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| author | Miao Xie <miaox@cn.fujitsu.com> | 2013-04-11 10:30:16 +0000 |
|---|---|---|
| committer | Josef Bacik <jbacik@fusionio.com> | 2013-05-06 15:54:46 -0400 |
| commit | ceda08642459e31673d24d7968d864390d2ce5fa (patch) | |
| tree | 57d1a9be32a9a2653011b5fedf6615731af48b7f /fs/btrfs/volumes.c | |
| parent | f42a34b2f10c411ef45f247f3000ed03ba4e80c0 (diff) | |
| download | linux-ceda08642459e31673d24d7968d864390d2ce5fa.tar.gz linux-ceda08642459e31673d24d7968d864390d2ce5fa.tar.bz2 linux-ceda08642459e31673d24d7968d864390d2ce5fa.zip | |
Btrfs: use a lock to protect incompat/compat flag of the super block
The following case will make the incompat/compat flag of the super block
be recovered.
Task1 |Task2
flags = btrfs_super_incompat_flags(); |
|flags = btrfs_super_incompat_flags();
flags |= new_flag1; |
|flags |= new_flag2;
btrfs_set_super_incompat_flags(flags); |
|btrfs_set_super_incompat_flags(flags);
the new_flag1 is recovered.
In order to avoid this problem, we introduce a lock named super_lock into
the btrfs_fs_info structure. If we want to update incompat/compat flags
of the super block, we must hold it.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Diffstat (limited to 'fs/btrfs/volumes.c')
| -rw-r--r-- | fs/btrfs/volumes.c | 10 |
1 files changed, 1 insertions, 9 deletions
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index 5aa52ee5c25e..76ded9eb77a7 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -3674,18 +3674,10 @@ static u32 find_raid56_stripe_len(u32 data_devices, u32 dev_stripe_target) static void check_raid56_incompat_flag(struct btrfs_fs_info *info, u64 type) { - u64 features; - if (!(type & (BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6))) return; - features = btrfs_super_incompat_flags(info->super_copy); - if (features & BTRFS_FEATURE_INCOMPAT_RAID56) - return; - - features |= BTRFS_FEATURE_INCOMPAT_RAID56; - btrfs_set_super_incompat_flags(info->super_copy, features); - printk(KERN_INFO "btrfs: setting RAID5/6 feature flag\n"); + btrfs_set_fs_incompat(info, RAID56); } static int __btrfs_alloc_chunk(struct btrfs_trans_handle *trans, |