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 | |
Martin K. Petersen | 7027ad7 | 2008-07-17 17:08:48 -0400 | [diff] [blame] | 68 | struct kmem_cache *scsi_sdb_cache; |
Boaz Harrosh | 6f9a35e | 2007-12-13 13:50:53 +0200 | [diff] [blame] | 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 | |
James Bottomley | 4f5299a | 2009-01-02 10:42:21 -0600 | [diff] [blame] | 94 | /** |
| 95 | * __scsi_queue_insert - private queue insertion |
| 96 | * @cmd: The SCSI command being requeued |
| 97 | * @reason: The reason for the requeue |
| 98 | * @unbusy: Whether the queue should be unbusied |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 99 | * |
James Bottomley | 4f5299a | 2009-01-02 10:42:21 -0600 | [diff] [blame] | 100 | * This is a private queue insertion. The public interface |
| 101 | * scsi_queue_insert() always assumes the queue should be unbusied |
| 102 | * because it's always called before the completion. This function is |
| 103 | * for a requeue after completion, which should only occur in this |
| 104 | * file. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 105 | */ |
James Bottomley | 4f5299a | 2009-01-02 10:42:21 -0600 | [diff] [blame] | 106 | static int __scsi_queue_insert(struct scsi_cmnd *cmd, int reason, int unbusy) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 107 | { |
| 108 | struct Scsi_Host *host = cmd->device->host; |
| 109 | struct scsi_device *device = cmd->device; |
Mike Christie | f0c0a37 | 2008-08-17 15:24:38 -0500 | [diff] [blame] | 110 | struct scsi_target *starget = scsi_target(device); |
Tejun Heo | a1bf9d1 | 2005-04-24 02:08:52 -0500 | [diff] [blame] | 111 | struct request_queue *q = device->request_queue; |
| 112 | unsigned long flags; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 113 | |
| 114 | SCSI_LOG_MLQUEUE(1, |
| 115 | printk("Inserting command %p into mlqueue\n", cmd)); |
| 116 | |
| 117 | /* |
Tejun Heo | d8c37e7 | 2005-05-14 00:46:08 +0900 | [diff] [blame] | 118 | * Set the appropriate busy bit for the device/host. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 119 | * |
| 120 | * If the host/device isn't busy, assume that something actually |
| 121 | * completed, and that we should be able to queue a command now. |
| 122 | * |
| 123 | * Note that the prior mid-layer assumption that any host could |
| 124 | * always queue at least one command is now broken. The mid-layer |
| 125 | * will implement a user specifiable stall (see |
| 126 | * scsi_host.max_host_blocked and scsi_device.max_device_blocked) |
| 127 | * if a command is requeued with no other commands outstanding |
| 128 | * either for the device or for the host. |
| 129 | */ |
Mike Christie | f0c0a37 | 2008-08-17 15:24:38 -0500 | [diff] [blame] | 130 | switch (reason) { |
| 131 | case SCSI_MLQUEUE_HOST_BUSY: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 132 | host->host_blocked = host->max_host_blocked; |
Mike Christie | f0c0a37 | 2008-08-17 15:24:38 -0500 | [diff] [blame] | 133 | break; |
| 134 | case SCSI_MLQUEUE_DEVICE_BUSY: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 135 | device->device_blocked = device->max_device_blocked; |
Mike Christie | f0c0a37 | 2008-08-17 15:24:38 -0500 | [diff] [blame] | 136 | break; |
| 137 | case SCSI_MLQUEUE_TARGET_BUSY: |
| 138 | starget->target_blocked = starget->max_target_blocked; |
| 139 | break; |
| 140 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 141 | |
| 142 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 143 | * Decrement the counters, since these commands are no longer |
| 144 | * active on the host/device. |
| 145 | */ |
James Bottomley | 4f5299a | 2009-01-02 10:42:21 -0600 | [diff] [blame] | 146 | if (unbusy) |
| 147 | scsi_device_unbusy(device); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 148 | |
| 149 | /* |
Tejun Heo | a1bf9d1 | 2005-04-24 02:08:52 -0500 | [diff] [blame] | 150 | * Requeue this command. It will go before all other commands |
| 151 | * that are already in the queue. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 152 | * |
| 153 | * NOTE: there is magic here about the way the queue is plugged if |
| 154 | * we have no outstanding commands. |
| 155 | * |
Tejun Heo | a1bf9d1 | 2005-04-24 02:08:52 -0500 | [diff] [blame] | 156 | * Although we *don't* plug the queue, we call the request |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 157 | * function. The SCSI request function detects the blocked condition |
| 158 | * and plugs the queue appropriately. |
Tejun Heo | a1bf9d1 | 2005-04-24 02:08:52 -0500 | [diff] [blame] | 159 | */ |
| 160 | spin_lock_irqsave(q->queue_lock, flags); |
James Bottomley | 59897da | 2005-09-14 12:57:42 -0400 | [diff] [blame] | 161 | blk_requeue_request(q, cmd->request); |
Tejun Heo | a1bf9d1 | 2005-04-24 02:08:52 -0500 | [diff] [blame] | 162 | spin_unlock_irqrestore(q->queue_lock, flags); |
| 163 | |
| 164 | scsi_run_queue(q); |
| 165 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 166 | return 0; |
| 167 | } |
| 168 | |
James Bottomley | 4f5299a | 2009-01-02 10:42:21 -0600 | [diff] [blame] | 169 | /* |
| 170 | * Function: scsi_queue_insert() |
| 171 | * |
| 172 | * Purpose: Insert a command in the midlevel queue. |
| 173 | * |
| 174 | * Arguments: cmd - command that we are adding to queue. |
| 175 | * reason - why we are inserting command to queue. |
| 176 | * |
| 177 | * Lock status: Assumed that lock is not held upon entry. |
| 178 | * |
| 179 | * Returns: Nothing. |
| 180 | * |
| 181 | * Notes: We do this for one of two cases. Either the host is busy |
| 182 | * and it cannot accept any more commands for the time being, |
| 183 | * or the device returned QUEUE_FULL and can accept no more |
| 184 | * commands. |
| 185 | * Notes: This could be called either from an interrupt context or a |
| 186 | * normal process context. |
| 187 | */ |
| 188 | int scsi_queue_insert(struct scsi_cmnd *cmd, int reason) |
| 189 | { |
| 190 | return __scsi_queue_insert(cmd, reason, 1); |
| 191 | } |
James Bottomley | 3921603 | 2005-06-15 18:48:29 -0500 | [diff] [blame] | 192 | /** |
James Bottomley | 33aa687 | 2005-08-28 11:31:14 -0500 | [diff] [blame] | 193 | * scsi_execute - insert request and wait for the result |
James Bottomley | 3921603 | 2005-06-15 18:48:29 -0500 | [diff] [blame] | 194 | * @sdev: scsi device |
| 195 | * @cmd: scsi command |
| 196 | * @data_direction: data direction |
| 197 | * @buffer: data buffer |
| 198 | * @bufflen: len of buffer |
| 199 | * @sense: optional sense buffer |
| 200 | * @timeout: request timeout in seconds |
| 201 | * @retries: number of times to retry request |
James Bottomley | 33aa687 | 2005-08-28 11:31:14 -0500 | [diff] [blame] | 202 | * @flags: or into request flags; |
FUJITA Tomonori | f4f4e47 | 2008-12-04 14:24:39 +0900 | [diff] [blame] | 203 | * @resid: optional residual length |
James Bottomley | 3921603 | 2005-06-15 18:48:29 -0500 | [diff] [blame] | 204 | * |
Michael Opdenacker | 59c5159 | 2007-05-09 08:57:56 +0200 | [diff] [blame] | 205 | * returns the req->errors value which is the scsi_cmnd result |
James Bottomley | ea73a9f | 2005-08-28 11:33:52 -0500 | [diff] [blame] | 206 | * field. |
Rob Landley | eb44820 | 2007-11-03 13:30:39 -0500 | [diff] [blame] | 207 | */ |
James Bottomley | 33aa687 | 2005-08-28 11:31:14 -0500 | [diff] [blame] | 208 | int scsi_execute(struct scsi_device *sdev, const unsigned char *cmd, |
| 209 | int data_direction, void *buffer, unsigned bufflen, |
FUJITA Tomonori | f4f4e47 | 2008-12-04 14:24:39 +0900 | [diff] [blame] | 210 | unsigned char *sense, int timeout, int retries, int flags, |
| 211 | int *resid) |
James Bottomley | 3921603 | 2005-06-15 18:48:29 -0500 | [diff] [blame] | 212 | { |
| 213 | struct request *req; |
| 214 | int write = (data_direction == DMA_TO_DEVICE); |
| 215 | int ret = DRIVER_ERROR << 24; |
| 216 | |
| 217 | req = blk_get_request(sdev->request_queue, write, __GFP_WAIT); |
| 218 | |
| 219 | if (bufflen && blk_rq_map_kern(sdev->request_queue, req, |
| 220 | buffer, bufflen, __GFP_WAIT)) |
| 221 | goto out; |
| 222 | |
| 223 | req->cmd_len = COMMAND_SIZE(cmd[0]); |
| 224 | memcpy(req->cmd, cmd, req->cmd_len); |
| 225 | req->sense = sense; |
| 226 | req->sense_len = 0; |
Mike Christie | 17e01f2 | 2005-11-11 05:31:37 -0600 | [diff] [blame] | 227 | req->retries = retries; |
James Bottomley | 3921603 | 2005-06-15 18:48:29 -0500 | [diff] [blame] | 228 | req->timeout = timeout; |
Jens Axboe | 4aff5e2 | 2006-08-10 08:44:47 +0200 | [diff] [blame] | 229 | req->cmd_type = REQ_TYPE_BLOCK_PC; |
| 230 | req->cmd_flags |= flags | REQ_QUIET | REQ_PREEMPT; |
James Bottomley | 3921603 | 2005-06-15 18:48:29 -0500 | [diff] [blame] | 231 | |
| 232 | /* |
| 233 | * head injection *required* here otherwise quiesce won't work |
| 234 | */ |
| 235 | blk_execute_rq(req->q, NULL, req, 1); |
| 236 | |
Alan Stern | bdb2b8c | 2008-06-24 14:03:14 -0400 | [diff] [blame] | 237 | /* |
| 238 | * Some devices (USB mass-storage in particular) may transfer |
| 239 | * garbage data together with a residue indicating that the data |
| 240 | * is invalid. Prevent the garbage from being misinterpreted |
| 241 | * and prevent security leaks by zeroing out the excess data. |
| 242 | */ |
| 243 | if (unlikely(req->data_len > 0 && req->data_len <= bufflen)) |
| 244 | memset(buffer + (bufflen - req->data_len), 0, req->data_len); |
| 245 | |
FUJITA Tomonori | f4f4e47 | 2008-12-04 14:24:39 +0900 | [diff] [blame] | 246 | if (resid) |
| 247 | *resid = req->data_len; |
James Bottomley | 3921603 | 2005-06-15 18:48:29 -0500 | [diff] [blame] | 248 | ret = req->errors; |
| 249 | out: |
| 250 | blk_put_request(req); |
| 251 | |
| 252 | return ret; |
| 253 | } |
James Bottomley | 33aa687 | 2005-08-28 11:31:14 -0500 | [diff] [blame] | 254 | EXPORT_SYMBOL(scsi_execute); |
James Bottomley | 3921603 | 2005-06-15 18:48:29 -0500 | [diff] [blame] | 255 | |
James Bottomley | ea73a9f | 2005-08-28 11:33:52 -0500 | [diff] [blame] | 256 | |
| 257 | int scsi_execute_req(struct scsi_device *sdev, const unsigned char *cmd, |
| 258 | int data_direction, void *buffer, unsigned bufflen, |
FUJITA Tomonori | f4f4e47 | 2008-12-04 14:24:39 +0900 | [diff] [blame] | 259 | struct scsi_sense_hdr *sshdr, int timeout, int retries, |
| 260 | int *resid) |
James Bottomley | ea73a9f | 2005-08-28 11:33:52 -0500 | [diff] [blame] | 261 | { |
| 262 | char *sense = NULL; |
akpm@osdl.org | 1ccb48b | 2005-06-26 00:12:51 -0700 | [diff] [blame] | 263 | int result; |
| 264 | |
James Bottomley | ea73a9f | 2005-08-28 11:33:52 -0500 | [diff] [blame] | 265 | if (sshdr) { |
Jes Sorensen | 24669f75 | 2006-01-16 10:31:18 -0500 | [diff] [blame] | 266 | sense = kzalloc(SCSI_SENSE_BUFFERSIZE, GFP_NOIO); |
James Bottomley | ea73a9f | 2005-08-28 11:33:52 -0500 | [diff] [blame] | 267 | if (!sense) |
| 268 | return DRIVER_ERROR << 24; |
James Bottomley | ea73a9f | 2005-08-28 11:33:52 -0500 | [diff] [blame] | 269 | } |
akpm@osdl.org | 1ccb48b | 2005-06-26 00:12:51 -0700 | [diff] [blame] | 270 | result = scsi_execute(sdev, cmd, data_direction, buffer, bufflen, |
FUJITA Tomonori | f4f4e47 | 2008-12-04 14:24:39 +0900 | [diff] [blame] | 271 | sense, timeout, retries, 0, resid); |
James Bottomley | ea73a9f | 2005-08-28 11:33:52 -0500 | [diff] [blame] | 272 | if (sshdr) |
James Bottomley | e514385 | 2005-08-09 11:55:36 -0500 | [diff] [blame] | 273 | scsi_normalize_sense(sense, SCSI_SENSE_BUFFERSIZE, sshdr); |
James Bottomley | ea73a9f | 2005-08-28 11:33:52 -0500 | [diff] [blame] | 274 | |
| 275 | kfree(sense); |
| 276 | return result; |
| 277 | } |
| 278 | EXPORT_SYMBOL(scsi_execute_req); |
| 279 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 280 | /* |
| 281 | * Function: scsi_init_cmd_errh() |
| 282 | * |
| 283 | * Purpose: Initialize cmd fields related to error handling. |
| 284 | * |
| 285 | * Arguments: cmd - command that is ready to be queued. |
| 286 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 287 | * Notes: This function has the job of initializing a number of |
| 288 | * fields related to error handling. Typically this will |
| 289 | * be called once for each command, as required. |
| 290 | */ |
Christoph Hellwig | 631c228 | 2006-07-08 20:42:15 +0200 | [diff] [blame] | 291 | static void scsi_init_cmd_errh(struct scsi_cmnd *cmd) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 292 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 293 | cmd->serial_number = 0; |
Boaz Harrosh | 30b0c37 | 2007-12-13 13:47:40 +0200 | [diff] [blame] | 294 | scsi_set_resid(cmd, 0); |
FUJITA Tomonori | b80ca4f | 2008-01-13 15:46:13 +0900 | [diff] [blame] | 295 | memset(cmd->sense_buffer, 0, SCSI_SENSE_BUFFERSIZE); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 296 | if (cmd->cmd_len == 0) |
Boaz Harrosh | db4742d | 2008-04-30 11:27:26 +0300 | [diff] [blame] | 297 | cmd->cmd_len = scsi_command_size(cmd->cmnd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 298 | } |
| 299 | |
| 300 | void scsi_device_unbusy(struct scsi_device *sdev) |
| 301 | { |
| 302 | struct Scsi_Host *shost = sdev->host; |
Mike Christie | f0c0a37 | 2008-08-17 15:24:38 -0500 | [diff] [blame] | 303 | struct scsi_target *starget = scsi_target(sdev); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 304 | unsigned long flags; |
| 305 | |
| 306 | spin_lock_irqsave(shost->host_lock, flags); |
| 307 | shost->host_busy--; |
Mike Christie | f0c0a37 | 2008-08-17 15:24:38 -0500 | [diff] [blame] | 308 | starget->target_busy--; |
James Bottomley | 939647e | 2005-09-18 15:05:20 -0500 | [diff] [blame] | 309 | if (unlikely(scsi_host_in_recovery(shost) && |
Tejun Heo | ee7863b | 2006-05-15 20:57:20 +0900 | [diff] [blame] | 310 | (shost->host_failed || shost->host_eh_scheduled))) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 311 | scsi_eh_wakeup(shost); |
| 312 | spin_unlock(shost->host_lock); |
| 152587d | 2005-04-12 16:22:06 -0500 | [diff] [blame] | 313 | spin_lock(sdev->request_queue->queue_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 314 | sdev->device_busy--; |
| 152587d | 2005-04-12 16:22:06 -0500 | [diff] [blame] | 315 | spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 316 | } |
| 317 | |
| 318 | /* |
| 319 | * Called for single_lun devices on IO completion. Clear starget_sdev_user, |
| 320 | * and call blk_run_queue for all the scsi_devices on the target - |
| 321 | * including current_sdev first. |
| 322 | * |
| 323 | * Called with *no* scsi locks held. |
| 324 | */ |
| 325 | static void scsi_single_lun_run(struct scsi_device *current_sdev) |
| 326 | { |
| 327 | struct Scsi_Host *shost = current_sdev->host; |
| 328 | struct scsi_device *sdev, *tmp; |
| 329 | struct scsi_target *starget = scsi_target(current_sdev); |
| 330 | unsigned long flags; |
| 331 | |
| 332 | spin_lock_irqsave(shost->host_lock, flags); |
| 333 | starget->starget_sdev_user = NULL; |
| 334 | spin_unlock_irqrestore(shost->host_lock, flags); |
| 335 | |
| 336 | /* |
| 337 | * Call blk_run_queue for all LUNs on the target, starting with |
| 338 | * current_sdev. We race with others (to set starget_sdev_user), |
| 339 | * but in most cases, we will be first. Ideally, each LU on the |
| 340 | * target would get some limited time or requests on the target. |
| 341 | */ |
| 342 | blk_run_queue(current_sdev->request_queue); |
| 343 | |
| 344 | spin_lock_irqsave(shost->host_lock, flags); |
| 345 | if (starget->starget_sdev_user) |
| 346 | goto out; |
| 347 | list_for_each_entry_safe(sdev, tmp, &starget->devices, |
| 348 | same_target_siblings) { |
| 349 | if (sdev == current_sdev) |
| 350 | continue; |
| 351 | if (scsi_device_get(sdev)) |
| 352 | continue; |
| 353 | |
| 354 | spin_unlock_irqrestore(shost->host_lock, flags); |
| 355 | blk_run_queue(sdev->request_queue); |
| 356 | spin_lock_irqsave(shost->host_lock, flags); |
| 357 | |
| 358 | scsi_device_put(sdev); |
| 359 | } |
| 360 | out: |
| 361 | spin_unlock_irqrestore(shost->host_lock, flags); |
| 362 | } |
| 363 | |
Kiyoshi Ueda | 9d11251 | 2008-10-04 14:11:06 -0400 | [diff] [blame] | 364 | static inline int scsi_device_is_busy(struct scsi_device *sdev) |
| 365 | { |
| 366 | if (sdev->device_busy >= sdev->queue_depth || sdev->device_blocked) |
| 367 | return 1; |
| 368 | |
| 369 | return 0; |
| 370 | } |
| 371 | |
Mike Christie | f0c0a37 | 2008-08-17 15:24:38 -0500 | [diff] [blame] | 372 | static inline int scsi_target_is_busy(struct scsi_target *starget) |
| 373 | { |
| 374 | return ((starget->can_queue > 0 && |
| 375 | starget->target_busy >= starget->can_queue) || |
| 376 | starget->target_blocked); |
| 377 | } |
| 378 | |
Kiyoshi Ueda | 9d11251 | 2008-10-04 14:11:06 -0400 | [diff] [blame] | 379 | static inline int scsi_host_is_busy(struct Scsi_Host *shost) |
| 380 | { |
| 381 | if ((shost->can_queue > 0 && shost->host_busy >= shost->can_queue) || |
| 382 | shost->host_blocked || shost->host_self_blocked) |
| 383 | return 1; |
| 384 | |
| 385 | return 0; |
| 386 | } |
| 387 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 388 | /* |
| 389 | * Function: scsi_run_queue() |
| 390 | * |
| 391 | * Purpose: Select a proper request queue to serve next |
| 392 | * |
| 393 | * Arguments: q - last request's queue |
| 394 | * |
| 395 | * Returns: Nothing |
| 396 | * |
| 397 | * Notes: The previous command was completely finished, start |
| 398 | * a new one if possible. |
| 399 | */ |
| 400 | static void scsi_run_queue(struct request_queue *q) |
| 401 | { |
Mike Christie | 2a3a59e | 2008-11-11 13:42:35 -0600 | [diff] [blame] | 402 | struct scsi_device *sdev = q->queuedata; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 403 | struct Scsi_Host *shost = sdev->host; |
Mike Christie | 2a3a59e | 2008-11-11 13:42:35 -0600 | [diff] [blame] | 404 | LIST_HEAD(starved_list); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 405 | unsigned long flags; |
| 406 | |
Tony Battersby | 25d7c36 | 2007-11-12 10:00:44 -0500 | [diff] [blame] | 407 | if (scsi_target(sdev)->single_lun) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 408 | scsi_single_lun_run(sdev); |
| 409 | |
| 410 | spin_lock_irqsave(shost->host_lock, flags); |
Mike Christie | 2a3a59e | 2008-11-11 13:42:35 -0600 | [diff] [blame] | 411 | list_splice_init(&shost->starved_list, &starved_list); |
| 412 | |
| 413 | while (!list_empty(&starved_list)) { |
Nick Piggin | 75ad23b | 2008-04-29 14:48:33 +0200 | [diff] [blame] | 414 | int flagset; |
| 415 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 416 | /* |
| 417 | * As long as shost is accepting commands and we have |
| 418 | * starved queues, call blk_run_queue. scsi_request_fn |
| 419 | * drops the queue_lock and can add us back to the |
| 420 | * starved_list. |
| 421 | * |
| 422 | * host_lock protects the starved_list and starved_entry. |
| 423 | * scsi_request_fn must get the host_lock before checking |
| 424 | * or modifying starved_list or starved_entry. |
| 425 | */ |
Mike Christie | 2a3a59e | 2008-11-11 13:42:35 -0600 | [diff] [blame] | 426 | if (scsi_host_is_busy(shost)) |
Mike Christie | f0c0a37 | 2008-08-17 15:24:38 -0500 | [diff] [blame] | 427 | break; |
Mike Christie | f0c0a37 | 2008-08-17 15:24:38 -0500 | [diff] [blame] | 428 | |
Mike Christie | 2a3a59e | 2008-11-11 13:42:35 -0600 | [diff] [blame] | 429 | sdev = list_entry(starved_list.next, |
| 430 | struct scsi_device, starved_entry); |
| 431 | list_del_init(&sdev->starved_entry); |
Mike Christie | f0c0a37 | 2008-08-17 15:24:38 -0500 | [diff] [blame] | 432 | if (scsi_target_is_busy(scsi_target(sdev))) { |
| 433 | list_move_tail(&sdev->starved_entry, |
| 434 | &shost->starved_list); |
| 435 | continue; |
| 436 | } |
| 437 | |
Nick Piggin | 75ad23b | 2008-04-29 14:48:33 +0200 | [diff] [blame] | 438 | spin_unlock(shost->host_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 439 | |
Nick Piggin | 75ad23b | 2008-04-29 14:48:33 +0200 | [diff] [blame] | 440 | spin_lock(sdev->request_queue->queue_lock); |
| 441 | flagset = test_bit(QUEUE_FLAG_REENTER, &q->queue_flags) && |
| 442 | !test_bit(QUEUE_FLAG_REENTER, |
| 443 | &sdev->request_queue->queue_flags); |
| 444 | if (flagset) |
| 445 | queue_flag_set(QUEUE_FLAG_REENTER, sdev->request_queue); |
| 446 | __blk_run_queue(sdev->request_queue); |
| 447 | if (flagset) |
| 448 | queue_flag_clear(QUEUE_FLAG_REENTER, sdev->request_queue); |
| 449 | spin_unlock(sdev->request_queue->queue_lock); |
Andreas Herrmann | 04846f2 | 2006-08-09 17:31:16 +0200 | [diff] [blame] | 450 | |
Nick Piggin | 75ad23b | 2008-04-29 14:48:33 +0200 | [diff] [blame] | 451 | spin_lock(shost->host_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 452 | } |
Mike Christie | 2a3a59e | 2008-11-11 13:42:35 -0600 | [diff] [blame] | 453 | /* put any unprocessed entries back */ |
| 454 | list_splice(&starved_list, &shost->starved_list); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 455 | spin_unlock_irqrestore(shost->host_lock, flags); |
| 456 | |
| 457 | blk_run_queue(q); |
| 458 | } |
| 459 | |
| 460 | /* |
| 461 | * Function: scsi_requeue_command() |
| 462 | * |
| 463 | * Purpose: Handle post-processing of completed commands. |
| 464 | * |
| 465 | * Arguments: q - queue to operate on |
| 466 | * cmd - command that may need to be requeued. |
| 467 | * |
| 468 | * Returns: Nothing |
| 469 | * |
| 470 | * Notes: After command completion, there may be blocks left |
| 471 | * over which weren't finished by the previous command |
| 472 | * this can be for a number of reasons - the main one is |
| 473 | * I/O errors in the middle of the request, in which case |
| 474 | * we need to request the blocks that come after the bad |
| 475 | * sector. |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 476 | * Notes: Upon return, cmd is a stale pointer. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 477 | */ |
| 478 | static void scsi_requeue_command(struct request_queue *q, struct scsi_cmnd *cmd) |
| 479 | { |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 480 | struct request *req = cmd->request; |
Tejun Heo | 283369c | 2005-04-24 02:06:36 -0500 | [diff] [blame] | 481 | unsigned long flags; |
| 482 | |
Tejun Heo | 283369c | 2005-04-24 02:06:36 -0500 | [diff] [blame] | 483 | spin_lock_irqsave(q->queue_lock, flags); |
James Bottomley | 02bd349 | 2008-12-12 13:28:29 -0600 | [diff] [blame] | 484 | scsi_unprep_request(req); |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 485 | blk_requeue_request(q, req); |
Tejun Heo | 283369c | 2005-04-24 02:06:36 -0500 | [diff] [blame] | 486 | spin_unlock_irqrestore(q->queue_lock, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 487 | |
| 488 | scsi_run_queue(q); |
| 489 | } |
| 490 | |
| 491 | void scsi_next_command(struct scsi_cmnd *cmd) |
| 492 | { |
Linus Torvalds | 49d7bc6 | 2005-12-12 11:25:04 -0800 | [diff] [blame] | 493 | struct scsi_device *sdev = cmd->device; |
| 494 | struct request_queue *q = sdev->request_queue; |
| 495 | |
| 496 | /* need to hold a reference on the device before we let go of the cmd */ |
| 497 | get_device(&sdev->sdev_gendev); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 498 | |
| 499 | scsi_put_command(cmd); |
| 500 | scsi_run_queue(q); |
Linus Torvalds | 49d7bc6 | 2005-12-12 11:25:04 -0800 | [diff] [blame] | 501 | |
| 502 | /* ok to remove device now */ |
| 503 | put_device(&sdev->sdev_gendev); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 504 | } |
| 505 | |
| 506 | void scsi_run_host_queues(struct Scsi_Host *shost) |
| 507 | { |
| 508 | struct scsi_device *sdev; |
| 509 | |
| 510 | shost_for_each_device(sdev, shost) |
| 511 | scsi_run_queue(sdev->request_queue); |
| 512 | } |
| 513 | |
James Bottomley | 79ed242 | 2009-01-06 13:15:20 -0600 | [diff] [blame] | 514 | static void __scsi_release_buffers(struct scsi_cmnd *, int); |
| 515 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 516 | /* |
| 517 | * Function: scsi_end_request() |
| 518 | * |
| 519 | * Purpose: Post-processing of completed commands (usually invoked at end |
| 520 | * of upper level post-processing and scsi_io_completion). |
| 521 | * |
| 522 | * Arguments: cmd - command that is complete. |
Kiyoshi Ueda | 610d8b0 | 2007-12-11 17:52:09 -0500 | [diff] [blame] | 523 | * error - 0 if I/O indicates success, < 0 for I/O error. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 524 | * bytes - number of bytes of completed I/O |
| 525 | * requeue - indicates whether we should requeue leftovers. |
| 526 | * |
| 527 | * Lock status: Assumed that lock is not held upon entry. |
| 528 | * |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 529 | * Returns: cmd if requeue required, NULL otherwise. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 530 | * |
| 531 | * Notes: This is called for block device requests in order to |
| 532 | * mark some number of sectors as complete. |
| 533 | * |
| 534 | * We are guaranteeing that the request queue will be goosed |
| 535 | * at some point during this call. |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 536 | * 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] | 537 | */ |
Kiyoshi Ueda | 610d8b0 | 2007-12-11 17:52:09 -0500 | [diff] [blame] | 538 | 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] | 539 | int bytes, int requeue) |
| 540 | { |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 541 | struct request_queue *q = cmd->device->request_queue; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 542 | struct request *req = cmd->request; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 543 | |
| 544 | /* |
| 545 | * If there are blocks left over at the end, set up the command |
| 546 | * to queue the remainder of them. |
| 547 | */ |
Kiyoshi Ueda | 610d8b0 | 2007-12-11 17:52:09 -0500 | [diff] [blame] | 548 | if (blk_end_request(req, error, bytes)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 549 | int leftover = (req->hard_nr_sectors << 9); |
| 550 | |
| 551 | if (blk_pc_request(req)) |
| 552 | leftover = req->data_len; |
| 553 | |
| 554 | /* kill remainder if no retrys */ |
Mike Christie | 4a27446 | 2008-08-19 18:45:31 -0500 | [diff] [blame] | 555 | if (error && scsi_noretry_cmd(cmd)) |
Kiyoshi Ueda | 610d8b0 | 2007-12-11 17:52:09 -0500 | [diff] [blame] | 556 | blk_end_request(req, error, leftover); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 557 | else { |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 558 | if (requeue) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 559 | /* |
| 560 | * Bleah. Leftovers again. Stick the |
| 561 | * leftovers in the front of the |
| 562 | * queue, and goose the queue again. |
| 563 | */ |
James Bottomley | 79ed242 | 2009-01-06 13:15:20 -0600 | [diff] [blame] | 564 | scsi_release_buffers(cmd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 565 | scsi_requeue_command(q, cmd); |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 566 | cmd = NULL; |
| 567 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 568 | return cmd; |
| 569 | } |
| 570 | } |
| 571 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 572 | /* |
| 573 | * This will goose the queue request function at the end, so we don't |
| 574 | * need to worry about launching another command. |
| 575 | */ |
James Bottomley | 79ed242 | 2009-01-06 13:15:20 -0600 | [diff] [blame] | 576 | __scsi_release_buffers(cmd, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 577 | scsi_next_command(cmd); |
| 578 | return NULL; |
| 579 | } |
| 580 | |
Jens Axboe | a8474ce | 2007-08-07 09:02:51 +0200 | [diff] [blame] | 581 | static inline unsigned int scsi_sgtable_index(unsigned short nents) |
| 582 | { |
| 583 | unsigned int index; |
| 584 | |
James Bottomley | d3f46f3 | 2008-01-15 11:11:46 -0600 | [diff] [blame] | 585 | BUG_ON(nents > SCSI_MAX_SG_SEGMENTS); |
| 586 | |
| 587 | if (nents <= 8) |
Jens Axboe | a8474ce | 2007-08-07 09:02:51 +0200 | [diff] [blame] | 588 | index = 0; |
James Bottomley | d3f46f3 | 2008-01-15 11:11:46 -0600 | [diff] [blame] | 589 | else |
| 590 | index = get_count_order(nents) - 3; |
Jens Axboe | a8474ce | 2007-08-07 09:02:51 +0200 | [diff] [blame] | 591 | |
| 592 | return index; |
| 593 | } |
| 594 | |
Jens Axboe | 5ed7959 | 2007-11-15 09:13:11 +0100 | [diff] [blame] | 595 | static void scsi_sg_free(struct scatterlist *sgl, unsigned int nents) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 596 | { |
| 597 | struct scsi_host_sg_pool *sgp; |
Jens Axboe | 5ed7959 | 2007-11-15 09:13:11 +0100 | [diff] [blame] | 598 | |
| 599 | sgp = scsi_sg_pools + scsi_sgtable_index(nents); |
| 600 | mempool_free(sgl, sgp->pool); |
| 601 | } |
| 602 | |
| 603 | static struct scatterlist *scsi_sg_alloc(unsigned int nents, gfp_t gfp_mask) |
| 604 | { |
| 605 | struct scsi_host_sg_pool *sgp; |
| 606 | |
| 607 | sgp = scsi_sg_pools + scsi_sgtable_index(nents); |
| 608 | return mempool_alloc(sgp->pool, gfp_mask); |
| 609 | } |
| 610 | |
Boaz Harrosh | 30b0c37 | 2007-12-13 13:47:40 +0200 | [diff] [blame] | 611 | static int scsi_alloc_sgtable(struct scsi_data_buffer *sdb, int nents, |
| 612 | gfp_t gfp_mask) |
Jens Axboe | 5ed7959 | 2007-11-15 09:13:11 +0100 | [diff] [blame] | 613 | { |
| 614 | int ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 615 | |
Boaz Harrosh | 30b0c37 | 2007-12-13 13:47:40 +0200 | [diff] [blame] | 616 | BUG_ON(!nents); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 617 | |
Boaz Harrosh | 30b0c37 | 2007-12-13 13:47:40 +0200 | [diff] [blame] | 618 | ret = __sg_alloc_table(&sdb->table, nents, SCSI_MAX_SG_SEGMENTS, |
| 619 | gfp_mask, scsi_sg_alloc); |
Jens Axboe | 5ed7959 | 2007-11-15 09:13:11 +0100 | [diff] [blame] | 620 | if (unlikely(ret)) |
Boaz Harrosh | 30b0c37 | 2007-12-13 13:47:40 +0200 | [diff] [blame] | 621 | __sg_free_table(&sdb->table, SCSI_MAX_SG_SEGMENTS, |
James Bottomley | 7cedb1f | 2008-01-13 14:15:28 -0600 | [diff] [blame] | 622 | scsi_sg_free); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 623 | |
Jens Axboe | a8474ce | 2007-08-07 09:02:51 +0200 | [diff] [blame] | 624 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 625 | } |
| 626 | |
Boaz Harrosh | 30b0c37 | 2007-12-13 13:47:40 +0200 | [diff] [blame] | 627 | static void scsi_free_sgtable(struct scsi_data_buffer *sdb) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 628 | { |
Boaz Harrosh | 30b0c37 | 2007-12-13 13:47:40 +0200 | [diff] [blame] | 629 | __sg_free_table(&sdb->table, SCSI_MAX_SG_SEGMENTS, scsi_sg_free); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 630 | } |
| 631 | |
James Bottomley | 79ed242 | 2009-01-06 13:15:20 -0600 | [diff] [blame] | 632 | static void __scsi_release_buffers(struct scsi_cmnd *cmd, int do_bidi_check) |
| 633 | { |
| 634 | |
| 635 | if (cmd->sdb.table.nents) |
| 636 | scsi_free_sgtable(&cmd->sdb); |
| 637 | |
| 638 | memset(&cmd->sdb, 0, sizeof(cmd->sdb)); |
| 639 | |
| 640 | if (do_bidi_check && scsi_bidi_cmnd(cmd)) { |
| 641 | struct scsi_data_buffer *bidi_sdb = |
| 642 | cmd->request->next_rq->special; |
| 643 | scsi_free_sgtable(bidi_sdb); |
| 644 | kmem_cache_free(scsi_sdb_cache, bidi_sdb); |
| 645 | cmd->request->next_rq->special = NULL; |
| 646 | } |
| 647 | |
| 648 | if (scsi_prot_sg_count(cmd)) |
| 649 | scsi_free_sgtable(cmd->prot_sdb); |
| 650 | } |
| 651 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 652 | /* |
| 653 | * Function: scsi_release_buffers() |
| 654 | * |
| 655 | * Purpose: Completion processing for block device I/O requests. |
| 656 | * |
| 657 | * Arguments: cmd - command that we are bailing. |
| 658 | * |
| 659 | * Lock status: Assumed that no lock is held upon entry. |
| 660 | * |
| 661 | * Returns: Nothing |
| 662 | * |
| 663 | * Notes: In the event that an upper level driver rejects a |
| 664 | * command, we must release resources allocated during |
| 665 | * the __init_io() function. Primarily this would involve |
| 666 | * the scatter-gather table, and potentially any bounce |
| 667 | * buffers. |
| 668 | */ |
Boaz Harrosh | bb52d82 | 2007-12-13 16:14:27 -0800 | [diff] [blame] | 669 | void scsi_release_buffers(struct scsi_cmnd *cmd) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 670 | { |
James Bottomley | 79ed242 | 2009-01-06 13:15:20 -0600 | [diff] [blame] | 671 | __scsi_release_buffers(cmd, 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 672 | } |
Boaz Harrosh | bb52d82 | 2007-12-13 16:14:27 -0800 | [diff] [blame] | 673 | EXPORT_SYMBOL(scsi_release_buffers); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 674 | |
| 675 | /* |
Boaz Harrosh | 6f9a35e | 2007-12-13 13:50:53 +0200 | [diff] [blame] | 676 | * Bidi commands Must be complete as a whole, both sides at once. |
| 677 | * If part of the bytes were written and lld returned |
| 678 | * scsi_in()->resid and/or scsi_out()->resid this information will be left |
| 679 | * in req->data_len and req->next_rq->data_len. The upper-layer driver can |
| 680 | * decide what to do with this information. |
| 681 | */ |
Adrian Bunk | 8c5e03d | 2008-03-31 01:53:55 +0300 | [diff] [blame] | 682 | static void scsi_end_bidi_request(struct scsi_cmnd *cmd) |
Boaz Harrosh | 6f9a35e | 2007-12-13 13:50:53 +0200 | [diff] [blame] | 683 | { |
Kiyoshi Ueda | b8de163 | 2008-01-18 12:02:15 -0500 | [diff] [blame] | 684 | struct request *req = cmd->request; |
| 685 | unsigned int dlen = req->data_len; |
| 686 | unsigned int next_dlen = req->next_rq->data_len; |
| 687 | |
| 688 | req->data_len = scsi_out(cmd)->resid; |
| 689 | req->next_rq->data_len = scsi_in(cmd)->resid; |
| 690 | |
| 691 | /* The req and req->next_rq have not been completed */ |
| 692 | BUG_ON(blk_end_bidi_request(req, 0, dlen, next_dlen)); |
| 693 | |
Boaz Harrosh | 6f9a35e | 2007-12-13 13:50:53 +0200 | [diff] [blame] | 694 | scsi_release_buffers(cmd); |
| 695 | |
| 696 | /* |
| 697 | * This will goose the queue request function at the end, so we don't |
| 698 | * need to worry about launching another command. |
| 699 | */ |
| 700 | scsi_next_command(cmd); |
| 701 | } |
| 702 | |
| 703 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 704 | * Function: scsi_io_completion() |
| 705 | * |
| 706 | * Purpose: Completion processing for block device I/O requests. |
| 707 | * |
| 708 | * Arguments: cmd - command that is finished. |
| 709 | * |
| 710 | * Lock status: Assumed that no lock is held upon entry. |
| 711 | * |
| 712 | * Returns: Nothing |
| 713 | * |
| 714 | * Notes: This function is matched in terms of capabilities to |
| 715 | * the function that created the scatter-gather list. |
| 716 | * In other words, if there are no bounce buffers |
| 717 | * (the normal case for most drivers), we don't need |
| 718 | * the logic to deal with cleaning up afterwards. |
| 719 | * |
Alan Stern | b60af5b | 2008-11-03 15:56:47 -0500 | [diff] [blame] | 720 | * We must call scsi_end_request(). This will finish off |
| 721 | * the specified number of sectors. If we are done, the |
| 722 | * command block will be released and the queue function |
| 723 | * will be goosed. If we are not done then we have to |
| 724 | * figure out what to do next: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 725 | * |
Alan Stern | b60af5b | 2008-11-03 15:56:47 -0500 | [diff] [blame] | 726 | * a) We can call scsi_requeue_command(). The request |
| 727 | * will be unprepared and put back on the queue. Then |
| 728 | * a new command will be created for it. This should |
| 729 | * be used if we made forward progress, or if we want |
| 730 | * to switch from READ(10) to READ(6) for example. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 731 | * |
Alan Stern | b60af5b | 2008-11-03 15:56:47 -0500 | [diff] [blame] | 732 | * b) We can call scsi_queue_insert(). The request will |
| 733 | * be put back on the queue and retried using the same |
| 734 | * command as before, possibly after a delay. |
| 735 | * |
| 736 | * c) We can call blk_end_request() with -EIO to fail |
| 737 | * the remainder of the request. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 738 | */ |
Luben Tuikov | 03aba2f | 2006-06-23 09:39:09 -0700 | [diff] [blame] | 739 | void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 740 | { |
| 741 | int result = cmd->result; |
James Bottomley | 44ea91c | 2008-09-20 00:31:50 +0000 | [diff] [blame] | 742 | int this_count; |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 743 | struct request_queue *q = cmd->device->request_queue; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 744 | struct request *req = cmd->request; |
James Bottomley | fa8e36c | 2008-04-02 18:11:52 -0500 | [diff] [blame] | 745 | int error = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 746 | struct scsi_sense_hdr sshdr; |
| 747 | int sense_valid = 0; |
| 748 | int sense_deferred = 0; |
Alan Stern | b60af5b | 2008-11-03 15:56:47 -0500 | [diff] [blame] | 749 | enum {ACTION_FAIL, ACTION_REPREP, ACTION_RETRY, |
| 750 | ACTION_DELAYED_RETRY} action; |
| 751 | char *description = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 752 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 753 | if (result) { |
| 754 | sense_valid = scsi_command_normalize_sense(cmd, &sshdr); |
| 755 | if (sense_valid) |
| 756 | sense_deferred = scsi_sense_is_deferred(&sshdr); |
| 757 | } |
Christoph Hellwig | 631c228 | 2006-07-08 20:42:15 +0200 | [diff] [blame] | 758 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 759 | if (blk_pc_request(req)) { /* SG_IO ioctl from block level */ |
| 760 | req->errors = result; |
| 761 | if (result) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 762 | if (sense_valid && req->sense) { |
| 763 | /* |
| 764 | * SG_IO wants current and deferred errors |
| 765 | */ |
| 766 | int len = 8 + cmd->sense_buffer[7]; |
| 767 | |
| 768 | if (len > SCSI_SENSE_BUFFERSIZE) |
| 769 | len = SCSI_SENSE_BUFFERSIZE; |
| 770 | memcpy(req->sense, cmd->sense_buffer, len); |
| 771 | req->sense_len = len; |
| 772 | } |
James Bottomley | fa8e36c | 2008-04-02 18:11:52 -0500 | [diff] [blame] | 773 | if (!sense_deferred) |
| 774 | error = -EIO; |
Pete Wyckoff | b22f687 | 2007-03-13 16:53:28 -0400 | [diff] [blame] | 775 | } |
Boaz Harrosh | 6f9a35e | 2007-12-13 13:50:53 +0200 | [diff] [blame] | 776 | if (scsi_bidi_cmnd(cmd)) { |
| 777 | /* will also release_buffers */ |
| 778 | scsi_end_bidi_request(cmd); |
| 779 | return; |
| 780 | } |
Boaz Harrosh | 30b0c37 | 2007-12-13 13:47:40 +0200 | [diff] [blame] | 781 | req->data_len = scsi_get_resid(cmd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 782 | } |
| 783 | |
Boaz Harrosh | 6f9a35e | 2007-12-13 13:50:53 +0200 | [diff] [blame] | 784 | 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] | 785 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 786 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 787 | * Next deal with any sectors which we were able to correctly |
| 788 | * handle. |
| 789 | */ |
James Bottomley | d6b0c53 | 2006-07-02 10:06:28 -0500 | [diff] [blame] | 790 | SCSI_LOG_HLCOMPLETE(1, printk("%ld sectors total, " |
| 791 | "%d bytes done.\n", |
| 792 | req->nr_sectors, good_bytes)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 793 | |
James Bottomley | d6b0c53 | 2006-07-02 10:06:28 -0500 | [diff] [blame] | 794 | /* A number of bytes were successfully read. If there |
| 795 | * are leftovers and there is some kind of error |
| 796 | * (result != 0), retry the rest. |
| 797 | */ |
James Bottomley | fa8e36c | 2008-04-02 18:11:52 -0500 | [diff] [blame] | 798 | if (scsi_end_request(cmd, error, good_bytes, result == 0) == NULL) |
James Bottomley | d6b0c53 | 2006-07-02 10:06:28 -0500 | [diff] [blame] | 799 | return; |
James Bottomley | 44ea91c | 2008-09-20 00:31:50 +0000 | [diff] [blame] | 800 | this_count = blk_rq_bytes(req); |
Luben Tuikov | 03aba2f | 2006-06-23 09:39:09 -0700 | [diff] [blame] | 801 | |
Martin K. Petersen | 3e695f8 | 2009-01-04 03:04:31 -0500 | [diff] [blame] | 802 | error = -EIO; |
| 803 | |
Alan Stern | b60af5b | 2008-11-03 15:56:47 -0500 | [diff] [blame] | 804 | if (host_byte(result) == DID_RESET) { |
| 805 | /* Third party bus reset or reset for error recovery |
| 806 | * reasons. Just retry the command and see what |
| 807 | * happens. |
| 808 | */ |
| 809 | action = ACTION_RETRY; |
| 810 | } else if (sense_valid && !sense_deferred) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 811 | switch (sshdr.sense_key) { |
| 812 | case UNIT_ATTENTION: |
| 813 | if (cmd->device->removable) { |
Luben Tuikov | 03aba2f | 2006-06-23 09:39:09 -0700 | [diff] [blame] | 814 | /* Detected disc change. Set a bit |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 815 | * and quietly refuse further access. |
| 816 | */ |
| 817 | cmd->device->changed = 1; |
Alan Stern | b60af5b | 2008-11-03 15:56:47 -0500 | [diff] [blame] | 818 | description = "Media Changed"; |
| 819 | action = ACTION_FAIL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 820 | } else { |
Luben Tuikov | 03aba2f | 2006-06-23 09:39:09 -0700 | [diff] [blame] | 821 | /* Must have been a power glitch, or a |
| 822 | * bus reset. Could not have been a |
| 823 | * media change, so we just retry the |
Alan Stern | b60af5b | 2008-11-03 15:56:47 -0500 | [diff] [blame] | 824 | * command and see what happens. |
Luben Tuikov | 03aba2f | 2006-06-23 09:39:09 -0700 | [diff] [blame] | 825 | */ |
Alan Stern | b60af5b | 2008-11-03 15:56:47 -0500 | [diff] [blame] | 826 | action = ACTION_RETRY; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 827 | } |
| 828 | break; |
| 829 | case ILLEGAL_REQUEST: |
Luben Tuikov | 03aba2f | 2006-06-23 09:39:09 -0700 | [diff] [blame] | 830 | /* If we had an ILLEGAL REQUEST returned, then |
| 831 | * we may have performed an unsupported |
| 832 | * command. The only thing this should be |
| 833 | * would be a ten byte read where only a six |
| 834 | * byte read was supported. Also, on a system |
| 835 | * where READ CAPACITY failed, we may have |
| 836 | * read past the end of the disk. |
| 837 | */ |
Jens Axboe | 26a6801 | 2005-11-29 21:03:34 +0100 | [diff] [blame] | 838 | if ((cmd->device->use_10_for_rw && |
| 839 | sshdr.asc == 0x20 && sshdr.ascq == 0x00) && |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 840 | (cmd->cmnd[0] == READ_10 || |
| 841 | cmd->cmnd[0] == WRITE_10)) { |
Alan Stern | b60af5b | 2008-11-03 15:56:47 -0500 | [diff] [blame] | 842 | /* This will issue a new 6-byte command. */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 843 | cmd->device->use_10_for_rw = 0; |
Alan Stern | b60af5b | 2008-11-03 15:56:47 -0500 | [diff] [blame] | 844 | action = ACTION_REPREP; |
Martin K. Petersen | 3e695f8 | 2009-01-04 03:04:31 -0500 | [diff] [blame] | 845 | } else if (sshdr.asc == 0x10) /* DIX */ { |
| 846 | description = "Host Data Integrity Failure"; |
| 847 | action = ACTION_FAIL; |
| 848 | error = -EILSEQ; |
Alan Stern | b60af5b | 2008-11-03 15:56:47 -0500 | [diff] [blame] | 849 | } else |
| 850 | action = ACTION_FAIL; |
| 851 | break; |
Martin K. Petersen | 511e44f | 2008-07-17 04:28:33 -0400 | [diff] [blame] | 852 | case ABORTED_COMMAND: |
James Bottomley | 126c098 | 2009-02-19 21:48:54 +0000 | [diff] [blame] | 853 | action = ACTION_FAIL; |
Martin K. Petersen | 511e44f | 2008-07-17 04:28:33 -0400 | [diff] [blame] | 854 | if (sshdr.asc == 0x10) { /* DIF */ |
Martin K. Petersen | 3e695f8 | 2009-01-04 03:04:31 -0500 | [diff] [blame] | 855 | description = "Target Data Integrity Failure"; |
Martin K. Petersen | 3e695f8 | 2009-01-04 03:04:31 -0500 | [diff] [blame] | 856 | error = -EILSEQ; |
James Bottomley | 126c098 | 2009-02-19 21:48:54 +0000 | [diff] [blame] | 857 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 858 | break; |
| 859 | case NOT_READY: |
Luben Tuikov | 03aba2f | 2006-06-23 09:39:09 -0700 | [diff] [blame] | 860 | /* If the device is in the process of becoming |
James Bottomley | f3e93f7 | 2006-04-25 16:48:30 -0500 | [diff] [blame] | 861 | * ready, or has a temporary blockage, retry. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 862 | */ |
James Bottomley | f3e93f7 | 2006-04-25 16:48:30 -0500 | [diff] [blame] | 863 | if (sshdr.asc == 0x04) { |
| 864 | switch (sshdr.ascq) { |
| 865 | case 0x01: /* becoming ready */ |
| 866 | case 0x04: /* format in progress */ |
| 867 | case 0x05: /* rebuild in progress */ |
| 868 | case 0x06: /* recalculation in progress */ |
| 869 | case 0x07: /* operation in progress */ |
| 870 | case 0x08: /* Long write in progress */ |
| 871 | case 0x09: /* self test in progress */ |
Alan Stern | b60af5b | 2008-11-03 15:56:47 -0500 | [diff] [blame] | 872 | action = ACTION_DELAYED_RETRY; |
James Bottomley | f3e93f7 | 2006-04-25 16:48:30 -0500 | [diff] [blame] | 873 | break; |
Alan Stern | 3dbf6a5 | 2008-12-15 10:31:28 -0500 | [diff] [blame] | 874 | default: |
| 875 | description = "Device not ready"; |
| 876 | action = ACTION_FAIL; |
| 877 | break; |
James Bottomley | f3e93f7 | 2006-04-25 16:48:30 -0500 | [diff] [blame] | 878 | } |
Alan Stern | b60af5b | 2008-11-03 15:56:47 -0500 | [diff] [blame] | 879 | } else { |
| 880 | description = "Device not ready"; |
| 881 | action = ACTION_FAIL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 882 | } |
Alan Stern | b60af5b | 2008-11-03 15:56:47 -0500 | [diff] [blame] | 883 | break; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 884 | case VOLUME_OVERFLOW: |
Luben Tuikov | 03aba2f | 2006-06-23 09:39:09 -0700 | [diff] [blame] | 885 | /* See SSC3rXX or current. */ |
Alan Stern | b60af5b | 2008-11-03 15:56:47 -0500 | [diff] [blame] | 886 | action = ACTION_FAIL; |
| 887 | break; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 888 | default: |
Alan Stern | b60af5b | 2008-11-03 15:56:47 -0500 | [diff] [blame] | 889 | description = "Unhandled sense code"; |
| 890 | action = ACTION_FAIL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 891 | break; |
| 892 | } |
Alan Stern | b60af5b | 2008-11-03 15:56:47 -0500 | [diff] [blame] | 893 | } else { |
| 894 | description = "Unhandled error code"; |
| 895 | action = ACTION_FAIL; |
Luben Tuikov | 03aba2f | 2006-06-23 09:39:09 -0700 | [diff] [blame] | 896 | } |
Alan Stern | b60af5b | 2008-11-03 15:56:47 -0500 | [diff] [blame] | 897 | |
| 898 | switch (action) { |
| 899 | case ACTION_FAIL: |
| 900 | /* Give up and fail the remainder of the request */ |
James Bottomley | 79ed242 | 2009-01-06 13:15:20 -0600 | [diff] [blame] | 901 | scsi_release_buffers(cmd); |
Jens Axboe | 4aff5e2 | 2006-08-10 08:44:47 +0200 | [diff] [blame] | 902 | if (!(req->cmd_flags & REQ_QUIET)) { |
Alan Stern | b60af5b | 2008-11-03 15:56:47 -0500 | [diff] [blame] | 903 | if (description) |
Alan Stern | 3dbf6a5 | 2008-12-15 10:31:28 -0500 | [diff] [blame] | 904 | scmd_printk(KERN_INFO, cmd, "%s\n", |
Alan Stern | b60af5b | 2008-11-03 15:56:47 -0500 | [diff] [blame] | 905 | description); |
Martin K. Petersen | a4d04a4 | 2007-02-27 22:40:27 -0500 | [diff] [blame] | 906 | scsi_print_result(cmd); |
James Bottomley | 3173d8c | 2005-09-04 11:32:05 -0500 | [diff] [blame] | 907 | if (driver_byte(result) & DRIVER_SENSE) |
| 908 | scsi_print_sense("", cmd); |
| 909 | } |
Alan Stern | b60af5b | 2008-11-03 15:56:47 -0500 | [diff] [blame] | 910 | blk_end_request(req, -EIO, blk_rq_bytes(req)); |
| 911 | scsi_next_command(cmd); |
| 912 | break; |
| 913 | case ACTION_REPREP: |
| 914 | /* Unprep the request and put it back at the head of the queue. |
| 915 | * A new command will be prepared and issued. |
| 916 | */ |
James Bottomley | 79ed242 | 2009-01-06 13:15:20 -0600 | [diff] [blame] | 917 | scsi_release_buffers(cmd); |
Alan Stern | b60af5b | 2008-11-03 15:56:47 -0500 | [diff] [blame] | 918 | scsi_requeue_command(q, cmd); |
| 919 | break; |
| 920 | case ACTION_RETRY: |
| 921 | /* Retry the same command immediately */ |
James Bottomley | 4f5299a | 2009-01-02 10:42:21 -0600 | [diff] [blame] | 922 | __scsi_queue_insert(cmd, SCSI_MLQUEUE_EH_RETRY, 0); |
Alan Stern | b60af5b | 2008-11-03 15:56:47 -0500 | [diff] [blame] | 923 | break; |
| 924 | case ACTION_DELAYED_RETRY: |
| 925 | /* Retry the same command after a delay */ |
James Bottomley | 4f5299a | 2009-01-02 10:42:21 -0600 | [diff] [blame] | 926 | __scsi_queue_insert(cmd, SCSI_MLQUEUE_DEVICE_BUSY, 0); |
Alan Stern | b60af5b | 2008-11-03 15:56:47 -0500 | [diff] [blame] | 927 | break; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 928 | } |
| 929 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 930 | |
Boaz Harrosh | 6f9a35e | 2007-12-13 13:50:53 +0200 | [diff] [blame] | 931 | static int scsi_init_sgtable(struct request *req, struct scsi_data_buffer *sdb, |
| 932 | gfp_t gfp_mask) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 933 | { |
Boaz Harrosh | 6f9a35e | 2007-12-13 13:50:53 +0200 | [diff] [blame] | 934 | int count; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 935 | |
| 936 | /* |
Christoph Hellwig | 3b00315 | 2006-11-04 20:10:55 +0100 | [diff] [blame] | 937 | * If sg table allocation fails, requeue request later. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 938 | */ |
Boaz Harrosh | 30b0c37 | 2007-12-13 13:47:40 +0200 | [diff] [blame] | 939 | if (unlikely(scsi_alloc_sgtable(sdb, req->nr_phys_segments, |
| 940 | gfp_mask))) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 941 | return BLKPREP_DEFER; |
Alan Stern | 7c72ce8 | 2005-10-14 11:23:27 -0400 | [diff] [blame] | 942 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 943 | |
Christoph Hellwig | 3b00315 | 2006-11-04 20:10:55 +0100 | [diff] [blame] | 944 | req->buffer = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 945 | |
| 946 | /* |
| 947 | * Next, walk the list, and fill in the addresses and sizes of |
| 948 | * each segment. |
| 949 | */ |
Boaz Harrosh | 30b0c37 | 2007-12-13 13:47:40 +0200 | [diff] [blame] | 950 | count = blk_rq_map_sg(req->q, req, sdb->table.sgl); |
| 951 | BUG_ON(count > sdb->table.nents); |
| 952 | sdb->table.nents = count; |
Tejun Heo | 6b00769 | 2008-02-19 11:36:35 +0100 | [diff] [blame] | 953 | if (blk_pc_request(req)) |
| 954 | sdb->length = req->data_len; |
| 955 | else |
| 956 | sdb->length = req->nr_sectors << 9; |
Rusty Russell | 4a03d90 | 2007-11-19 11:28:48 +1100 | [diff] [blame] | 957 | return BLKPREP_OK; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 958 | } |
Boaz Harrosh | 6f9a35e | 2007-12-13 13:50:53 +0200 | [diff] [blame] | 959 | |
| 960 | /* |
| 961 | * Function: scsi_init_io() |
| 962 | * |
| 963 | * Purpose: SCSI I/O initialize function. |
| 964 | * |
| 965 | * Arguments: cmd - Command descriptor we wish to initialize |
| 966 | * |
| 967 | * Returns: 0 on success |
| 968 | * BLKPREP_DEFER if the failure is retryable |
| 969 | * BLKPREP_KILL if the failure is fatal |
| 970 | */ |
| 971 | int scsi_init_io(struct scsi_cmnd *cmd, gfp_t gfp_mask) |
| 972 | { |
| 973 | int error = scsi_init_sgtable(cmd->request, &cmd->sdb, gfp_mask); |
| 974 | if (error) |
| 975 | goto err_exit; |
| 976 | |
| 977 | if (blk_bidi_rq(cmd->request)) { |
| 978 | struct scsi_data_buffer *bidi_sdb = kmem_cache_zalloc( |
Martin K. Petersen | 6362abd | 2008-06-05 23:30:03 -0400 | [diff] [blame] | 979 | scsi_sdb_cache, GFP_ATOMIC); |
Boaz Harrosh | 6f9a35e | 2007-12-13 13:50:53 +0200 | [diff] [blame] | 980 | if (!bidi_sdb) { |
| 981 | error = BLKPREP_DEFER; |
| 982 | goto err_exit; |
| 983 | } |
| 984 | |
| 985 | cmd->request->next_rq->special = bidi_sdb; |
| 986 | error = scsi_init_sgtable(cmd->request->next_rq, bidi_sdb, |
| 987 | GFP_ATOMIC); |
| 988 | if (error) |
| 989 | goto err_exit; |
| 990 | } |
| 991 | |
Martin K. Petersen | 7027ad7 | 2008-07-17 17:08:48 -0400 | [diff] [blame] | 992 | if (blk_integrity_rq(cmd->request)) { |
| 993 | struct scsi_data_buffer *prot_sdb = cmd->prot_sdb; |
| 994 | int ivecs, count; |
| 995 | |
| 996 | BUG_ON(prot_sdb == NULL); |
| 997 | ivecs = blk_rq_count_integrity_sg(cmd->request); |
| 998 | |
| 999 | if (scsi_alloc_sgtable(prot_sdb, ivecs, gfp_mask)) { |
| 1000 | error = BLKPREP_DEFER; |
| 1001 | goto err_exit; |
| 1002 | } |
| 1003 | |
| 1004 | count = blk_rq_map_integrity_sg(cmd->request, |
| 1005 | prot_sdb->table.sgl); |
| 1006 | BUG_ON(unlikely(count > ivecs)); |
| 1007 | |
| 1008 | cmd->prot_sdb = prot_sdb; |
| 1009 | cmd->prot_sdb->table.nents = count; |
| 1010 | } |
| 1011 | |
Boaz Harrosh | 6f9a35e | 2007-12-13 13:50:53 +0200 | [diff] [blame] | 1012 | return BLKPREP_OK ; |
| 1013 | |
| 1014 | err_exit: |
| 1015 | scsi_release_buffers(cmd); |
| 1016 | if (error == BLKPREP_KILL) |
| 1017 | scsi_put_command(cmd); |
| 1018 | else /* BLKPREP_DEFER */ |
| 1019 | scsi_unprep_request(cmd->request); |
| 1020 | |
| 1021 | return error; |
| 1022 | } |
Boaz Harrosh | bb52d82 | 2007-12-13 16:14:27 -0800 | [diff] [blame] | 1023 | EXPORT_SYMBOL(scsi_init_io); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1024 | |
Christoph Hellwig | 3b00315 | 2006-11-04 20:10:55 +0100 | [diff] [blame] | 1025 | static struct scsi_cmnd *scsi_get_cmd_from_req(struct scsi_device *sdev, |
| 1026 | struct request *req) |
| 1027 | { |
| 1028 | struct scsi_cmnd *cmd; |
| 1029 | |
| 1030 | if (!req->special) { |
| 1031 | cmd = scsi_get_command(sdev, GFP_ATOMIC); |
| 1032 | if (unlikely(!cmd)) |
| 1033 | return NULL; |
| 1034 | req->special = cmd; |
| 1035 | } else { |
| 1036 | cmd = req->special; |
| 1037 | } |
| 1038 | |
| 1039 | /* pull a tag out of the request if we have one */ |
| 1040 | cmd->tag = req->tag; |
| 1041 | cmd->request = req; |
| 1042 | |
Boaz Harrosh | 64a87b2 | 2008-04-30 11:19:47 +0300 | [diff] [blame] | 1043 | cmd->cmnd = req->cmd; |
| 1044 | |
Christoph Hellwig | 3b00315 | 2006-11-04 20:10:55 +0100 | [diff] [blame] | 1045 | return cmd; |
| 1046 | } |
| 1047 | |
James Bottomley | 7f9a6bc | 2007-08-04 10:06:25 -0500 | [diff] [blame] | 1048 | 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] | 1049 | { |
Christoph Hellwig | 3b00315 | 2006-11-04 20:10:55 +0100 | [diff] [blame] | 1050 | struct scsi_cmnd *cmd; |
James Bottomley | 7f9a6bc | 2007-08-04 10:06:25 -0500 | [diff] [blame] | 1051 | int ret = scsi_prep_state_check(sdev, req); |
| 1052 | |
| 1053 | if (ret != BLKPREP_OK) |
| 1054 | return ret; |
Christoph Hellwig | 3b00315 | 2006-11-04 20:10:55 +0100 | [diff] [blame] | 1055 | |
| 1056 | cmd = scsi_get_cmd_from_req(sdev, req); |
| 1057 | if (unlikely(!cmd)) |
| 1058 | return BLKPREP_DEFER; |
| 1059 | |
| 1060 | /* |
| 1061 | * BLOCK_PC requests may transfer data, in which case they must |
| 1062 | * a bio attached to them. Or they might contain a SCSI command |
| 1063 | * that does not transfer data, in which case they may optionally |
| 1064 | * submit a request without an attached bio. |
| 1065 | */ |
| 1066 | if (req->bio) { |
| 1067 | int ret; |
| 1068 | |
| 1069 | BUG_ON(!req->nr_phys_segments); |
| 1070 | |
Boaz Harrosh | bb52d82 | 2007-12-13 16:14:27 -0800 | [diff] [blame] | 1071 | ret = scsi_init_io(cmd, GFP_ATOMIC); |
Christoph Hellwig | 3b00315 | 2006-11-04 20:10:55 +0100 | [diff] [blame] | 1072 | if (unlikely(ret)) |
| 1073 | return ret; |
| 1074 | } else { |
| 1075 | BUG_ON(req->data_len); |
| 1076 | BUG_ON(req->data); |
| 1077 | |
Boaz Harrosh | 30b0c37 | 2007-12-13 13:47:40 +0200 | [diff] [blame] | 1078 | memset(&cmd->sdb, 0, sizeof(cmd->sdb)); |
Christoph Hellwig | 3b00315 | 2006-11-04 20:10:55 +0100 | [diff] [blame] | 1079 | req->buffer = NULL; |
| 1080 | } |
James Bottomley | 7b16318 | 2005-12-15 20:17:02 -0600 | [diff] [blame] | 1081 | |
James Bottomley | 7b16318 | 2005-12-15 20:17:02 -0600 | [diff] [blame] | 1082 | cmd->cmd_len = req->cmd_len; |
| 1083 | if (!req->data_len) |
| 1084 | cmd->sc_data_direction = DMA_NONE; |
| 1085 | else if (rq_data_dir(req) == WRITE) |
| 1086 | cmd->sc_data_direction = DMA_TO_DEVICE; |
| 1087 | else |
| 1088 | cmd->sc_data_direction = DMA_FROM_DEVICE; |
| 1089 | |
| 1090 | cmd->transfersize = req->data_len; |
| 1091 | cmd->allowed = req->retries; |
Christoph Hellwig | 3b00315 | 2006-11-04 20:10:55 +0100 | [diff] [blame] | 1092 | return BLKPREP_OK; |
| 1093 | } |
James Bottomley | 7f9a6bc | 2007-08-04 10:06:25 -0500 | [diff] [blame] | 1094 | EXPORT_SYMBOL(scsi_setup_blk_pc_cmnd); |
Christoph Hellwig | 3b00315 | 2006-11-04 20:10:55 +0100 | [diff] [blame] | 1095 | |
| 1096 | /* |
| 1097 | * Setup a REQ_TYPE_FS command. These are simple read/write request |
| 1098 | * from filesystems that still need to be translated to SCSI CDBs from |
| 1099 | * the ULD. |
| 1100 | */ |
James Bottomley | 7f9a6bc | 2007-08-04 10:06:25 -0500 | [diff] [blame] | 1101 | int scsi_setup_fs_cmnd(struct scsi_device *sdev, struct request *req) |
Christoph Hellwig | 3b00315 | 2006-11-04 20:10:55 +0100 | [diff] [blame] | 1102 | { |
| 1103 | struct scsi_cmnd *cmd; |
James Bottomley | 7f9a6bc | 2007-08-04 10:06:25 -0500 | [diff] [blame] | 1104 | int ret = scsi_prep_state_check(sdev, req); |
Christoph Hellwig | 3b00315 | 2006-11-04 20:10:55 +0100 | [diff] [blame] | 1105 | |
James Bottomley | 7f9a6bc | 2007-08-04 10:06:25 -0500 | [diff] [blame] | 1106 | if (ret != BLKPREP_OK) |
| 1107 | return ret; |
Chandra Seetharaman | a6a8d9f | 2008-05-01 14:49:46 -0700 | [diff] [blame] | 1108 | |
| 1109 | if (unlikely(sdev->scsi_dh_data && sdev->scsi_dh_data->scsi_dh |
| 1110 | && sdev->scsi_dh_data->scsi_dh->prep_fn)) { |
| 1111 | ret = sdev->scsi_dh_data->scsi_dh->prep_fn(sdev, req); |
| 1112 | if (ret != BLKPREP_OK) |
| 1113 | return ret; |
| 1114 | } |
| 1115 | |
Christoph Hellwig | 3b00315 | 2006-11-04 20:10:55 +0100 | [diff] [blame] | 1116 | /* |
| 1117 | * Filesystem requests must transfer data. |
| 1118 | */ |
| 1119 | BUG_ON(!req->nr_phys_segments); |
| 1120 | |
| 1121 | cmd = scsi_get_cmd_from_req(sdev, req); |
| 1122 | if (unlikely(!cmd)) |
| 1123 | return BLKPREP_DEFER; |
| 1124 | |
Boaz Harrosh | 64a87b2 | 2008-04-30 11:19:47 +0300 | [diff] [blame] | 1125 | memset(cmd->cmnd, 0, BLK_MAX_CDB); |
Boaz Harrosh | bb52d82 | 2007-12-13 16:14:27 -0800 | [diff] [blame] | 1126 | return scsi_init_io(cmd, GFP_ATOMIC); |
James Bottomley | 7b16318 | 2005-12-15 20:17:02 -0600 | [diff] [blame] | 1127 | } |
James Bottomley | 7f9a6bc | 2007-08-04 10:06:25 -0500 | [diff] [blame] | 1128 | EXPORT_SYMBOL(scsi_setup_fs_cmnd); |
James Bottomley | 7b16318 | 2005-12-15 20:17:02 -0600 | [diff] [blame] | 1129 | |
James Bottomley | 7f9a6bc | 2007-08-04 10:06:25 -0500 | [diff] [blame] | 1130 | int scsi_prep_state_check(struct scsi_device *sdev, struct request *req) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1131 | { |
Christoph Hellwig | 3b00315 | 2006-11-04 20:10:55 +0100 | [diff] [blame] | 1132 | int ret = BLKPREP_OK; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1133 | |
| 1134 | /* |
Christoph Hellwig | 3b00315 | 2006-11-04 20:10:55 +0100 | [diff] [blame] | 1135 | * If the device is not in running state we will reject some |
| 1136 | * or all commands. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1137 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1138 | if (unlikely(sdev->sdev_state != SDEV_RUNNING)) { |
Christoph Hellwig | 3b00315 | 2006-11-04 20:10:55 +0100 | [diff] [blame] | 1139 | switch (sdev->sdev_state) { |
| 1140 | case SDEV_OFFLINE: |
| 1141 | /* |
| 1142 | * If the device is offline we refuse to process any |
| 1143 | * commands. The device must be brought online |
| 1144 | * before trying any recovery commands. |
| 1145 | */ |
| 1146 | sdev_printk(KERN_ERR, sdev, |
| 1147 | "rejecting I/O to offline device\n"); |
| 1148 | ret = BLKPREP_KILL; |
| 1149 | break; |
| 1150 | case SDEV_DEL: |
| 1151 | /* |
| 1152 | * If the device is fully deleted, we refuse to |
| 1153 | * process any commands as well. |
| 1154 | */ |
James Bottomley | 9ccfc75 | 2005-10-02 11:45:08 -0500 | [diff] [blame] | 1155 | sdev_printk(KERN_ERR, sdev, |
| 1156 | "rejecting I/O to dead device\n"); |
Christoph Hellwig | 3b00315 | 2006-11-04 20:10:55 +0100 | [diff] [blame] | 1157 | ret = BLKPREP_KILL; |
| 1158 | break; |
| 1159 | case SDEV_QUIESCE: |
| 1160 | case SDEV_BLOCK: |
James Bottomley | 6f4267e | 2008-08-22 16:53:31 -0500 | [diff] [blame] | 1161 | case SDEV_CREATED_BLOCK: |
Christoph Hellwig | 3b00315 | 2006-11-04 20:10:55 +0100 | [diff] [blame] | 1162 | /* |
| 1163 | * If the devices is blocked we defer normal commands. |
| 1164 | */ |
| 1165 | if (!(req->cmd_flags & REQ_PREEMPT)) |
| 1166 | ret = BLKPREP_DEFER; |
| 1167 | break; |
| 1168 | default: |
| 1169 | /* |
| 1170 | * For any other not fully online state we only allow |
| 1171 | * special commands. In particular any user initiated |
| 1172 | * command is not allowed. |
| 1173 | */ |
| 1174 | if (!(req->cmd_flags & REQ_PREEMPT)) |
| 1175 | ret = BLKPREP_KILL; |
| 1176 | break; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1177 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1178 | } |
James Bottomley | 7f9a6bc | 2007-08-04 10:06:25 -0500 | [diff] [blame] | 1179 | return ret; |
| 1180 | } |
| 1181 | EXPORT_SYMBOL(scsi_prep_state_check); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1182 | |
James Bottomley | 7f9a6bc | 2007-08-04 10:06:25 -0500 | [diff] [blame] | 1183 | int scsi_prep_return(struct request_queue *q, struct request *req, int ret) |
| 1184 | { |
| 1185 | struct scsi_device *sdev = q->queuedata; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1186 | |
Christoph Hellwig | 3b00315 | 2006-11-04 20:10:55 +0100 | [diff] [blame] | 1187 | switch (ret) { |
| 1188 | case BLKPREP_KILL: |
| 1189 | req->errors = DID_NO_CONNECT << 16; |
James Bottomley | 7f9a6bc | 2007-08-04 10:06:25 -0500 | [diff] [blame] | 1190 | /* release the command and kill it */ |
| 1191 | if (req->special) { |
| 1192 | struct scsi_cmnd *cmd = req->special; |
| 1193 | scsi_release_buffers(cmd); |
| 1194 | scsi_put_command(cmd); |
| 1195 | req->special = NULL; |
| 1196 | } |
Christoph Hellwig | 3b00315 | 2006-11-04 20:10:55 +0100 | [diff] [blame] | 1197 | break; |
| 1198 | case BLKPREP_DEFER: |
| 1199 | /* |
| 1200 | * If we defer, the elv_next_request() returns NULL, but the |
| 1201 | * queue must be restarted, so we plug here if no returning |
| 1202 | * command will automatically do that. |
| 1203 | */ |
| 1204 | if (sdev->device_busy == 0) |
| 1205 | blk_plug_device(q); |
| 1206 | break; |
| 1207 | default: |
| 1208 | req->cmd_flags |= REQ_DONTPREP; |
| 1209 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1210 | |
Christoph Hellwig | 3b00315 | 2006-11-04 20:10:55 +0100 | [diff] [blame] | 1211 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1212 | } |
James Bottomley | 7f9a6bc | 2007-08-04 10:06:25 -0500 | [diff] [blame] | 1213 | EXPORT_SYMBOL(scsi_prep_return); |
| 1214 | |
James Bottomley | 751bf4d | 2008-01-02 11:14:30 -0600 | [diff] [blame] | 1215 | int scsi_prep_fn(struct request_queue *q, struct request *req) |
James Bottomley | 7f9a6bc | 2007-08-04 10:06:25 -0500 | [diff] [blame] | 1216 | { |
| 1217 | struct scsi_device *sdev = q->queuedata; |
| 1218 | int ret = BLKPREP_KILL; |
| 1219 | |
| 1220 | if (req->cmd_type == REQ_TYPE_BLOCK_PC) |
| 1221 | ret = scsi_setup_blk_pc_cmnd(sdev, req); |
| 1222 | return scsi_prep_return(q, req, ret); |
| 1223 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1224 | |
| 1225 | /* |
| 1226 | * scsi_dev_queue_ready: if we can send requests to sdev, return 1 else |
| 1227 | * return 0. |
| 1228 | * |
| 1229 | * Called with the queue_lock held. |
| 1230 | */ |
| 1231 | static inline int scsi_dev_queue_ready(struct request_queue *q, |
| 1232 | struct scsi_device *sdev) |
| 1233 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1234 | if (sdev->device_busy == 0 && sdev->device_blocked) { |
| 1235 | /* |
| 1236 | * unblock after device_blocked iterates to zero |
| 1237 | */ |
| 1238 | if (--sdev->device_blocked == 0) { |
| 1239 | SCSI_LOG_MLQUEUE(3, |
James Bottomley | 9ccfc75 | 2005-10-02 11:45:08 -0500 | [diff] [blame] | 1240 | sdev_printk(KERN_INFO, sdev, |
| 1241 | "unblocking device at zero depth\n")); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1242 | } else { |
| 1243 | blk_plug_device(q); |
| 1244 | return 0; |
| 1245 | } |
| 1246 | } |
Kiyoshi Ueda | 9d11251 | 2008-10-04 14:11:06 -0400 | [diff] [blame] | 1247 | if (scsi_device_is_busy(sdev)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1248 | return 0; |
| 1249 | |
| 1250 | return 1; |
| 1251 | } |
| 1252 | |
Mike Christie | f0c0a37 | 2008-08-17 15:24:38 -0500 | [diff] [blame] | 1253 | |
| 1254 | /* |
| 1255 | * scsi_target_queue_ready: checks if there we can send commands to target |
| 1256 | * @sdev: scsi device on starget to check. |
| 1257 | * |
| 1258 | * Called with the host lock held. |
| 1259 | */ |
| 1260 | static inline int scsi_target_queue_ready(struct Scsi_Host *shost, |
| 1261 | struct scsi_device *sdev) |
| 1262 | { |
| 1263 | struct scsi_target *starget = scsi_target(sdev); |
| 1264 | |
| 1265 | if (starget->single_lun) { |
| 1266 | if (starget->starget_sdev_user && |
| 1267 | starget->starget_sdev_user != sdev) |
| 1268 | return 0; |
| 1269 | starget->starget_sdev_user = sdev; |
| 1270 | } |
| 1271 | |
| 1272 | if (starget->target_busy == 0 && starget->target_blocked) { |
| 1273 | /* |
| 1274 | * unblock after target_blocked iterates to zero |
| 1275 | */ |
| 1276 | if (--starget->target_blocked == 0) { |
| 1277 | SCSI_LOG_MLQUEUE(3, starget_printk(KERN_INFO, starget, |
| 1278 | "unblocking target at zero depth\n")); |
| 1279 | } else { |
| 1280 | blk_plug_device(sdev->request_queue); |
| 1281 | return 0; |
| 1282 | } |
| 1283 | } |
| 1284 | |
| 1285 | if (scsi_target_is_busy(starget)) { |
| 1286 | if (list_empty(&sdev->starved_entry)) { |
| 1287 | list_add_tail(&sdev->starved_entry, |
| 1288 | &shost->starved_list); |
| 1289 | return 0; |
| 1290 | } |
| 1291 | } |
| 1292 | |
| 1293 | /* We're OK to process the command, so we can't be starved */ |
| 1294 | if (!list_empty(&sdev->starved_entry)) |
| 1295 | list_del_init(&sdev->starved_entry); |
| 1296 | return 1; |
| 1297 | } |
| 1298 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1321 | return 0; |
| 1322 | } |
| 1323 | } |
Kiyoshi Ueda | 9d11251 | 2008-10-04 14:11:06 -0400 | [diff] [blame] | 1324 | if (scsi_host_is_busy(shost)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1325 | if (list_empty(&sdev->starved_entry)) |
| 1326 | list_add_tail(&sdev->starved_entry, &shost->starved_list); |
| 1327 | return 0; |
| 1328 | } |
| 1329 | |
| 1330 | /* We're OK to process the command, so we can't be starved */ |
| 1331 | if (!list_empty(&sdev->starved_entry)) |
| 1332 | list_del_init(&sdev->starved_entry); |
| 1333 | |
| 1334 | return 1; |
| 1335 | } |
| 1336 | |
| 1337 | /* |
Kiyoshi Ueda | 6c5121b | 2008-10-04 14:11:35 -0400 | [diff] [blame] | 1338 | * Busy state exporting function for request stacking drivers. |
| 1339 | * |
| 1340 | * For efficiency, no lock is taken to check the busy state of |
| 1341 | * shost/starget/sdev, since the returned value is not guaranteed and |
| 1342 | * may be changed after request stacking drivers call the function, |
| 1343 | * regardless of taking lock or not. |
| 1344 | * |
| 1345 | * When scsi can't dispatch I/Os anymore and needs to kill I/Os |
| 1346 | * (e.g. !sdev), scsi needs to return 'not busy'. |
| 1347 | * Otherwise, request stacking drivers may hold requests forever. |
| 1348 | */ |
| 1349 | static int scsi_lld_busy(struct request_queue *q) |
| 1350 | { |
| 1351 | struct scsi_device *sdev = q->queuedata; |
| 1352 | struct Scsi_Host *shost; |
| 1353 | struct scsi_target *starget; |
| 1354 | |
| 1355 | if (!sdev) |
| 1356 | return 0; |
| 1357 | |
| 1358 | shost = sdev->host; |
| 1359 | starget = scsi_target(sdev); |
| 1360 | |
| 1361 | if (scsi_host_in_recovery(shost) || scsi_host_is_busy(shost) || |
| 1362 | scsi_target_is_busy(starget) || scsi_device_is_busy(sdev)) |
| 1363 | return 1; |
| 1364 | |
| 1365 | return 0; |
| 1366 | } |
| 1367 | |
| 1368 | /* |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 1369 | * Kill a request for a dead device |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1370 | */ |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 1371 | static void scsi_kill_request(struct request *req, struct request_queue *q) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1372 | { |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 1373 | struct scsi_cmnd *cmd = req->special; |
Tejun Heo | e36e0c8 | 2006-04-11 17:27:53 +0900 | [diff] [blame] | 1374 | struct scsi_device *sdev = cmd->device; |
Mike Christie | f0c0a37 | 2008-08-17 15:24:38 -0500 | [diff] [blame] | 1375 | struct scsi_target *starget = scsi_target(sdev); |
Tejun Heo | e36e0c8 | 2006-04-11 17:27:53 +0900 | [diff] [blame] | 1376 | struct Scsi_Host *shost = sdev->host; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1377 | |
James Bottomley | 788ce43 | 2005-09-09 13:40:23 -0500 | [diff] [blame] | 1378 | blkdev_dequeue_request(req); |
| 1379 | |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 1380 | if (unlikely(cmd == NULL)) { |
| 1381 | printk(KERN_CRIT "impossible request in %s.\n", |
Harvey Harrison | cadbd4a | 2008-07-03 23:47:27 -0700 | [diff] [blame] | 1382 | __func__); |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 1383 | BUG(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1384 | } |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 1385 | |
| 1386 | scsi_init_cmd_errh(cmd); |
| 1387 | cmd->result = DID_NO_CONNECT << 16; |
| 1388 | atomic_inc(&cmd->device->iorequest_cnt); |
Tejun Heo | e36e0c8 | 2006-04-11 17:27:53 +0900 | [diff] [blame] | 1389 | |
| 1390 | /* |
| 1391 | * SCSI request completion path will do scsi_device_unbusy(), |
| 1392 | * bump busy counts. To bump the counters, we need to dance |
| 1393 | * with the locks as normal issue path does. |
| 1394 | */ |
| 1395 | sdev->device_busy++; |
| 1396 | spin_unlock(sdev->request_queue->queue_lock); |
| 1397 | spin_lock(shost->host_lock); |
| 1398 | shost->host_busy++; |
Mike Christie | f0c0a37 | 2008-08-17 15:24:38 -0500 | [diff] [blame] | 1399 | starget->target_busy++; |
Tejun Heo | e36e0c8 | 2006-04-11 17:27:53 +0900 | [diff] [blame] | 1400 | spin_unlock(shost->host_lock); |
| 1401 | spin_lock(sdev->request_queue->queue_lock); |
| 1402 | |
Jens Axboe | 242f9dc | 2008-09-14 05:55:09 -0700 | [diff] [blame] | 1403 | blk_complete_request(req); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1404 | } |
| 1405 | |
Jens Axboe | 1aea643 | 2006-01-09 16:03:03 +0100 | [diff] [blame] | 1406 | static void scsi_softirq_done(struct request *rq) |
| 1407 | { |
Jens Axboe | 242f9dc | 2008-09-14 05:55:09 -0700 | [diff] [blame] | 1408 | struct scsi_cmnd *cmd = rq->special; |
| 1409 | unsigned long wait_for = (cmd->allowed + 1) * rq->timeout; |
Jens Axboe | 1aea643 | 2006-01-09 16:03:03 +0100 | [diff] [blame] | 1410 | int disposition; |
| 1411 | |
| 1412 | INIT_LIST_HEAD(&cmd->eh_entry); |
| 1413 | |
Jens Axboe | 242f9dc | 2008-09-14 05:55:09 -0700 | [diff] [blame] | 1414 | /* |
| 1415 | * Set the serial numbers back to zero |
| 1416 | */ |
| 1417 | cmd->serial_number = 0; |
| 1418 | |
| 1419 | atomic_inc(&cmd->device->iodone_cnt); |
| 1420 | if (cmd->result) |
| 1421 | atomic_inc(&cmd->device->ioerr_cnt); |
| 1422 | |
Jens Axboe | 1aea643 | 2006-01-09 16:03:03 +0100 | [diff] [blame] | 1423 | disposition = scsi_decide_disposition(cmd); |
| 1424 | if (disposition != SUCCESS && |
| 1425 | time_before(cmd->jiffies_at_alloc + wait_for, jiffies)) { |
| 1426 | sdev_printk(KERN_ERR, cmd->device, |
| 1427 | "timing out command, waited %lus\n", |
| 1428 | wait_for/HZ); |
| 1429 | disposition = SUCCESS; |
| 1430 | } |
| 1431 | |
| 1432 | scsi_log_completion(cmd, disposition); |
| 1433 | |
| 1434 | switch (disposition) { |
| 1435 | case SUCCESS: |
| 1436 | scsi_finish_command(cmd); |
| 1437 | break; |
| 1438 | case NEEDS_RETRY: |
Christoph Hellwig | 596f482 | 2007-01-02 12:56:00 +0100 | [diff] [blame] | 1439 | scsi_queue_insert(cmd, SCSI_MLQUEUE_EH_RETRY); |
Jens Axboe | 1aea643 | 2006-01-09 16:03:03 +0100 | [diff] [blame] | 1440 | break; |
| 1441 | case ADD_TO_MLQUEUE: |
| 1442 | scsi_queue_insert(cmd, SCSI_MLQUEUE_DEVICE_BUSY); |
| 1443 | break; |
| 1444 | default: |
| 1445 | if (!scsi_eh_scmd_add(cmd, 0)) |
| 1446 | scsi_finish_command(cmd); |
| 1447 | } |
| 1448 | } |
| 1449 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1450 | /* |
| 1451 | * Function: scsi_request_fn() |
| 1452 | * |
| 1453 | * Purpose: Main strategy routine for SCSI. |
| 1454 | * |
| 1455 | * Arguments: q - Pointer to actual queue. |
| 1456 | * |
| 1457 | * Returns: Nothing |
| 1458 | * |
| 1459 | * Lock status: IO request lock assumed to be held when called. |
| 1460 | */ |
| 1461 | static void scsi_request_fn(struct request_queue *q) |
| 1462 | { |
| 1463 | struct scsi_device *sdev = q->queuedata; |
| 1464 | struct Scsi_Host *shost; |
| 1465 | struct scsi_cmnd *cmd; |
| 1466 | struct request *req; |
| 1467 | |
| 1468 | if (!sdev) { |
| 1469 | printk("scsi: killing requests for dead queue\n"); |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 1470 | while ((req = elv_next_request(q)) != NULL) |
| 1471 | scsi_kill_request(req, q); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1472 | return; |
| 1473 | } |
| 1474 | |
| 1475 | if(!get_device(&sdev->sdev_gendev)) |
| 1476 | /* We must be tearing the block queue down already */ |
| 1477 | return; |
| 1478 | |
| 1479 | /* |
| 1480 | * To start with, we keep looping until the queue is empty, or until |
| 1481 | * the host is no longer able to accept any more requests. |
| 1482 | */ |
| 1483 | shost = sdev->host; |
| 1484 | while (!blk_queue_plugged(q)) { |
| 1485 | int rtn; |
| 1486 | /* |
| 1487 | * get next queueable request. We do this early to make sure |
| 1488 | * that the request is fully prepared even if we cannot |
| 1489 | * accept it. |
| 1490 | */ |
| 1491 | req = elv_next_request(q); |
| 1492 | if (!req || !scsi_dev_queue_ready(q, sdev)) |
| 1493 | break; |
| 1494 | |
| 1495 | if (unlikely(!scsi_device_online(sdev))) { |
James Bottomley | 9ccfc75 | 2005-10-02 11:45:08 -0500 | [diff] [blame] | 1496 | sdev_printk(KERN_ERR, sdev, |
| 1497 | "rejecting I/O to offline device\n"); |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 1498 | scsi_kill_request(req, q); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1499 | continue; |
| 1500 | } |
| 1501 | |
| 1502 | |
| 1503 | /* |
| 1504 | * Remove the request from the request list. |
| 1505 | */ |
| 1506 | if (!(blk_queue_tagged(q) && !blk_queue_start_tag(q, req))) |
| 1507 | blkdev_dequeue_request(req); |
| 1508 | sdev->device_busy++; |
| 1509 | |
| 1510 | spin_unlock(q->queue_lock); |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 1511 | cmd = req->special; |
| 1512 | if (unlikely(cmd == NULL)) { |
| 1513 | printk(KERN_CRIT "impossible request in %s.\n" |
| 1514 | "please mail a stack trace to " |
Jens Axboe | 4aff5e2 | 2006-08-10 08:44:47 +0200 | [diff] [blame] | 1515 | "linux-scsi@vger.kernel.org\n", |
Harvey Harrison | cadbd4a | 2008-07-03 23:47:27 -0700 | [diff] [blame] | 1516 | __func__); |
Jens Axboe | 4aff5e2 | 2006-08-10 08:44:47 +0200 | [diff] [blame] | 1517 | blk_dump_rq_flags(req, "foo"); |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 1518 | BUG(); |
| 1519 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1520 | spin_lock(shost->host_lock); |
| 1521 | |
Mike Christie | ecefe8a | 2008-07-11 19:50:35 -0500 | [diff] [blame] | 1522 | /* |
| 1523 | * We hit this when the driver is using a host wide |
| 1524 | * tag map. For device level tag maps the queue_depth check |
| 1525 | * in the device ready fn would prevent us from trying |
| 1526 | * to allocate a tag. Since the map is a shared host resource |
| 1527 | * we add the dev to the starved list so it eventually gets |
| 1528 | * a run when a tag is freed. |
| 1529 | */ |
Mike Christie | 6bd522f | 2008-07-22 15:34:38 -0500 | [diff] [blame] | 1530 | if (blk_queue_tagged(q) && !blk_rq_tagged(req)) { |
Mike Christie | ecefe8a | 2008-07-11 19:50:35 -0500 | [diff] [blame] | 1531 | if (list_empty(&sdev->starved_entry)) |
| 1532 | list_add_tail(&sdev->starved_entry, |
| 1533 | &shost->starved_list); |
| 1534 | goto not_ready; |
| 1535 | } |
| 1536 | |
Mike Christie | f0c0a37 | 2008-08-17 15:24:38 -0500 | [diff] [blame] | 1537 | if (!scsi_target_queue_ready(shost, sdev)) |
| 1538 | goto not_ready; |
| 1539 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1540 | if (!scsi_host_queue_ready(q, shost, sdev)) |
| 1541 | goto not_ready; |
Mike Christie | f0c0a37 | 2008-08-17 15:24:38 -0500 | [diff] [blame] | 1542 | |
| 1543 | scsi_target(sdev)->target_busy++; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1544 | shost->host_busy++; |
| 1545 | |
| 1546 | /* |
| 1547 | * XXX(hch): This is rather suboptimal, scsi_dispatch_cmd will |
| 1548 | * take the lock again. |
| 1549 | */ |
| 1550 | spin_unlock_irq(shost->host_lock); |
| 1551 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1552 | /* |
| 1553 | * Finally, initialize any error handling parameters, and set up |
| 1554 | * the timers for timeouts. |
| 1555 | */ |
| 1556 | scsi_init_cmd_errh(cmd); |
| 1557 | |
| 1558 | /* |
| 1559 | * Dispatch the command to the low-level driver. |
| 1560 | */ |
| 1561 | rtn = scsi_dispatch_cmd(cmd); |
| 1562 | spin_lock_irq(q->queue_lock); |
| 1563 | if(rtn) { |
| 1564 | /* we're refusing the command; because of |
| 1565 | * the way locks get dropped, we need to |
| 1566 | * check here if plugging is required */ |
| 1567 | if(sdev->device_busy == 0) |
| 1568 | blk_plug_device(q); |
| 1569 | |
| 1570 | break; |
| 1571 | } |
| 1572 | } |
| 1573 | |
| 1574 | goto out; |
| 1575 | |
| 1576 | not_ready: |
| 1577 | spin_unlock_irq(shost->host_lock); |
| 1578 | |
| 1579 | /* |
| 1580 | * lock q, handle tag, requeue req, and decrement device_busy. We |
| 1581 | * must return with queue_lock held. |
| 1582 | * |
| 1583 | * Decrementing device_busy without checking it is OK, as all such |
| 1584 | * cases (host limits or settings) should run the queue at some |
| 1585 | * later time. |
| 1586 | */ |
| 1587 | spin_lock_irq(q->queue_lock); |
| 1588 | blk_requeue_request(q, req); |
| 1589 | sdev->device_busy--; |
| 1590 | if(sdev->device_busy == 0) |
| 1591 | blk_plug_device(q); |
| 1592 | out: |
| 1593 | /* must be careful here...if we trigger the ->remove() function |
| 1594 | * we cannot be holding the q lock */ |
| 1595 | spin_unlock_irq(q->queue_lock); |
| 1596 | put_device(&sdev->sdev_gendev); |
| 1597 | spin_lock_irq(q->queue_lock); |
| 1598 | } |
| 1599 | |
| 1600 | u64 scsi_calculate_bounce_limit(struct Scsi_Host *shost) |
| 1601 | { |
| 1602 | struct device *host_dev; |
| 1603 | u64 bounce_limit = 0xffffffff; |
| 1604 | |
| 1605 | if (shost->unchecked_isa_dma) |
| 1606 | return BLK_BOUNCE_ISA; |
| 1607 | /* |
| 1608 | * Platforms with virtual-DMA translation |
| 1609 | * hardware have no practical limit. |
| 1610 | */ |
| 1611 | if (!PCI_DMA_BUS_IS_PHYS) |
| 1612 | return BLK_BOUNCE_ANY; |
| 1613 | |
| 1614 | host_dev = scsi_get_device(shost); |
| 1615 | if (host_dev && host_dev->dma_mask) |
| 1616 | bounce_limit = *host_dev->dma_mask; |
| 1617 | |
| 1618 | return bounce_limit; |
| 1619 | } |
| 1620 | EXPORT_SYMBOL(scsi_calculate_bounce_limit); |
| 1621 | |
FUJITA Tomonori | b58d915 | 2006-11-16 19:24:10 +0900 | [diff] [blame] | 1622 | struct request_queue *__scsi_alloc_queue(struct Scsi_Host *shost, |
| 1623 | request_fn_proc *request_fn) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1624 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1625 | struct request_queue *q; |
FUJITA Tomonori | 860ac56 | 2008-02-04 22:28:05 -0800 | [diff] [blame] | 1626 | struct device *dev = shost->shost_gendev.parent; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1627 | |
FUJITA Tomonori | b58d915 | 2006-11-16 19:24:10 +0900 | [diff] [blame] | 1628 | q = blk_init_queue(request_fn, NULL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1629 | if (!q) |
| 1630 | return NULL; |
| 1631 | |
Jens Axboe | a8474ce | 2007-08-07 09:02:51 +0200 | [diff] [blame] | 1632 | /* |
| 1633 | * this limit is imposed by hardware restrictions |
| 1634 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1635 | blk_queue_max_hw_segments(q, shost->sg_tablesize); |
James Bottomley | d3f46f3 | 2008-01-15 11:11:46 -0600 | [diff] [blame] | 1636 | blk_queue_max_phys_segments(q, SCSI_MAX_SG_CHAIN_SEGMENTS); |
Jens Axboe | a8474ce | 2007-08-07 09:02:51 +0200 | [diff] [blame] | 1637 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1638 | blk_queue_max_sectors(q, shost->max_sectors); |
| 1639 | blk_queue_bounce_limit(q, scsi_calculate_bounce_limit(shost)); |
| 1640 | blk_queue_segment_boundary(q, shost->dma_boundary); |
FUJITA Tomonori | 99c84db | 2008-02-04 22:28:17 -0800 | [diff] [blame] | 1641 | dma_set_seg_boundary(dev, shost->dma_boundary); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1642 | |
FUJITA Tomonori | 860ac56 | 2008-02-04 22:28:05 -0800 | [diff] [blame] | 1643 | blk_queue_max_segment_size(q, dma_get_max_seg_size(dev)); |
| 1644 | |
Nick Piggin | 75ad23b | 2008-04-29 14:48:33 +0200 | [diff] [blame] | 1645 | /* New queue, no concurrency on queue_flags */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1646 | if (!shost->use_clustering) |
Nick Piggin | 75ad23b | 2008-04-29 14:48:33 +0200 | [diff] [blame] | 1647 | queue_flag_clear_unlocked(QUEUE_FLAG_CLUSTER, q); |
James Bottomley | 465ff31 | 2008-01-01 10:00:10 -0600 | [diff] [blame] | 1648 | |
| 1649 | /* |
| 1650 | * set a reasonable default alignment on word boundaries: the |
| 1651 | * host and device may alter it using |
| 1652 | * blk_queue_update_dma_alignment() later. |
| 1653 | */ |
| 1654 | blk_queue_dma_alignment(q, 0x03); |
| 1655 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1656 | return q; |
| 1657 | } |
FUJITA Tomonori | b58d915 | 2006-11-16 19:24:10 +0900 | [diff] [blame] | 1658 | EXPORT_SYMBOL(__scsi_alloc_queue); |
| 1659 | |
| 1660 | struct request_queue *scsi_alloc_queue(struct scsi_device *sdev) |
| 1661 | { |
| 1662 | struct request_queue *q; |
| 1663 | |
| 1664 | q = __scsi_alloc_queue(sdev->host, scsi_request_fn); |
| 1665 | if (!q) |
| 1666 | return NULL; |
| 1667 | |
| 1668 | blk_queue_prep_rq(q, scsi_prep_fn); |
FUJITA Tomonori | b58d915 | 2006-11-16 19:24:10 +0900 | [diff] [blame] | 1669 | blk_queue_softirq_done(q, scsi_softirq_done); |
Jens Axboe | 242f9dc | 2008-09-14 05:55:09 -0700 | [diff] [blame] | 1670 | blk_queue_rq_timed_out(q, scsi_times_out); |
Kiyoshi Ueda | 6c5121b | 2008-10-04 14:11:35 -0400 | [diff] [blame] | 1671 | blk_queue_lld_busy(q, scsi_lld_busy); |
FUJITA Tomonori | b58d915 | 2006-11-16 19:24:10 +0900 | [diff] [blame] | 1672 | return q; |
| 1673 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1674 | |
| 1675 | void scsi_free_queue(struct request_queue *q) |
| 1676 | { |
| 1677 | blk_cleanup_queue(q); |
| 1678 | } |
| 1679 | |
| 1680 | /* |
| 1681 | * Function: scsi_block_requests() |
| 1682 | * |
| 1683 | * Purpose: Utility function used by low-level drivers to prevent further |
| 1684 | * commands from being queued to the device. |
| 1685 | * |
| 1686 | * Arguments: shost - Host in question |
| 1687 | * |
| 1688 | * Returns: Nothing |
| 1689 | * |
| 1690 | * Lock status: No locks are assumed held. |
| 1691 | * |
| 1692 | * Notes: There is no timer nor any other means by which the requests |
| 1693 | * get unblocked other than the low-level driver calling |
| 1694 | * scsi_unblock_requests(). |
| 1695 | */ |
| 1696 | void scsi_block_requests(struct Scsi_Host *shost) |
| 1697 | { |
| 1698 | shost->host_self_blocked = 1; |
| 1699 | } |
| 1700 | EXPORT_SYMBOL(scsi_block_requests); |
| 1701 | |
| 1702 | /* |
| 1703 | * Function: scsi_unblock_requests() |
| 1704 | * |
| 1705 | * Purpose: Utility function used by low-level drivers to allow further |
| 1706 | * commands from being queued to the device. |
| 1707 | * |
| 1708 | * Arguments: shost - Host in question |
| 1709 | * |
| 1710 | * Returns: Nothing |
| 1711 | * |
| 1712 | * Lock status: No locks are assumed held. |
| 1713 | * |
| 1714 | * Notes: There is no timer nor any other means by which the requests |
| 1715 | * get unblocked other than the low-level driver calling |
| 1716 | * scsi_unblock_requests(). |
| 1717 | * |
| 1718 | * This is done as an API function so that changes to the |
| 1719 | * internals of the scsi mid-layer won't require wholesale |
| 1720 | * changes to drivers that use this feature. |
| 1721 | */ |
| 1722 | void scsi_unblock_requests(struct Scsi_Host *shost) |
| 1723 | { |
| 1724 | shost->host_self_blocked = 0; |
| 1725 | scsi_run_host_queues(shost); |
| 1726 | } |
| 1727 | EXPORT_SYMBOL(scsi_unblock_requests); |
| 1728 | |
| 1729 | int __init scsi_init_queue(void) |
| 1730 | { |
| 1731 | int i; |
| 1732 | |
Martin K. Petersen | 6362abd | 2008-06-05 23:30:03 -0400 | [diff] [blame] | 1733 | scsi_sdb_cache = kmem_cache_create("scsi_data_buffer", |
| 1734 | sizeof(struct scsi_data_buffer), |
| 1735 | 0, 0, NULL); |
| 1736 | if (!scsi_sdb_cache) { |
| 1737 | printk(KERN_ERR "SCSI: can't init scsi sdb cache\n"); |
FUJITA Tomonori | f078727 | 2008-12-14 01:23:45 +0900 | [diff] [blame] | 1738 | return -ENOMEM; |
Boaz Harrosh | 6f9a35e | 2007-12-13 13:50:53 +0200 | [diff] [blame] | 1739 | } |
| 1740 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1741 | for (i = 0; i < SG_MEMPOOL_NR; i++) { |
| 1742 | struct scsi_host_sg_pool *sgp = scsi_sg_pools + i; |
| 1743 | int size = sgp->size * sizeof(struct scatterlist); |
| 1744 | |
| 1745 | sgp->slab = kmem_cache_create(sgp->name, size, 0, |
Paul Mundt | 20c2df8 | 2007-07-20 10:11:58 +0900 | [diff] [blame] | 1746 | SLAB_HWCACHE_ALIGN, NULL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1747 | if (!sgp->slab) { |
| 1748 | printk(KERN_ERR "SCSI: can't init sg slab %s\n", |
| 1749 | sgp->name); |
Martin K. Petersen | 6362abd | 2008-06-05 23:30:03 -0400 | [diff] [blame] | 1750 | goto cleanup_sdb; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1751 | } |
| 1752 | |
Matthew Dobson | 93d2341 | 2006-03-26 01:37:50 -0800 | [diff] [blame] | 1753 | sgp->pool = mempool_create_slab_pool(SG_MEMPOOL_SIZE, |
| 1754 | sgp->slab); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1755 | if (!sgp->pool) { |
| 1756 | printk(KERN_ERR "SCSI: can't init sg mempool %s\n", |
| 1757 | sgp->name); |
Martin K. Petersen | 6362abd | 2008-06-05 23:30:03 -0400 | [diff] [blame] | 1758 | goto cleanup_sdb; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1759 | } |
| 1760 | } |
| 1761 | |
| 1762 | return 0; |
FUJITA Tomonori | 3d9dd6e | 2008-01-25 23:25:14 +0900 | [diff] [blame] | 1763 | |
Martin K. Petersen | 6362abd | 2008-06-05 23:30:03 -0400 | [diff] [blame] | 1764 | cleanup_sdb: |
FUJITA Tomonori | 3d9dd6e | 2008-01-25 23:25:14 +0900 | [diff] [blame] | 1765 | for (i = 0; i < SG_MEMPOOL_NR; i++) { |
| 1766 | struct scsi_host_sg_pool *sgp = scsi_sg_pools + i; |
| 1767 | if (sgp->pool) |
| 1768 | mempool_destroy(sgp->pool); |
| 1769 | if (sgp->slab) |
| 1770 | kmem_cache_destroy(sgp->slab); |
| 1771 | } |
Martin K. Petersen | 6362abd | 2008-06-05 23:30:03 -0400 | [diff] [blame] | 1772 | kmem_cache_destroy(scsi_sdb_cache); |
FUJITA Tomonori | 3d9dd6e | 2008-01-25 23:25:14 +0900 | [diff] [blame] | 1773 | |
| 1774 | return -ENOMEM; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1775 | } |
| 1776 | |
| 1777 | void scsi_exit_queue(void) |
| 1778 | { |
| 1779 | int i; |
| 1780 | |
Martin K. Petersen | 6362abd | 2008-06-05 23:30:03 -0400 | [diff] [blame] | 1781 | kmem_cache_destroy(scsi_sdb_cache); |
Mike Christie | aa7b5cd | 2005-11-11 05:31:41 -0600 | [diff] [blame] | 1782 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1783 | for (i = 0; i < SG_MEMPOOL_NR; i++) { |
| 1784 | struct scsi_host_sg_pool *sgp = scsi_sg_pools + i; |
| 1785 | mempool_destroy(sgp->pool); |
| 1786 | kmem_cache_destroy(sgp->slab); |
| 1787 | } |
| 1788 | } |
James Bottomley | 5baba83 | 2006-03-18 14:10:35 -0600 | [diff] [blame] | 1789 | |
| 1790 | /** |
| 1791 | * scsi_mode_select - issue a mode select |
| 1792 | * @sdev: SCSI device to be queried |
| 1793 | * @pf: Page format bit (1 == standard, 0 == vendor specific) |
| 1794 | * @sp: Save page bit (0 == don't save, 1 == save) |
| 1795 | * @modepage: mode page being requested |
| 1796 | * @buffer: request buffer (may not be smaller than eight bytes) |
| 1797 | * @len: length of request buffer. |
| 1798 | * @timeout: command timeout |
| 1799 | * @retries: number of retries before failing |
| 1800 | * @data: returns a structure abstracting the mode header data |
Rob Landley | eb44820 | 2007-11-03 13:30:39 -0500 | [diff] [blame] | 1801 | * @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] | 1802 | * must be SCSI_SENSE_BUFFERSIZE big. |
| 1803 | * |
| 1804 | * Returns zero if successful; negative error number or scsi |
| 1805 | * status on error |
| 1806 | * |
| 1807 | */ |
| 1808 | int |
| 1809 | scsi_mode_select(struct scsi_device *sdev, int pf, int sp, int modepage, |
| 1810 | unsigned char *buffer, int len, int timeout, int retries, |
| 1811 | struct scsi_mode_data *data, struct scsi_sense_hdr *sshdr) |
| 1812 | { |
| 1813 | unsigned char cmd[10]; |
| 1814 | unsigned char *real_buffer; |
| 1815 | int ret; |
| 1816 | |
| 1817 | memset(cmd, 0, sizeof(cmd)); |
| 1818 | cmd[1] = (pf ? 0x10 : 0) | (sp ? 0x01 : 0); |
| 1819 | |
| 1820 | if (sdev->use_10_for_ms) { |
| 1821 | if (len > 65535) |
| 1822 | return -EINVAL; |
| 1823 | real_buffer = kmalloc(8 + len, GFP_KERNEL); |
| 1824 | if (!real_buffer) |
| 1825 | return -ENOMEM; |
| 1826 | memcpy(real_buffer + 8, buffer, len); |
| 1827 | len += 8; |
| 1828 | real_buffer[0] = 0; |
| 1829 | real_buffer[1] = 0; |
| 1830 | real_buffer[2] = data->medium_type; |
| 1831 | real_buffer[3] = data->device_specific; |
| 1832 | real_buffer[4] = data->longlba ? 0x01 : 0; |
| 1833 | real_buffer[5] = 0; |
| 1834 | real_buffer[6] = data->block_descriptor_length >> 8; |
| 1835 | real_buffer[7] = data->block_descriptor_length; |
| 1836 | |
| 1837 | cmd[0] = MODE_SELECT_10; |
| 1838 | cmd[7] = len >> 8; |
| 1839 | cmd[8] = len; |
| 1840 | } else { |
| 1841 | if (len > 255 || data->block_descriptor_length > 255 || |
| 1842 | data->longlba) |
| 1843 | return -EINVAL; |
| 1844 | |
| 1845 | real_buffer = kmalloc(4 + len, GFP_KERNEL); |
| 1846 | if (!real_buffer) |
| 1847 | return -ENOMEM; |
| 1848 | memcpy(real_buffer + 4, buffer, len); |
| 1849 | len += 4; |
| 1850 | real_buffer[0] = 0; |
| 1851 | real_buffer[1] = data->medium_type; |
| 1852 | real_buffer[2] = data->device_specific; |
| 1853 | real_buffer[3] = data->block_descriptor_length; |
| 1854 | |
| 1855 | |
| 1856 | cmd[0] = MODE_SELECT; |
| 1857 | cmd[4] = len; |
| 1858 | } |
| 1859 | |
| 1860 | ret = scsi_execute_req(sdev, cmd, DMA_TO_DEVICE, real_buffer, len, |
FUJITA Tomonori | f4f4e47 | 2008-12-04 14:24:39 +0900 | [diff] [blame] | 1861 | sshdr, timeout, retries, NULL); |
James Bottomley | 5baba83 | 2006-03-18 14:10:35 -0600 | [diff] [blame] | 1862 | kfree(real_buffer); |
| 1863 | return ret; |
| 1864 | } |
| 1865 | EXPORT_SYMBOL_GPL(scsi_mode_select); |
| 1866 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1867 | /** |
Rob Landley | eb44820 | 2007-11-03 13:30:39 -0500 | [diff] [blame] | 1868 | * 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] | 1869 | * @sdev: SCSI device to be queried |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1870 | * @dbd: set if mode sense will allow block descriptors to be returned |
| 1871 | * @modepage: mode page being requested |
| 1872 | * @buffer: request buffer (may not be smaller than eight bytes) |
| 1873 | * @len: length of request buffer. |
| 1874 | * @timeout: command timeout |
| 1875 | * @retries: number of retries before failing |
| 1876 | * @data: returns a structure abstracting the mode header data |
Rob Landley | eb44820 | 2007-11-03 13:30:39 -0500 | [diff] [blame] | 1877 | * @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] | 1878 | * must be SCSI_SENSE_BUFFERSIZE big. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1879 | * |
| 1880 | * Returns zero if unsuccessful, or the header offset (either 4 |
| 1881 | * or 8 depending on whether a six or ten byte command was |
| 1882 | * issued) if successful. |
Rob Landley | eb44820 | 2007-11-03 13:30:39 -0500 | [diff] [blame] | 1883 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1884 | int |
James Bottomley | 1cf7269 | 2005-08-28 11:27:01 -0500 | [diff] [blame] | 1885 | scsi_mode_sense(struct scsi_device *sdev, int dbd, int modepage, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1886 | unsigned char *buffer, int len, int timeout, int retries, |
James Bottomley | 5baba83 | 2006-03-18 14:10:35 -0600 | [diff] [blame] | 1887 | struct scsi_mode_data *data, struct scsi_sense_hdr *sshdr) |
| 1888 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1889 | unsigned char cmd[12]; |
| 1890 | int use_10_for_ms; |
| 1891 | int header_length; |
James Bottomley | 1cf7269 | 2005-08-28 11:27:01 -0500 | [diff] [blame] | 1892 | int result; |
James Bottomley | ea73a9f | 2005-08-28 11:33:52 -0500 | [diff] [blame] | 1893 | struct scsi_sense_hdr my_sshdr; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1894 | |
| 1895 | memset(data, 0, sizeof(*data)); |
| 1896 | memset(&cmd[0], 0, 12); |
| 1897 | cmd[1] = dbd & 0x18; /* allows DBD and LLBA bits */ |
| 1898 | cmd[2] = modepage; |
| 1899 | |
James Bottomley | ea73a9f | 2005-08-28 11:33:52 -0500 | [diff] [blame] | 1900 | /* caller might not be interested in sense, but we need it */ |
| 1901 | if (!sshdr) |
| 1902 | sshdr = &my_sshdr; |
| 1903 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1904 | retry: |
James Bottomley | 1cf7269 | 2005-08-28 11:27:01 -0500 | [diff] [blame] | 1905 | use_10_for_ms = sdev->use_10_for_ms; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1906 | |
| 1907 | if (use_10_for_ms) { |
| 1908 | if (len < 8) |
| 1909 | len = 8; |
| 1910 | |
| 1911 | cmd[0] = MODE_SENSE_10; |
| 1912 | cmd[8] = len; |
| 1913 | header_length = 8; |
| 1914 | } else { |
| 1915 | if (len < 4) |
| 1916 | len = 4; |
| 1917 | |
| 1918 | cmd[0] = MODE_SENSE; |
| 1919 | cmd[4] = len; |
| 1920 | header_length = 4; |
| 1921 | } |
| 1922 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1923 | memset(buffer, 0, len); |
| 1924 | |
James Bottomley | 1cf7269 | 2005-08-28 11:27:01 -0500 | [diff] [blame] | 1925 | result = scsi_execute_req(sdev, cmd, DMA_FROM_DEVICE, buffer, len, |
FUJITA Tomonori | f4f4e47 | 2008-12-04 14:24:39 +0900 | [diff] [blame] | 1926 | sshdr, timeout, retries, NULL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1927 | |
| 1928 | /* This code looks awful: what it's doing is making sure an |
| 1929 | * ILLEGAL REQUEST sense return identifies the actual command |
| 1930 | * byte as the problem. MODE_SENSE commands can return |
| 1931 | * ILLEGAL REQUEST if the code page isn't supported */ |
| 1932 | |
James Bottomley | 1cf7269 | 2005-08-28 11:27:01 -0500 | [diff] [blame] | 1933 | if (use_10_for_ms && !scsi_status_is_good(result) && |
| 1934 | (driver_byte(result) & DRIVER_SENSE)) { |
James Bottomley | ea73a9f | 2005-08-28 11:33:52 -0500 | [diff] [blame] | 1935 | if (scsi_sense_valid(sshdr)) { |
| 1936 | if ((sshdr->sense_key == ILLEGAL_REQUEST) && |
| 1937 | (sshdr->asc == 0x20) && (sshdr->ascq == 0)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1938 | /* |
| 1939 | * Invalid command operation code |
| 1940 | */ |
James Bottomley | 1cf7269 | 2005-08-28 11:27:01 -0500 | [diff] [blame] | 1941 | sdev->use_10_for_ms = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1942 | goto retry; |
| 1943 | } |
| 1944 | } |
| 1945 | } |
| 1946 | |
James Bottomley | 1cf7269 | 2005-08-28 11:27:01 -0500 | [diff] [blame] | 1947 | if(scsi_status_is_good(result)) { |
Al Viro | 6d73c85 | 2006-02-23 02:03:16 +0100 | [diff] [blame] | 1948 | if (unlikely(buffer[0] == 0x86 && buffer[1] == 0x0b && |
| 1949 | (modepage == 6 || modepage == 8))) { |
| 1950 | /* Initio breakage? */ |
| 1951 | header_length = 0; |
| 1952 | data->length = 13; |
| 1953 | data->medium_type = 0; |
| 1954 | data->device_specific = 0; |
| 1955 | data->longlba = 0; |
| 1956 | data->block_descriptor_length = 0; |
| 1957 | } else if(use_10_for_ms) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1958 | data->length = buffer[0]*256 + buffer[1] + 2; |
| 1959 | data->medium_type = buffer[2]; |
| 1960 | data->device_specific = buffer[3]; |
| 1961 | data->longlba = buffer[4] & 0x01; |
| 1962 | data->block_descriptor_length = buffer[6]*256 |
| 1963 | + buffer[7]; |
| 1964 | } else { |
| 1965 | data->length = buffer[0] + 1; |
| 1966 | data->medium_type = buffer[1]; |
| 1967 | data->device_specific = buffer[2]; |
| 1968 | data->block_descriptor_length = buffer[3]; |
| 1969 | } |
Al Viro | 6d73c85 | 2006-02-23 02:03:16 +0100 | [diff] [blame] | 1970 | data->header_length = header_length; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1971 | } |
| 1972 | |
James Bottomley | 1cf7269 | 2005-08-28 11:27:01 -0500 | [diff] [blame] | 1973 | return result; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1974 | } |
| 1975 | EXPORT_SYMBOL(scsi_mode_sense); |
| 1976 | |
James Bottomley | 001aac2 | 2007-12-02 19:10:40 +0200 | [diff] [blame] | 1977 | /** |
| 1978 | * scsi_test_unit_ready - test if unit is ready |
| 1979 | * @sdev: scsi device to change the state of. |
| 1980 | * @timeout: command timeout |
| 1981 | * @retries: number of retries before failing |
| 1982 | * @sshdr_external: Optional pointer to struct scsi_sense_hdr for |
| 1983 | * returning sense. Make sure that this is cleared before passing |
| 1984 | * in. |
| 1985 | * |
| 1986 | * Returns zero if unsuccessful or an error if TUR failed. For |
| 1987 | * removable media, a return of NOT_READY or UNIT_ATTENTION is |
| 1988 | * translated to success, with the ->changed flag updated. |
| 1989 | **/ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1990 | int |
James Bottomley | 001aac2 | 2007-12-02 19:10:40 +0200 | [diff] [blame] | 1991 | scsi_test_unit_ready(struct scsi_device *sdev, int timeout, int retries, |
| 1992 | struct scsi_sense_hdr *sshdr_external) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1993 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1994 | char cmd[] = { |
| 1995 | TEST_UNIT_READY, 0, 0, 0, 0, 0, |
| 1996 | }; |
James Bottomley | 001aac2 | 2007-12-02 19:10:40 +0200 | [diff] [blame] | 1997 | struct scsi_sense_hdr *sshdr; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1998 | int result; |
James Bottomley | 001aac2 | 2007-12-02 19:10:40 +0200 | [diff] [blame] | 1999 | |
| 2000 | if (!sshdr_external) |
| 2001 | sshdr = kzalloc(sizeof(*sshdr), GFP_KERNEL); |
| 2002 | else |
| 2003 | sshdr = sshdr_external; |
| 2004 | |
| 2005 | /* try to eat the UNIT_ATTENTION if there are enough retries */ |
| 2006 | do { |
| 2007 | result = scsi_execute_req(sdev, cmd, DMA_NONE, NULL, 0, sshdr, |
FUJITA Tomonori | f4f4e47 | 2008-12-04 14:24:39 +0900 | [diff] [blame] | 2008 | timeout, retries, NULL); |
James Bottomley | 32c356d | 2008-08-20 00:58:13 +0200 | [diff] [blame] | 2009 | if (sdev->removable && scsi_sense_valid(sshdr) && |
| 2010 | sshdr->sense_key == UNIT_ATTENTION) |
| 2011 | sdev->changed = 1; |
| 2012 | } while (scsi_sense_valid(sshdr) && |
| 2013 | sshdr->sense_key == UNIT_ATTENTION && --retries); |
James Bottomley | 001aac2 | 2007-12-02 19:10:40 +0200 | [diff] [blame] | 2014 | |
| 2015 | if (!sshdr) |
| 2016 | /* could not allocate sense buffer, so can't process it */ |
| 2017 | return result; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2018 | |
James Bottomley | 32c356d | 2008-08-20 00:58:13 +0200 | [diff] [blame] | 2019 | if (sdev->removable && scsi_sense_valid(sshdr) && |
| 2020 | (sshdr->sense_key == UNIT_ATTENTION || |
| 2021 | sshdr->sense_key == NOT_READY)) { |
| 2022 | sdev->changed = 1; |
| 2023 | result = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2024 | } |
James Bottomley | 001aac2 | 2007-12-02 19:10:40 +0200 | [diff] [blame] | 2025 | if (!sshdr_external) |
| 2026 | kfree(sshdr); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2027 | return result; |
| 2028 | } |
| 2029 | EXPORT_SYMBOL(scsi_test_unit_ready); |
| 2030 | |
| 2031 | /** |
Rob Landley | eb44820 | 2007-11-03 13:30:39 -0500 | [diff] [blame] | 2032 | * 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] | 2033 | * @sdev: scsi device to change the state of. |
| 2034 | * @state: state to change to. |
| 2035 | * |
| 2036 | * Returns zero if unsuccessful or an error if the requested |
| 2037 | * transition is illegal. |
Rob Landley | eb44820 | 2007-11-03 13:30:39 -0500 | [diff] [blame] | 2038 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2039 | int |
| 2040 | scsi_device_set_state(struct scsi_device *sdev, enum scsi_device_state state) |
| 2041 | { |
| 2042 | enum scsi_device_state oldstate = sdev->sdev_state; |
| 2043 | |
| 2044 | if (state == oldstate) |
| 2045 | return 0; |
| 2046 | |
| 2047 | switch (state) { |
| 2048 | case SDEV_CREATED: |
James Bottomley | 6f4267e | 2008-08-22 16:53:31 -0500 | [diff] [blame] | 2049 | switch (oldstate) { |
| 2050 | case SDEV_CREATED_BLOCK: |
| 2051 | break; |
| 2052 | default: |
| 2053 | goto illegal; |
| 2054 | } |
| 2055 | break; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2056 | |
| 2057 | case SDEV_RUNNING: |
| 2058 | switch (oldstate) { |
| 2059 | case SDEV_CREATED: |
| 2060 | case SDEV_OFFLINE: |
| 2061 | case SDEV_QUIESCE: |
| 2062 | case SDEV_BLOCK: |
| 2063 | break; |
| 2064 | default: |
| 2065 | goto illegal; |
| 2066 | } |
| 2067 | break; |
| 2068 | |
| 2069 | case SDEV_QUIESCE: |
| 2070 | switch (oldstate) { |
| 2071 | case SDEV_RUNNING: |
| 2072 | case SDEV_OFFLINE: |
| 2073 | break; |
| 2074 | default: |
| 2075 | goto illegal; |
| 2076 | } |
| 2077 | break; |
| 2078 | |
| 2079 | case SDEV_OFFLINE: |
| 2080 | switch (oldstate) { |
| 2081 | case SDEV_CREATED: |
| 2082 | case SDEV_RUNNING: |
| 2083 | case SDEV_QUIESCE: |
| 2084 | case SDEV_BLOCK: |
| 2085 | break; |
| 2086 | default: |
| 2087 | goto illegal; |
| 2088 | } |
| 2089 | break; |
| 2090 | |
| 2091 | case SDEV_BLOCK: |
| 2092 | switch (oldstate) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2093 | case SDEV_RUNNING: |
James Bottomley | 6f4267e | 2008-08-22 16:53:31 -0500 | [diff] [blame] | 2094 | case SDEV_CREATED_BLOCK: |
| 2095 | break; |
| 2096 | default: |
| 2097 | goto illegal; |
| 2098 | } |
| 2099 | break; |
| 2100 | |
| 2101 | case SDEV_CREATED_BLOCK: |
| 2102 | switch (oldstate) { |
| 2103 | case SDEV_CREATED: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2104 | break; |
| 2105 | default: |
| 2106 | goto illegal; |
| 2107 | } |
| 2108 | break; |
| 2109 | |
| 2110 | case SDEV_CANCEL: |
| 2111 | switch (oldstate) { |
| 2112 | case SDEV_CREATED: |
| 2113 | case SDEV_RUNNING: |
Alan Stern | 9ea7290 | 2006-06-23 14:25:34 -0400 | [diff] [blame] | 2114 | case SDEV_QUIESCE: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2115 | case SDEV_OFFLINE: |
| 2116 | case SDEV_BLOCK: |
| 2117 | break; |
| 2118 | default: |
| 2119 | goto illegal; |
| 2120 | } |
| 2121 | break; |
| 2122 | |
| 2123 | case SDEV_DEL: |
| 2124 | switch (oldstate) { |
Brian King | 309bd27 | 2006-06-27 11:10:43 -0500 | [diff] [blame] | 2125 | case SDEV_CREATED: |
| 2126 | case SDEV_RUNNING: |
| 2127 | case SDEV_OFFLINE: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2128 | case SDEV_CANCEL: |
| 2129 | break; |
| 2130 | default: |
| 2131 | goto illegal; |
| 2132 | } |
| 2133 | break; |
| 2134 | |
| 2135 | } |
| 2136 | sdev->sdev_state = state; |
| 2137 | return 0; |
| 2138 | |
| 2139 | illegal: |
| 2140 | SCSI_LOG_ERROR_RECOVERY(1, |
James Bottomley | 9ccfc75 | 2005-10-02 11:45:08 -0500 | [diff] [blame] | 2141 | sdev_printk(KERN_ERR, sdev, |
| 2142 | "Illegal state transition %s->%s\n", |
| 2143 | scsi_device_state_name(oldstate), |
| 2144 | scsi_device_state_name(state)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2145 | ); |
| 2146 | return -EINVAL; |
| 2147 | } |
| 2148 | EXPORT_SYMBOL(scsi_device_set_state); |
| 2149 | |
| 2150 | /** |
Jeff Garzik | a341cd0 | 2007-10-29 17:15:22 -0400 | [diff] [blame] | 2151 | * sdev_evt_emit - emit a single SCSI device uevent |
| 2152 | * @sdev: associated SCSI device |
| 2153 | * @evt: event to emit |
| 2154 | * |
| 2155 | * Send a single uevent (scsi_event) to the associated scsi_device. |
| 2156 | */ |
| 2157 | static void scsi_evt_emit(struct scsi_device *sdev, struct scsi_event *evt) |
| 2158 | { |
| 2159 | int idx = 0; |
| 2160 | char *envp[3]; |
| 2161 | |
| 2162 | switch (evt->evt_type) { |
| 2163 | case SDEV_EVT_MEDIA_CHANGE: |
| 2164 | envp[idx++] = "SDEV_MEDIA_CHANGE=1"; |
| 2165 | break; |
| 2166 | |
| 2167 | default: |
| 2168 | /* do nothing */ |
| 2169 | break; |
| 2170 | } |
| 2171 | |
| 2172 | envp[idx++] = NULL; |
| 2173 | |
| 2174 | kobject_uevent_env(&sdev->sdev_gendev.kobj, KOBJ_CHANGE, envp); |
| 2175 | } |
| 2176 | |
| 2177 | /** |
| 2178 | * sdev_evt_thread - send a uevent for each scsi event |
| 2179 | * @work: work struct for scsi_device |
| 2180 | * |
| 2181 | * Dispatch queued events to their associated scsi_device kobjects |
| 2182 | * as uevents. |
| 2183 | */ |
| 2184 | void scsi_evt_thread(struct work_struct *work) |
| 2185 | { |
| 2186 | struct scsi_device *sdev; |
| 2187 | LIST_HEAD(event_list); |
| 2188 | |
| 2189 | sdev = container_of(work, struct scsi_device, event_work); |
| 2190 | |
| 2191 | while (1) { |
| 2192 | struct scsi_event *evt; |
| 2193 | struct list_head *this, *tmp; |
| 2194 | unsigned long flags; |
| 2195 | |
| 2196 | spin_lock_irqsave(&sdev->list_lock, flags); |
| 2197 | list_splice_init(&sdev->event_list, &event_list); |
| 2198 | spin_unlock_irqrestore(&sdev->list_lock, flags); |
| 2199 | |
| 2200 | if (list_empty(&event_list)) |
| 2201 | break; |
| 2202 | |
| 2203 | list_for_each_safe(this, tmp, &event_list) { |
| 2204 | evt = list_entry(this, struct scsi_event, node); |
| 2205 | list_del(&evt->node); |
| 2206 | scsi_evt_emit(sdev, evt); |
| 2207 | kfree(evt); |
| 2208 | } |
| 2209 | } |
| 2210 | } |
| 2211 | |
| 2212 | /** |
| 2213 | * sdev_evt_send - send asserted event to uevent thread |
| 2214 | * @sdev: scsi_device event occurred on |
| 2215 | * @evt: event to send |
| 2216 | * |
| 2217 | * Assert scsi device event asynchronously. |
| 2218 | */ |
| 2219 | void sdev_evt_send(struct scsi_device *sdev, struct scsi_event *evt) |
| 2220 | { |
| 2221 | unsigned long flags; |
| 2222 | |
Kay Sievers | 4d1566e | 2008-03-19 13:04:47 +0100 | [diff] [blame] | 2223 | #if 0 |
| 2224 | /* FIXME: currently this check eliminates all media change events |
| 2225 | * for polled devices. Need to update to discriminate between AN |
| 2226 | * and polled events */ |
Jeff Garzik | a341cd0 | 2007-10-29 17:15:22 -0400 | [diff] [blame] | 2227 | if (!test_bit(evt->evt_type, sdev->supported_events)) { |
| 2228 | kfree(evt); |
| 2229 | return; |
| 2230 | } |
Kay Sievers | 4d1566e | 2008-03-19 13:04:47 +0100 | [diff] [blame] | 2231 | #endif |
Jeff Garzik | a341cd0 | 2007-10-29 17:15:22 -0400 | [diff] [blame] | 2232 | |
| 2233 | spin_lock_irqsave(&sdev->list_lock, flags); |
| 2234 | list_add_tail(&evt->node, &sdev->event_list); |
| 2235 | schedule_work(&sdev->event_work); |
| 2236 | spin_unlock_irqrestore(&sdev->list_lock, flags); |
| 2237 | } |
| 2238 | EXPORT_SYMBOL_GPL(sdev_evt_send); |
| 2239 | |
| 2240 | /** |
| 2241 | * sdev_evt_alloc - allocate a new scsi event |
| 2242 | * @evt_type: type of event to allocate |
| 2243 | * @gfpflags: GFP flags for allocation |
| 2244 | * |
| 2245 | * Allocates and returns a new scsi_event. |
| 2246 | */ |
| 2247 | struct scsi_event *sdev_evt_alloc(enum scsi_device_event evt_type, |
| 2248 | gfp_t gfpflags) |
| 2249 | { |
| 2250 | struct scsi_event *evt = kzalloc(sizeof(struct scsi_event), gfpflags); |
| 2251 | if (!evt) |
| 2252 | return NULL; |
| 2253 | |
| 2254 | evt->evt_type = evt_type; |
| 2255 | INIT_LIST_HEAD(&evt->node); |
| 2256 | |
| 2257 | /* evt_type-specific initialization, if any */ |
| 2258 | switch (evt_type) { |
| 2259 | case SDEV_EVT_MEDIA_CHANGE: |
| 2260 | default: |
| 2261 | /* do nothing */ |
| 2262 | break; |
| 2263 | } |
| 2264 | |
| 2265 | return evt; |
| 2266 | } |
| 2267 | EXPORT_SYMBOL_GPL(sdev_evt_alloc); |
| 2268 | |
| 2269 | /** |
| 2270 | * sdev_evt_send_simple - send asserted event to uevent thread |
| 2271 | * @sdev: scsi_device event occurred on |
| 2272 | * @evt_type: type of event to send |
| 2273 | * @gfpflags: GFP flags for allocation |
| 2274 | * |
| 2275 | * Assert scsi device event asynchronously, given an event type. |
| 2276 | */ |
| 2277 | void sdev_evt_send_simple(struct scsi_device *sdev, |
| 2278 | enum scsi_device_event evt_type, gfp_t gfpflags) |
| 2279 | { |
| 2280 | struct scsi_event *evt = sdev_evt_alloc(evt_type, gfpflags); |
| 2281 | if (!evt) { |
| 2282 | sdev_printk(KERN_ERR, sdev, "event %d eaten due to OOM\n", |
| 2283 | evt_type); |
| 2284 | return; |
| 2285 | } |
| 2286 | |
| 2287 | sdev_evt_send(sdev, evt); |
| 2288 | } |
| 2289 | EXPORT_SYMBOL_GPL(sdev_evt_send_simple); |
| 2290 | |
| 2291 | /** |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2292 | * scsi_device_quiesce - Block user issued commands. |
| 2293 | * @sdev: scsi device to quiesce. |
| 2294 | * |
| 2295 | * This works by trying to transition to the SDEV_QUIESCE state |
| 2296 | * (which must be a legal transition). When the device is in this |
| 2297 | * state, only special requests will be accepted, all others will |
| 2298 | * be deferred. Since special requests may also be requeued requests, |
| 2299 | * a successful return doesn't guarantee the device will be |
| 2300 | * totally quiescent. |
| 2301 | * |
| 2302 | * Must be called with user context, may sleep. |
| 2303 | * |
| 2304 | * Returns zero if unsuccessful or an error if not. |
Rob Landley | eb44820 | 2007-11-03 13:30:39 -0500 | [diff] [blame] | 2305 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2306 | int |
| 2307 | scsi_device_quiesce(struct scsi_device *sdev) |
| 2308 | { |
| 2309 | int err = scsi_device_set_state(sdev, SDEV_QUIESCE); |
| 2310 | if (err) |
| 2311 | return err; |
| 2312 | |
| 2313 | scsi_run_queue(sdev->request_queue); |
| 2314 | while (sdev->device_busy) { |
| 2315 | msleep_interruptible(200); |
| 2316 | scsi_run_queue(sdev->request_queue); |
| 2317 | } |
| 2318 | return 0; |
| 2319 | } |
| 2320 | EXPORT_SYMBOL(scsi_device_quiesce); |
| 2321 | |
| 2322 | /** |
| 2323 | * scsi_device_resume - Restart user issued commands to a quiesced device. |
| 2324 | * @sdev: scsi device to resume. |
| 2325 | * |
| 2326 | * Moves the device from quiesced back to running and restarts the |
| 2327 | * queues. |
| 2328 | * |
| 2329 | * Must be called with user context, may sleep. |
Rob Landley | eb44820 | 2007-11-03 13:30:39 -0500 | [diff] [blame] | 2330 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2331 | void |
| 2332 | scsi_device_resume(struct scsi_device *sdev) |
| 2333 | { |
| 2334 | if(scsi_device_set_state(sdev, SDEV_RUNNING)) |
| 2335 | return; |
| 2336 | scsi_run_queue(sdev->request_queue); |
| 2337 | } |
| 2338 | EXPORT_SYMBOL(scsi_device_resume); |
| 2339 | |
| 2340 | static void |
| 2341 | device_quiesce_fn(struct scsi_device *sdev, void *data) |
| 2342 | { |
| 2343 | scsi_device_quiesce(sdev); |
| 2344 | } |
| 2345 | |
| 2346 | void |
| 2347 | scsi_target_quiesce(struct scsi_target *starget) |
| 2348 | { |
| 2349 | starget_for_each_device(starget, NULL, device_quiesce_fn); |
| 2350 | } |
| 2351 | EXPORT_SYMBOL(scsi_target_quiesce); |
| 2352 | |
| 2353 | static void |
| 2354 | device_resume_fn(struct scsi_device *sdev, void *data) |
| 2355 | { |
| 2356 | scsi_device_resume(sdev); |
| 2357 | } |
| 2358 | |
| 2359 | void |
| 2360 | scsi_target_resume(struct scsi_target *starget) |
| 2361 | { |
| 2362 | starget_for_each_device(starget, NULL, device_resume_fn); |
| 2363 | } |
| 2364 | EXPORT_SYMBOL(scsi_target_resume); |
| 2365 | |
| 2366 | /** |
Rob Landley | eb44820 | 2007-11-03 13:30:39 -0500 | [diff] [blame] | 2367 | * 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] | 2368 | * @sdev: device to block |
| 2369 | * |
| 2370 | * Block request made by scsi lld's to temporarily stop all |
| 2371 | * scsi commands on the specified device. Called from interrupt |
| 2372 | * or normal process context. |
| 2373 | * |
| 2374 | * Returns zero if successful or error if not |
| 2375 | * |
| 2376 | * Notes: |
| 2377 | * This routine transitions the device to the SDEV_BLOCK state |
| 2378 | * (which must be a legal transition). When the device is in this |
| 2379 | * state, all commands are deferred until the scsi lld reenables |
| 2380 | * the device with scsi_device_unblock or device_block_tmo fires. |
| 2381 | * This routine assumes the host_lock is held on entry. |
Rob Landley | eb44820 | 2007-11-03 13:30:39 -0500 | [diff] [blame] | 2382 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2383 | int |
| 2384 | scsi_internal_device_block(struct scsi_device *sdev) |
| 2385 | { |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 2386 | struct request_queue *q = sdev->request_queue; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2387 | unsigned long flags; |
| 2388 | int err = 0; |
| 2389 | |
| 2390 | err = scsi_device_set_state(sdev, SDEV_BLOCK); |
James Bottomley | 6f4267e | 2008-08-22 16:53:31 -0500 | [diff] [blame] | 2391 | if (err) { |
| 2392 | err = scsi_device_set_state(sdev, SDEV_CREATED_BLOCK); |
| 2393 | |
| 2394 | if (err) |
| 2395 | return err; |
| 2396 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2397 | |
| 2398 | /* |
| 2399 | * The device has transitioned to SDEV_BLOCK. Stop the |
| 2400 | * block layer from calling the midlayer with this device's |
| 2401 | * request queue. |
| 2402 | */ |
| 2403 | spin_lock_irqsave(q->queue_lock, flags); |
| 2404 | blk_stop_queue(q); |
| 2405 | spin_unlock_irqrestore(q->queue_lock, flags); |
| 2406 | |
| 2407 | return 0; |
| 2408 | } |
| 2409 | EXPORT_SYMBOL_GPL(scsi_internal_device_block); |
| 2410 | |
| 2411 | /** |
| 2412 | * scsi_internal_device_unblock - resume a device after a block request |
| 2413 | * @sdev: device to resume |
| 2414 | * |
| 2415 | * Called by scsi lld's or the midlayer to restart the device queue |
| 2416 | * for the previously suspended scsi device. Called from interrupt or |
| 2417 | * normal process context. |
| 2418 | * |
| 2419 | * Returns zero if successful or error if not. |
| 2420 | * |
| 2421 | * Notes: |
| 2422 | * This routine transitions the device to the SDEV_RUNNING state |
| 2423 | * (which must be a legal transition) allowing the midlayer to |
| 2424 | * goose the queue for this device. This routine assumes the |
| 2425 | * host_lock is held upon entry. |
Rob Landley | eb44820 | 2007-11-03 13:30:39 -0500 | [diff] [blame] | 2426 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2427 | int |
| 2428 | scsi_internal_device_unblock(struct scsi_device *sdev) |
| 2429 | { |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 2430 | struct request_queue *q = sdev->request_queue; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2431 | int err; |
| 2432 | unsigned long flags; |
| 2433 | |
| 2434 | /* |
| 2435 | * Try to transition the scsi device to SDEV_RUNNING |
| 2436 | * and goose the device queue if successful. |
| 2437 | */ |
| 2438 | err = scsi_device_set_state(sdev, SDEV_RUNNING); |
James Bottomley | 6f4267e | 2008-08-22 16:53:31 -0500 | [diff] [blame] | 2439 | if (err) { |
| 2440 | err = scsi_device_set_state(sdev, SDEV_CREATED); |
| 2441 | |
| 2442 | if (err) |
| 2443 | return err; |
| 2444 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2445 | |
| 2446 | spin_lock_irqsave(q->queue_lock, flags); |
| 2447 | blk_start_queue(q); |
| 2448 | spin_unlock_irqrestore(q->queue_lock, flags); |
| 2449 | |
| 2450 | return 0; |
| 2451 | } |
| 2452 | EXPORT_SYMBOL_GPL(scsi_internal_device_unblock); |
| 2453 | |
| 2454 | static void |
| 2455 | device_block(struct scsi_device *sdev, void *data) |
| 2456 | { |
| 2457 | scsi_internal_device_block(sdev); |
| 2458 | } |
| 2459 | |
| 2460 | static int |
| 2461 | target_block(struct device *dev, void *data) |
| 2462 | { |
| 2463 | if (scsi_is_target_device(dev)) |
| 2464 | starget_for_each_device(to_scsi_target(dev), NULL, |
| 2465 | device_block); |
| 2466 | return 0; |
| 2467 | } |
| 2468 | |
| 2469 | void |
| 2470 | scsi_target_block(struct device *dev) |
| 2471 | { |
| 2472 | if (scsi_is_target_device(dev)) |
| 2473 | starget_for_each_device(to_scsi_target(dev), NULL, |
| 2474 | device_block); |
| 2475 | else |
| 2476 | device_for_each_child(dev, NULL, target_block); |
| 2477 | } |
| 2478 | EXPORT_SYMBOL_GPL(scsi_target_block); |
| 2479 | |
| 2480 | static void |
| 2481 | device_unblock(struct scsi_device *sdev, void *data) |
| 2482 | { |
| 2483 | scsi_internal_device_unblock(sdev); |
| 2484 | } |
| 2485 | |
| 2486 | static int |
| 2487 | target_unblock(struct device *dev, void *data) |
| 2488 | { |
| 2489 | if (scsi_is_target_device(dev)) |
| 2490 | starget_for_each_device(to_scsi_target(dev), NULL, |
| 2491 | device_unblock); |
| 2492 | return 0; |
| 2493 | } |
| 2494 | |
| 2495 | void |
| 2496 | scsi_target_unblock(struct device *dev) |
| 2497 | { |
| 2498 | if (scsi_is_target_device(dev)) |
| 2499 | starget_for_each_device(to_scsi_target(dev), NULL, |
| 2500 | device_unblock); |
| 2501 | else |
| 2502 | device_for_each_child(dev, NULL, target_unblock); |
| 2503 | } |
| 2504 | EXPORT_SYMBOL_GPL(scsi_target_unblock); |
Guennadi Liakhovetski | cdb8c2a | 2006-04-02 21:57:43 +0200 | [diff] [blame] | 2505 | |
| 2506 | /** |
| 2507 | * scsi_kmap_atomic_sg - find and atomically map an sg-elemnt |
Rob Landley | eb44820 | 2007-11-03 13:30:39 -0500 | [diff] [blame] | 2508 | * @sgl: scatter-gather list |
Guennadi Liakhovetski | cdb8c2a | 2006-04-02 21:57:43 +0200 | [diff] [blame] | 2509 | * @sg_count: number of segments in sg |
| 2510 | * @offset: offset in bytes into sg, on return offset into the mapped area |
| 2511 | * @len: bytes to map, on return number of bytes mapped |
| 2512 | * |
| 2513 | * Returns virtual address of the start of the mapped page |
| 2514 | */ |
Jens Axboe | c6132da | 2007-10-16 11:08:49 +0200 | [diff] [blame] | 2515 | void *scsi_kmap_atomic_sg(struct scatterlist *sgl, int sg_count, |
Guennadi Liakhovetski | cdb8c2a | 2006-04-02 21:57:43 +0200 | [diff] [blame] | 2516 | size_t *offset, size_t *len) |
| 2517 | { |
| 2518 | int i; |
| 2519 | size_t sg_len = 0, len_complete = 0; |
Jens Axboe | c6132da | 2007-10-16 11:08:49 +0200 | [diff] [blame] | 2520 | struct scatterlist *sg; |
Guennadi Liakhovetski | cdb8c2a | 2006-04-02 21:57:43 +0200 | [diff] [blame] | 2521 | struct page *page; |
| 2522 | |
Andrew Morton | 22cfefb | 2007-02-05 16:39:03 -0800 | [diff] [blame] | 2523 | WARN_ON(!irqs_disabled()); |
| 2524 | |
Jens Axboe | c6132da | 2007-10-16 11:08:49 +0200 | [diff] [blame] | 2525 | for_each_sg(sgl, sg, sg_count, i) { |
Guennadi Liakhovetski | cdb8c2a | 2006-04-02 21:57:43 +0200 | [diff] [blame] | 2526 | len_complete = sg_len; /* Complete sg-entries */ |
Jens Axboe | c6132da | 2007-10-16 11:08:49 +0200 | [diff] [blame] | 2527 | sg_len += sg->length; |
Guennadi Liakhovetski | cdb8c2a | 2006-04-02 21:57:43 +0200 | [diff] [blame] | 2528 | if (sg_len > *offset) |
| 2529 | break; |
| 2530 | } |
| 2531 | |
| 2532 | if (unlikely(i == sg_count)) { |
Andrew Morton | 169e1a2 | 2006-04-18 21:09:08 -0700 | [diff] [blame] | 2533 | printk(KERN_ERR "%s: Bytes in sg: %zu, requested offset %zu, " |
| 2534 | "elements %d\n", |
Harvey Harrison | cadbd4a | 2008-07-03 23:47:27 -0700 | [diff] [blame] | 2535 | __func__, sg_len, *offset, sg_count); |
Guennadi Liakhovetski | cdb8c2a | 2006-04-02 21:57:43 +0200 | [diff] [blame] | 2536 | WARN_ON(1); |
| 2537 | return NULL; |
| 2538 | } |
| 2539 | |
| 2540 | /* Offset starting from the beginning of first page in this sg-entry */ |
Jens Axboe | c6132da | 2007-10-16 11:08:49 +0200 | [diff] [blame] | 2541 | *offset = *offset - len_complete + sg->offset; |
Guennadi Liakhovetski | cdb8c2a | 2006-04-02 21:57:43 +0200 | [diff] [blame] | 2542 | |
| 2543 | /* Assumption: contiguous pages can be accessed as "page + i" */ |
Jens Axboe | 45711f1 | 2007-10-22 21:19:53 +0200 | [diff] [blame] | 2544 | page = nth_page(sg_page(sg), (*offset >> PAGE_SHIFT)); |
Guennadi Liakhovetski | cdb8c2a | 2006-04-02 21:57:43 +0200 | [diff] [blame] | 2545 | *offset &= ~PAGE_MASK; |
| 2546 | |
| 2547 | /* Bytes in this sg-entry from *offset to the end of the page */ |
| 2548 | sg_len = PAGE_SIZE - *offset; |
| 2549 | if (*len > sg_len) |
| 2550 | *len = sg_len; |
| 2551 | |
| 2552 | return kmap_atomic(page, KM_BIO_SRC_IRQ); |
| 2553 | } |
| 2554 | EXPORT_SYMBOL(scsi_kmap_atomic_sg); |
| 2555 | |
| 2556 | /** |
Rob Landley | eb44820 | 2007-11-03 13:30:39 -0500 | [diff] [blame] | 2557 | * 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] | 2558 | * @virt: virtual address to be unmapped |
| 2559 | */ |
| 2560 | void scsi_kunmap_atomic_sg(void *virt) |
| 2561 | { |
| 2562 | kunmap_atomic(virt, KM_BIO_SRC_IRQ); |
| 2563 | } |
| 2564 | EXPORT_SYMBOL(scsi_kunmap_atomic_sg); |