diff options
Diffstat (limited to 'fs/ceph/export.c')
| -rw-r--r-- | fs/ceph/export.c | 571 |
1 files changed, 571 insertions, 0 deletions
diff --git a/fs/ceph/export.c b/fs/ceph/export.c new file mode 100644 index 000000000..042bb4a02 --- /dev/null +++ b/fs/ceph/export.c @@ -0,0 +1,571 @@ +// 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; + + if (ceph_vino_is_reserved(vino)) + return ERR_PTR(-ESTALE); + + 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; + } + + if (ceph_vino_is_reserved(vino)) + return ERR_PTR(-ESTALE); + + 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, +}; |