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         u32 __pad;
 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 #if defined(CONFIG_BLK_DEV_IO_TRACE)
 146 extern int blk_trace_ioctl(struct block_device *, unsigned, char __user *);
 147 extern void blk_trace_shutdown(struct request_queue *);
 148 extern void __blk_add_trace(struct blk_trace *, sector_t, int, int, u32, int, int, void *);
 149
 150 /**
 151  * blk_add_trace_rq - Add a trace for a request oriented action
 152  * @q:          queue the io is for
 153  * @rq:         the source request
 154  * @what:       the action
 155  *
 156  * Description:
 157  *     Records an action against a request. Will log the bio offset + size.
 158  *
 159  **/
 160 static inline void blk_add_trace_rq(struct request_queue *q, struct request *rq,
 161                                     u32 what)
 162 {
 163         struct blk_trace *bt = q->blk_trace;
 164         int rw = rq->cmd_flags & 0x03;
 165
 166         if (likely(!bt))
 167                 return;
 168
 169         if (blk_pc_request(rq)) {
 170                 what |= BLK_TC_ACT(BLK_TC_PC);
 171                 __blk_add_trace(bt, 0, rq->data_len, rw, what, rq->errors, sizeof(rq->cmd), rq->cmd);
 172         } else  {
 173                 what |= BLK_TC_ACT(BLK_TC_FS);
 174                 __blk_add_trace(bt, rq->hard_sector, rq->hard_nr_sectors << 9, rw, what, rq->errors, 0, NULL);
 175         }
 176 }
 177
 178 /**
 179  * blk_add_trace_bio - Add a trace for a bio oriented action
 180  * @q:          queue the io is for
 181  * @bio:        the source bio
 182  * @what:       the action
 183  *
 184  * Description:
 185  *     Records an action against a bio. Will log the bio offset + size.
 186  *
 187  **/
 188 static inline void blk_add_trace_bio(struct request_queue *q, struct bio *bio,
 189                                      u32 what)
 190 {
 191         struct blk_trace *bt = q->blk_trace;
 192
 193         if (likely(!bt))
 194                 return;
 195
 196         __blk_add_trace(bt, bio->bi_sector, bio->bi_size, bio->bi_rw, what, !bio_flagged(bio, BIO_UPTODATE), 0, NULL);
 197 }
 198
 199 /**
 200  * blk_add_trace_generic - Add a trace for a generic action
 201  * @q:          queue the io is for
 202  * @bio:        the source bio
 203  * @rw:         the data direction
 204  * @what:       the action
 205  *
 206  * Description:
 207  *     Records a simple trace
 208  *
 209  **/
 210 static inline void blk_add_trace_generic(struct request_queue *q,
 211                                          struct bio *bio, int rw, u32 what)
 212 {
 213         struct blk_trace *bt = q->blk_trace;
 214
 215         if (likely(!bt))
 216                 return;
 217
 218         if (bio)
 219                 blk_add_trace_bio(q, bio, what);
 220         else
 221                 __blk_add_trace(bt, 0, 0, rw, what, 0, 0, NULL);
 222 }
 223
 224 /**
 225  * blk_add_trace_pdu_int - Add a trace for a bio with an integer payload
 226  * @q:          queue the io is for
 227  * @what:       the action
 228  * @bio:        the source bio
 229  * @pdu:        the integer payload
 230  *
 231  * Description:
 232  *     Adds a trace with some integer payload. This might be an unplug
 233  *     option given as the action, with the depth at unplug time given
 234  *     as the payload
 235  *
 236  **/
 237 static inline void blk_add_trace_pdu_int(struct request_queue *q, u32 what,
 238                                          struct bio *bio, unsigned int pdu)
 239 {
 240         struct blk_trace *bt = q->blk_trace;
 241         __be64 rpdu = cpu_to_be64(pdu);
 242
 243         if (likely(!bt))
 244                 return;
 245
 246         if (bio)
 247                 __blk_add_trace(bt, bio->bi_sector, bio->bi_size, bio->bi_rw, what, !bio_flagged(bio, BIO_UPTODATE), sizeof(rpdu), &rpdu);
 248         else
 249                 __blk_add_trace(bt, 0, 0, 0, what, 0, sizeof(rpdu), &rpdu);
 250 }
 251
 252 /**
 253  * blk_add_trace_remap - Add a trace for a remap operation
 254  * @q:          queue the io is for
 255  * @bio:        the source bio
 256  * @dev:        target device
 257  * @from:       source sector
 258  * @to:         target sector
 259  *
 260  * Description:
 261  *     Device mapper or raid target sometimes need to split a bio because
 262  *     it spans a stripe (or similar). Add a trace for that action.
 263  *
 264  **/
 265 static inline void blk_add_trace_remap(struct request_queue *q, struct bio *bio,
 266                                        dev_t dev, sector_t from, sector_t to)
 267 {
 268         struct blk_trace *bt = q->blk_trace;
 269         struct blk_io_trace_remap r;
 270
 271         if (likely(!bt))
 272                 return;
 273
 274         r.device = cpu_to_be32(dev);
 275         r.sector = cpu_to_be64(to);
 276
 277         __blk_add_trace(bt, from, bio->bi_size, bio->bi_rw, BLK_TA_REMAP, !bio_flagged(bio, BIO_UPTODATE), sizeof(r), &r);
 278 }
 279
 280 #else /* !CONFIG_BLK_DEV_IO_TRACE */
 281 #define blk_trace_ioctl(bdev, cmd, arg)         (-ENOTTY)
 282 #define blk_trace_shutdown(q)                   do { } while (0)
 283 #define blk_add_trace_rq(q, rq, what)           do { } while (0)
 284 #define blk_add_trace_bio(q, rq, what)          do { } while (0)
 285 #define blk_add_trace_generic(q, rq, rw, what)  do { } while (0)
 286 #define blk_add_trace_pdu_int(q, what, bio, pdu)        do { } while (0)
 287 #define blk_add_trace_remap(q, bio, dev, f, t)  do {} while (0)
 288 #endif /* CONFIG_BLK_DEV_IO_TRACE */
 289
 290 #endif