From Linux NFS
Index: fs/nfs/nfs4filelayout.c
===================================================================
RCS file: /cvs/nfsv4/cvs/pnfs/fs/nfs/nfs4filelayout.c,v
retrieving revision 1.22
diff -r1.22 nfs4filelayout.c
154a155,196
> >
> > /* This function is used by the layout driver to caclulate the
> > * offset of the file on the dserver based on whether the
> > * layout type is STRIPE_DENSE or STRIPE_SPARSE
> > */
> > loff_t
> > filelayout_get_dserver_offset(loff_t offset, struct nfs4_filelayout *
layout)
> > {
> > BUG_ON(layout == NULL);
> >
> > switch (layout->stripe_type) {
> > case STRIPE_SPARSE:
> > return offset;
> >
> > case STRIPE_DENSE:
> > {
> > u32 stripe_size;
> > u32 stripe_unit;
> > loff_t off;
> > loff_t tmp;
> > u32 stripe_unit_idx;
> >
> > stripe_size = layout->stripe_unit *
layout->num_devs;
> > /* XXX I do this because do_div seems to take a
32 bit dividend */
> > stripe_unit = layout->stripe_unit;
> > tmp = off = offset;
> >
> > do_div(off, stripe_size);
> > stripe_unit_idx = do_div(tmp, stripe_unit);
> >
> > return off * stripe_unit + stripe_unit_idx;
> > }
> >
> > default:
> > BUG();
> > }
> >
> > /* We should never get here... just to stop the gcc warning */
> > return 0;
> > }
> >
> >
196a239,245
> >
> > /* Now get the file offset on the dserver
> > * Set the read offset to this offset, and
> > * save the original offset in orig_offset
> > */
> > data->args.offset =
filelayout_get_dserver_offset(offset, nfslay);
> > data->orig_offset = offset;
202a252
> >
206a257,259
> >
> > /* In the case of synchronous reads, we reset the offset
here */
> > data->args.offset = data->orig_offset;
209a263,265
> > /* In the case of aync reads, the offset will be reset
in the
> > * call_ops->rpc_call_done() routine
> > */
253a310,316
> > /* Now get the file offset on the dserver
> > * Set the write offset to this offset, and
> > * save the original offset in orig_offset
> > */
> > data->args.offset = filelayout_get_dserver_offset(offset,
nfslay);
> > data->orig_offset = offset;
> >
262a326,328
> >
> > /* In the case of synchronous writes, we reset the
offset here */
> > data->args.offset = data->orig_offset;
265a332,334
> > /* In the case of aync writes, the offset will be
reset in the
> > * call_ops->rpc_call_done() routine
> > */
Index: fs/nfs/nfs4filelayout.h
===================================================================
RCS file: /cvs/nfsv4/cvs/pnfs/fs/nfs/nfs4filelayout.h,v
retrieving revision 1.3
diff -r1.3 nfs4filelayout.h
21a22,26
> > enum stripetype4 {
> > STRIPE_SPARSE = 1,
> > STRIPE_DENSE = 2
> > };
> >
Index: fs/nfs/read.c
===================================================================
RCS file: /cvs/nfsv4/cvs/pnfs/fs/nfs/read.c,v
retrieving revision 1.13
diff -r1.13 read.c
526a527,534
> > #ifdef CONFIG_NFS_V4
> > /* Restore the data->args->offset pointer to the actual offset
> > * if it was changed
> > */
> > if (data->orig_offset)
> > data->args.offset = data->orig_offset;
> > #endif
> >
569a578,585
> >
> > #ifdef CONFIG_NFS_V4
> > /* Restore the data->args->offset pointer to the actual offset
> > * if it was changed
> > */
> > if (data->orig_offset)
> > data->args.offset = data->orig_offset;
> > #endif
Index: fs/nfs/write.c
===================================================================
RCS file: /cvs/nfsv4/cvs/pnfs/fs/nfs/write.c,v
retrieving revision 1.24
diff -r1.24 write.c
1222a1223,1230
> > #ifdef CONFIG_NFS_V4
> > /* Restore the data->args->offset pointer to the actual offset
> > * if it was changed
> > */
> > if (data->orig_offset)
> > data->args.offset = data->orig_offset;
> > #endif
> >
1313a1322,1329
> >
> > #ifdef CONFIG_NFS_V4
> > /* Restore the data->args->offset pointer to the actual offset
> > * if it was changed
> > */
> > if (data->orig_offset)
> > data->args.offset = data->orig_offset;
> > #endif
Index: include/linux/nfs_xdr.h
===================================================================
RCS file: /cvs/nfsv4/cvs/pnfs/include/linux/nfs_xdr.h,v
retrieving revision 1.13
diff -r1.13 nfs_xdr.h
702a703
> > __u64 orig_offset;
729a731
> > __u64 orig_offset
