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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@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Kent Overstreet <kent.overstreet@gmail.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Matthew Wilcox (Oracle) 2021-02-24 12:01:55 -08:00 committed by Linus Torvalds
parent 0c7c575df5
commit ff993ba130
1 changed files with 38 additions and 44 deletions
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82
mm/filemap.c
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@ -2325,22 +2325,22 @@ static struct page *filemap_create_page(struct kiocb *iocb,
}
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)
@ -2348,17 +2348,17 @@ static int filemap_get_pages(struct kiocb *iocb, struct iov_iter *iter,
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);
@ -2366,9 +2366,9 @@ static int filemap_get_pages(struct kiocb *iocb, struct iov_iter *iter,
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;
}
@ -2379,9 +2379,9 @@ static int filemap_get_pages(struct kiocb *iocb, struct iov_iter *iter,
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;
}
@ -2389,17 +2389,17 @@ static int filemap_get_pages(struct kiocb *iocb, struct iov_iter *iter,
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;
/*
@ -2431,11 +2431,8 @@ ssize_t generic_file_buffered_read(struct kiocb *iocb,
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;
@ -2457,12 +2454,9 @@ ssize_t generic_file_buffered_read(struct kiocb *iocb,
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.
@ -2478,9 +2472,9 @@ ssize_t generic_file_buffered_read(struct kiocb *iocb,
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
@ -2494,11 +2488,11 @@ ssize_t generic_file_buffered_read(struct kiocb *iocb,
*/
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);
@ -2510,9 +2504,9 @@ ssize_t generic_file_buffered_read(struct kiocb *iocb,
* 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;
@ -2524,8 +2518,8 @@ ssize_t generic_file_buffered_read(struct kiocb *iocb,
}
}
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);