From 7d9eb12c8739e7dc80c78c6b3596f912ecd8f941 Mon Sep 17 00:00:00 2001 From: Chris Mason Date: Tue, 8 Jul 2008 14:19:17 -0400 Subject: [PATCH] Btrfs: Add locking around volume management (device add/remove/balance) Signed-off-by: Chris Mason --- fs/btrfs/ctree.c | 4 --- fs/btrfs/ctree.h | 1 + fs/btrfs/disk-io.c | 1 + fs/btrfs/extent-tree.c | 73 +++++++++++++++++++++++++++++++----------- fs/btrfs/ioctl.c | 6 ++-- fs/btrfs/volumes.c | 58 +++++++++++++++++++++++++-------- 6 files changed, 103 insertions(+), 40 deletions(-) diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c index c6759fc1004a..bbf9bf374066 100644 --- a/fs/btrfs/ctree.c +++ b/fs/btrfs/ctree.c @@ -1251,10 +1251,6 @@ int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root WARN_ON(p->nodes[0] != NULL); WARN_ON(cow && root == root->fs_info->extent_root && !mutex_is_locked(&root->fs_info->alloc_mutex)); - WARN_ON(root == root->fs_info->chunk_root && - !mutex_is_locked(&root->fs_info->chunk_mutex)); - WARN_ON(root == root->fs_info->dev_root && - !mutex_is_locked(&root->fs_info->chunk_mutex)); if (ins_len < 0) lowest_unlock = 2; again: diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index a28796482b4a..f3783dbd9b60 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -523,6 +523,7 @@ struct btrfs_fs_info { struct mutex alloc_mutex; struct mutex chunk_mutex; struct mutex drop_mutex; + struct mutex volume_mutex; struct list_head trans_list; struct list_head hashers; struct list_head dead_roots; diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 4cdc0b6a2672..8f4c40033e92 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -1287,6 +1287,7 @@ struct btrfs_root *open_ctree(struct super_block *sb, mutex_init(&fs_info->chunk_mutex); mutex_init(&fs_info->transaction_kthread_mutex); mutex_init(&fs_info->cleaner_mutex); + mutex_init(&fs_info->volume_mutex); #if 0 ret = add_hasher(fs_info, "crc32c"); diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index 5e0857ffbc35..8ebfa6be0790 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -245,6 +245,7 @@ static int noinline find_search_start(struct btrfs_root *root, u64 search_start = *start_ret; int wrapped = 0; + WARN_ON(!mutex_is_locked(&root->fs_info->alloc_mutex)); total_fs_bytes = btrfs_super_total_bytes(&root->fs_info->super_copy); free_space_cache = &root->fs_info->free_space_cache; @@ -1242,6 +1243,7 @@ static int update_block_group(struct btrfs_trans_handle *trans, u64 start; u64 end; + WARN_ON(!mutex_is_locked(&root->fs_info->alloc_mutex)); while(total) { cache = btrfs_lookup_block_group(info, bytenr); if (!cache) { @@ -1297,6 +1299,7 @@ static int update_pinned_extents(struct btrfs_root *root, struct btrfs_block_group_cache *cache; struct btrfs_fs_info *fs_info = root->fs_info; + WARN_ON(!mutex_is_locked(&root->fs_info->alloc_mutex)); if (pin) { set_extent_dirty(&fs_info->pinned_extents, bytenr, bytenr + num - 1, GFP_NOFS); @@ -1391,6 +1394,7 @@ static int finish_current_insert(struct btrfs_trans_handle *trans, int level; int err = 0; + WARN_ON(!mutex_is_locked(&extent_root->fs_info->alloc_mutex)); btrfs_set_stack_extent_refs(&extent_item, 1); btrfs_set_key_type(&ins, BTRFS_EXTENT_ITEM_KEY); path = btrfs_alloc_path(); @@ -1437,6 +1441,7 @@ static int pin_down_bytes(struct btrfs_root *root, u64 bytenr, u32 num_bytes, { int err = 0; + WARN_ON(!mutex_is_locked(&root->fs_info->alloc_mutex)); if (!pending) { struct extent_buffer *buf; buf = btrfs_find_tree_block(root, bytenr, num_bytes); @@ -1490,6 +1495,7 @@ static int __free_extent(struct btrfs_trans_handle *trans, struct btrfs_root struct btrfs_extent_item *ei; u32 refs; + WARN_ON(!mutex_is_locked(&root->fs_info->alloc_mutex)); key.objectid = bytenr; btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY); key.offset = num_bytes; @@ -1619,6 +1625,7 @@ static int del_pending_extents(struct btrfs_trans_handle *trans, struct struct extent_io_tree *pending_del; struct extent_io_tree *pinned_extents; + WARN_ON(!mutex_is_locked(&extent_root->fs_info->alloc_mutex)); pending_del = &extent_root->fs_info->pending_del; pinned_extents = &extent_root->fs_info->pinned_extents; @@ -2428,6 +2435,10 @@ int btrfs_drop_snapshot(struct btrfs_trans_handle *trans, struct btrfs_root btrfs_node_key(node, &found_key, path->slots[level]); WARN_ON(memcmp(&found_key, &root_item->drop_progress, sizeof(found_key))); + /* + * unlock our path, this is safe because only this + * function is allowed to delete this snapshot + */ for (i = 0; i < BTRFS_MAX_LEVEL; i++) { if (path->nodes[i] && path->locks[i]) { path->locks[i] = 0; @@ -2611,7 +2622,6 @@ static int find_root_for_ref(struct btrfs_root *root, u64 root_search_start = BTRFS_FS_TREE_OBJECTID; u64 found_bytenr; int ret; - int i; root_location.offset = (u64)-1; root_location.type = BTRFS_ROOT_ITEM_KEY; @@ -2635,12 +2645,6 @@ static int find_root_for_ref(struct btrfs_root *root, found_bytenr = path->nodes[level]->start; } - for (i = level; i < BTRFS_MAX_LEVEL; i++) { - if (!path->nodes[i]) - break; - free_extent_buffer(path->nodes[i]); - path->nodes[i] = NULL; - } btrfs_release_path(cur_root, path); if (found_bytenr == bytenr) { @@ -2689,6 +2693,8 @@ static int noinline relocate_one_reference(struct btrfs_root *extent_root, int ret; int level; + WARN_ON(!mutex_is_locked(&extent_root->fs_info->alloc_mutex)); + ref = btrfs_item_ptr(path->nodes[0], path->slots[0], struct btrfs_extent_ref); ref_root = btrfs_ref_root(path->nodes[0], ref); @@ -2707,6 +2713,7 @@ static int noinline relocate_one_reference(struct btrfs_root *extent_root, found_root = btrfs_read_fs_root_no_name(extent_root->fs_info, &root_location); BUG_ON(!found_root); + mutex_unlock(&extent_root->fs_info->alloc_mutex); if (ref_objectid >= BTRFS_FIRST_FREE_OBJECTID) { found_key.objectid = ref_objectid; @@ -2748,9 +2755,9 @@ static int noinline relocate_one_reference(struct btrfs_root *extent_root, /* this can happen if the reference is not against * the latest version of the tree root */ - if (is_bad_inode(inode)) { + if (is_bad_inode(inode)) goto out; - } + *last_file_objectid = inode->i_ino; *last_file_root = found_root->root_key.objectid; *last_file_offset = ref_offset; @@ -2760,7 +2767,7 @@ static int noinline relocate_one_reference(struct btrfs_root *extent_root, } else { struct btrfs_trans_handle *trans; struct extent_buffer *eb; - int i; + int needs_lock = 0; eb = read_tree_block(found_root, extent_key->objectid, extent_key->offset, 0); @@ -2782,26 +2789,40 @@ static int noinline relocate_one_reference(struct btrfs_root *extent_root, if (ret) goto out; + /* + * right here almost anything could happen to our key, + * but that's ok. The cow below will either relocate it + * or someone else will have relocated it. Either way, + * it is in a different spot than it was before and + * we're happy. + */ + trans = btrfs_start_transaction(found_root, 1); + if (found_root == extent_root->fs_info->extent_root || + found_root == extent_root->fs_info->chunk_root || + found_root == extent_root->fs_info->dev_root) { + needs_lock = 1; + mutex_lock(&extent_root->fs_info->alloc_mutex); + } + path->lowest_level = level; path->reada = 2; ret = btrfs_search_slot(trans, found_root, &found_key, path, 0, 1); path->lowest_level = 0; - for (i = level; i < BTRFS_MAX_LEVEL; i++) { - if (!path->nodes[i]) - break; - free_extent_buffer(path->nodes[i]); - path->nodes[i] = NULL; - } btrfs_release_path(found_root, path); + if (found_root == found_root->fs_info->extent_root) btrfs_extent_post_op(trans, found_root); + if (needs_lock) + mutex_unlock(&extent_root->fs_info->alloc_mutex); + btrfs_end_transaction(trans, found_root); - } + } out: + mutex_lock(&extent_root->fs_info->alloc_mutex); return 0; } @@ -2943,7 +2964,10 @@ int __alloc_chunk_for_shrink(struct btrfs_root *root, if (btrfs_block_group_used(&shrink_block_group->item) > 0) { + mutex_unlock(&root->fs_info->alloc_mutex); trans = btrfs_start_transaction(root, 1); + mutex_lock(&root->fs_info->alloc_mutex); + new_alloc_flags = update_block_group_flags(root, shrink_block_group->flags); if (new_alloc_flags != shrink_block_group->flags) { @@ -2954,7 +2978,10 @@ int __alloc_chunk_for_shrink(struct btrfs_root *root, } do_chunk_alloc(trans, root->fs_info->extent_root, calc + 2 * 1024 * 1024, new_alloc_flags, force); + + mutex_unlock(&root->fs_info->alloc_mutex); btrfs_end_transaction(trans, root); + mutex_lock(&root->fs_info->alloc_mutex); } return 0; } @@ -3031,9 +3058,9 @@ again: if (ret < 0) goto out; +next: leaf = path->nodes[0]; nritems = btrfs_header_nritems(leaf); -next: if (path->slots[0] >= nritems) { ret = btrfs_next_leaf(root, path); if (ret < 0) @@ -3083,6 +3110,7 @@ next: printk("btrfs relocate found %llu last extent was %llu\n", (unsigned long long)total_found, (unsigned long long)found_key.objectid); + mutex_unlock(&root->fs_info->alloc_mutex); trans = btrfs_start_transaction(tree_root, 1); btrfs_commit_transaction(trans, tree_root); @@ -3090,6 +3118,7 @@ next: trans = btrfs_start_transaction(tree_root, 1); btrfs_commit_transaction(trans, tree_root); + mutex_lock(&root->fs_info->alloc_mutex); goto again; } @@ -3097,7 +3126,10 @@ next: * we've freed all the extents, now remove the block * group item from the tree */ + mutex_unlock(&root->fs_info->alloc_mutex); + trans = btrfs_start_transaction(root, 1); + mutex_lock(&root->fs_info->alloc_mutex); memcpy(&key, &shrink_block_group->key, sizeof(key)); ret = btrfs_search_slot(trans, root, &key, path, -1, 1); @@ -3119,8 +3151,12 @@ next: kfree(shrink_block_group); btrfs_del_item(trans, root, path); + btrfs_release_path(root, path); + mutex_unlock(&root->fs_info->alloc_mutex); btrfs_commit_transaction(trans, root); + mutex_lock(&root->fs_info->alloc_mutex); + /* the code to unpin extents might set a few bits in the free * space cache for this range again */ @@ -3263,6 +3299,7 @@ int btrfs_make_block_group(struct btrfs_trans_handle *trans, struct btrfs_block_group_cache *cache; struct extent_io_tree *block_group_cache; + WARN_ON(!mutex_is_locked(&root->fs_info->alloc_mutex)); extent_root = root->fs_info->extent_root; block_group_cache = &root->fs_info->block_group_cache; diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index 026039a2ac58..83f17a5cbd6a 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -307,8 +307,7 @@ static int btrfs_ioctl_resize(struct btrfs_root *root, void __user *arg) goto out; } - mutex_lock(&root->fs_info->alloc_mutex); - mutex_lock(&root->fs_info->chunk_mutex); + mutex_lock(&root->fs_info->volume_mutex); sizestr = vol_args->name; devstr = strchr(sizestr, ':'); if (devstr) { @@ -378,8 +377,7 @@ static int btrfs_ioctl_resize(struct btrfs_root *root, void __user *arg) } out_unlock: - mutex_lock(&root->fs_info->alloc_mutex); - mutex_lock(&root->fs_info->chunk_mutex); + mutex_unlock(&root->fs_info->volume_mutex); out: kfree(vol_args); return ret; diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index 4e7cee27aab5..5e6ee7a6f738 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -56,6 +56,18 @@ void btrfs_unlock_volumes(void) mutex_unlock(&uuid_mutex); } +static void lock_chunks(struct btrfs_root *root) +{ + mutex_lock(&root->fs_info->alloc_mutex); + mutex_lock(&root->fs_info->chunk_mutex); +} + +static void unlock_chunks(struct btrfs_root *root) +{ + mutex_unlock(&root->fs_info->alloc_mutex); + mutex_unlock(&root->fs_info->chunk_mutex); +} + int btrfs_cleanup_fs_uuids(void) { struct btrfs_fs_devices *fs_devices; @@ -822,6 +834,7 @@ static int btrfs_rm_dev_item(struct btrfs_root *root, key.objectid = BTRFS_DEV_ITEMS_OBJECTID; key.type = BTRFS_DEV_ITEM_KEY; key.offset = device->devid; + lock_chunks(root); ret = btrfs_search_slot(trans, root, &key, path, -1, 1); if (ret < 0) @@ -856,6 +869,7 @@ static int btrfs_rm_dev_item(struct btrfs_root *root, total_bytes - 1); out: btrfs_free_path(path); + unlock_chunks(root); btrfs_commit_transaction(trans, root); return ret; } @@ -870,9 +884,8 @@ int btrfs_rm_device(struct btrfs_root *root, char *device_path) u64 devid; int ret = 0; - mutex_lock(&root->fs_info->alloc_mutex); - mutex_lock(&root->fs_info->chunk_mutex); mutex_lock(&uuid_mutex); + mutex_lock(&root->fs_info->volume_mutex); all_avail = root->fs_info->avail_data_alloc_bits | root->fs_info->avail_system_alloc_bits | @@ -988,9 +1001,8 @@ error_close: if (bdev) close_bdev_excl(bdev); out: + mutex_unlock(&root->fs_info->volume_mutex); mutex_unlock(&uuid_mutex); - mutex_unlock(&root->fs_info->chunk_mutex); - mutex_unlock(&root->fs_info->alloc_mutex); return ret; } @@ -1010,10 +1022,10 @@ int btrfs_init_new_device(struct btrfs_root *root, char *device_path) return -EIO; } - mutex_lock(&root->fs_info->alloc_mutex); - mutex_lock(&root->fs_info->chunk_mutex); + mutex_lock(&root->fs_info->volume_mutex); trans = btrfs_start_transaction(root, 1); + lock_chunks(root); devices = &root->fs_info->fs_devices->devices; list_for_each(cur, devices) { device = list_entry(cur, struct btrfs_device, dev_list); @@ -1065,9 +1077,9 @@ int btrfs_init_new_device(struct btrfs_root *root, char *device_path) root->fs_info->fs_devices->num_devices++; root->fs_info->fs_devices->open_devices++; out: + unlock_chunks(root); btrfs_end_transaction(trans, root); - mutex_unlock(&root->fs_info->chunk_mutex); - mutex_unlock(&root->fs_info->alloc_mutex); + mutex_unlock(&root->fs_info->volume_mutex); return ret; @@ -1122,7 +1134,7 @@ out: return ret; } -int btrfs_grow_device(struct btrfs_trans_handle *trans, +static int __btrfs_grow_device(struct btrfs_trans_handle *trans, struct btrfs_device *device, u64 new_size) { struct btrfs_super_block *super_copy = @@ -1134,6 +1146,16 @@ int btrfs_grow_device(struct btrfs_trans_handle *trans, return btrfs_update_device(trans, device); } +int btrfs_grow_device(struct btrfs_trans_handle *trans, + struct btrfs_device *device, u64 new_size) +{ + int ret; + lock_chunks(device->dev_root); + ret = __btrfs_grow_device(trans, device, new_size); + unlock_chunks(device->dev_root); + return ret; +} + static int btrfs_free_chunk(struct btrfs_trans_handle *trans, struct btrfs_root *root, u64 chunk_tree, u64 chunk_objectid, @@ -1234,6 +1256,8 @@ int btrfs_relocate_chunk(struct btrfs_root *root, trans = btrfs_start_transaction(root, 1); BUG_ON(!trans); + lock_chunks(root); + /* * step two, delete the device extents and the * chunk tree entries @@ -1278,6 +1302,7 @@ int btrfs_relocate_chunk(struct btrfs_root *root, /* once for us */ free_extent_map(em); + unlock_chunks(root); btrfs_end_transaction(trans, root); return 0; } @@ -1308,8 +1333,7 @@ int btrfs_balance(struct btrfs_root *dev_root) struct btrfs_key found_key; - BUG(); /* FIXME, needs locking */ - + mutex_lock(&dev_root->fs_info->volume_mutex); dev_root = dev_root->fs_info->dev_root; /* step one make some room on all the devices */ @@ -1355,13 +1379,14 @@ int btrfs_balance(struct btrfs_root *dev_root) ret = btrfs_previous_item(chunk_root, path, 0, BTRFS_CHUNK_ITEM_KEY); - if (ret) { + if (ret) break; - } + btrfs_item_key_to_cpu(path->nodes[0], &found_key, path->slots[0]); if (found_key.objectid != key.objectid) break; + chunk = btrfs_item_ptr(path->nodes[0], path->slots[0], struct btrfs_chunk); @@ -1370,16 +1395,17 @@ int btrfs_balance(struct btrfs_root *dev_root) if (key.offset == 0) break; + btrfs_release_path(chunk_root, path); ret = btrfs_relocate_chunk(chunk_root, chunk_root->root_key.objectid, found_key.objectid, found_key.offset); BUG_ON(ret); - btrfs_release_path(chunk_root, path); } ret = 0; error: btrfs_free_path(path); + mutex_unlock(&dev_root->fs_info->volume_mutex); return ret; } @@ -1419,14 +1445,18 @@ int btrfs_shrink_device(struct btrfs_device *device, u64 new_size) path->reada = 2; + lock_chunks(root); + device->total_bytes = new_size; ret = btrfs_update_device(trans, device); if (ret) { + unlock_chunks(root); btrfs_end_transaction(trans, root); goto done; } WARN_ON(diff > old_total); btrfs_set_super_total_bytes(super_copy, old_total - diff); + unlock_chunks(root); btrfs_end_transaction(trans, root); key.objectid = device->devid; -- 2.20.1