Messages in this thread | | | Date | Wed, 12 Oct 2022 03:10:26 +0100 | From | Matthew Wilcox <> | Subject | Re: [PATCH 1/4] filemap: find_lock_entries() now updates start offset |
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On Tue, Oct 11, 2022 at 02:56:31PM -0700, Vishal Moola (Oracle) wrote: > @@ -2116,7 +2118,16 @@ unsigned find_lock_entries(struct address_space *mapping, pgoff_t start, > folio_put(folio); > } > rcu_read_unlock(); > + nr = folio_batch_count(fbatch); > + > + if (nr) { > + folio = fbatch->folios[nr - 1]; > + nr = folio_nr_pages(folio); > > + if (folio_test_hugetlb(folio)) > + nr = 1; > + *start = folio->index + nr; > + }
Hmm ... this is going to go wrong if the folio is actually a shadow entry, isn't it?
> +++ b/mm/shmem.c > @@ -922,21 +922,18 @@ static void shmem_undo_range(struct inode *inode, loff_t lstart, loff_t lend, > > folio_batch_init(&fbatch); > index = start; > - while (index < end && find_lock_entries(mapping, index, end - 1, > + while (index < end && find_lock_entries(mapping, &index, end - 1, > &fbatch, indices)) { > for (i = 0; i < folio_batch_count(&fbatch); i++) { > folio = fbatch.folios[i]; > > - index = indices[i]; > - > if (xa_is_value(folio)) { > if (unfalloc) > continue; > nr_swaps_freed += !shmem_free_swap(mapping, > - index, folio); > + folio->index, folio);
We know this is a value entry, so we definitely can't look at folio->index. This should probably be:
+ indices[i], folio);
> @@ -510,20 +509,18 @@ unsigned long invalidate_mapping_pagevec(struct address_space *mapping, > int i; > > folio_batch_init(&fbatch); > - while (find_lock_entries(mapping, index, end, &fbatch, indices)) { > + while (find_lock_entries(mapping, &index, end, &fbatch, indices)) { > for (i = 0; i < folio_batch_count(&fbatch); i++) { > struct folio *folio = fbatch.folios[i]; > > /* We rely upon deletion not changing folio->index */ > - index = indices[i]; > > if (xa_is_value(folio)) { > count += invalidate_exceptional_entry(mapping, > - index, > - folio); > + folio->index, > + folio);
Same here. I'd fix the indent while you're at it to get more on that second line and not need a third line.
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