include/linux/blktrace_api.h

   1 #ifndef BLKTRACE_H
   2 #define BLKTRACE_H
   3
   4 #include <linux/blkdev.h>
   5 #include <linux/relay.h>
   6
   7 /*
   8  * Trace categories
   9  */
  10 enum blktrace_cat {
  11         BLK_TC_READ     = 1 << 0,       /* reads */
  12         BLK_TC_WRITE    = 1 << 1,       /* writes */
  13         BLK_TC_BARRIER  = 1 << 2,       /* barrier */
  14         BLK_TC_SYNC     = 1 << 3,       /* sync IO */
  15         BLK_TC_QUEUE    = 1 << 4,       /* queueing/merging */
  16         BLK_TC_REQUEUE  = 1 << 5,       /* requeueing */
  17         BLK_TC_ISSUE    = 1 << 6,       /* issue */
  18         BLK_TC_COMPLETE = 1 << 7,       /* completions */
  19         BLK_TC_FS       = 1 << 8,       /* fs requests */
  20         BLK_TC_PC       = 1 << 9,       /* pc requests */
  21         BLK_TC_NOTIFY   = 1 << 10,      /* special message */
  22         BLK_TC_AHEAD    = 1 << 11,      /* readahead */
  23         BLK_TC_META     = 1 << 12,      /* metadata */
  24
  25         BLK_TC_END      = 1 << 15,      /* only 16-bits, reminder */
  26 };
  27
  28 #define BLK_TC_SHIFT            (16)
  29 #define BLK_TC_ACT(act)         ((act) << BLK_TC_SHIFT)
  30
  31 /*
  32  * Basic trace actions
  33  */
  34 enum blktrace_act {
  35         __BLK_TA_QUEUE = 1,             /* queued */
  36         __BLK_TA_BACKMERGE,             /* back merged to existing rq */
  37         __BLK_TA_FRONTMERGE,            /* front merge to existing rq */
  38         __BLK_TA_GETRQ,                 /* allocated new request */
  39         __BLK_TA_SLEEPRQ,               /* sleeping on rq allocation */
  40         __BLK_TA_REQUEUE,               /* request requeued */
  41         __BLK_TA_ISSUE,                 /* sent to driver */
  42         __BLK_TA_COMPLETE,              /* completed by driver */
  43         __BLK_TA_PLUG,                  /* queue was plugged */
  44         __BLK_TA_UNPLUG_IO,             /* queue was unplugged by io */
  45         __BLK_TA_UNPLUG_TIMER,          /* queue was unplugged by timer */
  46         __BLK_TA_INSERT,                /* insert request */
  47         __BLK_TA_SPLIT,                 /* bio was split */
  48         __BLK_TA_BOUNCE,                /* bio was bounced */
  49         __BLK_TA_REMAP,                 /* bio was remapped */
  50 };
  51
  52 /*
  53  * Notify events.
  54  */
  55 enum blktrace_notify {
  56         __BLK_TN_PROCESS = 0,           /* establish pid/name mapping */
  57         __BLK_TN_TIMESTAMP,             /* include system clock */
  58 };
  59
  60
  61 /*
  62  * Trace actions in full. Additionally, read or write is masked
  63  */
  64 #define BLK_TA_QUEUE            (__BLK_TA_QUEUE | BLK_TC_ACT(BLK_TC_QUEUE))
  65 #define BLK_TA_BACKMERGE        (__BLK_TA_BACKMERGE | BLK_TC_ACT(BLK_TC_QUEUE))
  66 #define BLK_TA_FRONTMERGE       (__BLK_TA_FRONTMERGE | BLK_TC_ACT(BLK_TC_QUEUE))
  67 #define BLK_TA_GETRQ            (__BLK_TA_GETRQ | BLK_TC_ACT(BLK_TC_QUEUE))
  68 #define BLK_TA_SLEEPRQ          (__BLK_TA_SLEEPRQ | BLK_TC_ACT(BLK_TC_QUEUE))
  69 #define BLK_TA_REQUEUE          (__BLK_TA_REQUEUE | BLK_TC_ACT(BLK_TC_REQUEUE))
  70 #define BLK_TA_ISSUE            (__BLK_TA_ISSUE | BLK_TC_ACT(BLK_TC_ISSUE))
  71 #define BLK_TA_COMPLETE         (__BLK_TA_COMPLETE| BLK_TC_ACT(BLK_TC_COMPLETE))
  72 #define BLK_TA_PLUG             (__BLK_TA_PLUG | BLK_TC_ACT(BLK_TC_QUEUE))
  73 #define BLK_TA_UNPLUG_IO        (__BLK_TA_UNPLUG_IO | BLK_TC_ACT(BLK_TC_QUEUE))
  74 #define BLK_TA_UNPLUG_TIMER     (__BLK_TA_UNPLUG_TIMER | BLK_TC_ACT(BLK_TC_QUEUE))
  75 #define BLK_TA_INSERT           (__BLK_TA_INSERT | BLK_TC_ACT(BLK_TC_QUEUE))
  76 #define BLK_TA_SPLIT            (__BLK_TA_SPLIT)
  77 #define BLK_TA_BOUNCE           (__BLK_TA_BOUNCE)
  78 #define BLK_TA_REMAP            (__BLK_TA_REMAP | BLK_TC_ACT(BLK_TC_QUEUE))
  79
  80 #define BLK_TN_PROCESS          (__BLK_TN_PROCESS | BLK_TC_ACT(BLK_TC_NOTIFY))
  81 #define BLK_TN_TIMESTAMP        (__BLK_TN_TIMESTAMP | BLK_TC_ACT(BLK_TC_NOTIFY))
  82
  83 #define BLK_IO_TRACE_MAGIC      0x65617400
  84 #define BLK_IO_TRACE_VERSION    0x07
  85
  86 /*
  87  * The trace itself
  88  */
  89 struct blk_io_trace {
  90         u32 magic;              /* MAGIC << 8 | version */
  91         u32 sequence;           /* event number */
  92         u64 time;               /* in microseconds */
  93         u64 sector;             /* disk offset */
  94         u32 bytes;              /* transfer length */
  95         u32 action;             /* what happened */
  96         u32 pid;                /* who did it */
  97         u32 device;             /* device number */
  98         u32 cpu;                /* on what cpu did it happen */
  99         u16 error;              /* completion error */
 100         u16 pdu_len;            /* length of data after this trace */
 101 };
 102
 103 /*
 104  * The remap event
 105  */
 106 struct blk_io_trace_remap {
 107         __be32 device;
 108         __be32 device_from;
 109         __be64 sector;
 110 };
 111
 112 enum {
 113         Blktrace_setup = 1,
 114         Blktrace_running,
 115         Blktrace_stopped,
 116 };
 117
 118 struct blk_trace {
 119         int trace_state;
 120         struct rchan *rchan;
 121         unsigned long *sequence;
 122         u16 act_mask;
 123         u64 start_lba;
 124         u64 end_lba;
 125         u32 pid;
 126         u32 dev;
 127         struct dentry *dir;
 128         struct dentry *dropped_file;
 129         atomic_t dropped;
 130 };
 131
 132 /*
 133  * User setup structure passed with BLKTRACESTART
 134  */
 135 struct blk_user_trace_setup {
 136         char name[BDEVNAME_SIZE];       /* output */
 137         u16 act_mask;                   /* input */
 138         u32 buf_size;                   /* input */
 139         u32 buf_nr;                     /* input */
 140         u64 start_lba;
 141         u64 end_lba;
 142         u32 pid;
 143 };
 144
 145 #ifdef __KERNEL__
 146 #if defined(CONFIG_BLK_DEV_IO_TRACE)
 147 extern int blk_trace_ioctl(struct block_device *, unsigned, char __user *);
 148 extern void blk_trace_shutdown(struct request_queue *);
 149 extern void __blk_add_trace(struct blk_trace *, sector_t, int, int, u32, int, int, void *);
 150 extern int do_blk_trace_setup(struct request_queue *q,
 151         char *name, dev_t dev, struct blk_user_trace_setup *buts);
 152
 153
 154 /**
 155  * blk_add_trace_rq - Add a trace for a request oriented action
 156  * @q:          queue the io is for
 157  * @rq:         the source request
 158  * @what:       the action
 159  *
 160  * Description:
 161  *     Records an action against a request. Will log the bio offset + size.
 162  *
 163  **/
 164 static inline void blk_add_trace_rq(struct request_queue *q, struct request *rq,
 165                                     u32 what)
 166 {
 167         struct blk_trace *bt = q->blk_trace;
 168         int rw = rq->cmd_flags & 0x03;
 169
 170         if (likely(!bt))
 171                 return;
 172
 173         if (blk_pc_request(rq)) {
 174                 what |= BLK_TC_ACT(BLK_TC_PC);
 175                 __blk_add_trace(bt, 0, rq->data_len, rw, what, rq->errors, sizeof(rq->cmd), rq->cmd);
 176         } else  {
 177                 what |= BLK_TC_ACT(BLK_TC_FS);
 178                 __blk_add_trace(bt, rq->hard_sector, rq->hard_nr_sectors << 9, rw, what, rq->errors, 0, NULL);
 179         }
 180 }
 181
 182 /**
 183  * blk_add_trace_bio - Add a trace for a bio oriented action
 184  * @q:          queue the io is for
 185  * @bio:        the source bio
 186  * @what:       the action
 187  *
 188  * Description:
 189  *     Records an action against a bio. Will log the bio offset + size.
 190  *
 191  **/
 192 static inline void blk_add_trace_bio(struct request_queue *q, struct bio *bio,
 193                                      u32 what)
 194 {
 195         struct blk_trace *bt = q->blk_trace;
 196
 197         if (likely(!bt))
 198                 return;
 199
 200         __blk_add_trace(bt, bio->bi_sector, bio->bi_size, bio->bi_rw, what, !bio_flagged(bio, BIO_UPTODATE), 0, NULL);
 201 }
 202
 203 /**
 204  * blk_add_trace_generic - Add a trace for a generic action
 205  * @q:          queue the io is for
 206  * @bio:        the source bio
 207  * @rw:         the data direction
 208  * @what:       the action
 209  *
 210  * Description:
 211  *     Records a simple trace
 212  *
 213  **/
 214 static inline void blk_add_trace_generic(struct request_queue *q,
 215                                          struct bio *bio, int rw, u32 what)
 216 {
 217         struct blk_trace *bt = q->blk_trace;
 218
 219         if (likely(!bt))
 220                 return;
 221
 222         if (bio)
 223                 blk_add_trace_bio(q, bio, what);
 224         else
 225                 __blk_add_trace(bt, 0, 0, rw, what, 0, 0, NULL);
 226 }
 227
 228 /**
 229  * blk_add_trace_pdu_int - Add a trace for a bio with an integer payload
 230  * @q:          queue the io is for
 231  * @what:       the action
 232  * @bio:        the source bio
 233  * @pdu:        the integer payload
 234  *
 235  * Description:
 236  *     Adds a trace with some integer payload. This might be an unplug
 237  *     option given as the action, with the depth at unplug time given
 238  *     as the payload
 239  *
 240  **/
 241 static inline void blk_add_trace_pdu_int(struct request_queue *q, u32 what,
 242                                          struct bio *bio, unsigned int pdu)
 243 {
 244         struct blk_trace *bt = q->blk_trace;
 245         __be64 rpdu = cpu_to_be64(pdu);
 246
 247         if (likely(!bt))
 248                 return;
 249
 250         if (bio)
 251                 __blk_add_trace(bt, bio->bi_sector, bio->bi_size, bio->bi_rw, what, !bio_flagged(bio, BIO_UPTODATE), sizeof(rpdu), &rpdu);
 252         else
 253                 __blk_add_trace(bt, 0, 0, 0, what, 0, sizeof(rpdu), &rpdu);
 254 }
 255
 256 /**
 257  * blk_add_trace_remap - Add a trace for a remap operation
 258  * @q:          queue the io is for
 259  * @bio:        the source bio
 260  * @dev:        target device
 261  * @from:       source sector
 262  * @to:         target sector
 263  *
 264  * Description:
 265  *     Device mapper or raid target sometimes need to split a bio because
 266  *     it spans a stripe (or similar). Add a trace for that action.
 267  *
 268  **/
 269 static inline void blk_add_trace_remap(struct request_queue *q, struct bio *bio,
 270                                        dev_t dev, sector_t from, sector_t to)
 271 {
 272         struct blk_trace *bt = q->blk_trace;
 273         struct blk_io_trace_remap r;
 274
 275         if (likely(!bt))
 276                 return;
 277
 278         r.device = cpu_to_be32(dev);
 279         r.device_from = cpu_to_be32(bio->bi_bdev->bd_dev);
 280         r.sector = cpu_to_be64(to);
 281
 282         __blk_add_trace(bt, from, bio->bi_size, bio->bi_rw, BLK_TA_REMAP, !bio_flagged(bio, BIO_UPTODATE), sizeof(r), &r);
 283 }
 284
 285 extern int blk_trace_setup(struct request_queue *q, char *name, dev_t dev,
 286                            char __user *arg);
 287 extern int blk_trace_startstop(struct request_queue *q, int start);
 288 extern int blk_trace_remove(struct request_queue *q);
 289
 290 #else /* !CONFIG_BLK_DEV_IO_TRACE */
 291 #define blk_trace_ioctl(bdev, cmd, arg)         (-ENOTTY)
 292 #define blk_trace_shutdown(q)                   do { } while (0)
 293 #define blk_add_trace_rq(q, rq, what)           do { } while (0)
 294 #define blk_add_trace_bio(q, rq, what)          do { } while (0)
 295 #define blk_add_trace_generic(q, rq, rw, what)  do { } while (0)
 296 #define blk_add_trace_pdu_int(q, what, bio, pdu)        do { } while (0)
 297 #define blk_add_trace_remap(q, bio, dev, f, t)  do {} while (0)
 298 #define do_blk_trace_setup(q, name, dev, buts)  (-ENOTTY)
 299 #define blk_trace_setup(q, name, dev, arg)      (-ENOTTY)
 300 #define blk_trace_startstop(q, start)           (-ENOTTY)
 301 #define blk_trace_remove(q)                     (-ENOTTY)
 302 #endif /* CONFIG_BLK_DEV_IO_TRACE */
 303 #endif /* __KERNEL__ */
 304 #endif