On Wed, Jul 13, 2022 at 10:20:43AM +0200, mwilck@xxxxxxxx wrote: > From: Martin Wilck <mwilck@xxxxxxxx> > > sysfs_attr_set_value() returned 0 if not all requested bytes were written. > Change this to return the number of bytes written. Error checking is now > somewhat more involved; provide a helper macro for it. > Reviewed-by: Benjamin Marzinski <bmarzins@xxxxxxxxxx> > Signed-off-by: Martin Wilck <mwilck@xxxxxxxx> > --- > libmultipath/configure.c | 10 ++++-- > libmultipath/discovery.c | 74 +++++++++++++++++++++++++--------------- > libmultipath/sysfs.c | 6 ++-- > libmultipath/sysfs.h | 10 ++++++ > 4 files changed, 66 insertions(+), 34 deletions(-) > > diff --git a/libmultipath/configure.c b/libmultipath/configure.c > index 467bbaa..0607dba 100644 > --- a/libmultipath/configure.c > +++ b/libmultipath/configure.c > @@ -568,6 +568,7 @@ sysfs_set_max_sectors_kb(struct multipath *mpp, int is_reload) > struct pathgroup * pgp; > struct path *pp; > char buff[11]; > + ssize_t len; > int i, j, ret, err = 0; > struct udev_device *udd; > int max_sectors_kb; > @@ -600,14 +601,17 @@ sysfs_set_max_sectors_kb(struct multipath *mpp, int is_reload) > } > } > snprintf(buff, 11, "%d", max_sectors_kb); > + len = strlen(buff); > > vector_foreach_slot (mpp->pg, pgp, i) { > vector_foreach_slot(pgp->paths, pp, j) { > ret = sysfs_attr_set_value(pp->udev, > "queue/max_sectors_kb", > - buff, strlen(buff)); > - if (ret < 0) { > - condlog(1, "failed setting max_sectors_kb on %s : %s", pp->dev, strerror(-ret)); > + buff, len); > + if (ret != len) { > + log_sysfs_attr_set_value(1, ret, > + "failed setting max_sectors_kb on %s", > + pp->dev); > err = 1; > } > } > diff --git a/libmultipath/discovery.c b/libmultipath/discovery.c > index 54b1caf..ee29009 100644 > --- a/libmultipath/discovery.c > +++ b/libmultipath/discovery.c > @@ -598,13 +598,15 @@ sysfs_set_eh_deadline(struct path *pp) > len = sprintf(value, "%d", pp->eh_deadline); > > ret = sysfs_attr_set_value(hostdev, "eh_deadline", > - value, len + 1); > + value, len); > /* > * not all scsi drivers support setting eh_deadline, so failing > * is totally reasonable > */ > - if (ret <= 0) > - condlog(3, "%s: failed to set eh_deadline to %s, error %d", udev_device_get_sysname(hostdev), value, -ret); > + if (ret != len) > + log_sysfs_attr_set_value(3, ret, > + "%s: failed to set eh_deadline to %s", > + udev_device_get_sysname(hostdev), value); > > udev_device_unref(hostdev); > return (ret <= 0); > @@ -667,19 +669,22 @@ sysfs_set_rport_tmo(struct multipath *mpp, struct path *pp) > pp->fast_io_fail != MP_FAST_IO_FAIL_OFF) { > /* Check if we need to temporarily increase dev_loss_tmo */ > if ((unsigned int)pp->fast_io_fail >= tmo) { > + ssize_t len; > + > /* Increase dev_loss_tmo temporarily */ > snprintf(value, sizeof(value), "%u", > (unsigned int)pp->fast_io_fail + 1); > + len = strlen(value); > ret = sysfs_attr_set_value(rport_dev, "dev_loss_tmo", > - value, strlen(value)); > - if (ret <= 0) { > + value, len); > + if (ret != len) { > if (ret == -EBUSY) > condlog(3, "%s: rport blocked", > rport_id); > else > - condlog(0, "%s: failed to set " > - "dev_loss_tmo to %s, error %d", > - rport_id, value, -ret); > + log_sysfs_attr_set_value(0, ret, > + "%s: failed to set dev_loss_tmo to %s", > + rport_id, value); > goto out; > } > } > @@ -691,32 +696,39 @@ sysfs_set_rport_tmo(struct multipath *mpp, struct path *pp) > pp->dev_loss = DEFAULT_DEV_LOSS_TMO; > } > if (pp->fast_io_fail != MP_FAST_IO_FAIL_UNSET) { > + ssize_t len; > + > if (pp->fast_io_fail == MP_FAST_IO_FAIL_OFF) > sprintf(value, "off"); > else if (pp->fast_io_fail == MP_FAST_IO_FAIL_ZERO) > sprintf(value, "0"); > else > snprintf(value, 16, "%u", pp->fast_io_fail); > + len = strlen(value); > ret = sysfs_attr_set_value(rport_dev, "fast_io_fail_tmo", > - value, strlen(value)); > - if (ret <= 0) { > + value, len); > + if (ret != len) { > 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); > + log_sysfs_attr_set_value(0, ret, > + "%s: failed to set fast_io_fail_tmo to %s", > + rport_id, value); > } > } > if (pp->dev_loss != DEV_LOSS_TMO_UNSET) { > + ssize_t len; > + > snprintf(value, 16, "%u", pp->dev_loss); > - ret = sysfs_attr_set_value(rport_dev, "dev_loss_tmo", > - value, strlen(value)); > - if (ret <= 0) { > + len = strlen(value); > + ret = sysfs_attr_set_value(rport_dev, "dev_loss_tmo", value, len); > + if (ret != len) { > if (ret == -EBUSY) > condlog(3, "%s: rport blocked", rport_id); > else > - condlog(0, "%s: failed to set dev_loss_tmo to %s, error %d", > - rport_id, value, -ret); > + log_sysfs_attr_set_value(0, ret, > + "%s: failed to set dev_loss_tmo to %s", > + rport_id, value); > } > } > out: > @@ -754,12 +766,16 @@ sysfs_set_session_tmo(struct path *pp) > condlog(3, "%s: can't set fast_io_fail_tmo to '0'" > "on iSCSI", pp->dev); > } else { > + ssize_t len, ret; > + > snprintf(value, 11, "%u", pp->fast_io_fail); > - if (sysfs_attr_set_value(session_dev, "recovery_tmo", > - value, strlen(value)) <= 0) { > - condlog(3, "%s: Failed to set recovery_tmo, " > - " error %d", pp->dev, errno); > - } > + len = strlen(value); > + ret = sysfs_attr_set_value(session_dev, "recovery_tmo", > + value, len); > + if (ret != len) > + log_sysfs_attr_set_value(3, ret, > + "%s: Failed to set recovery_tmo to %s", > + pp->dev, value); > } > } > udev_device_unref(session_dev); > @@ -802,12 +818,16 @@ sysfs_set_nexus_loss_tmo(struct path *pp) > pp->sg_id.channel, pp->sg_id.scsi_id, end_dev_id); > > if (pp->dev_loss != DEV_LOSS_TMO_UNSET) { > + ssize_t len, ret; > + > snprintf(value, 11, "%u", pp->dev_loss); > - if (sysfs_attr_set_value(sas_dev, "I_T_nexus_loss_timeout", > - value, strlen(value)) <= 0) > - condlog(3, "%s: failed to update " > - "I_T Nexus loss timeout, error %d", > - pp->dev, errno); > + len = strlen(value); > + ret = sysfs_attr_set_value(sas_dev, "I_T_nexus_loss_timeout", > + value, len); > + if (ret != len) > + log_sysfs_attr_set_value(3, ret, > + "%s: failed to update I_T Nexus loss timeout", > + pp->dev); > } > udev_device_unref(sas_dev); > return; > diff --git a/libmultipath/sysfs.c b/libmultipath/sysfs.c > index 125f1c2..9c84af7 100644 > --- a/libmultipath/sysfs.c > +++ b/libmultipath/sysfs.c > @@ -134,7 +134,7 @@ ssize_t sysfs_attr_set_value(struct udev_device *dev, const char *attr_name, > /* write attribute value */ > fd = open(devpath, O_WRONLY); > if (fd < 0) { > - condlog(2, "%s: attribute '%s' can not be opened: %s", > + condlog(3, "%s: attribute '%s' can not be opened: %s", > __func__, devpath, strerror(errno)); > return -errno; > } > @@ -144,11 +144,9 @@ ssize_t sysfs_attr_set_value(struct udev_device *dev, const char *attr_name, > size = -errno; > condlog(3, "%s: write to %s failed: %s", __func__, > devpath, strerror(errno)); > - } else if (size < (ssize_t)value_len) { > + } else if (size < (ssize_t)value_len) > condlog(3, "%s: underflow writing %zu bytes to %s. Wrote %zd bytes", > __func__, value_len, devpath, size); > - size = 0; > - } > > close(fd); > return size; > diff --git a/libmultipath/sysfs.h b/libmultipath/sysfs.h > index cdc84e4..799f68e 100644 > --- a/libmultipath/sysfs.h > +++ b/libmultipath/sysfs.h > @@ -5,6 +5,7 @@ > #ifndef _LIBMULTIPATH_SYSFS_H > #define _LIBMULTIPATH_SYSFS_H > #include <stdbool.h> > +#include "strbuf.h" > > ssize_t sysfs_attr_set_value(struct udev_device *dev, const char *attr_name, > const char * value, size_t value_len); > @@ -25,6 +26,15 @@ ssize_t sysfs_bin_attr_get_value(struct udev_device *dev, const char *attr_name, > sysfs_attr_value_ok(__rc, __l); \ > }) > > +#define log_sysfs_attr_set_value(prio, rc, fmt, __args...) \ > +do { \ > + STRBUF_ON_STACK(__buf); \ > + if (print_strbuf(&__buf, fmt, ##__args) >= 0 && \ > + print_strbuf(&__buf, ": %s", rc < 0 ? strerror(-rc) : \ > + "write underflow") >= 0) \ > + condlog(prio, "%s", get_strbuf_str(&__buf)); \ > +} while(0) > + > int sysfs_get_size (struct path *pp, unsigned long long * size); > int sysfs_check_holders(char * check_devt, char * new_devt); > bool sysfs_is_multipathed(struct path *pp, bool set_wwid); > -- > 2.36.1 -- dm-devel mailing list dm-devel@xxxxxxxxxx https://listman.redhat.com/mailman/listinfo/dm-devel