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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};
v5.14.15
  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	}
161	return inode;
162}
163
164struct 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	}
173	return inode;
174}
175
176static struct dentry *__fh_to_dentry(struct super_block *sb, u64 ino)
177{
178	struct inode *inode = __lookup_inode(sb, ino);
 
179	int err;
180
181	if (IS_ERR(inode))
182		return ERR_CAST(inode);
183	/* We need LINK caps to reliably check i_nlink */
184	err = ceph_do_getattr(inode, CEPH_CAP_LINK_SHARED, false);
185	if (err) {
186		iput(inode);
187		return ERR_PTR(err);
188	}
189	/* -ESTALE if inode as been unlinked and no file is open */
190	if ((inode->i_nlink == 0) && (atomic_read(&inode->i_count) == 1)) {
191		iput(inode);
192		return ERR_PTR(-ESTALE);
193	}
194	return d_obtain_alias(inode);
195}
196
197static 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	}
221
222	if (ceph_vino_is_reserved(vino))
223		return ERR_PTR(-ESTALE);
224
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 */
261			inode = ERR_PTR(-EOPNOTSUPP);
262		}
263	} else {
264		inode = ERR_PTR(-ESTALE);
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	}
275	if (IS_ERR(inode))
276		return ERR_CAST(inode);
277	/* see comments in ceph_get_parent() */
278	return unlinked ? d_obtain_root(inode) : d_obtain_alias(inode);
279}
280
281/*
282 * convert regular fh to dentry
283 */
284static struct dentry *ceph_fh_to_dentry(struct super_block *sb,
285					struct fid *fid,
286					int fh_len, int fh_type)
287{
288	struct ceph_nfs_fh *fh = (void *)fid->raw;
289
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
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;
300
301	dout("fh_to_dentry %llx\n", fh->ino);
302	return __fh_to_dentry(sb, fh->ino);
303}
304
305static 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;
311	int mask;
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) {
320		req->r_inode = d_inode(child);
321		ihold(d_inode(child));
322	} else {
323		req->r_ino1 = (struct ceph_vino) {
324			.ino = ino,
325			.snap = CEPH_NOSNAP,
326		};
327	}
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
334	req->r_num_caps = 1;
335	err = ceph_mdsc_do_request(mdsc, NULL, req);
336	if (err) {
337		ceph_mdsc_put_request(req);
338		return ERR_PTR(err);
339	}
340
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
348	return d_obtain_alias(inode);
349}
350
351static struct dentry *ceph_get_parent(struct dentry *child)
352{
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	}
392out:
393	dout("get_parent %p ino %llx.%llx err=%ld\n",
394	     child, ceph_vinop(inode), (long)PTR_ERR_OR_ZERO(dn));
395	return dn;
396}
397
398/*
399 * convert regular fh to parent
400 */
401static struct dentry *ceph_fh_to_parent(struct super_block *sb,
402					struct fid *fid,
403					int fh_len, int fh_type)
404{
405	struct ceph_nfs_confh *cfh = (void *)fid->raw;
406	struct dentry *dentry;
407
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
413	if (fh_type != FILEID_INO32_GEN_PARENT)
414		return NULL;
415	if (fh_len < sizeof(*cfh) / 4)
416		return NULL;
417
418	dout("fh_to_parent %llx\n", cfh->parent_ino);
419	dentry = __get_parent(sb, NULL, cfh->ino);
420	if (unlikely(dentry == ERR_PTR(-ENOENT)))
421		dentry = __fh_to_dentry(sb, cfh->parent_ino);
422	return dentry;
423}
424
425static 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
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;
511	}
512	err = -ENOENT;
513out:
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
522static 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;
527	struct inode *inode = d_inode(child);
528	int err;
529
530	if (ceph_snap(inode) != CEPH_NOSNAP)
531		return __get_snap_name(parent, name, child);
532
533	mdsc = ceph_inode_to_client(inode)->mdsc;
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
539	inode_lock(d_inode(parent));
540
541	req->r_inode = inode;
542	ihold(inode);
543	req->r_ino2 = ceph_vino(d_inode(parent));
544	req->r_parent = d_inode(parent);
545	ihold(req->r_parent);
546	set_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags);
547	req->r_num_caps = 2;
548	err = ceph_mdsc_do_request(mdsc, NULL, req);
549
550	inode_unlock(d_inode(parent));
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",
557		     child, ceph_vinop(inode), name);
558	} else {
559		dout("get_name %p ino %llx.%llx err %d\n",
560		     child, ceph_vinop(inode), err);
561	}
562
563	ceph_mdsc_put_request(req);
564	return err;
565}
566
567const 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,
571	.get_parent = ceph_get_parent,
572	.get_name = ceph_get_name,
573};