Re: [PATCH 07/12] shmem: check if a block is uptodate before splice into pipe
From: kernel test robot
Date: Thu May 16 2024 - 09:20:15 EST
Hi Daniel,
kernel test robot noticed the following build errors:
[auto build test ERROR on akpm-mm/mm-everything]
[also build test ERROR on xfs-linux/for-next brauner-vfs/vfs.all linus/master v6.9 next-20240516]
[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/Daniel-Gomez/splice-don-t-check-for-uptodate-if-partially-uptodate-is-impl/20240515-135925
base: https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything
patch link: https://lore.kernel.org/r/20240515055719.32577-8-da.gomez%40samsung.com
patch subject: [PATCH 07/12] shmem: check if a block is uptodate before splice into pipe
config: arm-s5pv210_defconfig (https://download.01.org/0day-ci/archive/20240516/202405162045.kaXgB2n3-lkp@xxxxxxxxx/config)
compiler: arm-linux-gnueabi-gcc (GCC) 13.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240516/202405162045.kaXgB2n3-lkp@xxxxxxxxx/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@xxxxxxxxx>
| Closes: https://lore.kernel.org/oe-kbuild-all/202405162045.kaXgB2n3-lkp@xxxxxxxxx/
All errors (new ones prefixed by >>):
arm-linux-gnueabi-ld: mm/shmem.o: in function `shmem_file_splice_read':
>> mm/shmem.c:3240:(.text+0x5224): undefined reference to `__aeabi_ldivmod'
vim +3240 mm/shmem.c
3174
3175 static ssize_t shmem_file_splice_read(struct file *in, loff_t *ppos,
3176 struct pipe_inode_info *pipe,
3177 size_t len, unsigned int flags)
3178 {
3179 struct inode *inode = file_inode(in);
3180 struct address_space *mapping = inode->i_mapping;
3181 struct folio *folio = NULL;
3182 size_t total_spliced = 0, used, npages, n, part;
3183 loff_t isize;
3184 int error = 0;
3185
3186 /* Work out how much data we can actually add into the pipe */
3187 used = pipe_occupancy(pipe->head, pipe->tail);
3188 npages = max_t(ssize_t, pipe->max_usage - used, 0);
3189 len = min_t(size_t, len, npages * PAGE_SIZE);
3190
3191 do {
3192 if (*ppos >= i_size_read(inode))
3193 break;
3194
3195 error = shmem_get_folio(inode, *ppos / PAGE_SIZE, &folio,
3196 SGP_READ);
3197 if (error) {
3198 if (error == -EINVAL)
3199 error = 0;
3200 break;
3201 }
3202 if (folio) {
3203 folio_unlock(folio);
3204
3205 if (folio_test_hwpoison(folio) ||
3206 (folio_test_large(folio) &&
3207 folio_test_has_hwpoisoned(folio))) {
3208 error = -EIO;
3209 break;
3210 }
3211 }
3212
3213 /*
3214 * i_size must be checked after we know the pages are Uptodate.
3215 *
3216 * Checking i_size after the check allows us to calculate
3217 * the correct value for "nr", which means the zero-filled
3218 * part of the page is not copied back to userspace (unless
3219 * another truncate extends the file - this is desired though).
3220 */
3221 isize = i_size_read(inode);
3222 if (unlikely(*ppos >= isize))
3223 break;
3224 part = min_t(loff_t, isize - *ppos, len);
3225 if (folio && folio_test_large(folio) &&
3226 folio_test_private(folio)) {
3227 unsigned long from = offset_in_folio(folio, *ppos);
3228 unsigned int bfirst = from >> inode->i_blkbits;
3229 unsigned int blast, blast_upd;
3230
3231 len = min(folio_size(folio) - from, len);
3232 blast = (from + len - 1) >> inode->i_blkbits;
3233
3234 blast_upd = sfs_get_last_block_uptodate(folio, bfirst,
3235 blast);
3236 if (blast_upd <= blast) {
3237 unsigned int bsize = 1 << inode->i_blkbits;
3238 unsigned int blks = blast_upd - bfirst + 1;
3239 unsigned int bbytes = blks << inode->i_blkbits;
> 3240 unsigned int boff = (*ppos % bsize);
3241
3242 part = min_t(loff_t, bbytes - boff, len);
3243 }
3244 }
3245
3246 if (folio && shmem_is_block_uptodate(
3247 folio, offset_in_folio(folio, *ppos) >>
3248 inode->i_blkbits)) {
3249 /*
3250 * If users can be writing to this page using arbitrary
3251 * virtual addresses, take care about potential aliasing
3252 * before reading the page on the kernel side.
3253 */
3254 if (mapping_writably_mapped(mapping))
3255 flush_dcache_folio(folio);
3256 folio_mark_accessed(folio);
3257 /*
3258 * Ok, we have the page, and it's up-to-date, so we can
3259 * now splice it into the pipe.
3260 */
3261 n = splice_folio_into_pipe(pipe, folio, *ppos, part);
3262 folio_put(folio);
3263 folio = NULL;
3264 } else {
3265 n = splice_zeropage_into_pipe(pipe, *ppos, part);
3266 }
3267
3268 if (!n)
3269 break;
3270 len -= n;
3271 total_spliced += n;
3272 *ppos += n;
3273 in->f_ra.prev_pos = *ppos;
3274 if (pipe_full(pipe->head, pipe->tail, pipe->max_usage))
3275 break;
3276
3277 cond_resched();
3278 } while (len);
3279
3280 if (folio)
3281 folio_put(folio);
3282
3283 file_accessed(in);
3284 return total_spliced ? total_spliced : error;
3285 }
3286
--
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