diff options
| author | Fred Isaman <iisaman@netapp.com> | 2011-03-01 01:34:18 +0000 |
|---|---|---|
| committer | Trond Myklebust <Trond.Myklebust@netapp.com> | 2011-03-11 15:38:42 -0500 |
| commit | cfe7f4120f8b1b9465c333d1e42efd4669b1799f (patch) | |
| tree | a55e5fc7dbafdf43588a480a0348da0ad8e1eb9e /fs/nfs/nfs4filelayout.c | |
| parent | d83217c13531fd59730d77b5c2284e90e56c0a50 (diff) | |
NFSv4.1: filelayout i/o helpers
Prepare for filelayout_read_pagelist with helper functions that find the correct
data server, filehandle, and offset.
Signed-off-by: Andy Adamson <andros@citi.umich.edu>
Signed-off-by: Dean Hildebrand <dhildeb@us.ibm.com>
Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Marc Eshel <eshel@almaden.ibm.com>
Signed-off-by: Mike Sager <sager@netapp.com>
Signed-off-by: Oleg Drokin <green@linuxhacker.ru>
Signed-off-by: Tao Guo <guotao@nrchpc.ac.cn>
Signed-off-by: Tigran Mkrtchyan <tigran@anahit.desy.de>
Signed-off-by: Tigran Mkrtchyan <tigran.mkrtchyan@desy.de>
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Diffstat (limited to 'fs/nfs/nfs4filelayout.c')
| -rw-r--r-- | fs/nfs/nfs4filelayout.c | 34 |
1 files changed, 34 insertions, 0 deletions
diff --git a/fs/nfs/nfs4filelayout.c b/fs/nfs/nfs4filelayout.c index 0efe8cbd9e3c..ed833705dcee 100644 --- a/fs/nfs/nfs4filelayout.c +++ b/fs/nfs/nfs4filelayout.c @@ -66,6 +66,40 @@ filelayout_clear_layoutdriver(struct nfs_server *nfss) return 0; } +static loff_t +filelayout_get_dense_offset(struct nfs4_filelayout_segment *flseg, + loff_t offset) +{ + u32 stripe_width = flseg->stripe_unit * flseg->dsaddr->stripe_count; + u64 tmp; + + offset -= flseg->pattern_offset; + tmp = offset; + do_div(tmp, stripe_width); + + return tmp * flseg->stripe_unit + do_div(offset, flseg->stripe_unit); +} + +/* This function is used by the layout driver to calculate the + * offset of the file on the dserver based on whether the + * layout type is STRIPE_DENSE or STRIPE_SPARSE + */ +static loff_t +filelayout_get_dserver_offset(struct pnfs_layout_segment *lseg, loff_t offset) +{ + struct nfs4_filelayout_segment *flseg = FILELAYOUT_LSEG(lseg); + + switch (flseg->stripe_type) { + case STRIPE_SPARSE: + return offset; + + case STRIPE_DENSE: + return filelayout_get_dense_offset(flseg, offset); + } + + BUG(); +} + /* * filelayout_check_layout() * |