releases/4.19.31/nfs-don-t-use-page_file_mapping-after-removing-the-p.patch

   1 From 9884b3cdfef8d7d7324a23d8f688a96cef0b89b2 Mon Sep 17 00:00:00 2001
   2 From: Benjamin Coddington <bcodding@redhat.com>
   3 Date: Wed, 6 Feb 2019 06:09:43 -0500
   4 Subject: NFS: Don't use page_file_mapping after removing the page
   5
   6 [ Upstream commit d2ceb7e57086750ea6198a31fd942d98099a0786 ]
   7
   8 If nfs_page_async_flush() removes the page from the mapping, then we can't
   9 use page_file_mapping() on it as nfs_updatepate() is wont to do when
  10 receiving an error.  Instead, push the mapping to the stack before the page
  11 is possibly truncated.
  12
  13 Fixes: 8fc75bed96bb ("NFS: Fix up return value on fatal errors in nfs_page_async_flush()")
  14 Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
  15 Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
  16 Signed-off-by: Sasha Levin <sashal@kernel.org>
  17 ---
  18  fs/nfs/write.c | 11 ++++++-----
  19  1 file changed, 6 insertions(+), 5 deletions(-)
  20
  21 diff --git a/fs/nfs/write.c b/fs/nfs/write.c
  22 index d790faff8e47..51d0b7913c04 100644
  23 --- a/fs/nfs/write.c
  24 +++ b/fs/nfs/write.c
  25 @@ -238,9 +238,9 @@ out:
  26  }
  27
  28  /* A writeback failed: mark the page as bad, and invalidate the page cache */
  29 -static void nfs_set_pageerror(struct page *page)
  30 +static void nfs_set_pageerror(struct address_space *mapping)
  31  {
  32 -       nfs_zap_mapping(page_file_mapping(page)->host, page_file_mapping(page));
  33 +       nfs_zap_mapping(mapping->host, mapping);
  34  }
  35
  36  /*
  37 @@ -994,7 +994,7 @@ static void nfs_write_completion(struct nfs_pgio_header *hdr)
  38                 nfs_list_remove_request(req);
  39                 if (test_bit(NFS_IOHDR_ERROR, &hdr->flags) &&
  40                     (hdr->good_bytes < bytes)) {
  41 -                       nfs_set_pageerror(req->wb_page);
  42 +                       nfs_set_pageerror(page_file_mapping(req->wb_page));
  43                         nfs_context_set_write_error(req->wb_context, hdr->error);
  44                         goto remove_req;
  45                 }
  46 @@ -1330,7 +1330,8 @@ int nfs_updatepage(struct file *file, struct page *page,
  47                 unsigned int offset, unsigned int count)
  48  {
  49         struct nfs_open_context *ctx = nfs_file_open_context(file);
  50 -       struct inode    *inode = page_file_mapping(page)->host;
  51 +       struct address_space *mapping = page_file_mapping(page);
  52 +       struct inode    *inode = mapping->host;
  53         int             status = 0;
  54
  55         nfs_inc_stats(inode, NFSIOS_VFSUPDATEPAGE);
  56 @@ -1348,7 +1349,7 @@ int nfs_updatepage(struct file *file, struct page *page,
  57
  58         status = nfs_writepage_setup(ctx, page, offset, count);
  59         if (status < 0)
  60 -               nfs_set_pageerror(page);
  61 +               nfs_set_pageerror(mapping);
  62         else
  63                 __set_page_dirty_nobuffers(page);
  64  out:
  65 --
  66 2.19.1
  67