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