6.10-stable review patch. If anyone has any objections, please let me know.
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From: David Howells dhowells@redhat.com
commit 61ea6b3a3104fcd66364282391dd2152bc4c129a upstream.
At the moment, at the end of a DIO write, cifs calls netfs_resize_file() to adjust the size of the file if it needs it. This will reduce the zero_point (the point above which we assume a read will just return zeros) if it's more than the new i_size, but won't increase it.
With DIO writes, however, we definitely want to increase it as we have clobbered the local pagecache and then written some data that's not available locally.
Fix cifs to make the zero_point above the end of a DIO or unbuffered write.
This fixes corruption seen occasionally with the generic/708 xfs-test. In that case, the read-back of some of the written data is being short-circuited and replaced with zeroes.
Fixes: 3ee1a1fc3981 ("cifs: Cut over to using netfslib") Cc: stable@vger.kernel.org Reported-by: Steve French sfrench@samba.org Signed-off-by: David Howells dhowells@redhat.com Reviewed-by: Paulo Alcantara (Red Hat) pc@manguebit.com cc: Jeff Layton jlayton@kernel.org cc: linux-cifs@vger.kernel.org cc: netfs@lists.linux.dev cc: linux-fsdevel@vger.kernel.org Signed-off-by: Steve French stfrench@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/smb/client/file.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-)
--- a/fs/smb/client/file.c +++ b/fs/smb/client/file.c @@ -2364,13 +2364,18 @@ void cifs_write_subrequest_terminated(st bool was_async) { struct netfs_io_request *wreq = wdata->rreq; - loff_t new_server_eof; + struct netfs_inode *ictx = netfs_inode(wreq->inode); + loff_t wrend;
if (result > 0) { - new_server_eof = wdata->subreq.start + wdata->subreq.transferred + result; + wrend = wdata->subreq.start + wdata->subreq.transferred + result;
- if (new_server_eof > netfs_inode(wreq->inode)->remote_i_size) - netfs_resize_file(netfs_inode(wreq->inode), new_server_eof, true); + if (wrend > ictx->zero_point && + (wdata->rreq->origin == NETFS_UNBUFFERED_WRITE || + wdata->rreq->origin == NETFS_DIO_WRITE)) + ictx->zero_point = wrend; + if (wrend > ictx->remote_i_size) + netfs_resize_file(ictx, wrend, true); }
netfs_write_subrequest_terminated(&wdata->subreq, result, was_async);