Return-Path: linux-nfs-owner@vger.kernel.org Received: from mail-qa0-f43.google.com ([209.85.216.43]:64211 "EHLO mail-qa0-f43.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753553Ab3IZSlr (ORCPT ); Thu, 26 Sep 2013 14:41:47 -0400 Received: by mail-qa0-f43.google.com with SMTP id k15so4616997qaq.16 for ; Thu, 26 Sep 2013 11:41:47 -0700 (PDT) From: Benny Halevy To: " J. Bruce Fields" Cc: linux-nfs@vger.kernel.org Subject: [PATCH RFC v0 28/49] pnfsd: support layout segment merging Date: Thu, 26 Sep 2013 14:41:45 -0400 Message-Id: <1380220905-13964-1-git-send-email-bhalevy@primarydata.com> In-Reply-To: <52447EA0.7070004@primarydata.com> References: <52447EA0.7070004@primarydata.com> Sender: linux-nfs-owner@vger.kernel.org List-ID: Signed-off-by: Benny Halevy --- fs/nfsd/nfs4pnfsd.c | 75 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 75 insertions(+) diff --git a/fs/nfsd/nfs4pnfsd.c b/fs/nfsd/nfs4pnfsd.c index 386afa3..8d16b85 100644 --- a/fs/nfsd/nfs4pnfsd.c +++ b/fs/nfsd/nfs4pnfsd.c @@ -364,6 +364,66 @@ struct super_block * return id; } +/* + * are two octet ranges overlapping or adjacent? + */ +static bool +lo_seg_mergeable(struct nfsd4_layout_seg *l1, struct nfsd4_layout_seg *l2) +{ + u64 start1 = l1->offset; + u64 end1 = end_offset(start1, l1->length); + u64 start2 = l2->offset; + u64 end2 = end_offset(start2, l2->length); + + /* is end1 == start2 ranges are adjacent */ + return (end2 >= start1) && (end1 >= start2); +} + +static void +extend_layout(struct nfsd4_layout_seg *lo, struct nfsd4_layout_seg *lg) +{ + u64 lo_start = lo->offset; + u64 lo_end = end_offset(lo_start, lo->length); + u64 lg_start = lg->offset; + u64 lg_end = end_offset(lg_start, lg->length); + + /* lo already covers lg? */ + if (lo_start <= lg_start && lg_end <= lo_end) + return; + + /* extend start offset */ + if (lo_start > lg_start) + lo_start = lg_start; + + /* extend end offset */ + if (lo_end < lg_end) + lo_end = lg_end; + + lo->offset = lo_start; + lo->length = (lo_end == NFS4_MAX_UINT64) ? + lo_end : lo_end - lo_start; +} + +static bool +merge_layout(struct nfs4_layout_state *ls, struct nfsd4_layout_seg *seg) +{ + bool ret = false; + struct nfs4_layout *lp; + + spin_lock(&layout_lock); + list_for_each_entry (lp, &ls->ls_layouts, lo_perstate) + if (lp->lo_seg.layout_type == seg->layout_type && + lp->lo_seg.clientid == seg->clientid && + lp->lo_seg.iomode == seg->iomode && + (ret = lo_seg_mergeable(&lp->lo_seg, seg))) { + extend_layout(&lp->lo_seg, seg); + break; + } + spin_unlock(&layout_lock); + + return ret; +} + __be32 nfs4_pnfs_get_layout(struct svc_rqst *rqstp, struct nfsd4_pnfs_layoutget *lgp, @@ -373,6 +433,7 @@ struct super_block * __be32 nfserr; struct inode *ino = lgp->lg_fhp->fh_dentry->d_inode; struct super_block *sb = ino->i_sb; + int can_merge; struct nfs4_file *fp; struct nfs4_client *clp; struct nfs4_layout *lp = NULL; @@ -412,6 +473,9 @@ struct super_block * goto out; } + can_merge = sb->s_pnfs_op->can_merge_layouts != NULL && + sb->s_pnfs_op->can_merge_layouts(lgp->lg_seg.layout_type); + nfs4_lock_state(); fp = find_alloc_file(ino, lgp->lg_fhp); clp = find_confirmed_client((clientid_t *)&lgp->lg_seg.clientid, true, @@ -430,6 +494,9 @@ struct super_block * if (nfserr) goto out_unlock; + /* pre-alloc layout in case we can't merge after we call + * the file system + */ lp = alloc_layout(); if (!lp) { nfserr = nfserr_layouttrylater; @@ -486,6 +553,14 @@ struct super_block * lgp->lg_seg = res.lg_seg; lgp->lg_roc = res.lg_return_on_close; + /* SUCCESS! + * Can the new layout be merged into an existing one? + * If so, free unused layout struct + */ + if (can_merge && merge_layout(ls, &res.lg_seg)) + goto out_freelayout; + + /* Can't merge, so let's initialize this new layout */ init_layout(lp, ls, lgp->lg_fhp, &res.lg_seg, &lgp->lg_sid); out_unlock: if (ls) -- 1.8.3.1