From patchwork Wed Oct 31 10:59:38 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Martin Wilck X-Patchwork-Id: 10662481 X-Patchwork-Delegate: christophe.varoqui@free.fr Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id AE49E14DE for ; Wed, 31 Oct 2018 11:07:48 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 938B32A166 for ; Wed, 31 Oct 2018 11:07:48 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 850B52A194; Wed, 31 Oct 2018 11:07:48 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id E195B2A166 for ; Wed, 31 Oct 2018 11:07:47 +0000 (UTC) Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 59685307CDC2; Wed, 31 Oct 2018 11:07:45 +0000 (UTC) Received: from colo-mx.corp.redhat.com (colo-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.20]) by smtp.corp.redhat.com (Postfix) with ESMTPS id AC81460F87; Wed, 31 Oct 2018 11:07:44 +0000 (UTC) Received: from lists01.pubmisc.prod.ext.phx2.redhat.com (lists01.pubmisc.prod.ext.phx2.redhat.com [10.5.19.33]) by colo-mx.corp.redhat.com (Postfix) with ESMTP id 3F31018005B2; Wed, 31 Oct 2018 11:07:42 +0000 (UTC) Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) by lists01.pubmisc.prod.ext.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id w9VB0hYg031245 for ; Wed, 31 Oct 2018 07:00:43 -0400 Received: by smtp.corp.redhat.com (Postfix) id 6D79B17ABA; Wed, 31 Oct 2018 11:00:43 +0000 (UTC) Delivered-To: dm-devel@redhat.com Received: from mx1.redhat.com (ext-mx17.extmail.prod.ext.phx2.redhat.com [10.5.110.46]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 56491611AB; Wed, 31 Oct 2018 11:00:43 +0000 (UTC) Received: from smtp2.provo.novell.com (smtp2.provo.novell.com [137.65.250.81]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 7EA413082DD4; Wed, 31 Oct 2018 11:00:40 +0000 (UTC) Received: from apollon.suse.de.de (prv-ext-foundry1int.gns.novell.com [137.65.251.240]) by smtp2.provo.novell.com with ESMTP (TLS encrypted); Wed, 31 Oct 2018 05:00:33 -0600 From: Martin Wilck To: Christophe Varoqui Date: Wed, 31 Oct 2018 11:59:38 +0100 Message-Id: <20181031105939.22202-2-mwilck@suse.com> In-Reply-To: <20181031105939.22202-1-mwilck@suse.com> References: <20181031105939.22202-1-mwilck@suse.com> MIME-Version: 1.0 X-Greylist: Sender passed SPF test, Sender IP whitelisted by DNSRBL, ACL 216 matched, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.46]); Wed, 31 Oct 2018 11:00:41 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.46]); Wed, 31 Oct 2018 11:00:41 +0000 (UTC) for IP:'137.65.250.81' DOMAIN:'smtp2.provo.novell.com' HELO:'smtp2.provo.novell.com' FROM:'mwilck@suse.com' RCPT:'' X-RedHat-Spam-Score: -2.301 (RCVD_IN_DNSWL_MED, SPF_PASS) 137.65.250.81 smtp2.provo.novell.com 137.65.250.81 smtp2.provo.novell.com X-Scanned-By: MIMEDefang 2.84 on 10.5.110.46 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-loop: dm-devel@redhat.com Cc: Martin Wilck , dm-devel@redhat.com Subject: [dm-devel] [PATCH v4 03/22] libmultipath/checkers: replace message by msgid X-BeenThere: dm-devel@redhat.com X-Mailman-Version: 2.1.12 Precedence: junk List-Id: device-mapper development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dm-devel-bounces@redhat.com Errors-To: dm-devel-bounces@redhat.com X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.49]); Wed, 31 Oct 2018 11:07:46 +0000 (UTC) X-Virus-Scanned: ClamAV using ClamSMTP Replace the character array "message" in struct checker with a "message ID" field. The generic checker code defines a couple of standard message IDs and corresponding messages. Checker-specific message IDs start at CHECKER_FIRST_MSG. Checkers that implement specific message IDs must provide a table for converting the IDs into actual log messages. This simplifies the checker data structure and the handling of checker messages in the critical checker code path. It comes at the cost that only constant message strings are supported. It turns out that only a single checker log message (in the emc_clariion checker) was dynamically generated, and the missing information can be provided with a standard condlog message. Follow-up patches implement this for the existing checkers. checker_message() isn't thread-safe in its current form. This will be fixed in another follow-up patch. Reviewed-by: Benjamin Marzinski --- libmultipath/checkers.c | 70 +++++++++++++++++++++++++++++++++++------ libmultipath/checkers.h | 39 +++++++++++++++++++---- 2 files changed, 94 insertions(+), 15 deletions(-) diff --git a/libmultipath/checkers.c b/libmultipath/checkers.c index 0bacc864..96086686 100644 --- a/libmultipath/checkers.c +++ b/libmultipath/checkers.c @@ -141,6 +141,22 @@ struct checker * add_checker (char *multipath_dir, char * name) if (!c->free) goto out; + c->msgtable_size = 0; + c->msgtable = dlsym(c->handle, "libcheck_msgtable"); + + if (c->msgtable != NULL) { + const char **p; + + for (p = c->msgtable; + *p && (p - c->msgtable) < CHECKER_MSGTABLE_SIZE; p++) + /* nothing */; + + c->msgtable_size = p - c->msgtable; + } else + c->msgtable_size = 0; + condlog(3, "checker %s: message table size = %d", + c->name, c->msgtable_size); + done: c->fd = -1; c->sync = 1; @@ -222,16 +238,16 @@ int checker_check (struct checker * c, int path_state) if (!c) return PATH_WILD; - c->message[0] = '\0'; + c->msgid = CHECKER_MSGID_NONE; if (c->disable) { - MSG(c, "checker disabled"); + c->msgid = CHECKER_MSGID_DISABLED; return PATH_UNCHECKED; } if (!strncmp(c->name, NONE, 4)) return path_state; if (c->fd < 0) { - MSG(c, "no usable fd"); + c->msgid = CHECKER_MSGID_NO_FD; return PATH_WILD; } r = c->check(c); @@ -248,25 +264,59 @@ int checker_selected (struct checker * c) return (c->check) ? 1 : 0; } -char * checker_name (struct checker * c) +const char *checker_name(const struct checker *c) { if (!c) return NULL; return c->name; } -char * checker_message (struct checker * c) +static const char *generic_msg[CHECKER_GENERIC_MSGTABLE_SIZE] = { + [CHECKER_MSGID_NONE] = "", + [CHECKER_MSGID_DISABLED] = " is disabled", + [CHECKER_MSGID_NO_FD] = " has no usable fd", + [CHECKER_MSGID_INVALID] = " provided invalid message id", + [CHECKER_MSGID_UP] = " reports path is up", + [CHECKER_MSGID_DOWN] = " reports path is down", + [CHECKER_MSGID_GHOST] = " reports path is ghost", +}; + +static const char *_checker_message(const struct checker *c) { - if (!c) + int id; + + if (!c || c->msgid < 0 || + (c->msgid >= CHECKER_GENERIC_MSGTABLE_SIZE && + c->msgid < CHECKER_FIRST_MSGID)) return NULL; - return c->message; + + if (c->msgid < CHECKER_GENERIC_MSGTABLE_SIZE) + return generic_msg[c->msgid]; + + id = c->msgid - CHECKER_FIRST_MSGID; + if (id < c->msgtable_size) + return c->msgtable[id]; + return NULL; +} + +char *checker_message(const struct checker *c) +{ + static char buf[CHECKER_MSG_LEN]; + const char *msg = _checker_message(c); + + if (msg == NULL || *msg == '\0') + *buf = '\0'; + else + snprintf(buf, sizeof(buf), "%s checker%s", + c->name, msg); + return buf; } void checker_clear_message (struct checker *c) { if (!c) return; - c->message[0] = '\0'; + c->msgid = CHECKER_MSGID_NONE; } void checker_get (char *multipath_dir, struct checker * dst, char * name) @@ -288,10 +338,12 @@ void checker_get (char *multipath_dir, struct checker * dst, char * name) dst->fd = src->fd; dst->sync = src->sync; strncpy(dst->name, src->name, CHECKER_NAME_LEN); - strncpy(dst->message, src->message, CHECKER_MSG_LEN); + dst->msgid = CHECKER_MSGID_NONE; dst->check = src->check; dst->init = src->init; dst->free = src->free; + dst->msgtable = src->msgtable; + dst->msgtable_size = src->msgtable_size; dst->handle = NULL; src->refcount++; } diff --git a/libmultipath/checkers.h b/libmultipath/checkers.h index 7b18a1ac..60b1321b 100644 --- a/libmultipath/checkers.h +++ b/libmultipath/checkers.h @@ -97,6 +97,22 @@ enum path_check_state { #define CHECKER_DEV_LEN 256 #define LIB_CHECKER_NAMELEN 256 +/* + * Generic message IDs for use in checkers. + */ +enum { + CHECKER_MSGID_NONE = 0, + CHECKER_MSGID_DISABLED, + CHECKER_MSGID_NO_FD, + CHECKER_MSGID_INVALID, + CHECKER_MSGID_UP, + CHECKER_MSGID_DOWN, + CHECKER_MSGID_GHOST, + CHECKER_GENERIC_MSGTABLE_SIZE, + CHECKER_FIRST_MSGID = 100, /* lowest msgid for checkers */ + CHECKER_MSGTABLE_SIZE = 100, /* max msg table size for checkers */ +}; + struct checker { struct list_head node; void *handle; @@ -106,7 +122,7 @@ struct checker { unsigned int timeout; int disable; char name[CHECKER_NAME_LEN]; - char message[CHECKER_MSG_LEN]; /* comm with callers */ + short msgid; /* checker-internal extra status */ void * context; /* store for persistent data */ void ** mpcontext; /* store for persistent data shared multipath-wide. Use MALLOC if @@ -114,10 +130,10 @@ struct checker { int (*check)(struct checker *); int (*init)(struct checker *); /* to allocate the context */ void (*free)(struct checker *); /* to free the context */ + const char**msgtable; + short msgtable_size; }; -#define MSG(c, fmt, args...) snprintf((c)->message, CHECKER_MSG_LEN, fmt, ##args); - char * checker_state_name (int); int init_checkers (char *); void cleanup_checkers (void); @@ -134,14 +150,25 @@ void checker_enable (struct checker *); void checker_disable (struct checker *); int checker_check (struct checker *, int); int checker_selected (struct checker *); -char * checker_name (struct checker *); -char * checker_message (struct checker *); +const char *checker_name (const struct checker *); +char *checker_message (const struct checker *); void checker_clear_message (struct checker *c); void checker_get (char *, struct checker *, char *); -/* Functions exported by path checker dynamic libraries (.so) */ +/* Prototypes for symbols exported by path checker dynamic libraries (.so) */ int libcheck_check(struct checker *); int libcheck_init(struct checker *); void libcheck_free(struct checker *); +/* + * msgid => message map. + * + * It only needs to be provided if the checker defines specific + * message IDs. + * Message IDs available to checkers start at CHECKER_FIRST_MSG. + * The msgtable array is 0-based, i.e. msgtable[0] is the message + * for msgid == __CHECKER_FIRST_MSG. + * The table ends with a NULL element. + */ +extern const char *libcheck_msgtable[]; #endif /* _CHECKERS_H */ From patchwork Wed Oct 31 10:59:39 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Martin Wilck X-Patchwork-Id: 10662485 X-Patchwork-Delegate: christophe.varoqui@free.fr Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id B12F117DB for ; Wed, 31 Oct 2018 11:08:23 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id A0E542952C for ; 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Wed, 31 Oct 2018 11:00:40 +0000 (UTC) Received: from apollon.suse.de.de (prv-ext-foundry1int.gns.novell.com [137.65.251.240]) by smtp2.provo.novell.com with ESMTP (TLS encrypted); Wed, 31 Oct 2018 05:00:35 -0600 From: Martin Wilck To: Christophe Varoqui Date: Wed, 31 Oct 2018 11:59:39 +0100 Message-Id: <20181031105939.22202-3-mwilck@suse.com> In-Reply-To: <20181031105939.22202-1-mwilck@suse.com> References: <20181031105939.22202-1-mwilck@suse.com> MIME-Version: 1.0 X-Greylist: Sender passed SPF test, Sender IP whitelisted by DNSRBL, ACL 216 matched, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.47]); Wed, 31 Oct 2018 11:00:41 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.47]); Wed, 31 Oct 2018 11:00:41 +0000 (UTC) for IP:'137.65.250.81' DOMAIN:'smtp2.provo.novell.com' HELO:'smtp2.provo.novell.com' FROM:'mwilck@suse.com' RCPT:'' X-RedHat-Spam-Score: -2.301 (RCVD_IN_DNSWL_MED, SPF_PASS) 137.65.250.81 smtp2.provo.novell.com 137.65.250.81 smtp2.provo.novell.com X-Scanned-By: MIMEDefang 2.84 on 10.5.110.47 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-loop: dm-devel@redhat.com Cc: Martin Wilck , dm-devel@redhat.com Subject: [dm-devel] [PATCH v4 12/22] libmultipath/checkers: support unsupported paths X-BeenThere: dm-devel@redhat.com X-Mailman-Version: 2.1.12 Precedence: junk List-Id: device-mapper development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dm-devel-bounces@redhat.com Errors-To: dm-devel-bounces@redhat.com X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.27]); Wed, 31 Oct 2018 11:08:22 +0000 (UTC) X-Virus-Scanned: ClamAV using ClamSMTP We should be able to distinguish the case where a checker determines a path to be positively down from the case where the checker fails to obtain necessary information, e.g. because of a configuration problem (wrong checker). Use PATH_WILD for the latter case, as it's hardly used now. Provide a generic message for the situation that a path checker can't handle a certain path. Reviewed-by: Benjamin Marzinski --- libmultipath/checkers.c | 1 + libmultipath/checkers.h | 7 +++++-- 2 files changed, 6 insertions(+), 2 deletions(-) diff --git a/libmultipath/checkers.c b/libmultipath/checkers.c index 96086686..e31c028d 100644 --- a/libmultipath/checkers.c +++ b/libmultipath/checkers.c @@ -279,6 +279,7 @@ static const char *generic_msg[CHECKER_GENERIC_MSGTABLE_SIZE] = { [CHECKER_MSGID_UP] = " reports path is up", [CHECKER_MSGID_DOWN] = " reports path is down", [CHECKER_MSGID_GHOST] = " reports path is ghost", + [CHECKER_MSGID_UNSUPPORTED] = " doesn't support this device", }; static const char *_checker_message(const struct checker *c) diff --git a/libmultipath/checkers.h b/libmultipath/checkers.h index 60b1321b..f6d56db5 100644 --- a/libmultipath/checkers.h +++ b/libmultipath/checkers.h @@ -10,8 +10,10 @@ * Userspace (multipath/multipathd) path states * * PATH_WILD: - * - Use: None of the checkers (returned if we don't have an fd) - * - Description: Corner case where "fd < 0" for path fd (see checker_check()) + * - Use: Any checker + * - Description: Corner case where "fd < 0" for path fd (see checker_check()), + * or where a checker detects an unsupported device + * (e.g. wrong checker configured for a given device). * * PATH_UNCHECKED: * - Use: Only in directio checker @@ -108,6 +110,7 @@ enum { CHECKER_MSGID_UP, CHECKER_MSGID_DOWN, CHECKER_MSGID_GHOST, + CHECKER_MSGID_UNSUPPORTED, CHECKER_GENERIC_MSGTABLE_SIZE, CHECKER_FIRST_MSGID = 100, /* lowest msgid for checkers */ CHECKER_MSGTABLE_SIZE = 100, /* max msg table size for checkers */