similar to: [RFC][PATCH] Fix nodatacow check

Hello, This is updated version of nodatacow patch. To check whether a given file extent is referenced by multiple snapshots, the checker walks down the fs tree through dead root and checks all tree blocks in the path. We can easily detect whether a given tree block is directly referenced by other snapshot. We can also detect any indirect reference from other snapshot by checking

Hello, Trying to put together a list of TODO items for btrfs so we can update the wiki page fully. So far these things are on the list * Proper ENOSPC handling * O_DIRECT support (without checksumming) * AIO support * Subvolume quotas and inherited space usage information * Snapshot removal * QA Suite for automated regression testing * Reserved space for online fsck and the ability to add

I have a 3 disk raid1 filesystem mounted with nodatacow. I have a folder in said filesystem with the ''C'' NOCOW & ''Z'' Not_Compressed flags set for good measure. I then copy in a large file and proceed to make random modifications. Filefrag shows no additional extents created, good so far. A big thank you to the those devs who got that working. However, after

hello, Chris In the next several months, I will have a lot of spare time. I will be happy if you assign some work to me. I have learn linux kernel for years but only fix a few small bugs in IP stack. In the past few months, I read some EXT4/VFS codes. I began reading source of btrfs ten days ago and have read it twice now. Regards YZ

To reproduce the bug: # mount -o nodatacow /dev/sda7 /mnt/ # dd if=/dev/zero of=/mnt/tmp bs=4K count=1 1+0 records in 1+0 records out 4096 bytes (4.1 kB) copied, 0.000136115 s, 30.1 MB/s # dd if=/dev/zero of=/mnt/tmp bs=4K count=1 conv=notrunc oflag=direct dd: writing `/mnt/tmp'': Input/output error 1+0 records in 0+0 records out btrfs_ordered_update_i_size() may return

I set the C (NOCOW) and z (Not_Compressed) flags on a folder but the extent counts of files contained there keep increasing. Said files are large and frequently modified but not changing in size. This does not happen when the filesystem is mounted with nodatacow. I''m using this as a workaround since subvolumes can''t be mounted with different options simultaneously. ie. one with

Hello, is it possible to set nodatacow on a per-file basis? I couldn''t find anything. If not, wouldn''t that be a great feature to get around the performance issues with VM and database storage? Of course cloning should still cause COW. Thanks, Ralf-Peter -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to

Hello, This patch simplifies the nodatacow checker. If all references were created after the latest snapshot, then we can avoid COW safely. This patch also updates run_delalloc_nocow to do more fine-grained checking. Regards Signed-off-by: Yan Zheng <zheng.yan@oracle.com> --- diff -urp 3/fs/btrfs/ctree.h 4/fs/btrfs/ctree.h --- 3/fs/btrfs/ctree.h 2008-10-27 16:31:51.000000000 +0800 +++

Hi, I recompiled my kernel today, and when the btrfs-0.13 option is enabled (CONFIG_BTR_FS=y) I cannot boot on my reiserfs-3.6 partition any more. The kernel says that is cannot mount /dev/sdc6. I can boot the kernel when I recompile it with the same options and CONFIG_BTR_FS=n, and with the same boot options as well. Everything is amd64 on my system (kernel + programs). Here is a screenshot of

I was playing around with btrfs, and did a mkfs.btrfs on one of my partition. Mistakes, it was my data partition (ext3 based). I have not yet mounted the device, but the mkfs.btrfs continued to completion. Is it possible to salvage my ext3 filesystem? Anyway to reverse the effect of mkfs.btrfs? Thank you for your help/answer. -- Regards, Peter Teoh

I want to eliminate the COW feature on all of my OS files. It is a nice feature for user files, but I don''t see a clear benefit for the actual OS files. And I suspect that COW induced fragmentation is causing or aggravating problems with my system including the boot open_ctree problem. I had planned to recursively chattr these files to "nodatacow" status but then I ran

Hello, This patch adds rollback support for the converter, the converter can roll back a conversion if the image file haven't been modified. In addition, I rearrange some codes in convert.c and add a few comments. Regards YZ --- diff -r 12138d4beeb0 convert.c --- a/convert.c Fri Jan 04 11:29:55 2008 -0500 +++ b/convert.c Mon Jan 07 23:35:25 2008 +0800 @@ -33,6 +33,7 @@ #include

Hi all, I''m running btrfs in a 3-disk RAID1 configuration. After a hard power-off, I''m seeing a lot of hung I/O tasks on this volume, apparently due to a corrupt leaf. I first noticed the problem on kernel 3.4.7, and it''s persisted with 3.4.8. Relevant parts of the kernel log follow. [ 85.179621] block group 38684065792 has an wrong amount of free space [

Hello everyone, Btrfs v0.10 is now available for download from: http://oss.oracle.com/projects/btrfs/ Btrfs is still in an early alpha state, and the disk format is not finalized. v0.10 introduces a new disk format, and is not compatible with v0.9. The core of this release is explicit back references for all metadata blocks, data extents, and directory items. These are a crucial building

Hello everyone, Btrfs v0.10 is now available for download from: http://oss.oracle.com/projects/btrfs/ Btrfs is still in an early alpha state, and the disk format is not finalized. v0.10 introduces a new disk format, and is not compatible with v0.9. The core of this release is explicit back references for all metadata blocks, data extents, and directory items. These are a crucial building

Hi Seto, please could you update also the man page too ? Why it was not provided a way to clear a *single* flag ? To me it seems a bit too long to clear all the flag (btrfs mount-option clear) and then set the right one. As user interface I suggest something like chmod: btrfs mount-option set +ssd,skip_balance -nodatacow /dev/sdX or btrfs mount-option set =ssd,skip_balance,nodatacow

Hi, If i set strict allocate = yes in samba to speed up the transfer of a mssql database dump, then btrfs does not compress the file. I have tried it also by just copying a small file in Windows to the samba share and the same. I have tried btrfs mount options autodefrag and then btrfs fi defrag -c and the file still does not get compressed. I have tried kernels 3.6.11, 3.8 and 3.10.7 on FC16

Hi all, I am using a single volume across two devices sdb7 and sda1, initially created on sdb7, and added sda1 using btrfs-vol later. The fstab entry: /dev/disk/by-id/scsi-SATA_ST31000333AS_9TE12DSC-part7 /mnt/btrfs btrfs defaults 1 2 Now after boot I get: ---- device fsid c4822885057410c-d2d65a83c2f15fb4 devid 1 transid 73034 /dev/sdb7 btrfs: failed to read chunk tree on sdb7 ---- So I have

Hi, Here''s an implementation of NFS support for btrfs. It does not work in one particular case as described in http://www.mail-archive.com/linux-btrfs@vger.kernel.org/msg00298.html. This uses the btrfs_iget helper introduced previously. Comments ? --- Signed-off-by: Balaji Rao <balajirrao@gmail.com> diff -r 3f0eee804974 Makefile --- a/Makefile Thu Jun 26 10:34:20 2008 -0400

Christoph Hellwig wrote: > There are a lot of variables when using qemu. > > The most important one are: > > - the cache mode on the device. The default is cache=writethrough, > which is not quite optimal. You generally do want to use cache=none > which uses O_DIRECT in qemu. > - if the backing image is sparse or not. > - if you use barrier - both in the host