Commit 683b57b4 authored by Trond Myklebust's avatar Trond Myklebust
Browse files

NFSv4: Implement the fs_locations function call 



NFSv4 allows for the fact that filesystems may be replicated across
several servers or that they may be migrated to a backup server in case of
failure of the primary server.
fs_locations is an NFSv4 operation for retrieving information about the
location of migrated and/or replicated filesystems.

Based on an initial implementation by Jiaying Zhang <jiayingz@citi.umich.edu>
Signed-off-by: default avatarTrond Myklebust <Trond.Myklebust@netapp.com>
parent 8b23ea7b

fs/nfs/nfs4_fs.h

+2 −0
Original line number Diff line number Diff line
@@ -218,6 +218,8 @@ extern int nfs4_do_close(struct inode *inode, struct nfs4_state *state); 
extern struct dentry *nfs4_atomic_open(struct inode *, struct dentry *, struct nameidata *);

extern int nfs4_open_revalidate(struct inode *, struct dentry *, int, struct nameidata *);

extern int nfs4_server_capabilities(struct nfs_server *server, struct nfs_fh *fhandle);

extern int nfs4_proc_fs_locations(struct inode *dir, struct dentry *dentry,

		struct nfs_fs_locations *fs_locations, struct page *page);



extern struct nfs4_state_recovery_ops nfs4_reboot_recovery_ops;

extern struct nfs4_state_recovery_ops nfs4_network_partition_recovery_ops;

fs/nfs/nfs4proc.c

+29 −0
Original line number Diff line number Diff line
@@ -3570,6 +3570,35 @@ ssize_t nfs4_listxattr(struct dentry *dentry, char *buf, size_t buflen) 
	return len;

}



int nfs4_proc_fs_locations(struct inode *dir, struct dentry *dentry,

		struct nfs_fs_locations *fs_locations, struct page *page)

{

	struct nfs_server *server = NFS_SERVER(dir);

	u32 bitmask[2] = {

		[0] = server->attr_bitmask[0] | FATTR4_WORD0_FS_LOCATIONS,

		[1] = server->attr_bitmask[1],

	};

	struct nfs4_fs_locations_arg args = {

		.dir_fh = NFS_FH(dir),

		.name = &dentry->d_name,

		.page = page,

		.bitmask = bitmask,

	};

	struct rpc_message msg = {

		.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_FS_LOCATIONS],

		.rpc_argp = &args,

		.rpc_resp = &fs_locations,

	};

	int status;



	dprintk("%s: start\n", __FUNCTION__);

	fs_locations->fattr.valid = 0;

	fs_locations->server = server;

	status = rpc_call_sync(server->client, &msg, 0);

	dprintk("%s: returned status = %d\n", __FUNCTION__, status);

	return status;

}



struct nfs4_state_recovery_ops nfs4_reboot_recovery_ops = {

	.recover_open	= nfs4_open_reclaim,

	.recover_lock	= nfs4_lock_reclaim,

fs/nfs/nfs4xdr.c

+110 −2
Original line number Diff line number Diff line
@@ -411,6 +411,15 @@ static int nfs_stat_to_errno(int); 
#define NFS4_dec_setacl_sz	(compound_decode_hdr_maxsz + \

				decode_putfh_maxsz + \

				op_decode_hdr_maxsz + nfs4_fattr_bitmap_maxsz)

#define NFS4_enc_fs_locations_sz \

				(compound_encode_hdr_maxsz + \

				 encode_putfh_maxsz + \

				 encode_getattr_maxsz)

#define NFS4_dec_fs_locations_sz \

				(compound_decode_hdr_maxsz + \

				 decode_putfh_maxsz + \

				 op_decode_hdr_maxsz + \

				 nfs4_fattr_bitmap_maxsz)



static struct {

	unsigned int	mode;
@@ -2002,6 +2011,38 @@ out: 
	return status;

}



/*

 * Encode FS_LOCATIONS request

 */

static int nfs4_xdr_enc_fs_locations(struct rpc_rqst *req, uint32_t *p, struct nfs4_fs_locations_arg *args)

{

	struct xdr_stream xdr;

	struct compound_hdr hdr = {

		.nops = 3,

	};

	struct rpc_auth *auth = req->rq_task->tk_auth;

	int replen;

	int status;



	xdr_init_encode(&xdr, &req->rq_snd_buf, p);

	encode_compound_hdr(&xdr, &hdr);

	if ((status = encode_putfh(&xdr, args->dir_fh)) != 0)

		goto out;

	if ((status = encode_lookup(&xdr, args->name)) != 0)

		goto out;

	if ((status = encode_getfattr(&xdr, args->bitmask)) != 0)

		goto out;

	/* set up reply

	 *   toplevel_status + taglen + rescount + OP_PUTFH + status

	 *   + OP_LOOKUP + status + OP_GETATTR + status = 7

	 */

	replen = (RPC_REPHDRSIZE + auth->au_rslack + 7) << 2;

	xdr_inline_pages(&req->rq_rcv_buf, replen, &args->page,

			0, PAGE_SIZE);

out:

	return status;

}



/*

 * START OF "GENERIC" DECODE ROUTINES.

 *   These may look a little ugly since they are imported from a "generic"
@@ -2036,7 +2077,7 @@ out: 
	} \

} while (0)



static int decode_opaque_inline(struct xdr_stream *xdr, uint32_t *len, char **string)

static int decode_opaque_inline(struct xdr_stream *xdr, unsigned int *len, char **string)

{

	uint32_t *p;
@@ -2087,7 +2128,7 @@ static int decode_op_hdr(struct xdr_stream *xdr, enum nfs_opnum4 expected) 
static int decode_ace(struct xdr_stream *xdr, void *ace, struct nfs4_client *clp)

{

	uint32_t *p;

	uint32_t strlen;

	unsigned int strlen;

	char *str;



	READ_BUF(12);
@@ -2336,6 +2377,45 @@ static int decode_attr_files_total(struct xdr_stream *xdr, uint32_t *bitmap, uin 
	return status;

}



static int decode_attr_fs_locations(struct xdr_stream *xdr, uint32_t *bitmap, struct nfs_fs_locations *res)

{

	int n;

	uint32_t *p;

	int status = -EIO;



	if (unlikely(bitmap[0] & (FATTR4_WORD0_FS_LOCATIONS -1U)))

		goto out;

	status = 0;

	if (unlikely(!(bitmap[0] & FATTR4_WORD0_FS_LOCATIONS)))

		goto out;

	status = decode_opaque_inline(xdr, &res->fs_pathlen, &res->fs_path);

	if (unlikely(status != 0))

		goto out;

	READ_BUF(4);

	READ32(n);

	if (n <= 0)

		goto out_eio;

	res->nlocations = 0;

	while (res->nlocations < n) {

		struct nfs_fs_location *loc = &res->locations[res->nlocations];



		status = decode_opaque_inline(xdr, &loc->serverlen, &loc->server);

		if (unlikely(status != 0))

			goto out_eio;

		status = decode_opaque_inline(xdr, &loc->rootpathlen, &loc->rootpath);

		if (unlikely(status != 0))

			goto out_eio;

		if (res->nlocations < NFS_FS_LOCATIONS_MAXENTRIES)

			res->nlocations++;

	}

out:

	dprintk("%s: fs_locations done, error = %d\n", __FUNCTION__, status);

	return status;

out_eio:

	status = -EIO;

	goto out;

}



static int decode_attr_maxfilesize(struct xdr_stream *xdr, uint32_t *bitmap, uint64_t *res)

{

	uint32_t *p;
@@ -2867,6 +2947,10 @@ static int decode_getfattr(struct xdr_stream *xdr, struct nfs_fattr *fattr, cons 
		goto xdr_error;

	if ((status = decode_attr_fileid(xdr, bitmap, &fattr->fileid)) != 0)

		goto xdr_error;

	if ((status = decode_attr_fs_locations(xdr, bitmap, container_of(fattr,

						struct nfs_fs_locations,

						fattr))) != 0)

		goto xdr_error;

	if ((status = decode_attr_mode(xdr, bitmap, &fattr->mode)) != 0)

		goto xdr_error;

	fattr->mode |= fmode;
@@ -4210,6 +4294,29 @@ out: 
	return status;

}



/*

 * FS_LOCATIONS request

 */

static int nfs4_xdr_dec_fs_locations(struct rpc_rqst *req, uint32_t *p, struct nfs_fs_locations *res)

{

	struct xdr_stream xdr;

	struct compound_hdr hdr;

	int status;



	xdr_init_decode(&xdr, &req->rq_rcv_buf, p);

	status = decode_compound_hdr(&xdr, &hdr);

	if (status != 0)

		goto out;

	if ((status = decode_putfh(&xdr)) != 0)

		goto out;

	if ((status = decode_lookup(&xdr)) != 0)

		goto out;

	xdr_enter_page(&xdr, PAGE_SIZE);

	status = decode_getfattr(&xdr, &res->fattr, res->server);

out:

	return status;

}



uint32_t *nfs4_decode_dirent(uint32_t *p, struct nfs_entry *entry, int plus)

{

	uint32_t bitmap[2] = {0};
@@ -4381,6 +4488,7 @@ struct rpc_procinfo nfs4_procedures[] = { 
  PROC(DELEGRETURN,	enc_delegreturn, dec_delegreturn),

  PROC(GETACL,		enc_getacl,	dec_getacl),

  PROC(SETACL,		enc_setacl,	dec_setacl),

  PROC(FS_LOCATIONS,	enc_fs_locations, dec_fs_locations),

};



struct rpc_version		nfs_version4 = {

include/linux/nfs4.h

+1 −0
Original line number Diff line number Diff line
@@ -384,6 +384,7 @@ enum { 
	NFSPROC4_CLNT_DELEGRETURN,

	NFSPROC4_CLNT_GETACL,

	NFSPROC4_CLNT_SETACL,

	NFSPROC4_CLNT_FS_LOCATIONS,

};



#endif

include/linux/nfs_xdr.h

+24 −0
Original line number Diff line number Diff line
@@ -679,6 +679,30 @@ struct nfs4_server_caps_res { 
	u32				has_symlinks;

};



struct nfs_fs_location {

	unsigned int serverlen;

	char * server;

	unsigned int rootpathlen;

	char * rootpath;

};



#define NFS_FS_LOCATIONS_MAXENTRIES 10

struct nfs_fs_locations {

	struct nfs_fattr fattr;

	const struct nfs_server *server;

	unsigned int fs_pathlen;

	char * fs_path;

	int nlocations;

	struct nfs_fs_location locations[NFS_FS_LOCATIONS_MAXENTRIES];

};



struct nfs4_fs_locations_arg {

	const struct nfs_fh *dir_fh;

	const struct qstr *name;

	struct page *page;

	const u32 *bitmask;

};



#endif /* CONFIG_NFS_V4 */



struct nfs_page;

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