. A value of 0 means the array is not known to be in-sync at all. A value of MaxSector means the array is believed to be fully in-sync. When the size of member devices of an array (RAID1,RAID4/5/6) is increased, the array can be increased to match. This process sets resync_start to the old end-of-device offset so that the new part of the array gets resynced. However with RAID1 (and RAID6) a resync is not technically necessary and may be undesirable. So it would be good if the implied resync after the array is resized could be avoided. So: change 'resync_start' so the value can be changed while the array is active, and as a precaution only allow it to be changed while resync/recovery is 'frozen'. Changing it once resync has started is not going to be useful anyway. This allows the array to be resized without a resync by: write 'frozen' to 'sync_action' write new size to 'component_size' (this will set resync_start) write 'none' to 'resync_start' write 'idle' to 'sync_action'. Also slightly improve some tests on recovery_cp when resizing raid1/raid5. Now that an arbitrary value could be set we should be more careful in our tests. Signed-off-by: NeilBrown

md: reject a re-add request that cannot be honoured.

2011-05-11T04:26:20Z

The 'add_new_disk' ioctl can be used to add a device either as a spare, or as an active disk that just needs to be resynced based on write-intent-bitmap information (re-add) Currently if a re-add is requested but fails we add as a spare instead. This makes it impossible for user-space to check for failure. So change to require that a re-add attempt will either succeed or completely fail. User-space can then decide what to do next. Signed-off-by: NeilBrown