Introduce lo_rpcwaitq and sleep on it while there's an lseg marked invalid,
i.e. it is being returned (in the future, it could also be layoutget in progress).
Signed-off-by: Benny Halevy <bhalevy@xxxxxxxxxxx>
---
fs/nfs/inode.c | 1 +
fs/nfs/nfs4proc.c | 25 ++++++++++++++++++++++---
fs/nfs/pnfs.c | 26 ++++++++++++++++----------
include/linux/nfs_fs.h | 1 +
4 files changed, 40 insertions(+), 13 deletions(-)
diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index 8cdea1a..e3d44a9 100644
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -1459,6 +1459,7 @@ static inline void nfs4_init_once(struct nfs_inode *nfsi)
nfsi->delegation_state = 0;
init_rwsem(&nfsi->rwsem);
init_waitqueue_head(&nfsi->lo_waitq);
+ rpc_init_wait_queue(&nfsi->lo_rpcwaitq, "pNFS Layout");
nfsi->layout = NULL;
#endif
}
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index cd87704..ebf5127 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -5426,13 +5426,32 @@ nfs4_layoutget_prepare(struct rpc_task *task, void *calldata)
{
struct nfs4_layoutget *lgp = calldata;
struct inode *ino = lgp->args.inode;
+ struct nfs_inode *nfsi = NFS_I(ino);
struct nfs_server *server = NFS_SERVER(ino);
+ struct pnfs_layout_segment *lseg;
dprintk("--> %s\n", __func__);
- if (nfs4_setup_sequence(server, NULL, &lgp->args.seq_args,
- &lgp->res.seq_res, 0, task))
+ spin_lock(&ino->i_lock);
+ lseg = pnfs_has_layout(nfsi->layout, &lgp->args.range);
+ if (likely(!lseg)) {
+ spin_unlock(&ino->i_lock);
+ dprintk("%s: no lseg found, proceeding\n", __func__);
+ if (!nfs4_setup_sequence(server, NULL, &lgp->args.seq_args,
+ &lgp->res.seq_res, 0, task))
+ rpc_call_start(task);
return;
- rpc_call_start(task);
+ }
+ if (!lseg->valid) {
+ put_lseg_locked(lseg);
+ spin_unlock(&ino->i_lock);
+ dprintk("%s: invalid lseg found, waiting\n", __func__);
+ rpc_sleep_on(&nfsi->lo_rpcwaitq, task, NULL);
+ return;
+ }
+ *lgp->lsegpp = lseg;
+ spin_unlock(&ino->i_lock);
+ dprintk("%s: valid lseg found, no rpc required\n", __func__);
+ rpc_exit(task, NFS4_OK);
}
static void nfs4_layoutget_done(struct rpc_task *task, void *calldata)
diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
index 8339444..31a703d 100644
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -315,8 +315,10 @@ put_lseg_locked(struct pnfs_layout_segment *lseg)
do_wake_up = !lseg->valid;
nfsi = NFS_I(lseg->layout->inode);
kref_put(&lseg->kref, destroy_lseg);
- if (do_wake_up)
+ if (do_wake_up) {
wake_up(&nfsi->lo_waitq);
+ rpc_wake_up(&nfsi->lo_rpcwaitq);
+ }
}
EXPORT_SYMBOL_GPL(put_lseg_locked);
@@ -975,17 +977,21 @@ pnfs_update_layout(struct inode *ino,
/* Check to see if the layout for the given range already exists */
lseg = pnfs_has_layout(lo, &arg);
- if (lseg && !lseg->valid) {
- put_lseg_locked(lseg);
+ if (lseg) {
+ if (lseg->valid) {
+ dprintk("%s: Using cached lseg %p for %llu@%llu "
+ "iomode %d)\n",
+ __func__,
+ lseg,
+ arg.length,
+ arg.offset,
+ arg.iomode);
+
+ goto out_unlock;
+ }
/* someone is cleaning the layout */
+ put_lseg_locked(lseg);
lseg = NULL;
- goto out_unlock;
- }
-
- if (lseg) {
- dprintk("%s: Using cached lseg %p for iomode %d)\n",
- __func__, lseg, iomode);
- goto out_unlock;
}
/* if LAYOUTGET already failed once we don't try again */
diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h
index 3184e63..1af18fd 100644
--- a/include/linux/nfs_fs.h
+++ b/include/linux/nfs_fs.h
@@ -191,6 +191,7 @@ struct nfs_inode {
/* pNFS layout information */
wait_queue_head_t lo_waitq;
+ struct rpc_wait_queue lo_rpcwaitq;
struct pnfs_layout_hdr *layout;
#endif /* CONFIG_NFS_V4*/
#ifdef CONFIG_NFS_FSCACHE
--
1.7.2.3
--
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