From: Christoph Hellwig <hch@lst.de>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
"Rafael J. Wysocki" <rafael@kernel.org>,
Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Jens Axboe <axboe@kernel.dk>, Tejun Heo <tj@kernel.org>,
linux-block@vger.kernel.org, linux-xfs@vger.kernel.org,
linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH 06/13] sysfs: simplify sysfs_kf_seq_show
Date: Mon, 13 Sep 2021 07:41:14 +0200 [thread overview]
Message-ID: <20210913054121.616001-7-hch@lst.de> (raw)
In-Reply-To: <20210913054121.616001-1-hch@lst.de>
Contrary to the comment ->show is never called from lseek for sysfs,
given that sysfs does not use seq_lseek. So remove the NULL ->show
case and just WARN and return an error if some future code path ends
up here.
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
fs/sysfs/file.c | 15 ++++++---------
1 file changed, 6 insertions(+), 9 deletions(-)
diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c
index 74a2a8021c8bb..42dcf96881b68 100644
--- a/fs/sysfs/file.c
+++ b/fs/sysfs/file.c
@@ -45,6 +45,9 @@ static int sysfs_kf_seq_show(struct seq_file *sf, void *v)
ssize_t count;
char *buf;
+ if (WARN_ON_ONCE(!ops->show))
+ return -EINVAL;
+
/* acquire buffer and ensure that it's >= PAGE_SIZE and clear */
count = seq_get_buf(sf, &buf);
if (count < PAGE_SIZE) {
@@ -53,15 +56,9 @@ static int sysfs_kf_seq_show(struct seq_file *sf, void *v)
}
memset(buf, 0, PAGE_SIZE);
- /*
- * Invoke show(). Control may reach here via seq file lseek even
- * if @ops->show() isn't implemented.
- */
- if (ops->show) {
- count = ops->show(kobj, of->kn->priv, buf);
- if (count < 0)
- return count;
- }
+ count = ops->show(kobj, of->kn->priv, buf);
+ if (count < 0)
+ return count;
/*
* The code works fine with PAGE_SIZE return but it's likely to
--
2.30.2
next prev parent reply other threads:[~2021-09-13 5:48 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-13 5:41 start switching sysfs attributes to expose the seq_file Christoph Hellwig
2021-09-13 5:41 ` [PATCH 01/13] seq_file: mark seq_get_buf as deprecated Christoph Hellwig
2021-09-13 13:19 ` Christian Brauner
2021-09-13 16:22 ` Daniel Wagner
2021-09-13 16:29 ` Tejun Heo
2021-09-13 5:41 ` [PATCH 02/13] kernfs: remove kernfs_create_file and kernfs_create_file_ns Christoph Hellwig
2021-09-13 13:20 ` Christian Brauner
2021-09-13 5:41 ` [PATCH 03/13] kernfs: remove the unused lockdep_key field in struct kernfs_ops Christoph Hellwig
2021-09-13 13:21 ` Christian Brauner
2021-09-13 16:30 ` Tejun Heo
2021-09-13 5:41 ` [PATCH 04/13] sysfs: split out binary attribute handling from sysfs_add_file_mode_ns Christoph Hellwig
2021-09-13 13:26 ` Christian Brauner
2021-09-13 5:41 ` [PATCH 05/13] sysfs: refactor sysfs_add_file_mode_ns Christoph Hellwig
2021-09-13 13:27 ` Christian Brauner
2021-09-13 5:41 ` Christoph Hellwig [this message]
2021-09-13 5:41 ` [PATCH 07/13] sysfs: add ->seq_show support to sysfs_ops Christoph Hellwig
2021-09-13 13:30 ` Christian Brauner
2021-09-13 5:41 ` [PATCH 08/13] block: convert the blk_mq_hw_ctx attrs to use ->seq_show Christoph Hellwig
2021-09-13 5:41 ` [PATCH 09/13] block: convert the blk_integrity " Christoph Hellwig
2021-09-13 5:41 ` [PATCH 10/13] block: convert the request_queue " Christoph Hellwig
2021-09-13 5:41 ` [PATCH 11/13] block: convert the elevator_queue " Christoph Hellwig
2021-09-13 5:41 ` [PATCH 12/13] xfs: convert xfs_errortag " Christoph Hellwig
2021-09-13 5:41 ` [PATCH 13/13] xfs: convert xfs_sysfs " Christoph Hellwig
2021-09-13 6:27 ` Greg Kroah-Hartman
2021-09-14 1:20 ` Dave Chinner
2021-09-14 5:12 ` Greg Kroah-Hartman
2021-09-14 10:56 ` Dave Chinner
2021-09-14 7:30 ` Christoph Hellwig
2021-09-14 15:28 ` Greg Kroah-Hartman
2021-09-14 15:30 ` Christoph Hellwig
2021-09-14 15:41 ` Greg Kroah-Hartman
2021-09-15 7:04 ` Christoph Hellwig
2021-09-15 7:07 ` Greg Kroah-Hartman
2021-09-13 16:39 ` start switching sysfs attributes to expose the seq_file Bart Van Assche
2021-09-13 16:46 ` Greg Kroah-Hartman
2021-09-14 2:53 ` Bart Van Assche
2021-09-13 16:46 ` Tejun Heo
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