(2010/12/07 18:25), Li Zefan wrote: > 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. Yes, I also think so. But, I think that such a state is too long for only the update timing... > >> >> 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 >> > -- > To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > > -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
