btrfs-progs: tests: convert/014 use shell builtin for generating content

[platform/upstream/btrfs-progs.git] / Documentation / btrfs-rescue.asciidoc

diff --git a/Documentation/btrfs-rescue.asciidoc b/Documentation/btrfs-rescue.asciidoc
index 42aca64..f94a0ff 100644 (file)
--- a/Documentation/btrfs-rescue.asciidoc
+++ b/Documentation/btrfs-rescue.asciidoc
@@ -1,5 +1,5 @@
 btrfs-rescue(8)
-==============
+===============
 
 NAME
 ----
@@ -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.
 +
@@ -42,21 +62,22 @@ verbose mode.
 
 *zero-log* <device>::
 clear the filesystem log tree
-
++
 This command will clear the filesystem log tree. This may fix a specific
 set of problem when the filesystem mount fails due to the log replay. See below
 for sample stacktraces that may show up in system log.
-
-The common case where this happens has been fixed a long time ago,
-so it is unlikely that you will see this particular problem, but the utility is
++
+The common case where this happens was fixed a long time ago,
+so it is unlikely that you will see this particular problem, but the command is
 kept around.
-
++
 NOTE: clearing the log may lead to loss of changes that were made since the
 last transaction commit. This may be up to 30 seconds (default commit period)
 or less if the commit was implied by other filesystem activity.
-
++
 One can determine whether *zero-log* is needed according to the kernel
 backtrace:
++
 ----
 ? replay_one_dir_item+0xb5/0xb5 [btrfs]
 ? walk_log_tree+0x9c/0x19d [btrfs]
@@ -66,7 +87,7 @@ backtrace:
 ? btree_read_extent_buffer_pages+0x76/0xbc [btrfs]
 ? open_ctree+0xff6/0x132c [btrfs]
 ----
-
++
 If the errors are like above, then *zero-log* should be used to clear
 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