From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from aserp1040.oracle.com ([141.146.126.69]:31710 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751675AbdFJVKl (ORCPT ); Sat, 10 Jun 2017 17:10:41 -0400 Date: Sat, 10 Jun 2017 14:10:29 -0700 From: "Darrick J. Wong" Subject: Re: [PATCH] xfs: free uncommitted transactions during log recovery Message-ID: <20170610211029.GM4530@birch.djwong.org> References: <1497029889-12299-1-git-send-email-bfoster@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1497029889-12299-1-git-send-email-bfoster@redhat.com> Sender: linux-xfs-owner@vger.kernel.org List-ID: List-Id: xfs To: Brian Foster Cc: linux-xfs@vger.kernel.org On Fri, Jun 09, 2017 at 01:38:09PM -0400, Brian Foster wrote: > Log recovery allocates in-core transaction and member item data > structures on-demand as it processes the on-disk log. Transactions > are allocated on first encounter on-disk and stored in a hash table > structure where they are easily accessible for subsequent lookups. > Transaction items are also allocated on demand and are attached to > the associated transactions. > > When a commit record is encountered in the log, the transaction is > committed to the fs and the in-core structures are freed. If a > filesystem crashes or shuts down before all in-core log buffers are > flushed to the log, however, not all transactions may have commit > records in the log. As expected, the modifications in such an > incomplete transaction are not replayed to the fs. The in-core data > structures for the partial transaction are never freed, however, > resulting in a memory leak. > > Update xlog_do_recovery_pass() to walk the hash table of transaction > lists as the last step before it goes out of scope and free any > transactions that may remain on the lists. This prevents a memory > leak of partial transactions in the log. > > Signed-off-by: Brian Foster Looks ok, I think. Reviewed-by: Darrick J. Wong Do the log intent items get freed properly too? I /think/ the answer is yes, but that yes could use another set of eyes. :) --D > --- > > FYI, I suspect this has been a problem for a while and and rare/harmless > enough that this can target 4.13. > > Brian > > fs/xfs/xfs_log_recover.c | 14 ++++++++++++++ > 1 file changed, 14 insertions(+) > > diff --git a/fs/xfs/xfs_log_recover.c b/fs/xfs/xfs_log_recover.c > index 4a98762..37b34c5 100644 > --- a/fs/xfs/xfs_log_recover.c > +++ b/fs/xfs/xfs_log_recover.c > @@ -5224,6 +5224,7 @@ xlog_do_recovery_pass( > int error2 = 0; > int bblks, split_bblks; > int hblks, split_hblks, wrapped_hblks; > + int i; > struct hlist_head rhash[XLOG_RHASH_SIZE]; > LIST_HEAD (buffer_list); > > @@ -5466,6 +5467,19 @@ xlog_do_recovery_pass( > if (error && first_bad) > *first_bad = rhead_blk; > > + /* > + * Transactions are freed at commit time but transactions without commit > + * records on disk are never committed. Free any that may be left in the > + * hash table. > + */ > + for (i = 0; i < XLOG_RHASH_SIZE; i++) { > + struct hlist_node *tmp; > + struct xlog_recover *trans; > + > + hlist_for_each_entry_safe(trans, tmp, &rhash[i], r_list) > + xlog_recover_free_trans(trans); > + } > + > return error ? error : error2; > } > > -- > 2.7.5 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-xfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html