linuxautomaton/linuxautomaton/block.py

   1 #!/usr/bin/env python3
   2 #
   3 # The MIT License (MIT)
   4 #
   5 # Copyright (C) 2015 - Julien Desfossez <jdesfossez@efficios.com>
   6 #               2015 - Antoine Busque <abusque@efficios.com>
   7 #
   8 # Permission is hereby granted, free of charge, to any person obtaining a copy
   9 # of this software and associated documentation files (the "Software"), to deal
  10 # in the Software without restriction, including without limitation the rights
  11 # to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  12 # copies of the Software, and to permit persons to whom the Software is
  13 # furnished to do so, subject to the following conditions:
  14 #
  15 # The above copyright notice and this permission notice shall be included in
  16 # all copies or substantial portions of the Software.
  17 #
  18 # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  19 # IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  20 # FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  21 # AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  22 # LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  23 # OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  24 # SOFTWARE.
  25
  26 from linuxautomaton import sp, sv
  27
  28
  29 class BlockStateProvider(sp.StateProvider):
  30     def __init__(self, state):
  31         cbs = {
  32             'block_rq_complete': self._process_block_rq_complete,
  33             'block_rq_issue': self._process_block_rq_issue,
  34             'block_bio_remap': self._process_block_bio_remap,
  35             'block_bio_backmerge': self._process_block_bio_backmerge,
  36         }
  37
  38         self._state = state
  39         self._remap_requests = []
  40         self._register_cbs(cbs)
  41
  42     def process_event(self, ev):
  43         self._process_event_cb(ev)
  44
  45     def _process_block_bio_remap(self, event):
  46         dev = event['dev']
  47         sector = event['sector']
  48         old_dev = event['old_dev']
  49         old_sector = event['old_sector']
  50
  51         for req in self._remap_requests:
  52             if req.dev == old_dev and req.sector == old_sector:
  53                 req.dev = dev
  54                 req.sector = sector
  55                 return
  56
  57         req = sv.BlockRemapRequest(dev, sector, old_dev, old_sector)
  58         self._remap_requests.append(req)
  59
  60     # For backmerge requests, just remove the request from the
  61     # _remap_requests queue, because we rely later on the nr_sector
  62     # which has all the info we need
  63     def _process_block_bio_backmerge(self, event):
  64         dev = event['dev']
  65         sector = event['sector']
  66         for remap_req in self._remap_requests:
  67             if remap_req.dev == dev and remap_req.sector == sector:
  68                 self._remap_requests.remove(remap_req)
  69
  70     def _process_block_rq_issue(self, event):
  71         dev = event['dev']
  72         sector = event['sector']
  73         nr_sector = event['nr_sector']
  74
  75         if nr_sector == 0:
  76             return
  77
  78         req = sv.BlockIORequest.new_from_rq_issue(event)
  79
  80         for remap_req in self._remap_requests:
  81             if remap_req.dev == dev and remap_req.sector == sector:
  82                 dev = remap_req.old_dev
  83                 break
  84
  85         if dev not in self._state.disks:
  86             self._state.disks[dev] = sv.Disk()
  87
  88         self._state.disks[dev].pending_requests[sector] = req
  89
  90     def _process_block_rq_complete(self, event):
  91         dev = event['dev']
  92         sector = event['sector']
  93         nr_sector = event['nr_sector']
  94
  95         if nr_sector == 0:
  96             return
  97
  98         for remap_req in self._remap_requests:
  99             if remap_req.dev == dev and remap_req.sector == sector:
 100                 dev = remap_req.old_dev
 101                 self._remap_requests.remove(remap_req)
 102                 break
 103
 104         if dev not in self._state.disks:
 105             self._state.disks[dev] = sv.Disk()
 106
 107         disk = self._state.disks[dev]
 108
 109         # Ignore rq_complete without matching rq_issue
 110         if sector not in disk.pending_requests:
 111             return
 112
 113         req = disk.pending_requests[sector]
 114         # Ignore rq_complete if nr_sector does not match rq_issue's
 115         if req.nr_sector != nr_sector:
 116             return
 117
 118         req.update_from_rq_complete(event)
 119         proc = self._state.tids[req.tid]
 120         self._state.send_notification_cb('block_rq_complete', req=req,
 121                                          proc=proc)
 122         del disk.pending_requests[sector]