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1019 lines
25 KiB
1019 lines
25 KiB
// SPDX-License-Identifier: GPL-2.0 |
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/* |
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* Copyright (C) 2014 Facebook. All rights reserved. |
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*/ |
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|
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#include <linux/sched.h> |
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#include <linux/stacktrace.h> |
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#include "ctree.h" |
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#include "disk-io.h" |
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#include "locking.h" |
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#include "delayed-ref.h" |
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#include "ref-verify.h" |
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|
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/* |
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* Used to keep track the roots and number of refs each root has for a given |
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* bytenr. This just tracks the number of direct references, no shared |
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* references. |
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*/ |
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struct root_entry { |
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u64 root_objectid; |
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u64 num_refs; |
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struct rb_node node; |
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}; |
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|
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/* |
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* These are meant to represent what should exist in the extent tree, these can |
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* be used to verify the extent tree is consistent as these should all match |
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* what the extent tree says. |
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*/ |
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struct ref_entry { |
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u64 root_objectid; |
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u64 parent; |
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u64 owner; |
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u64 offset; |
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u64 num_refs; |
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struct rb_node node; |
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}; |
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#define MAX_TRACE 16 |
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/* |
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* Whenever we add/remove a reference we record the action. The action maps |
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* back to the delayed ref action. We hold the ref we are changing in the |
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* action so we can account for the history properly, and we record the root we |
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* were called with since it could be different from ref_root. We also store |
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* stack traces because that's how I roll. |
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*/ |
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struct ref_action { |
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int action; |
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u64 root; |
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struct ref_entry ref; |
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struct list_head list; |
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unsigned long trace[MAX_TRACE]; |
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unsigned int trace_len; |
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}; |
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|
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/* |
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* One of these for every block we reference, it holds the roots and references |
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* to it as well as all of the ref actions that have occurred to it. We never |
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* free it until we unmount the file system in order to make sure re-allocations |
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* are happening properly. |
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*/ |
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struct block_entry { |
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u64 bytenr; |
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u64 len; |
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u64 num_refs; |
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int metadata; |
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int from_disk; |
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struct rb_root roots; |
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struct rb_root refs; |
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struct rb_node node; |
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struct list_head actions; |
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}; |
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static struct block_entry *insert_block_entry(struct rb_root *root, |
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struct block_entry *be) |
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{ |
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struct rb_node **p = &root->rb_node; |
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struct rb_node *parent_node = NULL; |
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struct block_entry *entry; |
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|
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while (*p) { |
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parent_node = *p; |
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entry = rb_entry(parent_node, struct block_entry, node); |
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if (entry->bytenr > be->bytenr) |
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p = &(*p)->rb_left; |
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else if (entry->bytenr < be->bytenr) |
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p = &(*p)->rb_right; |
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else |
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return entry; |
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} |
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rb_link_node(&be->node, parent_node, p); |
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rb_insert_color(&be->node, root); |
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return NULL; |
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} |
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|
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static struct block_entry *lookup_block_entry(struct rb_root *root, u64 bytenr) |
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{ |
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struct rb_node *n; |
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struct block_entry *entry = NULL; |
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|
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n = root->rb_node; |
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while (n) { |
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entry = rb_entry(n, struct block_entry, node); |
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if (entry->bytenr < bytenr) |
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n = n->rb_right; |
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else if (entry->bytenr > bytenr) |
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n = n->rb_left; |
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else |
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return entry; |
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} |
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return NULL; |
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} |
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static struct root_entry *insert_root_entry(struct rb_root *root, |
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struct root_entry *re) |
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{ |
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struct rb_node **p = &root->rb_node; |
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struct rb_node *parent_node = NULL; |
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struct root_entry *entry; |
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|
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while (*p) { |
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parent_node = *p; |
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entry = rb_entry(parent_node, struct root_entry, node); |
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if (entry->root_objectid > re->root_objectid) |
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p = &(*p)->rb_left; |
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else if (entry->root_objectid < re->root_objectid) |
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p = &(*p)->rb_right; |
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else |
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return entry; |
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} |
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rb_link_node(&re->node, parent_node, p); |
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rb_insert_color(&re->node, root); |
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return NULL; |
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} |
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static int comp_refs(struct ref_entry *ref1, struct ref_entry *ref2) |
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{ |
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if (ref1->root_objectid < ref2->root_objectid) |
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return -1; |
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if (ref1->root_objectid > ref2->root_objectid) |
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return 1; |
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if (ref1->parent < ref2->parent) |
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return -1; |
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if (ref1->parent > ref2->parent) |
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return 1; |
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if (ref1->owner < ref2->owner) |
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return -1; |
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if (ref1->owner > ref2->owner) |
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return 1; |
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if (ref1->offset < ref2->offset) |
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return -1; |
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if (ref1->offset > ref2->offset) |
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return 1; |
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return 0; |
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} |
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static struct ref_entry *insert_ref_entry(struct rb_root *root, |
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struct ref_entry *ref) |
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{ |
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struct rb_node **p = &root->rb_node; |
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struct rb_node *parent_node = NULL; |
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struct ref_entry *entry; |
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int cmp; |
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while (*p) { |
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parent_node = *p; |
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entry = rb_entry(parent_node, struct ref_entry, node); |
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cmp = comp_refs(entry, ref); |
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if (cmp > 0) |
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p = &(*p)->rb_left; |
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else if (cmp < 0) |
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p = &(*p)->rb_right; |
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else |
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return entry; |
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} |
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rb_link_node(&ref->node, parent_node, p); |
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rb_insert_color(&ref->node, root); |
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return NULL; |
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} |
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static struct root_entry *lookup_root_entry(struct rb_root *root, u64 objectid) |
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{ |
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struct rb_node *n; |
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struct root_entry *entry = NULL; |
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|
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n = root->rb_node; |
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while (n) { |
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entry = rb_entry(n, struct root_entry, node); |
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if (entry->root_objectid < objectid) |
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n = n->rb_right; |
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else if (entry->root_objectid > objectid) |
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n = n->rb_left; |
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else |
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return entry; |
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} |
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return NULL; |
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} |
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#ifdef CONFIG_STACKTRACE |
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static void __save_stack_trace(struct ref_action *ra) |
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{ |
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ra->trace_len = stack_trace_save(ra->trace, MAX_TRACE, 2); |
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} |
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static void __print_stack_trace(struct btrfs_fs_info *fs_info, |
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struct ref_action *ra) |
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{ |
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if (ra->trace_len == 0) { |
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btrfs_err(fs_info, " ref-verify: no stacktrace"); |
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return; |
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} |
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stack_trace_print(ra->trace, ra->trace_len, 2); |
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} |
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#else |
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static inline void __save_stack_trace(struct ref_action *ra) |
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{ |
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} |
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static inline void __print_stack_trace(struct btrfs_fs_info *fs_info, |
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struct ref_action *ra) |
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{ |
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btrfs_err(fs_info, " ref-verify: no stacktrace support"); |
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} |
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#endif |
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static void free_block_entry(struct block_entry *be) |
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{ |
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struct root_entry *re; |
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struct ref_entry *ref; |
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struct ref_action *ra; |
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struct rb_node *n; |
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while ((n = rb_first(&be->roots))) { |
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re = rb_entry(n, struct root_entry, node); |
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rb_erase(&re->node, &be->roots); |
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kfree(re); |
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} |
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while((n = rb_first(&be->refs))) { |
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ref = rb_entry(n, struct ref_entry, node); |
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rb_erase(&ref->node, &be->refs); |
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kfree(ref); |
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} |
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while (!list_empty(&be->actions)) { |
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ra = list_first_entry(&be->actions, struct ref_action, |
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list); |
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list_del(&ra->list); |
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kfree(ra); |
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} |
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kfree(be); |
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} |
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static struct block_entry *add_block_entry(struct btrfs_fs_info *fs_info, |
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u64 bytenr, u64 len, |
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u64 root_objectid) |
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{ |
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struct block_entry *be = NULL, *exist; |
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struct root_entry *re = NULL; |
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re = kzalloc(sizeof(struct root_entry), GFP_KERNEL); |
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be = kzalloc(sizeof(struct block_entry), GFP_KERNEL); |
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if (!be || !re) { |
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kfree(re); |
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kfree(be); |
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return ERR_PTR(-ENOMEM); |
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} |
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be->bytenr = bytenr; |
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be->len = len; |
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re->root_objectid = root_objectid; |
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re->num_refs = 0; |
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spin_lock(&fs_info->ref_verify_lock); |
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exist = insert_block_entry(&fs_info->block_tree, be); |
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if (exist) { |
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if (root_objectid) { |
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struct root_entry *exist_re; |
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exist_re = insert_root_entry(&exist->roots, re); |
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if (exist_re) |
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kfree(re); |
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} else { |
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kfree(re); |
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} |
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kfree(be); |
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return exist; |
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} |
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be->num_refs = 0; |
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be->metadata = 0; |
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be->from_disk = 0; |
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be->roots = RB_ROOT; |
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be->refs = RB_ROOT; |
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INIT_LIST_HEAD(&be->actions); |
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if (root_objectid) |
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insert_root_entry(&be->roots, re); |
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else |
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kfree(re); |
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return be; |
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} |
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static int add_tree_block(struct btrfs_fs_info *fs_info, u64 ref_root, |
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u64 parent, u64 bytenr, int level) |
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{ |
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struct block_entry *be; |
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struct root_entry *re; |
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struct ref_entry *ref = NULL, *exist; |
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ref = kmalloc(sizeof(struct ref_entry), GFP_KERNEL); |
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if (!ref) |
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return -ENOMEM; |
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if (parent) |
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ref->root_objectid = 0; |
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else |
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ref->root_objectid = ref_root; |
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ref->parent = parent; |
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ref->owner = level; |
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ref->offset = 0; |
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ref->num_refs = 1; |
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be = add_block_entry(fs_info, bytenr, fs_info->nodesize, ref_root); |
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if (IS_ERR(be)) { |
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kfree(ref); |
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return PTR_ERR(be); |
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} |
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be->num_refs++; |
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be->from_disk = 1; |
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be->metadata = 1; |
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if (!parent) { |
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ASSERT(ref_root); |
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re = lookup_root_entry(&be->roots, ref_root); |
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ASSERT(re); |
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re->num_refs++; |
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} |
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exist = insert_ref_entry(&be->refs, ref); |
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if (exist) { |
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exist->num_refs++; |
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kfree(ref); |
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} |
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spin_unlock(&fs_info->ref_verify_lock); |
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return 0; |
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} |
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static int add_shared_data_ref(struct btrfs_fs_info *fs_info, |
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u64 parent, u32 num_refs, u64 bytenr, |
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u64 num_bytes) |
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{ |
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struct block_entry *be; |
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struct ref_entry *ref; |
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ref = kzalloc(sizeof(struct ref_entry), GFP_KERNEL); |
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if (!ref) |
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return -ENOMEM; |
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be = add_block_entry(fs_info, bytenr, num_bytes, 0); |
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if (IS_ERR(be)) { |
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kfree(ref); |
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return PTR_ERR(be); |
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} |
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be->num_refs += num_refs; |
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ref->parent = parent; |
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ref->num_refs = num_refs; |
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if (insert_ref_entry(&be->refs, ref)) { |
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spin_unlock(&fs_info->ref_verify_lock); |
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btrfs_err(fs_info, "existing shared ref when reading from disk?"); |
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kfree(ref); |
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return -EINVAL; |
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} |
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spin_unlock(&fs_info->ref_verify_lock); |
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return 0; |
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} |
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static int add_extent_data_ref(struct btrfs_fs_info *fs_info, |
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struct extent_buffer *leaf, |
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struct btrfs_extent_data_ref *dref, |
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u64 bytenr, u64 num_bytes) |
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{ |
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struct block_entry *be; |
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struct ref_entry *ref; |
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struct root_entry *re; |
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u64 ref_root = btrfs_extent_data_ref_root(leaf, dref); |
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u64 owner = btrfs_extent_data_ref_objectid(leaf, dref); |
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u64 offset = btrfs_extent_data_ref_offset(leaf, dref); |
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u32 num_refs = btrfs_extent_data_ref_count(leaf, dref); |
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ref = kzalloc(sizeof(struct ref_entry), GFP_KERNEL); |
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if (!ref) |
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return -ENOMEM; |
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be = add_block_entry(fs_info, bytenr, num_bytes, ref_root); |
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if (IS_ERR(be)) { |
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kfree(ref); |
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return PTR_ERR(be); |
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} |
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be->num_refs += num_refs; |
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ref->parent = 0; |
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ref->owner = owner; |
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ref->root_objectid = ref_root; |
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ref->offset = offset; |
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ref->num_refs = num_refs; |
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if (insert_ref_entry(&be->refs, ref)) { |
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spin_unlock(&fs_info->ref_verify_lock); |
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btrfs_err(fs_info, "existing ref when reading from disk?"); |
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kfree(ref); |
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return -EINVAL; |
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} |
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re = lookup_root_entry(&be->roots, ref_root); |
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if (!re) { |
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spin_unlock(&fs_info->ref_verify_lock); |
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btrfs_err(fs_info, "missing root in new block entry?"); |
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return -EINVAL; |
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} |
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re->num_refs += num_refs; |
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spin_unlock(&fs_info->ref_verify_lock); |
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return 0; |
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} |
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static int process_extent_item(struct btrfs_fs_info *fs_info, |
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struct btrfs_path *path, struct btrfs_key *key, |
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int slot, int *tree_block_level) |
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{ |
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struct btrfs_extent_item *ei; |
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struct btrfs_extent_inline_ref *iref; |
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struct btrfs_extent_data_ref *dref; |
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struct btrfs_shared_data_ref *sref; |
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struct extent_buffer *leaf = path->nodes[0]; |
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u32 item_size = btrfs_item_size_nr(leaf, slot); |
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unsigned long end, ptr; |
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u64 offset, flags, count; |
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int type, ret; |
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ei = btrfs_item_ptr(leaf, slot, struct btrfs_extent_item); |
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flags = btrfs_extent_flags(leaf, ei); |
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|
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if ((key->type == BTRFS_EXTENT_ITEM_KEY) && |
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flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) { |
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struct btrfs_tree_block_info *info; |
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info = (struct btrfs_tree_block_info *)(ei + 1); |
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*tree_block_level = btrfs_tree_block_level(leaf, info); |
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iref = (struct btrfs_extent_inline_ref *)(info + 1); |
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} else { |
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if (key->type == BTRFS_METADATA_ITEM_KEY) |
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*tree_block_level = key->offset; |
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iref = (struct btrfs_extent_inline_ref *)(ei + 1); |
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} |
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ptr = (unsigned long)iref; |
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end = (unsigned long)ei + item_size; |
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while (ptr < end) { |
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iref = (struct btrfs_extent_inline_ref *)ptr; |
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type = btrfs_extent_inline_ref_type(leaf, iref); |
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offset = btrfs_extent_inline_ref_offset(leaf, iref); |
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switch (type) { |
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case BTRFS_TREE_BLOCK_REF_KEY: |
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ret = add_tree_block(fs_info, offset, 0, key->objectid, |
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*tree_block_level); |
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break; |
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case BTRFS_SHARED_BLOCK_REF_KEY: |
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ret = add_tree_block(fs_info, 0, offset, key->objectid, |
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*tree_block_level); |
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break; |
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case BTRFS_EXTENT_DATA_REF_KEY: |
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dref = (struct btrfs_extent_data_ref *)(&iref->offset); |
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ret = add_extent_data_ref(fs_info, leaf, dref, |
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key->objectid, key->offset); |
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break; |
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case BTRFS_SHARED_DATA_REF_KEY: |
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sref = (struct btrfs_shared_data_ref *)(iref + 1); |
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count = btrfs_shared_data_ref_count(leaf, sref); |
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ret = add_shared_data_ref(fs_info, offset, count, |
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key->objectid, key->offset); |
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break; |
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default: |
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btrfs_err(fs_info, "invalid key type in iref"); |
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ret = -EINVAL; |
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break; |
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} |
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if (ret) |
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break; |
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ptr += btrfs_extent_inline_ref_size(type); |
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} |
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return ret; |
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} |
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|
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static int process_leaf(struct btrfs_root *root, |
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struct btrfs_path *path, u64 *bytenr, u64 *num_bytes, |
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int *tree_block_level) |
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{ |
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struct btrfs_fs_info *fs_info = root->fs_info; |
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struct extent_buffer *leaf = path->nodes[0]; |
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struct btrfs_extent_data_ref *dref; |
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struct btrfs_shared_data_ref *sref; |
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u32 count; |
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int i = 0, ret = 0; |
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struct btrfs_key key; |
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int nritems = btrfs_header_nritems(leaf); |
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|
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for (i = 0; i < nritems; i++) { |
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btrfs_item_key_to_cpu(leaf, &key, i); |
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switch (key.type) { |
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case BTRFS_EXTENT_ITEM_KEY: |
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*num_bytes = key.offset; |
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fallthrough; |
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case BTRFS_METADATA_ITEM_KEY: |
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*bytenr = key.objectid; |
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ret = process_extent_item(fs_info, path, &key, i, |
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tree_block_level); |
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break; |
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case BTRFS_TREE_BLOCK_REF_KEY: |
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ret = add_tree_block(fs_info, key.offset, 0, |
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key.objectid, *tree_block_level); |
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break; |
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case BTRFS_SHARED_BLOCK_REF_KEY: |
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ret = add_tree_block(fs_info, 0, key.offset, |
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key.objectid, *tree_block_level); |
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break; |
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case BTRFS_EXTENT_DATA_REF_KEY: |
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dref = btrfs_item_ptr(leaf, i, |
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struct btrfs_extent_data_ref); |
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ret = add_extent_data_ref(fs_info, leaf, dref, *bytenr, |
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*num_bytes); |
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break; |
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case BTRFS_SHARED_DATA_REF_KEY: |
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sref = btrfs_item_ptr(leaf, i, |
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struct btrfs_shared_data_ref); |
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count = btrfs_shared_data_ref_count(leaf, sref); |
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ret = add_shared_data_ref(fs_info, key.offset, count, |
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*bytenr, *num_bytes); |
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break; |
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default: |
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break; |
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} |
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if (ret) |
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break; |
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} |
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return ret; |
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} |
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|
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/* Walk down to the leaf from the given level */ |
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static int walk_down_tree(struct btrfs_root *root, struct btrfs_path *path, |
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int level, u64 *bytenr, u64 *num_bytes, |
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int *tree_block_level) |
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{ |
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struct extent_buffer *eb; |
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int ret = 0; |
|
|
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while (level >= 0) { |
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if (level) { |
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eb = btrfs_read_node_slot(path->nodes[level], |
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path->slots[level]); |
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if (IS_ERR(eb)) |
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return PTR_ERR(eb); |
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btrfs_tree_read_lock(eb); |
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path->nodes[level-1] = eb; |
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path->slots[level-1] = 0; |
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path->locks[level-1] = BTRFS_READ_LOCK; |
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} else { |
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ret = process_leaf(root, path, bytenr, num_bytes, |
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tree_block_level); |
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if (ret) |
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break; |
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} |
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level--; |
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} |
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return ret; |
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} |
|
|
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/* Walk up to the next node that needs to be processed */ |
|
static int walk_up_tree(struct btrfs_path *path, int *level) |
|
{ |
|
int l; |
|
|
|
for (l = 0; l < BTRFS_MAX_LEVEL; l++) { |
|
if (!path->nodes[l]) |
|
continue; |
|
if (l) { |
|
path->slots[l]++; |
|
if (path->slots[l] < |
|
btrfs_header_nritems(path->nodes[l])) { |
|
*level = l; |
|
return 0; |
|
} |
|
} |
|
btrfs_tree_unlock_rw(path->nodes[l], path->locks[l]); |
|
free_extent_buffer(path->nodes[l]); |
|
path->nodes[l] = NULL; |
|
path->slots[l] = 0; |
|
path->locks[l] = 0; |
|
} |
|
|
|
return 1; |
|
} |
|
|
|
static void dump_ref_action(struct btrfs_fs_info *fs_info, |
|
struct ref_action *ra) |
|
{ |
|
btrfs_err(fs_info, |
|
" Ref action %d, root %llu, ref_root %llu, parent %llu, owner %llu, offset %llu, num_refs %llu", |
|
ra->action, ra->root, ra->ref.root_objectid, ra->ref.parent, |
|
ra->ref.owner, ra->ref.offset, ra->ref.num_refs); |
|
__print_stack_trace(fs_info, ra); |
|
} |
|
|
|
/* |
|
* Dumps all the information from the block entry to printk, it's going to be |
|
* awesome. |
|
*/ |
|
static void dump_block_entry(struct btrfs_fs_info *fs_info, |
|
struct block_entry *be) |
|
{ |
|
struct ref_entry *ref; |
|
struct root_entry *re; |
|
struct ref_action *ra; |
|
struct rb_node *n; |
|
|
|
btrfs_err(fs_info, |
|
"dumping block entry [%llu %llu], num_refs %llu, metadata %d, from disk %d", |
|
be->bytenr, be->len, be->num_refs, be->metadata, |
|
be->from_disk); |
|
|
|
for (n = rb_first(&be->refs); n; n = rb_next(n)) { |
|
ref = rb_entry(n, struct ref_entry, node); |
|
btrfs_err(fs_info, |
|
" ref root %llu, parent %llu, owner %llu, offset %llu, num_refs %llu", |
|
ref->root_objectid, ref->parent, ref->owner, |
|
ref->offset, ref->num_refs); |
|
} |
|
|
|
for (n = rb_first(&be->roots); n; n = rb_next(n)) { |
|
re = rb_entry(n, struct root_entry, node); |
|
btrfs_err(fs_info, " root entry %llu, num_refs %llu", |
|
re->root_objectid, re->num_refs); |
|
} |
|
|
|
list_for_each_entry(ra, &be->actions, list) |
|
dump_ref_action(fs_info, ra); |
|
} |
|
|
|
/* |
|
* btrfs_ref_tree_mod: called when we modify a ref for a bytenr |
|
* |
|
* This will add an action item to the given bytenr and do sanity checks to make |
|
* sure we haven't messed something up. If we are making a new allocation and |
|
* this block entry has history we will delete all previous actions as long as |
|
* our sanity checks pass as they are no longer needed. |
|
*/ |
|
int btrfs_ref_tree_mod(struct btrfs_fs_info *fs_info, |
|
struct btrfs_ref *generic_ref) |
|
{ |
|
struct ref_entry *ref = NULL, *exist; |
|
struct ref_action *ra = NULL; |
|
struct block_entry *be = NULL; |
|
struct root_entry *re = NULL; |
|
int action = generic_ref->action; |
|
int ret = 0; |
|
bool metadata; |
|
u64 bytenr = generic_ref->bytenr; |
|
u64 num_bytes = generic_ref->len; |
|
u64 parent = generic_ref->parent; |
|
u64 ref_root = 0; |
|
u64 owner = 0; |
|
u64 offset = 0; |
|
|
|
if (!btrfs_test_opt(fs_info, REF_VERIFY)) |
|
return 0; |
|
|
|
if (generic_ref->type == BTRFS_REF_METADATA) { |
|
if (!parent) |
|
ref_root = generic_ref->tree_ref.root; |
|
owner = generic_ref->tree_ref.level; |
|
} else if (!parent) { |
|
ref_root = generic_ref->data_ref.ref_root; |
|
owner = generic_ref->data_ref.ino; |
|
offset = generic_ref->data_ref.offset; |
|
} |
|
metadata = owner < BTRFS_FIRST_FREE_OBJECTID; |
|
|
|
ref = kzalloc(sizeof(struct ref_entry), GFP_NOFS); |
|
ra = kmalloc(sizeof(struct ref_action), GFP_NOFS); |
|
if (!ra || !ref) { |
|
kfree(ref); |
|
kfree(ra); |
|
ret = -ENOMEM; |
|
goto out; |
|
} |
|
|
|
ref->parent = parent; |
|
ref->owner = owner; |
|
ref->root_objectid = ref_root; |
|
ref->offset = offset; |
|
ref->num_refs = (action == BTRFS_DROP_DELAYED_REF) ? -1 : 1; |
|
|
|
memcpy(&ra->ref, ref, sizeof(struct ref_entry)); |
|
/* |
|
* Save the extra info from the delayed ref in the ref action to make it |
|
* easier to figure out what is happening. The real ref's we add to the |
|
* ref tree need to reflect what we save on disk so it matches any |
|
* on-disk refs we pre-loaded. |
|
*/ |
|
ra->ref.owner = owner; |
|
ra->ref.offset = offset; |
|
ra->ref.root_objectid = ref_root; |
|
__save_stack_trace(ra); |
|
|
|
INIT_LIST_HEAD(&ra->list); |
|
ra->action = action; |
|
ra->root = generic_ref->real_root; |
|
|
|
/* |
|
* This is an allocation, preallocate the block_entry in case we haven't |
|
* used it before. |
|
*/ |
|
ret = -EINVAL; |
|
if (action == BTRFS_ADD_DELAYED_EXTENT) { |
|
/* |
|
* For subvol_create we'll just pass in whatever the parent root |
|
* is and the new root objectid, so let's not treat the passed |
|
* in root as if it really has a ref for this bytenr. |
|
*/ |
|
be = add_block_entry(fs_info, bytenr, num_bytes, ref_root); |
|
if (IS_ERR(be)) { |
|
kfree(ref); |
|
kfree(ra); |
|
ret = PTR_ERR(be); |
|
goto out; |
|
} |
|
be->num_refs++; |
|
if (metadata) |
|
be->metadata = 1; |
|
|
|
if (be->num_refs != 1) { |
|
btrfs_err(fs_info, |
|
"re-allocated a block that still has references to it!"); |
|
dump_block_entry(fs_info, be); |
|
dump_ref_action(fs_info, ra); |
|
kfree(ref); |
|
kfree(ra); |
|
goto out_unlock; |
|
} |
|
|
|
while (!list_empty(&be->actions)) { |
|
struct ref_action *tmp; |
|
|
|
tmp = list_first_entry(&be->actions, struct ref_action, |
|
list); |
|
list_del(&tmp->list); |
|
kfree(tmp); |
|
} |
|
} else { |
|
struct root_entry *tmp; |
|
|
|
if (!parent) { |
|
re = kmalloc(sizeof(struct root_entry), GFP_NOFS); |
|
if (!re) { |
|
kfree(ref); |
|
kfree(ra); |
|
ret = -ENOMEM; |
|
goto out; |
|
} |
|
/* |
|
* This is the root that is modifying us, so it's the |
|
* one we want to lookup below when we modify the |
|
* re->num_refs. |
|
*/ |
|
ref_root = generic_ref->real_root; |
|
re->root_objectid = generic_ref->real_root; |
|
re->num_refs = 0; |
|
} |
|
|
|
spin_lock(&fs_info->ref_verify_lock); |
|
be = lookup_block_entry(&fs_info->block_tree, bytenr); |
|
if (!be) { |
|
btrfs_err(fs_info, |
|
"trying to do action %d to bytenr %llu num_bytes %llu but there is no existing entry!", |
|
action, bytenr, num_bytes); |
|
dump_ref_action(fs_info, ra); |
|
kfree(ref); |
|
kfree(ra); |
|
goto out_unlock; |
|
} else if (be->num_refs == 0) { |
|
btrfs_err(fs_info, |
|
"trying to do action %d for a bytenr that has 0 total references", |
|
action); |
|
dump_block_entry(fs_info, be); |
|
dump_ref_action(fs_info, ra); |
|
kfree(ref); |
|
kfree(ra); |
|
goto out_unlock; |
|
} |
|
|
|
if (!parent) { |
|
tmp = insert_root_entry(&be->roots, re); |
|
if (tmp) { |
|
kfree(re); |
|
re = tmp; |
|
} |
|
} |
|
} |
|
|
|
exist = insert_ref_entry(&be->refs, ref); |
|
if (exist) { |
|
if (action == BTRFS_DROP_DELAYED_REF) { |
|
if (exist->num_refs == 0) { |
|
btrfs_err(fs_info, |
|
"dropping a ref for a existing root that doesn't have a ref on the block"); |
|
dump_block_entry(fs_info, be); |
|
dump_ref_action(fs_info, ra); |
|
kfree(ref); |
|
kfree(ra); |
|
goto out_unlock; |
|
} |
|
exist->num_refs--; |
|
if (exist->num_refs == 0) { |
|
rb_erase(&exist->node, &be->refs); |
|
kfree(exist); |
|
} |
|
} else if (!be->metadata) { |
|
exist->num_refs++; |
|
} else { |
|
btrfs_err(fs_info, |
|
"attempting to add another ref for an existing ref on a tree block"); |
|
dump_block_entry(fs_info, be); |
|
dump_ref_action(fs_info, ra); |
|
kfree(ref); |
|
kfree(ra); |
|
goto out_unlock; |
|
} |
|
kfree(ref); |
|
} else { |
|
if (action == BTRFS_DROP_DELAYED_REF) { |
|
btrfs_err(fs_info, |
|
"dropping a ref for a root that doesn't have a ref on the block"); |
|
dump_block_entry(fs_info, be); |
|
dump_ref_action(fs_info, ra); |
|
kfree(ref); |
|
kfree(ra); |
|
goto out_unlock; |
|
} |
|
} |
|
|
|
if (!parent && !re) { |
|
re = lookup_root_entry(&be->roots, ref_root); |
|
if (!re) { |
|
/* |
|
* This shouldn't happen because we will add our re |
|
* above when we lookup the be with !parent, but just in |
|
* case catch this case so we don't panic because I |
|
* didn't think of some other corner case. |
|
*/ |
|
btrfs_err(fs_info, "failed to find root %llu for %llu", |
|
generic_ref->real_root, be->bytenr); |
|
dump_block_entry(fs_info, be); |
|
dump_ref_action(fs_info, ra); |
|
kfree(ra); |
|
goto out_unlock; |
|
} |
|
} |
|
if (action == BTRFS_DROP_DELAYED_REF) { |
|
if (re) |
|
re->num_refs--; |
|
be->num_refs--; |
|
} else if (action == BTRFS_ADD_DELAYED_REF) { |
|
be->num_refs++; |
|
if (re) |
|
re->num_refs++; |
|
} |
|
list_add_tail(&ra->list, &be->actions); |
|
ret = 0; |
|
out_unlock: |
|
spin_unlock(&fs_info->ref_verify_lock); |
|
out: |
|
if (ret) |
|
btrfs_clear_opt(fs_info->mount_opt, REF_VERIFY); |
|
return ret; |
|
} |
|
|
|
/* Free up the ref cache */ |
|
void btrfs_free_ref_cache(struct btrfs_fs_info *fs_info) |
|
{ |
|
struct block_entry *be; |
|
struct rb_node *n; |
|
|
|
if (!btrfs_test_opt(fs_info, REF_VERIFY)) |
|
return; |
|
|
|
spin_lock(&fs_info->ref_verify_lock); |
|
while ((n = rb_first(&fs_info->block_tree))) { |
|
be = rb_entry(n, struct block_entry, node); |
|
rb_erase(&be->node, &fs_info->block_tree); |
|
free_block_entry(be); |
|
cond_resched_lock(&fs_info->ref_verify_lock); |
|
} |
|
spin_unlock(&fs_info->ref_verify_lock); |
|
} |
|
|
|
void btrfs_free_ref_tree_range(struct btrfs_fs_info *fs_info, u64 start, |
|
u64 len) |
|
{ |
|
struct block_entry *be = NULL, *entry; |
|
struct rb_node *n; |
|
|
|
if (!btrfs_test_opt(fs_info, REF_VERIFY)) |
|
return; |
|
|
|
spin_lock(&fs_info->ref_verify_lock); |
|
n = fs_info->block_tree.rb_node; |
|
while (n) { |
|
entry = rb_entry(n, struct block_entry, node); |
|
if (entry->bytenr < start) { |
|
n = n->rb_right; |
|
} else if (entry->bytenr > start) { |
|
n = n->rb_left; |
|
} else { |
|
be = entry; |
|
break; |
|
} |
|
/* We want to get as close to start as possible */ |
|
if (be == NULL || |
|
(entry->bytenr < start && be->bytenr > start) || |
|
(entry->bytenr < start && entry->bytenr > be->bytenr)) |
|
be = entry; |
|
} |
|
|
|
/* |
|
* Could have an empty block group, maybe have something to check for |
|
* this case to verify we were actually empty? |
|
*/ |
|
if (!be) { |
|
spin_unlock(&fs_info->ref_verify_lock); |
|
return; |
|
} |
|
|
|
n = &be->node; |
|
while (n) { |
|
be = rb_entry(n, struct block_entry, node); |
|
n = rb_next(n); |
|
if (be->bytenr < start && be->bytenr + be->len > start) { |
|
btrfs_err(fs_info, |
|
"block entry overlaps a block group [%llu,%llu]!", |
|
start, len); |
|
dump_block_entry(fs_info, be); |
|
continue; |
|
} |
|
if (be->bytenr < start) |
|
continue; |
|
if (be->bytenr >= start + len) |
|
break; |
|
if (be->bytenr + be->len > start + len) { |
|
btrfs_err(fs_info, |
|
"block entry overlaps a block group [%llu,%llu]!", |
|
start, len); |
|
dump_block_entry(fs_info, be); |
|
} |
|
rb_erase(&be->node, &fs_info->block_tree); |
|
free_block_entry(be); |
|
} |
|
spin_unlock(&fs_info->ref_verify_lock); |
|
} |
|
|
|
/* Walk down all roots and build the ref tree, meant to be called at mount */ |
|
int btrfs_build_ref_tree(struct btrfs_fs_info *fs_info) |
|
{ |
|
struct btrfs_path *path; |
|
struct extent_buffer *eb; |
|
int tree_block_level = 0; |
|
u64 bytenr = 0, num_bytes = 0; |
|
int ret, level; |
|
|
|
if (!btrfs_test_opt(fs_info, REF_VERIFY)) |
|
return 0; |
|
|
|
path = btrfs_alloc_path(); |
|
if (!path) |
|
return -ENOMEM; |
|
|
|
eb = btrfs_read_lock_root_node(fs_info->extent_root); |
|
level = btrfs_header_level(eb); |
|
path->nodes[level] = eb; |
|
path->slots[level] = 0; |
|
path->locks[level] = BTRFS_READ_LOCK; |
|
|
|
while (1) { |
|
/* |
|
* We have to keep track of the bytenr/num_bytes we last hit |
|
* because we could have run out of space for an inline ref, and |
|
* would have had to added a ref key item which may appear on a |
|
* different leaf from the original extent item. |
|
*/ |
|
ret = walk_down_tree(fs_info->extent_root, path, level, |
|
&bytenr, &num_bytes, &tree_block_level); |
|
if (ret) |
|
break; |
|
ret = walk_up_tree(path, &level); |
|
if (ret < 0) |
|
break; |
|
if (ret > 0) { |
|
ret = 0; |
|
break; |
|
} |
|
} |
|
if (ret) { |
|
btrfs_clear_opt(fs_info->mount_opt, REF_VERIFY); |
|
btrfs_free_ref_cache(fs_info); |
|
} |
|
btrfs_free_path(path); |
|
return ret; |
|
}
|
|
|