reiserfs: use generic xattr handlers

Christoph Hellwig had asked me quite some time ago to port the reiserfs
xattrs to the generic xattr interface.

This patch replaces the reiserfs-specific xattr handling code with the
generic struct xattr_handler.

However, since reiserfs doesn't split the prefix and name when accessing
xattrs, it can't leverage generic_{set,get,list,remove}xattr without
needlessly reconstructing the name on the back end.

Update 7/26/07: Added missing dput() to deletion path.
Update 8/30/07: Added missing mark_inode_dirty when i_mode is used to
                represent an ACL and no previous ACL existed.
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/reiserfs/super.c

@@ -2263,9 +2263,6 @@ static int __init init_reiserfs_fs(void)
 		return ret;
 	}
 
-	if ((ret = reiserfs_xattr_register_handlers()))
-		goto failed_reiserfs_xattr_register_handlers;
-
 	reiserfs_proc_info_global_init();
 	reiserfs_proc_register_global("version",
 				      reiserfs_global_version_in_proc);
@@ -2276,9 +2273,6 @@ static int __init init_reiserfs_fs(void)
 		return 0;
 	}
 
-	reiserfs_xattr_unregister_handlers();
-
-      failed_reiserfs_xattr_register_handlers:
 	reiserfs_proc_unregister_global("version");
 	reiserfs_proc_info_global_done();
 	destroy_inodecache();
@@ -2288,7 +2282,6 @@ static int __init init_reiserfs_fs(void)
 
 static void __exit exit_reiserfs_fs(void)
 {
-	reiserfs_xattr_unregister_handlers();
 	reiserfs_proc_unregister_global("version");
 	reiserfs_proc_info_global_done();
 	unregister_filesystem(&reiserfs_fs_type);

fs/reiserfs/xattr_acl.c

@@ -271,7 +271,7 @@ reiserfs_set_acl(struct inode *inode, int type, struct posix_acl *acl)
 	char *name;
 	void *value = NULL;
 	struct posix_acl **p_acl;
-	size_t size;
+	size_t size = 0;
 	int error;
 	struct reiserfs_inode_info *reiserfs_i = REISERFS_I(inode);
 
@@ -308,16 +308,21 @@ reiserfs_set_acl(struct inode *inode, int type, struct posix_acl *acl)
 		value = posix_acl_to_disk(acl, &size);
 		if (IS_ERR(value))
 			return (int)PTR_ERR(value);
-		error = reiserfs_xattr_set(inode, name, value, size, 0);
-	} else {
-		error = reiserfs_xattr_del(inode, name);
-		if (error == -ENODATA) {
-			/* This may seem odd here, but it means that the ACL was set
-			 * with a value representable with mode bits. If there was
-			 * an ACL before, reiserfs_xattr_del already dirtied the inode.
-			 */
+	}
+
+	error = __reiserfs_xattr_set(inode, name, value, size, 0);
+
+	/*
+	 * Ensure that the inode gets dirtied if we're only using
+	 * the mode bits and an old ACL didn't exist. We don't need
+	 * to check if the inode is hashed here since we won't get
+	 * called by reiserfs_inherit_default_acl().
+	 */
+	if (error == -ENODATA) {
+		error = 0;
+		if (type == ACL_TYPE_ACCESS) {
+			inode->i_ctime = CURRENT_TIME_SEC;
 			mark_inode_dirty(inode);
-			error = 0;
 		}
 	}
 
@@ -474,33 +479,22 @@ posix_acl_access_set(struct inode *inode, const char *name,
 	return xattr_set_acl(inode, ACL_TYPE_ACCESS, value, size);
 }
 
-static int posix_acl_access_del(struct inode *inode, const char *name)
-{
-	struct reiserfs_inode_info *reiserfs_i = REISERFS_I(inode);
-	if (strlen(name) != sizeof(POSIX_ACL_XATTR_ACCESS) - 1)
-		return -EINVAL;
-	iset_acl(inode, &reiserfs_i->i_acl_access, ERR_PTR(-ENODATA));
-	return 0;
-}
-
-static int
-posix_acl_access_list(struct inode *inode, const char *name, int namelen,
-		      char *out)
+static size_t posix_acl_access_list(struct inode *inode, char *list,
+				    size_t list_size, const char *name,
+				    size_t name_len)
 {
-	int len = namelen;
+	const size_t size = sizeof(POSIX_ACL_XATTR_ACCESS);
 	if (!reiserfs_posixacl(inode->i_sb))
 		return 0;
-	if (out)
-		memcpy(out, name, len);
-
-	return len;
+	if (list && size <= list_size)
+		memcpy(list, POSIX_ACL_XATTR_ACCESS, size);
+	return size;
 }
 
-struct reiserfs_xattr_handler posix_acl_access_handler = {
+struct xattr_handler reiserfs_posix_acl_access_handler = {
 	.prefix = POSIX_ACL_XATTR_ACCESS,
 	.get = posix_acl_access_get,
 	.set = posix_acl_access_set,
-	.del = posix_acl_access_del,
 	.list = posix_acl_access_list,
 };
 
@@ -522,32 +516,21 @@ posix_acl_default_set(struct inode *inode, const char *name,
 	return xattr_set_acl(inode, ACL_TYPE_DEFAULT, value, size);
 }
 
-static int posix_acl_default_del(struct inode *inode, const char *name)
+static size_t posix_acl_default_list(struct inode *inode, char *list,
+				     size_t list_size, const char *name,
+				     size_t name_len)
 {
-	struct reiserfs_inode_info *reiserfs_i = REISERFS_I(inode);
-	if (strlen(name) != sizeof(POSIX_ACL_XATTR_DEFAULT) - 1)
-		return -EINVAL;
-	iset_acl(inode, &reiserfs_i->i_acl_default, ERR_PTR(-ENODATA));
-	return 0;
-}
-
-static int
-posix_acl_default_list(struct inode *inode, const char *name, int namelen,
-		       char *out)
-{
-	int len = namelen;
+	const size_t size = sizeof(POSIX_ACL_XATTR_DEFAULT);
 	if (!reiserfs_posixacl(inode->i_sb))
 		return 0;
-	if (out)
-		memcpy(out, name, len);
-
-	return len;
+	if (list && size <= list_size)
+		memcpy(list, POSIX_ACL_XATTR_DEFAULT, size);
+	return size;
 }
 
-struct reiserfs_xattr_handler posix_acl_default_handler = {
+struct xattr_handler reiserfs_posix_acl_default_handler = {
 	.prefix = POSIX_ACL_XATTR_DEFAULT,
 	.get = posix_acl_default_get,
 	.set = posix_acl_default_set,
-	.del = posix_acl_default_del,
 	.list = posix_acl_default_list,
 };

fs/reiserfs/xattr_security.c

@@ -31,35 +31,25 @@ security_set(struct inode *inode, const char *name, const void *buffer,
 	return reiserfs_xattr_set(inode, name, buffer, size, flags);
 }
 
-static int security_del(struct inode *inode, const char *name)
+static size_t security_list(struct inode *inode, char *list, size_t list_len,
+			    const char *name, size_t namelen)
 {
-	if (strlen(name) < sizeof(XATTR_SECURITY_PREFIX))
-		return -EINVAL;
-
-	if (IS_PRIVATE(inode))
-		return -EPERM;
-
-	return 0;
-}
-
-static int
-security_list(struct inode *inode, const char *name, int namelen, char *out)
-{
-	int len = namelen;
+	const size_t len = namelen + 1;
 
 	if (IS_PRIVATE(inode))
 		return 0;
 
-	if (out)
-		memcpy(out, name, len);
+	if (list && len <= list_len) {
+		memcpy(list, name, namelen);
+		list[namelen] = '\0';
+	}
 
 	return len;
 }
 
-struct reiserfs_xattr_handler security_handler = {
+struct xattr_handler reiserfs_xattr_security_handler = {
 	.prefix = XATTR_SECURITY_PREFIX,
 	.get = security_get,
 	.set = security_set,
-	.del = security_del,
 	.list = security_list,
 };

fs/reiserfs/xattr_trusted.c

@@ -13,10 +13,7 @@ trusted_get(struct inode *inode, const char *name, void *buffer, size_t size)
 	if (strlen(name) < sizeof(XATTR_TRUSTED_PREFIX))
 		return -EINVAL;
 
-	if (!reiserfs_xattrs(inode->i_sb))
-		return -EOPNOTSUPP;
-
-	if (!(capable(CAP_SYS_ADMIN) || IS_PRIVATE(inode)))
+	if (!capable(CAP_SYS_ADMIN) || IS_PRIVATE(inode))
 		return -EPERM;
 
 	return reiserfs_xattr_get(inode, name, buffer, size);
@@ -29,50 +26,30 @@ trusted_set(struct inode *inode, const char *name, const void *buffer,
 	if (strlen(name) < sizeof(XATTR_TRUSTED_PREFIX))
 		return -EINVAL;
 
-	if (!reiserfs_xattrs(inode->i_sb))
-		return -EOPNOTSUPP;
-
-	if (!(capable(CAP_SYS_ADMIN) || IS_PRIVATE(inode)))
+	if (!capable(CAP_SYS_ADMIN) || IS_PRIVATE(inode))
 		return -EPERM;
 
 	return reiserfs_xattr_set(inode, name, buffer, size, flags);
 }
 
-static int trusted_del(struct inode *inode, const char *name)
+static size_t trusted_list(struct inode *inode, char *list, size_t list_size,
+			   const char *name, size_t name_len)
 {
-	if (strlen(name) < sizeof(XATTR_TRUSTED_PREFIX))
-		return -EINVAL;
+	const size_t len = name_len + 1;
 
-	if (!reiserfs_xattrs(inode->i_sb))
-		return -EOPNOTSUPP;
-
-	if (!(capable(CAP_SYS_ADMIN) || IS_PRIVATE(inode)))
-		return -EPERM;
-
-	return 0;
-}
-
-static int
-trusted_list(struct inode *inode, const char *name, int namelen, char *out)
-{
-	int len = namelen;
-
-	if (!reiserfs_xattrs(inode->i_sb))
+	if (!capable(CAP_SYS_ADMIN) || IS_PRIVATE(inode))
 		return 0;
 
-	if (!(capable(CAP_SYS_ADMIN) || IS_PRIVATE(inode)))
-		return 0;
-
-	if (out)
-		memcpy(out, name, len);
-
+	if (list && len <= list_size) {
+		memcpy(list, name, name_len);
+		list[name_len] = '\0';
+	}
 	return len;
 }
 
-struct reiserfs_xattr_handler trusted_handler = {
+struct xattr_handler reiserfs_xattr_trusted_handler = {
 	.prefix = XATTR_TRUSTED_PREFIX,
 	.get = trusted_get,
 	.set = trusted_set,
-	.del = trusted_del,
 	.list = trusted_list,
 };

fs/reiserfs/xattr_user.c

@@ -6,10 +6,6 @@
 #include <linux/reiserfs_xattr.h>
 #include <asm/uaccess.h>
 
-#ifdef CONFIG_REISERFS_FS_POSIX_ACL
-# include <linux/reiserfs_acl.h>
-#endif
-
 static int
 user_get(struct inode *inode, const char *name, void *buffer, size_t size)
 {
@@ -25,7 +21,6 @@ static int
 user_set(struct inode *inode, const char *name, const void *buffer,
 	 size_t size, int flags)
 {
-
 	if (strlen(name) < sizeof(XATTR_USER_PREFIX))
 		return -EINVAL;
 
@@ -34,33 +29,23 @@ user_set(struct inode *inode, const char *name, const void *buffer,
 	return reiserfs_xattr_set(inode, name, buffer, size, flags);
 }
 
-static int user_del(struct inode *inode, const char *name)
+static size_t user_list(struct inode *inode, char *list, size_t list_size,
+			const char *name, size_t name_len)
 {
-	if (strlen(name) < sizeof(XATTR_USER_PREFIX))
-		return -EINVAL;
-
-	if (!reiserfs_xattrs_user(inode->i_sb))
-		return -EOPNOTSUPP;
-	return 0;
-}
+	const size_t len = name_len + 1;
 
-static int
-user_list(struct inode *inode, const char *name, int namelen, char *out)
-{
-	int len = namelen;
 	if (!reiserfs_xattrs_user(inode->i_sb))
 		return 0;
-
-	if (out)
-		memcpy(out, name, len);
-
+	if (list && len <= list_size) {
+		memcpy(list, name, name_len);
+		list[name_len] = '\0';
+	}
 	return len;
 }
 
-struct reiserfs_xattr_handler user_handler = {
+struct xattr_handler reiserfs_xattr_user_handler = {
 	.prefix = XATTR_USER_PREFIX,
 	.get = user_get,
 	.set = user_set,
-	.del = user_del,
 	.list = user_list,
 };

include/linux/reiserfs_acl.h

@@ -52,10 +52,8 @@ int reiserfs_acl_chmod(struct inode *inode);
 int reiserfs_inherit_default_acl(struct inode *dir, struct dentry *dentry,
 				 struct inode *inode);
 int reiserfs_cache_default_acl(struct inode *dir);
-extern int reiserfs_xattr_posix_acl_init(void) __init;
-extern int reiserfs_xattr_posix_acl_exit(void);
-extern struct reiserfs_xattr_handler posix_acl_default_handler;
-extern struct reiserfs_xattr_handler posix_acl_access_handler;
+extern struct xattr_handler reiserfs_posix_acl_default_handler;
+extern struct xattr_handler reiserfs_posix_acl_access_handler;
 
 static inline void reiserfs_init_acl_access(struct inode *inode)
 {
@@ -75,16 +73,6 @@ static inline struct posix_acl *reiserfs_get_acl(struct inode *inode, int type)
 	return NULL;
 }
 
-static inline int reiserfs_xattr_posix_acl_init(void)
-{
-	return 0;
-}
-
-static inline int reiserfs_xattr_posix_acl_exit(void)
-{
-	return 0;
-}
-
 static inline int reiserfs_acl_chmod(struct inode *inode)
 {
 	return 0;

include/linux/reiserfs_fs_sb.h

@@ -451,7 +451,6 @@ enum reiserfs_mount_options {
 	REISERFS_NO_UNHASHED_RELOCATION,
 	REISERFS_HASHED_RELOCATION,
 	REISERFS_ATTRS,
-	REISERFS_XATTRS,
 	REISERFS_XATTRS_USER,
 	REISERFS_POSIXACL,
 	REISERFS_BARRIER_NONE,
@@ -489,7 +488,7 @@ enum reiserfs_mount_options {
 #define reiserfs_data_log(s) (REISERFS_SB(s)->s_mount_opt & (1 << REISERFS_DATA_LOG))
 #define reiserfs_data_ordered(s) (REISERFS_SB(s)->s_mount_opt & (1 << REISERFS_DATA_ORDERED))
 #define reiserfs_data_writeback(s) (REISERFS_SB(s)->s_mount_opt & (1 << REISERFS_DATA_WRITEBACK))
-#define reiserfs_xattrs(s) (REISERFS_SB(s)->s_mount_opt & (1 << REISERFS_XATTRS))
+#define reiserfs_xattrs(s) ((s)->s_xattr != NULL)
 #define reiserfs_xattrs_user(s) (REISERFS_SB(s)->s_mount_opt & (1 << REISERFS_XATTRS_USER))
 #define reiserfs_posixacl(s) (REISERFS_SB(s)->s_mount_opt & (1 << REISERFS_POSIXACL))
 #define reiserfs_xattrs_optional(s) (reiserfs_xattrs_user(s) || reiserfs_posixacl(s))

include/linux/reiserfs_xattr.h

@@ -29,20 +29,6 @@ struct iattr;
 struct super_block;
 struct nameidata;
 
-struct reiserfs_xattr_handler {
-	char *prefix;
-	int (*init) (void);
-	void (*exit) (void);
-	int (*get) (struct inode * inode, const char *name, void *buffer,
-		    size_t size);
-	int (*set) (struct inode * inode, const char *name, const void *buffer,
-		    size_t size, int flags);
-	int (*del) (struct inode * inode, const char *name);
-	int (*list) (struct inode * inode, const char *name, int namelen,
-		     char *out);
-	struct list_head handlers;
-};
-
 int reiserfs_xattr_register_handlers(void) __init;
 void reiserfs_xattr_unregister_handlers(void);
 int reiserfs_xattr_init(struct super_block *sb, int mount_flags);
@@ -59,13 +45,14 @@ ssize_t reiserfs_listxattr(struct dentry *dentry, char *buffer, size_t size);
 int reiserfs_removexattr(struct dentry *dentry, const char *name);
 int reiserfs_permission(struct inode *inode, int mask);
 
-int reiserfs_xattr_del(struct inode *, const char *);
-int reiserfs_xattr_get(const struct inode *, const char *, void *, size_t);
+int reiserfs_xattr_get(struct inode *, const char *, void *, size_t);
+int __reiserfs_xattr_set(struct inode *, const char *, const void *,
+			 size_t, int);
 int reiserfs_xattr_set(struct inode *, const char *, const void *, size_t, int);
 
-extern struct reiserfs_xattr_handler user_handler;
-extern struct reiserfs_xattr_handler trusted_handler;
-extern struct reiserfs_xattr_handler security_handler;
+extern struct xattr_handler reiserfs_xattr_user_handler;
+extern struct xattr_handler reiserfs_xattr_trusted_handler;
+extern struct xattr_handler reiserfs_xattr_security_handler;
 
 static inline void reiserfs_init_xattr_rwsem(struct inode *inode)
 {