Jens Axboe | 2056a78 | 2006-03-23 20:00:26 +0100 | [diff] [blame] | 1 | /* |
Jens Axboe | 0fe2347 | 2006-09-04 15:41:16 +0200 | [diff] [blame] | 2 | * Copyright (C) 2006 Jens Axboe <axboe@kernel.dk> |
Jens Axboe | 2056a78 | 2006-03-23 20:00:26 +0100 | [diff] [blame] | 3 | * |
| 4 | * This program is free software; you can redistribute it and/or modify |
| 5 | * it under the terms of the GNU General Public License version 2 as |
| 6 | * published by the Free Software Foundation. |
| 7 | * |
| 8 | * This program is distributed in the hope that it will be useful, |
| 9 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 10 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 11 | * GNU General Public License for more details. |
| 12 | * |
| 13 | * You should have received a copy of the GNU General Public License |
| 14 | * along with this program; if not, write to the Free Software |
| 15 | * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA |
| 16 | * |
| 17 | */ |
Jens Axboe | 2056a78 | 2006-03-23 20:00:26 +0100 | [diff] [blame] | 18 | #include <linux/kernel.h> |
| 19 | #include <linux/blkdev.h> |
| 20 | #include <linux/blktrace_api.h> |
| 21 | #include <linux/percpu.h> |
| 22 | #include <linux/init.h> |
| 23 | #include <linux/mutex.h> |
| 24 | #include <linux/debugfs.h> |
Olaf Kirch | be1c634 | 2006-12-01 10:39:12 +0100 | [diff] [blame] | 25 | #include <linux/time.h> |
Jens Axboe | 2056a78 | 2006-03-23 20:00:26 +0100 | [diff] [blame] | 26 | #include <asm/uaccess.h> |
| 27 | |
Jens Axboe | 2056a78 | 2006-03-23 20:00:26 +0100 | [diff] [blame] | 28 | static unsigned int blktrace_seq __read_mostly = 1; |
| 29 | |
| 30 | /* |
Olaf Kirch | be1c634 | 2006-12-01 10:39:12 +0100 | [diff] [blame] | 31 | * Send out a notify message. |
| 32 | */ |
Jens Axboe | a863055 | 2006-12-04 09:30:58 +0100 | [diff] [blame] | 33 | static void trace_note(struct blk_trace *bt, pid_t pid, int action, |
| 34 | const void *data, size_t len) |
Olaf Kirch | be1c634 | 2006-12-01 10:39:12 +0100 | [diff] [blame] | 35 | { |
| 36 | struct blk_io_trace *t; |
Olaf Kirch | be1c634 | 2006-12-01 10:39:12 +0100 | [diff] [blame] | 37 | |
| 38 | t = relay_reserve(bt->rchan, sizeof(*t) + len); |
Jens Axboe | d3d9d2a | 2006-12-04 09:27:41 +0100 | [diff] [blame] | 39 | if (t) { |
| 40 | const int cpu = smp_processor_id(); |
Olaf Kirch | be1c634 | 2006-12-01 10:39:12 +0100 | [diff] [blame] | 41 | |
Jens Axboe | d3d9d2a | 2006-12-04 09:27:41 +0100 | [diff] [blame] | 42 | t->magic = BLK_IO_TRACE_MAGIC | BLK_IO_TRACE_VERSION; |
Ingo Molnar | 2997c8c | 2008-01-11 13:35:54 +0100 | [diff] [blame] | 43 | t->time = ktime_to_ns(ktime_get()); |
Jens Axboe | d3d9d2a | 2006-12-04 09:27:41 +0100 | [diff] [blame] | 44 | t->device = bt->dev; |
| 45 | t->action = action; |
| 46 | t->pid = pid; |
| 47 | t->cpu = cpu; |
| 48 | t->pdu_len = len; |
| 49 | memcpy((void *) t + sizeof(*t), data, len); |
| 50 | } |
Olaf Kirch | be1c634 | 2006-12-01 10:39:12 +0100 | [diff] [blame] | 51 | } |
| 52 | |
| 53 | /* |
Jens Axboe | 2056a78 | 2006-03-23 20:00:26 +0100 | [diff] [blame] | 54 | * Send out a notify for this process, if we haven't done so since a trace |
| 55 | * started |
| 56 | */ |
| 57 | static void trace_note_tsk(struct blk_trace *bt, struct task_struct *tsk) |
| 58 | { |
Jens Axboe | a863055 | 2006-12-04 09:30:58 +0100 | [diff] [blame] | 59 | tsk->btrace_seq = blktrace_seq; |
| 60 | trace_note(bt, tsk->pid, BLK_TN_PROCESS, tsk->comm, sizeof(tsk->comm)); |
Olaf Kirch | be1c634 | 2006-12-01 10:39:12 +0100 | [diff] [blame] | 61 | } |
Jens Axboe | 2056a78 | 2006-03-23 20:00:26 +0100 | [diff] [blame] | 62 | |
Olaf Kirch | be1c634 | 2006-12-01 10:39:12 +0100 | [diff] [blame] | 63 | static void trace_note_time(struct blk_trace *bt) |
| 64 | { |
| 65 | struct timespec now; |
| 66 | unsigned long flags; |
| 67 | u32 words[2]; |
| 68 | |
| 69 | getnstimeofday(&now); |
| 70 | words[0] = now.tv_sec; |
| 71 | words[1] = now.tv_nsec; |
| 72 | |
| 73 | local_irq_save(flags); |
| 74 | trace_note(bt, 0, BLK_TN_TIMESTAMP, words, sizeof(words)); |
| 75 | local_irq_restore(flags); |
Jens Axboe | 2056a78 | 2006-03-23 20:00:26 +0100 | [diff] [blame] | 76 | } |
| 77 | |
| 78 | static int act_log_check(struct blk_trace *bt, u32 what, sector_t sector, |
| 79 | pid_t pid) |
| 80 | { |
| 81 | if (((bt->act_mask << BLK_TC_SHIFT) & what) == 0) |
| 82 | return 1; |
| 83 | if (sector < bt->start_lba || sector > bt->end_lba) |
| 84 | return 1; |
| 85 | if (bt->pid && pid != bt->pid) |
| 86 | return 1; |
| 87 | |
| 88 | return 0; |
| 89 | } |
| 90 | |
| 91 | /* |
| 92 | * Data direction bit lookup |
| 93 | */ |
| 94 | static u32 ddir_act[2] __read_mostly = { BLK_TC_ACT(BLK_TC_READ), BLK_TC_ACT(BLK_TC_WRITE) }; |
| 95 | |
| 96 | /* |
| 97 | * Bio action bits of interest |
| 98 | */ |
Jens Axboe | 7457e6e | 2006-07-23 02:12:01 +0200 | [diff] [blame] | 99 | static u32 bio_act[9] __read_mostly = { 0, BLK_TC_ACT(BLK_TC_BARRIER), BLK_TC_ACT(BLK_TC_SYNC), 0, BLK_TC_ACT(BLK_TC_AHEAD), 0, 0, 0, BLK_TC_ACT(BLK_TC_META) }; |
Jens Axboe | 2056a78 | 2006-03-23 20:00:26 +0100 | [diff] [blame] | 100 | |
| 101 | /* |
| 102 | * More could be added as needed, taking care to increment the decrementer |
| 103 | * to get correct indexing |
| 104 | */ |
| 105 | #define trace_barrier_bit(rw) \ |
| 106 | (((rw) & (1 << BIO_RW_BARRIER)) >> (BIO_RW_BARRIER - 0)) |
| 107 | #define trace_sync_bit(rw) \ |
| 108 | (((rw) & (1 << BIO_RW_SYNC)) >> (BIO_RW_SYNC - 1)) |
Nathan Scott | 40359cc | 2006-07-06 10:03:28 +0200 | [diff] [blame] | 109 | #define trace_ahead_bit(rw) \ |
Milton Miller | ad01b1c | 2006-07-25 15:04:13 +0200 | [diff] [blame] | 110 | (((rw) & (1 << BIO_RW_AHEAD)) << (2 - BIO_RW_AHEAD)) |
Jens Axboe | 7457e6e | 2006-07-23 02:12:01 +0200 | [diff] [blame] | 111 | #define trace_meta_bit(rw) \ |
| 112 | (((rw) & (1 << BIO_RW_META)) >> (BIO_RW_META - 3)) |
Jens Axboe | 2056a78 | 2006-03-23 20:00:26 +0100 | [diff] [blame] | 113 | |
| 114 | /* |
| 115 | * The worker for the various blk_add_trace*() types. Fills out a |
| 116 | * blk_io_trace structure and places it in a per-cpu subbuffer. |
| 117 | */ |
| 118 | void __blk_add_trace(struct blk_trace *bt, sector_t sector, int bytes, |
| 119 | int rw, u32 what, int error, int pdu_len, void *pdu_data) |
| 120 | { |
| 121 | struct task_struct *tsk = current; |
| 122 | struct blk_io_trace *t; |
| 123 | unsigned long flags; |
| 124 | unsigned long *sequence; |
| 125 | pid_t pid; |
| 126 | int cpu; |
| 127 | |
| 128 | if (unlikely(bt->trace_state != Blktrace_running)) |
| 129 | return; |
| 130 | |
| 131 | what |= ddir_act[rw & WRITE]; |
| 132 | what |= bio_act[trace_barrier_bit(rw)]; |
| 133 | what |= bio_act[trace_sync_bit(rw)]; |
Nathan Scott | 40359cc | 2006-07-06 10:03:28 +0200 | [diff] [blame] | 134 | what |= bio_act[trace_ahead_bit(rw)]; |
Jens Axboe | 7457e6e | 2006-07-23 02:12:01 +0200 | [diff] [blame] | 135 | what |= bio_act[trace_meta_bit(rw)]; |
Jens Axboe | 2056a78 | 2006-03-23 20:00:26 +0100 | [diff] [blame] | 136 | |
| 137 | pid = tsk->pid; |
| 138 | if (unlikely(act_log_check(bt, what, sector, pid))) |
| 139 | return; |
| 140 | |
| 141 | /* |
| 142 | * A word about the locking here - we disable interrupts to reserve |
| 143 | * some space in the relay per-cpu buffer, to prevent an irq |
| 144 | * from coming in and stepping on our toes. Once reserved, it's |
| 145 | * enough to get preemption disabled to prevent read of this data |
| 146 | * before we are through filling it. get_cpu()/put_cpu() does this |
| 147 | * for us |
| 148 | */ |
| 149 | local_irq_save(flags); |
| 150 | |
| 151 | if (unlikely(tsk->btrace_seq != blktrace_seq)) |
| 152 | trace_note_tsk(bt, tsk); |
| 153 | |
| 154 | t = relay_reserve(bt->rchan, sizeof(*t) + pdu_len); |
| 155 | if (t) { |
| 156 | cpu = smp_processor_id(); |
| 157 | sequence = per_cpu_ptr(bt->sequence, cpu); |
| 158 | |
| 159 | t->magic = BLK_IO_TRACE_MAGIC | BLK_IO_TRACE_VERSION; |
| 160 | t->sequence = ++(*sequence); |
Ingo Molnar | 2997c8c | 2008-01-11 13:35:54 +0100 | [diff] [blame] | 161 | t->time = ktime_to_ns(ktime_get()); |
Jens Axboe | 2056a78 | 2006-03-23 20:00:26 +0100 | [diff] [blame] | 162 | t->sector = sector; |
| 163 | t->bytes = bytes; |
| 164 | t->action = what; |
| 165 | t->pid = pid; |
| 166 | t->device = bt->dev; |
| 167 | t->cpu = cpu; |
| 168 | t->error = error; |
| 169 | t->pdu_len = pdu_len; |
| 170 | |
| 171 | if (pdu_len) |
| 172 | memcpy((void *) t + sizeof(*t), pdu_data, pdu_len); |
| 173 | } |
| 174 | |
| 175 | local_irq_restore(flags); |
| 176 | } |
| 177 | |
| 178 | EXPORT_SYMBOL_GPL(__blk_add_trace); |
| 179 | |
| 180 | static struct dentry *blk_tree_root; |
Jens Axboe | 11a5715 | 2008-01-11 13:37:01 +0100 | [diff] [blame] | 181 | static DEFINE_MUTEX(blk_tree_mutex); |
Jens Axboe | 2056a78 | 2006-03-23 20:00:26 +0100 | [diff] [blame] | 182 | static unsigned int root_users; |
| 183 | |
| 184 | static inline void blk_remove_root(void) |
| 185 | { |
| 186 | if (blk_tree_root) { |
| 187 | debugfs_remove(blk_tree_root); |
| 188 | blk_tree_root = NULL; |
| 189 | } |
| 190 | } |
| 191 | |
| 192 | static void blk_remove_tree(struct dentry *dir) |
| 193 | { |
| 194 | mutex_lock(&blk_tree_mutex); |
| 195 | debugfs_remove(dir); |
| 196 | if (--root_users == 0) |
| 197 | blk_remove_root(); |
| 198 | mutex_unlock(&blk_tree_mutex); |
| 199 | } |
| 200 | |
| 201 | static struct dentry *blk_create_tree(const char *blk_name) |
| 202 | { |
| 203 | struct dentry *dir = NULL; |
Aneesh Kumar K.V | 35fc51e | 2007-11-21 12:25:41 +0100 | [diff] [blame] | 204 | int created = 0; |
Jens Axboe | 2056a78 | 2006-03-23 20:00:26 +0100 | [diff] [blame] | 205 | |
| 206 | mutex_lock(&blk_tree_mutex); |
| 207 | |
| 208 | if (!blk_tree_root) { |
| 209 | blk_tree_root = debugfs_create_dir("block", NULL); |
| 210 | if (!blk_tree_root) |
| 211 | goto err; |
Aneesh Kumar K.V | 35fc51e | 2007-11-21 12:25:41 +0100 | [diff] [blame] | 212 | created = 1; |
Jens Axboe | 2056a78 | 2006-03-23 20:00:26 +0100 | [diff] [blame] | 213 | } |
| 214 | |
| 215 | dir = debugfs_create_dir(blk_name, blk_tree_root); |
| 216 | if (dir) |
| 217 | root_users++; |
Aneesh Kumar K.V | 35fc51e | 2007-11-21 12:25:41 +0100 | [diff] [blame] | 218 | else { |
| 219 | /* Delete root only if we created it */ |
| 220 | if (created) |
| 221 | blk_remove_root(); |
| 222 | } |
Jens Axboe | 2056a78 | 2006-03-23 20:00:26 +0100 | [diff] [blame] | 223 | |
| 224 | err: |
| 225 | mutex_unlock(&blk_tree_mutex); |
| 226 | return dir; |
| 227 | } |
| 228 | |
| 229 | static void blk_trace_cleanup(struct blk_trace *bt) |
| 230 | { |
| 231 | relay_close(bt->rchan); |
| 232 | debugfs_remove(bt->dropped_file); |
| 233 | blk_remove_tree(bt->dir); |
| 234 | free_percpu(bt->sequence); |
| 235 | kfree(bt); |
| 236 | } |
| 237 | |
Christof Schmitt | 6da127a | 2008-01-11 10:09:43 +0100 | [diff] [blame] | 238 | int blk_trace_remove(struct request_queue *q) |
Jens Axboe | 2056a78 | 2006-03-23 20:00:26 +0100 | [diff] [blame] | 239 | { |
| 240 | struct blk_trace *bt; |
| 241 | |
| 242 | bt = xchg(&q->blk_trace, NULL); |
| 243 | if (!bt) |
| 244 | return -EINVAL; |
| 245 | |
| 246 | if (bt->trace_state == Blktrace_setup || |
| 247 | bt->trace_state == Blktrace_stopped) |
| 248 | blk_trace_cleanup(bt); |
| 249 | |
| 250 | return 0; |
| 251 | } |
Christof Schmitt | 6da127a | 2008-01-11 10:09:43 +0100 | [diff] [blame] | 252 | EXPORT_SYMBOL_GPL(blk_trace_remove); |
Jens Axboe | 2056a78 | 2006-03-23 20:00:26 +0100 | [diff] [blame] | 253 | |
| 254 | static int blk_dropped_open(struct inode *inode, struct file *filp) |
| 255 | { |
Theodore Ts'o | 8e18e29 | 2006-09-27 01:50:46 -0700 | [diff] [blame] | 256 | filp->private_data = inode->i_private; |
Jens Axboe | 2056a78 | 2006-03-23 20:00:26 +0100 | [diff] [blame] | 257 | |
| 258 | return 0; |
| 259 | } |
| 260 | |
| 261 | static ssize_t blk_dropped_read(struct file *filp, char __user *buffer, |
| 262 | size_t count, loff_t *ppos) |
| 263 | { |
| 264 | struct blk_trace *bt = filp->private_data; |
| 265 | char buf[16]; |
| 266 | |
| 267 | snprintf(buf, sizeof(buf), "%u\n", atomic_read(&bt->dropped)); |
| 268 | |
| 269 | return simple_read_from_buffer(buffer, count, ppos, buf, strlen(buf)); |
| 270 | } |
| 271 | |
Arjan van de Ven | 2b8693c | 2007-02-12 00:55:32 -0800 | [diff] [blame] | 272 | static const struct file_operations blk_dropped_fops = { |
Jens Axboe | 2056a78 | 2006-03-23 20:00:26 +0100 | [diff] [blame] | 273 | .owner = THIS_MODULE, |
| 274 | .open = blk_dropped_open, |
| 275 | .read = blk_dropped_read, |
| 276 | }; |
| 277 | |
| 278 | /* |
| 279 | * Keep track of how many times we encountered a full subbuffer, to aid |
| 280 | * the user space app in telling how many lost events there were. |
| 281 | */ |
| 282 | static int blk_subbuf_start_callback(struct rchan_buf *buf, void *subbuf, |
| 283 | void *prev_subbuf, size_t prev_padding) |
| 284 | { |
| 285 | struct blk_trace *bt; |
| 286 | |
| 287 | if (!relay_buf_full(buf)) |
| 288 | return 1; |
| 289 | |
| 290 | bt = buf->chan->private_data; |
| 291 | atomic_inc(&bt->dropped); |
| 292 | return 0; |
| 293 | } |
| 294 | |
| 295 | static int blk_remove_buf_file_callback(struct dentry *dentry) |
| 296 | { |
| 297 | debugfs_remove(dentry); |
| 298 | return 0; |
| 299 | } |
| 300 | |
| 301 | static struct dentry *blk_create_buf_file_callback(const char *filename, |
| 302 | struct dentry *parent, |
| 303 | int mode, |
| 304 | struct rchan_buf *buf, |
| 305 | int *is_global) |
| 306 | { |
| 307 | return debugfs_create_file(filename, mode, parent, buf, |
| 308 | &relay_file_operations); |
| 309 | } |
| 310 | |
| 311 | static struct rchan_callbacks blk_relay_callbacks = { |
| 312 | .subbuf_start = blk_subbuf_start_callback, |
| 313 | .create_buf_file = blk_create_buf_file_callback, |
| 314 | .remove_buf_file = blk_remove_buf_file_callback, |
| 315 | }; |
| 316 | |
| 317 | /* |
| 318 | * Setup everything required to start tracing |
| 319 | */ |
Christof Schmitt | 6da127a | 2008-01-11 10:09:43 +0100 | [diff] [blame] | 320 | int do_blk_trace_setup(struct request_queue *q, char *name, dev_t dev, |
Arnd Bergmann | 171044d4 | 2007-10-09 13:23:53 +0200 | [diff] [blame] | 321 | struct blk_user_trace_setup *buts) |
Jens Axboe | 2056a78 | 2006-03-23 20:00:26 +0100 | [diff] [blame] | 322 | { |
Jens Axboe | 2056a78 | 2006-03-23 20:00:26 +0100 | [diff] [blame] | 323 | struct blk_trace *old_bt, *bt = NULL; |
| 324 | struct dentry *dir = NULL; |
Jens Axboe | 2056a78 | 2006-03-23 20:00:26 +0100 | [diff] [blame] | 325 | int ret, i; |
| 326 | |
Arnd Bergmann | 171044d4 | 2007-10-09 13:23:53 +0200 | [diff] [blame] | 327 | if (!buts->buf_size || !buts->buf_nr) |
Jens Axboe | 2056a78 | 2006-03-23 20:00:26 +0100 | [diff] [blame] | 328 | return -EINVAL; |
| 329 | |
Christof Schmitt | 6da127a | 2008-01-11 10:09:43 +0100 | [diff] [blame] | 330 | strcpy(buts->name, name); |
Jens Axboe | 2056a78 | 2006-03-23 20:00:26 +0100 | [diff] [blame] | 331 | |
| 332 | /* |
| 333 | * some device names have larger paths - convert the slashes |
| 334 | * to underscores for this to work as expected |
| 335 | */ |
Arnd Bergmann | 171044d4 | 2007-10-09 13:23:53 +0200 | [diff] [blame] | 336 | for (i = 0; i < strlen(buts->name); i++) |
| 337 | if (buts->name[i] == '/') |
| 338 | buts->name[i] = '_'; |
Jens Axboe | 2056a78 | 2006-03-23 20:00:26 +0100 | [diff] [blame] | 339 | |
| 340 | ret = -ENOMEM; |
| 341 | bt = kzalloc(sizeof(*bt), GFP_KERNEL); |
| 342 | if (!bt) |
| 343 | goto err; |
| 344 | |
| 345 | bt->sequence = alloc_percpu(unsigned long); |
| 346 | if (!bt->sequence) |
| 347 | goto err; |
| 348 | |
| 349 | ret = -ENOENT; |
Arnd Bergmann | 171044d4 | 2007-10-09 13:23:53 +0200 | [diff] [blame] | 350 | dir = blk_create_tree(buts->name); |
Jens Axboe | 2056a78 | 2006-03-23 20:00:26 +0100 | [diff] [blame] | 351 | if (!dir) |
| 352 | goto err; |
| 353 | |
| 354 | bt->dir = dir; |
Christof Schmitt | 6da127a | 2008-01-11 10:09:43 +0100 | [diff] [blame] | 355 | bt->dev = dev; |
Jens Axboe | 2056a78 | 2006-03-23 20:00:26 +0100 | [diff] [blame] | 356 | atomic_set(&bt->dropped, 0); |
| 357 | |
| 358 | ret = -EIO; |
| 359 | bt->dropped_file = debugfs_create_file("dropped", 0444, dir, bt, &blk_dropped_fops); |
| 360 | if (!bt->dropped_file) |
| 361 | goto err; |
| 362 | |
Arnd Bergmann | 171044d4 | 2007-10-09 13:23:53 +0200 | [diff] [blame] | 363 | bt->rchan = relay_open("trace", dir, buts->buf_size, |
| 364 | buts->buf_nr, &blk_relay_callbacks, bt); |
Jens Axboe | 2056a78 | 2006-03-23 20:00:26 +0100 | [diff] [blame] | 365 | if (!bt->rchan) |
| 366 | goto err; |
Jens Axboe | 2056a78 | 2006-03-23 20:00:26 +0100 | [diff] [blame] | 367 | |
Arnd Bergmann | 171044d4 | 2007-10-09 13:23:53 +0200 | [diff] [blame] | 368 | bt->act_mask = buts->act_mask; |
Jens Axboe | 2056a78 | 2006-03-23 20:00:26 +0100 | [diff] [blame] | 369 | if (!bt->act_mask) |
| 370 | bt->act_mask = (u16) -1; |
| 371 | |
Arnd Bergmann | 171044d4 | 2007-10-09 13:23:53 +0200 | [diff] [blame] | 372 | bt->start_lba = buts->start_lba; |
| 373 | bt->end_lba = buts->end_lba; |
Jens Axboe | 2056a78 | 2006-03-23 20:00:26 +0100 | [diff] [blame] | 374 | if (!bt->end_lba) |
| 375 | bt->end_lba = -1ULL; |
| 376 | |
Arnd Bergmann | 171044d4 | 2007-10-09 13:23:53 +0200 | [diff] [blame] | 377 | bt->pid = buts->pid; |
Jens Axboe | 2056a78 | 2006-03-23 20:00:26 +0100 | [diff] [blame] | 378 | bt->trace_state = Blktrace_setup; |
| 379 | |
| 380 | ret = -EBUSY; |
| 381 | old_bt = xchg(&q->blk_trace, bt); |
| 382 | if (old_bt) { |
| 383 | (void) xchg(&q->blk_trace, old_bt); |
| 384 | goto err; |
| 385 | } |
| 386 | |
| 387 | return 0; |
| 388 | err: |
| 389 | if (dir) |
| 390 | blk_remove_tree(dir); |
| 391 | if (bt) { |
| 392 | if (bt->dropped_file) |
| 393 | debugfs_remove(bt->dropped_file); |
Alan Stern | a120586 | 2006-12-06 20:32:37 -0800 | [diff] [blame] | 394 | free_percpu(bt->sequence); |
Jens Axboe | 2056a78 | 2006-03-23 20:00:26 +0100 | [diff] [blame] | 395 | if (bt->rchan) |
| 396 | relay_close(bt->rchan); |
| 397 | kfree(bt); |
| 398 | } |
| 399 | return ret; |
| 400 | } |
| 401 | |
Christof Schmitt | 6da127a | 2008-01-11 10:09:43 +0100 | [diff] [blame] | 402 | int blk_trace_setup(struct request_queue *q, char *name, dev_t dev, |
| 403 | char __user *arg) |
Arnd Bergmann | 171044d4 | 2007-10-09 13:23:53 +0200 | [diff] [blame] | 404 | { |
| 405 | struct blk_user_trace_setup buts; |
| 406 | int ret; |
| 407 | |
| 408 | ret = copy_from_user(&buts, arg, sizeof(buts)); |
| 409 | if (ret) |
| 410 | return -EFAULT; |
| 411 | |
Christof Schmitt | 6da127a | 2008-01-11 10:09:43 +0100 | [diff] [blame] | 412 | ret = do_blk_trace_setup(q, name, dev, &buts); |
Arnd Bergmann | 171044d4 | 2007-10-09 13:23:53 +0200 | [diff] [blame] | 413 | if (ret) |
| 414 | return ret; |
| 415 | |
| 416 | if (copy_to_user(arg, &buts, sizeof(buts))) |
| 417 | return -EFAULT; |
| 418 | |
| 419 | return 0; |
| 420 | } |
Christof Schmitt | 6da127a | 2008-01-11 10:09:43 +0100 | [diff] [blame] | 421 | EXPORT_SYMBOL_GPL(blk_trace_setup); |
Arnd Bergmann | 171044d4 | 2007-10-09 13:23:53 +0200 | [diff] [blame] | 422 | |
Christof Schmitt | 6da127a | 2008-01-11 10:09:43 +0100 | [diff] [blame] | 423 | int blk_trace_startstop(struct request_queue *q, int start) |
Jens Axboe | 2056a78 | 2006-03-23 20:00:26 +0100 | [diff] [blame] | 424 | { |
| 425 | struct blk_trace *bt; |
| 426 | int ret; |
| 427 | |
| 428 | if ((bt = q->blk_trace) == NULL) |
| 429 | return -EINVAL; |
| 430 | |
| 431 | /* |
| 432 | * For starting a trace, we can transition from a setup or stopped |
| 433 | * trace. For stopping a trace, the state must be running |
| 434 | */ |
| 435 | ret = -EINVAL; |
| 436 | if (start) { |
| 437 | if (bt->trace_state == Blktrace_setup || |
| 438 | bt->trace_state == Blktrace_stopped) { |
| 439 | blktrace_seq++; |
| 440 | smp_mb(); |
| 441 | bt->trace_state = Blktrace_running; |
Olaf Kirch | be1c634 | 2006-12-01 10:39:12 +0100 | [diff] [blame] | 442 | |
| 443 | trace_note_time(bt); |
Jens Axboe | 2056a78 | 2006-03-23 20:00:26 +0100 | [diff] [blame] | 444 | ret = 0; |
| 445 | } |
| 446 | } else { |
| 447 | if (bt->trace_state == Blktrace_running) { |
| 448 | bt->trace_state = Blktrace_stopped; |
| 449 | relay_flush(bt->rchan); |
| 450 | ret = 0; |
| 451 | } |
| 452 | } |
| 453 | |
| 454 | return ret; |
| 455 | } |
Christof Schmitt | 6da127a | 2008-01-11 10:09:43 +0100 | [diff] [blame] | 456 | EXPORT_SYMBOL_GPL(blk_trace_startstop); |
Jens Axboe | 2056a78 | 2006-03-23 20:00:26 +0100 | [diff] [blame] | 457 | |
| 458 | /** |
| 459 | * blk_trace_ioctl: - handle the ioctls associated with tracing |
| 460 | * @bdev: the block device |
| 461 | * @cmd: the ioctl cmd |
| 462 | * @arg: the argument data, if any |
| 463 | * |
| 464 | **/ |
| 465 | int blk_trace_ioctl(struct block_device *bdev, unsigned cmd, char __user *arg) |
| 466 | { |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 467 | struct request_queue *q; |
Jens Axboe | 2056a78 | 2006-03-23 20:00:26 +0100 | [diff] [blame] | 468 | int ret, start = 0; |
Christof Schmitt | 6da127a | 2008-01-11 10:09:43 +0100 | [diff] [blame] | 469 | char b[BDEVNAME_SIZE]; |
Jens Axboe | 2056a78 | 2006-03-23 20:00:26 +0100 | [diff] [blame] | 470 | |
| 471 | q = bdev_get_queue(bdev); |
| 472 | if (!q) |
| 473 | return -ENXIO; |
| 474 | |
| 475 | mutex_lock(&bdev->bd_mutex); |
| 476 | |
| 477 | switch (cmd) { |
| 478 | case BLKTRACESETUP: |
Jean Delvare | f36f21e | 2008-05-12 14:02:33 -0700 | [diff] [blame^] | 479 | bdevname(bdev, b); |
Christof Schmitt | 6da127a | 2008-01-11 10:09:43 +0100 | [diff] [blame] | 480 | ret = blk_trace_setup(q, b, bdev->bd_dev, arg); |
Jens Axboe | 2056a78 | 2006-03-23 20:00:26 +0100 | [diff] [blame] | 481 | break; |
| 482 | case BLKTRACESTART: |
| 483 | start = 1; |
| 484 | case BLKTRACESTOP: |
| 485 | ret = blk_trace_startstop(q, start); |
| 486 | break; |
| 487 | case BLKTRACETEARDOWN: |
| 488 | ret = blk_trace_remove(q); |
| 489 | break; |
| 490 | default: |
| 491 | ret = -ENOTTY; |
| 492 | break; |
| 493 | } |
| 494 | |
| 495 | mutex_unlock(&bdev->bd_mutex); |
| 496 | return ret; |
| 497 | } |
| 498 | |
| 499 | /** |
| 500 | * blk_trace_shutdown: - stop and cleanup trace structures |
| 501 | * @q: the request queue associated with the device |
| 502 | * |
| 503 | **/ |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 504 | void blk_trace_shutdown(struct request_queue *q) |
Jens Axboe | 2056a78 | 2006-03-23 20:00:26 +0100 | [diff] [blame] | 505 | { |
Alexey Dobriyan | 6c5c934 | 2006-09-29 01:59:40 -0700 | [diff] [blame] | 506 | if (q->blk_trace) { |
| 507 | blk_trace_startstop(q, 0); |
| 508 | blk_trace_remove(q); |
| 509 | } |
Jens Axboe | 2056a78 | 2006-03-23 20:00:26 +0100 | [diff] [blame] | 510 | } |