From b4b7ff4b08e691656c9d77c758fc355833128ac0 Mon Sep 17 00:00:00 2001 From: André Fabian Silva Delgado Date: Wed, 20 Jan 2016 14:01:31 -0300 Subject: Linux-libre 4.4-gnu --- drivers/scsi/cxlflash/vlun.c | 68 +++++++++++++++++++++++++++++++------------- 1 file changed, 49 insertions(+), 19 deletions(-) (limited to 'drivers/scsi/cxlflash/vlun.c') diff --git a/drivers/scsi/cxlflash/vlun.c b/drivers/scsi/cxlflash/vlun.c index 6155cb1d4..a53f583e2 100644 --- a/drivers/scsi/cxlflash/vlun.c +++ b/drivers/scsi/cxlflash/vlun.c @@ -132,7 +132,7 @@ static int ba_init(struct ba_lun *ba_lun) return -ENOMEM; } - /* Pass the allocated lun info as a handle to the user */ + /* Pass the allocated LUN info as a handle to the user */ ba_lun->ba_lun_handle = bali; pr_debug("%s: Successfully initialized the LUN: " @@ -165,7 +165,7 @@ static int find_free_range(u32 low, num_bits = (sizeof(*lam) * BITS_PER_BYTE); bit_pos = find_first_bit(lam, num_bits); - pr_devel("%s: Found free bit %llX in lun " + pr_devel("%s: Found free bit %llX in LUN " "map entry %llX at bitmap index = %X\n", __func__, bit_pos, bali->lun_alloc_map[i], i); @@ -400,6 +400,24 @@ static int init_vlun(struct llun_info *lli) * @lba: Logical block address to start write same. * @nblks: Number of logical blocks to write same. * + * The SCSI WRITE_SAME16 can take quite a while to complete. Should an EEH occur + * while in scsi_execute(), the EEH handler will attempt to recover. As part of + * the recovery, the handler drains all currently running ioctls, waiting until + * they have completed before proceeding with a reset. As this routine is used + * on the ioctl path, this can create a condition where the EEH handler becomes + * stuck, infinitely waiting for this ioctl thread. To avoid this behavior, + * temporarily unmark this thread as an ioctl thread by releasing the ioctl read + * semaphore. This will allow the EEH handler to proceed with a recovery while + * this thread is still running. Once the scsi_execute() returns, reacquire the + * ioctl read semaphore and check the adapter state in case it changed while + * inside of scsi_execute(). The state check will wait if the adapter is still + * being recovered or return a failure if the recovery failed. In the event that + * the adapter reset failed, simply return the failure as the ioctl would be + * unable to continue. + * + * Note that the above puts a requirement on this routine to only be called on + * an ioctl thread. + * * Return: 0 on success, -errno on failure */ static int write_same16(struct scsi_device *sdev, @@ -414,7 +432,7 @@ static int write_same16(struct scsi_device *sdev, int ws_limit = SISLITE_MAX_WS_BLOCKS; u64 offset = lba; int left = nblks; - u32 tout = sdev->request_queue->rq_timeout; + u32 to = sdev->request_queue->rq_timeout; struct cxlflash_cfg *cfg = (struct cxlflash_cfg *)sdev->host->hostdata; struct device *dev = &cfg->dev->dev; @@ -433,8 +451,20 @@ static int write_same16(struct scsi_device *sdev, put_unaligned_be32(ws_limit < left ? ws_limit : left, &scsi_cmd[10]); + /* Drop the ioctl read semahpore across lengthy call */ + up_read(&cfg->ioctl_rwsem); result = scsi_execute(sdev, scsi_cmd, DMA_TO_DEVICE, cmd_buf, - CMD_BUFSIZE, sense_buf, tout, 5, 0, NULL); + CMD_BUFSIZE, sense_buf, to, CMD_RETRIES, + 0, NULL); + down_read(&cfg->ioctl_rwsem); + rc = check_state(cfg); + if (rc) { + dev_err(dev, "%s: Failed state! result=0x08%X\n", + __func__, result); + rc = -ENODEV; + goto out; + } + if (result) { dev_err_ratelimited(dev, "%s: command failed for " "offset %lld result=0x%x\n", @@ -681,14 +711,14 @@ out: } /** - * _cxlflash_vlun_resize() - changes the size of a virtual lun + * _cxlflash_vlun_resize() - changes the size of a virtual LUN * @sdev: SCSI device associated with LUN owning virtual LUN. * @ctxi: Context owning resources. * @resize: Resize ioctl data structure. * * On successful return, the user is informed of the new size (in blocks) - * of the virtual lun in last LBA format. When the size of the virtual - * lun is zero, the last LBA is reflected as -1. See comment in the + * of the virtual LUN in last LBA format. When the size of the virtual + * LUN is zero, the last LBA is reflected as -1. See comment in the * prologue for _cxlflash_disk_release() regarding AFU syncs and contexts * on the error recovery list. * @@ -785,7 +815,7 @@ void cxlflash_restore_luntable(struct cxlflash_cfg *cfg) u32 chan; u32 lind; struct afu *afu = cfg->afu; - struct sisl_global_map *agm = &afu->afu_map->global; + struct sisl_global_map __iomem *agm = &afu->afu_map->global; mutex_lock(&global.mutex); @@ -830,7 +860,7 @@ static int init_luntable(struct cxlflash_cfg *cfg, struct llun_info *lli) u32 lind; int rc = 0; struct afu *afu = cfg->afu; - struct sisl_global_map *agm = &afu->afu_map->global; + struct sisl_global_map __iomem *agm = &afu->afu_map->global; mutex_lock(&global.mutex); @@ -885,8 +915,8 @@ out: * @arg: UVirtual ioctl data structure. * * On successful return, the user is informed of the resource handle - * to be used to identify the virtual lun and the size (in blocks) of - * the virtual lun in last LBA format. When the size of the virtual lun + * to be used to identify the virtual LUN and the size (in blocks) of + * the virtual LUN in last LBA format. When the size of the virtual LUN * is zero, the last LBA is reflected as -1. * * Return: 0 on success, -errno on failure @@ -914,16 +944,9 @@ int cxlflash_disk_virtual_open(struct scsi_device *sdev, void *arg) pr_debug("%s: ctxid=%llu ls=0x%llx\n", __func__, ctxid, lun_size); + /* Setup the LUNs block allocator on first call */ mutex_lock(&gli->mutex); if (gli->mode == MODE_NONE) { - /* Setup the LUN table and block allocator on first call */ - rc = init_luntable(cfg, lli); - if (rc) { - dev_err(dev, "%s: call to init_luntable failed " - "rc=%d!\n", __func__, rc); - goto err0; - } - rc = init_vlun(lli); if (rc) { dev_err(dev, "%s: call to init_vlun failed rc=%d!\n", @@ -941,6 +964,13 @@ int cxlflash_disk_virtual_open(struct scsi_device *sdev, void *arg) } mutex_unlock(&gli->mutex); + rc = init_luntable(cfg, lli); + if (rc) { + dev_err(dev, "%s: call to init_luntable failed rc=%d!\n", + __func__, rc); + goto err1; + } + ctxi = get_context(cfg, rctxid, lli, 0); if (unlikely(!ctxi)) { dev_err(dev, "%s: Bad context! (%llu)\n", __func__, ctxid); -- cgit v1.2.3-54-g00ecf