When we get the fs information, we forgot to acquire the mutex of device list, it might cause the problem we might access a device that was removed. Fix it by acquiring the device list mutex.
Signed-off-by: Miao Xie <[email protected]> --- fs/btrfs/super.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c index 089991d..6b98358 100644 --- a/fs/btrfs/super.c +++ b/fs/btrfs/super.c @@ -1703,7 +1703,11 @@ static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf) struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv; int ret; - /* holding chunk_muext to avoid allocating new chunks */ + /* + * holding chunk_muext to avoid allocating new chunks, holding + * device_list_mutex to avoid the device being removed + */ + mutex_lock(&fs_info->fs_devices->device_list_mutex); mutex_lock(&fs_info->chunk_mutex); rcu_read_lock(); list_for_each_entry_rcu(found, head, list) { @@ -1744,11 +1748,13 @@ static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf) ret = btrfs_calc_avail_data_space(fs_info->tree_root, &total_free_data); if (ret) { mutex_unlock(&fs_info->chunk_mutex); + mutex_unlock(&fs_info->fs_devices->device_list_mutex); return ret; } buf->f_bavail += div_u64(total_free_data, factor); buf->f_bavail = buf->f_bavail >> bits; mutex_unlock(&fs_info->chunk_mutex); + mutex_unlock(&fs_info->fs_devices->device_list_mutex); buf->f_type = BTRFS_SUPER_MAGIC; buf->f_bsize = dentry->d_sb->s_blocksize; -- 1.9.3 -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
