From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx1.manguebit.org (mx1.manguebit.org [143.255.12.172]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2AEDB374A16; Wed, 30 Sep 2026 03:28:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=143.255.12.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790738912; cv=none; b=rhSzd2GvkiFBKZ1aKPiT+azAGq2+H8XQqR6dBDlQJco8b1Gae44HOO6N8wPS/BHIyfFi7EF3fkh7/eCLoSDwrTRxZ2C9lofgJQ28b+/O1jMyJs5ckK1eawjK+hg+T1QsQ5uUx1a+JoaxMC3q1ci1Dj+Dtc+EVv52RMB8IhLY0BY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790738912; c=relaxed/simple; bh=YTNw+RvqTTQnAoK0W2mAgLyLtezDbLcDuAqFssp23dw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=HeuOWjLmhdwsrUxm0OAWSkQ1QbltO1/I+jgox4a1S34pLGgl4e14LVcSKFpbmRIoWARQ2IesI0gALULt1JO/eIy0BDbYlXdOhH4faT9TplLLUQNmJj+fhOZtKLbaDJmLp0k2g03qXMhCK1xx9lKG+OM/IGb1CfYr3lvzgObA6nA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=manguebit.org; spf=pass smtp.mailfrom=manguebit.org; dkim=pass (2048-bit key) header.d=manguebit.org header.i=@manguebit.org header.b=r0o0bwF+; arc=none smtp.client-ip=143.255.12.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=manguebit.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=manguebit.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=manguebit.org header.i=@manguebit.org header.b="r0o0bwF+" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=manguebit.org; s=dkim; h=Content-Transfer-Encoding:MIME-Version:References: In-Reply-To:Message-ID:Date:Subject:Cc:To:From:Sender:Content-Type:Reply-To: Content-ID:Content-Description; bh=z/o3u95/XvmcsscRb2ydgvBr+pPMDy66wtXzvXnXzOc=; b=r0o0bwF+xogCPeVfentUHr+q+v TcStXiIuFQAPIWwibmiUPcI15kgZPXPnJN8KIie1Bb9kHE5NY2pItXq2PpsZMB6Q6+VsXdeoAzIu+ mpioNADRH7bFqebYXLFvztpaU8vHh/+Xacqv4CmmPfZ1ssDJ4gG5emlBh+pubfdp9J1ZClBYQcVGX G50YRQ5XS5oVodwiqxg6IlxGb6hhK0s8KytIn2bTuNyiLJGP2chMEpaFIjV+d22WlJSCsOoQSdZoZ R6Fz5to77kD03fmdlExFyG/iwpDzMiJskO6eazKCZ4A87O9RGpMpiH/jg+N6gqlIhSTQdBQeh8iSx eZAfw34A==; Received: from pc by mx1.manguebit.org with local (Exim 4.99.5) id 1xBkza-00000002asZ-1ZGJ; Wed, 30 Sep 2026 00:28:26 -0300 From: Paulo Alcantara To: linux-cifs@vger.kernel.org, netfs@lists.linux.dev Cc: Christian Brauner , David Howells , Matthew Wilcox , Namjae Jeon , Ronnie Sahlberg , Shyam Prasad N , Tom Talpey , Bharath SM , stable@vger.kernel.org Subject: [PATCH v3 09/15] smb: client: drain and invalidate before server-side copy/clone Date: Wed, 30 Sep 2026 00:28:16 -0300 Message-ID: <20260930032822.1835287-10-pc@manguebit.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260930032822.1835287-1-pc@manguebit.org> References: <20260930032822.1835287-1-pc@manguebit.org> Precedence: bulk X-Mailing-List: linux-cifs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit cifs_file_copychunk_range() and the clone (FICLONE) path of cifs_remap_file_range() do not serialise the destination page cache against the server-side copy the way the other server-side range operations (smb3_zero_range(), smb3_punch_hole(), smb3_collapse_range() and smb3_insert_range()) do. cifs_file_copychunk_range() invalidates the destination range with filemap_invalidate_inode(), which takes and drops the mapping's invalidate_lock internally, so the lock is no longer held when the copychunk ioctl is issued. It also never drains in-flight netfs I/O on the target. The clone path never takes the invalidate_lock at all (only i_rwsem), uses a bare truncate_inode_pages_range() and likewise does not drain outstanding I/O. As a result an asynchronous destination writeback can complete after the server-side copy/clone has run and reinstate stale data over the region just written by the server, corrupting the file. This is the same class of corruption as commit d7d2adcd022b ("smb/client: flush dirty data before punching a hole") and has been seen randomly in generic/363 against Windows Server. Fix both paths to follow the established ordering: hold the target mapping's invalidate_lock across the flush and invalidation of the destination and the server ioctl, and call netfs_wait_for_outstanding_io() on the target to drain in-flight writes before the ioctl is issued. Only the target inode's invalidate_lock is required, as the source is merely flushed and not invalidated; i_rwsem (already held via lock_two_nondirectories()) is acquired before the invalidate_lock, matching the VFS lock ordering. Since filemap_invalidate_inode() takes that same lock internally, replace it with its own unmap/flush/invalidate steps instead of calling it, and return early on a zero-length copy to avoid a range underflow. Fixes: 8101d6e112e2 ("cifs: Fix copy offload to flush destination region") Fixes: c54fc3a4f375 ("cifs: Fix flushing, invalidation and file size with FICLONE") Signed-off-by: Paulo Alcantara Cc: Christian Brauner Cc: Matthew Wilcox Cc: Namjae Jeon Cc: Ronnie Sahlberg Cc: Shyam Prasad N Cc: Tom Talpey Cc: Bharath SM Cc: stable@vger.kernel.org --- fs/smb/client/cifsfs.c | 31 ++++++++++++++++++++++++++----- 1 file changed, 26 insertions(+), 5 deletions(-) diff --git a/fs/smb/client/cifsfs.c b/fs/smb/client/cifsfs.c index 6410249f529a..98b610b2a114 100644 --- a/fs/smb/client/cifsfs.c +++ b/fs/smb/client/cifsfs.c @@ -1412,6 +1412,7 @@ static loff_t cifs_remap_file_range(struct file *src_file, loff_t off, * server could even support copy of range where source = target */ lock_two_nondirectories(target_inode, src_inode); + filemap_invalidate_lock(target_inode->i_mapping); if (len == 0) { loff_t src_size = i_size_read(src_inode); @@ -1475,6 +1476,7 @@ static loff_t cifs_remap_file_range(struct file *src_file, loff_t off, cifs_dbg(FYI, "about to discard pages %llx-%llx\n", fstart, fend); truncate_inode_pages_range(&target_inode->i_data, min(fstart, i_size), fend); + netfs_wait_for_outstanding_io(target_inode); fscache_invalidate(cifs_inode_cookie(target_inode), NULL, i_size, 0); @@ -1513,6 +1515,7 @@ static loff_t cifs_remap_file_range(struct file *src_file, loff_t off, if (rc) CIFS_I(target_inode)->time = 0; unlock: + filemap_invalidate_unlock(target_inode->i_mapping); /* although unlocking in the reverse order from locking is not strictly necessary here it is a little cleaner to be consistent */ unlock_two_nondirectories(src_inode, target_inode); @@ -1536,6 +1539,9 @@ ssize_t cifs_file_copychunk_range(unsigned int xid, struct cifs_tcon *target_tcon; ssize_t rc; + if (len == 0) + return 0; + cifs_dbg(FYI, "copychunk range\n"); if (!src_file->private_data || !dst_file->private_data) { @@ -1565,6 +1571,7 @@ ssize_t cifs_file_copychunk_range(unsigned int xid, * server could even support copy of range where source = target */ lock_two_nondirectories(target_inode, src_inode); + filemap_invalidate_lock(target_inode->i_mapping); cifs_dbg(FYI, "about to flush pages\n"); @@ -1590,11 +1597,24 @@ ssize_t cifs_file_copychunk_range(unsigned int xid, * Start at the old EOF when extending so the folio straddling it, which * may hold data written past EOF through an mmap, is dropped too. */ - rc = filemap_invalidate_inode(target_inode, true, - min(destoff, i_size_read(target_inode)), - destoff + len - 1); - if (rc) - goto unlock; + if (target_inode->i_mapping->nrpages) { + loff_t fstart = min(destoff, i_size_read(target_inode)); + loff_t fend = destoff + len - 1; + + unmap_mapping_pages(target_inode->i_mapping, + fstart >> PAGE_SHIFT, + (fend >> PAGE_SHIFT) - + (fstart >> PAGE_SHIFT) + 1, + false); + rc = filemap_write_and_wait_range(target_inode->i_mapping, + fstart, fend); + if (rc) + goto unlock; + invalidate_inode_pages2_range(target_inode->i_mapping, + fstart >> PAGE_SHIFT, + fend >> PAGE_SHIFT); + } + netfs_wait_for_outstanding_io(target_inode); fscache_invalidate(cifs_inode_cookie(target_inode), NULL, i_size_read(target_inode), 0); @@ -1626,6 +1646,7 @@ ssize_t cifs_file_copychunk_range(unsigned int xid, CIFS_I(target_inode)->time = 0; unlock: + filemap_invalidate_unlock(target_inode->i_mapping); /* although unlocking in the reverse order from locking is not * strictly necessary here it is a little cleaner to be consistent */ -- 2.55.0