From: Dave Hansen <haveblue@us.ibm.com>
To: linux-kernel@vger.kernel.org
Cc: viro@ftp.linux.org.uk, herbert@13thfloor.at, hch@infradead.org,
Dave Hansen <haveblue@us.ibm.com>
Subject: [PATCH 11/28] elevate writer count for chown and friends
Date: Tue, 01 Aug 2006 16:52:48 -0700 [thread overview]
Message-ID: <20060801235248.0893CC0F@localhost.localdomain> (raw)
In-Reply-To: <20060801235240.82ADCA42@localhost.localdomain>
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.
Signed-off-by: Dave Hansen <haveblue@us.ibm.com>
---
lxc-dave/fs/open.c | 38 +++++++++++++++++++++++++++++++++-----
1 files changed, 33 insertions(+), 5 deletions(-)
diff -puN fs/open.c~C-elevate-writers-chown-and-friends fs/open.c
--- lxc/fs/open.c~C-elevate-writers-chown-and-friends 2006-08-01 16:35:13.000000000 -0700
+++ lxc-dave/fs/open.c 2006-08-01 16:35:22.000000000 -0700
@@ -644,9 +644,12 @@ asmlinkage long sys_fchmod(unsigned int
err = -EROFS;
if (IS_RDONLY(inode))
goto out_putf;
+ 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;
@@ -655,6 +658,8 @@ 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:
@@ -674,13 +679,16 @@ asmlinkage long sys_fchmodat(int dfd, co
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 out_drop_write;
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)
@@ -690,6 +698,8 @@ 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:
@@ -715,7 +725,7 @@ static int chown_common(struct dentry *
error = -EROFS;
if (IS_RDONLY(inode))
goto out;
- error = -EPERM;
+ error = -EPERM;
if (IS_IMMUTABLE(inode) || IS_APPEND(inode))
goto out;
newattrs.ia_valid = ATTR_CTIME;
@@ -744,7 +754,12 @@ 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;
@@ -764,7 +779,12 @@ 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;
@@ -778,7 +798,11 @@ 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);
+out_release:
path_release(&nd);
out:
return error;
@@ -794,10 +818,14 @@ asmlinkage long sys_fchown(unsigned int
file = fget(fd);
if (!file)
goto out;
-
+ error = mnt_want_write(file->f_vfsmnt);
+ if (error)
+ goto out_fput;
dentry = file->f_dentry;
audit_inode(NULL, dentry->d_inode);
error = chown_common(dentry, user, group);
+ mnt_drop_write(file->f_vfsmnt);
+out_fput:
fput(file);
out:
return error;
_
next prev parent reply other threads:[~2006-08-02 0:02 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-08-01 23:52 [PATCH 00/28] Mount writer count and read-only bind mounts (v5) Dave Hansen
2006-08-01 23:52 ` [PATCH 01/28] prepare for write access checks: collapse if() Dave Hansen
2006-08-03 14:32 ` Christoph Hellwig
2006-08-01 23:52 ` [PATCH 02/28] r/o bind mount prepwork: move open_namei()'s vfs_create() Dave Hansen
2006-08-03 14:33 ` Christoph Hellwig
2006-08-01 23:52 ` [PATCH 03/28] unlink: monitor i_nlink Dave Hansen
2006-08-03 14:35 ` Christoph Hellwig
2006-08-01 23:52 ` [PATCH 04/28] OCFS2 is screwy Dave Hansen
2006-08-02 2:14 ` Mark Fasheh
2006-08-02 3:19 ` [PATCH 04/28] OCFS2 is (not) screwy Dave Hansen
2006-08-02 3:21 ` [PATCH 04/28] OCFS2 is screwy Dave Hansen
2006-08-02 4:34 ` Mark Fasheh
2006-08-03 0:20 ` Mark Fasheh
2006-08-04 21:01 ` [PATCH] clean up OCFS2 nlink handling Dave Hansen
2006-08-04 21:38 ` Mark Fasheh
2006-08-01 23:52 ` [PATCH 05/28] monitor zeroing of i_nlink Dave Hansen
2006-08-01 23:52 ` [PATCH 06/28] reintroduce list of vfsmounts over superblock Dave Hansen
2006-08-03 14:39 ` Christoph Hellwig
2006-08-04 21:47 ` Dave Hansen
2006-08-01 23:52 ` [PATCH 07/28] Add vfsmount writer count Dave Hansen
2006-08-01 23:52 ` [PATCH 09/28] kill open files traverse on remount ro Dave Hansen
2006-08-01 23:52 ` [PATCH 08/28] record when sb_writer_count elevated for inode Dave Hansen
2006-08-01 23:52 ` [PATCH 10/28] increment sb writer count when nlink hits zero Dave Hansen
2006-08-01 23:52 ` Dave Hansen [this message]
2006-08-01 23:52 ` [PATCH 12/28] elevate mnt writers for callers of vfs_mkdir() Dave Hansen
2006-08-01 23:52 ` [PATCH 13/28] elevate write count during entire ncp_ioctl() Dave Hansen
2006-08-01 23:52 ` [PATCH 14/28] sys_symlinkat() elevate write count around vfs_symlink() Dave Hansen
2006-08-01 23:52 ` [PATCH 15/28] elevate mount count for extended attributes Dave Hansen
2006-08-01 23:52 ` [PATCH 16/28] sys_linkat(): elevate write count around vfs_link() Dave Hansen
2006-08-01 23:52 ` [PATCH 17/28] mount_is_safe(): add comment Dave Hansen
2006-08-01 23:52 ` [PATCH 18/28] unix_find_other() elevate write count for touch_atime() Dave Hansen
2006-08-01 23:52 ` [PATCH 19/28] elevate write count over calls to vfs_rename() Dave Hansen
2006-08-01 23:52 ` [PATCH 20/28] tricky: elevate write count files are open()ed Dave Hansen
2006-08-01 23:52 ` [PATCH 21/28] elevate writer count for do_sys_truncate() Dave Hansen
2006-08-01 23:52 ` [PATCH 22/28] elevate write count for do_utimes() Dave Hansen
2006-08-01 23:52 ` [PATCH 23/28] elevate write count for do_sys_utime() and touch_atime() Dave Hansen
2006-08-01 23:52 ` [PATCH 24/28] sys_mknodat(): elevate write count for vfs_mknod/create() Dave Hansen
2006-08-01 23:52 ` [PATCH 26/28] do_rmdir(): elevate write count Dave Hansen
2006-08-01 23:52 ` [PATCH 25/28] elevate mnt writers for vfs_unlink() callers Dave Hansen
2006-08-01 23:53 ` [PATCH 27/28] elevate writer count for custom 'struct file' Dave Hansen
2006-08-03 14:42 ` Christoph Hellwig
2006-08-11 20:31 ` Dave Hansen
2006-08-01 23:53 ` [PATCH 28/28] honor r/w changes at do_remount() time 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=20060801235248.0893CC0F@localhost.localdomain \
--to=haveblue@us.ibm.com \
--cc=hch@infradead.org \
--cc=herbert@13thfloor.at \
--cc=linux-kernel@vger.kernel.org \
--cc=viro@ftp.linux.org.uk \
/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