vfs: fix isize/pos/len checks for reflink & dedupe

Strengthen the checking of pos/len vs. i_size, clarify the return values
for the clone prep function, and remove pointless code.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Darrick J. Wong 2016-12-19 15:13:26 -08:00 committed by Al Viro
parent 33844e6651
commit 22725ce4e4
3 changed files with 13 additions and 9 deletions

View File

@ -4834,7 +4834,7 @@ int ocfs2_reflink_remap_range(struct file *file_in,
ret = vfs_clone_file_prep_inodes(inode_in, pos_in, inode_out, pos_out,
&len, is_dedupe);
if (ret || len == 0)
if (ret <= 0)
goto out_unlock;
/* Lock out changes to the allocation maps and remap. */

View File

@ -1669,6 +1669,9 @@ static int clone_verify_area(struct file *file, loff_t pos, u64 len, bool write)
* Check that the two inodes are eligible for cloning, the ranges make
* sense, and then flush all dirty data. Caller must ensure that the
* inodes have been locked against any other modifications.
*
* Returns: 0 for "nothing to clone", 1 for "something to clone", or
* the usual negative error code.
*/
int vfs_clone_file_prep_inodes(struct inode *inode_in, loff_t pos_in,
struct inode *inode_out, loff_t pos_out,
@ -1695,17 +1698,15 @@ int vfs_clone_file_prep_inodes(struct inode *inode_in, loff_t pos_in,
/* Are we going all the way to the end? */
isize = i_size_read(inode_in);
if (isize == 0) {
*len = 0;
if (isize == 0)
return 0;
}
/* Zero length dedupe exits immediately; reflink goes to EOF. */
if (*len == 0) {
if (is_dedupe) {
*len = 0;
if (is_dedupe || pos_in == isize)
return 0;
}
if (pos_in > isize)
return -EINVAL;
*len = isize - pos_in;
}
@ -1769,7 +1770,7 @@ int vfs_clone_file_prep_inodes(struct inode *inode_in, loff_t pos_in,
return -EBADE;
}
return 0;
return 1;
}
EXPORT_SYMBOL(vfs_clone_file_prep_inodes);
@ -1955,6 +1956,9 @@ int vfs_dedupe_file_range(struct file *file, struct file_dedupe_range *same)
goto out;
ret = 0;
if (off + len > i_size_read(src))
return -EINVAL;
/* pre-format output fields to sane values */
for (i = 0; i < count; i++) {
same->info[i].bytes_deduped = 0ULL;

View File

@ -1161,7 +1161,7 @@ xfs_reflink_remap_range(
ret = vfs_clone_file_prep_inodes(inode_in, pos_in, inode_out, pos_out,
&len, is_dedupe);
if (ret || len == 0)
if (ret <= 0)
goto out_unlock;
trace_xfs_reflink_remap_range(src, pos_in, len, dest, pos_out);