Return-Path: Received: from merit-proxy01.merit.edu ([207.75.116.193]:48155 "EHLO merit-proxy01.merit.edu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754073Ab1FNCc6 (ORCPT ); Mon, 13 Jun 2011 22:32:58 -0400 Message-Id: In-Reply-To: References: Subject: [PATCH 22/33] pnfsblock: merge rw extents To: Benny Halevy Cc: linux-nfs@vger.kernel.org, peter honeyman Date: Mon, 13 Jun 2011 22:32:56 -0400 From: Jim Rees Sender: linux-nfs-owner@vger.kernel.org List-ID: Content-Type: text/plain MIME-Version: 1.0 From: Fred Isaman Signed-off-by: Fred Isaman Signed-off-by: Benny Halevy --- fs/nfs/blocklayout/extents.c | 47 ++++++++++++++++++++++++++++++++++++++++++ 1 files changed, 47 insertions(+), 0 deletions(-) diff --git a/fs/nfs/blocklayout/extents.c b/fs/nfs/blocklayout/extents.c index 3d36f66..43a3601 100644 --- a/fs/nfs/blocklayout/extents.c +++ b/fs/nfs/blocklayout/extents.c @@ -501,3 +501,50 @@ find_get_extent(struct pnfs_block_layout *bl, sector_t isect, print_bl_extent(ret); return ret; } + +/* Helper function to set_to_rw that initialize a new extent */ +static void +_prep_new_extent(struct pnfs_block_extent *new, + struct pnfs_block_extent *orig, + sector_t offset, sector_t length, int state) +{ + kref_init(&new->be_refcnt); + /* don't need to INIT_LIST_HEAD(&new->be_node) */ + memcpy(&new->be_devid, &orig->be_devid, sizeof(struct nfs4_deviceid)); + new->be_mdev = orig->be_mdev; + new->be_f_offset = offset; + new->be_length = length; + new->be_v_offset = orig->be_v_offset - orig->be_f_offset + offset; + new->be_state = state; + new->be_inval = orig->be_inval; +} + +/* Tries to merge be with extent in front of it in list. + * Frees storage if not used. + */ +static struct pnfs_block_extent * +_front_merge(struct pnfs_block_extent *be, struct list_head *head, + struct pnfs_block_extent *storage) +{ + struct pnfs_block_extent *prev; + + if (!storage) + goto no_merge; + if (&be->be_node == head || be->be_node.prev == head) + goto no_merge; + prev = list_entry(be->be_node.prev, struct pnfs_block_extent, be_node); + if ((prev->be_f_offset + prev->be_length != be->be_f_offset) || + !extents_consistent(prev, be)) + goto no_merge; + _prep_new_extent(storage, prev, prev->be_f_offset, + prev->be_length + be->be_length, prev->be_state); + list_replace(&prev->be_node, &storage->be_node); + put_extent(prev); + list_del(&be->be_node); + put_extent(be); + return storage; + + no_merge: + kfree(storage); + return be; +} -- 1.7.4.1