[PATCH 5.2 106/143] Revert "NFSv4/flexfiles: Abort I/O early if the layout segment was invalidated"

[Greg Kroah-Hartman]

From: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>

commit d5711920ec6e578f51db95caa6f185f5090b865e upstream.

This reverts commit a79f194aa4879e9baad118c3f8bb2ca24dbef765.
The mechanism for aborting I/O is racy, since we are not guaranteed that
the request is asleep while we're changing both task->tk_status and
task->tk_action.

Signed-off-by: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx # v5.1
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 fs/nfs/flexfilelayout/flexfilelayout.c |   17 -----------------
 include/linux/sunrpc/sched.h           |    1 -
 net/sunrpc/xprt.c                      |    7 -------
 3 files changed, 25 deletions(-)

--- a/fs/nfs/flexfilelayout/flexfilelayout.c
+++ b/fs/nfs/flexfilelayout/flexfilelayout.c
@@ -1128,8 +1128,6 @@ static int ff_layout_async_handle_error_
 		break;
 	case -NFS4ERR_RETRY_UNCACHED_REP:
 		break;
-	case -EAGAIN:
-		return -NFS4ERR_RESET_TO_PNFS;
 	/* Invalidate Layout errors */
 	case -NFS4ERR_PNFS_NO_LAYOUT:
 	case -ESTALE:           /* mapped NFS4ERR_STALE */
@@ -1190,7 +1188,6 @@ static int ff_layout_async_handle_error_
 	case -EBADHANDLE:
 	case -ELOOP:
 	case -ENOSPC:
-	case -EAGAIN:
 		break;
 	case -EJUKEBOX:
 		nfs_inc_stats(lseg->pls_layout->plh_inode, NFSIOS_DELAY);
@@ -1425,16 +1422,6 @@ static void ff_layout_read_prepare_v4(st
 	ff_layout_read_prepare_common(task, hdr);
 }
 
-static void
-ff_layout_io_prepare_transmit(struct rpc_task *task,
-		void *data)
-{
-	struct nfs_pgio_header *hdr = data;
-
-	if (!pnfs_is_valid_lseg(hdr->lseg))
-		rpc_exit(task, -EAGAIN);
-}
-
 static void ff_layout_read_call_done(struct rpc_task *task, void *data)
 {
 	struct nfs_pgio_header *hdr = data;
@@ -1720,7 +1707,6 @@ static void ff_layout_commit_release(voi
 
 static const struct rpc_call_ops ff_layout_read_call_ops_v3 = {
 	.rpc_call_prepare = ff_layout_read_prepare_v3,
-	.rpc_call_prepare_transmit = ff_layout_io_prepare_transmit,
 	.rpc_call_done = ff_layout_read_call_done,
 	.rpc_count_stats = ff_layout_read_count_stats,
 	.rpc_release = ff_layout_read_release,
@@ -1728,7 +1714,6 @@ static const struct rpc_call_ops ff_layo
 
 static const struct rpc_call_ops ff_layout_read_call_ops_v4 = {
 	.rpc_call_prepare = ff_layout_read_prepare_v4,
-	.rpc_call_prepare_transmit = ff_layout_io_prepare_transmit,
 	.rpc_call_done = ff_layout_read_call_done,
 	.rpc_count_stats = ff_layout_read_count_stats,
 	.rpc_release = ff_layout_read_release,
@@ -1736,7 +1721,6 @@ static const struct rpc_call_ops ff_layo
 
 static const struct rpc_call_ops ff_layout_write_call_ops_v3 = {
 	.rpc_call_prepare = ff_layout_write_prepare_v3,
-	.rpc_call_prepare_transmit = ff_layout_io_prepare_transmit,
 	.rpc_call_done = ff_layout_write_call_done,
 	.rpc_count_stats = ff_layout_write_count_stats,
 	.rpc_release = ff_layout_write_release,
@@ -1744,7 +1728,6 @@ static const struct rpc_call_ops ff_layo
 
 static const struct rpc_call_ops ff_layout_write_call_ops_v4 = {
 	.rpc_call_prepare = ff_layout_write_prepare_v4,
-	.rpc_call_prepare_transmit = ff_layout_io_prepare_transmit,
 	.rpc_call_done = ff_layout_write_call_done,
 	.rpc_count_stats = ff_layout_write_count_stats,
 	.rpc_release = ff_layout_write_release,
--- a/include/linux/sunrpc/sched.h
+++ b/include/linux/sunrpc/sched.h
@@ -98,7 +98,6 @@ typedef void			(*rpc_action)(struct rpc_
 
 struct rpc_call_ops {
 	void (*rpc_call_prepare)(struct rpc_task *, void *);
-	void (*rpc_call_prepare_transmit)(struct rpc_task *, void *);
 	void (*rpc_call_done)(struct rpc_task *, void *);
 	void (*rpc_count_stats)(struct rpc_task *, void *);
 	void (*rpc_release)(void *);
--- a/net/sunrpc/xprt.c
+++ b/net/sunrpc/xprt.c
@@ -1380,13 +1380,6 @@ xprt_request_transmit(struct rpc_rqst *r
 			status = -EBADMSG;
 			goto out_dequeue;
 		}
-		if (task->tk_ops->rpc_call_prepare_transmit) {
-			task->tk_ops->rpc_call_prepare_transmit(task,
-					task->tk_calldata);
-			status = task->tk_status;
-			if (status < 0)
-				goto out_dequeue;
-		}
 		if (RPC_SIGNALLED(task)) {
 			status = -ERESTARTSYS;
 			goto out_dequeue;