jbd2: allocate transaction from separate slab cache

There is normally only a handful of these active at any one time, but
putting them in a separate slab cache makes debugging memory
corruption problems easier.  Manish Katiyar also wanted this make it
easier to test memory failure scenarios in the jbd2 layer.

Cc: Manish Katiyar <mkatiyar@gmail.com>
Signed-off-by: Yongqiang Yang <xiaoqiangnk@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
This commit is contained in:
Yongqiang Yang
2012-02-20 17:53:02 -05:00
committed by Theodore Ts'o
parent 18aadd47f8
commit 0c2022eccb
5 changed files with 43 additions and 5 deletions

View File

@@ -33,6 +33,35 @@
static void __jbd2_journal_temp_unlink_buffer(struct journal_head *jh);
static void __jbd2_journal_unfile_buffer(struct journal_head *jh);
static struct kmem_cache *transaction_cache;
int __init jbd2_journal_init_transaction_cache(void)
{
J_ASSERT(!transaction_cache);
transaction_cache = kmem_cache_create("jbd2_transaction_s",
sizeof(transaction_t),
0,
SLAB_HWCACHE_ALIGN|SLAB_TEMPORARY,
NULL);
if (transaction_cache)
return 0;
return -ENOMEM;
}
void jbd2_journal_destroy_transaction_cache(void)
{
if (transaction_cache) {
kmem_cache_destroy(transaction_cache);
transaction_cache = NULL;
}
}
void jbd2_journal_free_transaction(transaction_t *transaction)
{
if (unlikely(ZERO_OR_NULL_PTR(transaction)))
return;
kmem_cache_free(transaction_cache, transaction);
}
/*
* jbd2_get_transaction: obtain a new transaction_t object.
*
@@ -133,7 +162,8 @@ static int start_this_handle(journal_t *journal, handle_t *handle,
alloc_transaction:
if (!journal->j_running_transaction) {
new_transaction = kzalloc(sizeof(*new_transaction), gfp_mask);
new_transaction = kmem_cache_alloc(transaction_cache,
gfp_mask | __GFP_ZERO);
if (!new_transaction) {
/*
* If __GFP_FS is not present, then we may be
@@ -162,7 +192,7 @@ repeat:
if (is_journal_aborted(journal) ||
(journal->j_errno != 0 && !(journal->j_flags & JBD2_ACK_ERR))) {
read_unlock(&journal->j_state_lock);
kfree(new_transaction);
jbd2_journal_free_transaction(new_transaction);
return -EROFS;
}
@@ -284,7 +314,7 @@ repeat:
read_unlock(&journal->j_state_lock);
lock_map_acquire(&handle->h_lockdep_map);
kfree(new_transaction);
jbd2_journal_free_transaction(new_transaction);
return 0;
}