From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pa0-x22e.google.com ([2607:f8b0:400e:c03::22e]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1Ybf0M-0007Mv-MG for linux-mtd@lists.infradead.org; Sat, 28 Mar 2015 00:53:39 +0000 Received: by pacwe9 with SMTP id we9so110365529pac.1 for ; Fri, 27 Mar 2015 17:53:16 -0700 (PDT) Date: Fri, 27 Mar 2015 17:53:13 -0700 From: Brian Norris To: Dan Ehrenberg Subject: Re: [PATCH v3 2/3] mtd: part: Add sysfs variable for offset of partition Message-ID: <20150328005313.GB32500@ld-irv-0074> References: <1427484257-13708-1-git-send-email-dehrenberg@chromium.org> <1427484257-13708-3-git-send-email-dehrenberg@chromium.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1427484257-13708-3-git-send-email-dehrenberg@chromium.org> Cc: Richard Weinberger , gwendal@chromium.org, linux-mtd@lists.infradead.org, ezequiel@vanguardiasur.com.ar List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Fri, Mar 27, 2015 at 12:24:16PM -0700, Dan Ehrenberg wrote: > This patch makes a sysfs variable called 'offset' on each partition > which contains the offset in bytes from the beginning of the master > device that the partition starts. > > Signed-off-by: Dan Ehrenberg > --- > drivers/mtd/mtdpart.c | 29 +++++++++++++++++++++++++++++ > 1 file changed, 29 insertions(+) > > diff --git a/drivers/mtd/mtdpart.c b/drivers/mtd/mtdpart.c > index a19ec5a..b8ed202 100644 > --- a/drivers/mtd/mtdpart.c > +++ b/drivers/mtd/mtdpart.c > @@ -554,6 +554,30 @@ out_register: > return slave; > } > > +static ssize_t mtd_partition_offset_show(struct device *dev, > + struct device_attribute *attr, char *buf) > +{ > + struct mtd_info *mtd = dev_get_drvdata(dev); > + struct mtd_part *part = PART(mtd); > + return snprintf(buf, PAGE_SIZE, "%lld\n", part->offset); > +} > + > +static DEVICE_ATTR(offset, S_IRUGO, mtd_partition_offset_show, NULL); You'll want #include , just to be explicit. And if you're adding to the sysfs ABI, please update Documentation/ABI/testing/sysfs-class-mtd > + > +const static struct attribute *mtd_partition_attrs[] = { gcc complains: drivers/mtd/mtdpart.c:568:1: warning: 'static' is not at beginning of declaration [-Wold-style-declaration] > + &dev_attr_offset.attr, > + NULL > +}; > + > +int mtd_add_partition_attrs(struct mtd_part *new) gcc and sprase complain: drivers/mtd/mtdpart.c:573:5: warning: no previous prototype for 'mtd_add_partition_attrs' [-Wmissing-prototypes] drivers/mtd/mtdpart.c:573:5: warning: symbol 'mtd_add_partition_attrs' was not declared. Should it be static? [sparse] > +{ > + int ret = sysfs_create_files(&new->mtd.dev.kobj, mtd_partition_attrs); > + if (ret) > + printk(KERN_WARNING > + "mtd: failed to create partition attrs, err=%d\n", ret); > + return ret; > +} > + > int mtd_add_partition(struct mtd_info *master, const char *name, > long long offset, long long length) > { > @@ -603,6 +627,8 @@ int mtd_add_partition(struct mtd_info *master, const char *name, > > add_mtd_device(&new->mtd); > > + mtd_add_partition_attrs(new); Hmm, so you're adding the partition attribute only to dynamically created partitions? I think we'll want it for all partitions. I know the naming isn't completely straightforward, but some partitions are added through add_mtd_device(), without calling mtd_add_partition(). > + > return ret; > err_inv: > mutex_unlock(&mtd_partitions_mutex); > @@ -620,6 +646,8 @@ int mtd_del_partition(struct mtd_info *master, int partno) > list_for_each_entry_safe(slave, next, &mtd_partitions, list) > if ((slave->master == master) && > (slave->mtd.index == partno)) { > + sysfs_remove_files(&slave->mtd.dev.kobj, > + mtd_partition_attrs); > ret = del_mtd_device(&slave->mtd); > if (ret < 0) > break; > @@ -663,6 +691,7 @@ int add_mtd_partitions(struct mtd_info *master, > mutex_unlock(&mtd_partitions_mutex); > > add_mtd_device(&slave->mtd); > + mtd_add_partition_attrs(slave); > > cur_offset = slave->offset + slave->mtd.size; > } Brian