Commit 4163c028 authored by Jan Kara's avatar Jan Kara Committed by Luis Henriques

jbd2: avoid infinite loop when destroying aborted journal

commit 841df7df upstream.

Commit 6f6a6fda "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: default avatarEryu Guan <guaneryu@gmail.com>
Tested-by: default avatarEryu Guan <guaneryu@gmail.com>
Fixes: 6f6a6fdaSigned-off-by: default avatarJan Kara <jack@suse.com>
Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
[ luis: backported to 3.16: used Jan's backport ]
Signed-off-by: default avatarLuis Henriques <luis.henriques@canonical.com>
parent 10690398
......@@ -475,14 +475,15 @@ 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 the journal locked.
* Called with j_list_lock held.
* Returns number of buffers reaped (for debug)
*/
static int journal_clean_one_cp_list(struct journal_head *jh, int *released)
static int journal_clean_one_cp_list(struct journal_head *jh, bool destroy,
int *released)
{
struct journal_head *last_jh;
struct journal_head *next_jh = jh;
......@@ -496,7 +497,10 @@ static int journal_clean_one_cp_list(struct journal_head *jh, int *released)
do {
jh = next_jh;
next_jh = jh->b_cpnext;
if (!destroy)
ret = __try_to_free_cp_buf(jh);
else
ret = __jbd2_journal_remove_checkpoint(jh) + 1;
if (ret) {
freed++;
if (ret == 2) {
......@@ -521,13 +525,14 @@ static int journal_clean_one_cp_list(struct journal_head *jh, int *released)
* 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 the journal locked.
* Called with j_list_lock held.
* Returns number of buffers reaped (for debug)
*/
int __jbd2_journal_clean_checkpoint_list(journal_t *journal)
int __jbd2_journal_clean_checkpoint_list(journal_t *journal, bool destroy)
{
transaction_t *transaction, *last_transaction, *next_transaction;
int ret = 0;
......@@ -543,7 +548,7 @@ int __jbd2_journal_clean_checkpoint_list(journal_t *journal)
transaction = next_transaction;
next_transaction = transaction->t_cpnext;
ret += journal_clean_one_cp_list(transaction->
t_checkpoint_list, &released);
t_checkpoint_list, destroy, &released);
/*
* This function only frees up some memory if possible so we
* dont have an obligation to finish processing. Bail out if
......@@ -559,7 +564,7 @@ int __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, &released);
t_checkpoint_io_list, destroy, &released);
if (need_resched())
goto out;
} while (transaction != last_transaction);
......@@ -567,6 +572,28 @@ int __jbd2_journal_clean_checkpoint_list(journal_t *journal)
return ret;
}
/*
* 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
......
......@@ -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");
......
......@@ -1708,8 +1708,17 @@ 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);
}
......
......@@ -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 */
int __jbd2_journal_clean_checkpoint_list(journal_t *journal);
int __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 *);
......
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