diff options
Diffstat (limited to 'fs/btrfs/reflink.c')
| -rw-r--r-- | fs/btrfs/reflink.c | 30 |
1 files changed, 24 insertions, 6 deletions
diff --git a/fs/btrfs/reflink.c b/fs/btrfs/reflink.c index d60ea7ea5f27..6746460fd219 100644 --- a/fs/btrfs/reflink.c +++ b/fs/btrfs/reflink.c @@ -604,6 +604,20 @@ static void btrfs_double_extent_lock(struct inode *inode1, u64 loff1, lock_extent(&BTRFS_I(inode2)->io_tree, loff2, loff2 + len - 1); } +static void btrfs_double_mmap_lock(struct inode *inode1, struct inode *inode2) +{ + if (inode1 < inode2) + swap(inode1, inode2); + down_write(&BTRFS_I(inode1)->i_mmap_lock); + down_write_nested(&BTRFS_I(inode2)->i_mmap_lock, SINGLE_DEPTH_NESTING); +} + +static void btrfs_double_mmap_unlock(struct inode *inode1, struct inode *inode2) +{ + up_write(&BTRFS_I(inode1)->i_mmap_lock); + up_write(&BTRFS_I(inode2)->i_mmap_lock); +} + static int btrfs_extent_same_range(struct inode *src, u64 loff, u64 len, struct inode *dst, u64 dst_loff) { @@ -832,10 +846,12 @@ loff_t btrfs_remap_file_range(struct file *src_file, loff_t off, if (remap_flags & ~(REMAP_FILE_DEDUP | REMAP_FILE_ADVISORY)) return -EINVAL; - if (same_inode) - btrfs_inode_lock(src_inode, 0); - else + if (same_inode) { + btrfs_inode_lock(src_inode, BTRFS_ILOCK_MMAP); + } else { lock_two_nondirectories(src_inode, dst_inode); + btrfs_double_mmap_lock(src_inode, dst_inode); + } ret = btrfs_remap_file_range_prep(src_file, off, dst_file, destoff, &len, remap_flags); @@ -848,10 +864,12 @@ loff_t btrfs_remap_file_range(struct file *src_file, loff_t off, ret = btrfs_clone_files(dst_file, src_file, off, len, destoff); out_unlock: - if (same_inode) - btrfs_inode_unlock(src_inode, 0); - else + if (same_inode) { + btrfs_inode_unlock(src_inode, BTRFS_ILOCK_MMAP); + } else { + btrfs_double_mmap_unlock(src_inode, dst_inode); unlock_two_nondirectories(src_inode, dst_inode); + } return ret < 0 ? ret : len; } |