tmpfs: Use xattr handler infrastructure
Use the VFS xattr handler infrastructure and get rid of similar code in
the filesystem. For implementing shmem_xattr_handler_set, we need a
version of simple_xattr_set which removes the attribute when value is
NULL. Use this to implement kernfs_iop_removexattr as well.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Reviewed-by: James Morris <james.l.morris@oracle.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: linux-mm@kvack.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/mm/shmem.c b/mm/shmem.c
index 9187eee..fdfe6c8 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -2561,95 +2561,48 @@
return 0;
}
+static int shmem_xattr_handler_get(const struct xattr_handler *handler,
+ struct dentry *dentry, const char *name,
+ void *buffer, size_t size)
+{
+ struct shmem_inode_info *info = SHMEM_I(d_inode(dentry));
+
+ name = xattr_full_name(handler, name);
+ return simple_xattr_get(&info->xattrs, name, buffer, size);
+}
+
+static int shmem_xattr_handler_set(const struct xattr_handler *handler,
+ struct dentry *dentry, const char *name,
+ const void *value, size_t size, int flags)
+{
+ struct shmem_inode_info *info = SHMEM_I(d_inode(dentry));
+
+ name = xattr_full_name(handler, name);
+ return simple_xattr_set(&info->xattrs, name, value, size, flags);
+}
+
+static const struct xattr_handler shmem_security_xattr_handler = {
+ .prefix = XATTR_SECURITY_PREFIX,
+ .get = shmem_xattr_handler_get,
+ .set = shmem_xattr_handler_set,
+};
+
+static const struct xattr_handler shmem_trusted_xattr_handler = {
+ .prefix = XATTR_TRUSTED_PREFIX,
+ .get = shmem_xattr_handler_get,
+ .set = shmem_xattr_handler_set,
+};
+
static const struct xattr_handler *shmem_xattr_handlers[] = {
#ifdef CONFIG_TMPFS_POSIX_ACL
&posix_acl_access_xattr_handler,
&posix_acl_default_xattr_handler,
#endif
+ &shmem_security_xattr_handler,
+ &shmem_trusted_xattr_handler,
NULL
};
-static int shmem_xattr_validate(const char *name)
-{
- struct { const char *prefix; size_t len; } arr[] = {
- { XATTR_SECURITY_PREFIX, XATTR_SECURITY_PREFIX_LEN },
- { XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN }
- };
- int i;
-
- for (i = 0; i < ARRAY_SIZE(arr); i++) {
- size_t preflen = arr[i].len;
- if (strncmp(name, arr[i].prefix, preflen) == 0) {
- if (!name[preflen])
- return -EINVAL;
- return 0;
- }
- }
- return -EOPNOTSUPP;
-}
-
-static ssize_t shmem_getxattr(struct dentry *dentry, const char *name,
- void *buffer, size_t size)
-{
- struct shmem_inode_info *info = SHMEM_I(d_inode(dentry));
- int err;
-
- /*
- * If this is a request for a synthetic attribute in the system.*
- * namespace use the generic infrastructure to resolve a handler
- * for it via sb->s_xattr.
- */
- if (!strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN))
- return generic_getxattr(dentry, name, buffer, size);
-
- err = shmem_xattr_validate(name);
- if (err)
- return err;
-
- return simple_xattr_get(&info->xattrs, name, buffer, size);
-}
-
-static int shmem_setxattr(struct dentry *dentry, const char *name,
- const void *value, size_t size, int flags)
-{
- struct shmem_inode_info *info = SHMEM_I(d_inode(dentry));
- int err;
-
- /*
- * If this is a request for a synthetic attribute in the system.*
- * namespace use the generic infrastructure to resolve a handler
- * for it via sb->s_xattr.
- */
- if (!strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN))
- return generic_setxattr(dentry, name, value, size, flags);
-
- err = shmem_xattr_validate(name);
- if (err)
- return err;
-
- return simple_xattr_set(&info->xattrs, name, value, size, flags);
-}
-
-static int shmem_removexattr(struct dentry *dentry, const char *name)
-{
- struct shmem_inode_info *info = SHMEM_I(d_inode(dentry));
- int err;
-
- /*
- * If this is a request for a synthetic attribute in the system.*
- * namespace use the generic infrastructure to resolve a handler
- * for it via sb->s_xattr.
- */
- if (!strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN))
- return generic_removexattr(dentry, name);
-
- err = shmem_xattr_validate(name);
- if (err)
- return err;
-
- return simple_xattr_remove(&info->xattrs, name);
-}
-
static ssize_t shmem_listxattr(struct dentry *dentry, char *buffer, size_t size)
{
struct shmem_inode_info *info = SHMEM_I(d_inode(dentry));
@@ -2661,10 +2614,10 @@
.readlink = generic_readlink,
.follow_link = simple_follow_link,
#ifdef CONFIG_TMPFS_XATTR
- .setxattr = shmem_setxattr,
- .getxattr = shmem_getxattr,
+ .setxattr = generic_setxattr,
+ .getxattr = generic_getxattr,
.listxattr = shmem_listxattr,
- .removexattr = shmem_removexattr,
+ .removexattr = generic_removexattr,
#endif
};
@@ -2673,10 +2626,10 @@
.follow_link = shmem_follow_link,
.put_link = shmem_put_link,
#ifdef CONFIG_TMPFS_XATTR
- .setxattr = shmem_setxattr,
- .getxattr = shmem_getxattr,
+ .setxattr = generic_setxattr,
+ .getxattr = generic_getxattr,
.listxattr = shmem_listxattr,
- .removexattr = shmem_removexattr,
+ .removexattr = generic_removexattr,
#endif
};
@@ -3148,10 +3101,10 @@
.getattr = shmem_getattr,
.setattr = shmem_setattr,
#ifdef CONFIG_TMPFS_XATTR
- .setxattr = shmem_setxattr,
- .getxattr = shmem_getxattr,
+ .setxattr = generic_setxattr,
+ .getxattr = generic_getxattr,
.listxattr = shmem_listxattr,
- .removexattr = shmem_removexattr,
+ .removexattr = generic_removexattr,
.set_acl = simple_set_acl,
#endif
};
@@ -3170,10 +3123,10 @@
.tmpfile = shmem_tmpfile,
#endif
#ifdef CONFIG_TMPFS_XATTR
- .setxattr = shmem_setxattr,
- .getxattr = shmem_getxattr,
+ .setxattr = generic_setxattr,
+ .getxattr = generic_getxattr,
.listxattr = shmem_listxattr,
- .removexattr = shmem_removexattr,
+ .removexattr = generic_removexattr,
#endif
#ifdef CONFIG_TMPFS_POSIX_ACL
.setattr = shmem_setattr,
@@ -3183,10 +3136,10 @@
static const struct inode_operations shmem_special_inode_operations = {
#ifdef CONFIG_TMPFS_XATTR
- .setxattr = shmem_setxattr,
- .getxattr = shmem_getxattr,
+ .setxattr = generic_setxattr,
+ .getxattr = generic_getxattr,
.listxattr = shmem_listxattr,
- .removexattr = shmem_removexattr,
+ .removexattr = generic_removexattr,
#endif
#ifdef CONFIG_TMPFS_POSIX_ACL
.setattr = shmem_setattr,