The partial cluster zeroing code used during truncate usually assumes that
the rightmost byte in the range to be zeroed lies on a cluster boundary.
This makes sense for truncate, but punching holes might require zeroing on
non-aligned rightmost boundaries.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
Add code to the btree paths to support the removal of arbitrary regions
within an existing extent. With proper higher level support this can be used
to "punch holes" in a file. Truncate (a special case of hole punching) could
also be converted to use these methods.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
This can now be trivially supported with re-use of our existing extend code.
ocfs2_allocate_unwritten_extents() takes a start offset and a byte length
and iterates over the inode, adding extents (marked as unwritten) until len
is reached. Existing extents are skipped over.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
Writes to a region marked as unwritten might result in a record split or
merge. We can support splits by making minor changes to the existing insert
code. Merges require left rotations which mostly re-use right rotation
support functions.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
The top level calls and logic for growing a tree can easily be abstracted
out of ocfs2_insert_extent() into a seperate function - ocfs2_grow_tree().
This allows future code to easily grow btrees when needed.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
Now that we have a method to deallocate blocks from them, each node should
allocate extent blocks from their local suballocator file.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
Deallocation of suballocator blocks, most notably extent blocks, might
involve multiple suballocator inodes.
The locking for this can get extremely complicated, especially when the
suballocator inodes to delete from aren't known until deep within an
unrelated codepath.
Implement a simple scheme for recording the blocks to be unlinked so that
the actual deallocation can be done in a context which won't deadlock.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
Use of the alloc sem during truncate was too narrow - we want to protect
the i_size change and page truncation against mmap now.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
The extent map code was ripped out earlier because of an inability to deal
with holes. This patch adds back a simpler caching scheme requiring far less
code.
Our old extent map caching was designed back when meta data block caching in
Ocfs2 didn't work very well, resulting in many disk reads. These days our
metadata caching is much better, resulting in no un-necessary disk reads. As
a result, extent caching doesn't have to be as fancy, nor does it have to
cache as many extents. Keeping the last 3 extents seen should be sufficient
to give us a small performance boost on some streaming workloads.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
Return an optional extent flags field from our lookup functions and wire up
callers to treat unwritten regions as holes for the purpose of returning
zeros to the user.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
Due to the size of our group bitmaps, we'll never have a leaf node extent
record with more than 16 bits worth of clusters. Split e_clusters up so that
leaf nodes can get a flags field where we can mark unwritten extents.
Interior nodes whose length references all the child nodes beneath it can't
split their e_clusters field, so we use a union to preserve sizing there.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
Do this instead of filemap_fdatawrite() - this way we sync only the
range between i_size and the cluster boundary.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
Since we don't zero on extend anymore, truncate needs to be fixed up to zero
the part of a file between i_size and and end of it's cluster. Otherwise a
subsequent extend could expose bad data.
This introduced a new helper, which can be used in ocfs2_write().
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
For ocfs2_truncate_file(), we eliminate the "simple" truncate case which no
longer exists since i_size is not tied to i_clusters. In
ocfs2_extend_file(), we skip the allocation / page zeroing code for file
systems which understand sparse files.
The core truncate code is changed to do a bottom up tree traversal. This
gets abstracted out into it's own function. To make things more readable,
most of the special case handling for in-inode extents from
ocfs2_do_truncate() is also removed.
Though write support for sparse files comes in a later patch, we at least
update ocfs2_prepare_inode_for_write() to skip allocation for sparse files.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
The code in extent_map.c is not prepared to deal with a subtree being
rotated between lookups. This can happen when filling holes in sparse files.
Instead of a lengthy patch to update the code (which would likely lose the
benefit of caching subtree roots), we remove most of the algorithms and
implement a simple path based lookup. A less ambitious extent caching scheme
will be added in a later patch.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
Introduce tree rotations into the b-tree code. This will allow ocfs2 to
support sparse files. Much of the added code is designed to be generic (in
the ocfs2 sense) so that it can later be re-used to implement large
extended attributes.
This patch only adds the rotation code and does minimal updates to callers
of the extent api.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
All kcalloc() calls of the form "kcalloc(1,...)" are converted to the
equivalent kzalloc() calls, and a few kcalloc() calls with the incorrect
ordering of the first two arguments are fixed.
Signed-off-by: Robert P. J. Day <rpjday@mindspring.com>
Cc: Jeff Garzik <jeff@garzik.org>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: Adam Belay <ambx1@neo.rr.com>
Cc: James Bottomley <James.Bottomley@steeleye.com>
Cc: Greg KH <greg@kroah.com>
Cc: Mark Fasheh <mark.fasheh@oracle.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Conflicts:
drivers/ata/libata-scsi.c
include/linux/libata.h
Futher merge of Linus's head and compilation fixups.
Signed-Off-By: David Howells <dhowells@redhat.com>
This is mostly a search and replace as ocfs2_journal_handle is now no more
than a container for a handle_t pointer.
ocfs2_commit_trans() becomes very straight forward, and we remove some out
of date comments / code.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
All callers either pass in NULL directly, or a local variable that is
already set to NULL.
The internals of ocfs2_start_trans() get a nice cleanup as a result.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
No reason to use our wrapper struct in this function, so take the handle_t
directly.
Also fixes a bug where we were incorrectly setting the handle to NULL in
case of a failure from journal_restart()
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
The truncate code was never supposed to BUG() on an allocator it doesn't
know about, but rather to ignore it. Right now, this does nothing, but when
we change our allocation paths to use all suballocator files, this will
allow current versions of the fs module to work fine.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
This patch converts the inode semaphore to a mutex. I have tested it on
XFS and compiled as much as one can consider on an ia64. Anyway your
luck with it might be different.
Modified-by: Ingo Molnar <mingo@elte.hu>
(finished the conversion)
Signed-off-by: Jes Sorensen <jes@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Mark Fasheh
Robert P. J. Day
David Howells
Jes Sorensen