[PATCH 4.14 62/89] NFSv4: Fix locking in pnfs_generic_recover_commit_reqs

[Greg Kroah-Hartman]

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

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

From: Trond Myklebust <tron...@gmail.com>

commit d0fbb1d8a194c0ec0180c1d073ad709e45503a43 upstream.

The use of the inode->i_lock was converted to a mutex, but we forgot
to remove the old inode unlock/lock() pair that allowed the layout
segment to be put inside the loop.

Reported-by: Jia-Ju Bai <baijiaju1...@gmail.com>
Fixes: e824f99adaaf1 ("NFSv4: Use a mutex to protect the per-inode commit...")
Cc: sta...@vger.kernel.org # v4.14+
Signed-off-by: Trond Myklebust <trond.mykleb...@hammerspace.com>
Signed-off-by: Anna Schumaker <anna.schuma...@netapp.com>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>

---
 fs/nfs/pnfs_nfs.c |   16 +++++++---------
 1 file changed, 7 insertions(+), 9 deletions(-)

--- a/fs/nfs/pnfs_nfs.c
+++ b/fs/nfs/pnfs_nfs.c
@@ -61,7 +61,7 @@ EXPORT_SYMBOL_GPL(pnfs_generic_commit_re
 
 /* The generic layer is about to remove the req from the commit list.
  * If this will make the bucket empty, it will need to put the lseg reference.
- * Note this must be called holding i_lock
+ * Note this must be called holding nfsi->commit_mutex
  */
 void
 pnfs_generic_clear_request_commit(struct nfs_page *req,
@@ -149,9 +149,7 @@ restart:
                if (list_empty(&b->written)) {
                        freeme = b->wlseg;
                        b->wlseg = NULL;
-                       spin_unlock(&cinfo->inode->i_lock);
                        pnfs_put_lseg(freeme);
-                       spin_lock(&cinfo->inode->i_lock);
                        goto restart;
                }
        }
@@ -167,7 +165,7 @@ static void pnfs_generic_retry_commit(st
        LIST_HEAD(pages);
        int i;
 
-       spin_lock(&cinfo->inode->i_lock);
+       mutex_lock(&NFS_I(cinfo->inode)->commit_mutex);
        for (i = idx; i < fl_cinfo->nbuckets; i++) {
                bucket = &fl_cinfo->buckets[i];
                if (list_empty(&bucket->committing))
@@ -177,12 +175,12 @@ static void pnfs_generic_retry_commit(st
                list_for_each(pos, &bucket->committing)
                        cinfo->ds->ncommitting--;
                list_splice_init(&bucket->committing, &pages);
-               spin_unlock(&cinfo->inode->i_lock);
+               mutex_unlock(&NFS_I(cinfo->inode)->commit_mutex);
                nfs_retry_commit(&pages, freeme, cinfo, i);
                pnfs_put_lseg(freeme);
-               spin_lock(&cinfo->inode->i_lock);
+               mutex_lock(&NFS_I(cinfo->inode)->commit_mutex);
        }
-       spin_unlock(&cinfo->inode->i_lock);
+       mutex_unlock(&NFS_I(cinfo->inode)->commit_mutex);
 }
 
 static unsigned int
@@ -222,13 +220,13 @@ void pnfs_fetch_commit_bucket_list(struc
        struct list_head *pos;
 
        bucket = &cinfo->ds->buckets[data->ds_commit_index];
-       spin_lock(&cinfo->inode->i_lock);
+       mutex_lock(&NFS_I(cinfo->inode)->commit_mutex);
        list_for_each(pos, &bucket->committing)
                cinfo->ds->ncommitting--;
        list_splice_init(&bucket->committing, pages);
        data->lseg = bucket->clseg;
        bucket->clseg = NULL;
-       spin_unlock(&cinfo->inode->i_lock);
+       mutex_unlock(&NFS_I(cinfo->inode)->commit_mutex);
 
 }