Re: [PATCH 1/2] scsi-mq: Only show the CDB if available
From: Ming Lei <hidden>
Date: 2017-12-05 01:15:37
Also in:
linux-scsi
On Mon, Dec 04, 2017 at 04:38:08PM -0800, Bart Van Assche wrote:
Since the next patch will make it possible that scsi_show_rq() gets called before the CDB pointer is changed into a non-NULL value, only show the CDB if the CDB pointer is not NULL. Additionally, show the request timeout and SCSI command flags. This patch also fixes a bug that was reported by Ming Lei. See also Ming Lei, scsi_debugfs: fix crash in scsi_show_rq(), linux-scsi, 7 November 2017 (https://marc.info/?l=linux-block&m=151006655317188).
Please cook a patch for fixing the crash issue only, since we need to backport the fix to stable kernel.
Signed-off-by: Bart Van Assche <redacted> Cc: James E.J. Bottomley <redacted> Cc: Martin K. Petersen <martin.petersen@oracle.com> Cc: Ming Lei <redacted> Cc: Christoph Hellwig <hch@lst.de> Cc: Hannes Reinecke <hare@suse.com> Cc: Johannes Thumshirn <redacted>
Please Cc: [off-list ref]
quoted hunk ↗ jump to hunk
--- drivers/scsi/scsi_debugfs.c | 47 ++++++++++++++++++++++++++++++++++++++++----- 1 file changed, 42 insertions(+), 5 deletions(-)diff --git a/drivers/scsi/scsi_debugfs.c b/drivers/scsi/scsi_debugfs.c index 01f08c03f2c1..37ed6bb8e6ec 100644 --- a/drivers/scsi/scsi_debugfs.c +++ b/drivers/scsi/scsi_debugfs.c@@ -4,13 +4,50 @@ #include <scsi/scsi_dbg.h> #include "scsi_debugfs.h" +#define SCSI_CMD_FLAG_NAME(name) [ilog2(SCMD_##name)] = #name +static const char *const scsi_cmd_flags[] = { + SCSI_CMD_FLAG_NAME(TAGGED), + SCSI_CMD_FLAG_NAME(UNCHECKED_ISA_DMA), + SCSI_CMD_FLAG_NAME(ZONE_WRITE_LOCK), + SCSI_CMD_FLAG_NAME(INITIALIZED), +}; +#undef SCSI_CMD_FLAG_NAME + +static int scsi_flags_show(struct seq_file *m, const unsigned long flags, + const char *const *flag_name, int flag_name_count) +{ + bool sep = false; + int i; + + for (i = 0; i < sizeof(flags) * BITS_PER_BYTE; i++) { + if (!(flags & BIT(i))) + continue; + if (sep) + seq_puts(m, "|"); + sep = true; + if (i < flag_name_count && flag_name[i]) + seq_puts(m, flag_name[i]); + else + seq_printf(m, "%d", i); + } + return 0; +} + void scsi_show_rq(struct seq_file *m, struct request *rq) { struct scsi_cmnd *cmd = container_of(scsi_req(rq), typeof(*cmd), req); - int msecs = jiffies_to_msecs(jiffies - cmd->jiffies_at_alloc); - char buf[80]; + int alloc_ms = jiffies_to_msecs(jiffies - cmd->jiffies_at_alloc); + int timeout_ms = jiffies_to_msecs(rq->timeout); + const u8 *const cdb = READ_ONCE(cmd->cmnd); + char buf[80] = "(?)"; - __scsi_format_command(buf, sizeof(buf), cmd->cmnd, cmd->cmd_len); - seq_printf(m, ", .cmd=%s, .retries=%d, allocated %d.%03d s ago", buf, - cmd->retries, msecs / 1000, msecs % 1000); + if (cdb) + __scsi_format_command(buf, sizeof(buf), cdb, cmd->cmd_len); + seq_printf(m, ", .cmd=%s, .retries=%d, .result = %#x, .flags=", buf, + cmd->retries, cmd->result); + scsi_flags_show(m, cmd->flags, scsi_cmd_flags, + ARRAY_SIZE(scsi_cmd_flags)); + seq_printf(m, ", .timeout=%d.%03d, allocated %d.%03d s ago", + timeout_ms / 1000, timeout_ms % 1000, + alloc_ms / 1000, alloc_ms % 1000); }-- 2.15.0
-- Ming