Linux-Fsdevel Archive on lore.kernel.org
help / color / mirror / Atom feed
From: Gabriel Krisman Bertazi <krisman@collabora.com>
To: viro@zeniv.linux.org.uk
Cc: linux-fsdevel@vger.kernel.org, jack@suse.cz, khazhy@google.com,
	Gabriel Krisman Bertazi <krisman@collabora.com>,
	kernel@collabora.com
Subject: [PATCH v3 2/3] direct-io: don't force writeback for reads beyond EOF
Date: Sat,  5 Sep 2020 01:20:22 -0400	[thread overview]
Message-ID: <20200905052023.3719585-3-krisman@collabora.com> (raw)
In-Reply-To: <20200905052023.3719585-1-krisman@collabora.com>

If a DIO read starts past EOF, the kernel won't attempt it, so we don't
need to flush dirty pages before failing the syscall.

Suggested-by: Jan Kara <jack@suse.cz>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com>
---
 fs/direct-io.c | 24 +++++++++++-------------
 1 file changed, 11 insertions(+), 13 deletions(-)

diff --git a/fs/direct-io.c b/fs/direct-io.c
index 6c11db1cec27..c17efe58f1c9 100644
--- a/fs/direct-io.c
+++ b/fs/direct-io.c
@@ -1188,19 +1188,9 @@ do_blockdev_direct_IO(struct kiocb *iocb, struct inode *inode,
 	memset(dio, 0, offsetof(struct dio, pages));
 
 	dio->flags = flags;
-	if (dio->flags & DIO_LOCKING) {
-		if (iov_iter_rw(iter) == READ) {
-			struct address_space *mapping =
-					iocb->ki_filp->f_mapping;
-
-			/* will be released by direct_io_worker */
-			inode_lock(inode);
-
-			retval = filemap_write_and_wait_range(mapping, offset,
-							      end - 1);
-			if (retval)
-				goto fail_dio;
-		}
+	if (dio->flags & DIO_LOCKING && iov_iter_rw(iter) == READ) {
+		/* will be released by direct_io_worker */
+		inode_lock(inode);
 	}
 
 	/* Once we sampled i_size check for reads beyond EOF */
@@ -1210,6 +1200,14 @@ do_blockdev_direct_IO(struct kiocb *iocb, struct inode *inode,
 		goto fail_dio;
 	}
 
+	if (dio->flags & DIO_LOCKING && iov_iter_rw(iter) == READ) {
+		struct address_space *mapping = iocb->ki_filp->f_mapping;
+
+		retval = filemap_write_and_wait_range(mapping, offset, end - 1);
+		if (retval)
+			goto fail_dio;
+	}
+
 	/*
 	 * For file extending writes updating i_size before data writeouts
 	 * complete can expose uninitialized blocks in dumb filesystems.
-- 
2.28.0


  parent reply	other threads:[~2020-09-05  5:20 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-09-05  5:20 [PATCH v3 0/3] Unaligned DIO read error path fix and clean ups Gabriel Krisman Bertazi
2020-09-05  5:20 ` [PATCH v3 1/3] direct-io: clean up error paths of do_blockdev_direct_IO Gabriel Krisman Bertazi
2020-09-07  9:32   ` Jan Kara
2020-09-05  5:20 ` Gabriel Krisman Bertazi [this message]
2020-09-05  5:20 ` [PATCH v3 3/3] direct-io: defer alignment check until after the EOF check Gabriel Krisman Bertazi
2020-09-07  9:36   ` Jan Kara

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=20200905052023.3719585-3-krisman@collabora.com \
    --to=krisman@collabora.com \
    --cc=jack@suse.cz \
    --cc=kernel@collabora.com \
    --cc=khazhy@google.com \
    --cc=linux-fsdevel@vger.kernel.org \
    --cc=viro@zeniv.linux.org.uk \
    --subject='Re: [PATCH v3 2/3] direct-io: don'\''t force writeback for reads beyond EOF' \
    /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

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).