Messages in this thread | | | Date | Mon, 5 Apr 2004 10:54:21 +0200 | From | Jörn Engel <> | Subject | Re: [PATCH] cowlinks v2 |
| |
On Sat, 3 April 2004 12:47:58 -0700, Eric W. Biederman wrote: > > And a few scenarios to hopefully make things clear. > > So your fs starts out as: > > /file1 -> ino1 (link count 2) -> data block #1 > /file2 -> ino1 (link count 2) -> data block #1 > > file1 is only 4K long, so I only need to describe one data block. > > Actions: > > cowcopy(file2, file3): > > /file1 -> ino1 (link count 2) -> ino2 (link count 2) -> data block #1 > /file2 -> ino1 (link count 2) -> ino2 (link count 2) -> data block #1 > /file3 -> ino3 (link count 1) -> ino2 (link count 2) -> data block #1 > > > copyfile(file3, file4): > > /file1 -> ino1 (link count 2) -> ino2 (link count 3) -> data block #1 > /file2 -> ino1 (link count 2) -> ino2 (link count 3) -> data block #1 > /file3 -> ino3 (link count 1) -> ino2 (link count 3) -> data block #1 > /file4 -> ino4 (link count 1) -> ino2 (link count 3) -> data block #1 > > unlink(file2): > > /file1 -> ino1 (link count 1) -> ino2 (link count 3) -> data block #1 > /file3 -> ino3 (link count 1) -> ino2 (link count 3) -> data block #1 > /file4 -> ino4 (link count 1) -> ino2 (link count 3) -> data block #1 > > link(file4, file5): > > /file1 -> ino1 (link count 1) -> ino2 (link count 3) -> data block #1 > /file3 -> ino3 (link count 1) -> ino2 (link count 3) -> data block #1 > /file4 -> ino4 (link count 2) -> ino2 (link count 3) -> data block #1 > /file5 -> ino4 (link count 2) -> ino2 (link count 3) -> data block #1 > > write(file3): > > /file1 -> ino1 (link count 1) -> ino2 (link count 2) -> data block #1 > /file3 -> ino3 (link count 1) -> data block #2 > /file4 -> ino4 (link count 2) -> ino2 (link count 2) -> data block #1 > /file5 -> ino4 (link count 2) -> ino2 (link count 2) -> data block #1 > > write(file5): > > /file1 -> ino1 (link count 1) -> ino2 (link count 1) -> data block #1 > /file3 -> ino3 (link count 1) -> data block #2 > /file4 -> ino4 (link count 2) -> data block #3 > /file5 -> ino4 (link count 2) -> data block #3 > > write(file1): > > /file1 -> ino1 (link count 1) -> data block #1 (with modified contents) > /file3 -> ino3 (link count 1) -> data block #2 > /file4 -> ino4 (link count 2) -> data block #3 > /file5 -> ino4 (link count 2) -> data block #3 > > Does this make things clear?
Almost. What exactly do cowcopy() and copyfile() do? They look the same, so why the difference?
Jörn
-- The story so far: In the beginning the Universe was created. This has made a lot of people very angry and been widely regarded as a bad move. -- Douglas Adams? - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |