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>

3 files changed, 37 insertions, 94 deletions

diff --git a/fs/xfs/linux-2.6/xfs_acl.c b/fs/xfs/linux-2.6/xfs_acl.c
index 69e598b6986..2512125dfa7 100644
--- a/fs/xfs/linux-2.6/xfs_acl.c
+++ b/fs/xfs/linux-2.6/xfs_acl.c
@@ -354,37 +354,14 @@ xfs_acl_chmod(struct inode *inode)
         return error;
 }
 
-/*
- * System xattr handlers.
- *
- * Currently Posix ACLs are the only system namespace extended attribute
- * handlers supported by XFS, so we just implement the handlers here.
- * If we ever support other system extended attributes this will need
- * some refactoring.
- */
-
 static int
-xfs_decode_acl(const char *name)
-{
-        if (strcmp(name, "posix_acl_access") == 0)
-                return ACL_TYPE_ACCESS;
-        else if (strcmp(name, "posix_acl_default") == 0)
-                return ACL_TYPE_DEFAULT;
-        return -EINVAL;
-}
-
-static int
-xfs_xattr_system_get(struct inode *inode, const char *name,
-                void *value, size_t size)
+xfs_xattr_acl_get(struct dentry *dentry, const char *name,
+                void *value, size_t size, int type)
 {
         struct posix_acl *acl;
-        int type, error;
-
-        type = xfs_decode_acl(name);
-        if (type < 0)
-                return type;
+        int error;
 
-        acl = xfs_get_acl(inode, type);
+        acl = xfs_get_acl(dentry->d_inode, type);
         if (IS_ERR(acl))
                 return PTR_ERR(acl);
         if (acl == NULL)
@@ -397,15 +374,13 @@ xfs_xattr_system_get(struct inode *inode, const char *name,
 }
 
 static int
-xfs_xattr_system_set(struct inode *inode, const char *name,
-                const void *value, size_t size, int flags)
+xfs_xattr_acl_set(struct dentry *dentry, const char *name,
+                const void *value, size_t size, int flags, int type)
 {
+        struct inode *inode = dentry->d_inode;
         struct posix_acl *acl = NULL;
-        int error = 0, type;
+        int error = 0;
 
-        type = xfs_decode_acl(name);
-        if (type < 0)
-                return type;
         if (flags & XATTR_CREATE)
                 return -EINVAL;
         if (type == ACL_TYPE_DEFAULT && !S_ISDIR(inode->i_mode))
@@ -462,8 +437,16 @@ xfs_xattr_system_set(struct inode *inode, const char *name,
         return error;
 }
 
-struct xattr_handler xfs_xattr_system_handler = {
-        .prefix = XATTR_SYSTEM_PREFIX,
-        .get    = xfs_xattr_system_get,
-        .set    = xfs_xattr_system_set,
+struct xattr_handler xfs_xattr_acl_access_handler = {
+        .prefix = POSIX_ACL_XATTR_ACCESS,
+        .flags  = ACL_TYPE_ACCESS,
+        .get    = xfs_xattr_acl_get,
+        .set    = xfs_xattr_acl_set,
+};
+
+struct xattr_handler xfs_xattr_acl_default_handler = {
+        .prefix = POSIX_ACL_XATTR_DEFAULT,
+        .flags  = ACL_TYPE_DEFAULT,
+        .get    = xfs_xattr_acl_get,
+        .set    = xfs_xattr_acl_set,
 };
diff --git a/fs/xfs/linux-2.6/xfs_xattr.c b/fs/xfs/linux-2.6/xfs_xattr.c
index 497c7fb75cc..0b1878857fc 100644
--- a/fs/xfs/linux-2.6/xfs_xattr.c
+++ b/fs/xfs/linux-2.6/xfs_xattr.c
@@ -30,10 +30,10 @@
 
 
 static int
-__xfs_xattr_get(struct inode *inode, const char *name,
+xfs_xattr_get(struct dentry *dentry, const char *name,
                 void *value, size_t size, int xflags)
 {
-        struct xfs_inode *ip = XFS_I(inode);
+        struct xfs_inode *ip = XFS_I(dentry->d_inode);
         int error, asize = size;
 
         if (strcmp(name, "") == 0)
@@ -52,10 +52,10 @@ __xfs_xattr_get(struct inode *inode, const char *name,
 }
 
 static int
-__xfs_xattr_set(struct inode *inode, const char *name, const void *value,
+xfs_xattr_set(struct dentry *dentry, const char *name, const void *value,
                 size_t size, int flags, int xflags)
 {
-        struct xfs_inode *ip = XFS_I(inode);
+        struct xfs_inode *ip = XFS_I(dentry->d_inode);
 
         if (strcmp(name, "") == 0)
                 return -EINVAL;
@@ -71,75 +71,34 @@ __xfs_xattr_set(struct inode *inode, const char *name, const void *value,
         return -xfs_attr_set(ip, name, (void *)value, size, xflags);
 }
 
-static int
-xfs_xattr_user_get(struct inode *inode, const char *name,
-                void *value, size_t size)
-{
-        return __xfs_xattr_get(inode, name, value, size, 0);
-}
-
-static int
-xfs_xattr_user_set(struct inode *inode, const char *name,
-                const void *value, size_t size, int flags)
-{
-        return __xfs_xattr_set(inode, name, value, size, flags, 0);
-}
-
 static struct xattr_handler xfs_xattr_user_handler = {
         .prefix = XATTR_USER_PREFIX,
-        .get    = xfs_xattr_user_get,
-        .set    = xfs_xattr_user_set,
+        .flags  = 0, /* no flags implies user namespace */
+        .get    = xfs_xattr_get,
+        .set    = xfs_xattr_set,
 };
 
-
-static int
-xfs_xattr_trusted_get(struct inode *inode, const char *name,
-                void *value, size_t size)
-{
-        return __xfs_xattr_get(inode, name, value, size, ATTR_ROOT);
-}
-
-static int
-xfs_xattr_trusted_set(struct inode *inode, const char *name,
-                const void *value, size_t size, int flags)
-{
-        return __xfs_xattr_set(inode, name, value, size, flags, ATTR_ROOT);
-}
-
 static struct xattr_handler xfs_xattr_trusted_handler = {
         .prefix = XATTR_TRUSTED_PREFIX,
-        .get    = xfs_xattr_trusted_get,
-        .set    = xfs_xattr_trusted_set,
+        .flags  = ATTR_ROOT,
+        .get    = xfs_xattr_get,
+        .set    = xfs_xattr_set,
 };
 
-
-static int
-xfs_xattr_secure_get(struct inode *inode, const char *name,
-                void *value, size_t size)
-{
-        return __xfs_xattr_get(inode, name, value, size, ATTR_SECURE);
-}
-
-static int
-xfs_xattr_secure_set(struct inode *inode, const char *name,
-                const void *value, size_t size, int flags)
-{
-        return __xfs_xattr_set(inode, name, value, size, flags, ATTR_SECURE);
-}
-
 static struct xattr_handler xfs_xattr_security_handler = {
         .prefix = XATTR_SECURITY_PREFIX,
-        .get    = xfs_xattr_secure_get,
-        .set    = xfs_xattr_secure_set,
+        .flags  = ATTR_SECURE,
+        .get    = xfs_xattr_get,
+        .set    = xfs_xattr_set,
 };
 
-
 struct xattr_handler *xfs_xattr_handlers[] = {
         &xfs_xattr_user_handler,
         &xfs_xattr_trusted_handler,
         &xfs_xattr_security_handler,
 #ifdef CONFIG_XFS_POSIX_ACL
-        &xfs_xattr_system_handler,
+        &xfs_xattr_acl_access_handler,
+        &xfs_xattr_acl_default_handler,
 #endif
         NULL
 };
diff --git a/fs/xfs/xfs_acl.h b/fs/xfs/xfs_acl.h
index 947b150df8e..00fd357c3e4 100644
--- a/fs/xfs/xfs_acl.h
+++ b/fs/xfs/xfs_acl.h
@@ -49,7 +49,8 @@ extern int xfs_acl_chmod(struct inode *inode);
 extern int posix_acl_access_exists(struct inode *inode);
 extern int posix_acl_default_exists(struct inode *inode);
 
-extern struct xattr_handler xfs_xattr_system_handler;
+extern struct xattr_handler xfs_xattr_acl_access_handler;
+extern struct xattr_handler xfs_xattr_acl_default_handler;
 #else
 # define xfs_check_acl                                  NULL
 # define xfs_get_acl(inode, type)                       NULL