git.oblomov.eu Git - linux-2.6/blob - fs/btrfs/inode-map.c

   1 #include <linux/module.h>
   2 #include "ctree.h"
   3 #include "disk-io.h"
   4 #include "transaction.h"
   5
   6 int btrfs_find_highest_inode(struct btrfs_root *root, u64 *objectid)
   7 {
   8         struct btrfs_path *path;
   9         int ret;
  10         struct btrfs_leaf *l;
  11         struct btrfs_key search_key;
  12         int slot;
  13
  14         path = btrfs_alloc_path();
  15         BUG_ON(!path);
  16
  17         search_key.objectid = (u64)-1;
  18         search_key.offset = (u64)-1;
  19         ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0);
  20         if (ret < 0)
  21                 goto error;
  22         BUG_ON(ret == 0);
  23         if (path->slots[0] > 0) {
  24                 slot = path->slots[0] - 1;
  25                 l = btrfs_buffer_leaf(path->nodes[0]);
  26                 *objectid = btrfs_disk_key_objectid(&l->items[slot].key);
  27         } else {
  28                 *objectid = BTRFS_FIRST_FREE_OBJECTID;
  29         }
  30         ret = 0;
  31 error:
  32         btrfs_free_path(path);
  33         return ret;
  34 }
  35
  36 /*
  37  * walks the btree of allocated inodes and find a hole.
  38  */
  39 int btrfs_find_free_objectid(struct btrfs_trans_handle *trans,
  40                              struct btrfs_root *root,
  41                              u64 dirid, u64 *objectid)
  42 {
  43         struct btrfs_path *path;
  44         struct btrfs_key key;
  45         int ret;
  46         u64 hole_size = 0;
  47         int slot = 0;
  48         u64 last_ino = 0;
  49         int start_found;
  50         struct btrfs_leaf *l;
  51         struct btrfs_key search_key;
  52         u64 search_start = dirid;
  53
  54         path = btrfs_alloc_path();
  55         BUG_ON(!path);
  56         search_key.flags = 0;
  57         search_start = root->last_inode_alloc;
  58         search_start = max(search_start, BTRFS_FIRST_FREE_OBJECTID);
  59         search_key.objectid = search_start;
  60         search_key.offset = 0;
  61
  62         btrfs_init_path(path);
  63         start_found = 0;
  64         ret = btrfs_search_slot(trans, root, &search_key, path, 0, 0);
  65         if (ret < 0)
  66                 goto error;
  67
  68         if (path->slots[0] > 0)
  69                 path->slots[0]--;
  70
  71         while (1) {
  72                 l = btrfs_buffer_leaf(path->nodes[0]);
  73                 slot = path->slots[0];
  74                 if (slot >= btrfs_header_nritems(&l->header)) {
  75                         ret = btrfs_next_leaf(root, path);
  76                         if (ret == 0)
  77                                 continue;
  78                         if (ret < 0)
  79                                 goto error;
  80                         if (!start_found) {
  81                                 *objectid = search_start;
  82                                 start_found = 1;
  83                                 goto found;
  84                         }
  85                         *objectid = last_ino > search_start ?
  86                                 last_ino : search_start;
  87                         goto found;
  88                 }
  89                 btrfs_disk_key_to_cpu(&key, &l->items[slot].key);
  90                 if (key.objectid >= search_start) {
  91                         if (start_found) {
  92                                 if (last_ino < search_start)
  93                                         last_ino = search_start;
  94                                 hole_size = key.objectid - last_ino;
  95                                 if (hole_size > 0) {
  96                                         *objectid = last_ino;
  97                                         goto found;
  98                                 }
  99                         }
 100                 }
 101                 start_found = 1;
 102                 last_ino = key.objectid + 1;
 103                 path->slots[0]++;
 104         }
 105         // FIXME -ENOSPC
 106 found:
 107         root->last_inode_alloc = *objectid;
 108         btrfs_release_path(root, path);
 109         btrfs_free_path(path);
 110         BUG_ON(*objectid < search_start);
 111         return 0;
 112 error:
 113         btrfs_release_path(root, path);
 114         btrfs_free_path(path);
 115         return ret;
 116 }