On Thu, Aug 9, 2012 at 2:57 AM, Myklebust, Trond <Trond.Myklebust@xxxxxxxxxx> wrote: > On Wed, 2012-08-08 at 10:03 +0800, Peng Tao wrote: >> From: Peng Tao <tao.peng@xxxxxxx> >> >> We don't have the real IO size information in buffer read, but for direct >> read, we can get it from dreq->bytes_left. Let's make use of it. > > What's wrong with using the nfs_readpages arguments? The readahead code > will tell you exactly how many pages it is trying to read. > The nr_pages information gets dropped before calling into pnfs code... How about something like bellow for buffer reads? (untested patch and needs to integrate with DIO size for sure). diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c index 2e00fea..cec79c2 100644 --- a/fs/nfs/pnfs.c +++ b/fs/nfs/pnfs.c @@ -1162,7 +1162,7 @@ pnfs_generic_pg_init_read(struct nfs_pageio_descriptor *pgio, struct nfs_page *r pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode, req->wb_context, req_offset(req), - req->wb_bytes, + (unsigned)pgio->pg_layout_private, IOMODE_READ, GFP_KERNEL); /* If no lseg, fall back to read through mds */ diff --git a/fs/nfs/read.c b/fs/nfs/read.c index b6bdb18..64fb0e2 100644 --- a/fs/nfs/read.c +++ b/fs/nfs/read.c @@ -649,6 +649,7 @@ int nfs_readpages(struct file *filp, struct address_space *mapping, NFS_PROTO(inode)->read_pageio_init(&pgio, inode, &nfs_async_read_completion_ops); + pgio.pg_layout_private = (void *)nr_pages; ret = read_cache_pages(mapping, pages, readpage_async_filler, &desc); nfs_pageio_complete(&pgio); -- Thanks, Tao -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
