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 | 37 ++++++++++++++++++-------------------
fs/nfs/pnfs.h | 3 +++
include/linux/nfs_fs.h | 1 +
5 files changed, 45 insertions(+), 22 deletions(-)
diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index 7621cfc..059bdf7 100644
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -1462,6 +1462,7 @@ static inline void nfs4_init_once(struct nfs_inode *nfsi)
init_rwsem(&nfsi->rwsem);
#ifdef CONFIG_NFS_V4_1
init_waitqueue_head(&nfsi->lo_waitq);
+ rpc_init_wait_queue(&nfsi->lo_rpcwaitq, "pNFS Layout");
nfsi->pnfs_layout_suspend = 0;
nfsi->layout = NULL;
#endif /* CONFIG_NFS_V4_1 */
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 48a763e..f12568d 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -5442,13 +5442,32 @@ 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 bc4f0c1..2450383 100644
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -430,7 +430,7 @@ destroy_lseg(struct kref *kref)
PNFS_LD_IO_OPS(lseg->layout)->free_lseg(lseg);
}
-static void
+void
put_lseg_locked(struct pnfs_layout_segment *lseg)
{
bool do_wake_up;
@@ -444,8 +444,10 @@ put_lseg_locked(struct pnfs_layout_segment *lseg)
do_wake_up = !lseg->valid;
nfsi = PNFS_NFS_INODE(lseg->layout);
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);
+ }
}
void
@@ -999,7 +1001,7 @@ has_matching_lseg(struct pnfs_layout_segment *lseg,
/*
* lookup range in layout
*/
-static struct pnfs_layout_segment *
+struct pnfs_layout_segment *
pnfs_has_layout(struct pnfs_layout_hdr *lo,
struct pnfs_layout_range *range)
{
@@ -1057,22 +1059,20 @@ _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);
- /* someone is cleaning the layout */
- lseg = NULL;
- goto out_unlock;
- }
-
if (lseg) {
- dprintk("%s: Using cached lseg %p for %llu@%llu iomode %d)\n",
- __func__,
- lseg,
- arg.length,
- arg.offset,
- arg.iomode);
+ 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;
+ goto out_unlock;
+ }
+ /* someone is cleaning the layout */
+ put_lseg_locked(lseg);
}
/* if get layout already failed once goto out */
@@ -1097,8 +1097,7 @@ out:
nfsi->layout->state, lseg);
return;
out_unlock:
- if (lsegpp)
- *lsegpp = lseg;
+ *lsegpp = lseg;
spin_unlock(&ino->i_lock);
goto out;
}
diff --git a/fs/nfs/pnfs.h b/fs/nfs/pnfs.h
index ea70385..f7f567e 100644
--- a/fs/nfs/pnfs.h
+++ b/fs/nfs/pnfs.h
@@ -34,6 +34,9 @@ extern int nfs4_proc_layoutreturn(struct nfs4_layoutreturn *lrp, bool wait);
/* pnfs.c */
extern const nfs4_stateid zero_stateid;
+void put_lseg_locked(struct pnfs_layout_segment *);
+struct pnfs_layout_segment *pnfs_has_layout(struct pnfs_layout_hdr *,
+ struct pnfs_layout_range *);
void _pnfs_update_layout(struct inode *ino, struct nfs_open_context *ctx,
loff_t pos, u64 count, enum pnfs_iomode access_type,
struct pnfs_layout_segment **lsegpp);
diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h
index 5bafa95..196c0c6 100644
--- a/include/linux/nfs_fs.h
+++ b/include/linux/nfs_fs.h
@@ -213,6 +213,7 @@ struct nfs_inode {
/* pNFS layout information */
#if defined(CONFIG_NFS_V4_1)
wait_queue_head_t lo_waitq;
+ struct rpc_wait_queue lo_rpcwaitq;
struct pnfs_layout_hdr *layout;
time_t pnfs_layout_suspend;
#endif /* CONFIG_NFS_V4_1 */
--
1.7.2.2
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