7:12 a.m.
tree: https://github.com/ammarfaizi2/linux-block dhowells/linux-fs/netfs-maple
head: 429e2bb6fb190f390ed23afc0d2308e877c43be5
commit: e9340673baaf1ff587aed3391aa411cf554bc42e [34/35] netfs: Slice a writeback from a
dirty region
config: sparc-randconfig-s031-20220210
(https://download.01.org/0day-ci/archive/20220212/202202120413.rYahW6Tp-lk...)
compiler: sparc-linux-gcc (GCC) 11.2.0
reproduce:
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O
~/bin/make.cross
chmod +x ~/bin/make.cross
# apt-get install sparse
# sparse version: v0.6.4-dirty
#
https://github.com/ammarfaizi2/linux-block/commit/e9340673baaf1ff587aed33...
git remote add ammarfaizi2-block https://github.com/ammarfaizi2/linux-block
git fetch --no-tags ammarfaizi2-block dhowells/linux-fs/netfs-maple
git checkout e9340673baaf1ff587aed3391aa411cf554bc42e
# save the config file to linux build tree
mkdir build_dir
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross C=1
CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' O=build_dir ARCH=sparc SHELL=/bin/bash
fs/netfs/
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp(a)intel.com>
sparse warnings: (new ones prefixed by >>)
> fs/netfs/flush.c:400:56: sparse: sparse: Using plain integer as
NULL pointer
fs/netfs/flush.c:448:48: sparse: sparse: Using plain integer as NULL
pointer
vim +400 fs/netfs/flush.c
293
294 /*
295 * Flush some of the dirty queue, transforming a part of a sequence of dirty
296 * regions into a block we can flush.
297 *
298 * A number of things constrain us:
299 * - The region we write out should not be undergoing modification
300 * - We may need to expand or split the region for a number of reasons:
301 * - Filesystem storage block/object size
302 * - Filesystem RPC size (wsize)
303 * - Cache block size
304 * - Cache DIO block size
305 * - Crypto/compression block size
306 *
307 * This may be entered multiple times simultaneously. Automatic flushing by
308 * the VM is serialised on I_SYNC, but things like fsync() may enter multiple
309 * times simultaneously.
310 */
311 static int netfs_flush_dirty(struct netfs_writeback *wback,
312 struct writeback_control *wbc,
313 struct netfs_i_context *ctx,
314 struct ma_state *mas,
315 pgoff_t *_first, pgoff_t last,
316 struct netfs_dirty_region *spares[2])
317 {
318 struct netfs_dirty_region *region;
319 struct folio *folio;
320 pgoff_t first = *_first;
321 pgoff_t csize = 1UL << ctx->cache_order;
322 long ret;
323
324 XA_STATE(xas, &wback->mapping->i_pages, 0);
325
326 /* Round out the range we're looking through to accommodate whole cache
327 * blocks. The cache may only be able to store blocks of that size, in
328 * which case we may need to add non-dirty pages to the buffer too.
329 */
330 if (ctx->cache_order) {
331 first = round_down(first, csize);
332 last = round_up_incl(last, csize);
333 }
334
335 _enter("%lx-%lx", first, last);
336
337 rcu_read_lock();
338 mtree_lock(&ctx->dirty_regions);
339
340 /* Find the first dirty region that overlaps the requested range */
341 mas_set(mas, first);
342 do {
343 region = mas_find(mas, last);
344 if (!region)
345 goto found_nothing;
346 } while (netfs_mas_is_flushing(region));
347
348 _debug("query D=%x %lx-%lx",
349 netfs_mas_is_valid(region) ? region->debug_id : 0,
350 mas->index, mas->last);
351
352 wback->first = max(mas->index, first);
353 if (wback->first > 0) {
354 _debug("nonz %lx", wback->first);
355
356 /* The first folio might extend backwards beyond the start of
357 * the proposed region - in which case we need to include that
358 * also. But at least, in such a case, the folio size has to
359 * be an integer multiple of the cache blocksize.
360 */
361 if (mas->index < wback->first) {
362 _debug("check folio %lx", wback->first);
363 xas_set(&xas, wback->first);
364 do {
365 xas_reset(&xas);
366 folio = xas_load(&xas);
367 } while (xas_retry(&xas, folio));
368
369 if (folio && !xa_is_value(folio)) {
370 _debug("check folio %lx", folio->index);
371 /* A region span *should not* end in the middle of a folio. */
372 BUG_ON(folio->index < mas->index);
373 if (folio->index < wback->first) {
374 wback->first = folio->index;
375 mas_set_range(mas, wback->first, mas->last);
376 }
377 }
378 }
379
380 _debug("fol %lx", wback->first);
381
382 if (mas->index < wback->first) {
383 pgoff_t saved_last = mas->last;
384 _debug("splitf %lx-%lx %lx", mas->index, mas->last, first);
385 netfs_split_off_front(ctx, mas, region, &spares[0], first - 1,
386 netfs_dirty_trace_split_off_front);
387 mas_set_range(mas, first, saved_last);
388 }
389
390 wback->last = mas->last;
391 }
392
393 while (mas->last < last) {
394 _debug("store %lx-%lx", mas->index, mas->last);
395 wback->last = mas->last;
396 mas_store(mas, netfs_mas_set_flushing(region));
397 if (region != NETFS_COPY_TO_CACHE) {
398 netfs_get_dirty_region(ctx, region, netfs_region_trace_get_wback);
399 list_add_tail(®ion->flush_link, &wback->regions);
400 trace_netfs_dirty(ctx, region, 0, mas->index, mas->last,
401 netfs_dirty_trace_flush);
402 }
403
404 region = mas_next(mas, mas->last + 1);
405 if (!region || netfs_mas_is_flushing(region))
406 goto no_more;
407 if (mas->last >= last)
408 break;
409 _debug("query+ D=%x %lx-%lx",
410 netfs_mas_is_valid(region) ? region->debug_id : 0,
411 mas->index, mas->last);
412 }
413
414 /* Deal with the region we're looking at exceeding the specified range.
415 * In such a case, we need to split the region - and the last folio may
416 * extend beyond the end of the proposed region - in which case we need
417 * to include that also. And, again, the folio size has to be an
418 * integer multiple of the cache blocksize.
419 */
420 if (mas->last > last) {
421 xas_set(&xas, last);
422 do {
423 xas_reset(&xas);
424 folio = xas_load(&xas);
425 } while (xas_retry(&xas, folio));
426
427 if (folio && !xa_is_value(folio)) {
428 pgoff_t flast = folio_next_index(folio) - 1;
429
430 _debug("flast %lx %lx %lx", flast, mas->last, last);
431 /* A region span *should not* end in the middle of a folio. */
432 BUG_ON(flast > mas->last);
433 if (flast > last) {
434 last = flast;
435 mas_set_range(mas, mas->index, last);
436 }
437 }
438
439 region = netfs_split_off_front(ctx, mas, region, &spares[1], last,
440 netfs_dirty_trace_split_off_back);
441 }
442
443 wback->last = mas->last;
444 mas_store(mas, netfs_mas_set_flushing(region));
445 if (region != NETFS_COPY_TO_CACHE) {
446 netfs_get_dirty_region(ctx, region, netfs_region_trace_get_wback);
447 list_add_tail(®ion->flush_link, &wback->regions);
448 trace_netfs_dirty(ctx, region, 0, mas->index, mas->last,
449 netfs_dirty_trace_flush2);
450 }
451
452 no_more:
453 /* We've now got a contiguous span. Some of the subspans may only need
454 * writing to the cache, whilst others need writing to both the server
455 * and the cache.
456 */
457 _debug("span %lx-%lx", wback->first, wback->last);
458 *_first = last + 1;
459 mtree_unlock(&ctx->dirty_regions);
460 rcu_read_unlock();
461
462 /* Load the pages into the raw-data buffer and transition them over to
463 * the writeback state.
464 */
465 ret = netfs_flush_get_pages(wback, ctx);
466 if (ret < 0)
467 goto undo;
468
469 netfs_writeback_lock(wback);
470 netfs_writeback_start(wback);
471 trace_netfs_wback(wback);
472
473 wbc->nr_to_write -= wback->last - wback->first + 1;
474 *_first = wback->last + 1;
475 _leave(" = %lx [%lx]", wback->last - wback->first + 1, *_first);
476 return 1;
477
478 found_nothing:
479 *_first = last + 1;
480 mtree_unlock(&ctx->dirty_regions);
481 rcu_read_unlock();
482 return 0;
483
484 undo:
485 BUG(); // TODO
486 }
487
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org