[PATCH 08/18] libfuse: add upper level iomap ioend commands

Darrick J. Wong
2025-09-16T00:43:52Z

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 | 8 ++++++++
lib/fuse.c | 45 +++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 53 insertions(+)

diff --git a/include/fuse.h b/include/fuse.h
index 524b77b5d7bbd0..1357f4319bcc21 100644
--- a/include/fuse.h
+++ b/include/fuse.h
@@ -881,6 +881,14 @@ 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, size_t written_in,
+ uint32_t ioendflags_in, int error_in,
+ uint64_t new_addr_in);
};

/** Extra context that may be needed by some filesystems
diff --git a/lib/fuse.c b/lib/fuse.c
index 632e935b8dff3e..725ab615d456e3 100644
--- a/lib/fuse.c
+++ b/lib/fuse.c
@@ -2848,6 +2848,26 @@ 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,
+ size_t written, uint32_t ioendflags, int error,
+ uint64_t new_addr)
+{
+ 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\n",
+ path, nodeid, attr_ino, pos, written, ioendflags,
+ error);
+ }
+
+ return fs->op.iomap_ioend(path, nodeid, attr_ino, pos, written,
+ ioendflags, error, new_addr);
+}
+
static void fuse_lib_setattr(fuse_req_t req, fuse_ino_t ino, struct stat *attr,
int valid, struct fuse_file_info *fi)
{
@@ -4578,6 +4598,30 @@ 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,
+ uint64_t new_addr)
+{
+ struct fuse *f = req_fuse_prepare(req);
+ struct fuse_intr_data d;
+ char *path;
+ 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, new_addr);
+ fuse_finish_interrupt(f, req, &d);
+ free_path(f, nodeid, path);
+ reply_err(req, err);
+}
+
static int clean_delay(struct fuse *f)
{
/*
@@ -4681,6 +4725,7 @@ static struct fuse_lowlevel_ops fuse_path_ops = {
#endif
.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)