Commit | Line | Data |
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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 | ||
c862868b SW |
43 | /* |
44 | * The presence of @parent_inode here tells us whether NFS wants a | |
45 | * connectable file handle. However, we want to make a connectionable | |
46 | * file handle unconditionally so that the MDS gets as much of a hint | |
47 | * as possible. That means we only use @parent_dentry to indicate | |
48 | * whether nfsd wants a connectable fh, and whether we should indicate | |
49 | * failure from a too-small @max_len. | |
50 | */ | |
51 | static int ceph_encode_fh(struct inode *inode, u32 *rawfh, int *max_len, | |
52 | struct inode *parent_inode) | |
a8e63b7d | 53 | { |
92923dcb | 54 | int type; |
a8e63b7d SW |
55 | struct ceph_nfs_fh *fh = (void *)rawfh; |
56 | struct ceph_nfs_confh *cfh = (void *)rawfh; | |
92923dcb AK |
57 | int connected_handle_length = sizeof(*cfh)/4; |
58 | int handle_length = sizeof(*fh)/4; | |
c862868b SW |
59 | struct dentry *dentry = d_find_alias(inode); |
60 | struct dentry *parent; | |
a8e63b7d SW |
61 | |
62 | /* don't re-export snaps */ | |
63 | if (ceph_snap(inode) != CEPH_NOSNAP) | |
64 | return -EINVAL; | |
65 | ||
c862868b SW |
66 | /* if we found an alias, generate a connectable fh */ |
67 | if (*max_len >= connected_handle_length && dentry) { | |
a8e63b7d | 68 | dout("encode_fh %p connectable\n", dentry); |
c862868b SW |
69 | spin_lock(&dentry->d_lock); |
70 | parent = dentry->d_parent; | |
71 | cfh->ino = ceph_ino(inode); | |
a8e63b7d | 72 | cfh->parent_ino = ceph_ino(parent->d_inode); |
e5f86dc3 SW |
73 | cfh->parent_name_hash = ceph_dentry_hash(parent->d_inode, |
74 | dentry); | |
92923dcb | 75 | *max_len = connected_handle_length; |
a8e63b7d | 76 | type = 2; |
c862868b | 77 | spin_unlock(&dentry->d_lock); |
92923dcb | 78 | } else if (*max_len >= handle_length) { |
c862868b SW |
79 | if (parent_inode) { |
80 | /* nfsd wants connectable */ | |
bba0cd0e | 81 | *max_len = connected_handle_length; |
e5f86dc3 SW |
82 | type = 255; |
83 | } else { | |
84 | dout("encode_fh %p\n", dentry); | |
c862868b | 85 | fh->ino = ceph_ino(inode); |
e5f86dc3 SW |
86 | *max_len = handle_length; |
87 | type = 1; | |
bba0cd0e | 88 | } |
a8e63b7d | 89 | } else { |
bba0cd0e | 90 | *max_len = handle_length; |
e5f86dc3 | 91 | type = 255; |
a8e63b7d SW |
92 | } |
93 | return type; | |
94 | } | |
95 | ||
96 | /* | |
97 | * convert regular fh to dentry | |
98 | * | |
99 | * FIXME: we should try harder by querying the mds for the ino. | |
100 | */ | |
101 | static struct dentry *__fh_to_dentry(struct super_block *sb, | |
102 | struct ceph_nfs_fh *fh) | |
103 | { | |
3c454cf2 | 104 | struct ceph_mds_client *mdsc = ceph_sb_to_client(sb)->mdsc; |
a8e63b7d SW |
105 | struct inode *inode; |
106 | struct dentry *dentry; | |
107 | struct ceph_vino vino; | |
108 | int err; | |
109 | ||
110 | dout("__fh_to_dentry %llx\n", fh->ino); | |
111 | vino.ino = fh->ino; | |
112 | vino.snap = CEPH_NOSNAP; | |
113 | inode = ceph_find_inode(sb, vino); | |
3c454cf2 SW |
114 | if (!inode) { |
115 | struct ceph_mds_request *req; | |
116 | ||
117 | req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_LOOKUPINO, | |
118 | USE_ANY_MDS); | |
119 | if (IS_ERR(req)) | |
120 | return ERR_CAST(req); | |
121 | ||
122 | req->r_ino1 = vino; | |
123 | req->r_num_caps = 1; | |
124 | err = ceph_mdsc_do_request(mdsc, NULL, req); | |
45e3d3ee SW |
125 | inode = req->r_target_inode; |
126 | if (inode) | |
70b666c3 | 127 | ihold(inode); |
3c454cf2 | 128 | ceph_mdsc_put_request(req); |
3c454cf2 SW |
129 | if (!inode) |
130 | return ERR_PTR(-ESTALE); | |
131 | } | |
a8e63b7d SW |
132 | |
133 | dentry = d_obtain_alias(inode); | |
0d509c94 | 134 | if (IS_ERR(dentry)) { |
a8e63b7d SW |
135 | pr_err("fh_to_dentry %llx -- inode %p but ENOMEM\n", |
136 | fh->ino, inode); | |
137 | iput(inode); | |
0d509c94 | 138 | return dentry; |
a8e63b7d SW |
139 | } |
140 | err = ceph_init_dentry(dentry); | |
a8e63b7d SW |
141 | if (err < 0) { |
142 | iput(inode); | |
143 | return ERR_PTR(err); | |
144 | } | |
145 | dout("__fh_to_dentry %llx %p dentry %p\n", fh->ino, inode, dentry); | |
146 | return dentry; | |
147 | } | |
148 | ||
149 | /* | |
150 | * convert connectable fh to dentry | |
151 | */ | |
152 | static struct dentry *__cfh_to_dentry(struct super_block *sb, | |
153 | struct ceph_nfs_confh *cfh) | |
154 | { | |
3d14c5d2 | 155 | struct ceph_mds_client *mdsc = ceph_sb_to_client(sb)->mdsc; |
a8e63b7d SW |
156 | struct inode *inode; |
157 | struct dentry *dentry; | |
158 | struct ceph_vino vino; | |
159 | int err; | |
160 | ||
161 | dout("__cfh_to_dentry %llx (%llx/%x)\n", | |
162 | cfh->ino, cfh->parent_ino, cfh->parent_name_hash); | |
163 | ||
164 | vino.ino = cfh->ino; | |
165 | vino.snap = CEPH_NOSNAP; | |
166 | inode = ceph_find_inode(sb, vino); | |
167 | if (!inode) { | |
168 | struct ceph_mds_request *req; | |
169 | ||
170 | req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_LOOKUPHASH, | |
171 | USE_ANY_MDS); | |
172 | if (IS_ERR(req)) | |
7e34bc52 | 173 | return ERR_CAST(req); |
a8e63b7d SW |
174 | |
175 | req->r_ino1 = vino; | |
176 | req->r_ino2.ino = cfh->parent_ino; | |
177 | req->r_ino2.snap = CEPH_NOSNAP; | |
178 | req->r_path2 = kmalloc(16, GFP_NOFS); | |
179 | snprintf(req->r_path2, 16, "%d", cfh->parent_name_hash); | |
180 | req->r_num_caps = 1; | |
181 | err = ceph_mdsc_do_request(mdsc, NULL, req); | |
45e3d3ee SW |
182 | inode = req->r_target_inode; |
183 | if (inode) | |
70b666c3 | 184 | ihold(inode); |
a8e63b7d | 185 | ceph_mdsc_put_request(req); |
a8e63b7d SW |
186 | if (!inode) |
187 | return ERR_PTR(err ? err : -ESTALE); | |
188 | } | |
189 | ||
190 | dentry = d_obtain_alias(inode); | |
0d509c94 | 191 | if (IS_ERR(dentry)) { |
a8e63b7d SW |
192 | pr_err("cfh_to_dentry %llx -- inode %p but ENOMEM\n", |
193 | cfh->ino, inode); | |
194 | iput(inode); | |
0d509c94 | 195 | return dentry; |
a8e63b7d SW |
196 | } |
197 | err = ceph_init_dentry(dentry); | |
198 | if (err < 0) { | |
199 | iput(inode); | |
200 | return ERR_PTR(err); | |
201 | } | |
202 | dout("__cfh_to_dentry %llx %p dentry %p\n", cfh->ino, inode, dentry); | |
203 | return dentry; | |
204 | } | |
205 | ||
206 | static struct dentry *ceph_fh_to_dentry(struct super_block *sb, struct fid *fid, | |
207 | int fh_len, int fh_type) | |
208 | { | |
209 | if (fh_type == 1) | |
210 | return __fh_to_dentry(sb, (struct ceph_nfs_fh *)fid->raw); | |
211 | else | |
212 | return __cfh_to_dentry(sb, (struct ceph_nfs_confh *)fid->raw); | |
213 | } | |
214 | ||
215 | /* | |
216 | * get parent, if possible. | |
217 | * | |
218 | * FIXME: we could do better by querying the mds to discover the | |
219 | * parent. | |
220 | */ | |
221 | static struct dentry *ceph_fh_to_parent(struct super_block *sb, | |
222 | struct fid *fid, | |
223 | int fh_len, int fh_type) | |
224 | { | |
225 | struct ceph_nfs_confh *cfh = (void *)fid->raw; | |
226 | struct ceph_vino vino; | |
227 | struct inode *inode; | |
228 | struct dentry *dentry; | |
229 | int err; | |
230 | ||
231 | if (fh_type == 1) | |
232 | return ERR_PTR(-ESTALE); | |
233 | ||
234 | pr_debug("fh_to_parent %llx/%d\n", cfh->parent_ino, | |
235 | cfh->parent_name_hash); | |
236 | ||
237 | vino.ino = cfh->ino; | |
238 | vino.snap = CEPH_NOSNAP; | |
239 | inode = ceph_find_inode(sb, vino); | |
240 | if (!inode) | |
241 | return ERR_PTR(-ESTALE); | |
242 | ||
243 | dentry = d_obtain_alias(inode); | |
0d509c94 | 244 | if (IS_ERR(dentry)) { |
a8e63b7d SW |
245 | pr_err("fh_to_parent %llx -- inode %p but ENOMEM\n", |
246 | cfh->ino, inode); | |
247 | iput(inode); | |
0d509c94 | 248 | return dentry; |
a8e63b7d SW |
249 | } |
250 | err = ceph_init_dentry(dentry); | |
251 | if (err < 0) { | |
252 | iput(inode); | |
253 | return ERR_PTR(err); | |
254 | } | |
255 | dout("fh_to_parent %llx %p dentry %p\n", cfh->ino, inode, dentry); | |
256 | return dentry; | |
257 | } | |
258 | ||
259 | const struct export_operations ceph_export_ops = { | |
260 | .encode_fh = ceph_encode_fh, | |
261 | .fh_to_dentry = ceph_fh_to_dentry, | |
262 | .fh_to_parent = ceph_fh_to_parent, | |
263 | }; |