On Mon, May 9, 2011 at 1:06 PM, Benny Halevy <bhalevy@xxxxxxxxxxx> wrote:
> Add offset and count parameters to pnfs_update_layout and use them to get
> the layout in the pageio path.
>
> Test byte range against the layout segment in use in pnfs_{read,write}_pg_test
> so not to coalesce pages not using the same layout segment.
>
> Signed-off-by: Benny Halevy <bhalevy@xxxxxxxxxxx>
> ---
> fs/nfs/pnfs.c | 149 +++++++++++++++++++++++++++++++++++++++++++++-----------
> fs/nfs/pnfs.h | 4 +-
> fs/nfs/read.c | 10 +++-
> fs/nfs/write.c | 8 ++-
> 4 files changed, 136 insertions(+), 35 deletions(-)
>
> diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
> index d9ab972..e689bdf 100644
> --- a/fs/nfs/pnfs.c
> +++ b/fs/nfs/pnfs.c
> @@ -261,6 +261,65 @@ put_lseg(struct pnfs_layout_segment *lseg)
> }
> EXPORT_SYMBOL_GPL(put_lseg);
>
> +static inline u64
> +end_offset(u64 start, u64 len)
> +{
> + u64 end;
> +
> + end = start + len;
> + return end >= start ? end : NFS4_MAX_UINT64;
> +}
> +
> +/* last octet in a range */
> +static inline u64
> +last_byte_offset(u64 start, u64 len)
> +{
> + u64 end;
> +
> + BUG_ON(!len);
> + end = start + len;
> + return end > start ? end - 1 : NFS4_MAX_UINT64;
> +}
> +
> +/*
> + * is l2 fully contained in l1?
> + * start1 end1
> + * [----------------------------------)
> + * start2 end2
> + * [----------------)
> + */
> +static inline int
> +lo_seg_contained(struct pnfs_layout_range *l1,
> + struct pnfs_layout_range *l2)
> +{
> + u64 start1 = l1->offset;
> + u64 end1 = end_offset(start1, l1->length);
> + u64 start2 = l2->offset;
> + u64 end2 = end_offset(start2, l2->length);
> +
> + return (start1 <= start2) && (end1 >= end2);
> +}
> +
> +/*
> + * is l1 and l2 intersecting?
> + * start1 end1
> + * [----------------------------------)
> + * start2 end2
> + * [----------------)
> + */
> +static inline int
> +lo_seg_intersecting(struct pnfs_layout_range *l1,
> + struct pnfs_layout_range *l2)
> +{
> + u64 start1 = l1->offset;
> + u64 end1 = end_offset(start1, l1->length);
> + u64 start2 = l2->offset;
> + u64 end2 = end_offset(start2, l2->length);
> +
> + return (end1 == NFS4_MAX_UINT64 || end1 > start2) &&
> + (end2 == NFS4_MAX_UINT64 || end2 > start1);
> +}
> +
> static bool
> should_free_lseg(u32 lseg_iomode, u32 recall_iomode)
> {
> @@ -466,7 +525,7 @@ pnfs_choose_layoutget_stateid(nfs4_stateid *dst, struct pnfs_layout_hdr *lo,
> static struct pnfs_layout_segment *
> send_layoutget(struct pnfs_layout_hdr *lo,
> struct nfs_open_context *ctx,
> - u32 iomode)
> + struct pnfs_layout_range *range)
> {
> struct inode *ino = lo->plh_inode;
> struct nfs_server *server = NFS_SERVER(ino);
> @@ -497,11 +556,11 @@ send_layoutget(struct pnfs_layout_hdr *lo,
> goto out_err_free;
> }
>
> - lgp->args.minlength = NFS4_MAX_UINT64;
> + lgp->args.minlength = PAGE_CACHE_SIZE;
> + if (lgp->args.minlength > range->length)
> + lgp->args.minlength = range->length;
> lgp->args.maxcount = PNFS_LAYOUT_MAXSIZE;
> - lgp->args.range.iomode = iomode;
> - lgp->args.range.offset = 0;
> - lgp->args.range.length = NFS4_MAX_UINT64;
> + lgp->args.range = *range;
Do you want to align offet to page boundary?
> lgp->args.type = server->pnfs_curr_ld->id;
> lgp->args.inode = ino;
> lgp->args.ctx = get_nfs_open_context(ctx);
> @@ -515,7 +574,7 @@ send_layoutget(struct pnfs_layout_hdr *lo,
> nfs4_proc_layoutget(lgp);
> if (!lseg) {
> /* remember that LAYOUTGET failed and suspend trying */
> - set_bit(lo_fail_bit(iomode), &lo->plh_flags);
> + set_bit(lo_fail_bit(range->iomode), &lo->plh_flags);
> }
>
> /* free xdr pages */
> @@ -622,10 +681,24 @@ bool pnfs_roc_drain(struct inode *ino, u32 *barrier)
> * are seen first.
> */
> static s64
> -cmp_layout(u32 iomode1, u32 iomode2)
> +cmp_layout(struct pnfs_layout_range *l1,
> + struct pnfs_layout_range *l2)
> {
> + s64 d;
> +
> + /* higher offset > lower offset */
> + d = l1->offset - l2->offset;
> + if (d)
> + return d;
> +
> + /* longer length > shorter length */
> + d = l1->length - l2->length;
> + if (d)
> + return d;
> +
Assuming iomodes the same, don't we prefer seeing the longer to the shorter?
Wouldn't we prefer a short rw to a long ro?
> /* read > read/write */
> - return (int)(iomode2 == IOMODE_READ) - (int)(iomode1 == IOMODE_READ);
> + return (int)(l2->iomode == IOMODE_READ) -
> + (int)(l1->iomode == IOMODE_READ);
> }
>
> static void
> @@ -639,7 +712,7 @@ pnfs_insert_layout(struct pnfs_layout_hdr *lo,
>
> assert_spin_locked(&lo->plh_inode->i_lock);
> list_for_each_entry(lp, &lo->plh_segs, pls_list) {
> - if (cmp_layout(lp->pls_range.iomode, lseg->pls_range.iomode) > 0)
> + if (cmp_layout(&lp->pls_range, &lseg->pls_range) > 0)
> continue;
> list_add_tail(&lseg->pls_list, &lp->pls_list);
> dprintk("%s: inserted lseg %p "
> @@ -718,16 +791,28 @@ pnfs_find_alloc_layout(struct inode *ino)
> * READ RW true
> */
> static int
> -is_matching_lseg(struct pnfs_layout_segment *lseg, u32 iomode)
> +is_matching_lseg(struct pnfs_layout_segment *lseg,
> + struct pnfs_layout_range *range)
arguments to this should probably both be of struct pnfs_layout_range
> {
> - return (iomode != IOMODE_RW || lseg->pls_range.iomode == IOMODE_RW);
> + struct pnfs_layout_range range1;
> +
> + if ((range->iomode == IOMODE_RW &&
> + lseg->pls_range.iomode != IOMODE_RW) ||
> + !lo_seg_intersecting(&lseg->pls_range, range))
> + return 0;
> +
> + /* range1 covers only the first byte in the range */
> + range1 = *range;
> + range1.length = 1;
> + return lo_seg_contained(&lseg->pls_range, &range1);
> }
>
> /*
> * lookup range in layout
> */
> static struct pnfs_layout_segment *
> -pnfs_find_lseg(struct pnfs_layout_hdr *lo, u32 iomode)
> +pnfs_find_lseg(struct pnfs_layout_hdr *lo,
> + struct pnfs_layout_range *range)
> {
> struct pnfs_layout_segment *lseg, *ret = NULL;
>
> @@ -736,11 +821,11 @@ pnfs_find_lseg(struct pnfs_layout_hdr *lo, u32 iomode)
> assert_spin_locked(&lo->plh_inode->i_lock);
> list_for_each_entry(lseg, &lo->plh_segs, pls_list) {
> if (test_bit(NFS_LSEG_VALID, &lseg->pls_flags) &&
> - is_matching_lseg(lseg, iomode)) {
> + is_matching_lseg(lseg, range)) {
> ret = get_lseg(lseg);
> break;
> }
> - if (cmp_layout(iomode, lseg->pls_range.iomode) > 0)
> + if (cmp_layout(range, &lseg->pls_range) > 0)
> break;
> }
>
> @@ -756,8 +841,15 @@ pnfs_find_lseg(struct pnfs_layout_hdr *lo, u32 iomode)
> struct pnfs_layout_segment *
> pnfs_update_layout(struct inode *ino,
> struct nfs_open_context *ctx,
> + loff_t pos,
> + u64 count,
> enum pnfs_iomode iomode)
> {
> + struct pnfs_layout_range arg = {
> + .iomode = iomode,
> + .offset = pos,
> + .length = count,
> + };
> struct nfs_inode *nfsi = NFS_I(ino);
> struct nfs_client *clp = NFS_SERVER(ino)->nfs_client;
> struct pnfs_layout_hdr *lo;
> @@ -785,7 +877,7 @@ pnfs_update_layout(struct inode *ino,
> goto out_unlock;
>
> /* Check to see if the layout for the given range already exists */
> - lseg = pnfs_find_lseg(lo, iomode);
> + lseg = pnfs_find_lseg(lo, &arg);
> if (lseg)
> goto out_unlock;
>
> @@ -807,7 +899,7 @@ pnfs_update_layout(struct inode *ino,
> spin_unlock(&clp->cl_lock);
> }
>
> - lseg = send_layoutget(lo, ctx, iomode);
> + lseg = send_layoutget(lo, ctx, &arg);
> if (!lseg && first) {
> spin_lock(&clp->cl_lock);
> list_del_init(&lo->plh_layouts);
> @@ -834,17 +926,6 @@ pnfs_layout_process(struct nfs4_layoutget *lgp)
> struct nfs_client *clp = NFS_SERVER(ino)->nfs_client;
> int status = 0;
>
> - /* Verify we got what we asked for.
> - * Note that because the xdr parsing only accepts a single
> - * element array, this can fail even if the server is behaving
> - * correctly.
> - */
> - if (lgp->args.range.iomode > res->range.iomode ||
> - res->range.offset != 0 ||
> - res->range.length != NFS4_MAX_UINT64) {
> - status = -EINVAL;
> - goto out;
> - }
> /* Inject layout blob into I/O device driver */
> lseg = NFS_SERVER(ino)->pnfs_curr_ld->alloc_lseg(lo, res);
> if (!lseg || IS_ERR(lseg)) {
> @@ -899,8 +980,13 @@ static int pnfs_read_pg_test(struct nfs_pageio_descriptor *pgio,
> /* This is first coelesce call for a series of nfs_pages */
> pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
> prev->wb_context,
> + req_offset(req),
> + pgio->pg_count,
> IOMODE_READ);
> - }
> + } else if (pgio->pg_lseg &&
> + req_offset(req) > end_offset(pgio->pg_lseg->pls_range.offset,
> + pgio->pg_lseg->pls_range.length))
> + return 0;
> return NFS_SERVER(pgio->pg_inode)->pnfs_curr_ld->pg_test(pgio, prev, req);
> }
>
> @@ -921,8 +1007,13 @@ static int pnfs_write_pg_test(struct nfs_pageio_descriptor *pgio,
> /* This is first coelesce call for a series of nfs_pages */
> pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
> prev->wb_context,
> + req_offset(req),
> + pgio->pg_count,
> IOMODE_RW);
> - }
> + } else if (pgio->pg_lseg &&
> + req_offset(req) > end_offset(pgio->pg_lseg->pls_range.offset,
> + pgio->pg_lseg->pls_range.length))
> + return 0;
> return NFS_SERVER(pgio->pg_inode)->pnfs_curr_ld->pg_test(pgio, prev, req);
> }
>
> diff --git a/fs/nfs/pnfs.h b/fs/nfs/pnfs.h
> index 4cb0a0d..14a2af9 100644
> --- a/fs/nfs/pnfs.h
> +++ b/fs/nfs/pnfs.h
> @@ -129,7 +129,7 @@ void get_layout_hdr(struct pnfs_layout_hdr *lo);
> void put_lseg(struct pnfs_layout_segment *lseg);
> struct pnfs_layout_segment *
> pnfs_update_layout(struct inode *ino, struct nfs_open_context *ctx,
> - enum pnfs_iomode access_type);
> + loff_t pos, u64 count, enum pnfs_iomode access_type);
> void set_pnfs_layoutdriver(struct nfs_server *, u32 id);
> void unset_pnfs_layoutdriver(struct nfs_server *);
> enum pnfs_try_status pnfs_try_to_write_data(struct nfs_write_data *,
> @@ -248,7 +248,7 @@ static inline void put_lseg(struct pnfs_layout_segment *lseg)
>
> static inline struct pnfs_layout_segment *
> pnfs_update_layout(struct inode *ino, struct nfs_open_context *ctx,
> - enum pnfs_iomode access_type)
> + loff_t pos, u64 count, enum pnfs_iomode access_type)
> {
> return NULL;
> }
> diff --git a/fs/nfs/read.c b/fs/nfs/read.c
> index 7cded2b..10eff1c 100644
> --- a/fs/nfs/read.c
> +++ b/fs/nfs/read.c
> @@ -288,13 +288,17 @@ static int nfs_pagein_multi(struct nfs_pageio_descriptor *desc)
> atomic_set(&req->wb_complete, requests);
>
> BUG_ON(desc->pg_lseg != NULL);
> - lseg = pnfs_update_layout(desc->pg_inode, req->wb_context, IOMODE_READ);
> + lseg = pnfs_update_layout(desc->pg_inode, req->wb_context,
> + req_offset(req), desc->pg_count,
> + IOMODE_READ);
> ClearPageError(page);
> offset = 0;
> nbytes = desc->pg_count;
> do {
> int ret2;
>
> + /* FIXME: need a new layout segment? */
> +
No need for FIXME, since we assume strongly throughout that the
layouts are page aligned.
Fred
> data = list_entry(list.next, struct nfs_read_data, pages);
> list_del_init(&data->pages);
>
> @@ -351,7 +355,9 @@ static int nfs_pagein_one(struct nfs_pageio_descriptor *desc)
> }
> req = nfs_list_entry(data->pages.next);
> if ((!lseg) && list_is_singular(&data->pages))
> - lseg = pnfs_update_layout(desc->pg_inode, req->wb_context, IOMODE_READ);
> + lseg = pnfs_update_layout(desc->pg_inode, req->wb_context,
> + req_offset(req), desc->pg_count,
> + IOMODE_READ);
>
> ret = nfs_read_rpcsetup(req, data, &nfs_read_full_ops, desc->pg_count,
> 0, lseg);
> diff --git a/fs/nfs/write.c b/fs/nfs/write.c
> index e4cbc11..318e0a3 100644
> --- a/fs/nfs/write.c
> +++ b/fs/nfs/write.c
> @@ -940,7 +940,9 @@ static int nfs_flush_multi(struct nfs_pageio_descriptor *desc)
> atomic_set(&req->wb_complete, requests);
>
> BUG_ON(desc->pg_lseg);
> - lseg = pnfs_update_layout(desc->pg_inode, req->wb_context, IOMODE_RW);
> + lseg = pnfs_update_layout(desc->pg_inode, req->wb_context,
> + req_offset(req), desc->pg_count,
> + IOMODE_RW);
> ClearPageError(page);
> offset = 0;
> nbytes = desc->pg_count;
> @@ -1014,7 +1016,9 @@ static int nfs_flush_one(struct nfs_pageio_descriptor *desc)
> }
> req = nfs_list_entry(data->pages.next);
> if ((!lseg) && list_is_singular(&data->pages))
> - lseg = pnfs_update_layout(desc->pg_inode, req->wb_context, IOMODE_RW);
> + lseg = pnfs_update_layout(desc->pg_inode, req->wb_context,
> + req_offset(req), desc->pg_count,
> + IOMODE_RW);
>
> if ((desc->pg_ioflags & FLUSH_COND_STABLE) &&
> (desc->pg_moreio || NFS_I(desc->pg_inode)->ncommit))
> --
> 1.7.3.4
>
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