> -----Original Message----- > From: Benny Halevy [mailto:bhalevy@xxxxxxxxxx] > Sent: Wednesday, July 13, 2011 9:41 AM > To: Myklebust, Trond > Cc: linux-nfs@xxxxxxxxxxxxxxx > Subject: Re: [PATCH 6/8] NFS: Move the pnfs read code into pnfs.c > > On 2011-07-12 22:29, Trond Myklebust wrote: > > ...and ensure that we recoalese to take into account differences in > > block sizes when falling back to read through the MDS. > > > > Signed-off-by: Trond Myklebust <Trond.Myklebust@xxxxxxxxxx> > > --- > > fs/nfs/internal.h | 4 +++ > > fs/nfs/nfs4filelayout.c | 2 +- > > fs/nfs/objlayout/objio_osd.c | 2 +- > > fs/nfs/pnfs.c | 57 > ++++++++++++++++++++++++++++++++++++++++- > > fs/nfs/pnfs.h | 10 +------ > > fs/nfs/read.c | 46 ++++++++++++++------------------ > - > > include/linux/nfs_page.h | 1 - > > 7 files changed, 82 insertions(+), 40 deletions(-) > > > > diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h > > index 31e8b50..795b3e0 100644 > > --- a/fs/nfs/internal.h > > +++ b/fs/nfs/internal.h > > @@ -295,10 +295,14 @@ extern int nfs4_get_rootfh(struct nfs_server > *server, struct nfs_fh *mntfh); > > extern int nfs_initiate_read(struct nfs_read_data *data, struct > rpc_clnt *clnt, > > const struct rpc_call_ops *call_ops); > > extern void nfs_read_prepare(struct rpc_task *task, void *calldata); > > +extern int nfs_generic_pagein(struct nfs_pageio_descriptor *desc, > > + struct list_head *head); > > > > struct nfs_pageio_descriptor; > > extern void nfs_pageio_init_read_mds(struct nfs_pageio_descriptor > *pgio, > > struct inode *inode); > > +extern void nfs_pageio_reset_read_mds(struct nfs_pageio_descriptor > *pgio); > > +extern void nfs_readdata_release(struct nfs_read_data *rdata); > > > > /* write.c */ > > extern void nfs_pageio_init_write_mds(struct nfs_pageio_descriptor > *pgio, > > diff --git a/fs/nfs/nfs4filelayout.c b/fs/nfs/nfs4filelayout.c > > index af9bf9e..fc556d6 100644 > > --- a/fs/nfs/nfs4filelayout.c > > +++ b/fs/nfs/nfs4filelayout.c > > @@ -735,7 +735,7 @@ filelayout_pg_init_write(struct > nfs_pageio_descriptor *pgio, > > static const struct nfs_pageio_ops filelayout_pg_read_ops = { > > .pg_init = filelayout_pg_init_read, > > .pg_test = filelayout_pg_test, > > - .pg_doio = nfs_generic_pg_readpages, > > + .pg_doio = pnfs_generic_pg_readpages, > > }; > > > > static const struct nfs_pageio_ops filelayout_pg_write_ops = { > > diff --git a/fs/nfs/objlayout/objio_osd.c > b/fs/nfs/objlayout/objio_osd.c > > index 70272d5..add6289 100644 > > --- a/fs/nfs/objlayout/objio_osd.c > > +++ b/fs/nfs/objlayout/objio_osd.c > > @@ -1007,7 +1007,7 @@ static bool objio_pg_test(struct > nfs_pageio_descriptor *pgio, > > static const struct nfs_pageio_ops objio_pg_read_ops = { > > .pg_init = pnfs_generic_pg_init_read, > > .pg_test = objio_pg_test, > > - .pg_doio = nfs_generic_pg_readpages, > > + .pg_doio = pnfs_generic_pg_readpages, > > }; > > > > static const struct nfs_pageio_ops objio_pg_write_ops = { > > diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c > > index 5b3cc3f..9eca5a8 100644 > > --- a/fs/nfs/pnfs.c > > +++ b/fs/nfs/pnfs.c > > @@ -28,6 +28,7 @@ > > */ > > > > #include <linux/nfs_fs.h> > > +#include <linux/nfs_page.h> > > #include "internal.h" > > #include "pnfs.h" > > #include "iostat.h" > > @@ -1216,18 +1217,32 @@ pnfs_ld_read_done(struct nfs_read_data *data) > > } > > EXPORT_SYMBOL_GPL(pnfs_ld_read_done); > > > > +static void > > +pnfs_read_through_mds(struct nfs_pageio_descriptor *desc, > > + struct nfs_read_data *data) > > +{ > > + list_splice_tail_init(&data->pages, &desc->pg_list); > > + if (data->req && list_empty(&data->req->wb_list)) > > + nfs_list_add_request(data->req, &desc->pg_list); > > + nfs_pageio_reset_read_mds(desc); > > + desc->pg_recoalesce = 1; > > + nfs_readdata_release(data); > > I'm confused... > Isn't this function supposed to call the nfs read path? > No. The reason for doing the above is to avoid recursing back into the read/write code when we're already deep down in the stack. Instead, we put the requests back on the pg_list, set the pg_recoalesce flag, and then allow nfs_do_recoalesce() (which runs much further back up the stack) to do it's job. Cheers Trond -- 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
