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jbd2: avoid infinite loop when destroying aborted journal

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Commit 6f6a6fda29 "jbd2: fix ocfs2 corrupt when updating journal
superblock fails" changed jbd2_cleanup_journal_tail() to return EIO
when the journal is aborted. That makes logic in
jbd2_log_do_checkpoint() bail out which is fine, except that
jbd2_journal_destroy() expects jbd2_log_do_checkpoint() to always make
a progress in cleaning the journal. Without it jbd2_journal_destroy()
just loops in an infinite loop.

Fix jbd2_journal_destroy() to cleanup journal checkpoint lists of
jbd2_log_do_checkpoint() fails with error.

Reported-by: Eryu Guan <guaneryu@gmail.com>
Tested-by: Eryu Guan <guaneryu@gmail.com>
Fixes: 6f6a6fda29
Signed-off-by: Jan Kara <jack@suse.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
This commit is contained in:
Jan Kara 2015-07-28 14:57:14 -04:00 committed by Theodore Ts'o
parent 564bc40252
commit 841df7df19
4 changed files with 46 additions and 9 deletions
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39
fs/jbd2/checkpoint.c
View File

@ -417,12 +417,12 @@ int jbd2_cleanup_journal_tail(journal_t *journal)
* journal_clean_one_cp_list
*
* Find all the written-back checkpoint buffers in the given list and
* release them.
* release them. If 'destroy' is set, clean all buffers unconditionally.
*
* Called with j_list_lock held.
* Returns 1 if we freed the transaction, 0 otherwise.
*/
static int journal_clean_one_cp_list(struct journal_head *jh)
static int journal_clean_one_cp_list(struct journal_head *jh, bool destroy)
{
struct journal_head *last_jh;
struct journal_head *next_jh = jh;
@ -436,7 +436,10 @@ static int journal_clean_one_cp_list(struct journal_head *jh)
do {
jh = next_jh;
next_jh = jh->b_cpnext;
ret = __try_to_free_cp_buf(jh);
if (!destroy)
ret = __try_to_free_cp_buf(jh);
else
ret = __jbd2_journal_remove_checkpoint(jh) + 1;
if (!ret)
return freed;
if (ret == 2)
@ -459,10 +462,11 @@ static int journal_clean_one_cp_list(struct journal_head *jh)
* journal_clean_checkpoint_list
*
* Find all the written-back checkpoint buffers in the journal and release them.
* If 'destroy' is set, release all buffers unconditionally.
*
* Called with j_list_lock held.
*/
void __jbd2_journal_clean_checkpoint_list(journal_t *journal)
void __jbd2_journal_clean_checkpoint_list(journal_t *journal, bool destroy)
{
transaction_t *transaction, *last_transaction, *next_transaction;
int ret;
@ -476,7 +480,8 @@ void __jbd2_journal_clean_checkpoint_list(journal_t *journal)
do {
transaction = next_transaction;
next_transaction = transaction->t_cpnext;
ret = journal_clean_one_cp_list(transaction->t_checkpoint_list);
ret = journal_clean_one_cp_list(transaction->t_checkpoint_list,
destroy);
/*
* This function only frees up some memory if possible so we
* dont have an obligation to finish processing. Bail out if
@ -492,7 +497,7 @@ void __jbd2_journal_clean_checkpoint_list(journal_t *journal)
* we can possibly see not yet submitted buffers on io_list
*/
ret = journal_clean_one_cp_list(transaction->
t_checkpoint_io_list);
t_checkpoint_io_list, destroy);
if (need_resched())
return;
/*
@ -505,6 +510,28 @@ void __jbd2_journal_clean_checkpoint_list(journal_t *journal)
} while (transaction != last_transaction);
}
/*
* Remove buffers from all checkpoint lists as journal is aborted and we just
* need to free memory
*/
void jbd2_journal_destroy_checkpoint(journal_t *journal)
{
/*
* We loop because __jbd2_journal_clean_checkpoint_list() may abort
* early due to a need of rescheduling.
*/
while (1) {
spin_lock(&journal->j_list_lock);
if (!journal->j_checkpoint_transactions) {
spin_unlock(&journal->j_list_lock);
break;
}
__jbd2_journal_clean_checkpoint_list(journal, true);
spin_unlock(&journal->j_list_lock);
cond_resched();
}
}
/*
* journal_remove_checkpoint: called after a buffer has been committed
* to disk (either by being write-back flushed to disk, or being

2
fs/jbd2/commit.c
View File

@ -510,7 +510,7 @@ void jbd2_journal_commit_transaction(journal_t *journal)
* frees some memory
*/
spin_lock(&journal->j_list_lock);
__jbd2_journal_clean_checkpoint_list(journal);
__jbd2_journal_clean_checkpoint_list(journal, false);
spin_unlock(&journal->j_list_lock);
jbd_debug(3, "JBD2: commit phase 1\n");

11
fs/jbd2/journal.c
View File

@ -1693,8 +1693,17 @@ int jbd2_journal_destroy(journal_t *journal)
while (journal->j_checkpoint_transactions != NULL) {
spin_unlock(&journal->j_list_lock);
mutex_lock(&journal->j_checkpoint_mutex);
jbd2_log_do_checkpoint(journal);
err = jbd2_log_do_checkpoint(journal);
mutex_unlock(&journal->j_checkpoint_mutex);
/*
* If checkpointing failed, just free the buffers to avoid
* looping forever
*/
if (err) {
jbd2_journal_destroy_checkpoint(journal);
spin_lock(&journal->j_list_lock);
break;
}
spin_lock(&journal->j_list_lock);
}

3
include/linux/jbd2.h
View File

@ -1042,8 +1042,9 @@ void jbd2_update_log_tail(journal_t *journal, tid_t tid, unsigned long block);
extern void jbd2_journal_commit_transaction(journal_t *);
/* Checkpoint list management */
void __jbd2_journal_clean_checkpoint_list(journal_t *journal);
void __jbd2_journal_clean_checkpoint_list(journal_t *journal, bool destroy);
int __jbd2_journal_remove_checkpoint(struct journal_head *);
void jbd2_journal_destroy_checkpoint(journal_t *journal);
void __jbd2_journal_insert_checkpoint(struct journal_head *, transaction_t *);