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