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v3.15
 
  1#include <linux/ceph/ceph_debug.h>
  2
  3#include <linux/exportfs.h>
  4#include <linux/slab.h>
  5#include <asm/unaligned.h>
  6
  7#include "super.h"
  8#include "mds_client.h"
  9
 10/*
 11 * Basic fh
 12 */
 13struct ceph_nfs_fh {
 14	u64 ino;
 15} __attribute__ ((packed));
 16
 17/*
 18 * Larger fh that includes parent ino.
 19 */
 20struct ceph_nfs_confh {
 21	u64 ino, parent_ino;
 22} __attribute__ ((packed));
 23
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 24static int ceph_encode_fh(struct inode *inode, u32 *rawfh, int *max_len,
 25			  struct inode *parent_inode)
 26{
 
 
 
 
 27	int type;
 28	struct ceph_nfs_fh *fh = (void *)rawfh;
 29	struct ceph_nfs_confh *cfh = (void *)rawfh;
 30	int connected_handle_length = sizeof(*cfh)/4;
 31	int handle_length = sizeof(*fh)/4;
 32
 33	/* don't re-export snaps */
 34	if (ceph_snap(inode) != CEPH_NOSNAP)
 35		return -EINVAL;
 36
 37	if (parent_inode && (*max_len < connected_handle_length)) {
 38		*max_len = connected_handle_length;
 39		return FILEID_INVALID;
 40	} else if (*max_len < handle_length) {
 41		*max_len = handle_length;
 42		return FILEID_INVALID;
 43	}
 44
 45	if (parent_inode) {
 
 46		dout("encode_fh %llx with parent %llx\n",
 47		     ceph_ino(inode), ceph_ino(parent_inode));
 48		cfh->ino = ceph_ino(inode);
 49		cfh->parent_ino = ceph_ino(parent_inode);
 50		*max_len = connected_handle_length;
 51		type = FILEID_INO32_GEN_PARENT;
 52	} else {
 
 53		dout("encode_fh %llx\n", ceph_ino(inode));
 54		fh->ino = ceph_ino(inode);
 55		*max_len = handle_length;
 56		type = FILEID_INO32_GEN;
 57	}
 58	return type;
 59}
 60
 61static struct dentry *__fh_to_dentry(struct super_block *sb, u64 ino)
 62{
 63	struct ceph_mds_client *mdsc = ceph_sb_to_client(sb)->mdsc;
 64	struct inode *inode;
 65	struct dentry *dentry;
 66	struct ceph_vino vino;
 67	int err;
 68
 69	vino.ino = ino;
 70	vino.snap = CEPH_NOSNAP;
 
 
 
 
 71	inode = ceph_find_inode(sb, vino);
 72	if (!inode) {
 73		struct ceph_mds_request *req;
 
 74
 75		req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_LOOKUPINO,
 76					       USE_ANY_MDS);
 77		if (IS_ERR(req))
 78			return ERR_CAST(req);
 79
 
 
 
 
 
 80		req->r_ino1 = vino;
 81		req->r_num_caps = 1;
 82		err = ceph_mdsc_do_request(mdsc, NULL, req);
 83		inode = req->r_target_inode;
 84		if (inode)
 85			ihold(inode);
 86		ceph_mdsc_put_request(req);
 87		if (!inode)
 
 
 
 
 88			return ERR_PTR(-ESTALE);
 
 89	}
 
 
 90
 91	dentry = d_obtain_alias(inode);
 92	if (IS_ERR(dentry)) {
 
 
 
 
 93		iput(inode);
 94		return dentry;
 95	}
 96	err = ceph_init_dentry(dentry);
 97	if (err < 0) {
 98		dput(dentry);
 
 
 
 
 
 
 
 
 
 
 
 
 99		return ERR_PTR(err);
100	}
101	dout("__fh_to_dentry %llx %p dentry %p\n", ino, inode, dentry);
102	return dentry;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
103}
104
105/*
106 * convert regular fh to dentry
107 */
108static struct dentry *ceph_fh_to_dentry(struct super_block *sb,
109					struct fid *fid,
110					int fh_len, int fh_type)
111{
112	struct ceph_nfs_fh *fh = (void *)fid->raw;
113
 
 
 
 
 
114	if (fh_type != FILEID_INO32_GEN  &&
115	    fh_type != FILEID_INO32_GEN_PARENT)
116		return NULL;
117	if (fh_len < sizeof(*fh) / 4)
118		return NULL;
119
120	dout("fh_to_dentry %llx\n", fh->ino);
121	return __fh_to_dentry(sb, fh->ino);
122}
123
124static struct dentry *__get_parent(struct super_block *sb,
125				   struct dentry *child, u64 ino)
126{
127	struct ceph_mds_client *mdsc = ceph_sb_to_client(sb)->mdsc;
128	struct ceph_mds_request *req;
129	struct inode *inode;
130	struct dentry *dentry;
131	int err;
132
133	req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_LOOKUPPARENT,
134				       USE_ANY_MDS);
135	if (IS_ERR(req))
136		return ERR_CAST(req);
137
138	if (child) {
139		req->r_inode = child->d_inode;
140		ihold(child->d_inode);
141	} else {
142		req->r_ino1 = (struct ceph_vino) {
143			.ino = ino,
144			.snap = CEPH_NOSNAP,
145		};
146	}
 
 
 
 
 
 
147	req->r_num_caps = 1;
148	err = ceph_mdsc_do_request(mdsc, NULL, req);
 
 
 
 
 
149	inode = req->r_target_inode;
150	if (inode)
151		ihold(inode);
152	ceph_mdsc_put_request(req);
153	if (!inode)
154		return ERR_PTR(-ENOENT);
155
156	dentry = d_obtain_alias(inode);
157	if (IS_ERR(dentry)) {
158		iput(inode);
159		return dentry;
160	}
161	err = ceph_init_dentry(dentry);
162	if (err < 0) {
163		dput(dentry);
164		return ERR_PTR(err);
165	}
166	dout("__get_parent ino %llx parent %p ino %llx.%llx\n",
167	     child ? ceph_ino(child->d_inode) : ino,
168	     dentry, ceph_vinop(inode));
169	return dentry;
170}
171
172struct dentry *ceph_get_parent(struct dentry *child)
173{
174	/* don't re-export snaps */
175	if (ceph_snap(child->d_inode) != CEPH_NOSNAP)
176		return ERR_PTR(-EINVAL);
177
178	dout("get_parent %p ino %llx.%llx\n",
179	     child, ceph_vinop(child->d_inode));
180	return __get_parent(child->d_sb, child, 0);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
181}
182
183/*
184 * convert regular fh to parent
185 */
186static struct dentry *ceph_fh_to_parent(struct super_block *sb,
187					struct fid *fid,
188					int fh_len, int fh_type)
189{
190	struct ceph_nfs_confh *cfh = (void *)fid->raw;
191	struct dentry *dentry;
192
 
 
 
 
 
193	if (fh_type != FILEID_INO32_GEN_PARENT)
194		return NULL;
195	if (fh_len < sizeof(*cfh) / 4)
196		return NULL;
197
198	dout("fh_to_parent %llx\n", cfh->parent_ino);
199	dentry = __get_parent(sb, NULL, cfh->ino);
200	if (IS_ERR(dentry) && PTR_ERR(dentry) == -ENOENT)
201		dentry = __fh_to_dentry(sb, cfh->parent_ino);
202	return dentry;
203}
204
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
205static int ceph_get_name(struct dentry *parent, char *name,
206			 struct dentry *child)
207{
208	struct ceph_mds_client *mdsc;
209	struct ceph_mds_request *req;
 
210	int err;
211
212	mdsc = ceph_inode_to_client(child->d_inode)->mdsc;
 
 
 
213	req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_LOOKUPNAME,
214				       USE_ANY_MDS);
215	if (IS_ERR(req))
216		return PTR_ERR(req);
217
218	mutex_lock(&parent->d_inode->i_mutex);
219
220	req->r_inode = child->d_inode;
221	ihold(child->d_inode);
222	req->r_ino2 = ceph_vino(parent->d_inode);
223	req->r_locked_dir = parent->d_inode;
 
 
224	req->r_num_caps = 2;
225	err = ceph_mdsc_do_request(mdsc, NULL, req);
226
227	mutex_unlock(&parent->d_inode->i_mutex);
228
229	if (!err) {
230		struct ceph_mds_reply_info_parsed *rinfo = &req->r_reply_info;
231		memcpy(name, rinfo->dname, rinfo->dname_len);
232		name[rinfo->dname_len] = 0;
233		dout("get_name %p ino %llx.%llx name %s\n",
234		     child, ceph_vinop(child->d_inode), name);
235	} else {
236		dout("get_name %p ino %llx.%llx err %d\n",
237		     child, ceph_vinop(child->d_inode), err);
238	}
239
240	ceph_mdsc_put_request(req);
241	return err;
242}
243
244const struct export_operations ceph_export_ops = {
245	.encode_fh = ceph_encode_fh,
246	.fh_to_dentry = ceph_fh_to_dentry,
247	.fh_to_parent = ceph_fh_to_parent,
248	.get_parent = ceph_get_parent,
249	.get_name = ceph_get_name,
250};
v6.2
  1// SPDX-License-Identifier: GPL-2.0
  2#include <linux/ceph/ceph_debug.h>
  3
  4#include <linux/exportfs.h>
  5#include <linux/slab.h>
  6#include <asm/unaligned.h>
  7
  8#include "super.h"
  9#include "mds_client.h"
 10
 11/*
 12 * Basic fh
 13 */
 14struct ceph_nfs_fh {
 15	u64 ino;
 16} __attribute__ ((packed));
 17
 18/*
 19 * Larger fh that includes parent ino.
 20 */
 21struct ceph_nfs_confh {
 22	u64 ino, parent_ino;
 23} __attribute__ ((packed));
 24
 25/*
 26 * fh for snapped inode
 27 */
 28struct ceph_nfs_snapfh {
 29	u64 ino;
 30	u64 snapid;
 31	u64 parent_ino;
 32	u32 hash;
 33} __attribute__ ((packed));
 34
 35static int ceph_encode_snapfh(struct inode *inode, u32 *rawfh, int *max_len,
 36			      struct inode *parent_inode)
 37{
 38	static const int snap_handle_length =
 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;
 80out:
 81	dout("encode_snapfh %llx.%llx ret=%d\n", ceph_vinop(inode), ret);
 82	return ret;
 83}
 84
 85static int ceph_encode_fh(struct inode *inode, u32 *rawfh, int *max_len,
 86			  struct inode *parent_inode)
 87{
 88	static const int handle_length =
 89		sizeof(struct ceph_nfs_fh) >> 2;
 90	static const int connected_handle_length =
 91		sizeof(struct ceph_nfs_confh) >> 2;
 92	int type;
 
 
 
 
 93
 
 94	if (ceph_snap(inode) != CEPH_NOSNAP)
 95		return ceph_encode_snapfh(inode, rawfh, max_len, parent_inode);
 96
 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	}
104
105	if (parent_inode) {
106		struct ceph_nfs_confh *cfh = (void *)rawfh;
107		dout("encode_fh %llx with parent %llx\n",
108		     ceph_ino(inode), ceph_ino(parent_inode));
109		cfh->ino = ceph_ino(inode);
110		cfh->parent_ino = ceph_ino(parent_inode);
111		*max_len = connected_handle_length;
112		type = FILEID_INO32_GEN_PARENT;
113	} else {
114		struct ceph_nfs_fh *fh = (void *)rawfh;
115		dout("encode_fh %llx\n", ceph_ino(inode));
116		fh->ino = ceph_ino(inode);
117		*max_len = handle_length;
118		type = FILEID_INO32_GEN;
119	}
120	return type;
121}
122
123static struct inode *__lookup_inode(struct super_block *sb, u64 ino)
124{
125	struct ceph_mds_client *mdsc = ceph_sb_to_client(sb)->mdsc;
126	struct inode *inode;
 
127	struct ceph_vino vino;
128	int err;
129
130	vino.ino = ino;
131	vino.snap = CEPH_NOSNAP;
132
133	if (ceph_vino_is_reserved(vino))
134		return ERR_PTR(-ESTALE);
135
136	inode = ceph_find_inode(sb, vino);
137	if (!inode) {
138		struct ceph_mds_request *req;
139		int mask;
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
146		mask = CEPH_STAT_CAP_INODE;
147		if (ceph_security_xattr_wanted(d_inode(sb->s_root)))
148			mask |= CEPH_CAP_XATTR_SHARED;
149		req->r_args.lookupino.mask = cpu_to_le32(mask);
150
151		req->r_ino1 = vino;
152		req->r_num_caps = 1;
153		err = ceph_mdsc_do_request(mdsc, NULL, req);
154		inode = req->r_target_inode;
155		if (inode)
156			ihold(inode);
157		ceph_mdsc_put_request(req);
158		if (!inode)
159			return err < 0 ? ERR_PTR(err) : ERR_PTR(-ESTALE);
160	} else {
161		if (ceph_inode_is_shutdown(inode)) {
162			iput(inode);
163			return ERR_PTR(-ESTALE);
164		}
165	}
166	return inode;
167}
168
169struct inode *ceph_lookup_inode(struct super_block *sb, u64 ino)
170{
171	struct inode *inode = __lookup_inode(sb, ino);
172	if (IS_ERR(inode))
173		return inode;
174	if (inode->i_nlink == 0) {
175		iput(inode);
176		return ERR_PTR(-ESTALE);
177	}
178	return inode;
179}
180
181static struct dentry *__fh_to_dentry(struct super_block *sb, u64 ino)
182{
183	struct inode *inode = __lookup_inode(sb, ino);
184	struct ceph_inode_info *ci = ceph_inode(inode);
185	int err;
186
187	if (IS_ERR(inode))
188		return ERR_CAST(inode);
189	/* We need LINK caps to reliably check i_nlink */
190	err = ceph_do_getattr(inode, CEPH_CAP_LINK_SHARED, false);
191	if (err) {
192		iput(inode);
193		return ERR_PTR(err);
194	}
195	/* -ESTALE if inode as been unlinked and no file is open */
196	if ((inode->i_nlink == 0) && !__ceph_is_file_opened(ci)) {
197		iput(inode);
198		return ERR_PTR(-ESTALE);
199	}
200	return d_obtain_alias(inode);
201}
202
203static struct dentry *__snapfh_to_dentry(struct super_block *sb,
204					  struct ceph_nfs_snapfh *sfh,
205					  bool want_parent)
206{
207	struct ceph_mds_client *mdsc = ceph_sb_to_client(sb)->mdsc;
208	struct ceph_mds_request *req;
209	struct inode *inode;
210	struct ceph_vino vino;
211	int mask;
212	int err;
213	bool unlinked = false;
214
215	if (want_parent) {
216		vino.ino = sfh->parent_ino;
217		if (sfh->snapid == CEPH_SNAPDIR)
218			vino.snap = CEPH_NOSNAP;
219		else if (sfh->ino == sfh->parent_ino)
220			vino.snap = CEPH_SNAPDIR;
221		else
222			vino.snap = sfh->snapid;
223	} else {
224		vino.ino = sfh->ino;
225		vino.snap = sfh->snapid;
226	}
227
228	if (ceph_vino_is_reserved(vino))
229		return ERR_PTR(-ESTALE);
230
231	inode = ceph_find_inode(sb, vino);
232	if (inode) {
233		if (ceph_inode_is_shutdown(inode)) {
234			iput(inode);
235			return ERR_PTR(-ESTALE);
236		}
237		return d_obtain_alias(inode);
238	}
239
240	req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_LOOKUPINO,
241				       USE_ANY_MDS);
242	if (IS_ERR(req))
243		return ERR_CAST(req);
244
245	mask = CEPH_STAT_CAP_INODE;
246	if (ceph_security_xattr_wanted(d_inode(sb->s_root)))
247		mask |= CEPH_CAP_XATTR_SHARED;
248	req->r_args.lookupino.mask = cpu_to_le32(mask);
249	if (vino.snap < CEPH_NOSNAP) {
250		req->r_args.lookupino.snapid = cpu_to_le64(vino.snap);
251		if (!want_parent && sfh->ino != sfh->parent_ino) {
252			req->r_args.lookupino.parent =
253					cpu_to_le64(sfh->parent_ino);
254			req->r_args.lookupino.hash =
255					cpu_to_le32(sfh->hash);
256		}
257	}
258
259	req->r_ino1 = vino;
260	req->r_num_caps = 1;
261	err = ceph_mdsc_do_request(mdsc, NULL, req);
262	inode = req->r_target_inode;
263	if (inode) {
264		if (vino.snap == CEPH_SNAPDIR) {
265			if (inode->i_nlink == 0)
266				unlinked = true;
267			inode = ceph_get_snapdir(inode);
268		} else if (ceph_snap(inode) == vino.snap) {
269			ihold(inode);
270		} else {
271			/* mds does not support lookup snapped inode */
272			inode = ERR_PTR(-EOPNOTSUPP);
273		}
274	} else {
275		inode = ERR_PTR(-ESTALE);
276	}
277	ceph_mdsc_put_request(req);
278
279	if (want_parent) {
280		dout("snapfh_to_parent %llx.%llx\n err=%d\n",
281		     vino.ino, vino.snap, err);
282	} else {
283		dout("snapfh_to_dentry %llx.%llx parent %llx hash %x err=%d",
284		      vino.ino, vino.snap, sfh->parent_ino, sfh->hash, err);
285	}
286	if (IS_ERR(inode))
287		return ERR_CAST(inode);
288	/* see comments in ceph_get_parent() */
289	return unlinked ? d_obtain_root(inode) : d_obtain_alias(inode);
290}
291
292/*
293 * convert regular fh to dentry
294 */
295static struct dentry *ceph_fh_to_dentry(struct super_block *sb,
296					struct fid *fid,
297					int fh_len, int fh_type)
298{
299	struct ceph_nfs_fh *fh = (void *)fid->raw;
300
301	if (fh_type == FILEID_BTRFS_WITH_PARENT) {
302		struct ceph_nfs_snapfh *sfh = (void *)fid->raw;
303		return __snapfh_to_dentry(sb, sfh, false);
304	}
305
306	if (fh_type != FILEID_INO32_GEN  &&
307	    fh_type != FILEID_INO32_GEN_PARENT)
308		return NULL;
309	if (fh_len < sizeof(*fh) / 4)
310		return NULL;
311
312	dout("fh_to_dentry %llx\n", fh->ino);
313	return __fh_to_dentry(sb, fh->ino);
314}
315
316static struct dentry *__get_parent(struct super_block *sb,
317				   struct dentry *child, u64 ino)
318{
319	struct ceph_mds_client *mdsc = ceph_sb_to_client(sb)->mdsc;
320	struct ceph_mds_request *req;
321	struct inode *inode;
322	int mask;
323	int err;
324
325	req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_LOOKUPPARENT,
326				       USE_ANY_MDS);
327	if (IS_ERR(req))
328		return ERR_CAST(req);
329
330	if (child) {
331		req->r_inode = d_inode(child);
332		ihold(d_inode(child));
333	} else {
334		req->r_ino1 = (struct ceph_vino) {
335			.ino = ino,
336			.snap = CEPH_NOSNAP,
337		};
338	}
339
340	mask = CEPH_STAT_CAP_INODE;
341	if (ceph_security_xattr_wanted(d_inode(sb->s_root)))
342		mask |= CEPH_CAP_XATTR_SHARED;
343	req->r_args.getattr.mask = cpu_to_le32(mask);
344
345	req->r_num_caps = 1;
346	err = ceph_mdsc_do_request(mdsc, NULL, req);
347	if (err) {
348		ceph_mdsc_put_request(req);
349		return ERR_PTR(err);
350	}
351
352	inode = req->r_target_inode;
353	if (inode)
354		ihold(inode);
355	ceph_mdsc_put_request(req);
356	if (!inode)
357		return ERR_PTR(-ENOENT);
358
359	return d_obtain_alias(inode);
 
 
 
 
 
 
 
 
 
 
 
 
 
360}
361
362static struct dentry *ceph_get_parent(struct dentry *child)
363{
364	struct inode *inode = d_inode(child);
365	struct dentry *dn;
366
367	if (ceph_snap(inode) != CEPH_NOSNAP) {
368		struct inode* dir;
369		bool unlinked = false;
370		/* do not support non-directory */
371		if (!d_is_dir(child)) {
372			dn = ERR_PTR(-EINVAL);
373			goto out;
374		}
375		dir = __lookup_inode(inode->i_sb, ceph_ino(inode));
376		if (IS_ERR(dir)) {
377			dn = ERR_CAST(dir);
378			goto out;
379		}
380		/* There can be multiple paths to access snapped inode.
381		 * For simplicity, treat snapdir of head inode as parent */
382		if (ceph_snap(inode) != CEPH_SNAPDIR) {
383			struct inode *snapdir = ceph_get_snapdir(dir);
384			if (dir->i_nlink == 0)
385				unlinked = true;
386			iput(dir);
387			if (IS_ERR(snapdir)) {
388				dn = ERR_CAST(snapdir);
389				goto out;
390			}
391			dir = snapdir;
392		}
393		/* If directory has already been deleted, futher get_parent
394		 * will fail. Do not mark snapdir dentry as disconnected,
395		 * this prevent exportfs from doing futher get_parent. */
396		if (unlinked)
397			dn = d_obtain_root(dir);
398		else
399			dn = d_obtain_alias(dir);
400	} else {
401		dn = __get_parent(child->d_sb, child, 0);
402	}
403out:
404	dout("get_parent %p ino %llx.%llx err=%ld\n",
405	     child, ceph_vinop(inode), (long)PTR_ERR_OR_ZERO(dn));
406	return dn;
407}
408
409/*
410 * convert regular fh to parent
411 */
412static struct dentry *ceph_fh_to_parent(struct super_block *sb,
413					struct fid *fid,
414					int fh_len, int fh_type)
415{
416	struct ceph_nfs_confh *cfh = (void *)fid->raw;
417	struct dentry *dentry;
418
419	if (fh_type == FILEID_BTRFS_WITH_PARENT) {
420		struct ceph_nfs_snapfh *sfh = (void *)fid->raw;
421		return __snapfh_to_dentry(sb, sfh, true);
422	}
423
424	if (fh_type != FILEID_INO32_GEN_PARENT)
425		return NULL;
426	if (fh_len < sizeof(*cfh) / 4)
427		return NULL;
428
429	dout("fh_to_parent %llx\n", cfh->parent_ino);
430	dentry = __get_parent(sb, NULL, cfh->ino);
431	if (unlikely(dentry == ERR_PTR(-ENOENT)))
432		dentry = __fh_to_dentry(sb, cfh->parent_ino);
433	return dentry;
434}
435
436static int __get_snap_name(struct dentry *parent, char *name,
437			   struct dentry *child)
438{
439	struct inode *inode = d_inode(child);
440	struct inode *dir = d_inode(parent);
441	struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
442	struct ceph_mds_request *req = NULL;
443	char *last_name = NULL;
444	unsigned next_offset = 2;
445	int err = -EINVAL;
446
447	if (ceph_ino(inode) != ceph_ino(dir))
448		goto out;
449	if (ceph_snap(inode) == CEPH_SNAPDIR) {
450		if (ceph_snap(dir) == CEPH_NOSNAP) {
451			strcpy(name, fsc->mount_options->snapdir_name);
452			err = 0;
453		}
454		goto out;
455	}
456	if (ceph_snap(dir) != CEPH_SNAPDIR)
457		goto out;
458
459	while (1) {
460		struct ceph_mds_reply_info_parsed *rinfo;
461		struct ceph_mds_reply_dir_entry *rde;
462		int i;
463
464		req = ceph_mdsc_create_request(fsc->mdsc, CEPH_MDS_OP_LSSNAP,
465					       USE_AUTH_MDS);
466		if (IS_ERR(req)) {
467			err = PTR_ERR(req);
468			req = NULL;
469			goto out;
470		}
471		err = ceph_alloc_readdir_reply_buffer(req, inode);
472		if (err)
473			goto out;
474
475		req->r_direct_mode = USE_AUTH_MDS;
476		req->r_readdir_offset = next_offset;
477		req->r_args.readdir.flags =
478				cpu_to_le16(CEPH_READDIR_REPLY_BITFLAGS);
479		if (last_name) {
480			req->r_path2 = last_name;
481			last_name = NULL;
482		}
483
484		req->r_inode = dir;
485		ihold(dir);
486		req->r_dentry = dget(parent);
487
488		inode_lock(dir);
489		err = ceph_mdsc_do_request(fsc->mdsc, NULL, req);
490		inode_unlock(dir);
491
492		if (err < 0)
493			goto out;
494
495		rinfo = &req->r_reply_info;
496		for (i = 0; i < rinfo->dir_nr; i++) {
497			rde = rinfo->dir_entries + i;
498			BUG_ON(!rde->inode.in);
499			if (ceph_snap(inode) ==
500			    le64_to_cpu(rde->inode.in->snapid)) {
501				memcpy(name, rde->name, rde->name_len);
502				name[rde->name_len] = '\0';
503				err = 0;
504				goto out;
505			}
506		}
507
508		if (rinfo->dir_end)
509			break;
510
511		BUG_ON(rinfo->dir_nr <= 0);
512		rde = rinfo->dir_entries + (rinfo->dir_nr - 1);
513		next_offset += rinfo->dir_nr;
514		last_name = kstrndup(rde->name, rde->name_len, GFP_KERNEL);
515		if (!last_name) {
516			err = -ENOMEM;
517			goto out;
518		}
519
520		ceph_mdsc_put_request(req);
521		req = NULL;
522	}
523	err = -ENOENT;
524out:
525	if (req)
526		ceph_mdsc_put_request(req);
527	kfree(last_name);
528	dout("get_snap_name %p ino %llx.%llx err=%d\n",
529	     child, ceph_vinop(inode), err);
530	return err;
531}
532
533static int ceph_get_name(struct dentry *parent, char *name,
534			 struct dentry *child)
535{
536	struct ceph_mds_client *mdsc;
537	struct ceph_mds_request *req;
538	struct inode *inode = d_inode(child);
539	int err;
540
541	if (ceph_snap(inode) != CEPH_NOSNAP)
542		return __get_snap_name(parent, name, child);
543
544	mdsc = ceph_inode_to_client(inode)->mdsc;
545	req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_LOOKUPNAME,
546				       USE_ANY_MDS);
547	if (IS_ERR(req))
548		return PTR_ERR(req);
549
550	inode_lock(d_inode(parent));
551
552	req->r_inode = inode;
553	ihold(inode);
554	req->r_ino2 = ceph_vino(d_inode(parent));
555	req->r_parent = d_inode(parent);
556	ihold(req->r_parent);
557	set_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags);
558	req->r_num_caps = 2;
559	err = ceph_mdsc_do_request(mdsc, NULL, req);
560
561	inode_unlock(d_inode(parent));
562
563	if (!err) {
564		struct ceph_mds_reply_info_parsed *rinfo = &req->r_reply_info;
565		memcpy(name, rinfo->dname, rinfo->dname_len);
566		name[rinfo->dname_len] = 0;
567		dout("get_name %p ino %llx.%llx name %s\n",
568		     child, ceph_vinop(inode), name);
569	} else {
570		dout("get_name %p ino %llx.%llx err %d\n",
571		     child, ceph_vinop(inode), err);
572	}
573
574	ceph_mdsc_put_request(req);
575	return err;
576}
577
578const struct export_operations ceph_export_ops = {
579	.encode_fh = ceph_encode_fh,
580	.fh_to_dentry = ceph_fh_to_dentry,
581	.fh_to_parent = ceph_fh_to_parent,
582	.get_parent = ceph_get_parent,
583	.get_name = ceph_get_name,
584};