diff --git a/Makefile b/Makefile index 02f881e4..f2a9d41a 100644 --- a/Makefile +++ b/Makefile @@ -17,7 +17,7 @@ bindir = $(prefix)/bin LIBS=-luuid progs = btrfsctl mkfs.btrfs btrfs-debug-tree btrfs-show btrfs-vol btrfsck \ - btrfs-map-logical + btrfs-map-logical btrfs-list # make C=1 to enable sparse ifdef C @@ -36,6 +36,9 @@ all: version $(progs) manpages version: bash version.sh +btrfs-list: $(objects) btrfs-list.o + gcc $(CFLAGS) -o btrfs-list btrfs-list.o $(objects) $(LDFLAGS) $(LIBS) + btrfsctl: $(objects) btrfsctl.o gcc $(CFLAGS) -o btrfsctl btrfsctl.o $(objects) $(LDFLAGS) $(LIBS) diff --git a/btrfs-list.c b/btrfs-list.c new file mode 100644 index 00000000..c922f097 --- /dev/null +++ b/btrfs-list.c @@ -0,0 +1,466 @@ +/* + * Copyright (C) 2010 Oracle. All rights reserved. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public + * License v2 as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public + * License along with this program; if not, write to the + * Free Software Foundation, Inc., 59 Temple Place - Suite 330, + * Boston, MA 021110-1307, USA. + */ + +#ifndef __CHECKER__ +#include +#include +#include "ioctl.h" +#endif +#include +#include +#include +#include +#include +#include +#include +#include +#include "kerncompat.h" +#include "ctree.h" +#include "transaction.h" +#include "utils.h" +#include "version.h" + +/* we store all the roots we find in an rbtree so that we can + * search for them later. + */ +struct root_lookup { + struct rb_root root; +}; + +/* + * one of these for each root we find. + */ +struct root_info { + struct rb_node rb_node; + + /* this root's id */ + u64 root_id; + + /* the id of the root that references this one */ + u64 ref_tree; + + /* the dir id we're in from ref_tree */ + u64 dir_id; + + /* path from the subvol we live in to this root, including the + * root's name. This is null until we do the extra lookup ioctl. + */ + char *path; + + /* the name of this root in the directory it lives in */ + char name[]; +}; + +void root_lookup_init(struct root_lookup *tree) +{ + tree->root.rb_node = NULL; +} + +static int comp_entry(struct root_info *entry, u64 root_id, u64 ref_tree) +{ + if (entry->root_id > root_id) + return 1; + if (entry->root_id < root_id) + return -1; + if (entry->ref_tree > ref_tree) + return 1; + if (entry->ref_tree < ref_tree) + return -1; + return 0; +} + +/* + * insert a new root into the tree. returns the existing root entry + * if one is already there. Both root_id and ref_tree are used + * as the key + */ +static struct rb_node *tree_insert(struct rb_root *root, u64 root_id, + u64 ref_tree, struct rb_node *node) +{ + struct rb_node ** p = &root->rb_node; + struct rb_node * parent = NULL; + struct root_info *entry; + int comp; + + while(*p) { + parent = *p; + entry = rb_entry(parent, struct root_info, rb_node); + + comp = comp_entry(entry, root_id, ref_tree); + + if (comp < 0) + p = &(*p)->rb_left; + else if (comp > 0) + p = &(*p)->rb_right; + else + return parent; + } + + entry = rb_entry(parent, struct root_info, rb_node); + rb_link_node(node, parent, p); + rb_insert_color(node, root); + return NULL; +} + +/* + * find a given root id in the tree. We return the smallest one, + * rb_next can be used to move forward looking for more if required + */ +static struct root_info *tree_search(struct rb_root *root, u64 root_id) +{ + struct rb_node * n = root->rb_node; + struct root_info *entry; + + while(n) { + entry = rb_entry(n, struct root_info, rb_node); + + if (entry->root_id < root_id) + n = n->rb_left; + else if (entry->root_id > root_id) + n = n->rb_right; + else { + struct root_info *prev; + struct rb_node *prev_n; + while (1) { + prev_n = rb_prev(n); + if (!prev_n) + break; + prev = rb_entry(prev_n, struct root_info, + rb_node); + if (prev->root_id != root_id) + break; + entry = prev; + n = prev_n; + } + return entry; + } + } + return NULL; +} + +/* + * helper to open either a file or directory so that + * we can run ioctls on it. + */ +static int open_file_or_dir(const char *fname) +{ + int ret; + struct stat st; + DIR *dirstream; + int fd; + + ret = stat(fname, &st); + if (ret < 0) { + perror("stat:"); + exit(1); + } + if (S_ISDIR(st.st_mode)) { + dirstream = opendir(fname); + if (!dirstream) { + perror("opendir"); + exit(1); + } + fd = dirfd(dirstream); + } else { + fd = open(fname, O_RDWR); + } + if (fd < 0) { + perror("open"); + exit(1); + } + return fd; +} + +/* + * this allocates a new root in the lookup tree. + * + * root_id should be the object id of the root + * + * ref_tree is the objectid of the referring root. + * + * dir_id is the directory in ref_tree where this root_id can be found. + * + * name is the name of root_id in that directory + * + * name_len is the length of name + */ +static int add_root(struct root_lookup *root_lookup, + u64 root_id, u64 ref_tree, u64 dir_id, char *name, + int name_len) +{ + struct root_info *ri; + struct rb_node *ret; + ri = malloc(sizeof(*ri) + name_len); + if (!ri) { + printf("memory allocation failed\n"); + exit(1); + } + ri->path = NULL; + ri->dir_id = dir_id; + ri->root_id = root_id; + ri->ref_tree = ref_tree; + strncpy(ri->name, name, name_len); + + ret = tree_insert(&root_lookup->root, root_id, ref_tree, &ri->rb_node); + if (ret) { + printf("failed to insert tree %llu\n", (unsigned long long)root_id); + exit(1); + } + return 0; +} + +/* + * for a given root_info, search through the root_lookup tree to construct + * the full path name to it. + * + * This can't be called until all the root_info->path fields are filled + * in by lookup_ino_path + */ +static int resolve_root(struct root_lookup *rl, struct root_info *ri) +{ + u64 top_id; + char *full_path = NULL; + int len = 0; + struct root_info *found; + + /* + * we go backwards from the root_info object and add pathnames + * from parent directories as we go. + */ + found = ri; + while (1) { + char *tmp; + u64 next; + int add_len = strlen(found->path); + + /* room for / and for null */ + tmp = malloc(add_len + 2 + len); + if (full_path) { + memcpy(tmp + add_len + 1, full_path, len); + tmp[add_len] = '/'; + memcpy(tmp, found->path, add_len); + tmp [add_len + len + 1] = '\0'; + free(full_path); + full_path = tmp; + len += add_len + 1; + } else { + full_path = strdup(found->path); + len = add_len; + } + + next = found->ref_tree; + /* if the ref_tree refers to ourselves, we're at the top */ + if (next == found->root_id) { + top_id = next; + break; + } + + /* + * if the ref_tree wasn't in our tree of roots, we're + * at the top + */ + found = tree_search(&rl->root, next); + if (!found) { + top_id = next; + break; + } + } + printf("ID %llu top level %llu path %s\n", ri->root_id, top_id, + full_path); + free(full_path); + return 0; +} + +/* + * for a single root_info, ask the kernel to give us a path name + * inside it's ref_root for the dir_id where it lives. + * + * This fills in root_info->path with the path to the directory and and + * appends this root's name. + */ +static int lookup_ino_path(int fd, struct root_info *ri) +{ + struct btrfs_ioctl_ino_lookup_args args; + int ret; + + if (ri->path) + return 0; + + args.treeid = ri->ref_tree; + args.objectid = ri->dir_id; + args.name[0] = '\0'; + + ret = ioctl(fd, BTRFS_IOC_INO_LOOKUP, &args); + if (ret) { + fprintf(stderr, "Failed to lookup path for root %llu\n", + (unsigned long long)ri->ref_tree); + exit(1); + } + + if (args.name[0]) { + /* + * we're in a subdirectory of ref_tree, the kernel ioctl + * puts a / in there for us + */ + ri->path = malloc(strlen(ri->name) + strlen(args.name) + 1); + if (!ri->path) { + perror("malloc failed"); + exit(1); + } + strcpy(ri->path, args.name); + strcat(ri->path, ri->name); + } else { + /* we're at the root of ref_tree */ + ri->path = strdup(ri->name); + if (!ri->path) { + perror("strdup failed"); + exit(1); + } + } + return 0; +} + +static int list_subvols(int fd) +{ + struct root_lookup root_lookup; + struct rb_node *n; + int ret; + struct btrfs_ioctl_search_args args; + struct btrfs_ioctl_search_key *sk = &args.key; + struct btrfs_ioctl_search_header *sh; + struct btrfs_root_ref *ref; + unsigned long off = 0; + int name_len; + char *name; + u64 dir_id; + int i; + + root_lookup_init(&root_lookup); + + memset(&args, 0, sizeof(args)); + + /* search in the tree of tree roots */ + sk->tree_id = 1; + + /* + * set the min and max to backref keys. The search will + * only send back this type of key now. + */ + sk->max_type = BTRFS_ROOT_BACKREF_KEY; + sk->min_type = BTRFS_ROOT_BACKREF_KEY; + + /* + * set all the other params to the max, we'll take any objectid + * and any trans + */ + sk->max_objectid = (u64)-1; + sk->max_offset = (u64)-1; + sk->max_transid = (u64)-1; + + /* just a big number, doesn't matter much */ + sk->nr_items = 4096; + + while(1) { + ret = ioctl(fd, BTRFS_IOC_TREE_SEARCH, &args); + if (ret < 0) { + perror("ioctl:"); + break; + } + /* the ioctl returns the number of item it found in nr_items */ + if (sk->nr_items == 0) + break; + + off = 0; + + /* + * for each item, pull the key out of the header and then + * read the root_ref item it contains + */ + for (i = 0; i < sk->nr_items; i++) { + sh = (struct btrfs_ioctl_search_header *)(args.buf + + off); + off += sizeof(*sh); + + ref = (struct btrfs_root_ref *)(args.buf + off); + name_len = btrfs_stack_root_ref_name_len(ref); + name = (char *)(ref + 1); + dir_id = btrfs_stack_root_ref_dirid(ref); + + add_root(&root_lookup, sh->objectid, sh->offset, + dir_id, name, name_len); + + off += sh->len; + + /* + * record the mins in sk so we can make sure the + * next search doesn't repeat this root + */ + sk->min_objectid = sh->objectid; + sk->min_type = sh->type; + sk->min_offset = sh->offset; + } + sk->nr_items = 4096; + /* this iteration is done, step forward one root for the next + * ioctl + */ + if (sk->min_objectid < (u64)-1) + sk->min_objectid++; + else + break; + } + /* + * now we have an rbtree full of root_info objects, but we need to fill + * in their path names within the subvol that is referencing each one. + */ + n = rb_first(&root_lookup.root); + while (n) { + struct root_info *entry; + entry = rb_entry(n, struct root_info, rb_node); + lookup_ino_path(fd, entry); + n = rb_next(n); + } + + /* now that we have all the subvol-relative paths filled in, + * we have to string the subvols together so that we can get + * a path all the way back to the FS root + */ + n = rb_last(&root_lookup.root); + while (n) { + struct root_info *entry; + entry = rb_entry(n, struct root_info, rb_node); + resolve_root(&root_lookup, entry); + n = rb_prev(n); + } + + printf("%s\n", BTRFS_BUILD_VERSION); + return ret; +} + +int main(int ac, char **av) +{ + int fd; + + if (ac != 2) { + fprintf(stderr, "usage: btrfs-list mount_point\n"); + exit(1); + } + fd = open_file_or_dir(av[1]); + + return list_subvols(fd); +} + diff --git a/ctree.h b/ctree.h index a9062ea8..8c764cea 100644 --- a/ctree.h +++ b/ctree.h @@ -1325,6 +1325,10 @@ BTRFS_SETGET_FUNCS(root_ref_dirid, struct btrfs_root_ref, dirid, 64); BTRFS_SETGET_FUNCS(root_ref_sequence, struct btrfs_root_ref, sequence, 64); BTRFS_SETGET_FUNCS(root_ref_name_len, struct btrfs_root_ref, name_len, 16); +BTRFS_SETGET_STACK_FUNCS(stack_root_ref_dirid, struct btrfs_root_ref, dirid, 64); +BTRFS_SETGET_STACK_FUNCS(stack_root_ref_sequence, struct btrfs_root_ref, sequence, 64); +BTRFS_SETGET_STACK_FUNCS(stack_root_ref_name_len, struct btrfs_root_ref, name_len, 16); + /* struct btrfs_dir_item */ BTRFS_SETGET_FUNCS(dir_data_len, struct btrfs_dir_item, data_len, 16); BTRFS_SETGET_FUNCS(dir_type, struct btrfs_dir_item, type, 8); diff --git a/ioctl.h b/ioctl.h index 4410ac02..b0e5c0db 100644 --- a/ioctl.h +++ b/ioctl.h @@ -30,6 +30,68 @@ struct btrfs_ioctl_vol_args { char name[BTRFS_PATH_NAME_MAX + 1]; }; +struct btrfs_ioctl_search_key { + /* which root are we searching. 0 is the tree of tree roots */ + __u64 tree_id; + + /* keys returned will be >= min and <= max */ + __u64 min_objectid; + __u64 max_objectid; + + /* keys returned will be >= min and <= max */ + __u64 min_offset; + __u64 max_offset; + + /* max and min transids to search for */ + __u64 min_transid; + __u64 max_transid; + + /* keys returned will be >= min and <= max */ + __u32 min_type; + __u32 max_type; + + /* + * how many items did userland ask for, and how many are we + * returning + */ + __u32 nr_items; + + /* align to 64 bits */ + __u32 unused; + + /* some extra for later */ + __u64 unused1; + __u64 unused2; + __u64 unused3; + __u64 unused4; +}; + +struct btrfs_ioctl_search_header { + __u64 transid; + __u64 objectid; + __u64 offset; + __u32 type; + __u32 len; +}; + +#define BTRFS_SEARCH_ARGS_BUFSIZE (4096 - sizeof(struct btrfs_ioctl_search_key)) +/* + * the buf is an array of search headers where + * each header is followed by the actual item + * the type field is expanded to 32 bits for alignment + */ +struct btrfs_ioctl_search_args { + struct btrfs_ioctl_search_key key; + char buf[BTRFS_SEARCH_ARGS_BUFSIZE]; +}; + +#define BTRFS_INO_LOOKUP_PATH_MAX 4080 +struct btrfs_ioctl_ino_lookup_args { + __u64 treeid; + __u64 objectid; + char name[BTRFS_INO_LOOKUP_PATH_MAX]; +}; + #define BTRFS_IOC_SNAP_CREATE _IOW(BTRFS_IOCTL_MAGIC, 1, \ struct btrfs_ioctl_vol_args) #define BTRFS_IOC_DEFRAG _IOW(BTRFS_IOCTL_MAGIC, 2, \ @@ -59,4 +121,9 @@ struct btrfs_ioctl_vol_args { #define BTRFS_IOC_SNAP_DESTROY _IOW(BTRFS_IOCTL_MAGIC, 15, \ struct btrfs_ioctl_vol_args) + +#define BTRFS_IOC_TREE_SEARCH _IOWR(BTRFS_IOCTL_MAGIC, 17, \ + struct btrfs_ioctl_search_args) +#define BTRFS_IOC_INO_LOOKUP _IOWR(BTRFS_IOCTL_MAGIC, 18, \ + struct btrfs_ioctl_ino_lookup_args) #endif