[PATCH 05/23] afs: Convert afs_writepages_region() to use filemap_get_folios_tag()

Vishal Moola (Oracle)
2022-09-01T22:03:03Z

Convert to use folios throughout. This function is in preparation to
remove find_get_pages_range_tag().

Also modified this function to write the whole batch one at a time,
rather than calling for a new set every single write.

Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
---
fs/afs/write.c | 114 +++++++++++++++++++++++++------------------------
1 file changed, 59 insertions(+), 55 deletions(-)

diff --git a/fs/afs/write.c b/fs/afs/write.c
index 9ebdd36eaf2f..c17dbd82a38c 100644
--- a/fs/afs/write.c
+++ b/fs/afs/write.c
@@ -699,82 +699,86 @@ static int afs_writepages_region(struct address_space *mapping,
loff_t start, loff_t end, loff_t *_next)
{
struct folio *folio;
- struct page *head_page;
+ struct folio_batch fbatch;
ssize_t ret;
+ unsigned int i;
int n, skips = 0;

_enter("%llx,%llx,", start, end);
+ folio_batch_init(&fbatch);

do {
pgoff_t index = start / PAGE_SIZE;

- n = find_get_pages_range_tag(mapping, &index, end / PAGE_SIZE,
- PAGECACHE_TAG_DIRTY, 1, &head_page);
+ n = filemap_get_folios_tag(mapping, &index, end / PAGE_SIZE,
+ PAGECACHE_TAG_DIRTY, &fbatch);
+
if (!n)
break;
+ for (i = 0; i < n; i++) {
+ folio = fbatch.folios[i];
+ start = folio_pos(folio); /* May regress with THPs */

- folio = page_folio(head_page);
- start = folio_pos(folio); /* May regress with THPs */
-
- _debug("wback %lx", folio_index(folio));
+ _debug("wback %lx", folio_index(folio));

- /* At this point we hold neither the i_pages lock nor the
- * page lock: the page may be truncated or invalidated
- * (changing page->mapping to NULL), or even swizzled
- * back from swapper_space to tmpfs file mapping
- */
- if (wbc->sync_mode != WB_SYNC_NONE) {
- ret = folio_lock_killable(folio);
- if (ret < 0) {
- folio_put(folio);
- return ret;
- }
- } else {
- if (!folio_trylock(folio)) {
- folio_put(folio);
- return 0;
+ /* At this point we hold neither the i_pages lock nor the
+ * page lock: the page may be truncated or invalidated
+ * (changing page->mapping to NULL), or even swizzled
+ * back from swapper_space to tmpfs file mapping
+ */
+ if (wbc->sync_mode != WB_SYNC_NONE) {
+ ret = folio_lock_killable(folio);
+ if (ret < 0) {
+ folio_batch_release(&fbatch);
+ return ret;
+ }
+ } else {
+ if (!folio_trylock(folio))
+ continue;
}
- }

- if (folio_mapping(folio) != mapping ||
- !folio_test_dirty(folio)) {
- start += folio_size(folio);
- folio_unlock(folio);
- folio_put(folio);
- continue;
- }
+ if (folio->mapping != mapping ||
+ !folio_test_dirty(folio)) {
+ start += folio_size(folio);
+ folio_unlock(folio);
+ continue;
+ }

- if (folio_test_writeback(folio) ||
- folio_test_fscache(folio)) {
- folio_unlock(folio);
- if (wbc->sync_mode != WB_SYNC_NONE) {
- folio_wait_writeback(folio);
+ if (folio_test_writeback(folio) ||
+ folio_test_fscache(folio)) {
+ folio_unlock(folio);
+ if (wbc->sync_mode != WB_SYNC_NONE) {
+ folio_wait_writeback(folio);
#ifdef CONFIG_AFS_FSCACHE
- folio_wait_fscache(folio);
+ folio_wait_fscache(folio);
#endif
- } else {
- start += folio_size(folio);
+ } else {
+ start += folio_size(folio);
+ }
+ if (wbc->sync_mode == WB_SYNC_NONE) {
+ if (skips >= 5 || need_resched()) {
+ *_next = start;
+ _leave(" = 0 [%llx]", *_next);
+ return 0;
+ }
+ skips++;
+ }
+ continue;
}
- folio_put(folio);
- if (wbc->sync_mode == WB_SYNC_NONE) {
- if (skips >= 5 || need_resched())
- break;
- skips++;
+
+ if (!folio_clear_dirty_for_io(folio))
+ BUG();
+ ret = afs_write_back_from_locked_folio(mapping, wbc,
+ folio, start, end);
+ if (ret < 0) {
+ _leave(" = %zd", ret);
+ folio_batch_release(&fbatch);
+ return ret;
}
- continue;
- }

- if (!folio_clear_dirty_for_io(folio))
- BUG();
- ret = afs_write_back_from_locked_folio(mapping, wbc, folio, start, end);
- folio_put(folio);
- if (ret < 0) {
- _leave(" = %zd", ret);
- return ret;
+ start += ret;
}
-
- start += ret;
-
+ folio_batch_release(&fbatch);
cond_resched();
} while (wbc->nr_to_write > 0);

--
2.36.1