fs/exofs/ore_raid.h

   1 /*
   2  * Copyright (C) from 2011
   3  * Boaz Harrosh <bharrosh@panasas.com>
   4  *
   5  * This file is part of the objects raid engine (ore).
   6  *
   7  * It is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as published
   9  * by the Free Software Foundation.
  10  *
  11  * You should have received a copy of the GNU General Public License
  12  * along with "ore". If not, write to the Free Software Foundation, Inc:
  13  *      "Free Software Foundation <info@fsf.org>"
  14  */
  15
  16 #include <scsi/osd_ore.h>
  17
  18 #define ORE_ERR(fmt, a...) printk(KERN_ERR "ore: " fmt, ##a)
  19
  20 #ifdef CONFIG_EXOFS_DEBUG
  21 #define ORE_DBGMSG(fmt, a...) \
  22         printk(KERN_NOTICE "ore @%s:%d: " fmt, __func__, __LINE__, ##a)
  23 #else
  24 #define ORE_DBGMSG(fmt, a...) \
  25         do { if (0) printk(fmt, ##a); } while (0)
  26 #endif
  27
  28 /* u64 has problems with printk this will cast it to unsigned long long */
  29 #define _LLU(x) (unsigned long long)(x)
  30
  31 #define ORE_DBGMSG2(M...) do {} while (0)
  32 /* #define ORE_DBGMSG2 ORE_DBGMSG */
  33
  34 /* Calculate the component order in a stripe. eg the logical data unit
  35  * address within the stripe of @dev given the @par_dev of this stripe.
  36  */
  37 static inline unsigned _dev_order(unsigned devs_in_group, unsigned mirrors_p1,
  38                                   unsigned par_dev, unsigned dev)
  39 {
  40         unsigned first_dev = dev - dev % devs_in_group;
  41
  42         dev -= first_dev;
  43         par_dev -= first_dev;
  44
  45         if (devs_in_group == par_dev) /* The raid 0 case */
  46                 return dev / mirrors_p1;
  47         /* raid4/5/6 case */
  48         return ((devs_in_group + dev - par_dev - mirrors_p1) % devs_in_group) /
  49                mirrors_p1;
  50 }
  51
  52 /* ios_raid.c stuff needed by ios.c */
  53 int _ore_post_alloc_raid_stuff(struct ore_io_state *ios);
  54 void _ore_free_raid_stuff(struct ore_io_state *ios);
  55
  56 void _ore_add_sg_seg(struct ore_per_dev_state *per_dev, unsigned cur_len,
  57                  bool not_last);
  58 int _ore_add_parity_unit(struct ore_io_state *ios, struct ore_striping_info *si,
  59                      struct ore_per_dev_state *per_dev, unsigned cur_len);
  60 void _ore_add_stripe_page(struct __stripe_pages_2d *sp2d,
  61                        struct ore_striping_info *si, struct page *page);
  62 static inline void _add_stripe_page(struct __stripe_pages_2d *sp2d,
  63                                 struct ore_striping_info *si, struct page *page)
  64 {
  65         if (!sp2d) /* Inline the fast path */
  66                 return; /* Hay no raid stuff */
  67         _ore_add_stripe_page(sp2d, si, page);
  68 }
  69
  70 /* ios.c stuff needed by ios_raid.c */
  71 int  _ore_get_io_state(struct ore_layout *layout,
  72                         struct ore_components *oc, unsigned numdevs,
  73                         unsigned sgs_per_dev, unsigned num_par_pages,
  74                         struct ore_io_state **pios);
  75 int _ore_add_stripe_unit(struct ore_io_state *ios,  unsigned *cur_pg,
  76                 unsigned pgbase, struct page **pages,
  77                 struct ore_per_dev_state *per_dev, int cur_len);
  78 int _ore_read_mirror(struct ore_io_state *ios, unsigned cur_comp);
  79 int ore_io_execute(struct ore_io_state *ios);