Upstream jffs2 patches

[Milton Miller II]

Joel,

Please apply the following upstream fixes to our tree.
All apply as straight cherry-pick.

We have definitive evidence of the problem fixed by
be629 causing the application stack not to run because
the directory went missing.  The next 2 are a deadlock
reported as widely encountered and affecting garbage 
collection which is required for writes.

The last two affect error paths.

be629c62a603e5935f8177fd8a19e014100a259e 
   Fix directory hardlinks from deleted directories

157078f64b8a9cd7011b6b900b2f2498df850748 
   Revert "jffs2: Fix lock acquisition order bug in jffs2_write_begin"

49e91e7079febe59a20ca885a87dd1c54240d0f1 j
   ffs2: Fix page lock / f->sem deadlock

In addition consider these:

f93812846f31381d35c04c6c577d724254355e7f 
   jffs2: reduce the breakage on recovery from halfway failed rename()

eb042ec35956de2684de2a05a814cd15efe570ca 
   jffs2: fix a memleak in read_direntry()

Thanks,
milton