-/*
- * Flush all file writes out to disk.
- */
-static int
-xfs_file_wait_for_io(
- struct inode *inode,
- loff_t offset,
- size_t len)
-{
- loff_t rounding;
- loff_t ioffset;
- loff_t iendoffset;
- loff_t bs;
- int ret;
-
- bs = inode->i_sb->s_blocksize;
- inode_dio_wait(inode);
-
- rounding = max_t(xfs_off_t, bs, PAGE_SIZE);
- ioffset = round_down(offset, rounding);
- iendoffset = round_up(offset + len, rounding) - 1;
- ret = filemap_write_and_wait_range(inode->i_mapping, ioffset,
- iendoffset);
- return ret;
-}
-
-/* Hook up to the VFS reflink function */
-STATIC int
-xfs_file_share_range(
- struct file *file_in,
- loff_t pos_in,
- struct file *file_out,
- loff_t pos_out,
- u64 len,
- bool is_dedupe)
-{
- struct inode *inode_in;
- struct inode *inode_out;
- ssize_t ret;
- loff_t bs;
- loff_t isize;
- int same_inode;
- loff_t blen;
- unsigned int flags = 0;
-
- inode_in = file_inode(file_in);
- inode_out = file_inode(file_out);
- bs = inode_out->i_sb->s_blocksize;
-
- /* Don't touch certain kinds of inodes */
- if (IS_IMMUTABLE(inode_out))
- return -EPERM;
- if (IS_SWAPFILE(inode_in) ||
- IS_SWAPFILE(inode_out))
- return -ETXTBSY;
-
- /* Reflink only works within this filesystem. */
- if (inode_in->i_sb != inode_out->i_sb)
- return -EXDEV;
- same_inode = (inode_in->i_ino == inode_out->i_ino);
-
- /* Don't reflink dirs, pipes, sockets... */
- if (S_ISDIR(inode_in->i_mode) || S_ISDIR(inode_out->i_mode))
- return -EISDIR;
- if (S_ISFIFO(inode_in->i_mode) || S_ISFIFO(inode_out->i_mode))
- return -EINVAL;
- if (!S_ISREG(inode_in->i_mode) || !S_ISREG(inode_out->i_mode))
- return -EINVAL;
-
- /* Don't share DAX file data for now. */
- if (IS_DAX(inode_in) || IS_DAX(inode_out))
- return -EINVAL;
-
- /* Are we going all the way to the end? */
- isize = i_size_read(inode_in);
- if (isize == 0)
- return 0;
- if (len == 0)
- len = isize - pos_in;
-
- /* Ensure offsets don't wrap and the input is inside i_size */
- if (pos_in + len < pos_in || pos_out + len < pos_out ||
- pos_in + len > isize)
- return -EINVAL;
-
- /* Don't allow dedupe past EOF in the dest file */
- if (is_dedupe) {
- loff_t disize;
-
- disize = i_size_read(inode_out);
- if (pos_out >= disize || pos_out + len > disize)
- return -EINVAL;
- }
-
- /* If we're linking to EOF, continue to the block boundary. */
- if (pos_in + len == isize)
- blen = ALIGN(isize, bs) - pos_in;
- else
- blen = len;
-
- /* Only reflink if we're aligned to block boundaries */
- if (!IS_ALIGNED(pos_in, bs) || !IS_ALIGNED(pos_in + blen, bs) ||
- !IS_ALIGNED(pos_out, bs) || !IS_ALIGNED(pos_out + blen, bs))
- return -EINVAL;
-
- /* Don't allow overlapped reflink within the same file */
- if (same_inode && pos_out + blen > pos_in && pos_out < pos_in + blen)
- return -EINVAL;
-
- /* Wait for the completion of any pending IOs on srcfile */
- ret = xfs_file_wait_for_io(inode_in, pos_in, len);
- if (ret)
- goto out;
- ret = xfs_file_wait_for_io(inode_out, pos_out, len);
- if (ret)
- goto out;
-
- if (is_dedupe)
- flags |= XFS_REFLINK_DEDUPE;
- ret = xfs_reflink_remap_range(XFS_I(inode_in), pos_in, XFS_I(inode_out),
- pos_out, len, flags);
- if (ret < 0)
- goto out;
-
-out:
- return ret;
-}
-