[PATCH 1/4] remove permission check from xfs_change_file_space

[PATCH 1/4] remove permission check from xfs_change_file_space

[Christoph Hellwig]

Both callers of xfs_change_file_space alreaedy do the
file->f_mode & FMODE_WRITE check to ensure we have a file descriptor
that has been opened for write mode, so there is no need to re-check
that with xfs_iaccess.  Especially as the later might wrongly deny it
for corner cases like file descriptor passing through unix domain
sockets.


Signed-off-by: Christoph Hellwig <hch@lst.de>

Index: linux-2.6-xfs/fs/xfs/xfs_vnodeops.c
===================================================================
--- linux-2.6-xfs.orig/fs/xfs/xfs_vnodeops.c	2007-12-19 16:07:57.000000000 +0100
+++ linux-2.6-xfs/fs/xfs/xfs_vnodeops.c	2007-12-19 16:08:19.000000000 +0100
@@ -4311,21 +4311,9 @@ xfs_change_file_space(
 
 	xfs_itrace_entry(ip);
 
-	/*
-	 * must be a regular file and have write permission
-	 */
 	if (!S_ISREG(ip->i_d.di_mode))
 		return XFS_ERROR(EINVAL);
 
-	xfs_ilock(ip, XFS_ILOCK_SHARED);
-
-	if ((error = xfs_iaccess(ip, S_IWUSR, credp))) {
-		xfs_iunlock(ip, XFS_ILOCK_SHARED);
-		return error;
-	}
-
-	xfs_iunlock(ip, XFS_ILOCK_SHARED);
-
 	switch (bf->l_whence) {
 	case 0: /*SEEK_SET*/
 		break;