Jens Axboe | 242f9dc | 2008-09-14 05:55:09 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Functions related to generic timeout handling of requests. |
| 3 | */ |
| 4 | #include <linux/kernel.h> |
| 5 | #include <linux/module.h> |
| 6 | #include <linux/blkdev.h> |
Jens Axboe | 581d4e2 | 2008-09-14 05:56:33 -0700 | [diff] [blame] | 7 | #include <linux/fault-inject.h> |
Jens Axboe | 242f9dc | 2008-09-14 05:55:09 -0700 | [diff] [blame] | 8 | |
| 9 | #include "blk.h" |
Christoph Hellwig | 9041583 | 2014-09-22 10:21:48 -0600 | [diff] [blame] | 10 | #include "blk-mq.h" |
Jens Axboe | 242f9dc | 2008-09-14 05:55:09 -0700 | [diff] [blame] | 11 | |
Jens Axboe | 581d4e2 | 2008-09-14 05:56:33 -0700 | [diff] [blame] | 12 | #ifdef CONFIG_FAIL_IO_TIMEOUT |
| 13 | |
| 14 | static DECLARE_FAULT_ATTR(fail_io_timeout); |
| 15 | |
| 16 | static int __init setup_fail_io_timeout(char *str) |
| 17 | { |
| 18 | return setup_fault_attr(&fail_io_timeout, str); |
| 19 | } |
| 20 | __setup("fail_io_timeout=", setup_fail_io_timeout); |
| 21 | |
| 22 | int blk_should_fake_timeout(struct request_queue *q) |
| 23 | { |
| 24 | if (!test_bit(QUEUE_FLAG_FAIL_IO, &q->queue_flags)) |
| 25 | return 0; |
| 26 | |
| 27 | return should_fail(&fail_io_timeout, 1); |
| 28 | } |
| 29 | |
| 30 | static int __init fail_io_timeout_debugfs(void) |
| 31 | { |
Akinobu Mita | dd48c08 | 2011-08-03 16:21:01 -0700 | [diff] [blame] | 32 | struct dentry *dir = fault_create_debugfs_attr("fail_io_timeout", |
| 33 | NULL, &fail_io_timeout); |
| 34 | |
Duan Jiong | 8616ebb | 2013-11-06 15:55:44 +0800 | [diff] [blame] | 35 | return PTR_ERR_OR_ZERO(dir); |
Jens Axboe | 581d4e2 | 2008-09-14 05:56:33 -0700 | [diff] [blame] | 36 | } |
| 37 | |
| 38 | late_initcall(fail_io_timeout_debugfs); |
| 39 | |
| 40 | ssize_t part_timeout_show(struct device *dev, struct device_attribute *attr, |
| 41 | char *buf) |
| 42 | { |
| 43 | struct gendisk *disk = dev_to_disk(dev); |
| 44 | int set = test_bit(QUEUE_FLAG_FAIL_IO, &disk->queue->queue_flags); |
| 45 | |
| 46 | return sprintf(buf, "%d\n", set != 0); |
| 47 | } |
| 48 | |
| 49 | ssize_t part_timeout_store(struct device *dev, struct device_attribute *attr, |
| 50 | const char *buf, size_t count) |
| 51 | { |
| 52 | struct gendisk *disk = dev_to_disk(dev); |
| 53 | int val; |
| 54 | |
| 55 | if (count) { |
| 56 | struct request_queue *q = disk->queue; |
| 57 | char *p = (char *) buf; |
| 58 | |
| 59 | val = simple_strtoul(p, &p, 10); |
| 60 | spin_lock_irq(q->queue_lock); |
| 61 | if (val) |
| 62 | queue_flag_set(QUEUE_FLAG_FAIL_IO, q); |
| 63 | else |
| 64 | queue_flag_clear(QUEUE_FLAG_FAIL_IO, q); |
| 65 | spin_unlock_irq(q->queue_lock); |
| 66 | } |
| 67 | |
| 68 | return count; |
| 69 | } |
| 70 | |
| 71 | #endif /* CONFIG_FAIL_IO_TIMEOUT */ |
| 72 | |
Jens Axboe | 242f9dc | 2008-09-14 05:55:09 -0700 | [diff] [blame] | 73 | /* |
| 74 | * blk_delete_timer - Delete/cancel timer for a given function. |
| 75 | * @req: request that we are canceling timer for |
| 76 | * |
| 77 | */ |
| 78 | void blk_delete_timer(struct request *req) |
| 79 | { |
Jens Axboe | 242f9dc | 2008-09-14 05:55:09 -0700 | [diff] [blame] | 80 | list_del_init(&req->timeout_list); |
Jens Axboe | 242f9dc | 2008-09-14 05:55:09 -0700 | [diff] [blame] | 81 | } |
| 82 | |
| 83 | static void blk_rq_timed_out(struct request *req) |
| 84 | { |
| 85 | struct request_queue *q = req->q; |
Hannes Reinecke | 80bd718 | 2013-01-30 09:26:17 +0000 | [diff] [blame] | 86 | enum blk_eh_timer_return ret = BLK_EH_RESET_TIMER; |
Jens Axboe | 242f9dc | 2008-09-14 05:55:09 -0700 | [diff] [blame] | 87 | |
Hannes Reinecke | 80bd718 | 2013-01-30 09:26:17 +0000 | [diff] [blame] | 88 | if (q->rq_timed_out_fn) |
| 89 | ret = q->rq_timed_out_fn(req); |
Jens Axboe | 242f9dc | 2008-09-14 05:55:09 -0700 | [diff] [blame] | 90 | switch (ret) { |
| 91 | case BLK_EH_HANDLED: |
Jens Axboe | 320ae51 | 2013-10-24 09:20:05 +0100 | [diff] [blame] | 92 | /* Can we use req->errors here? */ |
Christoph Hellwig | 46f92d4 | 2014-09-13 16:40:12 -0700 | [diff] [blame] | 93 | __blk_complete_request(req); |
Jens Axboe | 242f9dc | 2008-09-14 05:55:09 -0700 | [diff] [blame] | 94 | break; |
| 95 | case BLK_EH_RESET_TIMER: |
Jens Axboe | 87ee7b1 | 2014-04-24 08:51:47 -0600 | [diff] [blame] | 96 | blk_add_timer(req); |
Jeff Moyer | 4912aa6 | 2013-10-08 14:36:41 -0400 | [diff] [blame] | 97 | blk_clear_rq_complete(req); |
Jens Axboe | 242f9dc | 2008-09-14 05:55:09 -0700 | [diff] [blame] | 98 | break; |
| 99 | case BLK_EH_NOT_HANDLED: |
| 100 | /* |
| 101 | * LLD handles this for now but in the future |
| 102 | * we can send a request msg to abort the command |
| 103 | * and we can move more of the generic scsi eh code to |
| 104 | * the blk layer. |
| 105 | */ |
| 106 | break; |
| 107 | default: |
| 108 | printk(KERN_ERR "block: bad eh return: %d\n", ret); |
| 109 | break; |
| 110 | } |
| 111 | } |
| 112 | |
Christoph Hellwig | 46f92d4 | 2014-09-13 16:40:12 -0700 | [diff] [blame] | 113 | static void blk_rq_check_expired(struct request *rq, unsigned long *next_timeout, |
Jens Axboe | 320ae51 | 2013-10-24 09:20:05 +0100 | [diff] [blame] | 114 | unsigned int *next_set) |
| 115 | { |
| 116 | if (time_after_eq(jiffies, rq->deadline)) { |
| 117 | list_del_init(&rq->timeout_list); |
| 118 | |
| 119 | /* |
| 120 | * Check if we raced with end io completion |
| 121 | */ |
| 122 | if (!blk_mark_rq_complete(rq)) |
| 123 | blk_rq_timed_out(rq); |
| 124 | } else if (!*next_set || time_after(*next_timeout, rq->deadline)) { |
| 125 | *next_timeout = rq->deadline; |
| 126 | *next_set = 1; |
| 127 | } |
| 128 | } |
| 129 | |
Christoph Hellwig | 287922e | 2015-10-30 20:57:30 +0800 | [diff] [blame] | 130 | void blk_timeout_work(struct work_struct *work) |
Jens Axboe | 242f9dc | 2008-09-14 05:55:09 -0700 | [diff] [blame] | 131 | { |
Christoph Hellwig | 287922e | 2015-10-30 20:57:30 +0800 | [diff] [blame] | 132 | struct request_queue *q = |
| 133 | container_of(work, struct request_queue, timeout_work); |
malahal@us.ibm.com | 565e411 | 2008-10-30 08:51:58 +0100 | [diff] [blame] | 134 | unsigned long flags, next = 0; |
Jens Axboe | 242f9dc | 2008-09-14 05:55:09 -0700 | [diff] [blame] | 135 | struct request *rq, *tmp; |
Richard Kennedy | a534dbe | 2010-04-14 20:54:03 +0200 | [diff] [blame] | 136 | int next_set = 0; |
Jens Axboe | 242f9dc | 2008-09-14 05:55:09 -0700 | [diff] [blame] | 137 | |
| 138 | spin_lock_irqsave(q->queue_lock, flags); |
| 139 | |
Jens Axboe | 320ae51 | 2013-10-24 09:20:05 +0100 | [diff] [blame] | 140 | list_for_each_entry_safe(rq, tmp, &q->timeout_list, timeout_list) |
| 141 | blk_rq_check_expired(rq, &next, &next_set); |
Jens Axboe | 242f9dc | 2008-09-14 05:55:09 -0700 | [diff] [blame] | 142 | |
Richard Kennedy | a534dbe | 2010-04-14 20:54:03 +0200 | [diff] [blame] | 143 | if (next_set) |
Alan Stern | 7838c15 | 2008-11-06 08:42:49 +0100 | [diff] [blame] | 144 | mod_timer(&q->timeout, round_jiffies_up(next)); |
Jens Axboe | 242f9dc | 2008-09-14 05:55:09 -0700 | [diff] [blame] | 145 | |
| 146 | spin_unlock_irqrestore(q->queue_lock, flags); |
| 147 | } |
| 148 | |
| 149 | /** |
| 150 | * blk_abort_request -- Request request recovery for the specified command |
| 151 | * @req: pointer to the request of interest |
| 152 | * |
| 153 | * This function requests that the block layer start recovery for the |
| 154 | * request by deleting the timer and calling the q's timeout function. |
| 155 | * LLDDs who implement their own error recovery MAY ignore the timeout |
| 156 | * event if they generated blk_abort_req. Must hold queue lock. |
| 157 | */ |
| 158 | void blk_abort_request(struct request *req) |
| 159 | { |
Jens Axboe | 7ba1fba | 2008-09-16 09:54:11 -0700 | [diff] [blame] | 160 | if (blk_mark_rq_complete(req)) |
| 161 | return; |
Christoph Hellwig | 55ce0da | 2015-10-30 20:47:04 +0800 | [diff] [blame] | 162 | |
| 163 | if (req->q->mq_ops) { |
Christoph Hellwig | 9041583 | 2014-09-22 10:21:48 -0600 | [diff] [blame] | 164 | blk_mq_rq_timed_out(req, false); |
Christoph Hellwig | 55ce0da | 2015-10-30 20:47:04 +0800 | [diff] [blame] | 165 | } else { |
| 166 | blk_delete_timer(req); |
Christoph Hellwig | 9041583 | 2014-09-22 10:21:48 -0600 | [diff] [blame] | 167 | blk_rq_timed_out(req); |
Christoph Hellwig | 55ce0da | 2015-10-30 20:47:04 +0800 | [diff] [blame] | 168 | } |
Jens Axboe | 242f9dc | 2008-09-14 05:55:09 -0700 | [diff] [blame] | 169 | } |
| 170 | EXPORT_SYMBOL_GPL(blk_abort_request); |
| 171 | |
Jens Axboe | 0d2602c | 2014-05-13 15:10:52 -0600 | [diff] [blame] | 172 | unsigned long blk_rq_timeout(unsigned long timeout) |
| 173 | { |
| 174 | unsigned long maxt; |
| 175 | |
| 176 | maxt = round_jiffies_up(jiffies + BLK_MAX_TIMEOUT); |
| 177 | if (time_after(timeout, maxt)) |
| 178 | timeout = maxt; |
| 179 | |
| 180 | return timeout; |
| 181 | } |
| 182 | |
Christoph Hellwig | c4a634f | 2014-04-25 14:14:48 +0200 | [diff] [blame] | 183 | /** |
| 184 | * blk_add_timer - Start timeout timer for a single request |
| 185 | * @req: request that is about to start running. |
| 186 | * |
| 187 | * Notes: |
| 188 | * Each request has its own timer, and as it is added to the queue, we |
| 189 | * set up the timer. When the request completes, we cancel the timer. |
Jens Axboe | 3b627a3 | 2015-11-24 15:58:53 -0700 | [diff] [blame] | 190 | * Queue lock must be held for the non-mq case, mq case doesn't care. |
Christoph Hellwig | c4a634f | 2014-04-25 14:14:48 +0200 | [diff] [blame] | 191 | */ |
| 192 | void blk_add_timer(struct request *req) |
Jens Axboe | 242f9dc | 2008-09-14 05:55:09 -0700 | [diff] [blame] | 193 | { |
| 194 | struct request_queue *q = req->q; |
| 195 | unsigned long expiry; |
| 196 | |
Ming Lei | 5e940aa | 2014-09-19 21:53:46 +0800 | [diff] [blame] | 197 | /* blk-mq has its own handler, so we don't need ->rq_timed_out_fn */ |
| 198 | if (!q->mq_ops && !q->rq_timed_out_fn) |
Jens Axboe | 242f9dc | 2008-09-14 05:55:09 -0700 | [diff] [blame] | 199 | return; |
| 200 | |
| 201 | BUG_ON(!list_empty(&req->timeout_list)); |
Jens Axboe | 242f9dc | 2008-09-14 05:55:09 -0700 | [diff] [blame] | 202 | |
Tejun Heo | 2eef33e | 2009-04-23 11:05:18 +0900 | [diff] [blame] | 203 | /* |
| 204 | * Some LLDs, like scsi, peek at the timeout to prevent a |
| 205 | * command from being retried forever. |
| 206 | */ |
| 207 | if (!req->timeout) |
Jens Axboe | 242f9dc | 2008-09-14 05:55:09 -0700 | [diff] [blame] | 208 | req->timeout = q->rq_timeout; |
Tejun Heo | 2eef33e | 2009-04-23 11:05:18 +0900 | [diff] [blame] | 209 | |
| 210 | req->deadline = jiffies + req->timeout; |
Jens Axboe | 3b627a3 | 2015-11-24 15:58:53 -0700 | [diff] [blame] | 211 | |
| 212 | /* |
| 213 | * Only the non-mq case needs to add the request to a protected list. |
| 214 | * For the mq case we simply scan the tag map. |
| 215 | */ |
Christoph Hellwig | c4a634f | 2014-04-25 14:14:48 +0200 | [diff] [blame] | 216 | if (!q->mq_ops) |
| 217 | list_add_tail(&req->timeout_list, &req->q->timeout_list); |
Jens Axboe | 242f9dc | 2008-09-14 05:55:09 -0700 | [diff] [blame] | 218 | |
| 219 | /* |
| 220 | * If the timer isn't already pending or this timeout is earlier |
Alan Stern | 7838c15 | 2008-11-06 08:42:49 +0100 | [diff] [blame] | 221 | * than an existing one, modify the timer. Round up to next nearest |
Jens Axboe | 242f9dc | 2008-09-14 05:55:09 -0700 | [diff] [blame] | 222 | * second. |
| 223 | */ |
Jens Axboe | 0d2602c | 2014-05-13 15:10:52 -0600 | [diff] [blame] | 224 | expiry = blk_rq_timeout(round_jiffies_up(req->deadline)); |
Jens Axboe | 242f9dc | 2008-09-14 05:55:09 -0700 | [diff] [blame] | 225 | |
| 226 | if (!timer_pending(&q->timeout) || |
Jens Axboe | f793aa5 | 2014-04-16 11:36:54 -0600 | [diff] [blame] | 227 | time_before(expiry, q->timeout.expires)) { |
| 228 | unsigned long diff = q->timeout.expires - expiry; |
| 229 | |
| 230 | /* |
| 231 | * Due to added timer slack to group timers, the timer |
| 232 | * will often be a little in front of what we asked for. |
| 233 | * So apply some tolerance here too, otherwise we keep |
| 234 | * modifying the timer because expires for value X |
| 235 | * will be X + something. |
| 236 | */ |
Jens Axboe | c7bca41 | 2014-05-30 15:41:39 -0600 | [diff] [blame] | 237 | if (!timer_pending(&q->timeout) || (diff >= HZ / 2)) |
Jens Axboe | f793aa5 | 2014-04-16 11:36:54 -0600 | [diff] [blame] | 238 | mod_timer(&q->timeout, expiry); |
| 239 | } |
Jens Axboe | 320ae51 | 2013-10-24 09:20:05 +0100 | [diff] [blame] | 240 | |
| 241 | } |