From 69c4b07a6466f9eeec791a166dc3206cc05f0892 Mon Sep 17 00:00:00 2001
From: Alexander Indenbaum <aindenba@redhat.com>
Date: Tue, 15 Jul 2025 12:38:18 +0300
Subject: [PATCH] librbd: add rbd_aio_write_with_crc32c API for precomputed
 checksums

Signed-off-by: Alexander Indenbaum <aindenba@redhat.com>
---
 src/include/rbd/librbd.h |  8 ++++++++
 src/librbd/librbd.cc     | 29 +++++++++++++++++++++++++++++
 src/tracing/librbd.tp    | 27 +++++++++++++++++++++++++++
 3 files changed, 64 insertions(+)

diff --git a/src/include/rbd/librbd.h b/src/include/rbd/librbd.h
index b347b03df9e..41f8e86ab20 100644
--- a/src/include/rbd/librbd.h
+++ b/src/include/rbd/librbd.h
@@ -1279,6 +1279,14 @@ CEPH_RBD_API int rbd_aio_write(rbd_image_t image, uint64_t off, size_t len,
 CEPH_RBD_API int rbd_aio_write2(rbd_image_t image, uint64_t off, size_t len,
                                 const char *buf, rbd_completion_t c,
                                 int op_flags);
+
+/*
+ * @param precomputed_crc32c: CRC32C checksum that was precomputed (e.g., by SPDK NVMf)
+ */
+CEPH_RBD_API int rbd_aio_write_with_crc32c(rbd_image_t image, uint64_t off,
+                                           size_t len, const char *buf,
+                                           uint32_t precomputed_crc32c,
+                                           rbd_completion_t c, int op_flags);
 CEPH_RBD_API int rbd_aio_writev(rbd_image_t image, const struct iovec *iov,
                                 int iovcnt, uint64_t off, rbd_completion_t c);
 CEPH_RBD_API int rbd_aio_read(rbd_image_t image, uint64_t off, size_t len,
diff --git a/src/librbd/librbd.cc b/src/librbd/librbd.cc
index 01ea33a5bd0..8e43f33394f 100644
--- a/src/librbd/librbd.cc
+++ b/src/librbd/librbd.cc
@@ -26,6 +26,7 @@
 #include "common/errno.h"
 #include "common/TracepointProvider.h"
 #include "include/Context.h"
+#include "include/buffer_raw.h"
 
 #include "cls/rbd/cls_rbd_client.h"
 #include "cls/rbd/cls_rbd_types.h"
@@ -115,6 +116,15 @@ static auto create_write_raw(librbd::ImageCtx *ictx, const char *buf,
       deleter(new UserBufferDeleter(ictx->cct, aio_completion))));
 }
 
+static auto create_write_raw_with_crc32c(librbd::ImageCtx *ictx, const char *buf,
+                                       size_t len, uint32_t precomputed_crc32c,
+                                       librbd::io::AioCompletion* aio_completion) {
+  auto raw_buffer = create_write_raw(ictx, buf, len, aio_completion);
+  raw_buffer->set_crc(std::make_pair(0, len),
+                      std::make_pair(0, precomputed_crc32c));
+  return raw_buffer;
+}
+
 static int get_iovec_length(const struct iovec *iov, int iovcnt, size_t &len)
 {
   len = 0;
@@ -6406,6 +6416,25 @@ extern "C" int rbd_aio_write2(rbd_image_t image, uint64_t off, size_t len,
   return 0;
 }
 
+extern "C" int rbd_aio_write_with_crc32c(rbd_image_t image, uint64_t off,
+                                         size_t len, const char *buf,
+                                         uint32_t precomputed_crc32c,
+                                         rbd_completion_t c, int op_flags)
+{
+  librbd::ImageCtx *ictx = (librbd::ImageCtx *)image;
+  librbd::RBD::AioCompletion *comp = (librbd::RBD::AioCompletion *)c;
+  tracepoint(librbd, aio_write_with_crc32c_enter, ictx, ictx->name.c_str(), ictx->snap_name.c_str(),
+         ictx->read_only, off, len, buf, precomputed_crc32c, comp->pc, op_flags);
+
+  auto aio_completion = get_aio_completion(comp);
+  bufferlist bl;
+  bl.push_back(create_write_raw_with_crc32c(ictx, buf, len, precomputed_crc32c, aio_completion));
+  librbd::api::Io<>::aio_write(
+    *ictx, aio_completion, off, len, std::move(bl), op_flags, true);
+  tracepoint(librbd, aio_write_exit, 0);
+  return 0;
+}
+
 extern "C" int rbd_aio_writev(rbd_image_t image, const struct iovec *iov,
                               int iovcnt, uint64_t off, rbd_completion_t c)
 {
diff --git a/src/tracing/librbd.tp b/src/tracing/librbd.tp
index 791171e27f5..99eecc60611 100644
--- a/src/tracing/librbd.tp
+++ b/src/tracing/librbd.tp
@@ -662,6 +662,33 @@ TRACEPOINT_EVENT(librbd, aio_write2_enter,
         ctf_integer(int, op_flags, op_flags)
     )
 )
+
+TRACEPOINT_EVENT(librbd, aio_write_with_crc32c_enter,
+    TP_ARGS(
+        void*, imagectx,
+        const char*, name,
+        const char*, snap_name,
+        char, read_only,
+        uint64_t, off,
+        size_t, len,
+        const char*, buf,
+        uint32_t, precomputed_crc32c,
+        const void*, completion,
+        int, op_flags),
+    TP_FIELDS(
+        ctf_integer_hex(void*, imagectx, imagectx)
+        ctf_string(name, name)
+        ctf_string(snap_name, snap_name)
+        ctf_integer(char, read_only, read_only)
+        ctf_integer(uint64_t, off, off)
+        ctf_integer(size_t, len, len)
+        ceph_ctf_sequence(unsigned char, buf, buf, size_t, len)
+        ctf_integer(uint32_t, precomputed_crc32c, precomputed_crc32c)
+        ctf_integer_hex(const void*, completion, completion)
+        ctf_integer(int, op_flags, op_flags)
+    )
+)
+
 TRACEPOINT_EVENT(librbd, aio_write_exit,
     TP_ARGS(
         int, retval),
-- 
2.39.5