2018-10-18 00:02:01

by Benjamin Coddington

[permalink] [raw]
Subject: [PATCH 1/2] nfs: remove redundant call to nfs_context_set_write_error()

We don't need to call this in the direct, read, or pnfs resend paths and
the only other caller is the write path in nfs_page_async_flush() which
already checks and sets the pg_error on the context.

Signed-off-by: Benjamin Coddington <[email protected]>
---
fs/nfs/pagelist.c | 5 -----
1 file changed, 5 deletions(-)

diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c
index 67d19cd92e44..cd3bc41ab68d 100644
--- a/fs/nfs/pagelist.c
+++ b/fs/nfs/pagelist.c
@@ -1168,11 +1168,6 @@ int nfs_pageio_add_request(struct nfs_pageio_descriptor *desc,
struct nfs_pgio_mirror *mirror;
void (*func)(struct list_head *);

- /* remember fatal errors */
- if (nfs_error_is_fatal(desc->pg_error))
- nfs_context_set_write_error(req->wb_context,
- desc->pg_error);
-
func = desc->pg_completion_ops->error_cleanup;
for (midx = 0; midx < desc->pg_mirror_count; midx++) {
mirror = &desc->pg_mirrors[midx];
--
2.14.3


2018-10-18 00:02:01

by Benjamin Coddington

[permalink] [raw]
Subject: [PATCH 2/2] nfs: Fix a missed page unlock after pg_doio()

We must check pg_error and call error_cleanup after any call to pg_doio.
Currently, we are skipping the unlock of a page if we encounter an error in
nfs_pageio_complete() before handing off the work to the RPC layer.

Signed-off-by: Benjamin Coddington <[email protected]>
---
fs/nfs/pagelist.c | 33 ++++++++++++++++++---------------
1 file changed, 18 insertions(+), 15 deletions(-)

diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c
index cd3bc41ab68d..54c2bfc45a57 100644
--- a/fs/nfs/pagelist.c
+++ b/fs/nfs/pagelist.c
@@ -1110,6 +1110,20 @@ static int nfs_pageio_add_request_mirror(struct nfs_pageio_descriptor *desc,
return ret;
}

+static void nfs_pageio_error_cleanup(struct nfs_pageio_descriptor *desc)
+{
+ u32 midx;
+ struct nfs_pgio_mirror *mirror;
+
+ if (!desc->pg_error)
+ return;
+
+ for (midx = 0; midx < desc->pg_mirror_count; midx++) {
+ mirror = &desc->pg_mirrors[midx];
+ desc->pg_completion_ops->error_cleanup(&mirror->pg_list);
+ }
+}
+
int nfs_pageio_add_request(struct nfs_pageio_descriptor *desc,
struct nfs_page *req)
{
@@ -1160,20 +1174,7 @@ int nfs_pageio_add_request(struct nfs_pageio_descriptor *desc,
return 1;

out_failed:
- /*
- * We might have failed before sending any reqs over wire.
- * Clean up rest of the reqs in mirror pg_list.
- */
- if (desc->pg_error) {
- struct nfs_pgio_mirror *mirror;
- void (*func)(struct list_head *);
-
- func = desc->pg_completion_ops->error_cleanup;
- for (midx = 0; midx < desc->pg_mirror_count; midx++) {
- mirror = &desc->pg_mirrors[midx];
- func(&mirror->pg_list);
- }
- }
+ nfs_pageio_error_cleanup(desc);
return 0;
}

@@ -1245,7 +1246,9 @@ void nfs_pageio_complete(struct nfs_pageio_descriptor *desc)
for (midx = 0; midx < desc->pg_mirror_count; midx++)
nfs_pageio_complete_mirror(desc, midx);

- if (desc->pg_ops->pg_cleanup)
+ if (desc->pg_error < 0)
+ nfs_pageio_error_cleanup(desc);
+ else if (desc->pg_ops->pg_cleanup)
desc->pg_ops->pg_cleanup(desc);
nfs_pageio_cleanup_mirroring(desc);
}
--
2.14.3

2018-10-17 17:34:48

by Trond Myklebust

[permalink] [raw]
Subject: Re: [PATCH 2/2] nfs: Fix a missed page unlock after pg_doio()

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2018-10-18 02:35:37

by Benjamin Coddington

[permalink] [raw]
Subject: Re: [PATCH 2/2] nfs: Fix a missed page unlock after pg_doio()

On 17 Oct 2018, at 13:34, Trond Myklebust wrote:

> On Wed, 2018-10-17 at 12:05 -0400, Benjamin Coddington wrote:
>> @@ -1245,7 +1246,9 @@ void nfs_pageio_complete(struct
>> nfs_pageio_descriptor *desc)
>> for (midx = 0; midx < desc->pg_mirror_count; midx++)
>> nfs_pageio_complete_mirror(desc, midx);
>>
>> - if (desc->pg_ops->pg_cleanup)
>> + if (desc->pg_error < 0)
>> + nfs_pageio_error_cleanup(desc);
>> + else if (desc->pg_ops->pg_cleanup)
>> desc->pg_ops->pg_cleanup(desc);
>
> Nice catch, but shouldn't we be calling both nfs_pageio_error_cleanup()
> and pg_cleanup()? The former would appear to be cleaning up the page
> stuff, while the latter is mainly cleaning up the layout.

Ah, yes .. I got pg_cleanup mixed up with pg_completion_ops->completion.
Hmm, pg_cleanup seems unnecessary at the moment. They all point to
pnfs_generic_pg_cleanup.

I'll send a v2 after testing with some pNFS..

>
>> nfs_pageio_cleanup_mirroring(desc);
>> }
>
> Should this perhaps be a stable fix?

There's a lot of churn in there so I gave up looking for a Fixes: tag. I'll
take another look and see if I can figure out how far back to go.

Thanks for the look,
Ben