From patchwork Tue Apr 27 21:57:09 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Douglas Gilbert X-Patchwork-Id: 12227581 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id EDD8CC43460 for ; Tue, 27 Apr 2021 21:59:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CD8CE613B0 for ; Tue, 27 Apr 2021 21:59:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239524AbhD0WAd (ORCPT ); Tue, 27 Apr 2021 18:00:33 -0400 Received: from smtp.infotech.no ([82.134.31.41]:38909 "EHLO smtp.infotech.no" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239446AbhD0V7w (ORCPT ); Tue, 27 Apr 2021 17:59:52 -0400 Received: from localhost (localhost [127.0.0.1]) by smtp.infotech.no (Postfix) with ESMTP id D2086204196; Tue, 27 Apr 2021 23:59:07 +0200 (CEST) X-Virus-Scanned: by amavisd-new-2.6.6 (20110518) (Debian) at infotech.no Received: from smtp.infotech.no ([127.0.0.1]) by localhost (smtp.infotech.no [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id VSNDZ7htTjSz; Tue, 27 Apr 2021 23:59:05 +0200 (CEST) Received: from xtwo70.bingwo.ca (host-45-58-219-4.dyn.295.ca [45.58.219.4]) by smtp.infotech.no (Postfix) with ESMTPA id 8F1BC2041AC; Tue, 27 Apr 2021 23:59:04 +0200 (CEST) From: Douglas Gilbert To: linux-scsi@vger.kernel.org Cc: martin.petersen@oracle.com, jejb@linux.vnet.ibm.com, hare@suse.de Subject: [PATCH v18 59/83] sg: add snap_dev flag and snapped in debugfs Date: Tue, 27 Apr 2021 17:57:09 -0400 Message-Id: <20210427215733.417746-61-dgilbert@interlog.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210427215733.417746-1-dgilbert@interlog.com> References: <20210427215733.417746-1-dgilbert@interlog.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org Add SG_CTL_FLAGM_SNAP_DEV flag to ioctl(SG_SET_GET_EXTENDED) to allow a snapshot of the current device's data structures to be sent to /sys/kernel/debug/scsi_generic/snapped programmatically. The format of the output is similar to what is seen in: 'cat /sys/kernel/debug/scsi_generic/snapshot' . Each "snap_dev" is prefixed by a "UTC time: ". The timestamp has microsecond resolution. Each "snap_dev" is appended to the single internal buffer which is reset to position zero after that buffer becomes half full. Signed-off-by: Douglas Gilbert --- drivers/scsi/sg.c | 107 +++++++++++++++++++++++++++++++++++++++++ include/uapi/scsi/sg.h | 3 +- 2 files changed, 109 insertions(+), 1 deletion(-) diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c index 7f62cd9bffe0..045aa96addac 100644 --- a/drivers/scsi/sg.c +++ b/drivers/scsi/sg.c @@ -194,6 +194,9 @@ static struct class_interface sg_interface = { .remove_dev = sg_remove_device, }; +static DEFINE_MUTEX(snapped_mutex); +static char *snapped_buf; + /* Subset of sg_io_hdr found in , has only [i] and [i->o] fields */ struct sg_slice_hdr3 { int interface_id; @@ -363,6 +366,11 @@ static int sg_srp_q_blk_poll(struct sg_request *srp, struct request_queue *q, static const char *sg_rq_st_str(enum sg_rq_state rq_st, bool long_str); static const char *sg_shr_str(enum sg_shr_var sh_var, bool long_str); #endif +#if IS_ENABLED(SG_PROC_OR_DEBUG_FS) +static int sg_proc_debug_sdev(struct sg_device *sdp, char *obp, int len, + int *fd_counterp, bool reduced); +static void sg_take_snap(struct sg_fd *sfp, bool clear_first); +#endif #define SG_WRITE_COUNT_LIMIT (32 * 1024 * 1024) @@ -390,6 +398,7 @@ static const char *sg_shr_str(enum sg_shr_var sh_var, bool long_str); */ #define SG_PROC_DEBUG_SZ 8192 +#define SG_SNAP_BUFF_SZ (SG_PROC_DEBUG_SZ * 8) #if IS_ENABLED(CONFIG_SCSI_LOGGING) && IS_ENABLED(SG_DEBUG) #define SG_LOG_BUFF_SZ 48 @@ -3574,6 +3583,62 @@ sg_any_persistent_orphans(struct sg_fd *sfp) return false; } +/* Ignore append if size already over half of available buffer */ +static void +sg_take_snap(struct sg_fd *sfp, bool dont_append) +{ + u32 hour, minute, second; + u64 n; + struct sg_device *sdp = sfp->parentdp; + struct timespec64 ts64; + char b[64]; + + if (!sdp) + return; + ktime_get_real_ts64(&ts64); + /* prefer local time but sys_tz.tz_minuteswest is always 0 */ + n = ts64.tv_sec; + second = (u32)do_div(n, 60); + minute = (u32)do_div(n, 60); + hour = (u32)do_div(n, 24); /* hour within a UTC day */ + snprintf(b, sizeof(b), "UTC time: %.2u:%.2u:%.2u:%.6u [tid=%d]", + hour, minute, second, (u32)ts64.tv_nsec / 1000, + (current ? current->pid : -1)); + mutex_lock(&snapped_mutex); + if (!snapped_buf) { + snapped_buf = kzalloc(SG_SNAP_BUFF_SZ, + GFP_KERNEL | __GFP_NOWARN); + if (!snapped_buf) + goto fini; + } else if (dont_append) { + memset(snapped_buf, 0, SG_SNAP_BUFF_SZ); + } +#if IS_ENABLED(SG_PROC_OR_DEBUG_FS) + if (true) { /* for some declarations */ + int n, prevlen, bp_len; + char *bp; + + prevlen = strlen(snapped_buf); + if (prevlen > SG_SNAP_BUFF_SZ / 2) + prevlen = 0; + bp_len = SG_SNAP_BUFF_SZ - prevlen; + bp = snapped_buf + prevlen; + n = scnprintf(bp, bp_len, "%s\n", b); + bp += n; + bp_len -= n; + if (bp_len < 2) + goto fini; + n = sg_proc_debug_sdev(sdp, bp, bp_len, NULL, false); + if (n >= bp_len - 1) { + if (bp[bp_len - 2] != '\n') + bp[bp_len - 2] = '\n'; + } + } +#endif +fini: + mutex_unlock(&snapped_mutex); +} + /* * Processing of ioctl(SG_SET_GET_EXTENDED(SG_SEIM_CTL_FLAGS)) which is a set * of boolean flags. Access abbreviations: [rw], read-write; [ro], read-only; @@ -3728,6 +3793,20 @@ sg_extended_bool_flags(struct sg_fd *sfp, struct sg_extended_info *seip) else c_flgs_val_out &= ~SG_CTL_FLAGM_EXCL_WAITQ; } + /* SNAP_DEV boolean, [rbw] */ + if (c_flgs_rm & SG_CTL_FLAGM_SNAP_DEV) { + mutex_lock(&snapped_mutex); + flg = (snapped_buf && strlen(snapped_buf) > 0); + mutex_unlock(&snapped_mutex); + } + if (c_flgs_wm & SG_CTL_FLAGM_SNAP_DEV) + sg_take_snap(sfp, !!(c_flgs_val_in & SG_CTL_FLAGM_SNAP_DEV)); + if (c_flgs_rm & SG_CTL_FLAGM_SNAP_DEV) { + if (flg) + c_flgs_val_out |= SG_CTL_FLAGM_SNAP_DEV; + else + c_flgs_val_out &= ~SG_CTL_FLAGM_SNAP_DEV; + } if (c_flgs_val_in != c_flgs_val_out) seip->ctl_flags = c_flgs_val_out; @@ -4977,6 +5056,7 @@ exit_sg(void) sg_dfs_exit(); if (IS_ENABLED(CONFIG_SCSI_PROC_FS)) remove_proc_subtree("scsi/sg", NULL); + kfree(snapped_buf); scsi_unregister_interface(&sg_interface); mempool_destroy(sg_sense_pool); kmem_cache_destroy(sg_sense_cache); @@ -6599,6 +6679,10 @@ sg_proc_debug_fd(struct sg_fd *fp, char *obp, int len, unsigned long idx, k = 0; xa_lock_irqsave(&fp->srp_arr, iflags); xa_for_each(&fp->srp_arr, idx, srp) { + if (srp->rq_idx != (unsigned long)idx) + n += scnprintf(obp + n, len - n, + ">>> xa_index=%lu, rq_idx=%d, bad\n", + idx, srp->rq_idx); if (xa_get_mark(&fp->srp_arr, idx, SG_XA_RQ_INACTIVE)) continue; n += sg_proc_debug_sreq(srp, fp->timeout, t_in_ns, obp + n, @@ -6858,6 +6942,28 @@ struct sg_dfs_attr { const struct seq_operations *seq_ops; }; +static int +sg_dfs_snapped_show(void *data, struct seq_file *m) +{ + mutex_lock(&snapped_mutex); + if (snapped_buf && snapped_buf[0]) + seq_puts(m, snapped_buf); + mutex_unlock(&snapped_mutex); + return 0; +} + +static ssize_t +sg_dfs_snapped_write(void *data, const char __user *buf, size_t count, + loff_t *ppos) +{ + /* Any write clears snapped buffer */ + mutex_lock(&snapped_mutex); + kfree(snapped_buf); + snapped_buf = NULL; + mutex_unlock(&snapped_mutex); + return count; +} + static int sg_dfs_snapshot_devs_show(void *data, struct seq_file *m) { @@ -7019,6 +7125,7 @@ static const struct seq_operations sg_snapshot_summ_seq_ops = { }; static const struct sg_dfs_attr sg_dfs_attrs[] = { + {"snapped", 0600, sg_dfs_snapped_show, sg_dfs_snapped_write}, {"snapshot", 0400, .seq_ops = &sg_snapshot_seq_ops}, {"snapshot_devs", 0600, sg_dfs_snapshot_devs_show, sg_dfs_snapshot_devs_write}, diff --git a/include/uapi/scsi/sg.h b/include/uapi/scsi/sg.h index 8b3fe773dfd5..bf947ebe06dd 100644 --- a/include/uapi/scsi/sg.h +++ b/include/uapi/scsi/sg.h @@ -211,7 +211,8 @@ typedef struct sg_req_info { /* used by SG_GET_REQUEST_TABLE ioctl() */ #define SG_CTL_FLAGM_NO_DURATION 0x400 /* don't calc command duration */ #define SG_CTL_FLAGM_MORE_ASYNC 0x800 /* yield EAGAIN in more cases */ #define SG_CTL_FLAGM_EXCL_WAITQ 0x1000 /* only 1 wake up per response */ -#define SG_CTL_FLAGM_ALL_BITS 0x1fff /* should be OR of previous items */ +#define SG_CTL_FLAGM_SNAP_DEV 0x2000 /* output to debugfs::snapped */ +#define SG_CTL_FLAGM_ALL_BITS 0x3fff /* should be OR of previous items */ /* Write one of the following values to sg_extended_info::read_value, get... */ #define SG_SEIRV_INT_MASK 0x0 /* get SG_SEIM_ALL_BITS */