[ndctl,v2] util: distinguish error codes for sysfs_{read, write}_attr()

Commit Message

Dan Williams June 9, 2017, 9:04 p.m. UTC

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.

Cc: Linda Knippers <[e-mail]>
[ljk: just return the errno directly]
Signed-off-by: Dan Williams <[e-mail]>
---
 util/sysfs.c |    8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

Patch

diff --git a/util/sysfs.c b/util/sysfs.c
index 31d1a898eba2..4178aeced087 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 -errno;
 	}
 	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 -errno;
 	}
 	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 -errno;
 	}
 	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 -errno;
 	}
 	return 0;
 }