Adding upstream version 4.19.249.upstream/4.19.249

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 242 insertions, 0 deletions

diff --git a/fs/xfs/xfs_xattr.c b/fs/xfs/xfs_xattr.c
new file mode 100644
index 000000000..9a6301600
--- /dev/null
+++ b/fs/xfs/xfs_xattr.c
@@ -0,0 +1,242 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2008 Christoph Hellwig.
+ * Portions Copyright (C) 2000-2008 Silicon Graphics, Inc.
+ */
+
+#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(const struct xattr_handler *handler, struct dentry *unused,
+		struct inode *inode, const char *name, void *value, size_t size)
+{
+	int xflags = handler->flags;
+	struct xfs_inode *ip = XFS_I(inode);
+	int error, asize = size;
+
+	/* 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;
+}
+
+void
+xfs_forget_acl(
+	struct inode		*inode,
+	const char		*name,
+	int			xflags)
+{
+	/*
+	 * Invalidate any cached ACLs if the user has bypassed the ACL
+	 * interface. We don't validate the content whatsoever so it is caller
+	 * responsibility to provide data in valid format and ensure i_mode is
+	 * consistent.
+	 */
+	if (xflags & ATTR_ROOT) {
+#ifdef CONFIG_XFS_POSIX_ACL
+		if (!strcmp(name, SGI_ACL_FILE))
+			forget_cached_acl(inode, ACL_TYPE_ACCESS);
+		else if (!strcmp(name, SGI_ACL_DEFAULT))
+			forget_cached_acl(inode, ACL_TYPE_DEFAULT);
+#endif
+	}
+}
+
+static int
+xfs_xattr_set(const struct xattr_handler *handler, struct dentry *unused,
+		struct inode *inode, const char *name, const void *value,
+		size_t size, int flags)
+{
+	int			xflags = handler->flags;
+	struct xfs_inode	*ip = XFS_I(inode);
+	int			error;
+
+	/* 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);
+	error = xfs_attr_set(ip, (unsigned char *)name,
+				(void *)value, size, xflags);
+	if (!error)
+		xfs_forget_acl(inode, name, xflags);
+
+	return error;
+}
+
+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 void
+__xfs_xattr_put_listent(
+	struct xfs_attr_list_context *context,
+	char *prefix,
+	int prefix_len,
+	unsigned char *name,
+	int namelen)
+{
+	char *offset;
+	int arraytop;
+
+	if (context->count < 0 || context->seen_enough)
+		return;
+
+	if (!context->alist)
+		goto compute_size;
+
+	arraytop = context->count + prefix_len + namelen + 1;
+	if (arraytop > context->firstu) {
+		context->count = -1;	/* insufficient space */
+		context->seen_enough = 1;
+		return;
+	}
+	offset = (char *)context->alist + context->count;
+	strncpy(offset, prefix, prefix_len);
+	offset += prefix_len;
+	strncpy(offset, (char *)name, namelen);			/* real name */
+	offset += namelen;
+	*offset = '\0';
+
+compute_size:
+	context->count += prefix_len + namelen + 1;
+	return;
+}
+
+static void
+xfs_xattr_put_listent(
+	struct xfs_attr_list_context *context,
+	int		flags,
+	unsigned char	*name,
+	int		namelen,
+	int		valuelen)
+{
+	char *prefix;
+	int prefix_len;
+
+	ASSERT(context->count >= 0);
+
+	if (flags & XFS_ATTR_ROOT) {
+#ifdef CONFIG_XFS_POSIX_ACL
+		if (namelen == SGI_ACL_FILE_SIZE &&
+		    strncmp(name, SGI_ACL_FILE,
+			    SGI_ACL_FILE_SIZE) == 0) {
+			__xfs_xattr_put_listent(
+					context, XATTR_SYSTEM_PREFIX,
+					XATTR_SYSTEM_PREFIX_LEN,
+					XATTR_POSIX_ACL_ACCESS,
+					strlen(XATTR_POSIX_ACL_ACCESS));
+		} else if (namelen == SGI_ACL_DEFAULT_SIZE &&
+			 strncmp(name, SGI_ACL_DEFAULT,
+				 SGI_ACL_DEFAULT_SIZE) == 0) {
+			__xfs_xattr_put_listent(
+					context, XATTR_SYSTEM_PREFIX,
+					XATTR_SYSTEM_PREFIX_LEN,
+					XATTR_POSIX_ACL_DEFAULT,
+					strlen(XATTR_POSIX_ACL_DEFAULT));
+		}
+#endif
+
+		/*
+		 * Only show root namespace entries if we are actually allowed to
+		 * see them.
+		 */
+		if (!capable(CAP_SYS_ADMIN))
+			return;
+
+		prefix = XATTR_TRUSTED_PREFIX;
+		prefix_len = XATTR_TRUSTED_PREFIX_LEN;
+	} else if (flags & XFS_ATTR_SECURE) {
+		prefix = XATTR_SECURITY_PREFIX;
+		prefix_len = XATTR_SECURITY_PREFIX_LEN;
+	} else {
+		prefix = XATTR_USER_PREFIX;
+		prefix_len = XATTR_USER_PREFIX_LEN;
+	}
+
+	__xfs_xattr_put_listent(context, prefix, prefix_len, name,
+				namelen);
+	return;
+}
+
+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 = size ? data : NULL;
+	context.bufsize = size;
+	context.firstu = context.bufsize;
+	context.put_listent = xfs_xattr_put_listent;
+
+	error = xfs_attr_list_int(&context);
+	if (error)
+		return error;
+	if (context.count < 0)
+		return -ERANGE;
+
+	return context.count;
+}