From: "Matthew Wilcox (Oracle)" <willy@infradead.org>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>,
linux-fsdevel@vger.kernel.org, linux-mm@kvack.org,
linux-kernel@vger.kernel.org,
Kent Overstreet <kent.overstreet@gmail.com>,
Christoph Hellwig <hch@lst.de>
Subject: [PATCH v5 13/18] mm/filemap: Add filemap_range_uptodate
Date: Fri, 22 Jan 2021 16:01:35 +0000 [thread overview]
Message-ID: <20210122160140.223228-14-willy@infradead.org> (raw)
In-Reply-To: <20210122160140.223228-1-willy@infradead.org>
Move the complicated condition and the calculations out of
filemap_update_page() into its own function.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Kent Overstreet <kent.overstreet@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
---
mm/filemap.c | 68 ++++++++++++++++++++++++++++++----------------------
1 file changed, 40 insertions(+), 28 deletions(-)
diff --git a/mm/filemap.c b/mm/filemap.c
index 9fbfb27483147..a3ebc6082022e 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -2246,11 +2246,36 @@ static int filemap_read_page(struct file *file, struct address_space *mapping,
return error;
}
+static bool filemap_range_uptodate(struct address_space *mapping,
+ loff_t pos, struct iov_iter *iter, struct page *page)
+{
+ int count;
+
+ if (PageUptodate(page))
+ return true;
+ /* pipes can't handle partially uptodate pages */
+ if (iov_iter_is_pipe(iter))
+ return false;
+ if (!mapping->a_ops->is_partially_uptodate)
+ return false;
+ if (mapping->host->i_blkbits >= (PAGE_SHIFT + thp_order(page)))
+ return false;
+
+ count = iter->count;
+ if (page_offset(page) > pos) {
+ count -= page_offset(page) - pos;
+ pos = 0;
+ } else {
+ pos -= page_offset(page);
+ }
+
+ return mapping->a_ops->is_partially_uptodate(page, pos, count);
+}
+
static int filemap_update_page(struct kiocb *iocb,
struct address_space *mapping, struct iov_iter *iter,
- struct page *page, loff_t pos, loff_t count)
+ struct page *page)
{
- struct inode *inode = mapping->host;
int error;
if (!trylock_page(page)) {
@@ -2267,34 +2292,25 @@ static int filemap_update_page(struct kiocb *iocb,
if (!page->mapping)
goto truncated;
- if (PageUptodate(page))
- goto uptodate;
- if (inode->i_blkbits == PAGE_SHIFT ||
- !mapping->a_ops->is_partially_uptodate)
- goto readpage;
- /* pipes can't handle partially uptodate pages */
- if (unlikely(iov_iter_is_pipe(iter)))
- goto readpage;
- if (!mapping->a_ops->is_partially_uptodate(page,
- pos & (thp_size(page) - 1), count))
- goto readpage;
-uptodate:
- unlock_page(page);
- return 0;
-readpage:
- if (iocb->ki_flags & (IOCB_NOIO | IOCB_NOWAIT | IOCB_WAITQ)) {
- unlock_page(page);
- return -EAGAIN;
- }
+ error = 0;
+ if (filemap_range_uptodate(mapping, iocb->ki_pos, iter, page))
+ goto unlock;
+
+ error = -EAGAIN;
+ if (iocb->ki_flags & (IOCB_NOIO | IOCB_NOWAIT | IOCB_WAITQ))
+ goto unlock;
+
error = filemap_read_page(iocb->ki_filp, mapping, page);
if (error == AOP_TRUNCATED_PAGE)
put_page(page);
return error;
truncated:
- unlock_page(page);
+ error = AOP_TRUNCATED_PAGE;
put_page(page);
- return AOP_TRUNCATED_PAGE;
+unlock:
+ unlock_page(page);
+ return error;
}
static int filemap_create_page(struct file *file,
@@ -2364,9 +2380,6 @@ static int filemap_get_pages(struct kiocb *iocb, struct iov_iter *iter,
{
struct page *page = pvec->pages[pvec->nr - 1];
pgoff_t pg_index = page->index;
- loff_t pg_pos = max(iocb->ki_pos,
- (loff_t) pg_index << PAGE_SHIFT);
- loff_t pg_count = iocb->ki_pos + iter->count - pg_pos;
if (PageReadahead(page)) {
if (iocb->ki_flags & IOCB_NOIO) {
@@ -2383,8 +2396,7 @@ static int filemap_get_pages(struct kiocb *iocb, struct iov_iter *iter,
if ((iocb->ki_flags & IOCB_WAITQ) &&
pagevec_count(pvec) > 1)
iocb->ki_flags |= IOCB_NOWAIT;
- err = filemap_update_page(iocb, mapping, iter, page,
- pg_pos, pg_count);
+ err = filemap_update_page(iocb, mapping, iter, page);
if (err) {
if (err < 0)
put_page(page);
--
2.29.2
next prev parent reply other threads:[~2021-01-22 16:14 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-22 16:01 [PATCH v5 00/18] Refactor generic_file_buffered_read Matthew Wilcox (Oracle)
2021-01-22 16:01 ` [PATCH v5 01/18] mm/filemap: Rename generic_file_buffered_read subfunctions Matthew Wilcox (Oracle)
2021-01-22 16:01 ` [PATCH v5 02/18] mm/filemap: Remove dynamically allocated array from filemap_read Matthew Wilcox (Oracle)
2021-01-22 16:01 ` [PATCH v5 03/18] mm/filemap: Convert filemap_get_pages to take a pagevec Matthew Wilcox (Oracle)
2021-01-22 16:01 ` [PATCH v5 04/18] mm/filemap: Use head pages in generic_file_buffered_read Matthew Wilcox (Oracle)
2021-01-22 16:01 ` [PATCH v5 05/18] mm/filemap: Pass a sleep state to put_and_wait_on_page_locked Matthew Wilcox (Oracle)
2021-01-22 16:01 ` [PATCH v5 06/18] mm/filemap: Support readpage splitting a page Matthew Wilcox (Oracle)
2021-01-22 16:01 ` [PATCH v5 07/18] mm/filemap: Inline __wait_on_page_locked_async into caller Matthew Wilcox (Oracle)
2021-01-22 16:01 ` [PATCH v5 08/18] mm/filemap: Don't call ->readpage if IOCB_WAITQ is set Matthew Wilcox (Oracle)
2021-01-22 16:01 ` [PATCH v5 09/18] mm/filemap: Change filemap_read_page calling conventions Matthew Wilcox (Oracle)
2021-01-22 16:01 ` [PATCH v5 10/18] mm/filemap: Change filemap_create_page " Matthew Wilcox (Oracle)
2021-01-22 16:01 ` [PATCH v5 11/18] mm/filemap: Convert filemap_update_page to return an errno Matthew Wilcox (Oracle)
2021-01-22 16:01 ` [PATCH v5 12/18] mm/filemap: Move the iocb checks into filemap_update_page Matthew Wilcox (Oracle)
2021-01-22 16:01 ` Matthew Wilcox (Oracle) [this message]
2021-01-22 16:01 ` [PATCH v5 14/18] mm/filemap: Split filemap_readahead out of filemap_get_pages Matthew Wilcox (Oracle)
2021-01-22 16:01 ` [PATCH v5 15/18] mm/filemap: Restructure filemap_get_pages Matthew Wilcox (Oracle)
2021-01-22 16:01 ` [PATCH v5 16/18] mm/filemap: Don't relock the page after calling readpage Matthew Wilcox (Oracle)
2021-01-22 16:01 ` [PATCH v5 17/18] mm/filemap: Rename generic_file_buffered_read to filemap_read Matthew Wilcox (Oracle)
2021-01-22 16:01 ` [PATCH v5 18/18] mm/filemap: Simplify generic_file_read_iter Matthew Wilcox (Oracle)
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