btrfs-progs/btrfs-list.c

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/*
* 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.
*/
#define _GNU_SOURCE
#ifndef __CHECKER__
#include <sys/ioctl.h>
#include <sys/mount.h>
#include "ioctl.h"
#endif
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <dirent.h>
#include <libgen.h>
#include "kerncompat.h"
#include "ctree.h"
#include "transaction.h"
#include "utils.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[];
};
static 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;
}
/*
* 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 + 1);
if (!ri) {
printf("memory allocation failed\n");
exit(1);
}
memset(ri, 0, sizeof(*ri) + name_len + 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, int print_parent)
{
u64 top_id;
u64 parent_id = 0;
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;
/* record the first parent */
if ( parent_id == 0 ) {
parent_id = next;
}
/* 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;
}
}
if (print_parent) {
printf("ID %llu parent %llu top level %llu path %s\n",
(unsigned long long)ri->root_id, (unsigned long long)parent_id, (unsigned long long)top_id,
full_path);
} else {
printf("ID %llu top level %llu path %s\n",
(unsigned long long)ri->root_id, (unsigned long long)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, e;
if (ri->path)
return 0;
memset(&args, 0, sizeof(args));
args.treeid = ri->ref_tree;
args.objectid = ri->dir_id;
ret = ioctl(fd, BTRFS_IOC_INO_LOOKUP, &args);
e = errno;
if (ret) {
fprintf(stderr, "ERROR: Failed to lookup path for root %llu - %s\n",
(unsigned long long)ri->ref_tree,
strerror(e));
return ret;
}
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;
}
/* finding the generation for a given path is a two step process.
* First we use the inode loookup routine to find out the root id
*
* Then we use the tree search ioctl to scan all the root items for a
* given root id and spit out the latest generation we can find
*/
static u64 find_root_gen(int fd)
{
struct btrfs_ioctl_ino_lookup_args ino_args;
int ret;
struct btrfs_ioctl_search_args args;
struct btrfs_ioctl_search_key *sk = &args.key;
struct btrfs_ioctl_search_header *sh;
unsigned long off = 0;
u64 max_found = 0;
int i;
int e;
memset(&ino_args, 0, sizeof(ino_args));
ino_args.objectid = BTRFS_FIRST_FREE_OBJECTID;
/* this ioctl fills in ino_args->treeid */
ret = ioctl(fd, BTRFS_IOC_INO_LOOKUP, &ino_args);
e = errno;
if (ret) {
fprintf(stderr, "ERROR: Failed to lookup path for dirid %llu - %s\n",
(unsigned long long)BTRFS_FIRST_FREE_OBJECTID,
strerror(e));
return 0;
}
memset(&args, 0, sizeof(args));
sk->tree_id = 1;
/*
* there may be more than one ROOT_ITEM key if there are
* snapshots pending deletion, we have to loop through
* them.
*/
sk->min_objectid = ino_args.treeid;
sk->max_objectid = ino_args.treeid;
sk->max_type = BTRFS_ROOT_ITEM_KEY;
sk->min_type = BTRFS_ROOT_ITEM_KEY;
sk->max_offset = (u64)-1;
sk->max_transid = (u64)-1;
sk->nr_items = 4096;
while (1) {
ret = ioctl(fd, BTRFS_IOC_TREE_SEARCH, &args);
e = errno;
if (ret < 0) {
fprintf(stderr, "ERROR: can't perform the search - %s\n",
strerror(e));
return 0;
}
/* the ioctl returns the number of item it found in nr_items */
if (sk->nr_items == 0)
break;
off = 0;
for (i = 0; i < sk->nr_items; i++) {
struct btrfs_root_item *item;
sh = (struct btrfs_ioctl_search_header *)(args.buf +
off);
off += sizeof(*sh);
item = (struct btrfs_root_item *)(args.buf + off);
off += sh->len;
sk->min_objectid = sh->objectid;
sk->min_type = sh->type;
sk->min_offset = sh->offset;
if (sh->objectid > ino_args.treeid)
break;
if (sh->objectid == ino_args.treeid &&
sh->type == BTRFS_ROOT_ITEM_KEY) {
max_found = max(max_found,
btrfs_root_generation(item));
}
}
if (sk->min_offset < (u64)-1)
sk->min_offset++;
else
break;
if (sk->min_type != BTRFS_ROOT_ITEM_KEY)
break;
if (sk->min_objectid != BTRFS_ROOT_ITEM_KEY)
break;
}
return max_found;
}
/* pass in a directory id and this will return
* the full path of the parent directory inside its
* subvolume root.
*
* It may return NULL if it is in the root, or an ERR_PTR if things
* go badly.
*/
static char *__ino_resolve(int fd, u64 dirid)
{
struct btrfs_ioctl_ino_lookup_args args;
int ret;
char *full;
int e;
memset(&args, 0, sizeof(args));
args.objectid = dirid;
ret = ioctl(fd, BTRFS_IOC_INO_LOOKUP, &args);
e = errno;
if (ret) {
fprintf(stderr, "ERROR: Failed to lookup path for dirid %llu - %s\n",
(unsigned long long)dirid, strerror(e) );
return ERR_PTR(ret);
}
if (args.name[0]) {
/*
* we're in a subdirectory of ref_tree, the kernel ioctl
* puts a / in there for us
*/
full = strdup(args.name);
if (!full) {
perror("malloc failed");
return ERR_PTR(-ENOMEM);
}
} else {
/* we're at the root of ref_tree */
full = NULL;
}
return full;
}
/*
* simple string builder, returning a new string with both
* dirid and name
*/
char *build_name(char *dirid, char *name)
{
char *full;
if (!dirid)
return strdup(name);
full = malloc(strlen(dirid) + strlen(name) + 1);
if (!full)
return NULL;
strcpy(full, dirid);
strcat(full, name);
return full;
}
/*
* given an inode number, this returns the full path name inside the subvolume
* to that file/directory. cache_dirid and cache_name are used to
* cache the results so we can avoid tree searches if a later call goes
* to the same directory or file name
*/
static char *ino_resolve(int fd, u64 ino, u64 *cache_dirid, char **cache_name)
{
u64 dirid;
char *dirname;
char *name;
char *full;
int ret;
struct btrfs_ioctl_search_args args;
struct btrfs_ioctl_search_key *sk = &args.key;
struct btrfs_ioctl_search_header *sh;
unsigned long off = 0;
int namelen;
int e;
memset(&args, 0, sizeof(args));
sk->tree_id = 0;
/*
* step one, we search for the inode back ref. We just use the first
* one
*/
sk->min_objectid = ino;
sk->max_objectid = ino;
sk->max_type = BTRFS_INODE_REF_KEY;
sk->max_offset = (u64)-1;
sk->min_type = BTRFS_INODE_REF_KEY;
sk->max_transid = (u64)-1;
sk->nr_items = 1;
ret = ioctl(fd, BTRFS_IOC_TREE_SEARCH, &args);
e = errno;
if (ret < 0) {
fprintf(stderr, "ERROR: can't perform the search - %s\n",
strerror(e));
return NULL;
}
/* the ioctl returns the number of item it found in nr_items */
if (sk->nr_items == 0)
return NULL;
off = 0;
sh = (struct btrfs_ioctl_search_header *)(args.buf + off);
if (sh->type == BTRFS_INODE_REF_KEY) {
struct btrfs_inode_ref *ref;
dirid = sh->offset;
ref = (struct btrfs_inode_ref *)(sh + 1);
namelen = btrfs_stack_inode_ref_name_len(ref);
name = (char *)(ref + 1);
name = strndup(name, namelen);
/* use our cached value */
if (dirid == *cache_dirid && *cache_name) {
dirname = *cache_name;
goto build;
}
} else {
return NULL;
}
/*
* the inode backref gives us the file name and the parent directory id.
* From here we use __ino_resolve to get the path to the parent
*/
dirname = __ino_resolve(fd, dirid);
build:
full = build_name(dirname, name);
if (*cache_name && dirname != *cache_name)
free(*cache_name);
*cache_name = dirname;
*cache_dirid = dirid;
free(name);
return full;
}
int list_subvols(int fd, int print_parent)
{
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;
int e;
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);
e = errno;
if (ret < 0) {
fprintf(stderr, "ERROR: can't perform the search - %s\n",
strerror(e));
return ret;
}
/* 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);
if (sh->type == BTRFS_ROOT_BACKREF_KEY) {
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++;
sk->min_type = BTRFS_ROOT_BACKREF_KEY;
sk->min_offset = 0;
} 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;
int ret;
entry = rb_entry(n, struct root_info, rb_node);
ret = lookup_ino_path(fd, entry);
if(ret < 0)
return ret;
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, print_parent);
n = rb_prev(n);
}
return ret;
}
static int print_one_extent(int fd, struct btrfs_ioctl_search_header *sh,
struct btrfs_file_extent_item *item,
u64 found_gen, u64 *cache_dirid,
char **cache_dir_name, u64 *cache_ino,
char **cache_full_name)
{
u64 len = 0;
u64 disk_start = 0;
u64 disk_offset = 0;
u8 type;
int compressed = 0;
int flags = 0;
char *name = NULL;
if (sh->objectid == *cache_ino) {
name = *cache_full_name;
} else if (*cache_full_name) {
free(*cache_full_name);
*cache_full_name = NULL;
}
if (!name) {
name = ino_resolve(fd, sh->objectid, cache_dirid,
cache_dir_name);
*cache_full_name = name;
*cache_ino = sh->objectid;
}
if (!name)
return -EIO;
type = btrfs_stack_file_extent_type(item);
compressed = btrfs_stack_file_extent_compression(item);
if (type == BTRFS_FILE_EXTENT_REG ||
type == BTRFS_FILE_EXTENT_PREALLOC) {
disk_start = btrfs_stack_file_extent_disk_bytenr(item);
disk_offset = btrfs_stack_file_extent_offset(item);
len = btrfs_stack_file_extent_num_bytes(item);
} else if (type == BTRFS_FILE_EXTENT_INLINE) {
disk_start = 0;
disk_offset = 0;
len = btrfs_stack_file_extent_ram_bytes(item);
} else {
printf("unhandled extent type %d for inode %llu "
"file offset %llu gen %llu\n",
type,
(unsigned long long)sh->objectid,
(unsigned long long)sh->offset,
(unsigned long long)found_gen);
return -EIO;
}
printf("inode %llu file offset %llu len %llu disk start %llu "
"offset %llu gen %llu flags ",
(unsigned long long)sh->objectid,
(unsigned long long)sh->offset,
(unsigned long long)len,
(unsigned long long)disk_start,
(unsigned long long)disk_offset,
(unsigned long long)found_gen);
if (compressed) {
printf("COMPRESS");
flags++;
}
if (type == BTRFS_FILE_EXTENT_PREALLOC) {
printf("%sPREALLOC", flags ? "|" : "");
flags++;
}
if (type == BTRFS_FILE_EXTENT_INLINE) {
printf("%sINLINE", flags ? "|" : "");
flags++;
}
if (!flags)
printf("NONE");
printf(" %s\n", name);
return 0;
}
int find_updated_files(int fd, u64 root_id, u64 oldest_gen)
{
int ret;
struct btrfs_ioctl_search_args args;
struct btrfs_ioctl_search_key *sk = &args.key;
struct btrfs_ioctl_search_header *sh;
struct btrfs_file_extent_item *item;
unsigned long off = 0;
u64 found_gen;
u64 max_found = 0;
int i;
int e;
u64 cache_dirid = 0;
u64 cache_ino = 0;
char *cache_dir_name = NULL;
char *cache_full_name = NULL;
struct btrfs_file_extent_item backup;
memset(&backup, 0, sizeof(backup));
memset(&args, 0, sizeof(args));
sk->tree_id = root_id;
/*
* 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;
sk->max_type = BTRFS_EXTENT_DATA_KEY;
sk->min_transid = oldest_gen;
/* just a big number, doesn't matter much */
sk->nr_items = 4096;
max_found = find_root_gen(fd);
while(1) {
ret = ioctl(fd, BTRFS_IOC_TREE_SEARCH, &args);
e = errno;
if (ret < 0) {
fprintf(stderr, "ERROR: can't perform the search- %s\n",
strerror(e));
return ret;
}
/* 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);
/*
* just in case the item was too big, pass something other
* than garbage
*/
if (sh->len == 0)
item = &backup;
else
item = (struct btrfs_file_extent_item *)(args.buf +
off);
found_gen = btrfs_stack_file_extent_generation(item);
if (sh->type == BTRFS_EXTENT_DATA_KEY &&
found_gen >= oldest_gen) {
print_one_extent(fd, sh, item, found_gen,
&cache_dirid, &cache_dir_name,
&cache_ino, &cache_full_name);
}
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_offset = sh->offset;
sk->min_type = sh->type;
}
sk->nr_items = 4096;
if (sk->min_offset < (u64)-1)
sk->min_offset++;
else if (sk->min_objectid < (u64)-1) {
sk->min_objectid++;
sk->min_offset = 0;
sk->min_type = 0;
} else
break;
}
free(cache_dir_name);
free(cache_full_name);
printf("transid marker was %llu\n", (unsigned long long)max_found);
return ret;
}