return error;
}
-/*
- * Read a page's worth of file data into the page cache. Return the page
- * locked.
- */
-static struct page *
-xfs_get_page(
- struct inode *inode,
- xfs_off_t offset)
-{
- struct address_space *mapping;
- struct page *page;
- pgoff_t n;
-
- n = offset >> PAGE_SHIFT;
- mapping = inode->i_mapping;
- page = read_mapping_page(mapping, n, NULL);
- if (IS_ERR(page))
- return page;
- if (!PageUptodate(page)) {
- put_page(page);
- return ERR_PTR(-EIO);
- }
- lock_page(page);
- return page;
-}
-
-/*
- * Compare extents of two files to see if they are the same.
- */
-static int
-xfs_compare_extents(
- struct inode *src,
- xfs_off_t srcoff,
- struct inode *dest,
- xfs_off_t destoff,
- xfs_off_t len,
- bool *is_same)
-{
- xfs_off_t src_poff;
- xfs_off_t dest_poff;
- void *src_addr;
- void *dest_addr;
- struct page *src_page;
- struct page *dest_page;
- xfs_off_t cmp_len;
- bool same;
- int error;
-
- error = -EINVAL;
- same = true;
- while (len) {
- src_poff = srcoff & (PAGE_SIZE - 1);
- dest_poff = destoff & (PAGE_SIZE - 1);
- cmp_len = min(PAGE_SIZE - src_poff,
- PAGE_SIZE - dest_poff);
- cmp_len = min(cmp_len, len);
- ASSERT(cmp_len > 0);
-
- trace_xfs_reflink_compare_extents(XFS_I(src), srcoff, cmp_len,
- XFS_I(dest), destoff);
-
- src_page = xfs_get_page(src, srcoff);
- if (IS_ERR(src_page)) {
- error = PTR_ERR(src_page);
- goto out_error;
- }
- dest_page = xfs_get_page(dest, destoff);
- if (IS_ERR(dest_page)) {
- error = PTR_ERR(dest_page);
- unlock_page(src_page);
- put_page(src_page);
- goto out_error;
- }
- src_addr = kmap_atomic(src_page);
- dest_addr = kmap_atomic(dest_page);
-
- flush_dcache_page(src_page);
- flush_dcache_page(dest_page);
-
- if (memcmp(src_addr + src_poff, dest_addr + dest_poff, cmp_len))
- same = false;
-
- kunmap_atomic(dest_addr);
- kunmap_atomic(src_addr);
- unlock_page(dest_page);
- unlock_page(src_page);
- put_page(dest_page);
- put_page(src_page);
-
- if (!same)
- break;
-
- srcoff += cmp_len;
- destoff += cmp_len;
- len -= cmp_len;
- }
-
- *is_same = same;
- return 0;
-
-out_error:
- trace_xfs_reflink_compare_extents_error(XFS_I(dest), error, _RET_IP_);
- return error;
-}
-
/*
* Link a range of blocks from one file to another.
*/
struct inode *inode_out = file_inode(file_out);
struct xfs_inode *dest = XFS_I(inode_out);
struct xfs_mount *mp = src->i_mount;
- loff_t bs = inode_out->i_sb->s_blocksize;
bool same_inode = (inode_in == inode_out);
xfs_fileoff_t sfsbno, dfsbno;
xfs_filblks_t fsblen;
xfs_extlen_t cowextsize;
- loff_t isize;
ssize_t ret;
- loff_t blen;
if (!xfs_sb_version_hasreflink(&mp->m_sb))
return -EOPNOTSUPP;
else
xfs_lock_two_inodes(src, dest, XFS_MMAPLOCK_EXCL);
- /* Don't touch certain kinds of inodes */
- ret = -EPERM;
- if (IS_IMMUTABLE(inode_out))
- goto out_unlock;
-
- ret = -ETXTBSY;
- if (IS_SWAPFILE(inode_in) || IS_SWAPFILE(inode_out))
- goto out_unlock;
-
-
- /* Don't reflink dirs, pipes, sockets... */
- ret = -EISDIR;
- if (S_ISDIR(inode_in->i_mode) || S_ISDIR(inode_out->i_mode))
- goto out_unlock;
+ /* Check file eligibility and prepare for block sharing. */
ret = -EINVAL;
- if (S_ISFIFO(inode_in->i_mode) || S_ISFIFO(inode_out->i_mode))
- goto out_unlock;
- if (!S_ISREG(inode_in->i_mode) || !S_ISREG(inode_out->i_mode))
- goto out_unlock;
-
/* Don't reflink realtime inodes */
if (XFS_IS_REALTIME_INODE(src) || XFS_IS_REALTIME_INODE(dest))
goto out_unlock;
if (IS_DAX(inode_in) || IS_DAX(inode_out))
goto out_unlock;
- /* Are we going all the way to the end? */
- isize = i_size_read(inode_in);
- if (isize == 0) {
- ret = 0;
- goto out_unlock;
- }
-
- /* Zero length dedupe exits immediately; reflink goes to EOF. */
- if (len == 0) {
- if (is_dedupe) {
- ret = 0;
- goto out_unlock;
- }
- 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)
- goto out_unlock;
-
- /* 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)
- goto out_unlock;
- }
-
- /* 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))
- goto out_unlock;
-
- /* Don't allow overlapped reflink within the same file */
- if (same_inode) {
- if (pos_out + blen > pos_in && pos_out < pos_in + blen)
- goto out_unlock;
- }
-
- /* Wait for the completion of any pending IOs on both files */
- inode_dio_wait(inode_in);
- if (!same_inode)
- inode_dio_wait(inode_out);
-
- ret = filemap_write_and_wait_range(inode_in->i_mapping,
- pos_in, pos_in + len - 1);
- if (ret)
- goto out_unlock;
-
- ret = filemap_write_and_wait_range(inode_out->i_mapping,
- pos_out, pos_out + len - 1);
- if (ret)
+ ret = vfs_clone_file_prep_inodes(inode_in, pos_in, inode_out, pos_out,
+ &len, is_dedupe);
+ if (ret || len == 0)
goto out_unlock;
trace_xfs_reflink_remap_range(src, pos_in, len, dest, pos_out);
- /*
- * Check that the extents are the same.
- */
- if (is_dedupe) {
- bool is_same = false;
-
- ret = xfs_compare_extents(inode_in, pos_in, inode_out, pos_out,
- len, &is_same);
- if (ret)
- goto out_unlock;
- if (!is_same) {
- ret = -EBADE;
- goto out_unlock;
- }
- }
-
+ /* Set flags and remap blocks. */
ret = xfs_reflink_set_inode_flag(src, dest);
if (ret)
goto out_unlock;
- /*
- * Invalidate the page cache so that we can clear any CoW mappings
- * in the destination file.
- */
- truncate_inode_pages_range(&inode_out->i_data, pos_out,
- PAGE_ALIGN(pos_out + len) - 1);
-
dfsbno = XFS_B_TO_FSBT(mp, pos_out);
sfsbno = XFS_B_TO_FSBT(mp, pos_in);
fsblen = XFS_B_TO_FSB(mp, len);
if (ret)
goto out_unlock;
+ /* Zap any page cache for the destination file's range. */
+ truncate_inode_pages_range(&inode_out->i_data, pos_out,
+ PAGE_ALIGN(pos_out + len) - 1);
+
/*
* Carry the cowextsize hint from src to dest if we're sharing the
* entire source file to the entire destination file, the source file
projects / karo-tx-linux.git / blobdiff