From fdebe2bd70047e057827cba85ba31b2545e31900 Mon Sep 17 00:00:00 2001
From: Yan <yanzheng@21cn.com>
Date: Mon, 14 Jan 2008 13:26:08 -0500
Subject: [PATCH] Btrfs: Add readonly inode flag
This patch adds readonly inode flag support. A file with this flag
can't be modified, but can be deleted.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
---
fs/btrfs/ctree.h | 6 +++---
fs/btrfs/inode.c | 16 ++++++++++++----
2 files changed, 15 insertions(+), 7 deletions(-)
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 0c0edacbc14c..245952cf7650 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -451,9 +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)
#define btrfs_set_flag(inode, flag) (BTRFS_I(inode)->flags |= \
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index fba0478a95f4..fd0e0d80333b 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -2850,6 +2850,13 @@ static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
btrfs_throttle(root);
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,
@@ -2866,12 +2873,12 @@ static struct inode_operations btrfs_dir_inode_operations = {
.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 = {
.llseek = generic_file_llseek,
.read = generic_read_dir,
@@ -2916,15 +2923,16 @@ static struct inode_operations btrfs_file_inode_operations = {
.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,
};
--
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