LKML Archive on lore.kernel.org
help / color / mirror / Atom feed
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 19/27] r-o-bind-mounts-elevate-writer-count-for-chown-and-friends
Date: Thu, 01 Nov 2007 16:08:51 -0700	[thread overview]
Message-ID: <20071101230851.4BE17E62@kernel> (raw)
In-Reply-To: <20071101230826.9A4F6E00@kernel>



chown/chmod,etc...  don't call permission in the same way that the normal
"open for write" calls do.  They still write to the filesystem, so bump the
write count during these operations.

This conflicts with the current (~2.6.23-rc7) audit git tree in -mm. 
wiggle'ing the patch merges it.

Signed-off-by: Dave Hansen <haveblue@us.ibm.com>
Acked-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 linux-2.6.git-dave/fs/open.c |   39 ++++++++++++++++++++++++++++++---------
 1 file changed, 30 insertions(+), 9 deletions(-)

diff -puN fs/open.c~r-o-bind-mounts-elevate-writer-count-for-chown-and-friends fs/open.c
--- linux-2.6.git/fs/open.c~r-o-bind-mounts-elevate-writer-count-for-chown-and-friends	2007-11-01 14:46:17.000000000 -0700
+++ linux-2.6.git-dave/fs/open.c	2007-11-01 14:46:17.000000000 -0700
@@ -571,12 +571,12 @@ asmlinkage long sys_fchmod(unsigned int 
 
 	audit_inode(NULL, dentry);
 
-	err = -EROFS;
-	if (IS_RDONLY(inode))
+	err = mnt_want_write(file->f_vfsmnt);
+	if (err)
 		goto out_putf;
 	err = -EPERM;
 	if (IS_IMMUTABLE(inode) || IS_APPEND(inode))
-		goto out_putf;
+		goto out_drop_write;
 	mutex_lock(&inode->i_mutex);
 	if (mode == (mode_t) -1)
 		mode = inode->i_mode;
@@ -585,6 +585,8 @@ asmlinkage long sys_fchmod(unsigned int 
 	err = notify_change(dentry, &newattrs);
 	mutex_unlock(&inode->i_mutex);
 
+out_drop_write:
+	mnt_drop_write(file->f_vfsmnt);
 out_putf:
 	fput(file);
 out:
@@ -604,13 +606,13 @@ asmlinkage long sys_fchmodat(int dfd, co
 		goto out;
 	inode = nd.dentry->d_inode;
 
-	error = -EROFS;
-	if (IS_RDONLY(inode))
+	error = mnt_want_write(nd.mnt);
+	if (error)
 		goto dput_and_out;
 
 	error = -EPERM;
 	if (IS_IMMUTABLE(inode) || IS_APPEND(inode))
-		goto dput_and_out;
+		goto out_drop_write;
 
 	mutex_lock(&inode->i_mutex);
 	if (mode == (mode_t) -1)
@@ -620,6 +622,8 @@ asmlinkage long sys_fchmodat(int dfd, co
 	error = notify_change(nd.dentry, &newattrs);
 	mutex_unlock(&inode->i_mutex);
 
+out_drop_write:
+	mnt_drop_write(nd.mnt);
 dput_and_out:
 	path_release(&nd);
 out:
@@ -642,9 +646,6 @@ static int chown_common(struct dentry * 
 		printk(KERN_ERR "chown_common: NULL inode\n");
 		goto out;
 	}
-	error = -EROFS;
-	if (IS_RDONLY(inode))
-		goto out;
 	error = -EPERM;
 	if (IS_IMMUTABLE(inode) || IS_APPEND(inode))
 		goto out;
@@ -675,7 +676,12 @@ asmlinkage long sys_chown(const char __u
 	error = user_path_walk(filename, &nd);
 	if (error)
 		goto out;
+	error = mnt_want_write(nd.mnt);
+	if (error)
+		goto out_release;
 	error = chown_common(nd.dentry, user, group);
+	mnt_drop_write(nd.mnt);
+out_release:
 	path_release(&nd);
 out:
 	return error;
@@ -695,7 +701,12 @@ asmlinkage long sys_fchownat(int dfd, co
 	error = __user_walk_fd(dfd, filename, follow, &nd);
 	if (error)
 		goto out;
+	error = mnt_want_write(nd.mnt);
+	if (error)
+		goto out_release;
 	error = chown_common(nd.dentry, user, group);
+	mnt_drop_write(nd.mnt);
+out_release:
 	path_release(&nd);
 out:
 	return error;
@@ -709,7 +720,12 @@ asmlinkage long sys_lchown(const char __
 	error = user_path_walk_link(filename, &nd);
 	if (error)
 		goto out;
+	error = mnt_want_write(nd.mnt);
+	if (error)
+		goto out_release;
 	error = chown_common(nd.dentry, user, group);
+	mnt_drop_write(nd.mnt);
+out_release:
 	path_release(&nd);
 out:
 	return error;
@@ -726,9 +742,14 @@ asmlinkage long sys_fchown(unsigned int 
 	if (!file)
 		goto out;
 
+	error = mnt_want_write(file->f_vfsmnt);
+	if (error)
+		goto out_fput;
 	dentry = file->f_path.dentry;
 	audit_inode(NULL, dentry);
 	error = chown_common(dentry, user, group);
+	mnt_drop_write(file->f_vfsmnt);
+out_fput:
 	fput(file);
 out:
 	return error;
_

  parent reply	other threads:[~2007-11-01 23:16 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 ` [PATCH 13/27] r-o-bind-mounts-elevate-write-count-for-do_utimes Dave Hansen
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 ` Dave Hansen [this message]
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

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20071101230851.4BE17E62@kernel \
    --to=haveblue@us.ibm.com \
    --cc=akpm@osdl.org \
    --cc=hch@infradead.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=miklos@szeredi.hu \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).