sanitize xattr handler prototypes

Add a flags argument to struct xattr_handler and pass it to all xattr
handler methods.  This allows using the same methods for multiple
handlers, e.g. for the ACL methods which perform exactly the same action
for the access and default ACLs, just using a different underlying
attribute.  With a little more groundwork it'll also allow sharing the
methods for the regular user/trusted/secure handlers in extN, ocfs2 and
jffs2 like it's already done for xfs in this patch.

Also change the inode argument to the handlers to a dentry to allow
using the handlers mechnism for filesystems that require it later,
e.g. cifs.

[with GFS2 bits updated by Steven Whitehouse <swhiteho@redhat.com>]

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: James Morris <jmorris@namei.org>
Acked-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

5 files changed, 73 insertions, 97 deletions

diff --git a/fs/ext4/acl.c b/fs/ext4/acl.c
index 0df88b2..8a2a29d 100644
--- a/fs/ext4/acl.c
+++ b/fs/ext4/acl.c
@@ -364,12 +364,12 @@ out:
  * Extended attribute handlers
  */
 static size_t
-ext4_xattr_list_acl_access(struct inode *inode, char *list, size_t list_len,
-			   const char *name, size_t name_len)
+ext4_xattr_list_acl_access(struct dentry *dentry, char *list, size_t list_len,
+			   const char *name, size_t name_len, int type)
 {
 	const size_t size = sizeof(POSIX_ACL_XATTR_ACCESS);
 
-	if (!test_opt(inode->i_sb, POSIX_ACL))
+	if (!test_opt(dentry->d_sb, POSIX_ACL))
 		return 0;
 	if (list && size <= list_len)
 		memcpy(list, POSIX_ACL_XATTR_ACCESS, size);
@@ -377,12 +377,12 @@ ext4_xattr_list_acl_access(struct inode *inode, char *list, size_t list_len,
 }
 
 static size_t
-ext4_xattr_list_acl_default(struct inode *inode, char *list, size_t list_len,
-			    const char *name, size_t name_len)
+ext4_xattr_list_acl_default(struct dentry *dentry, char *list, size_t list_len,
+			    const char *name, size_t name_len, int type)
 {
 	const size_t size = sizeof(POSIX_ACL_XATTR_DEFAULT);
 
-	if (!test_opt(inode->i_sb, POSIX_ACL))
+	if (!test_opt(dentry->d_sb, POSIX_ACL))
 		return 0;
 	if (list && size <= list_len)
 		memcpy(list, POSIX_ACL_XATTR_DEFAULT, size);
@@ -390,15 +390,18 @@ ext4_xattr_list_acl_default(struct inode *inode, char *list, size_t list_len,
 }
 
 static int
-ext4_xattr_get_acl(struct inode *inode, int type, void *buffer, size_t size)
+ext4_xattr_get_acl(struct dentry *dentry, const char *name, void *buffer,
+		   size_t size, int type)
 {
 	struct posix_acl *acl;
 	int error;
 
-	if (!test_opt(inode->i_sb, POSIX_ACL))
+	if (strcmp(name, "") != 0)
+		return -EINVAL;
+	if (!test_opt(dentry->d_sb, POSIX_ACL))
 		return -EOPNOTSUPP;
 
-	acl = ext4_get_acl(inode, type);
+	acl = ext4_get_acl(dentry->d_inode, type);
 	if (IS_ERR(acl))
 		return PTR_ERR(acl);
 	if (acl == NULL)
@@ -410,31 +413,16 @@ ext4_xattr_get_acl(struct inode *inode, int type, void *buffer, size_t size)
 }
 
 static int
-ext4_xattr_get_acl_access(struct inode *inode, const char *name,
-			  void *buffer, size_t size)
-{
-	if (strcmp(name, "") != 0)
-		return -EINVAL;
-	return ext4_xattr_get_acl(inode, ACL_TYPE_ACCESS, buffer, size);
-}
-
-static int
-ext4_xattr_get_acl_default(struct inode *inode, const char *name,
-			   void *buffer, size_t size)
-{
-	if (strcmp(name, "") != 0)
-		return -EINVAL;
-	return ext4_xattr_get_acl(inode, ACL_TYPE_DEFAULT, buffer, size);
-}
-
-static int
-ext4_xattr_set_acl(struct inode *inode, int type, const void *value,
-		   size_t size)
+ext4_xattr_set_acl(struct dentry *dentry, const char *name, const void *value,
+		   size_t size, int flags, int type)
 {
+	struct inode *inode = dentry->d_inode;
 	handle_t *handle;
 	struct posix_acl *acl;
 	int error, retries = 0;
 
+	if (strcmp(name, "") != 0)
+		return -EINVAL;
 	if (!test_opt(inode->i_sb, POSIX_ACL))
 		return -EOPNOTSUPP;
 	if (!is_owner_or_cap(inode))
@@ -466,34 +454,18 @@ release_and_out:
 	return error;
 }
 
-static int
-ext4_xattr_set_acl_access(struct inode *inode, const char *name,
-			  const void *value, size_t size, int flags)
-{
-	if (strcmp(name, "") != 0)
-		return -EINVAL;
-	return ext4_xattr_set_acl(inode, ACL_TYPE_ACCESS, value, size);
-}
-
-static int
-ext4_xattr_set_acl_default(struct inode *inode, const char *name,
-			   const void *value, size_t size, int flags)
-{
-	if (strcmp(name, "") != 0)
-		return -EINVAL;
-	return ext4_xattr_set_acl(inode, ACL_TYPE_DEFAULT, value, size);
-}
-
 struct xattr_handler ext4_xattr_acl_access_handler = {
 	.prefix	= POSIX_ACL_XATTR_ACCESS,
+	.flags	= ACL_TYPE_ACCESS,
 	.list	= ext4_xattr_list_acl_access,
-	.get	= ext4_xattr_get_acl_access,
-	.set	= ext4_xattr_set_acl_access,
+	.get	= ext4_xattr_get_acl,
+	.set	= ext4_xattr_set_acl,
 };
 
 struct xattr_handler ext4_xattr_acl_default_handler = {
 	.prefix	= POSIX_ACL_XATTR_DEFAULT,
+	.flags	= ACL_TYPE_DEFAULT,
 	.list	= ext4_xattr_list_acl_default,
-	.get	= ext4_xattr_get_acl_default,
-	.set	= ext4_xattr_set_acl_default,
+	.get	= ext4_xattr_get_acl,
+	.set	= ext4_xattr_set_acl,
 };
diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c
index 910bf9a..83218be 100644
--- a/fs/ext4/xattr.c
+++ b/fs/ext4/xattr.c
@@ -92,7 +92,7 @@ static struct buffer_head *ext4_xattr_cache_find(struct inode *,
 						 struct mb_cache_entry **);
 static void ext4_xattr_rehash(struct ext4_xattr_header *,
 			      struct ext4_xattr_entry *);
-static int ext4_xattr_list(struct inode *inode, char *buffer,
+static int ext4_xattr_list(struct dentry *dentry, char *buffer,
 			   size_t buffer_size);
 
 static struct mb_cache *ext4_xattr_cache;
@@ -140,7 +140,7 @@ ext4_xattr_handler(int name_index)
 ssize_t
 ext4_listxattr(struct dentry *dentry, char *buffer, size_t size)
 {
-	return ext4_xattr_list(dentry->d_inode, buffer, size);
+	return ext4_xattr_list(dentry, buffer, size);
 }
 
 static int
@@ -325,7 +325,7 @@ ext4_xattr_get(struct inode *inode, int name_index, const char *name,
 }
 
 static int
-ext4_xattr_list_entries(struct inode *inode, struct ext4_xattr_entry *entry,
+ext4_xattr_list_entries(struct dentry *dentry, struct ext4_xattr_entry *entry,
 			char *buffer, size_t buffer_size)
 {
 	size_t rest = buffer_size;
@@ -335,9 +335,10 @@ ext4_xattr_list_entries(struct inode *inode, struct ext4_xattr_entry *entry,
 			ext4_xattr_handler(entry->e_name_index);
 
 		if (handler) {
-			size_t size = handler->list(inode, buffer, rest,
+			size_t size = handler->list(dentry, buffer, rest,
 						    entry->e_name,
-						    entry->e_name_len);
+						    entry->e_name_len,
+						    handler->flags);
 			if (buffer) {
 				if (size > rest)
 					return -ERANGE;
@@ -350,8 +351,9 @@ ext4_xattr_list_entries(struct inode *inode, struct ext4_xattr_entry *entry,
 }
 
 static int
-ext4_xattr_block_list(struct inode *inode, char *buffer, size_t buffer_size)
+ext4_xattr_block_list(struct dentry *dentry, char *buffer, size_t buffer_size)
 {
+	struct inode *inode = dentry->d_inode;
 	struct buffer_head *bh = NULL;
 	int error;
 
@@ -376,7 +378,7 @@ ext4_xattr_block_list(struct inode *inode, char *buffer, size_t buffer_size)
 		goto cleanup;
 	}
 	ext4_xattr_cache_insert(bh);
-	error = ext4_xattr_list_entries(inode, BFIRST(bh), buffer, buffer_size);
+	error = ext4_xattr_list_entries(dentry, BFIRST(bh), buffer, buffer_size);
 
 cleanup:
 	brelse(bh);
@@ -385,8 +387,9 @@ cleanup:
 }
 
 static int
-ext4_xattr_ibody_list(struct inode *inode, char *buffer, size_t buffer_size)
+ext4_xattr_ibody_list(struct dentry *dentry, char *buffer, size_t buffer_size)
 {
+	struct inode *inode = dentry->d_inode;
 	struct ext4_xattr_ibody_header *header;
 	struct ext4_inode *raw_inode;
 	struct ext4_iloc iloc;
@@ -404,7 +407,7 @@ ext4_xattr_ibody_list(struct inode *inode, char *buffer, size_t buffer_size)
 	error = ext4_xattr_check_names(IFIRST(header), end);
 	if (error)
 		goto cleanup;
-	error = ext4_xattr_list_entries(inode, IFIRST(header),
+	error = ext4_xattr_list_entries(dentry, IFIRST(header),
 					buffer, buffer_size);
 
 cleanup:
@@ -423,12 +426,12 @@ cleanup:
  * used / required on success.
  */
 static int
-ext4_xattr_list(struct inode *inode, char *buffer, size_t buffer_size)
+ext4_xattr_list(struct dentry *dentry, char *buffer, size_t buffer_size)
 {
 	int i_error, b_error;
 
-	down_read(&EXT4_I(inode)->xattr_sem);
-	i_error = ext4_xattr_ibody_list(inode, buffer, buffer_size);
+	down_read(&EXT4_I(dentry->d_inode)->xattr_sem);
+	i_error = ext4_xattr_ibody_list(dentry, buffer, buffer_size);
 	if (i_error < 0) {
 		b_error = 0;
 	} else {
@@ -436,11 +439,11 @@ ext4_xattr_list(struct inode *inode, char *buffer, size_t buffer_size)
 			buffer += i_error;
 			buffer_size -= i_error;
 		}
-		b_error = ext4_xattr_block_list(inode, buffer, buffer_size);
+		b_error = ext4_xattr_block_list(dentry, buffer, buffer_size);
 		if (b_error < 0)
 			i_error = 0;
 	}
-	up_read(&EXT4_I(inode)->xattr_sem);
+	up_read(&EXT4_I(dentry->d_inode)->xattr_sem);
 	return i_error + b_error;
 }
 
diff --git a/fs/ext4/xattr_security.c b/fs/ext4/xattr_security.c
index ca5f89f..983c253 100644
--- a/fs/ext4/xattr_security.c
+++ b/fs/ext4/xattr_security.c
@@ -12,8 +12,8 @@
 #include "xattr.h"
 
 static size_t
-ext4_xattr_security_list(struct inode *inode, char *list, size_t list_size,
-			 const char *name, size_t name_len)
+ext4_xattr_security_list(struct dentry *dentry, char *list, size_t list_size,
+		const char *name, size_t name_len, int type)
 {
 	const size_t prefix_len = sizeof(XATTR_SECURITY_PREFIX)-1;
 	const size_t total_len = prefix_len + name_len + 1;
@@ -28,23 +28,23 @@ ext4_xattr_security_list(struct inode *inode, char *list, size_t list_size,
 }
 
 static int
-ext4_xattr_security_get(struct inode *inode, const char *name,
-		       void *buffer, size_t size)
+ext4_xattr_security_get(struct dentry *dentry, const char *name,
+		       void *buffer, size_t size, int type)
 {
 	if (strcmp(name, "") == 0)
 		return -EINVAL;
-	return ext4_xattr_get(inode, EXT4_XATTR_INDEX_SECURITY, name,
-			      buffer, size);
+	return ext4_xattr_get(dentry->d_inode, EXT4_XATTR_INDEX_SECURITY,
+			      name, buffer, size);
 }
 
 static int
-ext4_xattr_security_set(struct inode *inode, const char *name,
-		       const void *value, size_t size, int flags)
+ext4_xattr_security_set(struct dentry *dentry, const char *name,
+		const void *value, size_t size, int flags, int type)
 {
 	if (strcmp(name, "") == 0)
 		return -EINVAL;
-	return ext4_xattr_set(inode, EXT4_XATTR_INDEX_SECURITY, name,
-			      value, size, flags);
+	return ext4_xattr_set(dentry->d_inode, EXT4_XATTR_INDEX_SECURITY,
+			      name, value, size, flags);
 }
 
 int
diff --git a/fs/ext4/xattr_trusted.c b/fs/ext4/xattr_trusted.c
index ac1a52c..15b50ed 100644
--- a/fs/ext4/xattr_trusted.c
+++ b/fs/ext4/xattr_trusted.c
@@ -14,8 +14,8 @@
 #include "xattr.h"
 
 static size_t
-ext4_xattr_trusted_list(struct inode *inode, char *list, size_t list_size,
-			const char *name, size_t name_len)
+ext4_xattr_trusted_list(struct dentry *dentry, char *list, size_t list_size,
+		const char *name, size_t name_len, int type)
 {
 	const size_t prefix_len = XATTR_TRUSTED_PREFIX_LEN;
 	const size_t total_len = prefix_len + name_len + 1;
@@ -32,23 +32,23 @@ ext4_xattr_trusted_list(struct inode *inode, char *list, size_t list_size,
 }
 
 static int
-ext4_xattr_trusted_get(struct inode *inode, const char *name,
-		       void *buffer, size_t size)
+ext4_xattr_trusted_get(struct dentry *dentry, const char *name, void *buffer,
+		size_t size, int type)
 {
 	if (strcmp(name, "") == 0)
 		return -EINVAL;
-	return ext4_xattr_get(inode, EXT4_XATTR_INDEX_TRUSTED, name,
-			      buffer, size);
+	return ext4_xattr_get(dentry->d_inode, EXT4_XATTR_INDEX_TRUSTED,
+			      name, buffer, size);
 }
 
 static int
-ext4_xattr_trusted_set(struct inode *inode, const char *name,
-		       const void *value, size_t size, int flags)
+ext4_xattr_trusted_set(struct dentry *dentry, const char *name,
+		const void *value, size_t size, int flags, int type)
 {
 	if (strcmp(name, "") == 0)
 		return -EINVAL;
-	return ext4_xattr_set(inode, EXT4_XATTR_INDEX_TRUSTED, name,
-			      value, size, flags);
+	return ext4_xattr_set(dentry->d_inode, EXT4_XATTR_INDEX_TRUSTED,
+			      name, value, size, flags);
 }
 
 struct xattr_handler ext4_xattr_trusted_handler = {
diff --git a/fs/ext4/xattr_user.c b/fs/ext4/xattr_user.c
index d91aa61..c4ce057 100644
--- a/fs/ext4/xattr_user.c
+++ b/fs/ext4/xattr_user.c
@@ -13,13 +13,13 @@
 #include "xattr.h"
 
 static size_t
-ext4_xattr_user_list(struct inode *inode, char *list, size_t list_size,
-		     const char *name, size_t name_len)
+ext4_xattr_user_list(struct dentry *dentry, char *list, size_t list_size,
+		     const char *name, size_t name_len, int type)
 {
 	const size_t prefix_len = XATTR_USER_PREFIX_LEN;
 	const size_t total_len = prefix_len + name_len + 1;
 
-	if (!test_opt(inode->i_sb, XATTR_USER))
+	if (!test_opt(dentry->d_sb, XATTR_USER))
 		return 0;
 
 	if (list && total_len <= list_size) {
@@ -31,26 +31,27 @@ ext4_xattr_user_list(struct inode *inode, char *list, size_t list_size,
 }
 
 static int
-ext4_xattr_user_get(struct inode *inode, const char *name,
-		    void *buffer, size_t size)
+ext4_xattr_user_get(struct dentry *dentry, const char *name,
+		    void *buffer, size_t size, int type)
 {
 	if (strcmp(name, "") == 0)
 		return -EINVAL;
-	if (!test_opt(inode->i_sb, XATTR_USER))
+	if (!test_opt(dentry->d_sb, XATTR_USER))
 		return -EOPNOTSUPP;
-	return ext4_xattr_get(inode, EXT4_XATTR_INDEX_USER, name, buffer, size);
+	return ext4_xattr_get(dentry->d_inode, EXT4_XATTR_INDEX_USER,
+			      name, buffer, size);
 }
 
 static int
-ext4_xattr_user_set(struct inode *inode, const char *name,
-		    const void *value, size_t size, int flags)
+ext4_xattr_user_set(struct dentry *dentry, const char *name,
+		    const void *value, size_t size, int flags, int type)
 {
 	if (strcmp(name, "") == 0)
 		return -EINVAL;
-	if (!test_opt(inode->i_sb, XATTR_USER))
+	if (!test_opt(dentry->d_sb, XATTR_USER))
 		return -EOPNOTSUPP;
-	return ext4_xattr_set(inode, EXT4_XATTR_INDEX_USER, name,
-			      value, size, flags);
+	return ext4_xattr_set(dentry->d_inode, EXT4_XATTR_INDEX_USER,
+			      name, value, size, flags);
 }
 
 struct xattr_handler ext4_xattr_user_handler = {