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NFSv4.1: define nfs_generic_pg_test

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By default, unless pnfs is used coalesce pages until pg_bsize
(rsize or wsize) is reached.

pnfs layout drivers define their own pg_test methods that use
pnfs_generic_pg_test and need to define their own I/O size
limits (e.g. based on the file stripe size).

[Move a check from nfs_pageio_do_add_request to nfs_generic_pg_test]
Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
This commit is contained in:
Boaz Harrosh 2011-05-29 11:45:39 +03:00
parent 89a58e32d9
commit 5b36c7dc41
1 changed files with 20 additions and 24 deletions
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44
fs/nfs/pagelist.c
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@ -204,6 +204,21 @@ nfs_wait_on_request(struct nfs_page *req)
TASK_UNINTERRUPTIBLE);
}
static bool nfs_generic_pg_test(struct nfs_pageio_descriptor *desc, struct nfs_page *prev, struct nfs_page *req)
{
/*
* FIXME: ideally we should be able to coalesce all requests
* that are not block boundary aligned, but currently this
* is problematic for the case of bsize < PAGE_CACHE_SIZE,
* since nfs_flush_multi and nfs_pagein_multi assume you
* can have only one struct nfs_page.
*/
if (desc->pg_bsize < PAGE_SIZE)
return 0;
return desc->pg_count + req->wb_bytes <= desc->pg_bsize;
}
/**
* nfs_pageio_init - initialise a page io descriptor
* @desc: pointer to descriptor
@ -229,7 +244,7 @@ void nfs_pageio_init(struct nfs_pageio_descriptor *desc,
desc->pg_ioflags = io_flags;
desc->pg_error = 0;
desc->pg_lseg = NULL;
desc->pg_test = NULL;
desc->pg_test = nfs_generic_pg_test;
pnfs_pageio_init(desc, inode);
}
@ -260,13 +275,7 @@ static bool nfs_can_coalesce_requests(struct nfs_page *prev,
return false;
if (prev->wb_pgbase + prev->wb_bytes != PAGE_CACHE_SIZE)
return false;
/*
* 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 false;
return true;
return pgio->pg_test(pgio, prev, req);
}
/**
@ -280,31 +289,18 @@ static bool nfs_can_coalesce_requests(struct nfs_page *prev,
static int nfs_pageio_do_add_request(struct nfs_pageio_descriptor *desc,
struct nfs_page *req)
{
size_t newlen = req->wb_bytes;
if (desc->pg_count != 0) {
struct nfs_page *prev;
/*
* FIXME: ideally we should be able to coalesce all requests
* that are not block boundary aligned, but currently this
* is problematic for the case of bsize < PAGE_CACHE_SIZE,
* since nfs_flush_multi and nfs_pagein_multi assume you
* can have only one struct nfs_page.
*/
if (desc->pg_bsize < PAGE_SIZE)
return 0;
newlen += desc->pg_count;
if (newlen > desc->pg_bsize)
return 0;
prev = nfs_list_entry(desc->pg_list.prev);
if (!nfs_can_coalesce_requests(prev, req, desc))
return 0;
} else
} else {
desc->pg_base = req->wb_pgbase;
}
nfs_list_remove_request(req);
nfs_list_add_request(req, &desc->pg_list);
desc->pg_count = newlen;
desc->pg_count += req->wb_bytes;
return 1;
}