From: Christoph Hellwig <hch@lst.de>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Kent Overstreet <kent.overstreet@gmail.com>,
Matthew Wilcox <willy@infradead.org>,
linux-mm@kvack.org, linux-fsdevel@vger.kernel.org
Subject: [PATCH 03/13] mm: lift the nowait checks into generic_file_buffered_read_pagenotuptodate
Date: Sat, 31 Oct 2020 09:59:54 +0100 [thread overview]
Message-ID: <20201031090004.452516-4-hch@lst.de> (raw)
In-Reply-To: <20201031090004.452516-1-hch@lst.de>
Move the checks for IOCB_NOWAIT and IOCB_WAITQ from the only caller into
generic_file_buffered_read_pagenotuptodate, which simplifies the error
unwinding.
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
mm/filemap.c | 28 +++++++++++-----------------
1 file changed, 11 insertions(+), 17 deletions(-)
diff --git a/mm/filemap.c b/mm/filemap.c
index c717cfe35cc72a..bae5b905aa7bdc 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -2219,19 +2219,22 @@ static int filemap_readpage(struct kiocb *iocb, struct page *page)
static int generic_file_buffered_read_pagenotuptodate(struct kiocb *iocb,
struct iov_iter *iter, struct page *page, loff_t pos,
- loff_t count)
+ loff_t count, bool first)
{
struct address_space *mapping = iocb->ki_filp->f_mapping;
- int error;
+ int error = -EAGAIN;
+
+ if (iocb->ki_flags & IOCB_NOWAIT)
+ goto put_page;
/*
- * See comment in do_read_cache_page on why
- * wait_on_page_locked is used to avoid unnecessarily
- * serialisations and why it's safe.
+ * See comment in do_read_cache_page on why wait_on_page_locked is used
+ * to avoid unnecessarily serialisations and why it's safe.
*/
if (iocb->ki_flags & IOCB_WAITQ) {
- error = wait_on_page_locked_async(page,
- iocb->ki_waitq);
+ if (!first)
+ goto put_page;
+ error = wait_on_page_locked_async(page, iocb->ki_waitq);
} else {
error = wait_on_page_locked_killable(page);
}
@@ -2376,17 +2379,8 @@ static int generic_file_buffered_read_get_pages(struct kiocb *iocb,
}
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;
- err = -EAGAIN;
- break;
- }
-
err = generic_file_buffered_read_pagenotuptodate(iocb,
- iter, page, pg_pos, pg_count);
+ iter, page, pg_pos, pg_count, i == 0);
if (err) {
if (err == AOP_TRUNCATED_PAGE)
err = 0;
--
2.28.0
next prev parent reply other threads:[~2020-10-31 9:08 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-31 8:59 clean up the generic pagecache read helpers Christoph Hellwig
2020-10-31 8:59 ` [PATCH 01/13] mm: simplify generic_file_buffered_read_readpage Christoph Hellwig
2020-10-31 8:59 ` [PATCH 02/13] mm: simplify generic_file_buffered_read_pagenotuptodate Christoph Hellwig
2020-10-31 8:59 ` Christoph Hellwig [this message]
2020-10-31 8:59 ` [PATCH 04/13] mm: handle readahead in generic_file_buffered_read_pagenotuptodate Christoph Hellwig
2020-10-31 17:06 ` Matthew Wilcox
2020-11-01 10:31 ` Christoph Hellwig
2020-11-01 10:49 ` Matthew Wilcox
2020-11-01 10:51 ` Christoph Hellwig
2020-11-01 10:51 ` Christoph Hellwig
2020-11-01 11:04 ` Matthew Wilcox
2020-11-01 11:52 ` Christoph Hellwig
2020-11-01 14:55 ` Matthew Wilcox
2020-11-02 8:18 ` Christoph Hellwig
2020-10-31 8:59 ` [PATCH 05/13] mm: simplify generic_file_buffered_read_no_cached_page Christoph Hellwig
2020-10-31 16:20 ` Matthew Wilcox
2020-10-31 16:28 ` Matthew Wilcox
2020-11-01 10:29 ` Christoph Hellwig
2020-10-31 8:59 ` [PATCH 06/13] mm: factor out a filemap_find_get_pages helper Christoph Hellwig
2020-10-31 8:59 ` [PATCH 07/13] mm: refactor generic_file_buffered_read_get_pages Christoph Hellwig
2020-11-01 11:18 ` Matthew Wilcox
2020-10-31 8:59 ` [PATCH 08/13] mm: move putting the page on error out of filemap_readpage Christoph Hellwig
2020-10-31 9:00 ` [PATCH 09/13] mm: move putting the page on error out of filemap_make_page_uptodate Christoph Hellwig
2020-10-31 9:00 ` [PATCH 10/13] mm: open code readahead in filemap_new_page Christoph Hellwig
2020-11-01 11:20 ` Matthew Wilcox
2020-10-31 9:00 ` [PATCH 11/13] mm: streamline the partially uptodate checks in filemap_make_page_uptodate Christoph Hellwig
2020-11-01 11:23 ` Matthew Wilcox
2020-10-31 9:00 ` [PATCH 12/13] mm: rename generic_file_buffered_read to filemap_read Christoph Hellwig
2020-10-31 9:00 ` [PATCH 13/13] mm: simplify generic_file_read_iter Christoph Hellwig
2020-10-31 15:42 ` clean up the generic pagecache read helpers Matthew Wilcox
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