From: kernel test robot <lkp@intel.com>
To: David Howells <dhowells@redhat.com>
Cc: llvm@lists.linux.dev, oe-kbuild-all@lists.linux.dev
Subject: [dhowells-fs:netfs-crypt 55/68] fs/netfs/buffered_read.c:351:42: warning: variable 'subreq' is uninitialized when used here
Date: Sun, 03 May 2026 23:04:38 +0800 [thread overview]
Message-ID: <202605032211.ochIXzo6-lkp@intel.com> (raw)
tree: https://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs.git netfs-crypt
head: 390dd59a3747b71c4dcff11b2cc5240385cbfedf
commit: 7693c7841ea1917c01c8cb6ae171070f4b69102b [55/68] netfs: Set subrequest->source at alloc before trace emission
config: hexagon-allmodconfig (https://download.01.org/0day-ci/archive/20260503/202605032211.ochIXzo6-lkp@intel.com/config)
compiler: clang version 17.0.6 (https://github.com/llvm/llvm-project 6009708b4367171ccdbf4b5905cb6a803753fe18)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260503/202605032211.ochIXzo6-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/202605032211.ochIXzo6-lkp@intel.com/
All warnings (new ones prefixed by >>):
>> fs/netfs/buffered_read.c:351:42: warning: variable 'subreq' is uninitialized when used here [-Wuninitialized]
351 | __set_bit(NETFS_SREQ_COPY_TO_CACHE, &subreq->flags);
| ^~~~~~
include/linux/bitops.h:53:52: note: expanded from macro '__set_bit'
53 | #define __set_bit(nr, addr) bitop(___set_bit, nr, addr)
| ^~~~
include/linux/bitops.h:44:37: note: expanded from macro 'bitop'
44 | __builtin_constant_p((uintptr_t)(addr) != (uintptr_t)NULL) && \
| ^~~~
fs/netfs/buffered_read.c:273:37: note: initialize the variable 'subreq' to silence this warning
273 | struct netfs_io_subrequest *subreq;
| ^
| = NULL
1 warning generated.
vim +/subreq +351 fs/netfs/buffered_read.c
e2d46f2ec33253 David Howells 2024-12-16 247
ee4cdf7ba857a8 David Howells 2024-07-02 248 /*
ee4cdf7ba857a8 David Howells 2024-07-02 249 * Perform a read to the pagecache from a series of sources of different types,
ee4cdf7ba857a8 David Howells 2024-07-02 250 * slicing up the region to be read according to available cache blocks and
ee4cdf7ba857a8 David Howells 2024-07-02 251 * network rsize.
ee4cdf7ba857a8 David Howells 2024-07-02 252 */
5454216af502c6 David Howells 2026-03-13 253 static void netfs_read_to_pagecache(struct netfs_io_request *rreq)
ee4cdf7ba857a8 David Howells 2024-07-02 254 {
4cbdfd0da8d2d5 David Howells 2026-04-09 255 struct fscache_occupancy _occ = {
4cbdfd0da8d2d5 David Howells 2026-04-09 256 .query_from = rreq->start,
4cbdfd0da8d2d5 David Howells 2026-04-09 257 .query_to = rreq->start + rreq->len,
4cbdfd0da8d2d5 David Howells 2026-04-09 258 .cached_from[0] = 0,
4cbdfd0da8d2d5 David Howells 2026-04-09 259 .cached_to[0] = 0,
4cbdfd0da8d2d5 David Howells 2026-04-09 260 .cached_from[1] = ULLONG_MAX,
4cbdfd0da8d2d5 David Howells 2026-04-09 261 .cached_to[1] = ULLONG_MAX,
4cbdfd0da8d2d5 David Howells 2026-04-09 262 };
4cbdfd0da8d2d5 David Howells 2026-04-09 263 struct fscache_occupancy *occ = &_occ;
e192187e9d3cdb David Howells 2026-04-09 264 struct netfs_io_stream *stream = &rreq->io_streams[0];
ee4cdf7ba857a8 David Howells 2024-07-02 265 int ret = 0;
7e043a80b5dae5 David Howells 2022-11-03 266
615fc17c41427e David Howells 2026-04-09 267 _enter("R=%08x", rreq->debug_id);
615fc17c41427e David Howells 2026-04-09 268
e192187e9d3cdb David Howells 2026-04-09 269 bvecq_pos_set(&stream->dispatch_cursor, &rreq->load_cursor);
e192187e9d3cdb David Howells 2026-04-09 270 bvecq_pos_set(&rreq->collect_cursor, &rreq->load_cursor);
615fc17c41427e David Howells 2026-04-09 271
ee4cdf7ba857a8 David Howells 2024-07-02 272 do {
ee4cdf7ba857a8 David Howells 2024-07-02 273 struct netfs_io_subrequest *subreq;
7693c7841ea191 David Howells 2026-03-19 274 enum netfs_io_source source;
7693c7841ea191 David Howells 2026-03-19 275 unsigned long long hole_to, cache_to, start, stop;
7693c7841ea191 David Howells 2026-03-19 276 size_t len;
7693c7841ea191 David Howells 2026-03-19 277 bool copy;
5e51c627c5acbc David Howells 2022-11-04 278
4cbdfd0da8d2d5 David Howells 2026-04-09 279 /* If we don't have any, find out the next couple of data
4cbdfd0da8d2d5 David Howells 2026-04-09 280 * extents from the cache, containing of following the
4cbdfd0da8d2d5 David Howells 2026-04-09 281 * specified start offset. Holes have to be fetched from the
4cbdfd0da8d2d5 David Howells 2026-04-09 282 * server; data regions from the cache.
4cbdfd0da8d2d5 David Howells 2026-04-09 283 */
4cbdfd0da8d2d5 David Howells 2026-04-09 284 hole_to = occ->cached_from[0];
4cbdfd0da8d2d5 David Howells 2026-04-09 285 cache_to = occ->cached_to[0];
e192187e9d3cdb David Howells 2026-04-09 286 if (stream->issue_from >= cache_to) {
4cbdfd0da8d2d5 David Howells 2026-04-09 287 /* Extent exhausted; shuffle down. */
4cbdfd0da8d2d5 David Howells 2026-04-09 288 int i;
4cbdfd0da8d2d5 David Howells 2026-04-09 289
4cbdfd0da8d2d5 David Howells 2026-04-09 290 for (i = 0; i < ARRAY_SIZE(occ->cached_from) - 1; i++) {
4cbdfd0da8d2d5 David Howells 2026-04-09 291 occ->cached_from[i] = occ->cached_from[i + 1];
4cbdfd0da8d2d5 David Howells 2026-04-09 292 occ->cached_to[i] = occ->cached_to[i + 1];
4cbdfd0da8d2d5 David Howells 2026-04-09 293 occ->cached_type[i] = occ->cached_type[i + 1];
4cbdfd0da8d2d5 David Howells 2026-04-09 294 }
4cbdfd0da8d2d5 David Howells 2026-04-09 295 occ->cached_from[i] = ULLONG_MAX;
4cbdfd0da8d2d5 David Howells 2026-04-09 296 occ->cached_to[i] = ULLONG_MAX;
4cbdfd0da8d2d5 David Howells 2026-04-09 297
4cbdfd0da8d2d5 David Howells 2026-04-09 298 if (occ->cached_from[0] != ULLONG_MAX)
4cbdfd0da8d2d5 David Howells 2026-04-09 299 continue;
4cbdfd0da8d2d5 David Howells 2026-04-09 300
4cbdfd0da8d2d5 David Howells 2026-04-09 301 /* Get new extents */
e192187e9d3cdb David Howells 2026-04-09 302 netfs_read_query_cache(rreq, occ);
4cbdfd0da8d2d5 David Howells 2026-04-09 303 continue;
4cbdfd0da8d2d5 David Howells 2026-04-09 304 }
4cbdfd0da8d2d5 David Howells 2026-04-09 305
7693c7841ea191 David Howells 2026-03-19 306 start = stream->issue_from;
e192187e9d3cdb David Howells 2026-04-09 307 stop = stream->issue_from + stream->buffered;
4986700e02d674 David Howells 2026-04-27 308
09f608d47661d0 David Howells 2026-04-20 309 unsigned long long zero_point = netfs_read_zero_point(rreq->inode);
4cbdfd0da8d2d5 David Howells 2026-04-09 310 unsigned long long zlimit = umin(zero_point, rreq->i_size);
4cbdfd0da8d2d5 David Howells 2026-04-09 311
7693c7841ea191 David Howells 2026-03-19 312 _debug("rsub %llx %llx-%llx", start, hole_to, cache_to);
4cbdfd0da8d2d5 David Howells 2026-04-09 313
e192187e9d3cdb David Howells 2026-04-09 314 if (stream->issue_from >= hole_to && stream->issue_from < cache_to) {
4cbdfd0da8d2d5 David Howells 2026-04-09 315 /* Overlap with a cached region, where the cache may
4cbdfd0da8d2d5 David Howells 2026-04-09 316 * record a block of zeroes.
4cbdfd0da8d2d5 David Howells 2026-04-09 317 */
e192187e9d3cdb David Howells 2026-04-09 318 _debug("cached s=%llx c=%llx l=%zx",
e192187e9d3cdb David Howells 2026-04-09 319 stream->issue_from, cache_to, stream->buffered);
7693c7841ea191 David Howells 2026-03-19 320 len = umin(cache_to - stream->issue_from, stream->buffered);
7693c7841ea191 David Howells 2026-03-19 321 len = round_up(len, occ->granularity);
4cbdfd0da8d2d5 David Howells 2026-04-09 322 if (occ->cached_type[0] == FSCACHE_EXTENT_ZERO) {
7693c7841ea191 David Howells 2026-03-19 323 source = NETFS_FILL_WITH_ZEROES;
4cbdfd0da8d2d5 David Howells 2026-04-09 324 netfs_stat(&netfs_n_rh_zero);
4cbdfd0da8d2d5 David Howells 2026-04-09 325 } else {
7693c7841ea191 David Howells 2026-03-19 326 source = NETFS_READ_FROM_CACHE;
16211268fcb366 David Howells 2022-03-01 327 }
7693c7841ea191 David Howells 2026-03-19 328 } else if (start >= zlimit &&
7693c7841ea191 David Howells 2026-03-19 329 start < stop) {
4cbdfd0da8d2d5 David Howells 2026-04-09 330 /* If this range lies beyond the zero-point, that part
4cbdfd0da8d2d5 David Howells 2026-04-09 331 * can just be cleared locally.
4cbdfd0da8d2d5 David Howells 2026-04-09 332 */
7693c7841ea191 David Howells 2026-03-19 333 _debug("zero %llx-%llx", start, stop);
7693c7841ea191 David Howells 2026-03-19 334 len = stream->buffered;
7693c7841ea191 David Howells 2026-03-19 335 source = NETFS_FILL_WITH_ZEROES;
4cbdfd0da8d2d5 David Howells 2026-04-09 336 if (rreq->cache_resources.ops)
7693c7841ea191 David Howells 2026-03-19 337 copy = true;
4cbdfd0da8d2d5 David Howells 2026-04-09 338 netfs_stat(&netfs_n_rh_zero);
4cbdfd0da8d2d5 David Howells 2026-04-09 339 } else {
4cbdfd0da8d2d5 David Howells 2026-04-09 340 /* Read a cache hole from the server. If any part of
4cbdfd0da8d2d5 David Howells 2026-04-09 341 * this range lies beyond the zero-point or the EOF,
4cbdfd0da8d2d5 David Howells 2026-04-09 342 * that part can just be cleared locally.
4cbdfd0da8d2d5 David Howells 2026-04-09 343 */
e192187e9d3cdb David Howells 2026-04-09 344 unsigned long long limit = min3(zlimit, stop, hole_to);
4cbdfd0da8d2d5 David Howells 2026-04-09 345
4cbdfd0da8d2d5 David Howells 2026-04-09 346 _debug("limit %llx %llx", rreq->i_size, zero_point);
7693c7841ea191 David Howells 2026-03-19 347 _debug("download %llx-%llx", start, stop);
7693c7841ea191 David Howells 2026-03-19 348 len = umin(limit - start, ULONG_MAX);
7693c7841ea191 David Howells 2026-03-19 349 source = NETFS_DOWNLOAD_FROM_SERVER;
4cbdfd0da8d2d5 David Howells 2026-04-09 350 if (rreq->cache_resources.ops)
4cbdfd0da8d2d5 David Howells 2026-04-09 @351 __set_bit(NETFS_SREQ_COPY_TO_CACHE, &subreq->flags);
4cbdfd0da8d2d5 David Howells 2026-04-09 352 netfs_stat(&netfs_n_rh_download);
4cbdfd0da8d2d5 David Howells 2026-04-09 353 }
4cbdfd0da8d2d5 David Howells 2026-04-09 354
7693c7841ea191 David Howells 2026-03-19 355 if (len == 0) {
7693c7841ea191 David Howells 2026-03-19 356 pr_err("ZERO-LEN READ: R=%08x l=%zx/%zx s=%llx z=%llx i=%llx",
7693c7841ea191 David Howells 2026-03-19 357 rreq->debug_id, len, stream->buffered,
7693c7841ea191 David Howells 2026-03-19 358 start, zero_point, rreq->i_size);
16211268fcb366 David Howells 2022-03-01 359 break;
16211268fcb366 David Howells 2022-03-01 360 }
16211268fcb366 David Howells 2022-03-01 361
7693c7841ea191 David Howells 2026-03-19 362 subreq = netfs_alloc_read_subrequest(rreq, source);
7693c7841ea191 David Howells 2026-03-19 363 if (!subreq) {
7693c7841ea191 David Howells 2026-03-19 364 ret = -ENOMEM;
7693c7841ea191 David Howells 2026-03-19 365 break;
7693c7841ea191 David Howells 2026-03-19 366 }
7693c7841ea191 David Howells 2026-03-19 367
7693c7841ea191 David Howells 2026-03-19 368 subreq->start = start;
7693c7841ea191 David Howells 2026-03-19 369 subreq->len = len;
7693c7841ea191 David Howells 2026-03-19 370 if (copy)
7693c7841ea191 David Howells 2026-03-19 371 __set_bit(NETFS_SREQ_COPY_TO_CACHE, &subreq->flags);
7693c7841ea191 David Howells 2026-03-19 372
e2d46f2ec33253 David Howells 2024-12-16 373 netfs_issue_read(rreq, subreq);
5454216af502c6 David Howells 2026-03-13 374 netfs_maybe_bulk_drop_ra_refs(rreq);
6b43bbe7fa2c53 David Howells 2026-04-27 375
6b43bbe7fa2c53 David Howells 2026-04-27 376 if (test_bit(NETFS_RREQ_PAUSE, &rreq->flags))
6b43bbe7fa2c53 David Howells 2026-04-27 377 netfs_wait_for_paused_read(rreq);
6b43bbe7fa2c53 David Howells 2026-04-27 378 if (test_bit(NETFS_RREQ_FAILED, &rreq->flags))
6b43bbe7fa2c53 David Howells 2026-04-27 379 break;
ee4cdf7ba857a8 David Howells 2024-07-02 380 cond_resched();
e192187e9d3cdb David Howells 2026-04-09 381 } while (stream->buffered > 0);
ee4cdf7ba857a8 David Howells 2024-07-02 382
e192187e9d3cdb David Howells 2026-04-09 383 if (unlikely(!netfs_are_all_subreqs_queued(rreq))) {
e192187e9d3cdb David Howells 2026-04-09 384 netfs_all_subreqs_queued(rreq);
2b1424cd131cfa David Howells 2025-05-19 385 netfs_wake_collector(rreq);
e2d46f2ec33253 David Howells 2024-12-16 386 }
ee4cdf7ba857a8 David Howells 2024-07-02 387
ee4cdf7ba857a8 David Howells 2024-07-02 388 /* Defer error return as we may need to wait for outstanding I/O. */
e192187e9d3cdb David Howells 2026-04-09 389 if (ret < 0)
ee4cdf7ba857a8 David Howells 2024-07-02 390 cmpxchg(&rreq->error, 0, ret);
615fc17c41427e David Howells 2026-04-09 391
615fc17c41427e David Howells 2026-04-09 392 bvecq_pos_unset(&rreq->load_cursor);
e192187e9d3cdb David Howells 2026-04-09 393 bvecq_pos_unset(&stream->dispatch_cursor);
16211268fcb366 David Howells 2022-03-01 394 }
16211268fcb366 David Howells 2022-03-01 395
:::::: The code at line 351 was first introduced by commit
:::::: 4cbdfd0da8d2d5220304b2df6260465f6cc50c7c cachefiles: Don't rely on backing fs storage map for most use cases
:::::: TO: David Howells <dhowells@redhat.com>
:::::: CC: David Howells <dhowells@redhat.com>
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
next reply other threads:[~2026-05-03 15:04 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-05-03 15:04 kernel test robot [this message]
-- strict thread matches above, loose matches on Subject: below --
2026-05-02 18:15 [dhowells-fs:netfs-crypt 55/68] fs/netfs/buffered_read.c:351:42: warning: variable 'subreq' is uninitialized when used here kernel test robot
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