Hello,
This patch adds readonly inode flag support. A file with this flag
can't be modified, but can be deleted.
Regards
YZ
---
diff -r 067ba546ac2c ctree.h
--- a/ctree.h Wed Jan 09 15:55:33 2008 -0500
+++ b/ctree.h Mon Jan 14 14:25:01 2008 +0800
@@ -451,8 +451,9 @@ struct btrfs_root {
/*
* Inode flags
*/
-#define BTRFS_INODE_NODATASUM 0x1
-#define BTRFS_INODE_NODATACOW 0x2
+#define BTRFS_INODE_NODATASUM (1 << 0)
+#define BTRFS_INODE_NODATACOW (1 << 1)
+#define BTRFS_INODE_READONLY (1 << 2)
#define btrfs_clear_flag(inode, flag) (BTRFS_I(inode)->flags &= \
~BTRFS_INODE_##flag)
diff -r 067ba546ac2c inode.c
--- a/inode.c Wed Jan 09 15:55:33 2008 -0500
+++ b/inode.c Mon Jan 14 14:25:01 2008 +0800
@@ -2851,6 +2851,14 @@ out_fail:
return err;
}
+static int btrfs_permission(struct inode *inode, int mask,
+ struct nameidata *nd)
+{
+ if (btrfs_test_flag(inode, READONLY) && (mask & MAY_WRITE))
+ return -EACCES;
+ return generic_permission(inode, mask, NULL);
+}
+
static struct inode_operations btrfs_dir_inode_operations = {
.lookup = btrfs_lookup,
.create = btrfs_create,
@@ -2866,10 +2874,12 @@ static struct inode_operations btrfs_dir
.getxattr = generic_getxattr,
.listxattr = btrfs_listxattr,
.removexattr = generic_removexattr,
+ .permission = btrfs_permission,
};
static struct inode_operations btrfs_dir_ro_inode_operations = {
.lookup = btrfs_lookup,
+ .permission = btrfs_permission,
};
static struct file_operations btrfs_dir_file_operations = {
@@ -2916,15 +2926,18 @@ static struct inode_operations btrfs_fil
.getxattr = generic_getxattr,
.listxattr = btrfs_listxattr,
.removexattr = generic_removexattr,
+ .permission = btrfs_permission,
};
static struct inode_operations btrfs_special_inode_operations = {
.getattr = btrfs_getattr,
.setattr = btrfs_setattr,
+ .permission = btrfs_permission,
};
static struct inode_operations btrfs_symlink_inode_operations = {
.readlink = generic_readlink,
.follow_link = page_follow_link_light,
.put_link = page_put_link,
+ .permission = btrfs_permission,
};