git.ipfire.org Git - thirdparty/openembedded/openembedded-core-contrib.git/blob

   1 Upstream-Status: Inappropriate [Backport]
   2 From a6c54702d8973aef081cff81ed8d90427bb21768 Mon Sep 17 00:00:00 2001
   3 From: Chris Mason <chris.mason@oracle.com>
   4 Date: Wed, 15 Dec 2010 16:00:23 -0500
   5 Subject: [PATCH 1/5] Fill missing devices so degraded filesystems can be read
   6
   7 When a device is missing, the btrfs tools need to be able to read alternate
   8 copies from the remaining devices.  This creates placeholder devices
   9 that always return -EIO so the tools can limp along.
  10
  11 Signed-off-by: Chris Mason <chris.mason@oracle.com>
  12 ---
  13  disk-io.c |    1 +
  14  volumes.c |   15 +++++++++++++--
  15  2 files changed, 14 insertions(+), 2 deletions(-)
  16
  17 diff --git a/disk-io.c b/disk-io.c
  18 index 5bd9cfc..f4368f3 100644
  19 --- a/disk-io.c
  20 +++ b/disk-io.c
  21 @@ -204,6 +204,7 @@ struct extent_buffer *read_tree_block(struct btrfs_root *root, u64 bytenr,
  22                 eb->dev_bytenr = multi->stripes[0].physical;
  23                 kfree(multi);
  24                 ret = read_extent_from_disk(eb);
  25 +
  26                 if (ret == 0 && check_tree_block(root, eb) == 0 &&
  27                     csum_tree_block(root, eb, 1) == 0 &&
  28                     verify_parent_transid(eb->tree, eb, parent_transid) == 0) {
  29 diff --git a/volumes.c b/volumes.c
  30 index 4bb77e2..5773467 100644
  31 --- a/volumes.c
  32 +++ b/volumes.c
  33 @@ -1263,6 +1263,16 @@ int btrfs_chunk_readonly(struct btrfs_root *root, u64 chunk_offset)
  34         return readonly;
  35  }
  36
  37 +static struct btrfs_device *fill_missing_device(u64 devid)
  38 +{
  39 +       struct btrfs_device *device;
  40 +
  41 +       device = kzalloc(sizeof(*device), GFP_NOFS);
  42 +       device->devid = devid;
  43 +       device->fd = -1;
  44 +       return device;
  45 +}
  46 +
  47  static int read_one_chunk(struct btrfs_root *root, struct btrfs_key *key,
  48                           struct extent_buffer *leaf,
  49                           struct btrfs_chunk *chunk)
  50 @@ -1313,8 +1323,9 @@ static int read_one_chunk(struct btrfs_root *root, struct btrfs_key *key,
  51                 map->stripes[i].dev = btrfs_find_device(root, devid, uuid,
  52                                                         NULL);
  53                 if (!map->stripes[i].dev) {
  54 -                       kfree(map);
  55 -                       return -EIO;
  56 +                       map->stripes[i].dev = fill_missing_device(devid);
  57 +                       printf("warning, device %llu is missing\n",
  58 +                              (unsigned long long)devid);
  59                 }
  60
  61         }
  62 --
  63 1.7.2.3
  64