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From: Jan Kara <jack@suse.cz>
To: <linux-fsdevel@vger.kernel.org>
Cc: <linux-ext4@vger.kernel.org>,
	Christoph Hellwig <hch@infradead.org>,
	"Darrick J. Wong" <djwong@kernel.org>, Ted Tso <tytso@mit.edu>,
	Dave Chinner <david@fromorbit.com>,
	Matthew Wilcox <willy@infradead.org>, <linux-mm@kvack.org>,
	<linux-xfs@vger.kernel.org>,
	linux-f2fs-devel@lists.sourceforge.net,
	linux-cifs@vger.kernel.org, ceph-devel@vger.kernel.org,
	Jan Kara <jack@suse.cz>, Steve French <sfrench@samba.org>
Subject: [PATCH 14/14] cifs: Fix race between hole punch and page fault
Date: Thu, 15 Jul 2021 15:40:24 +0200	[thread overview]
Message-ID: <20210715134032.24868-14-jack@suse.cz> (raw)
In-Reply-To: <20210715133202.5975-1-jack@suse.cz>

Cifs has a following race between hole punching and page fault:

CPU1                                            CPU2
smb3_fallocate()
  smb3_punch_hole()
    truncate_pagecache_range()
                                                filemap_fault()
                                                  - loads old data into the
                                                    page cache
    SMB2_ioctl(..., FSCTL_SET_ZERO_DATA, ...)

And now we have stale data in the page cache. Fix the problem by locking
out faults (as well as reads) using mapping->invalidate_lock while hole
punch is running.

CC: Steve French <sfrench@samba.org>
CC: linux-cifs@vger.kernel.org
Signed-off-by: Jan Kara <jack@suse.cz>
---
 fs/cifs/smb2ops.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
index e4c8f603dd58..458c546ce8cd 100644
--- a/fs/cifs/smb2ops.c
+++ b/fs/cifs/smb2ops.c
@@ -3588,6 +3588,7 @@ static long smb3_punch_hole(struct file *file, struct cifs_tcon *tcon,
 		return rc;
 	}
 
+	filemap_invalidate_lock(inode->i_mapping);
 	/*
 	 * We implement the punch hole through ioctl, so we need remove the page
 	 * caches first, otherwise the data may be inconsistent with the server.
@@ -3605,6 +3606,7 @@ static long smb3_punch_hole(struct file *file, struct cifs_tcon *tcon,
 			sizeof(struct file_zero_data_information),
 			CIFSMaxBufSize, NULL, NULL);
 	free_xid(xid);
+	filemap_invalidate_unlock(inode->i_mapping);
 	return rc;
 }
 
-- 
2.26.2


  parent reply	other threads:[~2021-07-15 13:40 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-07-15 13:40 [PATCH 0/14 v10] fs: Hole punch vs page cache filling races Jan Kara
2021-07-15 13:40 ` [PATCH 01/14] mm: Fix comments mentioning i_mutex Jan Kara
2021-07-15 13:40 ` [PATCH 02/14] documentation: Sync file_operations members with reality Jan Kara
2021-07-15 13:40 ` [PATCH 03/14] mm: Protect operations adding pages to page cache with invalidate_lock Jan Kara
2021-07-15 13:40 ` [PATCH 04/14] mm: Add functions to lock invalidate_lock for two mappings Jan Kara
2021-07-15 13:40 ` [PATCH 05/14] ext4: Convert to use mapping->invalidate_lock Jan Kara
2021-07-15 13:40 ` [PATCH 06/14] ext2: Convert to using invalidate_lock Jan Kara
2021-07-15 13:40 ` [PATCH 07/14] xfs: Refactor xfs_isilocked() Jan Kara
2021-07-15 13:40 ` [PATCH 08/14] xfs: Convert to use invalidate_lock Jan Kara
2021-07-15 13:40 ` [PATCH 09/14] xfs: Convert double locking of MMAPLOCK to use VFS helpers Jan Kara
2021-07-15 13:40 ` [PATCH 10/14] zonefs: Convert to using invalidate_lock Jan Kara
2021-07-15 13:40 ` [PATCH 11/14] f2fs: " Jan Kara
2021-07-15 13:40 ` [PATCH 12/14] fuse: " Jan Kara
2021-07-15 13:40 ` [PATCH 13/14] ceph: Fix race between hole punch and page fault Jan Kara
2021-07-15 13:40 ` Jan Kara [this message]
2021-07-16  6:02 ` [PATCH 0/14 v10] fs: Hole punch vs page cache filling races Christoph Hellwig
2021-07-16 16:43   ` Darrick J. Wong
2021-07-16 16:57     ` Jan Kara
  -- strict thread matches above, loose matches on Subject: below --
2021-07-12 16:55 [PATCH 0/14 v9] " Jan Kara
2021-07-12 16:56 ` [PATCH 14/14] cifs: Fix race between hole punch and page fault Jan Kara
2021-06-15  9:17 [PATCH 0/14 v8] fs: Hole punch vs page cache filling races Jan Kara
2021-06-15  9:18 ` [PATCH 14/14] cifs: Fix race between hole punch and page fault Jan Kara
2021-06-07 14:52 [PATCH 0/14 v7] fs: Hole punch vs page cache filling races Jan Kara
2021-06-07 14:52 ` [PATCH 14/14] cifs: Fix race between hole punch and page fault Jan Kara

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