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| author | David Sterba <dsterba@suse.com> | 2017-11-14 16:16:54 +0100 |
|---|---|---|
| committer | David Sterba <dsterba@suse.com> | 2017-11-14 16:20:14 +0100 |
| commit | 561e6da4588663e04ecb03963179b608002b26c6 (patch) | |
| tree | 8c9aa17ea6160938021e0344180511c6e3c5a52f /Documentation/btrfs-rescue.asciidoc | |
| parent | f181e18f46de24b99a1341670a8936452cc55b12 (diff) | |
btrfs-progs: docs: move the rescue fix-device-size command and update
The subcommands are supposed to be in alphabetical order, move it to the
right spot and reword.
Signed-off-by: David Sterba <dsterba@suse.com>
Diffstat (limited to 'Documentation/btrfs-rescue.asciidoc')
| -rw-r--r-- | Documentation/btrfs-rescue.asciidoc | 49 |
1 files changed, 20 insertions, 29 deletions
diff --git a/Documentation/btrfs-rescue.asciidoc b/Documentation/btrfs-rescue.asciidoc index 815abe3c..58d82866 100644 --- a/Documentation/btrfs-rescue.asciidoc +++ b/Documentation/btrfs-rescue.asciidoc @@ -15,6 +15,7 @@ DESCRIPTION SUBCOMMAND ---------- + *chunk-recover* [options] <device>:: Recover the chunk tree by scanning the devices + @@ -30,6 +31,25 @@ help. NOTE: Since *chunk-recover* will scan the whole device, it will be *VERY* slow especially executed on a large device. +*fix-device-size* <device>:: +fix device size and super block total bytes values that are do not match ++ +Kernel 4.11 starts to check the device size more strictly and this might +mismatch the stored value of total bytes. See the exact error message below. +Newer kernel will refuse to mount the filesystem where the values do not match. +This error is not fatal and can be fixed. This command will fix the device +size values if possible. ++ +---- +BTRFS error (device sdb): super_total_bytes 92017859088384 mismatch with fs_devices total_rw_bytes 92017859094528 +---- ++ +The mismatch may also exhibit as a kernel warning: ++ +---- +WARNING: CPU: 3 PID: 439 at fs/btrfs/ctree.h:1559 btrfs_update_device+0x1c5/0x1d0 [btrfs] +---- + *super-recover* [options] <device>:: Recover bad superblocks from good copies. + @@ -73,35 +93,6 @@ the log and the filesystem may be mounted normally again. The keywords to look for are 'open_ctree' which says that it's during mount and function names that contain 'replay', 'recover' or 'log_tree'. -*fix-device-size* <device>:: -fix device size and super block total bytes -+ -This command will fix the following problems, by re-aligning all devices' total -bytes and re-calculating super block total bytes. -+ -1. Newer kernel refuse to mount btrfs caused by mismatch super block total bytes -+ ----- -BTRFS error (device sdb): super_total_bytes 92017859088384 mismatch with fs_devices total_rw_bytes 92017859094528 ----- -+ -2. Noisy kernel warning for newer kernels -+ ----- -WARNING: CPU: 3 PID: 439 at fs/btrfs/ctree.h:1559 btrfs_update_device+0x1c5/0x1d0 [btrfs] ----- -+ -And the corresponding line is the `WARN_ON()` line below: -+ ----- -{ - BUILD_BUG_ON(sizeof(u64) != - sizeof(((struct btrfs_dev_item *)0))->total_bytes); - WARN_ON(!IS_ALIGNED(val, eb->fs_info->sectorsize)); - btrfs_set_64(eb, s, offsetof(struct btrfs_dev_item, total_bytes), val); -} ----- - EXIT STATUS ----------- *btrfs rescue* returns a zero exit status if it succeeds. Non zero is |