From dad1c8ba3a52afd72dd4b6d46b985dac163925bf Mon Sep 17 00:00:00 2001 From: Qu Wenruo Date: Fri, 11 Apr 2014 10:43:53 +0800 Subject: [PATCH] btrfs-progs: Add explain on btrfs-zero-log. Add more explain on btrfs-zero-log about when to use it. Reviewed-by: Marc MERLIN Signed-off-by: Qu Wenruo Signed-off-by: David Sterba --- Documentation/btrfs-zero-log.txt | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) diff --git a/Documentation/btrfs-zero-log.txt b/Documentation/btrfs-zero-log.txt index e3041fa4..a8e4dd34 100644 --- a/Documentation/btrfs-zero-log.txt +++ b/Documentation/btrfs-zero-log.txt @@ -17,6 +17,24 @@ allow you to mount the filesystem again. The common case where this happens has been fixed a long time ago, so it is unlikely that you will see this particular problem. +One can determine whether 'btrfs-zero-log' is needed according to the kernel +backtrace: +---- +? replay_one_dir_item+0xb5/0xb5 [btrfs] +? walk_log_tree+0x9c/0x19d [btrfs] +? btrfs_read_fs_root_no_radix+0x169/0x1a1 [btrfs] +? btrfs_recover_log_trees+0x195/0x29c [btrfs] +? replay_one_dir_item+0xb5/0xb5 [btrfs] +? btree_read_extent_buffer_pages+0x76/0xbc [btrfs] +? open_ctree+0xff6/0x132c [btrfs] +---- + +If the errors are like above, then 'btrfs-zero-log' should be used to clear +the log and the filesystem may be mounted normally again. + +NOTE: If you use btrfs as the root filesystem, you may want to include +'btrfs-zero-log' into initramdisk if the log problems hits you often. + EXIT STATUS ----------- 'btrfs-zero-log' will return 0 if no error happened.