The ocfs2 write code loops through a page much like the block code, except
that ocfs2 allocation units can be any size, including larger than page
size. Typically it's equal to or larger than page size - most kernels run 4k
pages, the minimum ocfs2 allocation (cluster) size.
Some changes introduced during 2.6.23 changed the way writes to pages are
handled, and inadvertantly broke support for > 4k page size. Instead of just
writing one cluster at a time, we now handle the whole page in one pass.
This means that multiple (small) seperate allocations might happen in the
same pass. The allocation code howver typically optimizes by getting the
maximum which was reserved. This triggered a BUG_ON in the extend code where
it'd ask for a single bit (for one part of a > 4k page) and get back more
than it asked for.
Fix this by providing a variant of the high level allocation function which
allows the caller to specify a maximum. The traditional function remains and
just calls the new one with a maximum determined from the initial
reservation.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
We were setting i_blocks too early - before truncating any allocation.
Correct things to set i_blocks after the allocation change.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
We have to manually check the requested truncate size as the check in
vmtruncate() comes too late for Ocfs2.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
ocfs2_align_clusters_to_page_index() needs to cast the clusters shift to
pgoff_t and ocfs2_file_buffered_write() needs loff_t when calculating
destination start for memcpy.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
There's no need to recalculate things via ocfs2_max_file_offset() as we've
already done that to fill s_maxbytes, so use that instead. We can also
un-export ocfs2_max_file_offset() then.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
ocfs2_update_inode_atime() calls ocfs2_mark_inode_dirty() to push changes
from the struct inode into the ocfs2 disk inode. The problem is,
ocfs2_mark_inode_dirty() might change other fields, depending on what
happened to the struct inode. Since we don't always have locking to
serialize changes to other fields (like i_size, etc), just fix things up to
only touch the atime field.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
Mark variables with uninitialized_var() if such a warning appears,
and analysis proves that the var is initialized properly on all paths
it is used.
Signed-off-by: Jeff Garzik <jeff@garzik.org>
We re-use the RESVSP/UNRESVSP ioctls from xfs which allow the user to
allocate and deallocate regions to a file without zeroing data or changing
i_size.
Though renamed, the structure passed in from user is identical to struct
xfs_flock64. The three fields that are actually used right now are l_whence,
l_start and l_len.
This should get ocfs2 immediate compatibility with userspace software using
the pre-existing xfs ioctls.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
Provide an internal interface for the removal of arbitrary file regions.
ocfs2_remove_inode_range() takes a byte range within a file and will remove
existing extents within that range. Partial clusters will be zeroed so that
any read from within the region will return zeros.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
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>
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>
Update the write code to detect when the user is asking to write to an
unwritten extent. Like writing to a hole, we must zero the region between
the write and the cluster boundaries. Most of the existing cluster zeroing
logic can be re-used with some additional checks for the unwritten flag on
extent records.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
Use some ideas from the new-aops patch series and turn
ocfs2_buffered_write_cluster() into a 2 stage operation with the caller
copying data in between. The code now understands multiple cluster writes as
a result of having to deal with a full page write for greater than 4k pages.
This sets us up to easily call into the write path during ->page_mkwrite().
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 name 'pin' was badly chosen, it doesn't pin a pipe buffer
in the most commonly used sense in the kernel. So change the
name to 'confirm', after debating this issue with Hugh
Dickins a bit.
A good return from ->confirm() means that the buffer is really
there, and that the contents are good.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
We need to move even more stuff into the header so that folks can use
the splice_to_pipe() implementation instead of open-coding a lot of
pipe knowledge (see relay implementation), so move to our own header
file finally.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
They can use generic_file_splice_read() instead. Since sys_sendfile() now
prefers that, there should be no change in behaviour.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
A bit of a cheat, it actually just copies the data to userspace. But
this makes the interface nice and symmetric and enables people to build
on splice, with room for future improvement in performance.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
For direct splicing (or private splicing), the output may not be a file.
So abstract out the handling into a specified actor function and put
the data in the splice_desc structure earlier, so we can build on top
of that.
This is the first step in better splice handling for drivers, and also
for implementing vmsplice _to_ user memory.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Mark Fasheh
Jens Axboe
Jeff Garzik
Christoph Hellwig