xfs: only clear the suid bit once in xfs_write

file_remove_suid already calls into ->setattr to clear the suid and
sgid bits if needed, no need to start a second transaction to do it
ourselves.

Note that xfs_write_clear_setuid issues a sync transaction while the
path through ->setattr doesn't, but that is consistant with the
other filesystems.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Alex Elder <aelder@sgi.com>
Signed-off-by: Alex Elder <aelder@sgi.com>

3 files changed, 3 insertions, 55 deletions

diff --git a/fs/xfs/linux-2.6/xfs_lrw.c b/fs/xfs/linux-2.6/xfs_lrw.c
index c80fa00d2ad7..eac6f80d786d 100644
--- a/fs/xfs/linux-2.6/xfs_lrw.c
+++ b/fs/xfs/linux-2.6/xfs_lrw.c
@@ -630,18 +630,9 @@ start:
          * by root.  This keeps people from modifying setuid and
          * setgid binaries.
          */
-
-        if (((xip->i_d.di_mode & S_ISUID) ||
-            ((xip->i_d.di_mode & (S_ISGID | S_IXGRP)) ==
-                (S_ISGID | S_IXGRP))) &&
-             !capable(CAP_FSETID)) {
-                error = xfs_write_clear_setuid(xip);
-                if (likely(!error))
-                        error = -file_remove_suid(file);
-                if (unlikely(error)) {
-                        goto out_unlock_internal;
-                }
-        }
+        error = -file_remove_suid(file);
+        if (unlikely(error))
+                goto out_unlock_internal;
 
         /* We can write back this queue in page reclaim */
         current->backing_dev_info = mapping->backing_dev_info;
diff --git a/fs/xfs/xfs_rw.c b/fs/xfs/xfs_rw.c
index abb2c458b148..e336742a58a4 100644
--- a/fs/xfs/xfs_rw.c
+++ b/fs/xfs/xfs_rw.c
@@ -47,48 +47,6 @@
 #include "xfs_trace.h"
 
 /*
- * This is a subroutine for xfs_write() and other writers (xfs_ioctl)
- * which clears the setuid and setgid bits when a file is written.
- */
-int
-xfs_write_clear_setuid(
-        xfs_inode_t     *ip)
-{
-        xfs_mount_t     *mp;
-        xfs_trans_t     *tp;
-        int             error;
-
-        mp = ip->i_mount;
-        tp = xfs_trans_alloc(mp, XFS_TRANS_WRITEID);
-        if ((error = xfs_trans_reserve(tp, 0,
-                                      XFS_WRITEID_LOG_RES(mp),
-                                      0, 0, 0))) {
-                xfs_trans_cancel(tp, 0);
-                return error;
-        }
-        xfs_ilock(ip, XFS_ILOCK_EXCL);
-        xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
-        xfs_trans_ihold(tp, ip);
-        ip->i_d.di_mode &= ~S_ISUID;
-
-        /*
-         * Note that we don't have to worry about mandatory
-         * file locking being disabled here because we only
-         * clear the S_ISGID bit if the Group execute bit is
-         * on, but if it was on then mandatory locking wouldn't
-         * have been enabled.
-         */
-        if (ip->i_d.di_mode & S_IXGRP) {
-                ip->i_d.di_mode &= ~S_ISGID;
-        }
-        xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
-        xfs_trans_set_sync(tp);
-        error = xfs_trans_commit(tp, 0);
-        xfs_iunlock(ip, XFS_ILOCK_EXCL);
-        return 0;
-}
-
-/*
  * Force a shutdown of the filesystem instantly while keeping
  * the filesystem consistent. We don't do an unmount here; just shutdown
  * the shop, make sure that absolutely nothing persistent happens to
diff --git a/fs/xfs/xfs_rw.h b/fs/xfs/xfs_rw.h
index a54c3b7cd376..11c41ec6ed75 100644
--- a/fs/xfs/xfs_rw.h
+++ b/fs/xfs/xfs_rw.h
@@ -39,7 +39,6 @@ xfs_fsb_to_db(struct xfs_inode *ip, xfs_fsblock_t fsb)
 /*
  * Prototypes for functions in xfs_rw.c.
  */
-extern int xfs_write_clear_setuid(struct xfs_inode *ip);
 extern int xfs_read_buf(struct xfs_mount *mp, xfs_buftarg_t *btp,
                         xfs_daddr_t blkno, int len, uint flags,
                         struct xfs_buf **bpp);