This is a note to let you know that I've just added the patch titled scsi: sg: use standard lists for sg_requests to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: scsi-sg-use-standard-lists-for-sg_requests.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 109bade9c625c89bb5ea753aaa1a0a97e6fbb548 Mon Sep 17 00:00:00 2001 From: Hannes Reinecke <hare@xxxxxxx> Date: Fri, 7 Apr 2017 09:34:16 +0200 Subject: scsi: sg: use standard lists for sg_requests From: Hannes Reinecke <hare@xxxxxxx> commit 109bade9c625c89bb5ea753aaa1a0a97e6fbb548 upstream. 'Sg_request' is using a private list implementation; convert it to standard lists. Signed-off-by: Hannes Reinecke <hare@xxxxxxxx> Reviewed-by: Johannes Thumshirn <jthumshirn@xxxxxxx> Tested-by: Johannes Thumshirn <jthumshirn@xxxxxxx> Reviewed-by: Christoph Hellwig <hch@xxxxxx> Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/scsi/sg.c | 147 ++++++++++++++++++++++-------------------------------- 1 file changed, 61 insertions(+), 86 deletions(-) --- a/drivers/scsi/sg.c +++ b/drivers/scsi/sg.c @@ -133,7 +133,7 @@ struct sg_device; /* forward declaratio struct sg_fd; typedef struct sg_request { /* SG_MAX_QUEUE requests outstanding per file */ - struct sg_request *nextrp; /* NULL -> tail request (slist) */ + struct list_head entry; /* list entry */ struct sg_fd *parentfp; /* NULL -> not in use */ Sg_scatter_hold data; /* hold buffer, perhaps scatter list */ sg_io_hdr_t header; /* scsi command+info, see <scsi/sg.h> */ @@ -157,7 +157,7 @@ typedef struct sg_fd { /* holds the sta int timeout; /* defaults to SG_DEFAULT_TIMEOUT */ int timeout_user; /* defaults to SG_DEFAULT_TIMEOUT_USER */ Sg_scatter_hold reserve; /* buffer held for this file descriptor */ - Sg_request *headrp; /* head of request slist, NULL->empty */ + struct list_head rq_list; /* head of request list */ struct fasync_struct *async_qp; /* used by asynchronous notification */ Sg_request req_arr[SG_MAX_QUEUE]; /* used as singly-linked list */ char low_dma; /* as in parent but possibly overridden to 1 */ @@ -950,7 +950,7 @@ sg_ioctl(struct file *filp, unsigned int if (!access_ok(VERIFY_WRITE, ip, sizeof (int))) return -EFAULT; read_lock_irqsave(&sfp->rq_list_lock, iflags); - for (srp = sfp->headrp; srp; srp = srp->nextrp) { + list_for_each_entry(srp, &sfp->rq_list, entry) { if ((1 == srp->done) && (!srp->sg_io_owned)) { read_unlock_irqrestore(&sfp->rq_list_lock, iflags); @@ -963,7 +963,8 @@ sg_ioctl(struct file *filp, unsigned int return 0; case SG_GET_NUM_WAITING: read_lock_irqsave(&sfp->rq_list_lock, iflags); - for (val = 0, srp = sfp->headrp; srp; srp = srp->nextrp) { + val = 0; + list_for_each_entry(srp, &sfp->rq_list, entry) { if ((1 == srp->done) && (!srp->sg_io_owned)) ++val; } @@ -1038,35 +1039,33 @@ sg_ioctl(struct file *filp, unsigned int if (!rinfo) return -ENOMEM; read_lock_irqsave(&sfp->rq_list_lock, iflags); - for (srp = sfp->headrp, val = 0; val < SG_MAX_QUEUE; - ++val, srp = srp ? srp->nextrp : srp) { + val = 0; + list_for_each_entry(srp, &sfp->rq_list, entry) { + if (val > SG_MAX_QUEUE) + break; memset(&rinfo[val], 0, SZ_SG_REQ_INFO); - if (srp) { - rinfo[val].req_state = srp->done + 1; - rinfo[val].problem = - srp->header.masked_status & - srp->header.host_status & - srp->header.driver_status; - if (srp->done) - rinfo[val].duration = - srp->header.duration; - else { - ms = jiffies_to_msecs(jiffies); - rinfo[val].duration = - (ms > srp->header.duration) ? - (ms - srp->header.duration) : 0; - } - rinfo[val].orphan = srp->orphan; - rinfo[val].sg_io_owned = - srp->sg_io_owned; - rinfo[val].pack_id = - srp->header.pack_id; - rinfo[val].usr_ptr = - srp->header.usr_ptr; + rinfo[val].req_state = srp->done + 1; + rinfo[val].problem = + srp->header.masked_status & + srp->header.host_status & + srp->header.driver_status; + if (srp->done) + rinfo[val].duration = + srp->header.duration; + else { + ms = jiffies_to_msecs(jiffies); + rinfo[val].duration = + (ms > srp->header.duration) ? + (ms - srp->header.duration) : 0; } + rinfo[val].orphan = srp->orphan; + rinfo[val].sg_io_owned = srp->sg_io_owned; + rinfo[val].pack_id = srp->header.pack_id; + rinfo[val].usr_ptr = srp->header.usr_ptr; + val++; } read_unlock_irqrestore(&sfp->rq_list_lock, iflags); - result = __copy_to_user(p, rinfo, + result = __copy_to_user(p, rinfo, SZ_SG_REQ_INFO * SG_MAX_QUEUE); result = result ? -EFAULT : 0; kfree(rinfo); @@ -1172,7 +1171,7 @@ sg_poll(struct file *filp, poll_table * return POLLERR; poll_wait(filp, &sfp->read_wait, wait); read_lock_irqsave(&sfp->rq_list_lock, iflags); - for (srp = sfp->headrp; srp; srp = srp->nextrp) { + list_for_each_entry(srp, &sfp->rq_list, entry) { /* if any read waiting, flag it */ if ((0 == res) && (1 == srp->done) && (!srp->sg_io_owned)) res = POLLIN | POLLRDNORM; @@ -2070,7 +2069,7 @@ sg_get_rq_mark(Sg_fd * sfp, int pack_id) unsigned long iflags; write_lock_irqsave(&sfp->rq_list_lock, iflags); - for (resp = sfp->headrp; resp; resp = resp->nextrp) { + list_for_each_entry(resp, &sfp->rq_list, entry) { /* look for requests that are ready + not SG_IO owned */ if ((1 == resp->done) && (!resp->sg_io_owned) && ((-1 == pack_id) || (resp->header.pack_id == pack_id))) { @@ -2088,70 +2087,45 @@ sg_add_request(Sg_fd * sfp) { int k; unsigned long iflags; - Sg_request *resp; Sg_request *rp = sfp->req_arr; write_lock_irqsave(&sfp->rq_list_lock, iflags); - resp = sfp->headrp; - if (!resp) { - memset(rp, 0, sizeof (Sg_request)); - rp->parentfp = sfp; - resp = rp; - sfp->headrp = resp; - } else { - if (0 == sfp->cmd_q) - resp = NULL; /* command queuing disallowed */ - else { - for (k = 0; k < SG_MAX_QUEUE; ++k, ++rp) { - if (!rp->parentfp) - break; - } - if (k < SG_MAX_QUEUE) { - memset(rp, 0, sizeof (Sg_request)); - rp->parentfp = sfp; - while (resp->nextrp) - resp = resp->nextrp; - resp->nextrp = rp; - resp = rp; - } else - resp = NULL; + if (!list_empty(&sfp->rq_list)) { + if (!sfp->cmd_q) + goto out_unlock; + + for (k = 0; k < SG_MAX_QUEUE; ++k, ++rp) { + if (!rp->parentfp) + break; } + if (k >= SG_MAX_QUEUE) + goto out_unlock; } - if (resp) { - resp->nextrp = NULL; - resp->header.duration = jiffies_to_msecs(jiffies); - } + memset(rp, 0, sizeof (Sg_request)); + rp->parentfp = sfp; + rp->header.duration = jiffies_to_msecs(jiffies); + list_add_tail(&rp->entry, &sfp->rq_list); write_unlock_irqrestore(&sfp->rq_list_lock, iflags); - return resp; + return rp; +out_unlock: + write_unlock_irqrestore(&sfp->rq_list_lock, iflags); + return NULL; } /* Return of 1 for found; 0 for not found */ static int sg_remove_request(Sg_fd * sfp, Sg_request * srp) { - Sg_request *prev_rp; - Sg_request *rp; unsigned long iflags; int res = 0; - if ((!sfp) || (!srp) || (!sfp->headrp)) + if (!sfp || !srp || list_empty(&sfp->rq_list)) return res; write_lock_irqsave(&sfp->rq_list_lock, iflags); - prev_rp = sfp->headrp; - if (srp == prev_rp) { - sfp->headrp = prev_rp->nextrp; - prev_rp->parentfp = NULL; + if (!list_empty(&srp->entry)) { + list_del(&srp->entry); + srp->parentfp = NULL; res = 1; - } else { - while ((rp = prev_rp->nextrp)) { - if (srp == rp) { - prev_rp->nextrp = rp->nextrp; - rp->parentfp = NULL; - res = 1; - break; - } - prev_rp = rp; - } } write_unlock_irqrestore(&sfp->rq_list_lock, iflags); return res; @@ -2170,7 +2144,7 @@ sg_add_sfp(Sg_device * sdp) init_waitqueue_head(&sfp->read_wait); rwlock_init(&sfp->rq_list_lock); - + INIT_LIST_HEAD(&sfp->rq_list); kref_init(&sfp->f_ref); mutex_init(&sfp->f_mutex); sfp->timeout = SG_DEFAULT_TIMEOUT; @@ -2211,10 +2185,13 @@ sg_remove_sfp_usercontext(struct work_st { struct sg_fd *sfp = container_of(work, struct sg_fd, ew.work); struct sg_device *sdp = sfp->parentdp; + Sg_request *srp; /* Cleanup any responses which were never read(). */ - while (sfp->headrp) - sg_finish_rem_req(sfp->headrp); + while (!list_empty(&sfp->rq_list)) { + srp = list_first_entry(&sfp->rq_list, Sg_request, entry); + sg_finish_rem_req(srp); + } if (sfp->reserve.bufflen > 0) { SCSI_LOG_TIMEOUT(6, sg_printk(KERN_INFO, sdp, @@ -2617,7 +2594,7 @@ static int sg_proc_seq_show_devstrs(stru /* must be called while holding sg_index_lock */ static void sg_proc_debug_helper(struct seq_file *s, Sg_device * sdp) { - int k, m, new_interface, blen, usg; + int k, new_interface, blen, usg; Sg_request *srp; Sg_fd *fp; const sg_io_hdr_t *hp; @@ -2637,13 +2614,11 @@ static void sg_proc_debug_helper(struct seq_printf(s, " cmd_q=%d f_packid=%d k_orphan=%d closed=0\n", (int) fp->cmd_q, (int) fp->force_packid, (int) fp->keep_orphan); - for (m = 0, srp = fp->headrp; - srp != NULL; - ++m, srp = srp->nextrp) { + list_for_each_entry(srp, &fp->rq_list, entry) { hp = &srp->header; new_interface = (hp->interface_id == '\0') ? 0 : 1; if (srp->res_used) { - if (new_interface && + if (new_interface && (SG_FLAG_MMAP_IO & hp->flags)) cp = " mmap>> "; else @@ -2674,7 +2649,7 @@ static void sg_proc_debug_helper(struct seq_printf(s, "ms sgat=%d op=0x%02x\n", usg, (int) srp->data.cmd_opcode); } - if (0 == m) + if (list_empty(&fp->rq_list)) seq_puts(s, " No requests active\n"); read_unlock(&fp->rq_list_lock); } Patches currently in stable-queue which might be from hare@xxxxxxx are queue-4.4/scsi-sg-use-standard-lists-for-sg_requests.patch queue-4.4/scsi-sg-factor-out-sg_fill_request_table.patch queue-4.4/skd-submit-requests-to-firmware-before-triggering-the-doorbell.patch queue-4.4/scsi-sg-remove-save_scat_len.patch queue-4.4/block-relax-a-check-in-blk_start_queue.patch queue-4.4/skd-avoid-that-module-unloading-triggers-a-use-after-free.patch