tests/btrfs/092

   1 #! /bin/bash
   2 # FS QA Test No. btrfs/092
   3 #
   4 # Test btrfs incremental send after renaming and moving directories around in a
   5 # way that ends up making a directory have different dentries with the same name
   6 # but pointing to different inodes in the parent and send snapshots, and also
   7 # inverting the ancestor-descendent relationship between one of those inodes and
   8 # some other inode.
   9 #
  10 # Cases like this made an incremental send enter an infinite lopp when building
  11 # path strings, leading to -ENOMEM errors when the path string reached a length
  12 # of PATH_MAX.
  13 # This issue was fixed by the following linux kernel btrfs patch:
  14 #
  15 #   Btrfs: incremental send, check if orphanized dir inode needs delayed rename
  16 #
  17 #-----------------------------------------------------------------------
  18 # Copyright (C) 2015 SUSE Linux Products GmbH. All Rights Reserved.
  19 # Author: Filipe Manana <fdmanana@suse.com>
  20 #
  21 # This program is free software; you can redistribute it and/or
  22 # modify it under the terms of the GNU General Public License as
  23 # published by the Free Software Foundation.
  24 #
  25 # This program is distributed in the hope that it would be useful,
  26 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  27 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  28 # GNU General Public License for more details.
  29 #
  30 # You should have received a copy of the GNU General Public License
  31 # along with this program; if not, write the Free Software Foundation,
  32 # Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  33 #-----------------------------------------------------------------------
  34 #
  35
  36 seq=`basename $0`
  37 seqres=$RESULT_DIR/$seq
  38 echo "QA output created by $seq"
  39
  40 tmp=/tmp/$$
  41 status=1        # failure is the default!
  42 trap "_cleanup; exit \$status" 0 1 2 3 15
  43
  44 _cleanup()
  45 {
  46         rm -fr $send_files_dir
  47         rm -f $tmp.*
  48 }
  49
  50 # get standard environment, filters and checks
  51 . ./common/rc
  52 . ./common/filter
  53
  54 # real QA test starts here
  55 _supported_fs btrfs
  56 _supported_os Linux
  57 _require_scratch
  58 _require_fssum
  59
  60 send_files_dir=$TEST_DIR/btrfs-test-$seq
  61
  62 rm -f $seqres.full
  63 rm -fr $send_files_dir
  64 mkdir $send_files_dir
  65
  66 _scratch_mkfs >>$seqres.full 2>&1
  67 _scratch_mount
  68
  69 mkdir -p $SCRATCH_MNT/data/n1/n2
  70 mkdir $SCRATCH_MNT/data/n4
  71 mkdir -p $SCRATCH_MNT/data/t6/t7
  72 mkdir $SCRATCH_MNT/data/t5
  73 mkdir $SCRATCH_MNT/data/t7
  74 mkdir $SCRATCH_MNT/data/n4/t2
  75 mkdir $SCRATCH_MNT/data/t4
  76 mkdir $SCRATCH_MNT/data/t3
  77 mv $SCRATCH_MNT/data/t7 $SCRATCH_MNT/data/n4/t2
  78 mv $SCRATCH_MNT/data/t4 $SCRATCH_MNT/data/n4/t2/t7
  79 mv $SCRATCH_MNT/data/t5 $SCRATCH_MNT/data/n4/t2/t7/t4
  80 mv $SCRATCH_MNT/data/t6 $SCRATCH_MNT/data/n4/t2/t7/t4/t5
  81 mv $SCRATCH_MNT/data/n1/n2 $SCRATCH_MNT/data/n4/t2/t7/t4/t5/t6
  82 mv $SCRATCH_MNT/data/n1 $SCRATCH_MNT/data/n4/t2/t7/t4/t5/t6
  83 mv $SCRATCH_MNT/data/n4/t2/t7/t4/t5/t6/t7 $SCRATCH_MNT/data/n4/t2/t7/t4/t5/t6/n2
  84 mv $SCRATCH_MNT/data/t3 $SCRATCH_MNT/data/n4/t2/t7/t4/t5/t6/n2/t7
  85
  86 # Filesystem looks like:
  87 #
  88 # .                                                                   (ino 256)
  89 # |-- data/                                                           (ino 257)
  90 #       |-- n4/                                                       (ino 260)
  91 #            |-- t2/                                                  (ino 265)
  92 #                 |-- t7/                                             (ino 264)
  93 #                      |-- t4/                                        (ino 266)
  94 #                           |-- t5/                                   (ino 263)
  95 #                                |-- t6/                              (ino 261)
  96 #                                     |-- n1/                         (ino 258)
  97 #                                     |-- n2/                         (ino 259)
  98 #                                          |-- t7/                    (ino 262)
  99 #                                               |-- t3/               (ino 267)
 100 #
 101 _run_btrfs_util_prog subvolume snapshot -r $SCRATCH_MNT $SCRATCH_MNT/mysnap1
 102
 103 # The sequence of directory rename operations below made the btrfs incremental
 104 # send implementation enter an infinite loop when building path strings. The
 105 # reason for this was the following:
 106 #
 107 # * While processing inode 262 it ended up orphanizing inode 264 (rename it to
 108 #   "/o264-6-0"). This is because the parent inode 265 has a dentry with name
 109 #   t7 in the parent snapshot that refers to inode 264, which is ahead of the
 110 #   current send progress (inode 262) and our inode 262 has the name t7 in
 111 #   the directory inode 265 in the send snapshot - so in order to rename inode
 112 #   262 to its new name/location, it orphanizes (renames) 264 before 264 is
 113 #   processed;
 114 #
 115 # * When it processes inode 264 it was not checking if it needed to delay its
 116 #   rename operation. This was incorrect because in the parent snapshot inode
 117 #   267 is a descendent of inode 264 and inode 267 is an ancestor of inode 264
 118 #   in the send snapshot, which means the rename of inode 264 must happen after
 119 #   inode 267 is renamed in order to avoid the infinite loops when building
 120 #   path strings that involved inodes 264 and 267;
 121 #
 122 # * As a consequence as soon as the send progress moved to inode 265, the
 123 #   following loop when building a path string for inode 264 happened:
 124 #
 125 #     start inode 264, send progress of 265 for example
 126 #     parent of 264 -> 267
 127 #     parent of 267 -> 262
 128 #     parent of 262 -> 259
 129 #     parent of 259 -> 261
 130 #     parent of 261 -> 263
 131 #     parent of 263 -> 266
 132 #     parent of 266 -> 264
 133 #       |--> back to first iteration while current path string length
 134 #            is <= PATH_MAX, and fail with -ENOMEM otherwise
 135 #
 136 mv $SCRATCH_MNT/data/n4/t2/t7/t4/t5/t6/n1 $SCRATCH_MNT/data/n4
 137 mv $SCRATCH_MNT/data/n4/t2 $SCRATCH_MNT/data/n4/n1
 138 mv $SCRATCH_MNT/data/n4/n1/t2/t7/t4/t5/t6/n2 $SCRATCH_MNT/data/n4/n1/t2
 139 mv $SCRATCH_MNT/data/n4/n1/t2/n2/t7/t3 $SCRATCH_MNT/data/n4/n1/t2
 140 mv $SCRATCH_MNT/data/n4/n1/t2/t7/t4/t5/t6 $SCRATCH_MNT/data/n4/n1/t2
 141 mv $SCRATCH_MNT/data/n4/n1/t2/t7/t4 $SCRATCH_MNT/data/n4/n1/t2/t6
 142 mv $SCRATCH_MNT/data/n4/n1/t2/t7 $SCRATCH_MNT/data/n4/n1/t2/t3
 143 mv $SCRATCH_MNT/data/n4/n1/t2/n2/t7 $SCRATCH_MNT/data/n4/n1/t2
 144
 145 # Filesystem now looks like:
 146 #
 147 # .                                                                   (ino 256)
 148 # |-- data/                                                           (ino 257)
 149 #       |-- n4/                                                       (ino 260)
 150 #            |-- n1/                                                  (ino 258)
 151 #                 |-- t2/                                             (ino 265)
 152 #                      |-- n2/                                        (ino 259)
 153 #                      |-- t3/                                        (ino 267)
 154 #                      |    |-- t7                                    (ino 264)
 155 #                      |
 156 #                      |-- t6/                                        (ino 261)
 157 #                      |    |-- t4/                                   (ino 266)
 158 #                      |         |-- t5/                              (ino 263)
 159 #                      |
 160 #                      |-- t7/                                        (ino 262)
 161 #
 162 _run_btrfs_util_prog subvolume snapshot -r $SCRATCH_MNT $SCRATCH_MNT/mysnap2
 163
 164 run_check $FSSUM_PROG -A -f -w $send_files_dir/1.fssum $SCRATCH_MNT/mysnap1
 165 run_check $FSSUM_PROG -A -f -w $send_files_dir/2.fssum \
 166         -x $SCRATCH_MNT/mysnap2/mysnap1 $SCRATCH_MNT/mysnap2
 167
 168 _run_btrfs_util_prog send -f $send_files_dir/1.snap $SCRATCH_MNT/mysnap1
 169 _run_btrfs_util_prog send -p $SCRATCH_MNT/mysnap1 -f $send_files_dir/2.snap \
 170         $SCRATCH_MNT/mysnap2
 171
 172 # Now recreate the filesystem by receiving both send streams and verify we get
 173 # the same content that the original filesystem had.
 174 _scratch_unmount
 175 _scratch_mkfs >>$seqres.full 2>&1
 176 _scratch_mount
 177
 178 _run_btrfs_util_prog receive -f $send_files_dir/1.snap $SCRATCH_MNT
 179 run_check $FSSUM_PROG -r $send_files_dir/1.fssum $SCRATCH_MNT/mysnap1
 180 _run_btrfs_util_prog receive -f $send_files_dir/2.snap $SCRATCH_MNT
 181 run_check $FSSUM_PROG -r $send_files_dir/2.fssum $SCRATCH_MNT/mysnap2
 182
 183 echo "Silence is golden"
 184 status=0
 185 exit