nfs: modify pg_test interface to return size_t

This is a step toward allowing pg_test to inform the the
coalescing code to reduce the size of requests so they may fit in
whatever scheme the pg_test callback wants to define.

For now, just return the size of the request if there is space, or 0
if there is not.  This shouldn't change any behavior as it acts
the same as when the pg_test functions returned bool.

Signed-off-by: Weston Andros Adamson <dros@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
This commit is contained in:
Weston Andros Adamson 2014-05-15 11:56:43 -04:00 committed by Trond Myklebust
parent 8c8f1ac109
commit b4fdac1a51
7 changed files with 62 additions and 23 deletions

View File

@ -1189,13 +1189,17 @@ bl_pg_init_read(struct nfs_pageio_descriptor *pgio, struct nfs_page *req)
pnfs_generic_pg_init_read(pgio, req);
}
static bool
/*
* Return 0 if @req cannot be coalesced into @pgio, otherwise return the number
* of bytes (maximum @req->wb_bytes) that can be coalesced.
*/
static size_t
bl_pg_test_read(struct nfs_pageio_descriptor *pgio, struct nfs_page *prev,
struct nfs_page *req)
{
if (pgio->pg_dreq != NULL &&
!is_aligned_req(req, SECTOR_SIZE))
return false;
return 0;
return pnfs_generic_pg_test(pgio, prev, req);
}
@ -1241,13 +1245,17 @@ bl_pg_init_write(struct nfs_pageio_descriptor *pgio, struct nfs_page *req)
}
}
static bool
/*
* Return 0 if @req cannot be coalesced into @pgio, otherwise return the number
* of bytes (maximum @req->wb_bytes) that can be coalesced.
*/
static size_t
bl_pg_test_write(struct nfs_pageio_descriptor *pgio, struct nfs_page *prev,
struct nfs_page *req)
{
if (pgio->pg_dreq != NULL &&
!is_aligned_req(req, PAGE_CACHE_SIZE))
return false;
return 0;
return pnfs_generic_pg_test(pgio, prev, req);
}

View File

@ -915,10 +915,10 @@ filelayout_alloc_lseg(struct pnfs_layout_hdr *layoutid,
/*
* filelayout_pg_test(). Called by nfs_can_coalesce_requests()
*
* return true : coalesce page
* return false : don't coalesce page
* Return 0 if @req cannot be coalesced into @pgio, otherwise return the number
* of bytes (maximum @req->wb_bytes) that can be coalesced.
*/
static bool
static size_t
filelayout_pg_test(struct nfs_pageio_descriptor *pgio, struct nfs_page *prev,
struct nfs_page *req)
{
@ -927,7 +927,7 @@ filelayout_pg_test(struct nfs_pageio_descriptor *pgio, struct nfs_page *prev,
if (!pnfs_generic_pg_test(pgio, prev, req) ||
!nfs_generic_pg_test(pgio, prev, req))
return false;
return 0;
p_stripe = (u64)req_offset(prev);
r_stripe = (u64)req_offset(req);
@ -936,7 +936,9 @@ filelayout_pg_test(struct nfs_pageio_descriptor *pgio, struct nfs_page *prev,
do_div(p_stripe, stripe_unit);
do_div(r_stripe, stripe_unit);
return (p_stripe == r_stripe);
if (p_stripe == r_stripe)
return req->wb_bytes;
return 0;
}
static void

View File

@ -564,14 +564,19 @@ int objio_write_pagelist(struct nfs_pgio_data *wdata, int how)
return 0;
}
static bool objio_pg_test(struct nfs_pageio_descriptor *pgio,
/*
* Return 0 if @req cannot be coalesced into @pgio, otherwise return the number
* of bytes (maximum @req->wb_bytes) that can be coalesced.
*/
static size_t objio_pg_test(struct nfs_pageio_descriptor *pgio,
struct nfs_page *prev, struct nfs_page *req)
{
if (!pnfs_generic_pg_test(pgio, prev, req))
return false;
if (!pnfs_generic_pg_test(pgio, prev, req) ||
pgio->pg_count + req->wb_bytes >
(unsigned long)pgio->pg_layout_private)
return 0;
return pgio->pg_count + req->wb_bytes <=
(unsigned long)pgio->pg_layout_private;
return req->wb_bytes;
}
static void objio_init_read(struct nfs_pageio_descriptor *pgio, struct nfs_page *req)

View File

@ -280,7 +280,17 @@ nfs_wait_on_request(struct nfs_page *req)
TASK_UNINTERRUPTIBLE);
}
bool nfs_generic_pg_test(struct nfs_pageio_descriptor *desc, struct nfs_page *prev, struct nfs_page *req)
/*
* nfs_generic_pg_test - determine if requests can be coalesced
* @desc: pointer to descriptor
* @prev: previous request in desc, or NULL
* @req: this request
*
* Returns zero if @req can be coalesced into @desc, otherwise it returns
* the size of the request.
*/
size_t 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
@ -292,7 +302,9 @@ bool nfs_generic_pg_test(struct nfs_pageio_descriptor *desc, struct nfs_page *pr
if (desc->pg_bsize < PAGE_SIZE)
return 0;
return desc->pg_count + req->wb_bytes <= desc->pg_bsize;
if (desc->pg_count + req->wb_bytes <= desc->pg_bsize)
return req->wb_bytes;
return 0;
}
EXPORT_SYMBOL_GPL(nfs_generic_pg_test);
@ -747,6 +759,8 @@ static bool nfs_can_coalesce_requests(struct nfs_page *prev,
struct nfs_page *req,
struct nfs_pageio_descriptor *pgio)
{
size_t size;
if (!nfs_match_open_context(req->wb_context, prev->wb_context))
return false;
if (req->wb_context->dentry->d_inode->i_flock != NULL &&
@ -758,7 +772,9 @@ static bool nfs_can_coalesce_requests(struct nfs_page *prev,
return false;
if (req_offset(req) != req_offset(prev) + prev->wb_bytes)
return false;
return pgio->pg_ops->pg_test(pgio, prev, req);
size = pgio->pg_ops->pg_test(pgio, prev, req);
WARN_ON_ONCE(size && size != req->wb_bytes);
return size > 0;
}
/**

View File

@ -1434,7 +1434,11 @@ pnfs_generic_pg_init_write(struct nfs_pageio_descriptor *pgio,
}
EXPORT_SYMBOL_GPL(pnfs_generic_pg_init_write);
bool
/*
* Return 0 if @req cannot be coalesced into @pgio, otherwise return the number
* of bytes (maximum @req->wb_bytes) that can be coalesced.
*/
size_t
pnfs_generic_pg_test(struct nfs_pageio_descriptor *pgio, struct nfs_page *prev,
struct nfs_page *req)
{
@ -1455,8 +1459,10 @@ pnfs_generic_pg_test(struct nfs_pageio_descriptor *pgio, struct nfs_page *prev,
* first byte that lies outside the pnfs_layout_range. FIXME?
*
*/
return req_offset(req) < end_offset(pgio->pg_lseg->pls_range.offset,
pgio->pg_lseg->pls_range.length);
if (req_offset(req) < end_offset(pgio->pg_lseg->pls_range.offset,
pgio->pg_lseg->pls_range.length))
return req->wb_bytes;
return 0;
}
EXPORT_SYMBOL_GPL(pnfs_generic_pg_test);

View File

@ -187,7 +187,8 @@ int pnfs_generic_pg_readpages(struct nfs_pageio_descriptor *desc);
void pnfs_generic_pg_init_write(struct nfs_pageio_descriptor *pgio,
struct nfs_page *req, u64 wb_size);
int pnfs_generic_pg_writepages(struct nfs_pageio_descriptor *desc);
bool pnfs_generic_pg_test(struct nfs_pageio_descriptor *pgio, struct nfs_page *prev, struct nfs_page *req);
size_t pnfs_generic_pg_test(struct nfs_pageio_descriptor *pgio,
struct nfs_page *prev, struct nfs_page *req);
void pnfs_set_lo_fail(struct pnfs_layout_segment *lseg);
struct pnfs_layout_segment *pnfs_layout_process(struct nfs4_layoutget *lgp);
void pnfs_free_lseg_list(struct list_head *tmp_list);

View File

@ -46,7 +46,8 @@ struct nfs_page {
struct nfs_pageio_descriptor;
struct nfs_pageio_ops {
void (*pg_init)(struct nfs_pageio_descriptor *, struct nfs_page *);
bool (*pg_test)(struct nfs_pageio_descriptor *, struct nfs_page *, struct nfs_page *);
size_t (*pg_test)(struct nfs_pageio_descriptor *, struct nfs_page *,
struct nfs_page *);
int (*pg_doio)(struct nfs_pageio_descriptor *);
};
@ -102,7 +103,7 @@ extern int nfs_pageio_add_request(struct nfs_pageio_descriptor *,
struct nfs_page *);
extern void nfs_pageio_complete(struct nfs_pageio_descriptor *desc);
extern void nfs_pageio_cond_complete(struct nfs_pageio_descriptor *, pgoff_t);
extern bool nfs_generic_pg_test(struct nfs_pageio_descriptor *desc,
extern size_t nfs_generic_pg_test(struct nfs_pageio_descriptor *desc,
struct nfs_page *prev,
struct nfs_page *req);
extern int nfs_wait_on_request(struct nfs_page *);