multipath: fix scsi timeout code

sysfs_attr_set_value() returns the amount written on on success, or -1 on
failure.  sysfs_setc_scsi_tmo() was checking if the return was nonzero, and
failing if it was. This meant that it always failed out silently after writing
the first value. I've changed the check, and added some error messages.  I also
made sysfs_attr_set_value return -1 for all errors.

Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>

diff --git a/libmultipath/discovery.c b/libmultipath/discovery.c
index fdcffe7..298c2d3 100644 (file)
--- a/libmultipath/discovery.c
+++ b/libmultipath/discovery.c
@@ -316,8 +316,11 @@ sysfs_set_scsi_tmo (struct multipath *mpp)
                if (mpp->dev_loss){
                        snprintf(value, 11, "%u", mpp->dev_loss);
                        if (sysfs_attr_set_value(attr_path, "dev_loss_tmo",
-                                                value, 11))
+                                                value, 11) < 0) {
+                               condlog(0, "%s failed to set %s/dev_loss_tmo",
+                                       mpp->alias, attr_path);
                                return 1;
+                       }
                }
                if (mpp->fast_io_fail){
                        if (mpp->fast_io_fail == -1)
@@ -325,8 +328,12 @@ sysfs_set_scsi_tmo (struct multipath *mpp)
                        else
                                snprintf(value, 11, "%u", mpp->fast_io_fail);
                        if (sysfs_attr_set_value(attr_path, "fast_io_fail_tmo",
-                                                value, 11))
+                                                value, 11) < 0) {
+                               condlog(0,
+                                       "%s failed to set %s/fast_io_fail_tmo", 
+                                       mpp->alias, attr_path);
                                return 1;
+                       }
                }
        }
        return 0;

diff --git a/libmultipath/sysfs.c b/libmultipath/sysfs.c
index ff63a1b..16dce4a 100644 (file)
--- a/libmultipath/sysfs.c
+++ b/libmultipath/sysfs.c
@@ -351,7 +351,7 @@ ssize_t sysfs_attr_set_value(const char *devpath, const char *attr_name,
        char path_full[PATH_SIZE];
        struct stat statbuf;
        int fd;
-       ssize_t size = 0;
+       ssize_t size = -1;
        size_t sysfs_len;
 
        if (!attr_name || !value || !value_len)