patch-2.1.87 linux/fs/umsdos/dir.c

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diff -u --recursive --new-file v2.1.86/linux/fs/umsdos/dir.c linux/fs/umsdos/dir.c
@@ -24,11 +24,58 @@
 
 #define UMSDOS_SPECIAL_DIRFPOS	3
 extern struct inode *pseudo_root;
+
+
+/* P.T.Waltenberg
+   I've retained this to facilitate the lookup of some of the hard-wired files/directories UMSDOS
+   uses. It's easier to do once than hack all the other instances. Probably safer as well
+*/   
+int compat_UMSDOS_lookup(struct inode *dir,const char *name,int len, struct inode **inode)
+{
+  int rv;
+  struct dentry *dentry;
+
+  dentry = creat_dentry (name, len, NULL);
+  rv =  UMSDOS_lookup(dir,dentry);
+  
+  if (inode) *inode = dentry->d_inode;
+  return rv;
+}    
+
+
+int compat_umsdos_real_lookup(struct inode *dir,const char *name,int len, struct inode **inode)
+{
+  int rv;
+  struct dentry *dentry;
+
+  dentry = creat_dentry (name, len, NULL);
+  rv = umsdos_real_lookup(dir,dentry);
+  if (inode) *inode = dentry->d_inode;
+  
+  return rv;
+}    
+
+
+int compat_msdos_create(struct inode *dir,const char *name,int len, int mode, struct inode **inode)
+{
+  int rv;
+  struct dentry *dentry;
+
+  dentry = creat_dentry (name, len, NULL);
+  rv = msdos_create(dir,dentry,mode);
+  if(inode != NULL) *inode = dentry->d_inode;
+  
+  return rv;
+}    
+
+
 /*
 	So  grep *  doesn't complain in the presence of directories.
 */
-long UMSDOS_dir_read(struct inode *inode,struct file *filp,
-	char *buf, unsigned long count)
+int UMSDOS_dir_read(struct file *filp,
+		    char *buff,
+		    size_t size,
+		    loff_t * count)
 {
 	return -EISDIR;
 }
@@ -43,554 +90,585 @@
 /*
 	Record a single entry the first call.
 	Return -EINVAL the next one.
+	NOTE: filldir DOES NOT use a dentry
 */
 static int umsdos_dir_once(
 	void * buf,
-	const char * name,
-	int name_len,
+	const char *name,
+	int len,
 	off_t offset,
 	ino_t ino)
 {
-	int ret = -EINVAL;
-	struct UMSDOS_DIR_ONCE *d = (struct UMSDOS_DIR_ONCE *)buf;
-	if (d->count == 0){
-		#if 0
-			char zname[100];
-			memcpy (zname,name,name_len);
-			zname[name_len] = '\0';
-			Printk (("dir_once :%s: offset %Ld\n",zname,offset));
-		#endif
-		ret = d->filldir (d->dirbuf,name,name_len,offset,ino);
-		d->stop = ret < 0;
-		d->count = 1;
-	}
-	return ret;
+  int ret = -EINVAL;
+  struct UMSDOS_DIR_ONCE *d = (struct UMSDOS_DIR_ONCE *)buf;
+  if (d->count == 0){
+#if 0
+    char zname[100];
+    memcpy (zname,dentry->d_name,dentry->d_len);
+    zname[name_len] = '\0';
+    Printk ((KERN_DEBUG "dir_once :%s: offset %Ld\n",zname,offset));
+#endif
+    ret = d->filldir (d->dirbuf,name,len,offset,ino);
+    d->stop = ret < 0;
+    d->count = 1;
+  }
+  return ret;
 }
 
 /*
-	Read count directory entries from directory filp
-	Return a negative value from linux/errno.h.
-	Return > 0 if success (The amount of byte written by filldir).
-
-	This function is used by the normal readdir VFS entry point and by
-	some function who try to find out info on a file from a pure MSDOS
-	inode. See umsdos_locate_ancestor() below.
+  Read count directory entries from directory filp
+  Return a negative value from linux/errno.h.
+  Return > 0 if success (The amount of byte written by filldir).
+  
+  This function is used by the normal readdir VFS entry point and by
+  some function who try to find out info on a file from a pure MSDOS
+  inode. See umsdos_locate_ancestor() below.
 */
 static int umsdos_readdir_x(
-	struct inode *dir,		/* Point to a description of the super block */
-	struct file *filp,		/* Point to a directory which is read */
-    void *dirbuf,			/* Will hold count directory entry */
-							/* but filled by the filldir function */
-	int internal_read,		/* Called for internal purpose */
-	struct umsdos_dirent *u_entry,	/* Optional umsdos entry */
-	int follow_hlink,
-	filldir_t filldir)
-{
-	int ret = 0;
-	
-	umsdos_startlookup(dir);	
-	if (filp->f_pos == UMSDOS_SPECIAL_DIRFPOS
-		&& dir == pseudo_root
-		&& !internal_read){
-		/*
-			We don't need to simulate this pseudo directory
-			when umsdos_readdir_x is called for internal operation
-			of umsdos. This is why dirent_in_fs is tested
-		*/
-		/* #Specification: pseudo root / directory /DOS
-			When umsdos operates in pseudo root mode (C:\linux is the
-			linux root), it simulate a directory /DOS which points to
-			the real root of the file system.
-		*/
-		if (filldir (dirbuf,"DOS",3,UMSDOS_SPECIAL_DIRFPOS
-			,dir->i_sb->s_mounted->i_ino) == 0){
-			filp->f_pos++;
-		}
-	}else if (filp->f_pos < 2
-		|| (dir != dir->i_sb->s_mounted && filp->f_pos == 32)){
-		/* #Specification: readdir / . and ..
-			The msdos filesystem manage the . and .. entry properly
-			so the EMD file won't hold any info about it.
-
-			In readdir, we assume that for the root directory
-			the read position will be 0 for ".", 1 for "..". For
-			a non root directory, the read position will be 0 for "."
-			and 32 for "..".
-		*/
-		/*
-			This is a trick used by the msdos file system (fs/msdos/dir.c)
-			to manage . and .. for the root directory of a file system.
-			Since there is no such entry in the root, fs/msdos/dir.c
-			use the following:
-
-			if f_pos == 0, return ".".
-			if f_pos == 1, return "..".
-
-			So let msdos handle it
-
-			Since umsdos entries are much larger, we share the same f_pos.
-			if f_pos is 0 or 1 or 32, we are clearly looking at . and
-			..
-
-			As soon as we get f_pos == 2 or f_pos == 64, then back to
-			0, but this time we are reading the EMD file.
-
-			Well, not so true. The problem, is that UMSDOS_REC_SIZE is
-			also 64, so as soon as we read the first record in the
-			EMD, we are back at offset 64. So we set the offset
-			to UMSDOS_SPECIAL_DIRFPOS(3) as soon as we have read the
-			.. entry from msdos.
-			
-			Now (linux 1.3), umsdos_readdir can read more than one
-			entry even if we limit (umsdos_dir_once) to only one:
-			It skips over hidden file. So we switch to
-			UMSDOS_SPECIAL_DIRFPOS as soon as we have read successfully
-			the .. entry.
-		*/
-		int last_f_pos = filp->f_pos;	
-		struct UMSDOS_DIR_ONCE bufk;
-		bufk.dirbuf = dirbuf;
-		bufk.filldir = filldir;
-		bufk.count = 0;
-		ret = fat_readdir(dir,filp,&bufk,umsdos_dir_once);
-		if (last_f_pos > 0 && filp->f_pos > last_f_pos) filp->f_pos = UMSDOS_SPECIAL_DIRFPOS;
-		if (u_entry != NULL) u_entry->flags = 0;
-	}else{
-		struct inode *emd_dir = umsdos_emd_dir_lookup(dir,0);
-		if (emd_dir != NULL){
-			off_t start_fpos = filp->f_pos;
-			if (filp->f_pos <= UMSDOS_SPECIAL_DIRFPOS+1) filp->f_pos = 0;
-			PRINTK (("f_pos %lu i_size %ld\n",filp->f_pos,emd_dir->i_size));
-			ret = 0;
-			while (filp->f_pos < emd_dir->i_size){
-				struct umsdos_dirent entry;
-				off_t cur_f_pos = filp->f_pos;
-				if (umsdos_emd_dir_readentry (emd_dir,filp,&entry)!=0){
-					ret = -EIO;
-					break;
-				}else if (entry.name_len != 0){
-					/* #Specification: umsdos / readdir
-						umsdos_readdir() should fill a struct dirent with
-						an inode number. The cheap way to get it is to
-						do a lookup in the MSDOS directory for each
-						entry processed by the readdir() function.
-						This is not very efficient, but very simple. The
-						other way around is to maintain a copy of the inode
-						number in the EMD file. This is a problem because
-						this has to be maintained in sync using tricks.
-						Remember that MSDOS (the OS) does not update the
-						modification time (mtime) of a directory. There is
-						no easy way to tell that a directory was modified
-						during a DOS session and synchronise the EMD file.
-
-						Suggestion welcome.
-
-						So the easy way is used!
-					*/
-					struct umsdos_info info;
-					struct inode *inode;
-					int lret;
-					umsdos_parse (entry.name,entry.name_len,&info);
-					info.f_pos = cur_f_pos;
-					umsdos_manglename (&info);
-					lret = umsdos_real_lookup (dir,info.fake.fname
-						,info.fake.len,&inode);
-					PRINTK (("Cherche inode de %s lret %d flags %d\n"
-						,info.fake.fname,lret,entry.flags));
-					if (lret == 0
-						&& (entry.flags & UMSDOS_HLINK)
-						&& follow_hlink){
-						struct inode *rinode;
-						lret = umsdos_hlink2inode (inode,&rinode);
-						inode = rinode;
-					}
-					if (lret == 0){
-						/* #Specification: pseudo root / reading real root
-							The pseudo root (/linux) is logically
-							erased from the real root. This mean that
-							ls /DOS, won't show "linux". This avoids
-							infinite recursion /DOS/linux/DOS/linux while
-							walking the file system.
-						*/
-						if (inode != pseudo_root
-							&& (internal_read
-								|| !(entry.flags & UMSDOS_HIDDEN))){
-							if (filldir (dirbuf 
-								,entry.name,entry.name_len
-								,cur_f_pos, inode->i_ino) < 0){
-								filp->f_pos = cur_f_pos;
-							}
-							PRINTK (("Trouve ino %ld ",inode->i_ino));
-							if (u_entry != NULL) *u_entry = entry;
-							iput (inode);
-							break;
-						}
-						iput (inode);
-					}else{
-						/* #Specification: umsdos / readdir / not in MSDOS
-							During a readdir operation, if the file is not
-							in the MSDOS directory anymore, the entry is
-							removed from the EMD file silently.
-						*/
-						ret = umsdos_writeentry (dir,emd_dir,&info,1);
-						if (ret != 0){
-							break;
-						}
-					}
-				}
-			}
-			/*
-				If the fillbuf has failed, f_pos is back to 0.
-				To avoid getting back into the . and .. state
-				(see comments at the beginning), we put back
-				the special offset.
-			*/
-			if (filp->f_pos == 0) filp->f_pos = start_fpos;
-			iput(emd_dir);
-		}
+			    struct inode *dir,		/* Point to a description of the super block */
+			    struct file *filp,		/* Point to a directory which is read */
+			    void *dirbuf,			/* Will hold count directory entry */
+			    /* but filled by the filldir function */
+			    int internal_read,		/* Called for internal purpose */
+			    struct umsdos_dirent *u_entry,	/* Optional umsdos entry */
+			    int follow_hlink,
+			    filldir_t filldir)
+{
+  int ret = 0;
+  struct inode *root_inode;
+  
+  root_inode = iget(dir->i_sb,UMSDOS_ROOT_INO);
+  umsdos_startlookup(dir);	
+  if (filp->f_pos == UMSDOS_SPECIAL_DIRFPOS
+      && pseudo_root
+      && dir == pseudo_root
+      && !internal_read){
+      
+      Printk (("umsdos_readdir_x: what UMSDOS_SPECIAL_DIRFPOS /mn/?\n"));
+    /*
+      We don't need to simulate this pseudo directory
+      when umsdos_readdir_x is called for internal operation
+      of umsdos. This is why dirent_in_fs is tested
+    */
+    /* #Specification: pseudo root / directory /DOS
+       When umsdos operates in pseudo root mode (C:\linux is the
+       linux root), it simulate a directory /DOS which points to
+       the real root of the file system.
+    */
+    if (filldir (dirbuf,"DOS",3,UMSDOS_SPECIAL_DIRFPOS
+		 ,UMSDOS_ROOT_INO) == 0){
+      filp->f_pos++;
+    }
+  }else if (filp->f_pos < 2
+	    || (dir != root_inode && filp->f_pos == 32)){
+    /* #Specification: readdir / . and ..
+       The msdos filesystem manage the . and .. entry properly
+       so the EMD file won't hold any info about it.
+       
+       In readdir, we assume that for the root directory
+       the read position will be 0 for ".", 1 for "..". For
+       a non root directory, the read position will be 0 for "."
+       and 32 for "..".
+    */
+    /*
+      This is a trick used by the msdos file system (fs/msdos/dir.c)
+      to manage . and .. for the root directory of a file system.
+      Since there is no such entry in the root, fs/msdos/dir.c
+      use the following:
+      
+      if f_pos == 0, return ".".
+      if f_pos == 1, return "..".
+      
+      So let msdos handle it
+      
+      Since umsdos entries are much larger, we share the same f_pos.
+      if f_pos is 0 or 1 or 32, we are clearly looking at . and
+      ..
+      
+      As soon as we get f_pos == 2 or f_pos == 64, then back to
+      0, but this time we are reading the EMD file.
+      
+      Well, not so true. The problem, is that UMSDOS_REC_SIZE is
+      also 64, so as soon as we read the first record in the
+      EMD, we are back at offset 64. So we set the offset
+      to UMSDOS_SPECIAL_DIRFPOS(3) as soon as we have read the
+      .. entry from msdos.
+      
+      Now (linux 1.3), umsdos_readdir can read more than one
+      entry even if we limit (umsdos_dir_once) to only one:
+      It skips over hidden file. So we switch to
+      UMSDOS_SPECIAL_DIRFPOS as soon as we have read successfully
+      the .. entry.
+    */
+    int last_f_pos = filp->f_pos;	
+    struct UMSDOS_DIR_ONCE bufk;
+
+    Printk (("umsdos_readdir_x: . or .. /mn/?\n"));
+
+    bufk.dirbuf = dirbuf;
+    bufk.filldir = filldir;
+    bufk.count = 0;
+
+    ret = fat_readdir(filp,&bufk,umsdos_dir_once);
+    if (last_f_pos > 0 && filp->f_pos > last_f_pos) filp->f_pos = UMSDOS_SPECIAL_DIRFPOS;
+    if (u_entry != NULL) u_entry->flags = 0;
+  }else{
+    struct inode *emd_dir;
+    Printk (("umsdos_readdir_x: normal file /mn/?\n"));
+    emd_dir = umsdos_emd_dir_lookup(dir,0);
+    if (emd_dir != NULL){
+      off_t start_fpos = filp->f_pos;
+      Printk (("umsdos_readdir_x: emd_dir->i_ino=%d\n",emd_dir->i_ino));
+      if (filp->f_pos <= UMSDOS_SPECIAL_DIRFPOS+1) filp->f_pos = 0;
+      Printk (("f_pos %lu i_size %ld\n",filp->f_pos,emd_dir->i_size));
+      ret = 0;
+      while (filp->f_pos < emd_dir->i_size){
+	struct umsdos_dirent entry;
+	off_t cur_f_pos = filp->f_pos;
+	if (umsdos_emd_dir_readentry (emd_dir,filp,&entry)!=0){
+	  ret = -EIO;
+	  break;
+	}else if (entry.name_len != 0){
+	  /* #Specification: umsdos / readdir
+	     umsdos_readdir() should fill a struct dirent with
+	     an inode number. The cheap way to get it is to
+	     do a lookup in the MSDOS directory for each
+	     entry processed by the readdir() function.
+	     This is not very efficient, but very simple. The
+	     other way around is to maintain a copy of the inode
+	     number in the EMD file. This is a problem because
+	     this has to be maintained in sync using tricks.
+	     Remember that MSDOS (the OS) does not update the
+	     modification time (mtime) of a directory. There is
+	     no easy way to tell that a directory was modified
+	     during a DOS session and synchronise the EMD file.
+	     
+	     Suggestion welcome.
+	     
+	     So the easy way is used!
+	  */
+	  struct umsdos_info info;
+	  struct inode *inode;
+	  
+	  int lret;
+	  umsdos_parse (entry.name,entry.name_len,&info);
+	  info.f_pos = cur_f_pos;
+	  umsdos_manglename (&info);
+	  /* FIXME, fake a dentry --> /mn/ fixed ? */
+	  lret = compat_umsdos_real_lookup (dir,info.fake.fname,
+					    info.fake.len,&inode);
+	  Printk (("Cherche inode de %s lret %d flags %d\n"
+		   ,info.fake.fname,lret,entry.flags));
+	  if (lret == 0
+	      && (entry.flags & UMSDOS_HLINK)
+	      && follow_hlink){
+	    struct inode *rinode;
+	    lret = umsdos_hlink2inode (inode,&rinode);
+	    inode = rinode;
+	  }
+	  if (lret == 0){
+	    /* #Specification: pseudo root / reading real root
+	       The pseudo root (/linux) is logically
+	       erased from the real root. This mean that
+	       ls /DOS, won't show "linux". This avoids
+	       infinite recursion /DOS/linux/DOS/linux while
+	       walking the file system.
+	    */
+	    if (inode != pseudo_root
+		&& (internal_read
+		    || !(entry.flags & UMSDOS_HIDDEN))){
+	      if (filldir (dirbuf, 
+			   entry.name,
+			   entry.name_len,
+			   cur_f_pos, 
+			   inode->i_ino) < 0){
+		filp->f_pos = cur_f_pos;
+	      }
+	      Printk (("Trouve ino %ld ",inode->i_ino));
+	      if (u_entry != NULL) *u_entry = entry;
+	      iput (inode);
+	      break;
+	    }
+	    iput (inode);
+	  }else{
+	    /* #Specification: umsdos / readdir / not in MSDOS
+	       During a readdir operation, if the file is not
+	       in the MSDOS directory anymore, the entry is
+	       removed from the EMD file silently.
+	    */
+	    Printk (("'Silently' removing EMD for file\n"));
+	    ret = umsdos_writeentry (dir,emd_dir,&info,1);
+	    if (ret != 0){
+	      break;
+	    }
+	  }
 	}
-	umsdos_endlookup(dir);	
-	PRINTK (("read dir %p pos %Ld ret %d\n",dir,filp->f_pos,ret));
-	return ret;
+      }
+      /*
+	If the fillbuf has failed, f_pos is back to 0.
+	To avoid getting back into the . and .. state
+	(see comments at the beginning), we put back
+	the special offset.
+      */
+      if (filp->f_pos == 0) filp->f_pos = start_fpos;
+      iput(emd_dir);
+    }
+  }
+  umsdos_endlookup(dir);	
+  Printk (("read dir %p pos %Ld ret %d\n",dir,filp->f_pos,ret));
+  return ret;
 }
+
+
 /*
-	Read count directory entries from directory filp
-	Return a negative value from linux/errno.h.
-	Return 0 or positive if successful
+  Read count directory entries from directory filp
+  Return a negative value from linux/errno.h.
+  Return 0 or positive if successful
 */
 static int UMSDOS_readdir(
-	struct inode *dir,		/* Point to a description of the super block */
-	struct file *filp,		/* Point to a directory which is read */
-	void *dirbuf,			/* Will hold directory entries  */
-	filldir_t filldir)
-{
-	int ret = 0;
-	int count = 0;
-	struct UMSDOS_DIR_ONCE bufk;
-	bufk.dirbuf = dirbuf;
-	bufk.filldir = filldir;
-	bufk.stop = 0;
-	PRINTK (("UMSDOS_readdir in\n"));
-	while (ret == 0 && bufk.stop == 0){
-		struct umsdos_dirent entry;
-		bufk.count = 0;
-		ret = umsdos_readdir_x (dir,filp,&bufk,0,&entry,1,umsdos_dir_once);
-		if (bufk.count == 0) break;
-		count += bufk.count;
-	}
-	PRINTK (("UMSDOS_readdir out %d count %d pos %Ld\n",ret,count
-		,filp->f_pos));
-	return count?:ret;
+			  struct file *filp,		/* Point to a directory which is read */
+			  void *dirbuf,			/* Will hold directory entries  */
+			  filldir_t filldir)
+{
+  struct inode *dir = filp->f_dentry->d_inode;
+  int ret = 0;
+  int count = 0;
+  struct UMSDOS_DIR_ONCE bufk;
+  bufk.dirbuf = dirbuf;
+  bufk.filldir = filldir;
+  bufk.stop = 0;
+
+  Printk (("UMSDOS_readdir in\n"));
+  while (ret == 0 && bufk.stop == 0){
+    struct umsdos_dirent entry;
+    bufk.count = 0;
+    Printk (("UMSDOS_readdir: calling _x (%p,%p,%p,%d,%p,%d,%d)\n",dir,filp,&bufk,0,&entry,1,umsdos_dir_once));
+    ret = umsdos_readdir_x (dir,filp,&bufk,0,&entry,1,umsdos_dir_once);
+    if (bufk.count == 0) break;
+    count += bufk.count;
+  }
+  Printk (("UMSDOS_readdir out %d count %d pos %Ld\n",ret,count
+	   ,filp->f_pos));
+  return count?:ret;
 }
+
 /*
-	Complete the inode content with info from the EMD file
+  Complete the inode content with info from the EMD file
 */
 void umsdos_lookup_patch (
-	struct inode *dir,
-	struct inode *inode,
-	struct umsdos_dirent *entry,
-	off_t  emd_pos)
-{
-	/*
-		This function modify the state of a dir inode. It decides
-		if the dir is a umsdos dir or a dos dir. This is done
-		deeper in umsdos_patch_inode() called at the end of this function.
-
-		umsdos_patch_inode() may block because it is doing disk access.
-		At the same time, another process may get here to initialise
-		the same dir inode. There is 3 cases.
-
-		1-The inode is already initialised. We do nothing.
-		2-The inode is not initialised. We lock access and do it.
-		3-Like 2 but another process has lock the inode, so we try
-		  to lock it and right after check if initialisation is still
-		  needed.
-
-
-		Thanks to the mem option of the kernel command line, it was
-		possible to consistently reproduce this problem by limiting
-		my mem to 4 meg and running X.
-	*/
-	/*
-		Do this only if the inode is freshly read, because we will lose
-		the current (updated) content.
-	*/
-	/*
-		A lookup of a mount point directory yield the inode into
-		the other fs, so we don't care about initialising it. iget()
-		does this automatically.
-	*/
-	if (inode->i_sb == dir->i_sb && !umsdos_isinit(inode)){
-		if (S_ISDIR(inode->i_mode)) umsdos_lockcreate(inode);
-		if (!umsdos_isinit(inode)){
-			/* #Specification: umsdos / lookup / inode info
-				After successfully reading an inode from the MSDOS
-				filesystem, we use the EMD file to complete it.
-				We update the following field.
-
-				uid, gid, atime, ctime, mtime, mode.
-
-				We rely on MSDOS for mtime. If the file
-				was modified during an MSDOS session, at least
-				mtime will be meaningful. We do this only for regular
-				file.
-				
-				We don't rely on MSDOS for mtime for directory because
-				the MSDOS directory date is creation time (strange
-				MSDOS behavior) which fit nowhere in the three UNIX
-				time stamp.
-			*/
-			if (S_ISREG(entry->mode)) entry->mtime = inode->i_mtime;
-			inode->i_mode  = entry->mode;
-			inode->i_rdev  = to_kdev_t(entry->rdev);
-			inode->i_atime = entry->atime;
-			inode->i_ctime = entry->ctime;
-			inode->i_mtime = entry->mtime;
-			inode->i_uid   = entry->uid;
-			inode->i_gid   = entry->gid;
-			/* #Specification: umsdos / conversion mode
-				The msdos fs can do some inline conversion
-				of the data of a file. It can translate
-				silently from MsDOS text file format to Unix
-				one (crlf -> lf) while reading, and the reverse
-				while writing. This is activated using the mount
-				option conv=....
-
-				This is not useful for Linux file in promoted
-				directory. It can even be harmful. For this
-				reason, the binary (no conversion) mode is
-				always activated.
-			*/
-			/* #Specification: umsdos / conversion mode / todo
-				A flag could be added to file and directories
-				forcing an automatic conversion mode (as
-				done with the msdos fs).
-				
-				This flag could be setup on a directory basis
-				(instead of file) and all file in it would
-				logically inherited. If the conversion mode
-				is active (conv=) then the i_binary flag would
-				be left untouched in those directories.
-				
-				It was proposed that the sticky bit was used
-				to set this. The problem is that new file would
-				be written incorrectly. The other problem is that
-				the sticky bit has a meaning for directories. So
-				another bit should be used (there is some space
-				in the EMD file for it) and a special utilities
-				would be used to assign the flag to a directory).
-				I don't think it is useful to assign this flag
-				on a single file.
-			*/
-
-			MSDOS_I(inode)->i_binary = 1;
-			/* #Specification: umsdos / i_nlink
-				The nlink field of an inode is maintain by the MSDOS file system
-				for directory and by UMSDOS for other file. The logic is that
-				MSDOS is already figuring out what to do for directories and
-				does nothing for other files. For MSDOS, there are no hard link
-				so all file carry nlink==1. UMSDOS use some info in the
-				EMD file to plug the correct value.
-			*/
-			if (!S_ISDIR(entry->mode)){
-				if (entry->nlink > 0){
-					inode->i_nlink = entry->nlink;
-				}else{
-					printk ("UMSDOS: lookup_patch entry->nlink < 1 ???\n");
-				}
-			}
-			umsdos_patch_inode(inode,dir,emd_pos);
-		}
-		if (S_ISDIR(inode->i_mode)) umsdos_unlockcreate(inode);
-if (inode->u.umsdos_i.i_emd_owner==0) printk ("emd_owner still 0 ???\n");
+			  struct inode *dir,
+			  struct inode *inode,
+			  struct umsdos_dirent *entry,
+			  off_t  emd_pos)
+{
+  /*
+    This function modify the state of a dir inode. It decides
+    if the dir is a umsdos dir or a dos dir. This is done
+    deeper in umsdos_patch_inode() called at the end of this function.
+    
+    umsdos_patch_inode() may block because it is doing disk access.
+    At the same time, another process may get here to initialise
+    the same dir inode. There is 3 cases.
+    
+    1-The inode is already initialised. We do nothing.
+    2-The inode is not initialised. We lock access and do it.
+    3-Like 2 but another process has lock the inode, so we try
+    to lock it and right after check if initialisation is still
+    needed.
+    
+    
+    Thanks to the mem option of the kernel command line, it was
+    possible to consistently reproduce this problem by limiting
+    my mem to 4 meg and running X.
+  */
+  /*
+    Do this only if the inode is freshly read, because we will lose
+    the current (updated) content.
+  */
+  /*
+    A lookup of a mount point directory yield the inode into
+    the other fs, so we don't care about initialising it. iget()
+    does this automatically.
+  */
+  if (inode->i_sb == dir->i_sb && !umsdos_isinit(inode)){
+    if (S_ISDIR(inode->i_mode)) umsdos_lockcreate(inode);
+    if (!umsdos_isinit(inode)){
+      /* #Specification: umsdos / lookup / inode info
+	 After successfully reading an inode from the MSDOS
+	 filesystem, we use the EMD file to complete it.
+	 We update the following field.
+	 
+	 uid, gid, atime, ctime, mtime, mode.
+	 
+	 We rely on MSDOS for mtime. If the file
+	 was modified during an MSDOS session, at least
+	 mtime will be meaningful. We do this only for regular
+	 file.
+	 
+	 We don't rely on MSDOS for mtime for directory because
+	 the MSDOS directory date is creation time (strange
+	 MSDOS behavior) which fit nowhere in the three UNIX
+	 time stamp.
+      */
+      if (S_ISREG(entry->mode)) entry->mtime = inode->i_mtime;
+      inode->i_mode  = entry->mode;
+      inode->i_rdev  = to_kdev_t(entry->rdev);
+      inode->i_atime = entry->atime;
+      inode->i_ctime = entry->ctime;
+      inode->i_mtime = entry->mtime;
+      inode->i_uid   = entry->uid;
+      inode->i_gid   = entry->gid;
+      /* #Specification: umsdos / conversion mode
+	 The msdos fs can do some inline conversion
+	 of the data of a file. It can translate
+	 silently from MsDOS text file format to Unix
+	 one (crlf -> lf) while reading, and the reverse
+	 while writing. This is activated using the mount
+	 option conv=....
+	 
+	 This is not useful for Linux file in promoted
+	 directory. It can even be harmful. For this
+	 reason, the binary (no conversion) mode is
+	 always activated.
+      */
+      /* #Specification: umsdos / conversion mode / todo
+	 A flag could be added to file and directories
+	 forcing an automatic conversion mode (as
+	 done with the msdos fs).
+	 
+	 This flag could be setup on a directory basis
+	 (instead of file) and all file in it would
+	 logically inherited. If the conversion mode
+	 is active (conv=) then the i_binary flag would
+	 be left untouched in those directories.
+	 
+	 It was proposed that the sticky bit was used
+	 to set this. The problem is that new file would
+	 be written incorrectly. The other problem is that
+	 the sticky bit has a meaning for directories. So
+	 another bit should be used (there is some space
+	 in the EMD file for it) and a special utilities
+	 would be used to assign the flag to a directory).
+	 I don't think it is useful to assign this flag
+	 on a single file.
+      */
+      
+      MSDOS_I(inode)->i_binary = 1;
+      /* #Specification: umsdos / i_nlink
+	 The nlink field of an inode is maintain by the MSDOS file system
+	 for directory and by UMSDOS for other file. The logic is that
+	 MSDOS is already figuring out what to do for directories and
+	 does nothing for other files. For MSDOS, there are no hard link
+	 so all file carry nlink==1. UMSDOS use some info in the
+	 EMD file to plug the correct value.
+      */
+      if (!S_ISDIR(entry->mode)){
+	if (entry->nlink > 0){
+	  inode->i_nlink = entry->nlink;
+	}else{
+	  printk (KERN_ERR "UMSDOS: lookup_patch entry->nlink < 1 ???\n");
 	}
+      }
+      umsdos_patch_inode(inode,dir,emd_pos);
+    }
+    if (S_ISDIR(inode->i_mode)) umsdos_unlockcreate(inode);
+    if (inode->u.umsdos_i.i_emd_owner==0) printk (KERN_WARNING "emd_owner still 0 ???\n");
+  }
 }
 struct UMSDOS_DIRENT_K{
-	off_t f_pos; /* will hold the offset of the entry in EMD */
-	ino_t ino;
+  off_t f_pos; /* will hold the offset of the entry in EMD */
+  ino_t ino;
 };
 
 /*
-	Just to record the offset of one entry.
+  Just to record the offset of one entry.
 */
 static int umsdos_filldir_k(
-	void * buf,
-	const char * name,
-	int name_len,
-	off_t offset,
-	ino_t ino)
-{
-	struct UMSDOS_DIRENT_K *d = (struct UMSDOS_DIRENT_K *)buf;
-	d->f_pos = offset;
-	d->ino = ino;
-	return 0;
+			    void * buf,
+			    const char *name,
+			    int len,
+			    off_t offset,
+			    ino_t ino)
+{
+  struct UMSDOS_DIRENT_K *d = (struct UMSDOS_DIRENT_K *)buf;
+  d->f_pos = offset;
+  d->ino = ino;
+  return 0;
 }
 
 struct UMSDOS_DIR_SEARCH{
-	struct umsdos_dirent *entry;
-	int found;
-	ino_t search_ino;
+  struct umsdos_dirent *entry;
+  int found;
+  ino_t search_ino;
 };
 
 static int umsdos_dir_search (
-	void * buf,
-	const char * name,
-	int name_len,
-	off_t offset,
-	ino_t ino)
-{
-	int ret = 0;
-	struct UMSDOS_DIR_SEARCH *d = (struct UMSDOS_DIR_SEARCH *)buf;
-	if (d->search_ino == ino){
-		d->found = 1;
-		memcpy (d->entry->name,name,name_len);
-		d->entry->name[name_len] = '\0';
-		d->entry->name_len = name_len;
-		ret = 1;	/* So fat_readdir will terminate */
-	}
-	return ret;
+			      void * buf,
+			      const char *name,
+			      int len,
+			      off_t offset,
+			      ino_t ino)
+{
+  int ret = 0;
+  struct UMSDOS_DIR_SEARCH *d = (struct UMSDOS_DIR_SEARCH *)buf;
+  if (d->search_ino == ino){
+    d->found = 1;
+    memcpy (d->entry->name,name,len);
+    d->entry->name[len] = '\0';
+    d->entry->name_len = len;
+    ret = 1;	/* So fat_readdir will terminate */
+  }
+  return ret;
 }
 
 
 /*
-	Locate entry of an inode in a directory.
-	Return 0 or a negative error code.
-
-	Normally, this function must succeed. It means a strange corruption
-	in the file system if not.
+  Locate entry of an inode in a directory.
+  Return 0 or a negative error code.
+  
+  Normally, this function must succeed. It means a strange corruption
+  in the file system if not.
 */
 int umsdos_inode2entry (
-	struct inode *dir,
-	struct inode *inode,
-	struct umsdos_dirent *entry)	/* Will hold the entry */
-{
-	int ret = -ENOENT;
-	if (inode == pseudo_root){
-		/*
-			Quick way to find the name.
-			Also umsdos_readdir_x won't show /linux anyway
-		*/
-		memcpy (entry->name,UMSDOS_PSDROOT_NAME,UMSDOS_PSDROOT_LEN+1);
-		entry->name_len = UMSDOS_PSDROOT_LEN;
-		ret = 0;
-	}else{
-		struct inode *emddir = umsdos_emd_dir_lookup(dir,0);
-		iput (emddir);
-		if (emddir == NULL){
-			/* This is a DOS directory */
-			struct UMSDOS_DIR_SEARCH bufk;
-			struct file filp;
-			filp.f_reada = 1;
-			filp.f_pos = 0;
-			bufk.entry = entry;
-			bufk.search_ino = inode->i_ino;
-			fat_readdir (dir,&filp,&bufk,umsdos_dir_search);
-			if (bufk.found){
-				ret = 0;
-				inode->u.umsdos_i.i_dir_owner = dir->i_ino;
-				inode->u.umsdos_i.i_emd_owner = 0;
-				umsdos_setup_dir_inode(inode);
-			}
-		}else{
-			/* skip . and .. see umsdos_readdir_x() */
-			struct file filp;
-			filp.f_reada = 1;
-			filp.f_pos = UMSDOS_SPECIAL_DIRFPOS;
-			while (1){
-				struct UMSDOS_DIRENT_K bufk;
-				if (umsdos_readdir_x(dir,&filp,&bufk
-					,1,entry,0,umsdos_filldir_k) < 0){
-					printk ("UMSDOS: can't locate inode %ld in EMD file???\n"
-						,inode->i_ino);
-					break;
-				}else if (bufk.ino == inode->i_ino){
-					ret = 0;
-					umsdos_lookup_patch (dir,inode,entry,bufk.f_pos);
-					break;
-				}
-			}
-		}
+			struct inode *dir,
+			struct inode *inode,
+			struct umsdos_dirent *entry)	/* Will hold the entry */
+{
+  int ret = -ENOENT;
+  if (pseudo_root && inode == pseudo_root){
+    /*
+      Quick way to find the name.
+      Also umsdos_readdir_x won't show /linux anyway
+    */
+    memcpy (entry->name,UMSDOS_PSDROOT_NAME,UMSDOS_PSDROOT_LEN+1);
+    entry->name_len = UMSDOS_PSDROOT_LEN;
+    ret = 0;
+  }else{
+    struct inode *emddir = umsdos_emd_dir_lookup(dir,0);
+    iput (emddir);
+    if (emddir == NULL){
+      /* This is a DOS directory */
+      struct UMSDOS_DIR_SEARCH bufk;
+      struct file filp;
+      Printk ((KERN_ERR "umsdos_inode2entry emddir==NULL: WARNING: Known filp problem. segfaulting :) /mn/\n"));
+      filp.f_reada = 1;
+      filp.f_pos = 0;
+      bufk.entry = entry;
+      bufk.search_ino = inode->i_ino;
+      fat_readdir (&filp,&bufk,umsdos_dir_search);
+      if (bufk.found){
+	ret = 0;
+	inode->u.umsdos_i.i_dir_owner = dir->i_ino;
+	inode->u.umsdos_i.i_emd_owner = 0;
+	umsdos_setup_dir_inode(inode);
+      }
+    }else{
+      /* skip . and .. see umsdos_readdir_x() */
+      struct file filp;
+      filp.f_reada = 1;
+      filp.f_pos = UMSDOS_SPECIAL_DIRFPOS;
+      Printk ((KERN_ERR "umsdos_inode2entry skip./..: WARNING: Known filp problem. segfaulting :) /mn/\n"));
+      while (1){
+	struct UMSDOS_DIRENT_K bufk;
+	if (umsdos_readdir_x(dir,&filp,&bufk
+			     ,1,entry,0,umsdos_filldir_k) < 0){
+	  printk ("UMSDOS: can't locate inode %ld in EMD file???\n"
+		  ,inode->i_ino);
+	  break;
+	}else if (bufk.ino == inode->i_ino){
+	  ret = 0;
+	  umsdos_lookup_patch (dir,inode,entry,bufk.f_pos);
+	  break;
 	}
-	return ret;
+      }
+    }
+  }
+  return ret;
 }
+
+
 /*
-	Locate the parent of a directory and the info on that directory
-	Return 0 or a negative error code.
+  Locate the parent of a directory and the info on that directory
+  Return 0 or a negative error code.
 */
 static int umsdos_locate_ancestor (
-	struct inode *dir,
-	struct inode **result,
-	struct umsdos_dirent *entry)
-{
-	int ret;
-	umsdos_patch_inode (dir,NULL,0);
-	ret = umsdos_real_lookup (dir,"..",2,result);
-	PRINTK (("result %d %p ",ret,*result));
-	if (ret == 0){
-		struct inode *adir = *result;
-		ret = umsdos_inode2entry (adir,dir,entry);
-	}
-	PRINTK (("\n"));
-	return ret;
-}
-/*
-	Build the path name of an inode (relative to the file system.
-	This function is need to set (pseudo) hard link.
-
-	It uses the same strategy as the standard getcwd().
+				   struct inode *dir,
+				   struct inode **result,
+				   struct umsdos_dirent *entry)
+{
+  int ret;
+  
+  umsdos_patch_inode (dir,NULL,0);
+  /* FIXME */
+  ret = compat_umsdos_real_lookup (dir,"..",2,result);
+  Printk (("result %d %p ",ret,*result));
+  if (ret == 0){
+    struct inode *adir = *result;
+    ret = umsdos_inode2entry (adir,dir,entry);
+  }
+  Printk (("\n"));
+  return ret;
+}
+/*
+  Build the path name of an inode (relative to the file system.
+  This function is need to set (pseudo) hard link.
+  
+  It uses the same strategy as the standard getcwd().
 */
 int umsdos_locate_path (
-	struct inode *inode,
-	char *path)
+			struct inode *inode,
+			char *path)
 {
-	int ret = 0;
-	struct inode *dir = inode;
-	char *bpath = (char*)kmalloc(PATH_MAX,GFP_KERNEL);
-	if (bpath == NULL){
-		ret = -ENOMEM;
-	}else{
-		struct umsdos_dirent entry;
-		char *ptbpath = bpath+PATH_MAX-1;
-		*ptbpath = '\0';
-		PRINTK (("locate_path mode %x ",inode->i_mode));
-		if (!S_ISDIR(inode->i_mode)){
-			ret = umsdos_get_dirowner (inode,&dir);
-			PRINTK (("locate_path ret %d ",ret));
-			if (ret == 0){
-				ret = umsdos_inode2entry (dir,inode,&entry);
-				if (ret == 0){
-					ptbpath -= entry.name_len;
-					memcpy (ptbpath,entry.name,entry.name_len);
-					PRINTK (("ptbpath :%s: ",ptbpath));
-				}
-			}
-		}else{
-			atomic_inc(&dir->i_count);
-		}
-		if (ret == 0){
-			while (dir != dir->i_sb->s_mounted){
-				struct inode *adir;
-				ret = umsdos_locate_ancestor (dir,&adir,&entry);
-				iput (dir);
-				dir = NULL;
-				PRINTK (("ancestor %d ",ret));
-				if (ret == 0){
-					*--ptbpath = '/';
-					ptbpath -= entry.name_len;
-					memcpy (ptbpath,entry.name,entry.name_len);
-					dir = adir;
-					PRINTK (("ptbpath :%s: ",ptbpath));
-				}else{
-					break;
-				}
-			}
-		}
-		strcpy (path,ptbpath);
-		kfree (bpath);
+  int ret = 0;
+  struct inode *dir = inode;
+  struct inode *root_inode;
+  char *bpath = (char*)kmalloc(PATH_MAX,GFP_KERNEL);
+  root_inode = iget(inode->i_sb,UMSDOS_ROOT_INO);
+  if (bpath == NULL){
+    ret = -ENOMEM;
+  }else{
+    struct umsdos_dirent entry;
+    char *ptbpath = bpath+PATH_MAX-1;
+    *ptbpath = '\0';
+    Printk (("locate_path mode %x ",inode->i_mode));
+    if (!S_ISDIR(inode->i_mode)){
+      ret = umsdos_get_dirowner (inode,&dir);
+      Printk (("locate_path ret %d ",ret));
+      if (ret == 0){
+	ret = umsdos_inode2entry (dir,inode,&entry);
+	if (ret == 0){
+	  ptbpath -= entry.name_len;
+	  memcpy (ptbpath,entry.name,entry.name_len);
+	  Printk (("ptbpath :%s: ",ptbpath));
 	}
-	PRINTK (("\n"));
+      }
+    }else{
+      dir->i_count++;
+    }
+    if (ret == 0){
+      while (dir != root_inode){
+	struct inode *adir;
+	ret = umsdos_locate_ancestor (dir,&adir,&entry);
 	iput (dir);
-	return ret;
+	dir = NULL;
+	Printk (("ancestor %d ",ret));
+	if (ret == 0){
+	  *--ptbpath = '/';
+	  ptbpath -= entry.name_len;
+	  memcpy (ptbpath,entry.name,entry.name_len);
+	  dir = adir;
+	  Printk (("ptbpath :%s: ",ptbpath));
+	}else{
+	  break;
+	}
+      }
+    }
+    strcpy (path,ptbpath);
+    kfree (bpath);
+  }
+  Printk (("\n"));
+  iput (dir);
+  return ret;
 }
 
 /*
@@ -598,205 +676,262 @@
 */
 int umsdos_is_pseudodos (
 	struct inode *dir,
-	const char *name,
-	int len)
+	struct dentry *dentry)
 {
-	/* #Specification: pseudo root / DOS hard coded
-		The pseudo sub-directory DOS in the pseudo root is hard coded.
-		The name is DOS. This is done this way to help standardised
-		the umsdos layout. The idea is that from now on /DOS is
-		a reserved path and nobody will think of using such a path
-		for a package.
-	*/
-	return dir == pseudo_root
-		&& len == 3
-		&& name[0] == 'D' && name[1] == 'O' && name[2] == 'S';
+  /* #Specification: pseudo root / DOS hard coded
+     The pseudo sub-directory DOS in the pseudo root is hard coded.
+     The name is DOS. This is done this way to help standardised
+     the umsdos layout. The idea is that from now on /DOS is
+     a reserved path and nobody will think of using such a path
+     for a package.
+  */
+  return pseudo_root
+    && dir == pseudo_root
+    && dentry->d_name.len == 3
+    && dentry->d_name.name[0] == 'D' 
+    && dentry->d_name.name[1] == 'O' 
+    && dentry->d_name.name[2] == 'S';
 }
+
 /*
-	Check if a file exist in the current directory.
-	Return 0 if ok, negative error code if not (ex: -ENOENT).
+  Check if a file exist in the current directory.
+  Return 0 if ok, negative error code if not (ex: -ENOENT).
 */
 static int umsdos_lookup_x (
-	struct inode *dir,
-	const char *name,
-	int len,
-	struct inode **result,	/* Will hold inode of the file, if successful */
-	int nopseudo)			/* Don't care about pseudo root mode */
-{
-	int ret = -ENOENT;
-	*result = NULL;
-	umsdos_startlookup(dir);	
-	if (len == 1 && name[0] == '.'){
-		*result = dir;
-		atomic_inc(&dir->i_count);
-		ret = 0;
-	}else if (len == 2 && name[0] == '.' && name[1] == '.'){
-		if (pseudo_root != NULL && dir == pseudo_root->i_sb->s_mounted){
-			/* #Specification: pseudo root / .. in real root
-				Whenever a lookup is those in the real root for
-				the directory .., and pseudo root is active, the
-				pseudo root is returned.
-			*/
-			ret = 0;
-			*result = pseudo_root;
-			atomic_inc(&pseudo_root->i_count);
-		}else{
-			/* #Specification: locating .. / strategy
-				We use the msdos filesystem to locate the parent directory.
-				But it is more complicated than that.
-				
-				We have to step back even further to
-				get the parent of the parent, so we can get the EMD
-				of the parent of the parent. Using the EMD file, we can
-				locate all the info on the parent, such a permissions
-				and owner.
-			*/
-			ret = umsdos_real_lookup (dir,"..",2,result);
-			PRINTK (("ancestor ret %d dir %p *result %p ",ret,dir,*result));
-			if (ret == 0
-				&& *result != dir->i_sb->s_mounted
-				&& *result != pseudo_root){
-				struct inode *aadir;
-				struct umsdos_dirent entry;
-				ret = umsdos_locate_ancestor (*result,&aadir,&entry);
-				iput (aadir);
-			}
-		}
-	}else if (umsdos_is_pseudodos(dir,name,len)){
-		/* #Specification: pseudo root / lookup(DOS)
-			A lookup of DOS in the pseudo root will always succeed
-			and return the inode of the real root.
-		*/
-		*result = dir->i_sb->s_mounted;
-		atomic_inc(&((*result)->i_count));
-		ret = 0;
-	}else{
-		struct umsdos_info info;
-		ret = umsdos_parse (name,len,&info);
-		if (ret == 0) ret = umsdos_findentry (dir,&info,0);
-		PRINTK (("lookup %s pos %lu ret %d len %d ",info.fake.fname,info.f_pos,ret
-			,info.fake.len));
-		if (ret == 0){
-			/* #Specification: umsdos / lookup
-				A lookup for a file is done in two step. First, we locate
-				the file in the EMD file. If not present, we return
-				an error code (-ENOENT). If it is there, we repeat the
-				operation on the msdos file system. If this fails, it means
-				that the file system is not in sync with the emd file.
-				We silently remove this entry from the emd file,
-				and return ENOENT.
-			*/
-			struct inode *inode;
-			ret = umsdos_real_lookup (dir,info.fake.fname,info.fake.len,result);
-			inode = *result;
-			if (inode == NULL){
-				printk ("UMSDOS: Erase entry %s, out of sync with MsDOS\n"
-					,info.fake.fname);
-				umsdos_delentry (dir,&info,S_ISDIR(info.entry.mode));
-			}else{
-				umsdos_lookup_patch (dir,inode,&info.entry,info.f_pos);
-				PRINTK (("lookup ino %ld flags %d\n",inode->i_ino
-					,info.entry.flags));
-				if (info.entry.flags & UMSDOS_HLINK){
-					ret = umsdos_hlink2inode (inode,result);
-				}
-				if (*result == pseudo_root && !nopseudo){
-					/* #Specification: pseudo root / dir lookup
-						For the same reason as readdir, a lookup in /DOS for
-						the pseudo root directory (linux) will fail.
-					*/
-					/*
-						This has to be allowed for resolving hard link
-						which are recorded independently of the pseudo-root
-						mode.
-					*/
-					iput (pseudo_root);
-					*result = NULL;
-					ret = -ENOENT;
-				}
-			}
-		}
+			    struct inode *dir,
+			    struct dentry *dentry,
+			    int nopseudo)/* Don't care about pseudo root mode */
+{
+  int ret = -ENOENT;
+  struct inode *root_inode;
+  struct inode *pseudo_root_inode=NULL;
+  int len = dentry->d_name.len;
+  const char *name = dentry->d_name.name;
+  root_inode = iget(dir->i_sb,UMSDOS_ROOT_INO);
+  /*	pseudo_root_inode = iget( ... ) ? */
+  dentry->d_inode = NULL;
+  umsdos_startlookup(dir);	
+  if (len == 1 && name[0] == '.'){
+    dentry->d_inode = dir;
+    dir->i_count++;
+    ret = 0;
+  }else if (len == 2 && name[0] == '.' && name[1] == '.'){
+    if (pseudo_root && dir == pseudo_root_inode){
+      /* #Specification: pseudo root / .. in real root
+	 Whenever a lookup is those in the real root for
+	 the directory .., and pseudo root is active, the
+	 pseudo root is returned.
+      */
+      ret = 0;
+      dentry->d_inode = pseudo_root;
+      pseudo_root->i_count++;
+    }else{
+      /* #Specification: locating .. / strategy
+	 We use the msdos filesystem to locate the parent directory.
+	 But it is more complicated than that.
+	 
+	 We have to step back even further to
+	 get the parent of the parent, so we can get the EMD
+	 of the parent of the parent. Using the EMD file, we can
+	 locate all the info on the parent, such a permissions
+	 and owner.
+      */
+      
+      ret = compat_umsdos_real_lookup (dir,"..",2,&dentry->d_inode);
+      Printk (("ancestor ret %d dir %p *result %p ",ret,dir,dentry->d_inode));
+      if (ret == 0
+	  && dentry->d_inode != root_inode
+	  && dentry->d_inode != pseudo_root){
+	struct inode *aadir;
+	struct umsdos_dirent entry;
+	ret = umsdos_locate_ancestor (dentry->d_inode,&aadir,&entry);
+	iput (aadir);
+      }
+    }
+  }else if (umsdos_is_pseudodos(dir,dentry)){
+    /* #Specification: pseudo root / lookup(DOS)
+       A lookup of DOS in the pseudo root will always succeed
+       and return the inode of the real root.
+    */
+    dentry->d_inode = root_inode;
+    (dentry->d_inode)->i_count++;
+    ret = 0;
+  }else{
+    struct umsdos_info info;
+    ret = umsdos_parse (dentry->d_name.name,dentry->d_name.len,&info);
+    if (ret == 0) ret = umsdos_findentry (dir,&info,0);
+    Printk (("lookup %s pos %lu ret %d len %d ",info.fake.fname,info.f_pos,ret
+	     ,info.fake.len));
+    if (ret == 0){
+      /* #Specification: umsdos / lookup
+	 A lookup for a file is done in two step. First, we locate
+	 the file in the EMD file. If not present, we return
+	 an error code (-ENOENT). If it is there, we repeat the
+	 operation on the msdos file system. If this fails, it means
+	 that the file system is not in sync with the emd file.
+	 We silently remove this entry from the emd file,
+	 and return ENOENT.
+      */
+      struct inode *inode;
+      
+      ret = compat_umsdos_real_lookup (dir,info.fake.fname,info.fake.len,&inode);
+
+      Printk (("umsdos_lookup_x: compat_umsdos_real_lookup for %25s returned %d with inode=%p\n", info.fake.fname, ret, inode));
+
+      if (inode == NULL){
+	printk (KERN_WARNING "UMSDOS: Erase entry %s, out of sync with MsDOS\n"
+		,info.fake.fname);
+	umsdos_delentry (dir,&info,S_ISDIR(info.entry.mode));
+      }else{
+        Printk ((KERN_DEBUG "umsdos_lookup_x /mn/ debug: ino=%d\n",inode->i_ino));
+
+        /* we've found it. now get inode and put it in dentry. Is this ok /mn/ ? */
+        dentry->d_inode = iget(dir->i_sb, inode->i_ino);
+        
+	umsdos_lookup_patch (dir,inode,&info.entry,info.f_pos);
+	Printk (("lookup ino %ld flags %d\n",inode->i_ino
+		 ,info.entry.flags));
+	if (info.entry.flags & UMSDOS_HLINK){
+	  Printk ((KERN_ERR "umsdos_lookup_x: warning: untested /mn/ HLINK\n"));
+	  ret = umsdos_hlink2inode (inode,&dentry->d_inode);
 	}
-	umsdos_endlookup(dir);	
-	iput (dir);
-	return ret;
+	if (pseudo_root && dentry->d_inode == pseudo_root && !nopseudo){
+	  /* #Specification: pseudo root / dir lookup
+	     For the same reason as readdir, a lookup in /DOS for
+	     the pseudo root directory (linux) will fail.
+	  */
+	  /*
+	    This has to be allowed for resolving hard link
+	    which are recorded independently of the pseudo-root
+	    mode.
+	  */
+	  Printk ((KERN_ERR "umsdos_lookup_x: warning: untested /mn/ Pseudo_root thingy\n"));
+	  iput (pseudo_root);
+	  dentry->d_inode = NULL;
+	  ret = -ENOENT;
+	}
+      }
+    }
+  }
+  umsdos_endlookup(dir);	
+  iput (dir);
+  Printk ((KERN_DEBUG "umsdos_lookup_x: returning %d\n", ret));
+  return ret;
 }
+
+
 /*
-	Check if a file exist in the current directory.
-	Return 0 if ok, negative error code if not (ex: -ENOENT).
+  Check if a file exist in the current directory.
+  Return 0 if ok, negative error code if not (ex: -ENOENT).
+  
+  
 */
 int UMSDOS_lookup (
-	struct inode *dir,
-	const char *name,
-	int len,
-	struct inode **result)	/* Will hold inode of the file, if successful */
+		   struct inode *dir,
+		   struct dentry *dentry)
 {
-	return umsdos_lookup_x(dir,name,len,result,0);
+  return umsdos_lookup_x(dir,dentry,0);
 }
+
+
+
 /*
-	Locate the inode pointed by a (pseudo) hard link
-	Return 0 if ok, a negative error code if not.
+  Locate the inode pointed by a (pseudo) hard link
+  Return 0 if ok, a negative error code if not.
 */
 int umsdos_hlink2inode (struct inode *hlink, struct inode **result)
 {
-	int ret = -EIO;
-	char *path = (char*)kmalloc(PATH_MAX,GFP_KERNEL);
-	*result = NULL;
-	if (path == NULL){
-		ret = -ENOMEM;
-		iput (hlink);
-	}else{
-		struct file filp;
-		filp.f_reada = 1;
-		filp.f_pos = 0;
-		PRINTK (("hlink2inode "));
-		if (umsdos_file_read_kmem (hlink,&filp,path,hlink->i_size)
-			==hlink->i_size){
-			struct inode *dir;
-			char *pt = path;
-			dir = hlink->i_sb->s_mounted;
-			path[hlink->i_size] = '\0';
-			iput (hlink);
-			atomic_inc(&dir->i_count);
-			while (1){
-				char *start = pt;
-				int len;
-				while (*pt != '\0' && *pt != '/') pt++;
-				len = (int)(pt - start);
-				if (*pt == '/') *pt++ = '\0';
-				if (dir->u.umsdos_i.i_emd_dir == 0){
-					/* This is a DOS directory */
-					ret = umsdos_rlookup_x(dir,start,len,result,1);
-				}else{
-					ret = umsdos_lookup_x(dir,start,len,result,1);
-				}
-				PRINTK (("h2n lookup :%s: -> %d ",start,ret));
-				if (ret == 0 && *pt != '\0'){
-					dir = *result;
-				}else{
-					break;
-				}
-			}
-		}else{
-			iput (hlink);
-		}
-		PRINTK (("hlink2inode ret = %d %p -> %p\n",ret,hlink,*result));
-		kfree (path);
-	}
-	return ret;
+  struct inode *root_inode;
+  int ret = -EIO;
+  struct dentry *dentry_src, *dentry_dst;
+  char *path;
+  
+#if 0  	/* FIXME: DELME */
+  Printk (("FIXME: just test. hlink2inode returning -ENOENT\n /mn/\n"));
+  return -ENOENT;	/* /mn/ FIXME just for test */
+#endif
+  
+  path = (char*)kmalloc(PATH_MAX,GFP_KERNEL);
+
+  root_inode = iget(hlink->i_sb,UMSDOS_ROOT_INO);
+  *result = NULL;
+  if (path == NULL){
+    ret = -ENOMEM;
+    iput (hlink);
+  }else{
+    struct file filp;
+    loff_t offs = 0;
+
+    dentry_src = creat_dentry ("hlink-mn", 8, hlink);
+
+    memset (&filp, 0, sizeof (filp));
+
+    filp.f_pos = 0;
+    filp.f_reada = 1;
+    filp.f_flags = O_RDONLY;
+    filp.f_dentry = dentry_src;
+    filp.f_op = &umsdos_file_operations;	/* /mn/ - we have to fill it with dummy values so we won't segfault */
+    
+    Printk (("hlink2inode "));
+    if (umsdos_file_read_kmem (hlink, &filp, path, hlink->i_size, &offs) == hlink->i_size)
+      {
+	struct inode *dir;
+	char *pt = path;
+	dir = root_inode;
+	path[hlink->i_size] = '\0';
+/*	iput (hlink); / * FIXME! /mn/ */
+	dir->i_count++;
+	while (1)
+	  {
+	    char *start = pt;
+	    int len;
+	    while (*pt != '\0' && *pt != '/') pt++;
+	    len = (int)(pt - start);
+	    if (*pt == '/') *pt++ = '\0';
+	    /* FIXME. /mn/ fixed ? */
+
+            dentry_dst = creat_dentry (start, len, NULL);
+
+	    if (dir->u.umsdos_i.i_emd_dir == 0){
+	      /* This is a DOS directory */
+		
+	      Printk (("hlink2inode /mn/: doing umsdos_rlookup_x on %20s\n", dentry_dst->d_name.name));
+	      ret = umsdos_rlookup_x(dir,dentry_dst,1);
+	    }else{
+	      Printk (("hlink2inode /mn/: doing umsdos_lookup_x on %20s\n", dentry_dst->d_name.name));
+	      ret = umsdos_lookup_x(dir,dentry_dst,1);
+	    }
+	    Printk (("  returned %d\n", ret));
+
+	    Printk (("h2n lookup :%s: -> %d ",start,ret));
+	    if (ret == 0 && *pt != '\0'){
+	      dir = dentry_dst->d_inode;
+	    }else{
+	      break;
+	    }
+	  }
+      }else{
+	  Printk (("umsdos_hlink2inode: all those iput's() frighten me /mn/. Whatabout dput() ? FIXME!\n"));
+	  iput (hlink); /* FIXME */
+      }
+    Printk (("hlink2inode ret = %d %p -> %p\n",ret,hlink,*result));
+    kfree (path);
+  }
+  return ret;
 }
 
+
 static struct file_operations umsdos_dir_operations = {
 	NULL,				/* lseek - default */
-	UMSDOS_dir_read,	/* read */
+	UMSDOS_dir_read,		/* read */
 	NULL,				/* write - bad */
-	UMSDOS_readdir,		/* readdir */
+	UMSDOS_readdir,			/* readdir */
 	NULL,				/* poll - default */
-	UMSDOS_ioctl_dir,	/* ioctl - default */
+	UMSDOS_ioctl_dir,		/* ioctl - default */
 	NULL,				/* mmap */
 	NULL,				/* no special open code */
 	NULL,				/* no special release code */
-	NULL				/* fsync */
+	NULL				/* fsync */	/* in original NULL. changed to file_fsync. FIXME? /mn/ */
 };
 
 struct inode_operations umsdos_dir_inode_operations = {
@@ -811,14 +946,17 @@
 	UMSDOS_mknod,		/* mknod */
 	UMSDOS_rename,		/* rename */
 	NULL,			/* readlink */
-	NULL,			/* readpage */
+	NULL,                   /* followlink */
+	generic_readpage,	/* readpage */	/* in original NULL. changed to generic_readpage. FIXME? /mn/ */
 	NULL,			/* writepage */
-	NULL,			/* bmap */
+	fat_bmap,		/* bmap */	/* in original NULL. changed to fat_bmap. FIXME? /mn/ */
 	NULL,			/* truncate */
-	NULL			/* permission */
+	NULL,			/* permission */
+	NULL,			/* smap */
+	NULL,			/* updatepage */
+	NULL,			/* revalidate */
+	
 };
-
-
 
 
 

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TCL-scripts by Sam Shen, slshen@lbl.gov