tree: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master head: 4662b7adea50bb62e993a67f611f3be625d3df0d commit: 157be6ddd9e43835f36264b7bd41a918680ad841 [9878/10347] netfs: do not unlock and put the folio twice reproduce: make htmldocs If you fix the issue, kindly add following tag where applicable Reported-by: kernel test robot <lkp@xxxxxxxxx> All warnings (new ones prefixed by >>): >> Documentation/filesystems/netfs_library.rst:384: WARNING: Inline emphasis start-string without end-string. >> Documentation/filesystems/netfs_library:609: fs/netfs/buffered_read.c:318: WARNING: Inline emphasis start-string without end-string. vim +384 Documentation/filesystems/netfs_library.rst 309 310 * ``init_request()`` 311 312 [Optional] This is called to initialise the request structure. It is given 313 the file for reference. 314 315 * ``free_request()`` 316 317 [Optional] This is called as the request is being deallocated so that the 318 filesystem can clean up any state it has attached there. 319 320 * ``begin_cache_operation()`` 321 322 [Optional] This is called to ask the network filesystem to call into the 323 cache (if present) to initialise the caching state for this read. The netfs 324 library module cannot access the cache directly, so the cache should call 325 something like fscache_begin_read_operation() to do this. 326 327 The cache gets to store its state in ->cache_resources and must set a table 328 of operations of its own there (though of a different type). 329 330 This should return 0 on success and an error code otherwise. If an error is 331 reported, the operation may proceed anyway, just without local caching (only 332 out of memory and interruption errors cause failure here). 333 334 * ``expand_readahead()`` 335 336 [Optional] This is called to allow the filesystem to expand the size of a 337 readahead read request. The filesystem gets to expand the request in both 338 directions, though it's not permitted to reduce it as the numbers may 339 represent an allocation already made. If local caching is enabled, it gets 340 to expand the request first. 341 342 Expansion is communicated by changing ->start and ->len in the request 343 structure. Note that if any change is made, ->len must be increased by at 344 least as much as ->start is reduced. 345 346 * ``clamp_length()`` 347 348 [Optional] This is called to allow the filesystem to reduce the size of a 349 subrequest. The filesystem can use this, for example, to chop up a request 350 that has to be split across multiple servers or to put multiple reads in 351 flight. 352 353 This should return 0 on success and an error code on error. 354 355 * ``issue_read()`` 356 357 [Required] The helpers use this to dispatch a subrequest to the server for 358 reading. In the subrequest, ->start, ->len and ->transferred indicate what 359 data should be read from the server. 360 361 There is no return value; the netfs_subreq_terminated() function should be 362 called to indicate whether or not the operation succeeded and how much data 363 it transferred. The filesystem also should not deal with setting folios 364 uptodate, unlocking them or dropping their refs - the helpers need to deal 365 with this as they have to coordinate with copying to the local cache. 366 367 Note that the helpers have the folios locked, but not pinned. It is 368 possible to use the ITER_XARRAY iov iterator to refer to the range of the 369 inode that is being operated upon without the need to allocate large bvec 370 tables. 371 372 * ``is_still_valid()`` 373 374 [Optional] This is called to find out if the data just read from the local 375 cache is still valid. It should return true if it is still valid and false 376 if not. If it's not still valid, it will be reread from the server. 377 378 * ``check_write_begin()`` 379 380 [Optional] This is called from the netfs_write_begin() helper once it has 381 allocated/grabbed the folio to be modified to allow the filesystem to flush 382 conflicting state before allowing it to be modified. 383 > 384 It may unlock and discard the folio it was given and set the caller's folio 385 pointer to NULL. It should return 0 if everything is now fine (*foliop 386 left set) or the op should be retried (*foliop cleared) and any other error 387 code to abort the operation. 388 389 * ``done`` 390 391 [Optional] This is called after the folios in the request have all been 392 unlocked (and marked uptodate if applicable). 393 394 395 -- 0-DAY CI Kernel Test Service https://01.org/lkp
