path: root/drivers
diff options
authorNamhyung Kim <namhyung@gmail.com>2011-06-09 11:42:54 +1000
committerGreg Kroah-Hartman <gregkh@suse.de>2011-06-23 15:24:08 -0700
commit58d16045d9b84605251ca2a1faabaa665a1bc159 (patch)
treed1e20067ee1f7868887d9abab1e4cc3e8e1d8319 /drivers
parent21dfd57873ccc7e4ff42d3dbc281cafe03dfb4a4 (diff)
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>
Diffstat (limited to 'drivers')
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/md/md.c b/drivers/md/md.c
index 697a2c7bff2c..7c5129f6f4ed 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -2262,7 +2262,7 @@ 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);