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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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34
fs/nfs/nfs4filelayout.c
View file

@ -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()
*

7
fs/nfs/nfs4filelayout.h
View file

@ -83,9 +83,16 @@ FILELAYOUT_LSEG(struct pnfs_layout_segment *lseg)
generic_hdr);
}
extern struct nfs_fh *
nfs4_fl_select_ds_fh(struct pnfs_layout_segment *lseg, u32 j);
extern void nfs4_fl_free_deviceid_callback(struct pnfs_deviceid_node *);
extern void print_ds(struct nfs4_pnfs_ds *ds);
extern void print_deviceid(struct nfs4_deviceid *dev_id);
u32 nfs4_fl_calc_j_index(struct pnfs_layout_segment *lseg, loff_t offset);
u32 nfs4_fl_calc_ds_index(struct pnfs_layout_segment *lseg, u32 j);
struct nfs4_pnfs_ds *nfs4_fl_prepare_ds(struct pnfs_layout_segment *lseg,
u32 ds_idx);
extern struct nfs4_file_layout_dsaddr *
nfs4_fl_find_get_deviceid(struct nfs_client *, struct nfs4_deviceid *dev_id);
struct nfs4_file_layout_dsaddr *

67
fs/nfs/nfs4filelayoutdev.c
View file

@ -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;
}