fs/ceph/export.c

   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 dentry *dentry;
  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         }
  96
  97         dentry = d_obtain_alias(inode);
  98         if (IS_ERR(dentry))
  99                 return dentry;
 100         err = ceph_init_dentry(dentry);
 101         if (err < 0) {
 102                 dput(dentry);
 103                 return ERR_PTR(err);
 104         }
 105         dout("__fh_to_dentry %llx %p dentry %p\n", ino, inode, dentry);
 106         return dentry;
 107 }
 108
 109 /*
 110  * convert regular fh to dentry
 111  */
 112 static struct dentry *ceph_fh_to_dentry(struct super_block *sb,
 113                                         struct fid *fid,
 114                                         int fh_len, int fh_type)
 115 {
 116         struct ceph_nfs_fh *fh = (void *)fid->raw;
 117
 118         if (fh_type != FILEID_INO32_GEN  &&
 119             fh_type != FILEID_INO32_GEN_PARENT)
 120                 return NULL;
 121         if (fh_len < sizeof(*fh) / 4)
 122                 return NULL;
 123
 124         dout("fh_to_dentry %llx\n", fh->ino);
 125         return __fh_to_dentry(sb, fh->ino);
 126 }
 127
 128 static struct dentry *__get_parent(struct super_block *sb,
 129                                    struct dentry *child, u64 ino)
 130 {
 131         struct ceph_mds_client *mdsc = ceph_sb_to_client(sb)->mdsc;
 132         struct ceph_mds_request *req;
 133         struct inode *inode;
 134         struct dentry *dentry;
 135         int mask;
 136         int err;
 137
 138         req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_LOOKUPPARENT,
 139                                        USE_ANY_MDS);
 140         if (IS_ERR(req))
 141                 return ERR_CAST(req);
 142
 143         if (child) {
 144                 req->r_inode = d_inode(child);
 145                 ihold(d_inode(child));
 146         } else {
 147                 req->r_ino1 = (struct ceph_vino) {
 148                         .ino = ino,
 149                         .snap = CEPH_NOSNAP,
 150                 };
 151         }
 152
 153         mask = CEPH_STAT_CAP_INODE;
 154         if (ceph_security_xattr_wanted(d_inode(sb->s_root)))
 155                 mask |= CEPH_CAP_XATTR_SHARED;
 156         req->r_args.getattr.mask = cpu_to_le32(mask);
 157
 158         req->r_num_caps = 1;
 159         err = ceph_mdsc_do_request(mdsc, NULL, req);
 160         inode = req->r_target_inode;
 161         if (inode)
 162                 ihold(inode);
 163         ceph_mdsc_put_request(req);
 164         if (!inode)
 165                 return ERR_PTR(-ENOENT);
 166
 167         dentry = d_obtain_alias(inode);
 168         if (IS_ERR(dentry))
 169                 return dentry;
 170         err = ceph_init_dentry(dentry);
 171         if (err < 0) {
 172                 dput(dentry);
 173                 return ERR_PTR(err);
 174         }
 175         dout("__get_parent ino %llx parent %p ino %llx.%llx\n",
 176              child ? ceph_ino(d_inode(child)) : ino,
 177              dentry, ceph_vinop(inode));
 178         return dentry;
 179 }
 180
 181 static struct dentry *ceph_get_parent(struct dentry *child)
 182 {
 183         /* don't re-export snaps */
 184         if (ceph_snap(d_inode(child)) != CEPH_NOSNAP)
 185                 return ERR_PTR(-EINVAL);
 186
 187         dout("get_parent %p ino %llx.%llx\n",
 188              child, ceph_vinop(d_inode(child)));
 189         return __get_parent(child->d_sb, child, 0);
 190 }
 191
 192 /*
 193  * convert regular fh to parent
 194  */
 195 static struct dentry *ceph_fh_to_parent(struct super_block *sb,
 196                                         struct fid *fid,
 197                                         int fh_len, int fh_type)
 198 {
 199         struct ceph_nfs_confh *cfh = (void *)fid->raw;
 200         struct dentry *dentry;
 201
 202         if (fh_type != FILEID_INO32_GEN_PARENT)
 203                 return NULL;
 204         if (fh_len < sizeof(*cfh) / 4)
 205                 return NULL;
 206
 207         dout("fh_to_parent %llx\n", cfh->parent_ino);
 208         dentry = __get_parent(sb, NULL, cfh->ino);
 209         if (unlikely(dentry == ERR_PTR(-ENOENT)))
 210                 dentry = __fh_to_dentry(sb, cfh->parent_ino);
 211         return dentry;
 212 }
 213
 214 static int ceph_get_name(struct dentry *parent, char *name,
 215                          struct dentry *child)
 216 {
 217         struct ceph_mds_client *mdsc;
 218         struct ceph_mds_request *req;
 219         int err;
 220
 221         mdsc = ceph_inode_to_client(d_inode(child))->mdsc;
 222         req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_LOOKUPNAME,
 223                                        USE_ANY_MDS);
 224         if (IS_ERR(req))
 225                 return PTR_ERR(req);
 226
 227         inode_lock(d_inode(parent));
 228
 229         req->r_inode = d_inode(child);
 230         ihold(d_inode(child));
 231         req->r_ino2 = ceph_vino(d_inode(parent));
 232         req->r_locked_dir = d_inode(parent);
 233         req->r_num_caps = 2;
 234         err = ceph_mdsc_do_request(mdsc, NULL, req);
 235
 236         inode_unlock(d_inode(parent));
 237
 238         if (!err) {
 239                 struct ceph_mds_reply_info_parsed *rinfo = &req->r_reply_info;
 240                 memcpy(name, rinfo->dname, rinfo->dname_len);
 241                 name[rinfo->dname_len] = 0;
 242                 dout("get_name %p ino %llx.%llx name %s\n",
 243                      child, ceph_vinop(d_inode(child)), name);
 244         } else {
 245                 dout("get_name %p ino %llx.%llx err %d\n",
 246                      child, ceph_vinop(d_inode(child)), err);
 247         }
 248
 249         ceph_mdsc_put_request(req);
 250         return err;
 251 }
 252
 253 const struct export_operations ceph_export_ops = {
 254         .encode_fh = ceph_encode_fh,
 255         .fh_to_dentry = ceph_fh_to_dentry,
 256         .fh_to_parent = ceph_fh_to_parent,
 257         .get_parent = ceph_get_parent,
 258         .get_name = ceph_get_name,
 259 };