| Message ID | 20240515055719.32577-8-da.gomez@samsung.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | shmem/tmpfs: add large folios support | expand |
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@intel.com/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@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/202405162045.kaXgB2n3-lkp@intel.com/ 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
diff --git a/mm/shmem.c b/mm/shmem.c index 68fe769d91b1..e06cb6438ef8 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -3223,8 +3223,30 @@ static ssize_t shmem_file_splice_read(struct file *in, loff_t *ppos, if (unlikely(*ppos >= isize)) break; part = min_t(loff_t, isize - *ppos, len); + if (folio && folio_test_large(folio) && + folio_test_private(folio)) { + unsigned long from = offset_in_folio(folio, *ppos); + unsigned int bfirst = from >> inode->i_blkbits; + unsigned int blast, blast_upd; + + len = min(folio_size(folio) - from, len); + blast = (from + len - 1) >> inode->i_blkbits; + + blast_upd = sfs_get_last_block_uptodate(folio, bfirst, + blast); + if (blast_upd <= blast) { + unsigned int bsize = 1 << inode->i_blkbits; + unsigned int blks = blast_upd - bfirst + 1; + unsigned int bbytes = blks << inode->i_blkbits; + unsigned int boff = (*ppos % bsize); + + part = min_t(loff_t, bbytes - boff, len); + } + } - if (folio) { + if (folio && shmem_is_block_uptodate( + folio, offset_in_folio(folio, *ppos) >> + inode->i_blkbits)) { /* * If users can be writing to this page using arbitrary * virtual addresses, take care about potential aliasing
The splice_read() path assumes folios are always uptodate. Make sure all blocks in the given range are uptodate or else, splice zeropage into the pipe. Maximize the number of blocks that can be spliced into pipe at once by increasing the 'part' to the latest uptodate block found. Signed-off-by: Daniel Gomez <da.gomez@samsung.com> --- mm/shmem.c | 24 +++++++++++++++++++++++- 1 file changed, 23 insertions(+), 1 deletion(-)