All of lore.kernel.org
 help / color / mirror / Atom feed
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


  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

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20201031090004.452516-4-hch@lst.de \
    --to=hch@lst.de \
    --cc=akpm@linux-foundation.org \
    --cc=kent.overstreet@gmail.com \
    --cc=linux-fsdevel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=willy@infradead.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.