From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756284Ab3J2STt (ORCPT ); Tue, 29 Oct 2013 14:19:49 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:59462 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754051Ab3J2SJC (ORCPT ); Tue, 29 Oct 2013 14:09:02 -0400 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: "David S. Miller" , Kamal Mostafa Subject: [PATCH 3.8 58/81] esp_scsi: Fix tag state corruption when autosensing. Date: Tue, 29 Oct 2013 11:04:19 -0700 Message-Id: <1383069882-11437-59-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 1.8.1.2 In-Reply-To: <1383069882-11437-1-git-send-email-kamal@canonical.com> References: <1383069882-11437-1-git-send-email-kamal@canonical.com> X-Extended-Stable: 3.8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.8.13.12 -stable review patch. If anyone has any objections, please let me know. ------------------ From: "David S. Miller" [ Upstream commit 21af8107f27878813d0364733c0b08813c2c192a ] Meelis Roos reports a crash in esp_free_lun_tag() in the presense of a disk which has died. The issue is that when we issue an autosense command, we do so by hijacking the original command that caused the check-condition. When we do so we clear out the ent->tag[] array when we issue it via find_and_prep_issuable_command(). This is so that the autosense command is forced to be issued non-tagged. That is problematic, because it is the value of ent->tag[] which determines whether we issued the original scsi command as tagged vs. non-tagged (see esp_alloc_lun_tag()). And that, in turn, is what trips up the sanity checks in esp_free_lun_tag(). That function needs the original ->tag[] values in order to free up the tag slot properly. Fix this by remembering the original command's tag values, and having esp_alloc_lun_tag() and esp_free_lun_tag() use them. Reported-by: Meelis Roos Tested-by: Meelis Roos Signed-off-by: David S. Miller Signed-off-by: Kamal Mostafa --- drivers/scsi/esp_scsi.c | 14 ++++++++------ drivers/scsi/esp_scsi.h | 1 + 2 files changed, 9 insertions(+), 6 deletions(-) diff --git a/drivers/scsi/esp_scsi.c b/drivers/scsi/esp_scsi.c index 34552bf..55548dc 100644 --- a/drivers/scsi/esp_scsi.c +++ b/drivers/scsi/esp_scsi.c @@ -530,7 +530,7 @@ static int esp_need_to_nego_sync(struct esp_target_data *tp) static int esp_alloc_lun_tag(struct esp_cmd_entry *ent, struct esp_lun_data *lp) { - if (!ent->tag[0]) { + if (!ent->orig_tag[0]) { /* Non-tagged, slot already taken? */ if (lp->non_tagged_cmd) return -EBUSY; @@ -564,9 +564,9 @@ static int esp_alloc_lun_tag(struct esp_cmd_entry *ent, return -EBUSY; } - BUG_ON(lp->tagged_cmds[ent->tag[1]]); + BUG_ON(lp->tagged_cmds[ent->orig_tag[1]]); - lp->tagged_cmds[ent->tag[1]] = ent; + lp->tagged_cmds[ent->orig_tag[1]] = ent; lp->num_tagged++; return 0; @@ -575,9 +575,9 @@ static int esp_alloc_lun_tag(struct esp_cmd_entry *ent, static void esp_free_lun_tag(struct esp_cmd_entry *ent, struct esp_lun_data *lp) { - if (ent->tag[0]) { - BUG_ON(lp->tagged_cmds[ent->tag[1]] != ent); - lp->tagged_cmds[ent->tag[1]] = NULL; + if (ent->orig_tag[0]) { + BUG_ON(lp->tagged_cmds[ent->orig_tag[1]] != ent); + lp->tagged_cmds[ent->orig_tag[1]] = NULL; lp->num_tagged--; } else { BUG_ON(lp->non_tagged_cmd != ent); @@ -667,6 +667,8 @@ static struct esp_cmd_entry *find_and_prep_issuable_command(struct esp *esp) ent->tag[0] = 0; ent->tag[1] = 0; } + ent->orig_tag[0] = ent->tag[0]; + ent->orig_tag[1] = ent->tag[1]; if (esp_alloc_lun_tag(ent, lp) < 0) continue; diff --git a/drivers/scsi/esp_scsi.h b/drivers/scsi/esp_scsi.h index 28e22ac..cd68805 100644 --- a/drivers/scsi/esp_scsi.h +++ b/drivers/scsi/esp_scsi.h @@ -271,6 +271,7 @@ struct esp_cmd_entry { #define ESP_CMD_FLAG_AUTOSENSE 0x04 /* Doing automatic REQUEST_SENSE */ u8 tag[2]; + u8 orig_tag[2]; u8 status; u8 message; -- 1.8.1.2