Re: [PATCH 1/4] NFS/localio: Stop further I/O upon hitting an error

[Mike Snitzer <snitzer@kernel.org>]

On Sat, Jan 03, 2026 at 12:14:57PM -0500, Trond Myklebust wrote:
> From: Trond Myklebust <trond.myklebust@hammerspace.com>
> 
> If the call into the filesystem results in an I/O error, then the next
> chunk of data won't be contiguous with the end of the last successful
> chunk. So break out of the I/O loop and report the results.
> Currently the localio code will do this for a short read/write, but not
> for an error.
> 
> Fixes: 6a218b9c3183 ("nfs/localio: do not issue misaligned DIO out-of-order")
> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

Thanks, definitely cleaner to not have the awkward force_done flag,
sorry for that nastiness.

But this one needs to be rebased on tip of linus' master due to commit
3af870aedbff ("nfs/localio: fix regression due to out-of-order
__put_cred") which landed after the 6.19 merge.

Like so:

From: Trond Myklebust <trond.myklebust@hammerspace.com>
Date: Sat, 3 Jan 2026 12:14:57 -0500
Subject: [PATCH] NFS/localio: Stop further I/O upon hitting an error

If the call into the filesystem results in an I/O error, then the next
chunk of data won't be contiguous with the end of the last successful
chunk. So break out of the I/O loop and report the results.
Currently the localio code will do this for a short read/write, but not
for an error.

Fixes: 6a218b9c3183 ("nfs/localio: do not issue misaligned DIO out-of-order")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Reviewed-by: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
---
 fs/nfs/localio.c | 30 ++++++++++++++----------------
 1 file changed, 14 insertions(+), 16 deletions(-)

diff --git a/fs/nfs/localio.c b/fs/nfs/localio.c
index ed2a7efaf8f20..97e4733d04714 100644
--- a/fs/nfs/localio.c
+++ b/fs/nfs/localio.c
@@ -619,7 +619,6 @@ static void nfs_local_call_read(struct work_struct *work)
 		container_of(work, struct nfs_local_kiocb, work);
 	struct file *filp = iocb->kiocb.ki_filp;
 	const struct cred *save_cred;
-	bool force_done = false;
 	ssize_t status;
 	int n_iters;
 
@@ -639,13 +638,13 @@ static void nfs_local_call_read(struct work_struct *work)
 		status = filp->f_op->read_iter(&iocb->kiocb, &iocb->iters[i]);
 		revert_creds(save_cred);
 
-		if (status != -EIOCBQUEUED) {
-			if (unlikely(status >= 0 && status < iocb->iters[i].count))
-				force_done = true; /* Partial read */
-			if (nfs_local_pgio_done(iocb, status, force_done)) {
-				nfs_local_read_iocb_done(iocb);
-				break;
-			}
+		if (status == -EIOCBQUEUED)
+			continue;
+		/* Break on completion, errors, or short reads */
+		if (nfs_local_pgio_done(iocb, status, false) || status < 0 ||
+		    (size_t)status < iov_iter_count(&iocb->iters[i])) {
+			nfs_local_read_iocb_done(iocb);
+			break;
 		}
 	}
 }
@@ -824,7 +823,6 @@ static void nfs_local_call_write(struct work_struct *work)
 	struct file *filp = iocb->kiocb.ki_filp;
 	unsigned long old_flags = current->flags;
 	const struct cred *save_cred;
-	bool force_done = false;
 	ssize_t status;
 	int n_iters;
 
@@ -847,13 +845,13 @@ static void nfs_local_call_write(struct work_struct *work)
 		status = filp->f_op->write_iter(&iocb->kiocb, &iocb->iters[i]);
 		revert_creds(save_cred);
 
-		if (status != -EIOCBQUEUED) {
-			if (unlikely(status >= 0 && status < iocb->iters[i].count))
-				force_done = true; /* Partial write */
-			if (nfs_local_pgio_done(iocb, status, force_done)) {
-				nfs_local_write_iocb_done(iocb);
-				break;
-			}
+		if (status == -EIOCBQUEUED)
+			continue;
+		/* Break on completion, errors, or short writes */
+		if (nfs_local_pgio_done(iocb, status, false) || status < 0 ||
+		    (size_t)status < iov_iter_count(&iocb->iters[i])) {
+			nfs_local_write_iocb_done(iocb);
+			break;
 		}
 	}
 	file_end_write(filp);
-- 
2.44.0