kernfs: Switch to generic xattr handlers

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

5 files changed, 92 insertions, 86 deletions

diff --git a/fs/kernfs/dir.c b/fs/kernfs/dir.c
index e57174d43683..a6e430adf67d 100644
--- a/fs/kernfs/dir.c
+++ b/fs/kernfs/dir.c
@@ -1126,9 +1126,9 @@ const struct inode_operations kernfs_dir_iops = {
         .permission     = kernfs_iop_permission,
         .setattr        = kernfs_iop_setattr,
         .getattr        = kernfs_iop_getattr,
-        .setxattr       = kernfs_iop_setxattr,
-        .removexattr    = kernfs_iop_removexattr,
-        .getxattr       = kernfs_iop_getxattr,
+        .setxattr       = generic_setxattr,
+        .removexattr    = generic_removexattr,
+        .getxattr       = generic_getxattr,
         .listxattr      = kernfs_iop_listxattr,
 
         .mkdir          = kernfs_iop_mkdir,
diff --git a/fs/kernfs/inode.c b/fs/kernfs/inode.c
index 63b925d5ba1e..6bc87547dede 100644
--- a/fs/kernfs/inode.c
+++ b/fs/kernfs/inode.c
@@ -28,9 +28,9 @@ static const struct inode_operations kernfs_iops = {
         .permission     = kernfs_iop_permission,
         .setattr        = kernfs_iop_setattr,
         .getattr        = kernfs_iop_getattr,
-        .setxattr       = kernfs_iop_setxattr,
-        .removexattr    = kernfs_iop_removexattr,
-        .getxattr       = kernfs_iop_getxattr,
+        .setxattr       = generic_setxattr,
+        .removexattr    = generic_removexattr,
+        .getxattr       = generic_getxattr,
         .listxattr      = kernfs_iop_listxattr,
 };
 
@@ -138,17 +138,12 @@ out:
         return error;
 }
 
-static int kernfs_node_setsecdata(struct kernfs_node *kn, void **secdata,
+static int kernfs_node_setsecdata(struct kernfs_iattrs *attrs, void **secdata,
                                   u32 *secdata_len)
 {
-        struct kernfs_iattrs *attrs;
         void *old_secdata;
         size_t old_secdata_len;
 
-        attrs = kernfs_iattrs(kn);
-        if (!attrs)
-                return -ENOMEM;
-
         old_secdata = attrs->ia_secdata;
         old_secdata_len = attrs->ia_secdata_len;
 
@@ -160,71 +155,6 @@ static int kernfs_node_setsecdata(struct kernfs_node *kn, void **secdata,
         return 0;
 }
 
-int kernfs_iop_setxattr(struct dentry *unused, struct inode *inode,
-                        const char *name, const void *value,
-                        size_t size, int flags)
-{
-        struct kernfs_node *kn = inode->i_private;
-        struct kernfs_iattrs *attrs;
-        void *secdata;
-        int error;
-        u32 secdata_len = 0;
-
-        attrs = kernfs_iattrs(kn);
-        if (!attrs)
-                return -ENOMEM;
-
-        if (!strncmp(name, XATTR_SECURITY_PREFIX, XATTR_SECURITY_PREFIX_LEN)) {
-                const char *suffix = name + XATTR_SECURITY_PREFIX_LEN;
-                error = security_inode_setsecurity(inode, suffix,
-                                                value, size, flags);
-                if (error)
-                        return error;
-                error = security_inode_getsecctx(inode,
-                                                &secdata, &secdata_len);
-                if (error)
-                        return error;
-
-                mutex_lock(&kernfs_mutex);
-                error = kernfs_node_setsecdata(kn, &secdata, &secdata_len);
-                mutex_unlock(&kernfs_mutex);
-
-                if (secdata)
-                        security_release_secctx(secdata, secdata_len);
-                return error;
-        } else if (!strncmp(name, XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN)) {
-                return simple_xattr_set(&attrs->xattrs, name, value, size,
-                                        flags);
-        }
-
-        return -EINVAL;
-}
-
-int kernfs_iop_removexattr(struct dentry *dentry, const char *name)
-{
-        struct kernfs_node *kn = dentry->d_fsdata;
-        struct kernfs_iattrs *attrs;
-
-        attrs = kernfs_iattrs(kn);
-        if (!attrs)
-                return -ENOMEM;
-
-        return simple_xattr_set(&attrs->xattrs, name, NULL, 0, XATTR_REPLACE);
-}
-
-ssize_t kernfs_iop_getxattr(struct dentry *unused, struct inode *inode,
-                            const char *name, void *buf, size_t size)
-{
-        struct kernfs_node *kn = inode->i_private;
-        struct kernfs_iattrs *attrs;
-
-        attrs = kernfs_iattrs(kn);
-        if (!attrs)
-                return -ENOMEM;
-
-        return simple_xattr_get(&attrs->xattrs, name, buf, size);
-}
-
 ssize_t kernfs_iop_listxattr(struct dentry *dentry, char *buf, size_t size)
 {
         struct kernfs_node *kn = dentry->d_fsdata;
@@ -376,3 +306,83 @@ int kernfs_iop_permission(struct inode *inode, int mask)
 
         return generic_permission(inode, mask);
 }
+
+static int kernfs_xattr_get(const struct xattr_handler *handler,
+                            struct dentry *unused, struct inode *inode,
+                            const char *suffix, void *value, size_t size)
+{
+        const char *name = xattr_full_name(handler, suffix);
+        struct kernfs_node *kn = inode->i_private;
+        struct kernfs_iattrs *attrs;
+
+        attrs = kernfs_iattrs(kn);
+        if (!attrs)
+                return -ENOMEM;
+
+        return simple_xattr_get(&attrs->xattrs, name, value, size);
+}
+
+static int kernfs_xattr_set(const struct xattr_handler *handler,
+                            struct dentry *unused, struct inode *inode,
+                            const char *suffix, const void *value,
+                            size_t size, int flags)
+{
+        const char *name = xattr_full_name(handler, suffix);
+        struct kernfs_node *kn = inode->i_private;
+        struct kernfs_iattrs *attrs;
+
+        attrs = kernfs_iattrs(kn);
+        if (!attrs)
+                return -ENOMEM;
+
+        return simple_xattr_set(&attrs->xattrs, name, value, size, flags);
+}
+
+const struct xattr_handler kernfs_trusted_xattr_handler = {
+        .prefix = XATTR_TRUSTED_PREFIX,
+        .get = kernfs_xattr_get,
+        .set = kernfs_xattr_set,
+};
+
+static int kernfs_security_xattr_set(const struct xattr_handler *handler,
+                                     struct dentry *unused, struct inode *inode,
+                                     const char *suffix, const void *value,
+                                     size_t size, int flags)
+{
+        struct kernfs_node *kn = inode->i_private;
+        struct kernfs_iattrs *attrs;
+        void *secdata;
+        u32 secdata_len = 0;
+        int error;
+
+        attrs = kernfs_iattrs(kn);
+        if (!attrs)
+                return -ENOMEM;
+
+        error = security_inode_setsecurity(inode, suffix, value, size, flags);
+        if (error)
+                return error;
+        error = security_inode_getsecctx(inode, &secdata, &secdata_len);
+        if (error)
+                return error;
+
+        mutex_lock(&kernfs_mutex);
+        error = kernfs_node_setsecdata(attrs, &secdata, &secdata_len);
+        mutex_unlock(&kernfs_mutex);
+
+        if (secdata)
+                security_release_secctx(secdata, secdata_len);
+        return error;
+}
+
+const struct xattr_handler kernfs_security_xattr_handler = {
+        .prefix = XATTR_SECURITY_PREFIX,
+        .get = kernfs_xattr_get,
+        .set = kernfs_security_xattr_set,
+};
+
+const struct xattr_handler *kernfs_xattr_handlers[] = {
+        &kernfs_trusted_xattr_handler,
+        &kernfs_security_xattr_handler,
+        NULL
+};
diff --git a/fs/kernfs/kernfs-internal.h b/fs/kernfs/kernfs-internal.h
index 37159235ac10..bfd551bbf231 100644
--- a/fs/kernfs/kernfs-internal.h
+++ b/fs/kernfs/kernfs-internal.h
@@ -76,17 +76,12 @@ extern struct kmem_cache *kernfs_node_cache;
 /*
  * inode.c
  */
+extern const struct xattr_handler *kernfs_xattr_handlers[];
 void kernfs_evict_inode(struct inode *inode);
 int kernfs_iop_permission(struct inode *inode, int mask);
 int kernfs_iop_setattr(struct dentry *dentry, struct iattr *iattr);
 int kernfs_iop_getattr(struct vfsmount *mnt, struct dentry *dentry,
                        struct kstat *stat);
-int kernfs_iop_setxattr(struct dentry *dentry, struct inode *inode,
-                        const char *name, const void *value,
-                        size_t size, int flags);
-int kernfs_iop_removexattr(struct dentry *dentry, const char *name);
-ssize_t kernfs_iop_getxattr(struct dentry *dentry, struct inode *inode,
-                            const char *name, void *buf, size_t size);
 ssize_t kernfs_iop_listxattr(struct dentry *dentry, char *buf, size_t size);
 
 /*
diff --git a/fs/kernfs/mount.c b/fs/kernfs/mount.c
index b3d73ad52b22..d5b149a45be1 100644
--- a/fs/kernfs/mount.c
+++ b/fs/kernfs/mount.c
@@ -158,6 +158,7 @@ static int kernfs_fill_super(struct super_block *sb, unsigned long magic)
         sb->s_blocksize_bits = PAGE_SHIFT;
         sb->s_magic = magic;
         sb->s_op = &kernfs_sops;
+        sb->s_xattr = kernfs_xattr_handlers;
         sb->s_time_gran = 1;
 
         /* get root inode, initialize and unlock it */
diff --git a/fs/kernfs/symlink.c b/fs/kernfs/symlink.c
index 117b8b3416f9..549a14c7c50a 100644
--- a/fs/kernfs/symlink.c
+++ b/fs/kernfs/symlink.c
@@ -134,9 +134,9 @@ static const char *kernfs_iop_get_link(struct dentry *dentry,
 }
 
 const struct inode_operations kernfs_symlink_iops = {
-        .setxattr       = kernfs_iop_setxattr,
-        .removexattr    = kernfs_iop_removexattr,
-        .getxattr       = kernfs_iop_getxattr,
+        .setxattr       = generic_setxattr,
+        .removexattr    = generic_removexattr,
+        .getxattr       = generic_getxattr,
         .listxattr      = kernfs_iop_listxattr,
         .readlink       = generic_readlink,
         .get_link       = kernfs_iop_get_link,