On Tue, 30 Nov 2010 10:54:31 +0300
Pavel Shilovsky <piastryyy@xxxxxxxxx> wrote:
> On strict cache mode if we don't have Exclusive oplock we write a data to
> the server through cifs_user_write. Then if we Level II oplock store it in
> the cache, otherwise - invalidate inode pages affected by this writing.
>
> Signed-off-by: Pavel Shilovsky <piastryyy@xxxxxxxxx>
> ---
> fs/cifs/cifsfs.c | 51 ++++++++++++++++++++++++++++++++++++++++++++++-----
> 1 files changed, 46 insertions(+), 5 deletions(-)
>
> diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c
> index 370acdc..df17261 100644
> --- a/fs/cifs/cifsfs.c
> +++ b/fs/cifs/cifsfs.c
> @@ -611,12 +611,53 @@ static ssize_t cifs_file_aio_read(struct kiocb *iocb, const struct iovec *iov,
> static ssize_t cifs_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
> unsigned long nr_segs, loff_t pos)
> {
> - struct inode *inode = iocb->ki_filp->f_path.dentry->d_inode;
> - ssize_t written;
> + struct inode *inode;
> + struct cifs_sb_info *cifs_sb;
> + ssize_t written = 0, retval;
> + unsigned long i;
> +
> + inode = iocb->ki_filp->f_path.dentry->d_inode;
> +
> + if (CIFS_I(inode)->clientCanCacheAll)
> + return generic_file_aio_write(iocb, iov, nr_segs, pos);
> +
> + cifs_sb = CIFS_SB(iocb->ki_filp->f_path.dentry->d_sb);
> +
> + if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_STRICT_IO) == 0) {
> + int rc;
> +
> + written = generic_file_aio_write(iocb, iov, nr_segs, pos);
> +
> + rc = filemap_fdatawrite(inode->i_mapping);
> + if (rc)
> + cFYI(1, "cifs_file_aio_write: %d rc on %p inode",
> + rc, inode);
> + return written;
> + }
> +
> + /*
> + * 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.
> + */
> +
> + for (i = 0; i < nr_segs; i++) {
> + retval = cifs_user_write(iocb->ki_filp, iov[i].iov_base,
> + iov[i].iov_len, &pos);
> + if (retval < 0) {
> + written = written ? written : retval;
> + break;
> + }
> +
> + written += retval;
> + }
> +
Same problem as with the read patch. This is going to mean a bunch of
small writes on the wire just because the application sent you a set of
small iovecs. I think you want to batch those up into smaller set of
writes.
> + iocb->ki_pos = pos;
> +
> + if (written > 0)
> + CIFS_I(inode)->invalid_mapping = true;
>
> - written = generic_file_aio_write(iocb, iov, nr_segs, pos);
> - if (!CIFS_I(inode)->clientCanCacheAll)
> - filemap_fdatawrite(inode->i_mapping);
> return written;
> }
>
--
Jeff Layton <jlayton@xxxxxxxxx>
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