From: Jia He <justin.he@arm.com>
To: Linus Torvalds <torvalds@linux-foundation.org>,
Petr Mladek <pmladek@suse.com>,
Steven Rostedt <rostedt@goodmis.org>,
Sergey Senozhatsky <senozhatsky@chromium.org>,
Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
Rasmus Villemoes <linux@rasmusvillemoes.dk>,
Jonathan Corbet <corbet@lwn.net>,
Alexander Viro <viro@zeniv.linux.org.uk>,
Luca Coelho <luciano.coelho@intel.com>,
Kalle Valo <kvalo@codeaurora.org>,
"David S. Miller" <davem@davemloft.net>,
Jakub Kicinski <kuba@kernel.org>,
Heiko Carstens <hca@linux.ibm.com>,
Vasily Gorbik <gor@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>,
Johannes Berg <johannes.berg@intel.com>,
linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-wireless@vger.kernel.org, netdev@vger.kernel.org,
linux-s390@vger.kernel.org, Jia He <justin.he@arm.com>
Subject: [PATCH RFCv2 1/3] fs: introduce helper d_path_fast()
Date: Fri, 28 May 2021 19:39:49 +0800 [thread overview]
Message-ID: <20210528113951.6225-2-justin.he@arm.com> (raw)
In-Reply-To: <20210528113951.6225-1-justin.he@arm.com>
This helper is similar to d_path except that it doesn't take any
seqlock/spinlock. It is typical for debugging purpose.
Signed-off-by: Jia He <justin.he@arm.com>
---
fs/d_path.c | 21 +++++++++++++++++++++
include/linux/dcache.h | 1 +
2 files changed, 22 insertions(+)
diff --git a/fs/d_path.c b/fs/d_path.c
index 23a53f7b5c71..f9df68d62786 100644
--- a/fs/d_path.c
+++ b/fs/d_path.c
@@ -263,6 +263,27 @@ char *d_path(const struct path *path, char *buf, int buflen)
}
EXPORT_SYMBOL(d_path);
+/**
+ * d_path_fast - fast return the full path of a dentry without taking
+ * any seqlock/spinlock. This helper is typical for debugging purpose
+ */
+char *d_path_fast(const struct path *path, char *buf, int buflen)
+{
+ struct path root;
+ struct mount *mnt = real_mount(path->mnt);
+ DECLARE_BUFFER(b, buf, buflen);
+
+ rcu_read_lock();
+ get_fs_root_rcu(current->fs, &root);
+
+ prepend(&b, "", 1);
+ __prepend_path(path->dentry, mnt, &root, &b);
+ rcu_read_unlock();
+
+ return extract_string(&b);
+}
+EXPORT_SYMBOL(d_path_fast);
+
/*
* Helper function for dentry_operations.d_dname() members
*/
diff --git a/include/linux/dcache.h b/include/linux/dcache.h
index 9e23d33bb6f1..c4483fc887a5 100644
--- a/include/linux/dcache.h
+++ b/include/linux/dcache.h
@@ -301,6 +301,7 @@ char *dynamic_dname(struct dentry *, char *, int, const char *, ...);
extern char *__d_path(const struct path *, const struct path *, char *, int);
extern char *d_absolute_path(const struct path *, char *, int);
extern char *d_path(const struct path *, char *, int);
+extern char *d_path_fast(const struct path *, char *, int);
extern char *dentry_path_raw(const struct dentry *, char *, int);
extern char *dentry_path(const struct dentry *, char *, int);
--
2.17.1
next prev parent reply other threads:[~2021-05-28 11:40 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-28 11:39 [PATCH RFCv2 0/3] make '%pD' print full path for file Jia He
2021-05-28 11:39 ` Jia He [this message]
2021-05-28 12:44 ` [PATCH RFCv2 1/3] fs: introduce helper d_path_fast() Al Viro
2021-05-28 12:51 ` Matthew Wilcox
2021-05-28 14:23 ` Justin He
2021-05-28 11:39 ` [PATCH RFCv2 2/3] lib/vsprintf.c: make %pD print full path for file Jia He
2021-05-28 12:59 ` Matthew Wilcox
2021-05-28 14:22 ` Justin He
2021-05-28 14:52 ` Matthew Wilcox
2021-05-28 15:09 ` Justin He
2021-05-28 15:22 ` Matthew Wilcox
2021-05-31 0:39 ` Justin He
2021-06-01 14:42 ` Justin He
2021-06-01 15:30 ` Matthew Wilcox
2021-06-01 15:36 ` Andy Shevchenko
2021-06-01 15:44 ` Matthew Wilcox
2021-06-01 15:53 ` Andy Shevchenko
2021-06-01 16:10 ` Andy Shevchenko
2021-06-01 17:05 ` Matthew Wilcox
2021-06-01 19:01 ` Rasmus Villemoes
2021-06-02 5:47 ` Justin He
2021-05-28 20:06 ` Rasmus Villemoes
2021-05-30 15:18 ` Matthew Wilcox
2021-05-31 9:40 ` Petr Mladek
2021-05-28 11:39 ` [PATCH RFCv2 3/3] s390/hmcdrv: remove the redundant directory path in debug message Jia He
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