fs/reiser4/oid.c

   1 /* Copyright 2003 by Hans Reiser, licensing governed by reiser4/README */
   2
   3 #include "debug.h"
   4 #include "super.h"
   5 #include "txnmgr.h"
   6
   7 /* we used to have oid allocation plugin. It was removed because it
   8    was recognized as providing unneeded level of abstraction. If one
   9    ever will find it useful - look at yet_unneeded_abstractions/oid
  10 */
  11
  12 /*
  13  * initialize in-memory data for oid allocator at @super. @nr_files and @next
  14  * are provided by disk format plugin that reads them from the disk during
  15  * mount.
  16  */
  17 int oid_init_allocator(struct super_block *super, oid_t nr_files, oid_t next)
  18 {
  19         reiser4_super_info_data *sbinfo;
  20
  21         sbinfo = get_super_private(super);
  22
  23         sbinfo->next_to_use = next;
  24         sbinfo->oids_in_use = nr_files;
  25         return 0;
  26 }
  27
  28 /*
  29  * allocate oid and return it. ABSOLUTE_MAX_OID is returned when allocator
  30  * runs out of oids.
  31  */
  32 oid_t oid_allocate(struct super_block *super)
  33 {
  34         reiser4_super_info_data *sbinfo;
  35         oid_t oid;
  36
  37         sbinfo = get_super_private(super);
  38
  39         spin_lock_reiser4_super(sbinfo);
  40         if (sbinfo->next_to_use != ABSOLUTE_MAX_OID) {
  41                 oid = sbinfo->next_to_use++;
  42                 sbinfo->oids_in_use++;
  43         } else
  44                 oid = ABSOLUTE_MAX_OID;
  45         spin_unlock_reiser4_super(sbinfo);
  46         return oid;
  47 }
  48
  49 /*
  50  * Tell oid allocator that @oid is now free.
  51  */
  52 int oid_release(struct super_block *super, oid_t oid UNUSED_ARG)
  53 {
  54         reiser4_super_info_data *sbinfo;
  55
  56         sbinfo = get_super_private(super);
  57
  58         spin_lock_reiser4_super(sbinfo);
  59         sbinfo->oids_in_use--;
  60         spin_unlock_reiser4_super(sbinfo);
  61         return 0;
  62 }
  63
  64 /*
  65  * return next @oid that would be allocated (i.e., returned by oid_allocate())
  66  * without actually allocating it. This is used by disk format plugin to save
  67  * oid allocator state on the disk.
  68  */
  69 oid_t oid_next(const struct super_block *super)
  70 {
  71         reiser4_super_info_data *sbinfo;
  72         oid_t oid;
  73
  74         sbinfo = get_super_private(super);
  75
  76         spin_lock_reiser4_super(sbinfo);
  77         oid = sbinfo->next_to_use;
  78         spin_unlock_reiser4_super(sbinfo);
  79         return oid;
  80 }
  81
  82 /*
  83  * returns number of currently used oids. This is used by statfs(2) to report
  84  * number of "inodes" and by disk format plugin to save oid allocator state on
  85  * the disk.
  86  */
  87 long oids_used(const struct super_block *super)
  88 {
  89         reiser4_super_info_data *sbinfo;
  90         oid_t used;
  91
  92         sbinfo = get_super_private(super);
  93
  94         spin_lock_reiser4_super(sbinfo);
  95         used = sbinfo->oids_in_use;
  96         spin_unlock_reiser4_super(sbinfo);
  97         if (used < (__u64) ((long)~0) >> 1)
  98                 return (long)used;
  99         else
 100                 return (long)-1;
 101 }
 102
 103 /*
 104  * Count oid as allocated in atom. This is done after call to oid_allocate()
 105  * at the point when we are irrevocably committed to creation of the new file
 106  * (i.e., when oid allocation cannot be any longer rolled back due to some
 107  * error).
 108  */
 109 void oid_count_allocated(void)
 110 {
 111         txn_atom *atom;
 112
 113         atom = get_current_atom_locked();
 114         atom->nr_objects_created++;
 115         spin_unlock_atom(atom);
 116 }
 117
 118 /*
 119  * Count oid as free in atom. This is done after call to oid_release() at the
 120  * point when we are irrevocably committed to the deletion of the file (i.e.,
 121  * when oid release cannot be any longer rolled back due to some error).
 122  */
 123 void oid_count_released(void)
 124 {
 125         txn_atom *atom;
 126
 127         atom = get_current_atom_locked();
 128         atom->nr_objects_deleted++;
 129         spin_unlock_atom(atom);
 130 }
 131
 132 /*
 133    Local variables:
 134    c-indentation-style: "K&R"
 135    mode-name: "LC"
 136    c-basic-offset: 8
 137    tab-width: 8
 138    fill-column: 120
 139    scroll-step: 1
 140    End:
 141 */