[PATCH v20 11/23] posix_acl: Improve xattr fixup code

From	Andreas Gruenbacher <agruenba@redhat.com>
Newsgroups	linux.kernel
Subject	[PATCH v20 11/23] posix_acl: Improve xattr fixup code
Date	2016-03-16 23:30 +0100
Message-ID	<rds70-6Wr-5@gated-at.bofh.it> (permalink)
References	<rdrXj-6Sv-1@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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Both XATTR_NAME_POSIX_ACL_ACCESS and XATTR_NAME_POSIX_ACL_DEFAULT have
the same XATTR_SYSTEM_PREFIX prefix; don't check for the same prefix
repeatedly.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
---
 fs/xattr.c | 29 +++++++++++++++++++++++------
 1 file changed, 23 insertions(+), 6 deletions(-)

diff --git a/fs/xattr.c b/fs/xattr.c
index 4861322..c364696 100644
--- a/fs/xattr.c
+++ b/fs/xattr.c
@@ -295,6 +295,16 @@ out:
 }
 EXPORT_SYMBOL_GPL(vfs_removexattr);
 
+static void
+fix_xattr_from_user(const char *kname, void *kvalue, size_t size)
+{
+	if (strncmp(kname, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN))
+		return;
+	kname += XATTR_SYSTEM_PREFIX_LEN;
+	if (!strcmp(kname, XATTR_POSIX_ACL_ACCESS) ||
+	    !strcmp(kname, XATTR_POSIX_ACL_DEFAULT))
+		posix_acl_fix_xattr_from_user(kvalue, size);
+}
 
 /*
  * Extended attribute SET operations
@@ -329,9 +339,7 @@ setxattr(struct dentry *d, const char __user *name, const void __user *value,
 			error = -EFAULT;
 			goto out;
 		}
-		if ((strcmp(kname, XATTR_NAME_POSIX_ACL_ACCESS) == 0) ||
-		    (strcmp(kname, XATTR_NAME_POSIX_ACL_DEFAULT) == 0))
-			posix_acl_fix_xattr_from_user(kvalue, size);
+		fix_xattr_from_user(kname, kvalue, size);
 	}
 
 	error = vfs_setxattr(d, kname, kvalue, size, flags);
@@ -396,6 +404,17 @@ SYSCALL_DEFINE5(fsetxattr, int, fd, const char __user *, name,
 	return error;
 }
 
+static void
+fix_xattr_to_user(const char *kname, void *kvalue, size_t size)
+{
+	if (strncmp(kname, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN))
+		return;
+	kname += XATTR_SYSTEM_PREFIX_LEN;
+	if (!strcmp(kname, XATTR_POSIX_ACL_ACCESS) ||
+	    !strcmp(kname, XATTR_POSIX_ACL_DEFAULT))
+		posix_acl_fix_xattr_to_user(kvalue, size);
+}
+
 /*
  * Extended attribute GET operations
  */
@@ -426,9 +445,7 @@ getxattr(struct dentry *d, const char __user *name, void __user *value,
 
 	error = vfs_getxattr(d, kname, kvalue, size);
 	if (error > 0) {
-		if ((strcmp(kname, XATTR_NAME_POSIX_ACL_ACCESS) == 0) ||
-		    (strcmp(kname, XATTR_NAME_POSIX_ACL_DEFAULT) == 0))
-			posix_acl_fix_xattr_to_user(kvalue, size);
+		fix_xattr_to_user(kname, kvalue, size);
 		if (size && copy_to_user(value, kvalue, error))
 			error = -EFAULT;
 	} else if (error == -ERANGE && size >= XATTR_SIZE_MAX) {
-- 
2.5.0

Thread

[PATCH v20 00/23] Richacls (Core and Ext4) Andreas Gruenbacher <agruenba@redhat.com> - 2016-03-16 23:20 +0100
  [PATCH v20 03/23] vfs: Add MAY_DELETE_SELF and MAY_DELETE_CHILD permission flags Andreas Gruenbacher <agruenba@redhat.com> - 2016-03-16 23:20 +0100
  [PATCH v20 01/23] vfs: Add IS_ACL() and IS_RICHACL() tests Andreas Gruenbacher <agruenba@redhat.com> - 2016-03-16 23:20 +0100
  [PATCH v20 11/23] posix_acl: Improve xattr fixup code Andreas Gruenbacher <agruenba@redhat.com> - 2016-03-16 23:30 +0100
  [PATCH v20 13/23] vfs: Add get_richacl and set_richacl inode operations Andreas Gruenbacher <agruenba@redhat.com> - 2016-03-16 23:30 +0100
  [PATCH v20 05/23] vfs: Add permission flags for setting file attributes Andreas Gruenbacher <agruenba@redhat.com> - 2016-03-16 23:30 +0100
  [PATCH v20 09/23] richacl: Permission check algorithm Andreas Gruenbacher <agruenba@redhat.com> - 2016-03-16 23:30 +0100
  [PATCH v20 14/23] vfs: Cache richacl in struct inode Andreas Gruenbacher <agruenba@redhat.com> - 2016-03-16 23:30 +0100
  [PATCH v20 23/23] ext4: Add richacl feature flag Andreas Gruenbacher <agruenba@redhat.com> - 2016-03-16 23:30 +0100
  [PATCH v20 10/23] posix_acl: Unexport acl_by_type and make it static Andreas Gruenbacher <agruenba@redhat.com> - 2016-03-16 23:30 +0100
  [PATCH v20 04/23] vfs: Make the inode passed to inode_change_ok non-const Andreas Gruenbacher <agruenba@redhat.com> - 2016-03-16 23:30 +0100
  [PATCH v20 02/23] vfs: Add MAY_CREATE_FILE and MAY_CREATE_DIR permission flags Andreas Gruenbacher <agruenba@redhat.com> - 2016-03-16 23:30 +0100
  [PATCH v20 22/23] ext4: Add richacl support Andreas Gruenbacher <agruenba@redhat.com> - 2016-03-16 23:30 +0100
  [PATCH v20 08/23] richacl: Compute maximum file masks from an acl Andreas Gruenbacher <agruenba@redhat.com> - 2016-03-16 23:30 +0100
  [PATCH v20 16/23] richacl: Check if an acl is equivalent to a file mode Andreas Gruenbacher <agruenba@redhat.com> - 2016-03-16 23:30 +0100
  [PATCH v20 19/23] richacl: xattr mapping functions Andreas Gruenbacher <agruenba@redhat.com> - 2016-03-16 23:30 +0100
  [PATCH v20 06/23] richacl: In-memory representation and helper functions Andreas Gruenbacher <agruenba@redhat.com> - 2016-03-16 23:30 +0100
  [PATCH v20 21/23] vfs: Add richacl permission checking Andreas Gruenbacher <agruenba@redhat.com> - 2016-03-16 23:30 +0100
  [PATCH v20 07/23] richacl: Permission mapping functions Andreas Gruenbacher <agruenba@redhat.com> - 2016-03-16 23:30 +0100
  [PATCH v20 12/23] vfs: Cache base_acl objects in inodes Andreas Gruenbacher <agruenba@redhat.com> - 2016-03-16 23:30 +0100
  [PATCH v20 20/23] richacl: Add richacl xattr handler Andreas Gruenbacher <agruenba@redhat.com> - 2016-03-16 23:30 +0100
  [PATCH v20 18/23] richacl: Automatic Inheritance Andreas Gruenbacher <agruenba@redhat.com> - 2016-03-16 23:30 +0100
  [PATCH v20 15/23] richacl: Update the file masks in chmod() Andreas Gruenbacher <agruenba@redhat.com> - 2016-03-16 23:30 +0100
  [PATCH v20 17/23] richacl: Create-time inheritance Andreas Gruenbacher <agruenba@redhat.com> - 2016-03-16 23:30 +0100

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