xref: /openbmc/linux/fs/ceph/export.c (revision a06c488d)
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 dentry *dentry;
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 
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 		req->r_ino1 = vino;
81 		req->r_num_caps = 1;
82 		err = ceph_mdsc_do_request(mdsc, NULL, req);
83 		inode = req->r_target_inode;
84 		if (inode)
85 			ihold(inode);
86 		ceph_mdsc_put_request(req);
87 		if (!inode)
88 			return ERR_PTR(-ESTALE);
89 	}
90 
91 	dentry = d_obtain_alias(inode);
92 	if (IS_ERR(dentry)) {
93 		iput(inode);
94 		return dentry;
95 	}
96 	err = ceph_init_dentry(dentry);
97 	if (err < 0) {
98 		dput(dentry);
99 		return ERR_PTR(err);
100 	}
101 	dout("__fh_to_dentry %llx %p dentry %p\n", ino, inode, dentry);
102 	return dentry;
103 }
104 
105 /*
106  * convert regular fh to dentry
107  */
108 static struct dentry *ceph_fh_to_dentry(struct super_block *sb,
109 					struct fid *fid,
110 					int fh_len, int fh_type)
111 {
112 	struct ceph_nfs_fh *fh = (void *)fid->raw;
113 
114 	if (fh_type != FILEID_INO32_GEN  &&
115 	    fh_type != FILEID_INO32_GEN_PARENT)
116 		return NULL;
117 	if (fh_len < sizeof(*fh) / 4)
118 		return NULL;
119 
120 	dout("fh_to_dentry %llx\n", fh->ino);
121 	return __fh_to_dentry(sb, fh->ino);
122 }
123 
124 static struct dentry *__get_parent(struct super_block *sb,
125 				   struct dentry *child, u64 ino)
126 {
127 	struct ceph_mds_client *mdsc = ceph_sb_to_client(sb)->mdsc;
128 	struct ceph_mds_request *req;
129 	struct inode *inode;
130 	struct dentry *dentry;
131 	int err;
132 
133 	req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_LOOKUPPARENT,
134 				       USE_ANY_MDS);
135 	if (IS_ERR(req))
136 		return ERR_CAST(req);
137 
138 	if (child) {
139 		req->r_inode = d_inode(child);
140 		ihold(d_inode(child));
141 	} else {
142 		req->r_ino1 = (struct ceph_vino) {
143 			.ino = ino,
144 			.snap = CEPH_NOSNAP,
145 		};
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 	dentry = d_obtain_alias(inode);
157 	if (IS_ERR(dentry)) {
158 		iput(inode);
159 		return dentry;
160 	}
161 	err = ceph_init_dentry(dentry);
162 	if (err < 0) {
163 		dput(dentry);
164 		return ERR_PTR(err);
165 	}
166 	dout("__get_parent ino %llx parent %p ino %llx.%llx\n",
167 	     child ? ceph_ino(d_inode(child)) : ino,
168 	     dentry, ceph_vinop(inode));
169 	return dentry;
170 }
171 
172 static struct dentry *ceph_get_parent(struct dentry *child)
173 {
174 	/* don't re-export snaps */
175 	if (ceph_snap(d_inode(child)) != CEPH_NOSNAP)
176 		return ERR_PTR(-EINVAL);
177 
178 	dout("get_parent %p ino %llx.%llx\n",
179 	     child, ceph_vinop(d_inode(child)));
180 	return __get_parent(child->d_sb, child, 0);
181 }
182 
183 /*
184  * convert regular fh to parent
185  */
186 static struct dentry *ceph_fh_to_parent(struct super_block *sb,
187 					struct fid *fid,
188 					int fh_len, int fh_type)
189 {
190 	struct ceph_nfs_confh *cfh = (void *)fid->raw;
191 	struct dentry *dentry;
192 
193 	if (fh_type != FILEID_INO32_GEN_PARENT)
194 		return NULL;
195 	if (fh_len < sizeof(*cfh) / 4)
196 		return NULL;
197 
198 	dout("fh_to_parent %llx\n", cfh->parent_ino);
199 	dentry = __get_parent(sb, NULL, cfh->ino);
200 	if (IS_ERR(dentry) && PTR_ERR(dentry) == -ENOENT)
201 		dentry = __fh_to_dentry(sb, cfh->parent_ino);
202 	return dentry;
203 }
204 
205 static int ceph_get_name(struct dentry *parent, char *name,
206 			 struct dentry *child)
207 {
208 	struct ceph_mds_client *mdsc;
209 	struct ceph_mds_request *req;
210 	int err;
211 
212 	mdsc = ceph_inode_to_client(d_inode(child))->mdsc;
213 	req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_LOOKUPNAME,
214 				       USE_ANY_MDS);
215 	if (IS_ERR(req))
216 		return PTR_ERR(req);
217 
218 	inode_lock(d_inode(parent));
219 
220 	req->r_inode = d_inode(child);
221 	ihold(d_inode(child));
222 	req->r_ino2 = ceph_vino(d_inode(parent));
223 	req->r_locked_dir = d_inode(parent);
224 	req->r_num_caps = 2;
225 	err = ceph_mdsc_do_request(mdsc, NULL, req);
226 
227 	inode_unlock(d_inode(parent));
228 
229 	if (!err) {
230 		struct ceph_mds_reply_info_parsed *rinfo = &req->r_reply_info;
231 		memcpy(name, rinfo->dname, rinfo->dname_len);
232 		name[rinfo->dname_len] = 0;
233 		dout("get_name %p ino %llx.%llx name %s\n",
234 		     child, ceph_vinop(d_inode(child)), name);
235 	} else {
236 		dout("get_name %p ino %llx.%llx err %d\n",
237 		     child, ceph_vinop(d_inode(child)), err);
238 	}
239 
240 	ceph_mdsc_put_request(req);
241 	return err;
242 }
243 
244 const struct export_operations ceph_export_ops = {
245 	.encode_fh = ceph_encode_fh,
246 	.fh_to_dentry = ceph_fh_to_dentry,
247 	.fh_to_parent = ceph_fh_to_parent,
248 	.get_parent = ceph_get_parent,
249 	.get_name = ceph_get_name,
250 };
251