Return-Path: Received: from int-mailstore01.merit.edu ([207.75.116.232]:60772 "EHLO int-mailstore01.merit.edu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754543Ab1FLXoj (ORCPT ); Sun, 12 Jun 2011 19:44:39 -0400 Message-Id: In-Reply-To: References: Date: Sun, 12 Jun 2011 19:44:37 -0400 Subject: [PATCH 20/34] pnfsblock: find_get_extent From: Jim Rees To: linux-nfs@vger.kernel.org Cc: peter honeyman Sender: linux-nfs-owner@vger.kernel.org List-ID: Content-Type: text/plain MIME-Version: 1.0 From: Fred MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Implement find_get_extent(), one of the core extent manipulation routines. [pnfsblock: Lookup list entry of layouts and tags in reverse order] Signed-off-by: Zhang Jingwang Signed-off-by: Fred Isaman Signed-off-by: Benny Halevy pnfsblock: fix print format warnings for sector_t and size_t gcc spews warnings about these on x86_64, e.g.: fs/nfs/blocklayout/blocklayout.c:74: warning: format ‘%Lu’ expects type ‘long long unsigned int’, but argument 2 has type ‘sector_t’ fs/nfs/blocklayout/blocklayout.c:388: warning: format ‘%d’ expects type ‘int’, but argument 5 has type ‘size_t’ Signed-off-by: Benny Halevy --- fs/nfs/blocklayout/blocklayout.h | 3 ++ fs/nfs/blocklayout/extents.c | 47 ++++++++++++++++++++++++++++++++++++++ 2 files changed, 50 insertions(+), 0 deletions(-) diff --git a/fs/nfs/blocklayout/blocklayout.h b/fs/nfs/blocklayout/blocklayout.h index 293f009..06aa36a 100644 --- a/fs/nfs/blocklayout/blocklayout.h +++ b/fs/nfs/blocklayout/blocklayout.h @@ -219,6 +219,9 @@ int nfs4_blk_process_layoutget(struct pnfs_layout_hdr *lo, /* blocklayoutdm.c */ void free_block_dev(struct pnfs_block_dev *bdev); /* extents.c */ +struct pnfs_block_extent * +find_get_extent(struct pnfs_block_layout *bl, sector_t isect, + struct pnfs_block_extent **cow_read); void put_extent(struct pnfs_block_extent *be); struct pnfs_block_extent *alloc_extent(void); int add_and_merge_extent(struct pnfs_block_layout *bl, diff --git a/fs/nfs/blocklayout/extents.c b/fs/nfs/blocklayout/extents.c index 26c263f..f0b3f13 100644 --- a/fs/nfs/blocklayout/extents.c +++ b/fs/nfs/blocklayout/extents.c @@ -201,3 +201,50 @@ add_and_merge_extent(struct pnfs_block_layout *bl, put_extent(new); return -EIO; } + +/* Returns extent, or NULL. If a second READ extent exists, it is returned + * in cow_read, if given. + * + * The extents are kept in two seperate ordered lists, one for READ and NONE, + * one for READWRITE and INVALID. Within each list, we assume: + * 1. Extents are ordered by file offset. + * 2. For any given isect, there is at most one extents that matches. + */ +struct pnfs_block_extent * +find_get_extent(struct pnfs_block_layout *bl, sector_t isect, + struct pnfs_block_extent **cow_read) +{ + struct pnfs_block_extent *be, *cow, *ret; + int i; + + dprintk("%s enter with isect %llu\n", __func__, (u64)isect); + cow = ret = NULL; + spin_lock(&bl->bl_ext_lock); + for (i = 0; i < EXTENT_LISTS; i++) { + if (ret && + (!cow_read || ret->be_state != PNFS_BLOCK_INVALID_DATA)) + break; + list_for_each_entry_reverse(be, &bl->bl_extents[i], be_node) { + if (isect >= be->be_f_offset + be->be_length) + break; + if (isect >= be->be_f_offset) { + /* We have found an extent */ + dprintk("%s Get %p (%i)\n", __func__, be, + atomic_read(&be->be_refcnt.refcount)); + kref_get(&be->be_refcnt); + if (!ret) + ret = be; + else if (be->be_state != PNFS_BLOCK_READ_DATA) + put_extent(be); + else + cow = be; + break; + } + } + } + spin_unlock(&bl->bl_ext_lock); + if (cow_read) + *cow_read = cow; + print_bl_extent(ret); + return ret; +} -- 1.7.4.1