[mirror_ubuntu-jammy-kernel.git] / fs / ceph / export.c

// 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 */
			inode = ERR_PTR(-EOPNOTSUPP);
		}
	} else {
		inode = ERR_PTR(-ESTALE);
	}
	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 (IS_ERR(inode))
		return ERR_CAST(inode);
	/* 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);
	ihold(req->r_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,
};
Commit	Line	Data
b2441318	1	// SPDX-License-Identifier: GPL-2.0
3d14c5d2	2	#include <linux/ceph/ceph_debug.h>
a8e63b7d SW	3
a8e63b7d SW	4	#include <linux/exportfs.h>
5a0e3ad6	5	#include <linux/slab.h>
a8e63b7d SW	6	#include <asm/unaligned.h>
	7
	8	#include "super.h"
3d14c5d2	9	#include "mds_client.h"
a8e63b7d	10
a8e63b7d SW	11	/*
	12	* Basic fh
	13	*/
	14	struct ceph_nfs_fh {
	15	u64 ino;
	16	} __attribute__ ((packed));
	17
	18	/*
4f32b42d	19	* Larger fh that includes parent ino.
a8e63b7d SW	20	*/
	21	struct ceph_nfs_confh {
	22	u64 ino, parent_ino;
a8e63b7d SW	23	} __attribute__ ((packed));
a8e63b7d SW	24
570df4e9 YZ	25	/*
	26	* fh for snapped inode
	27	*/
	28	struct ceph_nfs_snapfh {
	29	u64 ino;
	30	u64 snapid;
	31	u64 parent_ino;
	32	u32 hash;
	33	} __attribute__ ((packed));
	34
	35	static int ceph_encode_snapfh(struct inode inode, u32 rawfh, int *max_len,
	36	struct inode *parent_inode)
	37	{
536cc331	38	static const int snap_handle_length =
570df4e9 YZ	39	sizeof(struct ceph_nfs_snapfh) >> 2;
	40	struct ceph_nfs_snapfh sfh = (void )rawfh;
	41	u64 snapid = ceph_snap(inode);
	42	int ret;
	43	bool no_parent = true;
	44
	45	if (*max_len < snap_handle_length) {
	46	*max_len = snap_handle_length;
	47	ret = FILEID_INVALID;
	48	goto out;
	49	}
	50
	51	ret = -EINVAL;
	52	if (snapid != CEPH_SNAPDIR) {
	53	struct inode *dir;
	54	struct dentry *dentry = d_find_alias(inode);
	55	if (!dentry)
	56	goto out;
	57
	58	rcu_read_lock();
	59	dir = d_inode_rcu(dentry->d_parent);
	60	if (ceph_snap(dir) != CEPH_SNAPDIR) {
	61	sfh->parent_ino = ceph_ino(dir);
	62	sfh->hash = ceph_dentry_hash(dir, dentry);
	63	no_parent = false;
	64	}
	65	rcu_read_unlock();
	66	dput(dentry);
	67	}
	68
	69	if (no_parent) {
	70	if (!S_ISDIR(inode->i_mode))
	71	goto out;
	72	sfh->parent_ino = sfh->ino;
	73	sfh->hash = 0;
	74	}
	75	sfh->ino = ceph_ino(inode);
	76	sfh->snapid = snapid;
	77
	78	*max_len = snap_handle_length;
	79	ret = FILEID_BTRFS_WITH_PARENT;
	80	out:
	81	dout("encode_snapfh %llx.%llx ret=%d\n", ceph_vinop(inode), ret);
	82	return ret;
	83	}
	84
c862868b SW	85	static int ceph_encode_fh(struct inode inode, u32 rawfh, int *max_len,
c862868b SW	86	struct inode *parent_inode)
a8e63b7d	87	{
536cc331	88	static const int handle_length =
570df4e9	89	sizeof(struct ceph_nfs_fh) >> 2;
536cc331	90	static const int connected_handle_length =
570df4e9	91	sizeof(struct ceph_nfs_confh) >> 2;
92923dcb	92	int type;
a8e63b7d	93
a8e63b7d	94	if (ceph_snap(inode) != CEPH_NOSNAP)
570df4e9	95	return ceph_encode_snapfh(inode, rawfh, max_len, parent_inode);
a8e63b7d	96
4f32b42d YZ	97	if (parent_inode && (*max_len < connected_handle_length)) {
	98	*max_len = connected_handle_length;
	99	return FILEID_INVALID;
	100	} else if (*max_len < handle_length) {
	101	*max_len = handle_length;
	102	return FILEID_INVALID;
	103	}
f6af75da	104
4f32b42d	105	if (parent_inode) {
570df4e9	106	struct ceph_nfs_confh cfh = (void )rawfh;
4f32b42d YZ	107	dout("encode_fh %llx with parent %llx\n",
4f32b42d YZ	108	ceph_ino(inode), ceph_ino(parent_inode));
c862868b	109	cfh->ino = ceph_ino(inode);
4f32b42d	110	cfh->parent_ino = ceph_ino(parent_inode);
92923dcb	111	*max_len = connected_handle_length;
4f32b42d	112	type = FILEID_INO32_GEN_PARENT;
a8e63b7d	113	} else {
570df4e9	114	struct ceph_nfs_fh fh = (void )rawfh;
4f32b42d YZ	115	dout("encode_fh %llx\n", ceph_ino(inode));
4f32b42d YZ	116	fh->ino = ceph_ino(inode);
bba0cd0e	117	*max_len = handle_length;
4f32b42d	118	type = FILEID_INO32_GEN;
a8e63b7d SW	119	}
	120	return type;
	121	}
	122
570df4e9	123	static struct inode __lookup_inode(struct super_block sb, u64 ino)
a8e63b7d	124	{
3c454cf2	125	struct ceph_mds_client *mdsc = ceph_sb_to_client(sb)->mdsc;
a8e63b7d	126	struct inode *inode;
a8e63b7d SW	127	struct ceph_vino vino;
	128	int err;
	129
4f32b42d	130	vino.ino = ino;
a8e63b7d	131	vino.snap = CEPH_NOSNAP;
d4f6b31d JL	132
	133	if (ceph_vino_is_reserved(vino))
	134	return ERR_PTR(-ESTALE);
	135
a8e63b7d	136	inode = ceph_find_inode(sb, vino);
3c454cf2 SW	137	if (!inode) {
3c454cf2 SW	138	struct ceph_mds_request *req;
315f2408	139	int mask;
3c454cf2 SW	140
	141	req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_LOOKUPINO,
	142	USE_ANY_MDS);
	143	if (IS_ERR(req))
	144	return ERR_CAST(req);
	145
315f2408 YZ	146	mask = CEPH_STAT_CAP_INODE;
	147	if (ceph_security_xattr_wanted(d_inode(sb->s_root)))
	148	mask \|= CEPH_CAP_XATTR_SHARED;
570df4e9	149	req->r_args.lookupino.mask = cpu_to_le32(mask);
315f2408	150
3c454cf2 SW	151	req->r_ino1 = vino;
	152	req->r_num_caps = 1;
	153	err = ceph_mdsc_do_request(mdsc, NULL, req);
45e3d3ee SW	154	inode = req->r_target_inode;
45e3d3ee SW	155	if (inode)
70b666c3	156	ihold(inode);
3c454cf2	157	ceph_mdsc_put_request(req);
3c454cf2	158	if (!inode)
3886274a	159	return err < 0 ? ERR_PTR(err) : ERR_PTR(-ESTALE);
3c454cf2	160	}
570df4e9 YZ	161	return inode;
570df4e9 YZ	162	}
a8e63b7d	163
570df4e9 YZ	164	struct inode ceph_lookup_inode(struct super_block sb, u64 ino)
	165	{
	166	struct inode *inode = __lookup_inode(sb, ino);
	167	if (IS_ERR(inode))
	168	return inode;
	169	if (inode->i_nlink == 0) {
	170	iput(inode);
	171	return ERR_PTR(-ESTALE);
	172	}
3886274a LH	173	return inode;
	174	}
	175
	176	static struct dentry __fh_to_dentry(struct super_block sb, u64 ino)
	177	{
570df4e9	178	struct inode *inode = __lookup_inode(sb, ino);
878dabb6 LH	179	int err;
878dabb6 LH	180
3886274a LH	181	if (IS_ERR(inode))
3886274a LH	182	return ERR_CAST(inode);
878dabb6 LH	183	/* We need LINK caps to reliably check i_nlink */
878dabb6 LH	184	err = ceph_do_getattr(inode, CEPH_CAP_LINK_SHARED, false);
1775c7dd JL	185	if (err) {
1775c7dd JL	186	iput(inode);
878dabb6	187	return ERR_PTR(err);
1775c7dd	188	}
878dabb6 LH	189	/* -ESTALE if inode as been unlinked and no file is open */
878dabb6 LH	190	if ((inode->i_nlink == 0) && (atomic_read(&inode->i_count) == 1)) {
570df4e9 YZ	191	iput(inode);
	192	return ERR_PTR(-ESTALE);
	193	}
ad5cb123	194	return d_obtain_alias(inode);
a8e63b7d SW	195	}
a8e63b7d SW	196
570df4e9 YZ	197	static struct dentry __snapfh_to_dentry(struct super_block sb,
	198	struct ceph_nfs_snapfh *sfh,
	199	bool want_parent)
	200	{
	201	struct ceph_mds_client *mdsc = ceph_sb_to_client(sb)->mdsc;
	202	struct ceph_mds_request *req;
	203	struct inode *inode;
	204	struct ceph_vino vino;
	205	int mask;
	206	int err;
	207	bool unlinked = false;
	208
	209	if (want_parent) {
	210	vino.ino = sfh->parent_ino;
	211	if (sfh->snapid == CEPH_SNAPDIR)
	212	vino.snap = CEPH_NOSNAP;
	213	else if (sfh->ino == sfh->parent_ino)
	214	vino.snap = CEPH_SNAPDIR;
	215	else
	216	vino.snap = sfh->snapid;
	217	} else {
	218	vino.ino = sfh->ino;
	219	vino.snap = sfh->snapid;
	220	}
d4f6b31d JL	221
	222	if (ceph_vino_is_reserved(vino))
	223	return ERR_PTR(-ESTALE);
	224
570df4e9 YZ	225	inode = ceph_find_inode(sb, vino);
	226	if (inode)
	227	return d_obtain_alias(inode);
	228
	229	req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_LOOKUPINO,
	230	USE_ANY_MDS);
	231	if (IS_ERR(req))
	232	return ERR_CAST(req);
	233
	234	mask = CEPH_STAT_CAP_INODE;
	235	if (ceph_security_xattr_wanted(d_inode(sb->s_root)))
	236	mask \|= CEPH_CAP_XATTR_SHARED;
	237	req->r_args.lookupino.mask = cpu_to_le32(mask);
	238	if (vino.snap < CEPH_NOSNAP) {
	239	req->r_args.lookupino.snapid = cpu_to_le64(vino.snap);
	240	if (!want_parent && sfh->ino != sfh->parent_ino) {
	241	req->r_args.lookupino.parent =
	242	cpu_to_le64(sfh->parent_ino);
	243	req->r_args.lookupino.hash =
	244	cpu_to_le32(sfh->hash);
	245	}
	246	}
	247
	248	req->r_ino1 = vino;
	249	req->r_num_caps = 1;
	250	err = ceph_mdsc_do_request(mdsc, NULL, req);
	251	inode = req->r_target_inode;
	252	if (inode) {
	253	if (vino.snap == CEPH_SNAPDIR) {
	254	if (inode->i_nlink == 0)
	255	unlinked = true;
	256	inode = ceph_get_snapdir(inode);
	257	} else if (ceph_snap(inode) == vino.snap) {
	258	ihold(inode);
	259	} else {
	260	/* mds does not support lookup snapped inode */
3e10a15f	261	inode = ERR_PTR(-EOPNOTSUPP);
570df4e9	262	}
3e10a15f JL	263	} else {
3e10a15f JL	264	inode = ERR_PTR(-ESTALE);
570df4e9 YZ	265	}
	266	ceph_mdsc_put_request(req);
	267
	268	if (want_parent) {
	269	dout("snapfh_to_parent %llx.%llx\n err=%d\n",
	270	vino.ino, vino.snap, err);
	271	} else {
	272	dout("snapfh_to_dentry %llx.%llx parent %llx hash %x err=%d",
	273	vino.ino, vino.snap, sfh->parent_ino, sfh->hash, err);
	274	}
3e10a15f JL	275	if (IS_ERR(inode))
3e10a15f JL	276	return ERR_CAST(inode);
570df4e9 YZ	277	/* see comments in ceph_get_parent() */
	278	return unlinked ? d_obtain_root(inode) : d_obtain_alias(inode);
	279	}
	280
a8e63b7d	281	/*
4f32b42d	282	* convert regular fh to dentry
a8e63b7d	283	*/
4f32b42d YZ	284	static struct dentry ceph_fh_to_dentry(struct super_block sb,
	285	struct fid *fid,
	286	int fh_len, int fh_type)
a8e63b7d	287	{
4f32b42d	288	struct ceph_nfs_fh fh = (void )fid->raw;
a8e63b7d	289
570df4e9 YZ	290	if (fh_type == FILEID_BTRFS_WITH_PARENT) {
	291	struct ceph_nfs_snapfh sfh = (void )fid->raw;
	292	return __snapfh_to_dentry(sb, sfh, false);
	293	}
	294
4f32b42d YZ	295	if (fh_type != FILEID_INO32_GEN &&
	296	fh_type != FILEID_INO32_GEN_PARENT)
	297	return NULL;
	298	if (fh_len < sizeof(*fh) / 4)
	299	return NULL;
a8e63b7d	300
4f32b42d YZ	301	dout("fh_to_dentry %llx\n", fh->ino);
4f32b42d YZ	302	return __fh_to_dentry(sb, fh->ino);
a8e63b7d SW	303	}
a8e63b7d SW	304
9017c2ec YZ	305	static struct dentry __get_parent(struct super_block sb,
	306	struct dentry *child, u64 ino)
	307	{
	308	struct ceph_mds_client *mdsc = ceph_sb_to_client(sb)->mdsc;
	309	struct ceph_mds_request *req;
	310	struct inode *inode;
315f2408	311	int mask;
9017c2ec YZ	312	int err;
	313
	314	req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_LOOKUPPARENT,
	315	USE_ANY_MDS);
	316	if (IS_ERR(req))
	317	return ERR_CAST(req);
	318
	319	if (child) {
2b0143b5 DH	320	req->r_inode = d_inode(child);
2b0143b5 DH	321	ihold(d_inode(child));
9017c2ec YZ	322	} else {
	323	req->r_ino1 = (struct ceph_vino) {
	324	.ino = ino,
	325	.snap = CEPH_NOSNAP,
	326	};
	327	}
315f2408 YZ	328
	329	mask = CEPH_STAT_CAP_INODE;
	330	if (ceph_security_xattr_wanted(d_inode(sb->s_root)))
	331	mask \|= CEPH_CAP_XATTR_SHARED;
	332	req->r_args.getattr.mask = cpu_to_le32(mask);
	333
9017c2ec YZ	334	req->r_num_caps = 1;
9017c2ec YZ	335	err = ceph_mdsc_do_request(mdsc, NULL, req);
c6d50296 QH	336	if (err) {
	337	ceph_mdsc_put_request(req);
	338	return ERR_PTR(err);
	339	}
	340
9017c2ec YZ	341	inode = req->r_target_inode;
	342	if (inode)
	343	ihold(inode);
	344	ceph_mdsc_put_request(req);
	345	if (!inode)
	346	return ERR_PTR(-ENOENT);
	347
ad5cb123	348	return d_obtain_alias(inode);
9017c2ec YZ	349	}
9017c2ec YZ	350
e84be11c	351	static struct dentry ceph_get_parent(struct dentry child)
9017c2ec	352	{
570df4e9 YZ	353	struct inode *inode = d_inode(child);
	354	struct dentry *dn;
	355
	356	if (ceph_snap(inode) != CEPH_NOSNAP) {
	357	struct inode* dir;
	358	bool unlinked = false;
	359	/* do not support non-directory */
	360	if (!d_is_dir(child)) {
	361	dn = ERR_PTR(-EINVAL);
	362	goto out;
	363	}
	364	dir = __lookup_inode(inode->i_sb, ceph_ino(inode));
	365	if (IS_ERR(dir)) {
	366	dn = ERR_CAST(dir);
	367	goto out;
	368	}
	369	/* There can be multiple paths to access snapped inode.
	370	* For simplicity, treat snapdir of head inode as parent */
	371	if (ceph_snap(inode) != CEPH_SNAPDIR) {
	372	struct inode *snapdir = ceph_get_snapdir(dir);
	373	if (dir->i_nlink == 0)
	374	unlinked = true;
	375	iput(dir);
	376	if (IS_ERR(snapdir)) {
	377	dn = ERR_CAST(snapdir);
	378	goto out;
	379	}
	380	dir = snapdir;
	381	}
	382	/* If directory has already been deleted, futher get_parent
	383	* will fail. Do not mark snapdir dentry as disconnected,
	384	* this prevent exportfs from doing futher get_parent. */
	385	if (unlinked)
	386	dn = d_obtain_root(dir);
	387	else
	388	dn = d_obtain_alias(dir);
	389	} else {
	390	dn = __get_parent(child->d_sb, child, 0);
	391	}
	392	out:
	393	dout("get_parent %p ino %llx.%llx err=%ld\n",
03af439a	394	child, ceph_vinop(inode), (long)PTR_ERR_OR_ZERO(dn));
570df4e9	395	return dn;
9017c2ec YZ	396	}
9017c2ec YZ	397
a8e63b7d	398	/*
8996f4f2	399	* convert regular fh to parent
a8e63b7d SW	400	*/
a8e63b7d SW	401	static struct dentry ceph_fh_to_parent(struct super_block sb,
8996f4f2	402	struct fid *fid,
a8e63b7d SW	403	int fh_len, int fh_type)
	404	{
	405	struct ceph_nfs_confh cfh = (void )fid->raw;
a8e63b7d	406	struct dentry *dentry;
a8e63b7d	407
570df4e9 YZ	408	if (fh_type == FILEID_BTRFS_WITH_PARENT) {
	409	struct ceph_nfs_snapfh sfh = (void )fid->raw;
	410	return __snapfh_to_dentry(sb, sfh, true);
	411	}
	412
8996f4f2 YZ	413	if (fh_type != FILEID_INO32_GEN_PARENT)
8996f4f2 YZ	414	return NULL;
35c2a7f4	415	if (fh_len < sizeof(*cfh) / 4)
8996f4f2	416	return NULL;
a8e63b7d	417
8996f4f2 YZ	418	dout("fh_to_parent %llx\n", cfh->parent_ino);
8996f4f2 YZ	419	dentry = __get_parent(sb, NULL, cfh->ino);
b42b90d1	420	if (unlikely(dentry == ERR_PTR(-ENOENT)))
8996f4f2	421	dentry = __fh_to_dentry(sb, cfh->parent_ino);
a8e63b7d SW	422	return dentry;
	423	}
	424
570df4e9 YZ	425	static int __get_snap_name(struct dentry parent, char name,
	426	struct dentry *child)
	427	{
	428	struct inode *inode = d_inode(child);
	429	struct inode *dir = d_inode(parent);
	430	struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
	431	struct ceph_mds_request *req = NULL;
	432	char *last_name = NULL;
	433	unsigned next_offset = 2;
	434	int err = -EINVAL;
	435
	436	if (ceph_ino(inode) != ceph_ino(dir))
	437	goto out;
	438	if (ceph_snap(inode) == CEPH_SNAPDIR) {
	439	if (ceph_snap(dir) == CEPH_NOSNAP) {
	440	strcpy(name, fsc->mount_options->snapdir_name);
	441	err = 0;
	442	}
	443	goto out;
	444	}
	445	if (ceph_snap(dir) != CEPH_SNAPDIR)
	446	goto out;
	447
	448	while (1) {
	449	struct ceph_mds_reply_info_parsed *rinfo;
	450	struct ceph_mds_reply_dir_entry *rde;
	451	int i;
	452
	453	req = ceph_mdsc_create_request(fsc->mdsc, CEPH_MDS_OP_LSSNAP,
	454	USE_AUTH_MDS);
	455	if (IS_ERR(req)) {
	456	err = PTR_ERR(req);
	457	req = NULL;
	458	goto out;
	459	}
	460	err = ceph_alloc_readdir_reply_buffer(req, inode);
	461	if (err)
	462	goto out;
	463
	464	req->r_direct_mode = USE_AUTH_MDS;
	465	req->r_readdir_offset = next_offset;
	466	req->r_args.readdir.flags =
	467	cpu_to_le16(CEPH_READDIR_REPLY_BITFLAGS);
	468	if (last_name) {
	469	req->r_path2 = last_name;
	470	last_name = NULL;
	471	}
	472
	473	req->r_inode = dir;
	474	ihold(dir);
	475	req->r_dentry = dget(parent);
	476
	477	inode_lock(dir);
	478	err = ceph_mdsc_do_request(fsc->mdsc, NULL, req);
	479	inode_unlock(dir);
	480
	481	if (err < 0)
	482	goto out;
	483
0ed26f36 ID	484	rinfo = &req->r_reply_info;
	485	for (i = 0; i < rinfo->dir_nr; i++) {
	486	rde = rinfo->dir_entries + i;
	487	BUG_ON(!rde->inode.in);
	488	if (ceph_snap(inode) ==
	489	le64_to_cpu(rde->inode.in->snapid)) {
	490	memcpy(name, rde->name, rde->name_len);
	491	name[rde->name_len] = '\0';
	492	err = 0;
	493	goto out;
	494	}
	495	}
	496
	497	if (rinfo->dir_end)
	498	break;
	499
	500	BUG_ON(rinfo->dir_nr <= 0);
	501	rde = rinfo->dir_entries + (rinfo->dir_nr - 1);
	502	next_offset += rinfo->dir_nr;
	503	last_name = kstrndup(rde->name, rde->name_len, GFP_KERNEL);
	504	if (!last_name) {
	505	err = -ENOMEM;
	506	goto out;
	507	}
	508
	509	ceph_mdsc_put_request(req);
	510	req = NULL;
570df4e9 YZ	511	}
	512	err = -ENOENT;
	513	out:
	514	if (req)
	515	ceph_mdsc_put_request(req);
	516	kfree(last_name);
	517	dout("get_snap_name %p ino %llx.%llx err=%d\n",
	518	child, ceph_vinop(inode), err);
	519	return err;
	520	}
	521
19913b4e YZ	522	static int ceph_get_name(struct dentry parent, char name,
	523	struct dentry *child)
	524	{
	525	struct ceph_mds_client *mdsc;
	526	struct ceph_mds_request *req;
570df4e9	527	struct inode *inode = d_inode(child);
19913b4e YZ	528	int err;
19913b4e YZ	529
570df4e9 YZ	530	if (ceph_snap(inode) != CEPH_NOSNAP)
	531	return __get_snap_name(parent, name, child);
	532
	533	mdsc = ceph_inode_to_client(inode)->mdsc;
19913b4e YZ	534	req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_LOOKUPNAME,
	535	USE_ANY_MDS);
	536	if (IS_ERR(req))
	537	return PTR_ERR(req);
	538
5955102c	539	inode_lock(d_inode(parent));
19913b4e	540
570df4e9 YZ	541	req->r_inode = inode;
570df4e9 YZ	542	ihold(inode);
2b0143b5	543	req->r_ino2 = ceph_vino(d_inode(parent));
3dd69aab	544	req->r_parent = d_inode(parent);
4c183472	545	ihold(req->r_parent);
3dd69aab	546	set_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags);
19913b4e YZ	547	req->r_num_caps = 2;
	548	err = ceph_mdsc_do_request(mdsc, NULL, req);
	549
5955102c	550	inode_unlock(d_inode(parent));
19913b4e YZ	551
	552	if (!err) {
	553	struct ceph_mds_reply_info_parsed *rinfo = &req->r_reply_info;
	554	memcpy(name, rinfo->dname, rinfo->dname_len);
	555	name[rinfo->dname_len] = 0;
	556	dout("get_name %p ino %llx.%llx name %s\n",
570df4e9	557	child, ceph_vinop(inode), name);
19913b4e YZ	558	} else {
19913b4e YZ	559	dout("get_name %p ino %llx.%llx err %d\n",
570df4e9	560	child, ceph_vinop(inode), err);
19913b4e YZ	561	}
	562
	563	ceph_mdsc_put_request(req);
	564	return err;
	565	}
	566
a8e63b7d SW	567	const struct export_operations ceph_export_ops = {
	568	.encode_fh = ceph_encode_fh,
	569	.fh_to_dentry = ceph_fh_to_dentry,
	570	.fh_to_parent = ceph_fh_to_parent,
9017c2ec	571	.get_parent = ceph_get_parent,
19913b4e	572	.get_name = ceph_get_name,
a8e63b7d	573	};