[PATCH 09/25] libfuse: add upper level iomap ioend commands

["Darrick J. Wong" <djwong@kernel.org>]

From: Darrick J. Wong <djwong@kernel.org>

Teach the upper level fuse library about iomap ioend events, which
happen when a write that isn't a pure overwrite completes.

Signed-off-by: "Darrick J. Wong" <djwong@kernel.org>
---
 include/fuse.h |    9 +++++++++
 lib/fuse.c     |   53 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 62 insertions(+)


diff --git a/include/fuse.h b/include/fuse.h
index 23b6d3f7c93303..dc4b79e98f6cd0 100644
--- a/include/fuse.h
+++ b/include/fuse.h
@@ -902,6 +902,15 @@ struct fuse_operations {
 			  off_t pos_in, uint64_t length_in,
 			  uint32_t opflags_in, ssize_t written_in,
 			  const struct fuse_file_iomap *iomap);
+
+	/**
+	 * Respond to the outcome of a file IO operation.
+	 */
+	int (*iomap_ioend) (const char *path, uint64_t nodeid,
+			    uint64_t attr_ino, off_t pos_in,
+			    uint64_t written_in, uint32_t ioendflags_in,
+			    int error_in, uint32_t dev_in,
+			    uint64_t new_addr_in, off_t *newsize);
 };
 
 /** Extra context that may be needed by some filesystems
diff --git a/lib/fuse.c b/lib/fuse.c
index 9662d007746809..8d6d1686fc733c 100644
--- a/lib/fuse.c
+++ b/lib/fuse.c
@@ -2863,6 +2863,28 @@ int fuse_fs_iomap_device_remove(int device_id)
 	return fuse_lowlevel_iomap_device_remove(se, device_id);
 }
 
+static int fuse_fs_iomap_ioend(struct fuse_fs *fs, const char *path,
+			       uint64_t nodeid, uint64_t attr_ino, off_t pos,
+			       uint64_t written, uint32_t ioendflags, int error,
+			       uint32_t dev, uint64_t new_addr, off_t *newsize)
+{
+	fuse_get_context()->private_data = fs->user_data;
+	if (!fs->op.iomap_ioend)
+		return -ENOSYS;
+
+	if (fs->debug) {
+		fuse_log(FUSE_LOG_DEBUG,
+			 "iomap_ioend[%s] nodeid %llu attr_ino %llu pos %llu written %zu ioendflags 0x%x error %d dev %u new_addr 0x%llx\n",
+			 path, (unsigned long long)nodeid,
+			 (unsigned long long)attr_ino, (unsigned long long)pos,
+			 written, ioendflags, error, dev,
+			 (unsigned long long)new_addr);
+	}
+
+	return fs->op.iomap_ioend(path, nodeid, attr_ino, pos, written,
+				  ioendflags, error, dev, new_addr, newsize);
+}
+
 static void fuse_lib_setattr(fuse_req_t req, fuse_ino_t ino, struct stat *attr,
 			     int valid, struct fuse_file_info *fi)
 {
@@ -4613,6 +4635,36 @@ static void fuse_lib_iomap_end(fuse_req_t req, fuse_ino_t nodeid,
 	reply_err(req, err);
 }
 
+static void fuse_lib_iomap_ioend(fuse_req_t req, fuse_ino_t nodeid,
+				 uint64_t attr_ino, off_t pos, size_t written,
+				 uint32_t ioendflags, int error, uint32_t dev,
+				 uint64_t new_addr)
+{
+	struct fuse *f = req_fuse_prepare(req);
+	struct fuse_intr_data d;
+	char *path;
+	off_t newsize = 0;
+	int err;
+
+	err = get_path_nullok(f, nodeid, &path);
+	if (err) {
+		reply_err(req, err);
+		return;
+	}
+
+	fuse_prepare_interrupt(f, req, &d);
+	err = fuse_fs_iomap_ioend(f->fs, path, nodeid, attr_ino, pos, written,
+				  ioendflags, error, dev, new_addr, &newsize);
+	fuse_finish_interrupt(f, req, &d);
+	free_path(f, nodeid, path);
+	if (err) {
+		reply_err(req, err);
+		return;
+	}
+
+	fuse_reply_iomap_ioend(req, newsize);
+}
+
 static int clean_delay(struct fuse *f)
 {
 	/*
@@ -4717,6 +4769,7 @@ static struct fuse_lowlevel_ops fuse_path_ops = {
 	.syncfs = fuse_lib_syncfs,
 	.iomap_begin = fuse_lib_iomap_begin,
 	.iomap_end = fuse_lib_iomap_end,
+	.iomap_ioend = fuse_lib_iomap_ioend,
 };
 
 int fuse_notify_poll(struct fuse_pollhandle *ph)