[Devel] [PATCH 18/25] elevate write count for do_sys_utime() and touch_atime()

[Dave Hansen]

Signed-off-by: Dave Hansen <haveblue at us.ibm.com>
---

 lxc-dave/fs/inode.c  |   20 ++++++++++++--------
 lxc-dave/fs/utimes.c |   15 +++++++++++----
 2 files changed, 23 insertions(+), 12 deletions(-)

diff -puN fs/inode.c~17-24-elevate-write-count-for-do-sys-utime-and-touch-atime fs/inode.c
--- lxc/fs/inode.c~17-24-elevate-write-count-for-do-sys-utime-and-touch-atime	2006-12-11 14:22:08.000000000 -0800
+++ lxc-dave/fs/inode.c	2006-12-11 14:22:08.000000000 -0800
@@ -1167,22 +1167,23 @@ void touch_atime(struct vfsmount *mnt, s
 
 	if (IS_RDONLY(inode))
 		return;
-	if (inode->i_flags & S_NOATIME)
+	if (mnt && mnt_want_write(mnt))
 		return;
+	if (inode->i_flags & S_NOATIME)
+		goto out;
 	if (inode->i_sb->s_flags & MS_NOATIME)
-		return;
+		goto out;
 	if ((inode->i_sb->s_flags & MS_NODIRATIME) && S_ISDIR(inode->i_mode))
-		return;
+		goto out;
 
 	/*
 	 * We may have a NULL vfsmount when coming from NFSD
 	 */
 	if (mnt) {
 		if (mnt->mnt_flags & MNT_NOATIME)
-			return;
+			goto out;
 		if ((mnt->mnt_flags & MNT_NODIRATIME) && S_ISDIR(inode->i_mode))
-			return;
-
+			goto out;
 		if (mnt->mnt_flags & MNT_RELATIME) {
 			/*
 			 * With relative atime, only update atime if the
@@ -1193,16 +1194,19 @@ void touch_atime(struct vfsmount *mnt, s
 						&inode->i_atime) < 0 &&
 			    timespec_compare(&inode->i_ctime,
 						&inode->i_atime) < 0)
-				return;
+				goto out;
 		}
 	}
 
 	now = current_fs_time(inode->i_sb);
 	if (timespec_equal(&inode->i_atime, &now))
-		return;
+		goto out;
 
 	inode->i_atime = now;
 	mark_inode_dirty_sync(inode);
+out:
+	if (mnt)
+		mnt_drop_write(mnt);
 }
 EXPORT_SYMBOL(touch_atime);
 
diff -puN fs/utimes.c~17-24-elevate-write-count-for-do-sys-utime-and-touch-atime fs/utimes.c
--- lxc/fs/utimes.c~17-24-elevate-write-count-for-do-sys-utime-and-touch-atime	2006-12-11 14:22:08.000000000 -0800
+++ lxc-dave/fs/utimes.c	2006-12-11 14:22:08.000000000 -0800
@@ -3,6 +3,7 @@
 #include <linux/linkage.h>
 #include <linux/namei.h>
 #include <linux/sched.h>
+#include <linux/mount.h>
 #include <linux/utime.h>
 #include <asm/uaccess.h>
 #include <asm/unistd.h>
@@ -32,6 +33,10 @@ asmlinkage long sys_utime(char __user * 
 		goto out;
 	inode = nd.dentry->d_inode;
 
+	error = mnt_want_write(nd.mnt);
+	if (error)
+		goto mnt_drop_write_and_out;
+
 	error = -EROFS;
 	if (IS_RDONLY(inode))
 		goto dput_and_out;
@@ -41,7 +46,7 @@ asmlinkage long sys_utime(char __user * 
 	if (times) {
 		error = -EPERM;
 		if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
-			goto dput_and_out;
+			goto mnt_drop_write_and_out;
 
 		error = get_user(newattrs.ia_atime.tv_sec, &times->actime);
 		newattrs.ia_atime.tv_nsec = 0;
@@ -49,21 +54,23 @@ asmlinkage long sys_utime(char __user * 
 			error = get_user(newattrs.ia_mtime.tv_sec, &times->modtime);
 		newattrs.ia_mtime.tv_nsec = 0;
 		if (error)
-			goto dput_and_out;
+			goto mnt_drop_write_and_out;
 
 		newattrs.ia_valid |= ATTR_ATIME_SET | ATTR_MTIME_SET;
 	} else {
                 error = -EACCES;
                 if (IS_IMMUTABLE(inode))
-                        goto dput_and_out;
+                        goto mnt_drop_write_and_out;
 
 		if (current->fsuid != inode->i_uid &&
 		    (error = vfs_permission(&nd, MAY_WRITE)) != 0)
-			goto dput_and_out;
+			goto mnt_drop_write_and_out;
 	}
 	mutex_lock(&inode->i_mutex);
 	error = notify_change(nd.dentry, &newattrs);
 	mutex_unlock(&inode->i_mutex);
+mnt_drop_write_and_out:
+	mnt_drop_write(nd.mnt);
 dput_and_out:
 	path_release(&nd);
 out:
_
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