From: Liu Bo <liubo2009@cn.fujitsu.com>
Date: Thu, 29 Mar 2012 13:57:45 +0000 (-0400)
Subject: Btrfs: do not bother to defrag an extent if it is a big real extent
X-Git-Tag: firefly_0821_release~3680^2~2940^2~40
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=66c2689226ac322fbc9acd2e8e418b78dcd52f51;p=firefly-linux-kernel-4.4.55.git
Btrfs: do not bother to defrag an extent if it is a big real extent
$ mkfs.btrfs /dev/sdb7
$ mount /dev/sdb7 /mnt/btrfs/ -oautodefrag
$ dd if=/dev/zero of=/mnt/btrfs/foobar bs=4k count=10 oflag=direct 2>/dev/null
$ filefrag -v /mnt/btrfs/foobar
Filesystem type is: 9123683e
File size of /mnt/btrfs/foobar is 40960 (10 blocks, blocksize 4096)
ext logical physical expected length flags
0 0 3072 10 eof
/mnt/btrfs/foobar: 1 extent found
Now we have a big real extent [0, 40960), but autodefrag will still defrag it.
$ sync
$ filefrag -v /mnt/btrfs/foobar
Filesystem type is: 9123683e
File size of /mnt/btrfs/foobar is 40960 (10 blocks, blocksize 4096)
ext logical physical expected length flags
0 0 3082 10 eof
/mnt/btrfs/foobar: 1 extent found
So if we already find a big real extent, we're ok about that, just skip it.
Signed-off-by: Liu Bo <liubo2009@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
---
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 6c39d1a55907..afde837644e5 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -1140,12 +1140,9 @@ int btrfs_defrag_file(struct inode *inode, struct file *file,
if (!(inode->i_sb->s_flags & MS_ACTIVE))
break;
- if (!newer_than &&
- !should_defrag_range(inode, (u64)i << PAGE_CACHE_SHIFT,
- PAGE_CACHE_SIZE,
- extent_thresh,
- &last_len, &skip,
- &defrag_end)) {
+ if (!should_defrag_range(inode, (u64)i << PAGE_CACHE_SHIFT,
+ PAGE_CACHE_SIZE, extent_thresh,
+ &last_len, &skip, &defrag_end)) {
unsigned long next;
/*
* the should_defrag function tells us how much to skip