+ ext4-use-pagevec_lookup_range-in-ext4_find_unwritten_pgoff.patch added to -mm tree

+ ext4-use-pagevec_lookup_range-in-ext4_find_unwritten_pgoff.patch added to -mm tree

[akpm]

The patch titled
     Subject: ext4: use pagevec_lookup_range() in ext4_find_unwritten_pgoff()
has been added to the -mm tree.  Its filename is
     ext4-use-pagevec_lookup_range-in-ext4_find_unwritten_pgoff.patch

This patch should soon appear at
    http://ozlabs.org/~akpm/mmots/broken-out/ext4-use-pagevec_lookup_range-in-ext4_find_unwritten_pgoff.patch
and later at
    http://ozlabs.org/~akpm/mmotm/broken-out/ext4-use-pagevec_lookup_range-in-ext4_find_unwritten_pgoff.patch

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------------------------------------------------------
From: Jan Kara <jack@suse.cz>
Subject: ext4: use pagevec_lookup_range() in ext4_find_unwritten_pgoff()

Use pagevec_lookup_range() in ext4_find_unwritten_pgoff() since we are
interested only in pages in the given range.  Simplify the logic as a
result of not getting pages out of range and index getting automatically
advanced.

Link: http://lkml.kernel.org/r/20170726114704.7626-6-jack@suse.cz
Signed-off-by: Jan Kara <jack@suse.cz>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 fs/ext4/file.c |   14 ++++----------
 1 file changed, 4 insertions(+), 10 deletions(-)

diff -puN fs/ext4/file.c~ext4-use-pagevec_lookup_range-in-ext4_find_unwritten_pgoff fs/ext4/file.c
--- a/fs/ext4/file.c~ext4-use-pagevec_lookup_range-in-ext4_find_unwritten_pgoff
+++ a/fs/ext4/file.c
@@ -464,12 +464,11 @@ static int ext4_find_unwritten_pgoff(str
 
 	pagevec_init(&pvec, 0);
 	do {
-		int i, num;
+		int i;
 		unsigned long nr_pages;
 
-		num = min_t(pgoff_t, end - index, PAGEVEC_SIZE - 1) + 1;
-		nr_pages = pagevec_lookup(&pvec, inode->i_mapping, &index,
-					  (pgoff_t)num);
+		nr_pages = pagevec_lookup_range(&pvec, inode->i_mapping,
+					&index, end, PAGEVEC_SIZE);
 		if (nr_pages == 0)
 			break;
 
@@ -488,9 +487,6 @@ static int ext4_find_unwritten_pgoff(str
 				goto out;
 			}
 
-			if (page->index > end)
-				goto out;
-
 			lock_page(page);
 
 			if (unlikely(page->mapping != inode->i_mapping)) {
@@ -530,12 +526,10 @@ static int ext4_find_unwritten_pgoff(str
 			unlock_page(page);
 		}
 
-		/* The no. of pages is less than our desired, we are done. */
-		if (nr_pages < num)
-			break;
 		pagevec_release(&pvec);
 	} while (index <= end);
 
+	/* There are no pages upto endoff - that would be a hole in there. */
 	if (whence == SEEK_HOLE && lastoff < endoff) {
 		found = 1;
 		*offset = lastoff;
_

Patches currently in -mm which might be from jack@suse.cz are

fscache-remove-unused-now_uncached-callback.patch
mm-make-pagevec_lookup-update-index.patch
mm-implement-find_get_pages_range.patch
fs-fix-performance-regression-in-clean_bdev_aliases.patch
ext4-use-pagevec_lookup_range-in-ext4_find_unwritten_pgoff.patch
ext4-use-pagevec_lookup_range-in-writeback-code.patch
hugetlbfs-use-pagevec_lookup_range-in-remove_inode_hugepages.patch
fs-use-pagevec_lookup_range-in-page_cache_seek_hole_data.patch
mm-use-find_get_pages_range-in-filemap_range_has_page.patch
mm-remove-nr_pages-argument-from-pagevec_lookup_range.patch