/* * Copyright (C) 2007 Oracle. All rights reserved. * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public * License v2 as published by the Free Software Foundation. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License for more details. * * You should have received a copy of the GNU General Public * License along with this program; if not, write to the * Free Software Foundation, Inc., 59 Temple Place - Suite 330, * Boston, MA 021110-1307, USA. */ #include #include "ctree.h" #include "disk-io.h" #include "print-tree.h" #include "transaction.h" #include "locking.h" /* * Defrag all the leaves in a given btree. * Read all the leaves and try to get key order to * better reflect disk order */ int btrfs_defrag_leaves(struct btrfs_trans_handle *trans, struct btrfs_root *root) { struct btrfs_path *path = NULL; struct btrfs_key key; int ret = 0; int wret; int level; int next_key_ret = 0; u64 last_ret = 0; u64 min_trans = 0; if (root->fs_info->extent_root == root) { /* * there's recursion here right now in the tree locking, * we can't defrag the extent root without deadlock */ goto out; } if (!test_bit(BTRFS_ROOT_REF_COWS, &root->state)) goto out; path = btrfs_alloc_path(); if (!path) return -ENOMEM; level = btrfs_header_level(root->node); if (level == 0) goto out; if (root->defrag_progress.objectid == 0) { struct extent_buffer *root_node; u32 nritems; root_node = btrfs_lock_root_node(root); btrfs_set_lock_blocking(root_node); nritems = btrfs_header_nritems(root_node); root->defrag_max.objectid = 0; /* from above we know this is not a leaf */ btrfs_node_key_to_cpu(root_node, &root->defrag_max, nritems - 1); btrfs_tree_unlock(root_node); free_extent_buffer(root_node); memset(&key, 0, sizeof(key)); } else { memcpy(&key, &root->defrag_progress, sizeof(key)); } path->keep_locks = 1; ret = btrfs_search_forward(root, &key, path, min_trans); if (ret < 0) goto out; if (ret > 0) { ret = 0; goto out; } btrfs_release_path(path); /* * We don't need a lock on a leaf. btrfs_realloc_node() will lock all * leafs from path->nodes[1], so set lowest_level to 1 to avoid later * a deadlock (attempting to write lock an already write locked leaf). */ path->lowest_level = 1; wret = btrfs_search_slot(trans, root, &key, path, 0, 1); if (wret < 0) { ret = wret; goto out; } if (!path->nodes[1]) { ret = 0; goto out; } /* * The node at level 1 must always be locked when our path has * keep_locks set and lowest_level is 1, regardless of the value of * path->slots[1]. */ BUG_ON(path->locks[1] == 0); ret = btrfs_realloc_node(trans, root, path->nodes[1], 0, &last_ret, &root->defrag_progress); if (ret) { WARN_ON(ret == -EAGAIN); goto out; } /* * Now that we reallocated the node we can find the next key. Note that * btrfs_find_next_key() can release our path and do another search * without COWing, this is because even with path->keep_locks = 1, * btrfs_search_slot() / ctree.c:unlock_up() does not keeps a lock on a * node when path->slots[node_level - 1] does not point to the last * item or a slot beyond the last item (ctree.c:unlock_up()). Therefore * we search for the next key after reallocating our node. */ path->slots[1] = btrfs_header_nritems(path->nodes[1]); next_key_ret = btrfs_find_next_key(root, path, &key, 1, min_trans); if (next_key_ret == 0) { memcpy(&root->defrag_progress, &key, sizeof(key)); ret = -EAGAIN; } out: btrfs_free_path(path); if (ret == -EAGAIN) { if (root->defrag_max.objectid > root->defrag_progress.objectid) goto done; if (root->defrag_max.type > root->defrag_progress.type) goto done; if (root->defrag_max.offset > root->defrag_progress.offset) goto done; ret = 0; } done: if (ret != -EAGAIN) { memset(&root->defrag_progress, 0, sizeof(root->defrag_progress)); root->defrag_trans_start = trans->transid; } return ret; } diff
authorBjorn Helgaas <bhelgaas@google.com>2017-01-27 15:00:45 -0600
committerBjorn Helgaas <bhelgaas@google.com>2017-01-27 15:00:45 -0600
commit030305d69fc6963c16003f50d7e8d74b02d0a143 (patch)
tree363a4e34d199178769b7e7eeb26ea2620a55847b /net/ceph/buffer.c
parent4d191b1b63c209e37bf27938ef365244d3c41084 (diff)
PCI/ASPM: Handle PCI-to-PCIe bridges as roots of PCIe hierarchies
In a struct pcie_link_state, link->root points to the pcie_link_state of the root of the PCIe hierarchy. For the topmost link, this points to itself (link->root = link). For others, we copy the pointer from the parent (link->root = link->parent->root). Previously we recognized that Root Ports originated PCIe hierarchies, but we treated PCI/PCI-X to PCIe Bridges as being in the middle of the hierarchy, and when we tried to copy the pointer from link->parent->root, there was no parent, and we dereferenced a NULL pointer: BUG: unable to handle kernel NULL pointer dereference at 0000000000000090 IP: [<ffffffff9e424350>] pcie_aspm_init_link_state+0x170/0x820 Recognize that PCI/PCI-X to PCIe Bridges originate PCIe hierarchies just like Root Ports do, so link->root for these devices should also point to itself. Fixes: 51ebfc92b72b ("PCI: Enumerate switches below PCI-to-PCIe bridges") Link: https://bugzilla.kernel.org/show_bug.cgi?id=193411 Link: https://bugzilla.opensuse.org/show_bug.cgi?id=1022181 Tested-by: lists@ssl-mail.com Tested-by: Jayachandran C. <jnair@caviumnetworks.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> CC: stable@vger.kernel.org # v4.2+
Diffstat (limited to 'net/ceph/buffer.c')