alistair23-linux/fs/btrfs/print-tree.c
Qu Wenruo b545993694 btrfs: print-tree: Add eb locking status output for debug build
It's pretty handy if we can get the debug output for locking status of
an extent buffer, specially for race condition related debugging.

So add the following output for btrfs_print_tree() and
btrfs_print_leaf():
- refs
- write_locks (as w:%d)
- read_locks (as r:%d)
- blocking_writers (as bw:%d)
- blocking_readers (as br:%d)
- spinning_writers (as sw:%d)
- spinning_readers (as sr:%d)
- lock_owner
- current->pid

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ update comment ]
Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28 18:07:26 +02:00

405 lines
12 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2007 Oracle. All rights reserved.
*/
#include "ctree.h"
#include "disk-io.h"
#include "print-tree.h"
static void print_chunk(struct extent_buffer *eb, struct btrfs_chunk *chunk)
{
int num_stripes = btrfs_chunk_num_stripes(eb, chunk);
int i;
pr_info("\t\tchunk length %llu owner %llu type %llu num_stripes %d\n",
btrfs_chunk_length(eb, chunk), btrfs_chunk_owner(eb, chunk),
btrfs_chunk_type(eb, chunk), num_stripes);
for (i = 0 ; i < num_stripes ; i++) {
pr_info("\t\t\tstripe %d devid %llu offset %llu\n", i,
btrfs_stripe_devid_nr(eb, chunk, i),
btrfs_stripe_offset_nr(eb, chunk, i));
}
}
static void print_dev_item(struct extent_buffer *eb,
struct btrfs_dev_item *dev_item)
{
pr_info("\t\tdev item devid %llu total_bytes %llu bytes used %llu\n",
btrfs_device_id(eb, dev_item),
btrfs_device_total_bytes(eb, dev_item),
btrfs_device_bytes_used(eb, dev_item));
}
static void print_extent_data_ref(struct extent_buffer *eb,
struct btrfs_extent_data_ref *ref)
{
pr_cont("extent data backref root %llu objectid %llu offset %llu count %u\n",
btrfs_extent_data_ref_root(eb, ref),
btrfs_extent_data_ref_objectid(eb, ref),
btrfs_extent_data_ref_offset(eb, ref),
btrfs_extent_data_ref_count(eb, ref));
}
static void print_extent_item(struct extent_buffer *eb, int slot, int type)
{
struct btrfs_extent_item *ei;
struct btrfs_extent_inline_ref *iref;
struct btrfs_extent_data_ref *dref;
struct btrfs_shared_data_ref *sref;
struct btrfs_disk_key key;
unsigned long end;
unsigned long ptr;
u32 item_size = btrfs_item_size_nr(eb, slot);
u64 flags;
u64 offset;
int ref_index = 0;
if (item_size < sizeof(*ei)) {
#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
struct btrfs_extent_item_v0 *ei0;
BUG_ON(item_size != sizeof(*ei0));
ei0 = btrfs_item_ptr(eb, slot, struct btrfs_extent_item_v0);
pr_info("\t\textent refs %u\n",
btrfs_extent_refs_v0(eb, ei0));
return;
#else
BUG();
#endif
}
ei = btrfs_item_ptr(eb, slot, struct btrfs_extent_item);
flags = btrfs_extent_flags(eb, ei);
pr_info("\t\textent refs %llu gen %llu flags %llu\n",
btrfs_extent_refs(eb, ei), btrfs_extent_generation(eb, ei),
flags);
if ((type == BTRFS_EXTENT_ITEM_KEY) &&
flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
struct btrfs_tree_block_info *info;
info = (struct btrfs_tree_block_info *)(ei + 1);
btrfs_tree_block_key(eb, info, &key);
pr_info("\t\ttree block key (%llu %u %llu) level %d\n",
btrfs_disk_key_objectid(&key), key.type,
btrfs_disk_key_offset(&key),
btrfs_tree_block_level(eb, info));
iref = (struct btrfs_extent_inline_ref *)(info + 1);
} else {
iref = (struct btrfs_extent_inline_ref *)(ei + 1);
}
ptr = (unsigned long)iref;
end = (unsigned long)ei + item_size;
while (ptr < end) {
iref = (struct btrfs_extent_inline_ref *)ptr;
type = btrfs_extent_inline_ref_type(eb, iref);
offset = btrfs_extent_inline_ref_offset(eb, iref);
pr_info("\t\tref#%d: ", ref_index++);
switch (type) {
case BTRFS_TREE_BLOCK_REF_KEY:
pr_cont("tree block backref root %llu\n", offset);
break;
case BTRFS_SHARED_BLOCK_REF_KEY:
pr_cont("shared block backref parent %llu\n", offset);
/*
* offset is supposed to be a tree block which
* must be aligned to nodesize.
*/
if (!IS_ALIGNED(offset, eb->fs_info->nodesize))
pr_info("\t\t\t(parent %llu is NOT ALIGNED to nodesize %llu)\n",
offset, (unsigned long long)eb->fs_info->nodesize);
break;
case BTRFS_EXTENT_DATA_REF_KEY:
dref = (struct btrfs_extent_data_ref *)(&iref->offset);
print_extent_data_ref(eb, dref);
break;
case BTRFS_SHARED_DATA_REF_KEY:
sref = (struct btrfs_shared_data_ref *)(iref + 1);
pr_cont("shared data backref parent %llu count %u\n",
offset, btrfs_shared_data_ref_count(eb, sref));
/*
* offset is supposed to be a tree block which
* must be aligned to nodesize.
*/
if (!IS_ALIGNED(offset, eb->fs_info->nodesize))
pr_info("\t\t\t(parent %llu is NOT ALIGNED to nodesize %llu)\n",
offset, (unsigned long long)eb->fs_info->nodesize);
break;
default:
pr_cont("(extent %llu has INVALID ref type %d)\n",
eb->start, type);
return;
}
ptr += btrfs_extent_inline_ref_size(type);
}
WARN_ON(ptr > end);
}
#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
static void print_extent_ref_v0(struct extent_buffer *eb, int slot)
{
struct btrfs_extent_ref_v0 *ref0;
ref0 = btrfs_item_ptr(eb, slot, struct btrfs_extent_ref_v0);
printk("\t\textent back ref root %llu gen %llu owner %llu num_refs %lu\n",
btrfs_ref_root_v0(eb, ref0),
btrfs_ref_generation_v0(eb, ref0),
btrfs_ref_objectid_v0(eb, ref0),
(unsigned long)btrfs_ref_count_v0(eb, ref0));
}
#endif
static void print_uuid_item(struct extent_buffer *l, unsigned long offset,
u32 item_size)
{
if (!IS_ALIGNED(item_size, sizeof(u64))) {
pr_warn("BTRFS: uuid item with illegal size %lu!\n",
(unsigned long)item_size);
return;
}
while (item_size) {
__le64 subvol_id;
read_extent_buffer(l, &subvol_id, offset, sizeof(subvol_id));
pr_info("\t\tsubvol_id %llu\n",
(unsigned long long)le64_to_cpu(subvol_id));
item_size -= sizeof(u64);
offset += sizeof(u64);
}
}
/*
* Helper to output refs and locking status of extent buffer. Useful to debug
* race condition related problems.
*/
static void print_eb_refs_lock(struct extent_buffer *eb)
{
#ifdef CONFIG_BTRFS_DEBUG
btrfs_info(eb->fs_info,
"refs %u lock (w:%d r:%d bw:%d br:%d sw:%d sr:%d) lock_owner %u current %u",
atomic_read(&eb->refs), atomic_read(&eb->write_locks),
atomic_read(&eb->read_locks),
atomic_read(&eb->blocking_writers),
atomic_read(&eb->blocking_readers),
atomic_read(&eb->spinning_writers),
atomic_read(&eb->spinning_readers),
eb->lock_owner, current->pid);
#endif
}
void btrfs_print_leaf(struct extent_buffer *l)
{
struct btrfs_fs_info *fs_info;
int i;
u32 type, nr;
struct btrfs_item *item;
struct btrfs_root_item *ri;
struct btrfs_dir_item *di;
struct btrfs_inode_item *ii;
struct btrfs_block_group_item *bi;
struct btrfs_file_extent_item *fi;
struct btrfs_extent_data_ref *dref;
struct btrfs_shared_data_ref *sref;
struct btrfs_dev_extent *dev_extent;
struct btrfs_key key;
struct btrfs_key found_key;
if (!l)
return;
fs_info = l->fs_info;
nr = btrfs_header_nritems(l);
btrfs_info(fs_info,
"leaf %llu gen %llu total ptrs %d free space %d owner %llu",
btrfs_header_bytenr(l), btrfs_header_generation(l), nr,
btrfs_leaf_free_space(fs_info, l), btrfs_header_owner(l));
print_eb_refs_lock(l);
for (i = 0 ; i < nr ; i++) {
item = btrfs_item_nr(i);
btrfs_item_key_to_cpu(l, &key, i);
type = key.type;
pr_info("\titem %d key (%llu %u %llu) itemoff %d itemsize %d\n",
i, key.objectid, type, key.offset,
btrfs_item_offset(l, item), btrfs_item_size(l, item));
switch (type) {
case BTRFS_INODE_ITEM_KEY:
ii = btrfs_item_ptr(l, i, struct btrfs_inode_item);
pr_info("\t\tinode generation %llu size %llu mode %o\n",
btrfs_inode_generation(l, ii),
btrfs_inode_size(l, ii),
btrfs_inode_mode(l, ii));
break;
case BTRFS_DIR_ITEM_KEY:
di = btrfs_item_ptr(l, i, struct btrfs_dir_item);
btrfs_dir_item_key_to_cpu(l, di, &found_key);
pr_info("\t\tdir oid %llu type %u\n",
found_key.objectid,
btrfs_dir_type(l, di));
break;
case BTRFS_ROOT_ITEM_KEY:
ri = btrfs_item_ptr(l, i, struct btrfs_root_item);
pr_info("\t\troot data bytenr %llu refs %u\n",
btrfs_disk_root_bytenr(l, ri),
btrfs_disk_root_refs(l, ri));
break;
case BTRFS_EXTENT_ITEM_KEY:
case BTRFS_METADATA_ITEM_KEY:
print_extent_item(l, i, type);
break;
case BTRFS_TREE_BLOCK_REF_KEY:
pr_info("\t\ttree block backref\n");
break;
case BTRFS_SHARED_BLOCK_REF_KEY:
pr_info("\t\tshared block backref\n");
break;
case BTRFS_EXTENT_DATA_REF_KEY:
dref = btrfs_item_ptr(l, i,
struct btrfs_extent_data_ref);
print_extent_data_ref(l, dref);
break;
case BTRFS_SHARED_DATA_REF_KEY:
sref = btrfs_item_ptr(l, i,
struct btrfs_shared_data_ref);
pr_info("\t\tshared data backref count %u\n",
btrfs_shared_data_ref_count(l, sref));
break;
case BTRFS_EXTENT_DATA_KEY:
fi = btrfs_item_ptr(l, i,
struct btrfs_file_extent_item);
if (btrfs_file_extent_type(l, fi) ==
BTRFS_FILE_EXTENT_INLINE) {
pr_info("\t\tinline extent data size %u\n",
btrfs_file_extent_inline_len(l, i, fi));
break;
}
pr_info("\t\textent data disk bytenr %llu nr %llu\n",
btrfs_file_extent_disk_bytenr(l, fi),
btrfs_file_extent_disk_num_bytes(l, fi));
pr_info("\t\textent data offset %llu nr %llu ram %llu\n",
btrfs_file_extent_offset(l, fi),
btrfs_file_extent_num_bytes(l, fi),
btrfs_file_extent_ram_bytes(l, fi));
break;
case BTRFS_EXTENT_REF_V0_KEY:
#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
print_extent_ref_v0(l, i);
#else
BUG();
#endif
break;
case BTRFS_BLOCK_GROUP_ITEM_KEY:
bi = btrfs_item_ptr(l, i,
struct btrfs_block_group_item);
pr_info(
"\t\tblock group used %llu chunk_objectid %llu flags %llu\n",
btrfs_disk_block_group_used(l, bi),
btrfs_disk_block_group_chunk_objectid(l, bi),
btrfs_disk_block_group_flags(l, bi));
break;
case BTRFS_CHUNK_ITEM_KEY:
print_chunk(l, btrfs_item_ptr(l, i,
struct btrfs_chunk));
break;
case BTRFS_DEV_ITEM_KEY:
print_dev_item(l, btrfs_item_ptr(l, i,
struct btrfs_dev_item));
break;
case BTRFS_DEV_EXTENT_KEY:
dev_extent = btrfs_item_ptr(l, i,
struct btrfs_dev_extent);
pr_info("\t\tdev extent chunk_tree %llu\n\t\tchunk objectid %llu chunk offset %llu length %llu\n",
btrfs_dev_extent_chunk_tree(l, dev_extent),
btrfs_dev_extent_chunk_objectid(l, dev_extent),
btrfs_dev_extent_chunk_offset(l, dev_extent),
btrfs_dev_extent_length(l, dev_extent));
break;
case BTRFS_PERSISTENT_ITEM_KEY:
pr_info("\t\tpersistent item objectid %llu offset %llu\n",
key.objectid, key.offset);
switch (key.objectid) {
case BTRFS_DEV_STATS_OBJECTID:
pr_info("\t\tdevice stats\n");
break;
default:
pr_info("\t\tunknown persistent item\n");
}
break;
case BTRFS_TEMPORARY_ITEM_KEY:
pr_info("\t\ttemporary item objectid %llu offset %llu\n",
key.objectid, key.offset);
switch (key.objectid) {
case BTRFS_BALANCE_OBJECTID:
pr_info("\t\tbalance status\n");
break;
default:
pr_info("\t\tunknown temporary item\n");
}
break;
case BTRFS_DEV_REPLACE_KEY:
pr_info("\t\tdev replace\n");
break;
case BTRFS_UUID_KEY_SUBVOL:
case BTRFS_UUID_KEY_RECEIVED_SUBVOL:
print_uuid_item(l, btrfs_item_ptr_offset(l, i),
btrfs_item_size_nr(l, i));
break;
};
}
}
void btrfs_print_tree(struct extent_buffer *c, bool follow)
{
struct btrfs_fs_info *fs_info;
int i; u32 nr;
struct btrfs_key key;
int level;
if (!c)
return;
fs_info = c->fs_info;
nr = btrfs_header_nritems(c);
level = btrfs_header_level(c);
if (level == 0) {
btrfs_print_leaf(c);
return;
}
btrfs_info(fs_info,
"node %llu level %d gen %llu total ptrs %d free spc %u owner %llu",
btrfs_header_bytenr(c), level, btrfs_header_generation(c),
nr, (u32)BTRFS_NODEPTRS_PER_BLOCK(fs_info) - nr,
btrfs_header_owner(c));
print_eb_refs_lock(c);
for (i = 0; i < nr; i++) {
btrfs_node_key_to_cpu(c, &key, i);
pr_info("\tkey %d (%llu %u %llu) block %llu gen %llu\n",
i, key.objectid, key.type, key.offset,
btrfs_node_blockptr(c, i),
btrfs_node_ptr_generation(c, i));
}
if (!follow)
return;
for (i = 0; i < nr; i++) {
struct btrfs_key first_key;
struct extent_buffer *next;
btrfs_node_key_to_cpu(c, &first_key, i);
next = read_tree_block(fs_info, btrfs_node_blockptr(c, i),
btrfs_node_ptr_generation(c, i),
level - 1, &first_key);
if (IS_ERR(next)) {
continue;
} else if (!extent_buffer_uptodate(next)) {
free_extent_buffer(next);
continue;
}
if (btrfs_is_leaf(next) &&
level != 1)
BUG();
if (btrfs_header_level(next) !=
level - 1)
BUG();
btrfs_print_tree(next, follow);
free_extent_buffer(next);
}
}