scsi_lib.c revision 6bd522f6a226f435508433d24e0de4619e016a9d
11da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds/* 21da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * scsi_lib.c Copyright (C) 1999 Eric Youngdale 31da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 41da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * SCSI queueing library. 51da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * Initial versions: Eric Youngdale (eric@andante.org). 61da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * Based upon conversations with large numbers 71da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * of people at Linux Expo. 81da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds */ 91da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 101da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <linux/bio.h> 111da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <linux/bitops.h> 121da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <linux/blkdev.h> 131da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <linux/completion.h> 141da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <linux/kernel.h> 151da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <linux/mempool.h> 161da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <linux/slab.h> 171da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <linux/init.h> 181da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <linux/pci.h> 191da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <linux/delay.h> 201da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <linux/hardirq.h> 211da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <linux/scatterlist.h> 221da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 231da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <scsi/scsi.h> 241da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <scsi/scsi_cmnd.h> 251da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <scsi/scsi_dbg.h> 261da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <scsi/scsi_device.h> 271da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <scsi/scsi_driver.h> 281da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <scsi/scsi_eh.h> 291da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <scsi/scsi_host.h> 301da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 311da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include "scsi_priv.h" 321da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include "scsi_logging.h" 331da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 341da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 351da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#define SG_MEMPOOL_NR ARRAY_SIZE(scsi_sg_pools) 361da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#define SG_MEMPOOL_SIZE 2 371da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 381da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsstruct scsi_host_sg_pool { 391da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds size_t size; 401da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds char *name; 411da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds struct kmem_cache *slab; 421da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds mempool_t *pool; 431da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds}; 441da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 451da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#define SP(x) { x, "sgpool-" __stringify(x) } 461da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#if (SCSI_MAX_SG_SEGMENTS < 32) 471da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#error SCSI_MAX_SG_SEGMENTS is too small (must be 32 or greater) 481da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#endif 491da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsstatic struct scsi_host_sg_pool scsi_sg_pools[] = { 501da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds SP(8), 511da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds SP(16), 521da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#if (SCSI_MAX_SG_SEGMENTS > 32) 531da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds SP(32), 541da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#if (SCSI_MAX_SG_SEGMENTS > 64) 551da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds SP(64), 561da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#if (SCSI_MAX_SG_SEGMENTS > 128) 57b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel SP(128), 581da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#if (SCSI_MAX_SG_SEGMENTS > 256) 591da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#error SCSI_MAX_SG_SEGMENTS is too large (256 MAX) 601da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#endif 611da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#endif 621da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#endif 631da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#endif 641da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds SP(SCSI_MAX_SG_SEGMENTS) 651da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds}; 661da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#undef SP 671da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 68b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidelstruct kmem_cache *scsi_sdb_cache; 691da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 701da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsstatic void scsi_run_queue(struct request_queue *q); 712e1973a3cd0b9fe31469be62df3583bdc5a34f51Markus Lidel 721da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds/* 731da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * Function: scsi_unprep_request() 741da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 751da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * Purpose: Remove all preparation done for a request, including its 76b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel * associated scsi_cmnd, so that it can be requeued. 77b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel * 781da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * Arguments: req - request to unprepare 791da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 801da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * Lock status: Assumed that no locks are held upon entry. 811da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 82b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel * Returns: Nothing. 831da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds */ 841da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsstatic void scsi_unprep_request(struct request *req) 851da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds{ 861da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds struct scsi_cmnd *cmd = req->special; 871da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 881da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds req->cmd_flags &= ~REQ_DONTPREP; 891da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds req->special = NULL; 901da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 911da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds scsi_put_command(cmd); 921da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds} 931da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 941da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds/* 951da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * Function: scsi_queue_insert() 961da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 971da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * Purpose: Insert a command in the midlevel queue. 981da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 991da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * Arguments: cmd - command that we are adding to queue. 1001da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * reason - why we are inserting command to queue. 1011da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 1021da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * Lock status: Assumed that lock is not held upon entry. 1031da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 1041da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * Returns: Nothing. 105b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel * 106b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel * Notes: We do this for one of two cases. Either the host is busy 107b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel * and it cannot accept any more commands for the time being, 108b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel * or the device returned QUEUE_FULL and can accept no more 109b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel * commands. 110b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel * Notes: This could be called either from an interrupt context or a 1111da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * normal process context. 1121da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds */ 113f10378fff658f61307496e0ae00095041725cf07Markus Lidelint scsi_queue_insert(struct scsi_cmnd *cmd, int reason) 114793fd15d9fafe5b1c71e50d3c041f1463895dbdeMarkus Lidel{ 115b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel struct Scsi_Host *host = cmd->device->host; 1161da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds struct scsi_device *device = cmd->device; 1171da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds struct request_queue *q = device->request_queue; 1181da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds unsigned long flags; 1191da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 1201da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds SCSI_LOG_MLQUEUE(1, 1211da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds printk("Inserting command %p into mlqueue\n", cmd)); 1221da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 1231da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds /* 1241da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * Set the appropriate busy bit for the device/host. 1251da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 1261da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * If the host/device isn't busy, assume that something actually 1271da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * completed, and that we should be able to queue a command now. 1281da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 1291da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * Note that the prior mid-layer assumption that any host could 1301da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * always queue at least one command is now broken. The mid-layer 1311da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * will implement a user specifiable stall (see 1321da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * scsi_host.max_host_blocked and scsi_device.max_device_blocked) 1331da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * if a command is requeued with no other commands outstanding 1341da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * either for the device or for the host. 1351da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds */ 1361da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds if (reason == SCSI_MLQUEUE_HOST_BUSY) 137b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel host->host_blocked = host->max_host_blocked; 1381da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds else if (reason == SCSI_MLQUEUE_DEVICE_BUSY) 1391da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds device->device_blocked = device->max_device_blocked; 1401da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 1411da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds /* 142b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel * Decrement the counters, since these commands are no longer 1431da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * active on the host/device. 1441da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds */ 1451da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds scsi_device_unbusy(device); 146f10378fff658f61307496e0ae00095041725cf07Markus Lidel 147793fd15d9fafe5b1c71e50d3c041f1463895dbdeMarkus Lidel /* 148b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel * Requeue this command. It will go before all other commands 1491da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * that are already in the queue. 1501da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 1511da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * NOTE: there is magic here about the way the queue is plugged if 1521da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * we have no outstanding commands. 1531da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 1541da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * Although we *don't* plug the queue, we call the request 1551da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * function. The SCSI request function detects the blocked condition 1561da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * and plugs the queue appropriately. 1571da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds */ 1581da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds spin_lock_irqsave(q->queue_lock, flags); 1591da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds blk_requeue_request(q, cmd->request); 1601da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds spin_unlock_irqrestore(q->queue_lock, flags); 1611da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 1621da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds scsi_run_queue(q); 1631da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 1641da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds return 0; 1651da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds} 1661da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 1671da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds/** 1681da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * scsi_execute - insert request and wait for the result 1691da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * @sdev: scsi device 1701da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * @cmd: scsi command 1711da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * @data_direction: data direction 1721da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * @buffer: data buffer 1731da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * @bufflen: len of buffer 1741da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * @sense: optional sense buffer 1751da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * @timeout: request timeout in seconds 1761da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * @retries: number of times to retry request 1771da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * @flags: or into request flags; 1781da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 1791da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * returns the req->errors value which is the scsi_cmnd result 1801da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * field. 1811da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds */ 1821da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsint scsi_execute(struct scsi_device *sdev, const unsigned char *cmd, 1831da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds int data_direction, void *buffer, unsigned bufflen, 1841da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds unsigned char *sense, int timeout, int retries, int flags) 1851da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds{ 1861da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds struct request *req; 1871da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds int write = (data_direction == DMA_TO_DEVICE); 188f88e119c4b824a5017456fa094950d0f4092d96cMarkus Lidel int ret = DRIVER_ERROR << 24; 189f88e119c4b824a5017456fa094950d0f4092d96cMarkus Lidel 1901da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds req = blk_get_request(sdev->request_queue, write, __GFP_WAIT); 1911da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 1921da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds if (bufflen && blk_rq_map_kern(sdev->request_queue, req, 1931da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds buffer, bufflen, __GFP_WAIT)) 194f10378fff658f61307496e0ae00095041725cf07Markus Lidel goto out; 1951da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 1961da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds req->cmd_len = COMMAND_SIZE(cmd[0]); 1971da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds memcpy(req->cmd, cmd, req->cmd_len); 1981da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds req->sense = sense; 1991da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds req->sense_len = 0; 2001da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds req->retries = retries; 2011da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds req->timeout = timeout; 2021da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds req->cmd_type = REQ_TYPE_BLOCK_PC; 2031da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds req->cmd_flags |= flags | REQ_QUIET | REQ_PREEMPT; 2041da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 2051da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds /* 2061da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * head injection *required* here otherwise quiesce won't work 2071da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds */ 2081da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds blk_execute_rq(req->q, NULL, req, 1); 2091da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 2101da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds /* 2111da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * Some devices (USB mass-storage in particular) may transfer 2121da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * garbage data together with a residue indicating that the data 2131da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * is invalid. Prevent the garbage from being misinterpreted 2141da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * and prevent security leaks by zeroing out the excess data. 2151da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds */ 2161da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds if (unlikely(req->data_len > 0 && req->data_len <= bufflen)) 2171da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds memset(buffer + (bufflen - req->data_len), 0, req->data_len); 2181da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 2191da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds ret = req->errors; 220b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel out: 221b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel blk_put_request(req); 2221da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 2233889b26bebd3e3cf5a3b95da683bab2f6462133dJeff Garzik return ret; 2241da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds} 2251da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus TorvaldsEXPORT_SYMBOL(scsi_execute); 2261da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 2271da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 2281da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsint scsi_execute_req(struct scsi_device *sdev, const unsigned char *cmd, 2291da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds int data_direction, void *buffer, unsigned bufflen, 2301da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds struct scsi_sense_hdr *sshdr, int timeout, int retries) 231b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel{ 232b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel char *sense = NULL; 233b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel int result; 234b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel 235b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel if (sshdr) { 236b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel sense = kzalloc(SCSI_SENSE_BUFFERSIZE, GFP_NOIO); 237b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel if (!sense) 238b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel return DRIVER_ERROR << 24; 239793fd15d9fafe5b1c71e50d3c041f1463895dbdeMarkus Lidel } 240b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel result = scsi_execute(sdev, cmd, data_direction, buffer, bufflen, 241793fd15d9fafe5b1c71e50d3c041f1463895dbdeMarkus Lidel sense, timeout, retries, 0); 242b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel if (sshdr) 243b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel scsi_normalize_sense(sense, SCSI_SENSE_BUFFERSIZE, sshdr); 244b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel 245793fd15d9fafe5b1c71e50d3c041f1463895dbdeMarkus Lidel kfree(sense); 246793fd15d9fafe5b1c71e50d3c041f1463895dbdeMarkus Lidel return result; 247793fd15d9fafe5b1c71e50d3c041f1463895dbdeMarkus Lidel} 248b2aaee33fbb354a2f08121aa1c1be55841102761Markus LidelEXPORT_SYMBOL(scsi_execute_req); 249b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel 250b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidelstruct scsi_io_context { 251b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel void *data; 252b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel void (*done)(void *data, char *sense, int result, int resid); 253b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel char sense[SCSI_SENSE_BUFFERSIZE]; 254b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel}; 255b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel 256793fd15d9fafe5b1c71e50d3c041f1463895dbdeMarkus Lidelstatic struct kmem_cache *scsi_io_context_cache; 257b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel 258b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidelstatic void scsi_end_async(struct request *req, int uptodate) 259793fd15d9fafe5b1c71e50d3c041f1463895dbdeMarkus Lidel{ 260b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel struct scsi_io_context *sioc = req->end_io_data; 261b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel 262b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel if (sioc->done) 263b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel sioc->done(sioc->data, sioc->sense, req->errors, req->data_len); 264b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel 265b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel kmem_cache_free(scsi_io_context_cache, sioc); 266b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel __blk_put_request(req->q, req); 267b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel} 268b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel 269b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidelstatic int scsi_merge_bio(struct request *rq, struct bio *bio) 270b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel{ 271b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel struct request_queue *q = rq->q; 272b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel 273b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel bio->bi_flags &= ~(1 << BIO_SEG_VALID); 274b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel if (rq_data_dir(rq) == WRITE) 275b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel bio->bi_rw |= (1 << BIO_RW); 276b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel blk_queue_bounce(q, &bio); 277b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel 278b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel return blk_rq_append_bio(q, rq, bio); 279b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel} 280b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel 2811da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsstatic void scsi_bi_endio(struct bio *bio, int error) 282b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel{ 2831da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds bio_put(bio); 284793fd15d9fafe5b1c71e50d3c041f1463895dbdeMarkus Lidel} 285793fd15d9fafe5b1c71e50d3c041f1463895dbdeMarkus Lidel 286793fd15d9fafe5b1c71e50d3c041f1463895dbdeMarkus Lidel/** 2871da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * scsi_req_map_sg - map a scatterlist into a request 2881da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * @rq: request to fill 2891da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * @sgl: scatterlist 290793fd15d9fafe5b1c71e50d3c041f1463895dbdeMarkus Lidel * @nsegs: number of elements 291793fd15d9fafe5b1c71e50d3c041f1463895dbdeMarkus Lidel * @bufflen: len of buffer 292793fd15d9fafe5b1c71e50d3c041f1463895dbdeMarkus Lidel * @gfp: memory allocation flags 293793fd15d9fafe5b1c71e50d3c041f1463895dbdeMarkus Lidel * 2941da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * scsi_req_map_sg maps a scatterlist into a request so that the 2951da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * request can be sent to the block layer. We do not trust the scatterlist 2961da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * sent to use, as some ULDs use that struct to only organize the pages. 2971da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds */ 298793fd15d9fafe5b1c71e50d3c041f1463895dbdeMarkus Lidelstatic int scsi_req_map_sg(struct request *rq, struct scatterlist *sgl, 299793fd15d9fafe5b1c71e50d3c041f1463895dbdeMarkus Lidel int nsegs, unsigned bufflen, gfp_t gfp) 3001da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds{ 301f10378fff658f61307496e0ae00095041725cf07Markus Lidel struct request_queue *q = rq->q; 3021da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds int nr_pages = (bufflen + sgl[0].offset + PAGE_SIZE - 1) >> PAGE_SHIFT; 3031da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds unsigned int data_len = bufflen, len, bytes, off; 304f10378fff658f61307496e0ae00095041725cf07Markus Lidel struct scatterlist *sg; 3051da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds struct page *page; 3061da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds struct bio *bio = NULL; 3073889b26bebd3e3cf5a3b95da683bab2f6462133dJeff Garzik int i, err, nr_vecs = 0; 3083889b26bebd3e3cf5a3b95da683bab2f6462133dJeff Garzik 3093889b26bebd3e3cf5a3b95da683bab2f6462133dJeff Garzik for_each_sg(sgl, sg, nsegs, i) { 3103889b26bebd3e3cf5a3b95da683bab2f6462133dJeff Garzik page = sg_page(sg); 311f10378fff658f61307496e0ae00095041725cf07Markus Lidel off = sg->offset; 312dcceafe25a5f47cf69e5b46b4da6f15186ec8386Markus Lidel len = sg->length; 313793fd15d9fafe5b1c71e50d3c041f1463895dbdeMarkus Lidel 314dcceafe25a5f47cf69e5b46b4da6f15186ec8386Markus Lidel while (len > 0 && data_len > 0) { 3151da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds /* 3161da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * sg sends a scatterlist that is larger than 3173889b26bebd3e3cf5a3b95da683bab2f6462133dJeff Garzik * the data_len it wants transferred for certain 3183889b26bebd3e3cf5a3b95da683bab2f6462133dJeff Garzik * IO sizes 3193889b26bebd3e3cf5a3b95da683bab2f6462133dJeff Garzik */ 3203889b26bebd3e3cf5a3b95da683bab2f6462133dJeff Garzik bytes = min_t(unsigned int, len, PAGE_SIZE - off); 3211da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds bytes = min(bytes, data_len); 3221da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 3231da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds if (!bio) { 3241da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds nr_vecs = min_t(int, BIO_MAX_PAGES, nr_pages); 3251da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds nr_pages -= nr_vecs; 3261da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 3271da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds bio = bio_alloc(gfp, nr_vecs); 3281da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds if (!bio) { 3291da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds err = -ENOMEM; 3301da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds goto free_bios; 3311da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds } 3321da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds bio->bi_end_io = scsi_bi_endio; 3331da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds } 3341da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 3351da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds if (bio_add_pc_page(q, bio, page, bytes, off) != 3361da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds bytes) { 3371da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds bio_put(bio); 3381da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds err = -EINVAL; 3391da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds goto free_bios; 3401da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds } 3411da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 3421da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds if (bio->bi_vcnt >= nr_vecs) { 3431da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds err = scsi_merge_bio(rq, bio); 3441da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds if (err) { 3451da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds bio_endio(bio, 0); 3461da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds goto free_bios; 3471da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds } 3481da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds bio = NULL; 3499e87545f06930c1d294423a8091d1077e7444a47Markus Lidel } 3501da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 3511da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds page++; 3521da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds len -= bytes; 3539e87545f06930c1d294423a8091d1077e7444a47Markus Lidel data_len -=bytes; 3549e87545f06930c1d294423a8091d1077e7444a47Markus Lidel off = 0; 3559e87545f06930c1d294423a8091d1077e7444a47Markus Lidel } 3561da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds } 3571da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 3581da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds rq->buffer = rq->data = NULL; 3591da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds rq->data_len = bufflen; 3601da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds return 0; 3611da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 3629e87545f06930c1d294423a8091d1077e7444a47Markus Lidelfree_bios: 3631da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds while ((bio = rq->bio) != NULL) { 3649e87545f06930c1d294423a8091d1077e7444a47Markus Lidel rq->bio = bio->bi_next; 3659e87545f06930c1d294423a8091d1077e7444a47Markus Lidel /* 3669e87545f06930c1d294423a8091d1077e7444a47Markus Lidel * call endio instead of bio_put incase it was bounced 3671da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds */ 3689e87545f06930c1d294423a8091d1077e7444a47Markus Lidel bio_endio(bio, 0); 3699e87545f06930c1d294423a8091d1077e7444a47Markus Lidel } 3701da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 3719e87545f06930c1d294423a8091d1077e7444a47Markus Lidel return err; 3729e87545f06930c1d294423a8091d1077e7444a47Markus Lidel} 3739e87545f06930c1d294423a8091d1077e7444a47Markus Lidel 3741da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds/** 3759e87545f06930c1d294423a8091d1077e7444a47Markus Lidel * scsi_execute_async - insert request 3769e87545f06930c1d294423a8091d1077e7444a47Markus Lidel * @sdev: scsi device 3779e87545f06930c1d294423a8091d1077e7444a47Markus Lidel * @cmd: scsi command 3781da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * @cmd_len: length of scsi cdb 3799e87545f06930c1d294423a8091d1077e7444a47Markus Lidel * @data_direction: DMA_TO_DEVICE, DMA_FROM_DEVICE, or DMA_NONE 3809e87545f06930c1d294423a8091d1077e7444a47Markus Lidel * @buffer: data buffer (this can be a kernel buffer or scatterlist) 3819e87545f06930c1d294423a8091d1077e7444a47Markus Lidel * @bufflen: len of buffer 3829e87545f06930c1d294423a8091d1077e7444a47Markus Lidel * @use_sg: if buffer is a scatterlist this is the number of elements 3839e87545f06930c1d294423a8091d1077e7444a47Markus Lidel * @timeout: request timeout in seconds 3849e87545f06930c1d294423a8091d1077e7444a47Markus Lidel * @retries: number of times to retry request 3859e87545f06930c1d294423a8091d1077e7444a47Markus Lidel * @privdata: data passed to done() 3861da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * @done: callback function when done 3879e87545f06930c1d294423a8091d1077e7444a47Markus Lidel * @gfp: memory allocation flags 3881da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds */ 3899e87545f06930c1d294423a8091d1077e7444a47Markus Lidelint scsi_execute_async(struct scsi_device *sdev, const unsigned char *cmd, 3909e87545f06930c1d294423a8091d1077e7444a47Markus Lidel int cmd_len, int data_direction, void *buffer, unsigned bufflen, 3911da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds int use_sg, int timeout, int retries, void *privdata, 3929e87545f06930c1d294423a8091d1077e7444a47Markus Lidel void (*done)(void *, char *, int, int), gfp_t gfp) 3939e87545f06930c1d294423a8091d1077e7444a47Markus Lidel{ 3949e87545f06930c1d294423a8091d1077e7444a47Markus Lidel struct request *req; 3959e87545f06930c1d294423a8091d1077e7444a47Markus Lidel struct scsi_io_context *sioc; 3969e87545f06930c1d294423a8091d1077e7444a47Markus Lidel int err = 0; 3979e87545f06930c1d294423a8091d1077e7444a47Markus Lidel int write = (data_direction == DMA_TO_DEVICE); 3989e87545f06930c1d294423a8091d1077e7444a47Markus Lidel 3999e87545f06930c1d294423a8091d1077e7444a47Markus Lidel sioc = kmem_cache_zalloc(scsi_io_context_cache, gfp); 4009e87545f06930c1d294423a8091d1077e7444a47Markus Lidel if (!sioc) 4019e87545f06930c1d294423a8091d1077e7444a47Markus Lidel return DRIVER_ERROR << 24; 4029e87545f06930c1d294423a8091d1077e7444a47Markus Lidel 4039e87545f06930c1d294423a8091d1077e7444a47Markus Lidel req = blk_get_request(sdev->request_queue, write, gfp); 4049e87545f06930c1d294423a8091d1077e7444a47Markus Lidel if (!req) 4059e87545f06930c1d294423a8091d1077e7444a47Markus Lidel goto free_sense; 4069e87545f06930c1d294423a8091d1077e7444a47Markus Lidel req->cmd_type = REQ_TYPE_BLOCK_PC; 4071da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds req->cmd_flags |= REQ_QUIET; 4089e87545f06930c1d294423a8091d1077e7444a47Markus Lidel 4099e87545f06930c1d294423a8091d1077e7444a47Markus Lidel if (use_sg) 4101da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds err = scsi_req_map_sg(req, buffer, use_sg, bufflen, gfp); 4119e87545f06930c1d294423a8091d1077e7444a47Markus Lidel else if (bufflen) 4121da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds err = blk_rq_map_kern(req->q, req, buffer, bufflen, gfp); 4139e87545f06930c1d294423a8091d1077e7444a47Markus Lidel 4149e87545f06930c1d294423a8091d1077e7444a47Markus Lidel if (err) 4159e87545f06930c1d294423a8091d1077e7444a47Markus Lidel goto free_req; 4169e87545f06930c1d294423a8091d1077e7444a47Markus Lidel 4179e87545f06930c1d294423a8091d1077e7444a47Markus Lidel req->cmd_len = cmd_len; 4189e87545f06930c1d294423a8091d1077e7444a47Markus Lidel memset(req->cmd, 0, BLK_MAX_CDB); /* ATAPI hates garbage after CDB */ 4199e87545f06930c1d294423a8091d1077e7444a47Markus Lidel memcpy(req->cmd, cmd, req->cmd_len); 4209e87545f06930c1d294423a8091d1077e7444a47Markus Lidel req->sense = sioc->sense; 4219e87545f06930c1d294423a8091d1077e7444a47Markus Lidel req->sense_len = 0; 4229e87545f06930c1d294423a8091d1077e7444a47Markus Lidel req->timeout = timeout; 4239e87545f06930c1d294423a8091d1077e7444a47Markus Lidel req->retries = retries; 4249e87545f06930c1d294423a8091d1077e7444a47Markus Lidel req->end_io_data = sioc; 4259e87545f06930c1d294423a8091d1077e7444a47Markus Lidel 4269e87545f06930c1d294423a8091d1077e7444a47Markus Lidel sioc->data = privdata; 4279e87545f06930c1d294423a8091d1077e7444a47Markus Lidel sioc->done = done; 428f88e119c4b824a5017456fa094950d0f4092d96cMarkus Lidel 4299e87545f06930c1d294423a8091d1077e7444a47Markus Lidel blk_execute_rq_nowait(req->q, NULL, req, 1, scsi_end_async); 4309e87545f06930c1d294423a8091d1077e7444a47Markus Lidel return 0; 4319e87545f06930c1d294423a8091d1077e7444a47Markus Lidel 4321da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsfree_req: 4331da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds blk_put_request(req); 4341da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsfree_sense: 4351da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds kmem_cache_free(scsi_io_context_cache, sioc); 4361da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds return DRIVER_ERROR << 24; 4371da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds} 4381da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus TorvaldsEXPORT_SYMBOL_GPL(scsi_execute_async); 4391da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 4401da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds/* 4411da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * Function: scsi_init_cmd_errh() 4421da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 4431da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * Purpose: Initialize cmd fields related to error handling. 4441da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 4451da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * Arguments: cmd - command that is ready to be queued. 4461da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 4471da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * Notes: This function has the job of initializing a number of 4481da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * fields related to error handling. Typically this will 4491da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * be called once for each command, as required. 4501da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds */ 4511da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsstatic void scsi_init_cmd_errh(struct scsi_cmnd *cmd) 4521da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds{ 4531da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds cmd->serial_number = 0; 4541da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds scsi_set_resid(cmd, 0); 4551da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds memset(cmd->sense_buffer, 0, SCSI_SENSE_BUFFERSIZE); 4561da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds if (cmd->cmd_len == 0) 4571da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds cmd->cmd_len = scsi_command_size(cmd->cmnd); 4581da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds} 4591da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 4601da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsvoid scsi_device_unbusy(struct scsi_device *sdev) 4611da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds{ 4621da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds struct Scsi_Host *shost = sdev->host; 4631da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds unsigned long flags; 4641da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 4651da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds spin_lock_irqsave(shost->host_lock, flags); 4661da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds shost->host_busy--; 4671da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds if (unlikely(scsi_host_in_recovery(shost) && 4681da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds (shost->host_failed || shost->host_eh_scheduled))) 4691da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds scsi_eh_wakeup(shost); 4701da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds spin_unlock(shost->host_lock); 4711da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds spin_lock(sdev->request_queue->queue_lock); 4721da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds sdev->device_busy--; 4731da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags); 4741da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds} 4751da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 4761da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds/* 4771da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * Called for single_lun devices on IO completion. Clear starget_sdev_user, 4781da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * and call blk_run_queue for all the scsi_devices on the target - 4791da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * including current_sdev first. 4801da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 4811da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * Called with *no* scsi locks held. 4821da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds */ 4831da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsstatic void scsi_single_lun_run(struct scsi_device *current_sdev) 484f88e119c4b824a5017456fa094950d0f4092d96cMarkus Lidel{ 4851da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds struct Scsi_Host *shost = current_sdev->host; 4861da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds struct scsi_device *sdev, *tmp; 4871da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds struct scsi_target *starget = scsi_target(current_sdev); 4881da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds unsigned long flags; 4891da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 4901da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds spin_lock_irqsave(shost->host_lock, flags); 4911da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds starget->starget_sdev_user = NULL; 4929e87545f06930c1d294423a8091d1077e7444a47Markus Lidel spin_unlock_irqrestore(shost->host_lock, flags); 4939e87545f06930c1d294423a8091d1077e7444a47Markus Lidel 4941da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds /* 4951da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * Call blk_run_queue for all LUNs on the target, starting with 4961da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * current_sdev. We race with others (to set starget_sdev_user), 4971da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * but in most cases, we will be first. Ideally, each LU on the 4981da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * target would get some limited time or requests on the target. 4991da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds */ 5001da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds blk_run_queue(current_sdev->request_queue); 5011da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 5021da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds spin_lock_irqsave(shost->host_lock, flags); 5031da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds if (starget->starget_sdev_user) 5041da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds goto out; 5051da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds list_for_each_entry_safe(sdev, tmp, &starget->devices, 5061da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds same_target_siblings) { 5071da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds if (sdev == current_sdev) 5081da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds continue; 5091da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds if (scsi_device_get(sdev)) 5101da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds continue; 5111da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 5121da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds spin_unlock_irqrestore(shost->host_lock, flags); 5131da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds blk_run_queue(sdev->request_queue); 5141da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds spin_lock_irqsave(shost->host_lock, flags); 5151da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 5161da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds scsi_device_put(sdev); 5171da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds } 5181da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds out: 5191da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds spin_unlock_irqrestore(shost->host_lock, flags); 5201da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds} 5211da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 522a1a5ea70a6e9db6332b27fe2d96666e17aa1436bMarkus Lidel/* 523f10378fff658f61307496e0ae00095041725cf07Markus Lidel * Function: scsi_run_queue() 524f10378fff658f61307496e0ae00095041725cf07Markus Lidel * 525f10378fff658f61307496e0ae00095041725cf07Markus Lidel * Purpose: Select a proper request queue to serve next 526f10378fff658f61307496e0ae00095041725cf07Markus Lidel * 527f10378fff658f61307496e0ae00095041725cf07Markus Lidel * Arguments: q - last request's queue 528f10378fff658f61307496e0ae00095041725cf07Markus Lidel * 529b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel * Returns: Nothing 530a1a5ea70a6e9db6332b27fe2d96666e17aa1436bMarkus Lidel * 531b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel * Notes: The previous command was completely finished, start 532b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel * a new one if possible. 5331da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds */ 5341da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsstatic void scsi_run_queue(struct request_queue *q) 5351da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds{ 5361da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds struct scsi_device *sdev = q->queuedata; 5371da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds struct Scsi_Host *shost = sdev->host; 5381da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds unsigned long flags; 5391da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 5401da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds if (scsi_target(sdev)->single_lun) 5411da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds scsi_single_lun_run(sdev); 5421da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 5431da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds spin_lock_irqsave(shost->host_lock, flags); 5441da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds while (!list_empty(&shost->starved_list) && 5451da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds !shost->host_blocked && !shost->host_self_blocked && 546b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel !((shost->can_queue > 0) && 5471da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds (shost->host_busy >= shost->can_queue))) { 5481da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 5491da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds int flagset; 5501da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 5511da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds /* 5521da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * As long as shost is accepting commands and we have 5531da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * starved queues, call blk_run_queue. scsi_request_fn 5541da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * drops the queue_lock and can add us back to the 5551da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * starved_list. 5561da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 5571da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * host_lock protects the starved_list and starved_entry. 5581da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * scsi_request_fn must get the host_lock before checking 559f10378fff658f61307496e0ae00095041725cf07Markus Lidel * or modifying starved_list or starved_entry. 560b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel */ 5611da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds sdev = list_entry(shost->starved_list.next, 5621da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds struct scsi_device, starved_entry); 5631da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds list_del_init(&sdev->starved_entry); 564f10378fff658f61307496e0ae00095041725cf07Markus Lidel spin_unlock(shost->host_lock); 565f10378fff658f61307496e0ae00095041725cf07Markus Lidel 566b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel spin_lock(sdev->request_queue->queue_lock); 5671da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds flagset = test_bit(QUEUE_FLAG_REENTER, &q->queue_flags) && 5681da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds !test_bit(QUEUE_FLAG_REENTER, 5691da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds &sdev->request_queue->queue_flags); 570f10378fff658f61307496e0ae00095041725cf07Markus Lidel if (flagset) 571f10378fff658f61307496e0ae00095041725cf07Markus Lidel queue_flag_set(QUEUE_FLAG_REENTER, sdev->request_queue); 572b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel __blk_run_queue(sdev->request_queue); 5731da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds if (flagset) 5741da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds queue_flag_clear(QUEUE_FLAG_REENTER, sdev->request_queue); 5751da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds spin_unlock(sdev->request_queue->queue_lock); 5761da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 5771da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds spin_lock(shost->host_lock); 5781da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds if (unlikely(!list_empty(&sdev->starved_entry))) 579b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel /* 580b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel * sdev lost a race, and was put back on the 581b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel * starved list. This is unlikely but without this 582b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel * in theory we could loop forever. 583b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel */ 584b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel break; 585b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel } 586b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel spin_unlock_irqrestore(shost->host_lock, flags); 587a1a5ea70a6e9db6332b27fe2d96666e17aa1436bMarkus Lidel 588a1a5ea70a6e9db6332b27fe2d96666e17aa1436bMarkus Lidel blk_run_queue(q); 589b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel} 590b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel 591b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel/* 592b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel * Function: scsi_requeue_command() 593b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel * 594b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel * Purpose: Handle post-processing of completed commands. 595beb40487508290f5d6565598c60a3f44261beef2Christoph Hellwig * 596b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel * Arguments: q - queue to operate on 597b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel * cmd - command that may need to be requeued. 598b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel * 599b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel * Returns: Nothing 600b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel * 601b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel * Notes: After command completion, there may be blocks left 602b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel * over which weren't finished by the previous command 603b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel * this can be for a number of reasons - the main one is 604b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel * I/O errors in the middle of the request, in which case 605b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel * we need to request the blocks that come after the bad 606b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel * sector. 607b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel * Notes: Upon return, cmd is a stale pointer. 608b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel */ 609b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidelstatic void scsi_requeue_command(struct request_queue *q, struct scsi_cmnd *cmd) 610b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel{ 611b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel struct request *req = cmd->request; 612b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel unsigned long flags; 613b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel 614b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel scsi_unprep_request(req); 615b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel spin_lock_irqsave(q->queue_lock, flags); 616b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel blk_requeue_request(q, req); 617b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel spin_unlock_irqrestore(q->queue_lock, flags); 618b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel 619b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel scsi_run_queue(q); 620b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel} 621b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel 622b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidelvoid scsi_next_command(struct scsi_cmnd *cmd) 623b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel{ 624b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel struct scsi_device *sdev = cmd->device; 625b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel struct request_queue *q = sdev->request_queue; 626b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel 627b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel /* need to hold a reference on the device before we let go of the cmd */ 628b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel get_device(&sdev->sdev_gendev); 629a1a5ea70a6e9db6332b27fe2d96666e17aa1436bMarkus Lidel 630a1a5ea70a6e9db6332b27fe2d96666e17aa1436bMarkus Lidel scsi_put_command(cmd); 6311da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds scsi_run_queue(q); 632b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel 633beb40487508290f5d6565598c60a3f44261beef2Christoph Hellwig /* ok to remove device now */ 6341da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds put_device(&sdev->sdev_gendev); 635a1a5ea70a6e9db6332b27fe2d96666e17aa1436bMarkus Lidel} 636a1a5ea70a6e9db6332b27fe2d96666e17aa1436bMarkus Lidel 6371da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsvoid scsi_run_host_queues(struct Scsi_Host *shost) 6381da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds{ 639a1a5ea70a6e9db6332b27fe2d96666e17aa1436bMarkus Lidel struct scsi_device *sdev; 6401da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 6411da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds shost_for_each_device(sdev, shost) 6421da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds scsi_run_queue(sdev->request_queue); 6431da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds} 6441da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 6451da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds/* 6461da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * Function: scsi_end_request() 6471da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 6481da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * Purpose: Post-processing of completed commands (usually invoked at end 6491da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * of upper level post-processing and scsi_io_completion). 6501da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 6511da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * Arguments: cmd - command that is complete. 6521da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * error - 0 if I/O indicates success, < 0 for I/O error. 6539e87545f06930c1d294423a8091d1077e7444a47Markus Lidel * bytes - number of bytes of completed I/O 6541da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * requeue - indicates whether we should requeue leftovers. 6551da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 6561da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * Lock status: Assumed that lock is not held upon entry. 6571da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 6581da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * Returns: cmd if requeue required, NULL otherwise. 6591da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 6601da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * Notes: This is called for block device requests in order to 6611da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * mark some number of sectors as complete. 662a1a5ea70a6e9db6332b27fe2d96666e17aa1436bMarkus Lidel * 6631da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * We are guaranteeing that the request queue will be goosed 6641da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * at some point during this call. 665a1a5ea70a6e9db6332b27fe2d96666e17aa1436bMarkus Lidel * Notes: If cmd was requeued, upon return it will be a stale pointer. 6661da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds */ 6671da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsstatic struct scsi_cmnd *scsi_end_request(struct scsi_cmnd *cmd, int error, 668b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel int bytes, int requeue) 669b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel{ 670a1a5ea70a6e9db6332b27fe2d96666e17aa1436bMarkus Lidel struct request_queue *q = cmd->device->request_queue; 671b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel struct request *req = cmd->request; 672b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel 673b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel /* 674b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel * If there are blocks left over at the end, set up the command 675b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel * to queue the remainder of them. 676b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel */ 677b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel if (blk_end_request(req, error, bytes)) { 678b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel int leftover = (req->hard_nr_sectors << 9); 679b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel 680b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel if (blk_pc_request(req)) 681b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel leftover = req->data_len; 682b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel 683b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel /* kill remainder if no retrys */ 684b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel if (error && blk_noretry_request(req)) 685f88e119c4b824a5017456fa094950d0f4092d96cMarkus Lidel blk_end_request(req, error, leftover); 6861da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds else { 6871da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds if (requeue) { 6881da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds /* 689a1a5ea70a6e9db6332b27fe2d96666e17aa1436bMarkus Lidel * Bleah. Leftovers again. Stick the 690a1a5ea70a6e9db6332b27fe2d96666e17aa1436bMarkus Lidel * leftovers in the front of the 6911da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * queue, and goose the queue again. 6921da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds */ 693a1a5ea70a6e9db6332b27fe2d96666e17aa1436bMarkus Lidel scsi_requeue_command(q, cmd); 6941da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds cmd = NULL; 6951da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds } 6961da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds return cmd; 6971da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds } 698b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel } 699b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel 700b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel /* 701a1a5ea70a6e9db6332b27fe2d96666e17aa1436bMarkus Lidel * This will goose the queue request function at the end, so we don't 702b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel * need to worry about launching another command. 703b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel */ 704b2aaee33fbb354a2f08121aa1c1be55841102761Markus Lidel scsi_next_command(cmd); 7051da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds return NULL; 7061da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds} 7071da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 7081da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsstatic inline unsigned int scsi_sgtable_index(unsigned short nents) 7091da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds{ 7101da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds unsigned int index; 7111da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 7121da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds BUG_ON(nents > SCSI_MAX_SG_SEGMENTS); 7131da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 7141da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds if (nents <= 8) 7151da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds index = 0; 7161da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds else 7171da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds index = get_count_order(nents) - 3; 7181da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 7191da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds return index; 7201da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds} 7211da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 722a1a5ea70a6e9db6332b27fe2d96666e17aa1436bMarkus Lidelstatic void scsi_sg_free(struct scatterlist *sgl, unsigned int nents) 7231da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds{ 7241da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds struct scsi_host_sg_pool *sgp; 7251da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 7261da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds sgp = scsi_sg_pools + scsi_sgtable_index(nents); 7271da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds mempool_free(sgl, sgp->pool); 7281da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds} 7291da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 7301da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsstatic struct scatterlist *scsi_sg_alloc(unsigned int nents, gfp_t gfp_mask) 7311da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds{ 732a1a5ea70a6e9db6332b27fe2d96666e17aa1436bMarkus Lidel struct scsi_host_sg_pool *sgp; 733a1a5ea70a6e9db6332b27fe2d96666e17aa1436bMarkus Lidel 7341da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds sgp = scsi_sg_pools + scsi_sgtable_index(nents); 7351da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds return mempool_alloc(sgp->pool, gfp_mask); 736a1a5ea70a6e9db6332b27fe2d96666e17aa1436bMarkus Lidel} 737a1a5ea70a6e9db6332b27fe2d96666e17aa1436bMarkus Lidel 738a1a5ea70a6e9db6332b27fe2d96666e17aa1436bMarkus Lidelstatic int scsi_alloc_sgtable(struct scsi_data_buffer *sdb, int nents, 739a1a5ea70a6e9db6332b27fe2d96666e17aa1436bMarkus Lidel gfp_t gfp_mask) 7401da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds{ 741e22bec266cd6f540da2a61db216914c3473135ccMarkus Lidel int ret; 7421da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 7431da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds BUG_ON(!nents); 7441da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 7451da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds ret = __sg_alloc_table(&sdb->table, nents, SCSI_MAX_SG_SEGMENTS, 7461da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds gfp_mask, scsi_sg_alloc); 7471da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds if (unlikely(ret)) 7481da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds __sg_free_table(&sdb->table, SCSI_MAX_SG_SEGMENTS, 7491da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds scsi_sg_free); 7501da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 7511da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds return ret; 7521da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds} 7531da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 7541da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsstatic void scsi_free_sgtable(struct scsi_data_buffer *sdb) 7551da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds{ 7561da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds __sg_free_table(&sdb->table, SCSI_MAX_SG_SEGMENTS, scsi_sg_free); 7571da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds} 7581da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 7591da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds/* 7601da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * Function: scsi_release_buffers() 7611da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 7621da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * Purpose: Completion processing for block device I/O requests. 7631da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 7641da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * Arguments: cmd - command that we are bailing. 7651da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 7661da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * Lock status: Assumed that no lock is held upon entry. 7671da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 7681da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * Returns: Nothing 7691da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 7701da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * Notes: In the event that an upper level driver rejects a 7711da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * command, we must release resources allocated during 7721da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * the __init_io() function. Primarily this would involve 7731da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * the scatter-gather table, and potentially any bounce 7741da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * buffers. 7751da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds */ 7761da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsvoid scsi_release_buffers(struct scsi_cmnd *cmd) 7771da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds{ 7781da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds if (cmd->sdb.table.nents) 7791da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds scsi_free_sgtable(&cmd->sdb); 7801da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 7811da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds memset(&cmd->sdb, 0, sizeof(cmd->sdb)); 7821da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 7831da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds if (scsi_bidi_cmnd(cmd)) { 7841da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds struct scsi_data_buffer *bidi_sdb = 7851da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds cmd->request->next_rq->special; 7861da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds scsi_free_sgtable(bidi_sdb); 7871da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds kmem_cache_free(scsi_sdb_cache, bidi_sdb); 7881da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds cmd->request->next_rq->special = NULL; 7891da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds } 7901da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 7911da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds if (scsi_prot_sg_count(cmd)) 7921da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds scsi_free_sgtable(cmd->prot_sdb); 7931da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds} 7941da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus TorvaldsEXPORT_SYMBOL(scsi_release_buffers); 7951da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 7961da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds/* 7971da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * Bidi commands Must be complete as a whole, both sides at once. 7981da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * If part of the bytes were written and lld returned 7991da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * scsi_in()->resid and/or scsi_out()->resid this information will be left 8001da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * in req->data_len and req->next_rq->data_len. The upper-layer driver can 8011da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * decide what to do with this information. 8021da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds */ 8031da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsstatic void scsi_end_bidi_request(struct scsi_cmnd *cmd) 8041da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds{ 8051da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds struct request *req = cmd->request; 8061da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds unsigned int dlen = req->data_len; 8071da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds unsigned int next_dlen = req->next_rq->data_len; 8081da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 8091da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds req->data_len = scsi_out(cmd)->resid; 8101da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds req->next_rq->data_len = scsi_in(cmd)->resid; 8111da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 8121da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds /* The req and req->next_rq have not been completed */ 8131da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds BUG_ON(blk_end_bidi_request(req, 0, dlen, next_dlen)); 8141da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 8151da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds scsi_release_buffers(cmd); 8161da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 8171da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds /* 8181da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * This will goose the queue request function at the end, so we don't 8191da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * need to worry about launching another command. 8201da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds */ 8211da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds scsi_next_command(cmd); 8221da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds} 8231da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 8241da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds/* 8251da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * Function: scsi_io_completion() 8261da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 8271da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * Purpose: Completion processing for block device I/O requests. 8281da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 829 * Arguments: cmd - command that is finished. 830 * 831 * Lock status: Assumed that no lock is held upon entry. 832 * 833 * Returns: Nothing 834 * 835 * Notes: This function is matched in terms of capabilities to 836 * the function that created the scatter-gather list. 837 * In other words, if there are no bounce buffers 838 * (the normal case for most drivers), we don't need 839 * the logic to deal with cleaning up afterwards. 840 * 841 * We must do one of several things here: 842 * 843 * a) Call scsi_end_request. This will finish off the 844 * specified number of sectors. If we are done, the 845 * command block will be released, and the queue 846 * function will be goosed. If we are not done, then 847 * scsi_end_request will directly goose the queue. 848 * 849 * b) We can just use scsi_requeue_command() here. This would 850 * be used if we just wanted to retry, for example. 851 */ 852void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes) 853{ 854 int result = cmd->result; 855 int this_count = scsi_bufflen(cmd); 856 struct request_queue *q = cmd->device->request_queue; 857 struct request *req = cmd->request; 858 int error = 0; 859 struct scsi_sense_hdr sshdr; 860 int sense_valid = 0; 861 int sense_deferred = 0; 862 863 if (result) { 864 sense_valid = scsi_command_normalize_sense(cmd, &sshdr); 865 if (sense_valid) 866 sense_deferred = scsi_sense_is_deferred(&sshdr); 867 } 868 869 if (blk_pc_request(req)) { /* SG_IO ioctl from block level */ 870 req->errors = result; 871 if (result) { 872 if (sense_valid && req->sense) { 873 /* 874 * SG_IO wants current and deferred errors 875 */ 876 int len = 8 + cmd->sense_buffer[7]; 877 878 if (len > SCSI_SENSE_BUFFERSIZE) 879 len = SCSI_SENSE_BUFFERSIZE; 880 memcpy(req->sense, cmd->sense_buffer, len); 881 req->sense_len = len; 882 } 883 if (!sense_deferred) 884 error = -EIO; 885 } 886 if (scsi_bidi_cmnd(cmd)) { 887 /* will also release_buffers */ 888 scsi_end_bidi_request(cmd); 889 return; 890 } 891 req->data_len = scsi_get_resid(cmd); 892 } 893 894 BUG_ON(blk_bidi_rq(req)); /* bidi not support for !blk_pc_request yet */ 895 scsi_release_buffers(cmd); 896 897 /* 898 * Next deal with any sectors which we were able to correctly 899 * handle. 900 */ 901 SCSI_LOG_HLCOMPLETE(1, printk("%ld sectors total, " 902 "%d bytes done.\n", 903 req->nr_sectors, good_bytes)); 904 905 /* A number of bytes were successfully read. If there 906 * are leftovers and there is some kind of error 907 * (result != 0), retry the rest. 908 */ 909 if (scsi_end_request(cmd, error, good_bytes, result == 0) == NULL) 910 return; 911 912 /* good_bytes = 0, or (inclusive) there were leftovers and 913 * result = 0, so scsi_end_request couldn't retry. 914 */ 915 if (sense_valid && !sense_deferred) { 916 switch (sshdr.sense_key) { 917 case UNIT_ATTENTION: 918 if (cmd->device->removable) { 919 /* Detected disc change. Set a bit 920 * and quietly refuse further access. 921 */ 922 cmd->device->changed = 1; 923 scsi_end_request(cmd, -EIO, this_count, 1); 924 return; 925 } else { 926 /* Must have been a power glitch, or a 927 * bus reset. Could not have been a 928 * media change, so we just retry the 929 * request and see what happens. 930 */ 931 scsi_requeue_command(q, cmd); 932 return; 933 } 934 break; 935 case ILLEGAL_REQUEST: 936 /* If we had an ILLEGAL REQUEST returned, then 937 * we may have performed an unsupported 938 * command. The only thing this should be 939 * would be a ten byte read where only a six 940 * byte read was supported. Also, on a system 941 * where READ CAPACITY failed, we may have 942 * read past the end of the disk. 943 */ 944 if ((cmd->device->use_10_for_rw && 945 sshdr.asc == 0x20 && sshdr.ascq == 0x00) && 946 (cmd->cmnd[0] == READ_10 || 947 cmd->cmnd[0] == WRITE_10)) { 948 cmd->device->use_10_for_rw = 0; 949 /* This will cause a retry with a 950 * 6-byte command. 951 */ 952 scsi_requeue_command(q, cmd); 953 } else if (sshdr.asc == 0x10) /* DIX */ 954 scsi_end_request(cmd, -EIO, this_count, 0); 955 else 956 scsi_end_request(cmd, -EIO, this_count, 1); 957 return; 958 case ABORTED_COMMAND: 959 if (sshdr.asc == 0x10) { /* DIF */ 960 scsi_end_request(cmd, -EIO, this_count, 0); 961 return; 962 } 963 break; 964 case NOT_READY: 965 /* If the device is in the process of becoming 966 * ready, or has a temporary blockage, retry. 967 */ 968 if (sshdr.asc == 0x04) { 969 switch (sshdr.ascq) { 970 case 0x01: /* becoming ready */ 971 case 0x04: /* format in progress */ 972 case 0x05: /* rebuild in progress */ 973 case 0x06: /* recalculation in progress */ 974 case 0x07: /* operation in progress */ 975 case 0x08: /* Long write in progress */ 976 case 0x09: /* self test in progress */ 977 scsi_requeue_command(q, cmd); 978 return; 979 default: 980 break; 981 } 982 } 983 if (!(req->cmd_flags & REQ_QUIET)) 984 scsi_cmd_print_sense_hdr(cmd, 985 "Device not ready", 986 &sshdr); 987 988 scsi_end_request(cmd, -EIO, this_count, 1); 989 return; 990 case VOLUME_OVERFLOW: 991 if (!(req->cmd_flags & REQ_QUIET)) { 992 scmd_printk(KERN_INFO, cmd, 993 "Volume overflow, CDB: "); 994 __scsi_print_command(cmd->cmnd); 995 scsi_print_sense("", cmd); 996 } 997 /* See SSC3rXX or current. */ 998 scsi_end_request(cmd, -EIO, this_count, 1); 999 return; 1000 default: 1001 break; 1002 } 1003 } 1004 if (host_byte(result) == DID_RESET) { 1005 /* Third party bus reset or reset for error recovery 1006 * reasons. Just retry the request and see what 1007 * happens. 1008 */ 1009 scsi_requeue_command(q, cmd); 1010 return; 1011 } 1012 if (result) { 1013 if (!(req->cmd_flags & REQ_QUIET)) { 1014 scsi_print_result(cmd); 1015 if (driver_byte(result) & DRIVER_SENSE) 1016 scsi_print_sense("", cmd); 1017 } 1018 } 1019 scsi_end_request(cmd, -EIO, this_count, !result); 1020} 1021 1022static int scsi_init_sgtable(struct request *req, struct scsi_data_buffer *sdb, 1023 gfp_t gfp_mask) 1024{ 1025 int count; 1026 1027 /* 1028 * If sg table allocation fails, requeue request later. 1029 */ 1030 if (unlikely(scsi_alloc_sgtable(sdb, req->nr_phys_segments, 1031 gfp_mask))) { 1032 return BLKPREP_DEFER; 1033 } 1034 1035 req->buffer = NULL; 1036 1037 /* 1038 * Next, walk the list, and fill in the addresses and sizes of 1039 * each segment. 1040 */ 1041 count = blk_rq_map_sg(req->q, req, sdb->table.sgl); 1042 BUG_ON(count > sdb->table.nents); 1043 sdb->table.nents = count; 1044 if (blk_pc_request(req)) 1045 sdb->length = req->data_len; 1046 else 1047 sdb->length = req->nr_sectors << 9; 1048 return BLKPREP_OK; 1049} 1050 1051/* 1052 * Function: scsi_init_io() 1053 * 1054 * Purpose: SCSI I/O initialize function. 1055 * 1056 * Arguments: cmd - Command descriptor we wish to initialize 1057 * 1058 * Returns: 0 on success 1059 * BLKPREP_DEFER if the failure is retryable 1060 * BLKPREP_KILL if the failure is fatal 1061 */ 1062int scsi_init_io(struct scsi_cmnd *cmd, gfp_t gfp_mask) 1063{ 1064 int error = scsi_init_sgtable(cmd->request, &cmd->sdb, gfp_mask); 1065 if (error) 1066 goto err_exit; 1067 1068 if (blk_bidi_rq(cmd->request)) { 1069 struct scsi_data_buffer *bidi_sdb = kmem_cache_zalloc( 1070 scsi_sdb_cache, GFP_ATOMIC); 1071 if (!bidi_sdb) { 1072 error = BLKPREP_DEFER; 1073 goto err_exit; 1074 } 1075 1076 cmd->request->next_rq->special = bidi_sdb; 1077 error = scsi_init_sgtable(cmd->request->next_rq, bidi_sdb, 1078 GFP_ATOMIC); 1079 if (error) 1080 goto err_exit; 1081 } 1082 1083 if (blk_integrity_rq(cmd->request)) { 1084 struct scsi_data_buffer *prot_sdb = cmd->prot_sdb; 1085 int ivecs, count; 1086 1087 BUG_ON(prot_sdb == NULL); 1088 ivecs = blk_rq_count_integrity_sg(cmd->request); 1089 1090 if (scsi_alloc_sgtable(prot_sdb, ivecs, gfp_mask)) { 1091 error = BLKPREP_DEFER; 1092 goto err_exit; 1093 } 1094 1095 count = blk_rq_map_integrity_sg(cmd->request, 1096 prot_sdb->table.sgl); 1097 BUG_ON(unlikely(count > ivecs)); 1098 1099 cmd->prot_sdb = prot_sdb; 1100 cmd->prot_sdb->table.nents = count; 1101 } 1102 1103 return BLKPREP_OK ; 1104 1105err_exit: 1106 scsi_release_buffers(cmd); 1107 if (error == BLKPREP_KILL) 1108 scsi_put_command(cmd); 1109 else /* BLKPREP_DEFER */ 1110 scsi_unprep_request(cmd->request); 1111 1112 return error; 1113} 1114EXPORT_SYMBOL(scsi_init_io); 1115 1116static struct scsi_cmnd *scsi_get_cmd_from_req(struct scsi_device *sdev, 1117 struct request *req) 1118{ 1119 struct scsi_cmnd *cmd; 1120 1121 if (!req->special) { 1122 cmd = scsi_get_command(sdev, GFP_ATOMIC); 1123 if (unlikely(!cmd)) 1124 return NULL; 1125 req->special = cmd; 1126 } else { 1127 cmd = req->special; 1128 } 1129 1130 /* pull a tag out of the request if we have one */ 1131 cmd->tag = req->tag; 1132 cmd->request = req; 1133 1134 cmd->cmnd = req->cmd; 1135 1136 return cmd; 1137} 1138 1139int scsi_setup_blk_pc_cmnd(struct scsi_device *sdev, struct request *req) 1140{ 1141 struct scsi_cmnd *cmd; 1142 int ret = scsi_prep_state_check(sdev, req); 1143 1144 if (ret != BLKPREP_OK) 1145 return ret; 1146 1147 cmd = scsi_get_cmd_from_req(sdev, req); 1148 if (unlikely(!cmd)) 1149 return BLKPREP_DEFER; 1150 1151 /* 1152 * BLOCK_PC requests may transfer data, in which case they must 1153 * a bio attached to them. Or they might contain a SCSI command 1154 * that does not transfer data, in which case they may optionally 1155 * submit a request without an attached bio. 1156 */ 1157 if (req->bio) { 1158 int ret; 1159 1160 BUG_ON(!req->nr_phys_segments); 1161 1162 ret = scsi_init_io(cmd, GFP_ATOMIC); 1163 if (unlikely(ret)) 1164 return ret; 1165 } else { 1166 BUG_ON(req->data_len); 1167 BUG_ON(req->data); 1168 1169 memset(&cmd->sdb, 0, sizeof(cmd->sdb)); 1170 req->buffer = NULL; 1171 } 1172 1173 cmd->cmd_len = req->cmd_len; 1174 if (!req->data_len) 1175 cmd->sc_data_direction = DMA_NONE; 1176 else if (rq_data_dir(req) == WRITE) 1177 cmd->sc_data_direction = DMA_TO_DEVICE; 1178 else 1179 cmd->sc_data_direction = DMA_FROM_DEVICE; 1180 1181 cmd->transfersize = req->data_len; 1182 cmd->allowed = req->retries; 1183 cmd->timeout_per_command = req->timeout; 1184 return BLKPREP_OK; 1185} 1186EXPORT_SYMBOL(scsi_setup_blk_pc_cmnd); 1187 1188/* 1189 * Setup a REQ_TYPE_FS command. These are simple read/write request 1190 * from filesystems that still need to be translated to SCSI CDBs from 1191 * the ULD. 1192 */ 1193int scsi_setup_fs_cmnd(struct scsi_device *sdev, struct request *req) 1194{ 1195 struct scsi_cmnd *cmd; 1196 int ret = scsi_prep_state_check(sdev, req); 1197 1198 if (ret != BLKPREP_OK) 1199 return ret; 1200 1201 if (unlikely(sdev->scsi_dh_data && sdev->scsi_dh_data->scsi_dh 1202 && sdev->scsi_dh_data->scsi_dh->prep_fn)) { 1203 ret = sdev->scsi_dh_data->scsi_dh->prep_fn(sdev, req); 1204 if (ret != BLKPREP_OK) 1205 return ret; 1206 } 1207 1208 /* 1209 * Filesystem requests must transfer data. 1210 */ 1211 BUG_ON(!req->nr_phys_segments); 1212 1213 cmd = scsi_get_cmd_from_req(sdev, req); 1214 if (unlikely(!cmd)) 1215 return BLKPREP_DEFER; 1216 1217 memset(cmd->cmnd, 0, BLK_MAX_CDB); 1218 return scsi_init_io(cmd, GFP_ATOMIC); 1219} 1220EXPORT_SYMBOL(scsi_setup_fs_cmnd); 1221 1222int scsi_prep_state_check(struct scsi_device *sdev, struct request *req) 1223{ 1224 int ret = BLKPREP_OK; 1225 1226 /* 1227 * If the device is not in running state we will reject some 1228 * or all commands. 1229 */ 1230 if (unlikely(sdev->sdev_state != SDEV_RUNNING)) { 1231 switch (sdev->sdev_state) { 1232 case SDEV_OFFLINE: 1233 /* 1234 * If the device is offline we refuse to process any 1235 * commands. The device must be brought online 1236 * before trying any recovery commands. 1237 */ 1238 sdev_printk(KERN_ERR, sdev, 1239 "rejecting I/O to offline device\n"); 1240 ret = BLKPREP_KILL; 1241 break; 1242 case SDEV_DEL: 1243 /* 1244 * If the device is fully deleted, we refuse to 1245 * process any commands as well. 1246 */ 1247 sdev_printk(KERN_ERR, sdev, 1248 "rejecting I/O to dead device\n"); 1249 ret = BLKPREP_KILL; 1250 break; 1251 case SDEV_QUIESCE: 1252 case SDEV_BLOCK: 1253 /* 1254 * If the devices is blocked we defer normal commands. 1255 */ 1256 if (!(req->cmd_flags & REQ_PREEMPT)) 1257 ret = BLKPREP_DEFER; 1258 break; 1259 default: 1260 /* 1261 * For any other not fully online state we only allow 1262 * special commands. In particular any user initiated 1263 * command is not allowed. 1264 */ 1265 if (!(req->cmd_flags & REQ_PREEMPT)) 1266 ret = BLKPREP_KILL; 1267 break; 1268 } 1269 } 1270 return ret; 1271} 1272EXPORT_SYMBOL(scsi_prep_state_check); 1273 1274int scsi_prep_return(struct request_queue *q, struct request *req, int ret) 1275{ 1276 struct scsi_device *sdev = q->queuedata; 1277 1278 switch (ret) { 1279 case BLKPREP_KILL: 1280 req->errors = DID_NO_CONNECT << 16; 1281 /* release the command and kill it */ 1282 if (req->special) { 1283 struct scsi_cmnd *cmd = req->special; 1284 scsi_release_buffers(cmd); 1285 scsi_put_command(cmd); 1286 req->special = NULL; 1287 } 1288 break; 1289 case BLKPREP_DEFER: 1290 /* 1291 * If we defer, the elv_next_request() returns NULL, but the 1292 * queue must be restarted, so we plug here if no returning 1293 * command will automatically do that. 1294 */ 1295 if (sdev->device_busy == 0) 1296 blk_plug_device(q); 1297 break; 1298 default: 1299 req->cmd_flags |= REQ_DONTPREP; 1300 } 1301 1302 return ret; 1303} 1304EXPORT_SYMBOL(scsi_prep_return); 1305 1306int scsi_prep_fn(struct request_queue *q, struct request *req) 1307{ 1308 struct scsi_device *sdev = q->queuedata; 1309 int ret = BLKPREP_KILL; 1310 1311 if (req->cmd_type == REQ_TYPE_BLOCK_PC) 1312 ret = scsi_setup_blk_pc_cmnd(sdev, req); 1313 return scsi_prep_return(q, req, ret); 1314} 1315 1316/* 1317 * scsi_dev_queue_ready: if we can send requests to sdev, return 1 else 1318 * return 0. 1319 * 1320 * Called with the queue_lock held. 1321 */ 1322static inline int scsi_dev_queue_ready(struct request_queue *q, 1323 struct scsi_device *sdev) 1324{ 1325 if (sdev->device_busy >= sdev->queue_depth) 1326 return 0; 1327 if (sdev->device_busy == 0 && sdev->device_blocked) { 1328 /* 1329 * unblock after device_blocked iterates to zero 1330 */ 1331 if (--sdev->device_blocked == 0) { 1332 SCSI_LOG_MLQUEUE(3, 1333 sdev_printk(KERN_INFO, sdev, 1334 "unblocking device at zero depth\n")); 1335 } else { 1336 blk_plug_device(q); 1337 return 0; 1338 } 1339 } 1340 if (sdev->device_blocked) 1341 return 0; 1342 1343 return 1; 1344} 1345 1346/* 1347 * scsi_host_queue_ready: if we can send requests to shost, return 1 else 1348 * return 0. We must end up running the queue again whenever 0 is 1349 * returned, else IO can hang. 1350 * 1351 * Called with host_lock held. 1352 */ 1353static inline int scsi_host_queue_ready(struct request_queue *q, 1354 struct Scsi_Host *shost, 1355 struct scsi_device *sdev) 1356{ 1357 if (scsi_host_in_recovery(shost)) 1358 return 0; 1359 if (shost->host_busy == 0 && shost->host_blocked) { 1360 /* 1361 * unblock after host_blocked iterates to zero 1362 */ 1363 if (--shost->host_blocked == 0) { 1364 SCSI_LOG_MLQUEUE(3, 1365 printk("scsi%d unblocking host at zero depth\n", 1366 shost->host_no)); 1367 } else { 1368 return 0; 1369 } 1370 } 1371 if ((shost->can_queue > 0 && shost->host_busy >= shost->can_queue) || 1372 shost->host_blocked || shost->host_self_blocked) { 1373 if (list_empty(&sdev->starved_entry)) 1374 list_add_tail(&sdev->starved_entry, &shost->starved_list); 1375 return 0; 1376 } 1377 1378 /* We're OK to process the command, so we can't be starved */ 1379 if (!list_empty(&sdev->starved_entry)) 1380 list_del_init(&sdev->starved_entry); 1381 1382 return 1; 1383} 1384 1385/* 1386 * Kill a request for a dead device 1387 */ 1388static void scsi_kill_request(struct request *req, struct request_queue *q) 1389{ 1390 struct scsi_cmnd *cmd = req->special; 1391 struct scsi_device *sdev = cmd->device; 1392 struct Scsi_Host *shost = sdev->host; 1393 1394 blkdev_dequeue_request(req); 1395 1396 if (unlikely(cmd == NULL)) { 1397 printk(KERN_CRIT "impossible request in %s.\n", 1398 __FUNCTION__); 1399 BUG(); 1400 } 1401 1402 scsi_init_cmd_errh(cmd); 1403 cmd->result = DID_NO_CONNECT << 16; 1404 atomic_inc(&cmd->device->iorequest_cnt); 1405 1406 /* 1407 * SCSI request completion path will do scsi_device_unbusy(), 1408 * bump busy counts. To bump the counters, we need to dance 1409 * with the locks as normal issue path does. 1410 */ 1411 sdev->device_busy++; 1412 spin_unlock(sdev->request_queue->queue_lock); 1413 spin_lock(shost->host_lock); 1414 shost->host_busy++; 1415 spin_unlock(shost->host_lock); 1416 spin_lock(sdev->request_queue->queue_lock); 1417 1418 __scsi_done(cmd); 1419} 1420 1421static void scsi_softirq_done(struct request *rq) 1422{ 1423 struct scsi_cmnd *cmd = rq->completion_data; 1424 unsigned long wait_for = (cmd->allowed + 1) * cmd->timeout_per_command; 1425 int disposition; 1426 1427 INIT_LIST_HEAD(&cmd->eh_entry); 1428 1429 disposition = scsi_decide_disposition(cmd); 1430 if (disposition != SUCCESS && 1431 time_before(cmd->jiffies_at_alloc + wait_for, jiffies)) { 1432 sdev_printk(KERN_ERR, cmd->device, 1433 "timing out command, waited %lus\n", 1434 wait_for/HZ); 1435 disposition = SUCCESS; 1436 } 1437 1438 scsi_log_completion(cmd, disposition); 1439 1440 switch (disposition) { 1441 case SUCCESS: 1442 scsi_finish_command(cmd); 1443 break; 1444 case NEEDS_RETRY: 1445 scsi_queue_insert(cmd, SCSI_MLQUEUE_EH_RETRY); 1446 break; 1447 case ADD_TO_MLQUEUE: 1448 scsi_queue_insert(cmd, SCSI_MLQUEUE_DEVICE_BUSY); 1449 break; 1450 default: 1451 if (!scsi_eh_scmd_add(cmd, 0)) 1452 scsi_finish_command(cmd); 1453 } 1454} 1455 1456/* 1457 * Function: scsi_request_fn() 1458 * 1459 * Purpose: Main strategy routine for SCSI. 1460 * 1461 * Arguments: q - Pointer to actual queue. 1462 * 1463 * Returns: Nothing 1464 * 1465 * Lock status: IO request lock assumed to be held when called. 1466 */ 1467static void scsi_request_fn(struct request_queue *q) 1468{ 1469 struct scsi_device *sdev = q->queuedata; 1470 struct Scsi_Host *shost; 1471 struct scsi_cmnd *cmd; 1472 struct request *req; 1473 1474 if (!sdev) { 1475 printk("scsi: killing requests for dead queue\n"); 1476 while ((req = elv_next_request(q)) != NULL) 1477 scsi_kill_request(req, q); 1478 return; 1479 } 1480 1481 if(!get_device(&sdev->sdev_gendev)) 1482 /* We must be tearing the block queue down already */ 1483 return; 1484 1485 /* 1486 * To start with, we keep looping until the queue is empty, or until 1487 * the host is no longer able to accept any more requests. 1488 */ 1489 shost = sdev->host; 1490 while (!blk_queue_plugged(q)) { 1491 int rtn; 1492 /* 1493 * get next queueable request. We do this early to make sure 1494 * that the request is fully prepared even if we cannot 1495 * accept it. 1496 */ 1497 req = elv_next_request(q); 1498 if (!req || !scsi_dev_queue_ready(q, sdev)) 1499 break; 1500 1501 if (unlikely(!scsi_device_online(sdev))) { 1502 sdev_printk(KERN_ERR, sdev, 1503 "rejecting I/O to offline device\n"); 1504 scsi_kill_request(req, q); 1505 continue; 1506 } 1507 1508 1509 /* 1510 * Remove the request from the request list. 1511 */ 1512 if (!(blk_queue_tagged(q) && !blk_queue_start_tag(q, req))) 1513 blkdev_dequeue_request(req); 1514 sdev->device_busy++; 1515 1516 spin_unlock(q->queue_lock); 1517 cmd = req->special; 1518 if (unlikely(cmd == NULL)) { 1519 printk(KERN_CRIT "impossible request in %s.\n" 1520 "please mail a stack trace to " 1521 "linux-scsi@vger.kernel.org\n", 1522 __FUNCTION__); 1523 blk_dump_rq_flags(req, "foo"); 1524 BUG(); 1525 } 1526 spin_lock(shost->host_lock); 1527 1528 /* 1529 * We hit this when the driver is using a host wide 1530 * tag map. For device level tag maps the queue_depth check 1531 * in the device ready fn would prevent us from trying 1532 * to allocate a tag. Since the map is a shared host resource 1533 * we add the dev to the starved list so it eventually gets 1534 * a run when a tag is freed. 1535 */ 1536 if (blk_queue_tagged(q) && !blk_rq_tagged(req)) { 1537 if (list_empty(&sdev->starved_entry)) 1538 list_add_tail(&sdev->starved_entry, 1539 &shost->starved_list); 1540 goto not_ready; 1541 } 1542 1543 if (!scsi_host_queue_ready(q, shost, sdev)) 1544 goto not_ready; 1545 if (scsi_target(sdev)->single_lun) { 1546 if (scsi_target(sdev)->starget_sdev_user && 1547 scsi_target(sdev)->starget_sdev_user != sdev) 1548 goto not_ready; 1549 scsi_target(sdev)->starget_sdev_user = sdev; 1550 } 1551 shost->host_busy++; 1552 1553 /* 1554 * XXX(hch): This is rather suboptimal, scsi_dispatch_cmd will 1555 * take the lock again. 1556 */ 1557 spin_unlock_irq(shost->host_lock); 1558 1559 /* 1560 * Finally, initialize any error handling parameters, and set up 1561 * the timers for timeouts. 1562 */ 1563 scsi_init_cmd_errh(cmd); 1564 1565 /* 1566 * Dispatch the command to the low-level driver. 1567 */ 1568 rtn = scsi_dispatch_cmd(cmd); 1569 spin_lock_irq(q->queue_lock); 1570 if(rtn) { 1571 /* we're refusing the command; because of 1572 * the way locks get dropped, we need to 1573 * check here if plugging is required */ 1574 if(sdev->device_busy == 0) 1575 blk_plug_device(q); 1576 1577 break; 1578 } 1579 } 1580 1581 goto out; 1582 1583 not_ready: 1584 spin_unlock_irq(shost->host_lock); 1585 1586 /* 1587 * lock q, handle tag, requeue req, and decrement device_busy. We 1588 * must return with queue_lock held. 1589 * 1590 * Decrementing device_busy without checking it is OK, as all such 1591 * cases (host limits or settings) should run the queue at some 1592 * later time. 1593 */ 1594 spin_lock_irq(q->queue_lock); 1595 blk_requeue_request(q, req); 1596 sdev->device_busy--; 1597 if(sdev->device_busy == 0) 1598 blk_plug_device(q); 1599 out: 1600 /* must be careful here...if we trigger the ->remove() function 1601 * we cannot be holding the q lock */ 1602 spin_unlock_irq(q->queue_lock); 1603 put_device(&sdev->sdev_gendev); 1604 spin_lock_irq(q->queue_lock); 1605} 1606 1607u64 scsi_calculate_bounce_limit(struct Scsi_Host *shost) 1608{ 1609 struct device *host_dev; 1610 u64 bounce_limit = 0xffffffff; 1611 1612 if (shost->unchecked_isa_dma) 1613 return BLK_BOUNCE_ISA; 1614 /* 1615 * Platforms with virtual-DMA translation 1616 * hardware have no practical limit. 1617 */ 1618 if (!PCI_DMA_BUS_IS_PHYS) 1619 return BLK_BOUNCE_ANY; 1620 1621 host_dev = scsi_get_device(shost); 1622 if (host_dev && host_dev->dma_mask) 1623 bounce_limit = *host_dev->dma_mask; 1624 1625 return bounce_limit; 1626} 1627EXPORT_SYMBOL(scsi_calculate_bounce_limit); 1628 1629struct request_queue *__scsi_alloc_queue(struct Scsi_Host *shost, 1630 request_fn_proc *request_fn) 1631{ 1632 struct request_queue *q; 1633 struct device *dev = shost->shost_gendev.parent; 1634 1635 q = blk_init_queue(request_fn, NULL); 1636 if (!q) 1637 return NULL; 1638 1639 /* 1640 * this limit is imposed by hardware restrictions 1641 */ 1642 blk_queue_max_hw_segments(q, shost->sg_tablesize); 1643 blk_queue_max_phys_segments(q, SCSI_MAX_SG_CHAIN_SEGMENTS); 1644 1645 blk_queue_max_sectors(q, shost->max_sectors); 1646 blk_queue_bounce_limit(q, scsi_calculate_bounce_limit(shost)); 1647 blk_queue_segment_boundary(q, shost->dma_boundary); 1648 dma_set_seg_boundary(dev, shost->dma_boundary); 1649 1650 blk_queue_max_segment_size(q, dma_get_max_seg_size(dev)); 1651 1652 /* New queue, no concurrency on queue_flags */ 1653 if (!shost->use_clustering) 1654 queue_flag_clear_unlocked(QUEUE_FLAG_CLUSTER, q); 1655 1656 /* 1657 * set a reasonable default alignment on word boundaries: the 1658 * host and device may alter it using 1659 * blk_queue_update_dma_alignment() later. 1660 */ 1661 blk_queue_dma_alignment(q, 0x03); 1662 1663 return q; 1664} 1665EXPORT_SYMBOL(__scsi_alloc_queue); 1666 1667struct request_queue *scsi_alloc_queue(struct scsi_device *sdev) 1668{ 1669 struct request_queue *q; 1670 1671 q = __scsi_alloc_queue(sdev->host, scsi_request_fn); 1672 if (!q) 1673 return NULL; 1674 1675 blk_queue_prep_rq(q, scsi_prep_fn); 1676 blk_queue_softirq_done(q, scsi_softirq_done); 1677 return q; 1678} 1679 1680void scsi_free_queue(struct request_queue *q) 1681{ 1682 blk_cleanup_queue(q); 1683} 1684 1685/* 1686 * Function: scsi_block_requests() 1687 * 1688 * Purpose: Utility function used by low-level drivers to prevent further 1689 * commands from being queued to the device. 1690 * 1691 * Arguments: shost - Host in question 1692 * 1693 * Returns: Nothing 1694 * 1695 * Lock status: No locks are assumed held. 1696 * 1697 * Notes: There is no timer nor any other means by which the requests 1698 * get unblocked other than the low-level driver calling 1699 * scsi_unblock_requests(). 1700 */ 1701void scsi_block_requests(struct Scsi_Host *shost) 1702{ 1703 shost->host_self_blocked = 1; 1704} 1705EXPORT_SYMBOL(scsi_block_requests); 1706 1707/* 1708 * Function: scsi_unblock_requests() 1709 * 1710 * Purpose: Utility function used by low-level drivers to allow further 1711 * commands from being queued to the device. 1712 * 1713 * Arguments: shost - Host in question 1714 * 1715 * Returns: Nothing 1716 * 1717 * Lock status: No locks are assumed held. 1718 * 1719 * Notes: There is no timer nor any other means by which the requests 1720 * get unblocked other than the low-level driver calling 1721 * scsi_unblock_requests(). 1722 * 1723 * This is done as an API function so that changes to the 1724 * internals of the scsi mid-layer won't require wholesale 1725 * changes to drivers that use this feature. 1726 */ 1727void scsi_unblock_requests(struct Scsi_Host *shost) 1728{ 1729 shost->host_self_blocked = 0; 1730 scsi_run_host_queues(shost); 1731} 1732EXPORT_SYMBOL(scsi_unblock_requests); 1733 1734int __init scsi_init_queue(void) 1735{ 1736 int i; 1737 1738 scsi_io_context_cache = kmem_cache_create("scsi_io_context", 1739 sizeof(struct scsi_io_context), 1740 0, 0, NULL); 1741 if (!scsi_io_context_cache) { 1742 printk(KERN_ERR "SCSI: can't init scsi io context cache\n"); 1743 return -ENOMEM; 1744 } 1745 1746 scsi_sdb_cache = kmem_cache_create("scsi_data_buffer", 1747 sizeof(struct scsi_data_buffer), 1748 0, 0, NULL); 1749 if (!scsi_sdb_cache) { 1750 printk(KERN_ERR "SCSI: can't init scsi sdb cache\n"); 1751 goto cleanup_io_context; 1752 } 1753 1754 for (i = 0; i < SG_MEMPOOL_NR; i++) { 1755 struct scsi_host_sg_pool *sgp = scsi_sg_pools + i; 1756 int size = sgp->size * sizeof(struct scatterlist); 1757 1758 sgp->slab = kmem_cache_create(sgp->name, size, 0, 1759 SLAB_HWCACHE_ALIGN, NULL); 1760 if (!sgp->slab) { 1761 printk(KERN_ERR "SCSI: can't init sg slab %s\n", 1762 sgp->name); 1763 goto cleanup_sdb; 1764 } 1765 1766 sgp->pool = mempool_create_slab_pool(SG_MEMPOOL_SIZE, 1767 sgp->slab); 1768 if (!sgp->pool) { 1769 printk(KERN_ERR "SCSI: can't init sg mempool %s\n", 1770 sgp->name); 1771 goto cleanup_sdb; 1772 } 1773 } 1774 1775 return 0; 1776 1777cleanup_sdb: 1778 for (i = 0; i < SG_MEMPOOL_NR; i++) { 1779 struct scsi_host_sg_pool *sgp = scsi_sg_pools + i; 1780 if (sgp->pool) 1781 mempool_destroy(sgp->pool); 1782 if (sgp->slab) 1783 kmem_cache_destroy(sgp->slab); 1784 } 1785 kmem_cache_destroy(scsi_sdb_cache); 1786cleanup_io_context: 1787 kmem_cache_destroy(scsi_io_context_cache); 1788 1789 return -ENOMEM; 1790} 1791 1792void scsi_exit_queue(void) 1793{ 1794 int i; 1795 1796 kmem_cache_destroy(scsi_io_context_cache); 1797 kmem_cache_destroy(scsi_sdb_cache); 1798 1799 for (i = 0; i < SG_MEMPOOL_NR; i++) { 1800 struct scsi_host_sg_pool *sgp = scsi_sg_pools + i; 1801 mempool_destroy(sgp->pool); 1802 kmem_cache_destroy(sgp->slab); 1803 } 1804} 1805 1806/** 1807 * scsi_mode_select - issue a mode select 1808 * @sdev: SCSI device to be queried 1809 * @pf: Page format bit (1 == standard, 0 == vendor specific) 1810 * @sp: Save page bit (0 == don't save, 1 == save) 1811 * @modepage: mode page being requested 1812 * @buffer: request buffer (may not be smaller than eight bytes) 1813 * @len: length of request buffer. 1814 * @timeout: command timeout 1815 * @retries: number of retries before failing 1816 * @data: returns a structure abstracting the mode header data 1817 * @sshdr: place to put sense data (or NULL if no sense to be collected). 1818 * must be SCSI_SENSE_BUFFERSIZE big. 1819 * 1820 * Returns zero if successful; negative error number or scsi 1821 * status on error 1822 * 1823 */ 1824int 1825scsi_mode_select(struct scsi_device *sdev, int pf, int sp, int modepage, 1826 unsigned char *buffer, int len, int timeout, int retries, 1827 struct scsi_mode_data *data, struct scsi_sense_hdr *sshdr) 1828{ 1829 unsigned char cmd[10]; 1830 unsigned char *real_buffer; 1831 int ret; 1832 1833 memset(cmd, 0, sizeof(cmd)); 1834 cmd[1] = (pf ? 0x10 : 0) | (sp ? 0x01 : 0); 1835 1836 if (sdev->use_10_for_ms) { 1837 if (len > 65535) 1838 return -EINVAL; 1839 real_buffer = kmalloc(8 + len, GFP_KERNEL); 1840 if (!real_buffer) 1841 return -ENOMEM; 1842 memcpy(real_buffer + 8, buffer, len); 1843 len += 8; 1844 real_buffer[0] = 0; 1845 real_buffer[1] = 0; 1846 real_buffer[2] = data->medium_type; 1847 real_buffer[3] = data->device_specific; 1848 real_buffer[4] = data->longlba ? 0x01 : 0; 1849 real_buffer[5] = 0; 1850 real_buffer[6] = data->block_descriptor_length >> 8; 1851 real_buffer[7] = data->block_descriptor_length; 1852 1853 cmd[0] = MODE_SELECT_10; 1854 cmd[7] = len >> 8; 1855 cmd[8] = len; 1856 } else { 1857 if (len > 255 || data->block_descriptor_length > 255 || 1858 data->longlba) 1859 return -EINVAL; 1860 1861 real_buffer = kmalloc(4 + len, GFP_KERNEL); 1862 if (!real_buffer) 1863 return -ENOMEM; 1864 memcpy(real_buffer + 4, buffer, len); 1865 len += 4; 1866 real_buffer[0] = 0; 1867 real_buffer[1] = data->medium_type; 1868 real_buffer[2] = data->device_specific; 1869 real_buffer[3] = data->block_descriptor_length; 1870 1871 1872 cmd[0] = MODE_SELECT; 1873 cmd[4] = len; 1874 } 1875 1876 ret = scsi_execute_req(sdev, cmd, DMA_TO_DEVICE, real_buffer, len, 1877 sshdr, timeout, retries); 1878 kfree(real_buffer); 1879 return ret; 1880} 1881EXPORT_SYMBOL_GPL(scsi_mode_select); 1882 1883/** 1884 * scsi_mode_sense - issue a mode sense, falling back from 10 to six bytes if necessary. 1885 * @sdev: SCSI device to be queried 1886 * @dbd: set if mode sense will allow block descriptors to be returned 1887 * @modepage: mode page being requested 1888 * @buffer: request buffer (may not be smaller than eight bytes) 1889 * @len: length of request buffer. 1890 * @timeout: command timeout 1891 * @retries: number of retries before failing 1892 * @data: returns a structure abstracting the mode header data 1893 * @sshdr: place to put sense data (or NULL if no sense to be collected). 1894 * must be SCSI_SENSE_BUFFERSIZE big. 1895 * 1896 * Returns zero if unsuccessful, or the header offset (either 4 1897 * or 8 depending on whether a six or ten byte command was 1898 * issued) if successful. 1899 */ 1900int 1901scsi_mode_sense(struct scsi_device *sdev, int dbd, int modepage, 1902 unsigned char *buffer, int len, int timeout, int retries, 1903 struct scsi_mode_data *data, struct scsi_sense_hdr *sshdr) 1904{ 1905 unsigned char cmd[12]; 1906 int use_10_for_ms; 1907 int header_length; 1908 int result; 1909 struct scsi_sense_hdr my_sshdr; 1910 1911 memset(data, 0, sizeof(*data)); 1912 memset(&cmd[0], 0, 12); 1913 cmd[1] = dbd & 0x18; /* allows DBD and LLBA bits */ 1914 cmd[2] = modepage; 1915 1916 /* caller might not be interested in sense, but we need it */ 1917 if (!sshdr) 1918 sshdr = &my_sshdr; 1919 1920 retry: 1921 use_10_for_ms = sdev->use_10_for_ms; 1922 1923 if (use_10_for_ms) { 1924 if (len < 8) 1925 len = 8; 1926 1927 cmd[0] = MODE_SENSE_10; 1928 cmd[8] = len; 1929 header_length = 8; 1930 } else { 1931 if (len < 4) 1932 len = 4; 1933 1934 cmd[0] = MODE_SENSE; 1935 cmd[4] = len; 1936 header_length = 4; 1937 } 1938 1939 memset(buffer, 0, len); 1940 1941 result = scsi_execute_req(sdev, cmd, DMA_FROM_DEVICE, buffer, len, 1942 sshdr, timeout, retries); 1943 1944 /* This code looks awful: what it's doing is making sure an 1945 * ILLEGAL REQUEST sense return identifies the actual command 1946 * byte as the problem. MODE_SENSE commands can return 1947 * ILLEGAL REQUEST if the code page isn't supported */ 1948 1949 if (use_10_for_ms && !scsi_status_is_good(result) && 1950 (driver_byte(result) & DRIVER_SENSE)) { 1951 if (scsi_sense_valid(sshdr)) { 1952 if ((sshdr->sense_key == ILLEGAL_REQUEST) && 1953 (sshdr->asc == 0x20) && (sshdr->ascq == 0)) { 1954 /* 1955 * Invalid command operation code 1956 */ 1957 sdev->use_10_for_ms = 0; 1958 goto retry; 1959 } 1960 } 1961 } 1962 1963 if(scsi_status_is_good(result)) { 1964 if (unlikely(buffer[0] == 0x86 && buffer[1] == 0x0b && 1965 (modepage == 6 || modepage == 8))) { 1966 /* Initio breakage? */ 1967 header_length = 0; 1968 data->length = 13; 1969 data->medium_type = 0; 1970 data->device_specific = 0; 1971 data->longlba = 0; 1972 data->block_descriptor_length = 0; 1973 } else if(use_10_for_ms) { 1974 data->length = buffer[0]*256 + buffer[1] + 2; 1975 data->medium_type = buffer[2]; 1976 data->device_specific = buffer[3]; 1977 data->longlba = buffer[4] & 0x01; 1978 data->block_descriptor_length = buffer[6]*256 1979 + buffer[7]; 1980 } else { 1981 data->length = buffer[0] + 1; 1982 data->medium_type = buffer[1]; 1983 data->device_specific = buffer[2]; 1984 data->block_descriptor_length = buffer[3]; 1985 } 1986 data->header_length = header_length; 1987 } 1988 1989 return result; 1990} 1991EXPORT_SYMBOL(scsi_mode_sense); 1992 1993/** 1994 * scsi_test_unit_ready - test if unit is ready 1995 * @sdev: scsi device to change the state of. 1996 * @timeout: command timeout 1997 * @retries: number of retries before failing 1998 * @sshdr_external: Optional pointer to struct scsi_sense_hdr for 1999 * returning sense. Make sure that this is cleared before passing 2000 * in. 2001 * 2002 * Returns zero if unsuccessful or an error if TUR failed. For 2003 * removable media, a return of NOT_READY or UNIT_ATTENTION is 2004 * translated to success, with the ->changed flag updated. 2005 **/ 2006int 2007scsi_test_unit_ready(struct scsi_device *sdev, int timeout, int retries, 2008 struct scsi_sense_hdr *sshdr_external) 2009{ 2010 char cmd[] = { 2011 TEST_UNIT_READY, 0, 0, 0, 0, 0, 2012 }; 2013 struct scsi_sense_hdr *sshdr; 2014 int result; 2015 2016 if (!sshdr_external) 2017 sshdr = kzalloc(sizeof(*sshdr), GFP_KERNEL); 2018 else 2019 sshdr = sshdr_external; 2020 2021 /* try to eat the UNIT_ATTENTION if there are enough retries */ 2022 do { 2023 result = scsi_execute_req(sdev, cmd, DMA_NONE, NULL, 0, sshdr, 2024 timeout, retries); 2025 } while ((driver_byte(result) & DRIVER_SENSE) && 2026 sshdr && sshdr->sense_key == UNIT_ATTENTION && 2027 --retries); 2028 2029 if (!sshdr) 2030 /* could not allocate sense buffer, so can't process it */ 2031 return result; 2032 2033 if ((driver_byte(result) & DRIVER_SENSE) && sdev->removable) { 2034 2035 if ((scsi_sense_valid(sshdr)) && 2036 ((sshdr->sense_key == UNIT_ATTENTION) || 2037 (sshdr->sense_key == NOT_READY))) { 2038 sdev->changed = 1; 2039 result = 0; 2040 } 2041 } 2042 if (!sshdr_external) 2043 kfree(sshdr); 2044 return result; 2045} 2046EXPORT_SYMBOL(scsi_test_unit_ready); 2047 2048/** 2049 * scsi_device_set_state - Take the given device through the device state model. 2050 * @sdev: scsi device to change the state of. 2051 * @state: state to change to. 2052 * 2053 * Returns zero if unsuccessful or an error if the requested 2054 * transition is illegal. 2055 */ 2056int 2057scsi_device_set_state(struct scsi_device *sdev, enum scsi_device_state state) 2058{ 2059 enum scsi_device_state oldstate = sdev->sdev_state; 2060 2061 if (state == oldstate) 2062 return 0; 2063 2064 switch (state) { 2065 case SDEV_CREATED: 2066 /* There are no legal states that come back to 2067 * created. This is the manually initialised start 2068 * state */ 2069 goto illegal; 2070 2071 case SDEV_RUNNING: 2072 switch (oldstate) { 2073 case SDEV_CREATED: 2074 case SDEV_OFFLINE: 2075 case SDEV_QUIESCE: 2076 case SDEV_BLOCK: 2077 break; 2078 default: 2079 goto illegal; 2080 } 2081 break; 2082 2083 case SDEV_QUIESCE: 2084 switch (oldstate) { 2085 case SDEV_RUNNING: 2086 case SDEV_OFFLINE: 2087 break; 2088 default: 2089 goto illegal; 2090 } 2091 break; 2092 2093 case SDEV_OFFLINE: 2094 switch (oldstate) { 2095 case SDEV_CREATED: 2096 case SDEV_RUNNING: 2097 case SDEV_QUIESCE: 2098 case SDEV_BLOCK: 2099 break; 2100 default: 2101 goto illegal; 2102 } 2103 break; 2104 2105 case SDEV_BLOCK: 2106 switch (oldstate) { 2107 case SDEV_CREATED: 2108 case SDEV_RUNNING: 2109 break; 2110 default: 2111 goto illegal; 2112 } 2113 break; 2114 2115 case SDEV_CANCEL: 2116 switch (oldstate) { 2117 case SDEV_CREATED: 2118 case SDEV_RUNNING: 2119 case SDEV_QUIESCE: 2120 case SDEV_OFFLINE: 2121 case SDEV_BLOCK: 2122 break; 2123 default: 2124 goto illegal; 2125 } 2126 break; 2127 2128 case SDEV_DEL: 2129 switch (oldstate) { 2130 case SDEV_CREATED: 2131 case SDEV_RUNNING: 2132 case SDEV_OFFLINE: 2133 case SDEV_CANCEL: 2134 break; 2135 default: 2136 goto illegal; 2137 } 2138 break; 2139 2140 } 2141 sdev->sdev_state = state; 2142 return 0; 2143 2144 illegal: 2145 SCSI_LOG_ERROR_RECOVERY(1, 2146 sdev_printk(KERN_ERR, sdev, 2147 "Illegal state transition %s->%s\n", 2148 scsi_device_state_name(oldstate), 2149 scsi_device_state_name(state)) 2150 ); 2151 return -EINVAL; 2152} 2153EXPORT_SYMBOL(scsi_device_set_state); 2154 2155/** 2156 * sdev_evt_emit - emit a single SCSI device uevent 2157 * @sdev: associated SCSI device 2158 * @evt: event to emit 2159 * 2160 * Send a single uevent (scsi_event) to the associated scsi_device. 2161 */ 2162static void scsi_evt_emit(struct scsi_device *sdev, struct scsi_event *evt) 2163{ 2164 int idx = 0; 2165 char *envp[3]; 2166 2167 switch (evt->evt_type) { 2168 case SDEV_EVT_MEDIA_CHANGE: 2169 envp[idx++] = "SDEV_MEDIA_CHANGE=1"; 2170 break; 2171 2172 default: 2173 /* do nothing */ 2174 break; 2175 } 2176 2177 envp[idx++] = NULL; 2178 2179 kobject_uevent_env(&sdev->sdev_gendev.kobj, KOBJ_CHANGE, envp); 2180} 2181 2182/** 2183 * sdev_evt_thread - send a uevent for each scsi event 2184 * @work: work struct for scsi_device 2185 * 2186 * Dispatch queued events to their associated scsi_device kobjects 2187 * as uevents. 2188 */ 2189void scsi_evt_thread(struct work_struct *work) 2190{ 2191 struct scsi_device *sdev; 2192 LIST_HEAD(event_list); 2193 2194 sdev = container_of(work, struct scsi_device, event_work); 2195 2196 while (1) { 2197 struct scsi_event *evt; 2198 struct list_head *this, *tmp; 2199 unsigned long flags; 2200 2201 spin_lock_irqsave(&sdev->list_lock, flags); 2202 list_splice_init(&sdev->event_list, &event_list); 2203 spin_unlock_irqrestore(&sdev->list_lock, flags); 2204 2205 if (list_empty(&event_list)) 2206 break; 2207 2208 list_for_each_safe(this, tmp, &event_list) { 2209 evt = list_entry(this, struct scsi_event, node); 2210 list_del(&evt->node); 2211 scsi_evt_emit(sdev, evt); 2212 kfree(evt); 2213 } 2214 } 2215} 2216 2217/** 2218 * sdev_evt_send - send asserted event to uevent thread 2219 * @sdev: scsi_device event occurred on 2220 * @evt: event to send 2221 * 2222 * Assert scsi device event asynchronously. 2223 */ 2224void sdev_evt_send(struct scsi_device *sdev, struct scsi_event *evt) 2225{ 2226 unsigned long flags; 2227 2228#if 0 2229 /* FIXME: currently this check eliminates all media change events 2230 * for polled devices. Need to update to discriminate between AN 2231 * and polled events */ 2232 if (!test_bit(evt->evt_type, sdev->supported_events)) { 2233 kfree(evt); 2234 return; 2235 } 2236#endif 2237 2238 spin_lock_irqsave(&sdev->list_lock, flags); 2239 list_add_tail(&evt->node, &sdev->event_list); 2240 schedule_work(&sdev->event_work); 2241 spin_unlock_irqrestore(&sdev->list_lock, flags); 2242} 2243EXPORT_SYMBOL_GPL(sdev_evt_send); 2244 2245/** 2246 * sdev_evt_alloc - allocate a new scsi event 2247 * @evt_type: type of event to allocate 2248 * @gfpflags: GFP flags for allocation 2249 * 2250 * Allocates and returns a new scsi_event. 2251 */ 2252struct scsi_event *sdev_evt_alloc(enum scsi_device_event evt_type, 2253 gfp_t gfpflags) 2254{ 2255 struct scsi_event *evt = kzalloc(sizeof(struct scsi_event), gfpflags); 2256 if (!evt) 2257 return NULL; 2258 2259 evt->evt_type = evt_type; 2260 INIT_LIST_HEAD(&evt->node); 2261 2262 /* evt_type-specific initialization, if any */ 2263 switch (evt_type) { 2264 case SDEV_EVT_MEDIA_CHANGE: 2265 default: 2266 /* do nothing */ 2267 break; 2268 } 2269 2270 return evt; 2271} 2272EXPORT_SYMBOL_GPL(sdev_evt_alloc); 2273 2274/** 2275 * sdev_evt_send_simple - send asserted event to uevent thread 2276 * @sdev: scsi_device event occurred on 2277 * @evt_type: type of event to send 2278 * @gfpflags: GFP flags for allocation 2279 * 2280 * Assert scsi device event asynchronously, given an event type. 2281 */ 2282void sdev_evt_send_simple(struct scsi_device *sdev, 2283 enum scsi_device_event evt_type, gfp_t gfpflags) 2284{ 2285 struct scsi_event *evt = sdev_evt_alloc(evt_type, gfpflags); 2286 if (!evt) { 2287 sdev_printk(KERN_ERR, sdev, "event %d eaten due to OOM\n", 2288 evt_type); 2289 return; 2290 } 2291 2292 sdev_evt_send(sdev, evt); 2293} 2294EXPORT_SYMBOL_GPL(sdev_evt_send_simple); 2295 2296/** 2297 * scsi_device_quiesce - Block user issued commands. 2298 * @sdev: scsi device to quiesce. 2299 * 2300 * This works by trying to transition to the SDEV_QUIESCE state 2301 * (which must be a legal transition). When the device is in this 2302 * state, only special requests will be accepted, all others will 2303 * be deferred. Since special requests may also be requeued requests, 2304 * a successful return doesn't guarantee the device will be 2305 * totally quiescent. 2306 * 2307 * Must be called with user context, may sleep. 2308 * 2309 * Returns zero if unsuccessful or an error if not. 2310 */ 2311int 2312scsi_device_quiesce(struct scsi_device *sdev) 2313{ 2314 int err = scsi_device_set_state(sdev, SDEV_QUIESCE); 2315 if (err) 2316 return err; 2317 2318 scsi_run_queue(sdev->request_queue); 2319 while (sdev->device_busy) { 2320 msleep_interruptible(200); 2321 scsi_run_queue(sdev->request_queue); 2322 } 2323 return 0; 2324} 2325EXPORT_SYMBOL(scsi_device_quiesce); 2326 2327/** 2328 * scsi_device_resume - Restart user issued commands to a quiesced device. 2329 * @sdev: scsi device to resume. 2330 * 2331 * Moves the device from quiesced back to running and restarts the 2332 * queues. 2333 * 2334 * Must be called with user context, may sleep. 2335 */ 2336void 2337scsi_device_resume(struct scsi_device *sdev) 2338{ 2339 if(scsi_device_set_state(sdev, SDEV_RUNNING)) 2340 return; 2341 scsi_run_queue(sdev->request_queue); 2342} 2343EXPORT_SYMBOL(scsi_device_resume); 2344 2345static void 2346device_quiesce_fn(struct scsi_device *sdev, void *data) 2347{ 2348 scsi_device_quiesce(sdev); 2349} 2350 2351void 2352scsi_target_quiesce(struct scsi_target *starget) 2353{ 2354 starget_for_each_device(starget, NULL, device_quiesce_fn); 2355} 2356EXPORT_SYMBOL(scsi_target_quiesce); 2357 2358static void 2359device_resume_fn(struct scsi_device *sdev, void *data) 2360{ 2361 scsi_device_resume(sdev); 2362} 2363 2364void 2365scsi_target_resume(struct scsi_target *starget) 2366{ 2367 starget_for_each_device(starget, NULL, device_resume_fn); 2368} 2369EXPORT_SYMBOL(scsi_target_resume); 2370 2371/** 2372 * scsi_internal_device_block - internal function to put a device temporarily into the SDEV_BLOCK state 2373 * @sdev: device to block 2374 * 2375 * Block request made by scsi lld's to temporarily stop all 2376 * scsi commands on the specified device. Called from interrupt 2377 * or normal process context. 2378 * 2379 * Returns zero if successful or error if not 2380 * 2381 * Notes: 2382 * This routine transitions the device to the SDEV_BLOCK state 2383 * (which must be a legal transition). When the device is in this 2384 * state, all commands are deferred until the scsi lld reenables 2385 * the device with scsi_device_unblock or device_block_tmo fires. 2386 * This routine assumes the host_lock is held on entry. 2387 */ 2388int 2389scsi_internal_device_block(struct scsi_device *sdev) 2390{ 2391 struct request_queue *q = sdev->request_queue; 2392 unsigned long flags; 2393 int err = 0; 2394 2395 err = scsi_device_set_state(sdev, SDEV_BLOCK); 2396 if (err) 2397 return err; 2398 2399 /* 2400 * The device has transitioned to SDEV_BLOCK. Stop the 2401 * block layer from calling the midlayer with this device's 2402 * request queue. 2403 */ 2404 spin_lock_irqsave(q->queue_lock, flags); 2405 blk_stop_queue(q); 2406 spin_unlock_irqrestore(q->queue_lock, flags); 2407 2408 return 0; 2409} 2410EXPORT_SYMBOL_GPL(scsi_internal_device_block); 2411 2412/** 2413 * scsi_internal_device_unblock - resume a device after a block request 2414 * @sdev: device to resume 2415 * 2416 * Called by scsi lld's or the midlayer to restart the device queue 2417 * for the previously suspended scsi device. Called from interrupt or 2418 * normal process context. 2419 * 2420 * Returns zero if successful or error if not. 2421 * 2422 * Notes: 2423 * This routine transitions the device to the SDEV_RUNNING state 2424 * (which must be a legal transition) allowing the midlayer to 2425 * goose the queue for this device. This routine assumes the 2426 * host_lock is held upon entry. 2427 */ 2428int 2429scsi_internal_device_unblock(struct scsi_device *sdev) 2430{ 2431 struct request_queue *q = sdev->request_queue; 2432 int err; 2433 unsigned long flags; 2434 2435 /* 2436 * Try to transition the scsi device to SDEV_RUNNING 2437 * and goose the device queue if successful. 2438 */ 2439 err = scsi_device_set_state(sdev, SDEV_RUNNING); 2440 if (err) 2441 return err; 2442 2443 spin_lock_irqsave(q->queue_lock, flags); 2444 blk_start_queue(q); 2445 spin_unlock_irqrestore(q->queue_lock, flags); 2446 2447 return 0; 2448} 2449EXPORT_SYMBOL_GPL(scsi_internal_device_unblock); 2450 2451static void 2452device_block(struct scsi_device *sdev, void *data) 2453{ 2454 scsi_internal_device_block(sdev); 2455} 2456 2457static int 2458target_block(struct device *dev, void *data) 2459{ 2460 if (scsi_is_target_device(dev)) 2461 starget_for_each_device(to_scsi_target(dev), NULL, 2462 device_block); 2463 return 0; 2464} 2465 2466void 2467scsi_target_block(struct device *dev) 2468{ 2469 if (scsi_is_target_device(dev)) 2470 starget_for_each_device(to_scsi_target(dev), NULL, 2471 device_block); 2472 else 2473 device_for_each_child(dev, NULL, target_block); 2474} 2475EXPORT_SYMBOL_GPL(scsi_target_block); 2476 2477static void 2478device_unblock(struct scsi_device *sdev, void *data) 2479{ 2480 scsi_internal_device_unblock(sdev); 2481} 2482 2483static int 2484target_unblock(struct device *dev, void *data) 2485{ 2486 if (scsi_is_target_device(dev)) 2487 starget_for_each_device(to_scsi_target(dev), NULL, 2488 device_unblock); 2489 return 0; 2490} 2491 2492void 2493scsi_target_unblock(struct device *dev) 2494{ 2495 if (scsi_is_target_device(dev)) 2496 starget_for_each_device(to_scsi_target(dev), NULL, 2497 device_unblock); 2498 else 2499 device_for_each_child(dev, NULL, target_unblock); 2500} 2501EXPORT_SYMBOL_GPL(scsi_target_unblock); 2502 2503/** 2504 * scsi_kmap_atomic_sg - find and atomically map an sg-elemnt 2505 * @sgl: scatter-gather list 2506 * @sg_count: number of segments in sg 2507 * @offset: offset in bytes into sg, on return offset into the mapped area 2508 * @len: bytes to map, on return number of bytes mapped 2509 * 2510 * Returns virtual address of the start of the mapped page 2511 */ 2512void *scsi_kmap_atomic_sg(struct scatterlist *sgl, int sg_count, 2513 size_t *offset, size_t *len) 2514{ 2515 int i; 2516 size_t sg_len = 0, len_complete = 0; 2517 struct scatterlist *sg; 2518 struct page *page; 2519 2520 WARN_ON(!irqs_disabled()); 2521 2522 for_each_sg(sgl, sg, sg_count, i) { 2523 len_complete = sg_len; /* Complete sg-entries */ 2524 sg_len += sg->length; 2525 if (sg_len > *offset) 2526 break; 2527 } 2528 2529 if (unlikely(i == sg_count)) { 2530 printk(KERN_ERR "%s: Bytes in sg: %zu, requested offset %zu, " 2531 "elements %d\n", 2532 __FUNCTION__, sg_len, *offset, sg_count); 2533 WARN_ON(1); 2534 return NULL; 2535 } 2536 2537 /* Offset starting from the beginning of first page in this sg-entry */ 2538 *offset = *offset - len_complete + sg->offset; 2539 2540 /* Assumption: contiguous pages can be accessed as "page + i" */ 2541 page = nth_page(sg_page(sg), (*offset >> PAGE_SHIFT)); 2542 *offset &= ~PAGE_MASK; 2543 2544 /* Bytes in this sg-entry from *offset to the end of the page */ 2545 sg_len = PAGE_SIZE - *offset; 2546 if (*len > sg_len) 2547 *len = sg_len; 2548 2549 return kmap_atomic(page, KM_BIO_SRC_IRQ); 2550} 2551EXPORT_SYMBOL(scsi_kmap_atomic_sg); 2552 2553/** 2554 * scsi_kunmap_atomic_sg - atomically unmap a virtual address, previously mapped with scsi_kmap_atomic_sg 2555 * @virt: virtual address to be unmapped 2556 */ 2557void scsi_kunmap_atomic_sg(void *virt) 2558{ 2559 kunmap_atomic(virt, KM_BIO_SRC_IRQ); 2560} 2561EXPORT_SYMBOL(scsi_kunmap_atomic_sg); 2562