From: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx> This simple helper will be the basis of the writeback iterator. To make this work, we need to remember the current index and end positions in writeback_control. Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx> Signed-off-by: Christoph Hellwig <hch@xxxxxx> --- include/linux/writeback.h | 2 ++ mm/page-writeback.c | 49 +++++++++++++++++++++------------------ 2 files changed, 29 insertions(+), 22 deletions(-) diff --git a/include/linux/writeback.h b/include/linux/writeback.h index 05e8add4b5ae3c..be960f92ad9dbd 100644 --- a/include/linux/writeback.h +++ b/include/linux/writeback.h @@ -81,6 +81,8 @@ struct writeback_control { /* internal fields used by the ->writepages implementation: */ struct folio_batch fbatch; + pgoff_t index; + pgoff_t end; /* inclusive */ pgoff_t done_index; int err; unsigned range_whole:1; /* entire file */ diff --git a/mm/page-writeback.c b/mm/page-writeback.c index 45309f3b8193f8..5d33e7b468e2cc 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -2378,6 +2378,22 @@ static int writeback_finish(struct address_space *mapping, return wbc->err; } +static void writeback_get_batch(struct address_space *mapping, + struct writeback_control *wbc) +{ + xa_mark_t tag; + + if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages) + tag = PAGECACHE_TAG_TOWRITE; + else + tag = PAGECACHE_TAG_DIRTY; + + folio_batch_release(&wbc->fbatch); + cond_resched(); + filemap_get_folios_tag(mapping, &wbc->index, wbc->end, tag, + &wbc->fbatch); +} + /** * write_cache_pages - walk the list of dirty pages of the given address space and write all of them. * @mapping: address space structure to write @@ -2414,41 +2430,32 @@ int write_cache_pages(struct address_space *mapping, void *data) { int error; - int nr_folios; - pgoff_t index; - pgoff_t end; /* Inclusive */ - xa_mark_t tag; if (wbc->range_cyclic) { - index = mapping->writeback_index; /* prev offset */ - end = -1; + wbc->index = mapping->writeback_index; /* prev offset */ + wbc->end = -1; } else { - index = wbc->range_start >> PAGE_SHIFT; - end = wbc->range_end >> PAGE_SHIFT; + wbc->index = wbc->range_start >> PAGE_SHIFT; + wbc->end = wbc->range_end >> PAGE_SHIFT; if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX) wbc->range_whole = 1; } - if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages) { - tag_pages_for_writeback(mapping, index, end); - tag = PAGECACHE_TAG_TOWRITE; - } else { - tag = PAGECACHE_TAG_DIRTY; - } + if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages) + tag_pages_for_writeback(mapping, wbc->index, wbc->end); - wbc->done_index = index; + wbc->done_index = wbc->index; folio_batch_init(&wbc->fbatch); wbc->err = 0; - while (index <= end) { + while (wbc->index <= wbc->end) { int i; - nr_folios = filemap_get_folios_tag(mapping, &index, end, - tag, &wbc->fbatch); + writeback_get_batch(mapping, wbc); - if (nr_folios == 0) + if (wbc->fbatch.nr == 0) break; - for (i = 0; i < nr_folios; i++) { + for (i = 0; i < wbc->fbatch.nr; i++) { struct folio *folio = wbc->fbatch.folios[i]; unsigned long nr; @@ -2526,8 +2533,6 @@ int write_cache_pages(struct address_space *mapping, wbc->sync_mode == WB_SYNC_NONE) return writeback_finish(mapping, wbc, true); } - folio_batch_release(&wbc->fbatch); - cond_resched(); } return writeback_finish(mapping, wbc, false); -- 2.39.2