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 07/24] elevate writer count for chown and friends
Date: Mon, 17 Sep 2007 11:27:27 -0700 [thread overview]
Message-ID: <20070917182727.DC8189F0@kernel> (raw)
In-Reply-To: <20070917182718.70494C9B@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.
Signed-off-by: Dave Hansen <haveblue@us.ibm.com>
---
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 2007-09-17 09:43:59.000000000 -0700
+++ lxc-dave/fs/open.c 2007-09-17 09:43:59.000000000 -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;
_
next prev parent reply other threads:[~2007-09-17 18:29 UTC|newest]
Thread overview: 61+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-09-17 18:27 [PATCH 00/24] Read-only bind mounts Dave Hansen
2007-09-17 18:27 ` [PATCH 01/24] filesystem helpers for custom 'struct file's Dave Hansen
2007-09-19 17:26 ` Christoph Hellwig
2007-09-19 17:47 ` [PATCH] docuement " Dave Hansen
2007-09-19 22:07 ` Randy Dunlap
2007-09-20 17:25 ` Dave Hansen
2007-09-20 17:30 ` Christoph Hellwig
2007-09-17 18:27 ` [PATCH 02/24] rearrange may_open() to be r/o friendly Dave Hansen
2007-09-19 17:27 ` Christoph Hellwig
2007-09-20 18:47 ` Dave Hansen
2007-09-17 18:27 ` [PATCH 03/24] create cleanup helper svc_msnfs() Dave Hansen
2007-09-19 17:28 ` Christoph Hellwig
2007-09-19 17:39 ` Jan Engelhardt
2007-09-19 17:45 ` Dave Hansen
2007-09-19 17:54 ` Trond Myklebust
2007-09-19 17:59 ` Christoph Hellwig
2007-09-19 18:10 ` Trond Myklebust
2007-09-17 18:27 ` [PATCH 04/24] r/o bind mounts: stub functions Dave Hansen
2007-09-19 17:28 ` Christoph Hellwig
2007-09-17 18:27 ` [PATCH 05/24] elevate write count open()'d files Dave Hansen
2007-09-19 17:30 ` Christoph Hellwig
2007-09-17 18:27 ` [PATCH 06/24] r/o bind mounts: elevate write count for some ioctls Dave Hansen
2007-09-19 17:31 ` Christoph Hellwig
2007-09-17 18:27 ` Dave Hansen [this message]
2007-09-19 17:31 ` [PATCH 07/24] elevate writer count for chown and friends Christoph Hellwig
2007-09-17 18:27 ` [PATCH 08/24] make access() use mnt check Dave Hansen
2007-09-19 17:32 ` Christoph Hellwig
2007-09-17 18:27 ` [PATCH 09/24] elevate mnt writers for callers of vfs_mkdir() Dave Hansen
2007-09-19 17:32 ` Christoph Hellwig
2007-09-17 18:27 ` [PATCH 10/24] elevate write count during entire ncp_ioctl() Dave Hansen
2007-09-19 17:33 ` Christoph Hellwig
2007-09-17 18:27 ` [PATCH 11/24] elevate write count for link and symlink calls Dave Hansen
2007-09-19 17:33 ` Christoph Hellwig
2007-09-17 18:27 ` [PATCH 12/24] elevate mount count for extended attributes Dave Hansen
2007-09-19 17:34 ` Christoph Hellwig
2007-09-17 18:27 ` [PATCH 13/24] elevate write count for file_update_time() Dave Hansen
2007-09-19 17:35 ` Christoph Hellwig
2007-09-17 18:27 ` [PATCH 14/24] unix_find_other() elevate write count for touch_atime() Dave Hansen
2007-09-19 17:35 ` Christoph Hellwig
2007-09-17 18:27 ` [PATCH 15/24] elevate write count over calls to vfs_rename() Dave Hansen
2007-09-19 17:35 ` Christoph Hellwig
2007-09-17 18:27 ` [PATCH 16/24] nfs: check mnt instead of superblock directly Dave Hansen
2007-09-19 17:36 ` Christoph Hellwig
2007-09-17 18:27 ` [PATCH 17/24] elevate writer count for do_sys_truncate() Dave Hansen
2007-09-19 17:36 ` Christoph Hellwig
2007-09-17 18:27 ` [PATCH 18/24] elevate write count for do_utimes() Dave Hansen
2007-09-19 17:36 ` Christoph Hellwig
2007-09-17 18:27 ` [PATCH 19/24] elevate write count for do_sys_utime() and touch_atime() Dave Hansen
2007-09-19 17:36 ` Christoph Hellwig
2007-09-17 18:27 ` [PATCH 20/24] sys_mknodat(): elevate write count for vfs_mknod/create() Dave Hansen
2007-09-19 17:38 ` Christoph Hellwig
2007-09-17 18:27 ` [PATCH 21/24] elevate mnt writers for vfs_unlink() callers Dave Hansen
2007-09-19 17:38 ` Christoph Hellwig
2007-09-17 18:27 ` [PATCH 22/24] do_rmdir(): elevate write count Dave Hansen
2007-09-19 17:39 ` Christoph Hellwig
2007-09-19 14:21 ` [PATCH 00/24] Read-only bind mounts Serge E. Hallyn
2007-09-19 17:44 ` Christoph Hellwig
2007-09-19 21:24 ` Andrew Morton
2007-09-19 21:56 ` Dave Hansen
2007-09-19 22:06 ` Andrew Morton
2007-09-20 9:58 ` Miklos Szeredi
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