diff options
| -rw-r--r-- | fs/btrfs/ioctl.c | 76 |
1 files changed, 60 insertions, 16 deletions
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index 9ebe2dd31f2a..af064946c9b2 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -2991,27 +2991,61 @@ static int btrfs_extent_same(struct inode *src, u64 loff, u64 olen, int ret; u64 len = olen; struct cmp_pages cmp; + int same_inode = 0; + u64 same_lock_start = 0; + u64 same_lock_len = 0; - /* - * btrfs_clone() can't handle extents in the same file - * yet. Once that works, we can drop this check and replace it - * with a check for the same inode, but overlapping extents. - */ if (src == dst) - return -EINVAL; + same_inode = 1; if (len == 0) return 0; - btrfs_double_inode_lock(src, dst); + if (same_inode) { + mutex_lock(&src->i_mutex); - ret = extent_same_check_offsets(src, loff, &len, olen); - if (ret) - goto out_unlock; + ret = extent_same_check_offsets(src, loff, &len, olen); + if (ret) + goto out_unlock; - ret = extent_same_check_offsets(dst, dst_loff, &len, olen); - if (ret) - goto out_unlock; + /* + * Single inode case wants the same checks, except we + * don't want our length pushed out past i_size as + * comparing that data range makes no sense. + * + * extent_same_check_offsets() will do this for an + * unaligned length at i_size, so catch it here and + * reject the request. + * + * This effectively means we require aligned extents + * for the single-inode case, whereas the other cases + * allow an unaligned length so long as it ends at + * i_size. + */ + if (len != olen) { + ret = -EINVAL; + goto out_unlock; + } + + /* Check for overlapping ranges */ + if (dst_loff + len > loff && dst_loff < loff + len) { + ret = -EINVAL; + goto out_unlock; + } + + same_lock_start = min_t(u64, loff, dst_loff); + same_lock_len = max_t(u64, loff, dst_loff) + len - same_lock_start; + } else { + btrfs_double_inode_lock(src, dst); + + ret = extent_same_check_offsets(src, loff, &len, olen); + if (ret) + goto out_unlock; + + ret = extent_same_check_offsets(dst, dst_loff, &len, olen); + if (ret) + goto out_unlock; + } /* don't make the dst file partly checksummed */ if ((BTRFS_I(src)->flags & BTRFS_INODE_NODATASUM) != @@ -3024,18 +3058,28 @@ static int btrfs_extent_same(struct inode *src, u64 loff, u64 olen, if (ret) goto out_unlock; - btrfs_double_extent_lock(src, loff, dst, dst_loff, len); + if (same_inode) + lock_extent_range(src, same_lock_start, same_lock_len); + else + btrfs_double_extent_lock(src, loff, dst, dst_loff, len); /* pass original length for comparison so we stay within i_size */ ret = btrfs_cmp_data(src, loff, dst, dst_loff, olen, &cmp); if (ret == 0) ret = btrfs_clone(src, dst, loff, olen, len, dst_loff); - btrfs_double_extent_unlock(src, loff, dst, dst_loff, len); + if (same_inode) + unlock_extent(&BTRFS_I(src)->io_tree, same_lock_start, + same_lock_start + same_lock_len - 1); + else + btrfs_double_extent_unlock(src, loff, dst, dst_loff, len); btrfs_cmp_data_free(&cmp); out_unlock: - btrfs_double_inode_unlock(src, dst); + if (same_inode) + mutex_unlock(&src->i_mutex); + else + btrfs_double_inode_unlock(src, dst); return ret; } |