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3d14c5d2 | 1 | #include <linux/ceph/ceph_debug.h> |
a8e63b7d SW |
2 | |
3 | #include <linux/exportfs.h> | |
5a0e3ad6 | 4 | #include <linux/slab.h> |
a8e63b7d SW |
5 | #include <asm/unaligned.h> |
6 | ||
7 | #include "super.h" | |
3d14c5d2 | 8 | #include "mds_client.h" |
a8e63b7d SW |
9 | |
10 | /* | |
11 | * NFS export support | |
12 | * | |
13 | * NFS re-export of a ceph mount is, at present, only semireliable. | |
14 | * The basic issue is that the Ceph architectures doesn't lend itself | |
15 | * well to generating filehandles that will remain valid forever. | |
16 | * | |
17 | * So, we do our best. If you're lucky, your inode will be in the | |
18 | * client's cache. If it's not, and you have a connectable fh, then | |
19 | * the MDS server may be able to find it for you. Otherwise, you get | |
20 | * ESTALE. | |
21 | * | |
22 | * There are ways to this more reliable, but in the non-connectable fh | |
23 | * case, we won't every work perfectly, and in the connectable case, | |
24 | * some changes are needed on the MDS side to work better. | |
25 | */ | |
26 | ||
27 | /* | |
28 | * Basic fh | |
29 | */ | |
30 | struct ceph_nfs_fh { | |
31 | u64 ino; | |
32 | } __attribute__ ((packed)); | |
33 | ||
34 | /* | |
35 | * Larger 'connectable' fh that includes parent ino and name hash. | |
36 | * Use this whenever possible, as it works more reliably. | |
37 | */ | |
38 | struct ceph_nfs_confh { | |
39 | u64 ino, parent_ino; | |
40 | u32 parent_name_hash; | |
41 | } __attribute__ ((packed)); | |
42 | ||
43 | static int ceph_encode_fh(struct dentry *dentry, u32 *rawfh, int *max_len, | |
44 | int connectable) | |
45 | { | |
92923dcb | 46 | int type; |
a8e63b7d SW |
47 | struct ceph_nfs_fh *fh = (void *)rawfh; |
48 | struct ceph_nfs_confh *cfh = (void *)rawfh; | |
e5f86dc3 | 49 | struct dentry *parent; |
a8e63b7d | 50 | struct inode *inode = dentry->d_inode; |
92923dcb AK |
51 | int connected_handle_length = sizeof(*cfh)/4; |
52 | int handle_length = sizeof(*fh)/4; | |
a8e63b7d SW |
53 | |
54 | /* don't re-export snaps */ | |
55 | if (ceph_snap(inode) != CEPH_NOSNAP) | |
56 | return -EINVAL; | |
57 | ||
e5f86dc3 | 58 | spin_lock(&dentry->d_lock); |
ee6b1baf | 59 | parent = dentry->d_parent; |
92923dcb | 60 | if (*max_len >= connected_handle_length) { |
a8e63b7d SW |
61 | dout("encode_fh %p connectable\n", dentry); |
62 | cfh->ino = ceph_ino(dentry->d_inode); | |
63 | cfh->parent_ino = ceph_ino(parent->d_inode); | |
e5f86dc3 SW |
64 | cfh->parent_name_hash = ceph_dentry_hash(parent->d_inode, |
65 | dentry); | |
92923dcb | 66 | *max_len = connected_handle_length; |
a8e63b7d | 67 | type = 2; |
92923dcb | 68 | } else if (*max_len >= handle_length) { |
bba0cd0e AK |
69 | if (connectable) { |
70 | *max_len = connected_handle_length; | |
e5f86dc3 SW |
71 | type = 255; |
72 | } else { | |
73 | dout("encode_fh %p\n", dentry); | |
74 | fh->ino = ceph_ino(dentry->d_inode); | |
75 | *max_len = handle_length; | |
76 | type = 1; | |
bba0cd0e | 77 | } |
a8e63b7d | 78 | } else { |
bba0cd0e | 79 | *max_len = handle_length; |
e5f86dc3 | 80 | type = 255; |
a8e63b7d | 81 | } |
ee6b1baf | 82 | spin_unlock(&dentry->d_lock); |
a8e63b7d SW |
83 | return type; |
84 | } | |
85 | ||
86 | /* | |
87 | * convert regular fh to dentry | |
88 | * | |
89 | * FIXME: we should try harder by querying the mds for the ino. | |
90 | */ | |
91 | static struct dentry *__fh_to_dentry(struct super_block *sb, | |
92 | struct ceph_nfs_fh *fh) | |
93 | { | |
3c454cf2 | 94 | struct ceph_mds_client *mdsc = ceph_sb_to_client(sb)->mdsc; |
a8e63b7d SW |
95 | struct inode *inode; |
96 | struct dentry *dentry; | |
97 | struct ceph_vino vino; | |
98 | int err; | |
99 | ||
100 | dout("__fh_to_dentry %llx\n", fh->ino); | |
101 | vino.ino = fh->ino; | |
102 | vino.snap = CEPH_NOSNAP; | |
103 | inode = ceph_find_inode(sb, vino); | |
3c454cf2 SW |
104 | if (!inode) { |
105 | struct ceph_mds_request *req; | |
106 | ||
107 | req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_LOOKUPINO, | |
108 | USE_ANY_MDS); | |
109 | if (IS_ERR(req)) | |
110 | return ERR_CAST(req); | |
111 | ||
112 | req->r_ino1 = vino; | |
113 | req->r_num_caps = 1; | |
114 | err = ceph_mdsc_do_request(mdsc, NULL, req); | |
45e3d3ee SW |
115 | inode = req->r_target_inode; |
116 | if (inode) | |
70b666c3 | 117 | ihold(inode); |
3c454cf2 | 118 | ceph_mdsc_put_request(req); |
3c454cf2 SW |
119 | if (!inode) |
120 | return ERR_PTR(-ESTALE); | |
121 | } | |
a8e63b7d SW |
122 | |
123 | dentry = d_obtain_alias(inode); | |
0d509c94 | 124 | if (IS_ERR(dentry)) { |
a8e63b7d SW |
125 | pr_err("fh_to_dentry %llx -- inode %p but ENOMEM\n", |
126 | fh->ino, inode); | |
127 | iput(inode); | |
0d509c94 | 128 | return dentry; |
a8e63b7d SW |
129 | } |
130 | err = ceph_init_dentry(dentry); | |
a8e63b7d SW |
131 | if (err < 0) { |
132 | iput(inode); | |
133 | return ERR_PTR(err); | |
134 | } | |
135 | dout("__fh_to_dentry %llx %p dentry %p\n", fh->ino, inode, dentry); | |
136 | return dentry; | |
137 | } | |
138 | ||
139 | /* | |
140 | * convert connectable fh to dentry | |
141 | */ | |
142 | static struct dentry *__cfh_to_dentry(struct super_block *sb, | |
143 | struct ceph_nfs_confh *cfh) | |
144 | { | |
3d14c5d2 | 145 | struct ceph_mds_client *mdsc = ceph_sb_to_client(sb)->mdsc; |
a8e63b7d SW |
146 | struct inode *inode; |
147 | struct dentry *dentry; | |
148 | struct ceph_vino vino; | |
149 | int err; | |
150 | ||
151 | dout("__cfh_to_dentry %llx (%llx/%x)\n", | |
152 | cfh->ino, cfh->parent_ino, cfh->parent_name_hash); | |
153 | ||
154 | vino.ino = cfh->ino; | |
155 | vino.snap = CEPH_NOSNAP; | |
156 | inode = ceph_find_inode(sb, vino); | |
157 | if (!inode) { | |
158 | struct ceph_mds_request *req; | |
159 | ||
160 | req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_LOOKUPHASH, | |
161 | USE_ANY_MDS); | |
162 | if (IS_ERR(req)) | |
7e34bc52 | 163 | return ERR_CAST(req); |
a8e63b7d SW |
164 | |
165 | req->r_ino1 = vino; | |
166 | req->r_ino2.ino = cfh->parent_ino; | |
167 | req->r_ino2.snap = CEPH_NOSNAP; | |
168 | req->r_path2 = kmalloc(16, GFP_NOFS); | |
169 | snprintf(req->r_path2, 16, "%d", cfh->parent_name_hash); | |
170 | req->r_num_caps = 1; | |
171 | err = ceph_mdsc_do_request(mdsc, NULL, req); | |
45e3d3ee SW |
172 | inode = req->r_target_inode; |
173 | if (inode) | |
70b666c3 | 174 | ihold(inode); |
a8e63b7d | 175 | ceph_mdsc_put_request(req); |
a8e63b7d SW |
176 | if (!inode) |
177 | return ERR_PTR(err ? err : -ESTALE); | |
178 | } | |
179 | ||
180 | dentry = d_obtain_alias(inode); | |
0d509c94 | 181 | if (IS_ERR(dentry)) { |
a8e63b7d SW |
182 | pr_err("cfh_to_dentry %llx -- inode %p but ENOMEM\n", |
183 | cfh->ino, inode); | |
184 | iput(inode); | |
0d509c94 | 185 | return dentry; |
a8e63b7d SW |
186 | } |
187 | err = ceph_init_dentry(dentry); | |
188 | if (err < 0) { | |
189 | iput(inode); | |
190 | return ERR_PTR(err); | |
191 | } | |
192 | dout("__cfh_to_dentry %llx %p dentry %p\n", cfh->ino, inode, dentry); | |
193 | return dentry; | |
194 | } | |
195 | ||
196 | static struct dentry *ceph_fh_to_dentry(struct super_block *sb, struct fid *fid, | |
197 | int fh_len, int fh_type) | |
198 | { | |
199 | if (fh_type == 1) | |
200 | return __fh_to_dentry(sb, (struct ceph_nfs_fh *)fid->raw); | |
201 | else | |
202 | return __cfh_to_dentry(sb, (struct ceph_nfs_confh *)fid->raw); | |
203 | } | |
204 | ||
205 | /* | |
206 | * get parent, if possible. | |
207 | * | |
208 | * FIXME: we could do better by querying the mds to discover the | |
209 | * parent. | |
210 | */ | |
211 | static struct dentry *ceph_fh_to_parent(struct super_block *sb, | |
212 | struct fid *fid, | |
213 | int fh_len, int fh_type) | |
214 | { | |
215 | struct ceph_nfs_confh *cfh = (void *)fid->raw; | |
216 | struct ceph_vino vino; | |
217 | struct inode *inode; | |
218 | struct dentry *dentry; | |
219 | int err; | |
220 | ||
221 | if (fh_type == 1) | |
222 | return ERR_PTR(-ESTALE); | |
223 | ||
224 | pr_debug("fh_to_parent %llx/%d\n", cfh->parent_ino, | |
225 | cfh->parent_name_hash); | |
226 | ||
227 | vino.ino = cfh->ino; | |
228 | vino.snap = CEPH_NOSNAP; | |
229 | inode = ceph_find_inode(sb, vino); | |
230 | if (!inode) | |
231 | return ERR_PTR(-ESTALE); | |
232 | ||
233 | dentry = d_obtain_alias(inode); | |
0d509c94 | 234 | if (IS_ERR(dentry)) { |
a8e63b7d SW |
235 | pr_err("fh_to_parent %llx -- inode %p but ENOMEM\n", |
236 | cfh->ino, inode); | |
237 | iput(inode); | |
0d509c94 | 238 | return dentry; |
a8e63b7d SW |
239 | } |
240 | err = ceph_init_dentry(dentry); | |
241 | if (err < 0) { | |
242 | iput(inode); | |
243 | return ERR_PTR(err); | |
244 | } | |
245 | dout("fh_to_parent %llx %p dentry %p\n", cfh->ino, inode, dentry); | |
246 | return dentry; | |
247 | } | |
248 | ||
249 | const struct export_operations ceph_export_ops = { | |
b0b0382b | 250 | #ifdef CEPH_BREAKAGE_FIXED |
a8e63b7d | 251 | .encode_fh = ceph_encode_fh, |
b0b0382b | 252 | #endif |
a8e63b7d SW |
253 | .fh_to_dentry = ceph_fh_to_dentry, |
254 | .fh_to_parent = ceph_fh_to_parent, | |
255 | }; |