nilfs2: deny write access to inodes in snapshots
Snapshots of nilfs are read-only.
After super block instances (sb) will be unified, nilfs will need to
check write access by a way other than implicit test with
IS_RDONLY(inode). This is because IS_RDONLY() refers to MS_RDONLY bit
of inode->i_sb->s_flags and it will become inaccurate after the
unification of sb.
To prepare for the issue, this uses i_op->permission to deny write
access to inodes in snapshots.
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
diff --git a/fs/nilfs2/nilfs.h b/fs/nilfs2/nilfs.h
index 3870c10..cf5507a 100644
--- a/fs/nilfs2/nilfs.h
+++ b/fs/nilfs2/nilfs.h
@@ -201,12 +201,9 @@
*/
#ifdef CONFIG_NILFS_POSIX_ACL
#error "NILFS: not yet supported POSIX ACL"
-extern int nilfs_permission(struct inode *, int, struct nameidata *);
extern int nilfs_acl_chmod(struct inode *);
extern int nilfs_init_acl(struct inode *, struct inode *);
#else
-#define nilfs_permission NULL
-
static inline int nilfs_acl_chmod(struct inode *inode)
{
return 0;
@@ -256,6 +253,7 @@
extern void nilfs_truncate(struct inode *);
extern void nilfs_evict_inode(struct inode *);
extern int nilfs_setattr(struct dentry *, struct iattr *);
+int nilfs_permission(struct inode *inode, int mask);
extern int nilfs_load_inode_block(struct nilfs_sb_info *, struct inode *,
struct buffer_head **);
extern int nilfs_inode_dirty(struct inode *);