Posix ACL Support

This change adds support for Posix ACLs by storing them as an xattr
which is common practice for many Linux file systems.  Since the
Posix ACL is stored as an xattr it will not overwrite any existing
ZFS/NFSv4 ACLs which may have been set.  The Posix ACL will also
be non-functional on other platforms although it may be visible
as an xattr if that platform understands SA based xattrs.

By default Posix ACLs are disabled but they may be enabled with
the new 'aclmode=noacl|posixacl' property.  Set the property to
'posixacl' to enable them.  If ZFS/NFSv4 ACL support is ever added
an appropriate acltype will be added.

This change passes the POSIX Test Suite cleanly with the exception
of xacl/00.t test 45 which is incorrect for Linux (Ext4 fails too).

  http://www.tuxera.com/community/posix-test-suite/

Signed-off-by: Massimo Maggi <[email protected]>
Signed-off-by: Richard Yao <[email protected]>
Signed-off-by: Brian Behlendorf <[email protected]>
Closes #170

1 files changed, 8 insertions, 4 deletions

diff --git a/module/zfs/zfs_vnops.c b/module/zfs/zfs_vnops.c
index 436a25eaf..423ca3800 100644
--- a/module/zfs/zfs_vnops.c
+++ b/module/zfs/zfs_vnops.c
@@ -3971,7 +3971,7 @@ zfs_putpage(struct inode *ip, struct page *pp, struct writeback_control *wbc)
 
 /*
  * Update the system attributes when the inode has been dirtied.  For the
- * moment we're conservative and only update the atime, mtime, and ctime.
+ * moment we only update the mode, atime, mtime, and ctime.
  */
 int
 zfs_dirty_inode(struct inode *ip, int flags)
@@ -3979,8 +3979,8 @@ zfs_dirty_inode(struct inode *ip, int flags)
 	znode_t		*zp = ITOZ(ip);
 	zfs_sb_t	*zsb = ITOZSB(ip);
 	dmu_tx_t	*tx;
-	uint64_t	atime[2], mtime[2], ctime[2];
-	sa_bulk_attr_t	bulk[3];
+	uint64_t	mode, atime[2], mtime[2], ctime[2];
+	sa_bulk_attr_t	bulk[4];
 	int		error;
 	int		cnt = 0;
 
@@ -3999,14 +3999,18 @@ zfs_dirty_inode(struct inode *ip, int flags)
 	}
 
 	mutex_enter(&zp->z_lock);
+	SA_ADD_BULK_ATTR(bulk, cnt, SA_ZPL_MODE(zsb), NULL, &mode, 8);
 	SA_ADD_BULK_ATTR(bulk, cnt, SA_ZPL_ATIME(zsb), NULL, &atime, 16);
 	SA_ADD_BULK_ATTR(bulk, cnt, SA_ZPL_MTIME(zsb), NULL, &mtime, 16);
 	SA_ADD_BULK_ATTR(bulk, cnt, SA_ZPL_CTIME(zsb), NULL, &ctime, 16);
 
-	/* Preserve the mtime and ctime provided by the inode */
+	/* Preserve the mode, mtime and ctime provided by the inode */
 	ZFS_TIME_ENCODE(&ip->i_atime, atime);
 	ZFS_TIME_ENCODE(&ip->i_mtime, mtime);
 	ZFS_TIME_ENCODE(&ip->i_ctime, ctime);
+	mode = ip->i_mode;
+
+	zp->z_mode = mode;
 	zp->z_atime_dirty = 0;
 
 	error = sa_bulk_update(zp->z_sa_hdl, bulk, cnt, tx);