xref: /openbmc/linux/fs/ceph/export.c (revision bb0eb050)
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 };
239