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NFSv4.1: filelayout i/o helpers

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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>
This commit is contained in:
Fred Isaman
2011-03-01 01:34:18 +00:00
committed by Trond Myklebust
parent d83217c135
commit cfe7f4120f
3 changed files with 108 additions and 0 deletions
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67
fs/nfs/nfs4filelayoutdev.c
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@@ -516,3 +516,70 @@ nfs4_fl_find_get_deviceid(struct nfs_client *clp, struct nfs4_deviceid *id)
return (d == NULL) ? NULL :
container_of(d, struct nfs4_file_layout_dsaddr, deviceid);
}
/*
* Want res = (offset - layout->pattern_offset)/ layout->stripe_unit
* Then: ((res + fsi) % dsaddr->stripe_count)
*/
u32
nfs4_fl_calc_j_index(struct pnfs_layout_segment *lseg, loff_t offset)
{
struct nfs4_filelayout_segment *flseg = FILELAYOUT_LSEG(lseg);
u64 tmp;
tmp = offset - flseg->pattern_offset;
do_div(tmp, flseg->stripe_unit);
tmp += flseg->first_stripe_index;
return do_div(tmp, flseg->dsaddr->stripe_count);
}
u32
nfs4_fl_calc_ds_index(struct pnfs_layout_segment *lseg, u32 j)
{
return FILELAYOUT_LSEG(lseg)->dsaddr->stripe_indices[j];
}
struct nfs_fh *
nfs4_fl_select_ds_fh(struct pnfs_layout_segment *lseg, u32 j)
{
struct nfs4_filelayout_segment *flseg = FILELAYOUT_LSEG(lseg);
u32 i;
if (flseg->stripe_type == STRIPE_SPARSE) {
if (flseg->num_fh == 1)
i = 0;
else if (flseg->num_fh == 0)
/* Use the MDS OPEN fh set in nfs_read_rpcsetup */
return NULL;
else
i = nfs4_fl_calc_ds_index(lseg, j);
} else
i = j;
return flseg->fh_array[i];
}
struct nfs4_pnfs_ds *
nfs4_fl_prepare_ds(struct pnfs_layout_segment *lseg, u32 ds_idx)
{
struct nfs4_file_layout_dsaddr *dsaddr = FILELAYOUT_LSEG(lseg)->dsaddr;
struct nfs4_pnfs_ds *ds = dsaddr->ds_list[ds_idx];
if (ds == NULL) {
printk(KERN_ERR "%s: No data server for offset index %d\n",
__func__, ds_idx);
return NULL;
}
if (!ds->ds_clp) {
int err;
err = nfs4_ds_connect(NFS_SERVER(lseg->pls_layout->plh_inode),
dsaddr->ds_list[ds_idx]);
if (err) {
printk(KERN_ERR "%s nfs4_ds_connect error %d\n",
__func__, err);
return NULL;
}
}
return ds;
}