[PATCH 23/28] elevate write count for do_sys_utime() and touch_atime()

Dave Hansen
2006-08-01T23:58:37Z

lxc-dave/fs/inode.c | 9 +++++++--
lxc-dave/fs/open.c | 16 +++++++++++-----
2 files changed, 18 insertions(+), 7 deletions(-)

diff -puN fs/inode.c~C-elevate-writers-opens-part2-do_sys_utime fs/inode.c
--- lxc/fs/inode.c~C-elevate-writers-opens-part2-do_sys_utime 2006-08-01 16:35:20.000000000 -0700
+++ lxc-dave/fs/inode.c 2006-08-01 16:35:30.000000000 -0700
@@ -1191,10 +1191,13 @@ void touch_atime(struct vfsmount *mnt, s
if (IS_RDONLY(inode))
return;

+ if (mnt_want_write(mnt))
+ return;
+
if ((inode->i_flags & S_NOATIME) ||
(inode->i_sb->s_flags & MS_NOATIME) ||
((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
@@ -1202,13 +1205,15 @@ void touch_atime(struct vfsmount *mnt, s
if (mnt &&
((mnt->mnt_flags & MNT_NOATIME) ||
((mnt->mnt_flags & MNT_NODIRATIME) && S_ISDIR(inode->i_mode))))
- return;
+ goto out;

now = current_fs_time(inode->i_sb);
if (!timespec_equal(&inode->i_atime, &now)) {
inode->i_atime = now;
mark_inode_dirty_sync(inode);
}
+out:
+ mnt_drop_write(mnt);
}

EXPORT_SYMBOL(touch_atime);
diff -puN fs/open.c~C-elevate-writers-opens-part2-do_sys_utime fs/open.c
--- lxc/fs/open.c~C-elevate-writers-opens-part2-do_sys_utime 2006-08-01 16:35:29.000000000 -0700
+++ lxc-dave/fs/open.c 2006-08-01 16:35:30.000000000 -0700
@@ -384,16 +384,20 @@ asmlinkage long sys_utime(char __user *
goto out;
inode = nd.dentry->d_inode;

+ error = mnt_want_write(nd.mnt);
+ if (error)
+ goto dput_and_out;
+
error = -EROFS;
if (IS_RDONLY(inode))
- goto dput_and_out;
+ goto mnt_drop_write_and_out;

/* Don't worry, the checks are done in inode_change_ok() */
newattrs.ia_valid = ATTR_CTIME | ATTR_MTIME | ATTR_ATIME;
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;
@@ -401,21 +405,23 @@ 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:
_