[PATCH v2 6/7] NFS/pNFS: Don't leak DS commits in pnfs_generic_retry_commit()

trondmy
2021-01-07T05:32:54Z

We must ensure that we pass a layout segment to nfs_retry_commit() when
we're cleaning up after pnfs_bucket_alloc_ds_commits(). Otherwise,
requests that should be committed to the DS will get committed to the
MDS.
Do so by ensuring that pnfs_bucket_get_committing() always tries to
return a layout segment when it returns a non-empty page list.

Fixes: c84bea59449a ("NFS/pNFS: Simplify bucket layout segment reference counting")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
---
fs/nfs/pnfs_nfs.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/fs/nfs/pnfs_nfs.c b/fs/nfs/pnfs_nfs.c
index df20bbe8d15e..49d3389bd813 100644
--- a/fs/nfs/pnfs_nfs.c
+++ b/fs/nfs/pnfs_nfs.c
@@ -403,12 +403,16 @@ pnfs_bucket_get_committing(struct list_head *head,
struct pnfs_commit_bucket *bucket,
struct nfs_commit_info *cinfo)
{
+ struct pnfs_layout_segment *lseg;
struct list_head *pos;

list_for_each(pos, &bucket->committing)
cinfo->ds->ncommitting--;
list_splice_init(&bucket->committing, head);
- return pnfs_free_bucket_lseg(bucket);
+ lseg = pnfs_free_bucket_lseg(bucket);
+ if (!lseg)
+ lseg = pnfs_get_lseg(bucket->lseg);
+ return lseg;
}

static struct nfs_commit_data *
@@ -420,8 +424,6 @@ pnfs_bucket_fetch_commitdata(struct pnfs_commit_bucket *bucket,
if (!data)
return NULL;
data->lseg = pnfs_bucket_get_committing(&data->pages, bucket, cinfo);
- if (!data->lseg)
- data->lseg = pnfs_get_lseg(bucket->lseg);
return data;
}

--
2.29.2