dir.c

  1// SPDX-License-Identifier: LGPL-2.1
  2/*
  3 *
  4 *   vfs operations that deal with dentries
  5 *
  6 *   Copyright (C) International Business Machines  Corp., 2002,2009
  7 *   Author(s): Steve French (sfrench@us.ibm.com)
  8 *
  9 */
 10#include <linux/fs.h>
 11#include <linux/stat.h>
 12#include <linux/slab.h>
 13#include <linux/namei.h>
 14#include <linux/mount.h>
 15#include <linux/file.h>
 16#include "cifsfs.h"
 17#include "cifspdu.h"
 18#include "cifsglob.h"
 19#include "cifsproto.h"
 20#include "cifs_debug.h"
 21#include "cifs_fs_sb.h"
 22#include "cifs_unicode.h"
 23#include "fs_context.h"
 24#include "cifs_ioctl.h"
 25#include "fscache.h"
 26#include "cached_dir.h"
 27
 28static void
 29renew_parental_timestamps(struct dentry *direntry)
 30{
 31	/* BB check if there is a way to get the kernel to do this or if we
 32	   really need this */
 33	do {
 34		cifs_set_time(direntry, jiffies);
 35		direntry = direntry->d_parent;
 36	} while (!IS_ROOT(direntry));
 37}
 38
 39char *
 40cifs_build_path_to_root(struct smb3_fs_context *ctx, struct cifs_sb_info *cifs_sb,
 41			struct cifs_tcon *tcon, int add_treename)
 42{
 43	int pplen = ctx->prepath ? strlen(ctx->prepath) + 1 : 0;
 44	int dfsplen;
 45	char *full_path = NULL;
 46
 47	/* if no prefix path, simply set path to the root of share to "" */
 48	if (pplen == 0) {
 49		full_path = kzalloc(1, GFP_KERNEL);
 50		return full_path;
 51	}
 52
 53	if (add_treename)
 54		dfsplen = strnlen(tcon->tree_name, MAX_TREE_SIZE + 1);
 55	else
 56		dfsplen = 0;
 57
 58	full_path = kmalloc(dfsplen + pplen + 1, GFP_KERNEL);
 59	if (full_path == NULL)
 60		return full_path;
 61
 62	if (dfsplen)
 63		memcpy(full_path, tcon->tree_name, dfsplen);
 64	full_path[dfsplen] = CIFS_DIR_SEP(cifs_sb);
 65	memcpy(full_path + dfsplen + 1, ctx->prepath, pplen);
 66	convert_delimiter(full_path, CIFS_DIR_SEP(cifs_sb));
 67	return full_path;
 68}
 69
 70/* Note: caller must free return buffer */
 71const char *
 72build_path_from_dentry(struct dentry *direntry, void *page)
 73{
 74	struct cifs_sb_info *cifs_sb = CIFS_SB(direntry->d_sb);
 75	struct cifs_tcon *tcon = cifs_sb_master_tcon(cifs_sb);
 76	bool prefix = tcon->Flags & SMB_SHARE_IS_IN_DFS;
 77
 78	return build_path_from_dentry_optional_prefix(direntry, page,
 79						      prefix);
 80}
 81
 82char *__build_path_from_dentry_optional_prefix(struct dentry *direntry, void *page,
 83					       const char *tree, int tree_len,
 84					       bool prefix)
 85{
 86	int dfsplen;
 87	int pplen = 0;
 88	struct cifs_sb_info *cifs_sb = CIFS_SB(direntry->d_sb);
 89	char dirsep = CIFS_DIR_SEP(cifs_sb);
 90	char *s;
 91
 92	if (unlikely(!page))
 93		return ERR_PTR(-ENOMEM);
 94
 95	if (prefix)
 96		dfsplen = strnlen(tree, tree_len + 1);
 97	else
 98		dfsplen = 0;
 99
100	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_USE_PREFIX_PATH)
101		pplen = cifs_sb->prepath ? strlen(cifs_sb->prepath) + 1 : 0;
102
103	s = dentry_path_raw(direntry, page, PATH_MAX);
104	if (IS_ERR(s))
105		return s;
106	if (!s[1])	// for root we want "", not "/"
107		s++;
108	if (s < (char *)page + pplen + dfsplen)
109		return ERR_PTR(-ENAMETOOLONG);
110	if (pplen) {
111		cifs_dbg(FYI, "using cifs_sb prepath <%s>\n", cifs_sb->prepath);
112		s -= pplen;
113		memcpy(s + 1, cifs_sb->prepath, pplen - 1);
114		*s = '/';
115	}
116	if (dirsep != '/') {
117		/* BB test paths to Windows with '/' in the midst of prepath */
118		char *p;
119
120		for (p = s; *p; p++)
121			if (*p == '/')
122				*p = dirsep;
123	}
124	if (dfsplen) {
125		s -= dfsplen;
126		memcpy(s, tree, dfsplen);
127		if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_POSIX_PATHS) {
128			int i;
129			for (i = 0; i < dfsplen; i++) {
130				if (s[i] == '\\')
131					s[i] = '/';
132			}
133		}
134	}
135	return s;
136}
137
138char *build_path_from_dentry_optional_prefix(struct dentry *direntry, void *page,
139					     bool prefix)
140{
141	struct cifs_sb_info *cifs_sb = CIFS_SB(direntry->d_sb);
142	struct cifs_tcon *tcon = cifs_sb_master_tcon(cifs_sb);
143
144	return __build_path_from_dentry_optional_prefix(direntry, page, tcon->tree_name,
145							MAX_TREE_SIZE, prefix);
146}
147
148/*
149 * Don't allow path components longer than the server max.
150 * Don't allow the separator character in a path component.
151 * The VFS will not allow "/", but "\" is allowed by posix.
152 */
153static int
154check_name(struct dentry *direntry, struct cifs_tcon *tcon)
155{
156	struct cifs_sb_info *cifs_sb = CIFS_SB(direntry->d_sb);
157	int i;
158
159	if (unlikely(tcon->fsAttrInfo.MaxPathNameComponentLength &&
160		     direntry->d_name.len >
161		     le32_to_cpu(tcon->fsAttrInfo.MaxPathNameComponentLength)))
162		return -ENAMETOOLONG;
163
164	if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_POSIX_PATHS)) {
165		for (i = 0; i < direntry->d_name.len; i++) {
166			if (direntry->d_name.name[i] == '\\') {
167				cifs_dbg(FYI, "Invalid file name\n");
168				return -EINVAL;
169			}
170		}
171	}
172	return 0;
173}
174
175
176/* Inode operations in similar order to how they appear in Linux file fs.h */
177
178static int cifs_do_create(struct inode *inode, struct dentry *direntry, unsigned int xid,
179			  struct tcon_link *tlink, unsigned int oflags, umode_t mode, __u32 *oplock,
180			  struct cifs_fid *fid, struct cifs_open_info_data *buf)
181{
182	int rc = -ENOENT;
183	int create_options = CREATE_NOT_DIR;
184	int desired_access;
185	struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
186	struct cifs_tcon *tcon = tlink_tcon(tlink);
187	const char *full_path;
188	void *page = alloc_dentry_path();
189	struct inode *newinode = NULL;
190	int disposition;
191	struct TCP_Server_Info *server = tcon->ses->server;
192	struct cifs_open_parms oparms;
193	struct cached_fid *parent_cfid = NULL;
194	int rdwr_for_fscache = 0;
195	__le32 lease_flags = 0;
196
197	*oplock = 0;
198	if (tcon->ses->server->oplocks)
199		*oplock = REQ_OPLOCK;
200
201	full_path = build_path_from_dentry(direntry, page);
202	if (IS_ERR(full_path)) {
203		rc = PTR_ERR(full_path);
204		goto out;
205	}
206
207	/* If we're caching, we need to be able to fill in around partial writes. */
208	if (cifs_fscache_enabled(inode) && (oflags & O_ACCMODE) == O_WRONLY)
209		rdwr_for_fscache = 1;
210
211#ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
212	if (tcon->unix_ext && cap_unix(tcon->ses) && !tcon->broken_posix_open &&
213	    (CIFS_UNIX_POSIX_PATH_OPS_CAP &
214			le64_to_cpu(tcon->fsUnixInfo.Capability))) {
215		rc = cifs_posix_open(full_path, &newinode, inode->i_sb, mode,
216				     oflags, oplock, &fid->netfid, xid);
217		switch (rc) {
218		case 0:
219			if (newinode == NULL) {
220				/* query inode info */
221				goto cifs_create_get_file_info;
222			}
223
224			if (S_ISDIR(newinode->i_mode)) {
225				CIFSSMBClose(xid, tcon, fid->netfid);
226				iput(newinode);
227				rc = -EISDIR;
228				goto out;
229			}
230
231			if (!S_ISREG(newinode->i_mode)) {
232				/*
233				 * The server may allow us to open things like
234				 * FIFOs, but the client isn't set up to deal
235				 * with that. If it's not a regular file, just
236				 * close it and proceed as if it were a normal
237				 * lookup.
238				 */
239				CIFSSMBClose(xid, tcon, fid->netfid);
240				goto cifs_create_get_file_info;
241			}
242			/* success, no need to query */
243			goto cifs_create_set_dentry;
244
245		case -ENOENT:
246			goto cifs_create_get_file_info;
247
248		case -EIO:
249		case -EINVAL:
250			/*
251			 * EIO could indicate that (posix open) operation is not
252			 * supported, despite what server claimed in capability
253			 * negotiation.
254			 *
255			 * POSIX open in samba versions 3.3.1 and earlier could
256			 * incorrectly fail with invalid parameter.
257			 */
258			tcon->broken_posix_open = true;
259			break;
260
261		case -EREMOTE:
262		case -EOPNOTSUPP:
263			/*
264			 * EREMOTE indicates DFS junction, which is not handled
265			 * in posix open.  If either that or op not supported
266			 * returned, follow the normal lookup.
267			 */
268			break;
269
270		default:
271			goto out;
272		}
273		/*
274		 * fallthrough to retry, using older open call, this is case
275		 * where server does not support this SMB level, and falsely
276		 * claims capability (also get here for DFS case which should be
277		 * rare for path not covered on files)
278		 */
279	}
280#endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
281
282	desired_access = 0;
283	if (OPEN_FMODE(oflags) & FMODE_READ)
284		desired_access |= GENERIC_READ; /* is this too little? */
285	if (OPEN_FMODE(oflags) & FMODE_WRITE)
286		desired_access |= GENERIC_WRITE;
287	if (rdwr_for_fscache == 1)
288		desired_access |= GENERIC_READ;
289
290	disposition = FILE_OVERWRITE_IF;
291	if ((oflags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL))
292		disposition = FILE_CREATE;
293	else if ((oflags & (O_CREAT | O_TRUNC)) == (O_CREAT | O_TRUNC))
294		disposition = FILE_OVERWRITE_IF;
295	else if ((oflags & O_CREAT) == O_CREAT)
296		disposition = FILE_OPEN_IF;
297	else
298		cifs_dbg(FYI, "Create flag not set in create function\n");
299
300	/*
301	 * BB add processing to set equivalent of mode - e.g. via CreateX with
302	 * ACLs
303	 */
304
305	if (!server->ops->open) {
306		rc = -ENOSYS;
307		goto out;
308	}
309
310	create_options |= cifs_open_create_options(oflags, create_options);
311	/*
312	 * if we're not using unix extensions, see if we need to set
313	 * ATTR_READONLY on the create call
314	 */
315	if (!tcon->unix_ext && (mode & S_IWUGO) == 0)
316		create_options |= CREATE_OPTION_READONLY;
317
318
319retry_open:
320	if (tcon->cfids && direntry->d_parent && server->dialect >= SMB30_PROT_ID) {
321		parent_cfid = NULL;
322		spin_lock(&tcon->cfids->cfid_list_lock);
323		list_for_each_entry(parent_cfid, &tcon->cfids->entries, entry) {
324			if (parent_cfid->dentry == direntry->d_parent) {
325				cifs_dbg(FYI, "found a parent cached file handle\n");
326				if (is_valid_cached_dir(parent_cfid)) {
327					lease_flags
328						|= SMB2_LEASE_FLAG_PARENT_LEASE_KEY_SET_LE;
329					memcpy(fid->parent_lease_key,
330					       parent_cfid->fid.lease_key,
331					       SMB2_LEASE_KEY_SIZE);
332					parent_cfid->dirents.is_valid = false;
333					parent_cfid->dirents.is_failed = true;
334				}
335				break;
336			}
337		}
338		spin_unlock(&tcon->cfids->cfid_list_lock);
339	}
340
341	oparms = (struct cifs_open_parms) {
342		.tcon = tcon,
343		.cifs_sb = cifs_sb,
344		.desired_access = desired_access,
345		.create_options = cifs_create_options(cifs_sb, create_options),
346		.disposition = disposition,
347		.path = full_path,
348		.fid = fid,
349		.lease_flags = lease_flags,
350		.mode = mode,
351	};
352	rc = server->ops->open(xid, &oparms, oplock, buf);
353	if (rc) {
354		cifs_dbg(FYI, "cifs_create returned 0x%x\n", rc);
355		if (rc == -EACCES && rdwr_for_fscache == 1) {
356			desired_access &= ~GENERIC_READ;
357			rdwr_for_fscache = 2;
358			goto retry_open;
359		}
360		goto out;
361	}
362	if (rdwr_for_fscache == 2)
363		cifs_invalidate_cache(inode, FSCACHE_INVAL_DIO_WRITE);
364
365#ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
366	/*
367	 * If Open reported that we actually created a file then we now have to
368	 * set the mode if possible.
369	 */
370	if ((tcon->unix_ext) && (*oplock & CIFS_CREATE_ACTION)) {
371		struct cifs_unix_set_info_args args = {
372				.mode	= mode,
373				.ctime	= NO_CHANGE_64,
374				.atime	= NO_CHANGE_64,
375				.mtime	= NO_CHANGE_64,
376				.device	= 0,
377		};
378
379		if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID) {
380			args.uid = current_fsuid();
381			if (inode->i_mode & S_ISGID)
382				args.gid = inode->i_gid;
383			else
384				args.gid = current_fsgid();
385		} else {
386			args.uid = INVALID_UID; /* no change */
387			args.gid = INVALID_GID; /* no change */
388		}
389		CIFSSMBUnixSetFileInfo(xid, tcon, &args, fid->netfid,
390				       current->tgid);
391	} else {
392		/*
393		 * BB implement mode setting via Windows security
394		 * descriptors e.g.
395		 */
396		/* CIFSSMBWinSetPerms(xid,tcon,path,mode,-1,-1,nls);*/
397
398		/* Could set r/o dos attribute if mode & 0222 == 0 */
399	}
400
401cifs_create_get_file_info:
402	/* server might mask mode so we have to query for it */
403	if (tcon->unix_ext)
404		rc = cifs_get_inode_info_unix(&newinode, full_path, inode->i_sb,
405					      xid);
406	else {
407#else
408	{
409#endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
410		/* TODO: Add support for calling POSIX query info here, but passing in fid */
411		rc = cifs_get_inode_info(&newinode, full_path, buf, inode->i_sb, xid, fid);
412		if (newinode) {
413			if (server->ops->set_lease_key)
414				server->ops->set_lease_key(newinode, fid);
415			if ((*oplock & CIFS_CREATE_ACTION) && S_ISREG(newinode->i_mode)) {
416				if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_DYNPERM)
417					newinode->i_mode = mode;
418				if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID) {
419					newinode->i_uid = current_fsuid();
420					if (inode->i_mode & S_ISGID)
421						newinode->i_gid = inode->i_gid;
422					else
423						newinode->i_gid = current_fsgid();
424				}
425			}
426		}
427	}
428
429#ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
430cifs_create_set_dentry:
431#endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
432	if (rc != 0) {
433		cifs_dbg(FYI, "Create worked, get_inode_info failed rc = %d\n",
434			 rc);
435		goto out_err;
436	}
437
438	if (newinode)
439		if (S_ISDIR(newinode->i_mode)) {
440			rc = -EISDIR;
441			goto out_err;
442		}
443
444	d_drop(direntry);
445	d_add(direntry, newinode);
446
447out:
448	free_dentry_path(page);
449	return rc;
450
451out_err:
452	if (server->ops->close)
453		server->ops->close(xid, tcon, fid);
454	if (newinode)
455		iput(newinode);
456	goto out;
457}
458
459int
460cifs_atomic_open(struct inode *inode, struct dentry *direntry,
461		 struct file *file, unsigned int oflags, umode_t mode)
462{
463	int rc;
464	unsigned int xid;
465	struct tcon_link *tlink;
466	struct cifs_tcon *tcon;
467	struct TCP_Server_Info *server;
468	struct cifs_fid fid = {};
469	struct cifs_pending_open open;
470	__u32 oplock;
471	struct cifsFileInfo *file_info;
472	struct cifs_open_info_data buf = {};
473
474	if (unlikely(cifs_forced_shutdown(CIFS_SB(inode->i_sb))))
475		return smb_EIO(smb_eio_trace_forced_shutdown);
476
477	/*
478	 * Posix open is only called (at lookup time) for file create now. For
479	 * opens (rather than creates), because we do not know if it is a file
480	 * or directory yet, and current Samba no longer allows us to do posix
481	 * open on dirs, we could end up wasting an open call on what turns out
482	 * to be a dir. For file opens, we wait to call posix open till
483	 * cifs_open.  It could be added to atomic_open in the future but the
484	 * performance tradeoff of the extra network request when EISDIR or
485	 * EACCES is returned would have to be weighed against the 50% reduction
486	 * in network traffic in the other paths.
487	 */
488	if (!(oflags & O_CREAT)) {
489		/*
490		 * Check for hashed negative dentry. We have already revalidated
491		 * the dentry and it is fine. No need to perform another lookup.
492		 */
493		if (!d_in_lookup(direntry))
494			return -ENOENT;
495
496		return finish_no_open(file, cifs_lookup(inode, direntry, 0));
497	}
498
499	xid = get_xid();
500
501	cifs_dbg(FYI, "parent inode = 0x%p name is: %pd and dentry = 0x%p\n",
502		 inode, direntry, direntry);
503
504	tlink = cifs_sb_tlink(CIFS_SB(inode->i_sb));
505	if (IS_ERR(tlink)) {
506		rc = PTR_ERR(tlink);
507		goto out_free_xid;
508	}
509
510	tcon = tlink_tcon(tlink);
511
512	rc = check_name(direntry, tcon);
513	if (rc)
514		goto out;
515
516	server = tcon->ses->server;
517
518	if (server->ops->new_lease_key)
519		server->ops->new_lease_key(&fid);
520
521	cifs_add_pending_open(&fid, tlink, &open);
522
523	rc = cifs_do_create(inode, direntry, xid, tlink, oflags, mode,
524			    &oplock, &fid, &buf);
525	if (rc) {
526		cifs_del_pending_open(&open);
527		goto out;
528	}
529
530	if ((oflags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL))
531		file->f_mode |= FMODE_CREATED;
532
533	rc = finish_open(file, direntry, generic_file_open);
534	if (rc) {
535		if (server->ops->close)
536			server->ops->close(xid, tcon, &fid);
537		cifs_del_pending_open(&open);
538		goto out;
539	}
540
541	if (file->f_flags & O_DIRECT &&
542	    CIFS_SB(inode->i_sb)->mnt_cifs_flags & CIFS_MOUNT_STRICT_IO) {
543		if (CIFS_SB(inode->i_sb)->mnt_cifs_flags & CIFS_MOUNT_NO_BRL)
544			file->f_op = &cifs_file_direct_nobrl_ops;
545		else
546			file->f_op = &cifs_file_direct_ops;
547		}
548
549	file_info = cifs_new_fileinfo(&fid, file, tlink, oplock, buf.symlink_target);
550	if (file_info == NULL) {
551		if (server->ops->close)
552			server->ops->close(xid, tcon, &fid);
553		cifs_del_pending_open(&open);
554		rc = -ENOMEM;
555		goto out;
556	}
557
558	fscache_use_cookie(cifs_inode_cookie(file_inode(file)),
559			   file->f_mode & FMODE_WRITE);
560
561out:
562	cifs_put_tlink(tlink);
563out_free_xid:
564	free_xid(xid);
565	cifs_free_open_info(&buf);
566	return rc;
567}
568
569int cifs_create(struct mnt_idmap *idmap, struct inode *inode,
570		struct dentry *direntry, umode_t mode, bool excl)
571{
572	int rc;
573	unsigned int xid = get_xid();
574	/*
575	 * BB below access is probably too much for mknod to request
576	 *    but we have to do query and setpathinfo so requesting
577	 *    less could fail (unless we want to request getatr and setatr
578	 *    permissions (only).  At least for POSIX we do not have to
579	 *    request so much.
580	 */
581	unsigned oflags = O_EXCL | O_CREAT | O_RDWR;
582	struct tcon_link *tlink;
583	struct cifs_tcon *tcon;
584	struct TCP_Server_Info *server;
585	struct cifs_fid fid;
586	__u32 oplock;
587	struct cifs_open_info_data buf = {};
588
589	cifs_dbg(FYI, "cifs_create parent inode = 0x%p name is: %pd and dentry = 0x%p\n",
590		 inode, direntry, direntry);
591
592	if (unlikely(cifs_forced_shutdown(CIFS_SB(inode->i_sb)))) {
593		rc = smb_EIO(smb_eio_trace_forced_shutdown);
594		goto out_free_xid;
595	}
596
597	tlink = cifs_sb_tlink(CIFS_SB(inode->i_sb));
598	rc = PTR_ERR(tlink);
599	if (IS_ERR(tlink))
600		goto out_free_xid;
601
602	tcon = tlink_tcon(tlink);
603	server = tcon->ses->server;
604
605	if (server->ops->new_lease_key)
606		server->ops->new_lease_key(&fid);
607
608	rc = cifs_do_create(inode, direntry, xid, tlink, oflags, mode, &oplock, &fid, &buf);
609	if (!rc && server->ops->close)
610		server->ops->close(xid, tcon, &fid);
611
612	cifs_free_open_info(&buf);
613	cifs_put_tlink(tlink);
614out_free_xid:
615	free_xid(xid);
616	return rc;
617}
618
619int cifs_mknod(struct mnt_idmap *idmap, struct inode *inode,
620	       struct dentry *direntry, umode_t mode, dev_t device_number)
621{
622	int rc = -EPERM;
623	unsigned int xid;
624	struct cifs_sb_info *cifs_sb;
625	struct tcon_link *tlink;
626	struct cifs_tcon *tcon;
627	const char *full_path;
628	void *page;
629
630	if (!old_valid_dev(device_number))
631		return -EINVAL;
632
633	cifs_sb = CIFS_SB(inode->i_sb);
634	if (unlikely(cifs_forced_shutdown(cifs_sb)))
635		return smb_EIO(smb_eio_trace_forced_shutdown);
636
637	tlink = cifs_sb_tlink(cifs_sb);
638	if (IS_ERR(tlink))
639		return PTR_ERR(tlink);
640
641	page = alloc_dentry_path();
642	tcon = tlink_tcon(tlink);
643	xid = get_xid();
644
645	full_path = build_path_from_dentry(direntry, page);
646	if (IS_ERR(full_path)) {
647		rc = PTR_ERR(full_path);
648		goto mknod_out;
649	}
650
651	trace_smb3_mknod_enter(xid, tcon->tid, tcon->ses->Suid, full_path);
652
653	rc = tcon->ses->server->ops->make_node(xid, inode, direntry, tcon,
654					       full_path, mode,
655					       device_number);
656
657mknod_out:
658	if (rc)
659		trace_smb3_mknod_err(xid,  tcon->tid, tcon->ses->Suid, rc);
660	else
661		trace_smb3_mknod_done(xid, tcon->tid, tcon->ses->Suid);
662
663	free_dentry_path(page);
664	free_xid(xid);
665	cifs_put_tlink(tlink);
666	return rc;
667}
668
669struct dentry *
670cifs_lookup(struct inode *parent_dir_inode, struct dentry *direntry,
671	    unsigned int flags)
672{
673	unsigned int xid;
674	int rc = 0; /* to get around spurious gcc warning, set to zero here */
675	struct cifs_sb_info *cifs_sb;
676	struct tcon_link *tlink;
677	struct cifs_tcon *pTcon;
678	struct inode *newInode = NULL;
679	const char *full_path;
680	void *page;
681	int retry_count = 0;
682	struct dentry *de;
683
684	xid = get_xid();
685
686	cifs_dbg(FYI, "parent inode = 0x%p name is: %pd and dentry = 0x%p\n",
687		 parent_dir_inode, direntry, direntry);
688
689	/* check whether path exists */
690
691	cifs_sb = CIFS_SB(parent_dir_inode->i_sb);
692	tlink = cifs_sb_tlink(cifs_sb);
693	if (IS_ERR(tlink)) {
694		de = ERR_CAST(tlink);
695		goto free_xid;
696	}
697	pTcon = tlink_tcon(tlink);
698
699	rc = check_name(direntry, pTcon);
700	if (unlikely(rc)) {
701		de = ERR_PTR(rc);
702		goto put_tlink;
703	}
704
705	/* can not grab the rename sem here since it would
706	deadlock in the cases (beginning of sys_rename itself)
707	in which we already have the sb rename sem */
708	page = alloc_dentry_path();
709	full_path = build_path_from_dentry(direntry, page);
710	if (IS_ERR(full_path)) {
711		de = ERR_CAST(full_path);
712		goto free_dentry_path;
713	}
714
715	if (d_really_is_positive(direntry)) {
716		cifs_dbg(FYI, "non-NULL inode in lookup\n");
717	} else {
718		struct cached_fid *cfid = NULL;
719
720		cifs_dbg(FYI, "NULL inode in lookup\n");
721
722		/*
723		 * We can only rely on negative dentries having the same
724		 * spelling as the cached dirent if case insensitivity is
725		 * forced on mount.
726		 *
727		 * XXX: if servers correctly announce Case Sensitivity Search
728		 * on GetInfo of FileFSAttributeInformation, then we can take
729		 * correct action even if case insensitive is not forced on
730		 * mount.
731		 */
732		if (pTcon->nocase && !open_cached_dir_by_dentry(pTcon, direntry->d_parent, &cfid)) {
733			/*
734			 * dentry is negative and parent is fully cached:
735			 * we can assume file does not exist
736			 */
737			if (cfid->dirents.is_valid) {
738				close_cached_dir(cfid);
739				goto out;
740			}
741			close_cached_dir(cfid);
742		}
743	}
744	cifs_dbg(FYI, "Full path: %s inode = 0x%p\n",
745		 full_path, d_inode(direntry));
746
747again:
748	if (pTcon->posix_extensions) {
749		rc = smb311_posix_get_inode_info(&newInode, full_path, NULL,
750						 parent_dir_inode->i_sb, xid);
751	} else if (pTcon->unix_ext) {
752		rc = cifs_get_inode_info_unix(&newInode, full_path,
753					      parent_dir_inode->i_sb, xid);
754	} else {
755		rc = cifs_get_inode_info(&newInode, full_path, NULL,
756				parent_dir_inode->i_sb, xid, NULL);
757	}
758
759	if (rc == 0) {
760		/* since paths are not looked up by component - the parent
761		   directories are presumed to be good here */
762		renew_parental_timestamps(direntry);
763	} else if (rc == -EAGAIN && retry_count++ < 10) {
764		goto again;
765	} else if (rc == -ENOENT) {
766		cifs_set_time(direntry, jiffies);
767		newInode = NULL;
768	} else {
769		if (rc != -EACCES) {
770			cifs_dbg(FYI, "Unexpected lookup error %d\n", rc);
771			/* We special case check for Access Denied - since that
772			is a common return code */
773		}
774		newInode = ERR_PTR(rc);
775	}
776
777out:
778	de = d_splice_alias(newInode, direntry);
779free_dentry_path:
780	free_dentry_path(page);
781put_tlink:
782	cifs_put_tlink(tlink);
783free_xid:
784	free_xid(xid);
785	return de;
786}
787
788static int
789cifs_d_revalidate(struct inode *dir, const struct qstr *name,
790		  struct dentry *direntry, unsigned int flags)
791{
792	if (flags & LOOKUP_RCU)
793		return -ECHILD;
794
795	if (d_really_is_positive(direntry)) {
796		int rc;
797		struct inode *inode = d_inode(direntry);
798
799		if ((flags & LOOKUP_REVAL) && !CIFS_CACHE_READ(CIFS_I(inode)))
800			CIFS_I(inode)->time = 0; /* force reval */
801
802		rc = cifs_revalidate_dentry(direntry);
803		if (rc) {
804			cifs_dbg(FYI, "cifs_revalidate_dentry failed with rc=%d", rc);
805			switch (rc) {
806			case -ENOENT:
807			case -ESTALE:
808				/*
809				 * Those errors mean the dentry is invalid
810				 * (file was deleted or recreated)
811				 */
812				return 0;
813			default:
814				/*
815				 * Otherwise some unexpected error happened
816				 * report it as-is to VFS layer
817				 */
818				return rc;
819			}
820		}
821		else {
822			/*
823			 * If the inode wasn't known to be a dfs entry when
824			 * the dentry was instantiated, such as when created
825			 * via ->readdir(), it needs to be set now since the
826			 * attributes will have been updated by
827			 * cifs_revalidate_dentry().
828			 */
829			if (IS_AUTOMOUNT(inode) &&
830			   !(direntry->d_flags & DCACHE_NEED_AUTOMOUNT)) {
831				spin_lock(&direntry->d_lock);
832				direntry->d_flags |= DCACHE_NEED_AUTOMOUNT;
833				spin_unlock(&direntry->d_lock);
834			}
835
836			return 1;
837		}
838	} else {
839		struct cifs_sb_info *cifs_sb = CIFS_SB(dir->i_sb);
840		struct cifs_tcon *tcon = cifs_sb_master_tcon(cifs_sb);
841		struct cached_fid *cfid;
842
843		if (!open_cached_dir_by_dentry(tcon, direntry->d_parent, &cfid)) {
844			/*
845			 * dentry is negative and parent is fully cached:
846			 * we can assume file does not exist
847			 */
848			if (cfid->dirents.is_valid) {
849				close_cached_dir(cfid);
850				return 1;
851			}
852			close_cached_dir(cfid);
853		}
854	}
855
856	/*
857	 * This may be nfsd (or something), anyway, we can't see the
858	 * intent of this. So, since this can be for creation, drop it.
859	 */
860	if (!flags)
861		return 0;
862
863	/*
864	 * Drop the negative dentry, in order to make sure to use the
865	 * case sensitive name which is specified by user if this is
866	 * for creation.
867	 */
868	if (flags & (LOOKUP_CREATE | LOOKUP_RENAME_TARGET))
869		return 0;
870
871	if (time_after(jiffies, cifs_get_time(direntry) + HZ) || !lookupCacheEnabled)
872		return 0;
873
874	return 1;
875}
876
877/* static int cifs_d_delete(struct dentry *direntry)
878{
879	int rc = 0;
880
881	cifs_dbg(FYI, "In cifs d_delete, name = %pd\n", direntry);
882
883	return rc;
884}     */
885
886const struct dentry_operations cifs_dentry_ops = {
887	.d_revalidate = cifs_d_revalidate,
888	.d_automount = cifs_d_automount,
889/* d_delete:       cifs_d_delete,      */ /* not needed except for debugging */
890};
891
892static int cifs_ci_hash(const struct dentry *dentry, struct qstr *q)
893{
894	struct nls_table *codepage = CIFS_SB(dentry->d_sb)->local_nls;
895	unsigned long hash;
896	wchar_t c;
897	int i, charlen;
898
899	hash = init_name_hash(dentry);
900	for (i = 0; i < q->len; i += charlen) {
901		charlen = codepage->char2uni(&q->name[i], q->len - i, &c);
902		/* error out if we can't convert the character */
903		if (unlikely(charlen < 0))
904			return charlen;
905		hash = partial_name_hash(cifs_toupper(c), hash);
906	}
907	q->hash = end_name_hash(hash);
908
909	return 0;
910}
911
912static int cifs_ci_compare(const struct dentry *dentry,
913		unsigned int len, const char *str, const struct qstr *name)
914{
915	struct nls_table *codepage = CIFS_SB(dentry->d_sb)->local_nls;
916	wchar_t c1, c2;
917	int i, l1, l2;
918
919	/*
920	 * We make the assumption here that uppercase characters in the local
921	 * codepage are always the same length as their lowercase counterparts.
922	 *
923	 * If that's ever not the case, then this will fail to match it.
924	 */
925	if (name->len != len)
926		return 1;
927
928	for (i = 0; i < len; i += l1) {
929		/* Convert characters in both strings to UTF-16. */
930		l1 = codepage->char2uni(&str[i], len - i, &c1);
931		l2 = codepage->char2uni(&name->name[i], name->len - i, &c2);
932
933		/*
934		 * If we can't convert either character, just declare it to
935		 * be 1 byte long and compare the original byte.
936		 */
937		if (unlikely(l1 < 0 && l2 < 0)) {
938			if (str[i] != name->name[i])
939				return 1;
940			l1 = 1;
941			continue;
942		}
943
944		/*
945		 * Here, we again ass|u|me that upper/lowercase versions of
946		 * a character are the same length in the local NLS.
947		 */
948		if (l1 != l2)
949			return 1;
950
951		/* Now compare uppercase versions of these characters */
952		if (cifs_toupper(c1) != cifs_toupper(c2))
953			return 1;
954	}
955
956	return 0;
957}
958
959const struct dentry_operations cifs_ci_dentry_ops = {
960	.d_revalidate = cifs_d_revalidate,
961	.d_hash = cifs_ci_hash,
962	.d_compare = cifs_ci_compare,
963	.d_automount = cifs_d_automount,
964};