[ECOS] jffs2 BUG:s in jffs2_garbage_collect_dnode

["Per Hedblom" <per dot hedblom at abem dot se>]

I have found that jffs2 fails to garbage collect the inode that it currently 
adds data to.
The result is that jffs2_garbage_collect_dnode ends with a BUG() call.
I have created a test case that I run on the ecos synt target.
My test stresses the jffs2 with a near to full file system.
I add files until I get ENOSPC and the remove an old file to make space for 
a new one.

Here is how it goes:
----------------------------
User level code:
Open file /small_files/127 for append (inode #186)
Write 12000 bytes to file /small_files/127
JFFS2:
jffs2_gc_fetch_inode  #169 link=1
jffs2_gc_fetch_inode  #167 link=1
jffs2_gc_fetch_inode  #166 link=1
jffs2_gc_fetch_inode  #172 link=1
jffs2_gc_fetch_inode  #172 link=1
jffs2_gc_fetch_inode  #178 link=1
jffs2_gc_fetch_inode  #173 link=1
jffs2_write_inode_range:increasing writtenlen by 204 #186
jffs2_write_inode_range:increasing writtenlen by 84 #186
jffs2_gc_fetch_inode  #186 link=1
BUG() at /home/perhedblom/redhat/ecos/packages/fs/jffs2/current/src/gc.c 
1161
----------------------------

The test that fails is BUG_ON(end > JFFS2_F_I_SIZE(f)) in the function 
jffs2_garbage_collect_dnode in gc.c.

The problem is that the 288(=204+84) bytes latest written are not added to 
the inode->i_size yet but already available in the frag tree.

I guess that this problem is only related to ecos/jffs2.
I can add code to modify the inode->i_size in the jffs2_write_inode_range 
after each successful written but I don't think this is correct to the jffs2 
architecture and I need to restore the i_size if  write fails later and 
needs to return an error code.

I can remove the BUG test in gc.c
I suppose it is correct of jffs2 to garbage collect the node that is 
currently added to.

Comments? Solutions?
--
Per Hedblom






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