* [dhowells-fs:netfs-crypt 36/37] fs/netfs/direct_read.c:291:25: warning: variable 'start' is uninitialized when used here
@ 2024-09-03 16:07 kernel test robot
0 siblings, 0 replies; only message in thread
From: kernel test robot @ 2024-09-03 16:07 UTC (permalink / raw)
To: David Howells; +Cc: llvm, oe-kbuild-all
tree: https://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs.git netfs-crypt
head: 3962f4beba4e7ffa6cfab018df8a612902a1d2c8
commit: 504a8d4b08293dbaa09e7057f3b4ea045ba52d29 [36/37] netfs: Implement bounce-buffering for unbuffered/DIO read
config: x86_64-allyesconfig (https://download.01.org/0day-ci/archive/20240904/202409040018.dK9qOlqV-lkp@intel.com/config)
compiler: clang version 18.1.5 (https://github.com/llvm/llvm-project 617a15a9eac96088ae5e9134248d8236e34b91b1)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240904/202409040018.dK9qOlqV-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/202409040018.dK9qOlqV-lkp@intel.com/
All warnings (new ones prefixed by >>):
>> fs/netfs/direct_read.c:291:25: warning: variable 'start' is uninitialized when used here [-Wuninitialized]
291 | _debug("bounce %llx", start);
| ^~~~~
fs/netfs/internal.h:445:17: note: expanded from macro '_debug'
445 | kdebug(FMT, ##__VA_ARGS__); \
| ^~~~~~~~~~~
fs/netfs/internal.h:422:43: note: expanded from macro 'kdebug'
422 | #define kdebug(FMT, ...) dbgprintk(FMT, ##__VA_ARGS__)
| ^~~~~~~~~~~
fs/netfs/internal.h:418:46: note: expanded from macro 'dbgprintk'
418 | printk("[%-6.6s] "FMT"\n", current->comm, ##__VA_ARGS__)
| ^~~~~~~~~~~
include/linux/printk.h:465:60: note: expanded from macro 'printk'
465 | #define printk(fmt, ...) printk_index_wrap(_printk, fmt, ##__VA_ARGS__)
| ^~~~~~~~~~~
include/linux/printk.h:437:19: note: expanded from macro 'printk_index_wrap'
437 | _p_func(_fmt, ##__VA_ARGS__); \
| ^~~~~~~~~~~
fs/netfs/direct_read.c:235:26: note: initialize the variable 'start' to silence this warning
235 | unsigned long long start;
| ^
| = 0
1 warning generated.
vim +/start +291 fs/netfs/direct_read.c
220
221 /**
222 * netfs_unbuffered_read_iter_locked - Perform an unbuffered or direct I/O read
223 * @iocb: The I/O control descriptor describing the read
224 * @iter: The output buffer (also specifies read length)
225 *
226 * Perform an unbuffered I/O or direct I/O from the file in @iocb to the
227 * output buffer. No use is made of the pagecache.
228 *
229 * The caller must hold any appropriate locks.
230 */
231 ssize_t netfs_unbuffered_read_iter_locked(struct kiocb *iocb, struct iov_iter *iter)
232 {
233 struct netfs_io_request *rreq;
234 struct netfs_inode *ictx;
235 unsigned long long start;
236 ssize_t ret;
237 size_t orig_count = iov_iter_count(iter);
238 bool sync = is_sync_kiocb(iocb);
239
240 _enter("");
241
242 if (!orig_count)
243 return 0; /* Don't update atime */
244
245 ret = kiocb_write_and_wait(iocb, orig_count);
246 if (ret < 0)
247 return ret;
248 file_accessed(iocb->ki_filp);
249
250 rreq = netfs_alloc_request(iocb->ki_filp->f_mapping, iocb->ki_filp,
251 iocb->ki_pos, orig_count,
252 NETFS_DIO_READ);
253 if (IS_ERR(rreq))
254 return PTR_ERR(rreq);
255
256 ictx = netfs_inode(rreq->inode);
257 netfs_stat(&netfs_n_rh_dio_read);
258 trace_netfs_read(rreq, rreq->start, rreq->len, netfs_read_trace_dio_read);
259
260 /* If this is an async op, we have to keep track of the destination
261 * buffer for ourselves as the caller's iterator will be trashed when
262 * we return.
263 *
264 * In such a case, extract an iterator to represent as much of the the
265 * output buffer as we can manage. Note that the extraction might not
266 * be able to allocate a sufficiently large bvec array and may shorten
267 * the request.
268 */
269 if (user_backed_iter(iter)) {
270 ret = netfs_extract_user_iter(iter, rreq->len, &rreq->buffer.iter, 0);
271 if (ret < 0)
272 goto out;
273 rreq->direct_bv = (struct bio_vec *)rreq->buffer.iter.bvec;
274 rreq->direct_bv_count = ret;
275 rreq->direct_bv_unpin = iov_iter_extract_will_pin(iter);
276 rreq->len = iov_iter_count(&rreq->buffer.iter);
277 } else {
278 rreq->buffer.iter = *iter;
279 rreq->len = orig_count;
280 rreq->direct_bv_unpin = false;
281 iov_iter_advance(iter, orig_count);
282 }
283
284 /* If we're going to use a bounce buffer, we need to set it up. We
285 * will then need to pad the request out to the minimum block size.
286 */
287 if (test_bit(NETFS_RREQ_USE_BOUNCE_BUFFER, &rreq->flags)) {
288 size_t min_bsize = 1UL << ictx->crypto_bshift;
289
290 rreq->bounce_alloc_to = round_down(rreq->start, min_bsize);
> 291 _debug("bounce %llx", start);
292
293 ret = netfs_alloc_bounce(rreq, rreq->bounce_alloc_to + min_bsize, GFP_KERNEL);
294 if (ret < 0)
295 goto out;
296 }
297
298 if (!sync)
299 rreq->iocb = iocb;
300
301 ret = netfs_unbuffered_read(rreq, sync);
302 if (ret < 0)
303 goto out; /* May be -EIOCBQUEUED */
304 if (sync) {
305 ret = netfs_dio_copy_bounce_to_dest(rreq, iocb);
306 if (ret == 0) {
307 iocb->ki_pos += rreq->transferred;
308 ret = rreq->transferred;
309 }
310 }
311
312 out:
313 netfs_put_request(rreq, false, netfs_rreq_trace_put_return);
314 if (ret > 0)
315 orig_count -= ret;
316 return ret;
317 }
318 EXPORT_SYMBOL(netfs_unbuffered_read_iter_locked);
319
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
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