From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from g2t2354.austin.hpe.com (g2t2354.austin.hpe.com [15.233.44.27]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id 1F7C021A143F1 for ; Fri, 9 Jun 2017 13:08:52 -0700 (PDT) Subject: Re: [ndctl PATCH] util: distinguish error codes for sysfs_{read, write}_attr() References: <149698606405.12023.3409783083697026090.stgit@dwillia2-desk3.amr.corp.intel.com> From: Linda Knippers Message-ID: <593B008C.60502@hpe.com> Date: Fri, 9 Jun 2017 16:09:48 -0400 MIME-Version: 1.0 In-Reply-To: <149698606405.12023.3409783083697026090.stgit@dwillia2-desk3.amr.corp.intel.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: linux-nvdimm-bounces@lists.01.org Sender: "Linux-nvdimm" To: Dan Williams , linux-nvdimm@lists.01.org List-ID: On 06/09/2017 01:27 AM, Dan Williams wrote: > There are occasions where it would be good to know the difference > between a sysfs attribute failing to be accessed because we could not > open versus could not read/write. I think it would be really helpful if you returned the actual errno value rather than something hard coded. The most common reason for not being able to write something is that it requires running as root, in which case you should get an EPERM. I think an accurate errno will help users figure out what's gone wrong. -- ljk > > Signed-off-by: Dan Williams > --- > util/sysfs.c | 8 ++++---- > 1 file changed, 4 insertions(+), 4 deletions(-) > > diff --git a/util/sysfs.c b/util/sysfs.c > index 31d1a898eba2..7905455890dc 100644 > --- a/util/sysfs.c > +++ b/util/sysfs.c > @@ -34,13 +34,13 @@ int __sysfs_read_attr(struct log_ctx *ctx, const char *path, char *buf) > > if (fd < 0) { > log_dbg(ctx, "failed to open %s: %s\n", path, strerror(errno)); > - return -1; > + return -ENOENT; > } > n = read(fd, buf, SYSFS_ATTR_SIZE); > close(fd); > if (n < 0 || n >= SYSFS_ATTR_SIZE) { > log_dbg(ctx, "failed to read %s: %s\n", path, strerror(errno)); > - return -1; > + return -EIO; > } > buf[n] = 0; > if (n && buf[n-1] == '\n') > @@ -56,7 +56,7 @@ static int write_attr(struct log_ctx *ctx, const char *path, > > if (fd < 0) { > log_dbg(ctx, "failed to open %s: %s\n", path, strerror(errno)); > - return -1; > + return -ENOENT; > } > n = write(fd, buf, len); > close(fd); > @@ -64,7 +64,7 @@ static int write_attr(struct log_ctx *ctx, const char *path, > if (!quiet) > log_dbg(ctx, "failed to write %s to %s: %s\n", buf, path, > strerror(errno)); > - return -1; > + return -EIO; > } > return 0; > } > > _______________________________________________ > Linux-nvdimm mailing list > Linux-nvdimm@lists.01.org > https://lists.01.org/mailman/listinfo/linux-nvdimm > _______________________________________________ Linux-nvdimm mailing list Linux-nvdimm@lists.01.org https://lists.01.org/mailman/listinfo/linux-nvdimm