From 5eda7b5e9b0bed864dd18284c7df9b3c8207dad7 Mon Sep 17 00:00:00 2001 From: Chris Mason Date: Fri, 22 Jun 2007 14:16:25 -0400 Subject: [PATCH] Btrfs: Add the ability to find and remove dead roots after a crash. Signed-off-by: Chris Mason --- fs/btrfs/ctree.h | 17 ++++++++-- fs/btrfs/disk-io.c | 44 +++++++++++++++++-------- fs/btrfs/disk-io.h | 3 ++ fs/btrfs/inode.c | 2 ++ fs/btrfs/root-tree.c | 75 +++++++++++++++++++++++++++++++++++++----- fs/btrfs/transaction.c | 54 ++++++++++++++++++++++++++---- fs/btrfs/transaction.h | 1 + 7 files changed, 164 insertions(+), 32 deletions(-) diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index 77071f273977..fb6fffb71dd0 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -122,12 +122,12 @@ struct btrfs_super_block { u8 fsid[16]; /* FS specific uuid */ __le64 blocknr; /* this block number */ __le64 magic; - __le32 blocksize; __le64 generation; __le64 root; __le64 total_blocks; __le64 blocks_used; __le64 root_dir_objectid; + __le32 blocksize; } __attribute__ ((__packed__)); /* @@ -226,10 +226,12 @@ struct btrfs_root_item { struct btrfs_inode_item inode; __le64 root_dirid; __le64 blocknr; - __le32 flags; __le64 block_limit; __le64 blocks_used; + __le32 flags; __le32 refs; + struct btrfs_disk_key drop_progress; + u8 drop_level; } __attribute__ ((__packed__)); #define BTRFS_FILE_EXTENT_REG 0 @@ -800,6 +802,16 @@ static inline void btrfs_set_root_refs(struct btrfs_root_item *item, u32 val) item->refs = cpu_to_le32(val); } +static inline u32 btrfs_root_flags(struct btrfs_root_item *item) +{ + return le32_to_cpu(item->flags); +} + +static inline void btrfs_set_root_flags(struct btrfs_root_item *item, u32 val) +{ + item->flags = cpu_to_le32(val); +} + static inline u64 btrfs_super_blocknr(struct btrfs_super_block *s) { return le64_to_cpu(s->blocknr); @@ -1076,6 +1088,7 @@ int btrfs_update_root(struct btrfs_trans_handle *trans, struct btrfs_root *item); int btrfs_find_last_root(struct btrfs_root *root, u64 objectid, struct btrfs_root_item *item, struct btrfs_key *key); +int btrfs_find_dead_roots(struct btrfs_root *root); /* dir-item.c */ int btrfs_insert_dir_item(struct btrfs_trans_handle *trans, struct btrfs_root *root, const char *name, int name_len, u64 dir, diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 865a284aa06c..d7615e1578cc 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -326,8 +326,8 @@ static int find_and_setup_root(int blocksize, return 0; } -struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info, - struct btrfs_key *location) +struct btrfs_root *btrfs_read_fs_root_no_radix(struct btrfs_fs_info *fs_info, + struct btrfs_key *location) { struct btrfs_root *root; struct btrfs_root *tree_root = fs_info->tree_root; @@ -336,11 +336,7 @@ struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info, u64 highest_inode; int ret = 0; - root = radix_tree_lookup(&fs_info->fs_roots_radix, - (unsigned long)location->objectid); - if (root) - return root; - root = kmalloc(sizeof(*root), GFP_NOFS); + root = kzalloc(sizeof(*root), GFP_NOFS); if (!root) return ERR_PTR(-ENOMEM); if (location->offset == (u64)-1) { @@ -383,6 +379,28 @@ out: BUG_ON(!root->node); insert: root->ref_cows = 1; + ret = btrfs_find_highest_inode(root, &highest_inode); + if (ret == 0) { + root->highest_inode = highest_inode; + root->last_inode_alloc = highest_inode; + } + return root; +} + +struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info, + struct btrfs_key *location) +{ + struct btrfs_root *root; + int ret; + + root = radix_tree_lookup(&fs_info->fs_roots_radix, + (unsigned long)location->objectid); + if (root) + return root; + + root = btrfs_read_fs_root_no_radix(fs_info, location); + if (IS_ERR(root)) + return root; ret = radix_tree_insert(&fs_info->fs_roots_radix, (unsigned long)root->root_key.objectid, root); @@ -391,11 +409,6 @@ insert: kfree(root); return ERR_PTR(ret); } - ret = btrfs_find_highest_inode(root, &highest_inode); - if (ret == 0) { - root->highest_inode = highest_inode; - root->last_inode_alloc = highest_inode; - } return root; } @@ -489,6 +502,9 @@ struct btrfs_root *open_ctree(struct super_block *sb) btrfs_read_block_groups(extent_root); fs_info->generation = btrfs_super_generation(disk_super) + 1; + ret = btrfs_find_dead_roots(tree_root); + if (ret) + goto fail_tree_root; mutex_unlock(&fs_info->fs_mutex); return tree_root; @@ -538,7 +554,7 @@ int write_ctree_super(struct btrfs_trans_handle *trans, struct btrfs_root return 0; } -static int free_fs_root(struct btrfs_fs_info *fs_info, struct btrfs_root *root) +int btrfs_free_fs_root(struct btrfs_fs_info *fs_info, struct btrfs_root *root) { radix_tree_delete(&fs_info->fs_roots_radix, (unsigned long)root->root_key.objectid); @@ -565,7 +581,7 @@ static int del_fs_roots(struct btrfs_fs_info *fs_info) if (!ret) break; for (i = 0; i < ret; i++) - free_fs_root(fs_info, gang[i]); + btrfs_free_fs_root(fs_info, gang[i]); } return 0; } diff --git a/fs/btrfs/disk-io.h b/fs/btrfs/disk-io.h index 7b76ccc48754..c4a695ac44f6 100644 --- a/fs/btrfs/disk-io.h +++ b/fs/btrfs/disk-io.h @@ -65,6 +65,8 @@ int btrfs_csum_data(struct btrfs_root * root, char *data, size_t len, char *result); struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info, struct btrfs_key *location); +struct btrfs_root *btrfs_read_fs_root_no_radix(struct btrfs_fs_info *fs_info, + struct btrfs_key *location); u64 bh_blocknr(struct buffer_head *bh); int btrfs_insert_dev_radix(struct btrfs_root *root, struct block_device *bdev, @@ -75,4 +77,5 @@ int btrfs_map_bh_to_logical(struct btrfs_root *root, struct buffer_head *bh, u64 logical); int btrfs_releasepage(struct page *page, gfp_t flags); void btrfs_btree_balance_dirty(struct btrfs_root *root); +int btrfs_free_fs_root(struct btrfs_fs_info *fs_info, struct btrfs_root *root); #endif diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 6d031daa7779..9d2a0a3f674d 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -2028,6 +2028,8 @@ static int create_subvol(struct btrfs_root *root, char *name, int namelen) btrfs_set_root_blocknr(&root_item, bh_blocknr(subvol)); btrfs_set_root_refs(&root_item, 1); + memset(&root_item.drop_progress, 0, sizeof(root_item.drop_progress)); + root_item.drop_level = 0; brelse(subvol); subvol = NULL; diff --git a/fs/btrfs/root-tree.c b/fs/btrfs/root-tree.c index ac0fae7780ff..737e5a38d17e 100644 --- a/fs/btrfs/root-tree.c +++ b/fs/btrfs/root-tree.c @@ -18,6 +18,7 @@ #include #include "ctree.h" +#include "transaction.h" #include "disk-io.h" #include "print-tree.h" @@ -32,7 +33,7 @@ int btrfs_find_last_root(struct btrfs_root *root, u64 objectid, search_key.objectid = objectid; search_key.flags = (u32)-1; - search_key.offset = (u32)-1; + search_key.offset = (u64)-1; path = btrfs_alloc_path(); BUG_ON(!path); @@ -50,6 +51,7 @@ int btrfs_find_last_root(struct btrfs_root *root, u64 objectid, memcpy(item, btrfs_item_ptr(l, slot, struct btrfs_root_item), sizeof(*item)); btrfs_disk_key_to_cpu(key, &l->items[slot].key); +printk("find last finds key %Lu %u %Lu slot %d search for obj %Lu\n", key->objectid, key->flags, key->offset, slot, objectid); ret = 0; out: btrfs_release_path(root, path); @@ -93,6 +95,67 @@ int btrfs_insert_root(struct btrfs_trans_handle *trans, struct btrfs_root return ret; } +int btrfs_find_dead_roots(struct btrfs_root *root) +{ + struct btrfs_root *dead_root; + struct btrfs_item *item; + struct btrfs_root_item *ri; + struct btrfs_key key; + struct btrfs_path *path; + int ret; + u32 nritems; + struct btrfs_leaf *leaf; + int slot; + + key.objectid = 0; + key.flags = 0; + btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY); + key.offset = 0; + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); + if (ret < 0) + goto err; + while(1) { + leaf = btrfs_buffer_leaf(path->nodes[0]); + nritems = btrfs_header_nritems(&leaf->header); + slot = path->slots[0]; + if (slot >= nritems) { + ret = btrfs_next_leaf(root, path); + if (ret) + break; + leaf = btrfs_buffer_leaf(path->nodes[0]); + nritems = btrfs_header_nritems(&leaf->header); + slot = path->slots[0]; + } + item = leaf->items + slot; + btrfs_disk_key_to_cpu(&key, &item->key); + if (btrfs_key_type(&key) != BTRFS_ROOT_ITEM_KEY) + goto next; + ri = btrfs_item_ptr(leaf, slot, struct btrfs_root_item); + if (btrfs_root_refs(ri) != 0) + goto next; + dead_root = btrfs_read_fs_root_no_radix(root->fs_info, &key); + if (IS_ERR(root)) { + ret = PTR_ERR(root); + goto err; + } +printk("found dead root %Lu %u %Lu\n", key.objectid, key.flags, key.offset); + ret = btrfs_add_dead_root(dead_root, + &root->fs_info->dead_roots); + if (ret) + goto err; +next: + slot++; + path->slots[0]++; + } + ret = 0; +err: + btrfs_free_path(path); + return ret; +} + int btrfs_del_root(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_key *key) { @@ -111,14 +174,8 @@ int btrfs_del_root(struct btrfs_trans_handle *trans, struct btrfs_root *root, path->slots[0], struct btrfs_root_item); refs = btrfs_root_refs(ri); - BUG_ON(refs == 0); - if (refs == 1) { - ret = btrfs_del_item(trans, root, path); - } else { - btrfs_set_root_refs(ri, refs - 1); - WARN_ON(1); - mark_buffer_dirty(path->nodes[0]); - } + BUG_ON(refs != 0); + ret = btrfs_del_item(trans, root, path); out: btrfs_release_path(root, path); btrfs_free_path(path); diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c index 321f8852755b..85a2a5e27148 100644 --- a/fs/btrfs/transaction.c +++ b/fs/btrfs/transaction.c @@ -85,11 +85,15 @@ struct btrfs_trans_handle *btrfs_start_transaction(struct btrfs_root *root, if (root != root->fs_info->tree_root && root->last_trans < running_trans_id) { - radix_tree_tag_set(&root->fs_info->fs_roots_radix, - (unsigned long)root->root_key.objectid, - BTRFS_ROOT_TRANS_TAG); - root->commit_root = root->node; - get_bh(root->node); + if (root->root_item.refs != 0) { + radix_tree_tag_set(&root->fs_info->fs_roots_radix, + (unsigned long)root->root_key.objectid, + BTRFS_ROOT_TRANS_TAG); + root->commit_root = root->node; + get_bh(root->node); + } else { + WARN_ON(1); + } } root->last_trans = running_trans_id; h->transid = running_trans_id; @@ -208,8 +212,24 @@ struct dirty_root { struct btrfs_key snap_key; struct buffer_head *commit_root; struct btrfs_root *root; + int free_on_drop; }; +int btrfs_add_dead_root(struct btrfs_root *root, struct list_head *dead_list) +{ + struct dirty_root *dirty; + + dirty = kmalloc(sizeof(*dirty), GFP_NOFS); + if (!dirty) + return -ENOMEM; + memcpy(&dirty->snap_key, &root->root_key, sizeof(root->root_key)); + dirty->commit_root = root->node; + dirty->root = root; + dirty->free_on_drop = 1; + list_add(&dirty->list, dead_list); + return 0; +} + static int add_dirty_roots(struct btrfs_trans_handle *trans, struct radix_tree_root *radix, struct list_head *list) @@ -217,9 +237,11 @@ static int add_dirty_roots(struct btrfs_trans_handle *trans, struct dirty_root *dirty; struct btrfs_root *gang[8]; struct btrfs_root *root; + struct btrfs_root_item tmp_item; int i; int ret; int err = 0; + u32 refs; while(1) { ret = radix_tree_gang_lookup_tag(radix, (void **)gang, 0, @@ -246,6 +268,9 @@ static int add_dirty_roots(struct btrfs_trans_handle *trans, dirty->commit_root = root->commit_root; root->commit_root = NULL; dirty->root = root; + dirty->free_on_drop = 0; + memcpy(&tmp_item, &root->root_item, sizeof(tmp_item)); + root->root_key.offset = root->fs_info->generation; btrfs_set_root_blocknr(&root->root_item, bh_blocknr(root->node)); @@ -254,7 +279,18 @@ static int add_dirty_roots(struct btrfs_trans_handle *trans, &root->root_item); if (err) break; - list_add(&dirty->list, list); + + refs = btrfs_root_refs(&tmp_item); + btrfs_set_root_refs(&tmp_item, refs - 1); + err = btrfs_update_root(trans, root->fs_info->tree_root, + &dirty->snap_key, + &tmp_item); + + BUG_ON(err); + if (refs == 1) + list_add(&dirty->list, list); + else + kfree(dirty); } } return err; @@ -270,16 +306,20 @@ static int drop_dirty_roots(struct btrfs_root *tree_root, mutex_lock(&tree_root->fs_info->fs_mutex); dirty = list_entry(list->next, struct dirty_root, list); list_del_init(&dirty->list); + trans = btrfs_start_transaction(tree_root, 1); +printk("deleting root %Lu %u %Lu\n", dirty->snap_key.objectid, dirty->snap_key.flags, dirty->snap_key.offset); ret = btrfs_drop_snapshot(trans, dirty->root, dirty->commit_root); BUG_ON(ret); - ret = btrfs_del_root(trans, tree_root, &dirty->snap_key); if (ret) break; ret = btrfs_end_transaction(trans, tree_root); BUG_ON(ret); + + if (dirty->free_on_drop) + kfree(dirty->root); kfree(dirty); mutex_unlock(&tree_root->fs_info->fs_mutex); btrfs_btree_balance_dirty(tree_root); diff --git a/fs/btrfs/transaction.h b/fs/btrfs/transaction.h index 5fb1d322aa10..ebf44f3e1118 100644 --- a/fs/btrfs/transaction.h +++ b/fs/btrfs/transaction.h @@ -69,5 +69,6 @@ void btrfs_transaction_flush_work(struct btrfs_root *root); void btrfs_transaction_queue_work(struct btrfs_root *root, int delay); void btrfs_init_transaction_sys(void); void btrfs_exit_transaction_sys(void); +int btrfs_add_dead_root(struct btrfs_root *root, struct list_head *dead_list); #endif -- 2.30.2