On Tue, Sep 21, 2010 at 3:00 PM, Benny Halevy <bhalevy@xxxxxxxxxxx> wrote:
> Base the LAYOUTGET arguments on the actual required byte ranges
> rather than asking for the whole file layout.
>
> Add a check in readpage_async_filler that the layout segment
> retrieved in pnfs_pageio_init_read still covers the current page
> and if not, try getting a new one.
>
> Signed-off-by: Benny Halevy <bhalevy@xxxxxxxxxxx>
> ---
> fs/nfs/file.c | 2 +-
> fs/nfs/pnfs.c | 13 ++++++-------
> fs/nfs/pnfs.h | 21 ++++++++-------------
> fs/nfs/read.c | 17 ++++++++++++++++-
> 4 files changed, 31 insertions(+), 22 deletions(-)
>
> diff --git a/fs/nfs/file.c b/fs/nfs/file.c
> index b05c1ff..228f41e 100644
> --- a/fs/nfs/file.c
> +++ b/fs/nfs/file.c
> @@ -390,7 +390,7 @@ static int nfs_write_begin(struct file *file, struct address_space *mapping,
>
> pnfs_update_layout(mapping->host,
> nfs_file_open_context(file),
> - 0, NFS4_MAX_UINT64, IOMODE_RW,
> + pos, len, IOMODE_RW,
> &lseg);
> start:
> /*
> diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
> index e6261a3..de716f6 100644
> --- a/fs/nfs/pnfs.c
> +++ b/fs/nfs/pnfs.c
> @@ -600,11 +600,10 @@ send_layoutget(struct inode *ino,
> pnfs_layout_release(lo, NULL);
> return -ENOMEM;
> }
> - lgp->args.minlength = NFS4_MAX_UINT64;
> + lgp->args.minlength = PAGE_CACHE_SIZE -
> + (range->offset & (PAGE_CACHE_SIZE-1));
> lgp->args.maxcount = PNFS_LAYOUT_MAXSIZE;
> - lgp->args.range.iomode = range->iomode;
> - lgp->args.range.offset = 0;
> - lgp->args.range.length = NFS4_MAX_UINT64;
> + lgp->args.range = *range;
> lgp->args.type = server->pnfs_curr_ld->id;
> lgp->args.inode = ino;
> lgp->lsegpp = lsegpp;
> @@ -1028,8 +1027,8 @@ _pnfs_update_layout(struct inode *ino,
> {
> struct pnfs_layout_range arg = {
> .iomode = iomode,
> - .offset = 0,
> - .length = NFS4_MAX_UINT64,
> + .offset = pos,
> + .length = count,
> };
> struct nfs_inode *nfsi = NFS_I(ino);
> struct pnfs_layout_hdr *lo;
> @@ -1330,7 +1329,7 @@ pnfs_pageio_init_read(struct nfs_pageio_descriptor *pgio,
> readahead_range(inode, pages, &loff, &count);
>
> if (count > 0) {
> - _pnfs_update_layout(inode, ctx, loff, count, IOMODE_READ,
> + pnfs_update_layout(inode, ctx, loff, count, IOMODE_READ,
Why this change? the pnfs_enabled_sb check has already been done at
the top of the function, hasn't it?
> &pgio->pg_lseg);
> if (!pgio->pg_lseg)
> return;
> diff --git a/fs/nfs/pnfs.h b/fs/nfs/pnfs.h
> index 81534aa..b666f53 100644
> --- a/fs/nfs/pnfs.h
> +++ b/fs/nfs/pnfs.h
> @@ -188,19 +188,14 @@ static inline int pnfs_return_layout(struct inode *ino,
> return 0;
> }
>
> -static inline void pnfs_update_layout(struct inode *ino,
> - struct nfs_open_context *ctx,
> - loff_t pos, u64 count, enum pnfs_iomode access_type,
> - struct pnfs_layout_segment **lsegpp)
> -{
> - struct nfs_server *nfss = NFS_SERVER(ino);
> -
> - if (pnfs_enabled_sb(nfss))
> - _pnfs_update_layout(ino, ctx, pos, count, access_type, lsegpp);
> - else {
> - if (lsegpp)
> - *lsegpp = NULL;
> - }
> +#define pnfs_update_layout(ino, ctx, pos, count, access_type, lsegpp) { \
> + if (pnfs_enabled_sb(NFS_SERVER(ino))) { \
> + dprintk("%s: updating %s layout pos %llu count %llu\n", __func__, \
> + (access_type) == IOMODE_READ ? "READ" : "WRITE", \
> + (unsigned long long)(pos), (unsigned long long)(count)); \
> + _pnfs_update_layout(ino, ctx, pos, count, access_type, lsegpp); \
> + } else \
> + *lsegpp = NULL; \
> }
Why this change? I much prefer the inline version to the define, and
I thought that this was generally being pushed.
>
> static inline int pnfs_get_write_status(struct nfs_write_data *data)
> diff --git a/fs/nfs/read.c b/fs/nfs/read.c
> index dde7996..36eef5e 100644
> --- a/fs/nfs/read.c
> +++ b/fs/nfs/read.c
> @@ -121,12 +121,14 @@ int nfs_readpage_async(struct nfs_open_context *ctx, struct inode *inode,
> LIST_HEAD(one_request);
> struct nfs_page *new;
> unsigned int len;
> + loff_t pgoffs;
> struct pnfs_layout_segment *lseg;
>
> len = nfs_page_length(page);
> if (len == 0)
> return nfs_return_empty_page(page);
> - pnfs_update_layout(inode, ctx, 0, NFS4_MAX_UINT64, IOMODE_READ, &lseg);
> + pgoffs = (loff_t)page->index << PAGE_CACHE_SHIFT;
> + pnfs_update_layout(inode, ctx, pgoffs, len, IOMODE_READ, &lseg);
> new = nfs_create_request(ctx, inode, page, 0, len, lseg);
> put_lseg(lseg);
> if (IS_ERR(new)) {
> @@ -603,14 +605,27 @@ readpage_async_filler(void *data, struct page *page)
> {
> struct nfs_readdesc *desc = (struct nfs_readdesc *)data;
> struct inode *inode = page->mapping->host;
> + struct pnfs_layout_range *range;
> struct nfs_page *new;
> unsigned int len;
> + loff_t pgoff;
> int error;
>
> len = nfs_page_length(page);
> if (len == 0)
> return nfs_return_empty_page(page);
>
> + pgoff = (loff_t)page->index << PAGE_CACHE_SHIFT;
> + range = desc->pgio->pg_lseg ? &desc->pgio->pg_lseg->range : NULL;
> + if (!range ||
> + (range->offset > pgoff + len) ||
> + (range->offset + range->length < pgoff)) {
> + put_lseg(desc->pgio->pg_lseg);
> + desc->pgio->pg_lseg = NULL;
> + pnfs_update_layout(inode, desc->ctx, pgoff, len, IOMODE_READ,
> + &desc->pgio->pg_lseg);
> + }
> +
> new = nfs_create_request(desc->ctx, inode, page, 0, len,
> desc->pgio->pg_lseg);
> if (IS_ERR(new))
> --
Wouldn't it be easier to just trim any returned layout to page
boundaries, and then pnfs_can_coalesce_requests will handle this
automatically.
Fred
> 1.7.2.3
>
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