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>
diff --git a/fs/jbd2/checkpoint.c b/fs/jbd2/checkpoint.c
index 453c906..253e9189 100644
--- a/fs/jbd2/checkpoint.c
+++ b/fs/jbd2/checkpoint.c
@@ -722,7 +722,7 @@
transaction->t_tid, stats);
__jbd2_journal_drop_transaction(journal, transaction);
- kfree(transaction);
+ jbd2_journal_free_transaction(transaction);
/* Just in case anybody was waiting for more transactions to be
checkpointed... */
diff --git a/fs/jbd2/commit.c b/fs/jbd2/commit.c
index 5069b84..8adc5d4 100644
--- a/fs/jbd2/commit.c
+++ b/fs/jbd2/commit.c
@@ -1048,7 +1048,7 @@
jbd_debug(1, "JBD2: commit %d complete, head %d\n",
journal->j_commit_sequence, journal->j_tail_sequence);
if (to_free)
- kfree(commit_transaction);
+ jbd2_journal_free_transaction(commit_transaction);
wake_up(&journal->j_wait_done_commit);
}
diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c
index 93a595c..aa8f598 100644
--- a/fs/jbd2/journal.c
+++ b/fs/jbd2/journal.c
@@ -2361,6 +2361,8 @@
ret = journal_init_jbd2_journal_head_cache();
if (ret == 0)
ret = journal_init_handle_cache();
+ if (ret == 0)
+ ret = jbd2_journal_init_transaction_cache();
return ret;
}
@@ -2369,6 +2371,7 @@
jbd2_journal_destroy_revoke_caches();
jbd2_journal_destroy_jbd2_journal_head_cache();
jbd2_journal_destroy_handle_cache();
+ jbd2_journal_destroy_transaction_cache();
jbd2_journal_destroy_slabs();
}
diff --git a/fs/jbd2/transaction.c b/fs/jbd2/transaction.c
index 52653306..d0a8b01 100644
--- a/fs/jbd2/transaction.c
+++ b/fs/jbd2/transaction.c
@@ -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 @@
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 @@
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 @@
read_unlock(&journal->j_state_lock);
lock_map_acquire(&handle->h_lockdep_map);
- kfree(new_transaction);
+ jbd2_journal_free_transaction(new_transaction);
return 0;
}
diff --git a/include/linux/jbd2.h b/include/linux/jbd2.h
index 5557bae..46eef77 100644
--- a/include/linux/jbd2.h
+++ b/include/linux/jbd2.h
@@ -1020,6 +1020,11 @@
/* Transaction locking */
extern void __wait_on_journal (journal_t *);
+/* Transaction cache support */
+extern void jbd2_journal_destroy_transaction_cache(void);
+extern int jbd2_journal_init_transaction_cache(void);
+extern void jbd2_journal_free_transaction(transaction_t *);
+
/*
* Journal locking.
*