60 lines
2.0 KiB
Diff
60 lines
2.0 KiB
Diff
|
From: Andreas Gruenbacher <agruen@suse.de>
|
||
|
|
Subject: Allow filesystems to handle MAY_APPEND
|
||
|
|
Patch-mainline: not yet
|
||
|
|
|
||
|
|
The MS_WITHAPPEND super_block flag tells the vfs that the permission
|
||
|
|
inode operation understands the MAY_APPEND flag. This is required for
|
||
|
|
implementing permission models which go beyond the traditional UNIX
|
||
|
|
semantics.
|
||
|
|
|
||
|
|
If a filesystem does not set the flag, the behavior is unchanged.
|
||
|
|
|
||
|
|
Signed-off-by: Andreas Gruenbacher <agruen@suse.de>
|
||
|
|
|
||
|
|
---
|
||
|
|
fs/namei.c | 6 +++++-
|
||
|
|
include/linux/fs.h | 2 ++
|
||
|
|
2 files changed, 7 insertions(+), 1 deletion(-)
|
||
|
|
|
||
|
|
--- a/fs/namei.c
|
||
|
|
+++ b/fs/namei.c
|
||
|
|
@@ -252,6 +252,7 @@ int generic_permission(struct inode *ino
|
||
|
|
int inode_permission(struct inode *inode, int mask)
|
||
|
|
{
|
||
|
|
int retval;
|
||
|
|
+ int submask = mask;
|
||
|
|
|
||
|
|
if (mask & MAY_WRITE) {
|
||
|
|
umode_t mode = inode->i_mode;
|
||
|
|
@@ -270,8 +271,11 @@ int inode_permission(struct inode *inode
|
||
|
|
return -EACCES;
|
||
|
|
}
|
||
|
|
|
||
|
|
+ if (!IS_WITHAPPEND(inode))
|
||
|
|
+ submask &= ~MAY_APPEND;
|
||
|
|
+
|
||
|
|
if (inode->i_op->permission)
|
||
|
|
- retval = inode->i_op->permission(inode, mask);
|
||
|
|
+ retval = inode->i_op->permission(inode, submask);
|
||
|
|
else
|
||
|
|
retval = generic_permission(inode, mask, inode->i_op->check_acl);
|
||
|
|
|
||
|
|
--- a/include/linux/fs.h
|
||
|
|
+++ b/include/linux/fs.h
|
||
|
|
@@ -209,6 +209,7 @@ struct inodes_stat_t {
|
||
|
|
#define MS_KERNMOUNT (1<<22) /* this is a kern_mount call */
|
||
|
|
#define MS_I_VERSION (1<<23) /* Update inode I_version field */
|
||
|
|
#define MS_STRICTATIME (1<<24) /* Always perform atime updates */
|
||
|
|
+#define MS_WITHAPPEND (1<<25) /* iop->permission() understands MAY_APPEND */
|
||
|
|
#define MS_ACTIVE (1<<30)
|
||
|
|
#define MS_NOUSER (1<<31)
|
||
|
|
|
||
|
|
@@ -259,6 +260,7 @@ struct inodes_stat_t {
|
||
|
|
#define IS_MANDLOCK(inode) __IS_FLG(inode, MS_MANDLOCK)
|
||
|
|
#define IS_NOATIME(inode) __IS_FLG(inode, MS_RDONLY|MS_NOATIME)
|
||
|
|
#define IS_I_VERSION(inode) __IS_FLG(inode, MS_I_VERSION)
|
||
|
|
+#define IS_WITHAPPEND(inode) __IS_FLG(inode, MS_WITHAPPEND)
|
||
|
|
|
||
|
|
#define IS_NOQUOTA(inode) ((inode)->i_flags & S_NOQUOTA)
|
||
|
|
#define IS_APPEND(inode) ((inode)->i_flags & S_APPEND)
|