From 52f21fc76965b4c7b39bc5e3d0f6e044f1ddb693 Mon Sep 17 00:00:00 2001 From: David Sterba Date: Thu, 12 Jan 2017 15:00:47 +0100 Subject: [PATCH] btrfs-progs: defrag: force using v2 defrag ioctl and make default 32M threshold actually work A user reported on IRC that the new 32M default for target extent size does not work. This happens because if there are no commandline options, the v1 ioctl is used that does not do any fine grained defrag. As the v2 ioctl has been introduced 6 years ago (2010, kernel 2.6.33) we won't keep backward compatibility anymore. Signed-off-by: David Sterba --- Documentation/btrfs-filesystem.asciidoc | 2 +- cmds-filesystem.c | 5 +++-- 2 files changed, 4 insertions(+), 3 deletions(-) diff --git a/Documentation/btrfs-filesystem.asciidoc b/Documentation/btrfs-filesystem.asciidoc index 9782af9b..0f7ea495 100644 --- a/Documentation/btrfs-filesystem.asciidoc +++ b/Documentation/btrfs-filesystem.asciidoc @@ -80,7 +80,7 @@ show sizes in TiB, or TB with --si If conflicting options are passed, the last one takes precedence. *defragment* [options] | [|...]:: -Defragment file data on a mounted filesystem. +Defragment file data on a mounted filesystem. Requires kernel 2.6.33 and newer. + If '-r' is passed, files in dir will be defragmented recursively. The start position and the number of bytes to defragment can be specified by diff --git a/cmds-filesystem.c b/cmds-filesystem.c index c66709b3..56a19a93 100644 --- a/cmds-filesystem.c +++ b/cmds-filesystem.c @@ -1042,14 +1042,15 @@ static int cmd_filesystem_defrag(int argc, char **argv) /* * Kernel has a different default (256K) that is supposed to be safe, * but it does not defragment very well. The 32M will likely lead to - * better results and is independent of the kernel default. + * better results and is independent of the kernel default. We have to + * use the v2 defrag ioctl. */ thresh = 32 * 1024 * 1024; + defrag_global_fancy_ioctl = 1; defrag_global_errors = 0; defrag_global_verbose = 0; defrag_global_errors = 0; - defrag_global_fancy_ioctl = 0; while(1) { int c = getopt(argc, argv, "vrc::fs:l:t:"); if (c < 0)