[Vserver] [PATCH 09/10] vfs: propagate the vfsmount into *xattr()

From: Herbert Pötzl <herbert@13thfloor.at>

Previously, the xattr VFS interface did not regard the VFS context
from which a dentry was acquired.

As the per-vfsmount flags may now affect the permissions, the vfsmount
structure must now be passed into the *xattr interface.

Checks are also added to setxattr() and removexattr() for the
MNT_RDONLY flag via MNT_IS_RDONLY, and EROFS returned accordingly.

Acked-by: Sam Vilain <sam.vilain@catalyst.net.nz>

---
 fs/xattr.c |   23 +++++++++++++++--------
 1 files changed, 15 insertions(+), 8 deletions(-)
diff --git a/fs/xattr.c b/fs/xattr.c
index 80eca7d..ad83a51 100644
--- a/fs/xattr.c
+++ b/fs/xattr.c
@@ -17,6 +17,7 @@
 #include <linux/syscalls.h>
 #include <linux/module.h>
 #include <linux/fsnotify.h>
+#include <linux/mount.h>
 #include <asm/uaccess.h>
 
 
@@ -167,7 +168,7 @@ EXPORT_SYMBOL_GPL(vfs_removexattr);
  */
 static long
 setxattr(struct dentry *d, char __user *name, void __user *value,
-	 size_t size, int flags)
+	 size_t size, int flags, struct vfsmount *mnt)
 {
 	int error;
 	void *kvalue = NULL;
@@ -194,6 +195,9 @@ setxattr(struct dentry *d, char __user *
 		}
 	}
 
+	if (MNT_IS_RDONLY(mnt))
+		return -EROFS;
+
 	error = vfs_setxattr(d, kname, kvalue, size, flags);
 	kfree(kvalue);
 	return error;
@@ -209,7 +213,7 @@ sys_setxattr(char __user *path, char __u
 	error = user_path_walk(path, &nd);
 	if (error)
 		return error;
-	error = setxattr(nd.dentry, name, value, size, flags);
+	error = setxattr(nd.dentry, name, value, size, flags, nd.mnt);
 	path_release(&nd);
 	return error;
 }
@@ -224,7 +228,7 @@ sys_lsetxattr(char __user *path, char __
 	error = user_path_walk_link(path, &nd);
 	if (error)
 		return error;
-	error = setxattr(nd.dentry, name, value, size, flags);
+	error = setxattr(nd.dentry, name, value, size, flags, nd.mnt);
 	path_release(&nd);
 	return error;
 }
@@ -239,7 +243,7 @@ sys_fsetxattr(int fd, char __user *name,
 	f = fget(fd);
 	if (!f)
 		return error;
-	error = setxattr(f->f_dentry, name, value, size, flags);
+	error = setxattr(f->f_dentry, name, value, size, flags, f->f_vfsmnt);
 	fput(f);
 	return error;
 }
@@ -412,7 +416,7 @@ sys_flistxattr(int fd, char __user *list
  * Extended attribute REMOVE operations
  */
 static long
-removexattr(struct dentry *d, char __user *name)
+removexattr(struct dentry *d, char __user *name, struct vfsmount *mnt)
 {
 	int error;
 	char kname[XATTR_NAME_MAX + 1];
@@ -423,6 +427,9 @@ removexattr(struct dentry *d, char __use
 	if (error < 0)
 		return error;
 
+	if (MNT_IS_RDONLY(mnt))
+		return -EROFS;
+
 	return vfs_removexattr(d, kname);
 }
 
@@ -435,7 +442,7 @@ sys_removexattr(char __user *path, char 
 	error = user_path_walk(path, &nd);
 	if (error)
 		return error;
-	error = removexattr(nd.dentry, name);
+	error = removexattr(nd.dentry, name, nd.mnt);
 	path_release(&nd);
 	return error;
 }
@@ -449,7 +456,7 @@ sys_lremovexattr(char __user *path, char
 	error = user_path_walk_link(path, &nd);
 	if (error)
 		return error;
-	error = removexattr(nd.dentry, name);
+	error = removexattr(nd.dentry, name, nd.mnt);
 	path_release(&nd);
 	return error;
 }
@@ -463,7 +470,7 @@ sys_fremovexattr(int fd, char __user *na
 	f = fget(fd);
 	if (!f)
 		return error;
-	error = removexattr(f->f_dentry, name);
+	error = removexattr(f->f_dentry, name, f->f_vfsmnt);
 	fput(f);
 	return error;
 }
_______________________________________________
Vserver mailing list
Vserver@list.linux-vserver.org
http://list.linux-vserver.org/mailman/listinfo/vserver