[PATCH -V6 05/26] vfs: Add generic IS_ACL() test for acl support

From: Aneesh Kumar K.V
Date: Mon Sep 05 2011 - 13:33:36 EST


From: Andreas Gruenbacher <agruen@xxxxxxxxxx>

When IS_POSIXACL() is true, the vfs does not apply the umask. Other acl
models will need the same exception, so introduce a separate IS_ACL()
test.

The IS_POSIX_ACL() test is still needed so that nfsd can determine when
the underlying file system supports POSIX ACLs (as opposed to some other
kind).

Signed-off-by: Andreas Gruenbacher <agruen@xxxxxxxxxx>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxxxxxxx>
---
fs/namei.c | 6 +++---
include/linux/fs.h | 8 +++++++-
2 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/fs/namei.c b/fs/namei.c
index 23bc030..a7a7ac0 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -2175,7 +2175,7 @@ static struct file *do_last(struct nameidata *nd, struct path *path,
/* Negative dentry, just create the file */
if (!dentry->d_inode) {
int mode = op->mode;
- if (!IS_POSIXACL(dir->d_inode))
+ if (!IS_ACL(dir->d_inode))
mode &= ~current_umask();
/*
* This write is needed to ensure that a
@@ -2493,7 +2493,7 @@ SYSCALL_DEFINE4(mknodat, int, dfd, const char __user *, filename, int, mode,
if (IS_ERR(dentry))
return PTR_ERR(dentry);

- if (!IS_POSIXACL(path.dentry->d_inode))
+ if (!IS_ACL(path.dentry->d_inode))
mode &= ~current_umask();
error = may_mknod(mode);
if (error)
@@ -2562,7 +2562,7 @@ SYSCALL_DEFINE3(mkdirat, int, dfd, const char __user *, pathname, int, mode)
if (IS_ERR(dentry))
return PTR_ERR(dentry);

- if (!IS_POSIXACL(path.dentry->d_inode))
+ if (!IS_ACL(path.dentry->d_inode))
mode &= ~current_umask();
error = mnt_want_write(path.mnt);
if (error)
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 45744ae..3e1726e 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -203,7 +203,7 @@ struct inodes_stat_t {
#define MS_VERBOSE 32768 /* War is peace. Verbosity is silence.
MS_VERBOSE is deprecated. */
#define MS_SILENT 32768
-#define MS_POSIXACL (1<<16) /* VFS does not apply the umask */
+#define MS_POSIXACL (1<<16) /* Supports POSIX ACLs */
#define MS_UNBINDABLE (1<<17) /* change to unbindable */
#define MS_PRIVATE (1<<18) /* change to private */
#define MS_SLAVE (1<<19) /* change to slave */
@@ -281,6 +281,12 @@ struct inodes_stat_t {
#define IS_AUTOMOUNT(inode) ((inode)->i_flags & S_AUTOMOUNT)
#define IS_NOSEC(inode) ((inode)->i_flags & S_NOSEC)

+/*
+ * IS_ACL() tells the VFS to not apply the umask
+ * and use check_acl for acl permission checks when defined.
+ */
+#define IS_ACL(inode) __IS_FLG(inode, MS_POSIXACL)
+
/* the read-only stuff doesn't really belong here, but any other place is
probably as bad and I don't want to create yet another include file. */

--
1.7.4.1

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