diff options
Diffstat (limited to 'fs/ocfs2/refcounttree.c')
| -rw-r--r-- | fs/ocfs2/refcounttree.c | 359 |
1 files changed, 359 insertions, 0 deletions
diff --git a/fs/ocfs2/refcounttree.c b/fs/ocfs2/refcounttree.c index eb0f4a047938..8d79de8637b8 100644 --- a/fs/ocfs2/refcounttree.c +++ b/fs/ocfs2/refcounttree.c @@ -27,6 +27,7 @@ #include "buffer_head_io.h" #include "blockcheck.h" #include "refcounttree.h" +#include "dlmglue.h" static inline struct ocfs2_refcount_tree * cache_info_to_refcount(struct ocfs2_caching_info *ci) @@ -156,3 +157,361 @@ static const struct ocfs2_caching_operations ocfs2_refcount_caching_ops = { .co_io_lock = ocfs2_refcount_cache_io_lock, .co_io_unlock = ocfs2_refcount_cache_io_unlock, }; + +static struct ocfs2_refcount_tree * +ocfs2_find_refcount_tree(struct ocfs2_super *osb, u64 blkno) +{ + struct rb_node *n = osb->osb_rf_lock_tree.rb_node; + struct ocfs2_refcount_tree *tree = NULL; + + while (n) { + tree = rb_entry(n, struct ocfs2_refcount_tree, rf_node); + + if (blkno < tree->rf_blkno) + n = n->rb_left; + else if (blkno > tree->rf_blkno) + n = n->rb_right; + else + return tree; + } + + return NULL; +} + +/* osb_lock is already locked. */ +static void ocfs2_insert_refcount_tree(struct ocfs2_super *osb, + struct ocfs2_refcount_tree *new) +{ + u64 rf_blkno = new->rf_blkno; + struct rb_node *parent = NULL; + struct rb_node **p = &osb->osb_rf_lock_tree.rb_node; + struct ocfs2_refcount_tree *tmp; + + while (*p) { + parent = *p; + + tmp = rb_entry(parent, struct ocfs2_refcount_tree, + rf_node); + + if (rf_blkno < tmp->rf_blkno) + p = &(*p)->rb_left; + else if (rf_blkno > tmp->rf_blkno) + p = &(*p)->rb_right; + else { + /* This should never happen! */ + mlog(ML_ERROR, "Duplicate refcount block %llu found!\n", + (unsigned long long)rf_blkno); + BUG(); + } + } + + rb_link_node(&new->rf_node, parent, p); + rb_insert_color(&new->rf_node, &osb->osb_rf_lock_tree); +} + +static void ocfs2_free_refcount_tree(struct ocfs2_refcount_tree *tree) +{ + ocfs2_metadata_cache_exit(&tree->rf_ci); + ocfs2_simple_drop_lockres(OCFS2_SB(tree->rf_sb), &tree->rf_lockres); + ocfs2_lock_res_free(&tree->rf_lockres); + kfree(tree); +} + +static inline void +ocfs2_erase_refcount_tree_from_list_no_lock(struct ocfs2_super *osb, + struct ocfs2_refcount_tree *tree) +{ + rb_erase(&tree->rf_node, &osb->osb_rf_lock_tree); + if (osb->osb_ref_tree_lru && osb->osb_ref_tree_lru == tree) + osb->osb_ref_tree_lru = NULL; +} + +static void ocfs2_erase_refcount_tree_from_list(struct ocfs2_super *osb, + struct ocfs2_refcount_tree *tree) +{ + spin_lock(&osb->osb_lock); + ocfs2_erase_refcount_tree_from_list_no_lock(osb, tree); + spin_unlock(&osb->osb_lock); +} + +void ocfs2_kref_remove_refcount_tree(struct kref *kref) +{ + struct ocfs2_refcount_tree *tree = + container_of(kref, struct ocfs2_refcount_tree, rf_getcnt); + + ocfs2_free_refcount_tree(tree); +} + +static inline void +ocfs2_refcount_tree_get(struct ocfs2_refcount_tree *tree) +{ + kref_get(&tree->rf_getcnt); +} + +static inline void +ocfs2_refcount_tree_put(struct ocfs2_refcount_tree *tree) +{ + kref_put(&tree->rf_getcnt, ocfs2_kref_remove_refcount_tree); +} + +static inline void ocfs2_init_refcount_tree_ci(struct ocfs2_refcount_tree *new, + struct super_block *sb) +{ + ocfs2_metadata_cache_init(&new->rf_ci, &ocfs2_refcount_caching_ops); + mutex_init(&new->rf_io_mutex); + new->rf_sb = sb; + spin_lock_init(&new->rf_lock); +} + +static inline void ocfs2_init_refcount_tree_lock(struct ocfs2_super *osb, + struct ocfs2_refcount_tree *new, + u64 rf_blkno, u32 generation) +{ + init_rwsem(&new->rf_sem); + ocfs2_refcount_lock_res_init(&new->rf_lockres, osb, + rf_blkno, generation); +} + +static int ocfs2_get_refcount_tree(struct ocfs2_super *osb, u64 rf_blkno, + struct ocfs2_refcount_tree **ret_tree) +{ + int ret = 0; + struct ocfs2_refcount_tree *tree, *new = NULL; + struct buffer_head *ref_root_bh = NULL; + struct ocfs2_refcount_block *ref_rb; + + spin_lock(&osb->osb_lock); + if (osb->osb_ref_tree_lru && + osb->osb_ref_tree_lru->rf_blkno == rf_blkno) + tree = osb->osb_ref_tree_lru; + else + tree = ocfs2_find_refcount_tree(osb, rf_blkno); + if (tree) + goto out; + + spin_unlock(&osb->osb_lock); + + new = kzalloc(sizeof(struct ocfs2_refcount_tree), GFP_NOFS); + if (!new) { + ret = -ENOMEM; + return ret; + } + + new->rf_blkno = rf_blkno; + kref_init(&new->rf_getcnt); + ocfs2_init_refcount_tree_ci(new, osb->sb); + + /* + * We need the generation to create the refcount tree lock and since + * it isn't changed during the tree modification, we are safe here to + * read without protection. + * We also have to purge the cache after we create the lock since the + * refcount block may have the stale data. It can only be trusted when + * we hold the refcount lock. + */ + ret = ocfs2_read_refcount_block(&new->rf_ci, rf_blkno, &ref_root_bh); + if (ret) { + mlog_errno(ret); + ocfs2_metadata_cache_exit(&new->rf_ci); + kfree(new); + return ret; + } + + ref_rb = (struct ocfs2_refcount_block *)ref_root_bh->b_data; + new->rf_generation = le32_to_cpu(ref_rb->rf_generation); + ocfs2_init_refcount_tree_lock(osb, new, rf_blkno, + new->rf_generation); + ocfs2_metadata_cache_purge(&new->rf_ci); + + spin_lock(&osb->osb_lock); + tree = ocfs2_find_refcount_tree(osb, rf_blkno); + if (tree) + goto out; + + ocfs2_insert_refcount_tree(osb, new); + + tree = new; + new = NULL; + +out: + *ret_tree = tree; + + osb->osb_ref_tree_lru = tree; + + spin_unlock(&osb->osb_lock); + + if (new) + ocfs2_free_refcount_tree(new); + + brelse(ref_root_bh); + return ret; +} + +static int ocfs2_get_refcount_block(struct inode *inode, u64 *ref_blkno) +{ + int ret; + struct buffer_head *di_bh = NULL; + struct ocfs2_dinode *di; + + ret = ocfs2_read_inode_block(inode, &di_bh); + if (ret) { + mlog_errno(ret); + goto out; + } + + BUG_ON(!(OCFS2_I(inode)->ip_dyn_features & OCFS2_HAS_REFCOUNT_FL)); + + di = (struct ocfs2_dinode *)di_bh->b_data; + *ref_blkno = le64_to_cpu(di->i_refcount_loc); + brelse(di_bh); +out: + return ret; +} + +static int __ocfs2_lock_refcount_tree(struct ocfs2_super *osb, + struct ocfs2_refcount_tree *tree, int rw) +{ + int ret; + + ret = ocfs2_refcount_lock(tree, rw); + if (ret) { + mlog_errno(ret); + goto out; + } + + if (rw) + down_write(&tree->rf_sem); + else + down_read(&tree->rf_sem); + +out: + return ret; +} + +/* + * Lock the refcount tree pointed by ref_blkno and return the tree. + * In most case, we lock the tree and read the refcount block. + * So read it here if the caller really needs it. + * + * If the tree has been re-created by other node, it will free the + * old one and re-create it. + */ +int ocfs2_lock_refcount_tree(struct ocfs2_super *osb, + u64 ref_blkno, int rw, + struct ocfs2_refcount_tree **ret_tree, + struct buffer_head **ref_bh) +{ + int ret, delete_tree = 0; + struct ocfs2_refcount_tree *tree = NULL; + struct buffer_head *ref_root_bh = NULL; + struct ocfs2_refcount_block *rb; + +again: + ret = ocfs2_get_refcount_tree(osb, ref_blkno, &tree); + if (ret) { + mlog_errno(ret); + return ret; + } + + ocfs2_refcount_tree_get(tree); + + ret = __ocfs2_lock_refcount_tree(osb, tree, rw); + if (ret) { + mlog_errno(ret); + ocfs2_refcount_tree_put(tree); + goto out; + } + + ret = ocfs2_read_refcount_block(&tree->rf_ci, tree->rf_blkno, + &ref_root_bh); + if (ret) { + mlog_errno(ret); + ocfs2_unlock_refcount_tree(osb, tree, rw); + ocfs2_refcount_tree_put(tree); + goto out; + } + + rb = (struct ocfs2_refcount_block *)ref_root_bh->b_data; + /* + * If the refcount block has been freed and re-created, we may need + * to recreate the refcount tree also. + * + * Here we just remove the tree from the rb-tree, and the last + * kref holder will unlock and delete this refcount_tree. + * Then we goto "again" and ocfs2_get_refcount_tree will create + * the new refcount tree for us. + */ + if (tree->rf_generation != le32_to_cpu(rb->rf_generation)) { + if (!tree->rf_removed) { + ocfs2_erase_refcount_tree_from_list(osb, tree); + tree->rf_removed = 1; + delete_tree = 1; + } + + ocfs2_unlock_refcount_tree(osb, tree, rw); + /* + * We get an extra reference when we create the refcount + * tree, so another put will destroy it. + */ + if (delete_tree) + ocfs2_refcount_tree_put(tree); + brelse(ref_root_bh); + ref_root_bh = NULL; + goto again; + } + + *ret_tree = tree; + if (ref_bh) { + *ref_bh = ref_root_bh; + ref_root_bh = NULL; + } +out: + brelse(ref_root_bh); + return ret; +} + +int ocfs2_lock_refcount_tree_by_inode(struct inode *inode, int rw, + struct ocfs2_refcount_tree **ret_tree, + struct buffer_head **ref_bh) +{ + int ret; + u64 ref_blkno; + + ret = ocfs2_get_refcount_block(inode, &ref_blkno); + if (ret) { + mlog_errno(ret); + return ret; + } + + return ocfs2_lock_refcount_tree(OCFS2_SB(inode->i_sb), ref_blkno, + rw, ret_tree, ref_bh); +} + +void ocfs2_unlock_refcount_tree(struct ocfs2_super *osb, + struct ocfs2_refcount_tree *tree, int rw) +{ + if (rw) + up_write(&tree->rf_sem); + else + up_read(&tree->rf_sem); + + ocfs2_refcount_unlock(tree, rw); + ocfs2_refcount_tree_put(tree); +} + +void ocfs2_purge_refcount_trees(struct ocfs2_super *osb) +{ + struct rb_node *node; + struct ocfs2_refcount_tree *tree; + struct rb_root *root = &osb->osb_rf_lock_tree; + + while ((node = rb_last(root)) != NULL) { + tree = rb_entry(node, struct ocfs2_refcount_tree, rf_node); + + mlog(0, "Purge tree %llu\n", + (unsigned long long) tree->rf_blkno); + + rb_erase(&tree->rf_node, root); + ocfs2_free_refcount_tree(tree); + } +} |