Skip to content

Commit

Permalink
ext4: add self-testing infrastructure to do a sanity check
Browse files Browse the repository at this point in the history 
This commit adds a self-testing infrastructure like extent tree does to
do a sanity check for extent status tree.  After status tree is as a
extent cache, we'd better to make sure that it caches right result.

After applied this commit, we will get a lot of messages when we run
xfstests as below.

...
kernel: ES len assertation failed for inode: 230 retval 1 != map->m_len
3 in ext4_map_blocks (allocation)
...
kernel: ES cache assertation failed for inode: 230 es_cached ex
[974/2/4781/20] != found ex [974/1/4781/1000]
...
kernel: ES insert assertation failed for inode: 635 ex_status
[0/45/21388/w] != es_status [44/1/21432/u]
...

Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: Zheng Liu <wenqing.lz@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
  • Loading branch information
Dmitry Monakhov authored and Theodore Ts'o committed Mar 11, 2013
1 parent bd38436 commit 921f266
Show file tree
Hide file tree
Showing 3 changed files with 277 additions and 0 deletions.
175 changes: 175 additions & 0 deletions fs/ext4/extents_status.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -399,6 +399,179 @@ ext4_es_try_to_merge_right(struct inode *inode, struct extent_status *es)
return es;
}

#ifdef ES_AGGRESSIVE_TEST
static void ext4_es_insert_extent_ext_check(struct inode *inode,
struct extent_status *es)
{
struct ext4_ext_path *path = NULL;
struct ext4_extent *ex;
ext4_lblk_t ee_block;
ext4_fsblk_t ee_start;
unsigned short ee_len;
int depth, ee_status, es_status;

path = ext4_ext_find_extent(inode, es->es_lblk, NULL);
if (IS_ERR(path))
return;

depth = ext_depth(inode);
ex = path[depth].p_ext;

if (ex) {

ee_block = le32_to_cpu(ex->ee_block);
ee_start = ext4_ext_pblock(ex);
ee_len = ext4_ext_get_actual_len(ex);

ee_status = ext4_ext_is_uninitialized(ex) ? 1 : 0;
es_status = ext4_es_is_unwritten(es) ? 1 : 0;

/*
* Make sure ex and es are not overlap when we try to insert
* a delayed/hole extent.
*/
if (!ext4_es_is_written(es) && !ext4_es_is_unwritten(es)) {
if (in_range(es->es_lblk, ee_block, ee_len)) {
pr_warn("ES insert assertation failed for "
"inode: %lu we can find an extent "
"at block [%d/%d/%llu/%c], but we "
"want to add an delayed/hole extent "
"[%d/%d/%llu/%llx]\n",
inode->i_ino, ee_block, ee_len,
ee_start, ee_status ? 'u' : 'w',
es->es_lblk, es->es_len,
ext4_es_pblock(es), ext4_es_status(es));
}
goto out;
}

/*
* We don't check ee_block == es->es_lblk, etc. because es
* might be a part of whole extent, vice versa.
*/
if (es->es_lblk < ee_block ||
ext4_es_pblock(es) != ee_start + es->es_lblk - ee_block) {
pr_warn("ES insert assertation failed for inode: %lu "
"ex_status [%d/%d/%llu/%c] != "
"es_status [%d/%d/%llu/%c]\n", inode->i_ino,
ee_block, ee_len, ee_start,
ee_status ? 'u' : 'w', es->es_lblk, es->es_len,
ext4_es_pblock(es), es_status ? 'u' : 'w');
goto out;
}

if (ee_status ^ es_status) {
pr_warn("ES insert assertation failed for inode: %lu "
"ex_status [%d/%d/%llu/%c] != "
"es_status [%d/%d/%llu/%c]\n", inode->i_ino,
ee_block, ee_len, ee_start,
ee_status ? 'u' : 'w', es->es_lblk, es->es_len,
ext4_es_pblock(es), es_status ? 'u' : 'w');
}
} else {
/*
* We can't find an extent on disk. So we need to make sure
* that we don't want to add an written/unwritten extent.
*/
if (!ext4_es_is_delayed(es) && !ext4_es_is_hole(es)) {
pr_warn("ES insert assertation failed for inode: %lu "
"can't find an extent at block %d but we want "
"to add an written/unwritten extent "
"[%d/%d/%llu/%llx]\n", inode->i_ino,
es->es_lblk, es->es_lblk, es->es_len,
ext4_es_pblock(es), ext4_es_status(es));
}
}
out:
if (path) {
ext4_ext_drop_refs(path);
kfree(path);
}
}

static void ext4_es_insert_extent_ind_check(struct inode *inode,
struct extent_status *es)
{
struct ext4_map_blocks map;
int retval;

/*
* Here we call ext4_ind_map_blocks to lookup a block mapping because
* 'Indirect' structure is defined in indirect.c. So we couldn't
* access direct/indirect tree from outside. It is too dirty to define
* this function in indirect.c file.
*/

map.m_lblk = es->es_lblk;
map.m_len = es->es_len;

retval = ext4_ind_map_blocks(NULL, inode, &map, 0);
if (retval > 0) {
if (ext4_es_is_delayed(es) || ext4_es_is_hole(es)) {
/*
* We want to add a delayed/hole extent but this
* block has been allocated.
*/
pr_warn("ES insert assertation failed for inode: %lu "
"We can find blocks but we want to add a "
"delayed/hole extent [%d/%d/%llu/%llx]\n",
inode->i_ino, es->es_lblk, es->es_len,
ext4_es_pblock(es), ext4_es_status(es));
return;
} else if (ext4_es_is_written(es)) {
if (retval != es->es_len) {
pr_warn("ES insert assertation failed for "
"inode: %lu retval %d != es_len %d\n",
inode->i_ino, retval, es->es_len);
return;
}
if (map.m_pblk != ext4_es_pblock(es)) {
pr_warn("ES insert assertation failed for "
"inode: %lu m_pblk %llu != "
"es_pblk %llu\n",
inode->i_ino, map.m_pblk,
ext4_es_pblock(es));
return;
}
} else {
/*
* We don't need to check unwritten extent because
* indirect-based file doesn't have it.
*/
BUG_ON(1);
}
} else if (retval == 0) {
if (ext4_es_is_written(es)) {
pr_warn("ES insert assertation failed for inode: %lu "
"We can't find the block but we want to add "
"an written extent [%d/%d/%llu/%llx]\n",
inode->i_ino, es->es_lblk, es->es_len,
ext4_es_pblock(es), ext4_es_status(es));
return;
}
}
}

static inline void ext4_es_insert_extent_check(struct inode *inode,
struct extent_status *es)
{
/*
* We don't need to worry about the race condition because
* caller takes i_data_sem locking.
*/
BUG_ON(!rwsem_is_locked(&EXT4_I(inode)->i_data_sem));
if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
ext4_es_insert_extent_ext_check(inode, es);
else
ext4_es_insert_extent_ind_check(inode, es);
}
#else
static inline void ext4_es_insert_extent_check(struct inode *inode,
struct extent_status *es)
{
}
#endif

static int __es_insert_extent(struct inode *inode, struct extent_status *newes)
{
struct ext4_es_tree *tree = &EXT4_I(inode)->i_es_tree;
Expand Down Expand Up @@ -481,6 +654,8 @@ int ext4_es_insert_extent(struct inode *inode, ext4_lblk_t lblk,
ext4_es_store_status(&newes, status);
trace_ext4_es_insert_extent(inode, &newes);

ext4_es_insert_extent_check(inode, &newes);

write_lock(&EXT4_I(inode)->i_es_lock);
err = __es_remove_extent(inode, lblk, end);
if (err != 0)
Expand Down
6 changes: 6 additions & 0 deletions fs/ext4/extents_status.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -20,6 +20,12 @@
#define es_debug(fmt, ...) no_printk(fmt, ##__VA_ARGS__)
#endif

/*
* With ES_AGGRESSIVE_TEST defined, the result of es caching will be
* checked with old map_block's result.
*/
#define ES_AGGRESSIVE_TEST__

/*
* These flags live in the high bits of extent_status.es_pblk
*/
Expand Down
96 changes: 96 additions & 0 deletions fs/ext4/inode.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -482,6 +482,58 @@ static pgoff_t ext4_num_dirty_pages(struct inode *inode, pgoff_t idx,
return num;
}

#ifdef ES_AGGRESSIVE_TEST
static void ext4_map_blocks_es_recheck(handle_t *handle,
struct inode *inode,
struct ext4_map_blocks *es_map,
struct ext4_map_blocks *map,
int flags)
{
int retval;

map->m_flags = 0;
/*
* There is a race window that the result is not the same.
* e.g. xfstests #223 when dioread_nolock enables. The reason
* is that we lookup a block mapping in extent status tree with
* out taking i_data_sem. So at the time the unwritten extent
* could be converted.
*/
if (!(flags & EXT4_GET_BLOCKS_NO_LOCK))
down_read((&EXT4_I(inode)->i_data_sem));
if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) {
retval = ext4_ext_map_blocks(handle, inode, map, flags &
EXT4_GET_BLOCKS_KEEP_SIZE);
} else {
retval = ext4_ind_map_blocks(handle, inode, map, flags &
EXT4_GET_BLOCKS_KEEP_SIZE);
}
if (!(flags & EXT4_GET_BLOCKS_NO_LOCK))
up_read((&EXT4_I(inode)->i_data_sem));
/*
* Clear EXT4_MAP_FROM_CLUSTER and EXT4_MAP_BOUNDARY flag
* because it shouldn't be marked in es_map->m_flags.
*/
map->m_flags &= ~(EXT4_MAP_FROM_CLUSTER | EXT4_MAP_BOUNDARY);

/*
* We don't check m_len because extent will be collpased in status
* tree. So the m_len might not equal.
*/
if (es_map->m_lblk != map->m_lblk ||
es_map->m_flags != map->m_flags ||
es_map->m_pblk != map->m_pblk) {
printk("ES cache assertation failed for inode: %lu "
"es_cached ex [%d/%d/%llu/%x] != "
"found ex [%d/%d/%llu/%x] retval %d flags %x\n",
inode->i_ino, es_map->m_lblk, es_map->m_len,
es_map->m_pblk, es_map->m_flags, map->m_lblk,
map->m_len, map->m_pblk, map->m_flags,
retval, flags);
}
}
#endif /* ES_AGGRESSIVE_TEST */

/*
* The ext4_map_blocks() function tries to look up the requested blocks,
* and returns if the blocks are already mapped.
Expand Down Expand Up @@ -509,6 +561,11 @@ int ext4_map_blocks(handle_t *handle, struct inode *inode,
{
struct extent_status es;
int retval;
#ifdef ES_AGGRESSIVE_TEST
struct ext4_map_blocks orig_map;

memcpy(&orig_map, map, sizeof(*map));
#endif

map->m_flags = 0;
ext_debug("ext4_map_blocks(): inode %lu, flag %d, max_blocks %u,"
Expand All @@ -531,6 +588,10 @@ int ext4_map_blocks(handle_t *handle, struct inode *inode,
} else {
BUG_ON(1);
}
#ifdef ES_AGGRESSIVE_TEST
ext4_map_blocks_es_recheck(handle, inode, map,
&orig_map, flags);
#endif
goto found;
}

Expand All @@ -551,6 +612,15 @@ int ext4_map_blocks(handle_t *handle, struct inode *inode,
int ret;
unsigned long long status;

#ifdef ES_AGGRESSIVE_TEST
if (retval != map->m_len) {
printk("ES len assertation failed for inode: %lu "
"retval %d != map->m_len %d "
"in %s (lookup)\n", inode->i_ino, retval,
map->m_len, __func__);
}
#endif

status = map->m_flags & EXT4_MAP_UNWRITTEN ?
EXTENT_STATUS_UNWRITTEN : EXTENT_STATUS_WRITTEN;
if (!(flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) &&
Expand Down Expand Up @@ -643,6 +713,15 @@ int ext4_map_blocks(handle_t *handle, struct inode *inode,
int ret;
unsigned long long status;

#ifdef ES_AGGRESSIVE_TEST
if (retval != map->m_len) {
printk("ES len assertation failed for inode: %lu "
"retval %d != map->m_len %d "
"in %s (allocation)\n", inode->i_ino, retval,
map->m_len, __func__);
}
#endif

status = map->m_flags & EXT4_MAP_UNWRITTEN ?
EXTENT_STATUS_UNWRITTEN : EXTENT_STATUS_WRITTEN;
if (!(flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) &&
Expand Down Expand Up @@ -1768,6 +1847,11 @@ static int ext4_da_map_blocks(struct inode *inode, sector_t iblock,
struct extent_status es;
int retval;
sector_t invalid_block = ~((sector_t) 0xffff);
#ifdef ES_AGGRESSIVE_TEST
struct ext4_map_blocks orig_map;

memcpy(&orig_map, map, sizeof(*map));
#endif

if (invalid_block < ext4_blocks_count(EXT4_SB(inode->i_sb)->s_es))
invalid_block = ~0;
Expand Down Expand Up @@ -1809,6 +1893,9 @@ static int ext4_da_map_blocks(struct inode *inode, sector_t iblock,
else
BUG_ON(1);

#ifdef ES_AGGRESSIVE_TEST
ext4_map_blocks_es_recheck(NULL, inode, map, &orig_map, 0);
#endif
return retval;
}

Expand Down Expand Up @@ -1873,6 +1960,15 @@ static int ext4_da_map_blocks(struct inode *inode, sector_t iblock,
int ret;
unsigned long long status;

#ifdef ES_AGGRESSIVE_TEST
if (retval != map->m_len) {
printk("ES len assertation failed for inode: %lu "
"retval %d != map->m_len %d "
"in %s (lookup)\n", inode->i_ino, retval,
map->m_len, __func__);
}
#endif

status = map->m_flags & EXT4_MAP_UNWRITTEN ?
EXTENT_STATUS_UNWRITTEN : EXTENT_STATUS_WRITTEN;
ret = ext4_es_insert_extent(inode, map->m_lblk, map->m_len,
Expand Down

0 comments on commit 921f266

Please sign in to comment.