sockfs: Get rid of getxattr iop

If we allow pseudo-filesystems created with mount_pseudo to have xattr
handlers, we can replace sockfs_getxattr with a sockfs_xattr_get handler
to use the xattr handler name parsing.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --git a/fs/libfs.c b/fs/libfs.c
index 74dc8b9..cfa9576 100644 (file)
--- a/fs/libfs.c
+++ b/fs/libfs.c
@@ -236,8 +236,8 @@ static const struct super_operations simple_super_operations = {
  * Common helper for pseudo-filesystems (sockfs, pipefs, bdev - stuff that
  * will never be mountable)
  */
-struct dentry *mount_pseudo(struct file_system_type *fs_type, char *name,
-       const struct super_operations *ops,
+struct dentry *mount_pseudo_xattr(struct file_system_type *fs_type, char *name,
+       const struct super_operations *ops, const struct xattr_handler **xattr,
        const struct dentry_operations *dops, unsigned long magic)
 {
        struct super_block *s;
@@ -254,6 +254,7 @@ struct dentry *mount_pseudo(struct file_system_type *fs_type, char *name,
        s->s_blocksize_bits = PAGE_SHIFT;
        s->s_magic = magic;
        s->s_op = ops ? ops : &simple_super_operations;
+       s->s_xattr = xattr;
        s->s_time_gran = 1;
        root = new_inode(s);
        if (!root)
@@ -281,7 +282,7 @@ Enomem:
        deactivate_locked_super(s);
        return ERR_PTR(-ENOMEM);
 }
-EXPORT_SYMBOL(mount_pseudo);
+EXPORT_SYMBOL(mount_pseudo_xattr);
 
 int simple_open(struct inode *inode, struct file *file)
 {

diff --git a/include/linux/fs.h b/include/linux/fs.h
index 901e25d..7540e87 100644 (file)
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2075,10 +2075,19 @@ struct super_block *sget(struct file_system_type *type,
                        int (*test)(struct super_block *,void *),
                        int (*set)(struct super_block *,void *),
                        int flags, void *data);
-extern struct dentry *mount_pseudo(struct file_system_type *, char *,
-       const struct super_operations *ops,
-       const struct dentry_operations *dops,
-       unsigned long);
+extern struct dentry *mount_pseudo_xattr(struct file_system_type *, char *,
+                                        const struct super_operations *ops,
+                                        const struct xattr_handler **xattr,
+                                        const struct dentry_operations *dops,
+                                        unsigned long);
+
+static inline struct dentry *
+mount_pseudo(struct file_system_type *fs_type, char *name,
+            const struct super_operations *ops,
+            const struct dentry_operations *dops, unsigned long magic)
+{
+       return mount_pseudo_xattr(fs_type, name, ops, NULL, dops, magic);
+}
 
 /* Alas, no aliases. Too much hassle with bringing module.h everywhere */
 #define fops_get(fops) \

diff --git a/net/socket.c b/net/socket.c
index 9b3dca6..976f732 100644 (file)
--- a/net/socket.c
+++ b/net/socket.c
@@ -320,11 +320,38 @@ static const struct dentry_operations sockfs_dentry_operations = {
        .d_dname  = sockfs_dname,
 };
 
+static int sockfs_xattr_get(const struct xattr_handler *handler,
+                           struct dentry *dentry, struct inode *inode,
+                           const char *suffix, void *value, size_t size)
+{
+       if (value) {
+               if (dentry->d_name.len + 1 > size)
+                       return -ERANGE;
+               memcpy(value, dentry->d_name.name, dentry->d_name.len + 1);
+       }
+       return dentry->d_name.len + 1;
+}
+
+#define XATTR_SOCKPROTONAME_SUFFIX "sockprotoname"
+#define XATTR_NAME_SOCKPROTONAME (XATTR_SYSTEM_PREFIX XATTR_SOCKPROTONAME_SUFFIX)
+#define XATTR_NAME_SOCKPROTONAME_LEN (sizeof(XATTR_NAME_SOCKPROTONAME)-1)
+
+static const struct xattr_handler sockfs_xattr_handler = {
+       .name = XATTR_NAME_SOCKPROTONAME,
+       .get = sockfs_xattr_get,
+};
+
+static const struct xattr_handler *sockfs_xattr_handlers[] = {
+       &sockfs_xattr_handler,
+       NULL
+};
+
 static struct dentry *sockfs_mount(struct file_system_type *fs_type,
                         int flags, const char *dev_name, void *data)
 {
-       return mount_pseudo(fs_type, "socket:", &sockfs_ops,
-               &sockfs_dentry_operations, SOCKFS_MAGIC);
+       return mount_pseudo_xattr(fs_type, "socket:", &sockfs_ops,
+                                 sockfs_xattr_handlers,
+                                 &sockfs_dentry_operations, SOCKFS_MAGIC);
 }
 
 static struct vfsmount *sock_mnt __read_mostly;
@@ -463,23 +490,6 @@ static struct socket *sockfd_lookup_light(int fd, int *err, int *fput_needed)
        return NULL;
 }
 
-#define XATTR_SOCKPROTONAME_SUFFIX "sockprotoname"
-#define XATTR_NAME_SOCKPROTONAME (XATTR_SYSTEM_PREFIX XATTR_SOCKPROTONAME_SUFFIX)
-#define XATTR_NAME_SOCKPROTONAME_LEN (sizeof(XATTR_NAME_SOCKPROTONAME)-1)
-static ssize_t sockfs_getxattr(struct dentry *dentry, struct inode *inode,
-                              const char *name, void *value, size_t size)
-{
-       if (!strcmp(name, XATTR_NAME_SOCKPROTONAME)) {
-               if (value) {
-                       if (dentry->d_name.len + 1 > size)
-                               return -ERANGE;
-                       memcpy(value, dentry->d_name.name, dentry->d_name.len + 1);
-               }
-               return dentry->d_name.len + 1;
-       }
-       return -EOPNOTSUPP;
-}
-
 static ssize_t sockfs_listxattr(struct dentry *dentry, char *buffer,
                                size_t size)
 {
@@ -509,7 +519,7 @@ static ssize_t sockfs_listxattr(struct dentry *dentry, char *buffer,
 }
 
 static const struct inode_operations sockfs_inode_ops = {
-       .getxattr = sockfs_getxattr,
+       .getxattr = generic_getxattr,
        .listxattr = sockfs_listxattr,
 };