fs/reiser4/plugin/item/extent.h

   1 /* Copyright 2001, 2002, 2003 by Hans Reiser, licensing governed by reiser4/README */
   2
   3 #ifndef __REISER4_EXTENT_H__
   4 #define __REISER4_EXTENT_H__
   5
   6 /* on disk extent */
   7 typedef struct {
   8         reiser4_dblock_nr start;
   9         reiser4_dblock_nr width;
  10 } reiser4_extent;
  11
  12 struct extent_stat {
  13         int unallocated_units;
  14         int unallocated_blocks;
  15         int allocated_units;
  16         int allocated_blocks;
  17         int hole_units;
  18         int hole_blocks;
  19 };
  20
  21 /* extents in an extent item can be either holes, or unallocated or allocated
  22    extents */
  23 typedef enum {
  24         HOLE_EXTENT,
  25         UNALLOCATED_EXTENT,
  26         ALLOCATED_EXTENT
  27 } extent_state;
  28
  29 #define HOLE_EXTENT_START 0
  30 #define UNALLOCATED_EXTENT_START 1
  31 #define UNALLOCATED_EXTENT_START2 2
  32
  33 struct extent_coord_extension {
  34         reiser4_block_nr pos_in_unit;
  35         reiser4_block_nr width; /* width of current unit */
  36         pos_in_node_t nr_units; /* number of units */
  37         int ext_offset;         /* offset from the beginning of zdata() */
  38         unsigned long expected_page;
  39 #if REISER4_DEBUG
  40         reiser4_extent extent;
  41 #endif
  42 };
  43
  44 /* macros to set/get fields of on-disk extent */
  45 static inline reiser4_block_nr extent_get_start(const reiser4_extent * ext)
  46 {
  47         return le64_to_cpu(ext->start);
  48 }
  49
  50 static inline reiser4_block_nr extent_get_width(const reiser4_extent * ext)
  51 {
  52         return le64_to_cpu(ext->width);
  53 }
  54
  55 extern __u64 reiser4_current_block_count(void);
  56
  57 static inline void
  58 extent_set_start(reiser4_extent * ext, reiser4_block_nr start)
  59 {
  60         cassert(sizeof(ext->start) == 8);
  61         assert("nikita-2510",
  62                ergo(start > 1, start < reiser4_current_block_count()));
  63         put_unaligned(cpu_to_le64(start), &ext->start);
  64 }
  65
  66 static inline void
  67 extent_set_width(reiser4_extent * ext, reiser4_block_nr width)
  68 {
  69         cassert(sizeof(ext->width) == 8);
  70         assert("", width > 0);
  71         put_unaligned(cpu_to_le64(width), &ext->width);
  72         assert("nikita-2511",
  73                ergo(extent_get_start(ext) > 1,
  74                     extent_get_start(ext) + width <=
  75                     reiser4_current_block_count()));
  76 }
  77
  78 #define extent_item(coord)                                      \
  79 ({                                                              \
  80         assert("nikita-3143", item_is_extent(coord));           \
  81         ((reiser4_extent *)item_body_by_coord (coord));         \
  82 })
  83
  84 #define extent_by_coord(coord)                                  \
  85 ({                                                              \
  86         assert("nikita-3144", item_is_extent(coord));           \
  87         (extent_item (coord) + (coord)->unit_pos);              \
  88 })
  89
  90 #define width_by_coord(coord)                                   \
  91 ({                                                              \
  92         assert("nikita-3145", item_is_extent(coord));           \
  93         extent_get_width (extent_by_coord(coord));              \
  94 })
  95
  96 struct carry_cut_data;
  97 struct carry_kill_data;
  98
  99 /* plugin->u.item.b.* */
 100 reiser4_key *max_key_inside_extent(const coord_t *, reiser4_key *);
 101 int can_contain_key_extent(const coord_t * coord, const reiser4_key * key,
 102                            const reiser4_item_data *);
 103 int mergeable_extent(const coord_t * p1, const coord_t * p2);
 104 pos_in_node_t nr_units_extent(const coord_t *);
 105 lookup_result lookup_extent(const reiser4_key *, lookup_bias, coord_t *);
 106 void init_coord_extent(coord_t *);
 107 int init_extent(coord_t *, reiser4_item_data *);
 108 int paste_extent(coord_t *, reiser4_item_data *, carry_plugin_info *);
 109 int can_shift_extent(unsigned free_space,
 110                      coord_t * source, znode * target, shift_direction,
 111                      unsigned *size, unsigned want);
 112 void copy_units_extent(coord_t * target, coord_t * source, unsigned from,
 113                        unsigned count, shift_direction where_is_free_space,
 114                        unsigned free_space);
 115 int kill_hook_extent(const coord_t *, pos_in_node_t from, pos_in_node_t count,
 116                      struct carry_kill_data *);
 117 int create_hook_extent(const coord_t * coord, void *arg);
 118 int cut_units_extent(coord_t * coord, pos_in_node_t from, pos_in_node_t to,
 119                      struct carry_cut_data *, reiser4_key * smallest_removed,
 120                      reiser4_key * new_first);
 121 int kill_units_extent(coord_t * coord, pos_in_node_t from, pos_in_node_t to,
 122                       struct carry_kill_data *, reiser4_key * smallest_removed,
 123                       reiser4_key * new_first);
 124 reiser4_key *unit_key_extent(const coord_t *, reiser4_key *);
 125 reiser4_key *max_unit_key_extent(const coord_t *, reiser4_key *);
 126 void print_extent(const char *, coord_t *);
 127 int utmost_child_extent(const coord_t * coord, sideof side, jnode ** child);
 128 int utmost_child_real_block_extent(const coord_t * coord, sideof side,
 129                                    reiser4_block_nr * block);
 130 void item_stat_extent(const coord_t * coord, void *vp);
 131 int reiser4_check_extent(const coord_t * coord, const char **error);
 132
 133 /* plugin->u.item.s.file.* */
 134 ssize_t reiser4_write_extent(struct file *, const char __user *,
 135                              size_t, loff_t *);
 136 int reiser4_read_extent(struct file *, flow_t *, hint_t *);
 137 int reiser4_readpage_extent(void *, struct page *);
 138 int reiser4_do_readpage_extent(reiser4_extent*, reiser4_block_nr, struct page*);
 139 reiser4_key *append_key_extent(const coord_t *, reiser4_key *);
 140 void init_coord_extension_extent(uf_coord_t *, loff_t offset);
 141 int get_block_address_extent(const coord_t *, sector_t block,
 142                              sector_t * result);
 143
 144 /* these are used in flush.c
 145    FIXME-VS: should they be somewhere in item_plugin? */
 146 int allocate_extent_item_in_place(coord_t *, lock_handle *, flush_pos_t * pos);
 147 int allocate_and_copy_extent(znode * left, coord_t * right, flush_pos_t * pos,
 148                              reiser4_key * stop_key);
 149
 150 int extent_is_unallocated(const coord_t * item);        /* True if this extent is unallocated (i.e., not a hole, not allocated). */
 151 __u64 extent_unit_index(const coord_t * item);  /* Block offset of this unit. */
 152 __u64 extent_unit_width(const coord_t * item);  /* Number of blocks in this unit. */
 153
 154 /* plugin->u.item.f. */
 155 int reiser4_scan_extent(flush_scan * scan);
 156 extern int key_by_offset_extent(struct inode *, loff_t, reiser4_key *);
 157
 158 reiser4_item_data *init_new_extent(reiser4_item_data * data, void *ext_unit,
 159                                    int nr_extents);
 160 reiser4_block_nr reiser4_extent_size(const coord_t * coord, pos_in_node_t nr);
 161 extent_state state_of_extent(reiser4_extent * ext);
 162 void reiser4_set_extent(reiser4_extent *, reiser4_block_nr start,
 163                         reiser4_block_nr width);
 164 int reiser4_update_extent(struct inode *, jnode *, loff_t pos,
 165                           int *plugged_hole);
 166
 167 #include "../../coord.h"
 168 #include "../../lock.h"
 169 #include "../../tap.h"
 170
 171 struct replace_handle {
 172         /* these are to be set before calling reiser4_replace_extent */
 173         coord_t *coord;
 174         lock_handle *lh;
 175         reiser4_key key;
 176         reiser4_key *pkey;
 177         reiser4_extent overwrite;
 178         reiser4_extent new_extents[2];
 179         int nr_new_extents;
 180         unsigned flags;
 181
 182         /* these are used by reiser4_replace_extent */
 183         reiser4_item_data item;
 184         coord_t coord_after;
 185         lock_handle lh_after;
 186         tap_t watch;
 187         reiser4_key paste_key;
 188 #if REISER4_DEBUG
 189         reiser4_extent orig_ext;
 190         reiser4_key tmp;
 191 #endif
 192 };
 193
 194 /* this structure is kmalloced before calling make_extent to avoid excessive
 195    stack consumption on plug_hole->reiser4_replace_extent */
 196 struct make_extent_handle {
 197         uf_coord_t *uf_coord;
 198         reiser4_block_nr blocknr;
 199         int created;
 200         struct inode *inode;
 201         union {
 202                 struct {
 203                 } append;
 204                 struct replace_handle replace;
 205         } u;
 206 };
 207
 208 int reiser4_replace_extent(struct replace_handle *,
 209                            int return_inserted_position);
 210 lock_handle *znode_lh(znode *);
 211
 212 /* the reiser4 repacker support */
 213 struct repacker_cursor;
 214 extern int process_extent_backward_for_repacking(tap_t *,
 215                                                  struct repacker_cursor *);
 216 extern int mark_extent_for_repacking(tap_t *, int);
 217
 218 #define coord_by_uf_coord(uf_coord) (&((uf_coord)->coord))
 219 #define ext_coord_by_uf_coord(uf_coord) (&((uf_coord)->extension.extent))
 220
 221 /* __REISER4_EXTENT_H__ */
 222 #endif
 223 /*
 224    Local variables:
 225    c-indentation-style: "K&R"
 226    mode-name: "LC"
 227    c-basic-offset: 8
 228    tab-width: 8
 229    fill-column: 120
 230    End:
 231 */