1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/ceph/ceph_debug.h>
3
4 #include <linux/exportfs.h>
5 #include <linux/slab.h>
6 #include <asm/unaligned.h>
7
8 #include "super.h"
9 #include "mds_client.h"
10
11 /*
12 * Basic fh
13 */
14 struct ceph_nfs_fh {
15 u64 ino;
16 } __attribute__ ((packed));
17
18 /*
19 * Larger fh that includes parent ino.
20 */
21 struct ceph_nfs_confh {
22 u64 ino, parent_ino;
23 } __attribute__ ((packed));
24
ceph_encode_fh(struct inode * inode,u32 * rawfh,int * max_len,struct inode * parent_inode)25 static int ceph_encode_fh(struct inode *inode, u32 *rawfh, int *max_len,
26 struct inode *parent_inode)
27 {
28 int type;
29 struct ceph_nfs_fh *fh = (void *)rawfh;
30 struct ceph_nfs_confh *cfh = (void *)rawfh;
31 int connected_handle_length = sizeof(*cfh)/4;
32 int handle_length = sizeof(*fh)/4;
33
34 /* don't re-export snaps */
35 if (ceph_snap(inode) != CEPH_NOSNAP)
36 return -EINVAL;
37
38 if (parent_inode && (*max_len < connected_handle_length)) {
39 *max_len = connected_handle_length;
40 return FILEID_INVALID;
41 } else if (*max_len < handle_length) {
42 *max_len = handle_length;
43 return FILEID_INVALID;
44 }
45
46 if (parent_inode) {
47 dout("encode_fh %llx with parent %llx\n",
48 ceph_ino(inode), ceph_ino(parent_inode));
49 cfh->ino = ceph_ino(inode);
50 cfh->parent_ino = ceph_ino(parent_inode);
51 *max_len = connected_handle_length;
52 type = FILEID_INO32_GEN_PARENT;
53 } else {
54 dout("encode_fh %llx\n", ceph_ino(inode));
55 fh->ino = ceph_ino(inode);
56 *max_len = handle_length;
57 type = FILEID_INO32_GEN;
58 }
59 return type;
60 }
61
__fh_to_dentry(struct super_block * sb,u64 ino)62 static struct dentry *__fh_to_dentry(struct super_block *sb, u64 ino)
63 {
64 struct ceph_mds_client *mdsc = ceph_sb_to_client(sb)->mdsc;
65 struct inode *inode;
66 struct ceph_vino vino;
67 int err;
68
69 vino.ino = ino;
70 vino.snap = CEPH_NOSNAP;
71 inode = ceph_find_inode(sb, vino);
72 if (!inode) {
73 struct ceph_mds_request *req;
74 int mask;
75
76 req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_LOOKUPINO,
77 USE_ANY_MDS);
78 if (IS_ERR(req))
79 return ERR_CAST(req);
80
81 mask = CEPH_STAT_CAP_INODE;
82 if (ceph_security_xattr_wanted(d_inode(sb->s_root)))
83 mask |= CEPH_CAP_XATTR_SHARED;
84 req->r_args.getattr.mask = cpu_to_le32(mask);
85
86 req->r_ino1 = vino;
87 req->r_num_caps = 1;
88 err = ceph_mdsc_do_request(mdsc, NULL, req);
89 inode = req->r_target_inode;
90 if (inode)
91 ihold(inode);
92 ceph_mdsc_put_request(req);
93 if (!inode)
94 return ERR_PTR(-ESTALE);
95 if (inode->i_nlink == 0) {
96 iput(inode);
97 return ERR_PTR(-ESTALE);
98 }
99 }
100
101 return d_obtain_alias(inode);
102 }
103
104 /*
105 * convert regular fh to dentry
106 */
ceph_fh_to_dentry(struct super_block * sb,struct fid * fid,int fh_len,int fh_type)107 static struct dentry *ceph_fh_to_dentry(struct super_block *sb,
108 struct fid *fid,
109 int fh_len, int fh_type)
110 {
111 struct ceph_nfs_fh *fh = (void *)fid->raw;
112
113 if (fh_type != FILEID_INO32_GEN &&
114 fh_type != FILEID_INO32_GEN_PARENT)
115 return NULL;
116 if (fh_len < sizeof(*fh) / 4)
117 return NULL;
118
119 dout("fh_to_dentry %llx\n", fh->ino);
120 return __fh_to_dentry(sb, fh->ino);
121 }
122
__get_parent(struct super_block * sb,struct dentry * child,u64 ino)123 static struct dentry *__get_parent(struct super_block *sb,
124 struct dentry *child, u64 ino)
125 {
126 struct ceph_mds_client *mdsc = ceph_sb_to_client(sb)->mdsc;
127 struct ceph_mds_request *req;
128 struct inode *inode;
129 int mask;
130 int err;
131
132 req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_LOOKUPPARENT,
133 USE_ANY_MDS);
134 if (IS_ERR(req))
135 return ERR_CAST(req);
136
137 if (child) {
138 req->r_inode = d_inode(child);
139 ihold(d_inode(child));
140 } else {
141 req->r_ino1 = (struct ceph_vino) {
142 .ino = ino,
143 .snap = CEPH_NOSNAP,
144 };
145 }
146
147 mask = CEPH_STAT_CAP_INODE;
148 if (ceph_security_xattr_wanted(d_inode(sb->s_root)))
149 mask |= CEPH_CAP_XATTR_SHARED;
150 req->r_args.getattr.mask = cpu_to_le32(mask);
151
152 req->r_num_caps = 1;
153 err = ceph_mdsc_do_request(mdsc, NULL, req);
154 if (err) {
155 ceph_mdsc_put_request(req);
156 return ERR_PTR(err);
157 }
158
159 inode = req->r_target_inode;
160 if (inode)
161 ihold(inode);
162 ceph_mdsc_put_request(req);
163 if (!inode)
164 return ERR_PTR(-ENOENT);
165
166 return d_obtain_alias(inode);
167 }
168
ceph_get_parent(struct dentry * child)169 static struct dentry *ceph_get_parent(struct dentry *child)
170 {
171 /* don't re-export snaps */
172 if (ceph_snap(d_inode(child)) != CEPH_NOSNAP)
173 return ERR_PTR(-EINVAL);
174
175 dout("get_parent %p ino %llx.%llx\n",
176 child, ceph_vinop(d_inode(child)));
177 return __get_parent(child->d_sb, child, 0);
178 }
179
180 /*
181 * convert regular fh to parent
182 */
ceph_fh_to_parent(struct super_block * sb,struct fid * fid,int fh_len,int fh_type)183 static struct dentry *ceph_fh_to_parent(struct super_block *sb,
184 struct fid *fid,
185 int fh_len, int fh_type)
186 {
187 struct ceph_nfs_confh *cfh = (void *)fid->raw;
188 struct dentry *dentry;
189
190 if (fh_type != FILEID_INO32_GEN_PARENT)
191 return NULL;
192 if (fh_len < sizeof(*cfh) / 4)
193 return NULL;
194
195 dout("fh_to_parent %llx\n", cfh->parent_ino);
196 dentry = __get_parent(sb, NULL, cfh->ino);
197 if (unlikely(dentry == ERR_PTR(-ENOENT)))
198 dentry = __fh_to_dentry(sb, cfh->parent_ino);
199 return dentry;
200 }
201
ceph_get_name(struct dentry * parent,char * name,struct dentry * child)202 static int ceph_get_name(struct dentry *parent, char *name,
203 struct dentry *child)
204 {
205 struct ceph_mds_client *mdsc;
206 struct ceph_mds_request *req;
207 int err;
208
209 mdsc = ceph_inode_to_client(d_inode(child))->mdsc;
210 req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_LOOKUPNAME,
211 USE_ANY_MDS);
212 if (IS_ERR(req))
213 return PTR_ERR(req);
214
215 inode_lock(d_inode(parent));
216
217 req->r_inode = d_inode(child);
218 ihold(d_inode(child));
219 req->r_ino2 = ceph_vino(d_inode(parent));
220 req->r_parent = d_inode(parent);
221 set_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags);
222 req->r_num_caps = 2;
223 err = ceph_mdsc_do_request(mdsc, NULL, req);
224
225 inode_unlock(d_inode(parent));
226
227 if (!err) {
228 struct ceph_mds_reply_info_parsed *rinfo = &req->r_reply_info;
229 memcpy(name, rinfo->dname, rinfo->dname_len);
230 name[rinfo->dname_len] = 0;
231 dout("get_name %p ino %llx.%llx name %s\n",
232 child, ceph_vinop(d_inode(child)), name);
233 } else {
234 dout("get_name %p ino %llx.%llx err %d\n",
235 child, ceph_vinop(d_inode(child)), err);
236 }
237
238 ceph_mdsc_put_request(req);
239 return err;
240 }
241
242 const struct export_operations ceph_export_ops = {
243 .encode_fh = ceph_encode_fh,
244 .fh_to_dentry = ceph_fh_to_dentry,
245 .fh_to_parent = ceph_fh_to_parent,
246 .get_parent = ceph_get_parent,
247 .get_name = ceph_get_name,
248 };
249