[PATCH] r/o bind mounts: elevate write count for ioctls()
Some ioctl()s can cause writes to the filesystem. Take these, and make them
use mnt_want/drop_write() instead.
[AV: updated]
Acked-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/reiserfs/ioctl.c b/fs/reiserfs/ioctl.c
index e0f0f09..74363a7 100644
--- a/fs/reiserfs/ioctl.c
+++ b/fs/reiserfs/ioctl.c
@@ -4,6 +4,7 @@
#include <linux/capability.h>
#include <linux/fs.h>
+#include <linux/mount.h>
#include <linux/reiserfs_fs.h>
#include <linux/time.h>
#include <asm/uaccess.h>
@@ -25,6 +26,7 @@
unsigned long arg)
{
unsigned int flags;
+ int err = 0;
switch (cmd) {
case REISERFS_IOC_UNPACK:
@@ -48,50 +50,67 @@
if (!reiserfs_attrs(inode->i_sb))
return -ENOTTY;
- if (IS_RDONLY(inode))
- return -EROFS;
+ err = mnt_want_write(filp->f_path.mnt);
+ if (err)
+ return err;
- if (!is_owner_or_cap(inode))
- return -EPERM;
-
- if (get_user(flags, (int __user *)arg))
- return -EFAULT;
-
- /* Is it quota file? Do not allow user to mess with it. */
- if (IS_NOQUOTA(inode))
- return -EPERM;
+ if (!is_owner_or_cap(inode)) {
+ err = -EPERM;
+ goto setflags_out;
+ }
+ if (get_user(flags, (int __user *)arg)) {
+ err = -EFAULT;
+ goto setflags_out;
+ }
+ /*
+ * Is it quota file? Do not allow user to mess with it
+ */
+ if (IS_NOQUOTA(inode)) {
+ err = -EPERM;
+ goto setflags_out;
+ }
if (((flags ^ REISERFS_I(inode)->
i_attrs) & (REISERFS_IMMUTABLE_FL |
REISERFS_APPEND_FL))
- && !capable(CAP_LINUX_IMMUTABLE))
- return -EPERM;
-
+ && !capable(CAP_LINUX_IMMUTABLE)) {
+ err = -EPERM;
+ goto setflags_out;
+ }
if ((flags & REISERFS_NOTAIL_FL) &&
S_ISREG(inode->i_mode)) {
int result;
result = reiserfs_unpack(inode, filp);
- if (result)
- return result;
+ if (result) {
+ err = result;
+ goto setflags_out;
+ }
}
sd_attrs_to_i_attrs(flags, inode);
REISERFS_I(inode)->i_attrs = flags;
inode->i_ctime = CURRENT_TIME_SEC;
mark_inode_dirty(inode);
- return 0;
+setflags_out:
+ mnt_drop_write(filp->f_path.mnt);
+ return err;
}
case REISERFS_IOC_GETVERSION:
return put_user(inode->i_generation, (int __user *)arg);
case REISERFS_IOC_SETVERSION:
if (!is_owner_or_cap(inode))
return -EPERM;
- if (IS_RDONLY(inode))
- return -EROFS;
- if (get_user(inode->i_generation, (int __user *)arg))
- return -EFAULT;
+ err = mnt_want_write(filp->f_path.mnt);
+ if (err)
+ return err;
+ if (get_user(inode->i_generation, (int __user *)arg)) {
+ err = -EFAULT;
+ goto setversion_out;
+ }
inode->i_ctime = CURRENT_TIME_SEC;
mark_inode_dirty(inode);
- return 0;
+setversion_out:
+ mnt_drop_write(filp->f_path.mnt);
+ return err;
default:
return -ENOTTY;
}