Return-Path: Received: from mx2.netapp.com ([216.240.18.37]:34588 "EHLO mx2.netapp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752817Ab1AFLg4 (ORCPT ); Thu, 6 Jan 2011 06:36:56 -0500 From: Fred Isaman To: linux-nfs@vger.kernel.org Cc: Trond Myklebust Subject: [PATCH 08/15] pnfs: serialize LAYOUTGET(openstateid) Date: Thu, 6 Jan 2011 06:36:25 -0500 Message-Id: <1294313792-14280-9-git-send-email-iisaman@netapp.com> In-Reply-To: <1294313792-14280-1-git-send-email-iisaman@netapp.com> References: <1294313792-14280-1-git-send-email-iisaman@netapp.com> Sender: linux-nfs-owner@vger.kernel.org List-ID: Content-Type: text/plain MIME-Version: 1.0 We shouldn't send a LAYOUTGET(openstateid) unless all outstanding RPCs using the previous stateid are completed. This requires choosing the stateid to encode earlier, so we can abort if one is not available (we want to use the open stateid, but a LAYOUTGET is already out using it), and adding a count of the number of outstanding rpc calls using layout state (which for now consist solely of LAYOUTGETs). Signed-off-by: Fred Isaman --- fs/nfs/nfs4proc.c | 7 ++++++- fs/nfs/nfs4xdr.c | 5 +---- fs/nfs/pnfs.c | 24 +++++++++++++++++++----- fs/nfs/pnfs.h | 1 + include/linux/nfs_xdr.h | 1 + 5 files changed, 28 insertions(+), 10 deletions(-) diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c index 5bee453..a3549ce 100644 --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -5304,6 +5304,12 @@ nfs4_layoutget_prepare(struct rpc_task *task, void *calldata) if (nfs4_setup_sequence(server, &lgp->args.seq_args, &lgp->res.seq_res, 0, task)) return; + if (pnfs_choose_layoutget_stateid(&lgp->args.stateid, + NFS_I(lgp->args.inode)->layout, + lgp->args.ctx->state)) { + rpc_exit(task, NFS4_OK); + return; + } rpc_call_start(task); } @@ -5338,7 +5344,6 @@ static void nfs4_layoutget_release(void *calldata) struct nfs4_layoutget *lgp = calldata; dprintk("--> %s\n", __func__); - put_layout_hdr(lgp->args.inode); if (lgp->res.layout.buf != NULL) free_page((unsigned long) lgp->res.layout.buf); put_nfs_open_context(lgp->args.ctx); diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c index 4e28242..3cbdd0c 100644 --- a/fs/nfs/nfs4xdr.c +++ b/fs/nfs/nfs4xdr.c @@ -1787,7 +1787,6 @@ encode_layoutget(struct xdr_stream *xdr, const struct nfs4_layoutget_args *args, struct compound_hdr *hdr) { - nfs4_stateid stateid; __be32 *p; p = reserve_space(xdr, 44 + NFS4_STATEID_SIZE); @@ -1798,9 +1797,7 @@ encode_layoutget(struct xdr_stream *xdr, p = xdr_encode_hyper(p, args->range.offset); p = xdr_encode_hyper(p, args->range.length); p = xdr_encode_hyper(p, args->minlength); - pnfs_choose_layoutget_stateid(&stateid, NFS_I(args->inode)->layout, - args->ctx->state); - p = xdr_encode_opaque_fixed(p, &stateid.data, NFS4_STATEID_SIZE); + p = xdr_encode_opaque_fixed(p, &args->stateid.data, NFS4_STATEID_SIZE); *p = cpu_to_be32(args->maxcount); dprintk("%s: 1st type:0x%x iomode:%d off:%lu len:%lu mc:%d\n", diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c index 212cbc2..59ed68b 100644 --- a/fs/nfs/pnfs.c +++ b/fs/nfs/pnfs.c @@ -371,6 +371,14 @@ pnfs_set_layout_stateid(struct pnfs_layout_hdr *lo, memcpy(&lo->plh_stateid, &new->stateid, sizeof(new->stateid)); } +/* lget is set to 1 if called from inside send_layoutget call chain */ +static bool +pnfs_layoutgets_blocked(struct pnfs_layout_hdr *lo, int lget) +{ + return (list_empty(&lo->plh_segs) && + (atomic_read(&lo->plh_outstanding) > lget)); +} + int pnfs_choose_layoutget_stateid(nfs4_stateid *dst, struct pnfs_layout_hdr *lo, struct nfs4_state *open_state) @@ -379,7 +387,9 @@ pnfs_choose_layoutget_stateid(nfs4_stateid *dst, struct pnfs_layout_hdr *lo, dprintk("--> %s\n", __func__); spin_lock(&lo->plh_inode->i_lock); - if (list_empty(&lo->plh_segs)) { + if (pnfs_layoutgets_blocked(lo, 1)) { + status = -EAGAIN; + } else if (list_empty(&lo->plh_segs)) { int seq; do { @@ -414,10 +424,8 @@ send_layoutget(struct pnfs_layout_hdr *lo, BUG_ON(ctx == NULL); lgp = kzalloc(sizeof(*lgp), GFP_KERNEL); - if (lgp == NULL) { - put_layout_hdr(lo->plh_inode); + if (lgp == NULL) return NULL; - } lgp->args.minlength = NFS4_MAX_UINT64; lgp->args.maxcount = PNFS_LAYOUT_MAXSIZE; lgp->args.range.iomode = iomode; @@ -613,10 +621,16 @@ pnfs_update_layout(struct inode *ino, if (test_bit(lo_fail_bit(iomode), &nfsi->layout->plh_flags)) goto out_unlock; - get_layout_hdr_locked(lo); /* Matched in nfs4_layoutget_release */ + if (pnfs_layoutgets_blocked(lo, 0)) + goto out_unlock; + atomic_inc(&lo->plh_outstanding); + + get_layout_hdr_locked(lo); spin_unlock(&ino->i_lock); lseg = send_layoutget(lo, ctx, iomode); + atomic_dec(&lo->plh_outstanding); + put_layout_hdr(ino); out: dprintk("%s end, state 0x%lx lseg %p\n", __func__, nfsi->layout->plh_flags, lseg); diff --git a/fs/nfs/pnfs.h b/fs/nfs/pnfs.h index 787253e..698380d 100644 --- a/fs/nfs/pnfs.h +++ b/fs/nfs/pnfs.h @@ -69,6 +69,7 @@ struct pnfs_layout_hdr { struct list_head plh_layouts; /* other client layouts */ struct list_head plh_segs; /* layout segments list */ nfs4_stateid plh_stateid; + atomic_t plh_outstanding; /* number of RPCs out */ unsigned long plh_flags; struct inode *plh_inode; }; diff --git a/include/linux/nfs_xdr.h b/include/linux/nfs_xdr.h index 8fcc542..83d36d3 100644 --- a/include/linux/nfs_xdr.h +++ b/include/linux/nfs_xdr.h @@ -208,6 +208,7 @@ struct nfs4_layoutget_args { struct inode *inode; struct nfs_open_context *ctx; struct nfs4_sequence_args seq_args; + nfs4_stateid stateid; }; struct nfs4_layoutget_res { -- 1.7.2.1