diff options
author | David Sterba <dsterba@suse.cz> | 2015-02-11 18:35:12 +0100 |
---|---|---|
committer | David Sterba <dsterba@suse.cz> | 2015-02-11 18:35:12 +0100 |
commit | e404d4fd703af915b31b279b748a57c287e7a654 (patch) | |
tree | a081668b2ec39f1b3f07b9bbe3ce18f6020b3cf7 | |
parent | 478a4f21e480096b6c2f54ee5dd6421a557f26ab (diff) | |
parent | d91d68294c40d63b7a8d0910e5ee0167f9a70228 (diff) |
Merge branch 'qu/find-root-v3-part1' into v3.19.x
-rw-r--r-- | Documentation/btrfs-find-root.txt | 2 | ||||
-rw-r--r-- | Makefile.in | 2 | ||||
-rw-r--r-- | btrfs-find-root.c | 380 | ||||
-rw-r--r-- | ctree.h | 2 | ||||
-rw-r--r-- | disk-io.c | 68 | ||||
-rw-r--r-- | disk-io.h | 15 | ||||
-rw-r--r-- | find-root.c | 139 | ||||
-rw-r--r-- | find-root.h | 87 |
8 files changed, 427 insertions, 268 deletions
diff --git a/Documentation/btrfs-find-root.txt b/Documentation/btrfs-find-root.txt index c934b4cb..e04cd3e8 100644 --- a/Documentation/btrfs-find-root.txt +++ b/Documentation/btrfs-find-root.txt @@ -16,6 +16,8 @@ root tree's objectid, generation, level. OPTIONS ------- +-a:: +Search through all the metadata extents, even the root is already found. -g <generation>:: Filter root tree by it's original transaction id, tree root's generation in default. -o <objectid>:: diff --git a/Makefile.in b/Makefile.in index 3a603983..ad4c56f0 100644 --- a/Makefile.in +++ b/Makefile.in @@ -35,7 +35,7 @@ objects = ctree.o disk-io.o radix-tree.o extent-tree.o print-tree.o \ extent-cache.o extent_io.o volumes.o utils.o repair.o \ qgroup.o raid6.o free-space-cache.o list_sort.o props.o \ ulist.o qgroup-verify.o backref.o string-table.o task-utils.o \ - inode.o file.o + inode.o file.o find-root.o cmds_objects = cmds-subvolume.o cmds-filesystem.o cmds-device.o cmds-scrub.o \ cmds-inspect.o cmds-balance.o cmds-send.o cmds-receive.o \ cmds-quota.o cmds-qgroup.o cmds-replace.o cmds-check.o \ diff --git a/btrfs-find-root.c b/btrfs-find-root.c index c6e6b82f..9e56c81d 100644 --- a/btrfs-find-root.c +++ b/btrfs-find-root.c @@ -31,271 +31,141 @@ #include "volumes.h" #include "utils.h" #include "crc32c.h" - -static u16 csum_size = 0; -static u64 search_objectid = BTRFS_ROOT_TREE_OBJECTID; -static u64 search_generation = 0; -static unsigned long search_level = 0; +#include "extent-cache.h" +#include "find-root.h" static void usage(void) { - fprintf(stderr, "Usage: find-roots [-o search_objectid] " + fprintf(stderr, "Usage: find-roots [-a] [-o search_objectid] " "[ -g search_generation ] [ -l search_level ] <device>\n"); } -static int csum_block(void *buf, u32 len) +/* + * Get reliable generation and level for given root. + * + * We have two sources of gen/level: superblock and tree root. + * superblock include the following level: + * Root, chunk, log + * and the following generations: + * Root, chunk, uuid + * Other gen/leven can only be read from its btrfs_tree_root if possible. + * + * Currently we only believe things from superblock. + */ +static void get_root_gen_and_level(u64 objectid, struct btrfs_fs_info *fs_info, + u64 *ret_gen, u8 *ret_level) { - char *result; - u32 crc = ~(u32)0; - int ret = 0; - - result = malloc(csum_size * sizeof(char)); - if (!result) { - fprintf(stderr, "No memory\n"); - return 1; + struct btrfs_super_block *super = fs_info->super_copy; + u64 gen = (u64)-1; + u8 level = (u8)-1; + + switch (objectid) { + case BTRFS_ROOT_TREE_OBJECTID: + level = btrfs_super_root_level(super); + gen = btrfs_super_generation(super); + break; + case BTRFS_CHUNK_TREE_OBJECTID: + level = btrfs_super_chunk_root_level(super); + gen = btrfs_super_chunk_root_generation(super); + printf("Search for chunk root is not supported yet\n"); + break; + case BTRFS_TREE_LOG_OBJECTID: + level = btrfs_super_log_root_level(super); + gen = btrfs_super_log_root_transid(super); + break; + case BTRFS_UUID_TREE_OBJECTID: + gen = btrfs_super_uuid_tree_generation(super); + break; } - - len -= BTRFS_CSUM_SIZE; - crc = crc32c(crc, buf + BTRFS_CSUM_SIZE, len); - btrfs_csum_final(crc, result); - - if (memcmp(buf, result, csum_size)) - ret = 1; - free(result); - return ret; -} - -static struct btrfs_root *open_ctree_broken(int fd, const char *device) -{ - struct btrfs_fs_info *fs_info; - struct btrfs_super_block *disk_super; - struct btrfs_fs_devices *fs_devices = NULL; - struct extent_buffer *eb; - int ret; - - fs_info = btrfs_new_fs_info(0, BTRFS_SUPER_INFO_OFFSET); - if (!fs_info) { - fprintf(stderr, "Failed to allocate memory for fs_info\n"); - return NULL; + if (gen != (u64)-1) { + printf("Superblock thinks the generation is %llu\n", gen); + if (ret_gen) + *ret_gen = gen; + } else { + printf("Superblock doesn't contain generation info for root %llu\n", + objectid); } - - ret = btrfs_scan_fs_devices(fd, device, &fs_devices, 0, 1, 0); - if (ret) - goto out; - - fs_info->fs_devices = fs_devices; - - ret = btrfs_open_devices(fs_devices, O_RDONLY); - if (ret) - goto out_devices; - - disk_super = fs_info->super_copy; - ret = btrfs_read_dev_super(fs_devices->latest_bdev, - disk_super, fs_info->super_bytenr, 1); - if (ret) { - printk("No valid btrfs found\n"); - goto out_devices; + if (level != (u8)-1) { + printf("Superblock thinks the level is %u\n", level); + if (ret_level) + *ret_level = level; + } else { + printf("Superblock doesn't contain the level info for root %llu\n", + objectid); } - - memcpy(fs_info->fsid, &disk_super->fsid, BTRFS_FSID_SIZE); - - ret = btrfs_check_fs_compatibility(disk_super, 0); - if (ret) - goto out_devices; - - ret = btrfs_setup_chunk_tree_and_device_map(fs_info); - if (ret) - goto out_chunk; - - eb = fs_info->chunk_root->node; - read_extent_buffer(eb, fs_info->chunk_tree_uuid, - btrfs_header_chunk_tree_uuid(eb), BTRFS_UUID_SIZE); - - return fs_info->chunk_root; -out_chunk: - free_extent_buffer(fs_info->chunk_root->node); - btrfs_cleanup_all_caches(fs_info); -out_devices: - btrfs_close_devices(fs_info->fs_devices); -out: - btrfs_free_fs_info(fs_info); - return NULL; -} - -static int search_iobuf(struct btrfs_root *root, void *iobuf, - size_t iobuf_size, off_t offset) -{ - u64 gen = search_generation; - u64 objectid = search_objectid; - u32 size = btrfs_super_nodesize(root->fs_info->super_copy); - u8 level = search_level; - size_t block_off = 0; - - while (block_off < iobuf_size) { - void *block = iobuf + block_off; - struct btrfs_header *header = block; - u64 h_byte, h_level, h_gen, h_owner; - -// printf("searching %Lu\n", offset + block_off); - h_byte = btrfs_stack_header_bytenr(header); - h_owner = btrfs_stack_header_owner(header); - h_level = header->level; - h_gen = btrfs_stack_header_generation(header); - - if (h_owner != objectid) - goto next; - if (h_byte != (offset + block_off)) - goto next; - if (h_level < level) - goto next; - level = h_level; - if (csum_block(block, size)) { - fprintf(stderr, "Well block %Lu seems good, " - "but the csum doesn't match\n", - h_byte); - goto next; - } - if (h_gen != gen) { - fprintf(stderr, "Well block %Lu seems great, " - "but generation doesn't match, " - "have=%Lu, want=%Lu level %Lu\n", h_byte, - h_gen, gen, h_level); - goto next; - } - printf("Found tree root at %Lu gen %Lu level %Lu\n", h_byte, - h_gen, h_level); - return 0; -next: - block_off += size; - } - - return 1; } -static int read_physical(struct btrfs_root *root, int fd, u64 offset, - u64 bytenr, u64 len) +static void print_one_result(struct cache_extent *tree_block, + u8 level, u64 generation, + struct btrfs_find_root_filter *filter) { - char *iobuf = malloc(len); - ssize_t done; - size_t total_read = 0; - int ret = 1; - - if (!iobuf) { - fprintf(stderr, "No memory\n"); - return -1; - } - - while (total_read < len) { - done = pread64(fd, iobuf + total_read, len - total_read, - bytenr + total_read); - if (done < 0) { - fprintf(stderr, "Failed to read: %s\n", - strerror(errno)); - ret = -1; - goto out; - } - total_read += done; - } - - ret = search_iobuf(root, iobuf, total_read, offset); -out: - free(iobuf); - return ret; + int unsure = 0; + + if (filter->match_gen == (u64)-1 || filter->match_level == (u8)-1) + unsure = 1; + printf("Well block %llu(gen: %llu level: %u) seems good, ", + tree_block->start, generation, level); + if (unsure) + printf("but we are unsure about the correct generation/level\n"); + else + printf("but generation/level doesn't match, want gen: %llu level: %u\n", + filter->match_gen, filter->match_level); } -static int find_root(struct btrfs_root *root) +static void print_find_root_result(struct cache_tree *result, + struct btrfs_find_root_filter *filter) { - struct btrfs_multi_bio *multi = NULL; - struct btrfs_device *device; - u64 metadata_offset = 0, metadata_size = 0; - off_t offset = 0; - off_t bytenr; - int fd; - int err; - int ret = 1; - - printf("Super think's the tree root is at %Lu, chunk root %Lu\n", - btrfs_super_root(root->fs_info->super_copy), - btrfs_super_chunk_root(root->fs_info->super_copy)); - - err = btrfs_next_metadata(&root->fs_info->mapping_tree, - &metadata_offset, &metadata_size); - if (err) - return ret; - - offset = metadata_offset; - while (1) { - u64 map_length = 4096; - u64 type; - - if (offset > - btrfs_super_total_bytes(root->fs_info->super_copy)) { - printf("Went past the fs size, exiting"); - break; - } - if (offset >= (metadata_offset + metadata_size)) { - err = btrfs_next_metadata(&root->fs_info->mapping_tree, - &metadata_offset, - &metadata_size); - if (err) { - printf("No more metdata to scan, exiting\n"); - break; - } - offset = metadata_offset; - } - err = __btrfs_map_block(&root->fs_info->mapping_tree, READ, - offset, &map_length, &type, - &multi, 0, NULL); - if (err) { - offset += map_length; + struct btrfs_find_root_gen_cache *gen_cache; + struct cache_extent *cache; + struct cache_extent *tree_block; + u64 generation = 0; + u8 level = 0; + + for (cache = last_cache_extent(result); + cache; cache = prev_cache_extent(cache)) { + gen_cache = container_of(cache, + struct btrfs_find_root_gen_cache, cache); + level = gen_cache->highest_level; + generation = cache->start; + if (level == filter->match_level && + generation == filter->match_gen) continue; - } - - if (!(type & BTRFS_BLOCK_GROUP_METADATA)) { - offset += map_length; - kfree(multi); - continue; - } - - device = multi->stripes[0].dev; - fd = device->fd; - bytenr = multi->stripes[0].physical; - kfree(multi); - - err = read_physical(root, fd, offset, bytenr, map_length); - if (!err) { - ret = 0; - break; - } else if (err < 0) { - ret = err; - break; - } - offset += map_length; + for (tree_block = last_cache_extent(&gen_cache->eb_tree); + tree_block; tree_block = prev_cache_extent(tree_block)) + print_one_result(tree_block, level, generation, filter); } - return ret; } int main(int argc, char **argv) { struct btrfs_root *root; - int dev_fd; + struct btrfs_find_root_filter filter = {0}; + struct cache_tree result; + struct cache_extent *found; int opt; int ret; - while ((opt = getopt(argc, argv, "l:o:g:")) != -1) { + /* Default to search root tree */ + filter.objectid = BTRFS_ROOT_TREE_OBJECTID; + filter.match_gen = (u64)-1; + filter.match_level = (u8)-1; + while ((opt = getopt(argc, argv, "al:o:g:")) != -1) { switch(opt) { - case 'o': - search_objectid = arg_strtou64(optarg); - break; - case 'g': - search_generation = arg_strtou64(optarg); - break; - case 'l': - search_level = arg_strtou64(optarg); - break; - default: - usage(); - exit(1); + case 'a': + filter.search_all = 1; + break; + case 'o': + filter.objectid = arg_strtou64(optarg); + break; + case 'g': + filter.generation = arg_strtou64(optarg); + break; + case 'l': + filter.level = arg_strtou64(optarg); + break; + default: + usage(); + exit(1); } } @@ -306,25 +176,29 @@ int main(int argc, char **argv) exit(1); } - dev_fd = open(argv[optind], O_RDONLY); - if (dev_fd < 0) { - fprintf(stderr, "Failed to open device %s\n", argv[optind]); - exit(1); - } - - root = open_ctree_broken(dev_fd, argv[optind]); - close(dev_fd); - + root = open_ctree(argv[optind], 0, OPEN_CTREE_CHUNK_ROOT_ONLY); if (!root) { fprintf(stderr, "Open ctree failed\n"); exit(1); } - - if (search_generation == 0) - search_generation = btrfs_super_generation(root->fs_info->super_copy); - - csum_size = btrfs_super_csum_size(root->fs_info->super_copy); - ret = find_root(root); + cache_tree_init(&result); + + get_root_gen_and_level(filter.objectid, root->fs_info, + &filter.match_gen, &filter.match_level); + ret = btrfs_find_root_search(root, &filter, &result, &found); + if (ret < 0) { + fprintf(stderr, "Fail to search the tree root: %s\n", + strerror(-ret)); + goto out; + } + if (ret > 0) { + printf("Found tree root at %llu gen %llu level %u\n", + found->start, filter.match_gen, filter.match_level); + ret = 0; + } + print_find_root_result(&result, &filter); +out: + btrfs_find_root_free(&result); close_ctree(root); return ret; } @@ -998,6 +998,7 @@ struct btrfs_fs_info { unsigned int on_restoring:1; unsigned int is_chunk_recover:1; unsigned int quota_enabled:1; + unsigned int suppress_check_block_errors:1; int (*free_extent_hook)(struct btrfs_trans_handle *trans, struct btrfs_root *root, @@ -1006,6 +1007,7 @@ struct btrfs_fs_info { int refs_to_drop); struct cache_tree *fsck_extent_cache; struct cache_tree *corrupt_blocks; + }; /* @@ -22,6 +22,7 @@ #include <sys/stat.h> #include <fcntl.h> #include <unistd.h> +#include <uuid/uuid.h> #include "kerncompat.h" #include "radix-tree.h" #include "ctree.h" @@ -33,17 +34,18 @@ #include "print-tree.h" #include "rbtree-utils.h" +/* specified errno for check_tree_block */ +#define BTRFS_BAD_BYTENR (-1) +#define BTRFS_BAD_FSID (-2) + static int check_tree_block(struct btrfs_root *root, struct extent_buffer *buf) { struct btrfs_fs_devices *fs_devices; - int ret = 1; + int ret = BTRFS_BAD_FSID; - if (buf->start != btrfs_header_bytenr(buf)) { - printk("Check tree block failed, want=%Lu, have=%Lu\n", - buf->start, btrfs_header_bytenr(buf)); - return ret; - } + if (buf->start != btrfs_header_bytenr(buf)) + return BTRFS_BAD_BYTENR; fs_devices = root->fs_info->fs_devices; while (fs_devices) { @@ -58,6 +60,30 @@ static int check_tree_block(struct btrfs_root *root, struct extent_buffer *buf) return ret; } +static void print_tree_block_error(struct btrfs_root *root, + struct extent_buffer *eb, + int err) +{ + char fs_uuid[BTRFS_UUID_UNPARSED_SIZE] = {'\0'}; + char found_uuid[BTRFS_UUID_UNPARSED_SIZE] = {'\0'}; + u8 buf[BTRFS_UUID_SIZE]; + + switch (err) { + case BTRFS_BAD_FSID: + read_extent_buffer(eb, buf, btrfs_header_fsid(), + BTRFS_UUID_SIZE); + uuid_unparse(buf, found_uuid); + uuid_unparse(root->fs_info->fsid, fs_uuid); + fprintf(stderr, "fsid mismatch, want=%s, have=%s\n", + fs_uuid, found_uuid); + break; + case BTRFS_BAD_BYTENR: + fprintf(stderr, "bytenr mismatch, want=%llu, have=%llu\n", + eb->start, btrfs_header_bytenr(eb)); + break; + } +} + u32 btrfs_csum_data(struct btrfs_root *root, char *data, u32 seed, size_t len) { return crc32c(seed, data, len); @@ -115,6 +141,8 @@ int csum_tree_block(struct btrfs_root *root, struct extent_buffer *buf, { u16 csum_size = btrfs_super_csum_size(root->fs_info->super_copy); + if (verify && root->fs_info->suppress_check_block_errors) + return verify_tree_block_csum_silent(buf, csum_size); return csum_tree_block_size(buf, csum_size, verify); } @@ -265,8 +293,8 @@ struct extent_buffer *read_tree_block(struct btrfs_root *root, u64 bytenr, while (1) { ret = read_whole_eb(root->fs_info, eb, mirror_num); - if (ret == 0 && check_tree_block(root, eb) == 0 && - csum_tree_block(root, eb, 1) == 0 && + if (ret == 0 && csum_tree_block(root, eb, 1) == 0 && + check_tree_block(root, eb) == 0 && verify_parent_transid(eb->tree, eb, parent_transid, ignore) == 0) { if (eb->flags & EXTENT_BAD_TRANSID && @@ -279,10 +307,14 @@ struct extent_buffer *read_tree_block(struct btrfs_root *root, u64 bytenr, return eb; } if (ignore) { - if (check_tree_block(root, eb)) - printk("read block failed check_tree_block\n"); - else - printk("Csum didn't match\n"); + if (check_tree_block(root, eb)) { + if (!root->fs_info->suppress_check_block_errors) + print_tree_block_error(root, eb, + check_tree_block(root, eb)); + } else { + if (!root->fs_info->suppress_check_block_errors) + fprintf(stderr, "Csum didn't match\n"); + } ret = -EIO; break; } @@ -343,8 +375,10 @@ static int write_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct extent_buffer *eb) { - if (check_tree_block(root, eb)) + if (check_tree_block(root, eb)) { + print_tree_block_error(root, eb, check_tree_block(root, eb)); BUG(); + } if (!btrfs_buffer_uptodate(eb, trans->transid)) BUG(); @@ -1113,6 +1147,8 @@ static struct btrfs_fs_info *__open_ctree_fd(int fp, const char *path, } if (flags & OPEN_CTREE_RESTORE) fs_info->on_restoring = 1; + if (flags & OPEN_CTREE_SUPPRESS_CHECK_BLOCK_ERRORS) + fs_info->suppress_check_block_errors = 1; ret = btrfs_scan_fs_devices(fp, path, &fs_devices, sb_bytenr, (flags & OPEN_CTREE_RECOVER_SUPER), @@ -1161,7 +1197,7 @@ static struct btrfs_fs_info *__open_ctree_fd(int fp, const char *path, BTRFS_UUID_SIZE); ret = btrfs_setup_all_roots(fs_info, root_tree_bytenr, flags); - if (ret) + if (ret && !(flags & __OPEN_CTREEE_RETURN_CHUNK_ROOT)) goto out_chunk; return fs_info; @@ -1206,6 +1242,8 @@ struct btrfs_root *open_ctree(const char *filename, u64 sb_bytenr, info = open_ctree_fs_info(filename, sb_bytenr, 0, flags); if (!info) return NULL; + if (flags & __OPEN_CTREEE_RETURN_CHUNK_ROOT) + return info->chunk_root; return info->fs_root; } @@ -1216,6 +1254,8 @@ struct btrfs_root *open_ctree_fd(int fp, const char *path, u64 sb_bytenr, info = __open_ctree_fd(fp, path, sb_bytenr, 0, flags); if (!info) return NULL; + if (flags & __OPEN_CTREEE_RETURN_CHUNK_ROOT) + return info->chunk_root; return info->fs_root; } @@ -34,6 +34,21 @@ enum btrfs_open_ctree_flags { OPEN_CTREE_NO_BLOCK_GROUPS = (1 << 5), OPEN_CTREE_EXCLUSIVE = (1 << 6), OPEN_CTREE_NO_DEVICES = (1 << 7), + /* + * Don't print error messages if bytenr or checksums do not match in + * tree block headers. Turn on by OPEN_CTREE_SUPPRESS_ERROR + */ + OPEN_CTREE_SUPPRESS_CHECK_BLOCK_ERRORS = (1 << 8), + /* Return chunk root */ + __OPEN_CTREEE_RETURN_CHUNK_ROOT = (1 << 9), + OPEN_CTREE_CHUNK_ROOT_ONLY = OPEN_CTREE_PARTIAL + + OPEN_CTREE_SUPPRESS_CHECK_BLOCK_ERRORS + + __OPEN_CTREEE_RETURN_CHUNK_ROOT, + /* + * TODO: cleanup: Split the open_ctree_flags into more indepent + * tree bits. + * Like split PARTIAL into SKIP_CSUM/SKIP_EXTENT + */ }; static inline u64 btrfs_sb_offset(int mirror) diff --git a/find-root.c b/find-root.c new file mode 100644 index 00000000..1af37b54 --- /dev/null +++ b/find-root.c @@ -0,0 +1,139 @@ +/* + * Copyright (C) 2015 Fujitsu. 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. + */ + +#include "kerncompat.h" + +#include <stdio.h> +#include <stdlib.h> +#include "ctree.h" +#include "utils.h" +#include "find-root.h" +#include "volumes.h" +#include "disk-io.h" +#include "extent-cache.h" + +/* Return value is the same as btrfs_find_root_search(). */ +static int add_eb_to_result(struct extent_buffer *eb, + struct cache_tree *result, + u32 leafsize, + struct btrfs_find_root_filter *filter, + struct cache_extent **match) +{ + u64 generation = btrfs_header_generation(eb); + u64 level = btrfs_header_level(eb); + u64 owner = btrfs_header_owner(eb); + u64 start = eb->start; + struct cache_extent *cache; + struct btrfs_find_root_gen_cache *gen_cache = NULL; + int ret = 0; + + if (owner != filter->objectid || level < filter->level || + generation < filter->generation) + return ret; + + /* Get the generation cache or create one */ + cache = search_cache_extent(result, generation); + if (!cache) { + gen_cache = malloc(sizeof(*gen_cache)); + BUG_ON(!gen_cache); + cache = &gen_cache->cache; + cache->start = generation; + cache->size = 1; + cache->objectid = 0; + gen_cache->highest_level = 0; + cache_tree_init(&gen_cache->eb_tree); + + ret = insert_cache_extent(result, cache); + if (ret < 0) + return ret; + } + gen_cache = container_of(cache, struct btrfs_find_root_gen_cache, + cache); + + /* Higher level, clean tree and insert the new one */ + if (level > gen_cache->highest_level) { + free_extent_cache_tree(&gen_cache->eb_tree); + gen_cache->highest_level = level; + /* Fall into the insert routine */ + } + + /* Same level, insert it into the eb_tree */ + if (level == gen_cache->highest_level) { + ret = add_cache_extent(&gen_cache->eb_tree, + start, leafsize); + if (ret < 0 && ret != -EEXIST) + return ret; + ret = 0; + } + if (generation == filter->match_gen && + level == filter->match_level && + !filter->search_all) { + ret = 1; + if (match) + *match = search_cache_extent(&gen_cache->eb_tree, + start); + } + return ret; +} + +/* + * Return 0 if iterating all the metadata extents. + * Return 1 if found root with given gen/level and set *match to it. + * Return <0 if error happens + */ +int btrfs_find_root_search(struct btrfs_root *chunk_root, + struct btrfs_find_root_filter *filter, + struct cache_tree *result, + struct cache_extent **match) +{ + struct btrfs_fs_info *fs_info = chunk_root->fs_info; + struct extent_buffer *eb; + u64 metadata_offset = 0; + u64 metadata_size = 0; + u64 offset = 0; + u32 leafsize = chunk_root->leafsize; + int suppress_errors = 0; + int ret = 0; + + suppress_errors = fs_info->suppress_check_block_errors; + fs_info->suppress_check_block_errors = 1; + while (1) { + ret = btrfs_next_metadata(&fs_info->mapping_tree, + &metadata_offset, &metadata_size); + if (ret) { + if (ret == -ENOENT) + ret = 0; + break; + } + for (offset = metadata_offset; + offset < metadata_offset + metadata_size; + offset += chunk_root->leafsize) { + eb = read_tree_block(chunk_root, offset, leafsize, 0); + if (!eb || IS_ERR(eb)) + continue; + ret = add_eb_to_result(eb, result, leafsize, filter, + match); + free_extent_buffer(eb); + if (ret) + goto out; + } + } +out: + fs_info->suppress_check_block_errors = suppress_errors; + return ret; +} diff --git a/find-root.h b/find-root.h new file mode 100644 index 00000000..1c67ebcc --- /dev/null +++ b/find-root.h @@ -0,0 +1,87 @@ +/* + * Copyright (C) 2015 Fujitsu. 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 __BTRFS_FIND_ROOT_H__ +#define __BTRFS_FIND_ROOT_H__ + +#include "kerncompat.h" + +#include "ctree.h" +#include "list.h" +#include "extent-cache.h" + +/* + * Find-root will restore the search result in a 2-level trees. + * Search result is a cache_tree consisted of generation_cache. + * Each generation cache records the highest level of this generation + * and all the tree blocks with this generation. + * + * <result> + * cache_tree ----> generation_cache: gen:1 level: 2 eb_tree ----> eb1 + * | |-> eb2 + * | ...... + * |-> generation_cache: gen:2 level: 3 eb_tree ---> eb3 + * + * In the above example, generation 1's highest level is 2, but have multiple + * eb with same generation, so the root of generation 1 must be missing, + * possibly has already been overwritten. + * On the other hand, generation 2's highest level is 3 and we find only one + * eb for it, so it may be the root of generation 2. + */ + +struct btrfs_find_root_gen_cache { + struct cache_extent cache; /* cache->start is generation */ + u64 highest_level; + struct cache_tree eb_tree; +}; + +struct btrfs_find_root_filter { + u64 objectid; /* Only search tree with this objectid */ + u64 generation; /* Only record tree block with higher or + equal generation */ + u8 level; /* Only record tree block with higher or + equal level */ + u8 match_level; + u64 match_gen; + int search_all; + /* + * If set search_all, even the tree block matches match_gen + * and match_level and objectid, still continue searching + * This *WILL* take *TONS* of extra time. + */ +}; +int btrfs_find_root_search(struct btrfs_root *chunk_root, + struct btrfs_find_root_filter *filter, + struct cache_tree *result, + struct cache_extent **match); +static inline void btrfs_find_root_free(struct cache_tree *result) +{ + struct btrfs_find_root_gen_cache *gen_cache; + struct cache_extent *cache; + + cache = first_cache_extent(result); + while (cache) { + gen_cache = container_of(cache, + struct btrfs_find_root_gen_cache, cache); + free_extent_cache_tree(&gen_cache->eb_tree); + remove_cache_extent(result, cache); + free(gen_cache); + cache = first_cache_extent(result); + } +} +#endif |