From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from youngberry.canonical.com ([91.189.89.112]:53437 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753377AbbJSKTB (ORCPT ); Mon, 19 Oct 2015 06:19:01 -0400 Date: Mon, 19 Oct 2015 11:18:57 +0100 From: Luis Henriques To: Jan Kara Cc: stable@vger.kernel.org, Jan@suse.cz, Theodore Ts'o Subject: Re: jbd2: avoid infinite loop when destroying aborted journal Message-ID: <20151019101857.GB3424@ares> References: <1444060446-18296-1-git-send-email-jack@suse.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <1444060446-18296-1-git-send-email-jack@suse.com> Sender: stable-owner@vger.kernel.org List-ID: On Mon, Oct 05, 2015 at 05:54:06PM +0200, Jan Kara wrote: > From: Jan Kara > Backport of commit 841df7df196237ea63233f0f9eaa41db53afd70f for > 3.11, 3.12, 3.14 stable kernels. > Thanks, using this for the 3.16 kernel as well. Cheers, -- Lu�s > 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 > Tested-by: Eryu Guan > Fixes: 6f6a6fda294506dfe0e3e0a253bb2d2923f28f0a > Signed-off-by: Jan Kara > Signed-off-by: Theodore Ts'o > > diff -rupX /crypted/home/jack/.kerndiffexclude linux-3.12-SLE12/fs/jbd2/checkpoint.c linux-3.12-SLE12-jbd2_loop/fs/jbd2/checkpoint.c > --- linux-3.12-SLE12/fs/jbd2/checkpoint.c 2015-08-28 11:43:12.372739350 +0200 > +++ linux-3.12-SLE12-jbd2_loop/fs/jbd2/checkpoint.c 2015-10-02 21:19:36.569652149 +0200 > @@ -475,14 +475,15 @@ int jbd2_cleanup_journal_tail(journal_t > * 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(str > 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) { > freed++; > if (ret == 2) { > @@ -521,13 +525,14 @@ static int journal_clean_one_cp_list(str > * 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 > 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 > * 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); > @@ -568,6 +573,28 @@ out: > } > > /* > + * 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 -rupX /crypted/home/jack/.kerndiffexclude linux-3.12-SLE12/fs/jbd2/commit.c linux-3.12-SLE12-jbd2_loop/fs/jbd2/commit.c > --- linux-3.12-SLE12/fs/jbd2/commit.c 2015-08-28 11:43:06.258721198 +0200 > +++ linux-3.12-SLE12-jbd2_loop/fs/jbd2/commit.c 2015-10-02 21:15:47.755275630 +0200 > @@ -510,7 +510,7 @@ void jbd2_journal_commit_transaction(jou > * 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 -rupX /crypted/home/jack/.kerndiffexclude linux-3.12-SLE12/fs/jbd2/journal.c linux-3.12-SLE12-jbd2_loop/fs/jbd2/journal.c > --- linux-3.12-SLE12/fs/jbd2/journal.c 2015-08-28 11:43:50.493852324 +0200 > +++ linux-3.12-SLE12-jbd2_loop/fs/jbd2/journal.c 2015-10-02 21:15:47.756275638 +0200 > @@ -1710,8 +1710,17 @@ int jbd2_journal_destroy(journal_t *jour > 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 -rupX /crypted/home/jack/.kerndiffexclude linux-3.12-SLE12/include/linux/jbd2.h linux-3.12-SLE12-jbd2_loop/include/linux/jbd2.h > --- linux-3.12-SLE12/include/linux/jbd2.h 2015-08-28 11:43:12.404739445 +0200 > +++ linux-3.12-SLE12-jbd2_loop/include/linux/jbd2.h 2015-10-02 21:16:33.938351449 +0200 > @@ -1042,8 +1042,9 @@ void jbd2_update_log_tail(journal_t *jou > 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 *); > > > -- > To unsubscribe from this list: send the line "unsubscribe stable" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html