lookup operation query.

lookup operation query.

[rajesh singarapu]

Hi All,

I have couple of questions in filesystems area.

1) I want to understand how lookup operation (of inode operation) find
if current dirent
is actually a directory or mount point?

2) if a write happening in mid of a file (and mid of a page frame once
pulled in to memory)
and write at that location lead to split of that page, but doesn't
completely fill the second page.
in this case, clearly there is some space unfilled in second page. (I
read this is going to be filled with '0's)
but how read/write rotines of filesystem exactly calculates the
offsets in this case correctly.

These can be simple questions. but I want to know how these are
handled, in say ext3 or any filesystem.


thanks
Rajesh