2 files changed, 329 insertions, 27 deletions

diff --git a/fs/ceph/export.c b/fs/ceph/export.c
index d64e7472fa41..d3ef7ee429ec 100644
--- a/fs/ceph/export.c
+++ b/fs/ceph/export.c
@@ -22,18 +22,77 @@ struct ceph_nfs_confh {
         u64 ino, parent_ino;
 } __attribute__ ((packed));
 
+/*
+ * fh for snapped inode
+ */
+struct ceph_nfs_snapfh {
+        u64 ino;
+        u64 snapid;
+        u64 parent_ino;
+        u32 hash;
+} __attribute__ ((packed));
+
+static int ceph_encode_snapfh(struct inode *inode, u32 *rawfh, int *max_len,
+                              struct inode *parent_inode)
+{
+        const static int snap_handle_length =
+                sizeof(struct ceph_nfs_snapfh) >> 2;
+        struct ceph_nfs_snapfh *sfh = (void *)rawfh;
+        u64 snapid = ceph_snap(inode);
+        int ret;
+        bool no_parent = true;
+
+        if (*max_len < snap_handle_length) {
+                *max_len = snap_handle_length;
+                ret = FILEID_INVALID;
+                goto out;
+        }
+
+        ret =  -EINVAL;
+        if (snapid != CEPH_SNAPDIR) {
+                struct inode *dir;
+                struct dentry *dentry = d_find_alias(inode);
+                if (!dentry)
+                        goto out;
+
+                rcu_read_lock();
+                dir = d_inode_rcu(dentry->d_parent);
+                if (ceph_snap(dir) != CEPH_SNAPDIR) {
+                        sfh->parent_ino = ceph_ino(dir);
+                        sfh->hash = ceph_dentry_hash(dir, dentry);
+                        no_parent = false;
+                }
+                rcu_read_unlock();
+                dput(dentry);
+        }
+
+        if (no_parent) {
+                if (!S_ISDIR(inode->i_mode))
+                        goto out;
+                sfh->parent_ino = sfh->ino;
+                sfh->hash = 0;
+        }
+        sfh->ino = ceph_ino(inode);
+        sfh->snapid = snapid;
+
+        *max_len = snap_handle_length;
+        ret = FILEID_BTRFS_WITH_PARENT;
+out:
+        dout("encode_snapfh %llx.%llx ret=%d\n", ceph_vinop(inode), ret);
+        return ret;
+}
+
 static int ceph_encode_fh(struct inode *inode, u32 *rawfh, int *max_len,
                           struct inode *parent_inode)
 {
+        const static int handle_length =
+                sizeof(struct ceph_nfs_fh) >> 2;
+        const static int connected_handle_length =
+                sizeof(struct ceph_nfs_confh) >> 2;
         int type;
-        struct ceph_nfs_fh *fh = (void *)rawfh;
-        struct ceph_nfs_confh *cfh = (void *)rawfh;
-        int connected_handle_length = sizeof(*cfh)/4;
-        int handle_length = sizeof(*fh)/4;
 
-        /* don't re-export snaps */
         if (ceph_snap(inode) != CEPH_NOSNAP)
-                return -EINVAL;
+                return ceph_encode_snapfh(inode, rawfh, max_len, parent_inode);
 
         if (parent_inode && (*max_len < connected_handle_length)) {
                 *max_len = connected_handle_length;
@@ -44,6 +103,7 @@ static int ceph_encode_fh(struct inode *inode, u32 *rawfh, int *max_len,
         }
 
         if (parent_inode) {
+                struct ceph_nfs_confh *cfh = (void *)rawfh;
                 dout("encode_fh %llx with parent %llx\n",
                      ceph_ino(inode), ceph_ino(parent_inode));
                 cfh->ino = ceph_ino(inode);
@@ -51,6 +111,7 @@ static int ceph_encode_fh(struct inode *inode, u32 *rawfh, int *max_len,
                 *max_len = connected_handle_length;
                 type = FILEID_INO32_GEN_PARENT;
         } else {
+                struct ceph_nfs_fh *fh = (void *)rawfh;
                 dout("encode_fh %llx\n", ceph_ino(inode));
                 fh->ino = ceph_ino(inode);
                 *max_len = handle_length;
@@ -59,7 +120,7 @@ static int ceph_encode_fh(struct inode *inode, u32 *rawfh, int *max_len,
         return type;
 }
 
-struct inode *ceph_lookup_inode(struct super_block *sb, u64 ino)
+static struct inode *__lookup_inode(struct super_block *sb, u64 ino)
 {
         struct ceph_mds_client *mdsc = ceph_sb_to_client(sb)->mdsc;
         struct inode *inode;
@@ -81,7 +142,7 @@ struct inode *ceph_lookup_inode(struct super_block *sb, u64 ino)
                 mask = CEPH_STAT_CAP_INODE;
                 if (ceph_security_xattr_wanted(d_inode(sb->s_root)))
                         mask |= CEPH_CAP_XATTR_SHARED;
-                req->r_args.getattr.mask = cpu_to_le32(mask);
+                req->r_args.lookupino.mask = cpu_to_le32(mask);
 
                 req->r_ino1 = vino;
                 req->r_num_caps = 1;
@@ -92,25 +153,113 @@ struct inode *ceph_lookup_inode(struct super_block *sb, u64 ino)
                 ceph_mdsc_put_request(req);
                 if (!inode)
                         return err < 0 ? ERR_PTR(err) : ERR_PTR(-ESTALE);
-                if (inode->i_nlink == 0) {
-                        iput(inode);
-                        return ERR_PTR(-ESTALE);
-                }
         }
+        return inode;
+}
 
+struct inode *ceph_lookup_inode(struct super_block *sb, u64 ino)
+{
+        struct inode *inode = __lookup_inode(sb, ino);
+        if (IS_ERR(inode))
+                return inode;
+        if (inode->i_nlink == 0) {
+                iput(inode);
+                return ERR_PTR(-ESTALE);
+        }
         return inode;
 }
 
 static struct dentry *__fh_to_dentry(struct super_block *sb, u64 ino)
 {
-        struct inode *inode = ceph_lookup_inode(sb, ino);
-
+        struct inode *inode = __lookup_inode(sb, ino);
         if (IS_ERR(inode))
                 return ERR_CAST(inode);
-
+        if (inode->i_nlink == 0) {
+                iput(inode);
+                return ERR_PTR(-ESTALE);
+        }
         return d_obtain_alias(inode);
 }
 
+static struct dentry *__snapfh_to_dentry(struct super_block *sb,
+                                          struct ceph_nfs_snapfh *sfh,
+                                          bool want_parent)
+{
+        struct ceph_mds_client *mdsc = ceph_sb_to_client(sb)->mdsc;
+        struct ceph_mds_request *req;
+        struct inode *inode;
+        struct ceph_vino vino;
+        int mask;
+        int err;
+        bool unlinked = false;
+
+        if (want_parent) {
+                vino.ino = sfh->parent_ino;
+                if (sfh->snapid == CEPH_SNAPDIR)
+                        vino.snap = CEPH_NOSNAP;
+                else if (sfh->ino == sfh->parent_ino)
+                        vino.snap = CEPH_SNAPDIR;
+                else
+                        vino.snap = sfh->snapid;
+        } else {
+                vino.ino = sfh->ino;
+                vino.snap = sfh->snapid;
+        }
+        inode = ceph_find_inode(sb, vino);
+        if (inode)
+                return d_obtain_alias(inode);
+
+        req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_LOOKUPINO,
+                                       USE_ANY_MDS);
+        if (IS_ERR(req))
+                return ERR_CAST(req);
+
+        mask = CEPH_STAT_CAP_INODE;
+        if (ceph_security_xattr_wanted(d_inode(sb->s_root)))
+                mask |= CEPH_CAP_XATTR_SHARED;
+        req->r_args.lookupino.mask = cpu_to_le32(mask);
+        if (vino.snap < CEPH_NOSNAP) {
+                req->r_args.lookupino.snapid = cpu_to_le64(vino.snap);
+                if (!want_parent && sfh->ino != sfh->parent_ino) {
+                        req->r_args.lookupino.parent =
+                                        cpu_to_le64(sfh->parent_ino);
+                        req->r_args.lookupino.hash =
+                                        cpu_to_le32(sfh->hash);
+                }
+        }
+
+        req->r_ino1 = vino;
+        req->r_num_caps = 1;
+        err = ceph_mdsc_do_request(mdsc, NULL, req);
+        inode = req->r_target_inode;
+        if (inode) {
+                if (vino.snap == CEPH_SNAPDIR) {
+                        if (inode->i_nlink == 0)
+                                unlinked = true;
+                        inode = ceph_get_snapdir(inode);
+                } else if (ceph_snap(inode) == vino.snap) {
+                        ihold(inode);
+                } else {
+                        /* mds does not support lookup snapped inode */
+                        err = -EOPNOTSUPP;
+                        inode = NULL;
+                }
+        }
+        ceph_mdsc_put_request(req);
+
+        if (want_parent) {
+                dout("snapfh_to_parent %llx.%llx\n err=%d\n",
+                     vino.ino, vino.snap, err);
+        } else {
+                dout("snapfh_to_dentry %llx.%llx parent %llx hash %x err=%d",
+                      vino.ino, vino.snap, sfh->parent_ino, sfh->hash, err);
+        }
+        if (!inode)
+                return ERR_PTR(-ESTALE);
+        /* see comments in ceph_get_parent() */
+        return unlinked ? d_obtain_root(inode) : d_obtain_alias(inode);
+}
+
 /*
  * convert regular fh to dentry
  */
@@ -120,6 +269,11 @@ static struct dentry *ceph_fh_to_dentry(struct super_block *sb,
 {
         struct ceph_nfs_fh *fh = (void *)fid->raw;
 
+        if (fh_type == FILEID_BTRFS_WITH_PARENT) {
+                struct ceph_nfs_snapfh *sfh = (void *)fid->raw;
+                return __snapfh_to_dentry(sb, sfh, false);
+        }
+
         if (fh_type != FILEID_INO32_GEN  &&
             fh_type != FILEID_INO32_GEN_PARENT)
                 return NULL;
@@ -173,13 +327,49 @@ static struct dentry *__get_parent(struct super_block *sb,
 
 static struct dentry *ceph_get_parent(struct dentry *child)
 {
-        /* don't re-export snaps */
-        if (ceph_snap(d_inode(child)) != CEPH_NOSNAP)
-                return ERR_PTR(-EINVAL);
-
-        dout("get_parent %p ino %llx.%llx\n",
-             child, ceph_vinop(d_inode(child)));
-        return __get_parent(child->d_sb, child, 0);
+        struct inode *inode = d_inode(child);
+        struct dentry *dn;
+
+        if (ceph_snap(inode) != CEPH_NOSNAP) {
+                struct inode* dir;
+                bool unlinked = false;
+                /* do not support non-directory */
+                if (!d_is_dir(child)) {
+                        dn = ERR_PTR(-EINVAL);
+                        goto out;
+                }
+                dir = __lookup_inode(inode->i_sb, ceph_ino(inode));
+                if (IS_ERR(dir)) {
+                        dn = ERR_CAST(dir);
+                        goto out;
+                }
+                /* There can be multiple paths to access snapped inode.
+                 * For simplicity, treat snapdir of head inode as parent */
+                if (ceph_snap(inode) != CEPH_SNAPDIR) {
+                        struct inode *snapdir = ceph_get_snapdir(dir);
+                        if (dir->i_nlink == 0)
+                                unlinked = true;
+                        iput(dir);
+                        if (IS_ERR(snapdir)) {
+                                dn = ERR_CAST(snapdir);
+                                goto out;
+                        }
+                        dir = snapdir;
+                }
+                /* If directory has already been deleted, futher get_parent
+                 * will fail. Do not mark snapdir dentry as disconnected,
+                 * this prevent exportfs from doing futher get_parent. */
+                if (unlinked)
+                        dn = d_obtain_root(dir);
+                else
+                        dn = d_obtain_alias(dir);
+        } else {
+                dn = __get_parent(child->d_sb, child, 0);
+        }
+out:
+        dout("get_parent %p ino %llx.%llx err=%ld\n",
+             child, ceph_vinop(inode), (IS_ERR(dn) ? PTR_ERR(dn) : 0));
+        return dn;
 }
 
 /*
@@ -192,6 +382,11 @@ static struct dentry *ceph_fh_to_parent(struct super_block *sb,
         struct ceph_nfs_confh *cfh = (void *)fid->raw;
         struct dentry *dentry;
 
+        if (fh_type == FILEID_BTRFS_WITH_PARENT) {
+                struct ceph_nfs_snapfh *sfh = (void *)fid->raw;
+                return __snapfh_to_dentry(sb, sfh, true);
+        }
+
         if (fh_type != FILEID_INO32_GEN_PARENT)
                 return NULL;
         if (fh_len < sizeof(*cfh) / 4)
@@ -204,14 +399,115 @@ static struct dentry *ceph_fh_to_parent(struct super_block *sb,
         return dentry;
 }
 
+static int __get_snap_name(struct dentry *parent, char *name,
+                           struct dentry *child)
+{
+        struct inode *inode = d_inode(child);
+        struct inode *dir = d_inode(parent);
+        struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
+        struct ceph_mds_request *req = NULL;
+        char *last_name = NULL;
+        unsigned next_offset = 2;
+        int err = -EINVAL;
+
+        if (ceph_ino(inode) != ceph_ino(dir))
+                goto out;
+        if (ceph_snap(inode) == CEPH_SNAPDIR) {
+                if (ceph_snap(dir) == CEPH_NOSNAP) {
+                        strcpy(name, fsc->mount_options->snapdir_name);
+                        err = 0;
+                }
+                goto out;
+        }
+        if (ceph_snap(dir) != CEPH_SNAPDIR)
+                goto out;
+
+        while (1) {
+                struct ceph_mds_reply_info_parsed *rinfo;
+                struct ceph_mds_reply_dir_entry *rde;
+                int i;
+
+                req = ceph_mdsc_create_request(fsc->mdsc, CEPH_MDS_OP_LSSNAP,
+                                               USE_AUTH_MDS);
+                if (IS_ERR(req)) {
+                        err = PTR_ERR(req);
+                        req = NULL;
+                        goto out;
+                }
+                err = ceph_alloc_readdir_reply_buffer(req, inode);
+                if (err)
+                        goto out;
+
+                req->r_direct_mode = USE_AUTH_MDS;
+                req->r_readdir_offset = next_offset;
+                req->r_args.readdir.flags =
+                                cpu_to_le16(CEPH_READDIR_REPLY_BITFLAGS);
+                if (last_name) {
+                        req->r_path2 = last_name;
+                        last_name = NULL;
+                }
+
+                req->r_inode = dir;
+                ihold(dir);
+                req->r_dentry = dget(parent);
+
+                inode_lock(dir);
+                err = ceph_mdsc_do_request(fsc->mdsc, NULL, req);
+                inode_unlock(dir);
+
+                if (err < 0)
+                        goto out;
+
+                 rinfo = &req->r_reply_info;
+                 for (i = 0; i < rinfo->dir_nr; i++) {
+                         rde = rinfo->dir_entries + i;
+                         BUG_ON(!rde->inode.in);
+                         if (ceph_snap(inode) ==
+                             le64_to_cpu(rde->inode.in->snapid)) {
+                                 memcpy(name, rde->name, rde->name_len);
+                                 name[rde->name_len] = '\0';
+                                 err = 0;
+                                 goto out;
+                         }
+                 }
+
+                 if (rinfo->dir_end)
+                         break;
+
+                 BUG_ON(rinfo->dir_nr <= 0);
+                 rde = rinfo->dir_entries + (rinfo->dir_nr - 1);
+                 next_offset += rinfo->dir_nr;
+                 last_name = kstrndup(rde->name, rde->name_len, GFP_KERNEL);
+                 if (!last_name) {
+                         err = -ENOMEM;
+                         goto out;
+                 }
+
+                 ceph_mdsc_put_request(req);
+                 req = NULL;
+        }
+        err = -ENOENT;
+out:
+        if (req)
+                ceph_mdsc_put_request(req);
+        kfree(last_name);
+        dout("get_snap_name %p ino %llx.%llx err=%d\n",
+             child, ceph_vinop(inode), err);
+        return err;
+}
+
 static int ceph_get_name(struct dentry *parent, char *name,
                          struct dentry *child)
 {
         struct ceph_mds_client *mdsc;
         struct ceph_mds_request *req;
+        struct inode *inode = d_inode(child);
         int err;
 
-        mdsc = ceph_inode_to_client(d_inode(child))->mdsc;
+        if (ceph_snap(inode) != CEPH_NOSNAP)
+                return __get_snap_name(parent, name, child);
+
+        mdsc = ceph_inode_to_client(inode)->mdsc;
         req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_LOOKUPNAME,
                                        USE_ANY_MDS);
         if (IS_ERR(req))
@@ -219,8 +515,8 @@ static int ceph_get_name(struct dentry *parent, char *name,
 
         inode_lock(d_inode(parent));
 
-        req->r_inode = d_inode(child);
-        ihold(d_inode(child));
+        req->r_inode = inode;
+        ihold(inode);
         req->r_ino2 = ceph_vino(d_inode(parent));
         req->r_parent = d_inode(parent);
         set_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags);
@@ -234,10 +530,10 @@ static int ceph_get_name(struct dentry *parent, char *name,
                 memcpy(name, rinfo->dname, rinfo->dname_len);
                 name[rinfo->dname_len] = 0;
                 dout("get_name %p ino %llx.%llx name %s\n",
-                     child, ceph_vinop(d_inode(child)), name);
+                     child, ceph_vinop(inode), name);
         } else {
                 dout("get_name %p ino %llx.%llx err %d\n",
-                     child, ceph_vinop(d_inode(child)), err);
+                     child, ceph_vinop(inode), err);
         }
 
         ceph_mdsc_put_request(req);
diff --git a/include/linux/ceph/ceph_fs.h b/include/linux/ceph/ceph_fs.h
index 4903deb0777a..3ac0feaf2b5e 100644
--- a/include/linux/ceph/ceph_fs.h
+++ b/include/linux/ceph/ceph_fs.h
@@ -436,6 +436,12 @@ union ceph_mds_request_args {
                 __le64 length; /* num bytes to lock from start */
                 __u8 wait; /* will caller wait for lock to become available? */
         } __attribute__ ((packed)) filelock_change;
+        struct {
+                __le32 mask;                 /* CEPH_CAP_* */
+                __le64 snapid;
+                __le64 parent;
+                __le32 hash;
+        } __attribute__ ((packed)) lookupino;
 } __attribute__ ((packed));
 
 #define CEPH_MDS_FLAG_REPLAY        1  /* this is a replayed op */