diff options
| -rw-r--r-- | fs/btrfs/ctree.h | 14 | ||||
| -rw-r--r-- | fs/btrfs/disk-io.c | 1 | ||||
| -rw-r--r-- | fs/btrfs/qgroup.c | 150 | ||||
| -rw-r--r-- | fs/btrfs/qgroup.h | 92 | ||||
| -rw-r--r-- | fs/btrfs/relocation.c | 7 | ||||
| -rw-r--r-- | fs/btrfs/transaction.c | 1 |
6 files changed, 265 insertions, 0 deletions
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index dd0ccc6403b0..007b0e81992a 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -1209,6 +1209,17 @@ enum { }; /* + * Record swapped tree blocks of a subvolume tree for delayed subtree trace + * code. For detail check comment in fs/btrfs/qgroup.c. + */ +struct btrfs_qgroup_swapped_blocks { + spinlock_t lock; + /* RM_EMPTY_ROOT() of above blocks[] */ + bool swapped; + struct rb_root blocks[BTRFS_MAX_LEVEL]; +}; + +/* * in ram representation of the tree. extent_root is used for all allocations * and for the extent tree extent_root root. */ @@ -1343,6 +1354,9 @@ struct btrfs_root { /* Number of active swapfiles */ atomic_t nr_swapfiles; + /* Record pairs of swapped blocks for qgroup */ + struct btrfs_qgroup_swapped_blocks swapped_blocks; + #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS u64 alloc_bytenr; #endif diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 9e24fdb57453..3d233608fa0f 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -1220,6 +1220,7 @@ static void __setup_root(struct btrfs_root *root, struct btrfs_fs_info *fs_info, root->anon_dev = 0; spin_lock_init(&root->root_item_lock); + btrfs_qgroup_init_swapped_blocks(&root->swapped_blocks); } static struct btrfs_root *btrfs_alloc_root(struct btrfs_fs_info *fs_info, diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c index 7a6948989655..7166d202b26a 100644 --- a/fs/btrfs/qgroup.c +++ b/fs/btrfs/qgroup.c @@ -3818,3 +3818,153 @@ void btrfs_qgroup_check_reserved_leak(struct inode *inode) } extent_changeset_release(&changeset); } + +void btrfs_qgroup_init_swapped_blocks( + struct btrfs_qgroup_swapped_blocks *swapped_blocks) +{ + int i; + + spin_lock_init(&swapped_blocks->lock); + for (i = 0; i < BTRFS_MAX_LEVEL; i++) + swapped_blocks->blocks[i] = RB_ROOT; + swapped_blocks->swapped = false; +} + +/* + * Delete all swapped blocks record of @root. + * Every record here means we skipped a full subtree scan for qgroup. + * + * Gets called when committing one transaction. + */ +void btrfs_qgroup_clean_swapped_blocks(struct btrfs_root *root) +{ + struct btrfs_qgroup_swapped_blocks *swapped_blocks; + int i; + + swapped_blocks = &root->swapped_blocks; + + spin_lock(&swapped_blocks->lock); + if (!swapped_blocks->swapped) + goto out; + for (i = 0; i < BTRFS_MAX_LEVEL; i++) { + struct rb_root *cur_root = &swapped_blocks->blocks[i]; + struct btrfs_qgroup_swapped_block *entry; + struct btrfs_qgroup_swapped_block *next; + + rbtree_postorder_for_each_entry_safe(entry, next, cur_root, + node) + kfree(entry); + swapped_blocks->blocks[i] = RB_ROOT; + } + swapped_blocks->swapped = false; +out: + spin_unlock(&swapped_blocks->lock); +} + +/* + * Add subtree roots record into @subvol_root. + * + * @subvol_root: tree root of the subvolume tree get swapped + * @bg: block group under balance + * @subvol_parent/slot: pointer to the subtree root in subvolume tree + * @reloc_parent/slot: pointer to the subtree root in reloc tree + * BOTH POINTERS ARE BEFORE TREE SWAP + * @last_snapshot: last snapshot generation of the subvolume tree + */ +int btrfs_qgroup_add_swapped_blocks(struct btrfs_trans_handle *trans, + struct btrfs_root *subvol_root, + struct btrfs_block_group_cache *bg, + struct extent_buffer *subvol_parent, int subvol_slot, + struct extent_buffer *reloc_parent, int reloc_slot, + u64 last_snapshot) +{ + struct btrfs_fs_info *fs_info = subvol_root->fs_info; + struct btrfs_qgroup_swapped_blocks *blocks = &subvol_root->swapped_blocks; + struct btrfs_qgroup_swapped_block *block; + struct rb_node **cur; + struct rb_node *parent = NULL; + int level = btrfs_header_level(subvol_parent) - 1; + int ret = 0; + + if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags)) + return 0; + + if (btrfs_node_ptr_generation(subvol_parent, subvol_slot) > + btrfs_node_ptr_generation(reloc_parent, reloc_slot)) { + btrfs_err_rl(fs_info, + "%s: bad parameter order, subvol_gen=%llu reloc_gen=%llu", + __func__, + btrfs_node_ptr_generation(subvol_parent, subvol_slot), + btrfs_node_ptr_generation(reloc_parent, reloc_slot)); + return -EUCLEAN; + } + + block = kmalloc(sizeof(*block), GFP_NOFS); + if (!block) { + ret = -ENOMEM; + goto out; + } + + /* + * @reloc_parent/slot is still before swap, while @block is going to + * record the bytenr after swap, so we do the swap here. + */ + block->subvol_bytenr = btrfs_node_blockptr(reloc_parent, reloc_slot); + block->subvol_generation = btrfs_node_ptr_generation(reloc_parent, + reloc_slot); + block->reloc_bytenr = btrfs_node_blockptr(subvol_parent, subvol_slot); + block->reloc_generation = btrfs_node_ptr_generation(subvol_parent, + subvol_slot); + block->last_snapshot = last_snapshot; + block->level = level; + if (bg->flags & BTRFS_BLOCK_GROUP_DATA) + block->trace_leaf = true; + else + block->trace_leaf = false; + btrfs_node_key_to_cpu(reloc_parent, &block->first_key, reloc_slot); + + /* Insert @block into @blocks */ + spin_lock(&blocks->lock); + cur = &blocks->blocks[level].rb_node; + while (*cur) { + struct btrfs_qgroup_swapped_block *entry; + + parent = *cur; + entry = rb_entry(parent, struct btrfs_qgroup_swapped_block, + node); + + if (entry->subvol_bytenr < block->subvol_bytenr) { + cur = &(*cur)->rb_left; + } else if (entry->subvol_bytenr > block->subvol_bytenr) { + cur = &(*cur)->rb_right; + } else { + if (entry->subvol_generation != + block->subvol_generation || + entry->reloc_bytenr != block->reloc_bytenr || + entry->reloc_generation != + block->reloc_generation) { + /* + * Duplicated but mismatch entry found. + * Shouldn't happen. + * + * Marking qgroup inconsistent should be enough + * for end users. + */ + WARN_ON(IS_ENABLED(CONFIG_BTRFS_DEBUG)); + ret = -EEXIST; + } + kfree(block); + goto out_unlock; + } + } + rb_link_node(&block->node, parent, cur); + rb_insert_color(&block->node, &blocks->blocks[level]); + blocks->swapped = true; +out_unlock: + spin_unlock(&blocks->lock); +out: + if (ret < 0) + fs_info->qgroup_flags |= + BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT; + return ret; +} diff --git a/fs/btrfs/qgroup.h b/fs/btrfs/qgroup.h index 20c6bd5fa701..8dc17020e5be 100644 --- a/fs/btrfs/qgroup.h +++ b/fs/btrfs/qgroup.h @@ -6,6 +6,8 @@ #ifndef BTRFS_QGROUP_H #define BTRFS_QGROUP_H +#include <linux/spinlock.h> +#include <linux/rbtree.h> #include "ulist.h" #include "delayed-ref.h" @@ -38,6 +40,66 @@ */ /* + * Special performance optimization for balance. + * + * For balance, we need to swap subtree of subvolume and reloc trees. + * In theory, we need to trace all subtree blocks of both subvolume and reloc + * trees, since their owner has changed during such swap. + * + * However since balance has ensured that both subtrees are containing the + * same contents and have the same tree structures, such swap won't cause + * qgroup number change. + * + * But there is a race window between subtree swap and transaction commit, + * during that window, if we increase/decrease tree level or merge/split tree + * blocks, we still need to trace the original subtrees. + * + * So for balance, we use a delayed subtree tracing, whose workflow is: + * + * 1) Record the subtree root block get swapped. + * + * During subtree swap: + * O = Old tree blocks + * N = New tree blocks + * reloc tree subvolume tree X + * Root Root + * / \ / \ + * NA OB OA OB + * / | | \ / | | \ + * NC ND OE OF OC OD OE OF + * + * In this case, NA and OA are going to be swapped, record (NA, OA) into + * subvolume tree X. + * + * 2) After subtree swap. + * reloc tree subvolume tree X + * Root Root + * / \ / \ + * OA OB NA OB + * / | | \ / | | \ + * OC OD OE OF NC ND OE OF + * + * 3a) COW happens for OB + * If we are going to COW tree block OB, we check OB's bytenr against + * tree X's swapped_blocks structure. + * If it doesn't fit any, nothing will happen. + * + * 3b) COW happens for NA + * Check NA's bytenr against tree X's swapped_blocks, and get a hit. + * Then we do subtree scan on both subtrees OA and NA. + * Resulting 6 tree blocks to be scanned (OA, OC, OD, NA, NC, ND). + * + * Then no matter what we do to subvolume tree X, qgroup numbers will + * still be correct. + * Then NA's record gets removed from X's swapped_blocks. + * + * 4) Transaction commit + * Any record in X's swapped_blocks gets removed, since there is no + * modification to the swapped subtrees, no need to trigger heavy qgroup + * subtree rescan for them. + */ + +/* * Record a dirty extent, and info qgroup to update quota on it * TODO: Use kmem cache to alloc it. */ @@ -48,6 +110,24 @@ struct btrfs_qgroup_extent_record { struct ulist *old_roots; }; +struct btrfs_qgroup_swapped_block { + struct rb_node node; + + int level; + bool trace_leaf; + + /* bytenr/generation of the tree block in subvolume tree after swap */ + u64 subvol_bytenr; + u64 subvol_generation; + + /* bytenr/generation of the tree block in reloc tree after swap */ + u64 reloc_bytenr; + u64 reloc_generation; + + u64 last_snapshot; + struct btrfs_key first_key; +}; + /* * Qgroup reservation types: * @@ -325,4 +405,16 @@ void btrfs_qgroup_convert_reserved_meta(struct btrfs_root *root, int num_bytes); void btrfs_qgroup_check_reserved_leak(struct inode *inode); +/* btrfs_qgroup_swapped_blocks related functions */ +void btrfs_qgroup_init_swapped_blocks( + struct btrfs_qgroup_swapped_blocks *swapped_blocks); + +void btrfs_qgroup_clean_swapped_blocks(struct btrfs_root *root); +int btrfs_qgroup_add_swapped_blocks(struct btrfs_trans_handle *trans, + struct btrfs_root *subvol_root, + struct btrfs_block_group_cache *bg, + struct extent_buffer *subvol_parent, int subvol_slot, + struct extent_buffer *reloc_parent, int reloc_slot, + u64 last_snapshot); + #endif diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c index b915f3e157bd..0c528918c844 100644 --- a/fs/btrfs/relocation.c +++ b/fs/btrfs/relocation.c @@ -1898,6 +1898,13 @@ again: if (ret < 0) break; + btrfs_node_key_to_cpu(parent, &first_key, slot); + ret = btrfs_qgroup_add_swapped_blocks(trans, dest, + rc->block_group, parent, slot, + path->nodes[level], path->slots[level], + last_snapshot); + if (ret < 0) + break; /* * swap blocks in fs tree and reloc tree. */ diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c index fdffe5d61739..0cc6d8b58191 100644 --- a/fs/btrfs/transaction.c +++ b/fs/btrfs/transaction.c @@ -122,6 +122,7 @@ static noinline void switch_commit_roots(struct btrfs_transaction *trans) if (is_fstree(root->root_key.objectid)) btrfs_unpin_free_ino(root); clear_btree_io_tree(&root->dirty_log_pages); + btrfs_qgroup_clean_swapped_blocks(root); } /* We can free old roots now. */ |