linux/fs/nfs/nfs4filelayout.h
Trond Myklebust a75b9df9d3 NFSv4.1: Ensure that layoutget uses the correct gfp modes
Currently, writebacks may end up recursing back into the filesystem due to
GFP_KERNEL direct reclaims in the pnfs subsystem.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-05-11 22:52:13 -04:00

110 lines
3.6 KiB
C

/*
* NFSv4 file layout driver data structures.
*
* Copyright (c) 2002
* The Regents of the University of Michigan
* All Rights Reserved
*
* Dean Hildebrand <dhildebz@umich.edu>
*
* Permission is granted to use, copy, create derivative works, and
* redistribute this software and such derivative works for any purpose,
* so long as the name of the University of Michigan is not used in
* any advertising or publicity pertaining to the use or distribution
* of this software without specific, written prior authorization. If
* the above copyright notice or any other identification of the
* University of Michigan is included in any copy of any portion of
* this software, then the disclaimer below must also be included.
*
* This software is provided as is, without representation or warranty
* of any kind either express or implied, including without limitation
* the implied warranties of merchantability, fitness for a particular
* purpose, or noninfringement. The Regents of the University of
* Michigan shall not be liable for any damages, including special,
* indirect, incidental, or consequential damages, with respect to any
* claim arising out of or in connection with the use of the software,
* even if it has been or is hereafter advised of the possibility of
* such damages.
*/
#ifndef FS_NFS_NFS4FILELAYOUT_H
#define FS_NFS_NFS4FILELAYOUT_H
#include "pnfs.h"
/*
* Field testing shows we need to support up to 4096 stripe indices.
* We store each index as a u8 (u32 on the wire) to keep the memory footprint
* reasonable. This in turn means we support a maximum of 256
* RFC 5661 multipath_list4 structures.
*/
#define NFS4_PNFS_MAX_STRIPE_CNT 4096
#define NFS4_PNFS_MAX_MULTI_CNT 256 /* 256 fit into a u8 stripe_index */
enum stripetype4 {
STRIPE_SPARSE = 1,
STRIPE_DENSE = 2
};
/* Individual ip address */
struct nfs4_pnfs_ds {
struct list_head ds_node; /* nfs4_pnfs_dev_hlist dev_dslist */
u32 ds_ip_addr;
u32 ds_port;
struct nfs_client *ds_clp;
atomic_t ds_count;
};
/* nfs4_file_layout_dsaddr flags */
#define NFS4_DEVICE_ID_NEG_ENTRY 0x00000001
struct nfs4_file_layout_dsaddr {
struct hlist_node node;
struct nfs4_deviceid deviceid;
atomic_t ref;
unsigned long flags;
u32 stripe_count;
u8 *stripe_indices;
u32 ds_num;
struct nfs4_pnfs_ds *ds_list[1];
};
struct nfs4_filelayout_segment {
struct pnfs_layout_segment generic_hdr;
u32 stripe_type;
u32 commit_through_mds;
u32 stripe_unit;
u32 first_stripe_index;
u64 pattern_offset;
struct nfs4_file_layout_dsaddr *dsaddr; /* Point to GETDEVINFO data */
unsigned int num_fh;
struct nfs_fh **fh_array;
struct list_head *commit_buckets; /* Sort commits to ds */
int number_of_buckets;
};
static inline struct nfs4_filelayout_segment *
FILELAYOUT_LSEG(struct pnfs_layout_segment *lseg)
{
return container_of(lseg,
struct nfs4_filelayout_segment,
generic_hdr);
}
extern struct nfs_fh *
nfs4_fl_select_ds_fh(struct pnfs_layout_segment *lseg, u32 j);
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 nfs4_deviceid *dev_id);
extern void nfs4_fl_put_deviceid(struct nfs4_file_layout_dsaddr *dsaddr);
struct nfs4_file_layout_dsaddr *
get_device_info(struct inode *inode, struct nfs4_deviceid *dev_id, gfp_t gfp_flags);
#endif /* FS_NFS_NFS4FILELAYOUT_H */