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> |
James Bottomley | d3f46f3 | 2008-01-15 11:11:46 -0600 | [diff] [blame] | 11 | #include <linux/bitops.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 12 | #include <linux/blkdev.h> |
| 13 | #include <linux/completion.h> |
| 14 | #include <linux/kernel.h> |
| 15 | #include <linux/mempool.h> |
| 16 | #include <linux/slab.h> |
| 17 | #include <linux/init.h> |
| 18 | #include <linux/pci.h> |
| 19 | #include <linux/delay.h> |
James Bottomley | faead26 | 2006-02-14 10:42:07 -0600 | [diff] [blame] | 20 | #include <linux/hardirq.h> |
Jens Axboe | c6132da | 2007-10-16 11:08:49 +0200 | [diff] [blame] | 21 | #include <linux/scatterlist.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 22 | |
| 23 | #include <scsi/scsi.h> |
Christoph Hellwig | beb4048 | 2006-06-10 18:01:03 +0200 | [diff] [blame] | 24 | #include <scsi/scsi_cmnd.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 25 | #include <scsi/scsi_dbg.h> |
| 26 | #include <scsi/scsi_device.h> |
| 27 | #include <scsi/scsi_driver.h> |
| 28 | #include <scsi/scsi_eh.h> |
| 29 | #include <scsi/scsi_host.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 30 | |
| 31 | #include "scsi_priv.h" |
| 32 | #include "scsi_logging.h" |
| 33 | |
| 34 | |
Tobias Klauser | 6391a11 | 2006-06-08 22:23:48 -0700 | [diff] [blame] | 35 | #define SG_MEMPOOL_NR ARRAY_SIZE(scsi_sg_pools) |
Jens Axboe | 5972511 | 2007-04-02 10:06:42 +0200 | [diff] [blame] | 36 | #define SG_MEMPOOL_SIZE 2 |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 37 | |
| 38 | struct scsi_host_sg_pool { |
| 39 | size_t size; |
Jens Axboe | a8474ce | 2007-08-07 09:02:51 +0200 | [diff] [blame] | 40 | char *name; |
Christoph Lameter | e18b890 | 2006-12-06 20:33:20 -0800 | [diff] [blame] | 41 | struct kmem_cache *slab; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 42 | mempool_t *pool; |
| 43 | }; |
| 44 | |
James Bottomley | d3f46f3 | 2008-01-15 11:11:46 -0600 | [diff] [blame] | 45 | #define SP(x) { x, "sgpool-" __stringify(x) } |
| 46 | #if (SCSI_MAX_SG_SEGMENTS < 32) |
| 47 | #error SCSI_MAX_SG_SEGMENTS is too small (must be 32 or greater) |
| 48 | #endif |
Adrian Bunk | 52c1da3 | 2005-06-23 22:05:33 -0700 | [diff] [blame] | 49 | static struct scsi_host_sg_pool scsi_sg_pools[] = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 50 | SP(8), |
| 51 | SP(16), |
FUJITA Tomonori | fd820f4 | 2007-09-18 12:14:37 +0200 | [diff] [blame] | 52 | #if (SCSI_MAX_SG_SEGMENTS > 32) |
James Bottomley | d3f46f3 | 2008-01-15 11:11:46 -0600 | [diff] [blame] | 53 | SP(32), |
FUJITA Tomonori | fd820f4 | 2007-09-18 12:14:37 +0200 | [diff] [blame] | 54 | #if (SCSI_MAX_SG_SEGMENTS > 64) |
James Bottomley | d3f46f3 | 2008-01-15 11:11:46 -0600 | [diff] [blame] | 55 | SP(64), |
| 56 | #if (SCSI_MAX_SG_SEGMENTS > 128) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 57 | SP(128), |
James Bottomley | d3f46f3 | 2008-01-15 11:11:46 -0600 | [diff] [blame] | 58 | #if (SCSI_MAX_SG_SEGMENTS > 256) |
| 59 | #error SCSI_MAX_SG_SEGMENTS is too large (256 MAX) |
FUJITA Tomonori | fd820f4 | 2007-09-18 12:14:37 +0200 | [diff] [blame] | 60 | #endif |
| 61 | #endif |
| 62 | #endif |
James Bottomley | d3f46f3 | 2008-01-15 11:11:46 -0600 | [diff] [blame] | 63 | #endif |
| 64 | SP(SCSI_MAX_SG_SEGMENTS) |
Jens Axboe | a8474ce | 2007-08-07 09:02:51 +0200 | [diff] [blame] | 65 | }; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 66 | #undef SP |
| 67 | |
Boaz Harrosh | 6f9a35e | 2007-12-13 13:50:53 +0200 | [diff] [blame] | 68 | static struct kmem_cache *scsi_bidi_sdb_cache; |
| 69 | |
Tejun Heo | a1bf9d1 | 2005-04-24 02:08:52 -0500 | [diff] [blame] | 70 | static void scsi_run_queue(struct request_queue *q); |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 71 | |
| 72 | /* |
| 73 | * Function: scsi_unprep_request() |
| 74 | * |
| 75 | * Purpose: Remove all preparation done for a request, including its |
| 76 | * associated scsi_cmnd, so that it can be requeued. |
| 77 | * |
| 78 | * Arguments: req - request to unprepare |
| 79 | * |
| 80 | * Lock status: Assumed that no locks are held upon entry. |
| 81 | * |
| 82 | * Returns: Nothing. |
| 83 | */ |
| 84 | static void scsi_unprep_request(struct request *req) |
| 85 | { |
| 86 | struct scsi_cmnd *cmd = req->special; |
| 87 | |
Jens Axboe | 4aff5e2 | 2006-08-10 08:44:47 +0200 | [diff] [blame] | 88 | req->cmd_flags &= ~REQ_DONTPREP; |
Christoph Hellwig | beb4048 | 2006-06-10 18:01:03 +0200 | [diff] [blame] | 89 | req->special = NULL; |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 90 | |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 91 | scsi_put_command(cmd); |
| 92 | } |
Tejun Heo | a1bf9d1 | 2005-04-24 02:08:52 -0500 | [diff] [blame] | 93 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 94 | /* |
| 95 | * Function: scsi_queue_insert() |
| 96 | * |
| 97 | * Purpose: Insert a command in the midlevel queue. |
| 98 | * |
| 99 | * Arguments: cmd - command that we are adding to queue. |
| 100 | * reason - why we are inserting command to queue. |
| 101 | * |
| 102 | * Lock status: Assumed that lock is not held upon entry. |
| 103 | * |
| 104 | * Returns: Nothing. |
| 105 | * |
| 106 | * Notes: We do this for one of two cases. Either the host is busy |
| 107 | * and it cannot accept any more commands for the time being, |
| 108 | * or the device returned QUEUE_FULL and can accept no more |
| 109 | * commands. |
| 110 | * Notes: This could be called either from an interrupt context or a |
| 111 | * normal process context. |
| 112 | */ |
| 113 | int scsi_queue_insert(struct scsi_cmnd *cmd, int reason) |
| 114 | { |
| 115 | struct Scsi_Host *host = cmd->device->host; |
| 116 | struct scsi_device *device = cmd->device; |
Tejun Heo | a1bf9d1 | 2005-04-24 02:08:52 -0500 | [diff] [blame] | 117 | struct request_queue *q = device->request_queue; |
| 118 | unsigned long flags; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 119 | |
| 120 | SCSI_LOG_MLQUEUE(1, |
| 121 | printk("Inserting command %p into mlqueue\n", cmd)); |
| 122 | |
| 123 | /* |
Tejun Heo | d8c37e7 | 2005-05-14 00:46:08 +0900 | [diff] [blame] | 124 | * Set the appropriate busy bit for the device/host. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 125 | * |
| 126 | * If the host/device isn't busy, assume that something actually |
| 127 | * completed, and that we should be able to queue a command now. |
| 128 | * |
| 129 | * Note that the prior mid-layer assumption that any host could |
| 130 | * always queue at least one command is now broken. The mid-layer |
| 131 | * will implement a user specifiable stall (see |
| 132 | * scsi_host.max_host_blocked and scsi_device.max_device_blocked) |
| 133 | * if a command is requeued with no other commands outstanding |
| 134 | * either for the device or for the host. |
| 135 | */ |
| 136 | if (reason == SCSI_MLQUEUE_HOST_BUSY) |
| 137 | host->host_blocked = host->max_host_blocked; |
| 138 | else if (reason == SCSI_MLQUEUE_DEVICE_BUSY) |
| 139 | device->device_blocked = device->max_device_blocked; |
| 140 | |
| 141 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 142 | * Decrement the counters, since these commands are no longer |
| 143 | * active on the host/device. |
| 144 | */ |
| 145 | scsi_device_unbusy(device); |
| 146 | |
| 147 | /* |
Tejun Heo | a1bf9d1 | 2005-04-24 02:08:52 -0500 | [diff] [blame] | 148 | * Requeue this command. It will go before all other commands |
| 149 | * that are already in the queue. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 150 | * |
| 151 | * NOTE: there is magic here about the way the queue is plugged if |
| 152 | * we have no outstanding commands. |
| 153 | * |
Tejun Heo | a1bf9d1 | 2005-04-24 02:08:52 -0500 | [diff] [blame] | 154 | * Although we *don't* plug the queue, we call the request |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 155 | * function. The SCSI request function detects the blocked condition |
| 156 | * and plugs the queue appropriately. |
Tejun Heo | a1bf9d1 | 2005-04-24 02:08:52 -0500 | [diff] [blame] | 157 | */ |
| 158 | spin_lock_irqsave(q->queue_lock, flags); |
James Bottomley | 59897da | 2005-09-14 12:57:42 -0400 | [diff] [blame] | 159 | blk_requeue_request(q, cmd->request); |
Tejun Heo | a1bf9d1 | 2005-04-24 02:08:52 -0500 | [diff] [blame] | 160 | spin_unlock_irqrestore(q->queue_lock, flags); |
| 161 | |
| 162 | scsi_run_queue(q); |
| 163 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 164 | return 0; |
| 165 | } |
| 166 | |
James Bottomley | 3921603 | 2005-06-15 18:48:29 -0500 | [diff] [blame] | 167 | /** |
James Bottomley | 33aa687 | 2005-08-28 11:31:14 -0500 | [diff] [blame] | 168 | * scsi_execute - insert request and wait for the result |
James Bottomley | 3921603 | 2005-06-15 18:48:29 -0500 | [diff] [blame] | 169 | * @sdev: scsi device |
| 170 | * @cmd: scsi command |
| 171 | * @data_direction: data direction |
| 172 | * @buffer: data buffer |
| 173 | * @bufflen: len of buffer |
| 174 | * @sense: optional sense buffer |
| 175 | * @timeout: request timeout in seconds |
| 176 | * @retries: number of times to retry request |
James Bottomley | 33aa687 | 2005-08-28 11:31:14 -0500 | [diff] [blame] | 177 | * @flags: or into request flags; |
James Bottomley | 3921603 | 2005-06-15 18:48:29 -0500 | [diff] [blame] | 178 | * |
Michael Opdenacker | 59c5159 | 2007-05-09 08:57:56 +0200 | [diff] [blame] | 179 | * returns the req->errors value which is the scsi_cmnd result |
James Bottomley | ea73a9f | 2005-08-28 11:33:52 -0500 | [diff] [blame] | 180 | * field. |
Rob Landley | eb44820 | 2007-11-03 13:30:39 -0500 | [diff] [blame] | 181 | */ |
James Bottomley | 33aa687 | 2005-08-28 11:31:14 -0500 | [diff] [blame] | 182 | int scsi_execute(struct scsi_device *sdev, const unsigned char *cmd, |
| 183 | int data_direction, void *buffer, unsigned bufflen, |
| 184 | unsigned char *sense, int timeout, int retries, int flags) |
James Bottomley | 3921603 | 2005-06-15 18:48:29 -0500 | [diff] [blame] | 185 | { |
| 186 | struct request *req; |
| 187 | int write = (data_direction == DMA_TO_DEVICE); |
| 188 | int ret = DRIVER_ERROR << 24; |
| 189 | |
| 190 | req = blk_get_request(sdev->request_queue, write, __GFP_WAIT); |
| 191 | |
| 192 | if (bufflen && blk_rq_map_kern(sdev->request_queue, req, |
| 193 | buffer, bufflen, __GFP_WAIT)) |
| 194 | goto out; |
| 195 | |
| 196 | req->cmd_len = COMMAND_SIZE(cmd[0]); |
| 197 | memcpy(req->cmd, cmd, req->cmd_len); |
| 198 | req->sense = sense; |
| 199 | req->sense_len = 0; |
Mike Christie | 17e01f2 | 2005-11-11 05:31:37 -0600 | [diff] [blame] | 200 | req->retries = retries; |
James Bottomley | 3921603 | 2005-06-15 18:48:29 -0500 | [diff] [blame] | 201 | req->timeout = timeout; |
Jens Axboe | 4aff5e2 | 2006-08-10 08:44:47 +0200 | [diff] [blame] | 202 | req->cmd_type = REQ_TYPE_BLOCK_PC; |
| 203 | req->cmd_flags |= flags | REQ_QUIET | REQ_PREEMPT; |
James Bottomley | 3921603 | 2005-06-15 18:48:29 -0500 | [diff] [blame] | 204 | |
| 205 | /* |
| 206 | * head injection *required* here otherwise quiesce won't work |
| 207 | */ |
| 208 | blk_execute_rq(req->q, NULL, req, 1); |
| 209 | |
| 210 | ret = req->errors; |
| 211 | out: |
| 212 | blk_put_request(req); |
| 213 | |
| 214 | return ret; |
| 215 | } |
James Bottomley | 33aa687 | 2005-08-28 11:31:14 -0500 | [diff] [blame] | 216 | EXPORT_SYMBOL(scsi_execute); |
James Bottomley | 3921603 | 2005-06-15 18:48:29 -0500 | [diff] [blame] | 217 | |
James Bottomley | ea73a9f | 2005-08-28 11:33:52 -0500 | [diff] [blame] | 218 | |
| 219 | int scsi_execute_req(struct scsi_device *sdev, const unsigned char *cmd, |
| 220 | int data_direction, void *buffer, unsigned bufflen, |
| 221 | struct scsi_sense_hdr *sshdr, int timeout, int retries) |
| 222 | { |
| 223 | char *sense = NULL; |
akpm@osdl.org | 1ccb48b | 2005-06-26 00:12:51 -0700 | [diff] [blame] | 224 | int result; |
| 225 | |
James Bottomley | ea73a9f | 2005-08-28 11:33:52 -0500 | [diff] [blame] | 226 | if (sshdr) { |
Jes Sorensen | 24669f75 | 2006-01-16 10:31:18 -0500 | [diff] [blame] | 227 | sense = kzalloc(SCSI_SENSE_BUFFERSIZE, GFP_NOIO); |
James Bottomley | ea73a9f | 2005-08-28 11:33:52 -0500 | [diff] [blame] | 228 | if (!sense) |
| 229 | return DRIVER_ERROR << 24; |
James Bottomley | ea73a9f | 2005-08-28 11:33:52 -0500 | [diff] [blame] | 230 | } |
akpm@osdl.org | 1ccb48b | 2005-06-26 00:12:51 -0700 | [diff] [blame] | 231 | result = scsi_execute(sdev, cmd, data_direction, buffer, bufflen, |
Jes Sorensen | 24669f75 | 2006-01-16 10:31:18 -0500 | [diff] [blame] | 232 | sense, timeout, retries, 0); |
James Bottomley | ea73a9f | 2005-08-28 11:33:52 -0500 | [diff] [blame] | 233 | if (sshdr) |
James Bottomley | e514385 | 2005-08-09 11:55:36 -0500 | [diff] [blame] | 234 | scsi_normalize_sense(sense, SCSI_SENSE_BUFFERSIZE, sshdr); |
James Bottomley | ea73a9f | 2005-08-28 11:33:52 -0500 | [diff] [blame] | 235 | |
| 236 | kfree(sense); |
| 237 | return result; |
| 238 | } |
| 239 | EXPORT_SYMBOL(scsi_execute_req); |
| 240 | |
Mike Christie | 6e68af6 | 2005-11-11 05:30:27 -0600 | [diff] [blame] | 241 | struct scsi_io_context { |
| 242 | void *data; |
| 243 | void (*done)(void *data, char *sense, int result, int resid); |
| 244 | char sense[SCSI_SENSE_BUFFERSIZE]; |
| 245 | }; |
| 246 | |
Christoph Lameter | e18b890 | 2006-12-06 20:33:20 -0800 | [diff] [blame] | 247 | static struct kmem_cache *scsi_io_context_cache; |
Mike Christie | aa7b5cd | 2005-11-11 05:31:41 -0600 | [diff] [blame] | 248 | |
Jens Axboe | e650c30 | 2006-01-06 12:38:30 +0100 | [diff] [blame] | 249 | static void scsi_end_async(struct request *req, int uptodate) |
Mike Christie | 6e68af6 | 2005-11-11 05:30:27 -0600 | [diff] [blame] | 250 | { |
| 251 | struct scsi_io_context *sioc = req->end_io_data; |
| 252 | |
| 253 | if (sioc->done) |
| 254 | sioc->done(sioc->data, sioc->sense, req->errors, req->data_len); |
| 255 | |
Mike Christie | aa7b5cd | 2005-11-11 05:31:41 -0600 | [diff] [blame] | 256 | kmem_cache_free(scsi_io_context_cache, sioc); |
Mike Christie | 6e68af6 | 2005-11-11 05:30:27 -0600 | [diff] [blame] | 257 | __blk_put_request(req->q, req); |
| 258 | } |
| 259 | |
| 260 | static int scsi_merge_bio(struct request *rq, struct bio *bio) |
| 261 | { |
| 262 | struct request_queue *q = rq->q; |
| 263 | |
| 264 | bio->bi_flags &= ~(1 << BIO_SEG_VALID); |
| 265 | if (rq_data_dir(rq) == WRITE) |
| 266 | bio->bi_rw |= (1 << BIO_RW); |
| 267 | blk_queue_bounce(q, &bio); |
| 268 | |
NeilBrown | 3001ca7 | 2007-08-16 13:31:27 +0200 | [diff] [blame] | 269 | return blk_rq_append_bio(q, rq, bio); |
Mike Christie | 6e68af6 | 2005-11-11 05:30:27 -0600 | [diff] [blame] | 270 | } |
| 271 | |
NeilBrown | 6712ecf | 2007-09-27 12:47:43 +0200 | [diff] [blame] | 272 | static void scsi_bi_endio(struct bio *bio, int error) |
Mike Christie | 6e68af6 | 2005-11-11 05:30:27 -0600 | [diff] [blame] | 273 | { |
Mike Christie | 6e68af6 | 2005-11-11 05:30:27 -0600 | [diff] [blame] | 274 | bio_put(bio); |
Mike Christie | 6e68af6 | 2005-11-11 05:30:27 -0600 | [diff] [blame] | 275 | } |
| 276 | |
| 277 | /** |
| 278 | * scsi_req_map_sg - map a scatterlist into a request |
| 279 | * @rq: request to fill |
Rob Landley | eb44820 | 2007-11-03 13:30:39 -0500 | [diff] [blame] | 280 | * @sgl: scatterlist |
Mike Christie | 6e68af6 | 2005-11-11 05:30:27 -0600 | [diff] [blame] | 281 | * @nsegs: number of elements |
| 282 | * @bufflen: len of buffer |
| 283 | * @gfp: memory allocation flags |
| 284 | * |
| 285 | * scsi_req_map_sg maps a scatterlist into a request so that the |
| 286 | * request can be sent to the block layer. We do not trust the scatterlist |
| 287 | * sent to use, as some ULDs use that struct to only organize the pages. |
| 288 | */ |
| 289 | static int scsi_req_map_sg(struct request *rq, struct scatterlist *sgl, |
| 290 | int nsegs, unsigned bufflen, gfp_t gfp) |
| 291 | { |
| 292 | struct request_queue *q = rq->q; |
Bryan Holty | f523596 | 2006-03-22 06:35:39 -0600 | [diff] [blame] | 293 | int nr_pages = (bufflen + sgl[0].offset + PAGE_SIZE - 1) >> PAGE_SHIFT; |
Mike Christie | bd441de | 2007-03-13 12:52:29 -0500 | [diff] [blame] | 294 | unsigned int data_len = bufflen, len, bytes, off; |
Jens Axboe | c6132da | 2007-10-16 11:08:49 +0200 | [diff] [blame] | 295 | struct scatterlist *sg; |
Mike Christie | 6e68af6 | 2005-11-11 05:30:27 -0600 | [diff] [blame] | 296 | struct page *page; |
| 297 | struct bio *bio = NULL; |
| 298 | int i, err, nr_vecs = 0; |
| 299 | |
Jens Axboe | c6132da | 2007-10-16 11:08:49 +0200 | [diff] [blame] | 300 | for_each_sg(sgl, sg, nsegs, i) { |
Jens Axboe | 45711f1 | 2007-10-22 21:19:53 +0200 | [diff] [blame] | 301 | page = sg_page(sg); |
Jens Axboe | c6132da | 2007-10-16 11:08:49 +0200 | [diff] [blame] | 302 | off = sg->offset; |
| 303 | len = sg->length; |
| 304 | data_len += len; |
Mike Christie | 6e68af6 | 2005-11-11 05:30:27 -0600 | [diff] [blame] | 305 | |
Mike Christie | bd441de | 2007-03-13 12:52:29 -0500 | [diff] [blame] | 306 | while (len > 0 && data_len > 0) { |
| 307 | /* |
| 308 | * sg sends a scatterlist that is larger than |
| 309 | * the data_len it wants transferred for certain |
| 310 | * IO sizes |
| 311 | */ |
Mike Christie | 6e68af6 | 2005-11-11 05:30:27 -0600 | [diff] [blame] | 312 | bytes = min_t(unsigned int, len, PAGE_SIZE - off); |
Mike Christie | bd441de | 2007-03-13 12:52:29 -0500 | [diff] [blame] | 313 | bytes = min(bytes, data_len); |
Mike Christie | 6e68af6 | 2005-11-11 05:30:27 -0600 | [diff] [blame] | 314 | |
| 315 | if (!bio) { |
| 316 | nr_vecs = min_t(int, BIO_MAX_PAGES, nr_pages); |
| 317 | nr_pages -= nr_vecs; |
| 318 | |
| 319 | bio = bio_alloc(gfp, nr_vecs); |
| 320 | if (!bio) { |
| 321 | err = -ENOMEM; |
| 322 | goto free_bios; |
| 323 | } |
| 324 | bio->bi_end_io = scsi_bi_endio; |
| 325 | } |
| 326 | |
| 327 | if (bio_add_pc_page(q, bio, page, bytes, off) != |
| 328 | bytes) { |
| 329 | bio_put(bio); |
| 330 | err = -EINVAL; |
| 331 | goto free_bios; |
| 332 | } |
| 333 | |
| 334 | if (bio->bi_vcnt >= nr_vecs) { |
| 335 | err = scsi_merge_bio(rq, bio); |
| 336 | if (err) { |
NeilBrown | 6712ecf | 2007-09-27 12:47:43 +0200 | [diff] [blame] | 337 | bio_endio(bio, 0); |
Mike Christie | 6e68af6 | 2005-11-11 05:30:27 -0600 | [diff] [blame] | 338 | goto free_bios; |
| 339 | } |
| 340 | bio = NULL; |
| 341 | } |
| 342 | |
| 343 | page++; |
| 344 | len -= bytes; |
Mike Christie | bd441de | 2007-03-13 12:52:29 -0500 | [diff] [blame] | 345 | data_len -=bytes; |
Mike Christie | 6e68af6 | 2005-11-11 05:30:27 -0600 | [diff] [blame] | 346 | off = 0; |
| 347 | } |
| 348 | } |
| 349 | |
| 350 | rq->buffer = rq->data = NULL; |
Mike Christie | bd441de | 2007-03-13 12:52:29 -0500 | [diff] [blame] | 351 | rq->data_len = bufflen; |
Mike Christie | 6e68af6 | 2005-11-11 05:30:27 -0600 | [diff] [blame] | 352 | return 0; |
| 353 | |
| 354 | free_bios: |
| 355 | while ((bio = rq->bio) != NULL) { |
| 356 | rq->bio = bio->bi_next; |
| 357 | /* |
| 358 | * call endio instead of bio_put incase it was bounced |
| 359 | */ |
NeilBrown | 6712ecf | 2007-09-27 12:47:43 +0200 | [diff] [blame] | 360 | bio_endio(bio, 0); |
Mike Christie | 6e68af6 | 2005-11-11 05:30:27 -0600 | [diff] [blame] | 361 | } |
| 362 | |
| 363 | return err; |
| 364 | } |
| 365 | |
| 366 | /** |
| 367 | * scsi_execute_async - insert request |
| 368 | * @sdev: scsi device |
| 369 | * @cmd: scsi command |
brking@us.ibm.com | bb1d107 | 2006-01-23 15:03:22 -0600 | [diff] [blame] | 370 | * @cmd_len: length of scsi cdb |
Rob Landley | eb44820 | 2007-11-03 13:30:39 -0500 | [diff] [blame] | 371 | * @data_direction: DMA_TO_DEVICE, DMA_FROM_DEVICE, or DMA_NONE |
Mike Christie | 6e68af6 | 2005-11-11 05:30:27 -0600 | [diff] [blame] | 372 | * @buffer: data buffer (this can be a kernel buffer or scatterlist) |
| 373 | * @bufflen: len of buffer |
| 374 | * @use_sg: if buffer is a scatterlist this is the number of elements |
| 375 | * @timeout: request timeout in seconds |
| 376 | * @retries: number of times to retry request |
Rob Landley | eb44820 | 2007-11-03 13:30:39 -0500 | [diff] [blame] | 377 | * @privdata: data passed to done() |
| 378 | * @done: callback function when done |
| 379 | * @gfp: memory allocation flags |
| 380 | */ |
Mike Christie | 6e68af6 | 2005-11-11 05:30:27 -0600 | [diff] [blame] | 381 | 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] | 382 | int cmd_len, int data_direction, void *buffer, unsigned bufflen, |
Mike Christie | 6e68af6 | 2005-11-11 05:30:27 -0600 | [diff] [blame] | 383 | int use_sg, int timeout, int retries, void *privdata, |
| 384 | void (*done)(void *, char *, int, int), gfp_t gfp) |
| 385 | { |
| 386 | struct request *req; |
| 387 | struct scsi_io_context *sioc; |
| 388 | int err = 0; |
| 389 | int write = (data_direction == DMA_TO_DEVICE); |
| 390 | |
Robert P. J. Day | c376222 | 2007-02-10 01:45:03 -0800 | [diff] [blame] | 391 | sioc = kmem_cache_zalloc(scsi_io_context_cache, gfp); |
Mike Christie | 6e68af6 | 2005-11-11 05:30:27 -0600 | [diff] [blame] | 392 | if (!sioc) |
| 393 | return DRIVER_ERROR << 24; |
| 394 | |
| 395 | req = blk_get_request(sdev->request_queue, write, gfp); |
| 396 | if (!req) |
| 397 | goto free_sense; |
Jens Axboe | 4aff5e2 | 2006-08-10 08:44:47 +0200 | [diff] [blame] | 398 | req->cmd_type = REQ_TYPE_BLOCK_PC; |
| 399 | req->cmd_flags |= REQ_QUIET; |
Mike Christie | 6e68af6 | 2005-11-11 05:30:27 -0600 | [diff] [blame] | 400 | |
| 401 | if (use_sg) |
| 402 | err = scsi_req_map_sg(req, buffer, use_sg, bufflen, gfp); |
| 403 | else if (bufflen) |
| 404 | err = blk_rq_map_kern(req->q, req, buffer, bufflen, gfp); |
| 405 | |
| 406 | if (err) |
| 407 | goto free_req; |
| 408 | |
brking@us.ibm.com | bb1d107 | 2006-01-23 15:03:22 -0600 | [diff] [blame] | 409 | req->cmd_len = cmd_len; |
Tejun Heo | 097b845 | 2006-11-16 01:19:31 -0800 | [diff] [blame] | 410 | memset(req->cmd, 0, BLK_MAX_CDB); /* ATAPI hates garbage after CDB */ |
Mike Christie | 6e68af6 | 2005-11-11 05:30:27 -0600 | [diff] [blame] | 411 | memcpy(req->cmd, cmd, req->cmd_len); |
| 412 | req->sense = sioc->sense; |
| 413 | req->sense_len = 0; |
| 414 | req->timeout = timeout; |
Mike Christie | 17e01f2 | 2005-11-11 05:31:37 -0600 | [diff] [blame] | 415 | req->retries = retries; |
Mike Christie | 6e68af6 | 2005-11-11 05:30:27 -0600 | [diff] [blame] | 416 | req->end_io_data = sioc; |
| 417 | |
| 418 | sioc->data = privdata; |
| 419 | sioc->done = done; |
| 420 | |
| 421 | blk_execute_rq_nowait(req->q, NULL, req, 1, scsi_end_async); |
| 422 | return 0; |
| 423 | |
| 424 | free_req: |
| 425 | blk_put_request(req); |
| 426 | free_sense: |
Arne Redlich | 6470f2b | 2006-09-30 15:49:40 +0200 | [diff] [blame] | 427 | kmem_cache_free(scsi_io_context_cache, sioc); |
Mike Christie | 6e68af6 | 2005-11-11 05:30:27 -0600 | [diff] [blame] | 428 | return DRIVER_ERROR << 24; |
| 429 | } |
| 430 | EXPORT_SYMBOL_GPL(scsi_execute_async); |
| 431 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 432 | /* |
| 433 | * Function: scsi_init_cmd_errh() |
| 434 | * |
| 435 | * Purpose: Initialize cmd fields related to error handling. |
| 436 | * |
| 437 | * Arguments: cmd - command that is ready to be queued. |
| 438 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 439 | * Notes: This function has the job of initializing a number of |
| 440 | * fields related to error handling. Typically this will |
| 441 | * be called once for each command, as required. |
| 442 | */ |
Christoph Hellwig | 631c228 | 2006-07-08 20:42:15 +0200 | [diff] [blame] | 443 | static void scsi_init_cmd_errh(struct scsi_cmnd *cmd) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 444 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 445 | cmd->serial_number = 0; |
Boaz Harrosh | 30b0c37 | 2007-12-13 13:47:40 +0200 | [diff] [blame] | 446 | scsi_set_resid(cmd, 0); |
FUJITA Tomonori | b80ca4f | 2008-01-13 15:46:13 +0900 | [diff] [blame] | 447 | memset(cmd->sense_buffer, 0, SCSI_SENSE_BUFFERSIZE); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 448 | if (cmd->cmd_len == 0) |
| 449 | cmd->cmd_len = COMMAND_SIZE(cmd->cmnd[0]); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 450 | } |
| 451 | |
| 452 | void scsi_device_unbusy(struct scsi_device *sdev) |
| 453 | { |
| 454 | struct Scsi_Host *shost = sdev->host; |
| 455 | unsigned long flags; |
| 456 | |
| 457 | spin_lock_irqsave(shost->host_lock, flags); |
| 458 | shost->host_busy--; |
James Bottomley | 939647e | 2005-09-18 15:05:20 -0500 | [diff] [blame] | 459 | if (unlikely(scsi_host_in_recovery(shost) && |
Tejun Heo | ee7863b | 2006-05-15 20:57:20 +0900 | [diff] [blame] | 460 | (shost->host_failed || shost->host_eh_scheduled))) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 461 | scsi_eh_wakeup(shost); |
| 462 | spin_unlock(shost->host_lock); |
| 152587d | 2005-04-12 16:22:06 -0500 | [diff] [blame] | 463 | spin_lock(sdev->request_queue->queue_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 464 | sdev->device_busy--; |
| 152587d | 2005-04-12 16:22:06 -0500 | [diff] [blame] | 465 | spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 466 | } |
| 467 | |
| 468 | /* |
| 469 | * Called for single_lun devices on IO completion. Clear starget_sdev_user, |
| 470 | * and call blk_run_queue for all the scsi_devices on the target - |
| 471 | * including current_sdev first. |
| 472 | * |
| 473 | * Called with *no* scsi locks held. |
| 474 | */ |
| 475 | static void scsi_single_lun_run(struct scsi_device *current_sdev) |
| 476 | { |
| 477 | struct Scsi_Host *shost = current_sdev->host; |
| 478 | struct scsi_device *sdev, *tmp; |
| 479 | struct scsi_target *starget = scsi_target(current_sdev); |
| 480 | unsigned long flags; |
| 481 | |
| 482 | spin_lock_irqsave(shost->host_lock, flags); |
| 483 | starget->starget_sdev_user = NULL; |
| 484 | spin_unlock_irqrestore(shost->host_lock, flags); |
| 485 | |
| 486 | /* |
| 487 | * Call blk_run_queue for all LUNs on the target, starting with |
| 488 | * current_sdev. We race with others (to set starget_sdev_user), |
| 489 | * but in most cases, we will be first. Ideally, each LU on the |
| 490 | * target would get some limited time or requests on the target. |
| 491 | */ |
| 492 | blk_run_queue(current_sdev->request_queue); |
| 493 | |
| 494 | spin_lock_irqsave(shost->host_lock, flags); |
| 495 | if (starget->starget_sdev_user) |
| 496 | goto out; |
| 497 | list_for_each_entry_safe(sdev, tmp, &starget->devices, |
| 498 | same_target_siblings) { |
| 499 | if (sdev == current_sdev) |
| 500 | continue; |
| 501 | if (scsi_device_get(sdev)) |
| 502 | continue; |
| 503 | |
| 504 | spin_unlock_irqrestore(shost->host_lock, flags); |
| 505 | blk_run_queue(sdev->request_queue); |
| 506 | spin_lock_irqsave(shost->host_lock, flags); |
| 507 | |
| 508 | scsi_device_put(sdev); |
| 509 | } |
| 510 | out: |
| 511 | spin_unlock_irqrestore(shost->host_lock, flags); |
| 512 | } |
| 513 | |
| 514 | /* |
| 515 | * Function: scsi_run_queue() |
| 516 | * |
| 517 | * Purpose: Select a proper request queue to serve next |
| 518 | * |
| 519 | * Arguments: q - last request's queue |
| 520 | * |
| 521 | * Returns: Nothing |
| 522 | * |
| 523 | * Notes: The previous command was completely finished, start |
| 524 | * a new one if possible. |
| 525 | */ |
| 526 | static void scsi_run_queue(struct request_queue *q) |
| 527 | { |
| 528 | struct scsi_device *sdev = q->queuedata; |
| 529 | struct Scsi_Host *shost = sdev->host; |
| 530 | unsigned long flags; |
| 531 | |
Tony Battersby | 25d7c36 | 2007-11-12 10:00:44 -0500 | [diff] [blame] | 532 | if (scsi_target(sdev)->single_lun) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 533 | scsi_single_lun_run(sdev); |
| 534 | |
| 535 | spin_lock_irqsave(shost->host_lock, flags); |
| 536 | while (!list_empty(&shost->starved_list) && |
| 537 | !shost->host_blocked && !shost->host_self_blocked && |
| 538 | !((shost->can_queue > 0) && |
| 539 | (shost->host_busy >= shost->can_queue))) { |
| 540 | /* |
| 541 | * As long as shost is accepting commands and we have |
| 542 | * starved queues, call blk_run_queue. scsi_request_fn |
| 543 | * drops the queue_lock and can add us back to the |
| 544 | * starved_list. |
| 545 | * |
| 546 | * host_lock protects the starved_list and starved_entry. |
| 547 | * scsi_request_fn must get the host_lock before checking |
| 548 | * or modifying starved_list or starved_entry. |
| 549 | */ |
| 550 | sdev = list_entry(shost->starved_list.next, |
| 551 | struct scsi_device, starved_entry); |
| 552 | list_del_init(&sdev->starved_entry); |
| 553 | spin_unlock_irqrestore(shost->host_lock, flags); |
| 554 | |
Andreas Herrmann | 04846f2 | 2006-08-09 17:31:16 +0200 | [diff] [blame] | 555 | |
| 556 | if (test_bit(QUEUE_FLAG_REENTER, &q->queue_flags) && |
| 557 | !test_and_set_bit(QUEUE_FLAG_REENTER, |
| 558 | &sdev->request_queue->queue_flags)) { |
| 559 | blk_run_queue(sdev->request_queue); |
| 560 | clear_bit(QUEUE_FLAG_REENTER, |
| 561 | &sdev->request_queue->queue_flags); |
| 562 | } else |
| 563 | blk_run_queue(sdev->request_queue); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 564 | |
| 565 | spin_lock_irqsave(shost->host_lock, flags); |
| 566 | if (unlikely(!list_empty(&sdev->starved_entry))) |
| 567 | /* |
| 568 | * sdev lost a race, and was put back on the |
| 569 | * starved list. This is unlikely but without this |
| 570 | * in theory we could loop forever. |
| 571 | */ |
| 572 | break; |
| 573 | } |
| 574 | spin_unlock_irqrestore(shost->host_lock, flags); |
| 575 | |
| 576 | blk_run_queue(q); |
| 577 | } |
| 578 | |
| 579 | /* |
| 580 | * Function: scsi_requeue_command() |
| 581 | * |
| 582 | * Purpose: Handle post-processing of completed commands. |
| 583 | * |
| 584 | * Arguments: q - queue to operate on |
| 585 | * cmd - command that may need to be requeued. |
| 586 | * |
| 587 | * Returns: Nothing |
| 588 | * |
| 589 | * Notes: After command completion, there may be blocks left |
| 590 | * over which weren't finished by the previous command |
| 591 | * this can be for a number of reasons - the main one is |
| 592 | * I/O errors in the middle of the request, in which case |
| 593 | * we need to request the blocks that come after the bad |
| 594 | * sector. |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 595 | * Notes: Upon return, cmd is a stale pointer. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 596 | */ |
| 597 | static void scsi_requeue_command(struct request_queue *q, struct scsi_cmnd *cmd) |
| 598 | { |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 599 | struct request *req = cmd->request; |
Tejun Heo | 283369c | 2005-04-24 02:06:36 -0500 | [diff] [blame] | 600 | unsigned long flags; |
| 601 | |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 602 | scsi_unprep_request(req); |
Tejun Heo | 283369c | 2005-04-24 02:06:36 -0500 | [diff] [blame] | 603 | spin_lock_irqsave(q->queue_lock, flags); |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 604 | blk_requeue_request(q, req); |
Tejun Heo | 283369c | 2005-04-24 02:06:36 -0500 | [diff] [blame] | 605 | spin_unlock_irqrestore(q->queue_lock, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 606 | |
| 607 | scsi_run_queue(q); |
| 608 | } |
| 609 | |
| 610 | void scsi_next_command(struct scsi_cmnd *cmd) |
| 611 | { |
Linus Torvalds | 49d7bc6 | 2005-12-12 11:25:04 -0800 | [diff] [blame] | 612 | struct scsi_device *sdev = cmd->device; |
| 613 | struct request_queue *q = sdev->request_queue; |
| 614 | |
| 615 | /* need to hold a reference on the device before we let go of the cmd */ |
| 616 | get_device(&sdev->sdev_gendev); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 617 | |
| 618 | scsi_put_command(cmd); |
| 619 | scsi_run_queue(q); |
Linus Torvalds | 49d7bc6 | 2005-12-12 11:25:04 -0800 | [diff] [blame] | 620 | |
| 621 | /* ok to remove device now */ |
| 622 | put_device(&sdev->sdev_gendev); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 623 | } |
| 624 | |
| 625 | void scsi_run_host_queues(struct Scsi_Host *shost) |
| 626 | { |
| 627 | struct scsi_device *sdev; |
| 628 | |
| 629 | shost_for_each_device(sdev, shost) |
| 630 | scsi_run_queue(sdev->request_queue); |
| 631 | } |
| 632 | |
| 633 | /* |
| 634 | * Function: scsi_end_request() |
| 635 | * |
| 636 | * Purpose: Post-processing of completed commands (usually invoked at end |
| 637 | * of upper level post-processing and scsi_io_completion). |
| 638 | * |
| 639 | * Arguments: cmd - command that is complete. |
Kiyoshi Ueda | 610d8b0 | 2007-12-11 17:52:09 -0500 | [diff] [blame] | 640 | * error - 0 if I/O indicates success, < 0 for I/O error. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 641 | * bytes - number of bytes of completed I/O |
| 642 | * requeue - indicates whether we should requeue leftovers. |
| 643 | * |
| 644 | * Lock status: Assumed that lock is not held upon entry. |
| 645 | * |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 646 | * Returns: cmd if requeue required, NULL otherwise. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 647 | * |
| 648 | * Notes: This is called for block device requests in order to |
| 649 | * mark some number of sectors as complete. |
| 650 | * |
| 651 | * We are guaranteeing that the request queue will be goosed |
| 652 | * at some point during this call. |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 653 | * 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] | 654 | */ |
Kiyoshi Ueda | 610d8b0 | 2007-12-11 17:52:09 -0500 | [diff] [blame] | 655 | 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] | 656 | int bytes, int requeue) |
| 657 | { |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 658 | struct request_queue *q = cmd->device->request_queue; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 659 | struct request *req = cmd->request; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 660 | |
| 661 | /* |
| 662 | * If there are blocks left over at the end, set up the command |
| 663 | * to queue the remainder of them. |
| 664 | */ |
Kiyoshi Ueda | 610d8b0 | 2007-12-11 17:52:09 -0500 | [diff] [blame] | 665 | if (blk_end_request(req, error, bytes)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 666 | int leftover = (req->hard_nr_sectors << 9); |
| 667 | |
| 668 | if (blk_pc_request(req)) |
| 669 | leftover = req->data_len; |
| 670 | |
| 671 | /* kill remainder if no retrys */ |
Kiyoshi Ueda | 610d8b0 | 2007-12-11 17:52:09 -0500 | [diff] [blame] | 672 | if (error && blk_noretry_request(req)) |
| 673 | blk_end_request(req, error, leftover); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 674 | else { |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 675 | if (requeue) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 676 | /* |
| 677 | * Bleah. Leftovers again. Stick the |
| 678 | * leftovers in the front of the |
| 679 | * queue, and goose the queue again. |
| 680 | */ |
| 681 | scsi_requeue_command(q, cmd); |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 682 | cmd = NULL; |
| 683 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 684 | return cmd; |
| 685 | } |
| 686 | } |
| 687 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 688 | /* |
| 689 | * This will goose the queue request function at the end, so we don't |
| 690 | * need to worry about launching another command. |
| 691 | */ |
| 692 | scsi_next_command(cmd); |
| 693 | return NULL; |
| 694 | } |
| 695 | |
Jens Axboe | a8474ce | 2007-08-07 09:02:51 +0200 | [diff] [blame] | 696 | static inline unsigned int scsi_sgtable_index(unsigned short nents) |
| 697 | { |
| 698 | unsigned int index; |
| 699 | |
James Bottomley | d3f46f3 | 2008-01-15 11:11:46 -0600 | [diff] [blame] | 700 | BUG_ON(nents > SCSI_MAX_SG_SEGMENTS); |
| 701 | |
| 702 | if (nents <= 8) |
Jens Axboe | a8474ce | 2007-08-07 09:02:51 +0200 | [diff] [blame] | 703 | index = 0; |
James Bottomley | d3f46f3 | 2008-01-15 11:11:46 -0600 | [diff] [blame] | 704 | else |
| 705 | index = get_count_order(nents) - 3; |
Jens Axboe | a8474ce | 2007-08-07 09:02:51 +0200 | [diff] [blame] | 706 | |
| 707 | return index; |
| 708 | } |
| 709 | |
Jens Axboe | 5ed7959 | 2007-11-15 09:13:11 +0100 | [diff] [blame] | 710 | static void scsi_sg_free(struct scatterlist *sgl, unsigned int nents) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 711 | { |
| 712 | struct scsi_host_sg_pool *sgp; |
Jens Axboe | 5ed7959 | 2007-11-15 09:13:11 +0100 | [diff] [blame] | 713 | |
| 714 | sgp = scsi_sg_pools + scsi_sgtable_index(nents); |
| 715 | mempool_free(sgl, sgp->pool); |
| 716 | } |
| 717 | |
| 718 | static struct scatterlist *scsi_sg_alloc(unsigned int nents, gfp_t gfp_mask) |
| 719 | { |
| 720 | struct scsi_host_sg_pool *sgp; |
| 721 | |
| 722 | sgp = scsi_sg_pools + scsi_sgtable_index(nents); |
| 723 | return mempool_alloc(sgp->pool, gfp_mask); |
| 724 | } |
| 725 | |
Boaz Harrosh | 30b0c37 | 2007-12-13 13:47:40 +0200 | [diff] [blame] | 726 | static int scsi_alloc_sgtable(struct scsi_data_buffer *sdb, int nents, |
| 727 | gfp_t gfp_mask) |
Jens Axboe | 5ed7959 | 2007-11-15 09:13:11 +0100 | [diff] [blame] | 728 | { |
| 729 | int ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 730 | |
Boaz Harrosh | 30b0c37 | 2007-12-13 13:47:40 +0200 | [diff] [blame] | 731 | BUG_ON(!nents); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 732 | |
Boaz Harrosh | 30b0c37 | 2007-12-13 13:47:40 +0200 | [diff] [blame] | 733 | ret = __sg_alloc_table(&sdb->table, nents, SCSI_MAX_SG_SEGMENTS, |
| 734 | gfp_mask, scsi_sg_alloc); |
Jens Axboe | 5ed7959 | 2007-11-15 09:13:11 +0100 | [diff] [blame] | 735 | if (unlikely(ret)) |
Boaz Harrosh | 30b0c37 | 2007-12-13 13:47:40 +0200 | [diff] [blame] | 736 | __sg_free_table(&sdb->table, SCSI_MAX_SG_SEGMENTS, |
James Bottomley | 7cedb1f | 2008-01-13 14:15:28 -0600 | [diff] [blame] | 737 | scsi_sg_free); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 738 | |
Jens Axboe | a8474ce | 2007-08-07 09:02:51 +0200 | [diff] [blame] | 739 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 740 | } |
| 741 | |
Boaz Harrosh | 30b0c37 | 2007-12-13 13:47:40 +0200 | [diff] [blame] | 742 | static void scsi_free_sgtable(struct scsi_data_buffer *sdb) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 743 | { |
Boaz Harrosh | 30b0c37 | 2007-12-13 13:47:40 +0200 | [diff] [blame] | 744 | __sg_free_table(&sdb->table, SCSI_MAX_SG_SEGMENTS, scsi_sg_free); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 745 | } |
| 746 | |
| 747 | /* |
| 748 | * Function: scsi_release_buffers() |
| 749 | * |
| 750 | * Purpose: Completion processing for block device I/O requests. |
| 751 | * |
| 752 | * Arguments: cmd - command that we are bailing. |
| 753 | * |
| 754 | * Lock status: Assumed that no lock is held upon entry. |
| 755 | * |
| 756 | * Returns: Nothing |
| 757 | * |
| 758 | * Notes: In the event that an upper level driver rejects a |
| 759 | * command, we must release resources allocated during |
| 760 | * the __init_io() function. Primarily this would involve |
| 761 | * the scatter-gather table, and potentially any bounce |
| 762 | * buffers. |
| 763 | */ |
Boaz Harrosh | bb52d82 | 2007-12-13 16:14:27 -0800 | [diff] [blame] | 764 | void scsi_release_buffers(struct scsi_cmnd *cmd) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 765 | { |
Boaz Harrosh | 30b0c37 | 2007-12-13 13:47:40 +0200 | [diff] [blame] | 766 | if (cmd->sdb.table.nents) |
| 767 | scsi_free_sgtable(&cmd->sdb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 768 | |
Boaz Harrosh | 30b0c37 | 2007-12-13 13:47:40 +0200 | [diff] [blame] | 769 | memset(&cmd->sdb, 0, sizeof(cmd->sdb)); |
Boaz Harrosh | 6f9a35e | 2007-12-13 13:50:53 +0200 | [diff] [blame] | 770 | |
| 771 | if (scsi_bidi_cmnd(cmd)) { |
| 772 | struct scsi_data_buffer *bidi_sdb = |
| 773 | cmd->request->next_rq->special; |
| 774 | scsi_free_sgtable(bidi_sdb); |
| 775 | kmem_cache_free(scsi_bidi_sdb_cache, bidi_sdb); |
| 776 | cmd->request->next_rq->special = NULL; |
| 777 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 778 | } |
Boaz Harrosh | bb52d82 | 2007-12-13 16:14:27 -0800 | [diff] [blame] | 779 | EXPORT_SYMBOL(scsi_release_buffers); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 780 | |
| 781 | /* |
Boaz Harrosh | 6f9a35e | 2007-12-13 13:50:53 +0200 | [diff] [blame] | 782 | * Bidi commands Must be complete as a whole, both sides at once. |
| 783 | * If part of the bytes were written and lld returned |
| 784 | * scsi_in()->resid and/or scsi_out()->resid this information will be left |
| 785 | * in req->data_len and req->next_rq->data_len. The upper-layer driver can |
| 786 | * decide what to do with this information. |
| 787 | */ |
| 788 | void scsi_end_bidi_request(struct scsi_cmnd *cmd) |
| 789 | { |
Kiyoshi Ueda | b8de163 | 2008-01-18 12:02:15 -0500 | [diff] [blame] | 790 | struct request *req = cmd->request; |
| 791 | unsigned int dlen = req->data_len; |
| 792 | unsigned int next_dlen = req->next_rq->data_len; |
| 793 | |
| 794 | req->data_len = scsi_out(cmd)->resid; |
| 795 | req->next_rq->data_len = scsi_in(cmd)->resid; |
| 796 | |
| 797 | /* The req and req->next_rq have not been completed */ |
| 798 | BUG_ON(blk_end_bidi_request(req, 0, dlen, next_dlen)); |
| 799 | |
Boaz Harrosh | 6f9a35e | 2007-12-13 13:50:53 +0200 | [diff] [blame] | 800 | scsi_release_buffers(cmd); |
| 801 | |
| 802 | /* |
| 803 | * This will goose the queue request function at the end, so we don't |
| 804 | * need to worry about launching another command. |
| 805 | */ |
| 806 | scsi_next_command(cmd); |
| 807 | } |
| 808 | |
| 809 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 810 | * Function: scsi_io_completion() |
| 811 | * |
| 812 | * Purpose: Completion processing for block device I/O requests. |
| 813 | * |
| 814 | * Arguments: cmd - command that is finished. |
| 815 | * |
| 816 | * Lock status: Assumed that no lock is held upon entry. |
| 817 | * |
| 818 | * Returns: Nothing |
| 819 | * |
| 820 | * Notes: This function is matched in terms of capabilities to |
| 821 | * the function that created the scatter-gather list. |
| 822 | * In other words, if there are no bounce buffers |
| 823 | * (the normal case for most drivers), we don't need |
| 824 | * the logic to deal with cleaning up afterwards. |
| 825 | * |
| 826 | * We must do one of several things here: |
| 827 | * |
| 828 | * a) Call scsi_end_request. This will finish off the |
| 829 | * specified number of sectors. If we are done, the |
| 830 | * command block will be released, and the queue |
| 831 | * function will be goosed. If we are not done, then |
| 832 | * scsi_end_request will directly goose the queue. |
| 833 | * |
| 834 | * b) We can just use scsi_requeue_command() here. This would |
| 835 | * be used if we just wanted to retry, for example. |
| 836 | */ |
Luben Tuikov | 03aba2f | 2006-06-23 09:39:09 -0700 | [diff] [blame] | 837 | void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 838 | { |
| 839 | int result = cmd->result; |
Boaz Harrosh | 30b0c37 | 2007-12-13 13:47:40 +0200 | [diff] [blame] | 840 | int this_count = scsi_bufflen(cmd); |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 841 | struct request_queue *q = cmd->device->request_queue; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 842 | struct request *req = cmd->request; |
| 843 | int clear_errors = 1; |
| 844 | struct scsi_sense_hdr sshdr; |
| 845 | int sense_valid = 0; |
| 846 | int sense_deferred = 0; |
| 847 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 848 | if (result) { |
| 849 | sense_valid = scsi_command_normalize_sense(cmd, &sshdr); |
| 850 | if (sense_valid) |
| 851 | sense_deferred = scsi_sense_is_deferred(&sshdr); |
| 852 | } |
Christoph Hellwig | 631c228 | 2006-07-08 20:42:15 +0200 | [diff] [blame] | 853 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 854 | if (blk_pc_request(req)) { /* SG_IO ioctl from block level */ |
| 855 | req->errors = result; |
| 856 | if (result) { |
| 857 | clear_errors = 0; |
| 858 | if (sense_valid && req->sense) { |
| 859 | /* |
| 860 | * SG_IO wants current and deferred errors |
| 861 | */ |
| 862 | int len = 8 + cmd->sense_buffer[7]; |
| 863 | |
| 864 | if (len > SCSI_SENSE_BUFFERSIZE) |
| 865 | len = SCSI_SENSE_BUFFERSIZE; |
| 866 | memcpy(req->sense, cmd->sense_buffer, len); |
| 867 | req->sense_len = len; |
| 868 | } |
Pete Wyckoff | b22f687 | 2007-03-13 16:53:28 -0400 | [diff] [blame] | 869 | } |
Boaz Harrosh | 6f9a35e | 2007-12-13 13:50:53 +0200 | [diff] [blame] | 870 | if (scsi_bidi_cmnd(cmd)) { |
| 871 | /* will also release_buffers */ |
| 872 | scsi_end_bidi_request(cmd); |
| 873 | return; |
| 874 | } |
Boaz Harrosh | 30b0c37 | 2007-12-13 13:47:40 +0200 | [diff] [blame] | 875 | req->data_len = scsi_get_resid(cmd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 876 | } |
| 877 | |
Boaz Harrosh | 6f9a35e | 2007-12-13 13:50:53 +0200 | [diff] [blame] | 878 | BUG_ON(blk_bidi_rq(req)); /* bidi not support for !blk_pc_request yet */ |
Boaz Harrosh | 30b0c37 | 2007-12-13 13:47:40 +0200 | [diff] [blame] | 879 | scsi_release_buffers(cmd); |
| 880 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 881 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 882 | * Next deal with any sectors which we were able to correctly |
| 883 | * handle. |
| 884 | */ |
James Bottomley | d6b0c53 | 2006-07-02 10:06:28 -0500 | [diff] [blame] | 885 | SCSI_LOG_HLCOMPLETE(1, printk("%ld sectors total, " |
| 886 | "%d bytes done.\n", |
| 887 | req->nr_sectors, good_bytes)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 888 | |
James Bottomley | d6b0c53 | 2006-07-02 10:06:28 -0500 | [diff] [blame] | 889 | if (clear_errors) |
| 890 | req->errors = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 891 | |
James Bottomley | d6b0c53 | 2006-07-02 10:06:28 -0500 | [diff] [blame] | 892 | /* A number of bytes were successfully read. If there |
| 893 | * are leftovers and there is some kind of error |
| 894 | * (result != 0), retry the rest. |
| 895 | */ |
Kiyoshi Ueda | 610d8b0 | 2007-12-11 17:52:09 -0500 | [diff] [blame] | 896 | if (scsi_end_request(cmd, 0, good_bytes, result == 0) == NULL) |
James Bottomley | d6b0c53 | 2006-07-02 10:06:28 -0500 | [diff] [blame] | 897 | return; |
Luben Tuikov | 03aba2f | 2006-06-23 09:39:09 -0700 | [diff] [blame] | 898 | |
| 899 | /* good_bytes = 0, or (inclusive) there were leftovers and |
| 900 | * result = 0, so scsi_end_request couldn't retry. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 901 | */ |
| 902 | if (sense_valid && !sense_deferred) { |
| 903 | switch (sshdr.sense_key) { |
| 904 | case UNIT_ATTENTION: |
| 905 | if (cmd->device->removable) { |
Luben Tuikov | 03aba2f | 2006-06-23 09:39:09 -0700 | [diff] [blame] | 906 | /* Detected disc change. Set a bit |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 907 | * and quietly refuse further access. |
| 908 | */ |
| 909 | cmd->device->changed = 1; |
Kiyoshi Ueda | 610d8b0 | 2007-12-11 17:52:09 -0500 | [diff] [blame] | 910 | scsi_end_request(cmd, -EIO, this_count, 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 911 | return; |
| 912 | } else { |
Luben Tuikov | 03aba2f | 2006-06-23 09:39:09 -0700 | [diff] [blame] | 913 | /* Must have been a power glitch, or a |
| 914 | * bus reset. Could not have been a |
| 915 | * media change, so we just retry the |
| 916 | * request and see what happens. |
| 917 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 918 | scsi_requeue_command(q, cmd); |
| 919 | return; |
| 920 | } |
| 921 | break; |
| 922 | case ILLEGAL_REQUEST: |
Luben Tuikov | 03aba2f | 2006-06-23 09:39:09 -0700 | [diff] [blame] | 923 | /* If we had an ILLEGAL REQUEST returned, then |
| 924 | * we may have performed an unsupported |
| 925 | * command. The only thing this should be |
| 926 | * would be a ten byte read where only a six |
| 927 | * byte read was supported. Also, on a system |
| 928 | * where READ CAPACITY failed, we may have |
| 929 | * read past the end of the disk. |
| 930 | */ |
Jens Axboe | 26a6801 | 2005-11-29 21:03:34 +0100 | [diff] [blame] | 931 | if ((cmd->device->use_10_for_rw && |
| 932 | sshdr.asc == 0x20 && sshdr.ascq == 0x00) && |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 933 | (cmd->cmnd[0] == READ_10 || |
| 934 | cmd->cmnd[0] == WRITE_10)) { |
| 935 | cmd->device->use_10_for_rw = 0; |
Luben Tuikov | 03aba2f | 2006-06-23 09:39:09 -0700 | [diff] [blame] | 936 | /* This will cause a retry with a |
| 937 | * 6-byte command. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 938 | */ |
| 939 | scsi_requeue_command(q, cmd); |
Luben Tuikov | 03aba2f | 2006-06-23 09:39:09 -0700 | [diff] [blame] | 940 | return; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 941 | } else { |
Kiyoshi Ueda | 610d8b0 | 2007-12-11 17:52:09 -0500 | [diff] [blame] | 942 | scsi_end_request(cmd, -EIO, this_count, 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 943 | return; |
| 944 | } |
| 945 | break; |
| 946 | case NOT_READY: |
Luben Tuikov | 03aba2f | 2006-06-23 09:39:09 -0700 | [diff] [blame] | 947 | /* If the device is in the process of becoming |
James Bottomley | f3e93f7 | 2006-04-25 16:48:30 -0500 | [diff] [blame] | 948 | * ready, or has a temporary blockage, retry. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 949 | */ |
James Bottomley | f3e93f7 | 2006-04-25 16:48:30 -0500 | [diff] [blame] | 950 | if (sshdr.asc == 0x04) { |
| 951 | switch (sshdr.ascq) { |
| 952 | case 0x01: /* becoming ready */ |
| 953 | case 0x04: /* format in progress */ |
| 954 | case 0x05: /* rebuild in progress */ |
| 955 | case 0x06: /* recalculation in progress */ |
| 956 | case 0x07: /* operation in progress */ |
| 957 | case 0x08: /* Long write in progress */ |
| 958 | case 0x09: /* self test in progress */ |
| 959 | scsi_requeue_command(q, cmd); |
| 960 | return; |
| 961 | default: |
| 962 | break; |
| 963 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 964 | } |
James Bottomley | 311b581 | 2007-09-23 09:08:46 -0500 | [diff] [blame] | 965 | if (!(req->cmd_flags & REQ_QUIET)) |
| 966 | scsi_cmd_print_sense_hdr(cmd, |
| 967 | "Device not ready", |
| 968 | &sshdr); |
| 969 | |
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 | case VOLUME_OVERFLOW: |
Jens Axboe | 4aff5e2 | 2006-08-10 08:44:47 +0200 | [diff] [blame] | 973 | if (!(req->cmd_flags & REQ_QUIET)) { |
Jeff Garzik | 3bf743e | 2005-10-24 18:04:06 -0400 | [diff] [blame] | 974 | scmd_printk(KERN_INFO, cmd, |
Luben Tuikov | 03aba2f | 2006-06-23 09:39:09 -0700 | [diff] [blame] | 975 | "Volume overflow, CDB: "); |
Christoph Hellwig | 631c228 | 2006-07-08 20:42:15 +0200 | [diff] [blame] | 976 | __scsi_print_command(cmd->cmnd); |
James Bottomley | 3173d8c | 2005-09-04 11:32:05 -0500 | [diff] [blame] | 977 | scsi_print_sense("", cmd); |
| 978 | } |
Luben Tuikov | 03aba2f | 2006-06-23 09:39:09 -0700 | [diff] [blame] | 979 | /* See SSC3rXX or current. */ |
Kiyoshi Ueda | 610d8b0 | 2007-12-11 17:52:09 -0500 | [diff] [blame] | 980 | scsi_end_request(cmd, -EIO, this_count, 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 981 | return; |
| 982 | default: |
| 983 | break; |
| 984 | } |
Luben Tuikov | 03aba2f | 2006-06-23 09:39:09 -0700 | [diff] [blame] | 985 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 986 | if (host_byte(result) == DID_RESET) { |
Luben Tuikov | 03aba2f | 2006-06-23 09:39:09 -0700 | [diff] [blame] | 987 | /* Third party bus reset or reset for error recovery |
| 988 | * reasons. Just retry the request and see what |
| 989 | * happens. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 990 | */ |
| 991 | scsi_requeue_command(q, cmd); |
| 992 | return; |
| 993 | } |
| 994 | if (result) { |
Jens Axboe | 4aff5e2 | 2006-08-10 08:44:47 +0200 | [diff] [blame] | 995 | if (!(req->cmd_flags & REQ_QUIET)) { |
Martin K. Petersen | a4d04a4 | 2007-02-27 22:40:27 -0500 | [diff] [blame] | 996 | scsi_print_result(cmd); |
James Bottomley | 3173d8c | 2005-09-04 11:32:05 -0500 | [diff] [blame] | 997 | if (driver_byte(result) & DRIVER_SENSE) |
| 998 | scsi_print_sense("", cmd); |
| 999 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1000 | } |
Kiyoshi Ueda | 610d8b0 | 2007-12-11 17:52:09 -0500 | [diff] [blame] | 1001 | scsi_end_request(cmd, -EIO, this_count, !result); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1002 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1003 | |
Boaz Harrosh | 6f9a35e | 2007-12-13 13:50:53 +0200 | [diff] [blame] | 1004 | static int scsi_init_sgtable(struct request *req, struct scsi_data_buffer *sdb, |
| 1005 | gfp_t gfp_mask) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1006 | { |
Boaz Harrosh | 6f9a35e | 2007-12-13 13:50:53 +0200 | [diff] [blame] | 1007 | int count; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1008 | |
| 1009 | /* |
Christoph Hellwig | 3b00315 | 2006-11-04 20:10:55 +0100 | [diff] [blame] | 1010 | * If sg table allocation fails, requeue request later. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1011 | */ |
Boaz Harrosh | 30b0c37 | 2007-12-13 13:47:40 +0200 | [diff] [blame] | 1012 | if (unlikely(scsi_alloc_sgtable(sdb, req->nr_phys_segments, |
| 1013 | gfp_mask))) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1014 | return BLKPREP_DEFER; |
Alan Stern | 7c72ce8 | 2005-10-14 11:23:27 -0400 | [diff] [blame] | 1015 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1016 | |
Christoph Hellwig | 3b00315 | 2006-11-04 20:10:55 +0100 | [diff] [blame] | 1017 | req->buffer = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1018 | if (blk_pc_request(req)) |
Boaz Harrosh | 30b0c37 | 2007-12-13 13:47:40 +0200 | [diff] [blame] | 1019 | sdb->length = req->data_len; |
Christoph Hellwig | 3b00315 | 2006-11-04 20:10:55 +0100 | [diff] [blame] | 1020 | else |
Boaz Harrosh | 30b0c37 | 2007-12-13 13:47:40 +0200 | [diff] [blame] | 1021 | sdb->length = req->nr_sectors << 9; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1022 | |
| 1023 | /* |
| 1024 | * Next, walk the list, and fill in the addresses and sizes of |
| 1025 | * each segment. |
| 1026 | */ |
Boaz Harrosh | 30b0c37 | 2007-12-13 13:47:40 +0200 | [diff] [blame] | 1027 | count = blk_rq_map_sg(req->q, req, sdb->table.sgl); |
| 1028 | BUG_ON(count > sdb->table.nents); |
| 1029 | sdb->table.nents = count; |
Rusty Russell | 4a03d90 | 2007-11-19 11:28:48 +1100 | [diff] [blame] | 1030 | return BLKPREP_OK; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1031 | } |
Boaz Harrosh | 6f9a35e | 2007-12-13 13:50:53 +0200 | [diff] [blame] | 1032 | |
| 1033 | /* |
| 1034 | * Function: scsi_init_io() |
| 1035 | * |
| 1036 | * Purpose: SCSI I/O initialize function. |
| 1037 | * |
| 1038 | * Arguments: cmd - Command descriptor we wish to initialize |
| 1039 | * |
| 1040 | * Returns: 0 on success |
| 1041 | * BLKPREP_DEFER if the failure is retryable |
| 1042 | * BLKPREP_KILL if the failure is fatal |
| 1043 | */ |
| 1044 | int scsi_init_io(struct scsi_cmnd *cmd, gfp_t gfp_mask) |
| 1045 | { |
| 1046 | int error = scsi_init_sgtable(cmd->request, &cmd->sdb, gfp_mask); |
| 1047 | if (error) |
| 1048 | goto err_exit; |
| 1049 | |
| 1050 | if (blk_bidi_rq(cmd->request)) { |
| 1051 | struct scsi_data_buffer *bidi_sdb = kmem_cache_zalloc( |
| 1052 | scsi_bidi_sdb_cache, GFP_ATOMIC); |
| 1053 | if (!bidi_sdb) { |
| 1054 | error = BLKPREP_DEFER; |
| 1055 | goto err_exit; |
| 1056 | } |
| 1057 | |
| 1058 | cmd->request->next_rq->special = bidi_sdb; |
| 1059 | error = scsi_init_sgtable(cmd->request->next_rq, bidi_sdb, |
| 1060 | GFP_ATOMIC); |
| 1061 | if (error) |
| 1062 | goto err_exit; |
| 1063 | } |
| 1064 | |
| 1065 | return BLKPREP_OK ; |
| 1066 | |
| 1067 | err_exit: |
| 1068 | scsi_release_buffers(cmd); |
| 1069 | if (error == BLKPREP_KILL) |
| 1070 | scsi_put_command(cmd); |
| 1071 | else /* BLKPREP_DEFER */ |
| 1072 | scsi_unprep_request(cmd->request); |
| 1073 | |
| 1074 | return error; |
| 1075 | } |
Boaz Harrosh | bb52d82 | 2007-12-13 16:14:27 -0800 | [diff] [blame] | 1076 | EXPORT_SYMBOL(scsi_init_io); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1077 | |
Christoph Hellwig | 3b00315 | 2006-11-04 20:10:55 +0100 | [diff] [blame] | 1078 | static struct scsi_cmnd *scsi_get_cmd_from_req(struct scsi_device *sdev, |
| 1079 | struct request *req) |
| 1080 | { |
| 1081 | struct scsi_cmnd *cmd; |
| 1082 | |
| 1083 | if (!req->special) { |
| 1084 | cmd = scsi_get_command(sdev, GFP_ATOMIC); |
| 1085 | if (unlikely(!cmd)) |
| 1086 | return NULL; |
| 1087 | req->special = cmd; |
| 1088 | } else { |
| 1089 | cmd = req->special; |
| 1090 | } |
| 1091 | |
| 1092 | /* pull a tag out of the request if we have one */ |
| 1093 | cmd->tag = req->tag; |
| 1094 | cmd->request = req; |
| 1095 | |
| 1096 | return cmd; |
| 1097 | } |
| 1098 | |
James Bottomley | 7f9a6bc | 2007-08-04 10:06:25 -0500 | [diff] [blame] | 1099 | 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] | 1100 | { |
Christoph Hellwig | 3b00315 | 2006-11-04 20:10:55 +0100 | [diff] [blame] | 1101 | struct scsi_cmnd *cmd; |
James Bottomley | 7f9a6bc | 2007-08-04 10:06:25 -0500 | [diff] [blame] | 1102 | int ret = scsi_prep_state_check(sdev, req); |
| 1103 | |
| 1104 | if (ret != BLKPREP_OK) |
| 1105 | return ret; |
Christoph Hellwig | 3b00315 | 2006-11-04 20:10:55 +0100 | [diff] [blame] | 1106 | |
| 1107 | cmd = scsi_get_cmd_from_req(sdev, req); |
| 1108 | if (unlikely(!cmd)) |
| 1109 | return BLKPREP_DEFER; |
| 1110 | |
| 1111 | /* |
| 1112 | * BLOCK_PC requests may transfer data, in which case they must |
| 1113 | * a bio attached to them. Or they might contain a SCSI command |
| 1114 | * that does not transfer data, in which case they may optionally |
| 1115 | * submit a request without an attached bio. |
| 1116 | */ |
| 1117 | if (req->bio) { |
| 1118 | int ret; |
| 1119 | |
| 1120 | BUG_ON(!req->nr_phys_segments); |
| 1121 | |
Boaz Harrosh | bb52d82 | 2007-12-13 16:14:27 -0800 | [diff] [blame] | 1122 | ret = scsi_init_io(cmd, GFP_ATOMIC); |
Christoph Hellwig | 3b00315 | 2006-11-04 20:10:55 +0100 | [diff] [blame] | 1123 | if (unlikely(ret)) |
| 1124 | return ret; |
| 1125 | } else { |
| 1126 | BUG_ON(req->data_len); |
| 1127 | BUG_ON(req->data); |
| 1128 | |
Boaz Harrosh | 30b0c37 | 2007-12-13 13:47:40 +0200 | [diff] [blame] | 1129 | memset(&cmd->sdb, 0, sizeof(cmd->sdb)); |
Christoph Hellwig | 3b00315 | 2006-11-04 20:10:55 +0100 | [diff] [blame] | 1130 | req->buffer = NULL; |
| 1131 | } |
James Bottomley | 7b16318 | 2005-12-15 20:17:02 -0600 | [diff] [blame] | 1132 | |
Alexey Dobriyan | 46c43db | 2006-10-08 15:55:55 +0400 | [diff] [blame] | 1133 | BUILD_BUG_ON(sizeof(req->cmd) > sizeof(cmd->cmnd)); |
James Bottomley | 7b16318 | 2005-12-15 20:17:02 -0600 | [diff] [blame] | 1134 | memcpy(cmd->cmnd, req->cmd, sizeof(cmd->cmnd)); |
| 1135 | cmd->cmd_len = req->cmd_len; |
| 1136 | if (!req->data_len) |
| 1137 | cmd->sc_data_direction = DMA_NONE; |
| 1138 | else if (rq_data_dir(req) == WRITE) |
| 1139 | cmd->sc_data_direction = DMA_TO_DEVICE; |
| 1140 | else |
| 1141 | cmd->sc_data_direction = DMA_FROM_DEVICE; |
| 1142 | |
| 1143 | cmd->transfersize = req->data_len; |
| 1144 | cmd->allowed = req->retries; |
| 1145 | cmd->timeout_per_command = req->timeout; |
Christoph Hellwig | 3b00315 | 2006-11-04 20:10:55 +0100 | [diff] [blame] | 1146 | return BLKPREP_OK; |
| 1147 | } |
James Bottomley | 7f9a6bc | 2007-08-04 10:06:25 -0500 | [diff] [blame] | 1148 | EXPORT_SYMBOL(scsi_setup_blk_pc_cmnd); |
Christoph Hellwig | 3b00315 | 2006-11-04 20:10:55 +0100 | [diff] [blame] | 1149 | |
| 1150 | /* |
| 1151 | * Setup a REQ_TYPE_FS command. These are simple read/write request |
| 1152 | * from filesystems that still need to be translated to SCSI CDBs from |
| 1153 | * the ULD. |
| 1154 | */ |
James Bottomley | 7f9a6bc | 2007-08-04 10:06:25 -0500 | [diff] [blame] | 1155 | int scsi_setup_fs_cmnd(struct scsi_device *sdev, struct request *req) |
Christoph Hellwig | 3b00315 | 2006-11-04 20:10:55 +0100 | [diff] [blame] | 1156 | { |
| 1157 | struct scsi_cmnd *cmd; |
James Bottomley | 7f9a6bc | 2007-08-04 10:06:25 -0500 | [diff] [blame] | 1158 | int ret = scsi_prep_state_check(sdev, req); |
Christoph Hellwig | 3b00315 | 2006-11-04 20:10:55 +0100 | [diff] [blame] | 1159 | |
James Bottomley | 7f9a6bc | 2007-08-04 10:06:25 -0500 | [diff] [blame] | 1160 | if (ret != BLKPREP_OK) |
| 1161 | return ret; |
Christoph Hellwig | 3b00315 | 2006-11-04 20:10:55 +0100 | [diff] [blame] | 1162 | /* |
| 1163 | * Filesystem requests must transfer data. |
| 1164 | */ |
| 1165 | BUG_ON(!req->nr_phys_segments); |
| 1166 | |
| 1167 | cmd = scsi_get_cmd_from_req(sdev, req); |
| 1168 | if (unlikely(!cmd)) |
| 1169 | return BLKPREP_DEFER; |
| 1170 | |
Boaz Harrosh | bb52d82 | 2007-12-13 16:14:27 -0800 | [diff] [blame] | 1171 | return scsi_init_io(cmd, GFP_ATOMIC); |
James Bottomley | 7b16318 | 2005-12-15 20:17:02 -0600 | [diff] [blame] | 1172 | } |
James Bottomley | 7f9a6bc | 2007-08-04 10:06:25 -0500 | [diff] [blame] | 1173 | EXPORT_SYMBOL(scsi_setup_fs_cmnd); |
James Bottomley | 7b16318 | 2005-12-15 20:17:02 -0600 | [diff] [blame] | 1174 | |
James Bottomley | 7f9a6bc | 2007-08-04 10:06:25 -0500 | [diff] [blame] | 1175 | int scsi_prep_state_check(struct scsi_device *sdev, struct request *req) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1176 | { |
Christoph Hellwig | 3b00315 | 2006-11-04 20:10:55 +0100 | [diff] [blame] | 1177 | int ret = BLKPREP_OK; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1178 | |
| 1179 | /* |
Christoph Hellwig | 3b00315 | 2006-11-04 20:10:55 +0100 | [diff] [blame] | 1180 | * If the device is not in running state we will reject some |
| 1181 | * or all commands. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1182 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1183 | if (unlikely(sdev->sdev_state != SDEV_RUNNING)) { |
Christoph Hellwig | 3b00315 | 2006-11-04 20:10:55 +0100 | [diff] [blame] | 1184 | switch (sdev->sdev_state) { |
| 1185 | case SDEV_OFFLINE: |
| 1186 | /* |
| 1187 | * If the device is offline we refuse to process any |
| 1188 | * commands. The device must be brought online |
| 1189 | * before trying any recovery commands. |
| 1190 | */ |
| 1191 | sdev_printk(KERN_ERR, sdev, |
| 1192 | "rejecting I/O to offline device\n"); |
| 1193 | ret = BLKPREP_KILL; |
| 1194 | break; |
| 1195 | case SDEV_DEL: |
| 1196 | /* |
| 1197 | * If the device is fully deleted, we refuse to |
| 1198 | * process any commands as well. |
| 1199 | */ |
James Bottomley | 9ccfc75 | 2005-10-02 11:45:08 -0500 | [diff] [blame] | 1200 | sdev_printk(KERN_ERR, sdev, |
| 1201 | "rejecting I/O to dead device\n"); |
Christoph Hellwig | 3b00315 | 2006-11-04 20:10:55 +0100 | [diff] [blame] | 1202 | ret = BLKPREP_KILL; |
| 1203 | break; |
| 1204 | case SDEV_QUIESCE: |
| 1205 | case SDEV_BLOCK: |
| 1206 | /* |
| 1207 | * If the devices is blocked we defer normal commands. |
| 1208 | */ |
| 1209 | if (!(req->cmd_flags & REQ_PREEMPT)) |
| 1210 | ret = BLKPREP_DEFER; |
| 1211 | break; |
| 1212 | default: |
| 1213 | /* |
| 1214 | * For any other not fully online state we only allow |
| 1215 | * special commands. In particular any user initiated |
| 1216 | * command is not allowed. |
| 1217 | */ |
| 1218 | if (!(req->cmd_flags & REQ_PREEMPT)) |
| 1219 | ret = BLKPREP_KILL; |
| 1220 | break; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1221 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1222 | } |
James Bottomley | 7f9a6bc | 2007-08-04 10:06:25 -0500 | [diff] [blame] | 1223 | return ret; |
| 1224 | } |
| 1225 | EXPORT_SYMBOL(scsi_prep_state_check); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1226 | |
James Bottomley | 7f9a6bc | 2007-08-04 10:06:25 -0500 | [diff] [blame] | 1227 | int scsi_prep_return(struct request_queue *q, struct request *req, int ret) |
| 1228 | { |
| 1229 | struct scsi_device *sdev = q->queuedata; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1230 | |
Christoph Hellwig | 3b00315 | 2006-11-04 20:10:55 +0100 | [diff] [blame] | 1231 | switch (ret) { |
| 1232 | case BLKPREP_KILL: |
| 1233 | req->errors = DID_NO_CONNECT << 16; |
James Bottomley | 7f9a6bc | 2007-08-04 10:06:25 -0500 | [diff] [blame] | 1234 | /* release the command and kill it */ |
| 1235 | if (req->special) { |
| 1236 | struct scsi_cmnd *cmd = req->special; |
| 1237 | scsi_release_buffers(cmd); |
| 1238 | scsi_put_command(cmd); |
| 1239 | req->special = NULL; |
| 1240 | } |
Christoph Hellwig | 3b00315 | 2006-11-04 20:10:55 +0100 | [diff] [blame] | 1241 | break; |
| 1242 | case BLKPREP_DEFER: |
| 1243 | /* |
| 1244 | * If we defer, the elv_next_request() returns NULL, but the |
| 1245 | * queue must be restarted, so we plug here if no returning |
| 1246 | * command will automatically do that. |
| 1247 | */ |
| 1248 | if (sdev->device_busy == 0) |
| 1249 | blk_plug_device(q); |
| 1250 | break; |
| 1251 | default: |
| 1252 | req->cmd_flags |= REQ_DONTPREP; |
| 1253 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1254 | |
Christoph Hellwig | 3b00315 | 2006-11-04 20:10:55 +0100 | [diff] [blame] | 1255 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1256 | } |
James Bottomley | 7f9a6bc | 2007-08-04 10:06:25 -0500 | [diff] [blame] | 1257 | EXPORT_SYMBOL(scsi_prep_return); |
| 1258 | |
James Bottomley | 751bf4d | 2008-01-02 11:14:30 -0600 | [diff] [blame] | 1259 | int scsi_prep_fn(struct request_queue *q, struct request *req) |
James Bottomley | 7f9a6bc | 2007-08-04 10:06:25 -0500 | [diff] [blame] | 1260 | { |
| 1261 | struct scsi_device *sdev = q->queuedata; |
| 1262 | int ret = BLKPREP_KILL; |
| 1263 | |
| 1264 | if (req->cmd_type == REQ_TYPE_BLOCK_PC) |
| 1265 | ret = scsi_setup_blk_pc_cmnd(sdev, req); |
| 1266 | return scsi_prep_return(q, req, ret); |
| 1267 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1268 | |
| 1269 | /* |
| 1270 | * scsi_dev_queue_ready: if we can send requests to sdev, return 1 else |
| 1271 | * return 0. |
| 1272 | * |
| 1273 | * Called with the queue_lock held. |
| 1274 | */ |
| 1275 | static inline int scsi_dev_queue_ready(struct request_queue *q, |
| 1276 | struct scsi_device *sdev) |
| 1277 | { |
| 1278 | if (sdev->device_busy >= sdev->queue_depth) |
| 1279 | return 0; |
| 1280 | if (sdev->device_busy == 0 && sdev->device_blocked) { |
| 1281 | /* |
| 1282 | * unblock after device_blocked iterates to zero |
| 1283 | */ |
| 1284 | if (--sdev->device_blocked == 0) { |
| 1285 | SCSI_LOG_MLQUEUE(3, |
James Bottomley | 9ccfc75 | 2005-10-02 11:45:08 -0500 | [diff] [blame] | 1286 | sdev_printk(KERN_INFO, sdev, |
| 1287 | "unblocking device at zero depth\n")); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1288 | } else { |
| 1289 | blk_plug_device(q); |
| 1290 | return 0; |
| 1291 | } |
| 1292 | } |
| 1293 | if (sdev->device_blocked) |
| 1294 | return 0; |
| 1295 | |
| 1296 | return 1; |
| 1297 | } |
| 1298 | |
| 1299 | /* |
| 1300 | * scsi_host_queue_ready: if we can send requests to shost, return 1 else |
| 1301 | * return 0. We must end up running the queue again whenever 0 is |
| 1302 | * returned, else IO can hang. |
| 1303 | * |
| 1304 | * Called with host_lock held. |
| 1305 | */ |
| 1306 | static inline int scsi_host_queue_ready(struct request_queue *q, |
| 1307 | struct Scsi_Host *shost, |
| 1308 | struct scsi_device *sdev) |
| 1309 | { |
James Bottomley | 939647e | 2005-09-18 15:05:20 -0500 | [diff] [blame] | 1310 | if (scsi_host_in_recovery(shost)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1311 | return 0; |
| 1312 | if (shost->host_busy == 0 && shost->host_blocked) { |
| 1313 | /* |
| 1314 | * unblock after host_blocked iterates to zero |
| 1315 | */ |
| 1316 | if (--shost->host_blocked == 0) { |
| 1317 | SCSI_LOG_MLQUEUE(3, |
| 1318 | printk("scsi%d unblocking host at zero depth\n", |
| 1319 | shost->host_no)); |
| 1320 | } else { |
| 1321 | blk_plug_device(q); |
| 1322 | return 0; |
| 1323 | } |
| 1324 | } |
| 1325 | if ((shost->can_queue > 0 && shost->host_busy >= shost->can_queue) || |
| 1326 | shost->host_blocked || shost->host_self_blocked) { |
| 1327 | if (list_empty(&sdev->starved_entry)) |
| 1328 | list_add_tail(&sdev->starved_entry, &shost->starved_list); |
| 1329 | return 0; |
| 1330 | } |
| 1331 | |
| 1332 | /* We're OK to process the command, so we can't be starved */ |
| 1333 | if (!list_empty(&sdev->starved_entry)) |
| 1334 | list_del_init(&sdev->starved_entry); |
| 1335 | |
| 1336 | return 1; |
| 1337 | } |
| 1338 | |
| 1339 | /* |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 1340 | * Kill a request for a dead device |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1341 | */ |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 1342 | static void scsi_kill_request(struct request *req, struct request_queue *q) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1343 | { |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 1344 | struct scsi_cmnd *cmd = req->special; |
Tejun Heo | e36e0c8 | 2006-04-11 17:27:53 +0900 | [diff] [blame] | 1345 | struct scsi_device *sdev = cmd->device; |
| 1346 | struct Scsi_Host *shost = sdev->host; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1347 | |
James Bottomley | 788ce43 | 2005-09-09 13:40:23 -0500 | [diff] [blame] | 1348 | blkdev_dequeue_request(req); |
| 1349 | |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 1350 | if (unlikely(cmd == NULL)) { |
| 1351 | printk(KERN_CRIT "impossible request in %s.\n", |
| 1352 | __FUNCTION__); |
| 1353 | BUG(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1354 | } |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 1355 | |
| 1356 | scsi_init_cmd_errh(cmd); |
| 1357 | cmd->result = DID_NO_CONNECT << 16; |
| 1358 | atomic_inc(&cmd->device->iorequest_cnt); |
Tejun Heo | e36e0c8 | 2006-04-11 17:27:53 +0900 | [diff] [blame] | 1359 | |
| 1360 | /* |
| 1361 | * SCSI request completion path will do scsi_device_unbusy(), |
| 1362 | * bump busy counts. To bump the counters, we need to dance |
| 1363 | * with the locks as normal issue path does. |
| 1364 | */ |
| 1365 | sdev->device_busy++; |
| 1366 | spin_unlock(sdev->request_queue->queue_lock); |
| 1367 | spin_lock(shost->host_lock); |
| 1368 | shost->host_busy++; |
| 1369 | spin_unlock(shost->host_lock); |
| 1370 | spin_lock(sdev->request_queue->queue_lock); |
| 1371 | |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 1372 | __scsi_done(cmd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1373 | } |
| 1374 | |
Jens Axboe | 1aea643 | 2006-01-09 16:03:03 +0100 | [diff] [blame] | 1375 | static void scsi_softirq_done(struct request *rq) |
| 1376 | { |
| 1377 | struct scsi_cmnd *cmd = rq->completion_data; |
Brian King | 8884efa | 2006-02-24 17:10:04 -0600 | [diff] [blame] | 1378 | unsigned long wait_for = (cmd->allowed + 1) * cmd->timeout_per_command; |
Jens Axboe | 1aea643 | 2006-01-09 16:03:03 +0100 | [diff] [blame] | 1379 | int disposition; |
| 1380 | |
| 1381 | INIT_LIST_HEAD(&cmd->eh_entry); |
| 1382 | |
| 1383 | disposition = scsi_decide_disposition(cmd); |
| 1384 | if (disposition != SUCCESS && |
| 1385 | time_before(cmd->jiffies_at_alloc + wait_for, jiffies)) { |
| 1386 | sdev_printk(KERN_ERR, cmd->device, |
| 1387 | "timing out command, waited %lus\n", |
| 1388 | wait_for/HZ); |
| 1389 | disposition = SUCCESS; |
| 1390 | } |
| 1391 | |
| 1392 | scsi_log_completion(cmd, disposition); |
| 1393 | |
| 1394 | switch (disposition) { |
| 1395 | case SUCCESS: |
| 1396 | scsi_finish_command(cmd); |
| 1397 | break; |
| 1398 | case NEEDS_RETRY: |
Christoph Hellwig | 596f482 | 2007-01-02 12:56:00 +0100 | [diff] [blame] | 1399 | scsi_queue_insert(cmd, SCSI_MLQUEUE_EH_RETRY); |
Jens Axboe | 1aea643 | 2006-01-09 16:03:03 +0100 | [diff] [blame] | 1400 | break; |
| 1401 | case ADD_TO_MLQUEUE: |
| 1402 | scsi_queue_insert(cmd, SCSI_MLQUEUE_DEVICE_BUSY); |
| 1403 | break; |
| 1404 | default: |
| 1405 | if (!scsi_eh_scmd_add(cmd, 0)) |
| 1406 | scsi_finish_command(cmd); |
| 1407 | } |
| 1408 | } |
| 1409 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1410 | /* |
| 1411 | * Function: scsi_request_fn() |
| 1412 | * |
| 1413 | * Purpose: Main strategy routine for SCSI. |
| 1414 | * |
| 1415 | * Arguments: q - Pointer to actual queue. |
| 1416 | * |
| 1417 | * Returns: Nothing |
| 1418 | * |
| 1419 | * Lock status: IO request lock assumed to be held when called. |
| 1420 | */ |
| 1421 | static void scsi_request_fn(struct request_queue *q) |
| 1422 | { |
| 1423 | struct scsi_device *sdev = q->queuedata; |
| 1424 | struct Scsi_Host *shost; |
| 1425 | struct scsi_cmnd *cmd; |
| 1426 | struct request *req; |
| 1427 | |
| 1428 | if (!sdev) { |
| 1429 | printk("scsi: killing requests for dead queue\n"); |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 1430 | while ((req = elv_next_request(q)) != NULL) |
| 1431 | scsi_kill_request(req, q); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1432 | return; |
| 1433 | } |
| 1434 | |
| 1435 | if(!get_device(&sdev->sdev_gendev)) |
| 1436 | /* We must be tearing the block queue down already */ |
| 1437 | return; |
| 1438 | |
| 1439 | /* |
| 1440 | * To start with, we keep looping until the queue is empty, or until |
| 1441 | * the host is no longer able to accept any more requests. |
| 1442 | */ |
| 1443 | shost = sdev->host; |
| 1444 | while (!blk_queue_plugged(q)) { |
| 1445 | int rtn; |
| 1446 | /* |
| 1447 | * get next queueable request. We do this early to make sure |
| 1448 | * that the request is fully prepared even if we cannot |
| 1449 | * accept it. |
| 1450 | */ |
| 1451 | req = elv_next_request(q); |
| 1452 | if (!req || !scsi_dev_queue_ready(q, sdev)) |
| 1453 | break; |
| 1454 | |
| 1455 | if (unlikely(!scsi_device_online(sdev))) { |
James Bottomley | 9ccfc75 | 2005-10-02 11:45:08 -0500 | [diff] [blame] | 1456 | sdev_printk(KERN_ERR, sdev, |
| 1457 | "rejecting I/O to offline device\n"); |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 1458 | scsi_kill_request(req, q); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1459 | continue; |
| 1460 | } |
| 1461 | |
| 1462 | |
| 1463 | /* |
| 1464 | * Remove the request from the request list. |
| 1465 | */ |
| 1466 | if (!(blk_queue_tagged(q) && !blk_queue_start_tag(q, req))) |
| 1467 | blkdev_dequeue_request(req); |
| 1468 | sdev->device_busy++; |
| 1469 | |
| 1470 | spin_unlock(q->queue_lock); |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 1471 | cmd = req->special; |
| 1472 | if (unlikely(cmd == NULL)) { |
| 1473 | printk(KERN_CRIT "impossible request in %s.\n" |
| 1474 | "please mail a stack trace to " |
Jens Axboe | 4aff5e2 | 2006-08-10 08:44:47 +0200 | [diff] [blame] | 1475 | "linux-scsi@vger.kernel.org\n", |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 1476 | __FUNCTION__); |
Jens Axboe | 4aff5e2 | 2006-08-10 08:44:47 +0200 | [diff] [blame] | 1477 | blk_dump_rq_flags(req, "foo"); |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 1478 | BUG(); |
| 1479 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1480 | spin_lock(shost->host_lock); |
| 1481 | |
| 1482 | if (!scsi_host_queue_ready(q, shost, sdev)) |
| 1483 | goto not_ready; |
Tony Battersby | 25d7c36 | 2007-11-12 10:00:44 -0500 | [diff] [blame] | 1484 | if (scsi_target(sdev)->single_lun) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1485 | if (scsi_target(sdev)->starget_sdev_user && |
| 1486 | scsi_target(sdev)->starget_sdev_user != sdev) |
| 1487 | goto not_ready; |
| 1488 | scsi_target(sdev)->starget_sdev_user = sdev; |
| 1489 | } |
| 1490 | shost->host_busy++; |
| 1491 | |
| 1492 | /* |
| 1493 | * XXX(hch): This is rather suboptimal, scsi_dispatch_cmd will |
| 1494 | * take the lock again. |
| 1495 | */ |
| 1496 | spin_unlock_irq(shost->host_lock); |
| 1497 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1498 | /* |
| 1499 | * Finally, initialize any error handling parameters, and set up |
| 1500 | * the timers for timeouts. |
| 1501 | */ |
| 1502 | scsi_init_cmd_errh(cmd); |
| 1503 | |
| 1504 | /* |
| 1505 | * Dispatch the command to the low-level driver. |
| 1506 | */ |
| 1507 | rtn = scsi_dispatch_cmd(cmd); |
| 1508 | spin_lock_irq(q->queue_lock); |
| 1509 | if(rtn) { |
| 1510 | /* we're refusing the command; because of |
| 1511 | * the way locks get dropped, we need to |
| 1512 | * check here if plugging is required */ |
| 1513 | if(sdev->device_busy == 0) |
| 1514 | blk_plug_device(q); |
| 1515 | |
| 1516 | break; |
| 1517 | } |
| 1518 | } |
| 1519 | |
| 1520 | goto out; |
| 1521 | |
| 1522 | not_ready: |
| 1523 | spin_unlock_irq(shost->host_lock); |
| 1524 | |
| 1525 | /* |
| 1526 | * lock q, handle tag, requeue req, and decrement device_busy. We |
| 1527 | * must return with queue_lock held. |
| 1528 | * |
| 1529 | * Decrementing device_busy without checking it is OK, as all such |
| 1530 | * cases (host limits or settings) should run the queue at some |
| 1531 | * later time. |
| 1532 | */ |
| 1533 | spin_lock_irq(q->queue_lock); |
| 1534 | blk_requeue_request(q, req); |
| 1535 | sdev->device_busy--; |
| 1536 | if(sdev->device_busy == 0) |
| 1537 | blk_plug_device(q); |
| 1538 | out: |
| 1539 | /* must be careful here...if we trigger the ->remove() function |
| 1540 | * we cannot be holding the q lock */ |
| 1541 | spin_unlock_irq(q->queue_lock); |
| 1542 | put_device(&sdev->sdev_gendev); |
| 1543 | spin_lock_irq(q->queue_lock); |
| 1544 | } |
| 1545 | |
| 1546 | u64 scsi_calculate_bounce_limit(struct Scsi_Host *shost) |
| 1547 | { |
| 1548 | struct device *host_dev; |
| 1549 | u64 bounce_limit = 0xffffffff; |
| 1550 | |
| 1551 | if (shost->unchecked_isa_dma) |
| 1552 | return BLK_BOUNCE_ISA; |
| 1553 | /* |
| 1554 | * Platforms with virtual-DMA translation |
| 1555 | * hardware have no practical limit. |
| 1556 | */ |
| 1557 | if (!PCI_DMA_BUS_IS_PHYS) |
| 1558 | return BLK_BOUNCE_ANY; |
| 1559 | |
| 1560 | host_dev = scsi_get_device(shost); |
| 1561 | if (host_dev && host_dev->dma_mask) |
| 1562 | bounce_limit = *host_dev->dma_mask; |
| 1563 | |
| 1564 | return bounce_limit; |
| 1565 | } |
| 1566 | EXPORT_SYMBOL(scsi_calculate_bounce_limit); |
| 1567 | |
FUJITA Tomonori | b58d915 | 2006-11-16 19:24:10 +0900 | [diff] [blame] | 1568 | struct request_queue *__scsi_alloc_queue(struct Scsi_Host *shost, |
| 1569 | request_fn_proc *request_fn) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1570 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1571 | struct request_queue *q; |
FUJITA Tomonori | 860ac56 | 2008-02-04 22:28:05 -0800 | [diff] [blame] | 1572 | struct device *dev = shost->shost_gendev.parent; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1573 | |
FUJITA Tomonori | b58d915 | 2006-11-16 19:24:10 +0900 | [diff] [blame] | 1574 | q = blk_init_queue(request_fn, NULL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1575 | if (!q) |
| 1576 | return NULL; |
| 1577 | |
Jens Axboe | a8474ce | 2007-08-07 09:02:51 +0200 | [diff] [blame] | 1578 | /* |
| 1579 | * this limit is imposed by hardware restrictions |
| 1580 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1581 | blk_queue_max_hw_segments(q, shost->sg_tablesize); |
James Bottomley | d3f46f3 | 2008-01-15 11:11:46 -0600 | [diff] [blame] | 1582 | blk_queue_max_phys_segments(q, SCSI_MAX_SG_CHAIN_SEGMENTS); |
Jens Axboe | a8474ce | 2007-08-07 09:02:51 +0200 | [diff] [blame] | 1583 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1584 | blk_queue_max_sectors(q, shost->max_sectors); |
| 1585 | blk_queue_bounce_limit(q, scsi_calculate_bounce_limit(shost)); |
| 1586 | blk_queue_segment_boundary(q, shost->dma_boundary); |
FUJITA Tomonori | 99c84db | 2008-02-04 22:28:17 -0800 | [diff] [blame] | 1587 | dma_set_seg_boundary(dev, shost->dma_boundary); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1588 | |
FUJITA Tomonori | 860ac56 | 2008-02-04 22:28:05 -0800 | [diff] [blame] | 1589 | blk_queue_max_segment_size(q, dma_get_max_seg_size(dev)); |
| 1590 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1591 | if (!shost->use_clustering) |
| 1592 | clear_bit(QUEUE_FLAG_CLUSTER, &q->queue_flags); |
James Bottomley | 465ff31 | 2008-01-01 10:00:10 -0600 | [diff] [blame] | 1593 | |
| 1594 | /* |
| 1595 | * set a reasonable default alignment on word boundaries: the |
| 1596 | * host and device may alter it using |
| 1597 | * blk_queue_update_dma_alignment() later. |
| 1598 | */ |
| 1599 | blk_queue_dma_alignment(q, 0x03); |
| 1600 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1601 | return q; |
| 1602 | } |
FUJITA Tomonori | b58d915 | 2006-11-16 19:24:10 +0900 | [diff] [blame] | 1603 | EXPORT_SYMBOL(__scsi_alloc_queue); |
| 1604 | |
| 1605 | struct request_queue *scsi_alloc_queue(struct scsi_device *sdev) |
| 1606 | { |
| 1607 | struct request_queue *q; |
| 1608 | |
| 1609 | q = __scsi_alloc_queue(sdev->host, scsi_request_fn); |
| 1610 | if (!q) |
| 1611 | return NULL; |
| 1612 | |
| 1613 | blk_queue_prep_rq(q, scsi_prep_fn); |
FUJITA Tomonori | b58d915 | 2006-11-16 19:24:10 +0900 | [diff] [blame] | 1614 | blk_queue_softirq_done(q, scsi_softirq_done); |
| 1615 | return q; |
| 1616 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1617 | |
| 1618 | void scsi_free_queue(struct request_queue *q) |
| 1619 | { |
| 1620 | blk_cleanup_queue(q); |
| 1621 | } |
| 1622 | |
| 1623 | /* |
| 1624 | * Function: scsi_block_requests() |
| 1625 | * |
| 1626 | * Purpose: Utility function used by low-level drivers to prevent further |
| 1627 | * commands from being queued to the device. |
| 1628 | * |
| 1629 | * Arguments: shost - Host in question |
| 1630 | * |
| 1631 | * Returns: Nothing |
| 1632 | * |
| 1633 | * Lock status: No locks are assumed held. |
| 1634 | * |
| 1635 | * Notes: There is no timer nor any other means by which the requests |
| 1636 | * get unblocked other than the low-level driver calling |
| 1637 | * scsi_unblock_requests(). |
| 1638 | */ |
| 1639 | void scsi_block_requests(struct Scsi_Host *shost) |
| 1640 | { |
| 1641 | shost->host_self_blocked = 1; |
| 1642 | } |
| 1643 | EXPORT_SYMBOL(scsi_block_requests); |
| 1644 | |
| 1645 | /* |
| 1646 | * Function: scsi_unblock_requests() |
| 1647 | * |
| 1648 | * Purpose: Utility function used by low-level drivers to allow further |
| 1649 | * commands from being queued to the device. |
| 1650 | * |
| 1651 | * Arguments: shost - Host in question |
| 1652 | * |
| 1653 | * Returns: Nothing |
| 1654 | * |
| 1655 | * Lock status: No locks are assumed held. |
| 1656 | * |
| 1657 | * Notes: There is no timer nor any other means by which the requests |
| 1658 | * get unblocked other than the low-level driver calling |
| 1659 | * scsi_unblock_requests(). |
| 1660 | * |
| 1661 | * This is done as an API function so that changes to the |
| 1662 | * internals of the scsi mid-layer won't require wholesale |
| 1663 | * changes to drivers that use this feature. |
| 1664 | */ |
| 1665 | void scsi_unblock_requests(struct Scsi_Host *shost) |
| 1666 | { |
| 1667 | shost->host_self_blocked = 0; |
| 1668 | scsi_run_host_queues(shost); |
| 1669 | } |
| 1670 | EXPORT_SYMBOL(scsi_unblock_requests); |
| 1671 | |
| 1672 | int __init scsi_init_queue(void) |
| 1673 | { |
| 1674 | int i; |
| 1675 | |
Mike Christie | aa7b5cd | 2005-11-11 05:31:41 -0600 | [diff] [blame] | 1676 | scsi_io_context_cache = kmem_cache_create("scsi_io_context", |
| 1677 | sizeof(struct scsi_io_context), |
Paul Mundt | 20c2df8 | 2007-07-20 10:11:58 +0900 | [diff] [blame] | 1678 | 0, 0, NULL); |
Mike Christie | aa7b5cd | 2005-11-11 05:31:41 -0600 | [diff] [blame] | 1679 | if (!scsi_io_context_cache) { |
| 1680 | printk(KERN_ERR "SCSI: can't init scsi io context cache\n"); |
| 1681 | return -ENOMEM; |
| 1682 | } |
| 1683 | |
Boaz Harrosh | 6f9a35e | 2007-12-13 13:50:53 +0200 | [diff] [blame] | 1684 | scsi_bidi_sdb_cache = kmem_cache_create("scsi_bidi_sdb", |
| 1685 | sizeof(struct scsi_data_buffer), |
| 1686 | 0, 0, NULL); |
| 1687 | if (!scsi_bidi_sdb_cache) { |
| 1688 | printk(KERN_ERR "SCSI: can't init scsi bidi sdb cache\n"); |
FUJITA Tomonori | 3d9dd6e | 2008-01-25 23:25:14 +0900 | [diff] [blame] | 1689 | goto cleanup_io_context; |
Boaz Harrosh | 6f9a35e | 2007-12-13 13:50:53 +0200 | [diff] [blame] | 1690 | } |
| 1691 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1692 | for (i = 0; i < SG_MEMPOOL_NR; i++) { |
| 1693 | struct scsi_host_sg_pool *sgp = scsi_sg_pools + i; |
| 1694 | int size = sgp->size * sizeof(struct scatterlist); |
| 1695 | |
| 1696 | sgp->slab = kmem_cache_create(sgp->name, size, 0, |
Paul Mundt | 20c2df8 | 2007-07-20 10:11:58 +0900 | [diff] [blame] | 1697 | SLAB_HWCACHE_ALIGN, NULL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1698 | if (!sgp->slab) { |
| 1699 | printk(KERN_ERR "SCSI: can't init sg slab %s\n", |
| 1700 | sgp->name); |
FUJITA Tomonori | 3d9dd6e | 2008-01-25 23:25:14 +0900 | [diff] [blame] | 1701 | goto cleanup_bidi_sdb; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1702 | } |
| 1703 | |
Matthew Dobson | 93d2341 | 2006-03-26 01:37:50 -0800 | [diff] [blame] | 1704 | sgp->pool = mempool_create_slab_pool(SG_MEMPOOL_SIZE, |
| 1705 | sgp->slab); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1706 | if (!sgp->pool) { |
| 1707 | printk(KERN_ERR "SCSI: can't init sg mempool %s\n", |
| 1708 | sgp->name); |
FUJITA Tomonori | 3d9dd6e | 2008-01-25 23:25:14 +0900 | [diff] [blame] | 1709 | goto cleanup_bidi_sdb; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1710 | } |
| 1711 | } |
| 1712 | |
| 1713 | return 0; |
FUJITA Tomonori | 3d9dd6e | 2008-01-25 23:25:14 +0900 | [diff] [blame] | 1714 | |
| 1715 | cleanup_bidi_sdb: |
| 1716 | for (i = 0; i < SG_MEMPOOL_NR; i++) { |
| 1717 | struct scsi_host_sg_pool *sgp = scsi_sg_pools + i; |
| 1718 | if (sgp->pool) |
| 1719 | mempool_destroy(sgp->pool); |
| 1720 | if (sgp->slab) |
| 1721 | kmem_cache_destroy(sgp->slab); |
| 1722 | } |
| 1723 | kmem_cache_destroy(scsi_bidi_sdb_cache); |
| 1724 | cleanup_io_context: |
| 1725 | kmem_cache_destroy(scsi_io_context_cache); |
| 1726 | |
| 1727 | return -ENOMEM; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1728 | } |
| 1729 | |
| 1730 | void scsi_exit_queue(void) |
| 1731 | { |
| 1732 | int i; |
| 1733 | |
Mike Christie | aa7b5cd | 2005-11-11 05:31:41 -0600 | [diff] [blame] | 1734 | kmem_cache_destroy(scsi_io_context_cache); |
FUJITA Tomonori | b172b6e | 2008-01-25 23:25:13 +0900 | [diff] [blame] | 1735 | kmem_cache_destroy(scsi_bidi_sdb_cache); |
Mike Christie | aa7b5cd | 2005-11-11 05:31:41 -0600 | [diff] [blame] | 1736 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1737 | for (i = 0; i < SG_MEMPOOL_NR; i++) { |
| 1738 | struct scsi_host_sg_pool *sgp = scsi_sg_pools + i; |
| 1739 | mempool_destroy(sgp->pool); |
| 1740 | kmem_cache_destroy(sgp->slab); |
| 1741 | } |
| 1742 | } |
James Bottomley | 5baba83 | 2006-03-18 14:10:35 -0600 | [diff] [blame] | 1743 | |
| 1744 | /** |
| 1745 | * scsi_mode_select - issue a mode select |
| 1746 | * @sdev: SCSI device to be queried |
| 1747 | * @pf: Page format bit (1 == standard, 0 == vendor specific) |
| 1748 | * @sp: Save page bit (0 == don't save, 1 == save) |
| 1749 | * @modepage: mode page being requested |
| 1750 | * @buffer: request buffer (may not be smaller than eight bytes) |
| 1751 | * @len: length of request buffer. |
| 1752 | * @timeout: command timeout |
| 1753 | * @retries: number of retries before failing |
| 1754 | * @data: returns a structure abstracting the mode header data |
Rob Landley | eb44820 | 2007-11-03 13:30:39 -0500 | [diff] [blame] | 1755 | * @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] | 1756 | * must be SCSI_SENSE_BUFFERSIZE big. |
| 1757 | * |
| 1758 | * Returns zero if successful; negative error number or scsi |
| 1759 | * status on error |
| 1760 | * |
| 1761 | */ |
| 1762 | int |
| 1763 | scsi_mode_select(struct scsi_device *sdev, int pf, int sp, int modepage, |
| 1764 | unsigned char *buffer, int len, int timeout, int retries, |
| 1765 | struct scsi_mode_data *data, struct scsi_sense_hdr *sshdr) |
| 1766 | { |
| 1767 | unsigned char cmd[10]; |
| 1768 | unsigned char *real_buffer; |
| 1769 | int ret; |
| 1770 | |
| 1771 | memset(cmd, 0, sizeof(cmd)); |
| 1772 | cmd[1] = (pf ? 0x10 : 0) | (sp ? 0x01 : 0); |
| 1773 | |
| 1774 | if (sdev->use_10_for_ms) { |
| 1775 | if (len > 65535) |
| 1776 | return -EINVAL; |
| 1777 | real_buffer = kmalloc(8 + len, GFP_KERNEL); |
| 1778 | if (!real_buffer) |
| 1779 | return -ENOMEM; |
| 1780 | memcpy(real_buffer + 8, buffer, len); |
| 1781 | len += 8; |
| 1782 | real_buffer[0] = 0; |
| 1783 | real_buffer[1] = 0; |
| 1784 | real_buffer[2] = data->medium_type; |
| 1785 | real_buffer[3] = data->device_specific; |
| 1786 | real_buffer[4] = data->longlba ? 0x01 : 0; |
| 1787 | real_buffer[5] = 0; |
| 1788 | real_buffer[6] = data->block_descriptor_length >> 8; |
| 1789 | real_buffer[7] = data->block_descriptor_length; |
| 1790 | |
| 1791 | cmd[0] = MODE_SELECT_10; |
| 1792 | cmd[7] = len >> 8; |
| 1793 | cmd[8] = len; |
| 1794 | } else { |
| 1795 | if (len > 255 || data->block_descriptor_length > 255 || |
| 1796 | data->longlba) |
| 1797 | return -EINVAL; |
| 1798 | |
| 1799 | real_buffer = kmalloc(4 + len, GFP_KERNEL); |
| 1800 | if (!real_buffer) |
| 1801 | return -ENOMEM; |
| 1802 | memcpy(real_buffer + 4, buffer, len); |
| 1803 | len += 4; |
| 1804 | real_buffer[0] = 0; |
| 1805 | real_buffer[1] = data->medium_type; |
| 1806 | real_buffer[2] = data->device_specific; |
| 1807 | real_buffer[3] = data->block_descriptor_length; |
| 1808 | |
| 1809 | |
| 1810 | cmd[0] = MODE_SELECT; |
| 1811 | cmd[4] = len; |
| 1812 | } |
| 1813 | |
| 1814 | ret = scsi_execute_req(sdev, cmd, DMA_TO_DEVICE, real_buffer, len, |
| 1815 | sshdr, timeout, retries); |
| 1816 | kfree(real_buffer); |
| 1817 | return ret; |
| 1818 | } |
| 1819 | EXPORT_SYMBOL_GPL(scsi_mode_select); |
| 1820 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1821 | /** |
Rob Landley | eb44820 | 2007-11-03 13:30:39 -0500 | [diff] [blame] | 1822 | * 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] | 1823 | * @sdev: SCSI device to be queried |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1824 | * @dbd: set if mode sense will allow block descriptors to be returned |
| 1825 | * @modepage: mode page being requested |
| 1826 | * @buffer: request buffer (may not be smaller than eight bytes) |
| 1827 | * @len: length of request buffer. |
| 1828 | * @timeout: command timeout |
| 1829 | * @retries: number of retries before failing |
| 1830 | * @data: returns a structure abstracting the mode header data |
Rob Landley | eb44820 | 2007-11-03 13:30:39 -0500 | [diff] [blame] | 1831 | * @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] | 1832 | * must be SCSI_SENSE_BUFFERSIZE big. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1833 | * |
| 1834 | * Returns zero if unsuccessful, or the header offset (either 4 |
| 1835 | * or 8 depending on whether a six or ten byte command was |
| 1836 | * issued) if successful. |
Rob Landley | eb44820 | 2007-11-03 13:30:39 -0500 | [diff] [blame] | 1837 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1838 | int |
James Bottomley | 1cf7269 | 2005-08-28 11:27:01 -0500 | [diff] [blame] | 1839 | scsi_mode_sense(struct scsi_device *sdev, int dbd, int modepage, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1840 | unsigned char *buffer, int len, int timeout, int retries, |
James Bottomley | 5baba83 | 2006-03-18 14:10:35 -0600 | [diff] [blame] | 1841 | struct scsi_mode_data *data, struct scsi_sense_hdr *sshdr) |
| 1842 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1843 | unsigned char cmd[12]; |
| 1844 | int use_10_for_ms; |
| 1845 | int header_length; |
James Bottomley | 1cf7269 | 2005-08-28 11:27:01 -0500 | [diff] [blame] | 1846 | int result; |
James Bottomley | ea73a9f | 2005-08-28 11:33:52 -0500 | [diff] [blame] | 1847 | struct scsi_sense_hdr my_sshdr; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1848 | |
| 1849 | memset(data, 0, sizeof(*data)); |
| 1850 | memset(&cmd[0], 0, 12); |
| 1851 | cmd[1] = dbd & 0x18; /* allows DBD and LLBA bits */ |
| 1852 | cmd[2] = modepage; |
| 1853 | |
James Bottomley | ea73a9f | 2005-08-28 11:33:52 -0500 | [diff] [blame] | 1854 | /* caller might not be interested in sense, but we need it */ |
| 1855 | if (!sshdr) |
| 1856 | sshdr = &my_sshdr; |
| 1857 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1858 | retry: |
James Bottomley | 1cf7269 | 2005-08-28 11:27:01 -0500 | [diff] [blame] | 1859 | use_10_for_ms = sdev->use_10_for_ms; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1860 | |
| 1861 | if (use_10_for_ms) { |
| 1862 | if (len < 8) |
| 1863 | len = 8; |
| 1864 | |
| 1865 | cmd[0] = MODE_SENSE_10; |
| 1866 | cmd[8] = len; |
| 1867 | header_length = 8; |
| 1868 | } else { |
| 1869 | if (len < 4) |
| 1870 | len = 4; |
| 1871 | |
| 1872 | cmd[0] = MODE_SENSE; |
| 1873 | cmd[4] = len; |
| 1874 | header_length = 4; |
| 1875 | } |
| 1876 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1877 | memset(buffer, 0, len); |
| 1878 | |
James Bottomley | 1cf7269 | 2005-08-28 11:27:01 -0500 | [diff] [blame] | 1879 | result = scsi_execute_req(sdev, cmd, DMA_FROM_DEVICE, buffer, len, |
James Bottomley | ea73a9f | 2005-08-28 11:33:52 -0500 | [diff] [blame] | 1880 | sshdr, timeout, retries); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1881 | |
| 1882 | /* This code looks awful: what it's doing is making sure an |
| 1883 | * ILLEGAL REQUEST sense return identifies the actual command |
| 1884 | * byte as the problem. MODE_SENSE commands can return |
| 1885 | * ILLEGAL REQUEST if the code page isn't supported */ |
| 1886 | |
James Bottomley | 1cf7269 | 2005-08-28 11:27:01 -0500 | [diff] [blame] | 1887 | if (use_10_for_ms && !scsi_status_is_good(result) && |
| 1888 | (driver_byte(result) & DRIVER_SENSE)) { |
James Bottomley | ea73a9f | 2005-08-28 11:33:52 -0500 | [diff] [blame] | 1889 | if (scsi_sense_valid(sshdr)) { |
| 1890 | if ((sshdr->sense_key == ILLEGAL_REQUEST) && |
| 1891 | (sshdr->asc == 0x20) && (sshdr->ascq == 0)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1892 | /* |
| 1893 | * Invalid command operation code |
| 1894 | */ |
James Bottomley | 1cf7269 | 2005-08-28 11:27:01 -0500 | [diff] [blame] | 1895 | sdev->use_10_for_ms = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1896 | goto retry; |
| 1897 | } |
| 1898 | } |
| 1899 | } |
| 1900 | |
James Bottomley | 1cf7269 | 2005-08-28 11:27:01 -0500 | [diff] [blame] | 1901 | if(scsi_status_is_good(result)) { |
Al Viro | 6d73c85 | 2006-02-23 02:03:16 +0100 | [diff] [blame] | 1902 | if (unlikely(buffer[0] == 0x86 && buffer[1] == 0x0b && |
| 1903 | (modepage == 6 || modepage == 8))) { |
| 1904 | /* Initio breakage? */ |
| 1905 | header_length = 0; |
| 1906 | data->length = 13; |
| 1907 | data->medium_type = 0; |
| 1908 | data->device_specific = 0; |
| 1909 | data->longlba = 0; |
| 1910 | data->block_descriptor_length = 0; |
| 1911 | } else if(use_10_for_ms) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1912 | data->length = buffer[0]*256 + buffer[1] + 2; |
| 1913 | data->medium_type = buffer[2]; |
| 1914 | data->device_specific = buffer[3]; |
| 1915 | data->longlba = buffer[4] & 0x01; |
| 1916 | data->block_descriptor_length = buffer[6]*256 |
| 1917 | + buffer[7]; |
| 1918 | } else { |
| 1919 | data->length = buffer[0] + 1; |
| 1920 | data->medium_type = buffer[1]; |
| 1921 | data->device_specific = buffer[2]; |
| 1922 | data->block_descriptor_length = buffer[3]; |
| 1923 | } |
Al Viro | 6d73c85 | 2006-02-23 02:03:16 +0100 | [diff] [blame] | 1924 | data->header_length = header_length; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1925 | } |
| 1926 | |
James Bottomley | 1cf7269 | 2005-08-28 11:27:01 -0500 | [diff] [blame] | 1927 | return result; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1928 | } |
| 1929 | EXPORT_SYMBOL(scsi_mode_sense); |
| 1930 | |
James Bottomley | 001aac2 | 2007-12-02 19:10:40 +0200 | [diff] [blame] | 1931 | /** |
| 1932 | * scsi_test_unit_ready - test if unit is ready |
| 1933 | * @sdev: scsi device to change the state of. |
| 1934 | * @timeout: command timeout |
| 1935 | * @retries: number of retries before failing |
| 1936 | * @sshdr_external: Optional pointer to struct scsi_sense_hdr for |
| 1937 | * returning sense. Make sure that this is cleared before passing |
| 1938 | * in. |
| 1939 | * |
| 1940 | * Returns zero if unsuccessful or an error if TUR failed. For |
| 1941 | * removable media, a return of NOT_READY or UNIT_ATTENTION is |
| 1942 | * translated to success, with the ->changed flag updated. |
| 1943 | **/ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1944 | int |
James Bottomley | 001aac2 | 2007-12-02 19:10:40 +0200 | [diff] [blame] | 1945 | scsi_test_unit_ready(struct scsi_device *sdev, int timeout, int retries, |
| 1946 | struct scsi_sense_hdr *sshdr_external) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1947 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1948 | char cmd[] = { |
| 1949 | TEST_UNIT_READY, 0, 0, 0, 0, 0, |
| 1950 | }; |
James Bottomley | 001aac2 | 2007-12-02 19:10:40 +0200 | [diff] [blame] | 1951 | struct scsi_sense_hdr *sshdr; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1952 | int result; |
James Bottomley | 001aac2 | 2007-12-02 19:10:40 +0200 | [diff] [blame] | 1953 | |
| 1954 | if (!sshdr_external) |
| 1955 | sshdr = kzalloc(sizeof(*sshdr), GFP_KERNEL); |
| 1956 | else |
| 1957 | sshdr = sshdr_external; |
| 1958 | |
| 1959 | /* try to eat the UNIT_ATTENTION if there are enough retries */ |
| 1960 | do { |
| 1961 | result = scsi_execute_req(sdev, cmd, DMA_NONE, NULL, 0, sshdr, |
| 1962 | timeout, retries); |
| 1963 | } while ((driver_byte(result) & DRIVER_SENSE) && |
| 1964 | sshdr && sshdr->sense_key == UNIT_ATTENTION && |
| 1965 | --retries); |
| 1966 | |
| 1967 | if (!sshdr) |
| 1968 | /* could not allocate sense buffer, so can't process it */ |
| 1969 | return result; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1970 | |
James Bottomley | 1cf7269 | 2005-08-28 11:27:01 -0500 | [diff] [blame] | 1971 | if ((driver_byte(result) & DRIVER_SENSE) && sdev->removable) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1972 | |
James Bottomley | 001aac2 | 2007-12-02 19:10:40 +0200 | [diff] [blame] | 1973 | if ((scsi_sense_valid(sshdr)) && |
| 1974 | ((sshdr->sense_key == UNIT_ATTENTION) || |
| 1975 | (sshdr->sense_key == NOT_READY))) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1976 | sdev->changed = 1; |
James Bottomley | 1cf7269 | 2005-08-28 11:27:01 -0500 | [diff] [blame] | 1977 | result = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1978 | } |
| 1979 | } |
James Bottomley | 001aac2 | 2007-12-02 19:10:40 +0200 | [diff] [blame] | 1980 | if (!sshdr_external) |
| 1981 | kfree(sshdr); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1982 | return result; |
| 1983 | } |
| 1984 | EXPORT_SYMBOL(scsi_test_unit_ready); |
| 1985 | |
| 1986 | /** |
Rob Landley | eb44820 | 2007-11-03 13:30:39 -0500 | [diff] [blame] | 1987 | * 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] | 1988 | * @sdev: scsi device to change the state of. |
| 1989 | * @state: state to change to. |
| 1990 | * |
| 1991 | * Returns zero if unsuccessful or an error if the requested |
| 1992 | * transition is illegal. |
Rob Landley | eb44820 | 2007-11-03 13:30:39 -0500 | [diff] [blame] | 1993 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1994 | int |
| 1995 | scsi_device_set_state(struct scsi_device *sdev, enum scsi_device_state state) |
| 1996 | { |
| 1997 | enum scsi_device_state oldstate = sdev->sdev_state; |
| 1998 | |
| 1999 | if (state == oldstate) |
| 2000 | return 0; |
| 2001 | |
| 2002 | switch (state) { |
| 2003 | case SDEV_CREATED: |
| 2004 | /* There are no legal states that come back to |
| 2005 | * created. This is the manually initialised start |
| 2006 | * state */ |
| 2007 | goto illegal; |
| 2008 | |
| 2009 | case SDEV_RUNNING: |
| 2010 | switch (oldstate) { |
| 2011 | case SDEV_CREATED: |
| 2012 | case SDEV_OFFLINE: |
| 2013 | case SDEV_QUIESCE: |
| 2014 | case SDEV_BLOCK: |
| 2015 | break; |
| 2016 | default: |
| 2017 | goto illegal; |
| 2018 | } |
| 2019 | break; |
| 2020 | |
| 2021 | case SDEV_QUIESCE: |
| 2022 | switch (oldstate) { |
| 2023 | case SDEV_RUNNING: |
| 2024 | case SDEV_OFFLINE: |
| 2025 | break; |
| 2026 | default: |
| 2027 | goto illegal; |
| 2028 | } |
| 2029 | break; |
| 2030 | |
| 2031 | case SDEV_OFFLINE: |
| 2032 | switch (oldstate) { |
| 2033 | case SDEV_CREATED: |
| 2034 | case SDEV_RUNNING: |
| 2035 | case SDEV_QUIESCE: |
| 2036 | case SDEV_BLOCK: |
| 2037 | break; |
| 2038 | default: |
| 2039 | goto illegal; |
| 2040 | } |
| 2041 | break; |
| 2042 | |
| 2043 | case SDEV_BLOCK: |
| 2044 | switch (oldstate) { |
| 2045 | case SDEV_CREATED: |
| 2046 | case SDEV_RUNNING: |
| 2047 | break; |
| 2048 | default: |
| 2049 | goto illegal; |
| 2050 | } |
| 2051 | break; |
| 2052 | |
| 2053 | case SDEV_CANCEL: |
| 2054 | switch (oldstate) { |
| 2055 | case SDEV_CREATED: |
| 2056 | case SDEV_RUNNING: |
Alan Stern | 9ea7290 | 2006-06-23 14:25:34 -0400 | [diff] [blame] | 2057 | case SDEV_QUIESCE: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2058 | case SDEV_OFFLINE: |
| 2059 | case SDEV_BLOCK: |
| 2060 | break; |
| 2061 | default: |
| 2062 | goto illegal; |
| 2063 | } |
| 2064 | break; |
| 2065 | |
| 2066 | case SDEV_DEL: |
| 2067 | switch (oldstate) { |
Brian King | 309bd27 | 2006-06-27 11:10:43 -0500 | [diff] [blame] | 2068 | case SDEV_CREATED: |
| 2069 | case SDEV_RUNNING: |
| 2070 | case SDEV_OFFLINE: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2071 | case SDEV_CANCEL: |
| 2072 | break; |
| 2073 | default: |
| 2074 | goto illegal; |
| 2075 | } |
| 2076 | break; |
| 2077 | |
| 2078 | } |
| 2079 | sdev->sdev_state = state; |
| 2080 | return 0; |
| 2081 | |
| 2082 | illegal: |
| 2083 | SCSI_LOG_ERROR_RECOVERY(1, |
James Bottomley | 9ccfc75 | 2005-10-02 11:45:08 -0500 | [diff] [blame] | 2084 | sdev_printk(KERN_ERR, sdev, |
| 2085 | "Illegal state transition %s->%s\n", |
| 2086 | scsi_device_state_name(oldstate), |
| 2087 | scsi_device_state_name(state)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2088 | ); |
| 2089 | return -EINVAL; |
| 2090 | } |
| 2091 | EXPORT_SYMBOL(scsi_device_set_state); |
| 2092 | |
| 2093 | /** |
Jeff Garzik | a341cd0 | 2007-10-29 17:15:22 -0400 | [diff] [blame] | 2094 | * sdev_evt_emit - emit a single SCSI device uevent |
| 2095 | * @sdev: associated SCSI device |
| 2096 | * @evt: event to emit |
| 2097 | * |
| 2098 | * Send a single uevent (scsi_event) to the associated scsi_device. |
| 2099 | */ |
| 2100 | static void scsi_evt_emit(struct scsi_device *sdev, struct scsi_event *evt) |
| 2101 | { |
| 2102 | int idx = 0; |
| 2103 | char *envp[3]; |
| 2104 | |
| 2105 | switch (evt->evt_type) { |
| 2106 | case SDEV_EVT_MEDIA_CHANGE: |
| 2107 | envp[idx++] = "SDEV_MEDIA_CHANGE=1"; |
| 2108 | break; |
| 2109 | |
| 2110 | default: |
| 2111 | /* do nothing */ |
| 2112 | break; |
| 2113 | } |
| 2114 | |
| 2115 | envp[idx++] = NULL; |
| 2116 | |
| 2117 | kobject_uevent_env(&sdev->sdev_gendev.kobj, KOBJ_CHANGE, envp); |
| 2118 | } |
| 2119 | |
| 2120 | /** |
| 2121 | * sdev_evt_thread - send a uevent for each scsi event |
| 2122 | * @work: work struct for scsi_device |
| 2123 | * |
| 2124 | * Dispatch queued events to their associated scsi_device kobjects |
| 2125 | * as uevents. |
| 2126 | */ |
| 2127 | void scsi_evt_thread(struct work_struct *work) |
| 2128 | { |
| 2129 | struct scsi_device *sdev; |
| 2130 | LIST_HEAD(event_list); |
| 2131 | |
| 2132 | sdev = container_of(work, struct scsi_device, event_work); |
| 2133 | |
| 2134 | while (1) { |
| 2135 | struct scsi_event *evt; |
| 2136 | struct list_head *this, *tmp; |
| 2137 | unsigned long flags; |
| 2138 | |
| 2139 | spin_lock_irqsave(&sdev->list_lock, flags); |
| 2140 | list_splice_init(&sdev->event_list, &event_list); |
| 2141 | spin_unlock_irqrestore(&sdev->list_lock, flags); |
| 2142 | |
| 2143 | if (list_empty(&event_list)) |
| 2144 | break; |
| 2145 | |
| 2146 | list_for_each_safe(this, tmp, &event_list) { |
| 2147 | evt = list_entry(this, struct scsi_event, node); |
| 2148 | list_del(&evt->node); |
| 2149 | scsi_evt_emit(sdev, evt); |
| 2150 | kfree(evt); |
| 2151 | } |
| 2152 | } |
| 2153 | } |
| 2154 | |
| 2155 | /** |
| 2156 | * sdev_evt_send - send asserted event to uevent thread |
| 2157 | * @sdev: scsi_device event occurred on |
| 2158 | * @evt: event to send |
| 2159 | * |
| 2160 | * Assert scsi device event asynchronously. |
| 2161 | */ |
| 2162 | void sdev_evt_send(struct scsi_device *sdev, struct scsi_event *evt) |
| 2163 | { |
| 2164 | unsigned long flags; |
| 2165 | |
| 2166 | if (!test_bit(evt->evt_type, sdev->supported_events)) { |
| 2167 | kfree(evt); |
| 2168 | return; |
| 2169 | } |
| 2170 | |
| 2171 | spin_lock_irqsave(&sdev->list_lock, flags); |
| 2172 | list_add_tail(&evt->node, &sdev->event_list); |
| 2173 | schedule_work(&sdev->event_work); |
| 2174 | spin_unlock_irqrestore(&sdev->list_lock, flags); |
| 2175 | } |
| 2176 | EXPORT_SYMBOL_GPL(sdev_evt_send); |
| 2177 | |
| 2178 | /** |
| 2179 | * sdev_evt_alloc - allocate a new scsi event |
| 2180 | * @evt_type: type of event to allocate |
| 2181 | * @gfpflags: GFP flags for allocation |
| 2182 | * |
| 2183 | * Allocates and returns a new scsi_event. |
| 2184 | */ |
| 2185 | struct scsi_event *sdev_evt_alloc(enum scsi_device_event evt_type, |
| 2186 | gfp_t gfpflags) |
| 2187 | { |
| 2188 | struct scsi_event *evt = kzalloc(sizeof(struct scsi_event), gfpflags); |
| 2189 | if (!evt) |
| 2190 | return NULL; |
| 2191 | |
| 2192 | evt->evt_type = evt_type; |
| 2193 | INIT_LIST_HEAD(&evt->node); |
| 2194 | |
| 2195 | /* evt_type-specific initialization, if any */ |
| 2196 | switch (evt_type) { |
| 2197 | case SDEV_EVT_MEDIA_CHANGE: |
| 2198 | default: |
| 2199 | /* do nothing */ |
| 2200 | break; |
| 2201 | } |
| 2202 | |
| 2203 | return evt; |
| 2204 | } |
| 2205 | EXPORT_SYMBOL_GPL(sdev_evt_alloc); |
| 2206 | |
| 2207 | /** |
| 2208 | * sdev_evt_send_simple - send asserted event to uevent thread |
| 2209 | * @sdev: scsi_device event occurred on |
| 2210 | * @evt_type: type of event to send |
| 2211 | * @gfpflags: GFP flags for allocation |
| 2212 | * |
| 2213 | * Assert scsi device event asynchronously, given an event type. |
| 2214 | */ |
| 2215 | void sdev_evt_send_simple(struct scsi_device *sdev, |
| 2216 | enum scsi_device_event evt_type, gfp_t gfpflags) |
| 2217 | { |
| 2218 | struct scsi_event *evt = sdev_evt_alloc(evt_type, gfpflags); |
| 2219 | if (!evt) { |
| 2220 | sdev_printk(KERN_ERR, sdev, "event %d eaten due to OOM\n", |
| 2221 | evt_type); |
| 2222 | return; |
| 2223 | } |
| 2224 | |
| 2225 | sdev_evt_send(sdev, evt); |
| 2226 | } |
| 2227 | EXPORT_SYMBOL_GPL(sdev_evt_send_simple); |
| 2228 | |
| 2229 | /** |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2230 | * scsi_device_quiesce - Block user issued commands. |
| 2231 | * @sdev: scsi device to quiesce. |
| 2232 | * |
| 2233 | * This works by trying to transition to the SDEV_QUIESCE state |
| 2234 | * (which must be a legal transition). When the device is in this |
| 2235 | * state, only special requests will be accepted, all others will |
| 2236 | * be deferred. Since special requests may also be requeued requests, |
| 2237 | * a successful return doesn't guarantee the device will be |
| 2238 | * totally quiescent. |
| 2239 | * |
| 2240 | * Must be called with user context, may sleep. |
| 2241 | * |
| 2242 | * Returns zero if unsuccessful or an error if not. |
Rob Landley | eb44820 | 2007-11-03 13:30:39 -0500 | [diff] [blame] | 2243 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2244 | int |
| 2245 | scsi_device_quiesce(struct scsi_device *sdev) |
| 2246 | { |
| 2247 | int err = scsi_device_set_state(sdev, SDEV_QUIESCE); |
| 2248 | if (err) |
| 2249 | return err; |
| 2250 | |
| 2251 | scsi_run_queue(sdev->request_queue); |
| 2252 | while (sdev->device_busy) { |
| 2253 | msleep_interruptible(200); |
| 2254 | scsi_run_queue(sdev->request_queue); |
| 2255 | } |
| 2256 | return 0; |
| 2257 | } |
| 2258 | EXPORT_SYMBOL(scsi_device_quiesce); |
| 2259 | |
| 2260 | /** |
| 2261 | * scsi_device_resume - Restart user issued commands to a quiesced device. |
| 2262 | * @sdev: scsi device to resume. |
| 2263 | * |
| 2264 | * Moves the device from quiesced back to running and restarts the |
| 2265 | * queues. |
| 2266 | * |
| 2267 | * Must be called with user context, may sleep. |
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 | void |
| 2270 | scsi_device_resume(struct scsi_device *sdev) |
| 2271 | { |
| 2272 | if(scsi_device_set_state(sdev, SDEV_RUNNING)) |
| 2273 | return; |
| 2274 | scsi_run_queue(sdev->request_queue); |
| 2275 | } |
| 2276 | EXPORT_SYMBOL(scsi_device_resume); |
| 2277 | |
| 2278 | static void |
| 2279 | device_quiesce_fn(struct scsi_device *sdev, void *data) |
| 2280 | { |
| 2281 | scsi_device_quiesce(sdev); |
| 2282 | } |
| 2283 | |
| 2284 | void |
| 2285 | scsi_target_quiesce(struct scsi_target *starget) |
| 2286 | { |
| 2287 | starget_for_each_device(starget, NULL, device_quiesce_fn); |
| 2288 | } |
| 2289 | EXPORT_SYMBOL(scsi_target_quiesce); |
| 2290 | |
| 2291 | static void |
| 2292 | device_resume_fn(struct scsi_device *sdev, void *data) |
| 2293 | { |
| 2294 | scsi_device_resume(sdev); |
| 2295 | } |
| 2296 | |
| 2297 | void |
| 2298 | scsi_target_resume(struct scsi_target *starget) |
| 2299 | { |
| 2300 | starget_for_each_device(starget, NULL, device_resume_fn); |
| 2301 | } |
| 2302 | EXPORT_SYMBOL(scsi_target_resume); |
| 2303 | |
| 2304 | /** |
Rob Landley | eb44820 | 2007-11-03 13:30:39 -0500 | [diff] [blame] | 2305 | * 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] | 2306 | * @sdev: device to block |
| 2307 | * |
| 2308 | * Block request made by scsi lld's to temporarily stop all |
| 2309 | * scsi commands on the specified device. Called from interrupt |
| 2310 | * or normal process context. |
| 2311 | * |
| 2312 | * Returns zero if successful or error if not |
| 2313 | * |
| 2314 | * Notes: |
| 2315 | * This routine transitions the device to the SDEV_BLOCK state |
| 2316 | * (which must be a legal transition). When the device is in this |
| 2317 | * state, all commands are deferred until the scsi lld reenables |
| 2318 | * the device with scsi_device_unblock or device_block_tmo fires. |
| 2319 | * This routine assumes the host_lock is held on entry. |
Rob Landley | eb44820 | 2007-11-03 13:30:39 -0500 | [diff] [blame] | 2320 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2321 | int |
| 2322 | scsi_internal_device_block(struct scsi_device *sdev) |
| 2323 | { |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 2324 | struct request_queue *q = sdev->request_queue; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2325 | unsigned long flags; |
| 2326 | int err = 0; |
| 2327 | |
| 2328 | err = scsi_device_set_state(sdev, SDEV_BLOCK); |
| 2329 | if (err) |
| 2330 | return err; |
| 2331 | |
| 2332 | /* |
| 2333 | * The device has transitioned to SDEV_BLOCK. Stop the |
| 2334 | * block layer from calling the midlayer with this device's |
| 2335 | * request queue. |
| 2336 | */ |
| 2337 | spin_lock_irqsave(q->queue_lock, flags); |
| 2338 | blk_stop_queue(q); |
| 2339 | spin_unlock_irqrestore(q->queue_lock, flags); |
| 2340 | |
| 2341 | return 0; |
| 2342 | } |
| 2343 | EXPORT_SYMBOL_GPL(scsi_internal_device_block); |
| 2344 | |
| 2345 | /** |
| 2346 | * scsi_internal_device_unblock - resume a device after a block request |
| 2347 | * @sdev: device to resume |
| 2348 | * |
| 2349 | * Called by scsi lld's or the midlayer to restart the device queue |
| 2350 | * for the previously suspended scsi device. Called from interrupt or |
| 2351 | * normal process context. |
| 2352 | * |
| 2353 | * Returns zero if successful or error if not. |
| 2354 | * |
| 2355 | * Notes: |
| 2356 | * This routine transitions the device to the SDEV_RUNNING state |
| 2357 | * (which must be a legal transition) allowing the midlayer to |
| 2358 | * goose the queue for this device. This routine assumes the |
| 2359 | * host_lock is held upon entry. |
Rob Landley | eb44820 | 2007-11-03 13:30:39 -0500 | [diff] [blame] | 2360 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2361 | int |
| 2362 | scsi_internal_device_unblock(struct scsi_device *sdev) |
| 2363 | { |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 2364 | struct request_queue *q = sdev->request_queue; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2365 | int err; |
| 2366 | unsigned long flags; |
| 2367 | |
| 2368 | /* |
| 2369 | * Try to transition the scsi device to SDEV_RUNNING |
| 2370 | * and goose the device queue if successful. |
| 2371 | */ |
| 2372 | err = scsi_device_set_state(sdev, SDEV_RUNNING); |
| 2373 | if (err) |
| 2374 | return err; |
| 2375 | |
| 2376 | spin_lock_irqsave(q->queue_lock, flags); |
| 2377 | blk_start_queue(q); |
| 2378 | spin_unlock_irqrestore(q->queue_lock, flags); |
| 2379 | |
| 2380 | return 0; |
| 2381 | } |
| 2382 | EXPORT_SYMBOL_GPL(scsi_internal_device_unblock); |
| 2383 | |
| 2384 | static void |
| 2385 | device_block(struct scsi_device *sdev, void *data) |
| 2386 | { |
| 2387 | scsi_internal_device_block(sdev); |
| 2388 | } |
| 2389 | |
| 2390 | static int |
| 2391 | target_block(struct device *dev, void *data) |
| 2392 | { |
| 2393 | if (scsi_is_target_device(dev)) |
| 2394 | starget_for_each_device(to_scsi_target(dev), NULL, |
| 2395 | device_block); |
| 2396 | return 0; |
| 2397 | } |
| 2398 | |
| 2399 | void |
| 2400 | scsi_target_block(struct device *dev) |
| 2401 | { |
| 2402 | if (scsi_is_target_device(dev)) |
| 2403 | starget_for_each_device(to_scsi_target(dev), NULL, |
| 2404 | device_block); |
| 2405 | else |
| 2406 | device_for_each_child(dev, NULL, target_block); |
| 2407 | } |
| 2408 | EXPORT_SYMBOL_GPL(scsi_target_block); |
| 2409 | |
| 2410 | static void |
| 2411 | device_unblock(struct scsi_device *sdev, void *data) |
| 2412 | { |
| 2413 | scsi_internal_device_unblock(sdev); |
| 2414 | } |
| 2415 | |
| 2416 | static int |
| 2417 | target_unblock(struct device *dev, void *data) |
| 2418 | { |
| 2419 | if (scsi_is_target_device(dev)) |
| 2420 | starget_for_each_device(to_scsi_target(dev), NULL, |
| 2421 | device_unblock); |
| 2422 | return 0; |
| 2423 | } |
| 2424 | |
| 2425 | void |
| 2426 | scsi_target_unblock(struct device *dev) |
| 2427 | { |
| 2428 | if (scsi_is_target_device(dev)) |
| 2429 | starget_for_each_device(to_scsi_target(dev), NULL, |
| 2430 | device_unblock); |
| 2431 | else |
| 2432 | device_for_each_child(dev, NULL, target_unblock); |
| 2433 | } |
| 2434 | EXPORT_SYMBOL_GPL(scsi_target_unblock); |
Guennadi Liakhovetski | cdb8c2a | 2006-04-02 21:57:43 +0200 | [diff] [blame] | 2435 | |
| 2436 | /** |
| 2437 | * scsi_kmap_atomic_sg - find and atomically map an sg-elemnt |
Rob Landley | eb44820 | 2007-11-03 13:30:39 -0500 | [diff] [blame] | 2438 | * @sgl: scatter-gather list |
Guennadi Liakhovetski | cdb8c2a | 2006-04-02 21:57:43 +0200 | [diff] [blame] | 2439 | * @sg_count: number of segments in sg |
| 2440 | * @offset: offset in bytes into sg, on return offset into the mapped area |
| 2441 | * @len: bytes to map, on return number of bytes mapped |
| 2442 | * |
| 2443 | * Returns virtual address of the start of the mapped page |
| 2444 | */ |
Jens Axboe | c6132da | 2007-10-16 11:08:49 +0200 | [diff] [blame] | 2445 | void *scsi_kmap_atomic_sg(struct scatterlist *sgl, int sg_count, |
Guennadi Liakhovetski | cdb8c2a | 2006-04-02 21:57:43 +0200 | [diff] [blame] | 2446 | size_t *offset, size_t *len) |
| 2447 | { |
| 2448 | int i; |
| 2449 | size_t sg_len = 0, len_complete = 0; |
Jens Axboe | c6132da | 2007-10-16 11:08:49 +0200 | [diff] [blame] | 2450 | struct scatterlist *sg; |
Guennadi Liakhovetski | cdb8c2a | 2006-04-02 21:57:43 +0200 | [diff] [blame] | 2451 | struct page *page; |
| 2452 | |
Andrew Morton | 22cfefb | 2007-02-05 16:39:03 -0800 | [diff] [blame] | 2453 | WARN_ON(!irqs_disabled()); |
| 2454 | |
Jens Axboe | c6132da | 2007-10-16 11:08:49 +0200 | [diff] [blame] | 2455 | for_each_sg(sgl, sg, sg_count, i) { |
Guennadi Liakhovetski | cdb8c2a | 2006-04-02 21:57:43 +0200 | [diff] [blame] | 2456 | len_complete = sg_len; /* Complete sg-entries */ |
Jens Axboe | c6132da | 2007-10-16 11:08:49 +0200 | [diff] [blame] | 2457 | sg_len += sg->length; |
Guennadi Liakhovetski | cdb8c2a | 2006-04-02 21:57:43 +0200 | [diff] [blame] | 2458 | if (sg_len > *offset) |
| 2459 | break; |
| 2460 | } |
| 2461 | |
| 2462 | if (unlikely(i == sg_count)) { |
Andrew Morton | 169e1a2 | 2006-04-18 21:09:08 -0700 | [diff] [blame] | 2463 | printk(KERN_ERR "%s: Bytes in sg: %zu, requested offset %zu, " |
| 2464 | "elements %d\n", |
Guennadi Liakhovetski | cdb8c2a | 2006-04-02 21:57:43 +0200 | [diff] [blame] | 2465 | __FUNCTION__, sg_len, *offset, sg_count); |
| 2466 | WARN_ON(1); |
| 2467 | return NULL; |
| 2468 | } |
| 2469 | |
| 2470 | /* Offset starting from the beginning of first page in this sg-entry */ |
Jens Axboe | c6132da | 2007-10-16 11:08:49 +0200 | [diff] [blame] | 2471 | *offset = *offset - len_complete + sg->offset; |
Guennadi Liakhovetski | cdb8c2a | 2006-04-02 21:57:43 +0200 | [diff] [blame] | 2472 | |
| 2473 | /* Assumption: contiguous pages can be accessed as "page + i" */ |
Jens Axboe | 45711f1 | 2007-10-22 21:19:53 +0200 | [diff] [blame] | 2474 | page = nth_page(sg_page(sg), (*offset >> PAGE_SHIFT)); |
Guennadi Liakhovetski | cdb8c2a | 2006-04-02 21:57:43 +0200 | [diff] [blame] | 2475 | *offset &= ~PAGE_MASK; |
| 2476 | |
| 2477 | /* Bytes in this sg-entry from *offset to the end of the page */ |
| 2478 | sg_len = PAGE_SIZE - *offset; |
| 2479 | if (*len > sg_len) |
| 2480 | *len = sg_len; |
| 2481 | |
| 2482 | return kmap_atomic(page, KM_BIO_SRC_IRQ); |
| 2483 | } |
| 2484 | EXPORT_SYMBOL(scsi_kmap_atomic_sg); |
| 2485 | |
| 2486 | /** |
Rob Landley | eb44820 | 2007-11-03 13:30:39 -0500 | [diff] [blame] | 2487 | * 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] | 2488 | * @virt: virtual address to be unmapped |
| 2489 | */ |
| 2490 | void scsi_kunmap_atomic_sg(void *virt) |
| 2491 | { |
| 2492 | kunmap_atomic(virt, KM_BIO_SRC_IRQ); |
| 2493 | } |
| 2494 | EXPORT_SYMBOL(scsi_kunmap_atomic_sg); |