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| author | Fred Isaman <iisaman@netapp.com> | 2011-03-01 01:34:14 +0000 |
|---|---|---|
| committer | Trond Myklebust <Trond.Myklebust@netapp.com> | 2011-03-11 15:38:42 -0500 |
| commit | 94ad1c80e28f9700c84b4d28d1e5302ddf63a6fd (patch) | |
| tree | 2c600c1f8e85648c7693b5f0018b5d0b7e960b5f /fs/nfs/nfs4filelayout.c | |
| parent | d684d2ae10a4f95d3035abf698d7d611ff2cd279 (diff) | |
| download | lwn-94ad1c80e28f9700c84b4d28d1e5302ddf63a6fd.tar.gz lwn-94ad1c80e28f9700c84b4d28d1e5302ddf63a6fd.zip | |
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: Andy Adamson <andros@netapp.com>
Signed-off-by: Andy Adamson <andros@citi.umich.edu>
Signed-off-by: Dean Hildebrand <dhildeb@us.ibm.com>
Signed-off-by: Fred Isaman <iisaman@citi.umich.edu>
Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: Oleg Drokin <green@linuxhacker.ru>
Signed-off-by: Tao Guo <guotao@nrchpc.ac.cn>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Diffstat (limited to 'fs/nfs/nfs4filelayout.c')
| -rw-r--r-- | fs/nfs/nfs4filelayout.c | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/fs/nfs/nfs4filelayout.c b/fs/nfs/nfs4filelayout.c index 23f930caf1e2..0efe8cbd9e3c 100644 --- a/fs/nfs/nfs4filelayout.c +++ b/fs/nfs/nfs4filelayout.c @@ -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) |