[Yaffs] Problems on "rm -rf" on Yaffs2(Sorry for long lines in the former mail)

Zhen Feng feng8310 at 126.com
Mon Sep 12 03:26:32 BST 2005


When I want to remove a directory using "rm -rf <dir>" command, a error message 
"The directory is not empty" occurs and serveral files in the directory are not deleted.

I traced into the code and found that yaffs_readdir() could be called serveral times by 
one time execution of "rm".Also, the file->f_pos are increased if a child(file) of this 
directory was found.

"rm" unlink the file read from directory entry:

rm->unlink()-> yaffs_unlink()-> yaffs_Unlink() ->yaffs_UnlinkWorker() -> 
yaffs_UnlinkFile()->yaffs_ChangeObjectName()->yaffs_AddObjectToDirectory(), the unlinked 
file will be add to "unlinked directory", in this case, this file is removed from its old 
parent directory's children list(obj->variant.directoryVariant.children) but added to the
 children of unlinked dir. (Is it right???) 

The question is when "rm" has to call readdir() again because of low buffer, file->f_pos 
is not 0 but a large number, the following code in yaffs_readdir() will bypass serveral
files:
   	
    offset = f->f_pos;
	....
   	curoffs = 1;
	list_for_each(i,&obj->variant.directoryVariant.children)
	{
		curoffs++;   
		if(curoffs >= offset)    
		{		

curoffs have to increase until it reaches f->f_pos, so readdir() miss serveral files in 
the front of obj->variant.directoryVariant.children


As a result, serveral files in the directory are not able to be unlinked, consequently, 
direcotry can not be removed.


I wonder if my traces are right, how could I fix my problem ? I delete a single file or 
directory with a small number of files, it is all right. 

My arm Kernel is 2.4.18 running on samsung S3C2410. Nand Flash is samsung 128Mb with 2k 
Large page. 

Thanks a Lot!!

--Zhen Feng





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