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| author | Namhyung Kim <namhyung@gmail.com> | 2011-06-09 11:42:54 +1000 |
|---|---|---|
| committer | Willy Tarreau <w@1wt.eu> | 2012-02-11 15:37:30 +0100 |
| commit | e97726577a6fd2aba08cb766758b3dfba24bb750 (patch) | |
| tree | eecaca7f47972fda7011e904e0301da84f0edc11 | |
| parent | 7b68dbd91fa2e635361b94d3e9c56cc6bad7a24e (diff) | |
| download | lwn-e97726577a6fd2aba08cb766758b3dfba24bb750.tar.gz lwn-e97726577a6fd2aba08cb766758b3dfba24bb750.zip | |
md: check ->hot_remove_disk when removing disk
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:
[<ffffffff8138496a>] ? slot_store+0xaa/0x265
[<ffffffff81384bae>] rdev_attr_store+0x89/0xa8
[<ffffffff8115a96a>] sysfs_write_file+0x108/0x144
[<ffffffff81106b87>] vfs_write+0xb1/0x10d
[<ffffffff8106e6c0>] ? trace_hardirqs_on_caller+0x111/0x135
[<ffffffff81106cac>] sys_write+0x4d/0x77
[<ffffffff814fe702>] system_call_fastpath+0x16/0x1b
Code: Bad RIP value.
RIP [< (null)>] (null)
RSP <ffff880085757df0>
CR2: 0000000000000000
---[ end trace ba5fc64319a826fb ]---
Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Willy Tarreau <w@1wt.eu>
| -rw-r--r-- | drivers/md/md.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/md/md.c b/drivers/md/md.c index d7bb62d4e591..cdaadf571718 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -2002,7 +2002,7 @@ slot_store(mdk_rdev_t *rdev, const char *buf, size_t len) if (rdev->raid_disk == -1) return -EEXIST; /* personality does all needed checks */ - if (rdev->mddev->pers->hot_add_disk == NULL) + if (rdev->mddev->pers->hot_remove_disk == NULL) return -EINVAL; err = rdev->mddev->pers-> hot_remove_disk(rdev->mddev, rdev->raid_disk); |