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.
21 #include <sys/ioctl.h>
22 #include <sys/mount.h>
27 #include <sys/types.h>
33 #include "kerncompat.h"
35 #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,
203 u64 *root_id, u64 *parent_id, u64 *top_id, char **path)
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.
218 int add_len = strlen(found->path);
220 /* room for / and for null */
221 tmp = malloc(add_len + 2 + len);
223 memcpy(tmp + add_len + 1, full_path, len);
225 memcpy(tmp, found->path, add_len);
226 tmp [add_len + len + 1] = '\0';
231 full_path = strdup(found->path);
235 next = found->ref_tree;
236 /* record the first parent */
240 /* if the ref_tree refers to ourselves, we're at the top */
241 if (next == found->root_id) {
247 * if the ref_tree wasn't in our tree of roots, we're
250 found = tree_search(&rl->root, next);
257 *root_id = ri->root_id;
264 * for a single root_info, ask the kernel to give us a path name
265 * inside it's ref_root for the dir_id where it lives.
267 * This fills in root_info->path with the path to the directory and and
268 * appends this root's name.
270 static int lookup_ino_path(int fd, struct root_info *ri)
272 struct btrfs_ioctl_ino_lookup_args args;
278 memset(&args, 0, sizeof(args));
279 args.treeid = ri->ref_tree;
280 args.objectid = ri->dir_id;
282 ret = ioctl(fd, BTRFS_IOC_INO_LOOKUP, &args);
285 fprintf(stderr, "ERROR: Failed to lookup path for root %llu - %s\n",
286 (unsigned long long)ri->ref_tree,
293 * we're in a subdirectory of ref_tree, the kernel ioctl
294 * puts a / in there for us
296 ri->path = malloc(strlen(ri->name) + strlen(args.name) + 1);
298 perror("malloc failed");
301 strcpy(ri->path, args.name);
302 strcat(ri->path, ri->name);
304 /* we're at the root of ref_tree */
305 ri->path = strdup(ri->name);
307 perror("strdup failed");
314 /* finding the generation for a given path is a two step process.
315 * First we use the inode loookup routine to find out the root id
317 * Then we use the tree search ioctl to scan all the root items for a
318 * given root id and spit out the latest generation we can find
320 static u64 find_root_gen(int fd)
322 struct btrfs_ioctl_ino_lookup_args ino_args;
324 struct btrfs_ioctl_search_args args;
325 struct btrfs_ioctl_search_key *sk = &args.key;
326 struct btrfs_ioctl_search_header *sh;
327 unsigned long off = 0;
332 memset(&ino_args, 0, sizeof(ino_args));
333 ino_args.objectid = BTRFS_FIRST_FREE_OBJECTID;
335 /* this ioctl fills in ino_args->treeid */
336 ret = ioctl(fd, BTRFS_IOC_INO_LOOKUP, &ino_args);
339 fprintf(stderr, "ERROR: Failed to lookup path for dirid %llu - %s\n",
340 (unsigned long long)BTRFS_FIRST_FREE_OBJECTID,
345 memset(&args, 0, sizeof(args));
350 * there may be more than one ROOT_ITEM key if there are
351 * snapshots pending deletion, we have to loop through
354 sk->min_objectid = ino_args.treeid;
355 sk->max_objectid = ino_args.treeid;
356 sk->max_type = BTRFS_ROOT_ITEM_KEY;
357 sk->min_type = BTRFS_ROOT_ITEM_KEY;
358 sk->max_offset = (u64)-1;
359 sk->max_transid = (u64)-1;
363 ret = ioctl(fd, BTRFS_IOC_TREE_SEARCH, &args);
366 fprintf(stderr, "ERROR: can't perform the search - %s\n",
370 /* the ioctl returns the number of item it found in nr_items */
371 if (sk->nr_items == 0)
375 for (i = 0; i < sk->nr_items; i++) {
376 struct btrfs_root_item *item;
377 sh = (struct btrfs_ioctl_search_header *)(args.buf +
381 item = (struct btrfs_root_item *)(args.buf + off);
384 sk->min_objectid = sh->objectid;
385 sk->min_type = sh->type;
386 sk->min_offset = sh->offset;
388 if (sh->objectid > ino_args.treeid)
391 if (sh->objectid == ino_args.treeid &&
392 sh->type == BTRFS_ROOT_ITEM_KEY) {
393 max_found = max(max_found,
394 btrfs_root_generation(item));
397 if (sk->min_offset < (u64)-1)
402 if (sk->min_type != BTRFS_ROOT_ITEM_KEY)
404 if (sk->min_objectid != BTRFS_ROOT_ITEM_KEY)
410 /* pass in a directory id and this will return
411 * the full path of the parent directory inside its
414 * It may return NULL if it is in the root, or an ERR_PTR if things
417 static char *__ino_resolve(int fd, u64 dirid)
419 struct btrfs_ioctl_ino_lookup_args args;
424 memset(&args, 0, sizeof(args));
425 args.objectid = dirid;
427 ret = ioctl(fd, BTRFS_IOC_INO_LOOKUP, &args);
430 fprintf(stderr, "ERROR: Failed to lookup path for dirid %llu - %s\n",
431 (unsigned long long)dirid, strerror(e) );
437 * we're in a subdirectory of ref_tree, the kernel ioctl
438 * puts a / in there for us
440 full = strdup(args.name);
442 perror("malloc failed");
443 return ERR_PTR(-ENOMEM);
446 /* we're at the root of ref_tree */
453 * simple string builder, returning a new string with both
456 char *build_name(char *dirid, char *name)
462 full = malloc(strlen(dirid) + strlen(name) + 1);
471 * given an inode number, this returns the full path name inside the subvolume
472 * to that file/directory. cache_dirid and cache_name are used to
473 * cache the results so we can avoid tree searches if a later call goes
474 * to the same directory or file name
476 static char *ino_resolve(int fd, u64 ino, u64 *cache_dirid, char **cache_name)
484 struct btrfs_ioctl_search_args args;
485 struct btrfs_ioctl_search_key *sk = &args.key;
486 struct btrfs_ioctl_search_header *sh;
487 unsigned long off = 0;
491 memset(&args, 0, sizeof(args));
496 * step one, we search for the inode back ref. We just use the first
499 sk->min_objectid = ino;
500 sk->max_objectid = ino;
501 sk->max_type = BTRFS_INODE_REF_KEY;
502 sk->max_offset = (u64)-1;
503 sk->min_type = BTRFS_INODE_REF_KEY;
504 sk->max_transid = (u64)-1;
507 ret = ioctl(fd, BTRFS_IOC_TREE_SEARCH, &args);
510 fprintf(stderr, "ERROR: can't perform the search - %s\n",
514 /* the ioctl returns the number of item it found in nr_items */
515 if (sk->nr_items == 0)
519 sh = (struct btrfs_ioctl_search_header *)(args.buf + off);
521 if (sh->type == BTRFS_INODE_REF_KEY) {
522 struct btrfs_inode_ref *ref;
525 ref = (struct btrfs_inode_ref *)(sh + 1);
526 namelen = btrfs_stack_inode_ref_name_len(ref);
528 name = (char *)(ref + 1);
529 name = strndup(name, namelen);
531 /* use our cached value */
532 if (dirid == *cache_dirid && *cache_name) {
533 dirname = *cache_name;
540 * the inode backref gives us the file name and the parent directory id.
541 * From here we use __ino_resolve to get the path to the parent
543 dirname = __ino_resolve(fd, dirid);
545 full = build_name(dirname, name);
546 if (*cache_name && dirname != *cache_name)
549 *cache_name = dirname;
550 *cache_dirid = dirid;
556 static int __list_subvol_search(int fd, struct root_lookup *root_lookup)
559 struct btrfs_ioctl_search_args args;
560 struct btrfs_ioctl_search_key *sk = &args.key;
561 struct btrfs_ioctl_search_header *sh;
562 struct btrfs_root_ref *ref;
563 unsigned long off = 0;
569 root_lookup_init(root_lookup);
570 memset(&args, 0, sizeof(args));
572 root_lookup_init(root_lookup);
574 memset(&args, 0, sizeof(args));
576 /* search in the tree of tree roots */
580 * set the min and max to backref keys. The search will
581 * only send back this type of key now.
583 sk->max_type = BTRFS_ROOT_BACKREF_KEY;
584 sk->min_type = BTRFS_ROOT_BACKREF_KEY;
587 * set all the other params to the max, we'll take any objectid
590 sk->max_objectid = (u64)-1;
591 sk->max_offset = (u64)-1;
592 sk->max_transid = (u64)-1;
594 /* just a big number, doesn't matter much */
598 ret = ioctl(fd, BTRFS_IOC_TREE_SEARCH, &args);
601 /* the ioctl returns the number of item it found in nr_items */
602 if (sk->nr_items == 0)
608 * for each item, pull the key out of the header and then
609 * read the root_ref item it contains
611 for (i = 0; i < sk->nr_items; i++) {
612 sh = (struct btrfs_ioctl_search_header *)(args.buf +
615 if (sh->type == BTRFS_ROOT_BACKREF_KEY) {
616 ref = (struct btrfs_root_ref *)(args.buf + off);
617 name_len = btrfs_stack_root_ref_name_len(ref);
618 name = (char *)(ref + 1);
619 dir_id = btrfs_stack_root_ref_dirid(ref);
621 add_root(root_lookup, sh->objectid, sh->offset,
622 dir_id, name, name_len);
628 * record the mins in sk so we can make sure the
629 * next search doesn't repeat this root
631 sk->min_objectid = sh->objectid;
632 sk->min_type = sh->type;
633 sk->min_offset = sh->offset;
636 /* this iteration is done, step forward one root for the next
639 if (sk->min_objectid < (u64)-1) {
641 sk->min_type = BTRFS_ROOT_BACKREF_KEY;
650 static int __list_subvol_fill_paths(int fd, struct root_lookup *root_lookup)
654 n = rb_first(&root_lookup->root);
656 struct root_info *entry;
658 entry = rb_entry(n, struct root_info, rb_node);
659 ret = lookup_ino_path(fd, entry);
668 int list_subvols(int fd, int print_parent)
670 struct root_lookup root_lookup;
674 ret = __list_subvol_search(fd, &root_lookup);
676 fprintf(stderr, "ERROR: can't perform the search - %s\n",
682 * now we have an rbtree full of root_info objects, but we need to fill
683 * in their path names within the subvol that is referencing each one.
685 ret = __list_subvol_fill_paths(fd, &root_lookup);
689 /* now that we have all the subvol-relative paths filled in,
690 * we have to string the subvols together so that we can get
691 * a path all the way back to the FS root
693 n = rb_last(&root_lookup.root);
695 struct root_info *entry;
700 entry = rb_entry(n, struct root_info, rb_node);
701 resolve_root(&root_lookup, entry, &root_id, &parent_id,
704 printf("ID %llu parent %llu top level %llu path %s\n",
705 (unsigned long long)root_id,
706 (unsigned long long)parent_id,
707 (unsigned long long)level, path);
709 printf("ID %llu top level %llu path %s\n",
710 (unsigned long long)root_id,
711 (unsigned long long)level, path);
720 static int print_one_extent(int fd, struct btrfs_ioctl_search_header *sh,
721 struct btrfs_file_extent_item *item,
722 u64 found_gen, u64 *cache_dirid,
723 char **cache_dir_name, u64 *cache_ino,
724 char **cache_full_name)
734 if (sh->objectid == *cache_ino) {
735 name = *cache_full_name;
736 } else if (*cache_full_name) {
737 free(*cache_full_name);
738 *cache_full_name = NULL;
741 name = ino_resolve(fd, sh->objectid, cache_dirid,
743 *cache_full_name = name;
744 *cache_ino = sh->objectid;
749 type = btrfs_stack_file_extent_type(item);
750 compressed = btrfs_stack_file_extent_compression(item);
752 if (type == BTRFS_FILE_EXTENT_REG ||
753 type == BTRFS_FILE_EXTENT_PREALLOC) {
754 disk_start = btrfs_stack_file_extent_disk_bytenr(item);
755 disk_offset = btrfs_stack_file_extent_offset(item);
756 len = btrfs_stack_file_extent_num_bytes(item);
757 } else if (type == BTRFS_FILE_EXTENT_INLINE) {
760 len = btrfs_stack_file_extent_ram_bytes(item);
762 printf("unhandled extent type %d for inode %llu "
763 "file offset %llu gen %llu\n",
765 (unsigned long long)sh->objectid,
766 (unsigned long long)sh->offset,
767 (unsigned long long)found_gen);
771 printf("inode %llu file offset %llu len %llu disk start %llu "
772 "offset %llu gen %llu flags ",
773 (unsigned long long)sh->objectid,
774 (unsigned long long)sh->offset,
775 (unsigned long long)len,
776 (unsigned long long)disk_start,
777 (unsigned long long)disk_offset,
778 (unsigned long long)found_gen);
784 if (type == BTRFS_FILE_EXTENT_PREALLOC) {
785 printf("%sPREALLOC", flags ? "|" : "");
788 if (type == BTRFS_FILE_EXTENT_INLINE) {
789 printf("%sINLINE", flags ? "|" : "");
795 printf(" %s\n", name);
799 int find_updated_files(int fd, u64 root_id, u64 oldest_gen)
802 struct btrfs_ioctl_search_args args;
803 struct btrfs_ioctl_search_key *sk = &args.key;
804 struct btrfs_ioctl_search_header *sh;
805 struct btrfs_file_extent_item *item;
806 unsigned long off = 0;
813 char *cache_dir_name = NULL;
814 char *cache_full_name = NULL;
815 struct btrfs_file_extent_item backup;
817 memset(&backup, 0, sizeof(backup));
818 memset(&args, 0, sizeof(args));
820 sk->tree_id = root_id;
823 * set all the other params to the max, we'll take any objectid
826 sk->max_objectid = (u64)-1;
827 sk->max_offset = (u64)-1;
828 sk->max_transid = (u64)-1;
829 sk->max_type = BTRFS_EXTENT_DATA_KEY;
830 sk->min_transid = oldest_gen;
831 /* just a big number, doesn't matter much */
834 max_found = find_root_gen(fd);
836 ret = ioctl(fd, BTRFS_IOC_TREE_SEARCH, &args);
839 fprintf(stderr, "ERROR: can't perform the search- %s\n",
843 /* the ioctl returns the number of item it found in nr_items */
844 if (sk->nr_items == 0)
850 * for each item, pull the key out of the header and then
851 * read the root_ref item it contains
853 for (i = 0; i < sk->nr_items; i++) {
854 sh = (struct btrfs_ioctl_search_header *)(args.buf +
859 * just in case the item was too big, pass something other
865 item = (struct btrfs_file_extent_item *)(args.buf +
867 found_gen = btrfs_stack_file_extent_generation(item);
868 if (sh->type == BTRFS_EXTENT_DATA_KEY &&
869 found_gen >= oldest_gen) {
870 print_one_extent(fd, sh, item, found_gen,
871 &cache_dirid, &cache_dir_name,
872 &cache_ino, &cache_full_name);
877 * record the mins in sk so we can make sure the
878 * next search doesn't repeat this root
880 sk->min_objectid = sh->objectid;
881 sk->min_offset = sh->offset;
882 sk->min_type = sh->type;
885 if (sk->min_offset < (u64)-1)
887 else if (sk->min_objectid < (u64)-1) {
894 free(cache_dir_name);
895 free(cache_full_name);
896 printf("transid marker was %llu\n", (unsigned long long)max_found);