On Fri, 2008-08-08 at 09:56 -0400, Chris Mason wrote: > So you mkfs ; dd large file ; rm large file ; look for discards? > > Try rm large file ; sync ; sync; look for discards Yeah, I did that. The actual data extent isn't getting removed. [root@dyn-226 /]# modprobe mtdram total_size=280000 [root@dyn-226 /]# modprobe mtdchar [root@dyn-226 /]# ftl_format /dev/mtd0 Partition size = 280000 kb, erase unit size = 128 kb, 1 transfer units Reserved 5%, formatted size = 262765 kb Erasing all blocks... +++++++*+++++++*+++++++*+++++++*+++++++*+++++++*+++++++*+++++++*+++++++*+++++++*+++++++*+++++++*+++++++*+++++++*+++++++*+++++++*+++++++*+++++++*+++++++*+++++++*+++++++*+++++++*+++++++*+++++++*+++++++*+++++++*+++++++*+++++++*+++++++*+++++++*+++++++*+++++++*+++++++*+++++++*+ Writing erase unit headers... format successful. [root@dyn-226 /]# modprobe ftl [root@dyn-226 /]# ~dwmw2/btrfs-progs-unstable/mkfs.btrfs /dev/ftla fs created label (null) on /dev/ftla nodesize 4096 leafsize 4096 sectorsize 4096 size 256.61MB Btrfs Btrfs v0.15 [root@dyn-226 /]# mount -tbtrfs /dev/ftla /mnt/spare [root@dyn-226 /]# cd /mnt/spare [root@dyn-226 spare]# cp /etc/services . [root@dyn-226 spare]# sync [root@dyn-226 spare]# hexdump -C /dev/ftla | grep /etc/services: 00c00000 23 20 2f 65 74 63 2f 73 65 72 76 69 63 65 73 3a |# /etc/services:| [root@dyn-226 spare]# dmesg -c > /dev/null [root@dyn-226 spare]# rm services [root@dyn-226 spare]# sync [root@dyn-226 spare]# dmesg num_bytes 4096, map_length 24576 Discard from stripe 0: 73808-8 FTL erase sector 73808 for 8 sectors num_bytes 4096, map_length 12288 Discard from stripe 0: 73832-8 FTL erase sector 73832 for 8 sectors num_bytes 4096, map_length 20480 Discard from stripe 0: 73816-8 FTL erase sector 73816 for 8 sectors [root@dyn-226 spare]# hexdump -C /dev/ftla | grep /etc/services: 00c00000 23 20 2f 65 74 63 2f 73 65 72 76 69 63 65 73 3a |# /etc/services:| [root@dyn-226 spare]# echo $((0xc00000/512)) 24576 -- dwmw2 -- 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
