All of lore.kernel.org
 help / color / mirror / Atom feed
From: Joseph Qi via Ocfs2-devel <ocfs2-devel@oss.oracle.com>
To: Dan Carpenter <dan.carpenter@oracle.com>
Cc: ocfs2-devel@oss.oracle.com
Subject: [Ocfs2-devel] [PATCH] ocfs2: clearly handle ocfs2_grab_pages_for_write() return value
Date: Mon,  6 Dec 2021 14:36:42 +0800	[thread overview]
Message-ID: <20211206063642.35411-1-joseph.qi@linux.alibaba.com> (raw)

ocfs2_grab_pages_for_write() may return -EAGAIN if write context type is
mmap and it could not lock the target page. In this case, we exit with
no error and no target page. And then trigger the caller page_mkwrite()
to retry.
Since there are other caller types, e.g. buffer and direct io, so make
the return value handling more clearly.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Joseph Qi <joseph.qi@linux.alibaba.com>
---
 fs/ocfs2/aops.c | 25 +++++++++++++------------
 1 file changed, 13 insertions(+), 12 deletions(-)

diff --git a/fs/ocfs2/aops.c b/fs/ocfs2/aops.c
index 68d11c295dd3..f983f982b321 100644
--- a/fs/ocfs2/aops.c
+++ b/fs/ocfs2/aops.c
@@ -1799,22 +1799,23 @@ int ocfs2_write_begin_nolock(struct address_space *mapping,
 	 */
 	ret = ocfs2_grab_pages_for_write(mapping, wc, wc->w_cpos, pos, len,
 					 cluster_of_pages, mmap_page);
-	if (ret && ret != -EAGAIN) {
+	if (ret) {
+		/*
+		 * ocfs2_grab_pages_for_write() returns -EAGAIN if it could not lock
+		 * the target page. In this case, we exit with no error and no target
+		 * page. This will trigger the caller, page_mkwrite(), to re-try
+		 * the operation.
+		 */
+		if (type == OCFS2_WRITE_MMAP && ret == -EAGAIN) {
+			BUG_ON(wc->w_target_page);
+			ret = 0;
+			goto out_quota;
+		}
+
 		mlog_errno(ret);
 		goto out_quota;
 	}
 
-	/*
-	 * ocfs2_grab_pages_for_write() returns -EAGAIN if it could not lock
-	 * the target page. In this case, we exit with no error and no target
-	 * page. This will trigger the caller, page_mkwrite(), to re-try
-	 * the operation.
-	 */
-	if (ret == -EAGAIN) {
-		BUG_ON(wc->w_target_page);
-		ret = 0;
-		goto out_quota;
-	}
 
 	ret = ocfs2_write_cluster_by_desc(mapping, data_ac, meta_ac, wc, pos,
 					  len);
-- 
2.19.1.6.gb485710b


_______________________________________________
Ocfs2-devel mailing list
Ocfs2-devel@oss.oracle.com
https://oss.oracle.com/mailman/listinfo/ocfs2-devel

                 reply	other threads:[~2021-12-06  6:37 UTC|newest]

Thread overview: [no followups] expand[flat|nested]  mbox.gz  Atom feed

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=20211206063642.35411-1-joseph.qi@linux.alibaba.com \
    --to=ocfs2-devel@oss.oracle.com \
    --cc=dan.carpenter@oracle.com \
    --cc=joseph.qi@linux.alibaba.com \
    /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.