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/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
index ede4f77..52b641f 100644
--- a/fs/fuse/fuse_i.h
+++ b/fs/fuse/fuse_i.h
@@ -484,6 +484,12 @@
/** Called on final put */
void (*release)(struct fuse_conn *);
+
+ /** Super block for this connection. */
+ struct super_block *sb;
+
+ /** Read/write semaphore to hold when accessing sb. */
+ struct rw_semaphore killsb;
};
static inline struct fuse_conn *get_fuse_conn_super(struct super_block *sb)
@@ -512,6 +518,11 @@
extern const struct dentry_operations fuse_dentry_operations;
/**
+ * Inode to nodeid comparison.
+ */
+int fuse_inode_eq(struct inode *inode, void *_nodeidp);
+
+/**
* Get a filled in inode
*/
struct inode *fuse_iget(struct super_block *sb, u64 nodeid,
@@ -711,6 +722,19 @@
u64 fuse_get_attr_version(struct fuse_conn *fc);
+/**
+ * File-system tells the kernel to invalidate cache for the given node id.
+ */
+int fuse_reverse_inval_inode(struct super_block *sb, u64 nodeid,
+ loff_t offset, loff_t len);
+
+/**
+ * File-system tells the kernel to invalidate parent attributes and
+ * the dentry matching parent/name.
+ */
+int fuse_reverse_inval_entry(struct super_block *sb, u64 parent_nodeid,
+ struct qstr *name);
+
int fuse_do_open(struct fuse_conn *fc, u64 nodeid, struct file *file,
bool isdir);
ssize_t fuse_direct_io(struct file *file, const char __user *buf,