Commit fdebe2bd authored by Yan's avatar Yan Committed by Chris Mason
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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: default avatarChris Mason <chris.mason@oracle.com>
parent 744f52f9

fs/btrfs/ctree.h

+3 −3
Original line number Diff line number Diff line
@@ -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 |= \

fs/btrfs/inode.c

+12 −4
Original line number Diff line number Diff line
@@ -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,

};