From patchwork Wed Jun 24 16:03:01 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Marek_Beh=C3=BAn?= X-Patchwork-Id: 11623603 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 111EB14E3 for ; Wed, 24 Jun 2020 16:03:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D6DE72077D for ; Wed, 24 Jun 2020 16:03:57 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=nic.cz header.i=@nic.cz header.b="Lqpviksj" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2404832AbgFXQDx (ORCPT ); Wed, 24 Jun 2020 12:03:53 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37024 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2404770AbgFXQD1 (ORCPT ); Wed, 24 Jun 2020 12:03:27 -0400 Received: from mail.nic.cz (mail.nic.cz [IPv6:2001:1488:800:400::400]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4268DC06179B for ; Wed, 24 Jun 2020 09:03:27 -0700 (PDT) Received: from dellmb.labs.office.nic.cz (unknown [IPv6:2001:1488:fffe:6:cac7:3539:7f1f:463]) by mail.nic.cz (Postfix) with ESMTP id EC4AB1409DB; Wed, 24 Jun 2020 18:03:23 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=nic.cz; s=default; t=1593014604; bh=qWiXjzOHr8zWJS0ZlptXsB3cPP0PKGBcswKjOvfzh0I=; h=From:To:Date; b=LqpviksjbDxbuD+kFWA/wDkZLhrKVCUQ/vdWDkwQG9iXHYR24VpIDgh7Y1g9ulFQp /+Gy8yWTd2deFTnfxDhbGqS8dWZWU/Vt6L6U2R23SaKm9awOG9O4I0TSsF2Bv9TCgo J62FEZMd/royDx5icnHqkPDDfxiUKmAgsVcpuabg= From: =?utf-8?q?Marek_Beh=C3=BAn?= To: u-boot@lists.denx.de Cc: =?utf-8?q?Alberto_S=C3=A1nchez_Molero?= , Marek Vasut , Pierre Bourdon , Simon Glass , Tom Rini , Yevgeny Popovych , linux-btrfs@vger.kernel.org, Qu Wenruo , =?utf-8?q?Marek_Beh=C3=BAn?= Subject: [PATCH U-BOOT v3 15/30] fs: btrfs: Crossport open_ctree_fs_info() from btrfs-progs Date: Wed, 24 Jun 2020 18:03:01 +0200 Message-Id: <20200624160316.5001-16-marek.behun@nic.cz> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200624160316.5001-1-marek.behun@nic.cz> References: <20200624160316.5001-1-marek.behun@nic.cz> MIME-Version: 1.0 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on mail.nic.cz X-Spam-Status: No, score=0.00 X-Spamd-Bar: / X-Virus-Scanned: clamav-milter 0.102.2 at mail X-Virus-Status: Clean Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org From: Qu Wenruo open_ctree_fs_info() is the main entry point to open btrfs. This version is a simplfied version of __open_ctree_fd() of btrfs-progs, the main differences are: - Parameters on how to specify a block device Instead of @fd and @path, U-Boot uses blk_desc and disk_partition_t. - Remove open_ctree flags There won't be multiple open ctree modes in U-Boot. Otherwise functions structures are all kept the same. With open_ctree_fs_info() implemented, also introduce the global current_fs_info pointer to show the current opened btrfs. Signed-off-by: Qu Wenruo Reviewed-by: Marek Behún --- fs/btrfs/Makefile | 2 +- fs/btrfs/btrfs.c | 15 +- fs/btrfs/btrfs.h | 1 + fs/btrfs/compat.h | 2 + fs/btrfs/ctree.h | 4 + fs/btrfs/disk-io.c | 509 +++++++++++++++++++++++++++++++++++++++++-- fs/btrfs/disk-io.h | 19 ++ fs/btrfs/root-tree.c | 47 ++++ 8 files changed, 579 insertions(+), 20 deletions(-) create mode 100644 fs/btrfs/root-tree.c diff --git a/fs/btrfs/Makefile b/fs/btrfs/Makefile index ec30aae765..8d76422ce2 100644 --- a/fs/btrfs/Makefile +++ b/fs/btrfs/Makefile @@ -4,4 +4,4 @@ obj-y := btrfs.o chunk-map.o compression.o ctree.o dev.o dir-item.o \ extent-io.o inode.o root.o subvolume.o crypto/hash.o disk-io.o \ - common/rbtree-utils.o extent-cache.o volumes.o + common/rbtree-utils.o extent-cache.o volumes.o root-tree.o diff --git a/fs/btrfs/btrfs.c b/fs/btrfs/btrfs.c index f5266f1b91..2bd2ec9ed9 100644 --- a/fs/btrfs/btrfs.c +++ b/fs/btrfs/btrfs.c @@ -14,6 +14,7 @@ #include "disk-io.h" struct btrfs_info btrfs_info; +struct btrfs_fs_info *current_fs_info; static int readdir_callback(const struct __btrfs_root *root, struct btrfs_dir_item *item) @@ -81,6 +82,9 @@ static int readdir_callback(const struct __btrfs_root *root, int btrfs_probe(struct blk_desc *fs_dev_desc, struct disk_partition *fs_partition) { + struct btrfs_fs_info *fs_info; + int ret = -1; + btrfs_blk_desc = fs_dev_desc; btrfs_part_info = fs_partition; @@ -111,7 +115,12 @@ int btrfs_probe(struct blk_desc *fs_dev_desc, return -1; } - return 0; + fs_info = open_ctree_fs_info(fs_dev_desc, fs_partition); + if (fs_info) { + current_fs_info = fs_info; + ret = 0; + } + return ret; } int btrfs_ls(const char *path) @@ -215,6 +224,10 @@ int btrfs_read(const char *file, void *buf, loff_t offset, loff_t len, void btrfs_close(void) { btrfs_chunk_map_exit(); + if (current_fs_info) { + close_ctree_fs_info(current_fs_info); + current_fs_info = NULL; + } } int btrfs_uuid(char *uuid_str) diff --git a/fs/btrfs/btrfs.h b/fs/btrfs/btrfs.h index 7dfdaf77ba..a52ff942f2 100644 --- a/fs/btrfs/btrfs.h +++ b/fs/btrfs/btrfs.h @@ -22,6 +22,7 @@ struct btrfs_info { }; extern struct btrfs_info btrfs_info; +extern struct btrfs_fs_info *current_fs_info; /* dev.c */ extern struct blk_desc *btrfs_blk_desc; diff --git a/fs/btrfs/compat.h b/fs/btrfs/compat.h index b6b75deb3e..4da88fc311 100644 --- a/fs/btrfs/compat.h +++ b/fs/btrfs/compat.h @@ -18,6 +18,8 @@ static inline void error(const char *fmt, ...) printf("\n"); } +#define ASSERT(c) assert(c) + #define BTRFS_UUID_UNPARSED_SIZE 37 /* diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index 7c814fd2a9..b050b5844d 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -1275,6 +1275,10 @@ const char *btrfs_super_csum_name(u16 csum_type); u16 btrfs_csum_type_size(u16 csum_type); size_t btrfs_super_num_csums(void); +/* root-tree.c */ +int btrfs_find_last_root(struct btrfs_root *root, u64 objectid, + struct btrfs_root_item *item, struct btrfs_key *key); + /* ctree.c */ int btrfs_comp_cpu_keys(const struct btrfs_key *k1, const struct btrfs_key *k2); enum btrfs_tree_block_status diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 65b4020ebe..4d08b0204a 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -4,6 +4,7 @@ #include #include #include "kernel-shared/btrfs_tree.h" +#include "common/rbtree-utils.h" #include "disk-io.h" #include "ctree.h" #include "btrfs.h" @@ -424,24 +425,6 @@ out: } -int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid) -{ - int ret; - - ret = extent_buffer_uptodate(buf); - if (!ret) - return ret; - - ret = verify_parent_transid(&buf->fs_info->extent_cache, buf, - parent_transid, 1); - return !ret; -} - -int btrfs_set_buffer_uptodate(struct extent_buffer *eb) -{ - return set_extent_buffer_uptodate(eb); -} - int read_whole_eb(struct btrfs_fs_info *info, struct extent_buffer *eb, int mirror) { unsigned long offset = 0; @@ -581,3 +564,493 @@ struct extent_buffer* read_tree_block(struct btrfs_fs_info *fs_info, u64 bytenr, free_extent_buffer(eb); return ERR_PTR(ret); } + +void btrfs_setup_root(struct btrfs_root *root, struct btrfs_fs_info *fs_info, + u64 objectid) +{ + root->node = NULL; + root->track_dirty = 0; + + root->fs_info = fs_info; + root->objectid = objectid; + root->last_trans = 0; + root->last_inode_alloc = 0; + + memset(&root->root_key, 0, sizeof(root->root_key)); + memset(&root->root_item, 0, sizeof(root->root_item)); + root->root_key.objectid = objectid; +} + +static int find_and_setup_root(struct btrfs_root *tree_root, + struct btrfs_fs_info *fs_info, + u64 objectid, struct btrfs_root *root) +{ + int ret; + u64 generation; + + btrfs_setup_root(root, fs_info, objectid); + ret = btrfs_find_last_root(tree_root, objectid, + &root->root_item, &root->root_key); + if (ret) + return ret; + + generation = btrfs_root_generation(&root->root_item); + root->node = read_tree_block(fs_info, + btrfs_root_bytenr(&root->root_item), generation); + if (!extent_buffer_uptodate(root->node)) + return -EIO; + + return 0; +} + +int btrfs_free_fs_root(struct btrfs_root *root) +{ + if (root->node) + free_extent_buffer(root->node); + kfree(root); + return 0; +} + +static void __free_fs_root(struct rb_node *node) +{ + struct btrfs_root *root; + + root = container_of(node, struct btrfs_root, rb_node); + btrfs_free_fs_root(root); +} + +FREE_RB_BASED_TREE(fs_roots, __free_fs_root); + +struct btrfs_root *btrfs_read_fs_root_no_cache(struct btrfs_fs_info *fs_info, + struct btrfs_key *location) +{ + struct btrfs_root *root; + struct btrfs_root *tree_root = fs_info->tree_root; + struct btrfs_path *path; + struct extent_buffer *l; + u64 generation; + int ret = 0; + + root = calloc(1, sizeof(*root)); + if (!root) + return ERR_PTR(-ENOMEM); + if (location->offset == (u64)-1) { + ret = find_and_setup_root(tree_root, fs_info, + location->objectid, root); + if (ret) { + free(root); + return ERR_PTR(ret); + } + goto insert; + } + + btrfs_setup_root(root, fs_info, + location->objectid); + + path = btrfs_alloc_path(); + if (!path) { + free(root); + return ERR_PTR(-ENOMEM); + } + + ret = btrfs_search_slot(NULL, tree_root, location, path, 0, 0); + if (ret != 0) { + if (ret > 0) + ret = -ENOENT; + goto out; + } + l = path->nodes[0]; + read_extent_buffer(l, &root->root_item, + btrfs_item_ptr_offset(l, path->slots[0]), + sizeof(root->root_item)); + memcpy(&root->root_key, location, sizeof(*location)); + + /* If this root is already an orphan, no need to read */ + if (btrfs_root_refs(&root->root_item) == 0) { + ret = -ENOENT; + goto out; + } + ret = 0; +out: + btrfs_free_path(path); + if (ret) { + free(root); + return ERR_PTR(ret); + } + generation = btrfs_root_generation(&root->root_item); + root->node = read_tree_block(fs_info, + btrfs_root_bytenr(&root->root_item), generation); + if (!extent_buffer_uptodate(root->node)) { + free(root); + return ERR_PTR(-EIO); + } +insert: + root->ref_cows = 1; + return root; +} + +static int btrfs_fs_roots_compare_objectids(struct rb_node *node, + void *data) +{ + u64 objectid = *((u64 *)data); + struct btrfs_root *root; + + root = rb_entry(node, struct btrfs_root, rb_node); + if (objectid > root->objectid) + return 1; + else if (objectid < root->objectid) + return -1; + else + return 0; +} + +int btrfs_fs_roots_compare_roots(struct rb_node *node1, struct rb_node *node2) +{ + struct btrfs_root *root; + + root = rb_entry(node2, struct btrfs_root, rb_node); + return btrfs_fs_roots_compare_objectids(node1, (void *)&root->objectid); +} + +struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info, + struct btrfs_key *location) +{ + struct btrfs_root *root; + struct rb_node *node; + int ret; + u64 objectid = location->objectid; + + if (location->objectid == BTRFS_ROOT_TREE_OBJECTID) + return fs_info->tree_root; + if (location->objectid == BTRFS_CHUNK_TREE_OBJECTID) + return fs_info->chunk_root; + if (location->objectid == BTRFS_CSUM_TREE_OBJECTID) + return fs_info->csum_root; + BUG_ON(location->objectid == BTRFS_TREE_RELOC_OBJECTID || + location->offset != (u64)-1); + + node = rb_search(&fs_info->fs_root_tree, (void *)&objectid, + btrfs_fs_roots_compare_objectids, NULL); + if (node) + return container_of(node, struct btrfs_root, rb_node); + + root = btrfs_read_fs_root_no_cache(fs_info, location); + if (IS_ERR(root)) + return root; + + ret = rb_insert(&fs_info->fs_root_tree, &root->rb_node, + btrfs_fs_roots_compare_roots); + BUG_ON(ret); + return root; +} + +void btrfs_free_fs_info(struct btrfs_fs_info *fs_info) +{ + free(fs_info->tree_root); + free(fs_info->chunk_root); + free(fs_info->csum_root); + free(fs_info->super_copy); + free(fs_info); +} + +struct btrfs_fs_info *btrfs_new_fs_info(void) +{ + struct btrfs_fs_info *fs_info; + + fs_info = calloc(1, sizeof(struct btrfs_fs_info)); + if (!fs_info) + return NULL; + + fs_info->tree_root = calloc(1, sizeof(struct btrfs_root)); + fs_info->chunk_root = calloc(1, sizeof(struct btrfs_root)); + fs_info->csum_root = calloc(1, sizeof(struct btrfs_root)); + fs_info->super_copy = calloc(1, BTRFS_SUPER_INFO_SIZE); + + if (!fs_info->tree_root || !fs_info->chunk_root || + !fs_info->csum_root || !fs_info->super_copy) + goto free_all; + + extent_io_tree_init(&fs_info->extent_cache); + + fs_info->fs_root_tree = RB_ROOT; + cache_tree_init(&fs_info->mapping_tree.cache_tree); + + mutex_init(&fs_info->fs_mutex); + + return fs_info; +free_all: + btrfs_free_fs_info(fs_info); + return NULL; +} + +static int setup_root_or_create_block(struct btrfs_fs_info *fs_info, + struct btrfs_root *info_root, + u64 objectid, char *str) +{ + struct btrfs_root *root = fs_info->tree_root; + int ret; + + ret = find_and_setup_root(root, fs_info, objectid, info_root); + if (ret) { + error("could not setup %s tree", str); + return -EIO; + } + + return 0; +} + +int btrfs_setup_all_roots(struct btrfs_fs_info *fs_info) +{ + struct btrfs_super_block *sb = fs_info->super_copy; + struct btrfs_root *root; + struct btrfs_key key; + u64 root_tree_bytenr; + u64 generation; + int ret; + + root = fs_info->tree_root; + btrfs_setup_root(root, fs_info, BTRFS_ROOT_TREE_OBJECTID); + generation = btrfs_super_generation(sb); + + root_tree_bytenr = btrfs_super_root(sb); + + root->node = read_tree_block(fs_info, root_tree_bytenr, generation); + if (!extent_buffer_uptodate(root->node)) { + fprintf(stderr, "Couldn't read tree root\n"); + return -EIO; + } + + ret = setup_root_or_create_block(fs_info, fs_info->csum_root, + BTRFS_CSUM_TREE_OBJECTID, "csum"); + if (ret) + return ret; + fs_info->csum_root->track_dirty = 1; + + fs_info->last_trans_committed = generation; + + key.objectid = BTRFS_FS_TREE_OBJECTID; + key.type = BTRFS_ROOT_ITEM_KEY; + key.offset = (u64)-1; + fs_info->fs_root = btrfs_read_fs_root(fs_info, &key); + + if (IS_ERR(fs_info->fs_root)) + return -EIO; + return 0; +} + +void btrfs_release_all_roots(struct btrfs_fs_info *fs_info) +{ + if (fs_info->csum_root) + free_extent_buffer(fs_info->csum_root->node); + if (fs_info->tree_root) + free_extent_buffer(fs_info->tree_root->node); + if (fs_info->chunk_root) + free_extent_buffer(fs_info->chunk_root->node); +} + +static void free_map_lookup(struct cache_extent *ce) +{ + struct map_lookup *map; + + map = container_of(ce, struct map_lookup, ce); + kfree(map); +} + +FREE_EXTENT_CACHE_BASED_TREE(mapping_cache, free_map_lookup); + +void btrfs_cleanup_all_caches(struct btrfs_fs_info *fs_info) +{ + free_mapping_cache_tree(&fs_info->mapping_tree.cache_tree); + extent_io_tree_cleanup(&fs_info->extent_cache); +} + +static int btrfs_scan_fs_devices(struct blk_desc *desc, + struct disk_partition *part, + struct btrfs_fs_devices **fs_devices) +{ + u64 total_devs; + int ret; + + if (round_up(BTRFS_SUPER_INFO_SIZE + BTRFS_SUPER_INFO_OFFSET, + desc->blksz) > (part->size << desc->log2blksz)) { + error("superblock end %u is larger than device size " LBAFU, + BTRFS_SUPER_INFO_SIZE + BTRFS_SUPER_INFO_OFFSET, + part->size << desc->log2blksz); + return -EINVAL; + } + + ret = btrfs_scan_one_device(desc, part, fs_devices, &total_devs); + if (ret) { + fprintf(stderr, "No valid Btrfs found\n"); + return ret; + } + return 0; +} + +int btrfs_check_fs_compatibility(struct btrfs_super_block *sb) +{ + u64 features; + + features = btrfs_super_incompat_flags(sb) & + ~BTRFS_FEATURE_INCOMPAT_SUPP; + if (features) { + printk("couldn't open because of unsupported " + "option features (%llx).\n", + (unsigned long long)features); + return -ENOTSUPP; + } + + features = btrfs_super_incompat_flags(sb); + if (!(features & BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF)) { + features |= BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF; + btrfs_set_super_incompat_flags(sb, features); + } + + return 0; +} + +static int btrfs_setup_chunk_tree_and_device_map(struct btrfs_fs_info *fs_info) +{ + struct btrfs_super_block *sb = fs_info->super_copy; + u64 chunk_root_bytenr; + u64 generation; + int ret; + + btrfs_setup_root(fs_info->chunk_root, fs_info, + BTRFS_CHUNK_TREE_OBJECTID); + + ret = btrfs_read_sys_array(fs_info); + if (ret) + return ret; + + generation = btrfs_super_chunk_root_generation(sb); + chunk_root_bytenr = btrfs_super_chunk_root(sb); + + fs_info->chunk_root->node = read_tree_block(fs_info, + chunk_root_bytenr, + generation); + if (!extent_buffer_uptodate(fs_info->chunk_root->node)) { + error("cannot read chunk root"); + return -EIO; + } + + ret = btrfs_read_chunk_tree(fs_info); + if (ret) { + fprintf(stderr, "Couldn't read chunk tree\n"); + return ret; + } + return 0; +} + +struct btrfs_fs_info *open_ctree_fs_info(struct blk_desc *desc, + struct disk_partition *part) +{ + 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(); + if (!fs_info) { + fprintf(stderr, "Failed to allocate memory for fs_info\n"); + return NULL; + } + + ret = btrfs_scan_fs_devices(desc, part, &fs_devices); + if (ret) + goto out; + + fs_info->fs_devices = fs_devices; + + ret = btrfs_open_devices(fs_devices); + if (ret) + goto out; + + disk_super = fs_info->super_copy; + ret = btrfs_read_dev_super(desc, part, disk_super); + if (ret) { + printk("No valid btrfs found\n"); + goto out_devices; + } + + if (btrfs_super_flags(disk_super) & BTRFS_SUPER_FLAG_CHANGING_FSID) { + fprintf(stderr, "ERROR: Filesystem UUID change in progress\n"); + goto out_devices; + } + + ASSERT(!memcmp(disk_super->fsid, fs_devices->fsid, BTRFS_FSID_SIZE)); + if (btrfs_fs_incompat(fs_info, METADATA_UUID)) + ASSERT(!memcmp(disk_super->metadata_uuid, + fs_devices->metadata_uuid, BTRFS_FSID_SIZE)); + + fs_info->sectorsize = btrfs_super_sectorsize(disk_super); + fs_info->nodesize = btrfs_super_nodesize(disk_super); + fs_info->stripesize = btrfs_super_stripesize(disk_super); + + ret = btrfs_check_fs_compatibility(fs_info->super_copy); + if (ret) + goto out_devices; + + ret = btrfs_setup_chunk_tree_and_device_map(fs_info); + if (ret) + goto out_chunk; + + /* Chunk tree root is unable to read, return directly */ + if (!fs_info->chunk_root) + return fs_info; + + eb = fs_info->chunk_root->node; + read_extent_buffer(eb, fs_info->chunk_tree_uuid, + btrfs_header_chunk_tree_uuid(eb), + BTRFS_UUID_SIZE); + + ret = btrfs_setup_all_roots(fs_info); + if (ret) + goto out_chunk; + + return fs_info; + +out_chunk: + btrfs_release_all_roots(fs_info); + btrfs_cleanup_all_caches(fs_info); +out_devices: + btrfs_close_devices(fs_devices); +out: + btrfs_free_fs_info(fs_info); + return NULL; +} + +int close_ctree_fs_info(struct btrfs_fs_info *fs_info) +{ + int ret; + int err = 0; + + free_fs_roots_tree(&fs_info->fs_root_tree); + + btrfs_release_all_roots(fs_info); + ret = btrfs_close_devices(fs_info->fs_devices); + btrfs_cleanup_all_caches(fs_info); + btrfs_free_fs_info(fs_info); + if (!err) + err = ret; + return err; +} + +int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid) +{ + int ret; + + ret = extent_buffer_uptodate(buf); + if (!ret) + return ret; + + ret = verify_parent_transid(&buf->fs_info->extent_cache, buf, + parent_transid, 1); + return !ret; +} + +int btrfs_set_buffer_uptodate(struct extent_buffer *eb) +{ + return set_extent_buffer_uptodate(eb); +} diff --git a/fs/btrfs/disk-io.h b/fs/btrfs/disk-io.h index ca731a5245..9daf959c57 100644 --- a/fs/btrfs/disk-io.h +++ b/fs/btrfs/disk-io.h @@ -22,6 +22,25 @@ struct extent_buffer* btrfs_find_create_tree_block( struct btrfs_fs_info *fs_info, u64 bytenr); struct extent_buffer *btrfs_find_tree_block(struct btrfs_fs_info *fs_info, u64 bytenr, u32 blocksize); +struct btrfs_root *btrfs_read_fs_root_no_cache(struct btrfs_fs_info *fs_info, + struct btrfs_key *location); +struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info, + struct btrfs_key *location); + +void btrfs_setup_root(struct btrfs_root *root, struct btrfs_fs_info *fs_info, + u64 objectid); + +void btrfs_free_fs_info(struct btrfs_fs_info *fs_info); +struct btrfs_fs_info *btrfs_new_fs_info(void); +int btrfs_check_fs_compatibility(struct btrfs_super_block *sb); +int btrfs_setup_all_roots(struct btrfs_fs_info *fs_info); +void btrfs_release_all_roots(struct btrfs_fs_info *fs_info); +void btrfs_cleanup_all_caches(struct btrfs_fs_info *fs_info); + +struct btrfs_fs_info *open_ctree_fs_info(struct blk_desc *desc, + struct disk_partition *part); +int close_ctree_fs_info(struct btrfs_fs_info *fs_info); + int btrfs_read_dev_super(struct blk_desc *desc, struct disk_partition *part, struct btrfs_super_block *sb); int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid); diff --git a/fs/btrfs/root-tree.c b/fs/btrfs/root-tree.c new file mode 100644 index 0000000000..a39ad72067 --- /dev/null +++ b/fs/btrfs/root-tree.c @@ -0,0 +1,47 @@ +// SPDX-License-Identifier: GPL-2.0+ + +#include "ctree.h" + +int btrfs_find_last_root(struct btrfs_root *root, u64 objectid, + struct btrfs_root_item *item, struct btrfs_key *key) +{ + struct btrfs_path *path; + struct btrfs_key search_key; + struct btrfs_key found_key; + struct extent_buffer *l; + int ret; + int slot; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + search_key.objectid = objectid; + search_key.type = BTRFS_ROOT_ITEM_KEY; + search_key.offset = (u64)-1; + + ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0); + if (ret < 0) + goto out; + if (path->slots[0] == 0) { + ret = -ENOENT; + goto out; + } + + BUG_ON(ret == 0); + l = path->nodes[0]; + slot = path->slots[0] - 1; + btrfs_item_key_to_cpu(l, &found_key, slot); + if (found_key.type != BTRFS_ROOT_ITEM_KEY || + found_key.objectid != objectid) { + ret = -ENOENT; + goto out; + } + read_extent_buffer(l, item, btrfs_item_ptr_offset(l, slot), + sizeof(*item)); + memcpy(key, &found_key, sizeof(found_key)); + ret = 0; +out: + btrfs_free_path(path); + return ret; +}