From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from userp1040.oracle.com ([156.151.31.81]:33869 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753976AbcLNTDw (ORCPT ); Wed, 14 Dec 2016 14:03:52 -0500 Date: Wed, 14 Dec 2016 11:03:09 -0800 From: Liu Bo To: linux-btrfs@vger.kernel.org Cc: David Sterba , fdmanana@gmail.com, wangxg.fnst@cn.fujitsu.com, Josef Bacik Subject: Re: [PATCH] Btrfs: fix btrfs_ordered_update_i_size to update disk_i_size properly Message-ID: <20161214190309.GA10388@localhost.localdomain> Reply-To: bo.li.liu@oracle.com References: <1480628770-18848-1-git-send-email-bo.li.liu@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <1480628770-18848-1-git-send-email-bo.li.liu@oracle.com> Sender: linux-btrfs-owner@vger.kernel.org List-ID: On Thu, Dec 01, 2016 at 01:46:10PM -0800, Liu Bo wrote: > btrfs_ordered_update_i_size can be called by truncate and endio, but only endio > takes ordered_extent which contains the completed IO. > > while truncating down a file, if there are some in-flight IOs, > btrfs_ordered_update_i_size in endio will set disk_i_size to @orig_offset that > is zero. If truncating-down fails somehow, we try to recover in memory isize > with this zero'd disk_i_size. > > Fix it by only updating disk_i_size with @orig_offset when > btrfs_ordered_update_i_size is not called from endio while truncating down and > waiting for in-flight IOs completing their work before recover in-memory size. > > Besides fixing the above issue, add an assertion for last_size to double check > we truncate down to the desired size. > > Signed-off-by: Liu Bo > --- > fs/btrfs/inode.c | 14 ++++++++++++++ > fs/btrfs/ordered-data.c | 9 +++++++-- > 2 files changed, 21 insertions(+), 2 deletions(-) > > diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c > index 09157dd..ef3594d 100644 > --- a/fs/btrfs/inode.c > +++ b/fs/btrfs/inode.c > @@ -4682,6 +4682,13 @@ int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans, > > btrfs_free_path(path); > > + if (err == 0) { > + /* only inline file may have last_size != new_size */ > + if (new_size >= root->sectorsize || > + new_size > root->fs_info->max_inline) > + ASSERT(last_size == new_size); > + } > + This ASSERT has been hit by fstests/generic/299, and it didn't show up the first time I tested, I'm trying to figure out whether we have problems in code or in this ASSERT. Thanks, -liubo > if (be_nice && bytes_deleted > SZ_32M) { > unsigned long updates = trans->delayed_ref_updates; > if (updates) { > @@ -5064,6 +5071,13 @@ static int btrfs_setsize(struct inode *inode, struct iattr *attr) > if (ret && inode->i_nlink) { > int err; > > + /* To get a stable disk_i_size */ > + err = btrfs_wait_ordered_range(inode, 0, (u64)-1); > + if (err) { > + btrfs_orphan_del(NULL, inode); > + return err; > + } > + > /* > * failed to truncate, disk_i_size is only adjusted down > * as we remove extents, so it should represent the true > diff --git a/fs/btrfs/ordered-data.c b/fs/btrfs/ordered-data.c > index b2d1e95..5eaa25a 100644 > --- a/fs/btrfs/ordered-data.c > +++ b/fs/btrfs/ordered-data.c > @@ -982,8 +982,13 @@ int btrfs_ordered_update_i_size(struct inode *inode, u64 offset, > } > disk_i_size = BTRFS_I(inode)->disk_i_size; > > - /* truncate file */ > - if (disk_i_size > i_size) { > + /* > + * truncate file. > + * If ordered is not NULL, then this is called from endio and > + * disk_i_size will be updated by either truncate itself or any > + * in-flight IOs which are inside the disk_i_size. > + */ > + if (!ordered && disk_i_size > i_size) { > BTRFS_I(inode)->disk_i_size = orig_offset; > ret = 0; > goto out; > -- > 2.5.5 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html