Re: Actual effect of mkfs.btrfs -m raid10 /dev/sdX ... -d raid10 /dev/sdX ...

2013-11-19 Thread Hugo Mills
On Mon, Nov 18, 2013 at 11:12:03PM -0600, deadhorseconsulting wrote: In theory (going by the man page and available documentation, not 100% clear) does the following command indeed actually work as advertised and specify how metadata should be placed and kept only on the devices specified

Re: Sync() causes null pointer dereference and warning message in run_clustered_refs()

2013-11-19 Thread Pedro Fonseca
Hi Liu, Sorry, somehow I missed your email. Let me know if you need additional information. Here's the result of objdump -d -S nearby run_clustered_refs+0x877: c12a854f: 83 c4 0cadd$0xc,%esp c12a8552: eb 3f jmpc12a8593 run_clustered_refs+0x8a6 *

Re: Triple parity and beyond

2013-11-19 Thread David Brown
On 19/11/13 00:25, H. Peter Anvin wrote: On 11/18/2013 02:35 PM, Andrea Mazzoleni wrote: Hi Peter, The Cauchy matrix has the mathematical property to always have itself and all submatrices not singular. So, we are sure that we can always solve the equations to recover the data disks.

[PATCH] btrfs: allow mounting btrfs subvolumes with different ro/rw options

2013-11-19 Thread harald
From: Harald Hoyer har...@redhat.com Given the following /etc/fstab entries: /dev/sda3 /mnt/foo btrfs subvol=foo,ro 0 0 /dev/sda3 /mnt/bar btrfs subvol=bar,rw 0 0 you can't issue: $ mount /mnt/foo $ mount /mnt/bar You would have to do: $ mount /mnt/foo $ mount -o remount,rw /mnt/foo $ mount

Re: [PATCH] btrfs: allow mounting btrfs subvolumes with different ro/rw options

2013-11-19 Thread Harald Hoyer
On 11/18/2013 11:53 AM, David Sterba wrote: On Sat, Sep 14, 2013 at 01:26:22PM +0200, Harald Hoyer wrote: Any comments? Not even a no, we don't want that ? Please resend. david done -- To unsubscribe from this list: send the line unsubscribe linux-btrfs in the body of a message to

Warning in record_one_backref()

2013-11-19 Thread Pedro Fonseca
Hi, In another test, I've encountered a few situations that triggered a warning message in record_one_backref(). I'm not sure if it's serious but it is probably related to the concurrent defragment operations executed during the test. Warning dump: [ 147.558178] [ cut here

Re: Warning in record_one_backref()

2013-11-19 Thread Emil Karlson
On Tue, Nov 19, 2013 at 1:00 PM, Pedro Fonseca pfons...@mpi-sws.org wrote: Hi, In another test, I've encountered a few situations that triggered a warning message in record_one_backref(). I'm not sure if it's serious but it is probably related to the concurrent defragment operations executed

[PATCH] btrfs: replace BUG in can_modify_feature

2013-11-19 Thread David Sterba
We don't need to crash hard here, it's just reading a sysfs file. The values considered in switch are from a fixed set, the default case should not happen at all. Signed-off-by: David Sterba dste...@suse.cz --- fs/btrfs/sysfs.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git

Re: [PATCH] btrfs: allow mounting btrfs subvolumes with different ro/rw options

2013-11-19 Thread Chris Mason
Quoting har...@redhat.com (2013-11-19 05:36:05) From: Harald Hoyer har...@redhat.com [ create new vfsmounts with different states ] Thanks for resending Harald. I'll give this a shot and see if I can find any problems with it. -chris -- To unsubscribe from this list: send the line

Re: [PATCH V2] Btrfs: add support for inode properties

2013-11-19 Thread Filipe David Manana
On Wed, Nov 13, 2013 at 6:59 PM, Goffredo Baroncelli kreij...@libero.it wrote: Hi Filipe, my comments below On 2013-11-13 02:21, Filipe David Borba Manana wrote: This change adds infrastructure to allow for generic properties for inodes. Properties are name/value pairs that can be associated

[PATCH] Btrfs: add missing sysfs group remove / fix leak

2013-11-19 Thread Filipe David Borba Manana
From kmemleak: hex dump (first 32 bytes): 03 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 backtrace: [8175f5f6] kmemleak_alloc+0x26/0x50 [8118f284] kmem_cache_alloc+0x114/0x200

[PATCH v3] Btrfs: add support for inode properties

2013-11-19 Thread Filipe David Borba Manana
This change adds infrastructure to allow for generic properties for inodes. Properties are name/value pairs that can be associated with inodes for different purposes. They're stored as xattrs with the prefix btrfs. Properties can be inherited - this means when a directory inode has inheritable

[PATCH] Btrfs: fix ordered extent check in btrfs_punch_hole

2013-11-19 Thread Filipe David Borba Manana
If the ordered extent's last byte was 1 less than our region's start byte, we would unnecessarily wait for the completion of that ordered extent, because it doesn't intersect our target range. Signed-off-by: Filipe David Borba Manana fdman...@gmail.com --- fs/btrfs/file.c |2 +- 1 file

Re: [PATCH] Btrfs: add missing sysfs group remove / fix leak

2013-11-19 Thread Jeff Mahoney
On 11/19/13, 11:07 AM, Filipe David Borba Manana wrote: From kmemleak: hex dump (first 32 bytes): 03 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 backtrace: [8175f5f6]

Re: Triple parity and beyond

2013-11-19 Thread Andrea Mazzoleni
Hi Peter, Yes, 251 disks for 6 parity. To build a NxM Cauchy matrix you need to pick N+M distinct values in the GF(2^8) and we have only 2^8 == 256 available. This means that for every row we add for an extra parity level, we have to remove one of the disk columns. Note that in true, I use an

Re: Triple parity and beyond

2013-11-19 Thread Andrea Mazzoleni
Hi David, Just to say that I know your good past work, and it helped me a lot. Thanks for that! Unfortunately the Cauchy matrix is not compatible with a triple parity implementation using power coefficients. They are different and incompatible roads. I partially agree on your considerations,

Re: [PATCH V2] Btrfs: add support for inode properties

2013-11-19 Thread Goffredo Baroncelli
Hi Filipe On 2013-11-19 17:06, Filipe David Manana wrote: On Wed, Nov 13, 2013 at 6:59 PM, Goffredo Baroncelli kreij...@libero.it wrote: Hi Filipe, my comments below On 2013-11-13 02:21, Filipe David Borba Manana wrote: This change adds infrastructure to allow for generic properties for

Re: Triple parity and beyond

2013-11-19 Thread Piergiorgio Sartor
On Mon, Nov 18, 2013 at 11:08:59PM +0100, Andrea Mazzoleni wrote: Hi, I want to report that I recently implemented a support for arbitrary number of parities that could be useful also for Linux RAID and Btrfs, both currently limited to double parity. In short, to generate the parity I use

Re: Actual effect of mkfs.btrfs -m raid10 /dev/sdX ... -d raid10 /dev/sdX ...

2013-11-19 Thread deadhorseconsulting
Interesting, this confirms what I was observing. Given the wording in man pages for -m and -d which states Specify how the metadata or data must be spanned across the devices specified. I took devices specified to literally mean the devices specified after the according switch. - DHC On Tue,

Re: Triple parity and beyond

2013-11-19 Thread Ric Wheeler
On 11/19/2013 12:28 PM, Andrea Mazzoleni wrote: Hi Peter, Yes, 251 disks for 6 parity. To build a NxM Cauchy matrix you need to pick N+M distinct values in the GF(2^8) and we have only 2^8 == 256 available. This means that for every row we add for an extra parity level, we have to remove one

Re: Actual effect of mkfs.btrfs -m raid10 /dev/sdX ... -d raid10 /dev/sdX ...

2013-11-19 Thread Duncan
deadhorseconsulting posted on Tue, 19 Nov 2013 13:24:01 -0600 as excerpted: Interesting, this confirms what I was observing. Given the wording in man pages for -m and -d which states Specify how the metadata or data must be spanned across the devices specified. I took devices specified to

[PATCH] Btrfs: fix very slow inode eviction and fs unmount

2013-11-19 Thread Filipe David Borba Manana
The inode eviction can be very slow, because during eviction we tell the VFS to truncate all of the inode's pages. This results in calls to btrfs_invalidatepage() which in turn does calls to lock_extent_bits() and clear_extent_bit(). These calls result in too many merges and splits of extent_state

Re: Triple parity and beyond

2013-11-19 Thread Drew
I'm not going to claim any expert status on this discussion (the theory makes my head spin) but I will say I agree with Andrea as far as prefering his implementation for triple parity and beyond. PSHUFB has been around the intel platform since the Core2 introduced it as part of SSSE3 back in Q1

Re: Actual effect of mkfs.btrfs -m raid10 /dev/sdX ... -d raid10 /dev/sdX ...

2013-11-19 Thread Duncan
Hugo Mills posted on Tue, 19 Nov 2013 09:06:02 + as excerpted: This will happen with RAID-10. The allocator will write stripes as wide as it can: in this case, the first stripes will run across all 8 devices, until the SSDs are full, and then will write across the remaining 4 devices.

Re: Triple parity and beyond

2013-11-19 Thread Chris Murphy
On Nov 19, 2013, at 3:51 PM, Drew drew@gmail.com wrote: I'm not going to claim any expert status on this discussion (the theory makes my head spin) but I will say I agree with Andrea as far as prefering his implementation for triple parity and beyond. PSHUFB has been around the intel

[PATCH] Btrfs: improve forever loop when doing balance relocation

2013-11-19 Thread Wang Shilong
We hit a forever loop when doing balance relocation,the reason is that we firstly reserve 4M(node size is 16k).and within transaction we will try to add extra reservation for snapshot roots,this will return -EAGAIN if there has been a thread flushing space to reserve space.We will do this again

Re: Triple parity and beyond

2013-11-19 Thread John Williams
On Tue, Nov 19, 2013 at 4:54 PM, Chris Murphy li...@colorremedies.com wrote: If anything, I'd like to see two implementations of RAID 6 dual parity. The existing implementation in the md driver and btrfs could remain the default, but users could opt into Cauchy matrix based dual parity which

btrfs warning on file system defrag

2013-11-19 Thread Szőts Ákos
Dear list members, While I was defragging my file system, the following warning showed up in the dmesg: [ 6323.296521] [ cut here ] [ 6323.296551] WARNING: CPU: 5 PID: 13598 at /home/abuild/rpmbuild/BUILD/kernel- desktop-3.12.0/linux-3.12/fs/btrfs/backref.c:934

Re: fs/btrfs/extent-tree.c:8430:9: error: format not a string literal and no format arguments

2013-11-19 Thread Fengguang Wu
On Tue, Nov 19, 2013 at 07:56:35PM -0800, Kees Cook wrote: Hi! Which tree is 'devel-snb'? I don't see that on the kernel.org trees. It's my local merge branch, based on the latest upstream release. Let's CC the btrfs developers for this warning. :) Thanks, Fengguang On Tue, Nov 19, 2013

Re: Actual effect of mkfs.btrfs -m raid10 /dev/sdX ... -d raid10 /dev/sdX ...

2013-11-19 Thread Martin
On 19/11/13 23:16, Duncan wrote: So we have: 1) raid1 is exactly two copies of data, paired devices. 2) raid0 is a stripe exactly two devices wide (reinforced by to read a stripe takes only two devices), so again paired devices. Which is fine for some occasions and a very good start

Re: Actual effect of mkfs.btrfs -m raid10 /dev/sdX ... -d raid10 /dev/sdX ...

2013-11-19 Thread Martin
On 19/11/13 19:24, deadhorseconsulting wrote: Interesting, this confirms what I was observing. Given the wording in man pages for -m and -d which states Specify how the metadata or data must be spanned across the devices specified. I took devices specified to literally mean the devices

btrfsck --repair /dev/sdc (Was: [PATCH] Btrfs-progs: allow --init-extent-tree to work when extent tree is borked)

2013-11-19 Thread Martin
It's now gone back to a pattern from a full week ago: (gdb) bt #0 0x0042d576 in read_extent_buffer () #1 0x0041ee79 in btrfs_check_node () #2 0x00420211 in check_block () #3 0x00420813 in btrfs_search_slot () #4 0x00427bb4 in btrfs_read_block_groups ()