From: Dave Hansen <haveblue@us.ibm.com>
To: akpm@osdl.org
Cc: linux-kernel@vger.kernel.org, hch@infradead.org,
Dave Hansen <haveblue@us.ibm.com>
Subject: [PATCH 08/25] elevate writer count for chown and friends
Date: Thu, 20 Sep 2007 12:52:58 -0700 [thread overview]
Message-ID: <20070920195258.EAC06921@kernel> (raw)
In-Reply-To: <20070920195249.852667D5@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>
---
lxc-dave/fs/open.c | 39 ++++++++++++++++++++++++++++++---------
1 file changed, 30 insertions(+), 9 deletions(-)
diff -puN fs/open.c~elevate-writer-count-for-chown-and-friends fs/open.c
--- lxc/fs/open.c~elevate-writer-count-for-chown-and-friends 2007-09-20 12:16:13.000000000 -0700
+++ lxc-dave/fs/open.c 2007-09-20 12:16:13.000000000 -0700
@@ -571,12 +571,12 @@ asmlinkage long sys_fchmod(unsigned int
audit_inode(NULL, inode);
- 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;
@@ -674,7 +675,12 @@ 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;
@@ -694,7 +700,12 @@ 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;
@@ -708,7 +719,12 @@ 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;
@@ -725,9 +741,14 @@ 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->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:[~2007-09-20 19:56 UTC|newest]
Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-09-20 19:52 [PATCH 00/25] Read-only bind mounts Dave Hansen
2007-09-20 19:52 ` [PATCH 01/25] filesystem helpers for custom 'struct file's Dave Hansen
2007-09-20 19:52 ` [PATCH 02/25] rearrange may_open() to be r/o friendly Dave Hansen
2007-09-20 19:52 ` [PATCH 03/25] give may_open() a local 'mnt' variable Dave Hansen
2007-09-20 19:57 ` Christoph Hellwig
2007-09-20 19:52 ` [PATCH 04/25] create cleanup helper svc_msnfs() Dave Hansen
2007-09-20 19:52 ` [PATCH 05/25] r/o bind mounts: stub functions Dave Hansen
2007-09-20 19:52 ` [PATCH 06/25] elevate write count open()'d files Dave Hansen
2007-11-28 8:41 ` Andrew Morton
2007-11-28 17:33 ` Dave Hansen
2007-09-20 19:52 ` [PATCH 07/25] r/o bind mounts: elevate write count for some ioctls Dave Hansen
2007-09-21 8:17 ` Andrew Morton
2007-09-21 21:15 ` Dave Hansen
2007-09-26 1:34 ` [RFC] detect missed mnt_want_write() calls Dave Hansen
2007-09-21 23:03 ` [PATCH 07/25] r/o bind mounts: elevate write count for some ioctls Andrew Morton
2007-09-21 23:39 ` Dave Hansen
2007-09-21 23:47 ` Andrew Morton
2007-09-20 19:52 ` Dave Hansen [this message]
2007-09-20 19:53 ` [PATCH 09/25] make access() use mnt check Dave Hansen
2007-09-20 19:53 ` [PATCH 10/25] elevate mnt writers for callers of vfs_mkdir() Dave Hansen
2007-09-20 19:53 ` [PATCH 11/25] elevate write count during entire ncp_ioctl() Dave Hansen
2007-09-20 19:53 ` [PATCH 12/25] elevate write count for link and symlink calls Dave Hansen
2007-09-20 19:53 ` [PATCH 13/25] elevate mount count for extended attributes Dave Hansen
2007-09-20 19:53 ` [PATCH 14/25] elevate write count for file_update_time() Dave Hansen
2007-09-20 19:53 ` [PATCH 15/25] unix_find_other() elevate write count for touch_atime() Dave Hansen
2007-09-20 19:53 ` [PATCH 16/25] elevate write count over calls to vfs_rename() Dave Hansen
2007-09-20 19:53 ` [PATCH 17/25] nfs: check mnt instead of superblock directly Dave Hansen
2007-09-20 19:53 ` [PATCH 18/25] elevate writer count for do_sys_truncate() Dave Hansen
2007-09-20 19:53 ` [PATCH 19/25] elevate write count for do_utimes() Dave Hansen
2007-09-20 19:53 ` [PATCH 20/25] elevate write count for do_sys_utime() and touch_atime() Dave Hansen
2007-09-20 19:53 ` [PATCH 21/25] sys_mknodat(): elevate write count for vfs_mknod/create() Dave Hansen
2007-09-20 19:53 ` [PATCH 22/25] elevate mnt writers for vfs_unlink() callers Dave Hansen
2007-09-20 19:53 ` [PATCH 23/25] do_rmdir(): elevate write count Dave Hansen
2007-09-20 19:53 ` [PATCH 24/25] r/o bind mounts: track number of mount writers Dave Hansen
2007-09-24 6:17 ` Andrew Morton
2007-09-24 14:34 ` Arjan van de Ven
2007-09-24 22:06 ` Dave Hansen
2007-09-24 22:25 ` Andrew Morton
2007-09-24 23:05 ` Dave Hansen
2007-09-24 23:15 ` Andrew Morton
2007-09-25 16:10 ` Dave Hansen
2007-09-24 17:54 ` Christoph Hellwig
2007-09-24 19:10 ` Andrew Morton
2007-09-24 19:24 ` Christoph Hellwig
2007-09-24 19:28 ` Dave Hansen
2007-09-24 19:42 ` Andrew Morton
2007-10-01 18:06 ` Dave Hansen
2007-09-20 19:53 ` [PATCH 25/25] honor r/w changes at do_remount() time Dave Hansen
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