| 1 | // SPDX-License-Identifier: GPL-2.0 |
| 2 | #include <linux/ceph/ceph_debug.h> |
| 3 | |
| 4 | #include <linux/exportfs.h> |
| 5 | #include <linux/slab.h> |
| 6 | #include <asm/unaligned.h> |
| 7 | |
| 8 | #include "super.h" |
| 9 | #include "mds_client.h" |
| 10 | |
| 11 | /* |
| 12 | * Basic fh |
| 13 | */ |
| 14 | struct ceph_nfs_fh { |
| 15 | u64 ino; |
| 16 | } __attribute__ ((packed)); |
| 17 | |
| 18 | /* |
| 19 | * Larger fh that includes parent ino. |
| 20 | */ |
| 21 | struct ceph_nfs_confh { |
| 22 | u64 ino, parent_ino; |
| 23 | } __attribute__ ((packed)); |
| 24 | |
| 25 | static int ceph_encode_fh(struct inode *inode, u32 *rawfh, int *max_len, |
| 26 | struct inode *parent_inode) |
| 27 | { |
| 28 | int type; |
| 29 | struct ceph_nfs_fh *fh = (void *)rawfh; |
| 30 | struct ceph_nfs_confh *cfh = (void *)rawfh; |
| 31 | int connected_handle_length = sizeof(*cfh)/4; |
| 32 | int handle_length = sizeof(*fh)/4; |
| 33 | |
| 34 | /* don't re-export snaps */ |
| 35 | if (ceph_snap(inode) != CEPH_NOSNAP) |
| 36 | return -EINVAL; |
| 37 | |
| 38 | if (parent_inode && (*max_len < connected_handle_length)) { |
| 39 | *max_len = connected_handle_length; |
| 40 | return FILEID_INVALID; |
| 41 | } else if (*max_len < handle_length) { |
| 42 | *max_len = handle_length; |
| 43 | return FILEID_INVALID; |
| 44 | } |
| 45 | |
| 46 | if (parent_inode) { |
| 47 | dout("encode_fh %llx with parent %llx\n", |
| 48 | ceph_ino(inode), ceph_ino(parent_inode)); |
| 49 | cfh->ino = ceph_ino(inode); |
| 50 | cfh->parent_ino = ceph_ino(parent_inode); |
| 51 | *max_len = connected_handle_length; |
| 52 | type = FILEID_INO32_GEN_PARENT; |
| 53 | } else { |
| 54 | dout("encode_fh %llx\n", ceph_ino(inode)); |
| 55 | fh->ino = ceph_ino(inode); |
| 56 | *max_len = handle_length; |
| 57 | type = FILEID_INO32_GEN; |
| 58 | } |
| 59 | return type; |
| 60 | } |
| 61 | |
| 62 | static struct dentry *__fh_to_dentry(struct super_block *sb, u64 ino) |
| 63 | { |
| 64 | struct ceph_mds_client *mdsc = ceph_sb_to_client(sb)->mdsc; |
| 65 | struct inode *inode; |
| 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 | int mask; |
| 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 | |
| 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 | |
| 86 | req->r_ino1 = vino; |
| 87 | req->r_num_caps = 1; |
| 88 | err = ceph_mdsc_do_request(mdsc, NULL, req); |
| 89 | inode = req->r_target_inode; |
| 90 | if (inode) |
| 91 | ihold(inode); |
| 92 | ceph_mdsc_put_request(req); |
| 93 | if (!inode) |
| 94 | return ERR_PTR(-ESTALE); |
| 95 | if (inode->i_nlink == 0) { |
| 96 | iput(inode); |
| 97 | return ERR_PTR(-ESTALE); |
| 98 | } |
| 99 | } |
| 100 | |
| 101 | return d_obtain_alias(inode); |
| 102 | } |
| 103 | |
| 104 | /* |
| 105 | * convert regular fh to dentry |
| 106 | */ |
| 107 | static struct dentry *ceph_fh_to_dentry(struct super_block *sb, |
| 108 | struct fid *fid, |
| 109 | int fh_len, int fh_type) |
| 110 | { |
| 111 | struct ceph_nfs_fh *fh = (void *)fid->raw; |
| 112 | |
| 113 | if (fh_type != FILEID_INO32_GEN && |
| 114 | fh_type != FILEID_INO32_GEN_PARENT) |
| 115 | return NULL; |
| 116 | if (fh_len < sizeof(*fh) / 4) |
| 117 | return NULL; |
| 118 | |
| 119 | dout("fh_to_dentry %llx\n", fh->ino); |
| 120 | return __fh_to_dentry(sb, fh->ino); |
| 121 | } |
| 122 | |
| 123 | static struct dentry *__get_parent(struct super_block *sb, |
| 124 | struct dentry *child, u64 ino) |
| 125 | { |
| 126 | struct ceph_mds_client *mdsc = ceph_sb_to_client(sb)->mdsc; |
| 127 | struct ceph_mds_request *req; |
| 128 | struct inode *inode; |
| 129 | int mask; |
| 130 | int err; |
| 131 | |
| 132 | req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_LOOKUPPARENT, |
| 133 | USE_ANY_MDS); |
| 134 | if (IS_ERR(req)) |
| 135 | return ERR_CAST(req); |
| 136 | |
| 137 | if (child) { |
| 138 | req->r_inode = d_inode(child); |
| 139 | ihold(d_inode(child)); |
| 140 | } else { |
| 141 | req->r_ino1 = (struct ceph_vino) { |
| 142 | .ino = ino, |
| 143 | .snap = CEPH_NOSNAP, |
| 144 | }; |
| 145 | } |
| 146 | |
| 147 | mask = CEPH_STAT_CAP_INODE; |
| 148 | if (ceph_security_xattr_wanted(d_inode(sb->s_root))) |
| 149 | mask |= CEPH_CAP_XATTR_SHARED; |
| 150 | req->r_args.getattr.mask = cpu_to_le32(mask); |
| 151 | |
| 152 | req->r_num_caps = 1; |
| 153 | err = ceph_mdsc_do_request(mdsc, NULL, req); |
| 154 | inode = req->r_target_inode; |
| 155 | if (inode) |
| 156 | ihold(inode); |
| 157 | ceph_mdsc_put_request(req); |
| 158 | if (!inode) |
| 159 | return ERR_PTR(-ENOENT); |
| 160 | |
| 161 | return d_obtain_alias(inode); |
| 162 | } |
| 163 | |
| 164 | static struct dentry *ceph_get_parent(struct dentry *child) |
| 165 | { |
| 166 | /* don't re-export snaps */ |
| 167 | if (ceph_snap(d_inode(child)) != CEPH_NOSNAP) |
| 168 | return ERR_PTR(-EINVAL); |
| 169 | |
| 170 | dout("get_parent %p ino %llx.%llx\n", |
| 171 | child, ceph_vinop(d_inode(child))); |
| 172 | return __get_parent(child->d_sb, child, 0); |
| 173 | } |
| 174 | |
| 175 | /* |
| 176 | * convert regular fh to parent |
| 177 | */ |
| 178 | static struct dentry *ceph_fh_to_parent(struct super_block *sb, |
| 179 | struct fid *fid, |
| 180 | int fh_len, int fh_type) |
| 181 | { |
| 182 | struct ceph_nfs_confh *cfh = (void *)fid->raw; |
| 183 | struct dentry *dentry; |
| 184 | |
| 185 | if (fh_type != FILEID_INO32_GEN_PARENT) |
| 186 | return NULL; |
| 187 | if (fh_len < sizeof(*cfh) / 4) |
| 188 | return NULL; |
| 189 | |
| 190 | dout("fh_to_parent %llx\n", cfh->parent_ino); |
| 191 | dentry = __get_parent(sb, NULL, cfh->ino); |
| 192 | if (unlikely(dentry == ERR_PTR(-ENOENT))) |
| 193 | dentry = __fh_to_dentry(sb, cfh->parent_ino); |
| 194 | return dentry; |
| 195 | } |
| 196 | |
| 197 | static int ceph_get_name(struct dentry *parent, char *name, |
| 198 | struct dentry *child) |
| 199 | { |
| 200 | struct ceph_mds_client *mdsc; |
| 201 | struct ceph_mds_request *req; |
| 202 | int err; |
| 203 | |
| 204 | mdsc = ceph_inode_to_client(d_inode(child))->mdsc; |
| 205 | req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_LOOKUPNAME, |
| 206 | USE_ANY_MDS); |
| 207 | if (IS_ERR(req)) |
| 208 | return PTR_ERR(req); |
| 209 | |
| 210 | inode_lock(d_inode(parent)); |
| 211 | |
| 212 | req->r_inode = d_inode(child); |
| 213 | ihold(d_inode(child)); |
| 214 | req->r_ino2 = ceph_vino(d_inode(parent)); |
| 215 | req->r_parent = d_inode(parent); |
| 216 | set_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags); |
| 217 | req->r_num_caps = 2; |
| 218 | err = ceph_mdsc_do_request(mdsc, NULL, req); |
| 219 | |
| 220 | inode_unlock(d_inode(parent)); |
| 221 | |
| 222 | if (!err) { |
| 223 | struct ceph_mds_reply_info_parsed *rinfo = &req->r_reply_info; |
| 224 | memcpy(name, rinfo->dname, rinfo->dname_len); |
| 225 | name[rinfo->dname_len] = 0; |
| 226 | dout("get_name %p ino %llx.%llx name %s\n", |
| 227 | child, ceph_vinop(d_inode(child)), name); |
| 228 | } else { |
| 229 | dout("get_name %p ino %llx.%llx err %d\n", |
| 230 | child, ceph_vinop(d_inode(child)), err); |
| 231 | } |
| 232 | |
| 233 | ceph_mdsc_put_request(req); |
| 234 | return err; |
| 235 | } |
| 236 | |
| 237 | const struct export_operations ceph_export_ops = { |
| 238 | .encode_fh = ceph_encode_fh, |
| 239 | .fh_to_dentry = ceph_fh_to_dentry, |
| 240 | .fh_to_parent = ceph_fh_to_parent, |
| 241 | .get_parent = ceph_get_parent, |
| 242 | .get_name = ceph_get_name, |
| 243 | }; |