[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/xfs/linux-2.6/xfs_ioctl.c b/fs/xfs/linux-2.6/xfs_ioctl.c
index bf77597..4ddb86b 100644
--- a/fs/xfs/linux-2.6/xfs_ioctl.c
+++ b/fs/xfs/linux-2.6/xfs_ioctl.c
@@ -535,8 +535,6 @@
char *kbuf;
int error = EFAULT;
- if (IS_RDONLY(inode))
- return -EROFS;
if (IS_IMMUTABLE(inode) || IS_APPEND(inode))
return EPERM;
if (len > XATTR_SIZE_MAX)
@@ -562,8 +560,6 @@
char *name,
__uint32_t flags)
{
- if (IS_RDONLY(inode))
- return -EROFS;
if (IS_IMMUTABLE(inode) || IS_APPEND(inode))
return EPERM;
return xfs_attr_remove(XFS_I(inode), name, flags);
@@ -573,6 +569,7 @@
xfs_attrmulti_by_handle(
xfs_mount_t *mp,
void __user *arg,
+ struct file *parfilp,
struct inode *parinode)
{
int error;
@@ -626,13 +623,21 @@
&ops[i].am_length, ops[i].am_flags);
break;
case ATTR_OP_SET:
+ ops[i].am_error = mnt_want_write(parfilp->f_path.mnt);
+ if (ops[i].am_error)
+ break;
ops[i].am_error = xfs_attrmulti_attr_set(inode,
attr_name, ops[i].am_attrvalue,
ops[i].am_length, ops[i].am_flags);
+ mnt_drop_write(parfilp->f_path.mnt);
break;
case ATTR_OP_REMOVE:
+ ops[i].am_error = mnt_want_write(parfilp->f_path.mnt);
+ if (ops[i].am_error)
+ break;
ops[i].am_error = xfs_attrmulti_attr_remove(inode,
attr_name, ops[i].am_flags);
+ mnt_drop_write(parfilp->f_path.mnt);
break;
default:
ops[i].am_error = EINVAL;
@@ -1133,7 +1138,7 @@
return xfs_attrlist_by_handle(mp, arg, inode);
case XFS_IOC_ATTRMULTI_BY_HANDLE:
- return xfs_attrmulti_by_handle(mp, arg, inode);
+ return xfs_attrmulti_by_handle(mp, arg, filp, inode);
case XFS_IOC_SWAPEXT: {
error = xfs_swapext((struct xfs_swapext __user *)arg);