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 | |
Josef Bacik | dc046b1 | 2014-09-10 16:20:45 -0400 | [diff] [blame] | 28 | /* Just an arbitrary number so we can be sure this happened */ |
| 29 | #define BACKREF_FOUND_SHARED 6 |
| 30 | |
Jan Schmidt | 976b190 | 2012-05-17 16:43:03 +0200 | [diff] [blame] | 31 | struct extent_inode_elem { |
| 32 | u64 inum; |
| 33 | u64 offset; |
| 34 | struct extent_inode_elem *next; |
| 35 | }; |
| 36 | |
| 37 | static int check_extent_in_eb(struct btrfs_key *key, struct extent_buffer *eb, |
| 38 | struct btrfs_file_extent_item *fi, |
| 39 | u64 extent_item_pos, |
| 40 | struct extent_inode_elem **eie) |
| 41 | { |
Josef Bacik | 8ca15e0 | 2013-07-05 13:58:19 -0400 | [diff] [blame] | 42 | u64 offset = 0; |
Jan Schmidt | 976b190 | 2012-05-17 16:43:03 +0200 | [diff] [blame] | 43 | struct extent_inode_elem *e; |
| 44 | |
Josef Bacik | 8ca15e0 | 2013-07-05 13:58:19 -0400 | [diff] [blame] | 45 | if (!btrfs_file_extent_compression(eb, fi) && |
| 46 | !btrfs_file_extent_encryption(eb, fi) && |
| 47 | !btrfs_file_extent_other_encoding(eb, fi)) { |
| 48 | u64 data_offset; |
| 49 | u64 data_len; |
Jan Schmidt | 976b190 | 2012-05-17 16:43:03 +0200 | [diff] [blame] | 50 | |
Josef Bacik | 8ca15e0 | 2013-07-05 13:58:19 -0400 | [diff] [blame] | 51 | data_offset = btrfs_file_extent_offset(eb, fi); |
| 52 | data_len = btrfs_file_extent_num_bytes(eb, fi); |
| 53 | |
| 54 | if (extent_item_pos < data_offset || |
| 55 | extent_item_pos >= data_offset + data_len) |
| 56 | return 1; |
| 57 | offset = extent_item_pos - data_offset; |
| 58 | } |
Jan Schmidt | 976b190 | 2012-05-17 16:43:03 +0200 | [diff] [blame] | 59 | |
| 60 | e = kmalloc(sizeof(*e), GFP_NOFS); |
| 61 | if (!e) |
| 62 | return -ENOMEM; |
| 63 | |
| 64 | e->next = *eie; |
| 65 | e->inum = key->objectid; |
Josef Bacik | 8ca15e0 | 2013-07-05 13:58:19 -0400 | [diff] [blame] | 66 | e->offset = key->offset + offset; |
Jan Schmidt | 976b190 | 2012-05-17 16:43:03 +0200 | [diff] [blame] | 67 | *eie = e; |
| 68 | |
| 69 | return 0; |
| 70 | } |
| 71 | |
Wang Shilong | f05c474 | 2014-01-28 19:13:38 +0800 | [diff] [blame] | 72 | static void free_inode_elem_list(struct extent_inode_elem *eie) |
| 73 | { |
| 74 | struct extent_inode_elem *eie_next; |
| 75 | |
| 76 | for (; eie; eie = eie_next) { |
| 77 | eie_next = eie->next; |
| 78 | kfree(eie); |
| 79 | } |
| 80 | } |
| 81 | |
Jan Schmidt | 976b190 | 2012-05-17 16:43:03 +0200 | [diff] [blame] | 82 | static int find_extent_in_eb(struct extent_buffer *eb, u64 wanted_disk_byte, |
| 83 | u64 extent_item_pos, |
| 84 | struct extent_inode_elem **eie) |
| 85 | { |
| 86 | u64 disk_byte; |
| 87 | struct btrfs_key key; |
| 88 | struct btrfs_file_extent_item *fi; |
| 89 | int slot; |
| 90 | int nritems; |
| 91 | int extent_type; |
| 92 | int ret; |
| 93 | |
| 94 | /* |
| 95 | * from the shared data ref, we only have the leaf but we need |
| 96 | * the key. thus, we must look into all items and see that we |
| 97 | * find one (some) with a reference to our extent item. |
| 98 | */ |
| 99 | nritems = btrfs_header_nritems(eb); |
| 100 | for (slot = 0; slot < nritems; ++slot) { |
| 101 | btrfs_item_key_to_cpu(eb, &key, slot); |
| 102 | if (key.type != BTRFS_EXTENT_DATA_KEY) |
| 103 | continue; |
| 104 | fi = btrfs_item_ptr(eb, slot, struct btrfs_file_extent_item); |
| 105 | extent_type = btrfs_file_extent_type(eb, fi); |
| 106 | if (extent_type == BTRFS_FILE_EXTENT_INLINE) |
| 107 | continue; |
| 108 | /* don't skip BTRFS_FILE_EXTENT_PREALLOC, we can handle that */ |
| 109 | disk_byte = btrfs_file_extent_disk_bytenr(eb, fi); |
| 110 | if (disk_byte != wanted_disk_byte) |
| 111 | continue; |
| 112 | |
| 113 | ret = check_extent_in_eb(&key, eb, fi, extent_item_pos, eie); |
| 114 | if (ret < 0) |
| 115 | return ret; |
| 116 | } |
| 117 | |
| 118 | return 0; |
| 119 | } |
| 120 | |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 121 | /* |
| 122 | * this structure records all encountered refs on the way up to the root |
| 123 | */ |
| 124 | struct __prelim_ref { |
| 125 | struct list_head list; |
| 126 | u64 root_id; |
Jan Schmidt | d5c88b7 | 2012-05-15 17:55:51 +0200 | [diff] [blame] | 127 | struct btrfs_key key_for_search; |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 128 | int level; |
| 129 | int count; |
Jan Schmidt | 3301958 | 2012-05-30 18:05:21 +0200 | [diff] [blame] | 130 | struct extent_inode_elem *inode_list; |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 131 | u64 parent; |
| 132 | u64 wanted_disk_byte; |
| 133 | }; |
| 134 | |
Wang Shilong | b9e9a6c | 2013-08-09 13:25:36 +0800 | [diff] [blame] | 135 | static struct kmem_cache *btrfs_prelim_ref_cache; |
| 136 | |
| 137 | int __init btrfs_prelim_ref_init(void) |
| 138 | { |
| 139 | btrfs_prelim_ref_cache = kmem_cache_create("btrfs_prelim_ref", |
| 140 | sizeof(struct __prelim_ref), |
| 141 | 0, |
| 142 | SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, |
| 143 | NULL); |
| 144 | if (!btrfs_prelim_ref_cache) |
| 145 | return -ENOMEM; |
| 146 | return 0; |
| 147 | } |
| 148 | |
| 149 | void btrfs_prelim_ref_exit(void) |
| 150 | { |
Kinglong Mee | 5598e90 | 2016-01-29 21:36:35 +0800 | [diff] [blame] | 151 | kmem_cache_destroy(btrfs_prelim_ref_cache); |
Wang Shilong | b9e9a6c | 2013-08-09 13:25:36 +0800 | [diff] [blame] | 152 | } |
| 153 | |
Jan Schmidt | d5c88b7 | 2012-05-15 17:55:51 +0200 | [diff] [blame] | 154 | /* |
| 155 | * the rules for all callers of this function are: |
| 156 | * - obtaining the parent is the goal |
| 157 | * - if you add a key, you must know that it is a correct key |
| 158 | * - if you cannot add the parent or a correct key, then we will look into the |
| 159 | * block later to set a correct key |
| 160 | * |
| 161 | * delayed refs |
| 162 | * ============ |
| 163 | * backref type | shared | indirect | shared | indirect |
| 164 | * information | tree | tree | data | data |
| 165 | * --------------------+--------+----------+--------+---------- |
| 166 | * parent logical | y | - | - | - |
| 167 | * key to resolve | - | y | y | y |
| 168 | * tree block logical | - | - | - | - |
| 169 | * root for resolving | y | y | y | y |
| 170 | * |
| 171 | * - column 1: we've the parent -> done |
| 172 | * - column 2, 3, 4: we use the key to find the parent |
| 173 | * |
| 174 | * on disk refs (inline or keyed) |
| 175 | * ============================== |
| 176 | * backref type | shared | indirect | shared | indirect |
| 177 | * information | tree | tree | data | data |
| 178 | * --------------------+--------+----------+--------+---------- |
| 179 | * parent logical | y | - | y | - |
| 180 | * key to resolve | - | - | - | y |
| 181 | * tree block logical | y | y | y | y |
| 182 | * root for resolving | - | y | y | y |
| 183 | * |
| 184 | * - column 1, 3: we've the parent -> done |
| 185 | * - column 2: we take the first key from the block to find the parent |
| 186 | * (see __add_missing_keys) |
| 187 | * - column 4: we use the key to find the parent |
| 188 | * |
| 189 | * additional information that's available but not required to find the parent |
| 190 | * block might help in merging entries to gain some speed. |
| 191 | */ |
| 192 | |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 193 | static int __add_prelim_ref(struct list_head *head, u64 root_id, |
Jan Schmidt | d5c88b7 | 2012-05-15 17:55:51 +0200 | [diff] [blame] | 194 | struct btrfs_key *key, int level, |
Wang Shilong | 742916b | 2013-08-06 10:29:54 +0800 | [diff] [blame] | 195 | u64 parent, u64 wanted_disk_byte, int count, |
| 196 | gfp_t gfp_mask) |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 197 | { |
| 198 | struct __prelim_ref *ref; |
| 199 | |
Liu Bo | 48ec473 | 2013-10-30 13:25:24 +0800 | [diff] [blame] | 200 | if (root_id == BTRFS_DATA_RELOC_TREE_OBJECTID) |
| 201 | return 0; |
| 202 | |
Wang Shilong | b9e9a6c | 2013-08-09 13:25:36 +0800 | [diff] [blame] | 203 | ref = kmem_cache_alloc(btrfs_prelim_ref_cache, gfp_mask); |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 204 | if (!ref) |
| 205 | return -ENOMEM; |
| 206 | |
| 207 | ref->root_id = root_id; |
Filipe Manana | d658910 | 2015-07-29 17:21:17 +0100 | [diff] [blame] | 208 | if (key) { |
Jan Schmidt | d5c88b7 | 2012-05-15 17:55:51 +0200 | [diff] [blame] | 209 | ref->key_for_search = *key; |
Filipe Manana | d658910 | 2015-07-29 17:21:17 +0100 | [diff] [blame] | 210 | /* |
| 211 | * We can often find data backrefs with an offset that is too |
| 212 | * large (>= LLONG_MAX, maximum allowed file offset) due to |
| 213 | * underflows when subtracting a file's offset with the data |
| 214 | * offset of its corresponding extent data item. This can |
| 215 | * happen for example in the clone ioctl. |
| 216 | * So if we detect such case we set the search key's offset to |
| 217 | * zero to make sure we will find the matching file extent item |
| 218 | * at add_all_parents(), otherwise we will miss it because the |
| 219 | * offset taken form the backref is much larger then the offset |
| 220 | * of the file extent item. This can make us scan a very large |
| 221 | * number of file extent items, but at least it will not make |
| 222 | * us miss any. |
| 223 | * This is an ugly workaround for a behaviour that should have |
| 224 | * never existed, but it does and a fix for the clone ioctl |
| 225 | * would touch a lot of places, cause backwards incompatibility |
| 226 | * and would not fix the problem for extents cloned with older |
| 227 | * kernels. |
| 228 | */ |
| 229 | if (ref->key_for_search.type == BTRFS_EXTENT_DATA_KEY && |
| 230 | ref->key_for_search.offset >= LLONG_MAX) |
| 231 | ref->key_for_search.offset = 0; |
| 232 | } else { |
Jan Schmidt | d5c88b7 | 2012-05-15 17:55:51 +0200 | [diff] [blame] | 233 | memset(&ref->key_for_search, 0, sizeof(ref->key_for_search)); |
Filipe Manana | d658910 | 2015-07-29 17:21:17 +0100 | [diff] [blame] | 234 | } |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 235 | |
Jan Schmidt | 3301958 | 2012-05-30 18:05:21 +0200 | [diff] [blame] | 236 | ref->inode_list = NULL; |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 237 | ref->level = level; |
| 238 | ref->count = count; |
| 239 | ref->parent = parent; |
| 240 | ref->wanted_disk_byte = wanted_disk_byte; |
| 241 | list_add_tail(&ref->list, head); |
| 242 | |
| 243 | return 0; |
| 244 | } |
| 245 | |
| 246 | static int add_all_parents(struct btrfs_root *root, struct btrfs_path *path, |
Josef Bacik | 7ef81ac | 2014-01-24 14:05:42 -0500 | [diff] [blame] | 247 | struct ulist *parents, struct __prelim_ref *ref, |
Josef Bacik | 4485386 | 2014-03-19 13:35:14 -0400 | [diff] [blame] | 248 | int level, u64 time_seq, const u64 *extent_item_pos, |
| 249 | u64 total_refs) |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 250 | { |
Alexander Block | 69bca40 | 2012-06-19 07:42:26 -0600 | [diff] [blame] | 251 | int ret = 0; |
| 252 | int slot; |
| 253 | struct extent_buffer *eb; |
| 254 | struct btrfs_key key; |
Josef Bacik | 7ef81ac | 2014-01-24 14:05:42 -0500 | [diff] [blame] | 255 | struct btrfs_key *key_for_search = &ref->key_for_search; |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 256 | struct btrfs_file_extent_item *fi; |
Josef Bacik | ed8c491 | 2013-07-05 14:03:47 -0400 | [diff] [blame] | 257 | struct extent_inode_elem *eie = NULL, *old = NULL; |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 258 | u64 disk_byte; |
Josef Bacik | 7ef81ac | 2014-01-24 14:05:42 -0500 | [diff] [blame] | 259 | u64 wanted_disk_byte = ref->wanted_disk_byte; |
| 260 | u64 count = 0; |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 261 | |
Alexander Block | 69bca40 | 2012-06-19 07:42:26 -0600 | [diff] [blame] | 262 | if (level != 0) { |
| 263 | eb = path->nodes[level]; |
| 264 | ret = ulist_add(parents, eb->start, 0, GFP_NOFS); |
Jan Schmidt | 3301958 | 2012-05-30 18:05:21 +0200 | [diff] [blame] | 265 | if (ret < 0) |
| 266 | return ret; |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 267 | return 0; |
Alexander Block | 69bca40 | 2012-06-19 07:42:26 -0600 | [diff] [blame] | 268 | } |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 269 | |
| 270 | /* |
Alexander Block | 69bca40 | 2012-06-19 07:42:26 -0600 | [diff] [blame] | 271 | * We normally enter this function with the path already pointing to |
| 272 | * the first item to check. But sometimes, we may enter it with |
| 273 | * 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] | 274 | */ |
Qu Wenruo | 21633fc | 2015-04-16 14:54:50 +0800 | [diff] [blame] | 275 | if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) { |
| 276 | if (time_seq == (u64)-1) |
| 277 | ret = btrfs_next_leaf(root, path); |
| 278 | else |
| 279 | ret = btrfs_next_old_leaf(root, path, time_seq); |
| 280 | } |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 281 | |
Josef Bacik | 4485386 | 2014-03-19 13:35:14 -0400 | [diff] [blame] | 282 | while (!ret && count < total_refs) { |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 283 | eb = path->nodes[0]; |
Alexander Block | 69bca40 | 2012-06-19 07:42:26 -0600 | [diff] [blame] | 284 | slot = path->slots[0]; |
| 285 | |
| 286 | btrfs_item_key_to_cpu(eb, &key, slot); |
| 287 | |
| 288 | if (key.objectid != key_for_search->objectid || |
| 289 | key.type != BTRFS_EXTENT_DATA_KEY) |
| 290 | break; |
| 291 | |
| 292 | fi = btrfs_item_ptr(eb, slot, struct btrfs_file_extent_item); |
| 293 | disk_byte = btrfs_file_extent_disk_bytenr(eb, fi); |
| 294 | |
| 295 | if (disk_byte == wanted_disk_byte) { |
| 296 | eie = NULL; |
Josef Bacik | ed8c491 | 2013-07-05 14:03:47 -0400 | [diff] [blame] | 297 | old = NULL; |
Josef Bacik | 7ef81ac | 2014-01-24 14:05:42 -0500 | [diff] [blame] | 298 | count++; |
Alexander Block | 69bca40 | 2012-06-19 07:42:26 -0600 | [diff] [blame] | 299 | if (extent_item_pos) { |
| 300 | ret = check_extent_in_eb(&key, eb, fi, |
| 301 | *extent_item_pos, |
| 302 | &eie); |
| 303 | if (ret < 0) |
| 304 | break; |
| 305 | } |
Josef Bacik | ed8c491 | 2013-07-05 14:03:47 -0400 | [diff] [blame] | 306 | if (ret > 0) |
| 307 | goto next; |
Takashi Iwai | 4eb1f66 | 2014-07-28 10:57:04 +0200 | [diff] [blame] | 308 | ret = ulist_add_merge_ptr(parents, eb->start, |
| 309 | eie, (void **)&old, GFP_NOFS); |
Josef Bacik | ed8c491 | 2013-07-05 14:03:47 -0400 | [diff] [blame] | 310 | if (ret < 0) |
| 311 | break; |
| 312 | if (!ret && extent_item_pos) { |
| 313 | while (old->next) |
| 314 | old = old->next; |
| 315 | old->next = eie; |
Alexander Block | 69bca40 | 2012-06-19 07:42:26 -0600 | [diff] [blame] | 316 | } |
Wang Shilong | f05c474 | 2014-01-28 19:13:38 +0800 | [diff] [blame] | 317 | eie = NULL; |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 318 | } |
Josef Bacik | ed8c491 | 2013-07-05 14:03:47 -0400 | [diff] [blame] | 319 | next: |
Qu Wenruo | 21633fc | 2015-04-16 14:54:50 +0800 | [diff] [blame] | 320 | if (time_seq == (u64)-1) |
| 321 | ret = btrfs_next_item(root, path); |
| 322 | else |
| 323 | ret = btrfs_next_old_item(root, path, time_seq); |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 324 | } |
| 325 | |
Alexander Block | 69bca40 | 2012-06-19 07:42:26 -0600 | [diff] [blame] | 326 | if (ret > 0) |
| 327 | ret = 0; |
Wang Shilong | f05c474 | 2014-01-28 19:13:38 +0800 | [diff] [blame] | 328 | else if (ret < 0) |
| 329 | free_inode_elem_list(eie); |
Alexander Block | 69bca40 | 2012-06-19 07:42:26 -0600 | [diff] [blame] | 330 | return ret; |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 331 | } |
| 332 | |
| 333 | /* |
| 334 | * resolve an indirect backref in the form (root_id, key, level) |
| 335 | * to a logical address |
| 336 | */ |
| 337 | static int __resolve_indirect_ref(struct btrfs_fs_info *fs_info, |
Josef Bacik | da61d31 | 2013-06-12 16:20:08 -0400 | [diff] [blame] | 338 | struct btrfs_path *path, u64 time_seq, |
| 339 | struct __prelim_ref *ref, |
| 340 | struct ulist *parents, |
Josef Bacik | 4485386 | 2014-03-19 13:35:14 -0400 | [diff] [blame] | 341 | const u64 *extent_item_pos, u64 total_refs) |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 342 | { |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 343 | struct btrfs_root *root; |
| 344 | struct btrfs_key root_key; |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 345 | struct extent_buffer *eb; |
| 346 | int ret = 0; |
| 347 | int root_level; |
| 348 | int level = ref->level; |
Wang Shilong | 538f72cd | 2014-01-23 13:47:48 +0800 | [diff] [blame] | 349 | int index; |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 350 | |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 351 | root_key.objectid = ref->root_id; |
| 352 | root_key.type = BTRFS_ROOT_ITEM_KEY; |
| 353 | root_key.offset = (u64)-1; |
Wang Shilong | 538f72cd | 2014-01-23 13:47:48 +0800 | [diff] [blame] | 354 | |
| 355 | index = srcu_read_lock(&fs_info->subvol_srcu); |
| 356 | |
Josef Bacik | 2d9e977 | 2015-11-05 14:37:58 -0800 | [diff] [blame] | 357 | root = btrfs_get_fs_root(fs_info, &root_key, false); |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 358 | if (IS_ERR(root)) { |
Wang Shilong | 538f72cd | 2014-01-23 13:47:48 +0800 | [diff] [blame] | 359 | srcu_read_unlock(&fs_info->subvol_srcu, index); |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 360 | ret = PTR_ERR(root); |
| 361 | goto out; |
| 362 | } |
| 363 | |
Josef Bacik | d9ee522 | 2015-10-05 10:35:29 -0400 | [diff] [blame] | 364 | if (btrfs_test_is_dummy_root(root)) { |
| 365 | srcu_read_unlock(&fs_info->subvol_srcu, index); |
| 366 | ret = -ENOENT; |
| 367 | goto out; |
| 368 | } |
| 369 | |
Josef Bacik | 9e351cc | 2014-03-13 15:42:13 -0400 | [diff] [blame] | 370 | if (path->search_commit_root) |
| 371 | root_level = btrfs_header_level(root->commit_root); |
Qu Wenruo | 21633fc | 2015-04-16 14:54:50 +0800 | [diff] [blame] | 372 | else if (time_seq == (u64)-1) |
| 373 | root_level = btrfs_header_level(root->node); |
Josef Bacik | 9e351cc | 2014-03-13 15:42:13 -0400 | [diff] [blame] | 374 | else |
| 375 | root_level = btrfs_old_root_level(root, time_seq); |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 376 | |
Wang Shilong | 538f72cd | 2014-01-23 13:47:48 +0800 | [diff] [blame] | 377 | if (root_level + 1 == level) { |
| 378 | srcu_read_unlock(&fs_info->subvol_srcu, index); |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 379 | goto out; |
Wang Shilong | 538f72cd | 2014-01-23 13:47:48 +0800 | [diff] [blame] | 380 | } |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 381 | |
| 382 | path->lowest_level = level; |
Qu Wenruo | 21633fc | 2015-04-16 14:54:50 +0800 | [diff] [blame] | 383 | if (time_seq == (u64)-1) |
| 384 | ret = btrfs_search_slot(NULL, root, &ref->key_for_search, path, |
| 385 | 0, 0); |
| 386 | else |
| 387 | ret = btrfs_search_old_slot(root, &ref->key_for_search, path, |
| 388 | time_seq); |
Wang Shilong | 538f72cd | 2014-01-23 13:47:48 +0800 | [diff] [blame] | 389 | |
| 390 | /* root node has been locked, we can release @subvol_srcu safely here */ |
| 391 | srcu_read_unlock(&fs_info->subvol_srcu, index); |
| 392 | |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 393 | pr_debug("search slot in root %llu (level %d, ref count %d) returned " |
| 394 | "%d for key (%llu %u %llu)\n", |
Geert Uytterhoeven | c1c9ff7 | 2013-08-20 13:20:07 +0200 | [diff] [blame] | 395 | ref->root_id, level, ref->count, ret, |
| 396 | ref->key_for_search.objectid, ref->key_for_search.type, |
| 397 | ref->key_for_search.offset); |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 398 | if (ret < 0) |
| 399 | goto out; |
| 400 | |
| 401 | eb = path->nodes[level]; |
Jan Schmidt | 9345457 | 2012-06-27 15:23:09 +0200 | [diff] [blame] | 402 | while (!eb) { |
Dulshani Gunawardhana | fae7f21 | 2013-10-31 10:30:08 +0530 | [diff] [blame] | 403 | if (WARN_ON(!level)) { |
Jan Schmidt | 9345457 | 2012-06-27 15:23:09 +0200 | [diff] [blame] | 404 | ret = 1; |
| 405 | goto out; |
| 406 | } |
| 407 | level--; |
| 408 | eb = path->nodes[level]; |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 409 | } |
| 410 | |
Josef Bacik | 7ef81ac | 2014-01-24 14:05:42 -0500 | [diff] [blame] | 411 | ret = add_all_parents(root, path, parents, ref, level, time_seq, |
Josef Bacik | 4485386 | 2014-03-19 13:35:14 -0400 | [diff] [blame] | 412 | extent_item_pos, total_refs); |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 413 | out: |
Josef Bacik | da61d31 | 2013-06-12 16:20:08 -0400 | [diff] [blame] | 414 | path->lowest_level = 0; |
| 415 | btrfs_release_path(path); |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 416 | return ret; |
| 417 | } |
| 418 | |
| 419 | /* |
| 420 | * resolve all indirect backrefs from the list |
| 421 | */ |
| 422 | static int __resolve_indirect_refs(struct btrfs_fs_info *fs_info, |
Josef Bacik | da61d31 | 2013-06-12 16:20:08 -0400 | [diff] [blame] | 423 | struct btrfs_path *path, u64 time_seq, |
Jan Schmidt | 976b190 | 2012-05-17 16:43:03 +0200 | [diff] [blame] | 424 | struct list_head *head, |
Josef Bacik | dc046b1 | 2014-09-10 16:20:45 -0400 | [diff] [blame] | 425 | const u64 *extent_item_pos, u64 total_refs, |
| 426 | u64 root_objectid) |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 427 | { |
| 428 | int err; |
| 429 | int ret = 0; |
| 430 | struct __prelim_ref *ref; |
| 431 | struct __prelim_ref *ref_safe; |
| 432 | struct __prelim_ref *new_ref; |
| 433 | struct ulist *parents; |
| 434 | struct ulist_node *node; |
Jan Schmidt | cd1b413 | 2012-05-22 14:56:50 +0200 | [diff] [blame] | 435 | struct ulist_iterator uiter; |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 436 | |
| 437 | parents = ulist_alloc(GFP_NOFS); |
| 438 | if (!parents) |
| 439 | return -ENOMEM; |
| 440 | |
| 441 | /* |
| 442 | * _safe allows us to insert directly after the current item without |
| 443 | * iterating over the newly inserted items. |
| 444 | * we're also allowed to re-assign ref during iteration. |
| 445 | */ |
| 446 | list_for_each_entry_safe(ref, ref_safe, head, list) { |
| 447 | if (ref->parent) /* already direct */ |
| 448 | continue; |
| 449 | if (ref->count == 0) |
| 450 | continue; |
Josef Bacik | dc046b1 | 2014-09-10 16:20:45 -0400 | [diff] [blame] | 451 | if (root_objectid && ref->root_id != root_objectid) { |
| 452 | ret = BACKREF_FOUND_SHARED; |
| 453 | goto out; |
| 454 | } |
Josef Bacik | da61d31 | 2013-06-12 16:20:08 -0400 | [diff] [blame] | 455 | err = __resolve_indirect_ref(fs_info, path, time_seq, ref, |
Josef Bacik | 4485386 | 2014-03-19 13:35:14 -0400 | [diff] [blame] | 456 | parents, extent_item_pos, |
| 457 | total_refs); |
Wang Shilong | 95def2ed | 2014-01-23 13:47:49 +0800 | [diff] [blame] | 458 | /* |
| 459 | * we can only tolerate ENOENT,otherwise,we should catch error |
| 460 | * and return directly. |
| 461 | */ |
| 462 | if (err == -ENOENT) { |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 463 | continue; |
Wang Shilong | 95def2ed | 2014-01-23 13:47:49 +0800 | [diff] [blame] | 464 | } else if (err) { |
| 465 | ret = err; |
| 466 | goto out; |
| 467 | } |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 468 | |
| 469 | /* we put the first parent into the ref at hand */ |
Jan Schmidt | cd1b413 | 2012-05-22 14:56:50 +0200 | [diff] [blame] | 470 | ULIST_ITER_INIT(&uiter); |
| 471 | node = ulist_next(parents, &uiter); |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 472 | ref->parent = node ? node->val : 0; |
Jan Schmidt | 995e01b | 2012-08-13 02:52:38 -0600 | [diff] [blame] | 473 | ref->inode_list = node ? |
Stefan Behrens | 35a3621 | 2013-08-14 18:12:25 +0200 | [diff] [blame] | 474 | (struct extent_inode_elem *)(uintptr_t)node->aux : NULL; |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 475 | |
| 476 | /* additional parents require new refs being added here */ |
Jan Schmidt | cd1b413 | 2012-05-22 14:56:50 +0200 | [diff] [blame] | 477 | while ((node = ulist_next(parents, &uiter))) { |
Wang Shilong | b9e9a6c | 2013-08-09 13:25:36 +0800 | [diff] [blame] | 478 | new_ref = kmem_cache_alloc(btrfs_prelim_ref_cache, |
| 479 | GFP_NOFS); |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 480 | if (!new_ref) { |
| 481 | ret = -ENOMEM; |
Wang Shilong | e36902d | 2013-04-15 10:26:38 +0000 | [diff] [blame] | 482 | goto out; |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 483 | } |
| 484 | memcpy(new_ref, ref, sizeof(*ref)); |
| 485 | new_ref->parent = node->val; |
Jan Schmidt | 995e01b | 2012-08-13 02:52:38 -0600 | [diff] [blame] | 486 | new_ref->inode_list = (struct extent_inode_elem *) |
| 487 | (uintptr_t)node->aux; |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 488 | list_add(&new_ref->list, &ref->list); |
| 489 | } |
| 490 | ulist_reinit(parents); |
| 491 | } |
Wang Shilong | e36902d | 2013-04-15 10:26:38 +0000 | [diff] [blame] | 492 | out: |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 493 | ulist_free(parents); |
| 494 | return ret; |
| 495 | } |
| 496 | |
Jan Schmidt | d5c88b7 | 2012-05-15 17:55:51 +0200 | [diff] [blame] | 497 | static inline int ref_for_same_block(struct __prelim_ref *ref1, |
| 498 | struct __prelim_ref *ref2) |
| 499 | { |
| 500 | if (ref1->level != ref2->level) |
| 501 | return 0; |
| 502 | if (ref1->root_id != ref2->root_id) |
| 503 | return 0; |
| 504 | if (ref1->key_for_search.type != ref2->key_for_search.type) |
| 505 | return 0; |
| 506 | if (ref1->key_for_search.objectid != ref2->key_for_search.objectid) |
| 507 | return 0; |
| 508 | if (ref1->key_for_search.offset != ref2->key_for_search.offset) |
| 509 | return 0; |
| 510 | if (ref1->parent != ref2->parent) |
| 511 | return 0; |
| 512 | |
| 513 | return 1; |
| 514 | } |
| 515 | |
| 516 | /* |
| 517 | * read tree blocks and add keys where required. |
| 518 | */ |
| 519 | static int __add_missing_keys(struct btrfs_fs_info *fs_info, |
| 520 | struct list_head *head) |
| 521 | { |
Geliang Tang | a7ca422 | 2015-12-21 23:50:23 +0800 | [diff] [blame] | 522 | struct __prelim_ref *ref; |
Jan Schmidt | d5c88b7 | 2012-05-15 17:55:51 +0200 | [diff] [blame] | 523 | struct extent_buffer *eb; |
| 524 | |
Geliang Tang | a7ca422 | 2015-12-21 23:50:23 +0800 | [diff] [blame] | 525 | list_for_each_entry(ref, head, list) { |
Jan Schmidt | d5c88b7 | 2012-05-15 17:55:51 +0200 | [diff] [blame] | 526 | if (ref->parent) |
| 527 | continue; |
| 528 | if (ref->key_for_search.type) |
| 529 | continue; |
| 530 | BUG_ON(!ref->wanted_disk_byte); |
| 531 | eb = read_tree_block(fs_info->tree_root, ref->wanted_disk_byte, |
David Sterba | ce86cd5 | 2014-06-15 01:07:32 +0200 | [diff] [blame] | 532 | 0); |
Liu Bo | 64c043d | 2015-05-25 17:30:15 +0800 | [diff] [blame] | 533 | if (IS_ERR(eb)) { |
| 534 | return PTR_ERR(eb); |
| 535 | } else if (!extent_buffer_uptodate(eb)) { |
Josef Bacik | 416bc65 | 2013-04-23 14:17:42 -0400 | [diff] [blame] | 536 | free_extent_buffer(eb); |
| 537 | return -EIO; |
| 538 | } |
Jan Schmidt | d5c88b7 | 2012-05-15 17:55:51 +0200 | [diff] [blame] | 539 | btrfs_tree_read_lock(eb); |
| 540 | if (btrfs_header_level(eb) == 0) |
| 541 | btrfs_item_key_to_cpu(eb, &ref->key_for_search, 0); |
| 542 | else |
| 543 | btrfs_node_key_to_cpu(eb, &ref->key_for_search, 0); |
| 544 | btrfs_tree_read_unlock(eb); |
| 545 | free_extent_buffer(eb); |
| 546 | } |
| 547 | return 0; |
| 548 | } |
| 549 | |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 550 | /* |
Qu Wenruo | 00db646 | 2015-04-01 14:39:06 +0800 | [diff] [blame] | 551 | * merge backrefs and adjust counts accordingly |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 552 | * |
| 553 | * mode = 1: merge identical keys, if key is set |
Jan Schmidt | d5c88b7 | 2012-05-15 17:55:51 +0200 | [diff] [blame] | 554 | * FIXME: if we add more keys in __add_prelim_ref, we can merge more here. |
| 555 | * additionally, we could even add a key range for the blocks we |
| 556 | * looked into to merge even more (-> replace unresolved refs by those |
| 557 | * having a parent). |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 558 | * mode = 2: merge identical parents |
| 559 | */ |
Wang Shilong | 692206b | 2013-04-11 07:08:55 +0000 | [diff] [blame] | 560 | static void __merge_refs(struct list_head *head, int mode) |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 561 | { |
Geliang Tang | 8e21785 | 2016-01-13 22:08:01 +0800 | [diff] [blame] | 562 | struct __prelim_ref *pos1; |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 563 | |
Geliang Tang | 8e21785 | 2016-01-13 22:08:01 +0800 | [diff] [blame] | 564 | list_for_each_entry(pos1, head, list) { |
| 565 | struct __prelim_ref *pos2 = pos1, *tmp; |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 566 | |
Geliang Tang | 8e21785 | 2016-01-13 22:08:01 +0800 | [diff] [blame] | 567 | list_for_each_entry_safe_continue(pos2, tmp, head, list) { |
Dave Jones | 8f682f6 | 2016-01-28 15:28:35 -0500 | [diff] [blame] | 568 | struct __prelim_ref *ref1 = pos1, *ref2 = pos2; |
Alexander Block | 3ef5969 | 2012-11-08 21:27:24 +0000 | [diff] [blame] | 569 | struct extent_inode_elem *eie; |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 570 | |
Qu Wenruo | 00db646 | 2015-04-01 14:39:06 +0800 | [diff] [blame] | 571 | if (!ref_for_same_block(ref1, ref2)) |
| 572 | continue; |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 573 | if (mode == 1) { |
Dave Jones | 8f682f6 | 2016-01-28 15:28:35 -0500 | [diff] [blame] | 574 | if (!ref1->parent && ref2->parent) |
| 575 | swap(ref1, ref2); |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 576 | } else { |
| 577 | if (ref1->parent != ref2->parent) |
| 578 | continue; |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 579 | } |
Alexander Block | 3ef5969 | 2012-11-08 21:27:24 +0000 | [diff] [blame] | 580 | |
| 581 | eie = ref1->inode_list; |
| 582 | while (eie && eie->next) |
| 583 | eie = eie->next; |
| 584 | if (eie) |
| 585 | eie->next = ref2->inode_list; |
| 586 | else |
| 587 | ref1->inode_list = ref2->inode_list; |
| 588 | ref1->count += ref2->count; |
| 589 | |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 590 | list_del(&ref2->list); |
Wang Shilong | b9e9a6c | 2013-08-09 13:25:36 +0800 | [diff] [blame] | 591 | kmem_cache_free(btrfs_prelim_ref_cache, ref2); |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 592 | } |
| 593 | |
| 594 | } |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 595 | } |
| 596 | |
| 597 | /* |
| 598 | * add all currently queued delayed refs from this head whose seq nr is |
| 599 | * smaller or equal that seq to the list |
| 600 | */ |
| 601 | static int __add_delayed_refs(struct btrfs_delayed_ref_head *head, u64 seq, |
Josef Bacik | dc046b1 | 2014-09-10 16:20:45 -0400 | [diff] [blame] | 602 | struct list_head *prefs, u64 *total_refs, |
| 603 | u64 inum) |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 604 | { |
Qu Wenruo | c6fc245 | 2015-03-30 17:03:00 +0800 | [diff] [blame] | 605 | struct btrfs_delayed_ref_node *node; |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 606 | struct btrfs_delayed_extent_op *extent_op = head->extent_op; |
Jan Schmidt | d5c88b7 | 2012-05-15 17:55:51 +0200 | [diff] [blame] | 607 | struct btrfs_key key; |
| 608 | struct btrfs_key op_key = {0}; |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 609 | int sgn; |
Jan Schmidt | b1375d6 | 2012-01-26 15:01:11 -0500 | [diff] [blame] | 610 | int ret = 0; |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 611 | |
| 612 | if (extent_op && extent_op->update_key) |
Jan Schmidt | d5c88b7 | 2012-05-15 17:55:51 +0200 | [diff] [blame] | 613 | btrfs_disk_key_to_cpu(&op_key, &extent_op->key); |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 614 | |
Josef Bacik | d7df2c7 | 2014-01-23 09:21:38 -0500 | [diff] [blame] | 615 | spin_lock(&head->lock); |
Qu Wenruo | c6fc245 | 2015-03-30 17:03:00 +0800 | [diff] [blame] | 616 | list_for_each_entry(node, &head->ref_list, list) { |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 617 | if (node->seq > seq) |
| 618 | continue; |
| 619 | |
| 620 | switch (node->action) { |
| 621 | case BTRFS_ADD_DELAYED_EXTENT: |
| 622 | case BTRFS_UPDATE_DELAYED_HEAD: |
| 623 | WARN_ON(1); |
| 624 | continue; |
| 625 | case BTRFS_ADD_DELAYED_REF: |
| 626 | sgn = 1; |
| 627 | break; |
| 628 | case BTRFS_DROP_DELAYED_REF: |
| 629 | sgn = -1; |
| 630 | break; |
| 631 | default: |
| 632 | BUG_ON(1); |
| 633 | } |
Josef Bacik | 4485386 | 2014-03-19 13:35:14 -0400 | [diff] [blame] | 634 | *total_refs += (node->ref_mod * sgn); |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 635 | switch (node->type) { |
| 636 | case BTRFS_TREE_BLOCK_REF_KEY: { |
| 637 | struct btrfs_delayed_tree_ref *ref; |
| 638 | |
| 639 | ref = btrfs_delayed_node_to_tree_ref(node); |
Jan Schmidt | d5c88b7 | 2012-05-15 17:55:51 +0200 | [diff] [blame] | 640 | ret = __add_prelim_ref(prefs, ref->root, &op_key, |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 641 | ref->level + 1, 0, node->bytenr, |
Wang Shilong | 742916b | 2013-08-06 10:29:54 +0800 | [diff] [blame] | 642 | node->ref_mod * sgn, GFP_ATOMIC); |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 643 | break; |
| 644 | } |
| 645 | case BTRFS_SHARED_BLOCK_REF_KEY: { |
| 646 | struct btrfs_delayed_tree_ref *ref; |
| 647 | |
| 648 | ref = btrfs_delayed_node_to_tree_ref(node); |
Liu Bo | acdf898 | 2015-07-28 18:03:30 +0800 | [diff] [blame] | 649 | ret = __add_prelim_ref(prefs, 0, NULL, |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 650 | ref->level + 1, ref->parent, |
| 651 | node->bytenr, |
Wang Shilong | 742916b | 2013-08-06 10:29:54 +0800 | [diff] [blame] | 652 | node->ref_mod * sgn, GFP_ATOMIC); |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 653 | break; |
| 654 | } |
| 655 | case BTRFS_EXTENT_DATA_REF_KEY: { |
| 656 | struct btrfs_delayed_data_ref *ref; |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 657 | ref = btrfs_delayed_node_to_data_ref(node); |
| 658 | |
| 659 | key.objectid = ref->objectid; |
| 660 | key.type = BTRFS_EXTENT_DATA_KEY; |
| 661 | key.offset = ref->offset; |
Josef Bacik | dc046b1 | 2014-09-10 16:20:45 -0400 | [diff] [blame] | 662 | |
| 663 | /* |
| 664 | * Found a inum that doesn't match our known inum, we |
| 665 | * know it's shared. |
| 666 | */ |
| 667 | if (inum && ref->objectid != inum) { |
| 668 | ret = BACKREF_FOUND_SHARED; |
| 669 | break; |
| 670 | } |
| 671 | |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 672 | ret = __add_prelim_ref(prefs, ref->root, &key, 0, 0, |
| 673 | node->bytenr, |
Wang Shilong | 742916b | 2013-08-06 10:29:54 +0800 | [diff] [blame] | 674 | node->ref_mod * sgn, GFP_ATOMIC); |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 675 | break; |
| 676 | } |
| 677 | case BTRFS_SHARED_DATA_REF_KEY: { |
| 678 | struct btrfs_delayed_data_ref *ref; |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 679 | |
| 680 | ref = btrfs_delayed_node_to_data_ref(node); |
Liu Bo | acdf898 | 2015-07-28 18:03:30 +0800 | [diff] [blame] | 681 | ret = __add_prelim_ref(prefs, 0, NULL, 0, |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 682 | ref->parent, node->bytenr, |
Wang Shilong | 742916b | 2013-08-06 10:29:54 +0800 | [diff] [blame] | 683 | node->ref_mod * sgn, GFP_ATOMIC); |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 684 | break; |
| 685 | } |
| 686 | default: |
| 687 | WARN_ON(1); |
| 688 | } |
Wang Shilong | 1149ab6 | 2013-04-10 11:22:50 +0000 | [diff] [blame] | 689 | if (ret) |
Josef Bacik | d7df2c7 | 2014-01-23 09:21:38 -0500 | [diff] [blame] | 690 | break; |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 691 | } |
Josef Bacik | d7df2c7 | 2014-01-23 09:21:38 -0500 | [diff] [blame] | 692 | spin_unlock(&head->lock); |
| 693 | return ret; |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 694 | } |
| 695 | |
| 696 | /* |
| 697 | * add all inline backrefs for bytenr to the list |
| 698 | */ |
| 699 | static int __add_inline_refs(struct btrfs_fs_info *fs_info, |
| 700 | struct btrfs_path *path, u64 bytenr, |
Josef Bacik | 4485386 | 2014-03-19 13:35:14 -0400 | [diff] [blame] | 701 | int *info_level, struct list_head *prefs, |
Josef Bacik | dc046b1 | 2014-09-10 16:20:45 -0400 | [diff] [blame] | 702 | u64 *total_refs, u64 inum) |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 703 | { |
Jan Schmidt | b1375d6 | 2012-01-26 15:01:11 -0500 | [diff] [blame] | 704 | int ret = 0; |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 705 | int slot; |
| 706 | struct extent_buffer *leaf; |
| 707 | struct btrfs_key key; |
Josef Bacik | 261c84b | 2013-06-28 13:11:22 -0400 | [diff] [blame] | 708 | struct btrfs_key found_key; |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 709 | unsigned long ptr; |
| 710 | unsigned long end; |
| 711 | struct btrfs_extent_item *ei; |
| 712 | u64 flags; |
| 713 | u64 item_size; |
| 714 | |
| 715 | /* |
| 716 | * enumerate all inline refs |
| 717 | */ |
| 718 | leaf = path->nodes[0]; |
Jan Schmidt | dadcaf7 | 2012-05-22 13:43:25 +0200 | [diff] [blame] | 719 | slot = path->slots[0]; |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 720 | |
| 721 | item_size = btrfs_item_size_nr(leaf, slot); |
| 722 | BUG_ON(item_size < sizeof(*ei)); |
| 723 | |
| 724 | ei = btrfs_item_ptr(leaf, slot, struct btrfs_extent_item); |
| 725 | flags = btrfs_extent_flags(leaf, ei); |
Josef Bacik | 4485386 | 2014-03-19 13:35:14 -0400 | [diff] [blame] | 726 | *total_refs += btrfs_extent_refs(leaf, ei); |
Josef Bacik | 261c84b | 2013-06-28 13:11:22 -0400 | [diff] [blame] | 727 | btrfs_item_key_to_cpu(leaf, &found_key, slot); |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 728 | |
| 729 | ptr = (unsigned long)(ei + 1); |
| 730 | end = (unsigned long)ei + item_size; |
| 731 | |
Josef Bacik | 261c84b | 2013-06-28 13:11:22 -0400 | [diff] [blame] | 732 | if (found_key.type == BTRFS_EXTENT_ITEM_KEY && |
| 733 | flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) { |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 734 | struct btrfs_tree_block_info *info; |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 735 | |
| 736 | info = (struct btrfs_tree_block_info *)ptr; |
| 737 | *info_level = btrfs_tree_block_level(leaf, info); |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 738 | ptr += sizeof(struct btrfs_tree_block_info); |
| 739 | BUG_ON(ptr > end); |
Josef Bacik | 261c84b | 2013-06-28 13:11:22 -0400 | [diff] [blame] | 740 | } else if (found_key.type == BTRFS_METADATA_ITEM_KEY) { |
| 741 | *info_level = found_key.offset; |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 742 | } else { |
| 743 | BUG_ON(!(flags & BTRFS_EXTENT_FLAG_DATA)); |
| 744 | } |
| 745 | |
| 746 | while (ptr < end) { |
| 747 | struct btrfs_extent_inline_ref *iref; |
| 748 | u64 offset; |
| 749 | int type; |
| 750 | |
| 751 | iref = (struct btrfs_extent_inline_ref *)ptr; |
| 752 | type = btrfs_extent_inline_ref_type(leaf, iref); |
| 753 | offset = btrfs_extent_inline_ref_offset(leaf, iref); |
| 754 | |
| 755 | switch (type) { |
| 756 | case BTRFS_SHARED_BLOCK_REF_KEY: |
Jan Schmidt | d5c88b7 | 2012-05-15 17:55:51 +0200 | [diff] [blame] | 757 | ret = __add_prelim_ref(prefs, 0, NULL, |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 758 | *info_level + 1, offset, |
Wang Shilong | 742916b | 2013-08-06 10:29:54 +0800 | [diff] [blame] | 759 | bytenr, 1, GFP_NOFS); |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 760 | break; |
| 761 | case BTRFS_SHARED_DATA_REF_KEY: { |
| 762 | struct btrfs_shared_data_ref *sdref; |
| 763 | int count; |
| 764 | |
| 765 | sdref = (struct btrfs_shared_data_ref *)(iref + 1); |
| 766 | count = btrfs_shared_data_ref_count(leaf, sdref); |
| 767 | ret = __add_prelim_ref(prefs, 0, NULL, 0, offset, |
Wang Shilong | 742916b | 2013-08-06 10:29:54 +0800 | [diff] [blame] | 768 | bytenr, count, GFP_NOFS); |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 769 | break; |
| 770 | } |
| 771 | case BTRFS_TREE_BLOCK_REF_KEY: |
Jan Schmidt | d5c88b7 | 2012-05-15 17:55:51 +0200 | [diff] [blame] | 772 | ret = __add_prelim_ref(prefs, offset, NULL, |
| 773 | *info_level + 1, 0, |
Wang Shilong | 742916b | 2013-08-06 10:29:54 +0800 | [diff] [blame] | 774 | bytenr, 1, GFP_NOFS); |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 775 | break; |
| 776 | case BTRFS_EXTENT_DATA_REF_KEY: { |
| 777 | struct btrfs_extent_data_ref *dref; |
| 778 | int count; |
| 779 | u64 root; |
| 780 | |
| 781 | dref = (struct btrfs_extent_data_ref *)(&iref->offset); |
| 782 | count = btrfs_extent_data_ref_count(leaf, dref); |
| 783 | key.objectid = btrfs_extent_data_ref_objectid(leaf, |
| 784 | dref); |
| 785 | key.type = BTRFS_EXTENT_DATA_KEY; |
| 786 | key.offset = btrfs_extent_data_ref_offset(leaf, dref); |
Josef Bacik | dc046b1 | 2014-09-10 16:20:45 -0400 | [diff] [blame] | 787 | |
| 788 | if (inum && key.objectid != inum) { |
| 789 | ret = BACKREF_FOUND_SHARED; |
| 790 | break; |
| 791 | } |
| 792 | |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 793 | root = btrfs_extent_data_ref_root(leaf, dref); |
Jan Schmidt | d5c88b7 | 2012-05-15 17:55:51 +0200 | [diff] [blame] | 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; |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 803 | ptr += btrfs_extent_inline_ref_size(type); |
| 804 | } |
| 805 | |
| 806 | return 0; |
| 807 | } |
| 808 | |
| 809 | /* |
| 810 | * add all non-inline backrefs for bytenr to the list |
| 811 | */ |
| 812 | static int __add_keyed_refs(struct btrfs_fs_info *fs_info, |
| 813 | struct btrfs_path *path, u64 bytenr, |
Josef Bacik | dc046b1 | 2014-09-10 16:20:45 -0400 | [diff] [blame] | 814 | int info_level, struct list_head *prefs, u64 inum) |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 815 | { |
| 816 | struct btrfs_root *extent_root = fs_info->extent_root; |
| 817 | int ret; |
| 818 | int slot; |
| 819 | struct extent_buffer *leaf; |
| 820 | struct btrfs_key key; |
| 821 | |
| 822 | while (1) { |
| 823 | ret = btrfs_next_item(extent_root, path); |
| 824 | if (ret < 0) |
| 825 | break; |
| 826 | if (ret) { |
| 827 | ret = 0; |
| 828 | break; |
| 829 | } |
| 830 | |
| 831 | slot = path->slots[0]; |
| 832 | leaf = path->nodes[0]; |
| 833 | btrfs_item_key_to_cpu(leaf, &key, slot); |
| 834 | |
| 835 | if (key.objectid != bytenr) |
| 836 | break; |
| 837 | if (key.type < BTRFS_TREE_BLOCK_REF_KEY) |
| 838 | continue; |
| 839 | if (key.type > BTRFS_SHARED_DATA_REF_KEY) |
| 840 | break; |
| 841 | |
| 842 | switch (key.type) { |
| 843 | case BTRFS_SHARED_BLOCK_REF_KEY: |
Jan Schmidt | d5c88b7 | 2012-05-15 17:55:51 +0200 | [diff] [blame] | 844 | ret = __add_prelim_ref(prefs, 0, NULL, |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 845 | info_level + 1, key.offset, |
Wang Shilong | 742916b | 2013-08-06 10:29:54 +0800 | [diff] [blame] | 846 | bytenr, 1, GFP_NOFS); |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 847 | break; |
| 848 | case BTRFS_SHARED_DATA_REF_KEY: { |
| 849 | struct btrfs_shared_data_ref *sdref; |
| 850 | int count; |
| 851 | |
| 852 | sdref = btrfs_item_ptr(leaf, slot, |
| 853 | struct btrfs_shared_data_ref); |
| 854 | count = btrfs_shared_data_ref_count(leaf, sdref); |
| 855 | ret = __add_prelim_ref(prefs, 0, NULL, 0, key.offset, |
Wang Shilong | 742916b | 2013-08-06 10:29:54 +0800 | [diff] [blame] | 856 | bytenr, count, GFP_NOFS); |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 857 | break; |
| 858 | } |
| 859 | case BTRFS_TREE_BLOCK_REF_KEY: |
Jan Schmidt | d5c88b7 | 2012-05-15 17:55:51 +0200 | [diff] [blame] | 860 | ret = __add_prelim_ref(prefs, key.offset, NULL, |
| 861 | info_level + 1, 0, |
Wang Shilong | 742916b | 2013-08-06 10:29:54 +0800 | [diff] [blame] | 862 | bytenr, 1, GFP_NOFS); |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 863 | break; |
| 864 | case BTRFS_EXTENT_DATA_REF_KEY: { |
| 865 | struct btrfs_extent_data_ref *dref; |
| 866 | int count; |
| 867 | u64 root; |
| 868 | |
| 869 | dref = btrfs_item_ptr(leaf, slot, |
| 870 | struct btrfs_extent_data_ref); |
| 871 | count = btrfs_extent_data_ref_count(leaf, dref); |
| 872 | key.objectid = btrfs_extent_data_ref_objectid(leaf, |
| 873 | dref); |
| 874 | key.type = BTRFS_EXTENT_DATA_KEY; |
| 875 | key.offset = btrfs_extent_data_ref_offset(leaf, dref); |
Josef Bacik | dc046b1 | 2014-09-10 16:20:45 -0400 | [diff] [blame] | 876 | |
| 877 | if (inum && key.objectid != inum) { |
| 878 | ret = BACKREF_FOUND_SHARED; |
| 879 | break; |
| 880 | } |
| 881 | |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 882 | root = btrfs_extent_data_ref_root(leaf, dref); |
| 883 | ret = __add_prelim_ref(prefs, root, &key, 0, 0, |
Wang Shilong | 742916b | 2013-08-06 10:29:54 +0800 | [diff] [blame] | 884 | bytenr, count, GFP_NOFS); |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 885 | break; |
| 886 | } |
| 887 | default: |
| 888 | WARN_ON(1); |
| 889 | } |
Wang Shilong | 1149ab6 | 2013-04-10 11:22:50 +0000 | [diff] [blame] | 890 | if (ret) |
| 891 | return ret; |
| 892 | |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 893 | } |
| 894 | |
| 895 | return ret; |
| 896 | } |
| 897 | |
| 898 | /* |
| 899 | * this adds all existing backrefs (inline backrefs, backrefs and delayed |
| 900 | * refs) for the given bytenr to the refs list, merges duplicates and resolves |
| 901 | * indirect refs to their parent bytenr. |
| 902 | * When roots are found, they're added to the roots list |
| 903 | * |
Mark Fasheh | 2c2ed5a | 2015-05-19 12:49:50 -0700 | [diff] [blame] | 904 | * NOTE: This can return values > 0 |
| 905 | * |
Qu Wenruo | 21633fc | 2015-04-16 14:54:50 +0800 | [diff] [blame] | 906 | * If time_seq is set to (u64)-1, it will not search delayed_refs, and behave |
| 907 | * much like trans == NULL case, the difference only lies in it will not |
| 908 | * commit root. |
| 909 | * The special case is for qgroup to search roots in commit_transaction(). |
| 910 | * |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 911 | * FIXME some caching might speed things up |
| 912 | */ |
| 913 | static int find_parent_nodes(struct btrfs_trans_handle *trans, |
| 914 | struct btrfs_fs_info *fs_info, u64 bytenr, |
Jan Schmidt | 097b8a7 | 2012-06-21 11:08:04 +0200 | [diff] [blame] | 915 | u64 time_seq, struct ulist *refs, |
Josef Bacik | dc046b1 | 2014-09-10 16:20:45 -0400 | [diff] [blame] | 916 | struct ulist *roots, const u64 *extent_item_pos, |
| 917 | u64 root_objectid, u64 inum) |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 918 | { |
| 919 | struct btrfs_key key; |
| 920 | struct btrfs_path *path; |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 921 | struct btrfs_delayed_ref_root *delayed_refs = NULL; |
Li Zefan | d3b0106 | 2012-03-03 07:41:15 -0500 | [diff] [blame] | 922 | struct btrfs_delayed_ref_head *head; |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 923 | int info_level = 0; |
| 924 | int ret; |
| 925 | struct list_head prefs_delayed; |
| 926 | struct list_head prefs; |
| 927 | struct __prelim_ref *ref; |
Wang Shilong | f05c474 | 2014-01-28 19:13:38 +0800 | [diff] [blame] | 928 | struct extent_inode_elem *eie = NULL; |
Josef Bacik | 4485386 | 2014-03-19 13:35:14 -0400 | [diff] [blame] | 929 | u64 total_refs = 0; |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 930 | |
| 931 | INIT_LIST_HEAD(&prefs); |
| 932 | INIT_LIST_HEAD(&prefs_delayed); |
| 933 | |
| 934 | key.objectid = bytenr; |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 935 | key.offset = (u64)-1; |
Josef Bacik | 261c84b | 2013-06-28 13:11:22 -0400 | [diff] [blame] | 936 | if (btrfs_fs_incompat(fs_info, SKINNY_METADATA)) |
| 937 | key.type = BTRFS_METADATA_ITEM_KEY; |
| 938 | else |
| 939 | key.type = BTRFS_EXTENT_ITEM_KEY; |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 940 | |
| 941 | path = btrfs_alloc_path(); |
| 942 | if (!path) |
| 943 | return -ENOMEM; |
Wang Shilong | e84752d | 2014-02-13 11:19:47 +0800 | [diff] [blame] | 944 | if (!trans) { |
Josef Bacik | da61d31 | 2013-06-12 16:20:08 -0400 | [diff] [blame] | 945 | path->search_commit_root = 1; |
Wang Shilong | e84752d | 2014-02-13 11:19:47 +0800 | [diff] [blame] | 946 | path->skip_locking = 1; |
| 947 | } |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 948 | |
Qu Wenruo | 21633fc | 2015-04-16 14:54:50 +0800 | [diff] [blame] | 949 | if (time_seq == (u64)-1) |
| 950 | path->skip_locking = 1; |
| 951 | |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 952 | /* |
| 953 | * grab both a lock on the path and a lock on the delayed ref head. |
| 954 | * We need both to get a consistent picture of how the refs look |
| 955 | * at a specified point in time |
| 956 | */ |
| 957 | again: |
Li Zefan | d3b0106 | 2012-03-03 07:41:15 -0500 | [diff] [blame] | 958 | head = NULL; |
| 959 | |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 960 | ret = btrfs_search_slot(trans, fs_info->extent_root, &key, path, 0, 0); |
| 961 | if (ret < 0) |
| 962 | goto out; |
| 963 | BUG_ON(ret == 0); |
| 964 | |
Josef Bacik | faa2dbf | 2014-05-07 17:06:09 -0400 | [diff] [blame] | 965 | #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS |
Qu Wenruo | 21633fc | 2015-04-16 14:54:50 +0800 | [diff] [blame] | 966 | if (trans && likely(trans->type != __TRANS_DUMMY) && |
| 967 | time_seq != (u64)-1) { |
Josef Bacik | faa2dbf | 2014-05-07 17:06:09 -0400 | [diff] [blame] | 968 | #else |
Qu Wenruo | 21633fc | 2015-04-16 14:54:50 +0800 | [diff] [blame] | 969 | if (trans && time_seq != (u64)-1) { |
Josef Bacik | faa2dbf | 2014-05-07 17:06:09 -0400 | [diff] [blame] | 970 | #endif |
Jan Schmidt | 7a3ae2f | 2012-03-23 17:32:28 +0100 | [diff] [blame] | 971 | /* |
| 972 | * look if there are updates for this ref queued and lock the |
| 973 | * head |
| 974 | */ |
| 975 | delayed_refs = &trans->transaction->delayed_refs; |
| 976 | spin_lock(&delayed_refs->lock); |
| 977 | head = btrfs_find_delayed_ref_head(trans, bytenr); |
| 978 | if (head) { |
| 979 | if (!mutex_trylock(&head->mutex)) { |
| 980 | atomic_inc(&head->node.refs); |
| 981 | spin_unlock(&delayed_refs->lock); |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 982 | |
Jan Schmidt | 7a3ae2f | 2012-03-23 17:32:28 +0100 | [diff] [blame] | 983 | btrfs_release_path(path); |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 984 | |
Jan Schmidt | 7a3ae2f | 2012-03-23 17:32:28 +0100 | [diff] [blame] | 985 | /* |
| 986 | * Mutex was contended, block until it's |
| 987 | * released and try again |
| 988 | */ |
| 989 | mutex_lock(&head->mutex); |
| 990 | mutex_unlock(&head->mutex); |
| 991 | btrfs_put_delayed_ref(&head->node); |
| 992 | goto again; |
| 993 | } |
Josef Bacik | d7df2c7 | 2014-01-23 09:21:38 -0500 | [diff] [blame] | 994 | spin_unlock(&delayed_refs->lock); |
Jan Schmidt | 097b8a7 | 2012-06-21 11:08:04 +0200 | [diff] [blame] | 995 | ret = __add_delayed_refs(head, time_seq, |
Josef Bacik | dc046b1 | 2014-09-10 16:20:45 -0400 | [diff] [blame] | 996 | &prefs_delayed, &total_refs, |
| 997 | inum); |
Jan Schmidt | 155725c | 2012-06-22 14:01:00 +0200 | [diff] [blame] | 998 | mutex_unlock(&head->mutex); |
Josef Bacik | d7df2c7 | 2014-01-23 09:21:38 -0500 | [diff] [blame] | 999 | if (ret) |
Jan Schmidt | 7a3ae2f | 2012-03-23 17:32:28 +0100 | [diff] [blame] | 1000 | goto out; |
Josef Bacik | d7df2c7 | 2014-01-23 09:21:38 -0500 | [diff] [blame] | 1001 | } else { |
| 1002 | spin_unlock(&delayed_refs->lock); |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 1003 | } |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 1004 | } |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 1005 | |
| 1006 | if (path->slots[0]) { |
| 1007 | struct extent_buffer *leaf; |
| 1008 | int slot; |
| 1009 | |
Jan Schmidt | dadcaf7 | 2012-05-22 13:43:25 +0200 | [diff] [blame] | 1010 | path->slots[0]--; |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 1011 | leaf = path->nodes[0]; |
Jan Schmidt | dadcaf7 | 2012-05-22 13:43:25 +0200 | [diff] [blame] | 1012 | slot = path->slots[0]; |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 1013 | btrfs_item_key_to_cpu(leaf, &key, slot); |
| 1014 | if (key.objectid == bytenr && |
Josef Bacik | 261c84b | 2013-06-28 13:11:22 -0400 | [diff] [blame] | 1015 | (key.type == BTRFS_EXTENT_ITEM_KEY || |
| 1016 | key.type == BTRFS_METADATA_ITEM_KEY)) { |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 1017 | ret = __add_inline_refs(fs_info, path, bytenr, |
Josef Bacik | 4485386 | 2014-03-19 13:35:14 -0400 | [diff] [blame] | 1018 | &info_level, &prefs, |
Josef Bacik | dc046b1 | 2014-09-10 16:20:45 -0400 | [diff] [blame] | 1019 | &total_refs, inum); |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 1020 | if (ret) |
| 1021 | goto out; |
Jan Schmidt | d5c88b7 | 2012-05-15 17:55:51 +0200 | [diff] [blame] | 1022 | ret = __add_keyed_refs(fs_info, path, bytenr, |
Josef Bacik | dc046b1 | 2014-09-10 16:20:45 -0400 | [diff] [blame] | 1023 | info_level, &prefs, inum); |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 1024 | if (ret) |
| 1025 | goto out; |
| 1026 | } |
| 1027 | } |
| 1028 | btrfs_release_path(path); |
| 1029 | |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 1030 | list_splice_init(&prefs_delayed, &prefs); |
| 1031 | |
Jan Schmidt | d5c88b7 | 2012-05-15 17:55:51 +0200 | [diff] [blame] | 1032 | ret = __add_missing_keys(fs_info, &prefs); |
| 1033 | if (ret) |
| 1034 | goto out; |
| 1035 | |
Wang Shilong | 692206b | 2013-04-11 07:08:55 +0000 | [diff] [blame] | 1036 | __merge_refs(&prefs, 1); |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 1037 | |
Josef Bacik | da61d31 | 2013-06-12 16:20:08 -0400 | [diff] [blame] | 1038 | ret = __resolve_indirect_refs(fs_info, path, time_seq, &prefs, |
Josef Bacik | dc046b1 | 2014-09-10 16:20:45 -0400 | [diff] [blame] | 1039 | extent_item_pos, total_refs, |
| 1040 | root_objectid); |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 1041 | if (ret) |
| 1042 | goto out; |
| 1043 | |
Wang Shilong | 692206b | 2013-04-11 07:08:55 +0000 | [diff] [blame] | 1044 | __merge_refs(&prefs, 2); |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 1045 | |
| 1046 | while (!list_empty(&prefs)) { |
| 1047 | ref = list_first_entry(&prefs, struct __prelim_ref, list); |
Julia Lawall | 6c1500f | 2012-11-03 20:30:18 +0000 | [diff] [blame] | 1048 | WARN_ON(ref->count < 0); |
Wang Shilong | 98cfee21 | 2014-02-01 00:42:05 +0800 | [diff] [blame] | 1049 | if (roots && ref->count && ref->root_id && ref->parent == 0) { |
Josef Bacik | dc046b1 | 2014-09-10 16:20:45 -0400 | [diff] [blame] | 1050 | if (root_objectid && ref->root_id != root_objectid) { |
| 1051 | ret = BACKREF_FOUND_SHARED; |
| 1052 | goto out; |
| 1053 | } |
| 1054 | |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 1055 | /* no parent == root of tree */ |
| 1056 | ret = ulist_add(roots, ref->root_id, 0, GFP_NOFS); |
Wang Shilong | f172393 | 2013-03-29 23:03:21 +0000 | [diff] [blame] | 1057 | if (ret < 0) |
| 1058 | goto out; |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 1059 | } |
| 1060 | if (ref->count && ref->parent) { |
Josef Bacik | 8a56457 | 2014-06-05 16:08:45 -0400 | [diff] [blame] | 1061 | if (extent_item_pos && !ref->inode_list && |
| 1062 | ref->level == 0) { |
Jan Schmidt | 976b190 | 2012-05-17 16:43:03 +0200 | [diff] [blame] | 1063 | struct extent_buffer *eb; |
David Sterba | 707e8a0 | 2014-06-04 19:22:26 +0200 | [diff] [blame] | 1064 | |
Jan Schmidt | 976b190 | 2012-05-17 16:43:03 +0200 | [diff] [blame] | 1065 | eb = read_tree_block(fs_info->extent_root, |
David Sterba | ce86cd5 | 2014-06-15 01:07:32 +0200 | [diff] [blame] | 1066 | ref->parent, 0); |
Liu Bo | 64c043d | 2015-05-25 17:30:15 +0800 | [diff] [blame] | 1067 | if (IS_ERR(eb)) { |
| 1068 | ret = PTR_ERR(eb); |
| 1069 | goto out; |
| 1070 | } else if (!extent_buffer_uptodate(eb)) { |
Josef Bacik | 416bc65 | 2013-04-23 14:17:42 -0400 | [diff] [blame] | 1071 | free_extent_buffer(eb); |
Wang Shilong | c16c2e2 | 2013-05-08 08:10:25 +0000 | [diff] [blame] | 1072 | ret = -EIO; |
| 1073 | goto out; |
Josef Bacik | 416bc65 | 2013-04-23 14:17:42 -0400 | [diff] [blame] | 1074 | } |
Filipe Manana | 6f7ff6d | 2014-07-02 20:07:54 +0100 | [diff] [blame] | 1075 | btrfs_tree_read_lock(eb); |
| 1076 | btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK); |
Jan Schmidt | 976b190 | 2012-05-17 16:43:03 +0200 | [diff] [blame] | 1077 | ret = find_extent_in_eb(eb, bytenr, |
| 1078 | *extent_item_pos, &eie); |
Filipe Manana | 6f7ff6d | 2014-07-02 20:07:54 +0100 | [diff] [blame] | 1079 | btrfs_tree_read_unlock_blocking(eb); |
Jan Schmidt | 976b190 | 2012-05-17 16:43:03 +0200 | [diff] [blame] | 1080 | free_extent_buffer(eb); |
Filipe David Borba Manana | f5929cd | 2013-07-31 00:26:35 +0100 | [diff] [blame] | 1081 | if (ret < 0) |
| 1082 | goto out; |
| 1083 | ref->inode_list = eie; |
Jan Schmidt | 976b190 | 2012-05-17 16:43:03 +0200 | [diff] [blame] | 1084 | } |
Takashi Iwai | 4eb1f66 | 2014-07-28 10:57:04 +0200 | [diff] [blame] | 1085 | ret = ulist_add_merge_ptr(refs, ref->parent, |
| 1086 | ref->inode_list, |
| 1087 | (void **)&eie, GFP_NOFS); |
Wang Shilong | f172393 | 2013-03-29 23:03:21 +0000 | [diff] [blame] | 1088 | if (ret < 0) |
| 1089 | goto out; |
Jan Schmidt | 3301958 | 2012-05-30 18:05:21 +0200 | [diff] [blame] | 1090 | if (!ret && extent_item_pos) { |
| 1091 | /* |
| 1092 | * we've recorded that parent, so we must extend |
| 1093 | * its inode list here |
| 1094 | */ |
| 1095 | BUG_ON(!eie); |
| 1096 | while (eie->next) |
| 1097 | eie = eie->next; |
| 1098 | eie->next = ref->inode_list; |
| 1099 | } |
Wang Shilong | f05c474 | 2014-01-28 19:13:38 +0800 | [diff] [blame] | 1100 | eie = NULL; |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 1101 | } |
Wang Shilong | a4fdb61 | 2013-08-08 13:04:17 +0800 | [diff] [blame] | 1102 | list_del(&ref->list); |
Wang Shilong | b9e9a6c | 2013-08-09 13:25:36 +0800 | [diff] [blame] | 1103 | kmem_cache_free(btrfs_prelim_ref_cache, ref); |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 1104 | } |
| 1105 | |
| 1106 | out: |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 1107 | btrfs_free_path(path); |
| 1108 | while (!list_empty(&prefs)) { |
| 1109 | ref = list_first_entry(&prefs, struct __prelim_ref, list); |
| 1110 | list_del(&ref->list); |
Wang Shilong | b9e9a6c | 2013-08-09 13:25:36 +0800 | [diff] [blame] | 1111 | kmem_cache_free(btrfs_prelim_ref_cache, ref); |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 1112 | } |
| 1113 | while (!list_empty(&prefs_delayed)) { |
| 1114 | ref = list_first_entry(&prefs_delayed, struct __prelim_ref, |
| 1115 | list); |
| 1116 | list_del(&ref->list); |
Wang Shilong | b9e9a6c | 2013-08-09 13:25:36 +0800 | [diff] [blame] | 1117 | kmem_cache_free(btrfs_prelim_ref_cache, ref); |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 1118 | } |
Wang Shilong | f05c474 | 2014-01-28 19:13:38 +0800 | [diff] [blame] | 1119 | if (ret < 0) |
| 1120 | free_inode_elem_list(eie); |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 1121 | return ret; |
| 1122 | } |
| 1123 | |
Jan Schmidt | 976b190 | 2012-05-17 16:43:03 +0200 | [diff] [blame] | 1124 | static void free_leaf_list(struct ulist *blocks) |
| 1125 | { |
| 1126 | struct ulist_node *node = NULL; |
| 1127 | struct extent_inode_elem *eie; |
Jan Schmidt | 976b190 | 2012-05-17 16:43:03 +0200 | [diff] [blame] | 1128 | struct ulist_iterator uiter; |
| 1129 | |
| 1130 | ULIST_ITER_INIT(&uiter); |
| 1131 | while ((node = ulist_next(blocks, &uiter))) { |
| 1132 | if (!node->aux) |
| 1133 | continue; |
Jan Schmidt | 995e01b | 2012-08-13 02:52:38 -0600 | [diff] [blame] | 1134 | eie = (struct extent_inode_elem *)(uintptr_t)node->aux; |
Wang Shilong | f05c474 | 2014-01-28 19:13:38 +0800 | [diff] [blame] | 1135 | free_inode_elem_list(eie); |
Jan Schmidt | 976b190 | 2012-05-17 16:43:03 +0200 | [diff] [blame] | 1136 | node->aux = 0; |
| 1137 | } |
| 1138 | |
| 1139 | ulist_free(blocks); |
| 1140 | } |
| 1141 | |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 1142 | /* |
| 1143 | * Finds all leafs with a reference to the specified combination of bytenr and |
| 1144 | * offset. key_list_head will point to a list of corresponding keys (caller must |
| 1145 | * free each list element). The leafs will be stored in the leafs ulist, which |
| 1146 | * must be freed with ulist_free. |
| 1147 | * |
| 1148 | * returns 0 on success, <0 on error |
| 1149 | */ |
| 1150 | static int btrfs_find_all_leafs(struct btrfs_trans_handle *trans, |
| 1151 | struct btrfs_fs_info *fs_info, u64 bytenr, |
Jan Schmidt | 097b8a7 | 2012-06-21 11:08:04 +0200 | [diff] [blame] | 1152 | u64 time_seq, struct ulist **leafs, |
Jan Schmidt | 976b190 | 2012-05-17 16:43:03 +0200 | [diff] [blame] | 1153 | const u64 *extent_item_pos) |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 1154 | { |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 1155 | int ret; |
| 1156 | |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 1157 | *leafs = ulist_alloc(GFP_NOFS); |
Wang Shilong | 98cfee21 | 2014-02-01 00:42:05 +0800 | [diff] [blame] | 1158 | if (!*leafs) |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 1159 | return -ENOMEM; |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 1160 | |
Jan Schmidt | 097b8a7 | 2012-06-21 11:08:04 +0200 | [diff] [blame] | 1161 | ret = find_parent_nodes(trans, fs_info, bytenr, |
Josef Bacik | dc046b1 | 2014-09-10 16:20:45 -0400 | [diff] [blame] | 1162 | time_seq, *leafs, NULL, extent_item_pos, 0, 0); |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 1163 | if (ret < 0 && ret != -ENOENT) { |
Jan Schmidt | 976b190 | 2012-05-17 16:43:03 +0200 | [diff] [blame] | 1164 | free_leaf_list(*leafs); |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 1165 | return ret; |
| 1166 | } |
| 1167 | |
| 1168 | return 0; |
| 1169 | } |
| 1170 | |
| 1171 | /* |
| 1172 | * walk all backrefs for a given extent to find all roots that reference this |
| 1173 | * extent. Walking a backref means finding all extents that reference this |
| 1174 | * extent and in turn walk the backrefs of those, too. Naturally this is a |
| 1175 | * recursive process, but here it is implemented in an iterative fashion: We |
| 1176 | * find all referencing extents for the extent in question and put them on a |
| 1177 | * list. In turn, we find all referencing extents for those, further appending |
| 1178 | * to the list. The way we iterate the list allows adding more elements after |
| 1179 | * the current while iterating. The process stops when we reach the end of the |
| 1180 | * list. Found roots are added to the roots list. |
| 1181 | * |
| 1182 | * returns 0 on success, < 0 on error. |
| 1183 | */ |
Josef Bacik | 9e351cc | 2014-03-13 15:42:13 -0400 | [diff] [blame] | 1184 | static int __btrfs_find_all_roots(struct btrfs_trans_handle *trans, |
| 1185 | struct btrfs_fs_info *fs_info, u64 bytenr, |
| 1186 | u64 time_seq, struct ulist **roots) |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 1187 | { |
| 1188 | struct ulist *tmp; |
| 1189 | struct ulist_node *node = NULL; |
Jan Schmidt | cd1b413 | 2012-05-22 14:56:50 +0200 | [diff] [blame] | 1190 | struct ulist_iterator uiter; |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 1191 | int ret; |
| 1192 | |
| 1193 | tmp = ulist_alloc(GFP_NOFS); |
| 1194 | if (!tmp) |
| 1195 | return -ENOMEM; |
| 1196 | *roots = ulist_alloc(GFP_NOFS); |
| 1197 | if (!*roots) { |
| 1198 | ulist_free(tmp); |
| 1199 | return -ENOMEM; |
| 1200 | } |
| 1201 | |
Jan Schmidt | cd1b413 | 2012-05-22 14:56:50 +0200 | [diff] [blame] | 1202 | ULIST_ITER_INIT(&uiter); |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 1203 | while (1) { |
Jan Schmidt | 097b8a7 | 2012-06-21 11:08:04 +0200 | [diff] [blame] | 1204 | ret = find_parent_nodes(trans, fs_info, bytenr, |
Josef Bacik | dc046b1 | 2014-09-10 16:20:45 -0400 | [diff] [blame] | 1205 | time_seq, tmp, *roots, NULL, 0, 0); |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 1206 | if (ret < 0 && ret != -ENOENT) { |
| 1207 | ulist_free(tmp); |
| 1208 | ulist_free(*roots); |
| 1209 | return ret; |
| 1210 | } |
Jan Schmidt | cd1b413 | 2012-05-22 14:56:50 +0200 | [diff] [blame] | 1211 | node = ulist_next(tmp, &uiter); |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 1212 | if (!node) |
| 1213 | break; |
| 1214 | bytenr = node->val; |
Wang Shilong | bca1a29 | 2014-01-26 22:32:18 +0800 | [diff] [blame] | 1215 | cond_resched(); |
Jan Schmidt | 8da6d58 | 2011-11-23 18:55:04 +0100 | [diff] [blame] | 1216 | } |
| 1217 | |
| 1218 | ulist_free(tmp); |
| 1219 | return 0; |
| 1220 | } |
| 1221 | |
Josef Bacik | 9e351cc | 2014-03-13 15:42:13 -0400 | [diff] [blame] | 1222 | int btrfs_find_all_roots(struct btrfs_trans_handle *trans, |
| 1223 | struct btrfs_fs_info *fs_info, u64 bytenr, |
| 1224 | u64 time_seq, struct ulist **roots) |
| 1225 | { |
| 1226 | int ret; |
| 1227 | |
| 1228 | if (!trans) |
| 1229 | down_read(&fs_info->commit_root_sem); |
| 1230 | ret = __btrfs_find_all_roots(trans, fs_info, bytenr, time_seq, roots); |
| 1231 | if (!trans) |
| 1232 | up_read(&fs_info->commit_root_sem); |
| 1233 | return ret; |
| 1234 | } |
| 1235 | |
Mark Fasheh | 2c2ed5a | 2015-05-19 12:49:50 -0700 | [diff] [blame] | 1236 | /** |
| 1237 | * btrfs_check_shared - tell us whether an extent is shared |
| 1238 | * |
| 1239 | * @trans: optional trans handle |
| 1240 | * |
| 1241 | * btrfs_check_shared uses the backref walking code but will short |
| 1242 | * circuit as soon as it finds a root or inode that doesn't match the |
| 1243 | * one passed in. This provides a significant performance benefit for |
| 1244 | * callers (such as fiemap) which want to know whether the extent is |
| 1245 | * shared but do not need a ref count. |
| 1246 | * |
| 1247 | * Return: 0 if extent is not shared, 1 if it is shared, < 0 on error. |
| 1248 | */ |
Josef Bacik | dc046b1 | 2014-09-10 16:20:45 -0400 | [diff] [blame] | 1249 | int btrfs_check_shared(struct btrfs_trans_handle *trans, |
| 1250 | struct btrfs_fs_info *fs_info, u64 root_objectid, |
| 1251 | u64 inum, u64 bytenr) |
| 1252 | { |
| 1253 | struct ulist *tmp = NULL; |
| 1254 | struct ulist *roots = NULL; |
| 1255 | struct ulist_iterator uiter; |
| 1256 | struct ulist_node *node; |
David Sterba | 3284da7 | 2015-02-25 15:47:32 +0100 | [diff] [blame] | 1257 | struct seq_list elem = SEQ_LIST_INIT(elem); |
Josef Bacik | dc046b1 | 2014-09-10 16:20:45 -0400 | [diff] [blame] | 1258 | int ret = 0; |
| 1259 | |
| 1260 | tmp = ulist_alloc(GFP_NOFS); |
| 1261 | roots = ulist_alloc(GFP_NOFS); |
| 1262 | if (!tmp || !roots) { |
| 1263 | ulist_free(tmp); |
| 1264 | ulist_free(roots); |
| 1265 | return -ENOMEM; |
| 1266 | } |
| 1267 | |
| 1268 | if (trans) |
| 1269 | btrfs_get_tree_mod_seq(fs_info, &elem); |
| 1270 | else |
| 1271 | down_read(&fs_info->commit_root_sem); |
| 1272 | ULIST_ITER_INIT(&uiter); |
| 1273 | while (1) { |
| 1274 | ret = find_parent_nodes(trans, fs_info, bytenr, elem.seq, tmp, |
| 1275 | roots, NULL, root_objectid, inum); |
| 1276 | if (ret == BACKREF_FOUND_SHARED) { |
Mark Fasheh | 2c2ed5a | 2015-05-19 12:49:50 -0700 | [diff] [blame] | 1277 | /* this is the only condition under which we return 1 */ |
Josef Bacik | dc046b1 | 2014-09-10 16:20:45 -0400 | [diff] [blame] | 1278 | ret = 1; |
| 1279 | break; |
| 1280 | } |
| 1281 | if (ret < 0 && ret != -ENOENT) |
| 1282 | break; |
Mark Fasheh | 2c2ed5a | 2015-05-19 12:49:50 -0700 | [diff] [blame] | 1283 | ret = 0; |
Josef Bacik | dc046b1 | 2014-09-10 16:20:45 -0400 | [diff] [blame] | 1284 | node = ulist_next(tmp, &uiter); |
| 1285 | if (!node) |
| 1286 | break; |
| 1287 | bytenr = node->val; |
| 1288 | cond_resched(); |
| 1289 | } |
| 1290 | if (trans) |
| 1291 | btrfs_put_tree_mod_seq(fs_info, &elem); |
| 1292 | else |
| 1293 | up_read(&fs_info->commit_root_sem); |
| 1294 | ulist_free(tmp); |
| 1295 | ulist_free(roots); |
| 1296 | return ret; |
| 1297 | } |
| 1298 | |
Mark Fasheh | f186373 | 2012-08-08 11:32:27 -0700 | [diff] [blame] | 1299 | int btrfs_find_one_extref(struct btrfs_root *root, u64 inode_objectid, |
| 1300 | u64 start_off, struct btrfs_path *path, |
| 1301 | struct btrfs_inode_extref **ret_extref, |
| 1302 | u64 *found_off) |
| 1303 | { |
| 1304 | int ret, slot; |
| 1305 | struct btrfs_key key; |
| 1306 | struct btrfs_key found_key; |
| 1307 | struct btrfs_inode_extref *extref; |
| 1308 | struct extent_buffer *leaf; |
| 1309 | unsigned long ptr; |
| 1310 | |
| 1311 | key.objectid = inode_objectid; |
David Sterba | 962a298 | 2014-06-04 18:41:45 +0200 | [diff] [blame] | 1312 | key.type = BTRFS_INODE_EXTREF_KEY; |
Mark Fasheh | f186373 | 2012-08-08 11:32:27 -0700 | [diff] [blame] | 1313 | key.offset = start_off; |
| 1314 | |
| 1315 | ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); |
| 1316 | if (ret < 0) |
| 1317 | return ret; |
| 1318 | |
| 1319 | while (1) { |
| 1320 | leaf = path->nodes[0]; |
| 1321 | slot = path->slots[0]; |
| 1322 | if (slot >= btrfs_header_nritems(leaf)) { |
| 1323 | /* |
| 1324 | * If the item at offset is not found, |
| 1325 | * btrfs_search_slot will point us to the slot |
| 1326 | * where it should be inserted. In our case |
| 1327 | * that will be the slot directly before the |
| 1328 | * next INODE_REF_KEY_V2 item. In the case |
| 1329 | * that we're pointing to the last slot in a |
| 1330 | * leaf, we must move one leaf over. |
| 1331 | */ |
| 1332 | ret = btrfs_next_leaf(root, path); |
| 1333 | if (ret) { |
| 1334 | if (ret >= 1) |
| 1335 | ret = -ENOENT; |
| 1336 | break; |
| 1337 | } |
| 1338 | continue; |
| 1339 | } |
| 1340 | |
| 1341 | btrfs_item_key_to_cpu(leaf, &found_key, slot); |
| 1342 | |
| 1343 | /* |
| 1344 | * Check that we're still looking at an extended ref key for |
| 1345 | * this particular objectid. If we have different |
| 1346 | * objectid or type then there are no more to be found |
| 1347 | * in the tree and we can exit. |
| 1348 | */ |
| 1349 | ret = -ENOENT; |
| 1350 | if (found_key.objectid != inode_objectid) |
| 1351 | break; |
David Sterba | 962a298 | 2014-06-04 18:41:45 +0200 | [diff] [blame] | 1352 | if (found_key.type != BTRFS_INODE_EXTREF_KEY) |
Mark Fasheh | f186373 | 2012-08-08 11:32:27 -0700 | [diff] [blame] | 1353 | break; |
| 1354 | |
| 1355 | ret = 0; |
| 1356 | ptr = btrfs_item_ptr_offset(leaf, path->slots[0]); |
| 1357 | extref = (struct btrfs_inode_extref *)ptr; |
| 1358 | *ret_extref = extref; |
| 1359 | if (found_off) |
| 1360 | *found_off = found_key.offset; |
| 1361 | break; |
| 1362 | } |
| 1363 | |
| 1364 | return ret; |
| 1365 | } |
| 1366 | |
Eric Sandeen | 48a3b63 | 2013-04-25 20:41:01 +0000 | [diff] [blame] | 1367 | /* |
| 1368 | * this iterates to turn a name (from iref/extref) into a full filesystem path. |
| 1369 | * Elements of the path are separated by '/' and the path is guaranteed to be |
| 1370 | * 0-terminated. the path is only given within the current file system. |
| 1371 | * Therefore, it never starts with a '/'. the caller is responsible to provide |
| 1372 | * "size" bytes in "dest". the dest buffer will be filled backwards. finally, |
| 1373 | * the start point of the resulting string is returned. this pointer is within |
| 1374 | * dest, normally. |
| 1375 | * in case the path buffer would overflow, the pointer is decremented further |
| 1376 | * as if output was written to the buffer, though no more output is actually |
| 1377 | * generated. that way, the caller can determine how much space would be |
| 1378 | * required for the path to fit into the buffer. in that case, the returned |
| 1379 | * value will be smaller than dest. callers must check this! |
| 1380 | */ |
Jan Schmidt | 96b5bd7 | 2012-10-15 08:30:45 +0000 | [diff] [blame] | 1381 | char *btrfs_ref_to_path(struct btrfs_root *fs_root, struct btrfs_path *path, |
| 1382 | u32 name_len, unsigned long name_off, |
| 1383 | struct extent_buffer *eb_in, u64 parent, |
| 1384 | char *dest, u32 size) |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1385 | { |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1386 | int slot; |
| 1387 | u64 next_inum; |
| 1388 | int ret; |
Gabriel de Perthuis | 661bec6 | 2012-10-10 08:50:47 -0600 | [diff] [blame] | 1389 | s64 bytes_left = ((s64)size) - 1; |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1390 | struct extent_buffer *eb = eb_in; |
| 1391 | struct btrfs_key found_key; |
Jan Schmidt | b916a59 | 2012-04-13 12:28:08 +0200 | [diff] [blame] | 1392 | int leave_spinning = path->leave_spinning; |
Mark Fasheh | d24bec3 | 2012-08-08 11:33:54 -0700 | [diff] [blame] | 1393 | struct btrfs_inode_ref *iref; |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1394 | |
| 1395 | if (bytes_left >= 0) |
| 1396 | dest[bytes_left] = '\0'; |
| 1397 | |
Jan Schmidt | b916a59 | 2012-04-13 12:28:08 +0200 | [diff] [blame] | 1398 | path->leave_spinning = 1; |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1399 | while (1) { |
Mark Fasheh | d24bec3 | 2012-08-08 11:33:54 -0700 | [diff] [blame] | 1400 | bytes_left -= name_len; |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1401 | if (bytes_left >= 0) |
| 1402 | read_extent_buffer(eb, dest + bytes_left, |
Mark Fasheh | d24bec3 | 2012-08-08 11:33:54 -0700 | [diff] [blame] | 1403 | name_off, name_len); |
Jan Schmidt | b916a59 | 2012-04-13 12:28:08 +0200 | [diff] [blame] | 1404 | if (eb != eb_in) { |
Filipe Manana | 0c0fe3b | 2016-02-03 19:17:27 +0000 | [diff] [blame] | 1405 | if (!path->skip_locking) |
| 1406 | btrfs_tree_read_unlock_blocking(eb); |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1407 | free_extent_buffer(eb); |
Jan Schmidt | b916a59 | 2012-04-13 12:28:08 +0200 | [diff] [blame] | 1408 | } |
David Sterba | c234a24 | 2015-01-02 19:03:17 +0100 | [diff] [blame] | 1409 | ret = btrfs_find_item(fs_root, path, parent, 0, |
| 1410 | BTRFS_INODE_REF_KEY, &found_key); |
Jan Schmidt | 8f24b49 | 2012-02-08 16:01:01 +0100 | [diff] [blame] | 1411 | if (ret > 0) |
| 1412 | ret = -ENOENT; |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1413 | if (ret) |
| 1414 | break; |
Mark Fasheh | d24bec3 | 2012-08-08 11:33:54 -0700 | [diff] [blame] | 1415 | |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1416 | next_inum = found_key.offset; |
| 1417 | |
| 1418 | /* regular exit ahead */ |
| 1419 | if (parent == next_inum) |
| 1420 | break; |
| 1421 | |
| 1422 | slot = path->slots[0]; |
| 1423 | eb = path->nodes[0]; |
| 1424 | /* make sure we can use eb after releasing the path */ |
Jan Schmidt | b916a59 | 2012-04-13 12:28:08 +0200 | [diff] [blame] | 1425 | if (eb != eb_in) { |
Filipe Manana | 0c0fe3b | 2016-02-03 19:17:27 +0000 | [diff] [blame] | 1426 | if (!path->skip_locking) |
| 1427 | btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK); |
| 1428 | path->nodes[0] = NULL; |
| 1429 | path->locks[0] = 0; |
Jan Schmidt | b916a59 | 2012-04-13 12:28:08 +0200 | [diff] [blame] | 1430 | } |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1431 | btrfs_release_path(path); |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1432 | iref = btrfs_item_ptr(eb, slot, struct btrfs_inode_ref); |
Mark Fasheh | d24bec3 | 2012-08-08 11:33:54 -0700 | [diff] [blame] | 1433 | |
| 1434 | name_len = btrfs_inode_ref_name_len(eb, iref); |
| 1435 | name_off = (unsigned long)(iref + 1); |
| 1436 | |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1437 | parent = next_inum; |
| 1438 | --bytes_left; |
| 1439 | if (bytes_left >= 0) |
| 1440 | dest[bytes_left] = '/'; |
| 1441 | } |
| 1442 | |
| 1443 | btrfs_release_path(path); |
Jan Schmidt | b916a59 | 2012-04-13 12:28:08 +0200 | [diff] [blame] | 1444 | path->leave_spinning = leave_spinning; |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1445 | |
| 1446 | if (ret) |
| 1447 | return ERR_PTR(ret); |
| 1448 | |
| 1449 | return dest + bytes_left; |
| 1450 | } |
| 1451 | |
| 1452 | /* |
| 1453 | * this makes the path point to (logical EXTENT_ITEM *) |
| 1454 | * returns BTRFS_EXTENT_FLAG_DATA for data, BTRFS_EXTENT_FLAG_TREE_BLOCK for |
| 1455 | * tree blocks and <0 on error. |
| 1456 | */ |
| 1457 | int extent_from_logical(struct btrfs_fs_info *fs_info, u64 logical, |
Liu Bo | 69917e4 | 2012-09-07 20:01:28 -0600 | [diff] [blame] | 1458 | struct btrfs_path *path, struct btrfs_key *found_key, |
| 1459 | u64 *flags_ret) |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1460 | { |
| 1461 | int ret; |
| 1462 | u64 flags; |
Josef Bacik | 261c84b | 2013-06-28 13:11:22 -0400 | [diff] [blame] | 1463 | u64 size = 0; |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1464 | u32 item_size; |
| 1465 | struct extent_buffer *eb; |
| 1466 | struct btrfs_extent_item *ei; |
| 1467 | struct btrfs_key key; |
| 1468 | |
Josef Bacik | 261c84b | 2013-06-28 13:11:22 -0400 | [diff] [blame] | 1469 | if (btrfs_fs_incompat(fs_info, SKINNY_METADATA)) |
| 1470 | key.type = BTRFS_METADATA_ITEM_KEY; |
| 1471 | else |
| 1472 | key.type = BTRFS_EXTENT_ITEM_KEY; |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1473 | key.objectid = logical; |
| 1474 | key.offset = (u64)-1; |
| 1475 | |
| 1476 | ret = btrfs_search_slot(NULL, fs_info->extent_root, &key, path, 0, 0); |
| 1477 | if (ret < 0) |
| 1478 | return ret; |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1479 | |
Wang Shilong | 850a8cd | 2014-02-06 20:02:29 +0800 | [diff] [blame] | 1480 | ret = btrfs_previous_extent_item(fs_info->extent_root, path, 0); |
| 1481 | if (ret) { |
| 1482 | if (ret > 0) |
| 1483 | ret = -ENOENT; |
| 1484 | return ret; |
Josef Bacik | 580f0a6 | 2014-01-23 16:03:45 -0500 | [diff] [blame] | 1485 | } |
Wang Shilong | 850a8cd | 2014-02-06 20:02:29 +0800 | [diff] [blame] | 1486 | 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] | 1487 | if (found_key->type == BTRFS_METADATA_ITEM_KEY) |
David Sterba | 707e8a0 | 2014-06-04 19:22:26 +0200 | [diff] [blame] | 1488 | size = fs_info->extent_root->nodesize; |
Josef Bacik | 261c84b | 2013-06-28 13:11:22 -0400 | [diff] [blame] | 1489 | else if (found_key->type == BTRFS_EXTENT_ITEM_KEY) |
| 1490 | size = found_key->offset; |
| 1491 | |
Josef Bacik | 580f0a6 | 2014-01-23 16:03:45 -0500 | [diff] [blame] | 1492 | if (found_key->objectid > logical || |
Josef Bacik | 261c84b | 2013-06-28 13:11:22 -0400 | [diff] [blame] | 1493 | found_key->objectid + size <= logical) { |
Geert Uytterhoeven | c1c9ff7 | 2013-08-20 13:20:07 +0200 | [diff] [blame] | 1494 | pr_debug("logical %llu is not within any extent\n", logical); |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1495 | return -ENOENT; |
Jan Schmidt | 4692cf5 | 2011-12-02 14:56:41 +0100 | [diff] [blame] | 1496 | } |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1497 | |
| 1498 | eb = path->nodes[0]; |
| 1499 | item_size = btrfs_item_size_nr(eb, path->slots[0]); |
| 1500 | BUG_ON(item_size < sizeof(*ei)); |
| 1501 | |
| 1502 | ei = btrfs_item_ptr(eb, path->slots[0], struct btrfs_extent_item); |
| 1503 | flags = btrfs_extent_flags(eb, ei); |
| 1504 | |
Jan Schmidt | 4692cf5 | 2011-12-02 14:56:41 +0100 | [diff] [blame] | 1505 | pr_debug("logical %llu is at position %llu within the extent (%llu " |
| 1506 | "EXTENT_ITEM %llu) flags %#llx size %u\n", |
Geert Uytterhoeven | c1c9ff7 | 2013-08-20 13:20:07 +0200 | [diff] [blame] | 1507 | logical, logical - found_key->objectid, found_key->objectid, |
| 1508 | found_key->offset, flags, item_size); |
Liu Bo | 69917e4 | 2012-09-07 20:01:28 -0600 | [diff] [blame] | 1509 | |
| 1510 | WARN_ON(!flags_ret); |
| 1511 | if (flags_ret) { |
| 1512 | if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) |
| 1513 | *flags_ret = BTRFS_EXTENT_FLAG_TREE_BLOCK; |
| 1514 | else if (flags & BTRFS_EXTENT_FLAG_DATA) |
| 1515 | *flags_ret = BTRFS_EXTENT_FLAG_DATA; |
| 1516 | else |
| 1517 | BUG_ON(1); |
| 1518 | return 0; |
| 1519 | } |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1520 | |
| 1521 | return -EIO; |
| 1522 | } |
| 1523 | |
| 1524 | /* |
| 1525 | * helper function to iterate extent inline refs. ptr must point to a 0 value |
| 1526 | * for the first call and may be modified. it is used to track state. |
| 1527 | * if more refs exist, 0 is returned and the next call to |
| 1528 | * __get_extent_inline_ref must pass the modified ptr parameter to get the |
| 1529 | * next ref. after the last ref was processed, 1 is returned. |
| 1530 | * returns <0 on error |
| 1531 | */ |
| 1532 | static int __get_extent_inline_ref(unsigned long *ptr, struct extent_buffer *eb, |
Liu Bo | 6eda71d | 2014-06-09 10:54:07 +0800 | [diff] [blame] | 1533 | struct btrfs_key *key, |
| 1534 | struct btrfs_extent_item *ei, u32 item_size, |
| 1535 | struct btrfs_extent_inline_ref **out_eiref, |
| 1536 | int *out_type) |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1537 | { |
| 1538 | unsigned long end; |
| 1539 | u64 flags; |
| 1540 | struct btrfs_tree_block_info *info; |
| 1541 | |
| 1542 | if (!*ptr) { |
| 1543 | /* first call */ |
| 1544 | flags = btrfs_extent_flags(eb, ei); |
| 1545 | if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) { |
Liu Bo | 6eda71d | 2014-06-09 10:54:07 +0800 | [diff] [blame] | 1546 | if (key->type == BTRFS_METADATA_ITEM_KEY) { |
| 1547 | /* a skinny metadata extent */ |
| 1548 | *out_eiref = |
| 1549 | (struct btrfs_extent_inline_ref *)(ei + 1); |
| 1550 | } else { |
| 1551 | WARN_ON(key->type != BTRFS_EXTENT_ITEM_KEY); |
| 1552 | info = (struct btrfs_tree_block_info *)(ei + 1); |
| 1553 | *out_eiref = |
| 1554 | (struct btrfs_extent_inline_ref *)(info + 1); |
| 1555 | } |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1556 | } else { |
| 1557 | *out_eiref = (struct btrfs_extent_inline_ref *)(ei + 1); |
| 1558 | } |
| 1559 | *ptr = (unsigned long)*out_eiref; |
Liu Bo | cd857dd | 2014-06-08 19:04:13 +0800 | [diff] [blame] | 1560 | if ((unsigned long)(*ptr) >= (unsigned long)ei + item_size) |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1561 | return -ENOENT; |
| 1562 | } |
| 1563 | |
| 1564 | end = (unsigned long)ei + item_size; |
Liu Bo | 6eda71d | 2014-06-09 10:54:07 +0800 | [diff] [blame] | 1565 | *out_eiref = (struct btrfs_extent_inline_ref *)(*ptr); |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1566 | *out_type = btrfs_extent_inline_ref_type(eb, *out_eiref); |
| 1567 | |
| 1568 | *ptr += btrfs_extent_inline_ref_size(*out_type); |
| 1569 | WARN_ON(*ptr > end); |
| 1570 | if (*ptr == end) |
| 1571 | return 1; /* last */ |
| 1572 | |
| 1573 | return 0; |
| 1574 | } |
| 1575 | |
| 1576 | /* |
| 1577 | * reads the tree block backref for an extent. tree level and root are returned |
| 1578 | * through out_level and out_root. ptr must point to a 0 value for the first |
| 1579 | * call and may be modified (see __get_extent_inline_ref comment). |
| 1580 | * returns 0 if data was provided, 1 if there was no more data to provide or |
| 1581 | * <0 on error. |
| 1582 | */ |
| 1583 | int tree_backref_for_extent(unsigned long *ptr, struct extent_buffer *eb, |
Liu Bo | 6eda71d | 2014-06-09 10:54:07 +0800 | [diff] [blame] | 1584 | struct btrfs_key *key, struct btrfs_extent_item *ei, |
| 1585 | u32 item_size, u64 *out_root, u8 *out_level) |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1586 | { |
| 1587 | int ret; |
| 1588 | int type; |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1589 | struct btrfs_extent_inline_ref *eiref; |
| 1590 | |
| 1591 | if (*ptr == (unsigned long)-1) |
| 1592 | return 1; |
| 1593 | |
| 1594 | while (1) { |
Liu Bo | 6eda71d | 2014-06-09 10:54:07 +0800 | [diff] [blame] | 1595 | ret = __get_extent_inline_ref(ptr, eb, key, ei, item_size, |
| 1596 | &eiref, &type); |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1597 | if (ret < 0) |
| 1598 | return ret; |
| 1599 | |
| 1600 | if (type == BTRFS_TREE_BLOCK_REF_KEY || |
| 1601 | type == BTRFS_SHARED_BLOCK_REF_KEY) |
| 1602 | break; |
| 1603 | |
| 1604 | if (ret == 1) |
| 1605 | return 1; |
| 1606 | } |
| 1607 | |
| 1608 | /* we can treat both ref types equally here */ |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1609 | *out_root = btrfs_extent_inline_ref_offset(eb, eiref); |
Filipe Manana | a1317f4 | 2014-12-15 16:04:42 +0000 | [diff] [blame] | 1610 | |
| 1611 | if (key->type == BTRFS_EXTENT_ITEM_KEY) { |
| 1612 | struct btrfs_tree_block_info *info; |
| 1613 | |
| 1614 | info = (struct btrfs_tree_block_info *)(ei + 1); |
| 1615 | *out_level = btrfs_tree_block_level(eb, info); |
| 1616 | } else { |
| 1617 | ASSERT(key->type == BTRFS_METADATA_ITEM_KEY); |
| 1618 | *out_level = (u8)key->offset; |
| 1619 | } |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1620 | |
| 1621 | if (ret == 1) |
| 1622 | *ptr = (unsigned long)-1; |
| 1623 | |
| 1624 | return 0; |
| 1625 | } |
| 1626 | |
Jan Schmidt | 976b190 | 2012-05-17 16:43:03 +0200 | [diff] [blame] | 1627 | static int iterate_leaf_refs(struct extent_inode_elem *inode_list, |
| 1628 | u64 root, u64 extent_item_objectid, |
Jan Schmidt | 4692cf5 | 2011-12-02 14:56:41 +0100 | [diff] [blame] | 1629 | iterate_extent_inodes_t *iterate, void *ctx) |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1630 | { |
Jan Schmidt | 976b190 | 2012-05-17 16:43:03 +0200 | [diff] [blame] | 1631 | struct extent_inode_elem *eie; |
Jan Schmidt | 4692cf5 | 2011-12-02 14:56:41 +0100 | [diff] [blame] | 1632 | int ret = 0; |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1633 | |
Jan Schmidt | 976b190 | 2012-05-17 16:43:03 +0200 | [diff] [blame] | 1634 | for (eie = inode_list; eie; eie = eie->next) { |
Jan Schmidt | 4692cf5 | 2011-12-02 14:56:41 +0100 | [diff] [blame] | 1635 | pr_debug("ref for %llu resolved, key (%llu EXTEND_DATA %llu), " |
Jan Schmidt | 976b190 | 2012-05-17 16:43:03 +0200 | [diff] [blame] | 1636 | "root %llu\n", extent_item_objectid, |
| 1637 | eie->inum, eie->offset, root); |
| 1638 | ret = iterate(eie->inum, eie->offset, root, ctx); |
Jan Schmidt | 4692cf5 | 2011-12-02 14:56:41 +0100 | [diff] [blame] | 1639 | if (ret) { |
Jan Schmidt | 976b190 | 2012-05-17 16:43:03 +0200 | [diff] [blame] | 1640 | pr_debug("stopping iteration for %llu due to ret=%d\n", |
| 1641 | extent_item_objectid, ret); |
Jan Schmidt | 4692cf5 | 2011-12-02 14:56:41 +0100 | [diff] [blame] | 1642 | break; |
| 1643 | } |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1644 | } |
| 1645 | |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1646 | return ret; |
| 1647 | } |
| 1648 | |
| 1649 | /* |
| 1650 | * calls iterate() for every inode that references the extent identified by |
Jan Schmidt | 4692cf5 | 2011-12-02 14:56:41 +0100 | [diff] [blame] | 1651 | * the given parameters. |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1652 | * when the iterator function returns a non-zero value, iteration stops. |
| 1653 | */ |
| 1654 | int iterate_extent_inodes(struct btrfs_fs_info *fs_info, |
Jan Schmidt | 4692cf5 | 2011-12-02 14:56:41 +0100 | [diff] [blame] | 1655 | u64 extent_item_objectid, u64 extent_item_pos, |
Jan Schmidt | 7a3ae2f | 2012-03-23 17:32:28 +0100 | [diff] [blame] | 1656 | int search_commit_root, |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1657 | iterate_extent_inodes_t *iterate, void *ctx) |
| 1658 | { |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1659 | int ret; |
Josef Bacik | da61d31 | 2013-06-12 16:20:08 -0400 | [diff] [blame] | 1660 | struct btrfs_trans_handle *trans = NULL; |
Jan Schmidt | 7a3ae2f | 2012-03-23 17:32:28 +0100 | [diff] [blame] | 1661 | struct ulist *refs = NULL; |
| 1662 | struct ulist *roots = NULL; |
Jan Schmidt | 4692cf5 | 2011-12-02 14:56:41 +0100 | [diff] [blame] | 1663 | struct ulist_node *ref_node = NULL; |
| 1664 | struct ulist_node *root_node = NULL; |
David Sterba | 3284da7 | 2015-02-25 15:47:32 +0100 | [diff] [blame] | 1665 | struct seq_list tree_mod_seq_elem = SEQ_LIST_INIT(tree_mod_seq_elem); |
Jan Schmidt | cd1b413 | 2012-05-22 14:56:50 +0200 | [diff] [blame] | 1666 | struct ulist_iterator ref_uiter; |
| 1667 | struct ulist_iterator root_uiter; |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1668 | |
Jan Schmidt | 4692cf5 | 2011-12-02 14:56:41 +0100 | [diff] [blame] | 1669 | pr_debug("resolving all inodes for extent %llu\n", |
| 1670 | extent_item_objectid); |
| 1671 | |
Josef Bacik | da61d31 | 2013-06-12 16:20:08 -0400 | [diff] [blame] | 1672 | if (!search_commit_root) { |
Jan Schmidt | 7a3ae2f | 2012-03-23 17:32:28 +0100 | [diff] [blame] | 1673 | trans = btrfs_join_transaction(fs_info->extent_root); |
| 1674 | if (IS_ERR(trans)) |
| 1675 | return PTR_ERR(trans); |
Jan Schmidt | 8445f61 | 2012-05-16 18:36:03 +0200 | [diff] [blame] | 1676 | btrfs_get_tree_mod_seq(fs_info, &tree_mod_seq_elem); |
Josef Bacik | 9e351cc | 2014-03-13 15:42:13 -0400 | [diff] [blame] | 1677 | } else { |
| 1678 | down_read(&fs_info->commit_root_sem); |
Jan Schmidt | 7a3ae2f | 2012-03-23 17:32:28 +0100 | [diff] [blame] | 1679 | } |
Jan Schmidt | 4692cf5 | 2011-12-02 14:56:41 +0100 | [diff] [blame] | 1680 | |
| 1681 | ret = btrfs_find_all_leafs(trans, fs_info, extent_item_objectid, |
Jan Schmidt | 097b8a7 | 2012-06-21 11:08:04 +0200 | [diff] [blame] | 1682 | tree_mod_seq_elem.seq, &refs, |
Jan Schmidt | 8445f61 | 2012-05-16 18:36:03 +0200 | [diff] [blame] | 1683 | &extent_item_pos); |
Jan Schmidt | 4692cf5 | 2011-12-02 14:56:41 +0100 | [diff] [blame] | 1684 | if (ret) |
| 1685 | goto out; |
| 1686 | |
Jan Schmidt | cd1b413 | 2012-05-22 14:56:50 +0200 | [diff] [blame] | 1687 | ULIST_ITER_INIT(&ref_uiter); |
| 1688 | while (!ret && (ref_node = ulist_next(refs, &ref_uiter))) { |
Josef Bacik | 9e351cc | 2014-03-13 15:42:13 -0400 | [diff] [blame] | 1689 | ret = __btrfs_find_all_roots(trans, fs_info, ref_node->val, |
| 1690 | tree_mod_seq_elem.seq, &roots); |
Jan Schmidt | 4692cf5 | 2011-12-02 14:56:41 +0100 | [diff] [blame] | 1691 | if (ret) |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1692 | break; |
Jan Schmidt | cd1b413 | 2012-05-22 14:56:50 +0200 | [diff] [blame] | 1693 | ULIST_ITER_INIT(&root_uiter); |
| 1694 | while (!ret && (root_node = ulist_next(roots, &root_uiter))) { |
Jan Schmidt | 976b190 | 2012-05-17 16:43:03 +0200 | [diff] [blame] | 1695 | pr_debug("root %llu references leaf %llu, data list " |
Alexander Block | 34d73f5 | 2012-07-28 16:18:58 +0200 | [diff] [blame] | 1696 | "%#llx\n", root_node->val, ref_node->val, |
Geert Uytterhoeven | c1c9ff7 | 2013-08-20 13:20:07 +0200 | [diff] [blame] | 1697 | ref_node->aux); |
Jan Schmidt | 995e01b | 2012-08-13 02:52:38 -0600 | [diff] [blame] | 1698 | ret = iterate_leaf_refs((struct extent_inode_elem *) |
| 1699 | (uintptr_t)ref_node->aux, |
| 1700 | root_node->val, |
| 1701 | extent_item_objectid, |
| 1702 | iterate, ctx); |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1703 | } |
Jan Schmidt | 976b190 | 2012-05-17 16:43:03 +0200 | [diff] [blame] | 1704 | ulist_free(roots); |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1705 | } |
| 1706 | |
Jan Schmidt | 976b190 | 2012-05-17 16:43:03 +0200 | [diff] [blame] | 1707 | free_leaf_list(refs); |
Jan Schmidt | 4692cf5 | 2011-12-02 14:56:41 +0100 | [diff] [blame] | 1708 | out: |
Jan Schmidt | 7a3ae2f | 2012-03-23 17:32:28 +0100 | [diff] [blame] | 1709 | if (!search_commit_root) { |
Jan Schmidt | 8445f61 | 2012-05-16 18:36:03 +0200 | [diff] [blame] | 1710 | btrfs_put_tree_mod_seq(fs_info, &tree_mod_seq_elem); |
Jan Schmidt | 7a3ae2f | 2012-03-23 17:32:28 +0100 | [diff] [blame] | 1711 | btrfs_end_transaction(trans, fs_info->extent_root); |
Josef Bacik | 9e351cc | 2014-03-13 15:42:13 -0400 | [diff] [blame] | 1712 | } else { |
| 1713 | up_read(&fs_info->commit_root_sem); |
Jan Schmidt | 7a3ae2f | 2012-03-23 17:32:28 +0100 | [diff] [blame] | 1714 | } |
| 1715 | |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1716 | return ret; |
| 1717 | } |
| 1718 | |
| 1719 | int iterate_inodes_from_logical(u64 logical, struct btrfs_fs_info *fs_info, |
| 1720 | struct btrfs_path *path, |
| 1721 | iterate_extent_inodes_t *iterate, void *ctx) |
| 1722 | { |
| 1723 | int ret; |
Jan Schmidt | 4692cf5 | 2011-12-02 14:56:41 +0100 | [diff] [blame] | 1724 | u64 extent_item_pos; |
Liu Bo | 69917e4 | 2012-09-07 20:01:28 -0600 | [diff] [blame] | 1725 | u64 flags = 0; |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1726 | struct btrfs_key found_key; |
Jan Schmidt | 7a3ae2f | 2012-03-23 17:32:28 +0100 | [diff] [blame] | 1727 | int search_commit_root = path->search_commit_root; |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1728 | |
Liu Bo | 69917e4 | 2012-09-07 20:01:28 -0600 | [diff] [blame] | 1729 | ret = extent_from_logical(fs_info, logical, path, &found_key, &flags); |
Jan Schmidt | 4692cf5 | 2011-12-02 14:56:41 +0100 | [diff] [blame] | 1730 | btrfs_release_path(path); |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1731 | if (ret < 0) |
| 1732 | return ret; |
Liu Bo | 69917e4 | 2012-09-07 20:01:28 -0600 | [diff] [blame] | 1733 | if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) |
Stefan Behrens | 3627bf4 | 2012-08-01 04:28:01 -0600 | [diff] [blame] | 1734 | return -EINVAL; |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1735 | |
Jan Schmidt | 4692cf5 | 2011-12-02 14:56:41 +0100 | [diff] [blame] | 1736 | extent_item_pos = logical - found_key.objectid; |
Jan Schmidt | 7a3ae2f | 2012-03-23 17:32:28 +0100 | [diff] [blame] | 1737 | ret = iterate_extent_inodes(fs_info, found_key.objectid, |
| 1738 | extent_item_pos, search_commit_root, |
| 1739 | iterate, ctx); |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1740 | |
| 1741 | return ret; |
| 1742 | } |
| 1743 | |
Mark Fasheh | d24bec3 | 2012-08-08 11:33:54 -0700 | [diff] [blame] | 1744 | typedef int (iterate_irefs_t)(u64 parent, u32 name_len, unsigned long name_off, |
| 1745 | struct extent_buffer *eb, void *ctx); |
| 1746 | |
| 1747 | static int iterate_inode_refs(u64 inum, struct btrfs_root *fs_root, |
| 1748 | struct btrfs_path *path, |
| 1749 | iterate_irefs_t *iterate, void *ctx) |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1750 | { |
Jan Schmidt | aefc1eb | 2012-04-13 12:28:00 +0200 | [diff] [blame] | 1751 | int ret = 0; |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1752 | int slot; |
| 1753 | u32 cur; |
| 1754 | u32 len; |
| 1755 | u32 name_len; |
| 1756 | u64 parent = 0; |
| 1757 | int found = 0; |
| 1758 | struct extent_buffer *eb; |
| 1759 | struct btrfs_item *item; |
| 1760 | struct btrfs_inode_ref *iref; |
| 1761 | struct btrfs_key found_key; |
| 1762 | |
Jan Schmidt | aefc1eb | 2012-04-13 12:28:00 +0200 | [diff] [blame] | 1763 | while (!ret) { |
David Sterba | c234a24 | 2015-01-02 19:03:17 +0100 | [diff] [blame] | 1764 | ret = btrfs_find_item(fs_root, path, inum, |
| 1765 | parent ? parent + 1 : 0, BTRFS_INODE_REF_KEY, |
| 1766 | &found_key); |
| 1767 | |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1768 | if (ret < 0) |
| 1769 | break; |
| 1770 | if (ret) { |
| 1771 | ret = found ? 0 : -ENOENT; |
| 1772 | break; |
| 1773 | } |
| 1774 | ++found; |
| 1775 | |
| 1776 | parent = found_key.offset; |
| 1777 | slot = path->slots[0]; |
Filipe David Borba Manana | 3fe81ce | 2013-12-15 12:43:58 +0000 | [diff] [blame] | 1778 | eb = btrfs_clone_extent_buffer(path->nodes[0]); |
| 1779 | if (!eb) { |
| 1780 | ret = -ENOMEM; |
| 1781 | break; |
| 1782 | } |
| 1783 | extent_buffer_get(eb); |
Jan Schmidt | b916a59 | 2012-04-13 12:28:08 +0200 | [diff] [blame] | 1784 | btrfs_tree_read_lock(eb); |
| 1785 | btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK); |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1786 | btrfs_release_path(path); |
| 1787 | |
Ross Kirk | dd3cc16 | 2013-09-16 15:58:09 +0100 | [diff] [blame] | 1788 | item = btrfs_item_nr(slot); |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1789 | iref = btrfs_item_ptr(eb, slot, struct btrfs_inode_ref); |
| 1790 | |
| 1791 | for (cur = 0; cur < btrfs_item_size(eb, item); cur += len) { |
| 1792 | name_len = btrfs_inode_ref_name_len(eb, iref); |
| 1793 | /* path must be released before calling iterate()! */ |
Jan Schmidt | 4692cf5 | 2011-12-02 14:56:41 +0100 | [diff] [blame] | 1794 | pr_debug("following ref at offset %u for inode %llu in " |
Geert Uytterhoeven | c1c9ff7 | 2013-08-20 13:20:07 +0200 | [diff] [blame] | 1795 | "tree %llu\n", cur, found_key.objectid, |
| 1796 | fs_root->objectid); |
Mark Fasheh | d24bec3 | 2012-08-08 11:33:54 -0700 | [diff] [blame] | 1797 | ret = iterate(parent, name_len, |
| 1798 | (unsigned long)(iref + 1), eb, ctx); |
Jan Schmidt | aefc1eb | 2012-04-13 12:28:00 +0200 | [diff] [blame] | 1799 | if (ret) |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1800 | break; |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1801 | len = sizeof(*iref) + name_len; |
| 1802 | iref = (struct btrfs_inode_ref *)((char *)iref + len); |
| 1803 | } |
Jan Schmidt | b916a59 | 2012-04-13 12:28:08 +0200 | [diff] [blame] | 1804 | btrfs_tree_read_unlock_blocking(eb); |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1805 | free_extent_buffer(eb); |
| 1806 | } |
| 1807 | |
| 1808 | btrfs_release_path(path); |
| 1809 | |
| 1810 | return ret; |
| 1811 | } |
| 1812 | |
Mark Fasheh | d24bec3 | 2012-08-08 11:33:54 -0700 | [diff] [blame] | 1813 | static int iterate_inode_extrefs(u64 inum, struct btrfs_root *fs_root, |
| 1814 | struct btrfs_path *path, |
| 1815 | iterate_irefs_t *iterate, void *ctx) |
| 1816 | { |
| 1817 | int ret; |
| 1818 | int slot; |
| 1819 | u64 offset = 0; |
| 1820 | u64 parent; |
| 1821 | int found = 0; |
| 1822 | struct extent_buffer *eb; |
| 1823 | struct btrfs_inode_extref *extref; |
Mark Fasheh | d24bec3 | 2012-08-08 11:33:54 -0700 | [diff] [blame] | 1824 | u32 item_size; |
| 1825 | u32 cur_offset; |
| 1826 | unsigned long ptr; |
| 1827 | |
| 1828 | while (1) { |
| 1829 | ret = btrfs_find_one_extref(fs_root, inum, offset, path, &extref, |
| 1830 | &offset); |
| 1831 | if (ret < 0) |
| 1832 | break; |
| 1833 | if (ret) { |
| 1834 | ret = found ? 0 : -ENOENT; |
| 1835 | break; |
| 1836 | } |
| 1837 | ++found; |
| 1838 | |
| 1839 | slot = path->slots[0]; |
Filipe David Borba Manana | 3fe81ce | 2013-12-15 12:43:58 +0000 | [diff] [blame] | 1840 | eb = btrfs_clone_extent_buffer(path->nodes[0]); |
| 1841 | if (!eb) { |
| 1842 | ret = -ENOMEM; |
| 1843 | break; |
| 1844 | } |
| 1845 | extent_buffer_get(eb); |
Mark Fasheh | d24bec3 | 2012-08-08 11:33:54 -0700 | [diff] [blame] | 1846 | |
| 1847 | btrfs_tree_read_lock(eb); |
| 1848 | btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK); |
| 1849 | btrfs_release_path(path); |
| 1850 | |
Chris Mason | 2849a85 | 2015-10-13 14:06:48 -0400 | [diff] [blame] | 1851 | item_size = btrfs_item_size_nr(eb, slot); |
| 1852 | ptr = btrfs_item_ptr_offset(eb, slot); |
Mark Fasheh | d24bec3 | 2012-08-08 11:33:54 -0700 | [diff] [blame] | 1853 | cur_offset = 0; |
| 1854 | |
| 1855 | while (cur_offset < item_size) { |
| 1856 | u32 name_len; |
| 1857 | |
| 1858 | extref = (struct btrfs_inode_extref *)(ptr + cur_offset); |
| 1859 | parent = btrfs_inode_extref_parent(eb, extref); |
| 1860 | name_len = btrfs_inode_extref_name_len(eb, extref); |
| 1861 | ret = iterate(parent, name_len, |
| 1862 | (unsigned long)&extref->name, eb, ctx); |
| 1863 | if (ret) |
| 1864 | break; |
| 1865 | |
Chris Mason | 2849a85 | 2015-10-13 14:06:48 -0400 | [diff] [blame] | 1866 | cur_offset += btrfs_inode_extref_name_len(eb, extref); |
Mark Fasheh | d24bec3 | 2012-08-08 11:33:54 -0700 | [diff] [blame] | 1867 | cur_offset += sizeof(*extref); |
| 1868 | } |
| 1869 | btrfs_tree_read_unlock_blocking(eb); |
| 1870 | free_extent_buffer(eb); |
| 1871 | |
| 1872 | offset++; |
| 1873 | } |
| 1874 | |
| 1875 | btrfs_release_path(path); |
| 1876 | |
| 1877 | return ret; |
| 1878 | } |
| 1879 | |
| 1880 | static int iterate_irefs(u64 inum, struct btrfs_root *fs_root, |
| 1881 | struct btrfs_path *path, iterate_irefs_t *iterate, |
| 1882 | void *ctx) |
| 1883 | { |
| 1884 | int ret; |
| 1885 | int found_refs = 0; |
| 1886 | |
| 1887 | ret = iterate_inode_refs(inum, fs_root, path, iterate, ctx); |
| 1888 | if (!ret) |
| 1889 | ++found_refs; |
| 1890 | else if (ret != -ENOENT) |
| 1891 | return ret; |
| 1892 | |
| 1893 | ret = iterate_inode_extrefs(inum, fs_root, path, iterate, ctx); |
| 1894 | if (ret == -ENOENT && found_refs) |
| 1895 | return 0; |
| 1896 | |
| 1897 | return ret; |
| 1898 | } |
| 1899 | |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1900 | /* |
| 1901 | * returns 0 if the path could be dumped (probably truncated) |
| 1902 | * returns <0 in case of an error |
| 1903 | */ |
Mark Fasheh | d24bec3 | 2012-08-08 11:33:54 -0700 | [diff] [blame] | 1904 | static int inode_to_path(u64 inum, u32 name_len, unsigned long name_off, |
| 1905 | struct extent_buffer *eb, void *ctx) |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1906 | { |
| 1907 | struct inode_fs_paths *ipath = ctx; |
| 1908 | char *fspath; |
| 1909 | char *fspath_min; |
| 1910 | int i = ipath->fspath->elem_cnt; |
| 1911 | const int s_ptr = sizeof(char *); |
| 1912 | u32 bytes_left; |
| 1913 | |
| 1914 | bytes_left = ipath->fspath->bytes_left > s_ptr ? |
| 1915 | ipath->fspath->bytes_left - s_ptr : 0; |
| 1916 | |
Chris Mason | 740c3d2 | 2011-11-02 15:48:34 -0400 | [diff] [blame] | 1917 | fspath_min = (char *)ipath->fspath->val + (i + 1) * s_ptr; |
Jan Schmidt | 96b5bd7 | 2012-10-15 08:30:45 +0000 | [diff] [blame] | 1918 | fspath = btrfs_ref_to_path(ipath->fs_root, ipath->btrfs_path, name_len, |
| 1919 | name_off, eb, inum, fspath_min, bytes_left); |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1920 | if (IS_ERR(fspath)) |
| 1921 | return PTR_ERR(fspath); |
| 1922 | |
| 1923 | if (fspath > fspath_min) { |
Jeff Mahoney | 745c4d8 | 2011-11-20 07:31:57 -0500 | [diff] [blame] | 1924 | ipath->fspath->val[i] = (u64)(unsigned long)fspath; |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1925 | ++ipath->fspath->elem_cnt; |
| 1926 | ipath->fspath->bytes_left = fspath - fspath_min; |
| 1927 | } else { |
| 1928 | ++ipath->fspath->elem_missed; |
| 1929 | ipath->fspath->bytes_missing += fspath_min - fspath; |
| 1930 | ipath->fspath->bytes_left = 0; |
| 1931 | } |
| 1932 | |
| 1933 | return 0; |
| 1934 | } |
| 1935 | |
| 1936 | /* |
| 1937 | * this dumps all file system paths to the inode into the ipath struct, provided |
| 1938 | * 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] | 1939 | * from ipath->fspath->val[i]. |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1940 | * 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] | 1941 | * in ipath->fspath->val[]. when the allocated space wasn't sufficient, the |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1942 | * number of missed paths in recored in ipath->fspath->elem_missed, otherwise, |
| 1943 | * it's zero. ipath->fspath->bytes_missing holds the number of bytes that would |
| 1944 | * have been needed to return all paths. |
| 1945 | */ |
| 1946 | int paths_from_inode(u64 inum, struct inode_fs_paths *ipath) |
| 1947 | { |
| 1948 | return iterate_irefs(inum, ipath->fs_root, ipath->btrfs_path, |
Mark Fasheh | d24bec3 | 2012-08-08 11:33:54 -0700 | [diff] [blame] | 1949 | inode_to_path, ipath); |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1950 | } |
| 1951 | |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1952 | struct btrfs_data_container *init_data_container(u32 total_bytes) |
| 1953 | { |
| 1954 | struct btrfs_data_container *data; |
| 1955 | size_t alloc_bytes; |
| 1956 | |
| 1957 | alloc_bytes = max_t(size_t, total_bytes, sizeof(*data)); |
Liu Bo | 425d17a | 2012-09-07 20:01:30 -0600 | [diff] [blame] | 1958 | data = vmalloc(alloc_bytes); |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 1959 | if (!data) |
| 1960 | return ERR_PTR(-ENOMEM); |
| 1961 | |
| 1962 | if (total_bytes >= sizeof(*data)) { |
| 1963 | data->bytes_left = total_bytes - sizeof(*data); |
| 1964 | data->bytes_missing = 0; |
| 1965 | } else { |
| 1966 | data->bytes_missing = sizeof(*data) - total_bytes; |
| 1967 | data->bytes_left = 0; |
| 1968 | } |
| 1969 | |
| 1970 | data->elem_cnt = 0; |
| 1971 | data->elem_missed = 0; |
| 1972 | |
| 1973 | return data; |
| 1974 | } |
| 1975 | |
| 1976 | /* |
| 1977 | * allocates space to return multiple file system paths for an inode. |
| 1978 | * total_bytes to allocate are passed, note that space usable for actual path |
| 1979 | * information will be total_bytes - sizeof(struct inode_fs_paths). |
| 1980 | * the returned pointer must be freed with free_ipath() in the end. |
| 1981 | */ |
| 1982 | struct inode_fs_paths *init_ipath(s32 total_bytes, struct btrfs_root *fs_root, |
| 1983 | struct btrfs_path *path) |
| 1984 | { |
| 1985 | struct inode_fs_paths *ifp; |
| 1986 | struct btrfs_data_container *fspath; |
| 1987 | |
| 1988 | fspath = init_data_container(total_bytes); |
| 1989 | if (IS_ERR(fspath)) |
| 1990 | return (void *)fspath; |
| 1991 | |
| 1992 | ifp = kmalloc(sizeof(*ifp), GFP_NOFS); |
| 1993 | if (!ifp) { |
| 1994 | kfree(fspath); |
| 1995 | return ERR_PTR(-ENOMEM); |
| 1996 | } |
| 1997 | |
| 1998 | ifp->btrfs_path = path; |
| 1999 | ifp->fspath = fspath; |
| 2000 | ifp->fs_root = fs_root; |
| 2001 | |
| 2002 | return ifp; |
| 2003 | } |
| 2004 | |
| 2005 | void free_ipath(struct inode_fs_paths *ipath) |
| 2006 | { |
Jesper Juhl | 4735fb2 | 2012-04-12 22:47:52 +0200 | [diff] [blame] | 2007 | if (!ipath) |
| 2008 | return; |
Liu Bo | 425d17a | 2012-09-07 20:01:30 -0600 | [diff] [blame] | 2009 | vfree(ipath->fspath); |
Jan Schmidt | a542ad1 | 2011-06-13 19:52:59 +0200 | [diff] [blame] | 2010 | kfree(ipath); |
| 2011 | } |