Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * scsi_lib.c Copyright (C) 1999 Eric Youngdale |
| 3 | * |
| 4 | * SCSI queueing library. |
| 5 | * Initial versions: Eric Youngdale (eric@andante.org). |
| 6 | * Based upon conversations with large numbers |
| 7 | * of people at Linux Expo. |
| 8 | */ |
| 9 | |
| 10 | #include <linux/bio.h> |
| 11 | #include <linux/blkdev.h> |
| 12 | #include <linux/completion.h> |
| 13 | #include <linux/kernel.h> |
| 14 | #include <linux/mempool.h> |
| 15 | #include <linux/slab.h> |
| 16 | #include <linux/init.h> |
| 17 | #include <linux/pci.h> |
| 18 | #include <linux/delay.h> |
James Bottomley | faead26 | 2006-02-14 10:42:07 -0600 | [diff] [blame] | 19 | #include <linux/hardirq.h> |
Jens Axboe | c6132da | 2007-10-16 11:08:49 +0200 | [diff] [blame] | 20 | #include <linux/scatterlist.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 21 | |
| 22 | #include <scsi/scsi.h> |
Christoph Hellwig | beb4048 | 2006-06-10 18:01:03 +0200 | [diff] [blame] | 23 | #include <scsi/scsi_cmnd.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 24 | #include <scsi/scsi_dbg.h> |
| 25 | #include <scsi/scsi_device.h> |
| 26 | #include <scsi/scsi_driver.h> |
| 27 | #include <scsi/scsi_eh.h> |
| 28 | #include <scsi/scsi_host.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 29 | |
| 30 | #include "scsi_priv.h" |
| 31 | #include "scsi_logging.h" |
| 32 | |
| 33 | |
Tobias Klauser | 6391a11 | 2006-06-08 22:23:48 -0700 | [diff] [blame] | 34 | #define SG_MEMPOOL_NR ARRAY_SIZE(scsi_sg_pools) |
Jens Axboe | 5972511 | 2007-04-02 10:06:42 +0200 | [diff] [blame] | 35 | #define SG_MEMPOOL_SIZE 2 |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 36 | |
FUJITA Tomonori | fd820f4 | 2007-09-18 12:14:37 +0200 | [diff] [blame] | 37 | /* |
| 38 | * The maximum number of SG segments that we will put inside a scatterlist |
| 39 | * (unless chaining is used). Should ideally fit inside a single page, to |
| 40 | * avoid a higher order allocation. |
| 41 | */ |
| 42 | #define SCSI_MAX_SG_SEGMENTS 128 |
| 43 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 44 | struct scsi_host_sg_pool { |
| 45 | size_t size; |
Jens Axboe | a8474ce | 2007-08-07 09:02:51 +0200 | [diff] [blame] | 46 | char *name; |
Christoph Lameter | e18b890 | 2006-12-06 20:33:20 -0800 | [diff] [blame] | 47 | struct kmem_cache *slab; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 48 | mempool_t *pool; |
| 49 | }; |
| 50 | |
Jens Axboe | a8474ce | 2007-08-07 09:02:51 +0200 | [diff] [blame] | 51 | #define SP(x) { x, "sgpool-" #x } |
Adrian Bunk | 52c1da3 | 2005-06-23 22:05:33 -0700 | [diff] [blame] | 52 | static struct scsi_host_sg_pool scsi_sg_pools[] = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 53 | SP(8), |
| 54 | SP(16), |
FUJITA Tomonori | fd820f4 | 2007-09-18 12:14:37 +0200 | [diff] [blame] | 55 | #if (SCSI_MAX_SG_SEGMENTS > 16) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 56 | SP(32), |
FUJITA Tomonori | fd820f4 | 2007-09-18 12:14:37 +0200 | [diff] [blame] | 57 | #if (SCSI_MAX_SG_SEGMENTS > 32) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 58 | SP(64), |
FUJITA Tomonori | fd820f4 | 2007-09-18 12:14:37 +0200 | [diff] [blame] | 59 | #if (SCSI_MAX_SG_SEGMENTS > 64) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 60 | SP(128), |
FUJITA Tomonori | fd820f4 | 2007-09-18 12:14:37 +0200 | [diff] [blame] | 61 | #endif |
| 62 | #endif |
| 63 | #endif |
Jens Axboe | a8474ce | 2007-08-07 09:02:51 +0200 | [diff] [blame] | 64 | }; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 65 | #undef SP |
| 66 | |
Tejun Heo | a1bf9d1d | 2005-04-24 02:08:52 -0500 | [diff] [blame] | 67 | static void scsi_run_queue(struct request_queue *q); |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 68 | |
| 69 | /* |
| 70 | * Function: scsi_unprep_request() |
| 71 | * |
| 72 | * Purpose: Remove all preparation done for a request, including its |
| 73 | * associated scsi_cmnd, so that it can be requeued. |
| 74 | * |
| 75 | * Arguments: req - request to unprepare |
| 76 | * |
| 77 | * Lock status: Assumed that no locks are held upon entry. |
| 78 | * |
| 79 | * Returns: Nothing. |
| 80 | */ |
| 81 | static void scsi_unprep_request(struct request *req) |
| 82 | { |
| 83 | struct scsi_cmnd *cmd = req->special; |
| 84 | |
Jens Axboe | 4aff5e2 | 2006-08-10 08:44:47 +0200 | [diff] [blame] | 85 | req->cmd_flags &= ~REQ_DONTPREP; |
Christoph Hellwig | beb4048 | 2006-06-10 18:01:03 +0200 | [diff] [blame] | 86 | req->special = NULL; |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 87 | |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 88 | scsi_put_command(cmd); |
| 89 | } |
Tejun Heo | a1bf9d1d | 2005-04-24 02:08:52 -0500 | [diff] [blame] | 90 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 91 | /* |
| 92 | * Function: scsi_queue_insert() |
| 93 | * |
| 94 | * Purpose: Insert a command in the midlevel queue. |
| 95 | * |
| 96 | * Arguments: cmd - command that we are adding to queue. |
| 97 | * reason - why we are inserting command to queue. |
| 98 | * |
| 99 | * Lock status: Assumed that lock is not held upon entry. |
| 100 | * |
| 101 | * Returns: Nothing. |
| 102 | * |
| 103 | * Notes: We do this for one of two cases. Either the host is busy |
| 104 | * and it cannot accept any more commands for the time being, |
| 105 | * or the device returned QUEUE_FULL and can accept no more |
| 106 | * commands. |
| 107 | * Notes: This could be called either from an interrupt context or a |
| 108 | * normal process context. |
| 109 | */ |
| 110 | int scsi_queue_insert(struct scsi_cmnd *cmd, int reason) |
| 111 | { |
| 112 | struct Scsi_Host *host = cmd->device->host; |
| 113 | struct scsi_device *device = cmd->device; |
Tejun Heo | a1bf9d1d | 2005-04-24 02:08:52 -0500 | [diff] [blame] | 114 | struct request_queue *q = device->request_queue; |
| 115 | unsigned long flags; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 116 | |
| 117 | SCSI_LOG_MLQUEUE(1, |
| 118 | printk("Inserting command %p into mlqueue\n", cmd)); |
| 119 | |
| 120 | /* |
Tejun Heo | d8c37e7 | 2005-05-14 00:46:08 +0900 | [diff] [blame] | 121 | * Set the appropriate busy bit for the device/host. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 122 | * |
| 123 | * If the host/device isn't busy, assume that something actually |
| 124 | * completed, and that we should be able to queue a command now. |
| 125 | * |
| 126 | * Note that the prior mid-layer assumption that any host could |
| 127 | * always queue at least one command is now broken. The mid-layer |
| 128 | * will implement a user specifiable stall (see |
| 129 | * scsi_host.max_host_blocked and scsi_device.max_device_blocked) |
| 130 | * if a command is requeued with no other commands outstanding |
| 131 | * either for the device or for the host. |
| 132 | */ |
| 133 | if (reason == SCSI_MLQUEUE_HOST_BUSY) |
| 134 | host->host_blocked = host->max_host_blocked; |
| 135 | else if (reason == SCSI_MLQUEUE_DEVICE_BUSY) |
| 136 | device->device_blocked = device->max_device_blocked; |
| 137 | |
| 138 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 139 | * Decrement the counters, since these commands are no longer |
| 140 | * active on the host/device. |
| 141 | */ |
| 142 | scsi_device_unbusy(device); |
| 143 | |
| 144 | /* |
Tejun Heo | a1bf9d1d | 2005-04-24 02:08:52 -0500 | [diff] [blame] | 145 | * Requeue this command. It will go before all other commands |
| 146 | * that are already in the queue. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 147 | * |
| 148 | * NOTE: there is magic here about the way the queue is plugged if |
| 149 | * we have no outstanding commands. |
| 150 | * |
Tejun Heo | a1bf9d1d | 2005-04-24 02:08:52 -0500 | [diff] [blame] | 151 | * Although we *don't* plug the queue, we call the request |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 152 | * function. The SCSI request function detects the blocked condition |
| 153 | * and plugs the queue appropriately. |
Tejun Heo | a1bf9d1d | 2005-04-24 02:08:52 -0500 | [diff] [blame] | 154 | */ |
| 155 | spin_lock_irqsave(q->queue_lock, flags); |
James Bottomley | 59897da | 2005-09-14 12:57:42 -0400 | [diff] [blame] | 156 | blk_requeue_request(q, cmd->request); |
Tejun Heo | a1bf9d1d | 2005-04-24 02:08:52 -0500 | [diff] [blame] | 157 | spin_unlock_irqrestore(q->queue_lock, flags); |
| 158 | |
| 159 | scsi_run_queue(q); |
| 160 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 161 | return 0; |
| 162 | } |
| 163 | |
James Bottomley | 3921603 | 2005-06-15 18:48:29 -0500 | [diff] [blame] | 164 | /** |
James Bottomley | 33aa687 | 2005-08-28 11:31:14 -0500 | [diff] [blame] | 165 | * scsi_execute - insert request and wait for the result |
James Bottomley | 3921603 | 2005-06-15 18:48:29 -0500 | [diff] [blame] | 166 | * @sdev: scsi device |
| 167 | * @cmd: scsi command |
| 168 | * @data_direction: data direction |
| 169 | * @buffer: data buffer |
| 170 | * @bufflen: len of buffer |
| 171 | * @sense: optional sense buffer |
| 172 | * @timeout: request timeout in seconds |
| 173 | * @retries: number of times to retry request |
James Bottomley | 33aa687 | 2005-08-28 11:31:14 -0500 | [diff] [blame] | 174 | * @flags: or into request flags; |
James Bottomley | 3921603 | 2005-06-15 18:48:29 -0500 | [diff] [blame] | 175 | * |
Michael Opdenacker | 59c5159 | 2007-05-09 08:57:56 +0200 | [diff] [blame] | 176 | * returns the req->errors value which is the scsi_cmnd result |
James Bottomley | ea73a9f | 2005-08-28 11:33:52 -0500 | [diff] [blame] | 177 | * field. |
Rob Landley | eb44820 | 2007-11-03 13:30:39 -0500 | [diff] [blame] | 178 | */ |
James Bottomley | 33aa687 | 2005-08-28 11:31:14 -0500 | [diff] [blame] | 179 | int scsi_execute(struct scsi_device *sdev, const unsigned char *cmd, |
| 180 | int data_direction, void *buffer, unsigned bufflen, |
| 181 | unsigned char *sense, int timeout, int retries, int flags) |
James Bottomley | 3921603 | 2005-06-15 18:48:29 -0500 | [diff] [blame] | 182 | { |
| 183 | struct request *req; |
| 184 | int write = (data_direction == DMA_TO_DEVICE); |
| 185 | int ret = DRIVER_ERROR << 24; |
| 186 | |
| 187 | req = blk_get_request(sdev->request_queue, write, __GFP_WAIT); |
| 188 | |
| 189 | if (bufflen && blk_rq_map_kern(sdev->request_queue, req, |
| 190 | buffer, bufflen, __GFP_WAIT)) |
| 191 | goto out; |
| 192 | |
| 193 | req->cmd_len = COMMAND_SIZE(cmd[0]); |
| 194 | memcpy(req->cmd, cmd, req->cmd_len); |
| 195 | req->sense = sense; |
| 196 | req->sense_len = 0; |
Mike Christie | 17e01f2 | 2005-11-11 05:31:37 -0600 | [diff] [blame] | 197 | req->retries = retries; |
James Bottomley | 3921603 | 2005-06-15 18:48:29 -0500 | [diff] [blame] | 198 | req->timeout = timeout; |
Jens Axboe | 4aff5e2 | 2006-08-10 08:44:47 +0200 | [diff] [blame] | 199 | req->cmd_type = REQ_TYPE_BLOCK_PC; |
| 200 | req->cmd_flags |= flags | REQ_QUIET | REQ_PREEMPT; |
James Bottomley | 3921603 | 2005-06-15 18:48:29 -0500 | [diff] [blame] | 201 | |
| 202 | /* |
| 203 | * head injection *required* here otherwise quiesce won't work |
| 204 | */ |
| 205 | blk_execute_rq(req->q, NULL, req, 1); |
| 206 | |
| 207 | ret = req->errors; |
| 208 | out: |
| 209 | blk_put_request(req); |
| 210 | |
| 211 | return ret; |
| 212 | } |
James Bottomley | 33aa687 | 2005-08-28 11:31:14 -0500 | [diff] [blame] | 213 | EXPORT_SYMBOL(scsi_execute); |
James Bottomley | 3921603 | 2005-06-15 18:48:29 -0500 | [diff] [blame] | 214 | |
James Bottomley | ea73a9f | 2005-08-28 11:33:52 -0500 | [diff] [blame] | 215 | |
| 216 | int scsi_execute_req(struct scsi_device *sdev, const unsigned char *cmd, |
| 217 | int data_direction, void *buffer, unsigned bufflen, |
| 218 | struct scsi_sense_hdr *sshdr, int timeout, int retries) |
| 219 | { |
| 220 | char *sense = NULL; |
akpm@osdl.org | 1ccb48b | 2005-06-26 00:12:51 -0700 | [diff] [blame] | 221 | int result; |
| 222 | |
James Bottomley | ea73a9f | 2005-08-28 11:33:52 -0500 | [diff] [blame] | 223 | if (sshdr) { |
Jes Sorensen | 24669f75 | 2006-01-16 10:31:18 -0500 | [diff] [blame] | 224 | sense = kzalloc(SCSI_SENSE_BUFFERSIZE, GFP_NOIO); |
James Bottomley | ea73a9f | 2005-08-28 11:33:52 -0500 | [diff] [blame] | 225 | if (!sense) |
| 226 | return DRIVER_ERROR << 24; |
James Bottomley | ea73a9f | 2005-08-28 11:33:52 -0500 | [diff] [blame] | 227 | } |
akpm@osdl.org | 1ccb48b | 2005-06-26 00:12:51 -0700 | [diff] [blame] | 228 | result = scsi_execute(sdev, cmd, data_direction, buffer, bufflen, |
Jes Sorensen | 24669f75 | 2006-01-16 10:31:18 -0500 | [diff] [blame] | 229 | sense, timeout, retries, 0); |
James Bottomley | ea73a9f | 2005-08-28 11:33:52 -0500 | [diff] [blame] | 230 | if (sshdr) |
James Bottomley | e514385 | 2005-08-09 11:55:36 -0500 | [diff] [blame] | 231 | scsi_normalize_sense(sense, SCSI_SENSE_BUFFERSIZE, sshdr); |
James Bottomley | ea73a9f | 2005-08-28 11:33:52 -0500 | [diff] [blame] | 232 | |
| 233 | kfree(sense); |
| 234 | return result; |
| 235 | } |
| 236 | EXPORT_SYMBOL(scsi_execute_req); |
| 237 | |
Mike Christie | 6e68af6 | 2005-11-11 05:30:27 -0600 | [diff] [blame] | 238 | struct scsi_io_context { |
| 239 | void *data; |
| 240 | void (*done)(void *data, char *sense, int result, int resid); |
| 241 | char sense[SCSI_SENSE_BUFFERSIZE]; |
| 242 | }; |
| 243 | |
Christoph Lameter | e18b890 | 2006-12-06 20:33:20 -0800 | [diff] [blame] | 244 | static struct kmem_cache *scsi_io_context_cache; |
Mike Christie | aa7b5cd | 2005-11-11 05:31:41 -0600 | [diff] [blame] | 245 | |
Jens Axboe | e650c30 | 2006-01-06 12:38:30 +0100 | [diff] [blame] | 246 | static void scsi_end_async(struct request *req, int uptodate) |
Mike Christie | 6e68af6 | 2005-11-11 05:30:27 -0600 | [diff] [blame] | 247 | { |
| 248 | struct scsi_io_context *sioc = req->end_io_data; |
| 249 | |
| 250 | if (sioc->done) |
| 251 | sioc->done(sioc->data, sioc->sense, req->errors, req->data_len); |
| 252 | |
Mike Christie | aa7b5cd | 2005-11-11 05:31:41 -0600 | [diff] [blame] | 253 | kmem_cache_free(scsi_io_context_cache, sioc); |
Mike Christie | 6e68af6 | 2005-11-11 05:30:27 -0600 | [diff] [blame] | 254 | __blk_put_request(req->q, req); |
| 255 | } |
| 256 | |
| 257 | static int scsi_merge_bio(struct request *rq, struct bio *bio) |
| 258 | { |
| 259 | struct request_queue *q = rq->q; |
| 260 | |
| 261 | bio->bi_flags &= ~(1 << BIO_SEG_VALID); |
| 262 | if (rq_data_dir(rq) == WRITE) |
| 263 | bio->bi_rw |= (1 << BIO_RW); |
| 264 | blk_queue_bounce(q, &bio); |
| 265 | |
NeilBrown | 3001ca7 | 2007-08-16 13:31:27 +0200 | [diff] [blame] | 266 | return blk_rq_append_bio(q, rq, bio); |
Mike Christie | 6e68af6 | 2005-11-11 05:30:27 -0600 | [diff] [blame] | 267 | } |
| 268 | |
NeilBrown | 6712ecf | 2007-09-27 12:47:43 +0200 | [diff] [blame] | 269 | static void scsi_bi_endio(struct bio *bio, int error) |
Mike Christie | 6e68af6 | 2005-11-11 05:30:27 -0600 | [diff] [blame] | 270 | { |
Mike Christie | 6e68af6 | 2005-11-11 05:30:27 -0600 | [diff] [blame] | 271 | bio_put(bio); |
Mike Christie | 6e68af6 | 2005-11-11 05:30:27 -0600 | [diff] [blame] | 272 | } |
| 273 | |
| 274 | /** |
| 275 | * scsi_req_map_sg - map a scatterlist into a request |
| 276 | * @rq: request to fill |
Rob Landley | eb44820 | 2007-11-03 13:30:39 -0500 | [diff] [blame] | 277 | * @sgl: scatterlist |
Mike Christie | 6e68af6 | 2005-11-11 05:30:27 -0600 | [diff] [blame] | 278 | * @nsegs: number of elements |
| 279 | * @bufflen: len of buffer |
| 280 | * @gfp: memory allocation flags |
| 281 | * |
| 282 | * scsi_req_map_sg maps a scatterlist into a request so that the |
| 283 | * request can be sent to the block layer. We do not trust the scatterlist |
| 284 | * sent to use, as some ULDs use that struct to only organize the pages. |
| 285 | */ |
| 286 | static int scsi_req_map_sg(struct request *rq, struct scatterlist *sgl, |
| 287 | int nsegs, unsigned bufflen, gfp_t gfp) |
| 288 | { |
| 289 | struct request_queue *q = rq->q; |
Bryan Holty | f523596 | 2006-03-22 06:35:39 -0600 | [diff] [blame] | 290 | int nr_pages = (bufflen + sgl[0].offset + PAGE_SIZE - 1) >> PAGE_SHIFT; |
Mike Christie | bd441de | 2007-03-13 12:52:29 -0500 | [diff] [blame] | 291 | unsigned int data_len = bufflen, len, bytes, off; |
Jens Axboe | c6132da | 2007-10-16 11:08:49 +0200 | [diff] [blame] | 292 | struct scatterlist *sg; |
Mike Christie | 6e68af6 | 2005-11-11 05:30:27 -0600 | [diff] [blame] | 293 | struct page *page; |
| 294 | struct bio *bio = NULL; |
| 295 | int i, err, nr_vecs = 0; |
| 296 | |
Jens Axboe | c6132da | 2007-10-16 11:08:49 +0200 | [diff] [blame] | 297 | for_each_sg(sgl, sg, nsegs, i) { |
Jens Axboe | 45711f1 | 2007-10-22 21:19:53 +0200 | [diff] [blame] | 298 | page = sg_page(sg); |
Jens Axboe | c6132da | 2007-10-16 11:08:49 +0200 | [diff] [blame] | 299 | off = sg->offset; |
| 300 | len = sg->length; |
| 301 | data_len += len; |
Mike Christie | 6e68af6 | 2005-11-11 05:30:27 -0600 | [diff] [blame] | 302 | |
Mike Christie | bd441de | 2007-03-13 12:52:29 -0500 | [diff] [blame] | 303 | while (len > 0 && data_len > 0) { |
| 304 | /* |
| 305 | * sg sends a scatterlist that is larger than |
| 306 | * the data_len it wants transferred for certain |
| 307 | * IO sizes |
| 308 | */ |
Mike Christie | 6e68af6 | 2005-11-11 05:30:27 -0600 | [diff] [blame] | 309 | bytes = min_t(unsigned int, len, PAGE_SIZE - off); |
Mike Christie | bd441de | 2007-03-13 12:52:29 -0500 | [diff] [blame] | 310 | bytes = min(bytes, data_len); |
Mike Christie | 6e68af6 | 2005-11-11 05:30:27 -0600 | [diff] [blame] | 311 | |
| 312 | if (!bio) { |
| 313 | nr_vecs = min_t(int, BIO_MAX_PAGES, nr_pages); |
| 314 | nr_pages -= nr_vecs; |
| 315 | |
| 316 | bio = bio_alloc(gfp, nr_vecs); |
| 317 | if (!bio) { |
| 318 | err = -ENOMEM; |
| 319 | goto free_bios; |
| 320 | } |
| 321 | bio->bi_end_io = scsi_bi_endio; |
| 322 | } |
| 323 | |
| 324 | if (bio_add_pc_page(q, bio, page, bytes, off) != |
| 325 | bytes) { |
| 326 | bio_put(bio); |
| 327 | err = -EINVAL; |
| 328 | goto free_bios; |
| 329 | } |
| 330 | |
| 331 | if (bio->bi_vcnt >= nr_vecs) { |
| 332 | err = scsi_merge_bio(rq, bio); |
| 333 | if (err) { |
NeilBrown | 6712ecf | 2007-09-27 12:47:43 +0200 | [diff] [blame] | 334 | bio_endio(bio, 0); |
Mike Christie | 6e68af6 | 2005-11-11 05:30:27 -0600 | [diff] [blame] | 335 | goto free_bios; |
| 336 | } |
| 337 | bio = NULL; |
| 338 | } |
| 339 | |
| 340 | page++; |
| 341 | len -= bytes; |
Mike Christie | bd441de | 2007-03-13 12:52:29 -0500 | [diff] [blame] | 342 | data_len -=bytes; |
Mike Christie | 6e68af6 | 2005-11-11 05:30:27 -0600 | [diff] [blame] | 343 | off = 0; |
| 344 | } |
| 345 | } |
| 346 | |
| 347 | rq->buffer = rq->data = NULL; |
Mike Christie | bd441de | 2007-03-13 12:52:29 -0500 | [diff] [blame] | 348 | rq->data_len = bufflen; |
Mike Christie | 6e68af6 | 2005-11-11 05:30:27 -0600 | [diff] [blame] | 349 | return 0; |
| 350 | |
| 351 | free_bios: |
| 352 | while ((bio = rq->bio) != NULL) { |
| 353 | rq->bio = bio->bi_next; |
| 354 | /* |
| 355 | * call endio instead of bio_put incase it was bounced |
| 356 | */ |
NeilBrown | 6712ecf | 2007-09-27 12:47:43 +0200 | [diff] [blame] | 357 | bio_endio(bio, 0); |
Mike Christie | 6e68af6 | 2005-11-11 05:30:27 -0600 | [diff] [blame] | 358 | } |
| 359 | |
| 360 | return err; |
| 361 | } |
| 362 | |
| 363 | /** |
| 364 | * scsi_execute_async - insert request |
| 365 | * @sdev: scsi device |
| 366 | * @cmd: scsi command |
brking@us.ibm.com | bb1d107 | 2006-01-23 15:03:22 -0600 | [diff] [blame] | 367 | * @cmd_len: length of scsi cdb |
Rob Landley | eb44820 | 2007-11-03 13:30:39 -0500 | [diff] [blame] | 368 | * @data_direction: DMA_TO_DEVICE, DMA_FROM_DEVICE, or DMA_NONE |
Mike Christie | 6e68af6 | 2005-11-11 05:30:27 -0600 | [diff] [blame] | 369 | * @buffer: data buffer (this can be a kernel buffer or scatterlist) |
| 370 | * @bufflen: len of buffer |
| 371 | * @use_sg: if buffer is a scatterlist this is the number of elements |
| 372 | * @timeout: request timeout in seconds |
| 373 | * @retries: number of times to retry request |
Rob Landley | eb44820 | 2007-11-03 13:30:39 -0500 | [diff] [blame] | 374 | * @privdata: data passed to done() |
| 375 | * @done: callback function when done |
| 376 | * @gfp: memory allocation flags |
| 377 | */ |
Mike Christie | 6e68af6 | 2005-11-11 05:30:27 -0600 | [diff] [blame] | 378 | int scsi_execute_async(struct scsi_device *sdev, const unsigned char *cmd, |
brking@us.ibm.com | bb1d107 | 2006-01-23 15:03:22 -0600 | [diff] [blame] | 379 | int cmd_len, int data_direction, void *buffer, unsigned bufflen, |
Mike Christie | 6e68af6 | 2005-11-11 05:30:27 -0600 | [diff] [blame] | 380 | int use_sg, int timeout, int retries, void *privdata, |
| 381 | void (*done)(void *, char *, int, int), gfp_t gfp) |
| 382 | { |
| 383 | struct request *req; |
| 384 | struct scsi_io_context *sioc; |
| 385 | int err = 0; |
| 386 | int write = (data_direction == DMA_TO_DEVICE); |
| 387 | |
Robert P. J. Day | c376222 | 2007-02-10 01:45:03 -0800 | [diff] [blame] | 388 | sioc = kmem_cache_zalloc(scsi_io_context_cache, gfp); |
Mike Christie | 6e68af6 | 2005-11-11 05:30:27 -0600 | [diff] [blame] | 389 | if (!sioc) |
| 390 | return DRIVER_ERROR << 24; |
| 391 | |
| 392 | req = blk_get_request(sdev->request_queue, write, gfp); |
| 393 | if (!req) |
| 394 | goto free_sense; |
Jens Axboe | 4aff5e2 | 2006-08-10 08:44:47 +0200 | [diff] [blame] | 395 | req->cmd_type = REQ_TYPE_BLOCK_PC; |
| 396 | req->cmd_flags |= REQ_QUIET; |
Mike Christie | 6e68af6 | 2005-11-11 05:30:27 -0600 | [diff] [blame] | 397 | |
| 398 | if (use_sg) |
| 399 | err = scsi_req_map_sg(req, buffer, use_sg, bufflen, gfp); |
| 400 | else if (bufflen) |
| 401 | err = blk_rq_map_kern(req->q, req, buffer, bufflen, gfp); |
| 402 | |
| 403 | if (err) |
| 404 | goto free_req; |
| 405 | |
brking@us.ibm.com | bb1d107 | 2006-01-23 15:03:22 -0600 | [diff] [blame] | 406 | req->cmd_len = cmd_len; |
Tejun Heo | 097b845 | 2006-11-16 01:19:31 -0800 | [diff] [blame] | 407 | memset(req->cmd, 0, BLK_MAX_CDB); /* ATAPI hates garbage after CDB */ |
Mike Christie | 6e68af6 | 2005-11-11 05:30:27 -0600 | [diff] [blame] | 408 | memcpy(req->cmd, cmd, req->cmd_len); |
| 409 | req->sense = sioc->sense; |
| 410 | req->sense_len = 0; |
| 411 | req->timeout = timeout; |
Mike Christie | 17e01f2 | 2005-11-11 05:31:37 -0600 | [diff] [blame] | 412 | req->retries = retries; |
Mike Christie | 6e68af6 | 2005-11-11 05:30:27 -0600 | [diff] [blame] | 413 | req->end_io_data = sioc; |
| 414 | |
| 415 | sioc->data = privdata; |
| 416 | sioc->done = done; |
| 417 | |
| 418 | blk_execute_rq_nowait(req->q, NULL, req, 1, scsi_end_async); |
| 419 | return 0; |
| 420 | |
| 421 | free_req: |
| 422 | blk_put_request(req); |
| 423 | free_sense: |
Arne Redlich | 6470f2b | 2006-09-30 15:49:40 +0200 | [diff] [blame] | 424 | kmem_cache_free(scsi_io_context_cache, sioc); |
Mike Christie | 6e68af6 | 2005-11-11 05:30:27 -0600 | [diff] [blame] | 425 | return DRIVER_ERROR << 24; |
| 426 | } |
| 427 | EXPORT_SYMBOL_GPL(scsi_execute_async); |
| 428 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 429 | /* |
| 430 | * Function: scsi_init_cmd_errh() |
| 431 | * |
| 432 | * Purpose: Initialize cmd fields related to error handling. |
| 433 | * |
| 434 | * Arguments: cmd - command that is ready to be queued. |
| 435 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 436 | * Notes: This function has the job of initializing a number of |
| 437 | * fields related to error handling. Typically this will |
| 438 | * be called once for each command, as required. |
| 439 | */ |
Christoph Hellwig | 631c228 | 2006-07-08 20:42:15 +0200 | [diff] [blame] | 440 | static void scsi_init_cmd_errh(struct scsi_cmnd *cmd) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 441 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 442 | cmd->serial_number = 0; |
Michael Reed | 52aeeca | 2007-09-17 15:11:39 -0700 | [diff] [blame] | 443 | cmd->resid = 0; |
FUJITA Tomonori | b80ca4f | 2008-01-13 15:46:13 +0900 | [diff] [blame] | 444 | memset(cmd->sense_buffer, 0, SCSI_SENSE_BUFFERSIZE); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 445 | if (cmd->cmd_len == 0) |
| 446 | cmd->cmd_len = COMMAND_SIZE(cmd->cmnd[0]); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 447 | } |
| 448 | |
| 449 | void scsi_device_unbusy(struct scsi_device *sdev) |
| 450 | { |
| 451 | struct Scsi_Host *shost = sdev->host; |
| 452 | unsigned long flags; |
| 453 | |
| 454 | spin_lock_irqsave(shost->host_lock, flags); |
| 455 | shost->host_busy--; |
James Bottomley | 939647e | 2005-09-18 15:05:20 -0500 | [diff] [blame] | 456 | if (unlikely(scsi_host_in_recovery(shost) && |
Tejun Heo | ee7863b | 2006-05-15 20:57:20 +0900 | [diff] [blame] | 457 | (shost->host_failed || shost->host_eh_scheduled))) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 458 | scsi_eh_wakeup(shost); |
| 459 | spin_unlock(shost->host_lock); |
| 152587d | 2005-04-12 16:22:06 -0500 | [diff] [blame] | 460 | spin_lock(sdev->request_queue->queue_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 461 | sdev->device_busy--; |
| 152587d | 2005-04-12 16:22:06 -0500 | [diff] [blame] | 462 | spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 463 | } |
| 464 | |
| 465 | /* |
| 466 | * Called for single_lun devices on IO completion. Clear starget_sdev_user, |
| 467 | * and call blk_run_queue for all the scsi_devices on the target - |
| 468 | * including current_sdev first. |
| 469 | * |
| 470 | * Called with *no* scsi locks held. |
| 471 | */ |
| 472 | static void scsi_single_lun_run(struct scsi_device *current_sdev) |
| 473 | { |
| 474 | struct Scsi_Host *shost = current_sdev->host; |
| 475 | struct scsi_device *sdev, *tmp; |
| 476 | struct scsi_target *starget = scsi_target(current_sdev); |
| 477 | unsigned long flags; |
| 478 | |
| 479 | spin_lock_irqsave(shost->host_lock, flags); |
| 480 | starget->starget_sdev_user = NULL; |
| 481 | spin_unlock_irqrestore(shost->host_lock, flags); |
| 482 | |
| 483 | /* |
| 484 | * Call blk_run_queue for all LUNs on the target, starting with |
| 485 | * current_sdev. We race with others (to set starget_sdev_user), |
| 486 | * but in most cases, we will be first. Ideally, each LU on the |
| 487 | * target would get some limited time or requests on the target. |
| 488 | */ |
| 489 | blk_run_queue(current_sdev->request_queue); |
| 490 | |
| 491 | spin_lock_irqsave(shost->host_lock, flags); |
| 492 | if (starget->starget_sdev_user) |
| 493 | goto out; |
| 494 | list_for_each_entry_safe(sdev, tmp, &starget->devices, |
| 495 | same_target_siblings) { |
| 496 | if (sdev == current_sdev) |
| 497 | continue; |
| 498 | if (scsi_device_get(sdev)) |
| 499 | continue; |
| 500 | |
| 501 | spin_unlock_irqrestore(shost->host_lock, flags); |
| 502 | blk_run_queue(sdev->request_queue); |
| 503 | spin_lock_irqsave(shost->host_lock, flags); |
| 504 | |
| 505 | scsi_device_put(sdev); |
| 506 | } |
| 507 | out: |
| 508 | spin_unlock_irqrestore(shost->host_lock, flags); |
| 509 | } |
| 510 | |
| 511 | /* |
| 512 | * Function: scsi_run_queue() |
| 513 | * |
| 514 | * Purpose: Select a proper request queue to serve next |
| 515 | * |
| 516 | * Arguments: q - last request's queue |
| 517 | * |
| 518 | * Returns: Nothing |
| 519 | * |
| 520 | * Notes: The previous command was completely finished, start |
| 521 | * a new one if possible. |
| 522 | */ |
| 523 | static void scsi_run_queue(struct request_queue *q) |
| 524 | { |
| 525 | struct scsi_device *sdev = q->queuedata; |
| 526 | struct Scsi_Host *shost = sdev->host; |
| 527 | unsigned long flags; |
| 528 | |
Tony Battersby | 25d7c36 | 2007-11-12 10:00:44 -0500 | [diff] [blame] | 529 | if (scsi_target(sdev)->single_lun) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 530 | scsi_single_lun_run(sdev); |
| 531 | |
| 532 | spin_lock_irqsave(shost->host_lock, flags); |
| 533 | while (!list_empty(&shost->starved_list) && |
| 534 | !shost->host_blocked && !shost->host_self_blocked && |
| 535 | !((shost->can_queue > 0) && |
| 536 | (shost->host_busy >= shost->can_queue))) { |
| 537 | /* |
| 538 | * As long as shost is accepting commands and we have |
| 539 | * starved queues, call blk_run_queue. scsi_request_fn |
| 540 | * drops the queue_lock and can add us back to the |
| 541 | * starved_list. |
| 542 | * |
| 543 | * host_lock protects the starved_list and starved_entry. |
| 544 | * scsi_request_fn must get the host_lock before checking |
| 545 | * or modifying starved_list or starved_entry. |
| 546 | */ |
| 547 | sdev = list_entry(shost->starved_list.next, |
| 548 | struct scsi_device, starved_entry); |
| 549 | list_del_init(&sdev->starved_entry); |
| 550 | spin_unlock_irqrestore(shost->host_lock, flags); |
| 551 | |
Andreas Herrmann | 04846f2 | 2006-08-09 17:31:16 +0200 | [diff] [blame] | 552 | |
| 553 | if (test_bit(QUEUE_FLAG_REENTER, &q->queue_flags) && |
| 554 | !test_and_set_bit(QUEUE_FLAG_REENTER, |
| 555 | &sdev->request_queue->queue_flags)) { |
| 556 | blk_run_queue(sdev->request_queue); |
| 557 | clear_bit(QUEUE_FLAG_REENTER, |
| 558 | &sdev->request_queue->queue_flags); |
| 559 | } else |
| 560 | blk_run_queue(sdev->request_queue); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 561 | |
| 562 | spin_lock_irqsave(shost->host_lock, flags); |
| 563 | if (unlikely(!list_empty(&sdev->starved_entry))) |
| 564 | /* |
| 565 | * sdev lost a race, and was put back on the |
| 566 | * starved list. This is unlikely but without this |
| 567 | * in theory we could loop forever. |
| 568 | */ |
| 569 | break; |
| 570 | } |
| 571 | spin_unlock_irqrestore(shost->host_lock, flags); |
| 572 | |
| 573 | blk_run_queue(q); |
| 574 | } |
| 575 | |
| 576 | /* |
| 577 | * Function: scsi_requeue_command() |
| 578 | * |
| 579 | * Purpose: Handle post-processing of completed commands. |
| 580 | * |
| 581 | * Arguments: q - queue to operate on |
| 582 | * cmd - command that may need to be requeued. |
| 583 | * |
| 584 | * Returns: Nothing |
| 585 | * |
| 586 | * Notes: After command completion, there may be blocks left |
| 587 | * over which weren't finished by the previous command |
| 588 | * this can be for a number of reasons - the main one is |
| 589 | * I/O errors in the middle of the request, in which case |
| 590 | * we need to request the blocks that come after the bad |
| 591 | * sector. |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 592 | * Notes: Upon return, cmd is a stale pointer. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 593 | */ |
| 594 | static void scsi_requeue_command(struct request_queue *q, struct scsi_cmnd *cmd) |
| 595 | { |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 596 | struct request *req = cmd->request; |
Tejun Heo | 283369c | 2005-04-24 02:06:36 -0500 | [diff] [blame] | 597 | unsigned long flags; |
| 598 | |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 599 | scsi_unprep_request(req); |
Tejun Heo | 283369c | 2005-04-24 02:06:36 -0500 | [diff] [blame] | 600 | spin_lock_irqsave(q->queue_lock, flags); |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 601 | blk_requeue_request(q, req); |
Tejun Heo | 283369c | 2005-04-24 02:06:36 -0500 | [diff] [blame] | 602 | spin_unlock_irqrestore(q->queue_lock, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 603 | |
| 604 | scsi_run_queue(q); |
| 605 | } |
| 606 | |
| 607 | void scsi_next_command(struct scsi_cmnd *cmd) |
| 608 | { |
Linus Torvalds | 49d7bc6 | 2005-12-12 11:25:04 -0800 | [diff] [blame] | 609 | struct scsi_device *sdev = cmd->device; |
| 610 | struct request_queue *q = sdev->request_queue; |
| 611 | |
| 612 | /* need to hold a reference on the device before we let go of the cmd */ |
| 613 | get_device(&sdev->sdev_gendev); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 614 | |
| 615 | scsi_put_command(cmd); |
| 616 | scsi_run_queue(q); |
Linus Torvalds | 49d7bc6 | 2005-12-12 11:25:04 -0800 | [diff] [blame] | 617 | |
| 618 | /* ok to remove device now */ |
| 619 | put_device(&sdev->sdev_gendev); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 620 | } |
| 621 | |
| 622 | void scsi_run_host_queues(struct Scsi_Host *shost) |
| 623 | { |
| 624 | struct scsi_device *sdev; |
| 625 | |
| 626 | shost_for_each_device(sdev, shost) |
| 627 | scsi_run_queue(sdev->request_queue); |
| 628 | } |
| 629 | |
| 630 | /* |
| 631 | * Function: scsi_end_request() |
| 632 | * |
| 633 | * Purpose: Post-processing of completed commands (usually invoked at end |
| 634 | * of upper level post-processing and scsi_io_completion). |
| 635 | * |
| 636 | * Arguments: cmd - command that is complete. |
Kiyoshi Ueda | 610d8b0 | 2007-12-11 17:52:09 -0500 | [diff] [blame] | 637 | * error - 0 if I/O indicates success, < 0 for I/O error. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 638 | * bytes - number of bytes of completed I/O |
| 639 | * requeue - indicates whether we should requeue leftovers. |
| 640 | * |
| 641 | * Lock status: Assumed that lock is not held upon entry. |
| 642 | * |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 643 | * Returns: cmd if requeue required, NULL otherwise. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 644 | * |
| 645 | * Notes: This is called for block device requests in order to |
| 646 | * mark some number of sectors as complete. |
| 647 | * |
| 648 | * We are guaranteeing that the request queue will be goosed |
| 649 | * at some point during this call. |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 650 | * Notes: If cmd was requeued, upon return it will be a stale pointer. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 651 | */ |
Kiyoshi Ueda | 610d8b0 | 2007-12-11 17:52:09 -0500 | [diff] [blame] | 652 | static struct scsi_cmnd *scsi_end_request(struct scsi_cmnd *cmd, int error, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 653 | int bytes, int requeue) |
| 654 | { |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 655 | struct request_queue *q = cmd->device->request_queue; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 656 | struct request *req = cmd->request; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 657 | |
| 658 | /* |
| 659 | * If there are blocks left over at the end, set up the command |
| 660 | * to queue the remainder of them. |
| 661 | */ |
Kiyoshi Ueda | 610d8b0 | 2007-12-11 17:52:09 -0500 | [diff] [blame] | 662 | if (blk_end_request(req, error, bytes)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 663 | int leftover = (req->hard_nr_sectors << 9); |
| 664 | |
| 665 | if (blk_pc_request(req)) |
| 666 | leftover = req->data_len; |
| 667 | |
| 668 | /* kill remainder if no retrys */ |
Kiyoshi Ueda | 610d8b0 | 2007-12-11 17:52:09 -0500 | [diff] [blame] | 669 | if (error && blk_noretry_request(req)) |
| 670 | blk_end_request(req, error, leftover); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 671 | else { |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 672 | if (requeue) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 673 | /* |
| 674 | * Bleah. Leftovers again. Stick the |
| 675 | * leftovers in the front of the |
| 676 | * queue, and goose the queue again. |
| 677 | */ |
| 678 | scsi_requeue_command(q, cmd); |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 679 | cmd = NULL; |
| 680 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 681 | return cmd; |
| 682 | } |
| 683 | } |
| 684 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 685 | /* |
| 686 | * This will goose the queue request function at the end, so we don't |
| 687 | * need to worry about launching another command. |
| 688 | */ |
| 689 | scsi_next_command(cmd); |
| 690 | return NULL; |
| 691 | } |
| 692 | |
Jens Axboe | a8474ce | 2007-08-07 09:02:51 +0200 | [diff] [blame] | 693 | /* |
Jens Axboe | a8474ce | 2007-08-07 09:02:51 +0200 | [diff] [blame] | 694 | * Like SCSI_MAX_SG_SEGMENTS, but for archs that have sg chaining. This limit |
| 695 | * is totally arbitrary, a setting of 2048 will get you at least 8mb ios. |
| 696 | */ |
| 697 | #define SCSI_MAX_SG_CHAIN_SEGMENTS 2048 |
| 698 | |
| 699 | static inline unsigned int scsi_sgtable_index(unsigned short nents) |
| 700 | { |
| 701 | unsigned int index; |
| 702 | |
| 703 | switch (nents) { |
| 704 | case 1 ... 8: |
| 705 | index = 0; |
| 706 | break; |
| 707 | case 9 ... 16: |
| 708 | index = 1; |
| 709 | break; |
FUJITA Tomonori | fd820f4 | 2007-09-18 12:14:37 +0200 | [diff] [blame] | 710 | #if (SCSI_MAX_SG_SEGMENTS > 16) |
Jens Axboe | a8474ce | 2007-08-07 09:02:51 +0200 | [diff] [blame] | 711 | case 17 ... 32: |
| 712 | index = 2; |
| 713 | break; |
FUJITA Tomonori | fd820f4 | 2007-09-18 12:14:37 +0200 | [diff] [blame] | 714 | #if (SCSI_MAX_SG_SEGMENTS > 32) |
Jens Axboe | a8474ce | 2007-08-07 09:02:51 +0200 | [diff] [blame] | 715 | case 33 ... 64: |
| 716 | index = 3; |
| 717 | break; |
FUJITA Tomonori | fd820f4 | 2007-09-18 12:14:37 +0200 | [diff] [blame] | 718 | #if (SCSI_MAX_SG_SEGMENTS > 64) |
| 719 | case 65 ... 128: |
Jens Axboe | a8474ce | 2007-08-07 09:02:51 +0200 | [diff] [blame] | 720 | index = 4; |
| 721 | break; |
FUJITA Tomonori | fd820f4 | 2007-09-18 12:14:37 +0200 | [diff] [blame] | 722 | #endif |
| 723 | #endif |
| 724 | #endif |
Jens Axboe | a8474ce | 2007-08-07 09:02:51 +0200 | [diff] [blame] | 725 | default: |
| 726 | printk(KERN_ERR "scsi: bad segment count=%d\n", nents); |
| 727 | BUG(); |
| 728 | } |
| 729 | |
| 730 | return index; |
| 731 | } |
| 732 | |
Jens Axboe | 5ed7959 | 2007-11-15 09:13:11 +0100 | [diff] [blame] | 733 | static void scsi_sg_free(struct scatterlist *sgl, unsigned int nents) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 734 | { |
| 735 | struct scsi_host_sg_pool *sgp; |
Jens Axboe | 5ed7959 | 2007-11-15 09:13:11 +0100 | [diff] [blame] | 736 | |
| 737 | sgp = scsi_sg_pools + scsi_sgtable_index(nents); |
| 738 | mempool_free(sgl, sgp->pool); |
| 739 | } |
| 740 | |
| 741 | static struct scatterlist *scsi_sg_alloc(unsigned int nents, gfp_t gfp_mask) |
| 742 | { |
| 743 | struct scsi_host_sg_pool *sgp; |
| 744 | |
| 745 | sgp = scsi_sg_pools + scsi_sgtable_index(nents); |
| 746 | return mempool_alloc(sgp->pool, gfp_mask); |
| 747 | } |
| 748 | |
| 749 | int scsi_alloc_sgtable(struct scsi_cmnd *cmd, gfp_t gfp_mask) |
| 750 | { |
| 751 | int ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 752 | |
| 753 | BUG_ON(!cmd->use_sg); |
| 754 | |
James Bottomley | 7cedb1f | 2008-01-13 14:15:28 -0600 | [diff] [blame] | 755 | ret = __sg_alloc_table(&cmd->sg_table, cmd->use_sg, |
| 756 | SCSI_MAX_SG_SEGMENTS, gfp_mask, scsi_sg_alloc); |
Jens Axboe | 5ed7959 | 2007-11-15 09:13:11 +0100 | [diff] [blame] | 757 | if (unlikely(ret)) |
James Bottomley | 7cedb1f | 2008-01-13 14:15:28 -0600 | [diff] [blame] | 758 | __sg_free_table(&cmd->sg_table, SCSI_MAX_SG_SEGMENTS, |
| 759 | scsi_sg_free); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 760 | |
Jens Axboe | 5ed7959 | 2007-11-15 09:13:11 +0100 | [diff] [blame] | 761 | cmd->request_buffer = cmd->sg_table.sgl; |
Jens Axboe | a8474ce | 2007-08-07 09:02:51 +0200 | [diff] [blame] | 762 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 763 | } |
| 764 | |
FUJITA Tomonori | b58d915 | 2006-11-16 19:24:10 +0900 | [diff] [blame] | 765 | EXPORT_SYMBOL(scsi_alloc_sgtable); |
| 766 | |
Jens Axboe | 0cde8d9 | 2007-10-16 11:12:37 +0200 | [diff] [blame] | 767 | void scsi_free_sgtable(struct scsi_cmnd *cmd) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 768 | { |
James Bottomley | 7cedb1f | 2008-01-13 14:15:28 -0600 | [diff] [blame] | 769 | __sg_free_table(&cmd->sg_table, SCSI_MAX_SG_SEGMENTS, scsi_sg_free); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 770 | } |
| 771 | |
FUJITA Tomonori | b58d915 | 2006-11-16 19:24:10 +0900 | [diff] [blame] | 772 | EXPORT_SYMBOL(scsi_free_sgtable); |
| 773 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 774 | /* |
| 775 | * Function: scsi_release_buffers() |
| 776 | * |
| 777 | * Purpose: Completion processing for block device I/O requests. |
| 778 | * |
| 779 | * Arguments: cmd - command that we are bailing. |
| 780 | * |
| 781 | * Lock status: Assumed that no lock is held upon entry. |
| 782 | * |
| 783 | * Returns: Nothing |
| 784 | * |
| 785 | * Notes: In the event that an upper level driver rejects a |
| 786 | * command, we must release resources allocated during |
| 787 | * the __init_io() function. Primarily this would involve |
| 788 | * the scatter-gather table, and potentially any bounce |
| 789 | * buffers. |
| 790 | */ |
| 791 | static void scsi_release_buffers(struct scsi_cmnd *cmd) |
| 792 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 793 | if (cmd->use_sg) |
Jens Axboe | 0cde8d9 | 2007-10-16 11:12:37 +0200 | [diff] [blame] | 794 | scsi_free_sgtable(cmd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 795 | |
| 796 | /* |
| 797 | * Zero these out. They now point to freed memory, and it is |
| 798 | * dangerous to hang onto the pointers. |
| 799 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 800 | cmd->request_buffer = NULL; |
| 801 | cmd->request_bufflen = 0; |
| 802 | } |
| 803 | |
| 804 | /* |
| 805 | * Function: scsi_io_completion() |
| 806 | * |
| 807 | * Purpose: Completion processing for block device I/O requests. |
| 808 | * |
| 809 | * Arguments: cmd - command that is finished. |
| 810 | * |
| 811 | * Lock status: Assumed that no lock is held upon entry. |
| 812 | * |
| 813 | * Returns: Nothing |
| 814 | * |
| 815 | * Notes: This function is matched in terms of capabilities to |
| 816 | * the function that created the scatter-gather list. |
| 817 | * In other words, if there are no bounce buffers |
| 818 | * (the normal case for most drivers), we don't need |
| 819 | * the logic to deal with cleaning up afterwards. |
| 820 | * |
| 821 | * We must do one of several things here: |
| 822 | * |
| 823 | * a) Call scsi_end_request. This will finish off the |
| 824 | * specified number of sectors. If we are done, the |
| 825 | * command block will be released, and the queue |
| 826 | * function will be goosed. If we are not done, then |
| 827 | * scsi_end_request will directly goose the queue. |
| 828 | * |
| 829 | * b) We can just use scsi_requeue_command() here. This would |
| 830 | * be used if we just wanted to retry, for example. |
| 831 | */ |
Luben Tuikov | 03aba2f | 2006-06-23 09:39:09 -0700 | [diff] [blame] | 832 | void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 833 | { |
| 834 | int result = cmd->result; |
Christoph Hellwig | 631c228 | 2006-07-08 20:42:15 +0200 | [diff] [blame] | 835 | int this_count = cmd->request_bufflen; |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 836 | struct request_queue *q = cmd->device->request_queue; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 837 | struct request *req = cmd->request; |
| 838 | int clear_errors = 1; |
| 839 | struct scsi_sense_hdr sshdr; |
| 840 | int sense_valid = 0; |
| 841 | int sense_deferred = 0; |
| 842 | |
Christoph Hellwig | 631c228 | 2006-07-08 20:42:15 +0200 | [diff] [blame] | 843 | scsi_release_buffers(cmd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 844 | |
| 845 | if (result) { |
| 846 | sense_valid = scsi_command_normalize_sense(cmd, &sshdr); |
| 847 | if (sense_valid) |
| 848 | sense_deferred = scsi_sense_is_deferred(&sshdr); |
| 849 | } |
Christoph Hellwig | 631c228 | 2006-07-08 20:42:15 +0200 | [diff] [blame] | 850 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 851 | if (blk_pc_request(req)) { /* SG_IO ioctl from block level */ |
| 852 | req->errors = result; |
| 853 | if (result) { |
| 854 | clear_errors = 0; |
| 855 | if (sense_valid && req->sense) { |
| 856 | /* |
| 857 | * SG_IO wants current and deferred errors |
| 858 | */ |
| 859 | int len = 8 + cmd->sense_buffer[7]; |
| 860 | |
| 861 | if (len > SCSI_SENSE_BUFFERSIZE) |
| 862 | len = SCSI_SENSE_BUFFERSIZE; |
| 863 | memcpy(req->sense, cmd->sense_buffer, len); |
| 864 | req->sense_len = len; |
| 865 | } |
Pete Wyckoff | b22f687 | 2007-03-13 16:53:28 -0400 | [diff] [blame] | 866 | } |
| 867 | req->data_len = cmd->resid; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 868 | } |
| 869 | |
| 870 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 871 | * Next deal with any sectors which we were able to correctly |
| 872 | * handle. |
| 873 | */ |
James Bottomley | d6b0c53 | 2006-07-02 10:06:28 -0500 | [diff] [blame] | 874 | SCSI_LOG_HLCOMPLETE(1, printk("%ld sectors total, " |
| 875 | "%d bytes done.\n", |
| 876 | req->nr_sectors, good_bytes)); |
| 877 | SCSI_LOG_HLCOMPLETE(1, printk("use_sg is %d\n", cmd->use_sg)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 878 | |
James Bottomley | d6b0c53 | 2006-07-02 10:06:28 -0500 | [diff] [blame] | 879 | if (clear_errors) |
| 880 | req->errors = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 881 | |
James Bottomley | d6b0c53 | 2006-07-02 10:06:28 -0500 | [diff] [blame] | 882 | /* A number of bytes were successfully read. If there |
| 883 | * are leftovers and there is some kind of error |
| 884 | * (result != 0), retry the rest. |
| 885 | */ |
Kiyoshi Ueda | 610d8b0 | 2007-12-11 17:52:09 -0500 | [diff] [blame] | 886 | if (scsi_end_request(cmd, 0, good_bytes, result == 0) == NULL) |
James Bottomley | d6b0c53 | 2006-07-02 10:06:28 -0500 | [diff] [blame] | 887 | return; |
Luben Tuikov | 03aba2f | 2006-06-23 09:39:09 -0700 | [diff] [blame] | 888 | |
| 889 | /* good_bytes = 0, or (inclusive) there were leftovers and |
| 890 | * result = 0, so scsi_end_request couldn't retry. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 891 | */ |
| 892 | if (sense_valid && !sense_deferred) { |
| 893 | switch (sshdr.sense_key) { |
| 894 | case UNIT_ATTENTION: |
| 895 | if (cmd->device->removable) { |
Luben Tuikov | 03aba2f | 2006-06-23 09:39:09 -0700 | [diff] [blame] | 896 | /* Detected disc change. Set a bit |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 897 | * and quietly refuse further access. |
| 898 | */ |
| 899 | cmd->device->changed = 1; |
Kiyoshi Ueda | 610d8b0 | 2007-12-11 17:52:09 -0500 | [diff] [blame] | 900 | scsi_end_request(cmd, -EIO, this_count, 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 901 | return; |
| 902 | } else { |
Luben Tuikov | 03aba2f | 2006-06-23 09:39:09 -0700 | [diff] [blame] | 903 | /* Must have been a power glitch, or a |
| 904 | * bus reset. Could not have been a |
| 905 | * media change, so we just retry the |
| 906 | * request and see what happens. |
| 907 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 908 | scsi_requeue_command(q, cmd); |
| 909 | return; |
| 910 | } |
| 911 | break; |
| 912 | case ILLEGAL_REQUEST: |
Luben Tuikov | 03aba2f | 2006-06-23 09:39:09 -0700 | [diff] [blame] | 913 | /* If we had an ILLEGAL REQUEST returned, then |
| 914 | * we may have performed an unsupported |
| 915 | * command. The only thing this should be |
| 916 | * would be a ten byte read where only a six |
| 917 | * byte read was supported. Also, on a system |
| 918 | * where READ CAPACITY failed, we may have |
| 919 | * read past the end of the disk. |
| 920 | */ |
Jens Axboe | 26a6801 | 2005-11-29 21:03:34 +0100 | [diff] [blame] | 921 | if ((cmd->device->use_10_for_rw && |
| 922 | sshdr.asc == 0x20 && sshdr.ascq == 0x00) && |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 923 | (cmd->cmnd[0] == READ_10 || |
| 924 | cmd->cmnd[0] == WRITE_10)) { |
| 925 | cmd->device->use_10_for_rw = 0; |
Luben Tuikov | 03aba2f | 2006-06-23 09:39:09 -0700 | [diff] [blame] | 926 | /* This will cause a retry with a |
| 927 | * 6-byte command. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 928 | */ |
| 929 | scsi_requeue_command(q, cmd); |
Luben Tuikov | 03aba2f | 2006-06-23 09:39:09 -0700 | [diff] [blame] | 930 | return; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 931 | } else { |
Kiyoshi Ueda | 610d8b0 | 2007-12-11 17:52:09 -0500 | [diff] [blame] | 932 | scsi_end_request(cmd, -EIO, this_count, 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 933 | return; |
| 934 | } |
| 935 | break; |
| 936 | case NOT_READY: |
Luben Tuikov | 03aba2f | 2006-06-23 09:39:09 -0700 | [diff] [blame] | 937 | /* If the device is in the process of becoming |
James Bottomley | f3e93f7 | 2006-04-25 16:48:30 -0500 | [diff] [blame] | 938 | * ready, or has a temporary blockage, retry. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 939 | */ |
James Bottomley | f3e93f7 | 2006-04-25 16:48:30 -0500 | [diff] [blame] | 940 | if (sshdr.asc == 0x04) { |
| 941 | switch (sshdr.ascq) { |
| 942 | case 0x01: /* becoming ready */ |
| 943 | case 0x04: /* format in progress */ |
| 944 | case 0x05: /* rebuild in progress */ |
| 945 | case 0x06: /* recalculation in progress */ |
| 946 | case 0x07: /* operation in progress */ |
| 947 | case 0x08: /* Long write in progress */ |
| 948 | case 0x09: /* self test in progress */ |
| 949 | scsi_requeue_command(q, cmd); |
| 950 | return; |
| 951 | default: |
| 952 | break; |
| 953 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 954 | } |
James Bottomley | 311b581 | 2007-09-23 09:08:46 -0500 | [diff] [blame] | 955 | if (!(req->cmd_flags & REQ_QUIET)) |
| 956 | scsi_cmd_print_sense_hdr(cmd, |
| 957 | "Device not ready", |
| 958 | &sshdr); |
| 959 | |
Kiyoshi Ueda | 610d8b0 | 2007-12-11 17:52:09 -0500 | [diff] [blame] | 960 | scsi_end_request(cmd, -EIO, this_count, 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 961 | return; |
| 962 | case VOLUME_OVERFLOW: |
Jens Axboe | 4aff5e2 | 2006-08-10 08:44:47 +0200 | [diff] [blame] | 963 | if (!(req->cmd_flags & REQ_QUIET)) { |
Jeff Garzik | 3bf743e | 2005-10-24 18:04:06 -0400 | [diff] [blame] | 964 | scmd_printk(KERN_INFO, cmd, |
Luben Tuikov | 03aba2f | 2006-06-23 09:39:09 -0700 | [diff] [blame] | 965 | "Volume overflow, CDB: "); |
Christoph Hellwig | 631c228 | 2006-07-08 20:42:15 +0200 | [diff] [blame] | 966 | __scsi_print_command(cmd->cmnd); |
James Bottomley | 3173d8c | 2005-09-04 11:32:05 -0500 | [diff] [blame] | 967 | scsi_print_sense("", cmd); |
| 968 | } |
Luben Tuikov | 03aba2f | 2006-06-23 09:39:09 -0700 | [diff] [blame] | 969 | /* See SSC3rXX or current. */ |
Kiyoshi Ueda | 610d8b0 | 2007-12-11 17:52:09 -0500 | [diff] [blame] | 970 | scsi_end_request(cmd, -EIO, this_count, 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 971 | return; |
| 972 | default: |
| 973 | break; |
| 974 | } |
Luben Tuikov | 03aba2f | 2006-06-23 09:39:09 -0700 | [diff] [blame] | 975 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 976 | if (host_byte(result) == DID_RESET) { |
Luben Tuikov | 03aba2f | 2006-06-23 09:39:09 -0700 | [diff] [blame] | 977 | /* Third party bus reset or reset for error recovery |
| 978 | * reasons. Just retry the request and see what |
| 979 | * happens. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 980 | */ |
| 981 | scsi_requeue_command(q, cmd); |
| 982 | return; |
| 983 | } |
| 984 | if (result) { |
Jens Axboe | 4aff5e2 | 2006-08-10 08:44:47 +0200 | [diff] [blame] | 985 | if (!(req->cmd_flags & REQ_QUIET)) { |
Martin K. Petersen | a4d04a4 | 2007-02-27 22:40:27 -0500 | [diff] [blame] | 986 | scsi_print_result(cmd); |
James Bottomley | 3173d8c | 2005-09-04 11:32:05 -0500 | [diff] [blame] | 987 | if (driver_byte(result) & DRIVER_SENSE) |
| 988 | scsi_print_sense("", cmd); |
| 989 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 990 | } |
Kiyoshi Ueda | 610d8b0 | 2007-12-11 17:52:09 -0500 | [diff] [blame] | 991 | scsi_end_request(cmd, -EIO, this_count, !result); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 992 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 993 | |
| 994 | /* |
| 995 | * Function: scsi_init_io() |
| 996 | * |
| 997 | * Purpose: SCSI I/O initialize function. |
| 998 | * |
| 999 | * Arguments: cmd - Command descriptor we wish to initialize |
| 1000 | * |
| 1001 | * Returns: 0 on success |
| 1002 | * BLKPREP_DEFER if the failure is retryable |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1003 | */ |
| 1004 | static int scsi_init_io(struct scsi_cmnd *cmd) |
| 1005 | { |
| 1006 | struct request *req = cmd->request; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1007 | int count; |
| 1008 | |
| 1009 | /* |
Christoph Hellwig | 3b00315 | 2006-11-04 20:10:55 +0100 | [diff] [blame] | 1010 | * We used to not use scatter-gather for single segment request, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1011 | * but now we do (it makes highmem I/O easier to support without |
| 1012 | * kmapping pages) |
| 1013 | */ |
| 1014 | cmd->use_sg = req->nr_phys_segments; |
| 1015 | |
| 1016 | /* |
Christoph Hellwig | 3b00315 | 2006-11-04 20:10:55 +0100 | [diff] [blame] | 1017 | * If sg table allocation fails, requeue request later. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1018 | */ |
Jens Axboe | 5ed7959 | 2007-11-15 09:13:11 +0100 | [diff] [blame] | 1019 | if (unlikely(scsi_alloc_sgtable(cmd, GFP_ATOMIC))) { |
Alan Stern | 7c72ce8 | 2005-10-14 11:23:27 -0400 | [diff] [blame] | 1020 | scsi_unprep_request(req); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1021 | return BLKPREP_DEFER; |
Alan Stern | 7c72ce8 | 2005-10-14 11:23:27 -0400 | [diff] [blame] | 1022 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1023 | |
Christoph Hellwig | 3b00315 | 2006-11-04 20:10:55 +0100 | [diff] [blame] | 1024 | req->buffer = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1025 | if (blk_pc_request(req)) |
| 1026 | cmd->request_bufflen = req->data_len; |
Christoph Hellwig | 3b00315 | 2006-11-04 20:10:55 +0100 | [diff] [blame] | 1027 | else |
| 1028 | cmd->request_bufflen = req->nr_sectors << 9; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1029 | |
| 1030 | /* |
| 1031 | * Next, walk the list, and fill in the addresses and sizes of |
| 1032 | * each segment. |
| 1033 | */ |
| 1034 | count = blk_rq_map_sg(req->q, req, cmd->request_buffer); |
Rusty Russell | 4a03d90 | 2007-11-19 11:28:48 +1100 | [diff] [blame] | 1035 | BUG_ON(count > cmd->use_sg); |
| 1036 | cmd->use_sg = count; |
| 1037 | return BLKPREP_OK; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1038 | } |
| 1039 | |
Christoph Hellwig | 3b00315 | 2006-11-04 20:10:55 +0100 | [diff] [blame] | 1040 | static struct scsi_cmnd *scsi_get_cmd_from_req(struct scsi_device *sdev, |
| 1041 | struct request *req) |
| 1042 | { |
| 1043 | struct scsi_cmnd *cmd; |
| 1044 | |
| 1045 | if (!req->special) { |
| 1046 | cmd = scsi_get_command(sdev, GFP_ATOMIC); |
| 1047 | if (unlikely(!cmd)) |
| 1048 | return NULL; |
| 1049 | req->special = cmd; |
| 1050 | } else { |
| 1051 | cmd = req->special; |
| 1052 | } |
| 1053 | |
| 1054 | /* pull a tag out of the request if we have one */ |
| 1055 | cmd->tag = req->tag; |
| 1056 | cmd->request = req; |
| 1057 | |
| 1058 | return cmd; |
| 1059 | } |
| 1060 | |
James Bottomley | 7f9a6bc | 2007-08-04 10:06:25 -0500 | [diff] [blame] | 1061 | int scsi_setup_blk_pc_cmnd(struct scsi_device *sdev, struct request *req) |
James Bottomley | 7b16318 | 2005-12-15 20:17:02 -0600 | [diff] [blame] | 1062 | { |
Christoph Hellwig | 3b00315 | 2006-11-04 20:10:55 +0100 | [diff] [blame] | 1063 | struct scsi_cmnd *cmd; |
James Bottomley | 7f9a6bc | 2007-08-04 10:06:25 -0500 | [diff] [blame] | 1064 | int ret = scsi_prep_state_check(sdev, req); |
| 1065 | |
| 1066 | if (ret != BLKPREP_OK) |
| 1067 | return ret; |
Christoph Hellwig | 3b00315 | 2006-11-04 20:10:55 +0100 | [diff] [blame] | 1068 | |
| 1069 | cmd = scsi_get_cmd_from_req(sdev, req); |
| 1070 | if (unlikely(!cmd)) |
| 1071 | return BLKPREP_DEFER; |
| 1072 | |
| 1073 | /* |
| 1074 | * BLOCK_PC requests may transfer data, in which case they must |
| 1075 | * a bio attached to them. Or they might contain a SCSI command |
| 1076 | * that does not transfer data, in which case they may optionally |
| 1077 | * submit a request without an attached bio. |
| 1078 | */ |
| 1079 | if (req->bio) { |
| 1080 | int ret; |
| 1081 | |
| 1082 | BUG_ON(!req->nr_phys_segments); |
| 1083 | |
| 1084 | ret = scsi_init_io(cmd); |
| 1085 | if (unlikely(ret)) |
| 1086 | return ret; |
| 1087 | } else { |
| 1088 | BUG_ON(req->data_len); |
| 1089 | BUG_ON(req->data); |
| 1090 | |
| 1091 | cmd->request_bufflen = 0; |
| 1092 | cmd->request_buffer = NULL; |
| 1093 | cmd->use_sg = 0; |
| 1094 | req->buffer = NULL; |
| 1095 | } |
James Bottomley | 7b16318 | 2005-12-15 20:17:02 -0600 | [diff] [blame] | 1096 | |
Alexey Dobriyan | 46c43db | 2006-10-08 15:55:55 +0400 | [diff] [blame] | 1097 | BUILD_BUG_ON(sizeof(req->cmd) > sizeof(cmd->cmnd)); |
James Bottomley | 7b16318 | 2005-12-15 20:17:02 -0600 | [diff] [blame] | 1098 | memcpy(cmd->cmnd, req->cmd, sizeof(cmd->cmnd)); |
| 1099 | cmd->cmd_len = req->cmd_len; |
| 1100 | if (!req->data_len) |
| 1101 | cmd->sc_data_direction = DMA_NONE; |
| 1102 | else if (rq_data_dir(req) == WRITE) |
| 1103 | cmd->sc_data_direction = DMA_TO_DEVICE; |
| 1104 | else |
| 1105 | cmd->sc_data_direction = DMA_FROM_DEVICE; |
| 1106 | |
| 1107 | cmd->transfersize = req->data_len; |
| 1108 | cmd->allowed = req->retries; |
| 1109 | cmd->timeout_per_command = req->timeout; |
Christoph Hellwig | 3b00315 | 2006-11-04 20:10:55 +0100 | [diff] [blame] | 1110 | return BLKPREP_OK; |
| 1111 | } |
James Bottomley | 7f9a6bc | 2007-08-04 10:06:25 -0500 | [diff] [blame] | 1112 | EXPORT_SYMBOL(scsi_setup_blk_pc_cmnd); |
Christoph Hellwig | 3b00315 | 2006-11-04 20:10:55 +0100 | [diff] [blame] | 1113 | |
| 1114 | /* |
| 1115 | * Setup a REQ_TYPE_FS command. These are simple read/write request |
| 1116 | * from filesystems that still need to be translated to SCSI CDBs from |
| 1117 | * the ULD. |
| 1118 | */ |
James Bottomley | 7f9a6bc | 2007-08-04 10:06:25 -0500 | [diff] [blame] | 1119 | int scsi_setup_fs_cmnd(struct scsi_device *sdev, struct request *req) |
Christoph Hellwig | 3b00315 | 2006-11-04 20:10:55 +0100 | [diff] [blame] | 1120 | { |
| 1121 | struct scsi_cmnd *cmd; |
James Bottomley | 7f9a6bc | 2007-08-04 10:06:25 -0500 | [diff] [blame] | 1122 | int ret = scsi_prep_state_check(sdev, req); |
Christoph Hellwig | 3b00315 | 2006-11-04 20:10:55 +0100 | [diff] [blame] | 1123 | |
James Bottomley | 7f9a6bc | 2007-08-04 10:06:25 -0500 | [diff] [blame] | 1124 | if (ret != BLKPREP_OK) |
| 1125 | return ret; |
Christoph Hellwig | 3b00315 | 2006-11-04 20:10:55 +0100 | [diff] [blame] | 1126 | /* |
| 1127 | * Filesystem requests must transfer data. |
| 1128 | */ |
| 1129 | BUG_ON(!req->nr_phys_segments); |
| 1130 | |
| 1131 | cmd = scsi_get_cmd_from_req(sdev, req); |
| 1132 | if (unlikely(!cmd)) |
| 1133 | return BLKPREP_DEFER; |
| 1134 | |
James Bottomley | 7f9a6bc | 2007-08-04 10:06:25 -0500 | [diff] [blame] | 1135 | return scsi_init_io(cmd); |
James Bottomley | 7b16318 | 2005-12-15 20:17:02 -0600 | [diff] [blame] | 1136 | } |
James Bottomley | 7f9a6bc | 2007-08-04 10:06:25 -0500 | [diff] [blame] | 1137 | EXPORT_SYMBOL(scsi_setup_fs_cmnd); |
James Bottomley | 7b16318 | 2005-12-15 20:17:02 -0600 | [diff] [blame] | 1138 | |
James Bottomley | 7f9a6bc | 2007-08-04 10:06:25 -0500 | [diff] [blame] | 1139 | int scsi_prep_state_check(struct scsi_device *sdev, struct request *req) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1140 | { |
Christoph Hellwig | 3b00315 | 2006-11-04 20:10:55 +0100 | [diff] [blame] | 1141 | int ret = BLKPREP_OK; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1142 | |
| 1143 | /* |
Christoph Hellwig | 3b00315 | 2006-11-04 20:10:55 +0100 | [diff] [blame] | 1144 | * If the device is not in running state we will reject some |
| 1145 | * or all commands. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1146 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1147 | if (unlikely(sdev->sdev_state != SDEV_RUNNING)) { |
Christoph Hellwig | 3b00315 | 2006-11-04 20:10:55 +0100 | [diff] [blame] | 1148 | switch (sdev->sdev_state) { |
| 1149 | case SDEV_OFFLINE: |
| 1150 | /* |
| 1151 | * If the device is offline we refuse to process any |
| 1152 | * commands. The device must be brought online |
| 1153 | * before trying any recovery commands. |
| 1154 | */ |
| 1155 | sdev_printk(KERN_ERR, sdev, |
| 1156 | "rejecting I/O to offline device\n"); |
| 1157 | ret = BLKPREP_KILL; |
| 1158 | break; |
| 1159 | case SDEV_DEL: |
| 1160 | /* |
| 1161 | * If the device is fully deleted, we refuse to |
| 1162 | * process any commands as well. |
| 1163 | */ |
James Bottomley | 9ccfc75 | 2005-10-02 11:45:08 -0500 | [diff] [blame] | 1164 | sdev_printk(KERN_ERR, sdev, |
| 1165 | "rejecting I/O to dead device\n"); |
Christoph Hellwig | 3b00315 | 2006-11-04 20:10:55 +0100 | [diff] [blame] | 1166 | ret = BLKPREP_KILL; |
| 1167 | break; |
| 1168 | case SDEV_QUIESCE: |
| 1169 | case SDEV_BLOCK: |
| 1170 | /* |
| 1171 | * If the devices is blocked we defer normal commands. |
| 1172 | */ |
| 1173 | if (!(req->cmd_flags & REQ_PREEMPT)) |
| 1174 | ret = BLKPREP_DEFER; |
| 1175 | break; |
| 1176 | default: |
| 1177 | /* |
| 1178 | * For any other not fully online state we only allow |
| 1179 | * special commands. In particular any user initiated |
| 1180 | * command is not allowed. |
| 1181 | */ |
| 1182 | if (!(req->cmd_flags & REQ_PREEMPT)) |
| 1183 | ret = BLKPREP_KILL; |
| 1184 | break; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1185 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1186 | } |
James Bottomley | 7f9a6bc | 2007-08-04 10:06:25 -0500 | [diff] [blame] | 1187 | return ret; |
| 1188 | } |
| 1189 | EXPORT_SYMBOL(scsi_prep_state_check); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1190 | |
James Bottomley | 7f9a6bc | 2007-08-04 10:06:25 -0500 | [diff] [blame] | 1191 | int scsi_prep_return(struct request_queue *q, struct request *req, int ret) |
| 1192 | { |
| 1193 | struct scsi_device *sdev = q->queuedata; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1194 | |
Christoph Hellwig | 3b00315 | 2006-11-04 20:10:55 +0100 | [diff] [blame] | 1195 | switch (ret) { |
| 1196 | case BLKPREP_KILL: |
| 1197 | req->errors = DID_NO_CONNECT << 16; |
James Bottomley | 7f9a6bc | 2007-08-04 10:06:25 -0500 | [diff] [blame] | 1198 | /* release the command and kill it */ |
| 1199 | if (req->special) { |
| 1200 | struct scsi_cmnd *cmd = req->special; |
| 1201 | scsi_release_buffers(cmd); |
| 1202 | scsi_put_command(cmd); |
| 1203 | req->special = NULL; |
| 1204 | } |
Christoph Hellwig | 3b00315 | 2006-11-04 20:10:55 +0100 | [diff] [blame] | 1205 | break; |
| 1206 | case BLKPREP_DEFER: |
| 1207 | /* |
| 1208 | * If we defer, the elv_next_request() returns NULL, but the |
| 1209 | * queue must be restarted, so we plug here if no returning |
| 1210 | * command will automatically do that. |
| 1211 | */ |
| 1212 | if (sdev->device_busy == 0) |
| 1213 | blk_plug_device(q); |
| 1214 | break; |
| 1215 | default: |
| 1216 | req->cmd_flags |= REQ_DONTPREP; |
| 1217 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1218 | |
Christoph Hellwig | 3b00315 | 2006-11-04 20:10:55 +0100 | [diff] [blame] | 1219 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1220 | } |
James Bottomley | 7f9a6bc | 2007-08-04 10:06:25 -0500 | [diff] [blame] | 1221 | EXPORT_SYMBOL(scsi_prep_return); |
| 1222 | |
James Bottomley | 751bf4d | 2008-01-02 11:14:30 -0600 | [diff] [blame] | 1223 | int scsi_prep_fn(struct request_queue *q, struct request *req) |
James Bottomley | 7f9a6bc | 2007-08-04 10:06:25 -0500 | [diff] [blame] | 1224 | { |
| 1225 | struct scsi_device *sdev = q->queuedata; |
| 1226 | int ret = BLKPREP_KILL; |
| 1227 | |
| 1228 | if (req->cmd_type == REQ_TYPE_BLOCK_PC) |
| 1229 | ret = scsi_setup_blk_pc_cmnd(sdev, req); |
| 1230 | return scsi_prep_return(q, req, ret); |
| 1231 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1232 | |
| 1233 | /* |
| 1234 | * scsi_dev_queue_ready: if we can send requests to sdev, return 1 else |
| 1235 | * return 0. |
| 1236 | * |
| 1237 | * Called with the queue_lock held. |
| 1238 | */ |
| 1239 | static inline int scsi_dev_queue_ready(struct request_queue *q, |
| 1240 | struct scsi_device *sdev) |
| 1241 | { |
| 1242 | if (sdev->device_busy >= sdev->queue_depth) |
| 1243 | return 0; |
| 1244 | if (sdev->device_busy == 0 && sdev->device_blocked) { |
| 1245 | /* |
| 1246 | * unblock after device_blocked iterates to zero |
| 1247 | */ |
| 1248 | if (--sdev->device_blocked == 0) { |
| 1249 | SCSI_LOG_MLQUEUE(3, |
James Bottomley | 9ccfc75 | 2005-10-02 11:45:08 -0500 | [diff] [blame] | 1250 | sdev_printk(KERN_INFO, sdev, |
| 1251 | "unblocking device at zero depth\n")); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1252 | } else { |
| 1253 | blk_plug_device(q); |
| 1254 | return 0; |
| 1255 | } |
| 1256 | } |
| 1257 | if (sdev->device_blocked) |
| 1258 | return 0; |
| 1259 | |
| 1260 | return 1; |
| 1261 | } |
| 1262 | |
| 1263 | /* |
| 1264 | * scsi_host_queue_ready: if we can send requests to shost, return 1 else |
| 1265 | * return 0. We must end up running the queue again whenever 0 is |
| 1266 | * returned, else IO can hang. |
| 1267 | * |
| 1268 | * Called with host_lock held. |
| 1269 | */ |
| 1270 | static inline int scsi_host_queue_ready(struct request_queue *q, |
| 1271 | struct Scsi_Host *shost, |
| 1272 | struct scsi_device *sdev) |
| 1273 | { |
James Bottomley | 939647e | 2005-09-18 15:05:20 -0500 | [diff] [blame] | 1274 | if (scsi_host_in_recovery(shost)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1275 | return 0; |
| 1276 | if (shost->host_busy == 0 && shost->host_blocked) { |
| 1277 | /* |
| 1278 | * unblock after host_blocked iterates to zero |
| 1279 | */ |
| 1280 | if (--shost->host_blocked == 0) { |
| 1281 | SCSI_LOG_MLQUEUE(3, |
| 1282 | printk("scsi%d unblocking host at zero depth\n", |
| 1283 | shost->host_no)); |
| 1284 | } else { |
| 1285 | blk_plug_device(q); |
| 1286 | return 0; |
| 1287 | } |
| 1288 | } |
| 1289 | if ((shost->can_queue > 0 && shost->host_busy >= shost->can_queue) || |
| 1290 | shost->host_blocked || shost->host_self_blocked) { |
| 1291 | if (list_empty(&sdev->starved_entry)) |
| 1292 | list_add_tail(&sdev->starved_entry, &shost->starved_list); |
| 1293 | return 0; |
| 1294 | } |
| 1295 | |
| 1296 | /* We're OK to process the command, so we can't be starved */ |
| 1297 | if (!list_empty(&sdev->starved_entry)) |
| 1298 | list_del_init(&sdev->starved_entry); |
| 1299 | |
| 1300 | return 1; |
| 1301 | } |
| 1302 | |
| 1303 | /* |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 1304 | * Kill a request for a dead device |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1305 | */ |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 1306 | static void scsi_kill_request(struct request *req, struct request_queue *q) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1307 | { |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 1308 | struct scsi_cmnd *cmd = req->special; |
Tejun Heo | e36e0c8 | 2006-04-11 17:27:53 +0900 | [diff] [blame] | 1309 | struct scsi_device *sdev = cmd->device; |
| 1310 | struct Scsi_Host *shost = sdev->host; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1311 | |
James Bottomley | 788ce43 | 2005-09-09 13:40:23 -0500 | [diff] [blame] | 1312 | blkdev_dequeue_request(req); |
| 1313 | |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 1314 | if (unlikely(cmd == NULL)) { |
| 1315 | printk(KERN_CRIT "impossible request in %s.\n", |
| 1316 | __FUNCTION__); |
| 1317 | BUG(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1318 | } |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 1319 | |
| 1320 | scsi_init_cmd_errh(cmd); |
| 1321 | cmd->result = DID_NO_CONNECT << 16; |
| 1322 | atomic_inc(&cmd->device->iorequest_cnt); |
Tejun Heo | e36e0c8 | 2006-04-11 17:27:53 +0900 | [diff] [blame] | 1323 | |
| 1324 | /* |
| 1325 | * SCSI request completion path will do scsi_device_unbusy(), |
| 1326 | * bump busy counts. To bump the counters, we need to dance |
| 1327 | * with the locks as normal issue path does. |
| 1328 | */ |
| 1329 | sdev->device_busy++; |
| 1330 | spin_unlock(sdev->request_queue->queue_lock); |
| 1331 | spin_lock(shost->host_lock); |
| 1332 | shost->host_busy++; |
| 1333 | spin_unlock(shost->host_lock); |
| 1334 | spin_lock(sdev->request_queue->queue_lock); |
| 1335 | |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 1336 | __scsi_done(cmd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1337 | } |
| 1338 | |
Jens Axboe | 1aea643 | 2006-01-09 16:03:03 +0100 | [diff] [blame] | 1339 | static void scsi_softirq_done(struct request *rq) |
| 1340 | { |
| 1341 | struct scsi_cmnd *cmd = rq->completion_data; |
Brian King | 8884efa | 2006-02-24 17:10:04 -0600 | [diff] [blame] | 1342 | unsigned long wait_for = (cmd->allowed + 1) * cmd->timeout_per_command; |
Jens Axboe | 1aea643 | 2006-01-09 16:03:03 +0100 | [diff] [blame] | 1343 | int disposition; |
| 1344 | |
| 1345 | INIT_LIST_HEAD(&cmd->eh_entry); |
| 1346 | |
| 1347 | disposition = scsi_decide_disposition(cmd); |
| 1348 | if (disposition != SUCCESS && |
| 1349 | time_before(cmd->jiffies_at_alloc + wait_for, jiffies)) { |
| 1350 | sdev_printk(KERN_ERR, cmd->device, |
| 1351 | "timing out command, waited %lus\n", |
| 1352 | wait_for/HZ); |
| 1353 | disposition = SUCCESS; |
| 1354 | } |
| 1355 | |
| 1356 | scsi_log_completion(cmd, disposition); |
| 1357 | |
| 1358 | switch (disposition) { |
| 1359 | case SUCCESS: |
| 1360 | scsi_finish_command(cmd); |
| 1361 | break; |
| 1362 | case NEEDS_RETRY: |
Christoph Hellwig | 596f482 | 2007-01-02 12:56:00 +0100 | [diff] [blame] | 1363 | scsi_queue_insert(cmd, SCSI_MLQUEUE_EH_RETRY); |
Jens Axboe | 1aea643 | 2006-01-09 16:03:03 +0100 | [diff] [blame] | 1364 | break; |
| 1365 | case ADD_TO_MLQUEUE: |
| 1366 | scsi_queue_insert(cmd, SCSI_MLQUEUE_DEVICE_BUSY); |
| 1367 | break; |
| 1368 | default: |
| 1369 | if (!scsi_eh_scmd_add(cmd, 0)) |
| 1370 | scsi_finish_command(cmd); |
| 1371 | } |
| 1372 | } |
| 1373 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1374 | /* |
| 1375 | * Function: scsi_request_fn() |
| 1376 | * |
| 1377 | * Purpose: Main strategy routine for SCSI. |
| 1378 | * |
| 1379 | * Arguments: q - Pointer to actual queue. |
| 1380 | * |
| 1381 | * Returns: Nothing |
| 1382 | * |
| 1383 | * Lock status: IO request lock assumed to be held when called. |
| 1384 | */ |
| 1385 | static void scsi_request_fn(struct request_queue *q) |
| 1386 | { |
| 1387 | struct scsi_device *sdev = q->queuedata; |
| 1388 | struct Scsi_Host *shost; |
| 1389 | struct scsi_cmnd *cmd; |
| 1390 | struct request *req; |
| 1391 | |
| 1392 | if (!sdev) { |
| 1393 | printk("scsi: killing requests for dead queue\n"); |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 1394 | while ((req = elv_next_request(q)) != NULL) |
| 1395 | scsi_kill_request(req, q); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1396 | return; |
| 1397 | } |
| 1398 | |
| 1399 | if(!get_device(&sdev->sdev_gendev)) |
| 1400 | /* We must be tearing the block queue down already */ |
| 1401 | return; |
| 1402 | |
| 1403 | /* |
| 1404 | * To start with, we keep looping until the queue is empty, or until |
| 1405 | * the host is no longer able to accept any more requests. |
| 1406 | */ |
| 1407 | shost = sdev->host; |
| 1408 | while (!blk_queue_plugged(q)) { |
| 1409 | int rtn; |
| 1410 | /* |
| 1411 | * get next queueable request. We do this early to make sure |
| 1412 | * that the request is fully prepared even if we cannot |
| 1413 | * accept it. |
| 1414 | */ |
| 1415 | req = elv_next_request(q); |
| 1416 | if (!req || !scsi_dev_queue_ready(q, sdev)) |
| 1417 | break; |
| 1418 | |
| 1419 | if (unlikely(!scsi_device_online(sdev))) { |
James Bottomley | 9ccfc75 | 2005-10-02 11:45:08 -0500 | [diff] [blame] | 1420 | sdev_printk(KERN_ERR, sdev, |
| 1421 | "rejecting I/O to offline device\n"); |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 1422 | scsi_kill_request(req, q); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1423 | continue; |
| 1424 | } |
| 1425 | |
| 1426 | |
| 1427 | /* |
| 1428 | * Remove the request from the request list. |
| 1429 | */ |
| 1430 | if (!(blk_queue_tagged(q) && !blk_queue_start_tag(q, req))) |
| 1431 | blkdev_dequeue_request(req); |
| 1432 | sdev->device_busy++; |
| 1433 | |
| 1434 | spin_unlock(q->queue_lock); |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 1435 | cmd = req->special; |
| 1436 | if (unlikely(cmd == NULL)) { |
| 1437 | printk(KERN_CRIT "impossible request in %s.\n" |
| 1438 | "please mail a stack trace to " |
Jens Axboe | 4aff5e2 | 2006-08-10 08:44:47 +0200 | [diff] [blame] | 1439 | "linux-scsi@vger.kernel.org\n", |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 1440 | __FUNCTION__); |
Jens Axboe | 4aff5e2 | 2006-08-10 08:44:47 +0200 | [diff] [blame] | 1441 | blk_dump_rq_flags(req, "foo"); |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 1442 | BUG(); |
| 1443 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1444 | spin_lock(shost->host_lock); |
| 1445 | |
| 1446 | if (!scsi_host_queue_ready(q, shost, sdev)) |
| 1447 | goto not_ready; |
Tony Battersby | 25d7c36 | 2007-11-12 10:00:44 -0500 | [diff] [blame] | 1448 | if (scsi_target(sdev)->single_lun) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1449 | if (scsi_target(sdev)->starget_sdev_user && |
| 1450 | scsi_target(sdev)->starget_sdev_user != sdev) |
| 1451 | goto not_ready; |
| 1452 | scsi_target(sdev)->starget_sdev_user = sdev; |
| 1453 | } |
| 1454 | shost->host_busy++; |
| 1455 | |
| 1456 | /* |
| 1457 | * XXX(hch): This is rather suboptimal, scsi_dispatch_cmd will |
| 1458 | * take the lock again. |
| 1459 | */ |
| 1460 | spin_unlock_irq(shost->host_lock); |
| 1461 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1462 | /* |
| 1463 | * Finally, initialize any error handling parameters, and set up |
| 1464 | * the timers for timeouts. |
| 1465 | */ |
| 1466 | scsi_init_cmd_errh(cmd); |
| 1467 | |
| 1468 | /* |
| 1469 | * Dispatch the command to the low-level driver. |
| 1470 | */ |
| 1471 | rtn = scsi_dispatch_cmd(cmd); |
| 1472 | spin_lock_irq(q->queue_lock); |
| 1473 | if(rtn) { |
| 1474 | /* we're refusing the command; because of |
| 1475 | * the way locks get dropped, we need to |
| 1476 | * check here if plugging is required */ |
| 1477 | if(sdev->device_busy == 0) |
| 1478 | blk_plug_device(q); |
| 1479 | |
| 1480 | break; |
| 1481 | } |
| 1482 | } |
| 1483 | |
| 1484 | goto out; |
| 1485 | |
| 1486 | not_ready: |
| 1487 | spin_unlock_irq(shost->host_lock); |
| 1488 | |
| 1489 | /* |
| 1490 | * lock q, handle tag, requeue req, and decrement device_busy. We |
| 1491 | * must return with queue_lock held. |
| 1492 | * |
| 1493 | * Decrementing device_busy without checking it is OK, as all such |
| 1494 | * cases (host limits or settings) should run the queue at some |
| 1495 | * later time. |
| 1496 | */ |
| 1497 | spin_lock_irq(q->queue_lock); |
| 1498 | blk_requeue_request(q, req); |
| 1499 | sdev->device_busy--; |
| 1500 | if(sdev->device_busy == 0) |
| 1501 | blk_plug_device(q); |
| 1502 | out: |
| 1503 | /* must be careful here...if we trigger the ->remove() function |
| 1504 | * we cannot be holding the q lock */ |
| 1505 | spin_unlock_irq(q->queue_lock); |
| 1506 | put_device(&sdev->sdev_gendev); |
| 1507 | spin_lock_irq(q->queue_lock); |
| 1508 | } |
| 1509 | |
| 1510 | u64 scsi_calculate_bounce_limit(struct Scsi_Host *shost) |
| 1511 | { |
| 1512 | struct device *host_dev; |
| 1513 | u64 bounce_limit = 0xffffffff; |
| 1514 | |
| 1515 | if (shost->unchecked_isa_dma) |
| 1516 | return BLK_BOUNCE_ISA; |
| 1517 | /* |
| 1518 | * Platforms with virtual-DMA translation |
| 1519 | * hardware have no practical limit. |
| 1520 | */ |
| 1521 | if (!PCI_DMA_BUS_IS_PHYS) |
| 1522 | return BLK_BOUNCE_ANY; |
| 1523 | |
| 1524 | host_dev = scsi_get_device(shost); |
| 1525 | if (host_dev && host_dev->dma_mask) |
| 1526 | bounce_limit = *host_dev->dma_mask; |
| 1527 | |
| 1528 | return bounce_limit; |
| 1529 | } |
| 1530 | EXPORT_SYMBOL(scsi_calculate_bounce_limit); |
| 1531 | |
FUJITA Tomonori | b58d915 | 2006-11-16 19:24:10 +0900 | [diff] [blame] | 1532 | struct request_queue *__scsi_alloc_queue(struct Scsi_Host *shost, |
| 1533 | request_fn_proc *request_fn) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1534 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1535 | struct request_queue *q; |
| 1536 | |
FUJITA Tomonori | b58d915 | 2006-11-16 19:24:10 +0900 | [diff] [blame] | 1537 | q = blk_init_queue(request_fn, NULL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1538 | if (!q) |
| 1539 | return NULL; |
| 1540 | |
Jens Axboe | a8474ce | 2007-08-07 09:02:51 +0200 | [diff] [blame] | 1541 | /* |
| 1542 | * this limit is imposed by hardware restrictions |
| 1543 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1544 | blk_queue_max_hw_segments(q, shost->sg_tablesize); |
Jens Axboe | a8474ce | 2007-08-07 09:02:51 +0200 | [diff] [blame] | 1545 | |
| 1546 | /* |
| 1547 | * In the future, sg chaining support will be mandatory and this |
| 1548 | * ifdef can then go away. Right now we don't have all archs |
| 1549 | * converted, so better keep it safe. |
| 1550 | */ |
| 1551 | #ifdef ARCH_HAS_SG_CHAIN |
FUJITA Tomonori | 9cb83c7 | 2007-10-16 11:24:32 +0200 | [diff] [blame] | 1552 | if (shost->use_sg_chaining) |
| 1553 | blk_queue_max_phys_segments(q, SCSI_MAX_SG_CHAIN_SEGMENTS); |
| 1554 | else |
| 1555 | blk_queue_max_phys_segments(q, SCSI_MAX_SG_SEGMENTS); |
Jens Axboe | a8474ce | 2007-08-07 09:02:51 +0200 | [diff] [blame] | 1556 | #else |
| 1557 | blk_queue_max_phys_segments(q, SCSI_MAX_SG_SEGMENTS); |
| 1558 | #endif |
| 1559 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1560 | blk_queue_max_sectors(q, shost->max_sectors); |
| 1561 | blk_queue_bounce_limit(q, scsi_calculate_bounce_limit(shost)); |
| 1562 | blk_queue_segment_boundary(q, shost->dma_boundary); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1563 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1564 | if (!shost->use_clustering) |
| 1565 | clear_bit(QUEUE_FLAG_CLUSTER, &q->queue_flags); |
James Bottomley | 465ff31 | 2008-01-01 10:00:10 -0600 | [diff] [blame] | 1566 | |
| 1567 | /* |
| 1568 | * set a reasonable default alignment on word boundaries: the |
| 1569 | * host and device may alter it using |
| 1570 | * blk_queue_update_dma_alignment() later. |
| 1571 | */ |
| 1572 | blk_queue_dma_alignment(q, 0x03); |
| 1573 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1574 | return q; |
| 1575 | } |
FUJITA Tomonori | b58d915 | 2006-11-16 19:24:10 +0900 | [diff] [blame] | 1576 | EXPORT_SYMBOL(__scsi_alloc_queue); |
| 1577 | |
| 1578 | struct request_queue *scsi_alloc_queue(struct scsi_device *sdev) |
| 1579 | { |
| 1580 | struct request_queue *q; |
| 1581 | |
| 1582 | q = __scsi_alloc_queue(sdev->host, scsi_request_fn); |
| 1583 | if (!q) |
| 1584 | return NULL; |
| 1585 | |
| 1586 | blk_queue_prep_rq(q, scsi_prep_fn); |
FUJITA Tomonori | b58d915 | 2006-11-16 19:24:10 +0900 | [diff] [blame] | 1587 | blk_queue_softirq_done(q, scsi_softirq_done); |
| 1588 | return q; |
| 1589 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1590 | |
| 1591 | void scsi_free_queue(struct request_queue *q) |
| 1592 | { |
| 1593 | blk_cleanup_queue(q); |
| 1594 | } |
| 1595 | |
| 1596 | /* |
| 1597 | * Function: scsi_block_requests() |
| 1598 | * |
| 1599 | * Purpose: Utility function used by low-level drivers to prevent further |
| 1600 | * commands from being queued to the device. |
| 1601 | * |
| 1602 | * Arguments: shost - Host in question |
| 1603 | * |
| 1604 | * Returns: Nothing |
| 1605 | * |
| 1606 | * Lock status: No locks are assumed held. |
| 1607 | * |
| 1608 | * Notes: There is no timer nor any other means by which the requests |
| 1609 | * get unblocked other than the low-level driver calling |
| 1610 | * scsi_unblock_requests(). |
| 1611 | */ |
| 1612 | void scsi_block_requests(struct Scsi_Host *shost) |
| 1613 | { |
| 1614 | shost->host_self_blocked = 1; |
| 1615 | } |
| 1616 | EXPORT_SYMBOL(scsi_block_requests); |
| 1617 | |
| 1618 | /* |
| 1619 | * Function: scsi_unblock_requests() |
| 1620 | * |
| 1621 | * Purpose: Utility function used by low-level drivers to allow further |
| 1622 | * commands from being queued to the device. |
| 1623 | * |
| 1624 | * Arguments: shost - Host in question |
| 1625 | * |
| 1626 | * Returns: Nothing |
| 1627 | * |
| 1628 | * Lock status: No locks are assumed held. |
| 1629 | * |
| 1630 | * Notes: There is no timer nor any other means by which the requests |
| 1631 | * get unblocked other than the low-level driver calling |
| 1632 | * scsi_unblock_requests(). |
| 1633 | * |
| 1634 | * This is done as an API function so that changes to the |
| 1635 | * internals of the scsi mid-layer won't require wholesale |
| 1636 | * changes to drivers that use this feature. |
| 1637 | */ |
| 1638 | void scsi_unblock_requests(struct Scsi_Host *shost) |
| 1639 | { |
| 1640 | shost->host_self_blocked = 0; |
| 1641 | scsi_run_host_queues(shost); |
| 1642 | } |
| 1643 | EXPORT_SYMBOL(scsi_unblock_requests); |
| 1644 | |
| 1645 | int __init scsi_init_queue(void) |
| 1646 | { |
| 1647 | int i; |
| 1648 | |
Mike Christie | aa7b5cd | 2005-11-11 05:31:41 -0600 | [diff] [blame] | 1649 | scsi_io_context_cache = kmem_cache_create("scsi_io_context", |
| 1650 | sizeof(struct scsi_io_context), |
Paul Mundt | 20c2df8 | 2007-07-20 10:11:58 +0900 | [diff] [blame] | 1651 | 0, 0, NULL); |
Mike Christie | aa7b5cd | 2005-11-11 05:31:41 -0600 | [diff] [blame] | 1652 | if (!scsi_io_context_cache) { |
| 1653 | printk(KERN_ERR "SCSI: can't init scsi io context cache\n"); |
| 1654 | return -ENOMEM; |
| 1655 | } |
| 1656 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1657 | for (i = 0; i < SG_MEMPOOL_NR; i++) { |
| 1658 | struct scsi_host_sg_pool *sgp = scsi_sg_pools + i; |
| 1659 | int size = sgp->size * sizeof(struct scatterlist); |
| 1660 | |
| 1661 | sgp->slab = kmem_cache_create(sgp->name, size, 0, |
Paul Mundt | 20c2df8 | 2007-07-20 10:11:58 +0900 | [diff] [blame] | 1662 | SLAB_HWCACHE_ALIGN, NULL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1663 | if (!sgp->slab) { |
| 1664 | printk(KERN_ERR "SCSI: can't init sg slab %s\n", |
| 1665 | sgp->name); |
| 1666 | } |
| 1667 | |
Matthew Dobson | 93d2341 | 2006-03-26 01:37:50 -0800 | [diff] [blame] | 1668 | sgp->pool = mempool_create_slab_pool(SG_MEMPOOL_SIZE, |
| 1669 | sgp->slab); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1670 | if (!sgp->pool) { |
| 1671 | printk(KERN_ERR "SCSI: can't init sg mempool %s\n", |
| 1672 | sgp->name); |
| 1673 | } |
| 1674 | } |
| 1675 | |
| 1676 | return 0; |
| 1677 | } |
| 1678 | |
| 1679 | void scsi_exit_queue(void) |
| 1680 | { |
| 1681 | int i; |
| 1682 | |
Mike Christie | aa7b5cd | 2005-11-11 05:31:41 -0600 | [diff] [blame] | 1683 | kmem_cache_destroy(scsi_io_context_cache); |
| 1684 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1685 | for (i = 0; i < SG_MEMPOOL_NR; i++) { |
| 1686 | struct scsi_host_sg_pool *sgp = scsi_sg_pools + i; |
| 1687 | mempool_destroy(sgp->pool); |
| 1688 | kmem_cache_destroy(sgp->slab); |
| 1689 | } |
| 1690 | } |
James Bottomley | 5baba83 | 2006-03-18 14:10:35 -0600 | [diff] [blame] | 1691 | |
| 1692 | /** |
| 1693 | * scsi_mode_select - issue a mode select |
| 1694 | * @sdev: SCSI device to be queried |
| 1695 | * @pf: Page format bit (1 == standard, 0 == vendor specific) |
| 1696 | * @sp: Save page bit (0 == don't save, 1 == save) |
| 1697 | * @modepage: mode page being requested |
| 1698 | * @buffer: request buffer (may not be smaller than eight bytes) |
| 1699 | * @len: length of request buffer. |
| 1700 | * @timeout: command timeout |
| 1701 | * @retries: number of retries before failing |
| 1702 | * @data: returns a structure abstracting the mode header data |
Rob Landley | eb44820 | 2007-11-03 13:30:39 -0500 | [diff] [blame] | 1703 | * @sshdr: place to put sense data (or NULL if no sense to be collected). |
James Bottomley | 5baba83 | 2006-03-18 14:10:35 -0600 | [diff] [blame] | 1704 | * must be SCSI_SENSE_BUFFERSIZE big. |
| 1705 | * |
| 1706 | * Returns zero if successful; negative error number or scsi |
| 1707 | * status on error |
| 1708 | * |
| 1709 | */ |
| 1710 | int |
| 1711 | scsi_mode_select(struct scsi_device *sdev, int pf, int sp, int modepage, |
| 1712 | unsigned char *buffer, int len, int timeout, int retries, |
| 1713 | struct scsi_mode_data *data, struct scsi_sense_hdr *sshdr) |
| 1714 | { |
| 1715 | unsigned char cmd[10]; |
| 1716 | unsigned char *real_buffer; |
| 1717 | int ret; |
| 1718 | |
| 1719 | memset(cmd, 0, sizeof(cmd)); |
| 1720 | cmd[1] = (pf ? 0x10 : 0) | (sp ? 0x01 : 0); |
| 1721 | |
| 1722 | if (sdev->use_10_for_ms) { |
| 1723 | if (len > 65535) |
| 1724 | return -EINVAL; |
| 1725 | real_buffer = kmalloc(8 + len, GFP_KERNEL); |
| 1726 | if (!real_buffer) |
| 1727 | return -ENOMEM; |
| 1728 | memcpy(real_buffer + 8, buffer, len); |
| 1729 | len += 8; |
| 1730 | real_buffer[0] = 0; |
| 1731 | real_buffer[1] = 0; |
| 1732 | real_buffer[2] = data->medium_type; |
| 1733 | real_buffer[3] = data->device_specific; |
| 1734 | real_buffer[4] = data->longlba ? 0x01 : 0; |
| 1735 | real_buffer[5] = 0; |
| 1736 | real_buffer[6] = data->block_descriptor_length >> 8; |
| 1737 | real_buffer[7] = data->block_descriptor_length; |
| 1738 | |
| 1739 | cmd[0] = MODE_SELECT_10; |
| 1740 | cmd[7] = len >> 8; |
| 1741 | cmd[8] = len; |
| 1742 | } else { |
| 1743 | if (len > 255 || data->block_descriptor_length > 255 || |
| 1744 | data->longlba) |
| 1745 | return -EINVAL; |
| 1746 | |
| 1747 | real_buffer = kmalloc(4 + len, GFP_KERNEL); |
| 1748 | if (!real_buffer) |
| 1749 | return -ENOMEM; |
| 1750 | memcpy(real_buffer + 4, buffer, len); |
| 1751 | len += 4; |
| 1752 | real_buffer[0] = 0; |
| 1753 | real_buffer[1] = data->medium_type; |
| 1754 | real_buffer[2] = data->device_specific; |
| 1755 | real_buffer[3] = data->block_descriptor_length; |
| 1756 | |
| 1757 | |
| 1758 | cmd[0] = MODE_SELECT; |
| 1759 | cmd[4] = len; |
| 1760 | } |
| 1761 | |
| 1762 | ret = scsi_execute_req(sdev, cmd, DMA_TO_DEVICE, real_buffer, len, |
| 1763 | sshdr, timeout, retries); |
| 1764 | kfree(real_buffer); |
| 1765 | return ret; |
| 1766 | } |
| 1767 | EXPORT_SYMBOL_GPL(scsi_mode_select); |
| 1768 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1769 | /** |
Rob Landley | eb44820 | 2007-11-03 13:30:39 -0500 | [diff] [blame] | 1770 | * scsi_mode_sense - issue a mode sense, falling back from 10 to six bytes if necessary. |
James Bottomley | 1cf7269 | 2005-08-28 11:27:01 -0500 | [diff] [blame] | 1771 | * @sdev: SCSI device to be queried |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1772 | * @dbd: set if mode sense will allow block descriptors to be returned |
| 1773 | * @modepage: mode page being requested |
| 1774 | * @buffer: request buffer (may not be smaller than eight bytes) |
| 1775 | * @len: length of request buffer. |
| 1776 | * @timeout: command timeout |
| 1777 | * @retries: number of retries before failing |
| 1778 | * @data: returns a structure abstracting the mode header data |
Rob Landley | eb44820 | 2007-11-03 13:30:39 -0500 | [diff] [blame] | 1779 | * @sshdr: place to put sense data (or NULL if no sense to be collected). |
James Bottomley | 1cf7269 | 2005-08-28 11:27:01 -0500 | [diff] [blame] | 1780 | * must be SCSI_SENSE_BUFFERSIZE big. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1781 | * |
| 1782 | * Returns zero if unsuccessful, or the header offset (either 4 |
| 1783 | * or 8 depending on whether a six or ten byte command was |
| 1784 | * issued) if successful. |
Rob Landley | eb44820 | 2007-11-03 13:30:39 -0500 | [diff] [blame] | 1785 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1786 | int |
James Bottomley | 1cf7269 | 2005-08-28 11:27:01 -0500 | [diff] [blame] | 1787 | scsi_mode_sense(struct scsi_device *sdev, int dbd, int modepage, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1788 | unsigned char *buffer, int len, int timeout, int retries, |
James Bottomley | 5baba83 | 2006-03-18 14:10:35 -0600 | [diff] [blame] | 1789 | struct scsi_mode_data *data, struct scsi_sense_hdr *sshdr) |
| 1790 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1791 | unsigned char cmd[12]; |
| 1792 | int use_10_for_ms; |
| 1793 | int header_length; |
James Bottomley | 1cf7269 | 2005-08-28 11:27:01 -0500 | [diff] [blame] | 1794 | int result; |
James Bottomley | ea73a9f | 2005-08-28 11:33:52 -0500 | [diff] [blame] | 1795 | struct scsi_sense_hdr my_sshdr; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1796 | |
| 1797 | memset(data, 0, sizeof(*data)); |
| 1798 | memset(&cmd[0], 0, 12); |
| 1799 | cmd[1] = dbd & 0x18; /* allows DBD and LLBA bits */ |
| 1800 | cmd[2] = modepage; |
| 1801 | |
James Bottomley | ea73a9f | 2005-08-28 11:33:52 -0500 | [diff] [blame] | 1802 | /* caller might not be interested in sense, but we need it */ |
| 1803 | if (!sshdr) |
| 1804 | sshdr = &my_sshdr; |
| 1805 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1806 | retry: |
James Bottomley | 1cf7269 | 2005-08-28 11:27:01 -0500 | [diff] [blame] | 1807 | use_10_for_ms = sdev->use_10_for_ms; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1808 | |
| 1809 | if (use_10_for_ms) { |
| 1810 | if (len < 8) |
| 1811 | len = 8; |
| 1812 | |
| 1813 | cmd[0] = MODE_SENSE_10; |
| 1814 | cmd[8] = len; |
| 1815 | header_length = 8; |
| 1816 | } else { |
| 1817 | if (len < 4) |
| 1818 | len = 4; |
| 1819 | |
| 1820 | cmd[0] = MODE_SENSE; |
| 1821 | cmd[4] = len; |
| 1822 | header_length = 4; |
| 1823 | } |
| 1824 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1825 | memset(buffer, 0, len); |
| 1826 | |
James Bottomley | 1cf7269 | 2005-08-28 11:27:01 -0500 | [diff] [blame] | 1827 | result = scsi_execute_req(sdev, cmd, DMA_FROM_DEVICE, buffer, len, |
James Bottomley | ea73a9f | 2005-08-28 11:33:52 -0500 | [diff] [blame] | 1828 | sshdr, timeout, retries); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1829 | |
| 1830 | /* This code looks awful: what it's doing is making sure an |
| 1831 | * ILLEGAL REQUEST sense return identifies the actual command |
| 1832 | * byte as the problem. MODE_SENSE commands can return |
| 1833 | * ILLEGAL REQUEST if the code page isn't supported */ |
| 1834 | |
James Bottomley | 1cf7269 | 2005-08-28 11:27:01 -0500 | [diff] [blame] | 1835 | if (use_10_for_ms && !scsi_status_is_good(result) && |
| 1836 | (driver_byte(result) & DRIVER_SENSE)) { |
James Bottomley | ea73a9f | 2005-08-28 11:33:52 -0500 | [diff] [blame] | 1837 | if (scsi_sense_valid(sshdr)) { |
| 1838 | if ((sshdr->sense_key == ILLEGAL_REQUEST) && |
| 1839 | (sshdr->asc == 0x20) && (sshdr->ascq == 0)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1840 | /* |
| 1841 | * Invalid command operation code |
| 1842 | */ |
James Bottomley | 1cf7269 | 2005-08-28 11:27:01 -0500 | [diff] [blame] | 1843 | sdev->use_10_for_ms = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1844 | goto retry; |
| 1845 | } |
| 1846 | } |
| 1847 | } |
| 1848 | |
James Bottomley | 1cf7269 | 2005-08-28 11:27:01 -0500 | [diff] [blame] | 1849 | if(scsi_status_is_good(result)) { |
Al Viro | 6d73c85 | 2006-02-23 02:03:16 +0100 | [diff] [blame] | 1850 | if (unlikely(buffer[0] == 0x86 && buffer[1] == 0x0b && |
| 1851 | (modepage == 6 || modepage == 8))) { |
| 1852 | /* Initio breakage? */ |
| 1853 | header_length = 0; |
| 1854 | data->length = 13; |
| 1855 | data->medium_type = 0; |
| 1856 | data->device_specific = 0; |
| 1857 | data->longlba = 0; |
| 1858 | data->block_descriptor_length = 0; |
| 1859 | } else if(use_10_for_ms) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1860 | data->length = buffer[0]*256 + buffer[1] + 2; |
| 1861 | data->medium_type = buffer[2]; |
| 1862 | data->device_specific = buffer[3]; |
| 1863 | data->longlba = buffer[4] & 0x01; |
| 1864 | data->block_descriptor_length = buffer[6]*256 |
| 1865 | + buffer[7]; |
| 1866 | } else { |
| 1867 | data->length = buffer[0] + 1; |
| 1868 | data->medium_type = buffer[1]; |
| 1869 | data->device_specific = buffer[2]; |
| 1870 | data->block_descriptor_length = buffer[3]; |
| 1871 | } |
Al Viro | 6d73c85 | 2006-02-23 02:03:16 +0100 | [diff] [blame] | 1872 | data->header_length = header_length; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1873 | } |
| 1874 | |
James Bottomley | 1cf7269 | 2005-08-28 11:27:01 -0500 | [diff] [blame] | 1875 | return result; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1876 | } |
| 1877 | EXPORT_SYMBOL(scsi_mode_sense); |
| 1878 | |
James Bottomley | 001aac2 | 2007-12-02 19:10:40 +0200 | [diff] [blame] | 1879 | /** |
| 1880 | * scsi_test_unit_ready - test if unit is ready |
| 1881 | * @sdev: scsi device to change the state of. |
| 1882 | * @timeout: command timeout |
| 1883 | * @retries: number of retries before failing |
| 1884 | * @sshdr_external: Optional pointer to struct scsi_sense_hdr for |
| 1885 | * returning sense. Make sure that this is cleared before passing |
| 1886 | * in. |
| 1887 | * |
| 1888 | * Returns zero if unsuccessful or an error if TUR failed. For |
| 1889 | * removable media, a return of NOT_READY or UNIT_ATTENTION is |
| 1890 | * translated to success, with the ->changed flag updated. |
| 1891 | **/ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1892 | int |
James Bottomley | 001aac2 | 2007-12-02 19:10:40 +0200 | [diff] [blame] | 1893 | scsi_test_unit_ready(struct scsi_device *sdev, int timeout, int retries, |
| 1894 | struct scsi_sense_hdr *sshdr_external) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1895 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1896 | char cmd[] = { |
| 1897 | TEST_UNIT_READY, 0, 0, 0, 0, 0, |
| 1898 | }; |
James Bottomley | 001aac2 | 2007-12-02 19:10:40 +0200 | [diff] [blame] | 1899 | struct scsi_sense_hdr *sshdr; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1900 | int result; |
James Bottomley | 001aac2 | 2007-12-02 19:10:40 +0200 | [diff] [blame] | 1901 | |
| 1902 | if (!sshdr_external) |
| 1903 | sshdr = kzalloc(sizeof(*sshdr), GFP_KERNEL); |
| 1904 | else |
| 1905 | sshdr = sshdr_external; |
| 1906 | |
| 1907 | /* try to eat the UNIT_ATTENTION if there are enough retries */ |
| 1908 | do { |
| 1909 | result = scsi_execute_req(sdev, cmd, DMA_NONE, NULL, 0, sshdr, |
| 1910 | timeout, retries); |
| 1911 | } while ((driver_byte(result) & DRIVER_SENSE) && |
| 1912 | sshdr && sshdr->sense_key == UNIT_ATTENTION && |
| 1913 | --retries); |
| 1914 | |
| 1915 | if (!sshdr) |
| 1916 | /* could not allocate sense buffer, so can't process it */ |
| 1917 | return result; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1918 | |
James Bottomley | 1cf7269 | 2005-08-28 11:27:01 -0500 | [diff] [blame] | 1919 | if ((driver_byte(result) & DRIVER_SENSE) && sdev->removable) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1920 | |
James Bottomley | 001aac2 | 2007-12-02 19:10:40 +0200 | [diff] [blame] | 1921 | if ((scsi_sense_valid(sshdr)) && |
| 1922 | ((sshdr->sense_key == UNIT_ATTENTION) || |
| 1923 | (sshdr->sense_key == NOT_READY))) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1924 | sdev->changed = 1; |
James Bottomley | 1cf7269 | 2005-08-28 11:27:01 -0500 | [diff] [blame] | 1925 | result = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1926 | } |
| 1927 | } |
James Bottomley | 001aac2 | 2007-12-02 19:10:40 +0200 | [diff] [blame] | 1928 | if (!sshdr_external) |
| 1929 | kfree(sshdr); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1930 | return result; |
| 1931 | } |
| 1932 | EXPORT_SYMBOL(scsi_test_unit_ready); |
| 1933 | |
| 1934 | /** |
Rob Landley | eb44820 | 2007-11-03 13:30:39 -0500 | [diff] [blame] | 1935 | * scsi_device_set_state - Take the given device through the device state model. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1936 | * @sdev: scsi device to change the state of. |
| 1937 | * @state: state to change to. |
| 1938 | * |
| 1939 | * Returns zero if unsuccessful or an error if the requested |
| 1940 | * transition is illegal. |
Rob Landley | eb44820 | 2007-11-03 13:30:39 -0500 | [diff] [blame] | 1941 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1942 | int |
| 1943 | scsi_device_set_state(struct scsi_device *sdev, enum scsi_device_state state) |
| 1944 | { |
| 1945 | enum scsi_device_state oldstate = sdev->sdev_state; |
| 1946 | |
| 1947 | if (state == oldstate) |
| 1948 | return 0; |
| 1949 | |
| 1950 | switch (state) { |
| 1951 | case SDEV_CREATED: |
| 1952 | /* There are no legal states that come back to |
| 1953 | * created. This is the manually initialised start |
| 1954 | * state */ |
| 1955 | goto illegal; |
| 1956 | |
| 1957 | case SDEV_RUNNING: |
| 1958 | switch (oldstate) { |
| 1959 | case SDEV_CREATED: |
| 1960 | case SDEV_OFFLINE: |
| 1961 | case SDEV_QUIESCE: |
| 1962 | case SDEV_BLOCK: |
| 1963 | break; |
| 1964 | default: |
| 1965 | goto illegal; |
| 1966 | } |
| 1967 | break; |
| 1968 | |
| 1969 | case SDEV_QUIESCE: |
| 1970 | switch (oldstate) { |
| 1971 | case SDEV_RUNNING: |
| 1972 | case SDEV_OFFLINE: |
| 1973 | break; |
| 1974 | default: |
| 1975 | goto illegal; |
| 1976 | } |
| 1977 | break; |
| 1978 | |
| 1979 | case SDEV_OFFLINE: |
| 1980 | switch (oldstate) { |
| 1981 | case SDEV_CREATED: |
| 1982 | case SDEV_RUNNING: |
| 1983 | case SDEV_QUIESCE: |
| 1984 | case SDEV_BLOCK: |
| 1985 | break; |
| 1986 | default: |
| 1987 | goto illegal; |
| 1988 | } |
| 1989 | break; |
| 1990 | |
| 1991 | case SDEV_BLOCK: |
| 1992 | switch (oldstate) { |
| 1993 | case SDEV_CREATED: |
| 1994 | case SDEV_RUNNING: |
| 1995 | break; |
| 1996 | default: |
| 1997 | goto illegal; |
| 1998 | } |
| 1999 | break; |
| 2000 | |
| 2001 | case SDEV_CANCEL: |
| 2002 | switch (oldstate) { |
| 2003 | case SDEV_CREATED: |
| 2004 | case SDEV_RUNNING: |
Alan Stern | 9ea7290 | 2006-06-23 14:25:34 -0400 | [diff] [blame] | 2005 | case SDEV_QUIESCE: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2006 | case SDEV_OFFLINE: |
| 2007 | case SDEV_BLOCK: |
| 2008 | break; |
| 2009 | default: |
| 2010 | goto illegal; |
| 2011 | } |
| 2012 | break; |
| 2013 | |
| 2014 | case SDEV_DEL: |
| 2015 | switch (oldstate) { |
Brian King | 309bd27 | 2006-06-27 11:10:43 -0500 | [diff] [blame] | 2016 | case SDEV_CREATED: |
| 2017 | case SDEV_RUNNING: |
| 2018 | case SDEV_OFFLINE: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2019 | case SDEV_CANCEL: |
| 2020 | break; |
| 2021 | default: |
| 2022 | goto illegal; |
| 2023 | } |
| 2024 | break; |
| 2025 | |
| 2026 | } |
| 2027 | sdev->sdev_state = state; |
| 2028 | return 0; |
| 2029 | |
| 2030 | illegal: |
| 2031 | SCSI_LOG_ERROR_RECOVERY(1, |
James Bottomley | 9ccfc75 | 2005-10-02 11:45:08 -0500 | [diff] [blame] | 2032 | sdev_printk(KERN_ERR, sdev, |
| 2033 | "Illegal state transition %s->%s\n", |
| 2034 | scsi_device_state_name(oldstate), |
| 2035 | scsi_device_state_name(state)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2036 | ); |
| 2037 | return -EINVAL; |
| 2038 | } |
| 2039 | EXPORT_SYMBOL(scsi_device_set_state); |
| 2040 | |
| 2041 | /** |
Jeff Garzik | a341cd0 | 2007-10-29 17:15:22 -0400 | [diff] [blame] | 2042 | * sdev_evt_emit - emit a single SCSI device uevent |
| 2043 | * @sdev: associated SCSI device |
| 2044 | * @evt: event to emit |
| 2045 | * |
| 2046 | * Send a single uevent (scsi_event) to the associated scsi_device. |
| 2047 | */ |
| 2048 | static void scsi_evt_emit(struct scsi_device *sdev, struct scsi_event *evt) |
| 2049 | { |
| 2050 | int idx = 0; |
| 2051 | char *envp[3]; |
| 2052 | |
| 2053 | switch (evt->evt_type) { |
| 2054 | case SDEV_EVT_MEDIA_CHANGE: |
| 2055 | envp[idx++] = "SDEV_MEDIA_CHANGE=1"; |
| 2056 | break; |
| 2057 | |
| 2058 | default: |
| 2059 | /* do nothing */ |
| 2060 | break; |
| 2061 | } |
| 2062 | |
| 2063 | envp[idx++] = NULL; |
| 2064 | |
| 2065 | kobject_uevent_env(&sdev->sdev_gendev.kobj, KOBJ_CHANGE, envp); |
| 2066 | } |
| 2067 | |
| 2068 | /** |
| 2069 | * sdev_evt_thread - send a uevent for each scsi event |
| 2070 | * @work: work struct for scsi_device |
| 2071 | * |
| 2072 | * Dispatch queued events to their associated scsi_device kobjects |
| 2073 | * as uevents. |
| 2074 | */ |
| 2075 | void scsi_evt_thread(struct work_struct *work) |
| 2076 | { |
| 2077 | struct scsi_device *sdev; |
| 2078 | LIST_HEAD(event_list); |
| 2079 | |
| 2080 | sdev = container_of(work, struct scsi_device, event_work); |
| 2081 | |
| 2082 | while (1) { |
| 2083 | struct scsi_event *evt; |
| 2084 | struct list_head *this, *tmp; |
| 2085 | unsigned long flags; |
| 2086 | |
| 2087 | spin_lock_irqsave(&sdev->list_lock, flags); |
| 2088 | list_splice_init(&sdev->event_list, &event_list); |
| 2089 | spin_unlock_irqrestore(&sdev->list_lock, flags); |
| 2090 | |
| 2091 | if (list_empty(&event_list)) |
| 2092 | break; |
| 2093 | |
| 2094 | list_for_each_safe(this, tmp, &event_list) { |
| 2095 | evt = list_entry(this, struct scsi_event, node); |
| 2096 | list_del(&evt->node); |
| 2097 | scsi_evt_emit(sdev, evt); |
| 2098 | kfree(evt); |
| 2099 | } |
| 2100 | } |
| 2101 | } |
| 2102 | |
| 2103 | /** |
| 2104 | * sdev_evt_send - send asserted event to uevent thread |
| 2105 | * @sdev: scsi_device event occurred on |
| 2106 | * @evt: event to send |
| 2107 | * |
| 2108 | * Assert scsi device event asynchronously. |
| 2109 | */ |
| 2110 | void sdev_evt_send(struct scsi_device *sdev, struct scsi_event *evt) |
| 2111 | { |
| 2112 | unsigned long flags; |
| 2113 | |
| 2114 | if (!test_bit(evt->evt_type, sdev->supported_events)) { |
| 2115 | kfree(evt); |
| 2116 | return; |
| 2117 | } |
| 2118 | |
| 2119 | spin_lock_irqsave(&sdev->list_lock, flags); |
| 2120 | list_add_tail(&evt->node, &sdev->event_list); |
| 2121 | schedule_work(&sdev->event_work); |
| 2122 | spin_unlock_irqrestore(&sdev->list_lock, flags); |
| 2123 | } |
| 2124 | EXPORT_SYMBOL_GPL(sdev_evt_send); |
| 2125 | |
| 2126 | /** |
| 2127 | * sdev_evt_alloc - allocate a new scsi event |
| 2128 | * @evt_type: type of event to allocate |
| 2129 | * @gfpflags: GFP flags for allocation |
| 2130 | * |
| 2131 | * Allocates and returns a new scsi_event. |
| 2132 | */ |
| 2133 | struct scsi_event *sdev_evt_alloc(enum scsi_device_event evt_type, |
| 2134 | gfp_t gfpflags) |
| 2135 | { |
| 2136 | struct scsi_event *evt = kzalloc(sizeof(struct scsi_event), gfpflags); |
| 2137 | if (!evt) |
| 2138 | return NULL; |
| 2139 | |
| 2140 | evt->evt_type = evt_type; |
| 2141 | INIT_LIST_HEAD(&evt->node); |
| 2142 | |
| 2143 | /* evt_type-specific initialization, if any */ |
| 2144 | switch (evt_type) { |
| 2145 | case SDEV_EVT_MEDIA_CHANGE: |
| 2146 | default: |
| 2147 | /* do nothing */ |
| 2148 | break; |
| 2149 | } |
| 2150 | |
| 2151 | return evt; |
| 2152 | } |
| 2153 | EXPORT_SYMBOL_GPL(sdev_evt_alloc); |
| 2154 | |
| 2155 | /** |
| 2156 | * sdev_evt_send_simple - send asserted event to uevent thread |
| 2157 | * @sdev: scsi_device event occurred on |
| 2158 | * @evt_type: type of event to send |
| 2159 | * @gfpflags: GFP flags for allocation |
| 2160 | * |
| 2161 | * Assert scsi device event asynchronously, given an event type. |
| 2162 | */ |
| 2163 | void sdev_evt_send_simple(struct scsi_device *sdev, |
| 2164 | enum scsi_device_event evt_type, gfp_t gfpflags) |
| 2165 | { |
| 2166 | struct scsi_event *evt = sdev_evt_alloc(evt_type, gfpflags); |
| 2167 | if (!evt) { |
| 2168 | sdev_printk(KERN_ERR, sdev, "event %d eaten due to OOM\n", |
| 2169 | evt_type); |
| 2170 | return; |
| 2171 | } |
| 2172 | |
| 2173 | sdev_evt_send(sdev, evt); |
| 2174 | } |
| 2175 | EXPORT_SYMBOL_GPL(sdev_evt_send_simple); |
| 2176 | |
| 2177 | /** |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2178 | * scsi_device_quiesce - Block user issued commands. |
| 2179 | * @sdev: scsi device to quiesce. |
| 2180 | * |
| 2181 | * This works by trying to transition to the SDEV_QUIESCE state |
| 2182 | * (which must be a legal transition). When the device is in this |
| 2183 | * state, only special requests will be accepted, all others will |
| 2184 | * be deferred. Since special requests may also be requeued requests, |
| 2185 | * a successful return doesn't guarantee the device will be |
| 2186 | * totally quiescent. |
| 2187 | * |
| 2188 | * Must be called with user context, may sleep. |
| 2189 | * |
| 2190 | * Returns zero if unsuccessful or an error if not. |
Rob Landley | eb44820 | 2007-11-03 13:30:39 -0500 | [diff] [blame] | 2191 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2192 | int |
| 2193 | scsi_device_quiesce(struct scsi_device *sdev) |
| 2194 | { |
| 2195 | int err = scsi_device_set_state(sdev, SDEV_QUIESCE); |
| 2196 | if (err) |
| 2197 | return err; |
| 2198 | |
| 2199 | scsi_run_queue(sdev->request_queue); |
| 2200 | while (sdev->device_busy) { |
| 2201 | msleep_interruptible(200); |
| 2202 | scsi_run_queue(sdev->request_queue); |
| 2203 | } |
| 2204 | return 0; |
| 2205 | } |
| 2206 | EXPORT_SYMBOL(scsi_device_quiesce); |
| 2207 | |
| 2208 | /** |
| 2209 | * scsi_device_resume - Restart user issued commands to a quiesced device. |
| 2210 | * @sdev: scsi device to resume. |
| 2211 | * |
| 2212 | * Moves the device from quiesced back to running and restarts the |
| 2213 | * queues. |
| 2214 | * |
| 2215 | * Must be called with user context, may sleep. |
Rob Landley | eb44820 | 2007-11-03 13:30:39 -0500 | [diff] [blame] | 2216 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2217 | void |
| 2218 | scsi_device_resume(struct scsi_device *sdev) |
| 2219 | { |
| 2220 | if(scsi_device_set_state(sdev, SDEV_RUNNING)) |
| 2221 | return; |
| 2222 | scsi_run_queue(sdev->request_queue); |
| 2223 | } |
| 2224 | EXPORT_SYMBOL(scsi_device_resume); |
| 2225 | |
| 2226 | static void |
| 2227 | device_quiesce_fn(struct scsi_device *sdev, void *data) |
| 2228 | { |
| 2229 | scsi_device_quiesce(sdev); |
| 2230 | } |
| 2231 | |
| 2232 | void |
| 2233 | scsi_target_quiesce(struct scsi_target *starget) |
| 2234 | { |
| 2235 | starget_for_each_device(starget, NULL, device_quiesce_fn); |
| 2236 | } |
| 2237 | EXPORT_SYMBOL(scsi_target_quiesce); |
| 2238 | |
| 2239 | static void |
| 2240 | device_resume_fn(struct scsi_device *sdev, void *data) |
| 2241 | { |
| 2242 | scsi_device_resume(sdev); |
| 2243 | } |
| 2244 | |
| 2245 | void |
| 2246 | scsi_target_resume(struct scsi_target *starget) |
| 2247 | { |
| 2248 | starget_for_each_device(starget, NULL, device_resume_fn); |
| 2249 | } |
| 2250 | EXPORT_SYMBOL(scsi_target_resume); |
| 2251 | |
| 2252 | /** |
Rob Landley | eb44820 | 2007-11-03 13:30:39 -0500 | [diff] [blame] | 2253 | * scsi_internal_device_block - internal function to put a device temporarily into the SDEV_BLOCK state |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2254 | * @sdev: device to block |
| 2255 | * |
| 2256 | * Block request made by scsi lld's to temporarily stop all |
| 2257 | * scsi commands on the specified device. Called from interrupt |
| 2258 | * or normal process context. |
| 2259 | * |
| 2260 | * Returns zero if successful or error if not |
| 2261 | * |
| 2262 | * Notes: |
| 2263 | * This routine transitions the device to the SDEV_BLOCK state |
| 2264 | * (which must be a legal transition). When the device is in this |
| 2265 | * state, all commands are deferred until the scsi lld reenables |
| 2266 | * the device with scsi_device_unblock or device_block_tmo fires. |
| 2267 | * This routine assumes the host_lock is held on entry. |
Rob Landley | eb44820 | 2007-11-03 13:30:39 -0500 | [diff] [blame] | 2268 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2269 | int |
| 2270 | scsi_internal_device_block(struct scsi_device *sdev) |
| 2271 | { |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 2272 | struct request_queue *q = sdev->request_queue; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2273 | unsigned long flags; |
| 2274 | int err = 0; |
| 2275 | |
| 2276 | err = scsi_device_set_state(sdev, SDEV_BLOCK); |
| 2277 | if (err) |
| 2278 | return err; |
| 2279 | |
| 2280 | /* |
| 2281 | * The device has transitioned to SDEV_BLOCK. Stop the |
| 2282 | * block layer from calling the midlayer with this device's |
| 2283 | * request queue. |
| 2284 | */ |
| 2285 | spin_lock_irqsave(q->queue_lock, flags); |
| 2286 | blk_stop_queue(q); |
| 2287 | spin_unlock_irqrestore(q->queue_lock, flags); |
| 2288 | |
| 2289 | return 0; |
| 2290 | } |
| 2291 | EXPORT_SYMBOL_GPL(scsi_internal_device_block); |
| 2292 | |
| 2293 | /** |
| 2294 | * scsi_internal_device_unblock - resume a device after a block request |
| 2295 | * @sdev: device to resume |
| 2296 | * |
| 2297 | * Called by scsi lld's or the midlayer to restart the device queue |
| 2298 | * for the previously suspended scsi device. Called from interrupt or |
| 2299 | * normal process context. |
| 2300 | * |
| 2301 | * Returns zero if successful or error if not. |
| 2302 | * |
| 2303 | * Notes: |
| 2304 | * This routine transitions the device to the SDEV_RUNNING state |
| 2305 | * (which must be a legal transition) allowing the midlayer to |
| 2306 | * goose the queue for this device. This routine assumes the |
| 2307 | * host_lock is held upon entry. |
Rob Landley | eb44820 | 2007-11-03 13:30:39 -0500 | [diff] [blame] | 2308 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2309 | int |
| 2310 | scsi_internal_device_unblock(struct scsi_device *sdev) |
| 2311 | { |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 2312 | struct request_queue *q = sdev->request_queue; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2313 | int err; |
| 2314 | unsigned long flags; |
| 2315 | |
| 2316 | /* |
| 2317 | * Try to transition the scsi device to SDEV_RUNNING |
| 2318 | * and goose the device queue if successful. |
| 2319 | */ |
| 2320 | err = scsi_device_set_state(sdev, SDEV_RUNNING); |
| 2321 | if (err) |
| 2322 | return err; |
| 2323 | |
| 2324 | spin_lock_irqsave(q->queue_lock, flags); |
| 2325 | blk_start_queue(q); |
| 2326 | spin_unlock_irqrestore(q->queue_lock, flags); |
| 2327 | |
| 2328 | return 0; |
| 2329 | } |
| 2330 | EXPORT_SYMBOL_GPL(scsi_internal_device_unblock); |
| 2331 | |
| 2332 | static void |
| 2333 | device_block(struct scsi_device *sdev, void *data) |
| 2334 | { |
| 2335 | scsi_internal_device_block(sdev); |
| 2336 | } |
| 2337 | |
| 2338 | static int |
| 2339 | target_block(struct device *dev, void *data) |
| 2340 | { |
| 2341 | if (scsi_is_target_device(dev)) |
| 2342 | starget_for_each_device(to_scsi_target(dev), NULL, |
| 2343 | device_block); |
| 2344 | return 0; |
| 2345 | } |
| 2346 | |
| 2347 | void |
| 2348 | scsi_target_block(struct device *dev) |
| 2349 | { |
| 2350 | if (scsi_is_target_device(dev)) |
| 2351 | starget_for_each_device(to_scsi_target(dev), NULL, |
| 2352 | device_block); |
| 2353 | else |
| 2354 | device_for_each_child(dev, NULL, target_block); |
| 2355 | } |
| 2356 | EXPORT_SYMBOL_GPL(scsi_target_block); |
| 2357 | |
| 2358 | static void |
| 2359 | device_unblock(struct scsi_device *sdev, void *data) |
| 2360 | { |
| 2361 | scsi_internal_device_unblock(sdev); |
| 2362 | } |
| 2363 | |
| 2364 | static int |
| 2365 | target_unblock(struct device *dev, void *data) |
| 2366 | { |
| 2367 | if (scsi_is_target_device(dev)) |
| 2368 | starget_for_each_device(to_scsi_target(dev), NULL, |
| 2369 | device_unblock); |
| 2370 | return 0; |
| 2371 | } |
| 2372 | |
| 2373 | void |
| 2374 | scsi_target_unblock(struct device *dev) |
| 2375 | { |
| 2376 | if (scsi_is_target_device(dev)) |
| 2377 | starget_for_each_device(to_scsi_target(dev), NULL, |
| 2378 | device_unblock); |
| 2379 | else |
| 2380 | device_for_each_child(dev, NULL, target_unblock); |
| 2381 | } |
| 2382 | EXPORT_SYMBOL_GPL(scsi_target_unblock); |
Guennadi Liakhovetski | cdb8c2a | 2006-04-02 21:57:43 +0200 | [diff] [blame] | 2383 | |
| 2384 | /** |
| 2385 | * scsi_kmap_atomic_sg - find and atomically map an sg-elemnt |
Rob Landley | eb44820 | 2007-11-03 13:30:39 -0500 | [diff] [blame] | 2386 | * @sgl: scatter-gather list |
Guennadi Liakhovetski | cdb8c2a | 2006-04-02 21:57:43 +0200 | [diff] [blame] | 2387 | * @sg_count: number of segments in sg |
| 2388 | * @offset: offset in bytes into sg, on return offset into the mapped area |
| 2389 | * @len: bytes to map, on return number of bytes mapped |
| 2390 | * |
| 2391 | * Returns virtual address of the start of the mapped page |
| 2392 | */ |
Jens Axboe | c6132da | 2007-10-16 11:08:49 +0200 | [diff] [blame] | 2393 | void *scsi_kmap_atomic_sg(struct scatterlist *sgl, int sg_count, |
Guennadi Liakhovetski | cdb8c2a | 2006-04-02 21:57:43 +0200 | [diff] [blame] | 2394 | size_t *offset, size_t *len) |
| 2395 | { |
| 2396 | int i; |
| 2397 | size_t sg_len = 0, len_complete = 0; |
Jens Axboe | c6132da | 2007-10-16 11:08:49 +0200 | [diff] [blame] | 2398 | struct scatterlist *sg; |
Guennadi Liakhovetski | cdb8c2a | 2006-04-02 21:57:43 +0200 | [diff] [blame] | 2399 | struct page *page; |
| 2400 | |
Andrew Morton | 22cfefb | 2007-02-05 16:39:03 -0800 | [diff] [blame] | 2401 | WARN_ON(!irqs_disabled()); |
| 2402 | |
Jens Axboe | c6132da | 2007-10-16 11:08:49 +0200 | [diff] [blame] | 2403 | for_each_sg(sgl, sg, sg_count, i) { |
Guennadi Liakhovetski | cdb8c2a | 2006-04-02 21:57:43 +0200 | [diff] [blame] | 2404 | len_complete = sg_len; /* Complete sg-entries */ |
Jens Axboe | c6132da | 2007-10-16 11:08:49 +0200 | [diff] [blame] | 2405 | sg_len += sg->length; |
Guennadi Liakhovetski | cdb8c2a | 2006-04-02 21:57:43 +0200 | [diff] [blame] | 2406 | if (sg_len > *offset) |
| 2407 | break; |
| 2408 | } |
| 2409 | |
| 2410 | if (unlikely(i == sg_count)) { |
Andrew Morton | 169e1a2 | 2006-04-18 21:09:08 -0700 | [diff] [blame] | 2411 | printk(KERN_ERR "%s: Bytes in sg: %zu, requested offset %zu, " |
| 2412 | "elements %d\n", |
Guennadi Liakhovetski | cdb8c2a | 2006-04-02 21:57:43 +0200 | [diff] [blame] | 2413 | __FUNCTION__, sg_len, *offset, sg_count); |
| 2414 | WARN_ON(1); |
| 2415 | return NULL; |
| 2416 | } |
| 2417 | |
| 2418 | /* Offset starting from the beginning of first page in this sg-entry */ |
Jens Axboe | c6132da | 2007-10-16 11:08:49 +0200 | [diff] [blame] | 2419 | *offset = *offset - len_complete + sg->offset; |
Guennadi Liakhovetski | cdb8c2a | 2006-04-02 21:57:43 +0200 | [diff] [blame] | 2420 | |
| 2421 | /* Assumption: contiguous pages can be accessed as "page + i" */ |
Jens Axboe | 45711f1 | 2007-10-22 21:19:53 +0200 | [diff] [blame] | 2422 | page = nth_page(sg_page(sg), (*offset >> PAGE_SHIFT)); |
Guennadi Liakhovetski | cdb8c2a | 2006-04-02 21:57:43 +0200 | [diff] [blame] | 2423 | *offset &= ~PAGE_MASK; |
| 2424 | |
| 2425 | /* Bytes in this sg-entry from *offset to the end of the page */ |
| 2426 | sg_len = PAGE_SIZE - *offset; |
| 2427 | if (*len > sg_len) |
| 2428 | *len = sg_len; |
| 2429 | |
| 2430 | return kmap_atomic(page, KM_BIO_SRC_IRQ); |
| 2431 | } |
| 2432 | EXPORT_SYMBOL(scsi_kmap_atomic_sg); |
| 2433 | |
| 2434 | /** |
Rob Landley | eb44820 | 2007-11-03 13:30:39 -0500 | [diff] [blame] | 2435 | * scsi_kunmap_atomic_sg - atomically unmap a virtual address, previously mapped with scsi_kmap_atomic_sg |
Guennadi Liakhovetski | cdb8c2a | 2006-04-02 21:57:43 +0200 | [diff] [blame] | 2436 | * @virt: virtual address to be unmapped |
| 2437 | */ |
| 2438 | void scsi_kunmap_atomic_sg(void *virt) |
| 2439 | { |
| 2440 | kunmap_atomic(virt, KM_BIO_SRC_IRQ); |
| 2441 | } |
| 2442 | EXPORT_SYMBOL(scsi_kunmap_atomic_sg); |