First of all some necessary notes about UFS by it self: To avoid waste of disk
space the tail of file consists not from blocks (which is ordinary big enough,
16K usually), it consists from fragments(which is ordinary 2K). When file is
growing its tail occupy 1 fragment, 2 fragments... At some stage decision to
allocate whole block is made and all fragments are moved to one block.
How this situation was handled before:
ufs_prepare_write
->block_prepare_write
->ufs_getfrag_block
->...
->ufs_new_fragments:
bh = sb_bread
bh->b_blocknr = result + i;
mark_buffer_dirty (bh);
This is wrong solution, because:
- it didn't take into consideration that there is another cache: "inode page
cache"
- because of sb_getblk uses not b_blocknr, (it uses page->index) to find
certain block, this breaks sb_getblk.
How this situation is handled now: we go though all "page inode cache", if
there are no such page in cache we load it into cache, and change b_blocknr.
Signed-off-by: Evgeniy Dushistov <dushistov@mail.ru>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* After block allocation, we map it on the same "address" as 8 others
blocks
* We nullify block several times: once in ufs/block.c and once in
block_*write_full_page, and use different "caches" for this.
Signed-off-by: Evgeniy Dushistov <dushistov@mail.ru>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Here is update of ufs cleanup patch, brought on by the recently fixed
ubh_get_usb_second() bug that made some ugly code rather painfully
obvious. It also includes
- fix compilation warnings which appears if debug mode turn on
- remove unnecessary duplication of code to support UFS2
I tested it on ufs1 and ufs2 file-systems.
Signed-off-by: Evgeniy Dushistov <dushistov@mail.ru>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
fs: Use <linux/capability.h> where capable() is used.
Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Acked-by: Tim Schmielau <tim@physik3.uni-rostock.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
We need to be sure that current data are sent to disk. Hence we call
ll_rw_block() with SWRITE.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Evgeniy Dushistov
Randy Dunlap
Jan Kara
Linus Torvalds