>From 2839d314353b6d9e88355dc0b30927d38b2cb7b7 Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Mon, 27 Jul 2015 21:42:08 +0200 Subject: [PATCH] jbd2: Avoid infinite loop when destroying aborted journal Commit 6f6a6fda2945 "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 Fixes: 6f6a6fda294506dfe0e3e0a253bb2d2923f28f0a Signed-off-by: Jan Kara --- fs/jbd2/checkpoint.c | 39 +++++++++++++++++++++++++++++++++------ fs/jbd2/commit.c | 2 +- fs/jbd2/journal.c | 11 ++++++++++- include/linux/jbd2.h | 3 ++- 4 files changed, 46 insertions(+), 9 deletions(-) diff --git a/fs/jbd2/checkpoint.c b/fs/jbd2/checkpoint.c index 4227dc4f7437..8c44654ce274 100644 --- a/fs/jbd2/checkpoint.c +++ b/fs/jbd2/checkpoint.c @@ -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; /* @@ -506,6 +511,28 @@ void __jbd2_journal_clean_checkpoint_list(journal_t *journal) } /* + * 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 * committed to the log). diff --git a/fs/jbd2/commit.c b/fs/jbd2/commit.c index b73e0215baa7..362e5f614450 100644 --- a/fs/jbd2/commit.c +++ b/fs/jbd2/commit.c @@ -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"); diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c index 4ff3fad4e9e3..2721513adb1f 100644 --- a/fs/jbd2/journal.c +++ b/fs/jbd2/journal.c @@ -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); } diff --git a/include/linux/jbd2.h b/include/linux/jbd2.h index edb640ae9a94..eb1cebed3f36 100644 --- a/include/linux/jbd2.h +++ b/include/linux/jbd2.h @@ -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 *); -- 2.1.4