Merge branch 'lookup-permissions-cleanup'

* lookup-permissions-cleanup:
  jffs2/jfs/xfs: switch over to 'check_acl' rather than 'permission()'
  ext[234]: move over to 'check_acl' permission model
  shmfs: use 'check_acl' instead of 'permission'
  Make 'check_acl()' a first-class filesystem op
  Simplify exec_permission_lite(), part 3
  Simplify exec_permission_lite() further
  Simplify exec_permission_lite() logic
  Do not call 'ima_path_check()' for each path component

23 files changed, 73 insertions, 109 deletions

diff --git a/fs/ext2/acl.c b/fs/ext2/acl.c
index d636e1297ca..a63d44256a7 100644
--- a/fs/ext2/acl.c
+++ b/fs/ext2/acl.c
@@ -230,7 +230,7 @@ ext2_set_acl(struct inode *inode, int type, struct posix_acl *acl)
 	return error;
 }
 
-static int
+int
 ext2_check_acl(struct inode *inode, int mask)
 {
 	struct posix_acl *acl = ext2_get_acl(inode, ACL_TYPE_ACCESS);
@@ -246,12 +246,6 @@ ext2_check_acl(struct inode *inode, int mask)
 	return -EAGAIN;
 }
 
-int
-ext2_permission(struct inode *inode, int mask)
-{
-	return generic_permission(inode, mask, ext2_check_acl);
-}
-
 /*
  * Initialize the ACLs of a new inode. Called from ext2_new_inode.
  *
diff --git a/fs/ext2/acl.h b/fs/ext2/acl.h
index ecefe478898..3ff6cbb9ac4 100644
--- a/fs/ext2/acl.h
+++ b/fs/ext2/acl.h
@@ -54,13 +54,13 @@ static inline int ext2_acl_count(size_t size)
 #ifdef CONFIG_EXT2_FS_POSIX_ACL
 
 /* acl.c */
-extern int ext2_permission (struct inode *, int);
+extern int ext2_check_acl (struct inode *, int);
 extern int ext2_acl_chmod (struct inode *);
 extern int ext2_init_acl (struct inode *, struct inode *);
 
 #else
 #include <linux/sched.h>
-#define ext2_permission NULL
+#define ext2_check_acl	NULL
 #define ext2_get_acl	NULL
 #define ext2_set_acl	NULL
 
diff --git a/fs/ext2/file.c b/fs/ext2/file.c
index 2b9e47dc922..a2f3afd1a1c 100644
--- a/fs/ext2/file.c
+++ b/fs/ext2/file.c
@@ -85,6 +85,6 @@ const struct inode_operations ext2_file_inode_operations = {
 	.removexattr	= generic_removexattr,
 #endif
 	.setattr	= ext2_setattr,
-	.permission	= ext2_permission,
+	.check_acl	= ext2_check_acl,
 	.fiemap		= ext2_fiemap,
 };
diff --git a/fs/ext2/namei.c b/fs/ext2/namei.c
index 78d9b925fc9..23701f289e9 100644
--- a/fs/ext2/namei.c
+++ b/fs/ext2/namei.c
@@ -400,7 +400,7 @@ const struct inode_operations ext2_dir_inode_operations = {
 	.removexattr	= generic_removexattr,
 #endif
 	.setattr	= ext2_setattr,
-	.permission	= ext2_permission,
+	.check_acl	= ext2_check_acl,
 };
 
 const struct inode_operations ext2_special_inode_operations = {
@@ -411,5 +411,5 @@ const struct inode_operations ext2_special_inode_operations = {
 	.removexattr	= generic_removexattr,
 #endif
 	.setattr	= ext2_setattr,
-	.permission	= ext2_permission,
+	.check_acl	= ext2_check_acl,
 };
diff --git a/fs/ext3/acl.c b/fs/ext3/acl.c
index e167bae37ef..c9b0df376b5 100644
--- a/fs/ext3/acl.c
+++ b/fs/ext3/acl.c
@@ -238,7 +238,7 @@ ext3_set_acl(handle_t *handle, struct inode *inode, int type,
 	return error;
 }
 
-static int
+int
 ext3_check_acl(struct inode *inode, int mask)
 {
 	struct posix_acl *acl = ext3_get_acl(inode, ACL_TYPE_ACCESS);
@@ -254,12 +254,6 @@ ext3_check_acl(struct inode *inode, int mask)
 	return -EAGAIN;
 }
 
-int
-ext3_permission(struct inode *inode, int mask)
-{
-	return generic_permission(inode, mask, ext3_check_acl);
-}
-
 /*
  * Initialize the ACLs of a new inode. Called from ext3_new_inode.
  *
diff --git a/fs/ext3/acl.h b/fs/ext3/acl.h
index 07d15a3a596..597334626de 100644
--- a/fs/ext3/acl.h
+++ b/fs/ext3/acl.h
@@ -54,13 +54,13 @@ static inline int ext3_acl_count(size_t size)
 #ifdef CONFIG_EXT3_FS_POSIX_ACL
 
 /* acl.c */
-extern int ext3_permission (struct inode *, int);
+extern int ext3_check_acl (struct inode *, int);
 extern int ext3_acl_chmod (struct inode *);
 extern int ext3_init_acl (handle_t *, struct inode *, struct inode *);
 
 #else  /* CONFIG_EXT3_FS_POSIX_ACL */
 #include <linux/sched.h>
-#define ext3_permission NULL
+#define ext3_check_acl NULL
 
 static inline int
 ext3_acl_chmod(struct inode *inode)
diff --git a/fs/ext3/file.c b/fs/ext3/file.c
index 5b49704b231..29925321478 100644
--- a/fs/ext3/file.c
+++ b/fs/ext3/file.c
@@ -137,7 +137,7 @@ const struct inode_operations ext3_file_inode_operations = {
 	.listxattr	= ext3_listxattr,
 	.removexattr	= generic_removexattr,
 #endif
-	.permission	= ext3_permission,
+	.check_acl	= ext3_check_acl,
 	.fiemap		= ext3_fiemap,
 };
 
diff --git a/fs/ext3/namei.c b/fs/ext3/namei.c
index 6ff7b973023..aad6400c9b7 100644
--- a/fs/ext3/namei.c
+++ b/fs/ext3/namei.c
@@ -2445,7 +2445,7 @@ const struct inode_operations ext3_dir_inode_operations = {
 	.listxattr	= ext3_listxattr,
 	.removexattr	= generic_removexattr,
 #endif
-	.permission	= ext3_permission,
+	.check_acl	= ext3_check_acl,
 };
 
 const struct inode_operations ext3_special_inode_operations = {
@@ -2456,5 +2456,5 @@ const struct inode_operations ext3_special_inode_operations = {
 	.listxattr	= ext3_listxattr,
 	.removexattr	= generic_removexattr,
 #endif
-	.permission	= ext3_permission,
+	.check_acl	= ext3_check_acl,
 };
diff --git a/fs/ext4/acl.c b/fs/ext4/acl.c
index f6d8967149c..0df88b2a69b 100644
--- a/fs/ext4/acl.c
+++ b/fs/ext4/acl.c
@@ -236,7 +236,7 @@ ext4_set_acl(handle_t *handle, struct inode *inode, int type,
 	return error;
 }
 
-static int
+int
 ext4_check_acl(struct inode *inode, int mask)
 {
 	struct posix_acl *acl = ext4_get_acl(inode, ACL_TYPE_ACCESS);
@@ -252,12 +252,6 @@ ext4_check_acl(struct inode *inode, int mask)
 	return -EAGAIN;
 }
 
-int
-ext4_permission(struct inode *inode, int mask)
-{
-	return generic_permission(inode, mask, ext4_check_acl);
-}
-
 /*
  * Initialize the ACLs of a new inode. Called from ext4_new_inode.
  *
diff --git a/fs/ext4/acl.h b/fs/ext4/acl.h
index 949789d2bba..9d843d5deac 100644
--- a/fs/ext4/acl.h
+++ b/fs/ext4/acl.h
@@ -54,13 +54,13 @@ static inline int ext4_acl_count(size_t size)
 #ifdef CONFIG_EXT4_FS_POSIX_ACL
 
 /* acl.c */
-extern int ext4_permission(struct inode *, int);
+extern int ext4_check_acl(struct inode *, int);
 extern int ext4_acl_chmod(struct inode *);
 extern int ext4_init_acl(handle_t *, struct inode *, struct inode *);
 
 #else  /* CONFIG_EXT4_FS_POSIX_ACL */
 #include <linux/sched.h>
-#define ext4_permission NULL
+#define ext4_check_acl NULL
 
 static inline int
 ext4_acl_chmod(struct inode *inode)
diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index 3f1873fef1c..27f3c5354c0 100644
--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c
@@ -207,7 +207,7 @@ const struct inode_operations ext4_file_inode_operations = {
 	.listxattr	= ext4_listxattr,
 	.removexattr	= generic_removexattr,
 #endif
-	.permission	= ext4_permission,
+	.check_acl	= ext4_check_acl,
 	.fallocate	= ext4_fallocate,
 	.fiemap		= ext4_fiemap,
 };
diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index de04013d16f..114abe5d2c1 100644
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -2536,7 +2536,7 @@ const struct inode_operations ext4_dir_inode_operations = {
 	.listxattr	= ext4_listxattr,
 	.removexattr	= generic_removexattr,
 #endif
-	.permission	= ext4_permission,
+	.check_acl	= ext4_check_acl,
 	.fiemap         = ext4_fiemap,
 };
 
@@ -2548,5 +2548,5 @@ const struct inode_operations ext4_special_inode_operations = {
 	.listxattr	= ext4_listxattr,
 	.removexattr	= generic_removexattr,
 #endif
-	.permission	= ext4_permission,
+	.check_acl	= ext4_check_acl,
 };
diff --git a/fs/jffs2/acl.c b/fs/jffs2/acl.c
index 8fcb6239218..7edb62e9741 100644
--- a/fs/jffs2/acl.c
+++ b/fs/jffs2/acl.c
@@ -258,7 +258,7 @@ static int jffs2_set_acl(struct inode *inode, int type, struct posix_acl *acl)
 	return rc;
 }
 
-static int jffs2_check_acl(struct inode *inode, int mask)
+int jffs2_check_acl(struct inode *inode, int mask)
 {
 	struct posix_acl *acl;
 	int rc;
@@ -274,11 +274,6 @@ static int jffs2_check_acl(struct inode *inode, int mask)
 	return -EAGAIN;
 }
 
-int jffs2_permission(struct inode *inode, int mask)
-{
-	return generic_permission(inode, mask, jffs2_check_acl);
-}
-
 int jffs2_init_acl_pre(struct inode *dir_i, struct inode *inode, int *i_mode)
 {
 	struct posix_acl *acl, *clone;
diff --git a/fs/jffs2/acl.h b/fs/jffs2/acl.h
index fc929f2a14f..f0ba63e3c36 100644
--- a/fs/jffs2/acl.h
+++ b/fs/jffs2/acl.h
@@ -26,7 +26,7 @@ struct jffs2_acl_header {
 
 #ifdef CONFIG_JFFS2_FS_POSIX_ACL
 
-extern int jffs2_permission(struct inode *, int);
+extern int jffs2_check_acl(struct inode *, int);
 extern int jffs2_acl_chmod(struct inode *);
 extern int jffs2_init_acl_pre(struct inode *, struct inode *, int *);
 extern int jffs2_init_acl_post(struct inode *);
@@ -36,7 +36,7 @@ extern struct xattr_handler jffs2_acl_default_xattr_handler;
 
 #else
 
-#define jffs2_permission			(NULL)
+#define jffs2_check_acl				(NULL)
 #define jffs2_acl_chmod(inode)			(0)
 #define jffs2_init_acl_pre(dir_i,inode,mode)	(0)
 #define jffs2_init_acl_post(inode)		(0)
diff --git a/fs/jffs2/dir.c b/fs/jffs2/dir.c
index 6f60cc910f4..7aa4417e085 100644
--- a/fs/jffs2/dir.c
+++ b/fs/jffs2/dir.c
@@ -55,7 +55,7 @@ const struct inode_operations jffs2_dir_inode_operations =
 	.rmdir =	jffs2_rmdir,
 	.mknod =	jffs2_mknod,
 	.rename =	jffs2_rename,
-	.permission =	jffs2_permission,
+	.check_acl =	jffs2_check_acl,
 	.setattr =	jffs2_setattr,
 	.setxattr =	jffs2_setxattr,
 	.getxattr =	jffs2_getxattr,
diff --git a/fs/jffs2/file.c b/fs/jffs2/file.c
index 23c94753986..b7b74e29914 100644
--- a/fs/jffs2/file.c
+++ b/fs/jffs2/file.c
@@ -56,7 +56,7 @@ const struct file_operations jffs2_file_operations =
 
 const struct inode_operations jffs2_file_inode_operations =
 {
-	.permission =	jffs2_permission,
+	.check_acl =	jffs2_check_acl,
 	.setattr =	jffs2_setattr,
 	.setxattr =	jffs2_setxattr,
 	.getxattr =	jffs2_getxattr,
diff --git a/fs/jffs2/symlink.c b/fs/jffs2/symlink.c
index b7339c3b6ad..4ec11e8bda8 100644
--- a/fs/jffs2/symlink.c
+++ b/fs/jffs2/symlink.c
@@ -21,7 +21,7 @@ const struct inode_operations jffs2_symlink_inode_operations =
 {
 	.readlink =	generic_readlink,
 	.follow_link =	jffs2_follow_link,
-	.permission =	jffs2_permission,
+	.check_acl =	jffs2_check_acl,
 	.setattr =	jffs2_setattr,
 	.setxattr =	jffs2_setxattr,
 	.getxattr =	jffs2_getxattr,
diff --git a/fs/jfs/acl.c b/fs/jfs/acl.c
index a29c7c3e3fb..d66477c3430 100644
--- a/fs/jfs/acl.c
+++ b/fs/jfs/acl.c
@@ -114,7 +114,7 @@ out:
 	return rc;
 }
 
-static int jfs_check_acl(struct inode *inode, int mask)
+int jfs_check_acl(struct inode *inode, int mask)
 {
 	struct posix_acl *acl = jfs_get_acl(inode, ACL_TYPE_ACCESS);
 
@@ -129,11 +129,6 @@ static int jfs_check_acl(struct inode *inode, int mask)
 	return -EAGAIN;
 }
 
-int jfs_permission(struct inode *inode, int mask)
-{
-	return generic_permission(inode, mask, jfs_check_acl);
-}
-
 int jfs_init_acl(tid_t tid, struct inode *inode, struct inode *dir)
 {
 	struct posix_acl *acl = NULL;
diff --git a/fs/jfs/file.c b/fs/jfs/file.c
index 7f6063acaa3..2b70fa78e4a 100644
--- a/fs/jfs/file.c
+++ b/fs/jfs/file.c
@@ -96,7 +96,7 @@ const struct inode_operations jfs_file_inode_operations = {
 	.removexattr	= jfs_removexattr,
 #ifdef CONFIG_JFS_POSIX_ACL
 	.setattr	= jfs_setattr,
-	.permission	= jfs_permission,
+	.check_acl	= jfs_check_acl,
 #endif
 };
 
diff --git a/fs/jfs/jfs_acl.h b/fs/jfs/jfs_acl.h
index 88475f10a38..b07bd417ef8 100644
--- a/fs/jfs/jfs_acl.h
+++ b/fs/jfs/jfs_acl.h
@@ -20,7 +20,7 @@
 
 #ifdef CONFIG_JFS_POSIX_ACL
 
-int jfs_permission(struct inode *, int);
+int jfs_check_acl(struct inode *, int);
 int jfs_init_acl(tid_t, struct inode *, struct inode *);
 int jfs_setattr(struct dentry *, struct iattr *);
 
diff --git a/fs/jfs/namei.c b/fs/jfs/namei.c
index 514ee2edb92..c79a4270f08 100644
--- a/fs/jfs/namei.c
+++ b/fs/jfs/namei.c
@@ -1543,7 +1543,7 @@ const struct inode_operations jfs_dir_inode_operations = {
 	.removexattr	= jfs_removexattr,
 #ifdef CONFIG_JFS_POSIX_ACL
 	.setattr	= jfs_setattr,
-	.permission	= jfs_permission,
+	.check_acl	= jfs_check_acl,
 #endif
 };
 
diff --git a/fs/namei.c b/fs/namei.c
index 1f13751693a..ed27bb205b7 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -169,19 +169,10 @@ void putname(const char *name)
 EXPORT_SYMBOL(putname);
 #endif
 
-
-/**
- * generic_permission  -  check for access rights on a Posix-like filesystem
- * @inode:	inode to check access rights for
- * @mask:	right to check for (%MAY_READ, %MAY_WRITE, %MAY_EXEC)
- * @check_acl:	optional callback to check for Posix ACLs
- *
- * Used to check for read/write/execute permissions on a file.
- * We use "fsuid" for this, letting us set arbitrary permissions
- * for filesystem access without changing the "normal" uids which
- * are used for other things..
+/*
+ * This does basic POSIX ACL permission checking
  */
-int generic_permission(struct inode *inode, int mask,
+static int acl_permission_check(struct inode *inode, int mask,
 		int (*check_acl)(struct inode *inode, int mask))
 {
 	umode_t			mode = inode->i_mode;
@@ -193,9 +184,7 @@ int generic_permission(struct inode *inode, int mask,
 	else {
 		if (IS_POSIXACL(inode) && (mode & S_IRWXG) && check_acl) {
 			int error = check_acl(inode, mask);
-			if (error == -EACCES)
-				goto check_capabilities;
-			else if (error != -EAGAIN)
+			if (error != -EAGAIN)
 				return error;
 		}
 
@@ -208,8 +197,32 @@ int generic_permission(struct inode *inode, int mask,
 	 */
 	if ((mask & ~mode) == 0)
 		return 0;
+	return -EACCES;
+}
+
+/**
+ * generic_permission  -  check for access rights on a Posix-like filesystem
+ * @inode:	inode to check access rights for
+ * @mask:	right to check for (%MAY_READ, %MAY_WRITE, %MAY_EXEC)
+ * @check_acl:	optional callback to check for Posix ACLs
+ *
+ * Used to check for read/write/execute permissions on a file.
+ * We use "fsuid" for this, letting us set arbitrary permissions
+ * for filesystem access without changing the "normal" uids which
+ * are used for other things..
+ */
+int generic_permission(struct inode *inode, int mask,
+		int (*check_acl)(struct inode *inode, int mask))
+{
+	int ret;
+
+	/*
+	 * Do the basic POSIX ACL permission checks.
+	 */
+	ret = acl_permission_check(inode, mask, check_acl);
+	if (ret != -EACCES)
+		return ret;
 
- check_capabilities:
 	/*
 	 * Read/write DACs are always overridable.
 	 * Executable DACs are overridable if at least one exec bit is set.
@@ -262,7 +275,7 @@ int inode_permission(struct inode *inode, int mask)
 	if (inode->i_op->permission)
 		retval = inode->i_op->permission(inode, mask);
 	else
-		retval = generic_permission(inode, mask, NULL);
+		retval = generic_permission(inode, mask, inode->i_op->check_acl);
 
 	if (retval)
 		return retval;
@@ -432,29 +445,22 @@ static struct dentry * cached_lookup(struct dentry * parent, struct qstr * name,
  */
 static int exec_permission_lite(struct inode *inode)
 {
-	umode_t	mode = inode->i_mode;
-
-	if (inode->i_op->permission)
-		return -EAGAIN;
-
-	if (current_fsuid() == inode->i_uid)
-		mode >>= 6;
-	else if (in_group_p(inode->i_gid))
-		mode >>= 3;
-
-	if (mode & MAY_EXEC)
-		goto ok;
+	int ret;
 
-	if ((inode->i_mode & S_IXUGO) && capable(CAP_DAC_OVERRIDE))
-		goto ok;
-
-	if (S_ISDIR(inode->i_mode) && capable(CAP_DAC_OVERRIDE))
+	if (inode->i_op->permission) {
+		ret = inode->i_op->permission(inode, MAY_EXEC);
+		if (!ret)
+			goto ok;
+		return ret;
+	}
+	ret = acl_permission_check(inode, MAY_EXEC, inode->i_op->check_acl);
+	if (!ret)
 		goto ok;
 
-	if (S_ISDIR(inode->i_mode) && capable(CAP_DAC_READ_SEARCH))
+	if (capable(CAP_DAC_OVERRIDE) || capable(CAP_DAC_READ_SEARCH))
 		goto ok;
 
-	return -EACCES;
+	return ret;
 ok:
 	return security_inode_permission(inode, MAY_EXEC);
 }
@@ -853,12 +859,6 @@ static int __link_path_walk(const char *name, struct nameidata *nd)
 
 		nd->flags |= LOOKUP_CONTINUE;
 		err = exec_permission_lite(inode);
-		if (err == -EAGAIN)
-			err = inode_permission(nd->path.dentry->d_inode,
-					       MAY_EXEC);
-		if (!err)
-			err = ima_path_check(&nd->path, MAY_EXEC,
-				             IMA_COUNT_UPDATE);
  		if (err)
 			break;
 
diff --git a/fs/xfs/linux-2.6/xfs_iops.c b/fs/xfs/linux-2.6/xfs_iops.c
index 8070b34cc28..6c32f1d63d8 100644
--- a/fs/xfs/linux-2.6/xfs_iops.c
+++ b/fs/xfs/linux-2.6/xfs_iops.c
@@ -485,14 +485,6 @@ xfs_vn_put_link(
 }
 
 STATIC int
-xfs_vn_permission(
-	struct inode		*inode,
-	int			mask)
-{
-	return generic_permission(inode, mask, xfs_check_acl);
-}
-
-STATIC int
 xfs_vn_getattr(
 	struct vfsmount		*mnt,
 	struct dentry		*dentry,
@@ -696,7 +688,7 @@ xfs_vn_fiemap(
 }
 
 static const struct inode_operations xfs_inode_operations = {
-	.permission		= xfs_vn_permission,
+	.check_acl		= xfs_check_acl,
 	.truncate		= xfs_vn_truncate,
 	.getattr		= xfs_vn_getattr,
 	.setattr		= xfs_vn_setattr,
@@ -724,7 +716,7 @@ static const struct inode_operations xfs_dir_inode_operations = {
 	.rmdir			= xfs_vn_unlink,
 	.mknod			= xfs_vn_mknod,
 	.rename			= xfs_vn_rename,
-	.permission		= xfs_vn_permission,
+	.check_acl		= xfs_check_acl,
 	.getattr		= xfs_vn_getattr,
 	.setattr		= xfs_vn_setattr,
 	.setxattr		= generic_setxattr,
@@ -749,7 +741,7 @@ static const struct inode_operations xfs_dir_ci_inode_operations = {
 	.rmdir			= xfs_vn_unlink,
 	.mknod			= xfs_vn_mknod,
 	.rename			= xfs_vn_rename,
-	.permission		= xfs_vn_permission,
+	.check_acl		= xfs_check_acl,
 	.getattr		= xfs_vn_getattr,
 	.setattr		= xfs_vn_setattr,
 	.setxattr		= generic_setxattr,
@@ -762,7 +754,7 @@ static const struct inode_operations xfs_symlink_inode_operations = {
 	.readlink		= generic_readlink,
 	.follow_link		= xfs_vn_follow_link,
 	.put_link		= xfs_vn_put_link,
-	.permission		= xfs_vn_permission,
+	.check_acl		= xfs_check_acl,
 	.getattr		= xfs_vn_getattr,
 	.setattr		= xfs_vn_setattr,
 	.setxattr		= generic_setxattr,