ceph: tolerate bad i_size for symlink inode
[deliverable/linux.git] / fs / ceph / export.c
CommitLineData
3d14c5d2 1#include <linux/ceph/ceph_debug.h>
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2
3#include <linux/exportfs.h>
5a0e3ad6 4#include <linux/slab.h>
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5#include <asm/unaligned.h>
6
7#include "super.h"
3d14c5d2 8#include "mds_client.h"
a8e63b7d 9
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10/*
11 * Basic fh
12 */
13struct ceph_nfs_fh {
14 u64 ino;
15} __attribute__ ((packed));
16
17/*
4f32b42d 18 * Larger fh that includes parent ino.
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19 */
20struct ceph_nfs_confh {
21 u64 ino, parent_ino;
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22} __attribute__ ((packed));
23
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24static int ceph_encode_fh(struct inode *inode, u32 *rawfh, int *max_len,
25 struct inode *parent_inode)
a8e63b7d 26{
92923dcb 27 int type;
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28 struct ceph_nfs_fh *fh = (void *)rawfh;
29 struct ceph_nfs_confh *cfh = (void *)rawfh;
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30 int connected_handle_length = sizeof(*cfh)/4;
31 int handle_length = sizeof(*fh)/4;
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32
33 /* don't re-export snaps */
34 if (ceph_snap(inode) != CEPH_NOSNAP)
35 return -EINVAL;
36
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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 }
f6af75da 44
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45 if (parent_inode) {
46 dout("encode_fh %llx with parent %llx\n",
47 ceph_ino(inode), ceph_ino(parent_inode));
c862868b 48 cfh->ino = ceph_ino(inode);
4f32b42d 49 cfh->parent_ino = ceph_ino(parent_inode);
92923dcb 50 *max_len = connected_handle_length;
4f32b42d 51 type = FILEID_INO32_GEN_PARENT;
a8e63b7d 52 } else {
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53 dout("encode_fh %llx\n", ceph_ino(inode));
54 fh->ino = ceph_ino(inode);
bba0cd0e 55 *max_len = handle_length;
4f32b42d 56 type = FILEID_INO32_GEN;
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57 }
58 return type;
59}
60
4f32b42d 61static struct dentry *__fh_to_dentry(struct super_block *sb, u64 ino)
a8e63b7d 62{
3c454cf2 63 struct ceph_mds_client *mdsc = ceph_sb_to_client(sb)->mdsc;
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64 struct inode *inode;
65 struct dentry *dentry;
66 struct ceph_vino vino;
67 int err;
68
4f32b42d 69 vino.ino = ino;
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70 vino.snap = CEPH_NOSNAP;
71 inode = ceph_find_inode(sb, vino);
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72 if (!inode) {
73 struct ceph_mds_request *req;
315f2408 74 int mask;
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75
76 req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_LOOKUPINO,
77 USE_ANY_MDS);
78 if (IS_ERR(req))
79 return ERR_CAST(req);
80
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81 mask = CEPH_STAT_CAP_INODE;
82 if (ceph_security_xattr_wanted(d_inode(sb->s_root)))
83 mask |= CEPH_CAP_XATTR_SHARED;
84 req->r_args.getattr.mask = cpu_to_le32(mask);
85
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86 req->r_ino1 = vino;
87 req->r_num_caps = 1;
88 err = ceph_mdsc_do_request(mdsc, NULL, req);
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89 inode = req->r_target_inode;
90 if (inode)
70b666c3 91 ihold(inode);
3c454cf2 92 ceph_mdsc_put_request(req);
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93 if (!inode)
94 return ERR_PTR(-ESTALE);
95 }
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96
97 dentry = d_obtain_alias(inode);
0d509c94 98 if (IS_ERR(dentry)) {
a8e63b7d 99 iput(inode);
0d509c94 100 return dentry;
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101 }
102 err = ceph_init_dentry(dentry);
a8e63b7d 103 if (err < 0) {
4f32b42d 104 dput(dentry);
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105 return ERR_PTR(err);
106 }
4f32b42d 107 dout("__fh_to_dentry %llx %p dentry %p\n", ino, inode, dentry);
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108 return dentry;
109}
110
111/*
4f32b42d 112 * convert regular fh to dentry
a8e63b7d 113 */
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114static struct dentry *ceph_fh_to_dentry(struct super_block *sb,
115 struct fid *fid,
116 int fh_len, int fh_type)
a8e63b7d 117{
4f32b42d 118 struct ceph_nfs_fh *fh = (void *)fid->raw;
a8e63b7d 119
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120 if (fh_type != FILEID_INO32_GEN &&
121 fh_type != FILEID_INO32_GEN_PARENT)
122 return NULL;
123 if (fh_len < sizeof(*fh) / 4)
124 return NULL;
a8e63b7d 125
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126 dout("fh_to_dentry %llx\n", fh->ino);
127 return __fh_to_dentry(sb, fh->ino);
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128}
129
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130static struct dentry *__get_parent(struct super_block *sb,
131 struct dentry *child, u64 ino)
132{
133 struct ceph_mds_client *mdsc = ceph_sb_to_client(sb)->mdsc;
134 struct ceph_mds_request *req;
135 struct inode *inode;
136 struct dentry *dentry;
315f2408 137 int mask;
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138 int err;
139
140 req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_LOOKUPPARENT,
141 USE_ANY_MDS);
142 if (IS_ERR(req))
143 return ERR_CAST(req);
144
145 if (child) {
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146 req->r_inode = d_inode(child);
147 ihold(d_inode(child));
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148 } else {
149 req->r_ino1 = (struct ceph_vino) {
150 .ino = ino,
151 .snap = CEPH_NOSNAP,
152 };
153 }
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154
155 mask = CEPH_STAT_CAP_INODE;
156 if (ceph_security_xattr_wanted(d_inode(sb->s_root)))
157 mask |= CEPH_CAP_XATTR_SHARED;
158 req->r_args.getattr.mask = cpu_to_le32(mask);
159
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160 req->r_num_caps = 1;
161 err = ceph_mdsc_do_request(mdsc, NULL, req);
162 inode = req->r_target_inode;
163 if (inode)
164 ihold(inode);
165 ceph_mdsc_put_request(req);
166 if (!inode)
167 return ERR_PTR(-ENOENT);
168
169 dentry = d_obtain_alias(inode);
170 if (IS_ERR(dentry)) {
171 iput(inode);
172 return dentry;
173 }
174 err = ceph_init_dentry(dentry);
175 if (err < 0) {
176 dput(dentry);
177 return ERR_PTR(err);
178 }
179 dout("__get_parent ino %llx parent %p ino %llx.%llx\n",
2b0143b5 180 child ? ceph_ino(d_inode(child)) : ino,
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181 dentry, ceph_vinop(inode));
182 return dentry;
183}
184
e84be11c 185static struct dentry *ceph_get_parent(struct dentry *child)
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186{
187 /* don't re-export snaps */
2b0143b5 188 if (ceph_snap(d_inode(child)) != CEPH_NOSNAP)
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189 return ERR_PTR(-EINVAL);
190
191 dout("get_parent %p ino %llx.%llx\n",
2b0143b5 192 child, ceph_vinop(d_inode(child)));
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193 return __get_parent(child->d_sb, child, 0);
194}
195
a8e63b7d 196/*
8996f4f2 197 * convert regular fh to parent
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198 */
199static struct dentry *ceph_fh_to_parent(struct super_block *sb,
8996f4f2 200 struct fid *fid,
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201 int fh_len, int fh_type)
202{
203 struct ceph_nfs_confh *cfh = (void *)fid->raw;
a8e63b7d 204 struct dentry *dentry;
a8e63b7d 205
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206 if (fh_type != FILEID_INO32_GEN_PARENT)
207 return NULL;
35c2a7f4 208 if (fh_len < sizeof(*cfh) / 4)
8996f4f2 209 return NULL;
a8e63b7d 210
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211 dout("fh_to_parent %llx\n", cfh->parent_ino);
212 dentry = __get_parent(sb, NULL, cfh->ino);
213 if (IS_ERR(dentry) && PTR_ERR(dentry) == -ENOENT)
214 dentry = __fh_to_dentry(sb, cfh->parent_ino);
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215 return dentry;
216}
217
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218static int ceph_get_name(struct dentry *parent, char *name,
219 struct dentry *child)
220{
221 struct ceph_mds_client *mdsc;
222 struct ceph_mds_request *req;
223 int err;
224
2b0143b5 225 mdsc = ceph_inode_to_client(d_inode(child))->mdsc;
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226 req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_LOOKUPNAME,
227 USE_ANY_MDS);
228 if (IS_ERR(req))
229 return PTR_ERR(req);
230
5955102c 231 inode_lock(d_inode(parent));
19913b4e 232
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DH
233 req->r_inode = d_inode(child);
234 ihold(d_inode(child));
235 req->r_ino2 = ceph_vino(d_inode(parent));
236 req->r_locked_dir = d_inode(parent);
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237 req->r_num_caps = 2;
238 err = ceph_mdsc_do_request(mdsc, NULL, req);
239
5955102c 240 inode_unlock(d_inode(parent));
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241
242 if (!err) {
243 struct ceph_mds_reply_info_parsed *rinfo = &req->r_reply_info;
244 memcpy(name, rinfo->dname, rinfo->dname_len);
245 name[rinfo->dname_len] = 0;
246 dout("get_name %p ino %llx.%llx name %s\n",
2b0143b5 247 child, ceph_vinop(d_inode(child)), name);
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248 } else {
249 dout("get_name %p ino %llx.%llx err %d\n",
2b0143b5 250 child, ceph_vinop(d_inode(child)), err);
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251 }
252
253 ceph_mdsc_put_request(req);
254 return err;
255}
256
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257const struct export_operations ceph_export_ops = {
258 .encode_fh = ceph_encode_fh,
259 .fh_to_dentry = ceph_fh_to_dentry,
260 .fh_to_parent = ceph_fh_to_parent,
9017c2ec 261 .get_parent = ceph_get_parent,
19913b4e 262 .get_name = ceph_get_name,
a8e63b7d 263};
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