| // 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) |
| { |
| static const 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) |
| { |
| static const int handle_length = |
| sizeof(struct ceph_nfs_fh) >> 2; |
| static const 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); |
| int err; |
| |
| if (IS_ERR(inode)) |
| return ERR_CAST(inode); |
| /* We need LINK caps to reliably check i_nlink */ |
| err = ceph_do_getattr(inode, CEPH_CAP_LINK_SHARED, false); |
| if (err) { |
| iput(inode); |
| return ERR_PTR(err); |
| } |
| /* -ESTALE if inode as been unlinked and no file is open */ |
| if ((inode->i_nlink == 0) && (atomic_read(&inode->i_count) == 1)) { |
| 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); |
| if (err) { |
| ceph_mdsc_put_request(req); |
| return ERR_PTR(err); |
| } |
| |
| 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, |
| }; |