Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / fs / xfs / xfs_xattr.c
diff --git a/kernel/fs/xfs/xfs_xattr.c b/kernel/fs/xfs/xfs_xattr.c
new file mode 100644 (file)
index 0000000..c036815
--- /dev/null
@@ -0,0 +1,243 @@
+/*
+ * Copyright (C) 2008 Christoph Hellwig.
+ * Portions Copyright (C) 2000-2008 Silicon Graphics, Inc.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it would be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write the Free Software Foundation,
+ * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
+#include "xfs.h"
+#include "xfs_format.h"
+#include "xfs_log_format.h"
+#include "xfs_trans_resv.h"
+#include "xfs_mount.h"
+#include "xfs_da_format.h"
+#include "xfs_inode.h"
+#include "xfs_attr.h"
+#include "xfs_attr_leaf.h"
+#include "xfs_acl.h"
+
+#include <linux/posix_acl_xattr.h>
+#include <linux/xattr.h>
+
+
+static int
+xfs_xattr_get(struct dentry *dentry, const char *name,
+               void *value, size_t size, int xflags)
+{
+       struct xfs_inode *ip = XFS_I(d_inode(dentry));
+       int error, asize = size;
+
+       if (strcmp(name, "") == 0)
+               return -EINVAL;
+
+       /* Convert Linux syscall to XFS internal ATTR flags */
+       if (!size) {
+               xflags |= ATTR_KERNOVAL;
+               value = NULL;
+       }
+
+       error = xfs_attr_get(ip, (unsigned char *)name, value, &asize, xflags);
+       if (error)
+               return error;
+       return asize;
+}
+
+static int
+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(d_inode(dentry));
+
+       if (strcmp(name, "") == 0)
+               return -EINVAL;
+
+       /* Convert Linux syscall to XFS internal ATTR flags */
+       if (flags & XATTR_CREATE)
+               xflags |= ATTR_CREATE;
+       if (flags & XATTR_REPLACE)
+               xflags |= ATTR_REPLACE;
+
+       if (!value)
+               return xfs_attr_remove(ip, (unsigned char *)name, xflags);
+       return xfs_attr_set(ip, (unsigned char *)name,
+                               (void *)value, size, xflags);
+}
+
+static const struct xattr_handler xfs_xattr_user_handler = {
+       .prefix = XATTR_USER_PREFIX,
+       .flags  = 0, /* no flags implies user namespace */
+       .get    = xfs_xattr_get,
+       .set    = xfs_xattr_set,
+};
+
+static const struct xattr_handler xfs_xattr_trusted_handler = {
+       .prefix = XATTR_TRUSTED_PREFIX,
+       .flags  = ATTR_ROOT,
+       .get    = xfs_xattr_get,
+       .set    = xfs_xattr_set,
+};
+
+static const struct xattr_handler xfs_xattr_security_handler = {
+       .prefix = XATTR_SECURITY_PREFIX,
+       .flags  = ATTR_SECURE,
+       .get    = xfs_xattr_get,
+       .set    = xfs_xattr_set,
+};
+
+const struct xattr_handler *xfs_xattr_handlers[] = {
+       &xfs_xattr_user_handler,
+       &xfs_xattr_trusted_handler,
+       &xfs_xattr_security_handler,
+#ifdef CONFIG_XFS_POSIX_ACL
+       &posix_acl_access_xattr_handler,
+       &posix_acl_default_xattr_handler,
+#endif
+       NULL
+};
+
+static unsigned int xfs_xattr_prefix_len(int flags)
+{
+       if (flags & XFS_ATTR_SECURE)
+               return sizeof("security");
+       else if (flags & XFS_ATTR_ROOT)
+               return sizeof("trusted");
+       else
+               return sizeof("user");
+}
+
+static const char *xfs_xattr_prefix(int flags)
+{
+       if (flags & XFS_ATTR_SECURE)
+               return xfs_xattr_security_handler.prefix;
+       else if (flags & XFS_ATTR_ROOT)
+               return xfs_xattr_trusted_handler.prefix;
+       else
+               return xfs_xattr_user_handler.prefix;
+}
+
+static int
+xfs_xattr_put_listent(
+       struct xfs_attr_list_context *context,
+       int             flags,
+       unsigned char   *name,
+       int             namelen,
+       int             valuelen,
+       unsigned char   *value)
+{
+       unsigned int prefix_len = xfs_xattr_prefix_len(flags);
+       char *offset;
+       int arraytop;
+
+       ASSERT(context->count >= 0);
+
+       /*
+        * Only show root namespace entries if we are actually allowed to
+        * see them.
+        */
+       if ((flags & XFS_ATTR_ROOT) && !capable(CAP_SYS_ADMIN))
+               return 0;
+
+       arraytop = context->count + prefix_len + namelen + 1;
+       if (arraytop > context->firstu) {
+               context->count = -1;    /* insufficient space */
+               return 1;
+       }
+       offset = (char *)context->alist + context->count;
+       strncpy(offset, xfs_xattr_prefix(flags), prefix_len);
+       offset += prefix_len;
+       strncpy(offset, (char *)name, namelen);                 /* real name */
+       offset += namelen;
+       *offset = '\0';
+       context->count += prefix_len + namelen + 1;
+       return 0;
+}
+
+static int
+xfs_xattr_put_listent_sizes(
+       struct xfs_attr_list_context *context,
+       int             flags,
+       unsigned char   *name,
+       int             namelen,
+       int             valuelen,
+       unsigned char   *value)
+{
+       context->count += xfs_xattr_prefix_len(flags) + namelen + 1;
+       return 0;
+}
+
+static int
+list_one_attr(const char *name, const size_t len, void *data,
+               size_t size, ssize_t *result)
+{
+       char *p = data + *result;
+
+       *result += len;
+       if (!size)
+               return 0;
+       if (*result > size)
+               return -ERANGE;
+
+       strcpy(p, name);
+       return 0;
+}
+
+ssize_t
+xfs_vn_listxattr(struct dentry *dentry, char *data, size_t size)
+{
+       struct xfs_attr_list_context context;
+       struct attrlist_cursor_kern cursor = { 0 };
+       struct inode            *inode = d_inode(dentry);
+       int                     error;
+
+       /*
+        * First read the regular on-disk attributes.
+        */
+       memset(&context, 0, sizeof(context));
+       context.dp = XFS_I(inode);
+       context.cursor = &cursor;
+       context.resynch = 1;
+       context.alist = data;
+       context.bufsize = size;
+       context.firstu = context.bufsize;
+
+       if (size)
+               context.put_listent = xfs_xattr_put_listent;
+       else
+               context.put_listent = xfs_xattr_put_listent_sizes;
+
+       xfs_attr_list_int(&context);
+       if (context.count < 0)
+               return -ERANGE;
+
+       /*
+        * Then add the two synthetic ACL attributes.
+        */
+       if (posix_acl_access_exists(inode)) {
+               error = list_one_attr(POSIX_ACL_XATTR_ACCESS,
+                               strlen(POSIX_ACL_XATTR_ACCESS) + 1,
+                               data, size, &context.count);
+               if (error)
+                       return error;
+       }
+
+       if (posix_acl_default_exists(inode)) {
+               error = list_one_attr(POSIX_ACL_XATTR_DEFAULT,
+                               strlen(POSIX_ACL_XATTR_DEFAULT) + 1,
+                               data, size, &context.count);
+               if (error)
+                       return error;
+       }
+
+       return context.count;
+}