Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752001AbaFDTVG (ORCPT ); Wed, 4 Jun 2014 15:21:06 -0400 Received: from p01c11o145.mxlogic.net ([208.65.144.68]:52716 "EHLO p01c11o145.mxlogic.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751434AbaFDTVC (ORCPT ); Wed, 4 Jun 2014 15:21:02 -0400 X-MXL-Hash: 538f719e6e12b533-e0851b01527702143d47a06c281b7ec295f6300f From: Joe Lawrence To: CC: Jens Axboe , Jeff Moyer , Joe Lawrence Subject: [PATCH v2 2/2] block,scsi: convert and handle ERR_PTR from blk_get_request Date: Wed, 4 Jun 2014 15:20:33 -0400 Message-ID: <1401909633-25931-3-git-send-email-joe.lawrence@stratus.com> X-Mailer: git-send-email 1.7.10.4 In-Reply-To: <1401909633-25931-1-git-send-email-joe.lawrence@stratus.com> References: <1401909633-25931-1-git-send-email-joe.lawrence@stratus.com> MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [134.111.199.152] X-AnalysisOut: [v=2.1 cv=P8i0h0wu c=1 sm=1 tr=0 a=o2bo05G+d1rlxuoNbFVhCw==] X-AnalysisOut: [:117 a=o2bo05G+d1rlxuoNbFVhCw==:17 a=Glimlxzx9zcA:10 a=_KQ] X-AnalysisOut: [qW7t0BisA:10 a=CdzKgOd8jloA:10 a=BLceEmwcHowA:10 a=uelBKuK] X-AnalysisOut: [pAAAA:8 a=YlVTAMxIAAAA:8 a=cOLrLDMxAAAA:8 a=20KFwNOVAAAA:8] X-AnalysisOut: [ a=NebqWWrlVvnvOuHW3zEA:9 a=kSViFEBMy1sA:10 a=3QEBi2iB_nEA] X-AnalysisOut: [:10 a=jEp0ucaQiEUA:10] X-Spam: [F=0.5000000000; CM=0.500; MH=0.500(2014060421); S=0.200(2014051901)] X-MAIL-FROM: X-SOURCE-IP: [134.111.1.18] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The blk_get_request function may fail in low-memory conditions or during device removal (even if __GFP_WAIT is set). To distinguish between these errors, modify the blk_get_request call stack to return the appropriate ERR_PTR. Verify that all callers check the return status and consider IS_ERR instead of a simple NULL pointer check. Signed-off-by: Joe Lawrence Acked-by: Jiri Kosina [for pktdvd] Acked-by: Boaz Harrosh [for osd] Reviewed-by: Jeff Moyer --- block/blk-core.c | 34 ++++++++++++++--------------- block/bsg.c | 8 +++---- block/scsi_ioctl.c | 12 +++++----- drivers/block/paride/pd.c | 4 ++-- drivers/block/pktcdvd.c | 4 ++-- drivers/block/sx8.c | 2 +- drivers/cdrom/cdrom.c | 4 ++-- drivers/ide/ide-park.c | 2 +- drivers/scsi/device_handler/scsi_dh_alua.c | 2 +- drivers/scsi/device_handler/scsi_dh_emc.c | 2 +- drivers/scsi/device_handler/scsi_dh_hp_sw.c | 4 ++-- drivers/scsi/device_handler/scsi_dh_rdac.c | 2 +- drivers/scsi/osd/osd_initiator.c | 4 ++-- drivers/scsi/osst.c | 2 +- drivers/scsi/scsi_error.c | 2 +- drivers/scsi/scsi_lib.c | 2 +- drivers/scsi/scsi_tgt_lib.c | 2 +- drivers/scsi/sg.c | 4 ++-- drivers/scsi/st.c | 2 +- drivers/target/target_core_pscsi.c | 2 +- 20 files changed, 50 insertions(+), 50 deletions(-) diff --git a/block/blk-core.c b/block/blk-core.c index a0e3096..cd0e9f3 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -891,9 +891,9 @@ static struct io_context *rq_ioc(struct bio *bio) * Get a free request from @q. This function may fail under memory * pressure or if @q is dead. * - * Must be callled with @q->queue_lock held and, - * Returns %NULL on failure, with @q->queue_lock held. - * Returns !%NULL on success, with @q->queue_lock *not held*. + * Must be called with @q->queue_lock held and, + * Returns ERR_PTR on failure, with @q->queue_lock held. + * Returns request pointer on success, with @q->queue_lock *not held*. */ static struct request *__get_request(struct request_list *rl, int rw_flags, struct bio *bio, gfp_t gfp_mask) @@ -907,7 +907,7 @@ static struct request *__get_request(struct request_list *rl, int rw_flags, int may_queue; if (unlikely(blk_queue_dying(q))) - return NULL; + return ERR_PTR(-ENODEV); may_queue = elv_may_queue(q, rw_flags); if (may_queue == ELV_MQUEUE_NO) @@ -932,7 +932,7 @@ static struct request *__get_request(struct request_list *rl, int rw_flags, * process is not a "batcher", and not * exempted by the IO scheduler */ - return NULL; + return ERR_PTR(-ENOMEM); } } } @@ -950,7 +950,7 @@ static struct request *__get_request(struct request_list *rl, int rw_flags, * allocated with any setting of ->nr_requests */ if (rl->count[is_sync] >= (3 * q->nr_requests / 2)) - return NULL; + return ERR_PTR(-ENOMEM); q->nr_rqs[is_sync]++; rl->count[is_sync]++; @@ -1055,7 +1055,7 @@ fail_alloc: rq_starved: if (unlikely(rl->count[is_sync] == 0)) rl->starved[is_sync] = 1; - return NULL; + return ERR_PTR(-ENOMEM); } /** @@ -1068,9 +1068,9 @@ rq_starved: * Get a free request from @q. If %__GFP_WAIT is set in @gfp_mask, this * function keeps retrying under memory pressure and fails iff @q is dead. * - * Must be callled with @q->queue_lock held and, - * Returns %NULL on failure, with @q->queue_lock held. - * Returns !%NULL on success, with @q->queue_lock *not held*. + * Must be called with @q->queue_lock held and, + * Returns ERR_PTR on failure, with @q->queue_lock held. + * Returns request pointer on success, with @q->queue_lock *not held*. */ static struct request *get_request(struct request_queue *q, int rw_flags, struct bio *bio, gfp_t gfp_mask) @@ -1083,12 +1083,12 @@ static struct request *get_request(struct request_queue *q, int rw_flags, rl = blk_get_rl(q, bio); /* transferred to @rq on success */ retry: rq = __get_request(rl, rw_flags, bio, gfp_mask); - if (rq) + if (!IS_ERR(rq)) return rq; if (!(gfp_mask & __GFP_WAIT) || unlikely(blk_queue_dying(q))) { blk_put_rl(rl); - return NULL; + return rq; } /* wait on @rl and retry */ @@ -1125,7 +1125,7 @@ static struct request *blk_old_get_request(struct request_queue *q, int rw, spin_lock_irq(q->queue_lock); rq = get_request(q, rw, NULL, gfp_mask); - if (!rq) + if (IS_ERR(rq)) spin_unlock_irq(q->queue_lock); /* q->queue_lock is unlocked at this point */ @@ -1177,8 +1177,8 @@ struct request *blk_make_request(struct request_queue *q, struct bio *bio, { struct request *rq = blk_get_request(q, bio_data_dir(bio), gfp_mask); - if (unlikely(!rq)) - return ERR_PTR(-ENOMEM); + if (IS_ERR(rq)) + return rq; for_each_bio(bio) { struct bio *bounce_bio = bio; @@ -1559,8 +1559,8 @@ get_rq: * Returns with the queue unlocked. */ req = get_request(q, rw_flags, bio, GFP_NOIO); - if (unlikely(!req)) { - bio_endio(bio, -ENODEV); /* @q is dead */ + if (IS_ERR(req)) { + bio_endio(bio, PTR_ERR(req)); /* @q is dead */ goto out_unlock; } diff --git a/block/bsg.c b/block/bsg.c index 420a5a9..50545e9 100644 --- a/block/bsg.c +++ b/block/bsg.c @@ -271,8 +271,8 @@ bsg_map_hdr(struct bsg_device *bd, struct sg_io_v4 *hdr, fmode_t has_write_perm, * map scatter-gather elements separately and string them to request */ rq = blk_get_request(q, rw, GFP_KERNEL); - if (!rq) - return ERR_PTR(-ENOMEM); + if (IS_ERR(rq)) + return rq; ret = blk_fill_sgv4_hdr_rq(q, rq, hdr, bd, has_write_perm); if (ret) goto out; @@ -284,8 +284,8 @@ bsg_map_hdr(struct bsg_device *bd, struct sg_io_v4 *hdr, fmode_t has_write_perm, } next_rq = blk_get_request(q, READ, GFP_KERNEL); - if (!next_rq) { - ret = -ENOMEM; + if (IS_ERR(next_rq)) { + ret = PTR_ERR(next_rq); goto out; } rq->next_rq = next_rq; diff --git a/block/scsi_ioctl.c b/block/scsi_ioctl.c index e6485c9..f901fb5 100644 --- a/block/scsi_ioctl.c +++ b/block/scsi_ioctl.c @@ -313,8 +313,8 @@ static int sg_io(struct request_queue *q, struct gendisk *bd_disk, } rq = blk_get_request(q, writing ? WRITE : READ, GFP_KERNEL); - if (!rq) - return -ENOMEM; + if (IS_ERR(rq)) + return PTR_ERR(rq); if (blk_fill_sghdr_rq(q, rq, hdr, mode)) { blk_put_request(rq); @@ -442,8 +442,8 @@ int sg_scsi_ioctl(struct request_queue *q, struct gendisk *disk, fmode_t mode, } rq = blk_get_request(q, in_len ? WRITE : READ, __GFP_WAIT); - if (!rq) { - err = -ENODEV; + if (IS_ERR(rq)) { + err = PTR_ERR(rq); goto error_free_buffer; } @@ -533,8 +533,8 @@ static int __blk_send_generic(struct request_queue *q, struct gendisk *bd_disk, int err; rq = blk_get_request(q, WRITE, __GFP_WAIT); - if (!rq) - return -ENODEV; + if (IS_ERR(rq)) + return PTR_ERR(rq); rq->cmd_type = REQ_TYPE_BLOCK_PC; rq->timeout = BLK_DEFAULT_SG_TIMEOUT; rq->cmd[0] = cmd; diff --git a/drivers/block/paride/pd.c b/drivers/block/paride/pd.c index 856178a..2af4101 100644 --- a/drivers/block/paride/pd.c +++ b/drivers/block/paride/pd.c @@ -722,8 +722,8 @@ static int pd_special_command(struct pd_unit *disk, int err = 0; rq = blk_get_request(disk->gd->queue, READ, __GFP_WAIT); - if (!rq) - return -ENODEV; + if (IS_ERR(rq)) + return PTR_ERR(rq); rq->cmd_type = REQ_TYPE_SPECIAL; rq->special = func; diff --git a/drivers/block/pktcdvd.c b/drivers/block/pktcdvd.c index ff39837..1de6e90 100644 --- a/drivers/block/pktcdvd.c +++ b/drivers/block/pktcdvd.c @@ -704,8 +704,8 @@ static int pkt_generic_packet(struct pktcdvd_device *pd, struct packet_command * rq = blk_get_request(q, (cgc->data_direction == CGC_DATA_WRITE) ? WRITE : READ, __GFP_WAIT); - if (!rq) - return -ENODEV; + if (IS_ERR(rq)) + return PTR_ERR(rq); if (cgc->buflen) { ret = blk_rq_map_kern(q, rq, cgc->buffer, cgc->buflen, diff --git a/drivers/block/sx8.c b/drivers/block/sx8.c index d5e2d12..5d55285 100644 --- a/drivers/block/sx8.c +++ b/drivers/block/sx8.c @@ -568,7 +568,7 @@ static struct carm_request *carm_get_special(struct carm_host *host) return NULL; rq = blk_get_request(host->oob_q, WRITE /* bogus */, GFP_KERNEL); - if (!rq) { + if (IS_ERR(rq)) { spin_lock_irqsave(&host->lock, flags); carm_put_request(host, crq); spin_unlock_irqrestore(&host->lock, flags); diff --git a/drivers/cdrom/cdrom.c b/drivers/cdrom/cdrom.c index 8a3aff7..85e63d3 100644 --- a/drivers/cdrom/cdrom.c +++ b/drivers/cdrom/cdrom.c @@ -2161,8 +2161,8 @@ static int cdrom_read_cdda_bpc(struct cdrom_device_info *cdi, __u8 __user *ubuf, len = nr * CD_FRAMESIZE_RAW; rq = blk_get_request(q, READ, GFP_KERNEL); - if (!rq) { - ret = -ENOMEM; + if (IS_ERR(rq)) { + ret = PTR_ERR(rq); break; } diff --git a/drivers/ide/ide-park.c b/drivers/ide/ide-park.c index f41558a..ca95860 100644 --- a/drivers/ide/ide-park.c +++ b/drivers/ide/ide-park.c @@ -46,7 +46,7 @@ static void issue_park_cmd(ide_drive_t *drive, unsigned long timeout) * timeout has expired, so power management will be reenabled. */ rq = blk_get_request(q, READ, GFP_NOWAIT); - if (unlikely(!rq)) + if (IS_ERR(rq)) goto out; rq->cmd[0] = REQ_UNPARK_HEADS; diff --git a/drivers/scsi/device_handler/scsi_dh_alua.c b/drivers/scsi/device_handler/scsi_dh_alua.c index 5248c88..5aefcf9 100644 --- a/drivers/scsi/device_handler/scsi_dh_alua.c +++ b/drivers/scsi/device_handler/scsi_dh_alua.c @@ -115,7 +115,7 @@ static struct request *get_alua_req(struct scsi_device *sdev, rq = blk_get_request(q, rw, GFP_NOIO); - if (!rq) { + if (IS_ERR(rq)) { sdev_printk(KERN_INFO, sdev, "%s: blk_get_request failed\n", __func__); return NULL; diff --git a/drivers/scsi/device_handler/scsi_dh_emc.c b/drivers/scsi/device_handler/scsi_dh_emc.c index e1c8be0..2ec3261 100644 --- a/drivers/scsi/device_handler/scsi_dh_emc.c +++ b/drivers/scsi/device_handler/scsi_dh_emc.c @@ -275,7 +275,7 @@ static struct request *get_req(struct scsi_device *sdev, int cmd, rq = blk_get_request(sdev->request_queue, (cmd != INQUIRY) ? WRITE : READ, GFP_NOIO); - if (!rq) { + if (IS_ERR(rq)) { sdev_printk(KERN_INFO, sdev, "get_req: blk_get_request failed"); return NULL; } diff --git a/drivers/scsi/device_handler/scsi_dh_hp_sw.c b/drivers/scsi/device_handler/scsi_dh_hp_sw.c index 084062b..1cf4019 100644 --- a/drivers/scsi/device_handler/scsi_dh_hp_sw.c +++ b/drivers/scsi/device_handler/scsi_dh_hp_sw.c @@ -117,7 +117,7 @@ static int hp_sw_tur(struct scsi_device *sdev, struct hp_sw_dh_data *h) retry: req = blk_get_request(sdev->request_queue, WRITE, GFP_NOIO); - if (!req) + if (IS_ERR(req)) return SCSI_DH_RES_TEMP_UNAVAIL; req->cmd_type = REQ_TYPE_BLOCK_PC; @@ -247,7 +247,7 @@ static int hp_sw_start_stop(struct hp_sw_dh_data *h) struct request *req; req = blk_get_request(h->sdev->request_queue, WRITE, GFP_ATOMIC); - if (!req) + if (IS_ERR(req)) return SCSI_DH_RES_TEMP_UNAVAIL; req->cmd_type = REQ_TYPE_BLOCK_PC; diff --git a/drivers/scsi/device_handler/scsi_dh_rdac.c b/drivers/scsi/device_handler/scsi_dh_rdac.c index 4b9cf93..5f6e5d8 100644 --- a/drivers/scsi/device_handler/scsi_dh_rdac.c +++ b/drivers/scsi/device_handler/scsi_dh_rdac.c @@ -274,7 +274,7 @@ static struct request *get_rdac_req(struct scsi_device *sdev, rq = blk_get_request(q, rw, GFP_NOIO); - if (!rq) { + if (IS_ERR(rq)) { sdev_printk(KERN_INFO, sdev, "get_rdac_req: blk_get_request failed.\n"); return NULL; diff --git a/drivers/scsi/osd/osd_initiator.c b/drivers/scsi/osd/osd_initiator.c index bac04c2..831f1f9 100644 --- a/drivers/scsi/osd/osd_initiator.c +++ b/drivers/scsi/osd/osd_initiator.c @@ -1567,8 +1567,8 @@ static struct request *_make_request(struct request_queue *q, bool has_write, struct request *req; req = blk_get_request(q, has_write ? WRITE : READ, flags); - if (unlikely(!req)) - return ERR_PTR(-ENOMEM); + if (IS_ERR(req)) + return req; return req; } diff --git a/drivers/scsi/osst.c b/drivers/scsi/osst.c index 21883a2..826cda9 100644 --- a/drivers/scsi/osst.c +++ b/drivers/scsi/osst.c @@ -362,7 +362,7 @@ static int osst_execute(struct osst_request *SRpnt, const unsigned char *cmd, int write = (data_direction == DMA_TO_DEVICE); req = blk_get_request(SRpnt->stp->device->request_queue, write, GFP_KERNEL); - if (!req) + if (IS_ERR(req)) return DRIVER_ERROR << 24; req->cmd_type = REQ_TYPE_BLOCK_PC; diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c index d50531f..ca038ee 100644 --- a/drivers/scsi/scsi_error.c +++ b/drivers/scsi/scsi_error.c @@ -1950,7 +1950,7 @@ static void scsi_eh_lock_door(struct scsi_device *sdev) * request becomes available */ req = blk_get_request(sdev->request_queue, READ, GFP_KERNEL); - if (!req) + if (IS_ERR(req)) return; req->cmd[0] = ALLOW_MEDIUM_REMOVAL; diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index 9db097a..b25fab0b 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -193,7 +193,7 @@ int scsi_execute(struct scsi_device *sdev, const unsigned char *cmd, int ret = DRIVER_ERROR << 24; req = blk_get_request(sdev->request_queue, write, __GFP_WAIT); - if (!req) + if (IS_ERR(req)) return ret; if (bufflen && blk_rq_map_kern(sdev->request_queue, req, diff --git a/drivers/scsi/scsi_tgt_lib.c b/drivers/scsi/scsi_tgt_lib.c index e51add0..b14c15b 100644 --- a/drivers/scsi/scsi_tgt_lib.c +++ b/drivers/scsi/scsi_tgt_lib.c @@ -97,7 +97,7 @@ struct scsi_cmnd *scsi_host_get_command(struct Scsi_Host *shost, * we are in target mode we want the opposite. */ rq = blk_get_request(shost->uspace_req_q, !write, gfp_mask); - if (!rq) + if (IS_ERR(rq)) goto free_tcmd; cmd = __scsi_get_command(shost, gfp_mask); diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c index df5e961..2e54684 100644 --- a/drivers/scsi/sg.c +++ b/drivers/scsi/sg.c @@ -1650,8 +1650,8 @@ static int sg_start_req(Sg_request *srp, unsigned char *cmd) dxfer_len)); rq = blk_get_request(q, rw, GFP_ATOMIC); - if (!rq) - return -ENOMEM; + if (IS_ERR(rq)) + return PTR_ERR(rq); memcpy(rq->cmd, cmd, hp->cmd_len); diff --git a/drivers/scsi/st.c b/drivers/scsi/st.c index afc834e..48a6cef 100644 --- a/drivers/scsi/st.c +++ b/drivers/scsi/st.c @@ -481,7 +481,7 @@ static int st_scsi_execute(struct st_request *SRpnt, const unsigned char *cmd, req = blk_get_request(SRpnt->stp->device->request_queue, write, GFP_KERNEL); - if (!req) + if (IS_ERR(req)) return DRIVER_ERROR << 24; req->cmd_type = REQ_TYPE_BLOCK_PC; diff --git a/drivers/target/target_core_pscsi.c b/drivers/target/target_core_pscsi.c index 0f199f6..23d340d 100644 --- a/drivers/target/target_core_pscsi.c +++ b/drivers/target/target_core_pscsi.c @@ -1050,7 +1050,7 @@ pscsi_execute_cmd(struct se_cmd *cmd) req = blk_get_request(pdv->pdv_sd->request_queue, (data_direction == DMA_TO_DEVICE), GFP_KERNEL); - if (!req) { + if (IS_ERR(req)) { pr_err("PSCSI: blk_get_request() failed\n"); ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; goto fail; -- 1.8.3.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/