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Commit 94ad1c80 authored by Fred Isaman's avatar Fred Isaman Committed by Trond Myklebust
Browse files

NFSv4.1: coelesce across layout stripes 



Add a pg_test layout driver hook which is used to avoid coelescing I/O across
layout stripes.

Signed-off-by: default avatarAndy Adamson <andros@netapp.com>
Signed-off-by: default avatarAndy Adamson <andros@citi.umich.edu>
Signed-off-by: default avatarDean Hildebrand <dhildeb@us.ibm.com>
Signed-off-by: default avatarFred Isaman <iisaman@citi.umich.edu>
Signed-off-by: default avatarFred Isaman <iisaman@netapp.com>
Signed-off-by: default avatarBenny Halevy <bhalevy@panasas.com>
Signed-off-by: default avatarBoaz Harrosh <bharrosh@panasas.com>
Signed-off-by: default avatarOleg Drokin <green@linuxhacker.ru>
Signed-off-by: default avatarTao Guo <guotao@nrchpc.ac.cn>
Signed-off-by: default avatarTrond Myklebust <Trond.Myklebust@netapp.com>
parent d684d2ae

fs/nfs/nfs4filelayout.c

+26 −0
Original line number Diff line number Diff line
@@ -252,6 +252,31 @@ filelayout_free_lseg(struct pnfs_layout_segment *lseg) 
	_filelayout_free_lseg(fl);

}



/*

 * filelayout_pg_test(). Called by nfs_can_coalesce_requests()

 *

 * return 1 :  coalesce page

 * return 0 :  don't coalesce page

 */

int

filelayout_pg_test(struct nfs_pageio_descriptor *pgio, struct nfs_page *prev,

		   struct nfs_page *req)

{

	u64 p_stripe, r_stripe;

	u32 stripe_unit;



	if (!pgio->pg_lseg)

		return 1;

	p_stripe = (u64)prev->wb_index << PAGE_CACHE_SHIFT;

	r_stripe = (u64)req->wb_index << PAGE_CACHE_SHIFT;

	stripe_unit = FILELAYOUT_LSEG(pgio->pg_lseg)->stripe_unit;



	do_div(p_stripe, stripe_unit);

	do_div(r_stripe, stripe_unit);



	return (p_stripe == r_stripe);

}



static struct pnfs_layoutdriver_type filelayout_type = {

	.id = LAYOUT_NFSV4_1_FILES,

	.name = "LAYOUT_NFSV4_1_FILES",
@@ -260,6 +285,7 @@ static struct pnfs_layoutdriver_type filelayout_type = { 
	.clear_layoutdriver = filelayout_clear_layoutdriver,

	.alloc_lseg              = filelayout_alloc_lseg,

	.free_lseg               = filelayout_free_lseg,

	.pg_test		= filelayout_pg_test,

};



static int __init nfs4filelayout_init(void)

fs/nfs/pagelist.c

+10 −2
Original line number Diff line number Diff line
@@ -226,6 +226,7 @@ void nfs_pageio_init(struct nfs_pageio_descriptor *desc, 
	desc->pg_doio = doio;

	desc->pg_ioflags = io_flags;

	desc->pg_error = 0;

	desc->pg_lseg = NULL;

}



/**
@@ -240,7 +241,8 @@ void nfs_pageio_init(struct nfs_pageio_descriptor *desc, 
 * Return 'true' if this is the case, else return 'false'.

 */

static int nfs_can_coalesce_requests(struct nfs_page *prev,

				     struct nfs_page *req)

				     struct nfs_page *req,

				     struct nfs_pageio_descriptor *pgio)

{

	if (req->wb_context->cred != prev->wb_context->cred)

		return 0;
@@ -254,6 +256,12 @@ static int nfs_can_coalesce_requests(struct nfs_page *prev, 
		return 0;

	if (prev->wb_pgbase + prev->wb_bytes != PAGE_CACHE_SIZE)

		return 0;

	/*

	 * Non-whole file layouts need to check that req is inside of

	 * pgio->pg_lseg.

	 */

	if (pgio->pg_test && !pgio->pg_test(pgio, prev, req))

		return 0;

	return 1;

}
@@ -286,7 +294,7 @@ static int nfs_pageio_do_add_request(struct nfs_pageio_descriptor *desc, 
		if (newlen > desc->pg_bsize)

			return 0;

		prev = nfs_list_entry(desc->pg_list.prev);

		if (!nfs_can_coalesce_requests(prev, req))

		if (!nfs_can_coalesce_requests(prev, req, desc))

			return 0;

	} else

		desc->pg_base = req->wb_pgbase;

fs/nfs/pnfs.c

+16 −0
Original line number Diff line number Diff line
@@ -858,6 +858,22 @@ pnfs_layout_process(struct nfs4_layoutget *lgp) 
	goto out;

}



static void

pnfs_set_pg_test(struct inode *inode, struct nfs_pageio_descriptor *pgio)

{

	struct pnfs_layoutdriver_type *ld;



	ld = NFS_SERVER(inode)->pnfs_curr_ld;

	pgio->pg_test = (ld ? ld->pg_test : NULL);

}



void

pnfs_pageio_init_read(struct nfs_pageio_descriptor *pgio,

		  struct inode *inode)

{

	pnfs_set_pg_test(inode, pgio);

}



/*

 * Device ID cache. Currently supports one layout type per struct nfs_client.

 * Add layout type to the lookup key to expand to support multiple types.

fs/nfs/pnfs.h

+12 −0
Original line number Diff line number Diff line
@@ -30,6 +30,8 @@ 
#ifndef FS_NFS_PNFS_H

#define FS_NFS_PNFS_H



#include <linux/nfs_page.h>



enum {

	NFS_LSEG_VALID = 0,	/* cleared when lseg is recalled/returned */

	NFS_LSEG_ROC,		/* roc bit received from server */
@@ -65,6 +67,9 @@ struct pnfs_layoutdriver_type { 
	int (*clear_layoutdriver) (struct nfs_server *);

	struct pnfs_layout_segment * (*alloc_lseg) (struct pnfs_layout_hdr *layoutid, struct nfs4_layoutget_res *lgr);

	void (*free_lseg) (struct pnfs_layout_segment *lseg);



	/* test for nfs page cache coalescing */

	int (*pg_test)(struct nfs_pageio_descriptor *, struct nfs_page *, struct nfs_page *);

};



struct pnfs_layout_hdr {
@@ -151,6 +156,7 @@ pnfs_update_layout(struct inode *ino, struct nfs_open_context *ctx, 
		   enum pnfs_iomode access_type);

void set_pnfs_layoutdriver(struct nfs_server *, u32 id);

void unset_pnfs_layoutdriver(struct nfs_server *);

void pnfs_pageio_init_read(struct nfs_pageio_descriptor *, struct inode *);

int pnfs_layout_process(struct nfs4_layoutget *lgp);

void pnfs_free_lseg_list(struct list_head *tmp_list);

void pnfs_destroy_layout(struct nfs_inode *);
@@ -250,6 +256,12 @@ static inline void unset_pnfs_layoutdriver(struct nfs_server *s) 
{

}



static inline void

pnfs_pageio_init_read(struct nfs_pageio_descriptor *pgio, struct inode *ino)

{

	pgio->pg_test = NULL;

}



#endif /* CONFIG_NFS_V4_1 */



#endif /* FS_NFS_PNFS_H */

fs/nfs/read.c

+1 −0
Original line number Diff line number Diff line
@@ -626,6 +626,7 @@ int nfs_readpages(struct file *filp, struct address_space *mapping, 
		goto read_complete; /* all pages were read */



	pnfs_update_layout(inode, desc.ctx, IOMODE_READ);

	pnfs_pageio_init_read(&pgio, inode);

	if (rsize < PAGE_CACHE_SIZE)

		nfs_pageio_init(&pgio, inode, nfs_pagein_multi, rsize, 0);

	else