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author | Miao Xie <miaox@cn.fujitsu.com> | 2013-11-22 10:47:59 (GMT) |
---|---|---|
committer | Chris Mason <clm@fb.com> | 2013-12-12 15:11:19 (GMT) |
commit | a7e252af5a819eb71c9494e62b2bfca982e92f84 (patch) | |
tree | 73554777e84f56b52adbfe58a52cb6b370ecbcdd /fs | |
parent | c0778e2534b81be6b85b5ee07c0e15ff774f7136 (diff) | |
download | linux-a7e252af5a819eb71c9494e62b2bfca982e92f84.tar.xz |
Btrfs: don't clear the default compression type
We met a oops caused by the wrong compression type:
[ 556.512356] BUG: unable to handle kernel NULL pointer dereference at (null)
[ 556.512370] IP: [<ffffffff811dbaa0>] __list_del_entry+0x1/0x98
[SNIP]
[ 556.512490] [<ffffffff811dbb44>] ? list_del+0xd/0x2b
[ 556.512539] [<ffffffffa05dd5ce>] find_workspace+0x97/0x175 [btrfs]
[ 556.512546] [<ffffffff813c14b5>] ? _raw_spin_lock+0xe/0x10
[ 556.512576] [<ffffffffa05de276>] btrfs_compress_pages+0x2d/0xa2 [btrfs]
[ 556.512601] [<ffffffffa05af060>] compress_file_range.constprop.54+0x1f2/0x4e8 [btrfs]
[ 556.512627] [<ffffffffa05af388>] async_cow_start+0x32/0x4d [btrfs]
[ 556.512655] [<ffffffffa05cc7a1>] worker_loop+0x144/0x4c3 [btrfs]
[ 556.512661] [<ffffffff81059404>] ? finish_task_switch+0x80/0xb8
[ 556.512689] [<ffffffffa05cc65d>] ? btrfs_queue_worker+0x244/0x244 [btrfs]
[ 556.512695] [<ffffffff8104fa4e>] kthread+0x8d/0x95
[ 556.512699] [<ffffffff81050000>] ? bit_waitqueue+0x34/0x7d
[ 556.512704] [<ffffffff8104f9c1>] ? __kthread_parkme+0x65/0x65
[ 556.512709] [<ffffffff813c7eec>] ret_from_fork+0x7c/0xb0
[ 556.512713] [<ffffffff8104f9c1>] ? __kthread_parkme+0x65/0x65
Steps to reproduce:
# mkfs.btrfs -f <dev>
# mount -o nodatacow <dev> <mnt>
# touch <mnt>/<file>
# chattr =c <mnt>/<file>
# dd if=/dev/zero of=<mnt>/<file> bs=1M count=10
It is because we cleared the default compression type when setting the
nodatacow. In fact, we needn't do it because we have used COMPRESS flag to
indicate if we need compressed the file data or not, needn't use the
variant -- compress_type -- in btrfs_info to do the same thing, and just
use it to hold the default compression type. Or we would get a wrong compress
type for a file whose own compress flag is set but the compress flag of its
filesystem is not set.
Reported-by: Tsutomu Itoh <t-itoh@jp.fujitsu.com>
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Chris Mason <clm@fb.com>
Diffstat (limited to 'fs')
-rw-r--r-- | fs/btrfs/super.c | 5 |
1 files changed, 2 insertions, 3 deletions
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c index 2d8ac1b..d71a11d 100644 --- a/fs/btrfs/super.c +++ b/fs/btrfs/super.c @@ -432,7 +432,6 @@ int btrfs_parse_options(struct btrfs_root *root, char *options) } else { printk(KERN_INFO "btrfs: setting nodatacow\n"); } - info->compress_type = BTRFS_COMPRESS_NONE; btrfs_clear_opt(info->mount_opt, COMPRESS); btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS); btrfs_set_opt(info->mount_opt, NODATACOW); @@ -461,7 +460,6 @@ int btrfs_parse_options(struct btrfs_root *root, char *options) btrfs_set_fs_incompat(info, COMPRESS_LZO); } else if (strncmp(args[0].from, "no", 2) == 0) { compress_type = "no"; - info->compress_type = BTRFS_COMPRESS_NONE; btrfs_clear_opt(info->mount_opt, COMPRESS); btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS); compress_force = false; @@ -474,9 +472,10 @@ int btrfs_parse_options(struct btrfs_root *root, char *options) btrfs_set_opt(info->mount_opt, FORCE_COMPRESS); pr_info("btrfs: force %s compression\n", compress_type); - } else + } else if (btrfs_test_opt(root, COMPRESS)) { pr_info("btrfs: use %s compression\n", compress_type); + } break; case Opt_ssd: printk(KERN_INFO "btrfs: use ssd allocation scheme\n"); |