From 119e9db233ad0f4cbd4cfb9f9385a7bca378b37d Mon Sep 17 00:00:00 2001 From: Zeng Chi Date: Mon, 21 Sep 2026 18:24:42 +0800 Subject: KVM: Don't pre-reserve xarray entries when storing empty/NULL attributes Skip the xarray reservation loop when clearing all memory attributes, as storing NULL only erases the entry and never needs to allocate, so no reservation (and no cleanup of a failed one) is required in that case. Suggested-by: Sean Christopherson Cc: David Ballesteros Signed-off-by: Zeng Chi Link: https://patch.msgid.link/20260921102442.1232375-1-zeng_chi911@163.com [sean: split to separate patch] Signed-off-by: Sean Christopherson --- drivers/scsi/scsi_debugfs.c | 75 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 75 insertions(+) create mode 100644 drivers/scsi/scsi_debugfs.c (limited to 'drivers/scsi/scsi_debugfs.c') diff --git a/drivers/scsi/scsi_debugfs.c b/drivers/scsi/scsi_debugfs.c new file mode 100644 index 000000000..eb52e39f3 --- /dev/null +++ b/drivers/scsi/scsi_debugfs.c @@ -0,0 +1,75 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include +#include +#include +#include +#include +#include "scsi_debugfs.h" + +#define SCSI_CMD_FLAG_NAME(name)[const_ilog2(SCMD_##name)] = #name +static const char *const scsi_cmd_flags[] = { + SCSI_CMD_FLAG_NAME(TAGGED), + SCSI_CMD_FLAG_NAME(INITIALIZED), + SCSI_CMD_FLAG_NAME(LAST), +}; +#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_each_set_bit(i, &flags, BITS_PER_LONG) { + 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; +} + +static const char *scsi_cmd_list_info(struct scsi_cmnd *cmd) +{ + struct Scsi_Host *shost = cmd->device->host; + struct scsi_cmnd *cmd2; + + guard(spinlock_irq)(shost->host_lock); + + list_for_each_entry(cmd2, &shost->eh_abort_list, eh_entry) + if (cmd == cmd2) + return "on eh_abort_list"; + + list_for_each_entry(cmd2, &shost->eh_cmd_q, eh_entry) + if (cmd == cmd2) + return "on eh_cmd_q"; + + return NULL; +} + +void scsi_show_rq(struct seq_file *m, struct request *rq) +{ + struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq); + int alloc_ms = jiffies_to_msecs(jiffies - cmd->jiffies_at_alloc); + int timeout_ms = jiffies_to_msecs(rq->timeout); + char buf[80] = "(?)"; + + if (cmd->flags & SCMD_INITIALIZED) { + const char *list_info = scsi_cmd_list_info(cmd); + + __scsi_format_command(buf, sizeof(buf), cmd->cmnd, cmd->cmd_len); + seq_printf(m, ", .cmd=%s, .retries=%d, .allowed=%d, .result = %#x%s%s", + buf, cmd->retries, cmd->allowed, cmd->result, + list_info ? ", " : "", list_info ? : ""); + seq_printf(m, ", .timeout=%d.%03d, allocated %d.%03d s ago", + timeout_ms / 1000, timeout_ms % 1000, + alloc_ms / 1000, alloc_ms % 1000); + } + seq_printf(m, ", .flags="); + scsi_flags_show(m, cmd->flags, scsi_cmd_flags, + ARRAY_SIZE(scsi_cmd_flags)); +} -- cgit v1.3.1