The patch below does not apply to the 4.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From eb2c50da9e256dbbb3ff27694440e4c1900cfef8 Mon Sep 17 00:00:00 2001

From: Trond Myklebust trond.myklebust@hammerspace.com Date: Mon, 12 Aug 2019 18:04:36 -0400 Subject: [PATCH] NFS: Ensure O_DIRECT reports an error if the bytes read/written is 0

If the attempt to resend the I/O results in no bytes being read/written, we must ensure that we report the error.

Signed-off-by: Trond Myklebust trond.myklebust@hammerspace.com Fixes: 0a00b77b331a ("nfs: mirroring support for direct io") Cc: stable@vger.kernel.org # v3.20+

diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c index 0cb442406168..222d7115db71 100644 --- a/fs/nfs/direct.c +++ b/fs/nfs/direct.c @@ -401,15 +401,21 @@ static void nfs_direct_read_completion(struct nfs_pgio_header *hdr) unsigned long bytes = 0; struct nfs_direct_req *dreq = hdr->dreq;

- if (test_bit(NFS_IOHDR_REDO, &hdr->flags)) - goto out_put; - spin_lock(&dreq->lock); - if (test_bit(NFS_IOHDR_ERROR, &hdr->flags) && (hdr->good_bytes == 0)) + if (test_bit(NFS_IOHDR_ERROR, &hdr->flags)) dreq->error = hdr->error; - else + + if (test_bit(NFS_IOHDR_REDO, &hdr->flags)) { + spin_unlock(&dreq->lock); + goto out_put; + } + + if (hdr->good_bytes != 0) nfs_direct_good_bytes(dreq, hdr);

+ if (test_bit(NFS_IOHDR_EOF, &hdr->flags)) + dreq->error = 0; + spin_unlock(&dreq->lock);

while (!list_empty(&hdr->pages)) { @@ -782,16 +788,19 @@ static void nfs_direct_write_completion(struct nfs_pgio_header *hdr) bool request_commit = false; struct nfs_page *req = nfs_list_entry(hdr->pages.next);

- if (test_bit(NFS_IOHDR_REDO, &hdr->flags)) - goto out_put; - nfs_init_cinfo_from_dreq(&cinfo, dreq);

spin_lock(&dreq->lock);

if (test_bit(NFS_IOHDR_ERROR, &hdr->flags)) dreq->error = hdr->error; - if (dreq->error == 0) { + + if (test_bit(NFS_IOHDR_REDO, &hdr->flags)) { + spin_unlock(&dreq->lock); + goto out_put; + } + + if (hdr->good_bytes != 0) { nfs_direct_good_bytes(dreq, hdr); if (nfs_write_need_commit(hdr)) { if (dreq->flags == NFS_ODIRECT_RESCHED_WRITES) diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c index 15c254753f88..56cefa0ab804 100644 --- a/fs/nfs/pagelist.c +++ b/fs/nfs/pagelist.c @@ -1266,6 +1266,7 @@ int nfs_pageio_resend(struct nfs_pageio_descriptor *desc, if (!list_empty(&pages)) { int err = desc->pg_error < 0 ? desc->pg_error : -EIO; hdr->completion_ops->error_cleanup(&pages, err); + nfs_set_pgio_error(hdr, err, hdr->io_start); return err; } return 0;