releases/4.14.69/nfsv4-fix-locking-in-pnfs_generic_recover_commit_reqs.patch

   1 From d0fbb1d8a194c0ec0180c1d073ad709e45503a43 Mon Sep 17 00:00:00 2001
   2 From: Trond Myklebust <trondmy@gmail.com>
   3 Date: Tue, 14 Aug 2018 17:25:37 -0400
   4 Subject: NFSv4: Fix locking in pnfs_generic_recover_commit_reqs
   5
   6 From: Trond Myklebust <trondmy@gmail.com>
   7
   8 commit d0fbb1d8a194c0ec0180c1d073ad709e45503a43 upstream.
   9
  10 The use of the inode->i_lock was converted to a mutex, but we forgot
  11 to remove the old inode unlock/lock() pair that allowed the layout
  12 segment to be put inside the loop.
  13
  14 Reported-by: Jia-Ju Bai <baijiaju1990@gmail.com>
  15 Fixes: e824f99adaaf1 ("NFSv4: Use a mutex to protect the per-inode commit...")
  16 Cc: stable@vger.kernel.org # v4.14+
  17 Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
  18 Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
  19 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  20
  21 ---
  22  fs/nfs/pnfs_nfs.c |   16 +++++++---------
  23  1 file changed, 7 insertions(+), 9 deletions(-)
  24
  25 --- a/fs/nfs/pnfs_nfs.c
  26 +++ b/fs/nfs/pnfs_nfs.c
  27 @@ -61,7 +61,7 @@ EXPORT_SYMBOL_GPL(pnfs_generic_commit_re
  28
  29  /* The generic layer is about to remove the req from the commit list.
  30   * If this will make the bucket empty, it will need to put the lseg reference.
  31 - * Note this must be called holding i_lock
  32 + * Note this must be called holding nfsi->commit_mutex
  33   */
  34  void
  35  pnfs_generic_clear_request_commit(struct nfs_page *req,
  36 @@ -149,9 +149,7 @@ restart:
  37                 if (list_empty(&b->written)) {
  38                         freeme = b->wlseg;
  39                         b->wlseg = NULL;
  40 -                       spin_unlock(&cinfo->inode->i_lock);
  41                         pnfs_put_lseg(freeme);
  42 -                       spin_lock(&cinfo->inode->i_lock);
  43                         goto restart;
  44                 }
  45         }
  46 @@ -167,7 +165,7 @@ static void pnfs_generic_retry_commit(st
  47         LIST_HEAD(pages);
  48         int i;
  49
  50 -       spin_lock(&cinfo->inode->i_lock);
  51 +       mutex_lock(&NFS_I(cinfo->inode)->commit_mutex);
  52         for (i = idx; i < fl_cinfo->nbuckets; i++) {
  53                 bucket = &fl_cinfo->buckets[i];
  54                 if (list_empty(&bucket->committing))
  55 @@ -177,12 +175,12 @@ static void pnfs_generic_retry_commit(st
  56                 list_for_each(pos, &bucket->committing)
  57                         cinfo->ds->ncommitting--;
  58                 list_splice_init(&bucket->committing, &pages);
  59 -               spin_unlock(&cinfo->inode->i_lock);
  60 +               mutex_unlock(&NFS_I(cinfo->inode)->commit_mutex);
  61                 nfs_retry_commit(&pages, freeme, cinfo, i);
  62                 pnfs_put_lseg(freeme);
  63 -               spin_lock(&cinfo->inode->i_lock);
  64 +               mutex_lock(&NFS_I(cinfo->inode)->commit_mutex);
  65         }
  66 -       spin_unlock(&cinfo->inode->i_lock);
  67 +       mutex_unlock(&NFS_I(cinfo->inode)->commit_mutex);
  68  }
  69
  70  static unsigned int
  71 @@ -222,13 +220,13 @@ void pnfs_fetch_commit_bucket_list(struc
  72         struct list_head *pos;
  73
  74         bucket = &cinfo->ds->buckets[data->ds_commit_index];
  75 -       spin_lock(&cinfo->inode->i_lock);
  76 +       mutex_lock(&NFS_I(cinfo->inode)->commit_mutex);
  77         list_for_each(pos, &bucket->committing)
  78                 cinfo->ds->ncommitting--;
  79         list_splice_init(&bucket->committing, pages);
  80         data->lseg = bucket->clseg;
  81         bucket->clseg = NULL;
  82 -       spin_unlock(&cinfo->inode->i_lock);
  83 +       mutex_unlock(&NFS_I(cinfo->inode)->commit_mutex);
  84
  85  }
  86