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authorMark Fasheh <mfasheh@suse.com>2009-12-07 13:10:48 -0800
committerJoel Becker <joel.becker@oracle.com>2010-05-05 18:17:30 -0700
commitd02f00cc057809d96c044cc72d5b9809d59f7d49 (patch)
tree44a6d81ecf9fb4b5aa91c0501a8da2ee36890a38 /fs/ocfs2/suballoc.h
parentec20cec7a351584ca6c70ead012e73d61f9a8e04 (diff)
ocfs2: allocation reservations
This patch improves Ocfs2 allocation policy by allowing an inode to reserve a portion of the local alloc bitmap for itself. The reserved portion (allocation window) is advisory in that other allocation windows might steal it if the local alloc bitmap becomes full. Otherwise, the reservations are honored and guaranteed to be free. When the local alloc window is moved to a different portion of the bitmap, existing reservations are discarded. Reservation windows are represented internally by a red-black tree. Within that tree, each node represents the reservation window of one inode. An LRU of active reservations is also maintained. When new data is written, we allocate it from the inodes window. When all bits in a window are exhausted, we allocate a new one as close to the previous one as possible. Should we not find free space, an existing reservation is pulled off the LRU and cannibalized. Signed-off-by: Mark Fasheh <mfasheh@suse.com>
Diffstat (limited to 'fs/ocfs2/suballoc.h')
-rw-r--r--fs/ocfs2/suballoc.h2
1 files changed, 2 insertions, 0 deletions
diff --git a/fs/ocfs2/suballoc.h b/fs/ocfs2/suballoc.h
index e0f46df357e6..da2f29a55ec3 100644
--- a/fs/ocfs2/suballoc.h
+++ b/fs/ocfs2/suballoc.h
@@ -54,6 +54,8 @@ struct ocfs2_alloc_context {
u64 ac_last_group;
u64 ac_max_block; /* Highest block number to allocate. 0 is
is the same as ~0 - unlimited */
+
+ struct ocfs2_alloc_reservation *ac_resv;
};
void ocfs2_init_steal_slots(struct ocfs2_super *osb);