* Re: [PATCH] smb: smbdirect: fix MR registration for coalesced SG lists
[not found] <4bf423bb.AU4AAJbgzlAAAAAAAAAABAMtJJMAAYKKIjQAAAAAAC-ZZgBp8Ww0@mailjet.com>
@ 2026-04-30 8:15 ` kernel test robot
0 siblings, 0 replies; only message in thread
From: kernel test robot @ 2026-04-30 8:15 UTC (permalink / raw)
To: Yi Kuo, smfrench, linkinjeon
Cc: llvm, oe-kbuild-all, metze, tom, linux-cifs, samba-technical,
linux-kernel, Yi Kuo
Hi Yi,
kernel test robot noticed the following build warnings:
[auto build test WARNING on v7.1-rc1]
[also build test WARNING on linus/master next-20260429]
[cannot apply to brauner-vfs/vfs.all]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]
url: https://github.com/intel-lab-lkp/linux/commits/Yi-Kuo/smb-smbdirect-fix-MR-registration-for-coalesced-SG-lists/20260429-221606
base: v7.1-rc1
patch link: https://lore.kernel.org/r/4bf423bb.AU4AAJbgzlAAAAAAAAAABAMtJJMAAYKKIjQAAAAAAC-ZZgBp8Ww0%40mailjet.com
patch subject: [PATCH] smb: smbdirect: fix MR registration for coalesced SG lists
config: x86_64-rhel-9.4-rust (https://download.01.org/0day-ci/archive/20260430/202604301612.XQrb9dxs-lkp@intel.com/config)
compiler: clang version 20.1.8 (https://github.com/llvm/llvm-project 87f0227cb60147a26a1eeb4fb06e3b505e9c7261)
rustc: rustc 1.88.0 (6b00bc388 2025-06-23)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260430/202604301612.XQrb9dxs-lkp@intel.com/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202604301612.XQrb9dxs-lkp@intel.com/
All warnings (new ones prefixed by >>):
>> fs/smb/smbdirect/mr.c:304:6: warning: variable 'ret' is used uninitialized whenever 'if' condition is true [-Wsometimes-uninitialized]
304 | if (!num_mapped) {
| ^~~~~~~~~~~
fs/smb/smbdirect/mr.c:361:40: note: uninitialized use occurs here
361 | smbdirect_socket_schedule_cleanup(sc, ret);
| ^~~
fs/smb/smbdirect/internal.h:63:23: note: expanded from macro 'smbdirect_socket_schedule_cleanup'
63 | __func__, __LINE__, __error, NULL)
| ^~~~~~~
fs/smb/smbdirect/mr.c:304:2: note: remove the 'if' if its condition is always false
304 | if (!num_mapped) {
| ^~~~~~~~~~~~~~~~~~
305 | smbdirect_log_rdma_mr(sc, SMBDIRECT_LOG_ERR,
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
306 | "ib_dma_map_sg num_pages=%u dir=%x num_mapped=%d\n",
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
307 | num_pages, mr->dir, num_mapped);
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
308 | goto dma_map_error;
| ~~~~~~~~~~~~~~~~~~~
309 | }
| ~
fs/smb/smbdirect/mr.c:272:9: note: initialize the variable 'ret' to silence this warning
272 | int ret, num_pages, num_mapped;
| ^
| = 0
1 warning generated.
vim +304 fs/smb/smbdirect/mr.c
256
257 /*
258 * Register memory for RDMA read/write
259 * iter: the buffer to register memory with
260 * writing: true if this is a RDMA write (SMB read), false for RDMA read
261 * need_invalidate: true if this MR needs to be locally invalidated after I/O
262 * return value: the MR registered, NULL if failed.
263 */
264 struct smbdirect_mr_io *
265 smbdirect_connection_register_mr_io(struct smbdirect_socket *sc,
266 struct iov_iter *iter,
267 bool writing,
268 bool need_invalidate)
269 {
270 const struct smbdirect_socket_parameters *sp = &sc->parameters;
271 struct smbdirect_mr_io *mr;
272 int ret, num_pages, num_mapped;
273 struct ib_reg_wr *reg_wr;
274
275 num_pages = iov_iter_npages(iter, sp->max_frmr_depth + 1);
276 if (num_pages > sp->max_frmr_depth) {
277 smbdirect_log_rdma_mr(sc, SMBDIRECT_LOG_ERR,
278 "num_pages=%d max_frmr_depth=%d\n",
279 num_pages, sp->max_frmr_depth);
280 WARN_ON_ONCE(1);
281 return NULL;
282 }
283
284 mr = smbdirect_connection_get_mr_io(sc);
285 if (!mr) {
286 smbdirect_log_rdma_mr(sc, SMBDIRECT_LOG_ERR,
287 "smbdirect_connection_get_mr_io returning NULL\n");
288 return NULL;
289 }
290
291 mutex_lock(&mr->mutex);
292
293 mr->dir = writing ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
294 mr->need_invalidate = need_invalidate;
295 mr->sgt.nents = 0;
296 mr->sgt.orig_nents = 0;
297
298 smbdirect_log_rdma_mr(sc, SMBDIRECT_LOG_INFO,
299 "num_pages=%u count=%zu depth=%u\n",
300 num_pages, iov_iter_count(iter), sp->max_frmr_depth);
301 smbdirect_iter_to_sgt(iter, &mr->sgt, sp->max_frmr_depth);
302
303 num_mapped = ib_dma_map_sg(sc->ib.dev, mr->sgt.sgl, mr->sgt.nents, mr->dir);
> 304 if (!num_mapped) {
305 smbdirect_log_rdma_mr(sc, SMBDIRECT_LOG_ERR,
306 "ib_dma_map_sg num_pages=%u dir=%x num_mapped=%d\n",
307 num_pages, mr->dir, num_mapped);
308 goto dma_map_error;
309 }
310
311 ret = ib_map_mr_sg(mr->mr, mr->sgt.sgl, num_mapped, NULL, PAGE_SIZE);
312 if (ret != num_mapped) {
313 smbdirect_log_rdma_mr(sc, SMBDIRECT_LOG_ERR,
314 "ib_map_mr_sg failed ret = %d num_mapped = %u\n",
315 ret, num_mapped);
316 goto map_mr_error;
317 }
318
319 ib_update_fast_reg_key(mr->mr, ib_inc_rkey(mr->mr->rkey));
320 reg_wr = &mr->wr;
321 reg_wr->wr.opcode = IB_WR_REG_MR;
322 mr->cqe.done = smbdirect_connection_mr_io_register_done;
323 reg_wr->wr.wr_cqe = &mr->cqe;
324 reg_wr->wr.num_sge = 0;
325 reg_wr->wr.send_flags = IB_SEND_SIGNALED;
326 reg_wr->mr = mr->mr;
327 reg_wr->key = mr->mr->rkey;
328 reg_wr->access = writing ?
329 IB_ACCESS_REMOTE_WRITE | IB_ACCESS_LOCAL_WRITE :
330 IB_ACCESS_REMOTE_READ;
331
332 /*
333 * There is no need for waiting for complemtion on ib_post_send
334 * on IB_WR_REG_MR. Hardware enforces a barrier and order of execution
335 * on the next ib_post_send when we actually send I/O to remote peer
336 */
337 ret = ib_post_send(sc->ib.qp, ®_wr->wr, NULL);
338 if (!ret) {
339 /*
340 * smbdirect_connection_get_mr_io() gave us a reference
341 * via kref_get(&mr->kref), we keep that and let
342 * the caller use smbdirect_connection_deregister_mr_io()
343 * to remove it again.
344 */
345 mutex_unlock(&mr->mutex);
346 return mr;
347 }
348
349 smbdirect_log_rdma_mr(sc, SMBDIRECT_LOG_ERR,
350 "ib_post_send failed ret=%d (%1pe) reg_wr->key=0x%x\n",
351 ret, SMBDIRECT_DEBUG_ERR_PTR(ret), reg_wr->key);
352
353 map_mr_error:
354 ib_dma_unmap_sg(sc->ib.dev, mr->sgt.sgl, mr->sgt.nents, mr->dir);
355
356 dma_map_error:
357 mr->sgt.nents = 0;
358 mr->state = SMBDIRECT_MR_ERROR;
359 atomic_dec(&sc->mr_io.used.count);
360
361 smbdirect_socket_schedule_cleanup(sc, ret);
362
363 /*
364 * smbdirect_connection_get_mr_io() gave us a reference
365 * via kref_get(&mr->kref), we need to remove it again
366 * on error.
367 *
368 * No kref_put_mutex() as it's already locked.
369 *
370 * If smbdirect_mr_io_free_locked() is called
371 * and the mutex is unlocked and mr is gone,
372 * in that case kref_put() returned 1.
373 *
374 * If kref_put() returned 0 we know that
375 * smbdirect_mr_io_free_locked() didn't
376 * run. Not by us nor by anyone else, as we
377 * still hold the mutex, so we need to unlock.
378 */
379 if (!kref_put(&mr->kref, smbdirect_mr_io_free_locked))
380 mutex_unlock(&mr->mutex);
381 return NULL;
382 }
383 __SMBDIRECT_EXPORT_SYMBOL__(smbdirect_connection_register_mr_io);
384
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
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