diff options
| author | Anand Jain | 2013-07-19 17:39:32 +0800 |
|---|---|---|
| committer | Chris Mason | 2013-09-01 08:04:15 -0400 |
| commit | a1b83ac52d23c85581b87836c346fb5cb90f6bfd (patch) | |
| tree | 2c4a8512cc3c6e8f464082b3c98c20fc98fd08ba /fs/btrfs/ioctl.c | |
| parent | d4c34f6bffe246bcf05a1471873667d678a47a54 (diff) | |
btrfs: fix get set label blocking against balance
btrfs_ioctl_get_fslabel() and btrfs_ioctl_set_fslabel()
used root->fs_info->volume_mutex mutex which caused operations
like balance to block set/get label operation until its
completion and generally balance operation takes a long
time to complete, so it will be annoying to the user when
cli appears hung
also this patch will add a bit of optimization within
the btrfs_ioctl_get_falabel() function.
v1->v2:
use fs_info->super_lock instead of uuid_mutex
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Diffstat (limited to 'fs/btrfs/ioctl.c')
| -rw-r--r-- | fs/btrfs/ioctl.c | 16 |
1 files changed, 10 insertions, 6 deletions
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index f856c97952db..556b3d5b18da 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -4042,18 +4042,22 @@ out: static int btrfs_ioctl_get_fslabel(struct file *file, void __user *arg) { struct btrfs_root *root = BTRFS_I(file_inode(file))->root; - const char *label = root->fs_info->super_copy->label; - size_t len = strnlen(label, BTRFS_LABEL_SIZE); + size_t len; int ret; + char label[BTRFS_LABEL_SIZE]; + + spin_lock(&root->fs_info->super_lock); + memcpy(label, root->fs_info->super_copy->label, BTRFS_LABEL_SIZE); + spin_unlock(&root->fs_info->super_lock); + + len = strnlen(label, BTRFS_LABEL_SIZE); if (len == BTRFS_LABEL_SIZE) { pr_warn("btrfs: label is too long, return the first %zu bytes\n", --len); } - mutex_lock(&root->fs_info->volume_mutex); ret = copy_to_user(arg, label, len); - mutex_unlock(&root->fs_info->volume_mutex); return ret ? -EFAULT : 0; } @@ -4082,18 +4086,18 @@ static int btrfs_ioctl_set_fslabel(struct file *file, void __user *arg) if (ret) return ret; - mutex_lock(&root->fs_info->volume_mutex); trans = btrfs_start_transaction(root, 0); if (IS_ERR(trans)) { ret = PTR_ERR(trans); goto out_unlock; } + spin_lock(&root->fs_info->super_lock); strcpy(super_block->label, label); + spin_unlock(&root->fs_info->super_lock); ret = btrfs_end_transaction(trans, root); out_unlock: - mutex_unlock(&root->fs_info->volume_mutex); mnt_drop_write_file(file); return ret; } |