tree: https://github.com/ammarfaizi2/linux-block dhowells/linux-fs/netfs-linked-list
head: ce4670495468b797b0c5927fcb661bc0da48b9ab
commit: b0af788660145c19754695953b240c9eaa311df8 [56/61] netfs: Implement truncation
config: x86_64-randconfig-m001 (https://download.01.org/0day-ci/archive/20220703/[email protected]/config)
compiler: gcc-11 (Debian 11.3.0-3) 11.3.0
If you fix the issue, kindly add following tag where applicable
Reported-by: kernel test robot <[email protected]>
Reported-by: Dan Carpenter <[email protected]>
smatch warnings:
fs/netfs/truncate.c:177 netfs_prepare_trunc_buffers() error: uninitialized symbol 'from'.
fs/netfs/truncate.c:189 netfs_prepare_trunc_buffers() error: uninitialized symbol 'to'.
vim +/from +177 fs/netfs/truncate.c
b0af788660145c David Howells 2021-09-30 144 static int netfs_prepare_trunc_buffers(struct netfs_io_request *treq)
b0af788660145c David Howells 2021-09-30 145 {
b0af788660145c David Howells 2021-09-30 146 struct netfs_inode *ctx = netfs_inode(treq->inode);
b0af788660145c David Howells 2021-09-30 147 struct iov_iter iter;
b0af788660145c David Howells 2021-09-30 148 struct folio *folio;
b0af788660145c David Howells 2021-09-30 149 unsigned long long base;
b0af788660145c David Howells 2021-09-30 150 pgoff_t from, to, fto;
b0af788660145c David Howells 2021-09-30 151 size_t offset, seg;
b0af788660145c David Howells 2021-09-30 152 size_t bsize = max_t(size_t, 1UL << ctx->min_bshift, PAGE_SIZE);
b0af788660145c David Howells 2021-09-30 153 int ret;
b0af788660145c David Howells 2021-09-30 154
b0af788660145c David Howells 2021-09-30 155 /* We want to hold the entire replacement block, but we round that out
b0af788660145c David Howells 2021-09-30 156 * to a multiple of pages.
b0af788660145c David Howells 2021-09-30 157 */
b0af788660145c David Howells 2021-09-30 158 base = round_down(treq->trunc_i_size, bsize);
b0af788660145c David Howells 2021-09-30 159 treq->start = base;
b0af788660145c David Howells 2021-09-30 160 treq->len = bsize;
b0af788660145c David Howells 2021-09-30 161 treq->first = base / PAGE_SIZE;
b0af788660145c David Howells 2021-09-30 162 treq->last = (base + bsize + 1) / PAGE_SIZE;
b0af788660145c David Howells 2021-09-30 163
b0af788660145c David Howells 2021-09-30 164 ret = netfs_add_folios_to_buffer(&treq->buffer, treq->first, treq->last,
b0af788660145c David Howells 2021-09-30 165 GFP_KERNEL);
b0af788660145c David Howells 2021-09-30 166 if (ret < 0)
b0af788660145c David Howells 2021-09-30 167 return ret;
b0af788660145c David Howells 2021-09-30 168
b0af788660145c David Howells 2021-09-30 169 ret = netfs_add_folios_to_buffer(&treq->bounce, treq->first, treq->last,
b0af788660145c David Howells 2021-09-30 170 GFP_KERNEL);
b0af788660145c David Howells 2021-09-30 171 if (ret < 0)
b0af788660145c David Howells 2021-09-30 172 return ret;
b0af788660145c David Howells 2021-09-30 173
b0af788660145c David Howells 2021-09-30 174 /* We need to fill the buffer. */
b0af788660145c David Howells 2021-09-30 175 iov_iter_xarray(&iter, READ, &treq->buffer, base, base + bsize);
b0af788660145c David Howells 2021-09-30 176 do {
b0af788660145c David Howells 2021-09-30 @177 folio = read_mapping_folio(treq->mapping, from, NULL);
^^^^
Uninitialized. Weird that kbuild is complaining about code from 2021,
though.
b0af788660145c David Howells 2021-09-30 178 if (IS_ERR(folio))
b0af788660145c David Howells 2021-09-30 179 return PTR_ERR(folio);
b0af788660145c David Howells 2021-09-30 180 if (folio->index > from ||
b0af788660145c David Howells 2021-09-30 181 folio->index + folio_nr_pages(folio) <= folio->index) {
b0af788660145c David Howells 2021-09-30 182 folio_put(folio);
b0af788660145c David Howells 2021-09-30 183 kleave("-EIO [unexpected folio %lx != %lx]", folio->index, from);
b0af788660145c David Howells 2021-09-30 184 return -EIO;
b0af788660145c David Howells 2021-09-30 185 }
b0af788660145c David Howells 2021-09-30 186
b0af788660145c David Howells 2021-09-30 187 offset = (from - folio->index);
b0af788660145c David Howells 2021-09-30 188 fto = folio->index + folio_nr_pages(folio) - 1;
b0af788660145c David Howells 2021-09-30 @189 seg = min(to, fto);
^^
Same.
b0af788660145c David Howells 2021-09-30 190 seg = (seg - from) + 1;
b0af788660145c David Howells 2021-09-30 191 kdebug("buf=%lx-%lx fol=%lx-%lx s=%lx@%lx",
b0af788660145c David Howells 2021-09-30 192 from, to, folio->index, fto, seg, offset);
b0af788660145c David Howells 2021-09-30 193 if (copy_folio_to_iter(folio, offset * PAGE_SIZE, seg * PAGE_SIZE, &iter)) {
b0af788660145c David Howells 2021-09-30 194 folio_put(folio);
b0af788660145c David Howells 2021-09-30 195 kleave(" = -EIO [copy failure]");
b0af788660145c David Howells 2021-09-30 196 return -EIO;
b0af788660145c David Howells 2021-09-30 197 }
b0af788660145c David Howells 2021-09-30 198
b0af788660145c David Howells 2021-09-30 199 /* We keep the refs to discard later - we don't want read
b0af788660145c David Howells 2021-09-30 200 * interfering with what we're up to.
b0af788660145c David Howells 2021-09-30 201 */
b0af788660145c David Howells 2021-09-30 202 from = fto;
b0af788660145c David Howells 2021-09-30 203 } while (from < to);
b0af788660145c David Howells 2021-09-30 204
b0af788660145c David Howells 2021-09-30 205 /* Lock the folios and clear the uptodate flag. Read must wait. */
b0af788660145c David Howells 2021-09-30 206
b0af788660145c David Howells 2021-09-30 207 /* Clear the region after the new EOF */
b0af788660145c David Howells 2021-09-30 208 iov_iter_xarray(&iter, READ, &treq->buffer, base, base + bsize);
b0af788660145c David Howells 2021-09-30 209 iov_iter_advance(&iter, treq->trunc_i_size - treq->start);
b0af788660145c David Howells 2021-09-30 210 iov_iter_zero(iov_iter_count(&iter), &iter);
b0af788660145c David Howells 2021-09-30 211 return 0;
b0af788660145c David Howells 2021-09-30 212 }
--
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