man/io_uring_register_buffers.3: add sparse buffer helper
@@ -13,16 +13,30 @@ io_uring_register_buffers - register buffers for fixed buffer operations
.BI "int io_uring_register_buffers(struct io_uring *" ring ",
.BI " const struct iovec *" iovecs ",
.BI " unsigned " nr_iovecs ");"
+.BI "
+.BI "int io_uring_register_buffers_sparse(struct io_uring *" ring ",
+.BI " unsigned " nr_iovecs ");"
.PP
.SH DESCRIPTION
.PP
-The io_uring_register_buffers() function registers
+The
+.BR io_uring_register_buffers (3)
+function registers
.I nr_iovecs
number of buffers defined by the array
.I iovecs
belonging to the
.I ring.
+The
+.BR io_uring_register_buffers_sparse (3)
+function registers
+.I nr_iovecs
+empty buffers belonging to the
+.I ring.
+These buffers must be updated before use, using eg
+.BR io_uring_register_buffers_update_tag (3).
+
After the caller has registered the buffers, they can be used with one of the
fixed buffers functions.
@@ -36,6 +50,9 @@ manipulating the page reference counts for each IO.
.SH RETURN VALUE
On success
.BR io_uring_register_buffers (3)
-returns 0. On failure it returns -errno.
+and
+.BR io_uring_register_buffers_sparse (3)
+return 0. On failure they return
+.B -errno.
.SH SEE ALSO
.BR io_uring_get_sqe (3), io_uring_unregister_buffers (3), io_uring_prep_read_fixed (3), io_uring_prep_write_fixed (3)
