Commit 0c2022ec authored by Yongqiang Yang's avatar Yongqiang Yang Committed by Theodore Ts'o
Browse files

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: default avatarYongqiang Yang <xiaoqiangnk@gmail.com>
Signed-off-by: default avatar"Theodore Ts'o" <tytso@mit.edu>
parent 18aadd47

fs/jbd2/checkpoint.c

+1 −1
Original line number Diff line number Diff line
@@ -722,7 +722,7 @@ int __jbd2_journal_remove_checkpoint(struct journal_head *jh) 
				    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... */

fs/jbd2/commit.c

+1 −1
Original line number Diff line number Diff line
@@ -1048,7 +1048,7 @@ restart_loop: 
	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);

}

fs/jbd2/journal.c

+3 −0
Original line number Diff line number Diff line
@@ -2361,6 +2361,8 @@ static int __init journal_init_caches(void) 
		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 @@ static void jbd2_journal_destroy_caches(void) 
	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();

}

fs/jbd2/transaction.c

+33 −3
Original line number Diff line number Diff line
@@ -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;

}

include/linux/jbd2.h

+5 −0
Original line number Diff line number Diff line
@@ -1020,6 +1020,11 @@ jbd2_journal_write_metadata_buffer(transaction_t *transaction, 
/* 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.

 *

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