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btrfs-progs: check: check extent_inline_ref in lowmem

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Lowmem check does not skip invalid type in extent_inline_ref and then
calls btrfs_extent_inline_ref_size(type) which causes a crash.

Error:

$ btrfs check --mode=lowmem  /tmp/data_small
Checking filesystem on /tmp/data_small
UUID: ee205d69-8724-4aa2-a4f5-bc8558a62169
checking extents
ERROR: extent[20971520 16384] backref type mismatch, missing bit: 2
ERROR: extent[20971520 16384] backref generation mismatch,
wanted: 7, have: 0
ERROR: extent[20971520 16384] is referred by other roots than 3
ctree.h:1754: btrfs_extent_inline_ref_size: BUG_ON `1` triggered,
value 1
btrfs(+0x543db)[0x55fabc2ab3db]
btrfs(+0x587f7)[0x55fabc2af7f7]
btrfs(+0x5fa44)[0x55fabc2b6a44]
btrfs(cmd_check+0x194a)[0x55fabc2bd717]
btrfs(main+0x88)[0x55fabc2682e0]
/usr/lib/libc.so.6(__libc_start_main+0xea)[0x7f021c3824ca]
btrfs(_start+0x2a)[0x55fabc267e7a]
[1] 5188 abort (core dumped)  btrfs check --mode=lowmem /tmp/data_small

Fix it by introducing check_extent_inline_ref() to check the type.
If the checker returns a non-zero value, we should not try to check the
corrupted extent item anymore.

Suggested-by: Qu Wenruo <quwenruo.btrfs@gmx.com>
Signed-off-by: Su Yue <suy.fnst@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
Su Yue 2017-09-27 14:34:39 +08:00 committed by David Sterba
parent c955dbd7fe
commit 801b7260fd
1 changed files with 33 additions and 0 deletions
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33
cmds-check.c
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@ -11580,6 +11580,29 @@ loop:
goto again;
}
static int check_extent_inline_ref(struct extent_buffer *eb,
struct btrfs_key *key, struct btrfs_extent_inline_ref *iref)
{
int ret;
u8 type = btrfs_extent_inline_ref_type(eb, iref);
switch (type) {
case BTRFS_TREE_BLOCK_REF_KEY:
case BTRFS_EXTENT_DATA_REF_KEY:
case BTRFS_SHARED_BLOCK_REF_KEY:
case BTRFS_SHARED_DATA_REF_KEY:
ret = 0;
break;
default:
error("extent[%llu %u %llu] has unknown ref type: %d",
key->objectid, key->type, key->offset, type);
ret = UNKNOWN_TYPE;
break;
}
return ret;
}
/*
* Check backrefs of a tree block given by @bytenr or @eb.
*
@ -11714,6 +11737,11 @@ static int check_tree_block_ref(struct btrfs_root *root,
type = btrfs_extent_inline_ref_type(leaf, iref);
offset = btrfs_extent_inline_ref_offset(leaf, iref);
ret = check_extent_inline_ref(leaf, &key, iref);
if (ret) {
err |= ret;
break;
}
if (type == BTRFS_TREE_BLOCK_REF_KEY) {
if (offset == root->objectid)
found_ref = 1;
@ -11991,6 +12019,11 @@ static int check_extent_data_item(struct btrfs_root *root,
type = btrfs_extent_inline_ref_type(leaf, iref);
dref = (struct btrfs_extent_data_ref *)(&iref->offset);
ret = check_extent_inline_ref(leaf, &dbref_key, iref);
if (ret) {
err |= ret;
break;
}
if (type == BTRFS_EXTENT_DATA_REF_KEY) {
ref_root = btrfs_extent_data_ref_root(leaf, dref);
if (ref_root == root->objectid)