1 files changed, 274 insertions, 14 deletions

diff --git a/fuse/include/fuse_lowlevel.h b/fuse/include/fuse_lowlevel.h
index f1cfeb954..36cf26ddf 100644
--- a/fuse/include/fuse_lowlevel.h
+++ b/fuse/include/fuse_lowlevel.h
@@ -77,9 +77,16 @@ struct fuse_entry_param {
 
 	/** Generation number for this entry.
 	 *
-	 * The ino/generation pair should be unique for the filesystem's
-	 * lifetime. It must be non-zero, otherwise FUSE will treat it as an
-	 * error.
+	 * If the file system will be exported over NFS, the
+	 * ino/generation pairs need to be unique over the file
+	 * system's lifetime (rather than just the mount time). So if
+	 * the file system reuses an inode after it has been deleted,
+	 * it must assign a new, previously unused generation number
+	 * to the inode at the same time.
+	 *
+	 * The generation must be non-zero, otherwise FUSE will treat
+	 * it as an error.
+	 *
 	 */
 	unsigned long generation;
 
@@ -114,6 +121,11 @@ struct fuse_ctx {
 	mode_t umask;
 };
 
+struct fuse_forget_data {
+	uint64_t ino;
+	uint64_t nlookup;
+};
+
 /* 'to_set' flags in setattr */
 #define FUSE_SET_ATTR_MODE	(1 << 0)
 #define FUSE_SET_ATTR_UID	(1 << 1)
@@ -188,18 +200,31 @@ struct fuse_lowlevel_ops {
 	/**
 	 * Forget about an inode
 	 *
-	 * The nlookup parameter indicates the number of lookups
-	 * previously performed on this inode.
+	 * This function is called when the kernel removes an inode
+	 * from its internal caches.
 	 *
-	 * If the filesystem implements inode lifetimes, it is recommended
-	 * that inodes acquire a single reference on each lookup, and lose
-	 * nlookup references on each forget.
+	 * The inode's lookup count increases by one for every call to
+	 * fuse_reply_entry and fuse_reply_create. The nlookup parameter
+	 * indicates by how much the lookup count should be decreased.
 	 *
-	 * The filesystem may ignore forget calls, if the inodes don't
-	 * need to have a limited lifetime.
+	 * Inodes with a non-zero lookup count may receive request from
+	 * the kernel even after calls to unlink, rmdir or (when
+	 * overwriting an existing file) rename. Filesystems must handle
+	 * such requests properly and it is recommended to defer removal
+	 * of the inode until the lookup count reaches zero. Calls to
+	 * unlink, remdir or rename will be followed closely by forget
+	 * unless the file or directory is open, in which case the
+	 * kernel issues forget only after the release or releasedir
+	 * calls.
 	 *
-	 * On unmount it is not guaranteed, that all referenced inodes
-	 * will receive a forget message.
+	 * Note that if a file system will be exported over NFS the
+	 * inodes lifetime must extend even beyond forget. See the
+	 * generation field in struct fuse_entry_param above.
+	 *
+	 * On unmount the lookup count for all inodes implicitly drops
+	 * to zero. It is not guaranteed that the file system will
+	 * receive corresponding forget messages for the affected
+	 * inodes.
 	 *
 	 * Valid replies:
 	 *   fuse_reply_none
@@ -303,6 +328,11 @@ struct fuse_lowlevel_ops {
 	/**
 	 * Remove a file
 	 *
+	 * If the file's inode's lookup count is non-zero, the file
+	 * system is expected to postpone any removal of the inode
+	 * until the lookup count reaches zero (see description of the
+	 * forget function).
+	 *
 	 * Valid replies:
 	 *   fuse_reply_err
 	 *
@@ -315,6 +345,11 @@ struct fuse_lowlevel_ops {
 	/**
 	 * Remove a directory
 	 *
+	 * If the directory's inode's lookup count is non-zero, the
+	 * file system is expected to postpone any removal of the
+	 * inode until the lookup count reaches zero (see description
+	 * of the forget function).
+	 *
 	 * Valid replies:
 	 *   fuse_reply_err
 	 *
@@ -341,6 +376,12 @@ struct fuse_lowlevel_ops {
 
 	/** Rename a file
 	 *
+	 * If the target exists it should be atomically replaced. If
+	 * the target's inode's lookup count is non-zero, the file
+	 * system is expected to postpone any removal of the inode
+	 * until the lookup count reaches zero (see description of the
+	 * forget function).
+	 *
 	 * Valid replies:
 	 *   fuse_reply_err
 	 *
@@ -412,6 +453,7 @@ struct fuse_lowlevel_ops {
 	 * Valid replies:
 	 *   fuse_reply_buf
 	 *   fuse_reply_iov
+	 *   fuse_reply_data
 	 *   fuse_reply_err
 	 *
 	 * @param req request handle
@@ -561,6 +603,7 @@ struct fuse_lowlevel_ops {
 	 *
 	 * Valid replies:
 	 *   fuse_reply_buf
+	 *   fuse_reply_data
 	 *   fuse_reply_err
 	 *
 	 * @param req request handle
@@ -646,6 +689,7 @@ struct fuse_lowlevel_ops {
 	 *
 	 * Valid replies:
 	 *   fuse_reply_buf
+	 *   fuse_reply_data
 	 *   fuse_reply_xattr
 	 *   fuse_reply_err
 	 *
@@ -672,6 +716,7 @@ struct fuse_lowlevel_ops {
 	 *
 	 * Valid replies:
 	 *   fuse_reply_buf
+	 *   fuse_reply_data
 	 *   fuse_reply_xattr
 	 *   fuse_reply_err
 	 *
@@ -787,7 +832,7 @@ struct fuse_lowlevel_ops {
 	 * @param req request handle
 	 * @param ino the inode number
 	 * @param fi file information
-	 * @param lock the region/type to test
+	 * @param lock the region/type to set
 	 * @param sleep locking operation may sleep
 	 */
 	void (*setlk) (fuse_req_t req, fuse_ino_t ino,
@@ -873,6 +918,104 @@ struct fuse_lowlevel_ops {
 	 */
 	void (*poll) (fuse_req_t req, fuse_ino_t ino, struct fuse_file_info *fi,
 		      struct fuse_pollhandle *ph);
+
+	/**
+	 * Write data made available in a buffer
+	 *
+	 * This is a more generic version of the ->write() method.  If
+	 * FUSE_CAP_SPLICE_READ is set in fuse_conn_info.want and the
+	 * kernel supports splicing from the fuse device, then the
+	 * data will be made available in pipe for supporting zero
+	 * copy data transfer.
+	 *
+	 * Introduced in version 2.9
+	 *
+	 * Valid replies:
+	 *   fuse_reply_write
+	 *   fuse_reply_err
+	 *
+	 * @param req request handle
+	 * @param ino the inode number
+	 * @param bufv buffer containing the data
+	 * @param off offset to write to
+	 * @param fi file information
+	 */
+	void (*write_buf) (fuse_req_t req, fuse_ino_t ino,
+			   struct fuse_bufvec *bufv, off64_t off,
+			   struct fuse_file_info *fi);
+
+	/**
+	 * Callback function for the retrieve request
+	 *
+	 * Introduced in version 2.9
+	 *
+	 * Valid replies:
+	 *	fuse_reply_none
+	 *
+	 * @param req request handle
+	 * @param cookie user data supplied to fuse_lowlevel_notify_retrieve()
+	 * @param ino the inode number supplied to fuse_lowlevel_notify_retrieve()
+	 * @param offset the offset supplied to fuse_lowlevel_notify_retrieve()
+	 * @param bufv the buffer containing the returned data
+	 */
+	void (*retrieve_reply) (fuse_req_t req, void *cookie, fuse_ino_t ino,
+				off64_t offset, struct fuse_bufvec *bufv);
+
+	/**
+	 * Forget about multiple inodes
+	 *
+	 * See description of the forget function for more
+	 * information.
+	 *
+	 * Introduced in version 2.9
+	 *
+	 * Valid replies:
+	 *   fuse_reply_none
+	 *
+	 * @param req request handle
+	 */
+	void (*forget_multi) (fuse_req_t req, size_t count,
+			      struct fuse_forget_data *forgets);
+
+	/**
+	 * Acquire, modify or release a BSD file lock
+	 *
+	 * Note: if the locking methods are not implemented, the kernel
+	 * will still allow file locking to work locally.  Hence these are
+	 * only interesting for network filesystems and similar.
+	 *
+	 * Introduced in version 2.9
+	 *
+	 * Valid replies:
+	 *   fuse_reply_err
+	 *
+	 * @param req request handle
+	 * @param ino the inode number
+	 * @param fi file information
+	 * @param op the locking operation, see flock(2)
+	 */
+	void (*flock) (fuse_req_t req, fuse_ino_t ino,
+		       struct fuse_file_info *fi, int op);
+
+	/**
+	 * Allocate requested space. If this function returns success then
+	 * subsequent writes to the specified range shall not fail due to the lack
+	 * of free space on the file system storage media.
+	 *
+	 * Introduced in version 2.9
+	 *
+	 * Valid replies:
+	 *   fuse_reply_err
+	 *
+	 * @param req request handle
+	 * @param ino the inode number
+	 * @param offset starting point for allocated region
+	 * @param length size of allocated region
+	 * @param mode determines the operation to be performed on the given range,
+	 *             see fallocate(2)
+	 */
+	void (*fallocate) (fuse_req_t req, fuse_ino_t ino, int mode,
+		       off64_t offset, off64_t length, struct fuse_file_info *fi);
 };
 
 /**
@@ -906,6 +1049,9 @@ void fuse_reply_none(fuse_req_t req);
  * Possible requests:
  *   lookup, mknod, mkdir, symlink, link
  *
+ * Side effects:
+ *   increments the lookup count on success
+ *
  * @param req request handle
  * @param e the entry parameters
  * @return zero for success, -errno for failure to send reply
@@ -921,6 +1067,9 @@ int fuse_reply_entry(fuse_req_t req, const struct fuse_entry_param *e);
  * Possible requests:
  *   create
  *
+ * Side effects:
+ *   increments the lookup count on success
+ *
  * @param req request handle
  * @param e the entry parameters
  * @param fi file information
@@ -996,6 +1145,20 @@ int fuse_reply_write(fuse_req_t req, size_t count);
 int fuse_reply_buf(fuse_req_t req, const char *buf, size_t size);
 
 /**
+ * Reply with data copied/moved from buffer(s)
+ *
+ * Possible requests:
+ *   read, readdir, getxattr, listxattr
+ *
+ * @param req request handle
+ * @param bufv buffer vector
+ * @param flags flags controlling the copy
+ * @return zero for success, -errno for failure to send reply
+ */
+int fuse_reply_data(fuse_req_t req, struct fuse_bufvec *bufv,
+		    enum fuse_buf_copy_flags flags);
+
+/**
  * Reply with data vector
  *
  * Possible requests:
@@ -1042,7 +1205,7 @@ int fuse_reply_xattr(fuse_req_t req, size_t count);
  * @param lock the lock information
  * @return zero for success, -errno for failure to send reply
  */
-int fuse_reply_lock(fuse_req_t req, struct flock *lock);
+int fuse_reply_lock(fuse_req_t req, const struct flock *lock);
 
 /**
  * Reply with block index
@@ -1181,6 +1344,75 @@ int fuse_lowlevel_notify_inval_inode(struct fuse_chan *ch, fuse_ino_t ino,
 int fuse_lowlevel_notify_inval_entry(struct fuse_chan *ch, fuse_ino_t parent,
                                      const char *name, size_t namelen);
 
+/**
+ * Notify to invalidate parent attributes and delete the dentry matching
+ * parent/name if the dentry's inode number matches child (otherwise it
+ * will invalidate the matching dentry).
+ *
+ * @param ch the channel through which to send the notification
+ * @param parent inode number
+ * @param child inode number
+ * @param name file name
+ * @param namelen strlen() of file name
+ * @return zero for success, -errno for failure
+ */
+int fuse_lowlevel_notify_delete(struct fuse_chan *ch,
+				fuse_ino_t parent, fuse_ino_t child,
+				const char *name, size_t namelen);
+
+/**
+ * Store data to the kernel buffers
+ *
+ * Synchronously store data in the kernel buffers belonging to the
+ * given inode.  The stored data is marked up-to-date (no read will be
+ * performed against it, unless it's invalidated or evicted from the
+ * cache).
+ *
+ * If the stored data overflows the current file size, then the size
+ * is extended, similarly to a write(2) on the filesystem.
+ *
+ * If this function returns an error, then the store wasn't fully
+ * completed, but it may have been partially completed.
+ *
+ * @param ch the channel through which to send the invalidation
+ * @param ino the inode number
+ * @param offset the starting offset into the file to store to
+ * @param bufv buffer vector
+ * @param flags flags controlling the copy
+ * @return zero for success, -errno for failure
+ */
+int fuse_lowlevel_notify_store(struct fuse_chan *ch, fuse_ino_t ino,
+			       off64_t offset, struct fuse_bufvec *bufv,
+			       enum fuse_buf_copy_flags flags);
+/**
+ * Retrieve data from the kernel buffers
+ *
+ * Retrieve data in the kernel buffers belonging to the given inode.
+ * If successful then the retrieve_reply() method will be called with
+ * the returned data.
+ *
+ * Only present pages are returned in the retrieve reply.  Retrieving
+ * stops when it finds a non-present page and only data prior to that is
+ * returned.
+ *
+ * If this function returns an error, then the retrieve will not be
+ * completed and no reply will be sent.
+ *
+ * This function doesn't change the dirty state of pages in the kernel
+ * buffer.  For dirty pages the write() method will be called
+ * regardless of having been retrieved previously.
+ *
+ * @param ch the channel through which to send the invalidation
+ * @param ino the inode number
+ * @param size the number of bytes to retrieve
+ * @param offset the starting offset into the file to retrieve from
+ * @param cookie user data to supply to the reply callback
+ * @return zero for success, -errno for failure
+ */
+int fuse_lowlevel_notify_retrieve(struct fuse_chan *ch, fuse_ino_t ino,
+				  size_t size, off64_t offset, void *cookie);
+
+
 /* ----------------------------------------------------------- *
  * Utility functions					       *
  * ----------------------------------------------------------- */
@@ -1377,6 +1609,34 @@ void fuse_session_process(struct fuse_session *se, const char *buf, size_t len,
 			  struct fuse_chan *ch);
 
 /**
+ * Process a raw request supplied in a generic buffer
+ *
+ * This is a more generic version of fuse_session_process().  The
+ * fuse_buf may contain a memory buffer or a pipe file descriptor.
+ *
+ * @param se the session
+ * @param buf the fuse_buf containing the request
+ * @param ch channel on which the request was received
+ */
+void fuse_session_process_buf(struct fuse_session *se,
+			      const struct fuse_buf *buf, struct fuse_chan *ch);
+
+/**
+ * Receive a raw request supplied in a generic buffer
+ *
+ * This is a more generic version of fuse_chan_recv().  The fuse_buf
+ * supplied to this function contains a suitably allocated memory
+ * buffer.  This may be overwritten with a file descriptor buffer.
+ *
+ * @param se the session
+ * @param buf the fuse_buf to store the request in
+ * @param chp pointer to the channel
+ * @return the actual size of the raw request, or -errno on error
+ */
+int fuse_session_receive_buf(struct fuse_session *se, struct fuse_buf *buf,
+			     struct fuse_chan **chp);
+
+/**
  * Destroy a session
  *
  * @param se the session