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// 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)		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;	}

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