[PATCH v5 10/23] ext4: Convert mpage_prepare_extent_to_map() to use filemap_get_folios_tag()

From: Vishal Moola (Oracle)
Date: Wed Jan 04 2023 - 16:17:18 EST


Converted the function to use folios throughout. This is in preparation
for the removal of find_get_pages_range_tag(). Now supports large
folios. This change removes 11 calls to compound_head().

Signed-off-by: Vishal Moola (Oracle) <vishal.moola@xxxxxxxxx>
---
fs/ext4/inode.c | 65 ++++++++++++++++++++++++-------------------------
1 file changed, 32 insertions(+), 33 deletions(-)

diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 9d9f414f99fe..fb6cd994e59a 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -2595,8 +2595,8 @@ static bool ext4_page_nomap_can_writeout(struct page *page)
static int mpage_prepare_extent_to_map(struct mpage_da_data *mpd)
{
struct address_space *mapping = mpd->inode->i_mapping;
- struct pagevec pvec;
- unsigned int nr_pages;
+ struct folio_batch fbatch;
+ unsigned int nr_folios;
long left = mpd->wbc->nr_to_write;
pgoff_t index = mpd->first_page;
pgoff_t end = mpd->last_page;
@@ -2610,18 +2610,17 @@ static int mpage_prepare_extent_to_map(struct mpage_da_data *mpd)
tag = PAGECACHE_TAG_TOWRITE;
else
tag = PAGECACHE_TAG_DIRTY;
-
- pagevec_init(&pvec);
+ folio_batch_init(&fbatch);
mpd->map.m_len = 0;
mpd->next_page = index;
while (index <= end) {
- nr_pages = pagevec_lookup_range_tag(&pvec, mapping, &index, end,
- tag);
- if (nr_pages == 0)
+ nr_folios = filemap_get_folios_tag(mapping, &index, end,
+ tag, &fbatch);
+ if (nr_folios == 0)
break;

- for (i = 0; i < nr_pages; i++) {
- struct page *page = pvec.pages[i];
+ for (i = 0; i < nr_folios; i++) {
+ struct folio *folio = fbatch.folios[i];

/*
* Accumulated enough dirty pages? This doesn't apply
@@ -2635,10 +2634,10 @@ static int mpage_prepare_extent_to_map(struct mpage_da_data *mpd)
goto out;

/* If we can't merge this page, we are done. */
- if (mpd->map.m_len > 0 && mpd->next_page != page->index)
+ if (mpd->map.m_len > 0 && mpd->next_page != folio->index)
goto out;

- lock_page(page);
+ folio_lock(folio);
/*
* If the page is no longer dirty, or its mapping no
* longer corresponds to inode we are writing (which
@@ -2646,16 +2645,16 @@ static int mpage_prepare_extent_to_map(struct mpage_da_data *mpd)
* page is already under writeback and we are not doing
* a data integrity writeback, skip the page
*/
- if (!PageDirty(page) ||
- (PageWriteback(page) &&
+ if (!folio_test_dirty(folio) ||
+ (folio_test_writeback(folio) &&
(mpd->wbc->sync_mode == WB_SYNC_NONE)) ||
- unlikely(page->mapping != mapping)) {
- unlock_page(page);
+ unlikely(folio->mapping != mapping)) {
+ folio_unlock(folio);
continue;
}

- wait_on_page_writeback(page);
- BUG_ON(PageWriteback(page));
+ folio_wait_writeback(folio);
+ BUG_ON(folio_test_writeback(folio));

/*
* Should never happen but for buggy code in
@@ -2666,49 +2665,49 @@ static int mpage_prepare_extent_to_map(struct mpage_da_data *mpd)
*
* [1] https://lore.kernel.org/linux-mm/20180103100430.GE4911@xxxxxxxxxxxxxx
*/
- if (!page_has_buffers(page)) {
- ext4_warning_inode(mpd->inode, "page %lu does not have buffers attached", page->index);
- ClearPageDirty(page);
- unlock_page(page);
+ if (!folio_buffers(folio)) {
+ ext4_warning_inode(mpd->inode, "page %lu does not have buffers attached", folio->index);
+ folio_clear_dirty(folio);
+ folio_unlock(folio);
continue;
}

if (mpd->map.m_len == 0)
- mpd->first_page = page->index;
- mpd->next_page = page->index + 1;
+ mpd->first_page = folio->index;
+ mpd->next_page = folio->index + folio_nr_pages(folio);
/*
* Writeout for transaction commit where we cannot
* modify metadata is simple. Just submit the page.
*/
if (!mpd->can_map) {
- if (ext4_page_nomap_can_writeout(page)) {
- err = mpage_submit_page(mpd, page);
+ if (ext4_page_nomap_can_writeout(&folio->page)) {
+ err = mpage_submit_page(mpd, &folio->page);
if (err < 0)
goto out;
} else {
- unlock_page(page);
- mpd->first_page++;
+ folio_unlock(folio);
+ mpd->first_page += folio_nr_pages(folio);
}
} else {
/* Add all dirty buffers to mpd */
- lblk = ((ext4_lblk_t)page->index) <<
+ lblk = ((ext4_lblk_t)folio->index) <<
(PAGE_SHIFT - blkbits);
- head = page_buffers(page);
+ head = folio_buffers(folio);
err = mpage_process_page_bufs(mpd, head, head,
- lblk);
+ lblk);
if (err <= 0)
goto out;
err = 0;
}
- left--;
+ left -= folio_nr_pages(folio);
}
- pagevec_release(&pvec);
+ folio_batch_release(&fbatch);
cond_resched();
}
mpd->scanned_until_end = 1;
return 0;
out:
- pagevec_release(&pvec);
+ folio_batch_release(&fbatch);
return err;
}

--
2.38.1