2 * Copyright (C) 2007 Oracle. All rights reserved.
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
21 #include "kerncompat.h"
22 #include "radix-tree.h"
25 #include "print-tree.h"
26 #include "transaction.h"
28 static int find_free_extent(struct btrfs_trans_handle
*trans
, struct btrfs_root
29 *orig_root
, u64 num_blocks
, u64 search_start
, u64
30 search_end
, struct btrfs_key
*ins
);
31 static int finish_current_insert(struct btrfs_trans_handle
*trans
, struct
32 btrfs_root
*extent_root
);
33 static int run_pending(struct btrfs_trans_handle
*trans
, struct btrfs_root
37 * pending extents are blocks that we're trying to allocate in the extent
38 * map while trying to grow the map because of other allocations. To avoid
39 * recursing, they are tagged in the radix tree and cleaned up after
40 * other allocations are done. The pending tag is also used in the same
43 #define CTREE_EXTENT_PENDING_DEL 0
45 static int inc_block_ref(struct btrfs_trans_handle
*trans
, struct btrfs_root
48 struct btrfs_path path
;
52 struct btrfs_extent_item
*item
;
56 find_free_extent(trans
, root
->fs_info
->extent_root
, 0, 0, (u64
)-1,
58 btrfs_init_path(&path
);
59 key
.objectid
= blocknr
;
61 btrfs_set_key_type(&key
, BTRFS_EXTENT_ITEM_KEY
);
63 ret
= btrfs_search_slot(trans
, root
->fs_info
->extent_root
, &key
, &path
,
68 l
= &path
.nodes
[0]->leaf
;
69 item
= btrfs_item_ptr(l
, path
.slots
[0], struct btrfs_extent_item
);
70 refs
= btrfs_extent_refs(item
);
71 btrfs_set_extent_refs(item
, refs
+ 1);
73 BUG_ON(list_empty(&path
.nodes
[0]->dirty
));
74 btrfs_release_path(root
->fs_info
->extent_root
, &path
);
75 finish_current_insert(trans
, root
->fs_info
->extent_root
);
76 run_pending(trans
, root
->fs_info
->extent_root
);
80 static int lookup_block_ref(struct btrfs_trans_handle
*trans
, struct btrfs_root
81 *root
, u64 blocknr
, u32
*refs
)
83 struct btrfs_path path
;
87 struct btrfs_extent_item
*item
;
88 btrfs_init_path(&path
);
89 key
.objectid
= blocknr
;
92 btrfs_set_key_type(&key
, BTRFS_EXTENT_ITEM_KEY
);
93 ret
= btrfs_search_slot(trans
, root
->fs_info
->extent_root
, &key
, &path
,
97 l
= &path
.nodes
[0]->leaf
;
98 item
= btrfs_item_ptr(l
, path
.slots
[0], struct btrfs_extent_item
);
99 *refs
= btrfs_extent_refs(item
);
100 btrfs_release_path(root
->fs_info
->extent_root
, &path
);
104 int btrfs_inc_ref(struct btrfs_trans_handle
*trans
, struct btrfs_root
*root
,
105 struct btrfs_buffer
*buf
)
112 if (btrfs_is_leaf(&buf
->node
))
115 for (i
= 0; i
< btrfs_header_nritems(&buf
->node
.header
); i
++) {
116 blocknr
= btrfs_node_blockptr(&buf
->node
, i
);
117 inc_block_ref(trans
, root
, blocknr
);
122 static int write_one_cache_group(struct btrfs_trans_handle
*trans
,
123 struct btrfs_root
*root
,
124 struct btrfs_path
*path
,
125 struct btrfs_block_group_cache
*cache
)
129 struct btrfs_root
*extent_root
= root
->fs_info
->extent_root
;
130 struct btrfs_block_group_item
*bi
;
131 struct btrfs_key ins
;
133 ret
= find_free_extent(trans
, root
, 0, 0, (u64
)-1, &ins
);
136 ret
= btrfs_search_slot(trans
, root
->fs_info
->extent_root
,
137 &cache
->key
, path
, 0, 1);
139 bi
= btrfs_item_ptr(&path
->nodes
[0]->leaf
, path
->slots
[0],
140 struct btrfs_block_group_item
);
141 memcpy(bi
, &cache
->item
, sizeof(*bi
));
142 dirty_tree_block(trans
, extent_root
, path
->nodes
[0]);
143 btrfs_release_path(extent_root
, path
);
144 finish_current_insert(trans
, root
);
145 pending_ret
= run_pending(trans
, root
);
154 int btrfs_write_dirty_block_groups(struct btrfs_trans_handle
*trans
,
155 struct btrfs_root
*root
)
157 struct btrfs_block_group_cache
*cache
[8];
161 struct radix_tree_root
*radix
= &root
->fs_info
->block_group_radix
;
163 struct btrfs_path path
;
164 btrfs_init_path(&path
);
167 ret
= radix_tree_gang_lookup_tag(radix
, (void **)cache
,
168 0, ARRAY_SIZE(cache
),
169 BTRFS_BLOCK_GROUP_DIRTY
);
172 for (i
= 0; i
< ret
; i
++) {
173 radix_tree_tag_clear(radix
, cache
[i
]->key
.objectid
+
174 cache
[i
]->key
.offset
-1,
175 BTRFS_BLOCK_GROUP_DIRTY
);
176 err
= write_one_cache_group(trans
, root
,
185 static int update_block_group(struct btrfs_trans_handle
*trans
,
186 struct btrfs_root
*root
,
187 u64 blocknr
, u64 num
, int alloc
)
189 struct btrfs_block_group_cache
*cache
;
190 struct btrfs_fs_info
*info
= root
->fs_info
;
197 ret
= radix_tree_gang_lookup(&info
->block_group_radix
,
198 (void **)&cache
, blocknr
, 1);
201 radix_tree_tag_set(&info
->block_group_radix
,
202 cache
->key
.objectid
+ cache
->key
.offset
- 1,
203 BTRFS_BLOCK_GROUP_DIRTY
);
205 block_in_group
= blocknr
- cache
->key
.objectid
;
206 old_val
= btrfs_block_group_used(&cache
->item
);
207 if (total
> cache
->key
.offset
- block_in_group
)
208 num
= cache
->key
.offset
- block_in_group
;
217 btrfs_set_block_group_used(&cache
->item
, old_val
);
222 int btrfs_finish_extent_commit(struct btrfs_trans_handle
*trans
, struct
225 unsigned long gang
[8];
231 ret
= radix_tree_gang_lookup(&root
->fs_info
->pinned_radix
,
238 for (i
= 0; i
< ret
; i
++) {
239 radix_tree_delete(&root
->fs_info
->pinned_radix
,
243 root
->fs_info
->last_insert
.objectid
= first
;
244 root
->fs_info
->last_insert
.offset
= 0;
248 static int finish_current_insert(struct btrfs_trans_handle
*trans
, struct
249 btrfs_root
*extent_root
)
251 struct btrfs_key ins
;
252 struct btrfs_extent_item extent_item
;
255 u64 super_blocks_used
;
256 struct btrfs_fs_info
*info
= extent_root
->fs_info
;
258 btrfs_set_extent_refs(&extent_item
, 1);
259 btrfs_set_extent_owner(&extent_item
, extent_root
->root_key
.objectid
);
262 btrfs_set_key_type(&ins
, BTRFS_EXTENT_ITEM_KEY
);
264 for (i
= 0; i
< extent_root
->fs_info
->current_insert
.flags
; i
++) {
265 ins
.objectid
= extent_root
->fs_info
->current_insert
.objectid
+
267 super_blocks_used
= btrfs_super_blocks_used(info
->disk_super
);
268 btrfs_set_super_blocks_used(info
->disk_super
,
269 super_blocks_used
+ 1);
270 ret
= btrfs_insert_item(trans
, extent_root
, &ins
, &extent_item
,
271 sizeof(extent_item
));
273 btrfs_print_tree(extent_root
, extent_root
->node
);
277 extent_root
->fs_info
->current_insert
.offset
= 0;
282 * remove an extent from the root, returns 0 on success
284 static int __free_extent(struct btrfs_trans_handle
*trans
, struct btrfs_root
285 *root
, u64 blocknr
, u64 num_blocks
, int pin
)
287 struct btrfs_path path
;
288 struct btrfs_key key
;
289 struct btrfs_fs_info
*info
= root
->fs_info
;
290 struct btrfs_root
*extent_root
= info
->extent_root
;
292 struct btrfs_extent_item
*ei
;
293 struct btrfs_key ins
;
296 BUG_ON(pin
&& num_blocks
!= 1);
297 key
.objectid
= blocknr
;
299 btrfs_set_key_type(&key
, BTRFS_EXTENT_ITEM_KEY
);
300 key
.offset
= num_blocks
;
302 find_free_extent(trans
, root
, 0, 0, (u64
)-1, &ins
);
303 btrfs_init_path(&path
);
304 ret
= btrfs_search_slot(trans
, extent_root
, &key
, &path
, -1, 1);
306 btrfs_print_tree(extent_root
, extent_root
->node
);
307 printf("failed to find %llu\n",
308 (unsigned long long)key
.objectid
);
311 ei
= btrfs_item_ptr(&path
.nodes
[0]->leaf
, path
.slots
[0],
312 struct btrfs_extent_item
);
313 BUG_ON(ei
->refs
== 0);
314 refs
= btrfs_extent_refs(ei
) - 1;
315 btrfs_set_extent_refs(ei
, refs
);
317 u64 super_blocks_used
;
320 unsigned long bl
= blocknr
;
321 radix_tree_preload(GFP_KERNEL
);
322 err
= radix_tree_insert(&info
->pinned_radix
,
323 blocknr
, (void *)bl
);
325 radix_tree_preload_end();
327 super_blocks_used
= btrfs_super_blocks_used(info
->disk_super
);
328 btrfs_set_super_blocks_used(info
->disk_super
,
329 super_blocks_used
- num_blocks
);
330 ret
= btrfs_del_item(trans
, extent_root
, &path
);
331 if (!pin
&& extent_root
->fs_info
->last_insert
.objectid
>
333 extent_root
->fs_info
->last_insert
.objectid
= blocknr
;
336 ret
= update_block_group(trans
, root
, blocknr
, num_blocks
, 0);
339 btrfs_release_path(extent_root
, &path
);
340 finish_current_insert(trans
, extent_root
);
345 * find all the blocks marked as pending in the radix tree and remove
346 * them from the extent map
348 static int del_pending_extents(struct btrfs_trans_handle
*trans
, struct
349 btrfs_root
*extent_root
)
352 struct btrfs_buffer
*gang
[4];
356 ret
= radix_tree_gang_lookup_tag(
357 &extent_root
->fs_info
->cache_radix
,
360 CTREE_EXTENT_PENDING_DEL
);
363 for (i
= 0; i
< ret
; i
++) {
364 ret
= __free_extent(trans
, extent_root
,
365 gang
[i
]->blocknr
, 1, 1);
366 radix_tree_tag_clear(&extent_root
->fs_info
->cache_radix
,
368 CTREE_EXTENT_PENDING_DEL
);
369 btrfs_block_release(extent_root
, gang
[i
]);
375 static int run_pending(struct btrfs_trans_handle
*trans
, struct btrfs_root
378 while(radix_tree_tagged(&extent_root
->fs_info
->cache_radix
,
379 CTREE_EXTENT_PENDING_DEL
))
380 del_pending_extents(trans
, extent_root
);
386 * remove an extent from the root, returns 0 on success
388 int btrfs_free_extent(struct btrfs_trans_handle
*trans
, struct btrfs_root
389 *root
, u64 blocknr
, u64 num_blocks
, int pin
)
391 struct btrfs_root
*extent_root
= root
->fs_info
->extent_root
;
392 struct btrfs_buffer
*t
;
396 if (root
== extent_root
) {
397 t
= find_tree_block(root
, blocknr
);
398 radix_tree_tag_set(&root
->fs_info
->cache_radix
, blocknr
,
399 CTREE_EXTENT_PENDING_DEL
);
402 ret
= __free_extent(trans
, root
, blocknr
, num_blocks
, pin
);
403 pending_ret
= run_pending(trans
, root
->fs_info
->extent_root
);
404 return ret
? ret
: pending_ret
;
408 * walks the btree of allocated extents and find a hole of a given size.
409 * The key ins is changed to record the hole:
410 * ins->objectid == block start
411 * ins->flags = BTRFS_EXTENT_ITEM_KEY
412 * ins->offset == number of blocks
413 * Any available blocks before search_start are skipped.
415 static int find_free_extent(struct btrfs_trans_handle
*trans
, struct btrfs_root
416 *orig_root
, u64 num_blocks
, u64 search_start
, u64
417 search_end
, struct btrfs_key
*ins
)
419 struct btrfs_path path
;
420 struct btrfs_key key
;
427 struct btrfs_leaf
*l
;
428 struct btrfs_root
* root
= orig_root
->fs_info
->extent_root
;
429 int total_needed
= num_blocks
;
431 total_needed
+= (btrfs_header_level(&root
->node
->node
.header
) + 1) * 3;
432 if (root
->fs_info
->last_insert
.objectid
> search_start
)
433 search_start
= root
->fs_info
->last_insert
.objectid
;
436 btrfs_set_key_type(ins
, BTRFS_EXTENT_ITEM_KEY
);
439 btrfs_init_path(&path
);
440 ins
->objectid
= search_start
;
443 ret
= btrfs_search_slot(trans
, root
, ins
, &path
, 0, 0);
447 if (path
.slots
[0] > 0)
451 l
= &path
.nodes
[0]->leaf
;
452 slot
= path
.slots
[0];
453 if (slot
>= btrfs_header_nritems(&l
->header
)) {
454 ret
= btrfs_next_leaf(root
, &path
);
460 ins
->objectid
= search_start
;
461 ins
->offset
= (u64
)-1 - search_start
;
465 ins
->objectid
= last_block
> search_start
?
466 last_block
: search_start
;
467 ins
->offset
= (u64
)-1 - ins
->objectid
;
470 btrfs_disk_key_to_cpu(&key
, &l
->items
[slot
].key
);
471 if (btrfs_key_type(&key
) != BTRFS_EXTENT_ITEM_KEY
)
473 if (key
.objectid
>= search_start
) {
475 if (last_block
< search_start
)
476 last_block
= search_start
;
477 hole_size
= key
.objectid
- last_block
;
478 if (hole_size
> total_needed
) {
479 ins
->objectid
= last_block
;
480 ins
->offset
= hole_size
;
486 last_block
= key
.objectid
+ key
.offset
;
492 /* we have to make sure we didn't find an extent that has already
493 * been allocated by the map tree or the original allocation
495 btrfs_release_path(root
, &path
);
496 BUG_ON(ins
->objectid
< search_start
);
497 for (test_block
= ins
->objectid
;
498 test_block
< ins
->objectid
+ total_needed
; test_block
++) {
499 if (radix_tree_lookup(&root
->fs_info
->pinned_radix
,
501 search_start
= test_block
+ 1;
505 BUG_ON(root
->fs_info
->current_insert
.offset
);
506 root
->fs_info
->current_insert
.offset
= total_needed
- num_blocks
;
507 root
->fs_info
->current_insert
.objectid
= ins
->objectid
+ num_blocks
;
508 root
->fs_info
->current_insert
.flags
= 0;
509 root
->fs_info
->last_insert
.objectid
= ins
->objectid
;
510 ins
->offset
= num_blocks
;
513 btrfs_release_path(root
, &path
);
517 * finds a free extent and does all the dirty work required for allocation
518 * returns the key for the extent through ins, and a tree buffer for
519 * the first block of the extent through buf.
521 * returns 0 if everything worked, non-zero otherwise.
523 static int alloc_extent(struct btrfs_trans_handle
*trans
, struct btrfs_root
524 *root
, u64 owner
, u64 num_blocks
,
525 u64 search_start
, u64
526 search_end
, struct btrfs_key
*ins
)
530 u64 super_blocks_used
;
531 struct btrfs_fs_info
*info
= root
->fs_info
;
532 struct btrfs_root
*extent_root
= info
->extent_root
;
533 struct btrfs_extent_item extent_item
;
535 btrfs_set_extent_refs(&extent_item
, 1);
536 btrfs_set_extent_owner(&extent_item
, owner
);
538 if (root
== extent_root
) {
539 BUG_ON(extent_root
->fs_info
->current_insert
.offset
== 0);
540 BUG_ON(num_blocks
!= 1);
541 BUG_ON(extent_root
->fs_info
->current_insert
.flags
==
542 extent_root
->fs_info
->current_insert
.offset
);
544 ins
->objectid
= extent_root
->fs_info
->current_insert
.objectid
+
545 extent_root
->fs_info
->current_insert
.flags
++;
548 ret
= find_free_extent(trans
, root
, num_blocks
, search_start
,
553 super_blocks_used
= btrfs_super_blocks_used(info
->disk_super
);
554 btrfs_set_super_blocks_used(info
->disk_super
, super_blocks_used
+
556 ret
= btrfs_insert_item(trans
, extent_root
, ins
, &extent_item
,
557 sizeof(extent_item
));
559 finish_current_insert(trans
, extent_root
);
560 pending_ret
= run_pending(trans
, extent_root
);
569 * helper function to allocate a block for a given tree
570 * returns the tree buffer or NULL.
572 struct btrfs_buffer
*btrfs_alloc_free_block(struct btrfs_trans_handle
*trans
,
573 struct btrfs_root
*root
)
575 struct btrfs_key ins
;
577 struct btrfs_buffer
*buf
;
579 ret
= alloc_extent(trans
, root
, root
->root_key
.objectid
,
580 1, 0, (unsigned long)-1, &ins
);
585 ret
= update_block_group(trans
, root
, ins
.objectid
, ins
.offset
, 1);
586 buf
= find_tree_block(root
, ins
.objectid
);
587 btrfs_set_header_generation(&buf
->node
.header
,
588 root
->root_key
.offset
+ 1);
589 btrfs_set_header_blocknr(&buf
->node
.header
, buf
->blocknr
);
590 memcpy(buf
->node
.header
.fsid
, root
->fs_info
->disk_super
->fsid
,
591 sizeof(buf
->node
.header
.fsid
));
592 dirty_tree_block(trans
, root
, buf
);
598 * helper function for drop_snapshot, this walks down the tree dropping ref
601 static int walk_down_tree(struct btrfs_trans_handle
*trans
, struct btrfs_root
602 *root
, struct btrfs_path
*path
, int *level
)
604 struct btrfs_buffer
*next
;
605 struct btrfs_buffer
*cur
;
610 ret
= lookup_block_ref(trans
, root
, path
->nodes
[*level
]->blocknr
,
616 * walk down to the last node level and free all the leaves
619 cur
= path
->nodes
[*level
];
620 if (path
->slots
[*level
] >=
621 btrfs_header_nritems(&cur
->node
.header
))
623 blocknr
= btrfs_node_blockptr(&cur
->node
, path
->slots
[*level
]);
624 ret
= lookup_block_ref(trans
, root
, blocknr
, &refs
);
625 if (refs
!= 1 || *level
== 1) {
626 path
->slots
[*level
]++;
627 ret
= btrfs_free_extent(trans
, root
, blocknr
, 1, 1);
632 next
= read_tree_block(root
, blocknr
);
633 if (path
->nodes
[*level
-1])
634 btrfs_block_release(root
, path
->nodes
[*level
-1]);
635 path
->nodes
[*level
-1] = next
;
636 *level
= btrfs_header_level(&next
->node
.header
);
637 path
->slots
[*level
] = 0;
640 ret
= btrfs_free_extent(trans
, root
, path
->nodes
[*level
]->blocknr
, 1,
642 btrfs_block_release(root
, path
->nodes
[*level
]);
643 path
->nodes
[*level
] = NULL
;
650 * helper for dropping snapshots. This walks back up the tree in the path
651 * to find the first node higher up where we haven't yet gone through
654 static int walk_up_tree(struct btrfs_trans_handle
*trans
, struct btrfs_root
655 *root
, struct btrfs_path
*path
, int *level
)
660 for(i
= *level
; i
< BTRFS_MAX_LEVEL
- 1 && path
->nodes
[i
]; i
++) {
661 slot
= path
->slots
[i
];
663 btrfs_header_nritems(&path
->nodes
[i
]->node
.header
)- 1) {
668 ret
= btrfs_free_extent(trans
, root
,
669 path
->nodes
[*level
]->blocknr
,
671 btrfs_block_release(root
, path
->nodes
[*level
]);
672 path
->nodes
[*level
] = NULL
;
681 * drop the reference count on the tree rooted at 'snap'. This traverses
682 * the tree freeing any blocks that have a ref count of zero after being
685 int btrfs_drop_snapshot(struct btrfs_trans_handle
*trans
, struct btrfs_root
686 *root
, struct btrfs_buffer
*snap
)
691 struct btrfs_path path
;
695 btrfs_init_path(&path
);
697 level
= btrfs_header_level(&snap
->node
.header
);
699 path
.nodes
[level
] = snap
;
700 path
.slots
[level
] = 0;
702 wret
= walk_down_tree(trans
, root
, &path
, &level
);
708 wret
= walk_up_tree(trans
, root
, &path
, &level
);
714 for (i
= 0; i
<= orig_level
; i
++) {
716 btrfs_block_release(root
, path
.nodes
[i
]);
722 int btrfs_free_block_groups(struct btrfs_fs_info
*info
)
725 struct btrfs_block_group_cache
*cache
[8];
729 ret
= radix_tree_gang_lookup(&info
->block_group_radix
,
734 for (i
= 0; i
< ret
; i
++) {
735 radix_tree_delete(&info
->block_group_radix
,
736 cache
[i
]->key
.objectid
+
737 cache
[i
]->key
.offset
- 1);
744 int btrfs_read_block_groups(struct btrfs_root
*root
)
746 struct btrfs_path path
;
749 struct btrfs_block_group_item
*bi
;
750 struct btrfs_block_group_cache
*cache
;
751 struct btrfs_key key
;
752 struct btrfs_key found_key
;
753 struct btrfs_leaf
*leaf
;
754 u64 group_size_blocks
= BTRFS_BLOCK_GROUP_SIZE
/ root
->blocksize
;
756 root
= root
->fs_info
->extent_root
;
758 key
.offset
= group_size_blocks
;
760 btrfs_set_key_type(&key
, BTRFS_BLOCK_GROUP_ITEM_KEY
);
761 btrfs_init_path(&path
);
764 ret
= btrfs_search_slot(NULL
, root
->fs_info
->extent_root
,
770 leaf
= &path
.nodes
[0]->leaf
;
771 btrfs_disk_key_to_cpu(&found_key
,
772 &leaf
->items
[path
.slots
[0]].key
);
773 cache
= malloc(sizeof(*cache
));
778 bi
= btrfs_item_ptr(leaf
, path
.slots
[0],
779 struct btrfs_block_group_item
);
780 memcpy(&cache
->item
, bi
, sizeof(*bi
));
781 memcpy(&cache
->key
, &found_key
, sizeof(found_key
));
782 key
.objectid
= found_key
.objectid
+ found_key
.offset
;
783 btrfs_release_path(root
, &path
);
784 ret
= radix_tree_insert(&root
->fs_info
->block_group_radix
,
786 found_key
.offset
- 1, (void *)cache
);
789 btrfs_super_total_blocks(root
->fs_info
->disk_super
))
792 btrfs_release_path(root
, &path
);
796 int btrfs_insert_block_group(struct btrfs_trans_handle
*trans
,
797 struct btrfs_root
*root
,
798 struct btrfs_key
*key
,
799 struct btrfs_block_group_item
*bi
)
801 struct btrfs_key ins
;
805 root
= root
->fs_info
->extent_root
;
806 ret
= find_free_extent(trans
, root
, 0, 0, (u64
)-1, &ins
);
809 ret
= btrfs_insert_item(trans
, root
, key
, bi
, sizeof(*bi
));
810 finish_current_insert(trans
, root
);
811 pending_ret
= run_pending(trans
, root
);