releases/2.6.32.17/0017-ext4-fix-error-handling-in-migrate.patch

   1 From 492c93e8097f0bf58b2884064af85242fabe5d71 Mon Sep 17 00:00:00 2001
   2 From: Dmitry Monakhov <dmonakhov@openvz.org>
   3 Date: Sun, 30 May 2010 22:49:31 -0400
   4 Subject: ext4: fix error handling in migrate
   5
   6 commit f39490bcd1691d65dc33689222a12e1fc13dd824 upstream (as of v2.6.33-git11)
   7
   8 Set i_nlink to zero for temporary inode from very beginning.
   9 otherwise we may fail to start new journal handle and this
  10 inode will be unreferenced but with i_nlink == 1
  11 Since we hold inode reference it can not be pruned.
  12
  13 Also add missed journal_start retval check.
  14
  15 Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
  16 Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
  17 Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
  18 ---
  19  fs/ext4/migrate.c |   29 ++++++++++++++---------------
  20  1 file changed, 14 insertions(+), 15 deletions(-)
  21
  22 --- a/fs/ext4/migrate.c
  23 +++ b/fs/ext4/migrate.c
  24 @@ -494,14 +494,10 @@ int ext4_ext_migrate(struct inode *inode
  25         }
  26         i_size_write(tmp_inode, i_size_read(inode));
  27         /*
  28 -        * We don't want the inode to be reclaimed
  29 -        * if we got interrupted in between. We have
  30 -        * this tmp inode carrying reference to the
  31 -        * data blocks of the original file. We set
  32 -        * the i_nlink to zero at the last stage after
  33 -        * switching the original file to extent format
  34 +        * Set the i_nlink to zero so it will be deleted later
  35 +        * when we drop inode reference.
  36          */
  37 -       tmp_inode->i_nlink = 1;
  38 +       tmp_inode->i_nlink = 0;
  39
  40         ext4_ext_tree_init(handle, tmp_inode);
  41         ext4_orphan_add(handle, tmp_inode);
  42 @@ -528,6 +524,16 @@ int ext4_ext_migrate(struct inode *inode
  43         up_read((&EXT4_I(inode)->i_data_sem));
  44
  45         handle = ext4_journal_start(inode, 1);
  46 +       if (IS_ERR(handle)) {
  47 +               /*
  48 +                * It is impossible to update on-disk structures without
  49 +                * a handle, so just rollback in-core changes and live other
  50 +                * work to orphan_list_cleanup()
  51 +                */
  52 +               ext4_orphan_del(NULL, tmp_inode);
  53 +               retval = PTR_ERR(handle);
  54 +               goto out;
  55 +       }
  56
  57         ei = EXT4_I(inode);
  58         i_data = ei->i_data;
  59 @@ -609,15 +615,8 @@ err_out:
  60
  61         /* Reset the extent details */
  62         ext4_ext_tree_init(handle, tmp_inode);
  63 -
  64 -       /*
  65 -        * Set the i_nlink to zero so that
  66 -        * generic_drop_inode really deletes the
  67 -        * inode
  68 -        */
  69 -       tmp_inode->i_nlink = 0;
  70 -
  71         ext4_journal_stop(handle);
  72 +out:
  73         unlock_new_inode(tmp_inode);
  74         iput(tmp_inode);
  75