| Message ID | 8e33931a4d078d1e1aa620aa5fe717f35146ef31.1721987605.git.wqu@suse.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | btrfs-progs: a more generic uuid tree rebuild ability | expand |
在 2024/7/26 19:29, Qu Wenruo 写道: [...] > +static int empty_tree(struct btrfs_root *root) > +{ > + struct btrfs_trans_handle *trans; > + struct btrfs_path path = { 0 }; > + struct btrfs_key key = { 0 }; > + int ret; > + > + trans = btrfs_start_transaction(root, 1); > + if (IS_ERR(trans)) { > + ret = PTR_ERR(trans); > + errno = -ret; > + error_msg(ERROR_MSG_START_TRANS, "emptry tree: %m"); One typo, "emptry" -> "empty" Fixed in my github repo. Thanks for the awesome CI codespell check! Qu > + return ret; > + } > + while (true) { > + int nr_items; > + > + ret = btrfs_search_slot(trans, root, &key, &path, -1, 1); > + if (ret < 0) { > + errno = -ret; > + error("failed to locate the first key of root %lld: %m", > + root->root_key.objectid); > + btrfs_abort_transaction(trans, ret); > + return ret; > + } > + UASSERT(ret > 0); > + nr_items = btrfs_header_nritems(path.nodes[0]); > + /* The tree is empty. */ > + if (nr_items == 0) { > + btrfs_release_path(&path); > + break; > + } > + ret = btrfs_del_items(trans, root, &path, 0, nr_items); > + btrfs_release_path(&path); > + if (ret < 0) { > + errno = -ret; > + error("failed to empty the first leaf of root %lld: %m", > + root->root_key.objectid); > + btrfs_abort_transaction(trans, ret); > + return ret; > + } > + } > + ret = btrfs_commit_transaction(trans, root); > + if (ret < 0) { > + errno = -ret; > + error_msg(ERROR_MSG_COMMIT_TRANS, "empty tree: %m"); > + } > + return ret; > +} > + > +static int rescan_subvol_uuid(struct btrfs_trans_handle *trans, > + struct btrfs_key *subvol_key) > +{ > + struct btrfs_fs_info *fs_info = trans->fs_info; > + struct btrfs_root *subvol; > + int ret; > + > + UASSERT(is_fstree(subvol_key->objectid)); > + > + /* > + * Read out the subvolume root and updates root::root_item. > + * This is to avoid de-sync between in-memory and on-disk root_items. > + */ > + subvol = btrfs_read_fs_root(fs_info, subvol_key); > + if (IS_ERR(subvol)) { > + ret = PTR_ERR(subvol); > + error("failed to read subvolume %llu: %m", > + subvol_key->objectid); > + btrfs_abort_transaction(trans, ret); > + return ret; > + } > + /* The uuid is not set, regenerate one. */ > + if (uuid_is_null(subvol->root_item.uuid)) { > + uuid_generate(subvol->root_item.uuid); > + ret = btrfs_update_root(trans, fs_info->tree_root, &subvol->root_key, > + &subvol->root_item); > + if (ret < 0) { > + error("failed to update subvolume %llu: %m", > + subvol_key->objectid); > + btrfs_abort_transaction(trans, ret); > + return ret; > + } > + } > + ret = btrfs_uuid_tree_add(trans, subvol->root_item.uuid, > + BTRFS_UUID_KEY_SUBVOL, > + subvol->root_key.objectid); > + if (ret < 0) { > + errno = -ret; > + error("failed to add uuid for subvolume %llu: %m", > + subvol_key->objectid); > + btrfs_abort_transaction(trans, ret); > + return ret; > + } > + if (!uuid_is_null(subvol->root_item.received_uuid)) { > + ret = btrfs_uuid_tree_add(trans, subvol->root_item.uuid, > + BTRFS_UUID_KEY_RECEIVED_SUBVOL, > + subvol->root_key.objectid); > + if (ret < 0) { > + errno = -ret; > + error("failed to add received_uuid for subvol %llu: %m", > + subvol->root_key.objectid); > + btrfs_abort_transaction(trans, ret); > + return ret; > + } > + } > + return 0; > +} > + > +static int rescan_uuid_tree(struct btrfs_fs_info *fs_info) > +{ > + struct btrfs_root *tree_root = fs_info->tree_root; > + struct btrfs_root *uuid_root = fs_info->uuid_root; > + struct btrfs_trans_handle *trans; > + struct btrfs_path path = { 0 }; > + struct btrfs_key key = { 0 }; > + int ret; > + > + UASSERT(uuid_root); > + trans = btrfs_start_transaction(uuid_root, 1); > + if (IS_ERR(trans)) { > + ret = PTR_ERR(trans); > + errno = -ret; > + error_msg(ERROR_MSG_START_TRANS, "rescan uuid tree: %m"); > + return ret; > + } > + key.objectid = BTRFS_LAST_FREE_OBJECTID; > + key.type = BTRFS_ROOT_ITEM_KEY; > + key.offset = (u64)-1; > + /* Iterate through all subvolumes except fs tree. */ > + while (true) { > + struct btrfs_key found_key; > + struct extent_buffer *leaf; > + int slot; > + > + /* No more subvolume. */ > + if (key.objectid < BTRFS_FIRST_FREE_OBJECTID) { > + ret = 0; > + break; > + } > + ret = btrfs_search_slot(NULL, tree_root, &key, &path, 0, 0); > + if (ret < 0) { > + errno = -ret; > + error_msg(ERROR_MSG_READ, "iterate subvolumes: %m"); > + btrfs_abort_transaction(trans, ret); > + return ret; > + } > + if (ret > 0) { > + ret = btrfs_previous_item(tree_root, &path, > + BTRFS_FIRST_FREE_OBJECTID, > + BTRFS_ROOT_ITEM_KEY); > + if (ret < 0) { > + errno = -ret; > + btrfs_release_path(&path); > + error_msg(ERROR_MSG_READ, "iterate subvolumes: %m"); > + btrfs_abort_transaction(trans, ret); > + return ret; > + } > + /* No more subvolume. */ > + if (ret > 0) { > + ret = 0; > + btrfs_release_path(&path); > + break; > + } > + } > + leaf = path.nodes[0]; > + slot = path.slots[0]; > + btrfs_item_key_to_cpu(leaf, &found_key, slot); > + btrfs_release_path(&path); > + key.objectid = found_key.objectid - 1; > + > + ret = rescan_subvol_uuid(trans, &found_key); > + if (ret < 0) { > + errno = -ret; > + error("failed to rescan the uuid of subvolume %llu: %m", > + found_key.objectid); > + btrfs_abort_transaction(trans, ret); > + return ret; > + } > + } > + > + /* Update fs tree uuid. */ > + key.objectid = BTRFS_FS_TREE_OBJECTID; > + key.type = BTRFS_ROOT_ITEM_KEY; > + key.offset = 0; > + ret = rescan_subvol_uuid(trans, &key); > + if (ret < 0) { > + errno = -ret; > + error("failed to rescan the uuid of subvolume %llu: %m", > + key.objectid); > + btrfs_abort_transaction(trans, ret); > + return ret; > + } > + ret = btrfs_commit_transaction(trans, uuid_root); > + if (ret < 0) { > + errno = -ret; > + error_msg(ERROR_MSG_COMMIT_TRANS, "rescan uuid tree: %m"); > + } > + return ret; > +} > + > +/* > + * Rebuild the whole uuid tree. > + * > + * If no uuid tree is present, create a new one. > + * If there is an existing uuid tree, all items would be deleted first. > + * > + * For all existing subvolumes (except fs tree), any uninitialized uuid > + * (all zero) be generated using a random uuid, and inserted into the new tree. > + * And if a subvolume has its UUID initialized, it would not be touched and > + * be added to the new uuid tree. > + */ > +int btrfs_rebuild_uuid_tree(struct btrfs_fs_info *fs_info) > +{ > + struct btrfs_root *uuid_root; > + struct btrfs_key key; > + int ret; > + > + if (!fs_info->uuid_root) { > + struct btrfs_trans_handle *trans; > + > + trans = btrfs_start_transaction(fs_info->tree_root, 1); > + if (IS_ERR(trans)) { > + ret = PTR_ERR(trans); > + errno = -ret; > + error_msg(ERROR_MSG_START_TRANS, "create uuid tree: %m"); > + return ret; > + } > + key.objectid = BTRFS_UUID_TREE_OBJECTID; > + key.type = BTRFS_ROOT_ITEM_KEY; > + key.offset = 0; > + uuid_root = btrfs_create_tree(trans, &key); > + if (IS_ERR(uuid_root)) { > + ret = PTR_ERR(uuid_root); > + errno = -ret; > + error("failed to create uuid root: %m"); > + btrfs_abort_transaction(trans, ret); > + return ret; > + } > + add_root_to_dirty_list(uuid_root); > + fs_info->uuid_root = uuid_root; > + ret = btrfs_commit_transaction(trans, fs_info->tree_root); > + if (ret < 0) { > + errno = -ret; > + error_msg(ERROR_MSG_COMMIT_TRANS, "create uuid tree: %m"); > + return ret; > + } > + } > + UASSERT(fs_info->uuid_root); > + ret = empty_tree(fs_info->uuid_root); > + if (ret < 0) { > + errno = -ret; > + error("failed to clear the existing uuid tree: %m"); > + return ret; > + } > + ret = rescan_uuid_tree(fs_info); > + if (ret < 0) { > + errno = -ret; > + error("failed to rescan the uuid tree: %m"); > + return ret; > + } > + return 0; > +} > diff --git a/common/root-tree-utils.h b/common/root-tree-utils.h > index 0c4ece24c7cc..3cb508022e0c 100644 > --- a/common/root-tree-utils.h > +++ b/common/root-tree-utils.h > @@ -26,5 +26,6 @@ int btrfs_link_subvolume(struct btrfs_trans_handle *trans, > struct btrfs_root *parent_root, > u64 parent_dir, const char *name, > int namelen, struct btrfs_root *subvol); > +int btrfs_rebuild_uuid_tree(struct btrfs_fs_info *fs_info); > > #endif > diff --git a/convert/main.c b/convert/main.c > index 078ef64e41ca..aa253781ee99 100644 > --- a/convert/main.c > +++ b/convert/main.c > @@ -1339,6 +1339,11 @@ static int do_convert(const char *devname, u32 convert_flags, u32 nodesize, > goto fail; > } > > + ret = btrfs_rebuild_uuid_tree(image_root->fs_info); > + if (ret < 0) { > + errno = -ret; > + goto fail; > + } > memset(root->fs_info->super_copy->label, 0, BTRFS_LABEL_SIZE); > if (convert_flags & CONVERT_FLAG_COPY_LABEL) { > strncpy_null(root->fs_info->super_copy->label, cctx.label, BTRFS_LABEL_SIZE); > diff --git a/mkfs/main.c b/mkfs/main.c > index b95f1c3372a3..00ccac14a41a 100644 > --- a/mkfs/main.c > +++ b/mkfs/main.c > @@ -736,35 +736,6 @@ static void update_chunk_allocation(struct btrfs_fs_info *fs_info, > } > } > > -static int create_uuid_tree(struct btrfs_trans_handle *trans) > -{ > - struct btrfs_fs_info *fs_info = trans->fs_info; > - struct btrfs_root *root; > - struct btrfs_key key = { > - .objectid = BTRFS_UUID_TREE_OBJECTID, > - .type = BTRFS_ROOT_ITEM_KEY, > - }; > - int ret = 0; > - > - UASSERT(fs_info->uuid_root == NULL); > - root = btrfs_create_tree(trans, &key); > - if (IS_ERR(root)) { > - ret = PTR_ERR(root); > - goto out; > - } > - > - add_root_to_dirty_list(root); > - fs_info->uuid_root = root; > - ret = btrfs_uuid_tree_add(trans, fs_info->fs_root->root_item.uuid, > - BTRFS_UUID_KEY_SUBVOL, > - fs_info->fs_root->root_key.objectid); > - if (ret < 0) > - btrfs_abort_transaction(trans, ret); > - > -out: > - return ret; > -} > - > static int create_global_root(struct btrfs_trans_handle *trans, u64 objectid, > int root_id) > { > @@ -1822,17 +1793,15 @@ raid_groups: > goto out; > } > > - ret = create_uuid_tree(trans); > - if (ret) > - warning( > - "unable to create uuid tree, will be created after mount: %d", ret); > - > ret = btrfs_commit_transaction(trans, root); > if (ret) { > errno = -ret; > error_msg(ERROR_MSG_START_TRANS, "%m"); > goto out; > } > + ret = btrfs_rebuild_uuid_tree(fs_info); > + if (ret < 0) > + goto out; > > ret = cleanup_temp_chunks(fs_info, &allocation, data_profile, > metadata_profile, metadata_profile);
On Fri, Jul 26, 2024 at 07:29:55PM +0930, Qu Wenruo wrote: > Currently mkfs uses its own create_uuid_tree(), but that function is > only handling FS_TREE. > > This means for btrfs-convert, we do not generate the uuid tree, nor > add the UUID of the image subvolume. > > This can be a problem if we're going to support multiple subvolumes > during mkfs time. > > To address this inconvenience, this patch introduces a new helper, > btrfs_rebuild_uuid_tree(), which will: > > - Create a new uuid tree if there is not one > > - Empty the existing uuid tree > > - Iterate through all subvolumes > * If the subvolume has no valid UUID, regenerate one > * Add the uuid entry for the subvolume UUID > * If the subvolume has received UUID, also add it to UUID tree > > By this, this new helper can handle all the uuid tree generation needs for: > > - Current mkfs > Only one uuid entry for FS_TREE > > - Current btrfs-convert > Only FS_TREE and the image subvolume > > - Future multi-subvolume mkfs > As we do the scan for all subvolumes. > > - Future "btrfs rescue rebuild-uuid-tree" > > Signed-off-by: Qu Wenruo <wqu@suse.com> > --- > common/root-tree-utils.c | 265 +++++++++++++++++++++++++++++++++++++++ > common/root-tree-utils.h | 1 + > convert/main.c | 5 + > mkfs/main.c | 37 +----- > 4 files changed, 274 insertions(+), 34 deletions(-) > > diff --git a/common/root-tree-utils.c b/common/root-tree-utils.c > index 6a57c51a8a74..13f89dbd5293 100644 > --- a/common/root-tree-utils.c > +++ b/common/root-tree-utils.c > @@ -15,9 +15,11 @@ > */ > > #include <time.h> > +#include <uuid/uuid.h> > #include "common/root-tree-utils.h" > #include "common/messages.h" > #include "kernel-shared/disk-io.h" > +#include "kernel-shared/uuid-tree.h" > > int btrfs_make_root_dir(struct btrfs_trans_handle *trans, > struct btrfs_root *root, u64 objectid) > @@ -212,3 +214,266 @@ abort: > btrfs_abort_transaction(trans, ret); > return ret; > } > + > +static int empty_tree(struct btrfs_root *root) > +{ > + struct btrfs_trans_handle *trans; > + struct btrfs_path path = { 0 }; > + struct btrfs_key key = { 0 }; > + int ret; > + > + trans = btrfs_start_transaction(root, 1); > + if (IS_ERR(trans)) { > + ret = PTR_ERR(trans); > + errno = -ret; > + error_msg(ERROR_MSG_START_TRANS, "emptry tree: %m"); > + return ret; > + } > + while (true) { > + int nr_items; > + > + ret = btrfs_search_slot(trans, root, &key, &path, -1, 1); > + if (ret < 0) { > + errno = -ret; > + error("failed to locate the first key of root %lld: %m", > + root->root_key.objectid); > + btrfs_abort_transaction(trans, ret); > + return ret; > + } > + UASSERT(ret > 0); > + nr_items = btrfs_header_nritems(path.nodes[0]); > + /* The tree is empty. */ > + if (nr_items == 0) { > + btrfs_release_path(&path); > + break; > + } > + ret = btrfs_del_items(trans, root, &path, 0, nr_items); > + btrfs_release_path(&path); > + if (ret < 0) { > + errno = -ret; > + error("failed to empty the first leaf of root %lld: %m", > + root->root_key.objectid); > + btrfs_abort_transaction(trans, ret); > + return ret; > + } > + } > + ret = btrfs_commit_transaction(trans, root); > + if (ret < 0) { > + errno = -ret; > + error_msg(ERROR_MSG_COMMIT_TRANS, "empty tree: %m"); > + } > + return ret; > +} > + > +static int rescan_subvol_uuid(struct btrfs_trans_handle *trans, > + struct btrfs_key *subvol_key) > +{ > + struct btrfs_fs_info *fs_info = trans->fs_info; > + struct btrfs_root *subvol; > + int ret; > + > + UASSERT(is_fstree(subvol_key->objectid)); > + > + /* > + * Read out the subvolume root and updates root::root_item. > + * This is to avoid de-sync between in-memory and on-disk root_items. > + */ > + subvol = btrfs_read_fs_root(fs_info, subvol_key); > + if (IS_ERR(subvol)) { > + ret = PTR_ERR(subvol); > + error("failed to read subvolume %llu: %m", > + subvol_key->objectid); > + btrfs_abort_transaction(trans, ret); > + return ret; > + } > + /* The uuid is not set, regenerate one. */ > + if (uuid_is_null(subvol->root_item.uuid)) { > + uuid_generate(subvol->root_item.uuid); > + ret = btrfs_update_root(trans, fs_info->tree_root, &subvol->root_key, > + &subvol->root_item); > + if (ret < 0) { > + error("failed to update subvolume %llu: %m", > + subvol_key->objectid); > + btrfs_abort_transaction(trans, ret); > + return ret; > + } > + } > + ret = btrfs_uuid_tree_add(trans, subvol->root_item.uuid, > + BTRFS_UUID_KEY_SUBVOL, > + subvol->root_key.objectid); > + if (ret < 0) { > + errno = -ret; > + error("failed to add uuid for subvolume %llu: %m", > + subvol_key->objectid); > + btrfs_abort_transaction(trans, ret); > + return ret; > + } > + if (!uuid_is_null(subvol->root_item.received_uuid)) { > + ret = btrfs_uuid_tree_add(trans, subvol->root_item.uuid, > + BTRFS_UUID_KEY_RECEIVED_SUBVOL, > + subvol->root_key.objectid); > + if (ret < 0) { > + errno = -ret; > + error("failed to add received_uuid for subvol %llu: %m", > + subvol->root_key.objectid); > + btrfs_abort_transaction(trans, ret); > + return ret; > + } > + } > + return 0; > +} > + > +static int rescan_uuid_tree(struct btrfs_fs_info *fs_info) > +{ > + struct btrfs_root *tree_root = fs_info->tree_root; > + struct btrfs_root *uuid_root = fs_info->uuid_root; > + struct btrfs_trans_handle *trans; > + struct btrfs_path path = { 0 }; > + struct btrfs_key key = { 0 }; > + int ret; > + > + UASSERT(uuid_root); > + trans = btrfs_start_transaction(uuid_root, 1); > + if (IS_ERR(trans)) { > + ret = PTR_ERR(trans); > + errno = -ret; > + error_msg(ERROR_MSG_START_TRANS, "rescan uuid tree: %m"); > + return ret; > + } > + key.objectid = BTRFS_LAST_FREE_OBJECTID; > + key.type = BTRFS_ROOT_ITEM_KEY; > + key.offset = (u64)-1; > + /* Iterate through all subvolumes except fs tree. */ > + while (true) { > + struct btrfs_key found_key; > + struct extent_buffer *leaf; > + int slot; > + > + /* No more subvolume. */ > + if (key.objectid < BTRFS_FIRST_FREE_OBJECTID) { > + ret = 0; > + break; > + } > + ret = btrfs_search_slot(NULL, tree_root, &key, &path, 0, 0); > + if (ret < 0) { > + errno = -ret; > + error_msg(ERROR_MSG_READ, "iterate subvolumes: %m"); > + btrfs_abort_transaction(trans, ret); > + return ret; > + } > + if (ret > 0) { > + ret = btrfs_previous_item(tree_root, &path, > + BTRFS_FIRST_FREE_OBJECTID, > + BTRFS_ROOT_ITEM_KEY); > + if (ret < 0) { > + errno = -ret; > + btrfs_release_path(&path); > + error_msg(ERROR_MSG_READ, "iterate subvolumes: %m"); > + btrfs_abort_transaction(trans, ret); > + return ret; > + } > + /* No more subvolume. */ > + if (ret > 0) { > + ret = 0; > + btrfs_release_path(&path); > + break; > + } > + } > + leaf = path.nodes[0]; > + slot = path.slots[0]; > + btrfs_item_key_to_cpu(leaf, &found_key, slot); > + btrfs_release_path(&path); > + key.objectid = found_key.objectid - 1; > + > + ret = rescan_subvol_uuid(trans, &found_key); > + if (ret < 0) { > + errno = -ret; > + error("failed to rescan the uuid of subvolume %llu: %m", > + found_key.objectid); > + btrfs_abort_transaction(trans, ret); > + return ret; > + } > + } > + > + /* Update fs tree uuid. */ > + key.objectid = BTRFS_FS_TREE_OBJECTID; > + key.type = BTRFS_ROOT_ITEM_KEY; > + key.offset = 0; > + ret = rescan_subvol_uuid(trans, &key); > + if (ret < 0) { > + errno = -ret; > + error("failed to rescan the uuid of subvolume %llu: %m", > + key.objectid); > + btrfs_abort_transaction(trans, ret); > + return ret; > + } > + ret = btrfs_commit_transaction(trans, uuid_root); > + if (ret < 0) { > + errno = -ret; > + error_msg(ERROR_MSG_COMMIT_TRANS, "rescan uuid tree: %m"); > + } > + return ret; > +} > + > +/* > + * Rebuild the whole uuid tree. > + * > + * If no uuid tree is present, create a new one. > + * If there is an existing uuid tree, all items would be deleted first. > + * > + * For all existing subvolumes (except fs tree), any uninitialized uuid > + * (all zero) be generated using a random uuid, and inserted into the new tree. > + * And if a subvolume has its UUID initialized, it would not be touched and > + * be added to the new uuid tree. > + */ > +int btrfs_rebuild_uuid_tree(struct btrfs_fs_info *fs_info) > +{ > + struct btrfs_root *uuid_root; > + struct btrfs_key key; > + int ret; > + > + if (!fs_info->uuid_root) { > + struct btrfs_trans_handle *trans; > + > + trans = btrfs_start_transaction(fs_info->tree_root, 1); > + if (IS_ERR(trans)) { > + ret = PTR_ERR(trans); > + errno = -ret; > + error_msg(ERROR_MSG_START_TRANS, "create uuid tree: %m"); > + return ret; > + } > + key.objectid = BTRFS_UUID_TREE_OBJECTID; > + key.type = BTRFS_ROOT_ITEM_KEY; > + key.offset = 0; > + uuid_root = btrfs_create_tree(trans, &key); > + if (IS_ERR(uuid_root)) { > + ret = PTR_ERR(uuid_root); > + errno = -ret; > + error("failed to create uuid root: %m"); > + btrfs_abort_transaction(trans, ret); > + return ret; > + } > + add_root_to_dirty_list(uuid_root); > + fs_info->uuid_root = uuid_root; > + ret = btrfs_commit_transaction(trans, fs_info->tree_root); > + if (ret < 0) { > + errno = -ret; > + error_msg(ERROR_MSG_COMMIT_TRANS, "create uuid tree: %m"); > + return ret; > + } > + } This can just be } else { ret = empty_tree(); } ret = rescan_uuid_tree(fs_info). Thanks, Josef
On Fri, Jul 26, 2024 at 07:29:55PM +0930, Qu Wenruo wrote: > Currently mkfs uses its own create_uuid_tree(), but that function is > only handling FS_TREE. > > This means for btrfs-convert, we do not generate the uuid tree, nor > add the UUID of the image subvolume. > > This can be a problem if we're going to support multiple subvolumes > during mkfs time. > > To address this inconvenience, this patch introduces a new helper, > btrfs_rebuild_uuid_tree(), which will: > > - Create a new uuid tree if there is not one > > - Empty the existing uuid tree > > - Iterate through all subvolumes > * If the subvolume has no valid UUID, regenerate one > * Add the uuid entry for the subvolume UUID > * If the subvolume has received UUID, also add it to UUID tree > > By this, this new helper can handle all the uuid tree generation needs for: > > - Current mkfs > Only one uuid entry for FS_TREE > > - Current btrfs-convert > Only FS_TREE and the image subvolume > > - Future multi-subvolume mkfs > As we do the scan for all subvolumes. > > - Future "btrfs rescue rebuild-uuid-tree" > > Signed-off-by: Qu Wenruo <wqu@suse.com> > --- > common/root-tree-utils.c | 265 +++++++++++++++++++++++++++++++++++++++ > common/root-tree-utils.h | 1 + > convert/main.c | 5 + > mkfs/main.c | 37 +----- > 4 files changed, 274 insertions(+), 34 deletions(-) > > diff --git a/common/root-tree-utils.c b/common/root-tree-utils.c > index 6a57c51a8a74..13f89dbd5293 100644 > --- a/common/root-tree-utils.c > +++ b/common/root-tree-utils.c > @@ -15,9 +15,11 @@ > */ > > #include <time.h> > +#include <uuid/uuid.h> > #include "common/root-tree-utils.h" > #include "common/messages.h" > #include "kernel-shared/disk-io.h" > +#include "kernel-shared/uuid-tree.h" > > int btrfs_make_root_dir(struct btrfs_trans_handle *trans, > struct btrfs_root *root, u64 objectid) > @@ -212,3 +214,266 @@ abort: > btrfs_abort_transaction(trans, ret); > return ret; > } > + > +static int empty_tree(struct btrfs_root *root) Please rename this, it's confusing as empty can be a noun and verb so it's not clear if it's a meant as a predicate or action.
在 2024/7/27 01:05, David Sterba 写道: > On Fri, Jul 26, 2024 at 07:29:55PM +0930, Qu Wenruo wrote: >> Currently mkfs uses its own create_uuid_tree(), but that function is >> only handling FS_TREE. >> >> This means for btrfs-convert, we do not generate the uuid tree, nor >> add the UUID of the image subvolume. >> >> This can be a problem if we're going to support multiple subvolumes >> during mkfs time. >> >> To address this inconvenience, this patch introduces a new helper, >> btrfs_rebuild_uuid_tree(), which will: >> >> - Create a new uuid tree if there is not one >> >> - Empty the existing uuid tree >> >> - Iterate through all subvolumes >> * If the subvolume has no valid UUID, regenerate one >> * Add the uuid entry for the subvolume UUID >> * If the subvolume has received UUID, also add it to UUID tree >> >> By this, this new helper can handle all the uuid tree generation needs for: >> >> - Current mkfs >> Only one uuid entry for FS_TREE >> >> - Current btrfs-convert >> Only FS_TREE and the image subvolume >> >> - Future multi-subvolume mkfs >> As we do the scan for all subvolumes. >> >> - Future "btrfs rescue rebuild-uuid-tree" >> >> Signed-off-by: Qu Wenruo <wqu@suse.com> >> --- >> common/root-tree-utils.c | 265 +++++++++++++++++++++++++++++++++++++++ >> common/root-tree-utils.h | 1 + >> convert/main.c | 5 + >> mkfs/main.c | 37 +----- >> 4 files changed, 274 insertions(+), 34 deletions(-) >> >> diff --git a/common/root-tree-utils.c b/common/root-tree-utils.c >> index 6a57c51a8a74..13f89dbd5293 100644 >> --- a/common/root-tree-utils.c >> +++ b/common/root-tree-utils.c >> @@ -15,9 +15,11 @@ >> */ >> >> #include <time.h> >> +#include <uuid/uuid.h> >> #include "common/root-tree-utils.h" >> #include "common/messages.h" >> #include "kernel-shared/disk-io.h" >> +#include "kernel-shared/uuid-tree.h" >> >> int btrfs_make_root_dir(struct btrfs_trans_handle *trans, >> struct btrfs_root *root, u64 objectid) >> @@ -212,3 +214,266 @@ abort: >> btrfs_abort_transaction(trans, ret); >> return ret; >> } >> + >> +static int empty_tree(struct btrfs_root *root) > > Please rename this, it's confusing as empty can be a noun and verb so > it's not clear if it's a meant as a predicate or action. > Any recommendation? clear_tree()? Thanks, Qu
On Sat, Jul 27, 2024 at 08:03:23AM +0930, Qu Wenruo wrote: > > > 在 2024/7/27 01:05, David Sterba 写道: > > On Fri, Jul 26, 2024 at 07:29:55PM +0930, Qu Wenruo wrote: > >> Currently mkfs uses its own create_uuid_tree(), but that function is > >> only handling FS_TREE. > >> > >> This means for btrfs-convert, we do not generate the uuid tree, nor > >> add the UUID of the image subvolume. > >> > >> This can be a problem if we're going to support multiple subvolumes > >> during mkfs time. > >> > >> To address this inconvenience, this patch introduces a new helper, > >> btrfs_rebuild_uuid_tree(), which will: > >> > >> - Create a new uuid tree if there is not one > >> > >> - Empty the existing uuid tree > >> > >> - Iterate through all subvolumes > >> * If the subvolume has no valid UUID, regenerate one > >> * Add the uuid entry for the subvolume UUID > >> * If the subvolume has received UUID, also add it to UUID tree > >> > >> By this, this new helper can handle all the uuid tree generation needs for: > >> > >> - Current mkfs > >> Only one uuid entry for FS_TREE > >> > >> - Current btrfs-convert > >> Only FS_TREE and the image subvolume > >> > >> - Future multi-subvolume mkfs > >> As we do the scan for all subvolumes. > >> > >> - Future "btrfs rescue rebuild-uuid-tree" > >> > >> Signed-off-by: Qu Wenruo <wqu@suse.com> > >> --- > >> common/root-tree-utils.c | 265 +++++++++++++++++++++++++++++++++++++++ > >> common/root-tree-utils.h | 1 + > >> convert/main.c | 5 + > >> mkfs/main.c | 37 +----- > >> 4 files changed, 274 insertions(+), 34 deletions(-) > >> > >> diff --git a/common/root-tree-utils.c b/common/root-tree-utils.c > >> index 6a57c51a8a74..13f89dbd5293 100644 > >> --- a/common/root-tree-utils.c > >> +++ b/common/root-tree-utils.c > >> @@ -15,9 +15,11 @@ > >> */ > >> > >> #include <time.h> > >> +#include <uuid/uuid.h> > >> #include "common/root-tree-utils.h" > >> #include "common/messages.h" > >> #include "kernel-shared/disk-io.h" > >> +#include "kernel-shared/uuid-tree.h" > >> > >> int btrfs_make_root_dir(struct btrfs_trans_handle *trans, > >> struct btrfs_root *root, u64 objectid) > >> @@ -212,3 +214,266 @@ abort: > >> btrfs_abort_transaction(trans, ret); > >> return ret; > >> } > >> + > >> +static int empty_tree(struct btrfs_root *root) > > > > Please rename this, it's confusing as empty can be a noun and verb so > > it's not clear if it's a meant as a predicate or action. > > > Any recommendation? clear_tree()? I've posted soem suggestions as the pull request review comments.
diff --git a/common/root-tree-utils.c b/common/root-tree-utils.c index 6a57c51a8a74..13f89dbd5293 100644 --- a/common/root-tree-utils.c +++ b/common/root-tree-utils.c @@ -15,9 +15,11 @@ */ #include <time.h> +#include <uuid/uuid.h> #include "common/root-tree-utils.h" #include "common/messages.h" #include "kernel-shared/disk-io.h" +#include "kernel-shared/uuid-tree.h" int btrfs_make_root_dir(struct btrfs_trans_handle *trans, struct btrfs_root *root, u64 objectid) @@ -212,3 +214,266 @@ abort: btrfs_abort_transaction(trans, ret); return ret; } + +static int empty_tree(struct btrfs_root *root) +{ + struct btrfs_trans_handle *trans; + struct btrfs_path path = { 0 }; + struct btrfs_key key = { 0 }; + int ret; + + trans = btrfs_start_transaction(root, 1); + if (IS_ERR(trans)) { + ret = PTR_ERR(trans); + errno = -ret; + error_msg(ERROR_MSG_START_TRANS, "emptry tree: %m"); + return ret; + } + while (true) { + int nr_items; + + ret = btrfs_search_slot(trans, root, &key, &path, -1, 1); + if (ret < 0) { + errno = -ret; + error("failed to locate the first key of root %lld: %m", + root->root_key.objectid); + btrfs_abort_transaction(trans, ret); + return ret; + } + UASSERT(ret > 0); + nr_items = btrfs_header_nritems(path.nodes[0]); + /* The tree is empty. */ + if (nr_items == 0) { + btrfs_release_path(&path); + break; + } + ret = btrfs_del_items(trans, root, &path, 0, nr_items); + btrfs_release_path(&path); + if (ret < 0) { + errno = -ret; + error("failed to empty the first leaf of root %lld: %m", + root->root_key.objectid); + btrfs_abort_transaction(trans, ret); + return ret; + } + } + ret = btrfs_commit_transaction(trans, root); + if (ret < 0) { + errno = -ret; + error_msg(ERROR_MSG_COMMIT_TRANS, "empty tree: %m"); + } + return ret; +} + +static int rescan_subvol_uuid(struct btrfs_trans_handle *trans, + struct btrfs_key *subvol_key) +{ + struct btrfs_fs_info *fs_info = trans->fs_info; + struct btrfs_root *subvol; + int ret; + + UASSERT(is_fstree(subvol_key->objectid)); + + /* + * Read out the subvolume root and updates root::root_item. + * This is to avoid de-sync between in-memory and on-disk root_items. + */ + subvol = btrfs_read_fs_root(fs_info, subvol_key); + if (IS_ERR(subvol)) { + ret = PTR_ERR(subvol); + error("failed to read subvolume %llu: %m", + subvol_key->objectid); + btrfs_abort_transaction(trans, ret); + return ret; + } + /* The uuid is not set, regenerate one. */ + if (uuid_is_null(subvol->root_item.uuid)) { + uuid_generate(subvol->root_item.uuid); + ret = btrfs_update_root(trans, fs_info->tree_root, &subvol->root_key, + &subvol->root_item); + if (ret < 0) { + error("failed to update subvolume %llu: %m", + subvol_key->objectid); + btrfs_abort_transaction(trans, ret); + return ret; + } + } + ret = btrfs_uuid_tree_add(trans, subvol->root_item.uuid, + BTRFS_UUID_KEY_SUBVOL, + subvol->root_key.objectid); + if (ret < 0) { + errno = -ret; + error("failed to add uuid for subvolume %llu: %m", + subvol_key->objectid); + btrfs_abort_transaction(trans, ret); + return ret; + } + if (!uuid_is_null(subvol->root_item.received_uuid)) { + ret = btrfs_uuid_tree_add(trans, subvol->root_item.uuid, + BTRFS_UUID_KEY_RECEIVED_SUBVOL, + subvol->root_key.objectid); + if (ret < 0) { + errno = -ret; + error("failed to add received_uuid for subvol %llu: %m", + subvol->root_key.objectid); + btrfs_abort_transaction(trans, ret); + return ret; + } + } + return 0; +} + +static int rescan_uuid_tree(struct btrfs_fs_info *fs_info) +{ + struct btrfs_root *tree_root = fs_info->tree_root; + struct btrfs_root *uuid_root = fs_info->uuid_root; + struct btrfs_trans_handle *trans; + struct btrfs_path path = { 0 }; + struct btrfs_key key = { 0 }; + int ret; + + UASSERT(uuid_root); + trans = btrfs_start_transaction(uuid_root, 1); + if (IS_ERR(trans)) { + ret = PTR_ERR(trans); + errno = -ret; + error_msg(ERROR_MSG_START_TRANS, "rescan uuid tree: %m"); + return ret; + } + key.objectid = BTRFS_LAST_FREE_OBJECTID; + key.type = BTRFS_ROOT_ITEM_KEY; + key.offset = (u64)-1; + /* Iterate through all subvolumes except fs tree. */ + while (true) { + struct btrfs_key found_key; + struct extent_buffer *leaf; + int slot; + + /* No more subvolume. */ + if (key.objectid < BTRFS_FIRST_FREE_OBJECTID) { + ret = 0; + break; + } + ret = btrfs_search_slot(NULL, tree_root, &key, &path, 0, 0); + if (ret < 0) { + errno = -ret; + error_msg(ERROR_MSG_READ, "iterate subvolumes: %m"); + btrfs_abort_transaction(trans, ret); + return ret; + } + if (ret > 0) { + ret = btrfs_previous_item(tree_root, &path, + BTRFS_FIRST_FREE_OBJECTID, + BTRFS_ROOT_ITEM_KEY); + if (ret < 0) { + errno = -ret; + btrfs_release_path(&path); + error_msg(ERROR_MSG_READ, "iterate subvolumes: %m"); + btrfs_abort_transaction(trans, ret); + return ret; + } + /* No more subvolume. */ + if (ret > 0) { + ret = 0; + btrfs_release_path(&path); + break; + } + } + leaf = path.nodes[0]; + slot = path.slots[0]; + btrfs_item_key_to_cpu(leaf, &found_key, slot); + btrfs_release_path(&path); + key.objectid = found_key.objectid - 1; + + ret = rescan_subvol_uuid(trans, &found_key); + if (ret < 0) { + errno = -ret; + error("failed to rescan the uuid of subvolume %llu: %m", + found_key.objectid); + btrfs_abort_transaction(trans, ret); + return ret; + } + } + + /* Update fs tree uuid. */ + key.objectid = BTRFS_FS_TREE_OBJECTID; + key.type = BTRFS_ROOT_ITEM_KEY; + key.offset = 0; + ret = rescan_subvol_uuid(trans, &key); + if (ret < 0) { + errno = -ret; + error("failed to rescan the uuid of subvolume %llu: %m", + key.objectid); + btrfs_abort_transaction(trans, ret); + return ret; + } + ret = btrfs_commit_transaction(trans, uuid_root); + if (ret < 0) { + errno = -ret; + error_msg(ERROR_MSG_COMMIT_TRANS, "rescan uuid tree: %m"); + } + return ret; +} + +/* + * Rebuild the whole uuid tree. + * + * If no uuid tree is present, create a new one. + * If there is an existing uuid tree, all items would be deleted first. + * + * For all existing subvolumes (except fs tree), any uninitialized uuid + * (all zero) be generated using a random uuid, and inserted into the new tree. + * And if a subvolume has its UUID initialized, it would not be touched and + * be added to the new uuid tree. + */ +int btrfs_rebuild_uuid_tree(struct btrfs_fs_info *fs_info) +{ + struct btrfs_root *uuid_root; + struct btrfs_key key; + int ret; + + if (!fs_info->uuid_root) { + struct btrfs_trans_handle *trans; + + trans = btrfs_start_transaction(fs_info->tree_root, 1); + if (IS_ERR(trans)) { + ret = PTR_ERR(trans); + errno = -ret; + error_msg(ERROR_MSG_START_TRANS, "create uuid tree: %m"); + return ret; + } + key.objectid = BTRFS_UUID_TREE_OBJECTID; + key.type = BTRFS_ROOT_ITEM_KEY; + key.offset = 0; + uuid_root = btrfs_create_tree(trans, &key); + if (IS_ERR(uuid_root)) { + ret = PTR_ERR(uuid_root); + errno = -ret; + error("failed to create uuid root: %m"); + btrfs_abort_transaction(trans, ret); + return ret; + } + add_root_to_dirty_list(uuid_root); + fs_info->uuid_root = uuid_root; + ret = btrfs_commit_transaction(trans, fs_info->tree_root); + if (ret < 0) { + errno = -ret; + error_msg(ERROR_MSG_COMMIT_TRANS, "create uuid tree: %m"); + return ret; + } + } + UASSERT(fs_info->uuid_root); + ret = empty_tree(fs_info->uuid_root); + if (ret < 0) { + errno = -ret; + error("failed to clear the existing uuid tree: %m"); + return ret; + } + ret = rescan_uuid_tree(fs_info); + if (ret < 0) { + errno = -ret; + error("failed to rescan the uuid tree: %m"); + return ret; + } + return 0; +} diff --git a/common/root-tree-utils.h b/common/root-tree-utils.h index 0c4ece24c7cc..3cb508022e0c 100644 --- a/common/root-tree-utils.h +++ b/common/root-tree-utils.h @@ -26,5 +26,6 @@ int btrfs_link_subvolume(struct btrfs_trans_handle *trans, struct btrfs_root *parent_root, u64 parent_dir, const char *name, int namelen, struct btrfs_root *subvol); +int btrfs_rebuild_uuid_tree(struct btrfs_fs_info *fs_info); #endif diff --git a/convert/main.c b/convert/main.c index 078ef64e41ca..aa253781ee99 100644 --- a/convert/main.c +++ b/convert/main.c @@ -1339,6 +1339,11 @@ static int do_convert(const char *devname, u32 convert_flags, u32 nodesize, goto fail; } + ret = btrfs_rebuild_uuid_tree(image_root->fs_info); + if (ret < 0) { + errno = -ret; + goto fail; + } memset(root->fs_info->super_copy->label, 0, BTRFS_LABEL_SIZE); if (convert_flags & CONVERT_FLAG_COPY_LABEL) { strncpy_null(root->fs_info->super_copy->label, cctx.label, BTRFS_LABEL_SIZE); diff --git a/mkfs/main.c b/mkfs/main.c index b95f1c3372a3..00ccac14a41a 100644 --- a/mkfs/main.c +++ b/mkfs/main.c @@ -736,35 +736,6 @@ static void update_chunk_allocation(struct btrfs_fs_info *fs_info, } } -static int create_uuid_tree(struct btrfs_trans_handle *trans) -{ - struct btrfs_fs_info *fs_info = trans->fs_info; - struct btrfs_root *root; - struct btrfs_key key = { - .objectid = BTRFS_UUID_TREE_OBJECTID, - .type = BTRFS_ROOT_ITEM_KEY, - }; - int ret = 0; - - UASSERT(fs_info->uuid_root == NULL); - root = btrfs_create_tree(trans, &key); - if (IS_ERR(root)) { - ret = PTR_ERR(root); - goto out; - } - - add_root_to_dirty_list(root); - fs_info->uuid_root = root; - ret = btrfs_uuid_tree_add(trans, fs_info->fs_root->root_item.uuid, - BTRFS_UUID_KEY_SUBVOL, - fs_info->fs_root->root_key.objectid); - if (ret < 0) - btrfs_abort_transaction(trans, ret); - -out: - return ret; -} - static int create_global_root(struct btrfs_trans_handle *trans, u64 objectid, int root_id) { @@ -1822,17 +1793,15 @@ raid_groups: goto out; } - ret = create_uuid_tree(trans); - if (ret) - warning( - "unable to create uuid tree, will be created after mount: %d", ret); - ret = btrfs_commit_transaction(trans, root); if (ret) { errno = -ret; error_msg(ERROR_MSG_START_TRANS, "%m"); goto out; } + ret = btrfs_rebuild_uuid_tree(fs_info); + if (ret < 0) + goto out; ret = cleanup_temp_chunks(fs_info, &allocation, data_profile, metadata_profile, metadata_profile);
Currently mkfs uses its own create_uuid_tree(), but that function is only handling FS_TREE. This means for btrfs-convert, we do not generate the uuid tree, nor add the UUID of the image subvolume. This can be a problem if we're going to support multiple subvolumes during mkfs time. To address this inconvenience, this patch introduces a new helper, btrfs_rebuild_uuid_tree(), which will: - Create a new uuid tree if there is not one - Empty the existing uuid tree - Iterate through all subvolumes * If the subvolume has no valid UUID, regenerate one * Add the uuid entry for the subvolume UUID * If the subvolume has received UUID, also add it to UUID tree By this, this new helper can handle all the uuid tree generation needs for: - Current mkfs Only one uuid entry for FS_TREE - Current btrfs-convert Only FS_TREE and the image subvolume - Future multi-subvolume mkfs As we do the scan for all subvolumes. - Future "btrfs rescue rebuild-uuid-tree" Signed-off-by: Qu Wenruo <wqu@suse.com> --- common/root-tree-utils.c | 265 +++++++++++++++++++++++++++++++++++++++ common/root-tree-utils.h | 1 + convert/main.c | 5 + mkfs/main.c | 37 +----- 4 files changed, 274 insertions(+), 34 deletions(-)