[PATCH 06/13] sysfs: simplify sysfs_kf_seq_show
From: Christoph Hellwig <hch@lst.de>
Date: 2021-09-13 05:48:35
Also in:
linux-fsdevel, linux-xfs, lkml
Subsystem:
driver core, kobjects, debugfs and sysfs, filesystems (vfs and infrastructure), the rest · Maintainers:
Greg Kroah-Hartman, "Rafael J. Wysocki", Danilo Krummrich, Alexander Viro, Christian Brauner, Linus Torvalds
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