From mboxrd@z Thu Jan 1 00:00:00 1970 From: Li Zefan Subject: Re: The value displayed by 'ls -s' command is strange. Date: Tue, 07 Dec 2010 17:25:38 +0800 Message-ID: <4CFDFD92.9090208@cn.fujitsu.com> References: <4CFDE978.9050407@jp.fujitsu.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-2022-JP Cc: Linux Btrfs To: Tsutomu Itoh Return-path: In-Reply-To: <4CFDE978.9050407@jp.fujitsu.com> List-ID: Tsutomu Itoh wrote: > Hi, > > I think that the disk allocation size of each file becomes a monotone increase > when the file is made. > But, it sometimes return to 0. Is it correct? > The # of blocks is: stat->blocks = (inode_get_bytes(inode) + BTRFS_I(inode)->delalloc_bytes) >> 9; So I think after sub(delalloc_bytes) and before inode_add_bytes(), you may see 0 value. > > The result of the test at 2.6.37-rc4 is shown below. > (see inode no. 291) > > # df -T /test14 > Filesystem Type 1K-blocks Used Available Use% Mounted on > /dev/sdd14 btrfs 4162560 8736 3709440 1% /test14 > # dd if=/dev/zero of=/test14/dir/as001.26603 bs=1M count=100 > # dd if=/dev/zero of=/test14/dir/as002.26603 bs=1M count=200 > # dd if=/dev/zero of=/test14/dir/sy001.26603 bs=1M count=300 oflag=direct > # dd if=/dev/zero of=/test14/dir/as003.26603 bs=1M count=400 > # ls -lis /test14/dir > total 406528 > 288 0 -rw-r--r-- 1 root root 104857600 Dec 7 15:07 as001.26603 > 289 0 -rw-r--r-- 1 root root 209715200 Dec 7 15:07 as002.26603 > -> 291 99328 -rw-r--r-- 1 root root 419430400 Dec 7 15:08 as003.26603 > 290 307200 -rw-r--r-- 1 root root 314572800 Dec 7 15:08 sy001.26603 > # sleep 3 > # ls -lis /test14/dir > total 406528 > 288 0 -rw-r--r-- 1 root root 104857600 Dec 7 15:07 as001.26603 > 289 0 -rw-r--r-- 1 root root 209715200 Dec 7 15:07 as002.26603 > -> 291 99328 -rw-r--r-- 1 root root 419430400 Dec 7 15:08 as003.26603 > 290 307200 -rw-r--r-- 1 root root 314572800 Dec 7 15:08 sy001.26603 > # sleep 3 > # ls -lis /test14/dir > total 307200 > 288 0 -rw-r--r-- 1 root root 104857600 Dec 7 15:07 as001.26603 > 289 0 -rw-r--r-- 1 root root 209715200 Dec 7 15:07 as002.26603 > -> 291 0 -rw-r--r-- 1 root root 419430400 Dec 7 15:08 as003.26603 > 290 307200 -rw-r--r-- 1 root root 314572800 Dec 7 15:08 sy001.26603 > # sleep 3 > # ls -lis /test14/dir > total 409600 > 288 102400 -rw-r--r-- 1 root root 104857600 Dec 7 15:07 as001.26603 > 289 0 -rw-r--r-- 1 root root 209715200 Dec 7 15:07 as002.26603 > -> 291 0 -rw-r--r-- 1 root root 419430400 Dec 7 15:08 as003.26603 > 290 307200 -rw-r--r-- 1 root root 314572800 Dec 7 15:08 sy001.26603 > # sync > # ls -lis /test14/dir > total 1024000 > 288 102400 -rw-r--r-- 1 root root 104857600 Dec 7 15:07 as001.26603 > 289 204800 -rw-r--r-- 1 root root 209715200 Dec 7 15:07 as002.26603 > -> 291 409600 -rw-r--r-- 1 root root 419430400 Dec 7 15:08 as003.26603 > 290 307200 -rw-r--r-- 1 root root 314572800 Dec 7 15:08 sy001.26603 > > The trace result of btrfs_getattr() is shown below. > > Dec 7 15:08:03 luna kernel: ino:291 blocks:198656 i_blocks:0 i_bytes:0 delalloc_bytes:101711872 > Dec 7 15:08:06 luna kernel: ino:291 blocks:198656 i_blocks:0 i_bytes:0 delalloc_bytes:101711872 > Dec 7 15:08:09 luna kernel: ino:291 blocks:0 i_blocks:0 i_bytes:0 delalloc_bytes:0 > Dec 7 15:08:12 luna kernel: ino:291 blocks:0 i_blocks:0 i_bytes:0 delalloc_bytes:0 > Dec 7 15:08:18 luna kernel: ino:291 blocks:819200 i_blocks:819200 i_bytes:0 delalloc_bytes:0 > > > Regards, > Itoh >