tmpfs: Use xattr handler infrastructure

Use the VFS xattr handler infrastructure and get rid of similar code in
the filesystem.  For implementing shmem_xattr_handler_set, we need a
version of simple_xattr_set which removes the attribute when value is
NULL.  Use this to implement kernfs_iop_removexattr as well.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Reviewed-by: James Morris <james.l.morris@oracle.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: linux-mm@kvack.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

2 files changed, 17 insertions, 33 deletions

diff --git a/fs/kernfs/inode.c b/fs/kernfs/inode.c
index 756dd56aaf60..f97e1f7790b1 100644
--- a/fs/kernfs/inode.c
+++ b/fs/kernfs/inode.c
@@ -205,7 +205,7 @@ int kernfs_iop_removexattr(struct dentry *dentry, const char *name)
 	if (!attrs)
 		return -ENOMEM;
 
-	return simple_xattr_remove(&attrs->xattrs, name);
+	return simple_xattr_set(&attrs->xattrs, name, NULL, 0, XATTR_REPLACE);
 }
 
 ssize_t kernfs_iop_getxattr(struct dentry *dentry, const char *name, void *buf,
diff --git a/fs/xattr.c b/fs/xattr.c
index 418ad691cf4e..4ef8b378dc90 100644
--- a/fs/xattr.c
+++ b/fs/xattr.c
@@ -851,8 +851,22 @@ int simple_xattr_get(struct simple_xattrs *xattrs, const char *name,
 	return ret;
 }
 
-static int __simple_xattr_set(struct simple_xattrs *xattrs, const char *name,
-			      const void *value, size_t size, int flags)
+/**
+ * simple_xattr_set - xattr SET operation for in-memory/pseudo filesystems
+ * @xattrs: target simple_xattr list
+ * @name: name of the extended attribute
+ * @value: value of the xattr. If %NULL, will remove the attribute.
+ * @size: size of the new xattr
+ * @flags: %XATTR_{CREATE|REPLACE}
+ *
+ * %XATTR_CREATE is set, the xattr shouldn't exist already; otherwise fails
+ * with -EEXIST.  If %XATTR_REPLACE is set, the xattr should exist;
+ * otherwise, fails with -ENODATA.
+ *
+ * Returns 0 on success, -errno on failure.
+ */
+int simple_xattr_set(struct simple_xattrs *xattrs, const char *name,
+		     const void *value, size_t size, int flags)
 {
 	struct simple_xattr *xattr;
 	struct simple_xattr *new_xattr = NULL;
@@ -902,36 +916,6 @@ out:
 
 }
 
-/**
- * simple_xattr_set - xattr SET operation for in-memory/pseudo filesystems
- * @xattrs: target simple_xattr list
- * @name: name of the new extended attribute
- * @value: value of the new xattr. If %NULL, will remove the attribute
- * @size: size of the new xattr
- * @flags: %XATTR_{CREATE|REPLACE}
- *
- * %XATTR_CREATE is set, the xattr shouldn't exist already; otherwise fails
- * with -EEXIST.  If %XATTR_REPLACE is set, the xattr should exist;
- * otherwise, fails with -ENODATA.
- *
- * Returns 0 on success, -errno on failure.
- */
-int simple_xattr_set(struct simple_xattrs *xattrs, const char *name,
-		     const void *value, size_t size, int flags)
-{
-	if (size == 0)
-		value = ""; /* empty EA, do not remove */
-	return __simple_xattr_set(xattrs, name, value, size, flags);
-}
-
-/*
- * xattr REMOVE operation for in-memory/pseudo filesystems
- */
-int simple_xattr_remove(struct simple_xattrs *xattrs, const char *name)
-{
-	return __simple_xattr_set(xattrs, name, NULL, 0, XATTR_REPLACE);
-}
-
 static bool xattr_is_trusted(const char *name)
 {
 	return !strncmp(name, XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN);