Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2011 STRATO. All rights reserved. |
| 3 | * |
| 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. |
| 7 | * |
| 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. |
| 12 | * |
| 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. |
| 17 | */ |
| 18 | |
Liu Bo | 425d17a | 2012-09-07 20:01:30 -0600 | [diff] [blame] | 19 | #include <linux/vmalloc.h> |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 20 | #include "ctree.h" |
| 21 | #include "disk-io.h" |
| 22 | #include "backref.h" |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 23 | #include "ulist.h" |
| 24 | #include "transaction.h" |
| 25 | #include "delayed-ref.h" |
Jan Schmidt | b916a59 | 2012-04-13 12:28:08 +0200 | [diff] [blame] | 26 | #include "locking.h" |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 27 | |
Jan Schmidt | 976b190 | 2012-05-17 16:43:03 +0200 | [diff] [blame] | 28 | struct extent_inode_elem { |
| 29 | u64 inum; |
| 30 | u64 offset; |
| 31 | struct extent_inode_elem *next; |
| 32 | }; |
| 33 | |
| 34 | static int check_extent_in_eb(struct btrfs_key *key, struct extent_buffer *eb, |
| 35 | struct btrfs_file_extent_item *fi, |
| 36 | u64 extent_item_pos, |
| 37 | struct extent_inode_elem **eie) |
| 38 | { |
Josef Bacik | 8ca15e0 | 2013-07-05 13:58:19 -0400 | [diff] [blame] | 39 | u64 offset = 0; |
Jan Schmidt | 976b190 | 2012-05-17 16:43:03 +0200 | [diff] [blame] | 40 | struct extent_inode_elem *e; |
| 41 | |
Josef Bacik | 8ca15e0 | 2013-07-05 13:58:19 -0400 | [diff] [blame] | 42 | if (!btrfs_file_extent_compression(eb, fi) && |
| 43 | !btrfs_file_extent_encryption(eb, fi) && |
| 44 | !btrfs_file_extent_other_encoding(eb, fi)) { |
| 45 | u64 data_offset; |
| 46 | u64 data_len; |
Jan Schmidt | 976b190 | 2012-05-17 16:43:03 +0200 | [diff] [blame] | 47 | |
Josef Bacik | 8ca15e0 | 2013-07-05 13:58:19 -0400 | [diff] [blame] | 48 | data_offset = btrfs_file_extent_offset(eb, fi); |
| 49 | data_len = btrfs_file_extent_num_bytes(eb, fi); |
| 50 | |
| 51 | if (extent_item_pos < data_offset || |
| 52 | extent_item_pos >= data_offset + data_len) |
| 53 | return 1; |
| 54 | offset = extent_item_pos - data_offset; |
| 55 | } |
Jan Schmidt | 976b190 | 2012-05-17 16:43:03 +0200 | [diff] [blame] | 56 | |
| 57 | e = kmalloc(sizeof(*e), GFP_NOFS); |
| 58 | if (!e) |
| 59 | return -ENOMEM; |
| 60 | |
| 61 | e->next = *eie; |
| 62 | e->inum = key->objectid; |
Josef Bacik | 8ca15e0 | 2013-07-05 13:58:19 -0400 | [diff] [blame] | 63 | e->offset = key->offset + offset; |
Jan Schmidt | 976b190 | 2012-05-17 16:43:03 +0200 | [diff] [blame] | 64 | *eie = e; |
| 65 | |
| 66 | return 0; |
| 67 | } |
| 68 | |
| 69 | static int find_extent_in_eb(struct extent_buffer *eb, u64 wanted_disk_byte, |
| 70 | u64 extent_item_pos, |
| 71 | struct extent_inode_elem **eie) |
| 72 | { |
| 73 | u64 disk_byte; |
| 74 | struct btrfs_key key; |
| 75 | struct btrfs_file_extent_item *fi; |
| 76 | int slot; |
| 77 | int nritems; |
| 78 | int extent_type; |
| 79 | int ret; |
| 80 | |
| 81 | /* |
| 82 | * from the shared data ref, we only have the leaf but we need |
| 83 | * the key. thus, we must look into all items and see that we |
| 84 | * find one (some) with a reference to our extent item. |
| 85 | */ |
| 86 | nritems = btrfs_header_nritems(eb); |
| 87 | for (slot = 0; slot < nritems; ++slot) { |
| 88 | btrfs_item_key_to_cpu(eb, &key, slot); |
| 89 | if (key.type != BTRFS_EXTENT_DATA_KEY) |
| 90 | continue; |
| 91 | fi = btrfs_item_ptr(eb, slot, struct btrfs_file_extent_item); |
| 92 | extent_type = btrfs_file_extent_type(eb, fi); |
| 93 | if (extent_type == BTRFS_FILE_EXTENT_INLINE) |
| 94 | continue; |
| 95 | /* don't skip BTRFS_FILE_EXTENT_PREALLOC, we can handle that */ |
| 96 | disk_byte = btrfs_file_extent_disk_bytenr(eb, fi); |
| 97 | if (disk_byte != wanted_disk_byte) |
| 98 | continue; |
| 99 | |
| 100 | ret = check_extent_in_eb(&key, eb, fi, extent_item_pos, eie); |
| 101 | if (ret < 0) |
| 102 | return ret; |
| 103 | } |
| 104 | |
| 105 | return 0; |
| 106 | } |
| 107 | |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 108 | /* |
| 109 | * this structure records all encountered refs on the way up to the root |
| 110 | */ |
| 111 | struct __prelim_ref { |
| 112 | struct list_head list; |
| 113 | u64 root_id; |
Jan Schmidt | d5c88b7 | 2012-05-15 17:55:51 +0200 | [diff] [blame] | 114 | struct btrfs_key key_for_search; |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 115 | int level; |
| 116 | int count; |
Jan Schmidt | 3301958 | 2012-05-30 18:05:21 +0200 | [diff] [blame] | 117 | struct extent_inode_elem *inode_list; |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 118 | u64 parent; |
| 119 | u64 wanted_disk_byte; |
| 120 | }; |
| 121 | |
Wang Shilong | b9e9a6c | 2013-08-09 13:25:36 +0800 | [diff] [blame] | 122 | static struct kmem_cache *btrfs_prelim_ref_cache; |
| 123 | |
| 124 | int __init btrfs_prelim_ref_init(void) |
| 125 | { |
| 126 | btrfs_prelim_ref_cache = kmem_cache_create("btrfs_prelim_ref", |
| 127 | sizeof(struct __prelim_ref), |
| 128 | 0, |
| 129 | SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, |
| 130 | NULL); |
| 131 | if (!btrfs_prelim_ref_cache) |
| 132 | return -ENOMEM; |
| 133 | return 0; |
| 134 | } |
| 135 | |
| 136 | void btrfs_prelim_ref_exit(void) |
| 137 | { |
| 138 | if (btrfs_prelim_ref_cache) |
| 139 | kmem_cache_destroy(btrfs_prelim_ref_cache); |
| 140 | } |
| 141 | |
Jan Schmidt | d5c88b7 | 2012-05-15 17:55:51 +0200 | [diff] [blame] | 142 | /* |
| 143 | * the rules for all callers of this function are: |
| 144 | * - obtaining the parent is the goal |
| 145 | * - if you add a key, you must know that it is a correct key |
| 146 | * - if you cannot add the parent or a correct key, then we will look into the |
| 147 | * block later to set a correct key |
| 148 | * |
| 149 | * delayed refs |
| 150 | * ============ |
| 151 | * backref type | shared | indirect | shared | indirect |
| 152 | * information | tree | tree | data | data |
| 153 | * --------------------+--------+----------+--------+---------- |
| 154 | * parent logical | y | - | - | - |
| 155 | * key to resolve | - | y | y | y |
| 156 | * tree block logical | - | - | - | - |
| 157 | * root for resolving | y | y | y | y |
| 158 | * |
| 159 | * - column 1: we've the parent -> done |
| 160 | * - column 2, 3, 4: we use the key to find the parent |
| 161 | * |
| 162 | * on disk refs (inline or keyed) |
| 163 | * ============================== |
| 164 | * backref type | shared | indirect | shared | indirect |
| 165 | * information | tree | tree | data | data |
| 166 | * --------------------+--------+----------+--------+---------- |
| 167 | * parent logical | y | - | y | - |
| 168 | * key to resolve | - | - | - | y |
| 169 | * tree block logical | y | y | y | y |
| 170 | * root for resolving | - | y | y | y |
| 171 | * |
| 172 | * - column 1, 3: we've the parent -> done |
| 173 | * - column 2: we take the first key from the block to find the parent |
| 174 | * (see __add_missing_keys) |
| 175 | * - column 4: we use the key to find the parent |
| 176 | * |
| 177 | * additional information that's available but not required to find the parent |
| 178 | * block might help in merging entries to gain some speed. |
| 179 | */ |
| 180 | |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 181 | static int __add_prelim_ref(struct list_head *head, u64 root_id, |
Jan Schmidt | d5c88b7 | 2012-05-15 17:55:51 +0200 | [diff] [blame] | 182 | struct btrfs_key *key, int level, |
Wang Shilong | 742916b | 2013-08-06 10:29:54 +0800 | [diff] [blame] | 183 | u64 parent, u64 wanted_disk_byte, int count, |
| 184 | gfp_t gfp_mask) |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 185 | { |
| 186 | struct __prelim_ref *ref; |
| 187 | |
Liu Bo | 48ec473 | 2013-10-30 13:25:24 +0800 | [diff] [blame] | 188 | if (root_id == BTRFS_DATA_RELOC_TREE_OBJECTID) |
| 189 | return 0; |
| 190 | |
Wang Shilong | b9e9a6c | 2013-08-09 13:25:36 +0800 | [diff] [blame] | 191 | ref = kmem_cache_alloc(btrfs_prelim_ref_cache, gfp_mask); |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 192 | if (!ref) |
| 193 | return -ENOMEM; |
| 194 | |
| 195 | ref->root_id = root_id; |
| 196 | if (key) |
Jan Schmidt | d5c88b7 | 2012-05-15 17:55:51 +0200 | [diff] [blame] | 197 | ref->key_for_search = *key; |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 198 | else |
Jan Schmidt | d5c88b7 | 2012-05-15 17:55:51 +0200 | [diff] [blame] | 199 | memset(&ref->key_for_search, 0, sizeof(ref->key_for_search)); |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 200 | |
Jan Schmidt | 3301958 | 2012-05-30 18:05:21 +0200 | [diff] [blame] | 201 | ref->inode_list = NULL; |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 202 | ref->level = level; |
| 203 | ref->count = count; |
| 204 | ref->parent = parent; |
| 205 | ref->wanted_disk_byte = wanted_disk_byte; |
| 206 | list_add_tail(&ref->list, head); |
| 207 | |
| 208 | return 0; |
| 209 | } |
| 210 | |
| 211 | static int add_all_parents(struct btrfs_root *root, struct btrfs_path *path, |
Jan Schmidt | 976b190 | 2012-05-17 16:43:03 +0200 | [diff] [blame] | 212 | struct ulist *parents, int level, |
Alexander Block | 69bca40 | 2012-06-19 07:42:26 -0600 | [diff] [blame] | 213 | struct btrfs_key *key_for_search, u64 time_seq, |
Jan Schmidt | 3d7806e | 2012-06-11 08:29:29 +0200 | [diff] [blame] | 214 | u64 wanted_disk_byte, |
Jan Schmidt | 976b190 | 2012-05-17 16:43:03 +0200 | [diff] [blame] | 215 | const u64 *extent_item_pos) |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 216 | { |
Alexander Block | 69bca40 | 2012-06-19 07:42:26 -0600 | [diff] [blame] | 217 | int ret = 0; |
| 218 | int slot; |
| 219 | struct extent_buffer *eb; |
| 220 | struct btrfs_key key; |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 221 | struct btrfs_file_extent_item *fi; |
Josef Bacik | ed8c491 | 2013-07-05 14:03:47 -0400 | [diff] [blame] | 222 | struct extent_inode_elem *eie = NULL, *old = NULL; |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 223 | u64 disk_byte; |
| 224 | |
Alexander Block | 69bca40 | 2012-06-19 07:42:26 -0600 | [diff] [blame] | 225 | if (level != 0) { |
| 226 | eb = path->nodes[level]; |
| 227 | ret = ulist_add(parents, eb->start, 0, GFP_NOFS); |
Jan Schmidt | 3301958 | 2012-05-30 18:05:21 +0200 | [diff] [blame] | 228 | if (ret < 0) |
| 229 | return ret; |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 230 | return 0; |
Alexander Block | 69bca40 | 2012-06-19 07:42:26 -0600 | [diff] [blame] | 231 | } |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 232 | |
| 233 | /* |
Alexander Block | 69bca40 | 2012-06-19 07:42:26 -0600 | [diff] [blame] | 234 | * We normally enter this function with the path already pointing to |
| 235 | * the first item to check. But sometimes, we may enter it with |
| 236 | * slot==nritems. In that case, go to the next leaf before we continue. |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 237 | */ |
Alexander Block | 69bca40 | 2012-06-19 07:42:26 -0600 | [diff] [blame] | 238 | if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) |
Jan Schmidt | 3d7806e | 2012-06-11 08:29:29 +0200 | [diff] [blame] | 239 | ret = btrfs_next_old_leaf(root, path, time_seq); |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 240 | |
Alexander Block | 69bca40 | 2012-06-19 07:42:26 -0600 | [diff] [blame] | 241 | while (!ret) { |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 242 | eb = path->nodes[0]; |
Alexander Block | 69bca40 | 2012-06-19 07:42:26 -0600 | [diff] [blame] | 243 | slot = path->slots[0]; |
| 244 | |
| 245 | btrfs_item_key_to_cpu(eb, &key, slot); |
| 246 | |
| 247 | if (key.objectid != key_for_search->objectid || |
| 248 | key.type != BTRFS_EXTENT_DATA_KEY) |
| 249 | break; |
| 250 | |
| 251 | fi = btrfs_item_ptr(eb, slot, struct btrfs_file_extent_item); |
| 252 | disk_byte = btrfs_file_extent_disk_bytenr(eb, fi); |
| 253 | |
| 254 | if (disk_byte == wanted_disk_byte) { |
| 255 | eie = NULL; |
Josef Bacik | ed8c491 | 2013-07-05 14:03:47 -0400 | [diff] [blame] | 256 | old = NULL; |
Alexander Block | 69bca40 | 2012-06-19 07:42:26 -0600 | [diff] [blame] | 257 | if (extent_item_pos) { |
| 258 | ret = check_extent_in_eb(&key, eb, fi, |
| 259 | *extent_item_pos, |
| 260 | &eie); |
| 261 | if (ret < 0) |
| 262 | break; |
| 263 | } |
Josef Bacik | ed8c491 | 2013-07-05 14:03:47 -0400 | [diff] [blame] | 264 | if (ret > 0) |
| 265 | goto next; |
| 266 | ret = ulist_add_merge(parents, eb->start, |
| 267 | (uintptr_t)eie, |
| 268 | (u64 *)&old, GFP_NOFS); |
| 269 | if (ret < 0) |
| 270 | break; |
| 271 | if (!ret && extent_item_pos) { |
| 272 | while (old->next) |
| 273 | old = old->next; |
| 274 | old->next = eie; |
Alexander Block | 69bca40 | 2012-06-19 07:42:26 -0600 | [diff] [blame] | 275 | } |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 276 | } |
Josef Bacik | ed8c491 | 2013-07-05 14:03:47 -0400 | [diff] [blame] | 277 | next: |
Alexander Block | 69bca40 | 2012-06-19 07:42:26 -0600 | [diff] [blame] | 278 | ret = btrfs_next_old_item(root, path, time_seq); |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 279 | } |
| 280 | |
Alexander Block | 69bca40 | 2012-06-19 07:42:26 -0600 | [diff] [blame] | 281 | if (ret > 0) |
| 282 | ret = 0; |
| 283 | return ret; |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 284 | } |
| 285 | |
| 286 | /* |
| 287 | * resolve an indirect backref in the form (root_id, key, level) |
| 288 | * to a logical address |
| 289 | */ |
| 290 | static int __resolve_indirect_ref(struct btrfs_fs_info *fs_info, |
Josef Bacik | da61d31 | 2013-06-12 16:20:08 -0400 | [diff] [blame] | 291 | struct btrfs_path *path, u64 time_seq, |
| 292 | struct __prelim_ref *ref, |
| 293 | struct ulist *parents, |
| 294 | const u64 *extent_item_pos) |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 295 | { |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 296 | struct btrfs_root *root; |
| 297 | struct btrfs_key root_key; |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 298 | struct extent_buffer *eb; |
| 299 | int ret = 0; |
| 300 | int root_level; |
| 301 | int level = ref->level; |
| 302 | |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 303 | root_key.objectid = ref->root_id; |
| 304 | root_key.type = BTRFS_ROOT_ITEM_KEY; |
| 305 | root_key.offset = (u64)-1; |
| 306 | root = btrfs_read_fs_root_no_name(fs_info, &root_key); |
| 307 | if (IS_ERR(root)) { |
| 308 | ret = PTR_ERR(root); |
| 309 | goto out; |
| 310 | } |
| 311 | |
Jan Schmidt | 5b6602e | 2012-10-23 11:28:27 +0200 | [diff] [blame] | 312 | root_level = btrfs_old_root_level(root, time_seq); |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 313 | |
| 314 | if (root_level + 1 == level) |
| 315 | goto out; |
| 316 | |
| 317 | path->lowest_level = level; |
Jan Schmidt | 8445f61 | 2012-05-16 18:36:03 +0200 | [diff] [blame] | 318 | ret = btrfs_search_old_slot(root, &ref->key_for_search, path, time_seq); |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 319 | pr_debug("search slot in root %llu (level %d, ref count %d) returned " |
| 320 | "%d for key (%llu %u %llu)\n", |
Geert Uytterhoeven | c1c9ff7 | 2013-08-20 13:20:07 +0200 | [diff] [blame] | 321 | ref->root_id, level, ref->count, ret, |
| 322 | ref->key_for_search.objectid, ref->key_for_search.type, |
| 323 | ref->key_for_search.offset); |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 324 | if (ret < 0) |
| 325 | goto out; |
| 326 | |
| 327 | eb = path->nodes[level]; |
Jan Schmidt | 9345457 | 2012-06-27 15:23:09 +0200 | [diff] [blame] | 328 | while (!eb) { |
Dulshani Gunawardhana | fae7f21 | 2013-10-31 10:30:08 +0530 | [diff] [blame] | 329 | if (WARN_ON(!level)) { |
Jan Schmidt | 9345457 | 2012-06-27 15:23:09 +0200 | [diff] [blame] | 330 | ret = 1; |
| 331 | goto out; |
| 332 | } |
| 333 | level--; |
| 334 | eb = path->nodes[level]; |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 335 | } |
| 336 | |
Alexander Block | 69bca40 | 2012-06-19 07:42:26 -0600 | [diff] [blame] | 337 | ret = add_all_parents(root, path, parents, level, &ref->key_for_search, |
| 338 | time_seq, ref->wanted_disk_byte, |
| 339 | extent_item_pos); |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 340 | out: |
Josef Bacik | da61d31 | 2013-06-12 16:20:08 -0400 | [diff] [blame] | 341 | path->lowest_level = 0; |
| 342 | btrfs_release_path(path); |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 343 | return ret; |
| 344 | } |
| 345 | |
| 346 | /* |
| 347 | * resolve all indirect backrefs from the list |
| 348 | */ |
| 349 | static int __resolve_indirect_refs(struct btrfs_fs_info *fs_info, |
Josef Bacik | da61d31 | 2013-06-12 16:20:08 -0400 | [diff] [blame] | 350 | struct btrfs_path *path, u64 time_seq, |
Jan Schmidt | 976b190 | 2012-05-17 16:43:03 +0200 | [diff] [blame] | 351 | struct list_head *head, |
| 352 | const u64 *extent_item_pos) |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 353 | { |
| 354 | int err; |
| 355 | int ret = 0; |
| 356 | struct __prelim_ref *ref; |
| 357 | struct __prelim_ref *ref_safe; |
| 358 | struct __prelim_ref *new_ref; |
| 359 | struct ulist *parents; |
| 360 | struct ulist_node *node; |
Jan Schmidt | cd1b413 | 2012-05-22 14:56:50 +0200 | [diff] [blame] | 361 | struct ulist_iterator uiter; |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 362 | |
| 363 | parents = ulist_alloc(GFP_NOFS); |
| 364 | if (!parents) |
| 365 | return -ENOMEM; |
| 366 | |
| 367 | /* |
| 368 | * _safe allows us to insert directly after the current item without |
| 369 | * iterating over the newly inserted items. |
| 370 | * we're also allowed to re-assign ref during iteration. |
| 371 | */ |
| 372 | list_for_each_entry_safe(ref, ref_safe, head, list) { |
| 373 | if (ref->parent) /* already direct */ |
| 374 | continue; |
| 375 | if (ref->count == 0) |
| 376 | continue; |
Josef Bacik | da61d31 | 2013-06-12 16:20:08 -0400 | [diff] [blame] | 377 | err = __resolve_indirect_ref(fs_info, path, time_seq, ref, |
| 378 | parents, extent_item_pos); |
Wang Shilong | e36902d | 2013-04-15 10:26:38 +0000 | [diff] [blame] | 379 | if (err == -ENOMEM) |
| 380 | goto out; |
Jan Schmidt | ca60ebf | 2013-02-21 15:35:27 +0000 | [diff] [blame] | 381 | if (err) |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 382 | continue; |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 383 | |
| 384 | /* we put the first parent into the ref at hand */ |
Jan Schmidt | cd1b413 | 2012-05-22 14:56:50 +0200 | [diff] [blame] | 385 | ULIST_ITER_INIT(&uiter); |
| 386 | node = ulist_next(parents, &uiter); |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 387 | ref->parent = node ? node->val : 0; |
Jan Schmidt | 995e01b | 2012-08-13 02:52:38 -0600 | [diff] [blame] | 388 | ref->inode_list = node ? |
Stefan Behrens | 35a3621 | 2013-08-14 18:12:25 +0200 | [diff] [blame] | 389 | (struct extent_inode_elem *)(uintptr_t)node->aux : NULL; |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 390 | |
| 391 | /* additional parents require new refs being added here */ |
Jan Schmidt | cd1b413 | 2012-05-22 14:56:50 +0200 | [diff] [blame] | 392 | while ((node = ulist_next(parents, &uiter))) { |
Wang Shilong | b9e9a6c | 2013-08-09 13:25:36 +0800 | [diff] [blame] | 393 | new_ref = kmem_cache_alloc(btrfs_prelim_ref_cache, |
| 394 | GFP_NOFS); |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 395 | if (!new_ref) { |
| 396 | ret = -ENOMEM; |
Wang Shilong | e36902d | 2013-04-15 10:26:38 +0000 | [diff] [blame] | 397 | goto out; |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 398 | } |
| 399 | memcpy(new_ref, ref, sizeof(*ref)); |
| 400 | new_ref->parent = node->val; |
Jan Schmidt | 995e01b | 2012-08-13 02:52:38 -0600 | [diff] [blame] | 401 | new_ref->inode_list = (struct extent_inode_elem *) |
| 402 | (uintptr_t)node->aux; |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 403 | list_add(&new_ref->list, &ref->list); |
| 404 | } |
| 405 | ulist_reinit(parents); |
| 406 | } |
Wang Shilong | e36902d | 2013-04-15 10:26:38 +0000 | [diff] [blame] | 407 | out: |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 408 | ulist_free(parents); |
| 409 | return ret; |
| 410 | } |
| 411 | |
Jan Schmidt | d5c88b7 | 2012-05-15 17:55:51 +0200 | [diff] [blame] | 412 | static inline int ref_for_same_block(struct __prelim_ref *ref1, |
| 413 | struct __prelim_ref *ref2) |
| 414 | { |
| 415 | if (ref1->level != ref2->level) |
| 416 | return 0; |
| 417 | if (ref1->root_id != ref2->root_id) |
| 418 | return 0; |
| 419 | if (ref1->key_for_search.type != ref2->key_for_search.type) |
| 420 | return 0; |
| 421 | if (ref1->key_for_search.objectid != ref2->key_for_search.objectid) |
| 422 | return 0; |
| 423 | if (ref1->key_for_search.offset != ref2->key_for_search.offset) |
| 424 | return 0; |
| 425 | if (ref1->parent != ref2->parent) |
| 426 | return 0; |
| 427 | |
| 428 | return 1; |
| 429 | } |
| 430 | |
| 431 | /* |
| 432 | * read tree blocks and add keys where required. |
| 433 | */ |
| 434 | static int __add_missing_keys(struct btrfs_fs_info *fs_info, |
| 435 | struct list_head *head) |
| 436 | { |
| 437 | struct list_head *pos; |
| 438 | struct extent_buffer *eb; |
| 439 | |
| 440 | list_for_each(pos, head) { |
| 441 | struct __prelim_ref *ref; |
| 442 | ref = list_entry(pos, struct __prelim_ref, list); |
| 443 | |
| 444 | if (ref->parent) |
| 445 | continue; |
| 446 | if (ref->key_for_search.type) |
| 447 | continue; |
| 448 | BUG_ON(!ref->wanted_disk_byte); |
| 449 | eb = read_tree_block(fs_info->tree_root, ref->wanted_disk_byte, |
| 450 | fs_info->tree_root->leafsize, 0); |
Josef Bacik | 416bc65 | 2013-04-23 14:17:42 -0400 | [diff] [blame] | 451 | if (!eb || !extent_buffer_uptodate(eb)) { |
| 452 | free_extent_buffer(eb); |
| 453 | return -EIO; |
| 454 | } |
Jan Schmidt | d5c88b7 | 2012-05-15 17:55:51 +0200 | [diff] [blame] | 455 | btrfs_tree_read_lock(eb); |
| 456 | if (btrfs_header_level(eb) == 0) |
| 457 | btrfs_item_key_to_cpu(eb, &ref->key_for_search, 0); |
| 458 | else |
| 459 | btrfs_node_key_to_cpu(eb, &ref->key_for_search, 0); |
| 460 | btrfs_tree_read_unlock(eb); |
| 461 | free_extent_buffer(eb); |
| 462 | } |
| 463 | return 0; |
| 464 | } |
| 465 | |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 466 | /* |
| 467 | * merge two lists of backrefs and adjust counts accordingly |
| 468 | * |
| 469 | * mode = 1: merge identical keys, if key is set |
Jan Schmidt | d5c88b7 | 2012-05-15 17:55:51 +0200 | [diff] [blame] | 470 | * FIXME: if we add more keys in __add_prelim_ref, we can merge more here. |
| 471 | * additionally, we could even add a key range for the blocks we |
| 472 | * looked into to merge even more (-> replace unresolved refs by those |
| 473 | * having a parent). |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 474 | * mode = 2: merge identical parents |
| 475 | */ |
Wang Shilong | 692206b | 2013-04-11 07:08:55 +0000 | [diff] [blame] | 476 | static void __merge_refs(struct list_head *head, int mode) |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 477 | { |
| 478 | struct list_head *pos1; |
| 479 | |
| 480 | list_for_each(pos1, head) { |
| 481 | struct list_head *n2; |
| 482 | struct list_head *pos2; |
| 483 | struct __prelim_ref *ref1; |
| 484 | |
| 485 | ref1 = list_entry(pos1, struct __prelim_ref, list); |
| 486 | |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 487 | for (pos2 = pos1->next, n2 = pos2->next; pos2 != head; |
| 488 | pos2 = n2, n2 = pos2->next) { |
| 489 | struct __prelim_ref *ref2; |
Jan Schmidt | d5c88b7 | 2012-05-15 17:55:51 +0200 | [diff] [blame] | 490 | struct __prelim_ref *xchg; |
Alexander Block | 3ef5969 | 2012-11-08 21:27:24 +0000 | [diff] [blame] | 491 | struct extent_inode_elem *eie; |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 492 | |
| 493 | ref2 = list_entry(pos2, struct __prelim_ref, list); |
| 494 | |
| 495 | if (mode == 1) { |
Jan Schmidt | d5c88b7 | 2012-05-15 17:55:51 +0200 | [diff] [blame] | 496 | if (!ref_for_same_block(ref1, ref2)) |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 497 | continue; |
Jan Schmidt | d5c88b7 | 2012-05-15 17:55:51 +0200 | [diff] [blame] | 498 | if (!ref1->parent && ref2->parent) { |
| 499 | xchg = ref1; |
| 500 | ref1 = ref2; |
| 501 | ref2 = xchg; |
| 502 | } |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 503 | } else { |
| 504 | if (ref1->parent != ref2->parent) |
| 505 | continue; |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 506 | } |
Alexander Block | 3ef5969 | 2012-11-08 21:27:24 +0000 | [diff] [blame] | 507 | |
| 508 | eie = ref1->inode_list; |
| 509 | while (eie && eie->next) |
| 510 | eie = eie->next; |
| 511 | if (eie) |
| 512 | eie->next = ref2->inode_list; |
| 513 | else |
| 514 | ref1->inode_list = ref2->inode_list; |
| 515 | ref1->count += ref2->count; |
| 516 | |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 517 | list_del(&ref2->list); |
Wang Shilong | b9e9a6c | 2013-08-09 13:25:36 +0800 | [diff] [blame] | 518 | kmem_cache_free(btrfs_prelim_ref_cache, ref2); |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 519 | } |
| 520 | |
| 521 | } |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 522 | } |
| 523 | |
| 524 | /* |
| 525 | * add all currently queued delayed refs from this head whose seq nr is |
| 526 | * smaller or equal that seq to the list |
| 527 | */ |
| 528 | static int __add_delayed_refs(struct btrfs_delayed_ref_head *head, u64 seq, |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 529 | struct list_head *prefs) |
| 530 | { |
| 531 | struct btrfs_delayed_extent_op *extent_op = head->extent_op; |
| 532 | struct rb_node *n = &head->node.rb_node; |
Jan Schmidt | d5c88b7 | 2012-05-15 17:55:51 +0200 | [diff] [blame] | 533 | struct btrfs_key key; |
| 534 | struct btrfs_key op_key = {0}; |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 535 | int sgn; |
Jan Schmidt | b1375d6 | 2012-01-26 15:01:11 -0500 | [diff] [blame] | 536 | int ret = 0; |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 537 | |
| 538 | if (extent_op && extent_op->update_key) |
Jan Schmidt | d5c88b7 | 2012-05-15 17:55:51 +0200 | [diff] [blame] | 539 | btrfs_disk_key_to_cpu(&op_key, &extent_op->key); |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 540 | |
| 541 | while ((n = rb_prev(n))) { |
| 542 | struct btrfs_delayed_ref_node *node; |
| 543 | node = rb_entry(n, struct btrfs_delayed_ref_node, |
| 544 | rb_node); |
| 545 | if (node->bytenr != head->node.bytenr) |
| 546 | break; |
| 547 | WARN_ON(node->is_head); |
| 548 | |
| 549 | if (node->seq > seq) |
| 550 | continue; |
| 551 | |
| 552 | switch (node->action) { |
| 553 | case BTRFS_ADD_DELAYED_EXTENT: |
| 554 | case BTRFS_UPDATE_DELAYED_HEAD: |
| 555 | WARN_ON(1); |
| 556 | continue; |
| 557 | case BTRFS_ADD_DELAYED_REF: |
| 558 | sgn = 1; |
| 559 | break; |
| 560 | case BTRFS_DROP_DELAYED_REF: |
| 561 | sgn = -1; |
| 562 | break; |
| 563 | default: |
| 564 | BUG_ON(1); |
| 565 | } |
| 566 | switch (node->type) { |
| 567 | case BTRFS_TREE_BLOCK_REF_KEY: { |
| 568 | struct btrfs_delayed_tree_ref *ref; |
| 569 | |
| 570 | ref = btrfs_delayed_node_to_tree_ref(node); |
Jan Schmidt | d5c88b7 | 2012-05-15 17:55:51 +0200 | [diff] [blame] | 571 | ret = __add_prelim_ref(prefs, ref->root, &op_key, |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 572 | ref->level + 1, 0, node->bytenr, |
Wang Shilong | 742916b | 2013-08-06 10:29:54 +0800 | [diff] [blame] | 573 | node->ref_mod * sgn, GFP_ATOMIC); |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 574 | break; |
| 575 | } |
| 576 | case BTRFS_SHARED_BLOCK_REF_KEY: { |
| 577 | struct btrfs_delayed_tree_ref *ref; |
| 578 | |
| 579 | ref = btrfs_delayed_node_to_tree_ref(node); |
Jan Schmidt | d5c88b7 | 2012-05-15 17:55:51 +0200 | [diff] [blame] | 580 | ret = __add_prelim_ref(prefs, ref->root, NULL, |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 581 | ref->level + 1, ref->parent, |
| 582 | node->bytenr, |
Wang Shilong | 742916b | 2013-08-06 10:29:54 +0800 | [diff] [blame] | 583 | node->ref_mod * sgn, GFP_ATOMIC); |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 584 | break; |
| 585 | } |
| 586 | case BTRFS_EXTENT_DATA_REF_KEY: { |
| 587 | struct btrfs_delayed_data_ref *ref; |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 588 | ref = btrfs_delayed_node_to_data_ref(node); |
| 589 | |
| 590 | key.objectid = ref->objectid; |
| 591 | key.type = BTRFS_EXTENT_DATA_KEY; |
| 592 | key.offset = ref->offset; |
| 593 | ret = __add_prelim_ref(prefs, ref->root, &key, 0, 0, |
| 594 | node->bytenr, |
Wang Shilong | 742916b | 2013-08-06 10:29:54 +0800 | [diff] [blame] | 595 | node->ref_mod * sgn, GFP_ATOMIC); |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 596 | break; |
| 597 | } |
| 598 | case BTRFS_SHARED_DATA_REF_KEY: { |
| 599 | struct btrfs_delayed_data_ref *ref; |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 600 | |
| 601 | ref = btrfs_delayed_node_to_data_ref(node); |
| 602 | |
| 603 | key.objectid = ref->objectid; |
| 604 | key.type = BTRFS_EXTENT_DATA_KEY; |
| 605 | key.offset = ref->offset; |
| 606 | ret = __add_prelim_ref(prefs, ref->root, &key, 0, |
| 607 | ref->parent, node->bytenr, |
Wang Shilong | 742916b | 2013-08-06 10:29:54 +0800 | [diff] [blame] | 608 | node->ref_mod * sgn, GFP_ATOMIC); |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 609 | break; |
| 610 | } |
| 611 | default: |
| 612 | WARN_ON(1); |
| 613 | } |
Wang Shilong | 1149ab6 | 2013-04-10 11:22:50 +0000 | [diff] [blame] | 614 | if (ret) |
| 615 | return ret; |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 616 | } |
| 617 | |
| 618 | return 0; |
| 619 | } |
| 620 | |
| 621 | /* |
| 622 | * add all inline backrefs for bytenr to the list |
| 623 | */ |
| 624 | static int __add_inline_refs(struct btrfs_fs_info *fs_info, |
| 625 | struct btrfs_path *path, u64 bytenr, |
Jan Schmidt | d5c88b7 | 2012-05-15 17:55:51 +0200 | [diff] [blame] | 626 | int *info_level, struct list_head *prefs) |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 627 | { |
Jan Schmidt | b1375d6 | 2012-01-26 15:01:11 -0500 | [diff] [blame] | 628 | int ret = 0; |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 629 | int slot; |
| 630 | struct extent_buffer *leaf; |
| 631 | struct btrfs_key key; |
Josef Bacik | 261c84b | 2013-06-28 13:11:22 -0400 | [diff] [blame] | 632 | struct btrfs_key found_key; |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 633 | unsigned long ptr; |
| 634 | unsigned long end; |
| 635 | struct btrfs_extent_item *ei; |
| 636 | u64 flags; |
| 637 | u64 item_size; |
| 638 | |
| 639 | /* |
| 640 | * enumerate all inline refs |
| 641 | */ |
| 642 | leaf = path->nodes[0]; |
Jan Schmidt | dadcaf7 | 2012-05-22 13:43:25 +0200 | [diff] [blame] | 643 | slot = path->slots[0]; |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 644 | |
| 645 | item_size = btrfs_item_size_nr(leaf, slot); |
| 646 | BUG_ON(item_size < sizeof(*ei)); |
| 647 | |
| 648 | ei = btrfs_item_ptr(leaf, slot, struct btrfs_extent_item); |
| 649 | flags = btrfs_extent_flags(leaf, ei); |
Josef Bacik | 261c84b | 2013-06-28 13:11:22 -0400 | [diff] [blame] | 650 | btrfs_item_key_to_cpu(leaf, &found_key, slot); |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 651 | |
| 652 | ptr = (unsigned long)(ei + 1); |
| 653 | end = (unsigned long)ei + item_size; |
| 654 | |
Josef Bacik | 261c84b | 2013-06-28 13:11:22 -0400 | [diff] [blame] | 655 | if (found_key.type == BTRFS_EXTENT_ITEM_KEY && |
| 656 | flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) { |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 657 | struct btrfs_tree_block_info *info; |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 658 | |
| 659 | info = (struct btrfs_tree_block_info *)ptr; |
| 660 | *info_level = btrfs_tree_block_level(leaf, info); |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 661 | ptr += sizeof(struct btrfs_tree_block_info); |
| 662 | BUG_ON(ptr > end); |
Josef Bacik | 261c84b | 2013-06-28 13:11:22 -0400 | [diff] [blame] | 663 | } else if (found_key.type == BTRFS_METADATA_ITEM_KEY) { |
| 664 | *info_level = found_key.offset; |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 665 | } else { |
| 666 | BUG_ON(!(flags & BTRFS_EXTENT_FLAG_DATA)); |
| 667 | } |
| 668 | |
| 669 | while (ptr < end) { |
| 670 | struct btrfs_extent_inline_ref *iref; |
| 671 | u64 offset; |
| 672 | int type; |
| 673 | |
| 674 | iref = (struct btrfs_extent_inline_ref *)ptr; |
| 675 | type = btrfs_extent_inline_ref_type(leaf, iref); |
| 676 | offset = btrfs_extent_inline_ref_offset(leaf, iref); |
| 677 | |
| 678 | switch (type) { |
| 679 | case BTRFS_SHARED_BLOCK_REF_KEY: |
Jan Schmidt | d5c88b7 | 2012-05-15 17:55:51 +0200 | [diff] [blame] | 680 | ret = __add_prelim_ref(prefs, 0, NULL, |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 681 | *info_level + 1, offset, |
Wang Shilong | 742916b | 2013-08-06 10:29:54 +0800 | [diff] [blame] | 682 | bytenr, 1, GFP_NOFS); |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 683 | break; |
| 684 | case BTRFS_SHARED_DATA_REF_KEY: { |
| 685 | struct btrfs_shared_data_ref *sdref; |
| 686 | int count; |
| 687 | |
| 688 | sdref = (struct btrfs_shared_data_ref *)(iref + 1); |
| 689 | count = btrfs_shared_data_ref_count(leaf, sdref); |
| 690 | ret = __add_prelim_ref(prefs, 0, NULL, 0, offset, |
Wang Shilong | 742916b | 2013-08-06 10:29:54 +0800 | [diff] [blame] | 691 | bytenr, count, GFP_NOFS); |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 692 | break; |
| 693 | } |
| 694 | case BTRFS_TREE_BLOCK_REF_KEY: |
Jan Schmidt | d5c88b7 | 2012-05-15 17:55:51 +0200 | [diff] [blame] | 695 | ret = __add_prelim_ref(prefs, offset, NULL, |
| 696 | *info_level + 1, 0, |
Wang Shilong | 742916b | 2013-08-06 10:29:54 +0800 | [diff] [blame] | 697 | bytenr, 1, GFP_NOFS); |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 698 | break; |
| 699 | case BTRFS_EXTENT_DATA_REF_KEY: { |
| 700 | struct btrfs_extent_data_ref *dref; |
| 701 | int count; |
| 702 | u64 root; |
| 703 | |
| 704 | dref = (struct btrfs_extent_data_ref *)(&iref->offset); |
| 705 | count = btrfs_extent_data_ref_count(leaf, dref); |
| 706 | key.objectid = btrfs_extent_data_ref_objectid(leaf, |
| 707 | dref); |
| 708 | key.type = BTRFS_EXTENT_DATA_KEY; |
| 709 | key.offset = btrfs_extent_data_ref_offset(leaf, dref); |
| 710 | root = btrfs_extent_data_ref_root(leaf, dref); |
Jan Schmidt | d5c88b7 | 2012-05-15 17:55:51 +0200 | [diff] [blame] | 711 | ret = __add_prelim_ref(prefs, root, &key, 0, 0, |
Wang Shilong | 742916b | 2013-08-06 10:29:54 +0800 | [diff] [blame] | 712 | bytenr, count, GFP_NOFS); |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 713 | break; |
| 714 | } |
| 715 | default: |
| 716 | WARN_ON(1); |
| 717 | } |
Wang Shilong | 1149ab6 | 2013-04-10 11:22:50 +0000 | [diff] [blame] | 718 | if (ret) |
| 719 | return ret; |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 720 | ptr += btrfs_extent_inline_ref_size(type); |
| 721 | } |
| 722 | |
| 723 | return 0; |
| 724 | } |
| 725 | |
| 726 | /* |
| 727 | * add all non-inline backrefs for bytenr to the list |
| 728 | */ |
| 729 | static int __add_keyed_refs(struct btrfs_fs_info *fs_info, |
| 730 | struct btrfs_path *path, u64 bytenr, |
Jan Schmidt | d5c88b7 | 2012-05-15 17:55:51 +0200 | [diff] [blame] | 731 | int info_level, struct list_head *prefs) |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 732 | { |
| 733 | struct btrfs_root *extent_root = fs_info->extent_root; |
| 734 | int ret; |
| 735 | int slot; |
| 736 | struct extent_buffer *leaf; |
| 737 | struct btrfs_key key; |
| 738 | |
| 739 | while (1) { |
| 740 | ret = btrfs_next_item(extent_root, path); |
| 741 | if (ret < 0) |
| 742 | break; |
| 743 | if (ret) { |
| 744 | ret = 0; |
| 745 | break; |
| 746 | } |
| 747 | |
| 748 | slot = path->slots[0]; |
| 749 | leaf = path->nodes[0]; |
| 750 | btrfs_item_key_to_cpu(leaf, &key, slot); |
| 751 | |
| 752 | if (key.objectid != bytenr) |
| 753 | break; |
| 754 | if (key.type < BTRFS_TREE_BLOCK_REF_KEY) |
| 755 | continue; |
| 756 | if (key.type > BTRFS_SHARED_DATA_REF_KEY) |
| 757 | break; |
| 758 | |
| 759 | switch (key.type) { |
| 760 | case BTRFS_SHARED_BLOCK_REF_KEY: |
Jan Schmidt | d5c88b7 | 2012-05-15 17:55:51 +0200 | [diff] [blame] | 761 | ret = __add_prelim_ref(prefs, 0, NULL, |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 762 | info_level + 1, key.offset, |
Wang Shilong | 742916b | 2013-08-06 10:29:54 +0800 | [diff] [blame] | 763 | bytenr, 1, GFP_NOFS); |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 764 | break; |
| 765 | case BTRFS_SHARED_DATA_REF_KEY: { |
| 766 | struct btrfs_shared_data_ref *sdref; |
| 767 | int count; |
| 768 | |
| 769 | sdref = btrfs_item_ptr(leaf, slot, |
| 770 | struct btrfs_shared_data_ref); |
| 771 | count = btrfs_shared_data_ref_count(leaf, sdref); |
| 772 | ret = __add_prelim_ref(prefs, 0, NULL, 0, key.offset, |
Wang Shilong | 742916b | 2013-08-06 10:29:54 +0800 | [diff] [blame] | 773 | bytenr, count, GFP_NOFS); |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 774 | break; |
| 775 | } |
| 776 | case BTRFS_TREE_BLOCK_REF_KEY: |
Jan Schmidt | d5c88b7 | 2012-05-15 17:55:51 +0200 | [diff] [blame] | 777 | ret = __add_prelim_ref(prefs, key.offset, NULL, |
| 778 | info_level + 1, 0, |
Wang Shilong | 742916b | 2013-08-06 10:29:54 +0800 | [diff] [blame] | 779 | bytenr, 1, GFP_NOFS); |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 780 | break; |
| 781 | case BTRFS_EXTENT_DATA_REF_KEY: { |
| 782 | struct btrfs_extent_data_ref *dref; |
| 783 | int count; |
| 784 | u64 root; |
| 785 | |
| 786 | dref = btrfs_item_ptr(leaf, slot, |
| 787 | struct btrfs_extent_data_ref); |
| 788 | count = btrfs_extent_data_ref_count(leaf, dref); |
| 789 | key.objectid = btrfs_extent_data_ref_objectid(leaf, |
| 790 | dref); |
| 791 | key.type = BTRFS_EXTENT_DATA_KEY; |
| 792 | key.offset = btrfs_extent_data_ref_offset(leaf, dref); |
| 793 | root = btrfs_extent_data_ref_root(leaf, dref); |
| 794 | ret = __add_prelim_ref(prefs, root, &key, 0, 0, |
Wang Shilong | 742916b | 2013-08-06 10:29:54 +0800 | [diff] [blame] | 795 | bytenr, count, GFP_NOFS); |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 796 | break; |
| 797 | } |
| 798 | default: |
| 799 | WARN_ON(1); |
| 800 | } |
Wang Shilong | 1149ab6 | 2013-04-10 11:22:50 +0000 | [diff] [blame] | 801 | if (ret) |
| 802 | return ret; |
| 803 | |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 804 | } |
| 805 | |
| 806 | return ret; |
| 807 | } |
| 808 | |
| 809 | /* |
| 810 | * this adds all existing backrefs (inline backrefs, backrefs and delayed |
| 811 | * refs) for the given bytenr to the refs list, merges duplicates and resolves |
| 812 | * indirect refs to their parent bytenr. |
| 813 | * When roots are found, they're added to the roots list |
| 814 | * |
| 815 | * FIXME some caching might speed things up |
| 816 | */ |
| 817 | static int find_parent_nodes(struct btrfs_trans_handle *trans, |
| 818 | struct btrfs_fs_info *fs_info, u64 bytenr, |
Jan Schmidt | 097b8a7 | 2012-06-21 11:08:04 +0200 | [diff] [blame] | 819 | u64 time_seq, struct ulist *refs, |
| 820 | struct ulist *roots, const u64 *extent_item_pos) |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 821 | { |
| 822 | struct btrfs_key key; |
| 823 | struct btrfs_path *path; |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 824 | struct btrfs_delayed_ref_root *delayed_refs = NULL; |
Li Zefan | d3b0106 | 2012-03-03 07:41:15 -0500 | [diff] [blame] | 825 | struct btrfs_delayed_ref_head *head; |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 826 | int info_level = 0; |
| 827 | int ret; |
| 828 | struct list_head prefs_delayed; |
| 829 | struct list_head prefs; |
| 830 | struct __prelim_ref *ref; |
| 831 | |
| 832 | INIT_LIST_HEAD(&prefs); |
| 833 | INIT_LIST_HEAD(&prefs_delayed); |
| 834 | |
| 835 | key.objectid = bytenr; |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 836 | key.offset = (u64)-1; |
Josef Bacik | 261c84b | 2013-06-28 13:11:22 -0400 | [diff] [blame] | 837 | if (btrfs_fs_incompat(fs_info, SKINNY_METADATA)) |
| 838 | key.type = BTRFS_METADATA_ITEM_KEY; |
| 839 | else |
| 840 | key.type = BTRFS_EXTENT_ITEM_KEY; |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 841 | |
| 842 | path = btrfs_alloc_path(); |
| 843 | if (!path) |
| 844 | return -ENOMEM; |
Josef Bacik | da61d31 | 2013-06-12 16:20:08 -0400 | [diff] [blame] | 845 | if (!trans) |
| 846 | path->search_commit_root = 1; |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 847 | |
| 848 | /* |
| 849 | * grab both a lock on the path and a lock on the delayed ref head. |
| 850 | * We need both to get a consistent picture of how the refs look |
| 851 | * at a specified point in time |
| 852 | */ |
| 853 | again: |
Li Zefan | d3b0106 | 2012-03-03 07:41:15 -0500 | [diff] [blame] | 854 | head = NULL; |
| 855 | |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 856 | ret = btrfs_search_slot(trans, fs_info->extent_root, &key, path, 0, 0); |
| 857 | if (ret < 0) |
| 858 | goto out; |
| 859 | BUG_ON(ret == 0); |
| 860 | |
Josef Bacik | da61d31 | 2013-06-12 16:20:08 -0400 | [diff] [blame] | 861 | if (trans) { |
Jan Schmidt | 7a3ae2f | 2012-03-23 17:32:28 +0100 | [diff] [blame] | 862 | /* |
| 863 | * look if there are updates for this ref queued and lock the |
| 864 | * head |
| 865 | */ |
| 866 | delayed_refs = &trans->transaction->delayed_refs; |
| 867 | spin_lock(&delayed_refs->lock); |
| 868 | head = btrfs_find_delayed_ref_head(trans, bytenr); |
| 869 | if (head) { |
| 870 | if (!mutex_trylock(&head->mutex)) { |
| 871 | atomic_inc(&head->node.refs); |
| 872 | spin_unlock(&delayed_refs->lock); |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 873 | |
Jan Schmidt | 7a3ae2f | 2012-03-23 17:32:28 +0100 | [diff] [blame] | 874 | btrfs_release_path(path); |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 875 | |
Jan Schmidt | 7a3ae2f | 2012-03-23 17:32:28 +0100 | [diff] [blame] | 876 | /* |
| 877 | * Mutex was contended, block until it's |
| 878 | * released and try again |
| 879 | */ |
| 880 | mutex_lock(&head->mutex); |
| 881 | mutex_unlock(&head->mutex); |
| 882 | btrfs_put_delayed_ref(&head->node); |
| 883 | goto again; |
| 884 | } |
Jan Schmidt | 097b8a7 | 2012-06-21 11:08:04 +0200 | [diff] [blame] | 885 | ret = __add_delayed_refs(head, time_seq, |
Jan Schmidt | 8445f61 | 2012-05-16 18:36:03 +0200 | [diff] [blame] | 886 | &prefs_delayed); |
Jan Schmidt | 155725c | 2012-06-22 14:01:00 +0200 | [diff] [blame] | 887 | mutex_unlock(&head->mutex); |
Jan Schmidt | 7a3ae2f | 2012-03-23 17:32:28 +0100 | [diff] [blame] | 888 | if (ret) { |
| 889 | spin_unlock(&delayed_refs->lock); |
| 890 | goto out; |
| 891 | } |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 892 | } |
Jan Schmidt | 7a3ae2f | 2012-03-23 17:32:28 +0100 | [diff] [blame] | 893 | spin_unlock(&delayed_refs->lock); |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 894 | } |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 895 | |
| 896 | if (path->slots[0]) { |
| 897 | struct extent_buffer *leaf; |
| 898 | int slot; |
| 899 | |
Jan Schmidt | dadcaf7 | 2012-05-22 13:43:25 +0200 | [diff] [blame] | 900 | path->slots[0]--; |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 901 | leaf = path->nodes[0]; |
Jan Schmidt | dadcaf7 | 2012-05-22 13:43:25 +0200 | [diff] [blame] | 902 | slot = path->slots[0]; |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 903 | btrfs_item_key_to_cpu(leaf, &key, slot); |
| 904 | if (key.objectid == bytenr && |
Josef Bacik | 261c84b | 2013-06-28 13:11:22 -0400 | [diff] [blame] | 905 | (key.type == BTRFS_EXTENT_ITEM_KEY || |
| 906 | key.type == BTRFS_METADATA_ITEM_KEY)) { |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 907 | ret = __add_inline_refs(fs_info, path, bytenr, |
Jan Schmidt | d5c88b7 | 2012-05-15 17:55:51 +0200 | [diff] [blame] | 908 | &info_level, &prefs); |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 909 | if (ret) |
| 910 | goto out; |
Jan Schmidt | d5c88b7 | 2012-05-15 17:55:51 +0200 | [diff] [blame] | 911 | ret = __add_keyed_refs(fs_info, path, bytenr, |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 912 | info_level, &prefs); |
| 913 | if (ret) |
| 914 | goto out; |
| 915 | } |
| 916 | } |
| 917 | btrfs_release_path(path); |
| 918 | |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 919 | list_splice_init(&prefs_delayed, &prefs); |
| 920 | |
Jan Schmidt | d5c88b7 | 2012-05-15 17:55:51 +0200 | [diff] [blame] | 921 | ret = __add_missing_keys(fs_info, &prefs); |
| 922 | if (ret) |
| 923 | goto out; |
| 924 | |
Wang Shilong | 692206b | 2013-04-11 07:08:55 +0000 | [diff] [blame] | 925 | __merge_refs(&prefs, 1); |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 926 | |
Josef Bacik | da61d31 | 2013-06-12 16:20:08 -0400 | [diff] [blame] | 927 | ret = __resolve_indirect_refs(fs_info, path, time_seq, &prefs, |
| 928 | extent_item_pos); |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 929 | if (ret) |
| 930 | goto out; |
| 931 | |
Wang Shilong | 692206b | 2013-04-11 07:08:55 +0000 | [diff] [blame] | 932 | __merge_refs(&prefs, 2); |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 933 | |
| 934 | while (!list_empty(&prefs)) { |
| 935 | ref = list_first_entry(&prefs, struct __prelim_ref, list); |
Julia Lawall | 6c1500f | 2012-11-03 20:30:18 +0000 | [diff] [blame] | 936 | WARN_ON(ref->count < 0); |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 937 | if (ref->count && ref->root_id && ref->parent == 0) { |
| 938 | /* no parent == root of tree */ |
| 939 | ret = ulist_add(roots, ref->root_id, 0, GFP_NOFS); |
Wang Shilong | f172393 | 2013-03-29 23:03:21 +0000 | [diff] [blame] | 940 | if (ret < 0) |
| 941 | goto out; |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 942 | } |
| 943 | if (ref->count && ref->parent) { |
Jan Schmidt | 976b190 | 2012-05-17 16:43:03 +0200 | [diff] [blame] | 944 | struct extent_inode_elem *eie = NULL; |
Jan Schmidt | 3301958 | 2012-05-30 18:05:21 +0200 | [diff] [blame] | 945 | if (extent_item_pos && !ref->inode_list) { |
Jan Schmidt | 976b190 | 2012-05-17 16:43:03 +0200 | [diff] [blame] | 946 | u32 bsz; |
| 947 | struct extent_buffer *eb; |
| 948 | bsz = btrfs_level_size(fs_info->extent_root, |
| 949 | info_level); |
| 950 | eb = read_tree_block(fs_info->extent_root, |
| 951 | ref->parent, bsz, 0); |
Josef Bacik | 416bc65 | 2013-04-23 14:17:42 -0400 | [diff] [blame] | 952 | if (!eb || !extent_buffer_uptodate(eb)) { |
| 953 | free_extent_buffer(eb); |
Wang Shilong | c16c2e2 | 2013-05-08 08:10:25 +0000 | [diff] [blame] | 954 | ret = -EIO; |
| 955 | goto out; |
Josef Bacik | 416bc65 | 2013-04-23 14:17:42 -0400 | [diff] [blame] | 956 | } |
Jan Schmidt | 976b190 | 2012-05-17 16:43:03 +0200 | [diff] [blame] | 957 | ret = find_extent_in_eb(eb, bytenr, |
| 958 | *extent_item_pos, &eie); |
| 959 | free_extent_buffer(eb); |
Filipe David Borba Manana | f5929cd | 2013-07-31 00:26:35 +0100 | [diff] [blame] | 960 | if (ret < 0) |
| 961 | goto out; |
| 962 | ref->inode_list = eie; |
Jan Schmidt | 976b190 | 2012-05-17 16:43:03 +0200 | [diff] [blame] | 963 | } |
Jan Schmidt | 3301958 | 2012-05-30 18:05:21 +0200 | [diff] [blame] | 964 | ret = ulist_add_merge(refs, ref->parent, |
Jan Schmidt | 995e01b | 2012-08-13 02:52:38 -0600 | [diff] [blame] | 965 | (uintptr_t)ref->inode_list, |
Alexander Block | 34d73f5 | 2012-07-28 16:18:58 +0200 | [diff] [blame] | 966 | (u64 *)&eie, GFP_NOFS); |
Wang Shilong | f172393 | 2013-03-29 23:03:21 +0000 | [diff] [blame] | 967 | if (ret < 0) |
| 968 | goto out; |
Jan Schmidt | 3301958 | 2012-05-30 18:05:21 +0200 | [diff] [blame] | 969 | if (!ret && extent_item_pos) { |
| 970 | /* |
| 971 | * we've recorded that parent, so we must extend |
| 972 | * its inode list here |
| 973 | */ |
| 974 | BUG_ON(!eie); |
| 975 | while (eie->next) |
| 976 | eie = eie->next; |
| 977 | eie->next = ref->inode_list; |
| 978 | } |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 979 | } |
Wang Shilong | a4fdb61 | 2013-08-08 13:04:17 +0800 | [diff] [blame] | 980 | list_del(&ref->list); |
Wang Shilong | b9e9a6c | 2013-08-09 13:25:36 +0800 | [diff] [blame] | 981 | kmem_cache_free(btrfs_prelim_ref_cache, ref); |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 982 | } |
| 983 | |
| 984 | out: |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 985 | btrfs_free_path(path); |
| 986 | while (!list_empty(&prefs)) { |
| 987 | ref = list_first_entry(&prefs, struct __prelim_ref, list); |
| 988 | list_del(&ref->list); |
Wang Shilong | b9e9a6c | 2013-08-09 13:25:36 +0800 | [diff] [blame] | 989 | kmem_cache_free(btrfs_prelim_ref_cache, ref); |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 990 | } |
| 991 | while (!list_empty(&prefs_delayed)) { |
| 992 | ref = list_first_entry(&prefs_delayed, struct __prelim_ref, |
| 993 | list); |
| 994 | list_del(&ref->list); |
Wang Shilong | b9e9a6c | 2013-08-09 13:25:36 +0800 | [diff] [blame] | 995 | kmem_cache_free(btrfs_prelim_ref_cache, ref); |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 996 | } |
| 997 | |
| 998 | return ret; |
| 999 | } |
| 1000 | |
Jan Schmidt | 976b190 | 2012-05-17 16:43:03 +0200 | [diff] [blame] | 1001 | static void free_leaf_list(struct ulist *blocks) |
| 1002 | { |
| 1003 | struct ulist_node *node = NULL; |
| 1004 | struct extent_inode_elem *eie; |
| 1005 | struct extent_inode_elem *eie_next; |
| 1006 | struct ulist_iterator uiter; |
| 1007 | |
| 1008 | ULIST_ITER_INIT(&uiter); |
| 1009 | while ((node = ulist_next(blocks, &uiter))) { |
| 1010 | if (!node->aux) |
| 1011 | continue; |
Jan Schmidt | 995e01b | 2012-08-13 02:52:38 -0600 | [diff] [blame] | 1012 | eie = (struct extent_inode_elem *)(uintptr_t)node->aux; |
Jan Schmidt | 976b190 | 2012-05-17 16:43:03 +0200 | [diff] [blame] | 1013 | for (; eie; eie = eie_next) { |
| 1014 | eie_next = eie->next; |
| 1015 | kfree(eie); |
| 1016 | } |
| 1017 | node->aux = 0; |
| 1018 | } |
| 1019 | |
| 1020 | ulist_free(blocks); |
| 1021 | } |
| 1022 | |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 1023 | /* |
| 1024 | * Finds all leafs with a reference to the specified combination of bytenr and |
| 1025 | * offset. key_list_head will point to a list of corresponding keys (caller must |
| 1026 | * free each list element). The leafs will be stored in the leafs ulist, which |
| 1027 | * must be freed with ulist_free. |
| 1028 | * |
| 1029 | * returns 0 on success, <0 on error |
| 1030 | */ |
| 1031 | static int btrfs_find_all_leafs(struct btrfs_trans_handle *trans, |
| 1032 | struct btrfs_fs_info *fs_info, u64 bytenr, |
Jan Schmidt | 097b8a7 | 2012-06-21 11:08:04 +0200 | [diff] [blame] | 1033 | u64 time_seq, struct ulist **leafs, |
Jan Schmidt | 976b190 | 2012-05-17 16:43:03 +0200 | [diff] [blame] | 1034 | const u64 *extent_item_pos) |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 1035 | { |
| 1036 | struct ulist *tmp; |
| 1037 | int ret; |
| 1038 | |
| 1039 | tmp = ulist_alloc(GFP_NOFS); |
| 1040 | if (!tmp) |
| 1041 | return -ENOMEM; |
| 1042 | *leafs = ulist_alloc(GFP_NOFS); |
| 1043 | if (!*leafs) { |
| 1044 | ulist_free(tmp); |
| 1045 | return -ENOMEM; |
| 1046 | } |
| 1047 | |
Jan Schmidt | 097b8a7 | 2012-06-21 11:08:04 +0200 | [diff] [blame] | 1048 | ret = find_parent_nodes(trans, fs_info, bytenr, |
Jan Schmidt | 8445f61 | 2012-05-16 18:36:03 +0200 | [diff] [blame] | 1049 | time_seq, *leafs, tmp, extent_item_pos); |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 1050 | ulist_free(tmp); |
| 1051 | |
| 1052 | if (ret < 0 && ret != -ENOENT) { |
Jan Schmidt | 976b190 | 2012-05-17 16:43:03 +0200 | [diff] [blame] | 1053 | free_leaf_list(*leafs); |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 1054 | return ret; |
| 1055 | } |
| 1056 | |
| 1057 | return 0; |
| 1058 | } |
| 1059 | |
| 1060 | /* |
| 1061 | * walk all backrefs for a given extent to find all roots that reference this |
| 1062 | * extent. Walking a backref means finding all extents that reference this |
| 1063 | * extent and in turn walk the backrefs of those, too. Naturally this is a |
| 1064 | * recursive process, but here it is implemented in an iterative fashion: We |
| 1065 | * find all referencing extents for the extent in question and put them on a |
| 1066 | * list. In turn, we find all referencing extents for those, further appending |
| 1067 | * to the list. The way we iterate the list allows adding more elements after |
| 1068 | * the current while iterating. The process stops when we reach the end of the |
| 1069 | * list. Found roots are added to the roots list. |
| 1070 | * |
| 1071 | * returns 0 on success, < 0 on error. |
| 1072 | */ |
| 1073 | int btrfs_find_all_roots(struct btrfs_trans_handle *trans, |
| 1074 | struct btrfs_fs_info *fs_info, u64 bytenr, |
Jan Schmidt | 097b8a7 | 2012-06-21 11:08:04 +0200 | [diff] [blame] | 1075 | u64 time_seq, struct ulist **roots) |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 1076 | { |
| 1077 | struct ulist *tmp; |
| 1078 | struct ulist_node *node = NULL; |
Jan Schmidt | cd1b413 | 2012-05-22 14:56:50 +0200 | [diff] [blame] | 1079 | struct ulist_iterator uiter; |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 1080 | int ret; |
| 1081 | |
| 1082 | tmp = ulist_alloc(GFP_NOFS); |
| 1083 | if (!tmp) |
| 1084 | return -ENOMEM; |
| 1085 | *roots = ulist_alloc(GFP_NOFS); |
| 1086 | if (!*roots) { |
| 1087 | ulist_free(tmp); |
| 1088 | return -ENOMEM; |
| 1089 | } |
| 1090 | |
Jan Schmidt | cd1b413 | 2012-05-22 14:56:50 +0200 | [diff] [blame] | 1091 | ULIST_ITER_INIT(&uiter); |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 1092 | while (1) { |
Jan Schmidt | 097b8a7 | 2012-06-21 11:08:04 +0200 | [diff] [blame] | 1093 | ret = find_parent_nodes(trans, fs_info, bytenr, |
Jan Schmidt | 8445f61 | 2012-05-16 18:36:03 +0200 | [diff] [blame] | 1094 | time_seq, tmp, *roots, NULL); |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 1095 | if (ret < 0 && ret != -ENOENT) { |
| 1096 | ulist_free(tmp); |
| 1097 | ulist_free(*roots); |
| 1098 | return ret; |
| 1099 | } |
Jan Schmidt | cd1b413 | 2012-05-22 14:56:50 +0200 | [diff] [blame] | 1100 | node = ulist_next(tmp, &uiter); |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 1101 | if (!node) |
| 1102 | break; |
| 1103 | bytenr = node->val; |
| 1104 | } |
| 1105 | |
| 1106 | ulist_free(tmp); |
| 1107 | return 0; |
| 1108 | } |
| 1109 | |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1110 | /* |
| 1111 | * this makes the path point to (inum INODE_ITEM ioff) |
| 1112 | */ |
| 1113 | int inode_item_info(u64 inum, u64 ioff, struct btrfs_root *fs_root, |
| 1114 | struct btrfs_path *path) |
| 1115 | { |
| 1116 | struct btrfs_key key; |
Kelley Nielsen | e33d5c3 | 2013-11-04 19:33:33 -0800 | [diff] [blame^] | 1117 | return btrfs_find_item(fs_root, path, inum, ioff, |
| 1118 | BTRFS_INODE_ITEM_KEY, &key); |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1119 | } |
| 1120 | |
| 1121 | static int inode_ref_info(u64 inum, u64 ioff, struct btrfs_root *fs_root, |
| 1122 | struct btrfs_path *path, |
| 1123 | struct btrfs_key *found_key) |
| 1124 | { |
Kelley Nielsen | e33d5c3 | 2013-11-04 19:33:33 -0800 | [diff] [blame^] | 1125 | return btrfs_find_item(fs_root, path, inum, ioff, |
| 1126 | BTRFS_INODE_REF_KEY, found_key); |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1127 | } |
| 1128 | |
Mark Fasheh | f186373 | 2012-08-08 11:32:27 -0700 | [diff] [blame] | 1129 | int btrfs_find_one_extref(struct btrfs_root *root, u64 inode_objectid, |
| 1130 | u64 start_off, struct btrfs_path *path, |
| 1131 | struct btrfs_inode_extref **ret_extref, |
| 1132 | u64 *found_off) |
| 1133 | { |
| 1134 | int ret, slot; |
| 1135 | struct btrfs_key key; |
| 1136 | struct btrfs_key found_key; |
| 1137 | struct btrfs_inode_extref *extref; |
| 1138 | struct extent_buffer *leaf; |
| 1139 | unsigned long ptr; |
| 1140 | |
| 1141 | key.objectid = inode_objectid; |
| 1142 | btrfs_set_key_type(&key, BTRFS_INODE_EXTREF_KEY); |
| 1143 | key.offset = start_off; |
| 1144 | |
| 1145 | ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); |
| 1146 | if (ret < 0) |
| 1147 | return ret; |
| 1148 | |
| 1149 | while (1) { |
| 1150 | leaf = path->nodes[0]; |
| 1151 | slot = path->slots[0]; |
| 1152 | if (slot >= btrfs_header_nritems(leaf)) { |
| 1153 | /* |
| 1154 | * If the item at offset is not found, |
| 1155 | * btrfs_search_slot will point us to the slot |
| 1156 | * where it should be inserted. In our case |
| 1157 | * that will be the slot directly before the |
| 1158 | * next INODE_REF_KEY_V2 item. In the case |
| 1159 | * that we're pointing to the last slot in a |
| 1160 | * leaf, we must move one leaf over. |
| 1161 | */ |
| 1162 | ret = btrfs_next_leaf(root, path); |
| 1163 | if (ret) { |
| 1164 | if (ret >= 1) |
| 1165 | ret = -ENOENT; |
| 1166 | break; |
| 1167 | } |
| 1168 | continue; |
| 1169 | } |
| 1170 | |
| 1171 | btrfs_item_key_to_cpu(leaf, &found_key, slot); |
| 1172 | |
| 1173 | /* |
| 1174 | * Check that we're still looking at an extended ref key for |
| 1175 | * this particular objectid. If we have different |
| 1176 | * objectid or type then there are no more to be found |
| 1177 | * in the tree and we can exit. |
| 1178 | */ |
| 1179 | ret = -ENOENT; |
| 1180 | if (found_key.objectid != inode_objectid) |
| 1181 | break; |
| 1182 | if (btrfs_key_type(&found_key) != BTRFS_INODE_EXTREF_KEY) |
| 1183 | break; |
| 1184 | |
| 1185 | ret = 0; |
| 1186 | ptr = btrfs_item_ptr_offset(leaf, path->slots[0]); |
| 1187 | extref = (struct btrfs_inode_extref *)ptr; |
| 1188 | *ret_extref = extref; |
| 1189 | if (found_off) |
| 1190 | *found_off = found_key.offset; |
| 1191 | break; |
| 1192 | } |
| 1193 | |
| 1194 | return ret; |
| 1195 | } |
| 1196 | |
Eric Sandeen | 48a3b63 | 2013-04-25 20:41:01 +0000 | [diff] [blame] | 1197 | /* |
| 1198 | * this iterates to turn a name (from iref/extref) into a full filesystem path. |
| 1199 | * Elements of the path are separated by '/' and the path is guaranteed to be |
| 1200 | * 0-terminated. the path is only given within the current file system. |
| 1201 | * Therefore, it never starts with a '/'. the caller is responsible to provide |
| 1202 | * "size" bytes in "dest". the dest buffer will be filled backwards. finally, |
| 1203 | * the start point of the resulting string is returned. this pointer is within |
| 1204 | * dest, normally. |
| 1205 | * in case the path buffer would overflow, the pointer is decremented further |
| 1206 | * as if output was written to the buffer, though no more output is actually |
| 1207 | * generated. that way, the caller can determine how much space would be |
| 1208 | * required for the path to fit into the buffer. in that case, the returned |
| 1209 | * value will be smaller than dest. callers must check this! |
| 1210 | */ |
Jan Schmidt | 96b5bd7 | 2012-10-15 08:30:45 +0000 | [diff] [blame] | 1211 | char *btrfs_ref_to_path(struct btrfs_root *fs_root, struct btrfs_path *path, |
| 1212 | u32 name_len, unsigned long name_off, |
| 1213 | struct extent_buffer *eb_in, u64 parent, |
| 1214 | char *dest, u32 size) |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1215 | { |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1216 | int slot; |
| 1217 | u64 next_inum; |
| 1218 | int ret; |
Gabriel de Perthuis | 661bec6 | 2012-10-10 08:50:47 -0600 | [diff] [blame] | 1219 | s64 bytes_left = ((s64)size) - 1; |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1220 | struct extent_buffer *eb = eb_in; |
| 1221 | struct btrfs_key found_key; |
Jan Schmidt | b916a59 | 2012-04-13 12:28:08 +0200 | [diff] [blame] | 1222 | int leave_spinning = path->leave_spinning; |
Mark Fasheh | d24bec3 | 2012-08-08 11:33:54 -0700 | [diff] [blame] | 1223 | struct btrfs_inode_ref *iref; |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1224 | |
| 1225 | if (bytes_left >= 0) |
| 1226 | dest[bytes_left] = '\0'; |
| 1227 | |
Jan Schmidt | b916a59 | 2012-04-13 12:28:08 +0200 | [diff] [blame] | 1228 | path->leave_spinning = 1; |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1229 | while (1) { |
Mark Fasheh | d24bec3 | 2012-08-08 11:33:54 -0700 | [diff] [blame] | 1230 | bytes_left -= name_len; |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1231 | if (bytes_left >= 0) |
| 1232 | read_extent_buffer(eb, dest + bytes_left, |
Mark Fasheh | d24bec3 | 2012-08-08 11:33:54 -0700 | [diff] [blame] | 1233 | name_off, name_len); |
Jan Schmidt | b916a59 | 2012-04-13 12:28:08 +0200 | [diff] [blame] | 1234 | if (eb != eb_in) { |
| 1235 | btrfs_tree_read_unlock_blocking(eb); |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1236 | free_extent_buffer(eb); |
Jan Schmidt | b916a59 | 2012-04-13 12:28:08 +0200 | [diff] [blame] | 1237 | } |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1238 | ret = inode_ref_info(parent, 0, fs_root, path, &found_key); |
Jan Schmidt | 8f24b49 | 2012-02-08 16:01:01 +0100 | [diff] [blame] | 1239 | if (ret > 0) |
| 1240 | ret = -ENOENT; |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1241 | if (ret) |
| 1242 | break; |
Mark Fasheh | d24bec3 | 2012-08-08 11:33:54 -0700 | [diff] [blame] | 1243 | |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1244 | next_inum = found_key.offset; |
| 1245 | |
| 1246 | /* regular exit ahead */ |
| 1247 | if (parent == next_inum) |
| 1248 | break; |
| 1249 | |
| 1250 | slot = path->slots[0]; |
| 1251 | eb = path->nodes[0]; |
| 1252 | /* make sure we can use eb after releasing the path */ |
Jan Schmidt | b916a59 | 2012-04-13 12:28:08 +0200 | [diff] [blame] | 1253 | if (eb != eb_in) { |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1254 | atomic_inc(&eb->refs); |
Jan Schmidt | b916a59 | 2012-04-13 12:28:08 +0200 | [diff] [blame] | 1255 | btrfs_tree_read_lock(eb); |
| 1256 | btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK); |
| 1257 | } |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1258 | btrfs_release_path(path); |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1259 | iref = btrfs_item_ptr(eb, slot, struct btrfs_inode_ref); |
Mark Fasheh | d24bec3 | 2012-08-08 11:33:54 -0700 | [diff] [blame] | 1260 | |
| 1261 | name_len = btrfs_inode_ref_name_len(eb, iref); |
| 1262 | name_off = (unsigned long)(iref + 1); |
| 1263 | |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1264 | parent = next_inum; |
| 1265 | --bytes_left; |
| 1266 | if (bytes_left >= 0) |
| 1267 | dest[bytes_left] = '/'; |
| 1268 | } |
| 1269 | |
| 1270 | btrfs_release_path(path); |
Jan Schmidt | b916a59 | 2012-04-13 12:28:08 +0200 | [diff] [blame] | 1271 | path->leave_spinning = leave_spinning; |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1272 | |
| 1273 | if (ret) |
| 1274 | return ERR_PTR(ret); |
| 1275 | |
| 1276 | return dest + bytes_left; |
| 1277 | } |
| 1278 | |
| 1279 | /* |
| 1280 | * this makes the path point to (logical EXTENT_ITEM *) |
| 1281 | * returns BTRFS_EXTENT_FLAG_DATA for data, BTRFS_EXTENT_FLAG_TREE_BLOCK for |
| 1282 | * tree blocks and <0 on error. |
| 1283 | */ |
| 1284 | int extent_from_logical(struct btrfs_fs_info *fs_info, u64 logical, |
Liu Bo | 69917e4 | 2012-09-07 20:01:28 -0600 | [diff] [blame] | 1285 | struct btrfs_path *path, struct btrfs_key *found_key, |
| 1286 | u64 *flags_ret) |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1287 | { |
| 1288 | int ret; |
| 1289 | u64 flags; |
Josef Bacik | 261c84b | 2013-06-28 13:11:22 -0400 | [diff] [blame] | 1290 | u64 size = 0; |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1291 | u32 item_size; |
| 1292 | struct extent_buffer *eb; |
| 1293 | struct btrfs_extent_item *ei; |
| 1294 | struct btrfs_key key; |
| 1295 | |
Josef Bacik | 261c84b | 2013-06-28 13:11:22 -0400 | [diff] [blame] | 1296 | if (btrfs_fs_incompat(fs_info, SKINNY_METADATA)) |
| 1297 | key.type = BTRFS_METADATA_ITEM_KEY; |
| 1298 | else |
| 1299 | key.type = BTRFS_EXTENT_ITEM_KEY; |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1300 | key.objectid = logical; |
| 1301 | key.offset = (u64)-1; |
| 1302 | |
| 1303 | ret = btrfs_search_slot(NULL, fs_info->extent_root, &key, path, 0, 0); |
| 1304 | if (ret < 0) |
| 1305 | return ret; |
| 1306 | ret = btrfs_previous_item(fs_info->extent_root, path, |
| 1307 | 0, BTRFS_EXTENT_ITEM_KEY); |
| 1308 | if (ret < 0) |
| 1309 | return ret; |
| 1310 | |
| 1311 | btrfs_item_key_to_cpu(path->nodes[0], found_key, path->slots[0]); |
Josef Bacik | 261c84b | 2013-06-28 13:11:22 -0400 | [diff] [blame] | 1312 | if (found_key->type == BTRFS_METADATA_ITEM_KEY) |
| 1313 | size = fs_info->extent_root->leafsize; |
| 1314 | else if (found_key->type == BTRFS_EXTENT_ITEM_KEY) |
| 1315 | size = found_key->offset; |
| 1316 | |
| 1317 | if ((found_key->type != BTRFS_EXTENT_ITEM_KEY && |
| 1318 | found_key->type != BTRFS_METADATA_ITEM_KEY) || |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1319 | found_key->objectid > logical || |
Josef Bacik | 261c84b | 2013-06-28 13:11:22 -0400 | [diff] [blame] | 1320 | found_key->objectid + size <= logical) { |
Geert Uytterhoeven | c1c9ff7 | 2013-08-20 13:20:07 +0200 | [diff] [blame] | 1321 | pr_debug("logical %llu is not within any extent\n", logical); |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1322 | return -ENOENT; |
Jan Schmidt | 4692cf5 | 2011-12-02 14:56:41 +0100 | [diff] [blame] | 1323 | } |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1324 | |
| 1325 | eb = path->nodes[0]; |
| 1326 | item_size = btrfs_item_size_nr(eb, path->slots[0]); |
| 1327 | BUG_ON(item_size < sizeof(*ei)); |
| 1328 | |
| 1329 | ei = btrfs_item_ptr(eb, path->slots[0], struct btrfs_extent_item); |
| 1330 | flags = btrfs_extent_flags(eb, ei); |
| 1331 | |
Jan Schmidt | 4692cf5 | 2011-12-02 14:56:41 +0100 | [diff] [blame] | 1332 | pr_debug("logical %llu is at position %llu within the extent (%llu " |
| 1333 | "EXTENT_ITEM %llu) flags %#llx size %u\n", |
Geert Uytterhoeven | c1c9ff7 | 2013-08-20 13:20:07 +0200 | [diff] [blame] | 1334 | logical, logical - found_key->objectid, found_key->objectid, |
| 1335 | found_key->offset, flags, item_size); |
Liu Bo | 69917e4 | 2012-09-07 20:01:28 -0600 | [diff] [blame] | 1336 | |
| 1337 | WARN_ON(!flags_ret); |
| 1338 | if (flags_ret) { |
| 1339 | if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) |
| 1340 | *flags_ret = BTRFS_EXTENT_FLAG_TREE_BLOCK; |
| 1341 | else if (flags & BTRFS_EXTENT_FLAG_DATA) |
| 1342 | *flags_ret = BTRFS_EXTENT_FLAG_DATA; |
| 1343 | else |
| 1344 | BUG_ON(1); |
| 1345 | return 0; |
| 1346 | } |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1347 | |
| 1348 | return -EIO; |
| 1349 | } |
| 1350 | |
| 1351 | /* |
| 1352 | * helper function to iterate extent inline refs. ptr must point to a 0 value |
| 1353 | * for the first call and may be modified. it is used to track state. |
| 1354 | * if more refs exist, 0 is returned and the next call to |
| 1355 | * __get_extent_inline_ref must pass the modified ptr parameter to get the |
| 1356 | * next ref. after the last ref was processed, 1 is returned. |
| 1357 | * returns <0 on error |
| 1358 | */ |
| 1359 | static int __get_extent_inline_ref(unsigned long *ptr, struct extent_buffer *eb, |
| 1360 | struct btrfs_extent_item *ei, u32 item_size, |
| 1361 | struct btrfs_extent_inline_ref **out_eiref, |
| 1362 | int *out_type) |
| 1363 | { |
| 1364 | unsigned long end; |
| 1365 | u64 flags; |
| 1366 | struct btrfs_tree_block_info *info; |
| 1367 | |
| 1368 | if (!*ptr) { |
| 1369 | /* first call */ |
| 1370 | flags = btrfs_extent_flags(eb, ei); |
| 1371 | if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) { |
| 1372 | info = (struct btrfs_tree_block_info *)(ei + 1); |
| 1373 | *out_eiref = |
| 1374 | (struct btrfs_extent_inline_ref *)(info + 1); |
| 1375 | } else { |
| 1376 | *out_eiref = (struct btrfs_extent_inline_ref *)(ei + 1); |
| 1377 | } |
| 1378 | *ptr = (unsigned long)*out_eiref; |
| 1379 | if ((void *)*ptr >= (void *)ei + item_size) |
| 1380 | return -ENOENT; |
| 1381 | } |
| 1382 | |
| 1383 | end = (unsigned long)ei + item_size; |
| 1384 | *out_eiref = (struct btrfs_extent_inline_ref *)*ptr; |
| 1385 | *out_type = btrfs_extent_inline_ref_type(eb, *out_eiref); |
| 1386 | |
| 1387 | *ptr += btrfs_extent_inline_ref_size(*out_type); |
| 1388 | WARN_ON(*ptr > end); |
| 1389 | if (*ptr == end) |
| 1390 | return 1; /* last */ |
| 1391 | |
| 1392 | return 0; |
| 1393 | } |
| 1394 | |
| 1395 | /* |
| 1396 | * reads the tree block backref for an extent. tree level and root are returned |
| 1397 | * through out_level and out_root. ptr must point to a 0 value for the first |
| 1398 | * call and may be modified (see __get_extent_inline_ref comment). |
| 1399 | * returns 0 if data was provided, 1 if there was no more data to provide or |
| 1400 | * <0 on error. |
| 1401 | */ |
| 1402 | int tree_backref_for_extent(unsigned long *ptr, struct extent_buffer *eb, |
| 1403 | struct btrfs_extent_item *ei, u32 item_size, |
| 1404 | u64 *out_root, u8 *out_level) |
| 1405 | { |
| 1406 | int ret; |
| 1407 | int type; |
| 1408 | struct btrfs_tree_block_info *info; |
| 1409 | struct btrfs_extent_inline_ref *eiref; |
| 1410 | |
| 1411 | if (*ptr == (unsigned long)-1) |
| 1412 | return 1; |
| 1413 | |
| 1414 | while (1) { |
| 1415 | ret = __get_extent_inline_ref(ptr, eb, ei, item_size, |
| 1416 | &eiref, &type); |
| 1417 | if (ret < 0) |
| 1418 | return ret; |
| 1419 | |
| 1420 | if (type == BTRFS_TREE_BLOCK_REF_KEY || |
| 1421 | type == BTRFS_SHARED_BLOCK_REF_KEY) |
| 1422 | break; |
| 1423 | |
| 1424 | if (ret == 1) |
| 1425 | return 1; |
| 1426 | } |
| 1427 | |
| 1428 | /* we can treat both ref types equally here */ |
| 1429 | info = (struct btrfs_tree_block_info *)(ei + 1); |
| 1430 | *out_root = btrfs_extent_inline_ref_offset(eb, eiref); |
| 1431 | *out_level = btrfs_tree_block_level(eb, info); |
| 1432 | |
| 1433 | if (ret == 1) |
| 1434 | *ptr = (unsigned long)-1; |
| 1435 | |
| 1436 | return 0; |
| 1437 | } |
| 1438 | |
Jan Schmidt | 976b190 | 2012-05-17 16:43:03 +0200 | [diff] [blame] | 1439 | static int iterate_leaf_refs(struct extent_inode_elem *inode_list, |
| 1440 | u64 root, u64 extent_item_objectid, |
Jan Schmidt | 4692cf5 | 2011-12-02 14:56:41 +0100 | [diff] [blame] | 1441 | iterate_extent_inodes_t *iterate, void *ctx) |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1442 | { |
Jan Schmidt | 976b190 | 2012-05-17 16:43:03 +0200 | [diff] [blame] | 1443 | struct extent_inode_elem *eie; |
Jan Schmidt | 4692cf5 | 2011-12-02 14:56:41 +0100 | [diff] [blame] | 1444 | int ret = 0; |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1445 | |
Jan Schmidt | 976b190 | 2012-05-17 16:43:03 +0200 | [diff] [blame] | 1446 | for (eie = inode_list; eie; eie = eie->next) { |
Jan Schmidt | 4692cf5 | 2011-12-02 14:56:41 +0100 | [diff] [blame] | 1447 | pr_debug("ref for %llu resolved, key (%llu EXTEND_DATA %llu), " |
Jan Schmidt | 976b190 | 2012-05-17 16:43:03 +0200 | [diff] [blame] | 1448 | "root %llu\n", extent_item_objectid, |
| 1449 | eie->inum, eie->offset, root); |
| 1450 | ret = iterate(eie->inum, eie->offset, root, ctx); |
Jan Schmidt | 4692cf5 | 2011-12-02 14:56:41 +0100 | [diff] [blame] | 1451 | if (ret) { |
Jan Schmidt | 976b190 | 2012-05-17 16:43:03 +0200 | [diff] [blame] | 1452 | pr_debug("stopping iteration for %llu due to ret=%d\n", |
| 1453 | extent_item_objectid, ret); |
Jan Schmidt | 4692cf5 | 2011-12-02 14:56:41 +0100 | [diff] [blame] | 1454 | break; |
| 1455 | } |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1456 | } |
| 1457 | |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1458 | return ret; |
| 1459 | } |
| 1460 | |
| 1461 | /* |
| 1462 | * calls iterate() for every inode that references the extent identified by |
Jan Schmidt | 4692cf5 | 2011-12-02 14:56:41 +0100 | [diff] [blame] | 1463 | * the given parameters. |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1464 | * when the iterator function returns a non-zero value, iteration stops. |
| 1465 | */ |
| 1466 | int iterate_extent_inodes(struct btrfs_fs_info *fs_info, |
Jan Schmidt | 4692cf5 | 2011-12-02 14:56:41 +0100 | [diff] [blame] | 1467 | u64 extent_item_objectid, u64 extent_item_pos, |
Jan Schmidt | 7a3ae2f | 2012-03-23 17:32:28 +0100 | [diff] [blame] | 1468 | int search_commit_root, |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1469 | iterate_extent_inodes_t *iterate, void *ctx) |
| 1470 | { |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1471 | int ret; |
Josef Bacik | da61d31 | 2013-06-12 16:20:08 -0400 | [diff] [blame] | 1472 | struct btrfs_trans_handle *trans = NULL; |
Jan Schmidt | 7a3ae2f | 2012-03-23 17:32:28 +0100 | [diff] [blame] | 1473 | struct ulist *refs = NULL; |
| 1474 | struct ulist *roots = NULL; |
Jan Schmidt | 4692cf5 | 2011-12-02 14:56:41 +0100 | [diff] [blame] | 1475 | struct ulist_node *ref_node = NULL; |
| 1476 | struct ulist_node *root_node = NULL; |
Jan Schmidt | 8445f61 | 2012-05-16 18:36:03 +0200 | [diff] [blame] | 1477 | struct seq_list tree_mod_seq_elem = {}; |
Jan Schmidt | cd1b413 | 2012-05-22 14:56:50 +0200 | [diff] [blame] | 1478 | struct ulist_iterator ref_uiter; |
| 1479 | struct ulist_iterator root_uiter; |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1480 | |
Jan Schmidt | 4692cf5 | 2011-12-02 14:56:41 +0100 | [diff] [blame] | 1481 | pr_debug("resolving all inodes for extent %llu\n", |
| 1482 | extent_item_objectid); |
| 1483 | |
Josef Bacik | da61d31 | 2013-06-12 16:20:08 -0400 | [diff] [blame] | 1484 | if (!search_commit_root) { |
Jan Schmidt | 7a3ae2f | 2012-03-23 17:32:28 +0100 | [diff] [blame] | 1485 | trans = btrfs_join_transaction(fs_info->extent_root); |
| 1486 | if (IS_ERR(trans)) |
| 1487 | return PTR_ERR(trans); |
Jan Schmidt | 8445f61 | 2012-05-16 18:36:03 +0200 | [diff] [blame] | 1488 | btrfs_get_tree_mod_seq(fs_info, &tree_mod_seq_elem); |
Jan Schmidt | 7a3ae2f | 2012-03-23 17:32:28 +0100 | [diff] [blame] | 1489 | } |
Jan Schmidt | 4692cf5 | 2011-12-02 14:56:41 +0100 | [diff] [blame] | 1490 | |
| 1491 | ret = btrfs_find_all_leafs(trans, fs_info, extent_item_objectid, |
Jan Schmidt | 097b8a7 | 2012-06-21 11:08:04 +0200 | [diff] [blame] | 1492 | tree_mod_seq_elem.seq, &refs, |
Jan Schmidt | 8445f61 | 2012-05-16 18:36:03 +0200 | [diff] [blame] | 1493 | &extent_item_pos); |
Jan Schmidt | 4692cf5 | 2011-12-02 14:56:41 +0100 | [diff] [blame] | 1494 | if (ret) |
| 1495 | goto out; |
| 1496 | |
Jan Schmidt | cd1b413 | 2012-05-22 14:56:50 +0200 | [diff] [blame] | 1497 | ULIST_ITER_INIT(&ref_uiter); |
| 1498 | while (!ret && (ref_node = ulist_next(refs, &ref_uiter))) { |
Jan Schmidt | 976b190 | 2012-05-17 16:43:03 +0200 | [diff] [blame] | 1499 | ret = btrfs_find_all_roots(trans, fs_info, ref_node->val, |
Jan Schmidt | 097b8a7 | 2012-06-21 11:08:04 +0200 | [diff] [blame] | 1500 | tree_mod_seq_elem.seq, &roots); |
Jan Schmidt | 4692cf5 | 2011-12-02 14:56:41 +0100 | [diff] [blame] | 1501 | if (ret) |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1502 | break; |
Jan Schmidt | cd1b413 | 2012-05-22 14:56:50 +0200 | [diff] [blame] | 1503 | ULIST_ITER_INIT(&root_uiter); |
| 1504 | while (!ret && (root_node = ulist_next(roots, &root_uiter))) { |
Jan Schmidt | 976b190 | 2012-05-17 16:43:03 +0200 | [diff] [blame] | 1505 | pr_debug("root %llu references leaf %llu, data list " |
Alexander Block | 34d73f5 | 2012-07-28 16:18:58 +0200 | [diff] [blame] | 1506 | "%#llx\n", root_node->val, ref_node->val, |
Geert Uytterhoeven | c1c9ff7 | 2013-08-20 13:20:07 +0200 | [diff] [blame] | 1507 | ref_node->aux); |
Jan Schmidt | 995e01b | 2012-08-13 02:52:38 -0600 | [diff] [blame] | 1508 | ret = iterate_leaf_refs((struct extent_inode_elem *) |
| 1509 | (uintptr_t)ref_node->aux, |
| 1510 | root_node->val, |
| 1511 | extent_item_objectid, |
| 1512 | iterate, ctx); |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1513 | } |
Jan Schmidt | 976b190 | 2012-05-17 16:43:03 +0200 | [diff] [blame] | 1514 | ulist_free(roots); |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1515 | } |
| 1516 | |
Jan Schmidt | 976b190 | 2012-05-17 16:43:03 +0200 | [diff] [blame] | 1517 | free_leaf_list(refs); |
Jan Schmidt | 4692cf5 | 2011-12-02 14:56:41 +0100 | [diff] [blame] | 1518 | out: |
Jan Schmidt | 7a3ae2f | 2012-03-23 17:32:28 +0100 | [diff] [blame] | 1519 | if (!search_commit_root) { |
Jan Schmidt | 8445f61 | 2012-05-16 18:36:03 +0200 | [diff] [blame] | 1520 | btrfs_put_tree_mod_seq(fs_info, &tree_mod_seq_elem); |
Jan Schmidt | 7a3ae2f | 2012-03-23 17:32:28 +0100 | [diff] [blame] | 1521 | btrfs_end_transaction(trans, fs_info->extent_root); |
| 1522 | } |
| 1523 | |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1524 | return ret; |
| 1525 | } |
| 1526 | |
| 1527 | int iterate_inodes_from_logical(u64 logical, struct btrfs_fs_info *fs_info, |
| 1528 | struct btrfs_path *path, |
| 1529 | iterate_extent_inodes_t *iterate, void *ctx) |
| 1530 | { |
| 1531 | int ret; |
Jan Schmidt | 4692cf5 | 2011-12-02 14:56:41 +0100 | [diff] [blame] | 1532 | u64 extent_item_pos; |
Liu Bo | 69917e4 | 2012-09-07 20:01:28 -0600 | [diff] [blame] | 1533 | u64 flags = 0; |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1534 | struct btrfs_key found_key; |
Jan Schmidt | 7a3ae2f | 2012-03-23 17:32:28 +0100 | [diff] [blame] | 1535 | int search_commit_root = path->search_commit_root; |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1536 | |
Liu Bo | 69917e4 | 2012-09-07 20:01:28 -0600 | [diff] [blame] | 1537 | ret = extent_from_logical(fs_info, logical, path, &found_key, &flags); |
Jan Schmidt | 4692cf5 | 2011-12-02 14:56:41 +0100 | [diff] [blame] | 1538 | btrfs_release_path(path); |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1539 | if (ret < 0) |
| 1540 | return ret; |
Liu Bo | 69917e4 | 2012-09-07 20:01:28 -0600 | [diff] [blame] | 1541 | if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) |
Stefan Behrens | 3627bf4 | 2012-08-01 04:28:01 -0600 | [diff] [blame] | 1542 | return -EINVAL; |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1543 | |
Jan Schmidt | 4692cf5 | 2011-12-02 14:56:41 +0100 | [diff] [blame] | 1544 | extent_item_pos = logical - found_key.objectid; |
Jan Schmidt | 7a3ae2f | 2012-03-23 17:32:28 +0100 | [diff] [blame] | 1545 | ret = iterate_extent_inodes(fs_info, found_key.objectid, |
| 1546 | extent_item_pos, search_commit_root, |
| 1547 | iterate, ctx); |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1548 | |
| 1549 | return ret; |
| 1550 | } |
| 1551 | |
Mark Fasheh | d24bec3 | 2012-08-08 11:33:54 -0700 | [diff] [blame] | 1552 | typedef int (iterate_irefs_t)(u64 parent, u32 name_len, unsigned long name_off, |
| 1553 | struct extent_buffer *eb, void *ctx); |
| 1554 | |
| 1555 | static int iterate_inode_refs(u64 inum, struct btrfs_root *fs_root, |
| 1556 | struct btrfs_path *path, |
| 1557 | iterate_irefs_t *iterate, void *ctx) |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1558 | { |
Jan Schmidt | aefc1eb | 2012-04-13 12:28:00 +0200 | [diff] [blame] | 1559 | int ret = 0; |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1560 | int slot; |
| 1561 | u32 cur; |
| 1562 | u32 len; |
| 1563 | u32 name_len; |
| 1564 | u64 parent = 0; |
| 1565 | int found = 0; |
| 1566 | struct extent_buffer *eb; |
| 1567 | struct btrfs_item *item; |
| 1568 | struct btrfs_inode_ref *iref; |
| 1569 | struct btrfs_key found_key; |
| 1570 | |
Jan Schmidt | aefc1eb | 2012-04-13 12:28:00 +0200 | [diff] [blame] | 1571 | while (!ret) { |
Jan Schmidt | b916a59 | 2012-04-13 12:28:08 +0200 | [diff] [blame] | 1572 | path->leave_spinning = 1; |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1573 | ret = inode_ref_info(inum, parent ? parent+1 : 0, fs_root, path, |
Mark Fasheh | d24bec3 | 2012-08-08 11:33:54 -0700 | [diff] [blame] | 1574 | &found_key); |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1575 | if (ret < 0) |
| 1576 | break; |
| 1577 | if (ret) { |
| 1578 | ret = found ? 0 : -ENOENT; |
| 1579 | break; |
| 1580 | } |
| 1581 | ++found; |
| 1582 | |
| 1583 | parent = found_key.offset; |
| 1584 | slot = path->slots[0]; |
| 1585 | eb = path->nodes[0]; |
| 1586 | /* make sure we can use eb after releasing the path */ |
| 1587 | atomic_inc(&eb->refs); |
Jan Schmidt | b916a59 | 2012-04-13 12:28:08 +0200 | [diff] [blame] | 1588 | btrfs_tree_read_lock(eb); |
| 1589 | btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK); |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1590 | btrfs_release_path(path); |
| 1591 | |
Ross Kirk | dd3cc16 | 2013-09-16 15:58:09 +0100 | [diff] [blame] | 1592 | item = btrfs_item_nr(slot); |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1593 | iref = btrfs_item_ptr(eb, slot, struct btrfs_inode_ref); |
| 1594 | |
| 1595 | for (cur = 0; cur < btrfs_item_size(eb, item); cur += len) { |
| 1596 | name_len = btrfs_inode_ref_name_len(eb, iref); |
| 1597 | /* path must be released before calling iterate()! */ |
Jan Schmidt | 4692cf5 | 2011-12-02 14:56:41 +0100 | [diff] [blame] | 1598 | pr_debug("following ref at offset %u for inode %llu in " |
Geert Uytterhoeven | c1c9ff7 | 2013-08-20 13:20:07 +0200 | [diff] [blame] | 1599 | "tree %llu\n", cur, found_key.objectid, |
| 1600 | fs_root->objectid); |
Mark Fasheh | d24bec3 | 2012-08-08 11:33:54 -0700 | [diff] [blame] | 1601 | ret = iterate(parent, name_len, |
| 1602 | (unsigned long)(iref + 1), eb, ctx); |
Jan Schmidt | aefc1eb | 2012-04-13 12:28:00 +0200 | [diff] [blame] | 1603 | if (ret) |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1604 | break; |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1605 | len = sizeof(*iref) + name_len; |
| 1606 | iref = (struct btrfs_inode_ref *)((char *)iref + len); |
| 1607 | } |
Jan Schmidt | b916a59 | 2012-04-13 12:28:08 +0200 | [diff] [blame] | 1608 | btrfs_tree_read_unlock_blocking(eb); |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1609 | free_extent_buffer(eb); |
| 1610 | } |
| 1611 | |
| 1612 | btrfs_release_path(path); |
| 1613 | |
| 1614 | return ret; |
| 1615 | } |
| 1616 | |
Mark Fasheh | d24bec3 | 2012-08-08 11:33:54 -0700 | [diff] [blame] | 1617 | static int iterate_inode_extrefs(u64 inum, struct btrfs_root *fs_root, |
| 1618 | struct btrfs_path *path, |
| 1619 | iterate_irefs_t *iterate, void *ctx) |
| 1620 | { |
| 1621 | int ret; |
| 1622 | int slot; |
| 1623 | u64 offset = 0; |
| 1624 | u64 parent; |
| 1625 | int found = 0; |
| 1626 | struct extent_buffer *eb; |
| 1627 | struct btrfs_inode_extref *extref; |
| 1628 | struct extent_buffer *leaf; |
| 1629 | u32 item_size; |
| 1630 | u32 cur_offset; |
| 1631 | unsigned long ptr; |
| 1632 | |
| 1633 | while (1) { |
| 1634 | ret = btrfs_find_one_extref(fs_root, inum, offset, path, &extref, |
| 1635 | &offset); |
| 1636 | if (ret < 0) |
| 1637 | break; |
| 1638 | if (ret) { |
| 1639 | ret = found ? 0 : -ENOENT; |
| 1640 | break; |
| 1641 | } |
| 1642 | ++found; |
| 1643 | |
| 1644 | slot = path->slots[0]; |
| 1645 | eb = path->nodes[0]; |
| 1646 | /* make sure we can use eb after releasing the path */ |
| 1647 | atomic_inc(&eb->refs); |
| 1648 | |
| 1649 | btrfs_tree_read_lock(eb); |
| 1650 | btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK); |
| 1651 | btrfs_release_path(path); |
| 1652 | |
| 1653 | leaf = path->nodes[0]; |
Valentina Giusti | e94acd8 | 2013-11-04 22:34:28 +0100 | [diff] [blame] | 1654 | item_size = btrfs_item_size_nr(leaf, slot); |
| 1655 | ptr = btrfs_item_ptr_offset(leaf, slot); |
Mark Fasheh | d24bec3 | 2012-08-08 11:33:54 -0700 | [diff] [blame] | 1656 | cur_offset = 0; |
| 1657 | |
| 1658 | while (cur_offset < item_size) { |
| 1659 | u32 name_len; |
| 1660 | |
| 1661 | extref = (struct btrfs_inode_extref *)(ptr + cur_offset); |
| 1662 | parent = btrfs_inode_extref_parent(eb, extref); |
| 1663 | name_len = btrfs_inode_extref_name_len(eb, extref); |
| 1664 | ret = iterate(parent, name_len, |
| 1665 | (unsigned long)&extref->name, eb, ctx); |
| 1666 | if (ret) |
| 1667 | break; |
| 1668 | |
| 1669 | cur_offset += btrfs_inode_extref_name_len(leaf, extref); |
| 1670 | cur_offset += sizeof(*extref); |
| 1671 | } |
| 1672 | btrfs_tree_read_unlock_blocking(eb); |
| 1673 | free_extent_buffer(eb); |
| 1674 | |
| 1675 | offset++; |
| 1676 | } |
| 1677 | |
| 1678 | btrfs_release_path(path); |
| 1679 | |
| 1680 | return ret; |
| 1681 | } |
| 1682 | |
| 1683 | static int iterate_irefs(u64 inum, struct btrfs_root *fs_root, |
| 1684 | struct btrfs_path *path, iterate_irefs_t *iterate, |
| 1685 | void *ctx) |
| 1686 | { |
| 1687 | int ret; |
| 1688 | int found_refs = 0; |
| 1689 | |
| 1690 | ret = iterate_inode_refs(inum, fs_root, path, iterate, ctx); |
| 1691 | if (!ret) |
| 1692 | ++found_refs; |
| 1693 | else if (ret != -ENOENT) |
| 1694 | return ret; |
| 1695 | |
| 1696 | ret = iterate_inode_extrefs(inum, fs_root, path, iterate, ctx); |
| 1697 | if (ret == -ENOENT && found_refs) |
| 1698 | return 0; |
| 1699 | |
| 1700 | return ret; |
| 1701 | } |
| 1702 | |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1703 | /* |
| 1704 | * returns 0 if the path could be dumped (probably truncated) |
| 1705 | * returns <0 in case of an error |
| 1706 | */ |
Mark Fasheh | d24bec3 | 2012-08-08 11:33:54 -0700 | [diff] [blame] | 1707 | static int inode_to_path(u64 inum, u32 name_len, unsigned long name_off, |
| 1708 | struct extent_buffer *eb, void *ctx) |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1709 | { |
| 1710 | struct inode_fs_paths *ipath = ctx; |
| 1711 | char *fspath; |
| 1712 | char *fspath_min; |
| 1713 | int i = ipath->fspath->elem_cnt; |
| 1714 | const int s_ptr = sizeof(char *); |
| 1715 | u32 bytes_left; |
| 1716 | |
| 1717 | bytes_left = ipath->fspath->bytes_left > s_ptr ? |
| 1718 | ipath->fspath->bytes_left - s_ptr : 0; |
| 1719 | |
Chris Mason | 740c3d2 | 2011-11-02 15:48:34 -0400 | [diff] [blame] | 1720 | fspath_min = (char *)ipath->fspath->val + (i + 1) * s_ptr; |
Jan Schmidt | 96b5bd7 | 2012-10-15 08:30:45 +0000 | [diff] [blame] | 1721 | fspath = btrfs_ref_to_path(ipath->fs_root, ipath->btrfs_path, name_len, |
| 1722 | name_off, eb, inum, fspath_min, bytes_left); |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1723 | if (IS_ERR(fspath)) |
| 1724 | return PTR_ERR(fspath); |
| 1725 | |
| 1726 | if (fspath > fspath_min) { |
Jeff Mahoney | 745c4d8 | 2011-11-20 07:31:57 -0500 | [diff] [blame] | 1727 | ipath->fspath->val[i] = (u64)(unsigned long)fspath; |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1728 | ++ipath->fspath->elem_cnt; |
| 1729 | ipath->fspath->bytes_left = fspath - fspath_min; |
| 1730 | } else { |
| 1731 | ++ipath->fspath->elem_missed; |
| 1732 | ipath->fspath->bytes_missing += fspath_min - fspath; |
| 1733 | ipath->fspath->bytes_left = 0; |
| 1734 | } |
| 1735 | |
| 1736 | return 0; |
| 1737 | } |
| 1738 | |
| 1739 | /* |
| 1740 | * this dumps all file system paths to the inode into the ipath struct, provided |
| 1741 | * is has been created large enough. each path is zero-terminated and accessed |
Chris Mason | 740c3d2 | 2011-11-02 15:48:34 -0400 | [diff] [blame] | 1742 | * from ipath->fspath->val[i]. |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1743 | * when it returns, there are ipath->fspath->elem_cnt number of paths available |
Chris Mason | 740c3d2 | 2011-11-02 15:48:34 -0400 | [diff] [blame] | 1744 | * in ipath->fspath->val[]. when the allocated space wasn't sufficient, the |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1745 | * number of missed paths in recored in ipath->fspath->elem_missed, otherwise, |
| 1746 | * it's zero. ipath->fspath->bytes_missing holds the number of bytes that would |
| 1747 | * have been needed to return all paths. |
| 1748 | */ |
| 1749 | int paths_from_inode(u64 inum, struct inode_fs_paths *ipath) |
| 1750 | { |
| 1751 | return iterate_irefs(inum, ipath->fs_root, ipath->btrfs_path, |
Mark Fasheh | d24bec3 | 2012-08-08 11:33:54 -0700 | [diff] [blame] | 1752 | inode_to_path, ipath); |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1753 | } |
| 1754 | |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1755 | struct btrfs_data_container *init_data_container(u32 total_bytes) |
| 1756 | { |
| 1757 | struct btrfs_data_container *data; |
| 1758 | size_t alloc_bytes; |
| 1759 | |
| 1760 | alloc_bytes = max_t(size_t, total_bytes, sizeof(*data)); |
Liu Bo | 425d17a | 2012-09-07 20:01:30 -0600 | [diff] [blame] | 1761 | data = vmalloc(alloc_bytes); |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1762 | if (!data) |
| 1763 | return ERR_PTR(-ENOMEM); |
| 1764 | |
| 1765 | if (total_bytes >= sizeof(*data)) { |
| 1766 | data->bytes_left = total_bytes - sizeof(*data); |
| 1767 | data->bytes_missing = 0; |
| 1768 | } else { |
| 1769 | data->bytes_missing = sizeof(*data) - total_bytes; |
| 1770 | data->bytes_left = 0; |
| 1771 | } |
| 1772 | |
| 1773 | data->elem_cnt = 0; |
| 1774 | data->elem_missed = 0; |
| 1775 | |
| 1776 | return data; |
| 1777 | } |
| 1778 | |
| 1779 | /* |
| 1780 | * allocates space to return multiple file system paths for an inode. |
| 1781 | * total_bytes to allocate are passed, note that space usable for actual path |
| 1782 | * information will be total_bytes - sizeof(struct inode_fs_paths). |
| 1783 | * the returned pointer must be freed with free_ipath() in the end. |
| 1784 | */ |
| 1785 | struct inode_fs_paths *init_ipath(s32 total_bytes, struct btrfs_root *fs_root, |
| 1786 | struct btrfs_path *path) |
| 1787 | { |
| 1788 | struct inode_fs_paths *ifp; |
| 1789 | struct btrfs_data_container *fspath; |
| 1790 | |
| 1791 | fspath = init_data_container(total_bytes); |
| 1792 | if (IS_ERR(fspath)) |
| 1793 | return (void *)fspath; |
| 1794 | |
| 1795 | ifp = kmalloc(sizeof(*ifp), GFP_NOFS); |
| 1796 | if (!ifp) { |
| 1797 | kfree(fspath); |
| 1798 | return ERR_PTR(-ENOMEM); |
| 1799 | } |
| 1800 | |
| 1801 | ifp->btrfs_path = path; |
| 1802 | ifp->fspath = fspath; |
| 1803 | ifp->fs_root = fs_root; |
| 1804 | |
| 1805 | return ifp; |
| 1806 | } |
| 1807 | |
| 1808 | void free_ipath(struct inode_fs_paths *ipath) |
| 1809 | { |
Jesper Juhl | 4735fb2 | 2012-04-12 22:47:52 +0200 | [diff] [blame] | 1810 | if (!ipath) |
| 1811 | return; |
Liu Bo | 425d17a | 2012-09-07 20:01:30 -0600 | [diff] [blame] | 1812 | vfree(ipath->fspath); |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1813 | kfree(ipath); |
| 1814 | } |