From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx173.postini.com [74.125.245.173]) by kanga.kvack.org (Postfix) with SMTP id 27C726B0033 for ; Thu, 9 May 2013 15:24:31 -0400 (EDT) Received: from /spool/local by e9.ny.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Thu, 9 May 2013 15:24:30 -0400 Received: from d01relay06.pok.ibm.com (d01relay06.pok.ibm.com [9.56.227.116]) by d01dlp02.pok.ibm.com (Postfix) with ESMTP id C183F6E8047 for ; Thu, 9 May 2013 15:24:23 -0400 (EDT) Received: from d03av04.boulder.ibm.com (d03av04.boulder.ibm.com [9.17.195.170]) by d01relay06.pok.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id r49JOQTU41353348 for ; Thu, 9 May 2013 15:24:26 -0400 Received: from d03av04.boulder.ibm.com (loopback [127.0.0.1]) by d03av04.boulder.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id r49JOMZr010412 for ; Thu, 9 May 2013 13:24:25 -0600 Date: Thu, 9 May 2013 14:24:20 -0500 From: Seth Jennings Subject: Re: [PATCHv10 1/4] debugfs: add get/set for atomic types Message-ID: <20130509192420.GA13705@medulla> References: <1368052661-27143-1-git-send-email-sjenning@linux.vnet.ibm.com> <1368052661-27143-2-git-send-email-sjenning@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: owner-linux-mm@kvack.org List-ID: To: Greg Thelen Cc: Andrew Morton , Greg Kroah-Hartman , Nitin Gupta , Minchan Kim , Konrad Rzeszutek Wilk , Dan Magenheimer , Robert Jennings , Jenifer Hopper , Mel Gorman , Johannes Weiner , Rik van Riel , Larry Woodman , Benjamin Herrenschmidt , Dave Hansen , Joe Perches , Joonsoo Kim , Cody P Schafer , Hugh Dickens , Paul Mackerras , Heesub Shin , linux-mm@kvack.org, linux-kernel@vger.kernel.org, devel@driverdev.osuosl.org On Thu, May 09, 2013 at 11:58:49AM -0700, Greg Thelen wrote: > On Wed, May 08 2013, Seth Jennings wrote: > > > debugfs currently lack the ability to create attributes > > that set/get atomic_t values. > > > > This patch adds support for this through a new > > debugfs_create_atomic_t() function. > > > > Signed-off-by: Seth Jennings > > Acked-by: Greg Kroah-Hartman > > Acked-by: Mel Gorman > > --- > > fs/debugfs/file.c | 42 ++++++++++++++++++++++++++++++++++++++++++ > > include/linux/debugfs.h | 2 ++ > > 2 files changed, 44 insertions(+) > > > > diff --git a/fs/debugfs/file.c b/fs/debugfs/file.c > > index c5ca6ae..fa26d5b 100644 > > --- a/fs/debugfs/file.c > > +++ b/fs/debugfs/file.c > > @@ -21,6 +21,7 @@ > > #include > > #include > > #include > > +#include > > > > static ssize_t default_read_file(struct file *file, char __user *buf, > > size_t count, loff_t *ppos) > > @@ -403,6 +404,47 @@ struct dentry *debugfs_create_size_t(const char *name, umode_t mode, > > } > > EXPORT_SYMBOL_GPL(debugfs_create_size_t); > > > > +static int debugfs_atomic_t_set(void *data, u64 val) > > +{ > > + atomic_set((atomic_t *)data, val); > > + return 0; > > +} > > +static int debugfs_atomic_t_get(void *data, u64 *val) > > +{ > > + *val = atomic_read((atomic_t *)data); > > + return 0; > > +} > > +DEFINE_SIMPLE_ATTRIBUTE(fops_atomic_t, debugfs_atomic_t_get, > > + debugfs_atomic_t_set, "%llu\n"); > > +DEFINE_SIMPLE_ATTRIBUTE(fops_atomic_t_ro, debugfs_atomic_t_get, NULL, "%llu\n"); > > +DEFINE_SIMPLE_ATTRIBUTE(fops_atomic_t_wo, NULL, debugfs_atomic_t_set, "%llu\n"); > > + > > +/** > > + * debugfs_create_atomic_t - create a debugfs file that is used to read and > > + * write an atomic_t value > > + * @name: a pointer to a string containing the name of the file to create. > > + * @mode: the permission that the file should have > > + * @parent: a pointer to the parent dentry for this file. This should be a > > + * directory dentry if set. If this parameter is %NULL, then the > > + * file will be created in the root of the debugfs filesystem. > > + * @value: a pointer to the variable that the file should read to and write > > + * from. > > + */ > > +struct dentry *debugfs_create_atomic_t(const char *name, umode_t mode, > > + struct dentry *parent, atomic_t *value) > > +{ > > + /* if there are no write bits set, make read only */ > > + if (!(mode & S_IWUGO)) > > + return debugfs_create_file(name, mode, parent, value, > > + &fops_atomic_t_ro); > > + /* if there are no read bits set, make write only */ > > + if (!(mode & S_IRUGO)) > > + return debugfs_create_file(name, mode, parent, value, > > + &fops_atomic_t_wo); > > + > > + return debugfs_create_file(name, mode, parent, value, &fops_atomic_t); > > +} > > +EXPORT_SYMBOL_GPL(debugfs_create_atomic_t); > > > > static ssize_t read_file_bool(struct file *file, char __user *user_buf, > > size_t count, loff_t *ppos) > > diff --git a/include/linux/debugfs.h b/include/linux/debugfs.h > > index 63f2465..d68b4ea 100644 > > --- a/include/linux/debugfs.h > > +++ b/include/linux/debugfs.h > > @@ -79,6 +79,8 @@ struct dentry *debugfs_create_x64(const char *name, umode_t mode, > > struct dentry *parent, u64 *value); > > struct dentry *debugfs_create_size_t(const char *name, umode_t mode, > > struct dentry *parent, size_t *value); > > +struct dentry *debugfs_create_atomic_t(const char *name, umode_t mode, > > + struct dentry *parent, atomic_t *value); > > struct dentry *debugfs_create_bool(const char *name, umode_t mode, > > struct dentry *parent, u32 *value); > > Looking at v3.9 I see a conflicting definition of > debugfs_create_atomic_t() in lib/fault-inject.c. A kernel with this > patch and CONFIG_FAULT_INJECTION=y and CONFIG_FAULT_INJECTION_DEBUG_FS=y > will not build: > > lib/fault-inject.c:196:23: error: static declaration of 'debugfs_create_atomic_t' follows non-static declaration > include/linux/debugfs.h:87:16: note: previous declaration of 'debugfs_create_atomic_t' was here > Wow... didn't think to look for debugfs functions _outside_ the debugfs code :-/ Great find though, thanks Greg! Seth -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org