The patch titled
Subject: filemap: add filemap_get_folios_contig()
has been added to the -mm mm-unstable branch. Its filename is
filemap-add-filemap_get_folios_contig.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/filemap-add-filemap_get_folios_contig.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: "Vishal Moola (Oracle)" <vishal.moola@xxxxxxxxx>
Subject: filemap: add filemap_get_folios_contig()
Date: Tue, 23 Aug 2022 17:40:17 -0700
Patch series "Convert to filemap_get_folios_contig()", v3.
This patch series replaces find_get_pages_contig() with
filemap_get_folios_contig().
This patch (of 7):
This function is meant to replace find_get_pages_contig().
Unlike find_get_pages_contig(), filemap_get_folios_contig() no longer
takes in a target number of pages to find - It returns up to 15 contiguous
folios.
To be more consistent with filemap_get_folios(),
filemap_get_folios_contig() now also updates the start index passed in,
and takes an end index.
Link: https://lkml.kernel.org/r/20220824004023.77310-1-vishal.moola@xxxxxxxxx
Link: https://lkml.kernel.org/r/20220824004023.77310-2-vishal.moola@xxxxxxxxx
Signed-off-by: Vishal Moola (Oracle) <vishal.moola@xxxxxxxxx>
Cc: Chris Mason <clm@xxxxxx>
Cc: Josef Bacik <josef@xxxxxxxxxxxxxx>
Cc: David Sterba <dsterba@xxxxxxxx>
Cc: Ryusuke Konishi <konishi.ryusuke@xxxxxxxxx>
Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Cc: David Sterba <dsterb@xxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/pagemap.h | 2 +
mm/filemap.c | 73 ++++++++++++++++++++++++++++++++++++++
2 files changed, 75 insertions(+)
--- a/include/linux/pagemap.h~filemap-add-filemap_get_folios_contig
+++ a/include/linux/pagemap.h
@@ -718,6 +718,8 @@ static inline struct page *find_subpage(
unsigned filemap_get_folios(struct address_space *mapping, pgoff_t *start,
pgoff_t end, struct folio_batch *fbatch);
+unsigned filemap_get_folios_contig(struct address_space *mapping,
+ pgoff_t *start, pgoff_t end, struct folio_batch *fbatch);
unsigned find_get_pages_contig(struct address_space *mapping, pgoff_t start,
unsigned int nr_pages, struct page **pages);
unsigned find_get_pages_range_tag(struct address_space *mapping, pgoff_t *index,
--- a/mm/filemap.c~filemap-add-filemap_get_folios_contig
+++ a/mm/filemap.c
@@ -2189,6 +2189,79 @@ bool folio_more_pages(struct folio *foli
}
/**
+ * filemap_get_folios_contig - Get a batch of contiguous folios
+ * @mapping: The address_space to search
+ * @start: The starting page index
+ * @end: The final page index (inclusive)
+ * @fbatch: The batch to fill
+ *
+ * filemap_get_folios_contig() works exactly like filemap_get_folios(),
+ * except the returned folios are guaranteed to be contiguous. This may
+ * not return all contiguous folios if the batch gets filled up.
+ *
+ * Return: The number of folios found.
+ * Also update @start to be positioned for traversal of the next folio.
+ */
+
+unsigned filemap_get_folios_contig(struct address_space *mapping,
+ pgoff_t *start, pgoff_t end, struct folio_batch *fbatch)
+{
+ XA_STATE(xas, &mapping->i_pages, *start);
+ unsigned long nr;
+ struct folio *folio;
+
+ rcu_read_lock();
+
+ for (folio = xas_load(&xas); folio && xas.xa_index <= end;
+ folio = xas_next(&xas)) {
+ if (xas_retry(&xas, folio))
+ continue;
+ /*
+ * If the entry has been swapped out, we can stop looking.
+ * No current caller is looking for DAX entries.
+ */
+ if (xa_is_value(folio))
+ goto update_start;
+
+ if (!folio_try_get_rcu(folio))
+ goto retry;
+
+ if (unlikely(folio != xas_reload(&xas)))
+ goto put_folio;
+
+ if (!folio_batch_add(fbatch, folio)) {
+ nr = folio_nr_pages(folio);
+
+ if (folio_test_hugetlb(folio))
+ nr = 1;
+ *start = folio->index + nr;
+ goto out;
+ }
+ continue;
+put_folio:
+ folio_put(folio);
+
+retry:
+ xas_reset(&xas);
+ }
+
+update_start:
+ nr = folio_batch_count(fbatch);
+
+ if (nr) {
+ folio = fbatch->folios[nr - 1];
+ if (folio_test_hugetlb(folio))
+ *start = folio->index + 1;
+ else
+ *start = folio->index + folio_nr_pages(folio);
+ }
+out:
+ rcu_read_unlock();
+ return folio_batch_count(fbatch);
+}
+EXPORT_SYMBOL(filemap_get_folios_contig);
+
+/**
* find_get_pages_contig - gang contiguous pagecache lookup
* @mapping: The address_space to search
* @index: The starting page index
_
Patches currently in -mm which might be from vishal.moola@xxxxxxxxx are
filemap-add-filemap_get_folios_contig.patch
btrfs-convert-__process_pages_contig-to-use-filemap_get_folios_contig.patch
btrfs-convert-end_compressed_writeback-to-use-filemap_get_folios.patch
btrfs-convert-process_page_range-to-use-filemap_get_folios_contig.patch
nilfs2-convert-nilfs_find_uncommited_extent-to-use-filemap_get_folios_contig.patch
ramfs-convert-ramfs_nommu_get_unmapped_area-to-use-filemap_get_folios_contig.patch
filemap-remove-find_get_pages_contig.patch
