2011-06-13 22:54:56

by Fred Isaman

Subject: [PATCH 1/1] nfs4.1: fix several problems with _pnfs_return_layout

_pnfs_return_layout had the following problems:

- it did not call pnfs_free_lseg_list on all paths
- it unintentionally did a forgetful return when there was no outstanding io
- it raced with concurrent LAYOUTGETS

Signed-off-by: Fred Isaman <[email protected]>
---
fs/nfs/nfs4proc.c | 8 ++++----
fs/nfs/pnfs.c | 8 +++++---
2 files changed, 9 insertions(+), 7 deletions(-)

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index bc78597..2b2f51b 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -5757,6 +5757,7 @@ static void nfs4_layoutreturn_done(struct rpc_task *task, void *calldata)
{
struct nfs4_layoutreturn *lrp = calldata;
struct nfs_server *server;
+ struct pnfs_layout_hdr *lo = NFS_I(lrp->args.inode)->layout;

dprintk("--> %s\n", __func__);

@@ -5768,16 +5769,15 @@ static void nfs4_layoutreturn_done(struct rpc_task *task, void *calldata)
nfs_restart_rpc(task, lrp->clp);
return;
}
+ spin_lock(&lo->plh_inode->i_lock);
if (task->tk_status == 0) {
- struct pnfs_layout_hdr *lo = NFS_I(lrp->args.inode)->layout;
-
if (lrp->res.lrs_present) {
- spin_lock(&lo->plh_inode->i_lock);
pnfs_set_layout_stateid(lo, &lrp->res.stateid, true);
- spin_unlock(&lo->plh_inode->i_lock);
} else
BUG_ON(!list_empty(&lo->plh_segs));
}
+ lo->plh_block_lgets--;
+ spin_unlock(&lo->plh_inode->i_lock);
dprintk("<-- %s\n", __func__);
}

diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
index 8ff8c1b..1abb300 100644
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -640,12 +640,14 @@ _pnfs_return_layout(struct inode *ino)

spin_lock(&ino->i_lock);
lo = nfsi->layout;
- if (!lo || !mark_matching_lsegs_invalid(lo, &tmp_list, NULL)) {
+ if (!lo) {
spin_unlock(&ino->i_lock);
- dprintk("%s: no layout segments to return\n", __func__);
- goto out;
+ dprintk("%s: no layout to return\n", __func__);
+ return status;
}
stateid = nfsi->layout->plh_stateid;
+ mark_matching_lsegs_invalid(lo, &tmp_list, NULL);
+ lo->plh_block_lgets++;
/* Reference matched in nfs4_layoutreturn_release */
get_layout_hdr(lo);
spin_unlock(&ino->i_lock);
--
1.7.2.1

2011-06-14 14:55:46

by Benny Halevy

Subject: Re: [PATCH 1/1] nfs4.1: fix several problems with _pnfs_return_layout

On 2011-06-13 18:54, Fred Isaman wrote:
> _pnfs_return_layout had the following problems:
>
> - it did not call pnfs_free_lseg_list on all paths
> - it unintentionally did a forgetful return when there was no outstanding io
> - it raced with concurrent LAYOUTGETS
>
> Signed-off-by: Fred Isaman <[email protected]>

ACK

Benny

> ---
> fs/nfs/nfs4proc.c | 8 ++++----
> fs/nfs/pnfs.c | 8 +++++---
> 2 files changed, 9 insertions(+), 7 deletions(-)
>
> diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
> index bc78597..2b2f51b 100644
> --- a/fs/nfs/nfs4proc.c
> +++ b/fs/nfs/nfs4proc.c
> @@ -5757,6 +5757,7 @@ static void nfs4_layoutreturn_done(struct rpc_task *task, void *calldata)
> {
> struct nfs4_layoutreturn *lrp = calldata;
> struct nfs_server *server;
> + struct pnfs_layout_hdr *lo = NFS_I(lrp->args.inode)->layout;
>
> dprintk("--> %s\n", __func__);
>
> @@ -5768,16 +5769,15 @@ static void nfs4_layoutreturn_done(struct rpc_task *task, void *calldata)
> nfs_restart_rpc(task, lrp->clp);
> return;
> }
> + spin_lock(&lo->plh_inode->i_lock);
> if (task->tk_status == 0) {
> - struct pnfs_layout_hdr *lo = NFS_I(lrp->args.inode)->layout;
> -
> if (lrp->res.lrs_present) {
> - spin_lock(&lo->plh_inode->i_lock);
> pnfs_set_layout_stateid(lo, &lrp->res.stateid, true);
> - spin_unlock(&lo->plh_inode->i_lock);
> } else
> BUG_ON(!list_empty(&lo->plh_segs));
> }
> + lo->plh_block_lgets--;
> + spin_unlock(&lo->plh_inode->i_lock);
> dprintk("<-- %s\n", __func__);
> }
>
> diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
> index 8ff8c1b..1abb300 100644
> --- a/fs/nfs/pnfs.c
> +++ b/fs/nfs/pnfs.c
> @@ -640,12 +640,14 @@ _pnfs_return_layout(struct inode *ino)
>
> spin_lock(&ino->i_lock);
> lo = nfsi->layout;
> - if (!lo || !mark_matching_lsegs_invalid(lo, &tmp_list, NULL)) {
> + if (!lo) {
> spin_unlock(&ino->i_lock);
> - dprintk("%s: no layout segments to return\n", __func__);
> - goto out;
> + dprintk("%s: no layout to return\n", __func__);
> + return status;
> }
> stateid = nfsi->layout->plh_stateid;
> + mark_matching_lsegs_invalid(lo, &tmp_list, NULL);
> + lo->plh_block_lgets++;
> /* Reference matched in nfs4_layoutreturn_release */
> get_layout_hdr(lo);
> spin_unlock(&ino->i_lock);

--
Benny Halevy
CTO, Tonian Inc.

Tel: +972-54-802-8340
[email protected]