diff options
| author | Josef Bacik <josef@toxicpanda.com> | 2021-03-11 11:23:15 -0500 |
|---|---|---|
| committer | David Sterba <dsterba@suse.com> | 2021-03-17 19:42:09 +0100 |
| commit | 82d62d06db404d03836cdabbca41d38646d97cbb (patch) | |
| tree | c823a9281461c857ea5a56b048858416006e6790 /fs/btrfs/volumes.c | |
| parent | f3da882eae2d6ba6c72062a46344ba096a7c2b3d (diff) | |
btrfs: do not initialize dev stats if we have no dev_root
Neal reported a panic trying to use -o rescue=all
BUG: kernel NULL pointer dereference, address: 0000000000000030
PGD 0 P4D 0
Oops: 0000 [#1] SMP PTI
CPU: 0 PID: 4095 Comm: mount Not tainted 5.11.0-0.rc7.149.fc34.x86_64 #1
RIP: 0010:btrfs_device_init_dev_stats+0x4c/0x1f0
RSP: 0018:ffffa60285fbfb68 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff88b88f806498 RCX: ffff88b82e7a2a10
RDX: ffffa60285fbfb97 RSI: ffff88b82e7a2a10 RDI: 0000000000000000
RBP: ffff88b88f806b3c R08: 0000000000000000 R09: 0000000000000000
R10: ffff88b82e7a2a10 R11: 0000000000000000 R12: ffff88b88f806a00
R13: ffff88b88f806478 R14: ffff88b88f806a00 R15: ffff88b82e7a2a10
FS: 00007f698be1ec40(0000) GS:ffff88b937e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000030 CR3: 0000000092c9c006 CR4: 00000000003706f0
Call Trace:
? btrfs_init_dev_stats+0x1f/0xf0
btrfs_init_dev_stats+0x62/0xf0
open_ctree+0x1019/0x15ff
btrfs_mount_root.cold+0x13/0xfa
legacy_get_tree+0x27/0x40
vfs_get_tree+0x25/0xb0
vfs_kern_mount.part.0+0x71/0xb0
btrfs_mount+0x131/0x3d0
? legacy_get_tree+0x27/0x40
? btrfs_show_options+0x640/0x640
legacy_get_tree+0x27/0x40
vfs_get_tree+0x25/0xb0
path_mount+0x441/0xa80
__x64_sys_mount+0xf4/0x130
do_syscall_64+0x33/0x40
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7f698c04e52e
This happens because we unconditionally attempt to initialize device
stats on mount, but we may not have been able to read the device root.
Fix this by skipping initializing the device stats if we do not have a
device root.
Reported-by: Neal Gompa <ngompa13@gmail.com>
CC: stable@vger.kernel.org # 5.11+
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Diffstat (limited to 'fs/btrfs/volumes.c')
| -rw-r--r-- | fs/btrfs/volumes.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index b8fab44394f5..e2df6e6e2c18 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -7448,6 +7448,9 @@ static int btrfs_device_init_dev_stats(struct btrfs_device *device, int item_size; int i, ret, slot; + if (!device->fs_info->dev_root) + return 0; + key.objectid = BTRFS_DEV_STATS_OBJECTID; key.type = BTRFS_PERSISTENT_ITEM_KEY; key.offset = device->devid; |