2 * Copyright (C) 2010 Oracle. All rights reserved.
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
20 #include <sys/ioctl.h>
21 #include <sys/mount.h>
26 #include <sys/types.h>
32 #include "kerncompat.h"
34 #include "transaction.h"
38 /* we store all the roots we find in an rbtree so that we can
39 * search for them later.
46 * one of these for each root we find.
49 struct rb_node rb_node;
54 /* the id of the root that references this one */
57 /* the dir id we're in from ref_tree */
60 /* path from the subvol we live in to this root, including the
61 * root's name. This is null until we do the extra lookup ioctl.
65 /* the name of this root in the directory it lives in */
69 static void root_lookup_init(struct root_lookup *tree)
71 tree->root.rb_node = NULL;
74 static int comp_entry(struct root_info *entry, u64 root_id, u64 ref_tree)
76 if (entry->root_id > root_id)
78 if (entry->root_id < root_id)
80 if (entry->ref_tree > ref_tree)
82 if (entry->ref_tree < ref_tree)
88 * insert a new root into the tree. returns the existing root entry
89 * if one is already there. Both root_id and ref_tree are used
92 static struct rb_node *tree_insert(struct rb_root *root, u64 root_id,
93 u64 ref_tree, struct rb_node *node)
95 struct rb_node ** p = &root->rb_node;
96 struct rb_node * parent = NULL;
97 struct root_info *entry;
102 entry = rb_entry(parent, struct root_info, rb_node);
104 comp = comp_entry(entry, root_id, ref_tree);
114 entry = rb_entry(parent, struct root_info, rb_node);
115 rb_link_node(node, parent, p);
116 rb_insert_color(node, root);
121 * find a given root id in the tree. We return the smallest one,
122 * rb_next can be used to move forward looking for more if required
124 static struct root_info *tree_search(struct rb_root *root, u64 root_id)
126 struct rb_node * n = root->rb_node;
127 struct root_info *entry;
130 entry = rb_entry(n, struct root_info, rb_node);
132 if (entry->root_id < root_id)
134 else if (entry->root_id > root_id)
137 struct root_info *prev;
138 struct rb_node *prev_n;
143 prev = rb_entry(prev_n, struct root_info,
145 if (prev->root_id != root_id)
157 * this allocates a new root in the lookup tree.
159 * root_id should be the object id of the root
161 * ref_tree is the objectid of the referring root.
163 * dir_id is the directory in ref_tree where this root_id can be found.
165 * name is the name of root_id in that directory
167 * name_len is the length of name
169 static int add_root(struct root_lookup *root_lookup,
170 u64 root_id, u64 ref_tree, u64 dir_id, char *name,
173 struct root_info *ri;
175 ri = malloc(sizeof(*ri) + name_len + 1);
177 printf("memory allocation failed\n");
180 memset(ri, 0, sizeof(*ri) + name_len + 1);
183 ri->root_id = root_id;
184 ri->ref_tree = ref_tree;
185 strncpy(ri->name, name, name_len);
187 ret = tree_insert(&root_lookup->root, root_id, ref_tree, &ri->rb_node);
189 printf("failed to insert tree %llu\n", (unsigned long long)root_id);
196 * for a given root_info, search through the root_lookup tree to construct
197 * the full path name to it.
199 * This can't be called until all the root_info->path fields are filled
200 * in by lookup_ino_path
202 static int resolve_root(struct root_lookup *rl, struct root_info *ri)
205 char *full_path = NULL;
207 struct root_info *found;
210 * we go backwards from the root_info object and add pathnames
211 * from parent directories as we go.
217 int add_len = strlen(found->path);
219 /* room for / and for null */
220 tmp = malloc(add_len + 2 + len);
222 memcpy(tmp + add_len + 1, full_path, len);
224 memcpy(tmp, found->path, add_len);
225 tmp [add_len + len + 1] = '\0';
230 full_path = strdup(found->path);
234 next = found->ref_tree;
235 /* if the ref_tree refers to ourselves, we're at the top */
236 if (next == found->root_id) {
242 * if the ref_tree wasn't in our tree of roots, we're
245 found = tree_search(&rl->root, next);
251 printf("ID %llu top level %llu path %s\n", ri->root_id, top_id,
258 * for a single root_info, ask the kernel to give us a path name
259 * inside it's ref_root for the dir_id where it lives.
261 * This fills in root_info->path with the path to the directory and and
262 * appends this root's name.
264 static int lookup_ino_path(int fd, struct root_info *ri)
266 struct btrfs_ioctl_ino_lookup_args args;
272 memset(&args, 0, sizeof(args));
273 args.treeid = ri->ref_tree;
274 args.objectid = ri->dir_id;
276 ret = ioctl(fd, BTRFS_IOC_INO_LOOKUP, &args);
278 fprintf(stderr, "ERROR: Failed to lookup path for root %llu\n",
279 (unsigned long long)ri->ref_tree);
285 * we're in a subdirectory of ref_tree, the kernel ioctl
286 * puts a / in there for us
288 ri->path = malloc(strlen(ri->name) + strlen(args.name) + 1);
290 perror("malloc failed");
293 strcpy(ri->path, args.name);
294 strcat(ri->path, ri->name);
296 /* we're at the root of ref_tree */
297 ri->path = strdup(ri->name);
299 perror("strdup failed");
306 /* finding the generation for a given path is a two step process.
307 * First we use the inode loookup routine to find out the root id
309 * Then we use the tree search ioctl to scan all the root items for a
310 * given root id and spit out the latest generation we can find
312 static u64 find_root_gen(int fd)
314 struct btrfs_ioctl_ino_lookup_args ino_args;
316 struct btrfs_ioctl_search_args args;
317 struct btrfs_ioctl_search_key *sk = &args.key;
318 struct btrfs_ioctl_search_header *sh;
319 unsigned long off = 0;
323 memset(&ino_args, 0, sizeof(ino_args));
324 ino_args.objectid = BTRFS_FIRST_FREE_OBJECTID;
326 /* this ioctl fills in ino_args->treeid */
327 ret = ioctl(fd, BTRFS_IOC_INO_LOOKUP, &ino_args);
329 fprintf(stderr, "ERROR: Failed to lookup path for dirid %llu\n",
330 (unsigned long long)BTRFS_FIRST_FREE_OBJECTID);
334 memset(&args, 0, sizeof(args));
339 * there may be more than one ROOT_ITEM key if there are
340 * snapshots pending deletion, we have to loop through
343 sk->min_objectid = ino_args.treeid;
344 sk->max_objectid = ino_args.treeid;
345 sk->max_type = BTRFS_ROOT_ITEM_KEY;
346 sk->min_type = BTRFS_ROOT_ITEM_KEY;
347 sk->max_offset = (u64)-1;
348 sk->max_transid = (u64)-1;
352 ret = ioctl(fd, BTRFS_IOC_TREE_SEARCH, &args);
354 fprintf(stderr, "ERROR: can't perform the search\n");
357 /* the ioctl returns the number of item it found in nr_items */
358 if (sk->nr_items == 0)
362 for (i = 0; i < sk->nr_items; i++) {
363 struct btrfs_root_item *item;
364 sh = (struct btrfs_ioctl_search_header *)(args.buf +
368 item = (struct btrfs_root_item *)(args.buf + off);
371 sk->min_objectid = sh->objectid;
372 sk->min_type = sh->type;
373 sk->min_offset = sh->offset;
375 if (sh->objectid > ino_args.treeid)
378 if (sh->objectid == ino_args.treeid &&
379 sh->type == BTRFS_ROOT_ITEM_KEY) {
380 max_found = max(max_found,
381 btrfs_root_generation(item));
384 if (sk->min_offset < (u64)-1)
389 if (sk->min_type != BTRFS_ROOT_ITEM_KEY)
391 if (sk->min_objectid != BTRFS_ROOT_ITEM_KEY)
397 /* pass in a directory id and this will return
398 * the full path of the parent directory inside its
401 * It may return NULL if it is in the root, or an ERR_PTR if things
404 static char *__ino_resolve(int fd, u64 dirid)
406 struct btrfs_ioctl_ino_lookup_args args;
410 memset(&args, 0, sizeof(args));
411 args.objectid = dirid;
413 ret = ioctl(fd, BTRFS_IOC_INO_LOOKUP, &args);
415 fprintf(stderr, "ERROR: Failed to lookup path for dirid %llu\n",
416 (unsigned long long)dirid);
422 * we're in a subdirectory of ref_tree, the kernel ioctl
423 * puts a / in there for us
425 full = strdup(args.name);
427 perror("malloc failed");
428 return ERR_PTR(-ENOMEM);
431 /* we're at the root of ref_tree */
438 * simple string builder, returning a new string with both
441 char *build_name(char *dirid, char *name)
447 full = malloc(strlen(dirid) + strlen(name) + 1);
456 * given an inode number, this returns the full path name inside the subvolume
457 * to that file/directory. cache_dirid and cache_name are used to
458 * cache the results so we can avoid tree searches if a later call goes
459 * to the same directory or file name
461 static char *ino_resolve(int fd, u64 ino, u64 *cache_dirid, char **cache_name)
469 struct btrfs_ioctl_search_args args;
470 struct btrfs_ioctl_search_key *sk = &args.key;
471 struct btrfs_ioctl_search_header *sh;
472 unsigned long off = 0;
475 memset(&args, 0, sizeof(args));
480 * step one, we search for the inode back ref. We just use the first
483 sk->min_objectid = ino;
484 sk->max_objectid = ino;
485 sk->max_type = BTRFS_INODE_REF_KEY;
486 sk->max_offset = (u64)-1;
487 sk->min_type = BTRFS_INODE_REF_KEY;
488 sk->max_transid = (u64)-1;
491 ret = ioctl(fd, BTRFS_IOC_TREE_SEARCH, &args);
493 fprintf(stderr, "ERROR: can't perform the search\n");
496 /* the ioctl returns the number of item it found in nr_items */
497 if (sk->nr_items == 0)
501 sh = (struct btrfs_ioctl_search_header *)(args.buf + off);
503 if (sh->type == BTRFS_INODE_REF_KEY) {
504 struct btrfs_inode_ref *ref;
507 ref = (struct btrfs_inode_ref *)(sh + 1);
508 namelen = btrfs_stack_inode_ref_name_len(ref);
510 name = (char *)(ref + 1);
511 name = strndup(name, namelen);
513 /* use our cached value */
514 if (dirid == *cache_dirid && *cache_name) {
515 dirname = *cache_name;
522 * the inode backref gives us the file name and the parent directory id.
523 * From here we use __ino_resolve to get the path to the parent
525 dirname = __ino_resolve(fd, dirid);
527 full = build_name(dirname, name);
528 if (*cache_name && dirname != *cache_name)
531 *cache_name = dirname;
532 *cache_dirid = dirid;
538 int list_subvols(int fd)
540 struct root_lookup root_lookup;
543 struct btrfs_ioctl_search_args args;
544 struct btrfs_ioctl_search_key *sk = &args.key;
545 struct btrfs_ioctl_search_header *sh;
546 struct btrfs_root_ref *ref;
547 unsigned long off = 0;
553 root_lookup_init(&root_lookup);
555 memset(&args, 0, sizeof(args));
557 /* search in the tree of tree roots */
561 * set the min and max to backref keys. The search will
562 * only send back this type of key now.
564 sk->max_type = BTRFS_ROOT_BACKREF_KEY;
565 sk->min_type = BTRFS_ROOT_BACKREF_KEY;
568 * set all the other params to the max, we'll take any objectid
571 sk->max_objectid = (u64)-1;
572 sk->max_offset = (u64)-1;
573 sk->max_transid = (u64)-1;
575 /* just a big number, doesn't matter much */
579 ret = ioctl(fd, BTRFS_IOC_TREE_SEARCH, &args);
581 fprintf(stderr, "ERROR: can't perform the search\n");
584 /* the ioctl returns the number of item it found in nr_items */
585 if (sk->nr_items == 0)
591 * for each item, pull the key out of the header and then
592 * read the root_ref item it contains
594 for (i = 0; i < sk->nr_items; i++) {
595 sh = (struct btrfs_ioctl_search_header *)(args.buf +
598 if (sh->type == BTRFS_ROOT_BACKREF_KEY) {
599 ref = (struct btrfs_root_ref *)(args.buf + off);
600 name_len = btrfs_stack_root_ref_name_len(ref);
601 name = (char *)(ref + 1);
602 dir_id = btrfs_stack_root_ref_dirid(ref);
604 add_root(&root_lookup, sh->objectid, sh->offset,
605 dir_id, name, name_len);
611 * record the mins in sk so we can make sure the
612 * next search doesn't repeat this root
614 sk->min_objectid = sh->objectid;
615 sk->min_type = sh->type;
616 sk->min_offset = sh->offset;
619 /* this iteration is done, step forward one root for the next
622 if (sk->min_objectid < (u64)-1) {
624 sk->min_type = BTRFS_ROOT_BACKREF_KEY;
630 * now we have an rbtree full of root_info objects, but we need to fill
631 * in their path names within the subvol that is referencing each one.
633 n = rb_first(&root_lookup.root);
635 struct root_info *entry;
637 entry = rb_entry(n, struct root_info, rb_node);
638 ret = lookup_ino_path(fd, entry);
644 /* now that we have all the subvol-relative paths filled in,
645 * we have to string the subvols together so that we can get
646 * a path all the way back to the FS root
648 n = rb_last(&root_lookup.root);
650 struct root_info *entry;
651 entry = rb_entry(n, struct root_info, rb_node);
652 resolve_root(&root_lookup, entry);
659 static int print_one_extent(int fd, struct btrfs_ioctl_search_header *sh,
660 struct btrfs_file_extent_item *item,
661 u64 found_gen, u64 *cache_dirid,
662 char **cache_dir_name, u64 *cache_ino,
663 char **cache_full_name)
673 if (sh->objectid == *cache_ino) {
674 name = *cache_full_name;
675 } else if (*cache_full_name) {
676 free(*cache_full_name);
677 *cache_full_name = NULL;
680 name = ino_resolve(fd, sh->objectid, cache_dirid,
682 *cache_full_name = name;
683 *cache_ino = sh->objectid;
688 type = btrfs_stack_file_extent_type(item);
689 compressed = btrfs_stack_file_extent_compression(item);
691 if (type == BTRFS_FILE_EXTENT_REG ||
692 type == BTRFS_FILE_EXTENT_PREALLOC) {
693 disk_start = btrfs_stack_file_extent_disk_bytenr(item);
694 disk_offset = btrfs_stack_file_extent_offset(item);
695 len = btrfs_stack_file_extent_num_bytes(item);
696 } else if (type == BTRFS_FILE_EXTENT_INLINE) {
699 len = btrfs_stack_file_extent_ram_bytes(item);
701 printf("inode %llu file offset %llu len %llu disk start %llu "
702 "offset %llu gen %llu flags ",
703 (unsigned long long)sh->objectid,
704 (unsigned long long)sh->offset,
705 (unsigned long long)len,
706 (unsigned long long)disk_start,
707 (unsigned long long)disk_offset,
708 (unsigned long long)found_gen);
714 if (type == BTRFS_FILE_EXTENT_PREALLOC) {
715 printf("%sPREALLOC", flags ? "|" : "");
718 if (type == BTRFS_FILE_EXTENT_INLINE) {
719 printf("%sINLINE", flags ? "|" : "");
725 printf(" %s\n", name);
729 int find_updated_files(int fd, u64 root_id, u64 oldest_gen)
732 struct btrfs_ioctl_search_args args;
733 struct btrfs_ioctl_search_key *sk = &args.key;
734 struct btrfs_ioctl_search_header *sh;
735 struct btrfs_file_extent_item *item;
736 unsigned long off = 0;
742 char *cache_dir_name = NULL;
743 char *cache_full_name = NULL;
744 struct btrfs_file_extent_item backup;
746 memset(&backup, 0, sizeof(backup));
747 memset(&args, 0, sizeof(args));
749 sk->tree_id = root_id;
752 * set all the other params to the max, we'll take any objectid
755 sk->max_objectid = (u64)-1;
756 sk->max_offset = (u64)-1;
757 sk->max_transid = (u64)-1;
758 sk->max_type = BTRFS_EXTENT_DATA_KEY;
759 sk->min_transid = oldest_gen;
760 /* just a big number, doesn't matter much */
763 max_found = find_root_gen(fd);
765 ret = ioctl(fd, BTRFS_IOC_TREE_SEARCH, &args);
767 fprintf(stderr, "ERROR: can't perform the search\n");
770 /* the ioctl returns the number of item it found in nr_items */
771 if (sk->nr_items == 0)
777 * for each item, pull the key out of the header and then
778 * read the root_ref item it contains
780 for (i = 0; i < sk->nr_items; i++) {
781 sh = (struct btrfs_ioctl_search_header *)(args.buf +
786 * just in case the item was too big, pass something other
792 item = (struct btrfs_file_extent_item *)(args.buf +
794 found_gen = btrfs_stack_file_extent_generation(item);
795 if (sh->type == BTRFS_EXTENT_DATA_KEY &&
796 found_gen >= oldest_gen) {
797 print_one_extent(fd, sh, item, found_gen,
798 &cache_dirid, &cache_dir_name,
799 &cache_ino, &cache_full_name);
804 * record the mins in sk so we can make sure the
805 * next search doesn't repeat this root
807 sk->min_objectid = sh->objectid;
808 sk->min_offset = sh->offset;
809 sk->min_type = sh->type;
812 if (sk->min_offset < (u64)-1)
814 else if (sk->min_objectid < (u64)-1) {
821 free(cache_dir_name);
822 free(cache_full_name);
823 printf("transid marker was %llu\n", (unsigned long long)max_found);