The current code to set fast_io_fail_tmo and dev_loss_tmo fails
if you want to set fast_io_fail_tmo from "off" to 600. Also,
it often unnecessarily sets dev_loss_tmo to itself before setting
it to the final value. This patch cleans up these issues.
Signed-off-by: Benjamin Marzinski <bmarzins@xxxxxxxxxx>
---
libmultipath/discovery.c | 79 ++++++++++++++++++++++++-----------------------
1 file changed, 42 insertions(+), 37 deletions(-)
Index: multipath-tools-130724/libmultipath/discovery.c
===================================================================
--- multipath-tools-130724.orig/libmultipath/discovery.c
+++ multipath-tools-130724/libmultipath/discovery.c
@@ -322,9 +322,12 @@ sysfs_set_rport_tmo(struct multipath *mp
struct udev_device *rport_dev = NULL;
char value[16];
char rport_id[32];
- unsigned long long tmo = 0;
+ int delay_fast_io_fail = 0;
+ int current_dev_loss = 0;
int ret;
+ if (!mpp->dev_loss && mpp->fast_io_fail == MP_FAST_IO_FAIL_UNSET)
+ return;
sprintf(rport_id, "rport-%d:%d-%d",
pp->sg_id.host_no, pp->sg_id.channel, pp->sg_id.transport_id);
rport_dev = udev_device_new_from_subsystem_sysname(conf->udev,
@@ -337,22 +340,8 @@ sysfs_set_rport_tmo(struct multipath *mp
condlog(4, "target%d:%d:%d -> %s", pp->sg_id.host_no,
pp->sg_id.channel, pp->sg_id.scsi_id, rport_id);
- /*
- * This is tricky.
- * dev_loss_tmo will be limited to 600 if fast_io_fail
- * is _not_ set.
- * fast_io_fail will be limited by the current dev_loss_tmo
- * setting.
- * So to get everything right we first need to increase
- * dev_loss_tmo to the fast_io_fail setting (if present),
- * then set fast_io_fail, and _then_ set dev_loss_tmo
- * to the correct value.
- */
memset(value, 0, 16);
- if (mpp->fast_io_fail != MP_FAST_IO_FAIL_UNSET &&
- mpp->fast_io_fail != MP_FAST_IO_FAIL_ZERO &&
- mpp->fast_io_fail != MP_FAST_IO_FAIL_OFF) {
- /* Check if we need to temporarily increase dev_loss_tmo */
+ if (mpp->fast_io_fail != MP_FAST_IO_FAIL_UNSET) {
ret = sysfs_attr_get_value(rport_dev, "dev_loss_tmo",
value, 16);
if (ret <= 0) {
@@ -360,38 +349,40 @@ sysfs_set_rport_tmo(struct multipath *mp
"error %d", rport_id, -ret);
goto out;
}
- if (sscanf(value, "%llu\n", &tmo) != 1) {
+ if (sscanf(value, "%u\n", ¤t_dev_loss) != 1) {
condlog(0, "%s: Cannot parse dev_loss_tmo "
"attribute '%s'", rport_id, value);
goto out;
}
- if (mpp->fast_io_fail >= tmo) {
- snprintf(value, 16, "%u", mpp->fast_io_fail + 1);
- }
- } else if (mpp->dev_loss > 600) {
- condlog(3, "%s: limiting dev_loss_tmo to 600, since "
- "fast_io_fail is not set", rport_id);
- snprintf(value, 16, "%u", 600);
- } else {
- snprintf(value, 16, "%u", mpp->dev_loss);
- }
- if (strlen(value)) {
- ret = sysfs_attr_set_value(rport_dev, "dev_loss_tmo",
- value, strlen(value));
- if (ret <= 0) {
- if (ret == -EBUSY)
- condlog(3, "%s: rport blocked", rport_id);
+ if ((mpp->dev_loss &&
+ mpp->fast_io_fail >= (int)mpp->dev_loss) ||
+ (!mpp->dev_loss &&
+ mpp->fast_io_fail >= (int)current_dev_loss)) {
+ condlog(3, "%s: limiting fast_io_fail_tmo to %d, since "
+ "it must be less than dev_loss_tmo",
+ rport_id, mpp->dev_loss - 1);
+ if (mpp->dev_loss)
+ mpp->fast_io_fail = mpp->dev_loss - 1;
else
- condlog(0, "%s: failed to set dev_loss_tmo to %s, error %d",
- rport_id, value, -ret);
- goto out;
+ mpp->fast_io_fail = current_dev_loss - 1;
}
+ if (mpp->fast_io_fail >= (int)current_dev_loss)
+ delay_fast_io_fail = 1;
+ }
+ if (mpp->dev_loss > 600 &&
+ (mpp->fast_io_fail == MP_FAST_IO_FAIL_OFF ||
+ mpp->fast_io_fail == MP_FAST_IO_FAIL_UNSET)) {
+ condlog(3, "%s: limiting dev_loss_tmo to 600, since "
+ "fast_io_fail is unset or off", rport_id);
+ mpp->dev_loss = 600;
}
if (mpp->fast_io_fail != MP_FAST_IO_FAIL_UNSET) {
if (mpp->fast_io_fail == MP_FAST_IO_FAIL_OFF)
sprintf(value, "off");
else if (mpp->fast_io_fail == MP_FAST_IO_FAIL_ZERO)
sprintf(value, "0");
+ else if (delay_fast_io_fail)
+ snprintf(value, 16, "%u", current_dev_loss - 1);
else
snprintf(value, 16, "%u", mpp->fast_io_fail);
ret = sysfs_attr_set_value(rport_dev, "fast_io_fail_tmo",
@@ -402,9 +393,10 @@ sysfs_set_rport_tmo(struct multipath *mp
else
condlog(0, "%s: failed to set fast_io_fail_tmo to %s, error %d",
rport_id, value, -ret);
+ goto out;
}
}
- if (tmo > 0) {
+ if (mpp->dev_loss) {
snprintf(value, 16, "%u", mpp->dev_loss);
ret = sysfs_attr_set_value(rport_dev, "dev_loss_tmo",
value, strlen(value));
@@ -414,6 +406,19 @@ sysfs_set_rport_tmo(struct multipath *mp
else
condlog(0, "%s: failed to set dev_loss_tmo to %s, error %d",
rport_id, value, -ret);
+ goto out;
+ }
+ }
+ if (delay_fast_io_fail) {
+ snprintf(value, 16, "%u", mpp->fast_io_fail);
+ ret = sysfs_attr_set_value(rport_dev, "fast_io_fail_tmo",
+ value, strlen(value));
+ if (ret <= 0) {
+ if (ret == -EBUSY)
+ condlog(3, "%s: rport blocked", rport_id);
+ else
+ condlog(0, "%s: failed to set fast_io_fail_tmo to %s, error %d",
+ rport_id, value, -ret);
}
}
out:
--
dm-devel mailing list
dm-devel@xxxxxxxxxx
https://www.redhat.com/mailman/listinfo/dm-devel
