| Message ID | 20170622145913.23714-10-mwilck@suse.com (mailing list archive) |
|---|---|
| State | Not Applicable, archived |
| Delegated to: | christophe varoqui |
| Headers | show |
On Thu, Jun 22, 2017 at 04:59:11PM +0200, Martin Wilck wrote: > Kernels 4.3 and newer (commit 1bab0de0 "dm-mpath, scsi_dh: don't > let dm detach device handlers") imply "retain_attached_hw_handler yes". > > Clarify this in the propsel code, log messages, and documentation. ACK -Ben > > Signed-off-by: Martin Wilck <mwilck@suse.com> > Reviewed-by: Hannes Reinecke <hare@suse.com> > --- > libmultipath/configure.c | 3 ++- > libmultipath/dmparser.c | 3 ++- > libmultipath/propsel.c | 7 ++++++- > libmultipath/util.c | 36 ++++++++++++++++++++++++++++++++++++ > libmultipath/util.h | 2 ++ > multipath/multipath.conf.5 | 15 +++++++++++---- > 6 files changed, 59 insertions(+), 7 deletions(-) > > diff --git a/libmultipath/configure.c b/libmultipath/configure.c > index a7f2b443..74b6f52a 100644 > --- a/libmultipath/configure.c > +++ b/libmultipath/configure.c > @@ -572,7 +572,8 @@ select_action (struct multipath * mpp, vector curmp, int force_reload) > } > > if (mpp->retain_hwhandler != RETAIN_HWHANDLER_UNDEF && > - mpp->retain_hwhandler != cmpp->retain_hwhandler) { > + mpp->retain_hwhandler != cmpp->retain_hwhandler && > + get_linux_version_code() < KERNEL_VERSION(4, 3, 0)) { > mpp->action = ACT_RELOAD; > condlog(3, "%s: set ACT_RELOAD (retain_hwhandler change)", > mpp->alias); > diff --git a/libmultipath/dmparser.c b/libmultipath/dmparser.c > index 1121c715..b647c256 100644 > --- a/libmultipath/dmparser.c > +++ b/libmultipath/dmparser.c > @@ -97,7 +97,8 @@ assemble_map (struct multipath * mp, char * params, int len) > } else if (mp->no_path_retry != NO_PATH_RETRY_UNDEF) { > add_feature(&f, no_path_retry); > } > - if (mp->retain_hwhandler == RETAIN_HWHANDLER_ON) > + if (mp->retain_hwhandler == RETAIN_HWHANDLER_ON && > + get_linux_version_code() < KERNEL_VERSION(4, 3, 0)) > add_feature(&f, retain_hwhandler); > > APPEND(p, end, "%s %s %i %i", f, mp->hwhandler, nr_priority_groups, > diff --git a/libmultipath/propsel.c b/libmultipath/propsel.c > index e885a845..d609394e 100644 > --- a/libmultipath/propsel.c > +++ b/libmultipath/propsel.c > @@ -628,7 +628,12 @@ int select_retain_hwhandler(struct config *conf, struct multipath *mp) > > if (!VERSION_GE(conf->version, minv_dm_retain)) { > mp->retain_hwhandler = RETAIN_HWHANDLER_OFF; > - origin = "(setting: WARNING, requires kernel version >= 1.5.0)"; > + origin = "(setting: WARNING, requires kernel dm-mpath version >= 1.5.0)"; > + goto out; > + } > + if (get_linux_version_code() >= KERNEL_VERSION(4, 3, 0)) { > + mp->retain_hwhandler = RETAIN_HWHANDLER_ON; > + origin = "(setting: implied in kernel >= 4.3.0)"; > goto out; > } > mp_set_ovr(retain_hwhandler); > diff --git a/libmultipath/util.c b/libmultipath/util.c > index b90cd8b0..dff2ed3c 100644 > --- a/libmultipath/util.c > +++ b/libmultipath/util.c > @@ -6,6 +6,7 @@ > #include <sys/stat.h> > #include <sys/sysmacros.h> > #include <sys/types.h> > +#include <sys/utsname.h> > #include <dirent.h> > #include <unistd.h> > #include <errno.h> > @@ -380,3 +381,38 @@ int systemd_service_enabled(const char *dev) > found = systemd_service_enabled_in(dev, "/run"); > return found; > } > + > +static int _linux_version_code; > +static pthread_once_t _lvc_initialized = PTHREAD_ONCE_INIT; > + > +/* Returns current kernel version encoded as major*65536 + minor*256 + patch, > + * so, for example, to check if the kernel is greater than 2.2.11: > + * > + * if (get_linux_version_code() > KERNEL_VERSION(2,2,11)) { <stuff> } > + * > + * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org> > + * Code copied from busybox (GPLv2 or later) > + */ > +static void > +_set_linux_version_code(void) > +{ > + struct utsname name; > + char *t; > + int i, r; > + > + uname(&name); /* never fails */ > + t = name.release; > + r = 0; > + for (i = 0; i < 3; i++) { > + t = strtok(t, "."); > + r = r * 256 + (t ? atoi(t) : 0); > + t = NULL; > + } > + _linux_version_code = r; > +} > + > +int get_linux_version_code(void) > +{ > + pthread_once(&_lvc_initialized, _set_linux_version_code); > + return _linux_version_code; > +} > diff --git a/libmultipath/util.h b/libmultipath/util.h > index b087e32e..45291be8 100644 > --- a/libmultipath/util.h > +++ b/libmultipath/util.h > @@ -15,6 +15,8 @@ char *convert_dev(char *dev, int is_path_device); > char *parse_uid_attribute_by_attrs(char *uid_attrs, char *path_dev); > void setup_thread_attr(pthread_attr_t *attr, size_t stacksize, int detached); > int systemd_service_enabled(const char *dev); > +int get_linux_version_code(void); > +#define KERNEL_VERSION(maj, min, ptc) ((((maj) * 256) + (min)) * 256 + (ptc)) > > #define safe_sprintf(var, format, args...) \ > snprintf(var, sizeof(var), format, ##args) >= sizeof(var) > diff --git a/multipath/multipath.conf.5 b/multipath/multipath.conf.5 > index b32d0383..3b4e5187 100644 > --- a/multipath/multipath.conf.5 > +++ b/multipath/multipath.conf.5 > @@ -698,15 +698,16 @@ The default is: \fB<unset>\fR > . > .TP > .B retain_attached_hw_handler > -If set to > +(Obsolete for kernels >= 4.3) If set to > .I yes > and the SCSI layer has already attached a hardware_handler to the device, > multipath will not force the device to use the hardware_handler specified by > mutipath.conf. If the SCSI layer has not attached a hardware handler, > multipath will continue to use its configured hardware handler. > .RS > -.TP > -The default is: \fByes\fR > +.PP > +The default is: \fByes\fR. Linux kernel 4.3 or newer always behaves as if > +\fB"retain_attached_hw_handler yes"\fR was set. > .RE > . > . > @@ -1182,8 +1183,14 @@ Active/Standby mode exclusively. > .I 1 alua > (Hardware-dependent) > Hardware handler for SCSI-3 ALUA compatible arrays. > -.TP > +.PP > The default is: \fB<unset>\fR > +.PP > +\fBImportant Note:\fR Linux kernels 4.3 and newer automatically attach a device > +handler to known devices (which includes all devices supporting SCSI-3 ALUA) > +and disallow changing the handler > +afterwards. Setting \fBhardware_handler\fR for such devices on these kernels > +has no effect. > .RE > . > . > -- > 2.13.1 -- dm-devel mailing list dm-devel@redhat.com https://www.redhat.com/mailman/listinfo/dm-devel
On 06/22/2017 04:59 PM, Martin Wilck wrote: > Kernels 4.3 and newer (commit 1bab0de0 "dm-mpath, scsi_dh: don't > let dm detach device handlers") imply "retain_attached_hw_handler yes". > > Clarify this in the propsel code, log messages, and documentation. > > Signed-off-by: Martin Wilck <mwilck@suse.com> > Reviewed-by: Hannes Reinecke <hare@suse.com> > --- > libmultipath/configure.c | 3 ++- > libmultipath/dmparser.c | 3 ++- > libmultipath/propsel.c | 7 ++++++- > libmultipath/util.c | 36 ++++++++++++++++++++++++++++++++++++ > libmultipath/util.h | 2 ++ > multipath/multipath.conf.5 | 15 +++++++++++---- > 6 files changed, 59 insertions(+), 7 deletions(-) [...] > --- a/libmultipath/propsel.c > +++ b/libmultipath/propsel.c > @@ -628,7 +628,12 @@ int select_retain_hwhandler(struct config *conf, struct multipath *mp) > > if (!VERSION_GE(conf->version, minv_dm_retain)) { > mp->retain_hwhandler = RETAIN_HWHANDLER_OFF; > - origin = "(setting: WARNING, requires kernel version >= 1.5.0)"; > + origin = "(setting: WARNING, requires kernel dm-mpath version >= 1.5.0)"; It would be more informative replace the dm-mpath version with the kernel version. No one cares about subsystems versions. -- dm-devel mailing list dm-devel@redhat.com https://www.redhat.com/mailman/listinfo/dm-devel
On Fri, 2017-06-23 at 19:25 +0200, Xose Vazquez Perez wrote: > On 06/22/2017 04:59 PM, Martin Wilck wrote: > > > Kernels 4.3 and newer (commit 1bab0de0 "dm-mpath, scsi_dh: don't > > let dm detach device handlers") imply "retain_attached_hw_handler > > yes". > > > > Clarify this in the propsel code, log messages, and documentation. > > > > Signed-off-by: Martin Wilck <mwilck@suse.com> > > Reviewed-by: Hannes Reinecke <hare@suse.com> > > --- > > libmultipath/configure.c | 3 ++- > > libmultipath/dmparser.c | 3 ++- > > libmultipath/propsel.c | 7 ++++++- > > libmultipath/util.c | 36 > > ++++++++++++++++++++++++++++++++++++ > > libmultipath/util.h | 2 ++ > > multipath/multipath.conf.5 | 15 +++++++++++---- > > 6 files changed, 59 insertions(+), 7 deletions(-) > > [...] > > --- a/libmultipath/propsel.c > > +++ b/libmultipath/propsel.c > > @@ -628,7 +628,12 @@ int select_retain_hwhandler(struct config > > *conf, struct multipath *mp) > > > > if (!VERSION_GE(conf->version, minv_dm_retain)) { > > mp->retain_hwhandler = RETAIN_HWHANDLER_OFF; > > - origin = "(setting: WARNING, requires kernel > > version >= 1.5.0)"; > > + origin = "(setting: WARNING, requires kernel dm- > > mpath version >= 1.5.0)"; > > It would be more informative replace the dm-mpath version with the > kernel version. No one cares about subsystems versions. I disagree. This code should also work for vendor kernels which may e.g. contain patches to update dm-mpath without updating the main kernel (utsname) version. The reason I used get_linux_version_code() for the new check my patch introduced was that unfortunately, the dm-mpath version has not been changed when the "retain_attached_hwhandler" feature was removed in 4.3. The next dm-mpath version change (to 1.10) happened in 4.4. Thus I couldn't use the dm-mpath version and had to fallback to utsname. Thinking about it, the new check should probably be (dm_mpath version >= 1.10 OR kernel verson >= 4.3). IMO that can be handled in an incremental patch. Regards, Martin
diff --git a/libmultipath/configure.c b/libmultipath/configure.c index a7f2b443..74b6f52a 100644 --- a/libmultipath/configure.c +++ b/libmultipath/configure.c @@ -572,7 +572,8 @@ select_action (struct multipath * mpp, vector curmp, int force_reload) } if (mpp->retain_hwhandler != RETAIN_HWHANDLER_UNDEF && - mpp->retain_hwhandler != cmpp->retain_hwhandler) { + mpp->retain_hwhandler != cmpp->retain_hwhandler && + get_linux_version_code() < KERNEL_VERSION(4, 3, 0)) { mpp->action = ACT_RELOAD; condlog(3, "%s: set ACT_RELOAD (retain_hwhandler change)", mpp->alias); diff --git a/libmultipath/dmparser.c b/libmultipath/dmparser.c index 1121c715..b647c256 100644 --- a/libmultipath/dmparser.c +++ b/libmultipath/dmparser.c @@ -97,7 +97,8 @@ assemble_map (struct multipath * mp, char * params, int len) } else if (mp->no_path_retry != NO_PATH_RETRY_UNDEF) { add_feature(&f, no_path_retry); } - if (mp->retain_hwhandler == RETAIN_HWHANDLER_ON) + if (mp->retain_hwhandler == RETAIN_HWHANDLER_ON && + get_linux_version_code() < KERNEL_VERSION(4, 3, 0)) add_feature(&f, retain_hwhandler); APPEND(p, end, "%s %s %i %i", f, mp->hwhandler, nr_priority_groups, diff --git a/libmultipath/propsel.c b/libmultipath/propsel.c index e885a845..d609394e 100644 --- a/libmultipath/propsel.c +++ b/libmultipath/propsel.c @@ -628,7 +628,12 @@ int select_retain_hwhandler(struct config *conf, struct multipath *mp) if (!VERSION_GE(conf->version, minv_dm_retain)) { mp->retain_hwhandler = RETAIN_HWHANDLER_OFF; - origin = "(setting: WARNING, requires kernel version >= 1.5.0)"; + origin = "(setting: WARNING, requires kernel dm-mpath version >= 1.5.0)"; + goto out; + } + if (get_linux_version_code() >= KERNEL_VERSION(4, 3, 0)) { + mp->retain_hwhandler = RETAIN_HWHANDLER_ON; + origin = "(setting: implied in kernel >= 4.3.0)"; goto out; } mp_set_ovr(retain_hwhandler); diff --git a/libmultipath/util.c b/libmultipath/util.c index b90cd8b0..dff2ed3c 100644 --- a/libmultipath/util.c +++ b/libmultipath/util.c @@ -6,6 +6,7 @@ #include <sys/stat.h> #include <sys/sysmacros.h> #include <sys/types.h> +#include <sys/utsname.h> #include <dirent.h> #include <unistd.h> #include <errno.h> @@ -380,3 +381,38 @@ int systemd_service_enabled(const char *dev) found = systemd_service_enabled_in(dev, "/run"); return found; } + +static int _linux_version_code; +static pthread_once_t _lvc_initialized = PTHREAD_ONCE_INIT; + +/* Returns current kernel version encoded as major*65536 + minor*256 + patch, + * so, for example, to check if the kernel is greater than 2.2.11: + * + * if (get_linux_version_code() > KERNEL_VERSION(2,2,11)) { <stuff> } + * + * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org> + * Code copied from busybox (GPLv2 or later) + */ +static void +_set_linux_version_code(void) +{ + struct utsname name; + char *t; + int i, r; + + uname(&name); /* never fails */ + t = name.release; + r = 0; + for (i = 0; i < 3; i++) { + t = strtok(t, "."); + r = r * 256 + (t ? atoi(t) : 0); + t = NULL; + } + _linux_version_code = r; +} + +int get_linux_version_code(void) +{ + pthread_once(&_lvc_initialized, _set_linux_version_code); + return _linux_version_code; +} diff --git a/libmultipath/util.h b/libmultipath/util.h index b087e32e..45291be8 100644 --- a/libmultipath/util.h +++ b/libmultipath/util.h @@ -15,6 +15,8 @@ char *convert_dev(char *dev, int is_path_device); char *parse_uid_attribute_by_attrs(char *uid_attrs, char *path_dev); void setup_thread_attr(pthread_attr_t *attr, size_t stacksize, int detached); int systemd_service_enabled(const char *dev); +int get_linux_version_code(void); +#define KERNEL_VERSION(maj, min, ptc) ((((maj) * 256) + (min)) * 256 + (ptc)) #define safe_sprintf(var, format, args...) \ snprintf(var, sizeof(var), format, ##args) >= sizeof(var) diff --git a/multipath/multipath.conf.5 b/multipath/multipath.conf.5 index b32d0383..3b4e5187 100644 --- a/multipath/multipath.conf.5 +++ b/multipath/multipath.conf.5 @@ -698,15 +698,16 @@ The default is: \fB<unset>\fR . .TP .B retain_attached_hw_handler -If set to +(Obsolete for kernels >= 4.3) If set to .I yes and the SCSI layer has already attached a hardware_handler to the device, multipath will not force the device to use the hardware_handler specified by mutipath.conf. If the SCSI layer has not attached a hardware handler, multipath will continue to use its configured hardware handler. .RS -.TP -The default is: \fByes\fR +.PP +The default is: \fByes\fR. Linux kernel 4.3 or newer always behaves as if +\fB"retain_attached_hw_handler yes"\fR was set. .RE . . @@ -1182,8 +1183,14 @@ Active/Standby mode exclusively. .I 1 alua (Hardware-dependent) Hardware handler for SCSI-3 ALUA compatible arrays. -.TP +.PP The default is: \fB<unset>\fR +.PP +\fBImportant Note:\fR Linux kernels 4.3 and newer automatically attach a device +handler to known devices (which includes all devices supporting SCSI-3 ALUA) +and disallow changing the handler +afterwards. Setting \fBhardware_handler\fR for such devices on these kernels +has no effect. .RE . .