| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Date: Tue, 28 May 2013 13:18:56 +0400
From: Dmitry Monakhov <dmonakhov@...nvz.org>
To: linux-ext4@...r.kernel.org
Cc: jack@...e.cz, Dmitry Monakhov <dmonakhov@...nvz.org>
Subject: [PATCH 1/6] jbd2: optimize jbd2_journal_force_commit
Current implementation of jbd2_journal_force_commit() is suboptimal because
result in empty and useless commits. But callers just want to force and wait
any unfinished commits. We already has jbd2_journal_force_commit_nested()
which does exactly what we want, except we are guaranteed that we do not hold
journal transaction open.
Signed-off-by: Dmitry Monakhov <dmonakhov@...nvz.org>
---
fs/jbd2/journal.c | 55 ++++++++++++++++++++++++++++++++++++------------
fs/jbd2/transaction.c | 23 --------------------
include/linux/jbd2.h | 2 +-
3 files changed, 42 insertions(+), 38 deletions(-)
diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c
index 886ec2f..078e8ea 100644
--- a/fs/jbd2/journal.c
+++ b/fs/jbd2/journal.c
@@ -566,21 +566,19 @@ int jbd2_log_start_commit(journal_t *journal, tid_t tid)
}
/*
- * Force and wait upon a commit if the calling process is not within
- * transaction. This is used for forcing out undo-protected data which contains
- * bitmaps, when the fs is running out of space.
- *
- * We can only force the running transaction if we don't have an active handle;
- * otherwise, we will deadlock.
- *
- * Returns true if a transaction was started.
+ * Force and wait any uncommitted transactions. We can only force the running
+ * transaction if we don't have an active handle, otherwise, we will deadlock.
*/
-int jbd2_journal_force_commit_nested(journal_t *journal)
+int __jbd2_journal_force_commit(journal_t *journal, int nested, int *progress)
{
transaction_t *transaction = NULL;
tid_t tid;
- int need_to_start = 0;
+ int need_to_start = 0, ret = 0;
+ J_ASSERT(!current->journal_info || nested);
+
+ if (progress)
+ *progress = 0;
read_lock(&journal->j_state_lock);
if (journal->j_running_transaction && !current->journal_info) {
transaction = journal->j_running_transaction;
@@ -590,16 +588,45 @@ int jbd2_journal_force_commit_nested(journal_t *journal)
transaction = journal->j_committing_transaction;
if (!transaction) {
+ /* Nothing to commit */
read_unlock(&journal->j_state_lock);
- return 0; /* Nothing to retry */
+ return 0;
}
-
tid = transaction->t_tid;
read_unlock(&journal->j_state_lock);
if (need_to_start)
jbd2_log_start_commit(journal, tid);
- jbd2_log_wait_commit(journal, tid);
- return 1;
+ ret = jbd2_log_wait_commit(journal, tid);
+ if (!ret && progress)
+ *progress = 1;
+
+ return ret;
+}
+
+/**
+ * Force and wait upon a commit if the calling process is not within
+ * transaction. This is used for forcing out undo-protected data which contains
+ * bitmaps, when the fs is running out of space.
+ *
+ * @journal: journal to force
+ * Returns true if progress was made.
+ */
+int jbd2_journal_force_commit_nested(journal_t *journal)
+{
+ int progress;
+
+ __jbd2_journal_force_commit(journal, 1, &progress);
+ return progress;
+}
+
+/**
+ * int journal_force_commit() - force any uncommitted transactions
+ * @journal: journal to force
+ *
+ */
+int jbd2_journal_force_commit(journal_t *journal)
+{
+ return __jbd2_journal_force_commit(journal, 0, NULL);
}
/*
diff --git a/fs/jbd2/transaction.c b/fs/jbd2/transaction.c
index 10f524c..dae6b3d 100644
--- a/fs/jbd2/transaction.c
+++ b/fs/jbd2/transaction.c
@@ -1522,29 +1522,6 @@ int jbd2_journal_stop(handle_t *handle)
return err;
}
-/**
- * int jbd2_journal_force_commit() - force any uncommitted transactions
- * @journal: journal to force
- *
- * For synchronous operations: force any uncommitted transactions
- * to disk. May seem kludgy, but it reuses all the handle batching
- * code in a very simple manner.
- */
-int jbd2_journal_force_commit(journal_t *journal)
-{
- handle_t *handle;
- int ret;
-
- handle = jbd2_journal_start(journal, 1);
- if (IS_ERR(handle)) {
- ret = PTR_ERR(handle);
- } else {
- handle->h_sync = 1;
- ret = jbd2_journal_stop(handle);
- }
- return ret;
-}
-
/*
*
* List management code snippets: various functions for manipulating the
diff --git a/include/linux/jbd2.h b/include/linux/jbd2.h
index 6e051f4..c9e1ab6 100644
--- a/include/linux/jbd2.h
+++ b/include/linux/jbd2.h
@@ -1125,6 +1125,7 @@ extern void jbd2_journal_ack_err (journal_t *);
extern int jbd2_journal_clear_err (journal_t *);
extern int jbd2_journal_bmap(journal_t *, unsigned long, unsigned long long *);
extern int jbd2_journal_force_commit(journal_t *);
+extern int jbd2_journal_force_commit_nested(journal_t *);
extern int jbd2_journal_file_inode(handle_t *handle, struct jbd2_inode *inode);
extern int jbd2_journal_begin_ordered_truncate(journal_t *journal,
struct jbd2_inode *inode, loff_t new_size);
@@ -1199,7 +1200,6 @@ int __jbd2_log_space_left(journal_t *); /* Called with journal locked */
int jbd2_log_start_commit(journal_t *journal, tid_t tid);
int __jbd2_log_start_commit(journal_t *journal, tid_t tid);
int jbd2_journal_start_commit(journal_t *journal, tid_t *tid);
-int jbd2_journal_force_commit_nested(journal_t *journal);
int jbd2_log_wait_commit(journal_t *journal, tid_t tid);
int jbd2_complete_transaction(journal_t *journal, tid_t tid);
int jbd2_log_do_checkpoint(journal_t *journal);
--
1.7.1
--
To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Powered by blists - more mailing lists