[PATCH 6.1 3/6] Revert "NFS: More O_DIRECT accounting fixes for error paths"

[Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>]

6.1-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

This reverts commit 1f49386d67792424028acfe781d466b010f8fa3f which is
commit 8982f7aff39fb526aba4441fff2525fcedd5e1a3 upstream.

There are reported NFS problems in the 6.1.56 release, so revert a set
of NFS patches to hopefully resolve the issue.

Reported-by: poester <poester@xxxxxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20231012165439.137237-2-kernel@xxxxxxxxxxxx
Reported-by: Daniel Díaz <daniel.diaz@xxxxxxxxxx>
Link: https://lore.kernel.org/r/2023100755-livestock-barcode-fe41@gregkh
Cc: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
Cc: Anna Schumaker <Anna.Schumaker@xxxxxxxxxx>
Cc: Sasha Levin <sashal@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 fs/nfs/direct.c |   47 ++++++++++++++++-------------------------------
 1 file changed, 16 insertions(+), 31 deletions(-)

--- a/fs/nfs/direct.c
+++ b/fs/nfs/direct.c
@@ -93,10 +93,12 @@ nfs_direct_handle_truncated(struct nfs_d
 		dreq->max_count = dreq_len;
 		if (dreq->count > dreq_len)
 			dreq->count = dreq_len;
-	}
 
-	if (test_bit(NFS_IOHDR_ERROR, &hdr->flags) && !dreq->error)
-		dreq->error = hdr->error;
+		if (test_bit(NFS_IOHDR_ERROR, &hdr->flags))
+			dreq->error = hdr->error;
+		else /* Clear outstanding error if this is EOF */
+			dreq->error = 0;
+	}
 }
 
 static void
@@ -118,18 +120,6 @@ nfs_direct_count_bytes(struct nfs_direct
 		dreq->count = dreq_len;
 }
 
-static void nfs_direct_truncate_request(struct nfs_direct_req *dreq,
-					struct nfs_page *req)
-{
-	loff_t offs = req_offset(req);
-	size_t req_start = (size_t)(offs - dreq->io_start);
-
-	if (req_start < dreq->max_count)
-		dreq->max_count = req_start;
-	if (req_start < dreq->count)
-		dreq->count = req_start;
-}
-
 /**
  * nfs_swap_rw - NFS address space operation for swap I/O
  * @iocb: target I/O control block
@@ -549,6 +539,10 @@ static void nfs_direct_write_reschedule(
 
 	nfs_direct_join_group(&reqs, dreq->inode);
 
+	dreq->count = 0;
+	dreq->max_count = 0;
+	list_for_each_entry(req, &reqs, wb_list)
+		dreq->max_count += req->wb_bytes;
 	nfs_clear_pnfs_ds_commit_verifiers(&dreq->ds_cinfo);
 	get_dreq(dreq);
 
@@ -582,14 +576,10 @@ static void nfs_direct_write_reschedule(
 		req = nfs_list_entry(reqs.next);
 		nfs_list_remove_request(req);
 		nfs_unlock_and_release_request(req);
-		if (desc.pg_error == -EAGAIN) {
+		if (desc.pg_error == -EAGAIN)
 			nfs_mark_request_commit(req, NULL, &cinfo, 0);
-		} else {
-			spin_lock(&dreq->lock);
-			nfs_direct_truncate_request(dreq, req);
-			spin_unlock(&dreq->lock);
+		else
 			nfs_release_request(req);
-		}
 	}
 
 	if (put_dreq(dreq))
@@ -609,6 +599,8 @@ static void nfs_direct_commit_complete(s
 	if (status < 0) {
 		/* Errors in commit are fatal */
 		dreq->error = status;
+		dreq->max_count = 0;
+		dreq->count = 0;
 		dreq->flags = NFS_ODIRECT_DONE;
 	} else {
 		status = dreq->error;
@@ -619,12 +611,7 @@ static void nfs_direct_commit_complete(s
 	while (!list_empty(&data->pages)) {
 		req = nfs_list_entry(data->pages.next);
 		nfs_list_remove_request(req);
-		if (status < 0) {
-			spin_lock(&dreq->lock);
-			nfs_direct_truncate_request(dreq, req);
-			spin_unlock(&dreq->lock);
-			nfs_release_request(req);
-		} else if (!nfs_write_match_verf(verf, req)) {
+		if (status >= 0 && !nfs_write_match_verf(verf, req)) {
 			dreq->flags = NFS_ODIRECT_RESCHED_WRITES;
 			/*
 			 * Despite the reboot, the write was successful,
@@ -632,7 +619,7 @@ static void nfs_direct_commit_complete(s
 			 */
 			req->wb_nio = 0;
 			nfs_mark_request_commit(req, NULL, &cinfo, 0);
-		} else
+		} else /* Error or match */
 			nfs_release_request(req);
 		nfs_unlock_and_release_request(req);
 	}
@@ -685,7 +672,6 @@ static void nfs_direct_write_clear_reqs(
 	while (!list_empty(&reqs)) {
 		req = nfs_list_entry(reqs.next);
 		nfs_list_remove_request(req);
-		nfs_direct_truncate_request(dreq, req);
 		nfs_release_request(req);
 		nfs_unlock_and_release_request(req);
 	}
@@ -735,8 +721,7 @@ static void nfs_direct_write_completion(
 	}
 
 	nfs_direct_count_bytes(dreq, hdr);
-	if (test_bit(NFS_IOHDR_UNSTABLE_WRITES, &hdr->flags) &&
-	    !test_bit(NFS_IOHDR_ERROR, &hdr->flags)) {
+	if (test_bit(NFS_IOHDR_UNSTABLE_WRITES, &hdr->flags)) {
 		if (!dreq->flags)
 			dreq->flags = NFS_ODIRECT_DO_COMMIT;
 		flags = dreq->flags;