From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 BD2E84E80CD; Fri, 9 Oct 2026 14:50:58 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791557459; cv=none; b=TSQhkYmJrLnGKck3pmqqOI69kb/QKngaVKnaGGI7ZbAofcVLHolg7ZNCqZfQ0tGqzN/GltbDNhLnCcjcBmzQwlq3OOTxiiTynLzDIeL6muzMtqmnHH5DVicyKB1LXVUbzOm1bmD5Mkynj24RzY4O4dAZFqxmjqBhaKpBRfXQy4g= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791557459; c=relaxed/simple; bh=ZbV2+Xp1fuabZWuqXrDB/owN+CcToY2zrOBxd9uslAs=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=dPKZsL75kQNF4EGHsG+pBWZZvYlArCjk1O7V+l9BIR01NqXEfIos76WSZucEtrH4XJwdq59y78XJ4PPapemgAW6OdrEwV8cyqjFqvTu6pF1/1yo0DLoJ0sCO2wcgE4eIrKIojkz7gRinTamQMJCxLD9dR71S74w6WHZi5HAFv40= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=Q7+2SElm; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="Q7+2SElm" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2F7731F000FF; Fri, 9 Oct 2026 14:50:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1791557458; bh=2VzrfWwPyf43O+6179HMh47zIR47u3qVK8dPgPj1WWk=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=Q7+2SElm1DdeQ6h7DpPai8XgIyTxj6w0ZZoQ3GIHTTDabLoi/owTAF0J9l+L8vg9S EGeDT6be9aba8T2nHRNoI/Qq5yZybMNi01sDDmWbREQAqpQ3g7Vw+IkEryt9Ikg9ag /4WTsPppmGiAvBuiDPEgRT+ac33t/zavhTsOmZ+8= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, David Howells , Namjae Jeon , Paulo Alcantara , Christian Brauner , Matthew Wilcox , Ronnie Sahlberg , Shyam Prasad N , Tom Talpey , Bharath SM Subject: [PATCH 7.2 367/428] smb: client: drain and invalidate before server-side copy/clone Date: Fri, 9 Oct 2026 16:11:44 +0200 Message-ID: <20261009140954.240985036@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261009140946.008206689@linuxfoundation.org> References: <20261009140946.008206689@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 7.2-stable review patch. If anyone has any objections, please let me know. ------------------ From: Paulo Alcantara commit c9b1194e8ec99d95db25db45edd2fbf690f043ab upstream. 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") Reviewed-by: David Howells Reviewed-by: Namjae Jeon Signed-off-by: Paulo Alcantara Cc: Christian Brauner Cc: Matthew Wilcox Cc: Ronnie Sahlberg Cc: Shyam Prasad N Cc: Tom Talpey Cc: Bharath SM Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman --- fs/smb/client/cifsfs.c | 31 ++++++++++++++++++++++++++----- 1 file changed, 26 insertions(+), 5 deletions(-) --- a/fs/smb/client/cifsfs.c +++ b/fs/smb/client/cifsfs.c @@ -1412,6 +1412,7 @@ static loff_t cifs_remap_file_range(stru * 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(stru 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); @@ -1517,6 +1519,7 @@ static loff_t cifs_remap_file_range(stru 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); @@ -1540,6 +1543,9 @@ ssize_t cifs_file_copychunk_range(unsign 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) { @@ -1569,6 +1575,7 @@ ssize_t cifs_file_copychunk_range(unsign * 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"); @@ -1594,11 +1601,24 @@ ssize_t cifs_file_copychunk_range(unsign * 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); @@ -1630,6 +1650,7 @@ ssize_t cifs_file_copychunk_range(unsign 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 */