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From: Dave Hansen <haveblue@us.ibm.com>
To: akpm@osdl.org
Cc: linux-kernel@vger.kernel.org, miklos@szeredi.hu,
	hch@infradead.org, Dave Hansen <haveblue@us.ibm.com>
Subject: [PATCH 13/27] r-o-bind-mounts-elevate-write-count-for-do_utimes
Date: Thu, 01 Nov 2007 16:08:43 -0700	[thread overview]
Message-ID: <20071101230843.AB6A629C@kernel> (raw)
In-Reply-To: <20071101230826.9A4F6E00@kernel>


Now includes fix for oops seen by akpm.

"never let a libc developer write your kernel code" - hch

"nor, apparently, a kernel developer" - akpm

Acked-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Valdis Kletnieks <Valdis.Kletnieks@vt.edu>
Cc: Balbir Singh <balbir@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 linux-2.6.git-dave/fs/utimes.c |   18 ++++++++++++------
 1 file changed, 12 insertions(+), 6 deletions(-)

diff -puN fs/utimes.c~r-o-bind-mounts-elevate-write-count-for-do_utimes fs/utimes.c
--- linux-2.6.git/fs/utimes.c~r-o-bind-mounts-elevate-write-count-for-do_utimes	2007-11-01 14:46:13.000000000 -0700
+++ linux-2.6.git-dave/fs/utimes.c	2007-11-01 14:46:13.000000000 -0700
@@ -2,6 +2,7 @@
 #include <linux/file.h>
 #include <linux/fs.h>
 #include <linux/linkage.h>
+#include <linux/mount.h>
 #include <linux/namei.h>
 #include <linux/sched.h>
 #include <linux/stat.h>
@@ -58,6 +59,7 @@ long do_utimes(int dfd, char __user *fil
 	struct inode *inode;
 	struct iattr newattrs;
 	struct file *f = NULL;
+	struct vfsmount *mnt;
 
 	error = -EINVAL;
 	if (times && (!nsec_valid(times[0].tv_nsec) ||
@@ -78,18 +80,20 @@ long do_utimes(int dfd, char __user *fil
 		if (!f)
 			goto out;
 		dentry = f->f_path.dentry;
+		mnt = f->f_path.mnt;
 	} else {
 		error = __user_walk_fd(dfd, filename, (flags & AT_SYMLINK_NOFOLLOW) ? 0 : LOOKUP_FOLLOW, &nd);
 		if (error)
 			goto out;
 
 		dentry = nd.dentry;
+		mnt = nd.mnt;
 	}
 
 	inode = dentry->d_inode;
 
-	error = -EROFS;
-	if (IS_RDONLY(inode))
+	error = mnt_want_write(mnt);
+	if (error)
 		goto dput_and_out;
 
 	/* Don't worry, the checks are done in inode_change_ok() */
@@ -97,7 +101,7 @@ long do_utimes(int dfd, char __user *fil
 	if (times) {
 		error = -EPERM;
                 if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
-                        goto dput_and_out;
+			goto mnt_drop_write_and_out;
 
 		if (times[0].tv_nsec == UTIME_OMIT)
 			newattrs.ia_valid &= ~ATTR_ATIME;
@@ -117,22 +121,24 @@ long do_utimes(int dfd, char __user *fil
 	} else {
 		error = -EACCES;
                 if (IS_IMMUTABLE(inode))
-                        goto dput_and_out;
+			goto mnt_drop_write_and_out;
 
 		if (!is_owner_or_cap(inode)) {
 			if (f) {
 				if (!(f->f_mode & FMODE_WRITE))
-					goto dput_and_out;
+					goto mnt_drop_write_and_out;
 			} else {
 				error = vfs_permission(&nd, MAY_WRITE);
 				if (error)
-					goto dput_and_out;
+					goto mnt_drop_write_and_out;
 			}
 		}
 	}
 	mutex_lock(&inode->i_mutex);
 	error = notify_change(dentry, &newattrs);
 	mutex_unlock(&inode->i_mutex);
+mnt_drop_write_and_out:
+	mnt_drop_write(mnt);
 dput_and_out:
 	if (f)
 		fput(f);
_

  parent reply	other threads:[~2007-11-01 23:12 UTC|newest]

Thread overview: 39+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-11-01 23:08 [PATCH 00/27] Read-only bind mounts (-mm resend) Dave Hansen
2007-11-01 23:08 ` [PATCH 01/27] do namei_flags calculation inside open_namei() Dave Hansen
2007-11-01 23:08 ` [PATCH 02/27] make open_namei() return a filp Dave Hansen
2007-11-01 23:08 ` [PATCH 03/27] kill do_filp_open() Dave Hansen
2007-11-01 23:08 ` [PATCH 04/27] kill filp_open() Dave Hansen
2008-01-16  8:52   ` Andrew Morton
2008-01-16 17:04     ` Dave Hansen
2008-01-16 17:10       ` Christoph Hellwig
2008-01-16 17:41         ` Dave Hansen
2008-01-16 17:47           ` Christoph Hellwig
2008-01-16 17:12       ` Bryn M. Reeves
2007-11-01 23:08 ` [PATCH 05/27] rename open_namei() to open_pathname() Dave Hansen
2007-11-26 14:33   ` Christoph Hellwig
2007-11-01 23:08 ` [PATCH 06/27] r-o-bind-mounts-stub-functions Dave Hansen
2007-11-01 23:08 ` [PATCH 07/27] r-o-bind-mounts-do_rmdir-elevate-write-count Dave Hansen
2007-11-01 23:08 ` [PATCH 08/27] r-o-bind-mounts-elevate-mnt-writers-for-callers-of-vfs_mkdir Dave Hansen
2007-11-01 23:08 ` [PATCH 09/27] r-o-bind-mounts-elevate-mnt-writers-for-vfs_unlink-callers Dave Hansen
2007-11-01 23:08 ` [PATCH 10/27] r-o-bind-mounts-elevate-mount-count-for-extended-attributes Dave Hansen
2007-11-01 23:08 ` [PATCH 11/27] r-o-bind-mounts-elevate-write-count-during-entire-ncp_ioctl Dave Hansen
2007-11-01 23:08 ` [PATCH 12/27] r-o-bind-mounts-elevate-write-count-for-do_sys_utime-and-touch_atime Dave Hansen
2007-11-01 23:08 ` Dave Hansen [this message]
2007-11-01 23:08 ` [PATCH 14/27] r-o-bind-mounts-elevate-write-count-for-file_update_time Dave Hansen
2007-11-01 23:08 ` [PATCH 15/27] r-o-bind-mounts-elevate-write-count-for-link-and-symlink-calls Dave Hansen
2007-11-01 23:08 ` [PATCH 16/27] r-o-bind-mounts-elevate-write-count-for-some-ioctls Dave Hansen
2007-11-05 23:23   ` Andrew Morton
2007-11-06  9:01     ` Jan Kara
2007-11-06  9:12       ` Andrew Morton
2007-11-01 23:08 ` [PATCH 17/27] r-o-bind-mounts-elevate-write-count-opend-files Dave Hansen
2007-11-01 23:08 ` [PATCH 18/27] r-o-bind-mounts-elevate-write-count-over-calls-to-vfs_rename Dave Hansen
2007-11-01 23:08 ` [PATCH 19/27] r-o-bind-mounts-elevate-writer-count-for-chown-and-friends Dave Hansen
2007-11-01 23:08 ` [PATCH 20/27] r-o-bind-mounts-elevate-writer-count-for-do_sys_truncate Dave Hansen
2007-11-01 23:08 ` [PATCH 21/27] r-o-bind-mounts-make-access-use-mnt-check Dave Hansen
2007-11-01 23:08 ` [PATCH 22/27] r-o-bind-mounts-nfs-check-mnt-instead-of-superblock-directly Dave Hansen
2007-11-01 23:08 ` [PATCH 23/27] r-o-bind-mounts-sys_mknodat-elevate-write-count-for-vfs_mknod-create Dave Hansen
2007-11-01 23:08 ` [PATCH 24/27] r-o-bind-mounts-track-number-of-mount-writers Dave Hansen
2007-11-01 23:09 ` [PATCH 25/27] r-o-bind-mounts-track-number-of-mount-writers-make-lockdep-happy-with-r-o-bind-mounts Dave Hansen
2007-11-05 23:35   ` Andrew Morton
2007-11-01 23:09 ` [PATCH 26/27] r-o-bind-mounts-honor-r-w-changes-at-do_remount-time Dave Hansen
2007-11-01 23:09 ` [PATCH 27/27] keep track of mnt_writer state of struct file Dave Hansen

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