[XFS] Use the generic xattr methods.

Add missing file fs/xfs/linux-2.6/xfs_xattr.c

SGI-PV: 982343

SGI-Modid: xfs-linux-melb:xfs-kern:31234a
Signed-off-by: NChristoph Hellwig <hch@infradead.org>
Signed-off-by: NTim Shimmin <tes@sgi.com>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>

fs/xfs/linux-2.6/xfs_xattr.c

+/*
+ * 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_da_btree.h"
+#include "xfs_bmap_btree.h"
+#include "xfs_inode.h"
+#include "xfs_attr.h"
+#include "xfs_attr_leaf.h"
+#include "xfs_acl.h"
+#include "xfs_vnodeops.h"
+
+#include <linux/posix_acl_xattr.h>
+#include <linux/xattr.h>
+
+
+/*
+ * ACL handling.  Should eventually be moved into xfs_acl.c
+ */
+
+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;
+}
+
+/*
+ * Get system extended attributes which at the moment only
+ * includes Posix ACLs.
+ */
+static int
+xfs_xattr_system_get(struct inode *inode, const char *name,
+		void *buffer, size_t size)
+{
+	int acl;
+
+	acl = xfs_decode_acl(name);
+	if (acl < 0)
+		return acl;
+
+	return xfs_acl_vget(inode, buffer, size, acl);
+}
+
+static int
+xfs_xattr_system_set(struct inode *inode, const char *name,
+		const void *value, size_t size, int flags)
+{
+	int error, acl;
+
+	acl = xfs_decode_acl(name);
+	if (acl < 0)
+		return acl;
+	if (flags & XATTR_CREATE)
+		return -EINVAL;
+
+	if (!value)
+		return xfs_acl_vremove(inode, acl);
+
+	error = xfs_acl_vset(inode, (void *)value, size, acl);
+	if (!error)
+		vn_revalidate(inode);
+	return error;
+}
+
+static struct xattr_handler xfs_xattr_system_handler = {
+	.prefix	= XATTR_SYSTEM_PREFIX,
+	.get	= xfs_xattr_system_get,
+	.set	= xfs_xattr_system_set,
+};
+
+
+/*
+ * Real xattr handling.  The only difference between the namespaces is
+ * a flag passed to the low-level attr code.
+ */
+
+static int
+__xfs_xattr_get(struct inode *inode, const char *name,
+		void *value, size_t size, int xflags)
+{
+	struct xfs_inode *ip = XFS_I(inode);
+	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, name, value, &asize, xflags);
+	if (error)
+		return error;
+	return asize;
+}
+
+static int
+__xfs_xattr_set(struct inode *inode, const char *name, const void *value,
+		size_t size, int flags, int xflags)
+{
+	struct xfs_inode *ip = XFS_I(inode);
+
+	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, name, xflags);
+	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,
+};
+
+
+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,
+};
+
+
+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,
+};
+
+
+struct xattr_handler *xfs_xattr_handlers[] = {
+	&xfs_xattr_user_handler,
+	&xfs_xattr_trusted_handler,
+	&xfs_xattr_security_handler,
+	&xfs_xattr_system_handler,
+	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,
+		char *name, int namelen, int valuelen, 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, 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,
+		char *name, int namelen, int valuelen, 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 = dentry->d_inode;
+	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 (xfs_acl_vhasacl_access(inode)) {
+		error = list_one_attr(POSIX_ACL_XATTR_ACCESS,
+				strlen(POSIX_ACL_XATTR_ACCESS) + 1,
+				data, size, &context.count);
+		if (error)
+			return error;
+	}
+
+	if (xfs_acl_vhasacl_default(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;
+}