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