From: Mike Christie <michael.christie@oracle.com> To: linux-scsi@vger.kernel.org, target-devel@vger.kernel.org, mst@redhat.com, jasowang@redhat.com, pbonzini@redhat.com, stefanha@redhat.com, virtualization@lists.linux-foundation.org Subject: [PATCH 3/5] vhost scsi: fix cmd completion race Date: Tue, 10 Nov 2020 05:33:21 +0000 [thread overview] Message-ID: <1604986403-4931-4-git-send-email-michael.christie@oracle.com> (raw) In-Reply-To: <1604986403-4931-1-git-send-email-michael.christie@oracle.com> We might not do the final se_cmd put from vhost_scsi_complete_cmd_work. When the last put happens a little later then we could race where vhost_scsi_complete_cmd_work does vhost_signal, the guest runs and sends more IO, and vhost_scsi_handle_vq runs but does not find any free cmds. This patch has us delay completing the cmd until the last lio core ref is dropped. We then know that once we signal to the guest that the cmd is completed that if it queues a new command it will find a free cmd. Signed-off-by: Mike Christie <michael.christie@oracle.com> Reviewed-by: Maurizio Lombardi <mlombard@redhat.com> --- drivers/vhost/scsi.c | 42 +++++++++++++++--------------------------- 1 file changed, 15 insertions(+), 27 deletions(-) diff --git a/drivers/vhost/scsi.c b/drivers/vhost/scsi.c index e31339b..5d8850f 100644 --- a/drivers/vhost/scsi.c +++ b/drivers/vhost/scsi.c @@ -322,7 +322,7 @@ static u32 vhost_scsi_tpg_get_inst_index(struct se_portal_group *se_tpg) return 1; } -static void vhost_scsi_release_cmd(struct se_cmd *se_cmd) +static void vhost_scsi_release_cmd_res(struct se_cmd *se_cmd) { struct vhost_scsi_cmd *tv_cmd = container_of(se_cmd, struct vhost_scsi_cmd, tvc_se_cmd); @@ -344,6 +344,16 @@ static void vhost_scsi_release_cmd(struct se_cmd *se_cmd) vhost_scsi_put_inflight(inflight); } +static void vhost_scsi_release_cmd(struct se_cmd *se_cmd) +{ + struct vhost_scsi_cmd *cmd = container_of(se_cmd, + struct vhost_scsi_cmd, tvc_se_cmd); + struct vhost_scsi *vs = cmd->tvc_vhost; + + llist_add(&cmd->tvc_completion_list, &vs->vs_completion_list); + vhost_work_queue(&vs->dev, &vs->vs_completion_work); +} + static u32 vhost_scsi_sess_get_index(struct se_session *se_sess) { return 0; @@ -366,28 +376,15 @@ static int vhost_scsi_get_cmd_state(struct se_cmd *se_cmd) return 0; } -static void vhost_scsi_complete_cmd(struct vhost_scsi_cmd *cmd) -{ - struct vhost_scsi *vs = cmd->tvc_vhost; - - llist_add(&cmd->tvc_completion_list, &vs->vs_completion_list); - - vhost_work_queue(&vs->dev, &vs->vs_completion_work); -} - static int vhost_scsi_queue_data_in(struct se_cmd *se_cmd) { - struct vhost_scsi_cmd *cmd = container_of(se_cmd, - struct vhost_scsi_cmd, tvc_se_cmd); - vhost_scsi_complete_cmd(cmd); + transport_generic_free_cmd(se_cmd, 0); return 0; } static int vhost_scsi_queue_status(struct se_cmd *se_cmd) { - struct vhost_scsi_cmd *cmd = container_of(se_cmd, - struct vhost_scsi_cmd, tvc_se_cmd); - vhost_scsi_complete_cmd(cmd); + transport_generic_free_cmd(se_cmd, 0); return 0; } @@ -433,15 +430,6 @@ static void vhost_scsi_free_evt(struct vhost_scsi *vs, struct vhost_scsi_evt *ev return evt; } -static void vhost_scsi_free_cmd(struct vhost_scsi_cmd *cmd) -{ - struct se_cmd *se_cmd = &cmd->tvc_se_cmd; - - /* TODO locking against target/backend threads? */ - transport_generic_free_cmd(se_cmd, 0); - -} - static int vhost_scsi_check_stop_free(struct se_cmd *se_cmd) { return target_put_sess_cmd(se_cmd); @@ -560,7 +548,7 @@ static void vhost_scsi_complete_cmd_work(struct vhost_work *work) } else pr_err("Faulted on virtio_scsi_cmd_resp\n"); - vhost_scsi_free_cmd(cmd); + vhost_scsi_release_cmd_res(se_cmd); } vq = -1; @@ -1091,7 +1079,7 @@ static void vhost_scsi_submission_work(struct work_struct *work) &prot_iter, exp_data_len, &data_iter))) { vq_err(vq, "Failed to map iov to sgl\n"); - vhost_scsi_release_cmd(&cmd->tvc_se_cmd); + vhost_scsi_release_cmd_res(&cmd->tvc_se_cmd); goto err; } } -- 1.8.3.1
WARNING: multiple messages have this Message-ID (diff)
From: Mike Christie <michael.christie@oracle.com> To: linux-scsi@vger.kernel.org, target-devel@vger.kernel.org, mst@redhat.com, jasowang@redhat.com, pbonzini@redhat.com, stefanha@redhat.com, virtualization@lists.linux-foundation.org Subject: [PATCH 3/5] vhost scsi: fix cmd completion race Date: Mon, 9 Nov 2020 23:33:21 -0600 [thread overview] Message-ID: <1604986403-4931-4-git-send-email-michael.christie@oracle.com> (raw) In-Reply-To: <1604986403-4931-1-git-send-email-michael.christie@oracle.com> We might not do the final se_cmd put from vhost_scsi_complete_cmd_work. When the last put happens a little later then we could race where vhost_scsi_complete_cmd_work does vhost_signal, the guest runs and sends more IO, and vhost_scsi_handle_vq runs but does not find any free cmds. This patch has us delay completing the cmd until the last lio core ref is dropped. We then know that once we signal to the guest that the cmd is completed that if it queues a new command it will find a free cmd. Signed-off-by: Mike Christie <michael.christie@oracle.com> Reviewed-by: Maurizio Lombardi <mlombard@redhat.com> --- drivers/vhost/scsi.c | 42 +++++++++++++++--------------------------- 1 file changed, 15 insertions(+), 27 deletions(-) diff --git a/drivers/vhost/scsi.c b/drivers/vhost/scsi.c index e31339b..5d8850f 100644 --- a/drivers/vhost/scsi.c +++ b/drivers/vhost/scsi.c @@ -322,7 +322,7 @@ static u32 vhost_scsi_tpg_get_inst_index(struct se_portal_group *se_tpg) return 1; } -static void vhost_scsi_release_cmd(struct se_cmd *se_cmd) +static void vhost_scsi_release_cmd_res(struct se_cmd *se_cmd) { struct vhost_scsi_cmd *tv_cmd = container_of(se_cmd, struct vhost_scsi_cmd, tvc_se_cmd); @@ -344,6 +344,16 @@ static void vhost_scsi_release_cmd(struct se_cmd *se_cmd) vhost_scsi_put_inflight(inflight); } +static void vhost_scsi_release_cmd(struct se_cmd *se_cmd) +{ + struct vhost_scsi_cmd *cmd = container_of(se_cmd, + struct vhost_scsi_cmd, tvc_se_cmd); + struct vhost_scsi *vs = cmd->tvc_vhost; + + llist_add(&cmd->tvc_completion_list, &vs->vs_completion_list); + vhost_work_queue(&vs->dev, &vs->vs_completion_work); +} + static u32 vhost_scsi_sess_get_index(struct se_session *se_sess) { return 0; @@ -366,28 +376,15 @@ static int vhost_scsi_get_cmd_state(struct se_cmd *se_cmd) return 0; } -static void vhost_scsi_complete_cmd(struct vhost_scsi_cmd *cmd) -{ - struct vhost_scsi *vs = cmd->tvc_vhost; - - llist_add(&cmd->tvc_completion_list, &vs->vs_completion_list); - - vhost_work_queue(&vs->dev, &vs->vs_completion_work); -} - static int vhost_scsi_queue_data_in(struct se_cmd *se_cmd) { - struct vhost_scsi_cmd *cmd = container_of(se_cmd, - struct vhost_scsi_cmd, tvc_se_cmd); - vhost_scsi_complete_cmd(cmd); + transport_generic_free_cmd(se_cmd, 0); return 0; } static int vhost_scsi_queue_status(struct se_cmd *se_cmd) { - struct vhost_scsi_cmd *cmd = container_of(se_cmd, - struct vhost_scsi_cmd, tvc_se_cmd); - vhost_scsi_complete_cmd(cmd); + transport_generic_free_cmd(se_cmd, 0); return 0; } @@ -433,15 +430,6 @@ static void vhost_scsi_free_evt(struct vhost_scsi *vs, struct vhost_scsi_evt *ev return evt; } -static void vhost_scsi_free_cmd(struct vhost_scsi_cmd *cmd) -{ - struct se_cmd *se_cmd = &cmd->tvc_se_cmd; - - /* TODO locking against target/backend threads? */ - transport_generic_free_cmd(se_cmd, 0); - -} - static int vhost_scsi_check_stop_free(struct se_cmd *se_cmd) { return target_put_sess_cmd(se_cmd); @@ -560,7 +548,7 @@ static void vhost_scsi_complete_cmd_work(struct vhost_work *work) } else pr_err("Faulted on virtio_scsi_cmd_resp\n"); - vhost_scsi_free_cmd(cmd); + vhost_scsi_release_cmd_res(se_cmd); } vq = -1; @@ -1091,7 +1079,7 @@ static void vhost_scsi_submission_work(struct work_struct *work) &prot_iter, exp_data_len, &data_iter))) { vq_err(vq, "Failed to map iov to sgl\n"); - vhost_scsi_release_cmd(&cmd->tvc_se_cmd); + vhost_scsi_release_cmd_res(&cmd->tvc_se_cmd); goto err; } } -- 1.8.3.1
next prev parent reply other threads:[~2020-11-10 5:33 UTC|newest] Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-11-10 5:33 [PATCH 0/5 V5] vhost-scsi: IO error fixups Mike Christie 2020-11-10 5:33 ` Mike Christie 2020-11-10 5:33 ` [PATCH 1/5] vhost: add helper to check if a vq has been setup Mike Christie 2020-11-10 5:33 ` Mike Christie 2020-11-10 7:20 ` Jason Wang 2020-11-10 7:20 ` Jason Wang 2020-11-10 7:20 ` Jason Wang 2020-11-10 5:33 ` [PATCH 2/5] vhost scsi: alloc cmds per vq instead of session Mike Christie 2020-11-10 5:33 ` Mike Christie 2020-11-12 17:11 ` Maurizio Lombardi 2020-11-12 17:11 ` Maurizio Lombardi 2020-11-10 5:33 ` Mike Christie [this message] 2020-11-10 5:33 ` [PATCH 3/5] vhost scsi: fix cmd completion race Mike Christie 2020-11-10 5:33 ` [PATCH 4/5] vhost scsi: add lun parser helper Mike Christie 2020-11-10 5:33 ` Mike Christie 2020-11-10 5:33 ` [PATCH 5/5] vhost scsi: Add support for LUN resets Mike Christie 2020-11-10 5:33 ` Mike Christie 2020-11-12 17:00 ` [PATCH 0/5 V5] vhost-scsi: IO error fixups Stefan Hajnoczi 2020-11-12 17:00 ` Stefan Hajnoczi
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=1604986403-4931-4-git-send-email-michael.christie@oracle.com \ --to=michael.christie@oracle.com \ --cc=jasowang@redhat.com \ --cc=linux-scsi@vger.kernel.org \ --cc=mst@redhat.com \ --cc=pbonzini@redhat.com \ --cc=stefanha@redhat.com \ --cc=target-devel@vger.kernel.org \ --cc=virtualization@lists.linux-foundation.org \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: linkBe sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes, see mirroring instructions on how to clone and mirror all data and code used by this external index.