xref: /linux/fs/nfsd/flexfilelayout.c (revision e5c86679d5e864947a52fb31e45a425dea3e7fa9)
1 /*
2  * Copyright (c) 2016 Tom Haynes <loghyr@primarydata.com>
3  *
4  * The following implements a super-simple flex-file server
5  * where the NFSv4.1 mds is also the ds. And the storage is
6  * the same. I.e., writing to the mds via a NFSv4.1 WRITE
7  * goes to the same location as the NFSv3 WRITE.
8  */
9 #include <linux/slab.h>
10 
11 #include <linux/nfsd/debug.h>
12 
13 #include <linux/sunrpc/addr.h>
14 
15 #include "flexfilelayoutxdr.h"
16 #include "pnfs.h"
17 
18 #define NFSDDBG_FACILITY	NFSDDBG_PNFS
19 
20 static __be32
21 nfsd4_ff_proc_layoutget(struct inode *inode, const struct svc_fh *fhp,
22 		struct nfsd4_layoutget *args)
23 {
24 	struct nfsd4_layout_seg *seg = &args->lg_seg;
25 	u32 device_generation = 0;
26 	int error;
27 	uid_t u;
28 
29 	struct pnfs_ff_layout *fl;
30 
31 	/*
32 	 * The super simple flex file server has 1 mirror, 1 data server,
33 	 * and 1 file handle. So instead of 4 allocs, do 1 for now.
34 	 * Zero it out for the stateid - don't want junk in there!
35 	 */
36 	error = -ENOMEM;
37 	fl = kzalloc(sizeof(*fl), GFP_KERNEL);
38 	if (!fl)
39 		goto out_error;
40 	args->lg_content = fl;
41 
42 	/*
43 	 * Avoid layout commit, try to force the I/O to the DS,
44 	 * and for fun, cause all IOMODE_RW layout segments to
45 	 * effectively be WRITE only.
46 	 */
47 	fl->flags = FF_FLAGS_NO_LAYOUTCOMMIT | FF_FLAGS_NO_IO_THRU_MDS |
48 		    FF_FLAGS_NO_READ_IO;
49 
50 	/* Do not allow a IOMODE_READ segment to have write pemissions */
51 	if (seg->iomode == IOMODE_READ) {
52 		u = from_kuid(&init_user_ns, inode->i_uid) + 1;
53 		fl->uid = make_kuid(&init_user_ns, u);
54 	} else
55 		fl->uid = inode->i_uid;
56 	fl->gid = inode->i_gid;
57 
58 	error = nfsd4_set_deviceid(&fl->deviceid, fhp, device_generation);
59 	if (error)
60 		goto out_error;
61 
62 	fl->fh.size = fhp->fh_handle.fh_size;
63 	memcpy(fl->fh.data, &fhp->fh_handle.fh_base, fl->fh.size);
64 
65 	/* Give whole file layout segments */
66 	seg->offset = 0;
67 	seg->length = NFS4_MAX_UINT64;
68 
69 	dprintk("GET: 0x%llx:0x%llx %d\n", seg->offset, seg->length,
70 		seg->iomode);
71 	return 0;
72 
73 out_error:
74 	seg->length = 0;
75 	return nfserrno(error);
76 }
77 
78 static __be32
79 nfsd4_ff_proc_getdeviceinfo(struct super_block *sb, struct svc_rqst *rqstp,
80 		struct nfs4_client *clp, struct nfsd4_getdeviceinfo *gdp)
81 {
82 	struct pnfs_ff_device_addr *da;
83 
84 	u16 port;
85 	char addr[INET6_ADDRSTRLEN];
86 
87 	da = kzalloc(sizeof(struct pnfs_ff_device_addr), GFP_KERNEL);
88 	if (!da)
89 		return nfserrno(-ENOMEM);
90 
91 	gdp->gd_device = da;
92 
93 	da->version = 3;
94 	da->minor_version = 0;
95 
96 	da->rsize = svc_max_payload(rqstp);
97 	da->wsize = da->rsize;
98 
99 	rpc_ntop((struct sockaddr *)&rqstp->rq_daddr,
100 		 addr, INET6_ADDRSTRLEN);
101 	if (rqstp->rq_daddr.ss_family == AF_INET) {
102 		struct sockaddr_in *sin;
103 
104 		sin = (struct sockaddr_in *)&rqstp->rq_daddr;
105 		port = ntohs(sin->sin_port);
106 		snprintf(da->netaddr.netid, FF_NETID_LEN + 1, "tcp");
107 		da->netaddr.netid_len = 3;
108 	} else {
109 		struct sockaddr_in6 *sin6;
110 
111 		sin6 = (struct sockaddr_in6 *)&rqstp->rq_daddr;
112 		port = ntohs(sin6->sin6_port);
113 		snprintf(da->netaddr.netid, FF_NETID_LEN + 1, "tcp6");
114 		da->netaddr.netid_len = 4;
115 	}
116 
117 	da->netaddr.addr_len =
118 		snprintf(da->netaddr.addr, FF_ADDR_LEN + 1,
119 			 "%s.%hhu.%hhu", addr, port >> 8, port & 0xff);
120 
121 	da->tightly_coupled = false;
122 
123 	return 0;
124 }
125 
126 const struct nfsd4_layout_ops ff_layout_ops = {
127 	.notify_types		=
128 			NOTIFY_DEVICEID4_DELETE | NOTIFY_DEVICEID4_CHANGE,
129 	.disable_recalls	= true,
130 	.proc_getdeviceinfo	= nfsd4_ff_proc_getdeviceinfo,
131 	.encode_getdeviceinfo	= nfsd4_ff_encode_getdeviceinfo,
132 	.proc_layoutget		= nfsd4_ff_proc_layoutget,
133 	.encode_layoutget	= nfsd4_ff_encode_layoutget,
134 };
135