From: Brian Foster <bfoster@redhat.com>
To: "Darrick J. Wong" <darrick.wong@oracle.com>
Cc: xfs <linux-xfs@vger.kernel.org>,
Matthew Wilcox <willy@infradead.org>,
linux-fsdevel@vger.kernel.org, fstests@vger.kernel.org,
Jeff Layton <jlayton@kernel.org>
Subject: Re: [PATCH v3] fs: clear writeback errors in inode_init_always
Date: Tue, 22 May 2018 14:40:09 -0400 [thread overview]
Message-ID: <20180522184009.GC25403@bfoster.bfoster> (raw)
In-Reply-To: <20180522164359.GB12940@magnolia>
On Tue, May 22, 2018 at 09:43:59AM -0700, Darrick J. Wong wrote:
> From: Darrick J. Wong <darrick.wong@oracle.com>
>
> In inode_init_always(), we clear the inode mapping flags, which clears
> any retained error (AS_EIO, AS_ENOSPC) bits. Unfortunately, we do not
> also clear wb_err, which means that old mapping errors can leak through
> to new inodes.
>
> This is crucial for the XFS inode allocation path because we recycle old
> in-core inodes and we do not want error state from an old file to leak
> into the new file. This bug was discovered by running generic/036 and
> generic/047 in a loop and noticing that the EIOs generated by the
> collision of direct and buffered writes in generic/036 would survive the
> remount between 036 and 047, and get reported to the fsyncs (on
> different files!) in generic/047.
>
> Since we're changing the semantics of inode_init_always, we must also
> change xfs_reinit_inode to retain the writeback error state when we go
> to recover an inode that has been torn down in the vfs but not yet
> disposed of by XFS.
>
> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
> Reviewed-by: Jeff Layton <jlayton@kernel.org>
> ---
> v3: clear error state when allocating new inode
> v2: retain AS_EIO/AS_ENOSPC across xfs inode reinit
> ---
> fs/inode.c | 1 +
> fs/xfs/xfs_icache.c | 9 +++++++++
> fs/xfs/xfs_inode.c | 5 +++++
> 3 files changed, 15 insertions(+)
>
> diff --git a/fs/inode.c b/fs/inode.c
> index 13ceb98c3bd3..3b55391072f3 100644
> --- a/fs/inode.c
> +++ b/fs/inode.c
> @@ -178,6 +178,7 @@ int inode_init_always(struct super_block *sb, struct inode *inode)
> mapping->a_ops = &empty_aops;
> mapping->host = inode;
> mapping->flags = 0;
> + mapping->wb_err = 0;
> atomic_set(&mapping->i_mmap_writable, 0);
> mapping_set_gfp_mask(mapping, GFP_HIGHUSER_MOVABLE);
> mapping->private_data = NULL;
> diff --git a/fs/xfs/xfs_icache.c b/fs/xfs/xfs_icache.c
> index 164350d91efc..d01f9544ff01 100644
> --- a/fs/xfs/xfs_icache.c
> +++ b/fs/xfs/xfs_icache.c
> @@ -298,6 +298,10 @@ xfs_reinit_inode(
> uint64_t version = inode_peek_iversion(inode);
> umode_t mode = inode->i_mode;
> dev_t dev = inode->i_rdev;
> + errseq_t old_err = inode->i_mapping->wb_err;
> + bool as_eio = test_bit(AS_EIO, &inode->i_mapping->flags);
> + bool as_enospc = test_bit(AS_ENOSPC,
> + &inode->i_mapping->flags);
>
> error = inode_init_always(mp->m_super, inode);
>
> @@ -306,6 +310,11 @@ xfs_reinit_inode(
> inode_set_iversion_queried(inode, version);
> inode->i_mode = mode;
> inode->i_rdev = dev;
> + inode->i_mapping->wb_err = old_err;
> + if (as_eio)
> + set_bit(AS_EIO, &inode->i_mapping->flags);
> + if (as_enospc)
> + set_bit(AS_ENOSPC, &inode->i_mapping->flags);
> return error;
> }
>
> diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
> index 02eae5059231..6c47ea3e577b 100644
> --- a/fs/xfs/xfs_inode.c
> +++ b/fs/xfs/xfs_inode.c
> @@ -835,6 +835,11 @@ xfs_ialloc(
> inode->i_mode |= S_ISGID;
> }
>
> + /* Reset all vfs error state. */
I'd prefer a comment that reminds why we have to do this. E.g.,
something like:
/*
* In-core inode reinit carries over vfs error state. Reset it
* so we don't leak error state from a previous generation of
* the inode.
*/
... but feel free to reword that.
> + inode->i_mapping->wb_err = 0;
> + clear_bit(AS_EIO, &inode->i_mapping->flags);
> + clear_bit(AS_ENOSPC, &inode->i_mapping->flags);
> +
I also wonder whether it might be cleaner to just reset this stuff in
xfs_ifree() where we kill the i_mode and bump the gen and whatnot, but
afaict this should work too. With the comment fix, at least:
Reviewed-by: Brian Foster <bfoster@redhat.com>
> /*
> * If the group ID of the new file does not match the effective group
> * ID or one of the supplementary group IDs, the S_ISGID bit is cleared
> --
> 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
next prev parent reply other threads:[~2018-05-22 18:40 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-05-18 22:50 commit b4678df184b causing xfstests regressions Theodore Y. Ts'o
2018-05-19 2:17 ` Matthew Wilcox
2018-05-19 13:09 ` Jeff Layton
2018-05-19 15:25 ` Darrick J. Wong
2018-05-19 15:27 ` [PATCH] fs: clear writeback errors in inode_init_always Darrick J. Wong
2018-05-19 15:36 ` Matthew Wilcox
2018-05-21 17:54 ` Darrick J. Wong
2018-05-22 10:30 ` Jeff Layton
2018-05-22 22:09 ` Dave Chinner
2018-05-23 10:56 ` Jeff Layton
2018-05-24 3:59 ` Dave Chinner
2018-05-19 23:19 ` Theodore Y. Ts'o
2018-05-20 11:45 ` Jeff Layton
2018-05-20 12:58 ` Matthew Wilcox
2018-05-20 13:18 ` Jeff Layton
2018-05-20 16:29 ` Theodore Y. Ts'o
2018-05-20 19:20 ` Matthew Wilcox
2018-05-20 19:41 ` Theodore Y. Ts'o
2018-05-21 11:20 ` Jeff Layton
2018-05-21 14:43 ` Theodore Y. Ts'o
2018-05-20 17:57 ` Theodore Y. Ts'o
2018-05-22 4:06 ` [PATCH v2] " Darrick J. Wong
2018-05-22 10:14 ` Jeff Layton
2018-05-22 12:14 ` Brian Foster
2018-05-22 14:37 ` Darrick J. Wong
2018-05-22 16:43 ` [PATCH v3] " Darrick J. Wong
2018-05-22 18:40 ` Brian Foster [this message]
2018-05-22 18:47 ` Darrick J. Wong
2018-05-22 22:05 ` Dave Chinner
2018-05-23 3:00 ` Darrick J. Wong
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