Ocfs2's local allocator disables itself for the duration of a mount point
when it has trouble allocating a large enough area from the primary bitmap.
That can cause performance problems, especially for disks which were only
temporarily full or fragmented. This patch allows for the allocator to
shrink it's window first, before being disabled. Later, it can also be
re-enabled so that any performance drop is minimized.
To do this, we allow the value of osb->local_alloc_bits to be shrunk when
needed. The default value is recorded in a mostly read-only variable so that
we can re-initialize when required.
Locking had to be updated so that we could protect changes to
local_alloc_bits. Mostly this involves protecting various local alloc values
with the osb spinlock. A new state is also added, OCFS2_LA_THROTTLED, which
is used when the local allocator is has shrunk, but is not disabled. If the
available space dips below 1 megabyte, the local alloc file is disabled. In
either case, local alloc is re-enabled 30 seconds after the event, or when
an appropriate amount of bits is seen in the primary bitmap.
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
In inode stealing, we no longer restrict the allocation to
happen in the local node. So it is neccessary for us to add
a new member in ocfs2_alloc_context to indicate which slot
we are using for allocation. We also modify the process of
local alloc so that this member can be used there also.
Signed-off-by: Tao Ma <tao.ma@oracle.com>
Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
This patch adds the ability for a userspace program to request an extend of
last cluster group on an Ocfs2 file system. The request is made via ioctl,
OCFS2_IOC_GROUP_EXTEND. This is derived from EXT3_IOC_GROUP_EXTEND, but is
obviously Ocfs2 specific.
tunefs.ocfs2 would call this for an online-resize operation if the last
cluster group isn't full.
Signed-off-by: Tao Ma <tao.ma@oracle.com>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
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>
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>
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>
Instead we record our state on the allocation context structure which all
callers already know about and lifetime correctly. This means the
reservation functions don't need a handle passed in any more, and we can
also take it off the alloc context.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
Record the most recently used allocation group on the allocation context, so
that subsequent allocations can attempt to optimize for contiguousness.
Local alloc especially should benefit from this as the current chain search
tends to let it spew across the disk.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
