The patch titled
Subject: mm/filemap: convert filemap_get_pages to take a pagevec
has been added to the -mm tree. Its filename is
mm-filemap-convert-filemap_get_pages-to-take-a-pagevec.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/mm-filemap-convert-filemap_get_pages-to-take-a-pagevec.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/mm-filemap-convert-filemap_get_pages-to-take-a-pagevec.patch
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx>
Subject: mm/filemap: convert filemap_get_pages to take a pagevec
Using a pagevec lets us keep the pages and the number of pages together
which simplifies a lot of the calling conventions.
Link: https://lkml.kernel.org/r/20210122160140.223228-4-willy@xxxxxxxxxxxxx
Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
Cc: Kent Overstreet <kent.overstreet@xxxxxxxxx>
Cc: Miaohe Lin <linmiaohe@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/filemap.c | 82 ++++++++++++++++++++++---------------------------
1 file changed, 38 insertions(+), 44 deletions(-)
--- a/mm/filemap.c~mm-filemap-convert-filemap_get_pages-to-take-a-pagevec
+++ a/mm/filemap.c
@@ -2319,22 +2319,22 @@ static struct page *filemap_create_page(
}
static int filemap_get_pages(struct kiocb *iocb, struct iov_iter *iter,
- struct page **pages, unsigned int nr)
+ struct pagevec *pvec)
{
struct file *filp = iocb->ki_filp;
struct address_space *mapping = filp->f_mapping;
struct file_ra_state *ra = &filp->f_ra;
pgoff_t index = iocb->ki_pos >> PAGE_SHIFT;
pgoff_t last_index = (iocb->ki_pos + iter->count + PAGE_SIZE-1) >> PAGE_SHIFT;
- int i, j, nr_got, err = 0;
+ unsigned int nr = min_t(unsigned long, last_index - index, PAGEVEC_SIZE);
+ int i, j, err = 0;
- nr = min_t(unsigned long, last_index - index, nr);
find_page:
if (fatal_signal_pending(current))
return -EINTR;
- nr_got = find_get_pages_contig(mapping, index, nr, pages);
- if (nr_got)
+ pvec->nr = find_get_pages_contig(mapping, index, nr, pvec->pages);
+ if (pvec->nr)
goto got_pages;
if (iocb->ki_flags & IOCB_NOIO)
@@ -2342,17 +2342,17 @@ find_page:
page_cache_sync_readahead(mapping, ra, filp, index, last_index - index);
- nr_got = find_get_pages_contig(mapping, index, nr, pages);
- if (nr_got)
+ pvec->nr = find_get_pages_contig(mapping, index, nr, pvec->pages);
+ if (pvec->nr)
goto got_pages;
- pages[0] = filemap_create_page(iocb, iter);
- err = PTR_ERR_OR_ZERO(pages[0]);
- if (!IS_ERR_OR_NULL(pages[0]))
- nr_got = 1;
+ pvec->pages[0] = filemap_create_page(iocb, iter);
+ err = PTR_ERR_OR_ZERO(pvec->pages[0]);
+ if (!IS_ERR_OR_NULL(pvec->pages[0]))
+ pvec->nr = 1;
got_pages:
- for (i = 0; i < nr_got; i++) {
- struct page *page = pages[i];
+ for (i = 0; i < pvec->nr; i++) {
+ struct page *page = pvec->pages[i];
pgoff_t pg_index = index + i;
loff_t pg_pos = max(iocb->ki_pos,
(loff_t) pg_index << PAGE_SHIFT);
@@ -2360,9 +2360,9 @@ got_pages:
if (PageReadahead(page)) {
if (iocb->ki_flags & IOCB_NOIO) {
- for (j = i; j < nr_got; j++)
- put_page(pages[j]);
- nr_got = i;
+ for (j = i; j < pvec->nr; j++)
+ put_page(pvec->pages[j]);
+ pvec->nr = i;
err = -EAGAIN;
break;
}
@@ -2373,9 +2373,9 @@ got_pages:
if (!PageUptodate(page)) {
if ((iocb->ki_flags & IOCB_NOWAIT) ||
((iocb->ki_flags & IOCB_WAITQ) && i)) {
- for (j = i; j < nr_got; j++)
- put_page(pages[j]);
- nr_got = i;
+ for (j = i; j < pvec->nr; j++)
+ put_page(pvec->pages[j]);
+ pvec->nr = i;
err = -EAGAIN;
break;
}
@@ -2383,17 +2383,17 @@ got_pages:
page = filemap_update_page(iocb, filp, iter, page,
pg_pos, pg_count);
if (IS_ERR_OR_NULL(page)) {
- for (j = i + 1; j < nr_got; j++)
- put_page(pages[j]);
- nr_got = i;
+ for (j = i + 1; j < pvec->nr; j++)
+ put_page(pvec->pages[j]);
+ pvec->nr = i;
err = PTR_ERR_OR_ZERO(page);
break;
}
}
}
- if (likely(nr_got))
- return nr_got;
+ if (likely(pvec->nr))
+ return 0;
if (err)
return err;
/*
@@ -2425,11 +2425,8 @@ ssize_t generic_file_buffered_read(struc
struct file_ra_state *ra = &filp->f_ra;
struct address_space *mapping = filp->f_mapping;
struct inode *inode = mapping->host;
- struct page *pages[PAGEVEC_SIZE];
- unsigned int nr_pages = min_t(unsigned int, PAGEVEC_SIZE,
- ((iocb->ki_pos + iter->count + PAGE_SIZE - 1) >> PAGE_SHIFT) -
- (iocb->ki_pos >> PAGE_SHIFT));
- int i, pg_nr, error = 0;
+ struct pagevec pvec;
+ int i, error = 0;
bool writably_mapped;
loff_t isize, end_offset;
@@ -2451,12 +2448,9 @@ ssize_t generic_file_buffered_read(struc
if ((iocb->ki_flags & IOCB_WAITQ) && written)
iocb->ki_flags |= IOCB_NOWAIT;
- i = 0;
- pg_nr = filemap_get_pages(iocb, iter, pages, nr_pages);
- if (pg_nr < 0) {
- error = pg_nr;
+ error = filemap_get_pages(iocb, iter, &pvec);
+ if (error < 0)
break;
- }
/*
* i_size must be checked after we know the pages are Uptodate.
@@ -2472,9 +2466,9 @@ ssize_t generic_file_buffered_read(struc
end_offset = min_t(loff_t, isize, iocb->ki_pos + iter->count);
- while ((iocb->ki_pos >> PAGE_SHIFT) + pg_nr >
+ while ((iocb->ki_pos >> PAGE_SHIFT) + pvec.nr >
(end_offset + PAGE_SIZE - 1) >> PAGE_SHIFT)
- put_page(pages[--pg_nr]);
+ put_page(pvec.pages[--pvec.nr]);
/*
* Once we start copying data, we don't want to be touching any
@@ -2488,11 +2482,11 @@ ssize_t generic_file_buffered_read(struc
*/
if (iocb->ki_pos >> PAGE_SHIFT !=
ra->prev_pos >> PAGE_SHIFT)
- mark_page_accessed(pages[0]);
- for (i = 1; i < pg_nr; i++)
- mark_page_accessed(pages[i]);
+ mark_page_accessed(pvec.pages[0]);
+ for (i = 1; i < pagevec_count(&pvec); i++)
+ mark_page_accessed(pvec.pages[i]);
- for (i = 0; i < pg_nr; i++) {
+ for (i = 0; i < pagevec_count(&pvec); i++) {
unsigned int offset = iocb->ki_pos & ~PAGE_MASK;
unsigned int bytes = min_t(loff_t, end_offset - iocb->ki_pos,
PAGE_SIZE - offset);
@@ -2504,9 +2498,9 @@ ssize_t generic_file_buffered_read(struc
* before reading the page on the kernel side.
*/
if (writably_mapped)
- flush_dcache_page(pages[i]);
+ flush_dcache_page(pvec.pages[i]);
- copied = copy_page_to_iter(pages[i], offset, bytes, iter);
+ copied = copy_page_to_iter(pvec.pages[i], offset, bytes, iter);
written += copied;
iocb->ki_pos += copied;
@@ -2518,8 +2512,8 @@ ssize_t generic_file_buffered_read(struc
}
}
put_pages:
- for (i = 0; i < pg_nr; i++)
- put_page(pages[i]);
+ for (i = 0; i < pagevec_count(&pvec); i++)
+ put_page(pvec.pages[i]);
} while (iov_iter_count(iter) && iocb->ki_pos < isize && !error);
file_accessed(filp);
_
Patches currently in -mm which might be from willy@xxxxxxxxxxxxx are
mm-debug-improve-memcg-debugging.patch
mm-filemap-rename-generic_file_buffered_read-subfunctions.patch
mm-filemap-remove-dynamically-allocated-array-from-filemap_read.patch
mm-filemap-convert-filemap_get_pages-to-take-a-pagevec.patch
mm-filemap-use-head-pages-in-generic_file_buffered_read.patch
mm-filemap-pass-a-sleep-state-to-put_and_wait_on_page_locked.patch
mm-filemap-support-readpage-splitting-a-page.patch
mm-filemap-inline-__wait_on_page_locked_async-into-caller.patch
mm-filemap-dont-call-readpage-if-iocb_waitq-is-set.patch
mm-filemap-change-filemap_read_page-calling-conventions.patch
mm-filemap-change-filemap_create_page-calling-conventions.patch
mm-filemap-convert-filemap_update_page-to-return-an-errno.patch
mm-filemap-move-the-iocb-checks-into-filemap_update_page.patch
mm-filemap-add-filemap_range_uptodate.patch
mm-filemap-split-filemap_readahead-out-of-filemap_get_pages.patch
mm-filemap-restructure-filemap_get_pages.patch
mm-filemap-dont-relock-the-page-after-calling-readpage.patch
mm-make-pagecache-tagged-lookups-return-only-head-pages.patch
mm-shmem-use-pagevec_lookup-in-shmem_unlock_mapping.patch
mm-swap-optimise-get_shadow_from_swap_cache.patch
mm-add-fgp_entry.patch
mm-filemap-rename-find_get_entry-to-mapping_get_entry.patch
mm-filemap-add-helper-for-finding-pages.patch
mm-filemap-add-helper-for-finding-pages-fix.patch
mm-filemap-add-mapping_seek_hole_data.patch
mm-filemap-add-mapping_seek_hole_data-fix.patch
iomap-use-mapping_seek_hole_data.patch
mm-add-and-use-find_lock_entries.patch
mm-add-and-use-find_lock_entries-fix.patch
mm-add-an-end-parameter-to-find_get_entries.patch
mm-add-an-end-parameter-to-pagevec_lookup_entries.patch
mm-remove-nr_entries-parameter-from-pagevec_lookup_entries.patch
mm-pass-pvec-directly-to-find_get_entries.patch
mm-remove-pagevec_lookup_entries.patch
