From 25078105fbe14e7b3270391eaa11514bec787a52 Mon Sep 17 00:00:00 2001 From: Pavel Shilovsky Date: Wed, 19 Sep 2012 06:22:45 -0700 Subject: [PATCH] CIFS: Fix cache coherency for read oplock case When we have a file opened with read oplock and we are writing a data to this file, we need to store the data in the cache and then send to the server to ensure that the next read operation will get a coherent data. Also mark it as CONFIG_CIFS_SMB2 because it's more suitable for SMB2 code but can fix some CIFS problems too (when server delays sending an oplock break after a write request). We can drop this ifdefs dependence in future. Signed-off-by: Pavel Shilovsky Signed-off-by: Steve French --- fs/cifs/file.c | 27 +++++++++++++++++++++++---- 1 file changed, 23 insertions(+), 4 deletions(-) diff --git a/fs/cifs/file.c b/fs/cifs/file.c index ccad858..e93e3d2 100644 --- a/fs/cifs/file.c +++ b/fs/cifs/file.c @@ -2461,11 +2461,30 @@ cifs_strict_writev(struct kiocb *iocb, const struct iovec *iov, iocb->ki_filp->private_data; struct cifs_tcon *tcon = tlink_tcon(cfile->tlink); +#ifdef CONFIG_CIFS_SMB2 /* - * In strict cache mode we need to write the data to the server exactly - * from the pos to pos+len-1 rather than flush all affected pages - * because it may cause a error with mandatory locks on these pages but - * not on the region from pos to ppos+len-1. + * If we have an oplock for read and want to write a data to the file + * we need to store it in the page cache and then push it to the server + * to be sure the next read will get a valid data. + */ + if (!cinode->clientCanCacheAll && cinode->clientCanCacheRead) { + ssize_t written; + int rc; + + written = generic_file_aio_write(iocb, iov, nr_segs, pos); + rc = filemap_fdatawrite(inode->i_mapping); + if (rc) + return (ssize_t)rc; + + return written; + } +#endif + + /* + * For non-oplocked files in strict cache mode we need to write the data + * to the server exactly from the pos to pos+len-1 rather than flush all + * affected pages because it may cause a error with mandatory locks on + * these pages but not on the region from pos to ppos+len-1. */ if (!cinode->clientCanCacheAll) -- 2.7.4