// SPDX-License-Identifier: GPL-2.0 #include <linux/ceph/ceph_debug.h> #include <linux/exportfs.h> #include <linux/slab.h> #include <asm/unaligned.h> #include "super.h" #include "mds_client.h" /* * Basic fh */ struct ceph_nfs_fh { u64 ino; } __attribute__ ((packed)); /* * Larger fh that includes parent ino. */ 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; if (ceph_snap(inode) != CEPH_NOSNAP) return ceph_encode_snapfh(inode, rawfh, max_len, parent_inode); if (parent_inode && (*max_len < connected_handle_length)) { *max_len = connected_handle_length; return FILEID_INVALID; } else if (*max_len < handle_length) { *max_len = handle_length; return FILEID_INVALID; } 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); cfh->parent_ino = ceph_ino(parent_inode); *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; type = FILEID_INO32_GEN; } return type; } 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; struct ceph_vino vino; int err; vino.ino = ino; vino.snap = CEPH_NOSNAP; inode = ceph_find_inode(sb, vino); if (!inode) { struct ceph_mds_request *req; int mask; 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); req->r_ino1 = vino; req->r_num_caps = 1; err = ceph_mdsc_do_request(mdsc, NULL, req); inode = req->r_target_inode; if (inode) ihold(inode); ceph_mdsc_put_request(req); if (!inode) return err < 0 ? ERR_PTR(err) : 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 = __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 */ static struct dentry *ceph_fh_to_dentry(struct super_block *sb, struct fid *fid, int fh_len, int fh_type) { 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; if (fh_len < sizeof(*fh) / 4) return NULL; dout("fh_to_dentry %llx\n", fh->ino); return __fh_to_dentry(sb, fh->ino); } static struct dentry *__get_parent(struct super_block *sb, struct dentry *child, u64 ino) { struct ceph_mds_client *mdsc = ceph_sb_to_client(sb)->mdsc; struct ceph_mds_request *req; struct inode *inode; int mask; int err; req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_LOOKUPPARENT, USE_ANY_MDS); if (IS_ERR(req)) return ERR_CAST(req); if (child) { req->r_inode = d_inode(child); ihold(d_inode(child)); } else { req->r_ino1 = (struct ceph_vino) { .ino = ino, .snap = CEPH_NOSNAP, }; } 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_num_caps = 1; err = ceph_mdsc_do_request(mdsc, NULL, req); inode = req->r_target_inode; if (inode) ihold(inode); ceph_mdsc_put_request(req); if (!inode) return ERR_PTR(-ENOENT); return d_obtain_alias(inode); } static struct dentry *ceph_get_parent(struct dentry *child) { 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), (long)PTR_ERR_OR_ZERO(dn)); return dn; } /* * convert regular fh to parent */ static struct dentry *ceph_fh_to_parent(struct super_block *sb, struct fid *fid, int fh_len, int fh_type) { 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) return NULL; dout("fh_to_parent %llx\n", cfh->parent_ino); dentry = __get_parent(sb, NULL, cfh->ino); if (unlikely(dentry == ERR_PTR(-ENOENT))) dentry = __fh_to_dentry(sb, cfh->parent_ino); 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; 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)) return PTR_ERR(req); inode_lock(d_inode(parent)); 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); req->r_num_caps = 2; err = ceph_mdsc_do_request(mdsc, NULL, req); inode_unlock(d_inode(parent)); if (!err) { struct ceph_mds_reply_info_parsed *rinfo = &req->r_reply_info; 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(inode), name); } else { dout("get_name %p ino %llx.%llx err %d\n", child, ceph_vinop(inode), err); } ceph_mdsc_put_request(req); return err; } const struct export_operations ceph_export_ops = { .encode_fh = ceph_encode_fh, .fh_to_dentry = ceph_fh_to_dentry, .fh_to_parent = ceph_fh_to_parent, .get_parent = ceph_get_parent, .get_name = ceph_get_name, };