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From: Vasily Averin <vvs@virtuozzo.com>
To: linux-kernel@vger.kernel.org
Cc: NeilBrown <neilb@suse.com>
Subject: [PATCH] seq_read: info message about buggy .next functions
Date: Fri, 24 Jan 2020 10:47:13 +0300	[thread overview]
Message-ID: <7c24087c-e280-e580-5b0c-0cdaeb14cd18@virtuozzo.com> (raw)
In-Reply-To: <244674e5-760c-86bd-d08a-047042881748@virtuozzo.com>

It helps to detect missed or out-of-tree incorect .next seq_file functions

https://bugzilla.kernel.org/show_bug.cgi?id=206283
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
---
 fs/seq_file.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/fs/seq_file.c b/fs/seq_file.c
index 1600034..07c6909 100644
--- a/fs/seq_file.c
+++ b/fs/seq_file.c
@@ -256,9 +256,12 @@ ssize_t seq_read(struct file *file, char __user *buf, size_t size, loff_t *ppos)
 		loff_t pos = m->index;
 
 		p = m->op->next(m, p, &m->index);
-		if (pos == m->index)
-			/* Buggy ->next function */
+		if (pos == m->index) {
+			pr_info("buggy seq_file .next function %ps "
+				"did not updated position index\n",
+				m->op->next);
 			m->index++;
+		}
 		if (!p || IS_ERR(p)) {
 			err = PTR_ERR(p);
 			break;
-- 
1.8.3.1


  reply	other threads:[~2020-01-24  7:47 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-01-24  7:02 [PATCH 0/7] seq_file .next functions should increase position index Vasily Averin
2020-01-24  7:47 ` Vasily Averin [this message]
2020-01-24 15:50 ` Steven Rostedt
2020-01-25  8:27   ` Vasily Averin

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