fuse: invalidation reverse calls
Add notification messages that allow the filesystem to invalidate VFS
caches.
Two notifications are added:
1) inode invalidation
- invalidate cached attributes
- invalidate a range of pages in the page cache (this is optional)
2) dentry invalidation
- try to invalidate a subtree in the dentry cache
Care must be taken while accessing the 'struct super_block' for the
mount, as it can go away while an invalidation is in progress. To
prevent this, introduce a rw-semaphore, that is taken for read during
the invalidation and taken for write in the ->kill_sb callback.
Cc: Csaba Henk <csaba@gluster.com>
Cc: Anand Avati <avati@zresearch.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
diff --git a/include/linux/fuse.h b/include/linux/fuse.h
index e2b816a..cf593bf 100644
--- a/include/linux/fuse.h
+++ b/include/linux/fuse.h
@@ -28,6 +28,8 @@
*
* 7.12
* - add umask flag to input argument of open, mknod and mkdir
+ * - add notification messages for invalidation of inodes and
+ * directory entries
*/
#ifndef _LINUX_FUSE_H
@@ -229,6 +231,8 @@
enum fuse_notify_code {
FUSE_NOTIFY_POLL = 1,
+ FUSE_NOTIFY_INVAL_INODE = 2,
+ FUSE_NOTIFY_INVAL_ENTRY = 3,
FUSE_NOTIFY_CODE_MAX,
};
@@ -524,4 +528,16 @@
#define FUSE_DIRENT_SIZE(d) \
FUSE_DIRENT_ALIGN(FUSE_NAME_OFFSET + (d)->namelen)
+struct fuse_notify_inval_inode_out {
+ __u64 ino;
+ __s64 off;
+ __s64 len;
+};
+
+struct fuse_notify_inval_entry_out {
+ __u64 parent;
+ __u32 namelen;
+ __u32 padding;
+};
+
#endif /* _LINUX_FUSE_H */