Creating snapshot passes extent_root to commit its transaction,
but it can lead to the warning of checking root for quota in
the __btrfs_end_transaction() when someone else is committing
the current transaction. Since we've recorded the needed root
in trans_handle, just use it to get rid of the warning.
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
If one of qgroup fails to reserve firstly, we should return immediately,
it is unnecessary to continue check.
Signed-off-by: Wang Shilong <wangsl-fnst@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
The callers of lookup_inline_extent_info all handle getting an error back
properly, so return an error if we have corruption instead of being a jerk and
panicing. Still WARN_ON() since this is kind of crucial and I've been seeing it
a bit too much recently for my taste, I think we're doing something wrong
somewhere. Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Doing this would reliably fail with -EBUSY for me:
# mount /dev/sdb2 /mnt/scratch; umount /mnt/scratch; mkfs.btrfs -f /dev/sdb2
...
unable to open /dev/sdb2: Device or resource busy
because mkfs.btrfs tries to open the device O_EXCL, and somebody still has it.
Using systemtap to track bdev gets & puts shows a kworker thread doing a
blkdev put after mkfs attempts a get; this is left over from the unmount
path:
btrfs_close_devices
__btrfs_close_devices
call_rcu(&device->rcu, free_device);
free_device
INIT_WORK(&device->rcu_work, __free_device);
schedule_work(&device->rcu_work);
so unmount might complete before __free_device fires & does its blkdev_put.
Adding an rcu_barrier() to btrfs_close_devices() causes unmount to wait
until all blkdev_put()s are done, and the device is truly free once
unmount completes.
Cc: stable@vger.kernel.org
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Remove a useless function declaration
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Using spinning case instead of blocking will result in better concurrency
overall.
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
The delayed inode code batches up changes to the btree in hopes of doing
them in bulk. As the changes build up, processes kick off worker
threads and wait for them to make progress.
The current code kicks off an async work queue item for each delayed
node, which creates a lot of churn. It also uses a fixed 1 HZ waiting
period for the throttle, which allows us to build a lot of pending
work and can slow down the commit.
This changes us to watch a sequence counter as it is bumped during the
operations. We kick off fewer work items and have each work item do
more work.
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Raid56 merge (merge commit e942f88) had mistakenly removed a call to
__cancel_balance(), which resulted in balance not cleaning up after itself
after a successful finish. (Cleanup includes switching the state, removing
the balance item and releasing mut_ex_op testnset lock.) Bring it back.
Reported-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Commit 24542bf7ea changed preallocation of
extents to cap the max size we try to allocate. It's a valid change,
but the extent reservation code is also used by balance, and that
can't tolerate a smaller extent being allocated.
__btrfs_prealloc_file_range already has a min_size parameter, which is
used by relocation to request a specific extent size. This commit
adds an extra check to enforce that minimum extent size.
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Reported-by: Stefan Behrens <sbehrens@giantdisaster.de>
Commit 5ac00add added a testnset mutex and code that disallows
running administrative tasks in parallel. It is prevented that
the device add/delete/balance/replace/resize operations are
started in parallel. By mistake, the defragmentation operation
was included in the check for mutually exclusiveness as well.
This is fixed with this commit.
Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Only let one trans handle to wait for other handles, otherwise we
will get ABBA issues.
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Btrfs balance can easily hit BUG_ON in these places, but we want
to it bail out gracefully after we force the whole filesystem to
readonly. So we use btrfs_std_error hook in place of BUG_ON.
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
We can bail out from here gracefully instead of a cold BUG_ON.
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
We first use btrfs_std_error hook to replace with BUG_ON, and we
also need to cleanup what is left, including reloc roots rbtree
and reloc roots list.
Here we use a helper function to cleanup both rbtree and list, and
since this function can also be used in the balance recover path,
we also make the change as well to keep code simple.
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
If the async transaction commitment failed, we need close the
current transaction handler, or the current transaction will be
blocked to commit because of this orphan handler.
We fix the problem by doing sync transaction commitment, that is
to invoke btrfs_commit_transaction().
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
There are several bugs at error path of create_snapshot() when the
transaction commitment failed.
- access the freed transaction handler. At the end of the
transaction commitment, the transaction handler was freed, so we
should not access it after the transaction commitment.
- we were not aware of the error which happened during the snapshot
creation if we submitted a async transaction commitment.
- pending snapshot access vs pending snapshot free. when something
wrong happened after we submitted a async transaction commitment,
the transaction committer would cleanup the pending snapshots and
free them. But the snapshot creators were not aware of it, they
would access the freed pending snapshots.
This patch fixes the above problems by:
- remove the dangerous code that accessed the freed handler
- assign ->error if the error happens during the snapshot creation
- the transaction committer doesn't free the pending snapshots,
just assigns the error number and evicts them before we unblock
the transaction.
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
We need to inc the nlink of deleted entries when running replay so we can do the
unlink on the fs_root and get everything cleaned up and then have the orphan
cleanup do the right thing. The problem is inc_nlink complains about this, even
thought it still does the right thing. So use set_nlink() if our i_nlink is 0
to keep users from seeing the warnings during log replay. Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
tilegx_defconfig:
fs/btrfs/raid56.c: In function 'btrfs_alloc_stripe_hash_table':
fs/btrfs/raid56.c:206:3: error: implicit declaration of function 'vzalloc' [-Werror=implicit-function-declaration]
fs/btrfs/raid56.c:206:9: warning: assignment makes pointer from integer without a cast [enabled by default]
fs/btrfs/raid56.c:226:4: error: implicit declaration of function 'vfree' [-Werror=implicit-function-declaration]
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
We want to avoid module.h where posible, since it in turn includes
nearly all of header space. This means removing it where it is not
required, and using export.h where we are only exporting symbols via
EXPORT_SYMBOL and friends.
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Apparently when we do inline extents we allow the data to overlap the last chunk
of the btrfs_file_extent_item, which means that we can possibly have a
btrfs_file_extent_item that isn't actually as large as a btrfs_file_extent_item.
This messes with us when we try to overwrite the extent when logging new extents
since we expect for it to be the right size. To fix this just delete the item
and try to do the insert again which will give us the proper sized
btrfs_file_extent_item. This fixes a panic where map_private_extent_buffer
would blow up because we're trying to write past the end of the leaf. Thanks,
Cc: stable@vger.kernel.org
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
The stripe hash table is large, starting with allocation order 4 and can go as
high as order 7 in case lock debugging is turned on and structure padding
happens.
Observed mount failure:
mount: page allocation failure: order:7, mode:0x200050
Pid: 8234, comm: mount Tainted: G W 3.8.0-default+ #267
Call Trace:
[<ffffffff81114353>] warn_alloc_failed+0xf3/0x140
[<ffffffff811171d2>] ? __alloc_pages_direct_compact+0x92/0x250
[<ffffffff81117ac3>] __alloc_pages_nodemask+0x733/0x9d0
[<ffffffff81152878>] ? cache_alloc_refill+0x3f8/0x840
[<ffffffff811528bc>] cache_alloc_refill+0x43c/0x840
[<ffffffff811302eb>] ? is_kernel_percpu_address+0x4b/0x90
[<ffffffffa00a00ac>] ? btrfs_alloc_stripe_hash_table+0x5c/0x130 [btrfs]
[<ffffffff811531d7>] kmem_cache_alloc_trace+0x247/0x270
[<ffffffffa00a00ac>] btrfs_alloc_stripe_hash_table+0x5c/0x130 [btrfs]
[<ffffffffa003133f>] open_ctree+0xb2f/0x1f90 [btrfs]
[<ffffffff81397289>] ? string+0x49/0xe0
[<ffffffff813987b3>] ? vsnprintf+0x443/0x5d0
[<ffffffffa0007cb6>] btrfs_mount+0x526/0x600 [btrfs]
[<ffffffff8115127c>] ? cache_alloc_debugcheck_after+0x4c/0x200
[<ffffffff81162b90>] mount_fs+0x20/0xe0
[<ffffffff8117db26>] vfs_kern_mount+0x76/0x120
[<ffffffff811801b6>] do_mount+0x386/0x980
[<ffffffff8112a5cb>] ? strndup_user+0x5b/0x80
[<ffffffff81180840>] sys_mount+0x90/0xe0
[<ffffffff81962e99>] system_call_fastpath+0x16/0x1b
Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
The original code is a little confusing and not clear, The right
way to deal with the kernel code like this:
[...]
if (ret)
goto out;
[...]
So i move the common clean_up code to the place labeled with
out_fail, this will be easier to maintain.
Signed-off-by: Wang Shilong <wangsl-fnst@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
commit eb6b88d92c leads into another bug.
If it is just because qgroup_reserve fails, the function btrfs_qgroup_free
should not be called, otherwise, it will cause the wrong quota accounting.
Signed-off-by: Wang Shilong <wangsl-fnst@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
The check work has been done just before the function btrfs_clean_quota_tree
is called, it is not necessary to check it again, remove it.
Signed-off-by: Wang Shilong <wangsl-fnst@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Return ENOMEM rather trigger BUG_ON, fix it.
Signed-off-by: Wang Shilong <wangsl-fnst@cn.fujitsu.com>
Reviewed-by: Miao Xie <miaox@cn.fujitsu.com>
Reviewed-by: Zach Brown <zab@redhat.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Steps to reproduce:
i=0
ncases=100
mkfs.btrfs <disk>
mount <disk> <mnt>
btrfs quota enable <mnt>
btrfs qgroup create 2/1 <mnt>
while [ $i -le $ncases ]
do
btrfs qgroup create 1/$i <mnt>
btrfs qgroup assign 1/$i 2/1 <mnt>
i=$(($i+1))
done
btrfs quota disable <mnt>
umount <mnt>
btrfsck <mnt>
You can also use the commands:
btrfs-debug-tree <disk> | grep QGROUP
You will find there are still items existed.The reasons why this happens
is because the original code just checks slots[0]==0 and returns.
We try to fix it by deleting the leaf one by one.
Signed-off-by: Wang Shilong <wangsl-fnst@cn.fujitsu.com>
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
The nodesize is capped at 64k and there are enough pages preallocated in
extent_buffer::inline_pages. The fallback to kmalloc never happened
because even on the smallest page size considered (4k) inline_pages
covered the needs.
Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
When deleting a snapshot/subvolume, we need remove root ref/backref,
dir entries and update the dir inode, so we must reserve free space
for those operations.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
There are two problems in the space reservation of the snapshot/
subvolume creation.
- don't reserve the space for the root item insertion
- the space which is reserved in the qgroup is different with
the free space reservation. we need reserve free space for
7 items, but in qgroup reservation, we need reserve space only
for 3 items.
So we implement new metadata reservation functions for the
snapshot/subvolume creation.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Since we have grabbed the parent inode at the beginning of the
snapshot creation, and both sync and async snapshot creation
release it after the pending snapshots are actually created,
it is safe to access the parent inode directly during the snapshot
creation, we needn't use dget_parent/dput to fix the parent dentry
and get the dir inode.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Dave pointed out that he saw messages from btrfs although there was no
such filesystem on his computers. The automatic device scan is called on
every new blockdevice if the usual distro udev rule set is used. The
printk introduced in 6f60cbd3ae was a remainder from copying
portions of code from btrfs_get_bdev_and_sb which is used under
different conditions and the warning makes sense there.
Reported-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
While doing cleanup work on an aborted transaction, we've set
the global running transaction pointer to NULL _before_ waiting all
other transaction handles to finish, so others'd hit NULL pointer
crash when referencing the global running transaction pointer.
This first sets a hint to avoid new transaction handle joining, then
waits other existing handles to abort or finish so that we can safely
set the above global pointer to NULL.
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
When we abort a transaction while fsyncing, we'll skip freeing log roots
part of committing a transaction, which leads to memory leak.
This adds a 'free log roots' in putting super when no more users hold
references on log roots, so it's safe and clean.
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
I noticed while looking into a tree logging bug that we aren't logging inline
extents properly. Since this requires copying and it shouldn't happen too often
just force us to copy everything for the inode into the tree log when we have an
inline extent. With this patch we have valid data after a crash when we write
an inline extent. Thanks,
Cc: stable@vger.kernel.org
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Though most of the btrfs codes are using ALIGN macro for page alignment,
there are still some codes using open-coded alignment like the
following:
------
u64 mask = ((u64)root->stripesize - 1);
u64 ret = (val + mask) & ~mask;
------
Or even hidden one:
------
num_bytes = (end - start + blocksize) & ~(blocksize - 1);
------
Sometimes these open-coded alignment is not so easy to understand for
newbie like me.
This commit changes the open-coded alignment to the ALIGN macro for a
better readability.
Also there is a previous patch from David Sterba with similar changes,
but the patch is for 3.2 kernel and seems not merged.
http://www.spinics.net/lists/linux-btrfs/msg12747.html
Cc: David Sterba <dave@jikos.cz>
Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Before we forced to change a file's NOCOW and COMPRESS flag due to
the parent directory's, but this ends up a bad idea, because it
confuses end users a lot about file's NOCOW status, eg. if someone
change a file to NOCOW via 'chattr' and then rename it in the current
directory which is without NOCOW attribute, the file will lose the
NOCOW flag silently.
This diables 'change flags in rename', so from now on we'll only
inherit flags from the parent directory on creation stage while in
other places we can use 'chattr' to set NOCOW or COMPRESS flags.
Reported-by: Marios Titas <redneb8888@gmail.com>
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
While inserting dir index and updating inode for a snapshot, we'd
add delayed items which consume trans->block_rsv, if we don't have
any space reserved in this trans handle, we either just return or
reserve space again.
But before creating pending snapshots during committing transaction,
we've done a release on this trans handle, so we don't have space reserved
in it at this stage.
What we're using is block_rsv of pending snapshots which has already
reserved well enough space for both inserting dir index and updating
inode, so we need to set trans handle to indicate that we have space
now.
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
I've experienced filesystem freezes with permanent spikes in the active
process count for quite a while, particularly on filesystems whose
available raw space has already been fully allocated to chunks.
While looking into this, I found a pretty obvious error in
do_chunk_alloc: it sets space_info->chunk_alloc, but if
btrfs_alloc_chunk returns an error other than ENOSPC, it returns leaving
that flag set, which causes any other threads waiting for
space_info->chunk_alloc to become zero to spin indefinitely.
I haven't double-checked that this patch fixes the failure I've observed
fully (it's not exactly trivial to trigger), but it surely is a bug and
the fix is trivial, so... Please put it in :-)
What I saw in that function also happens to explain why in some cases I
see filesystems allocate a huge number of chunks that remain unused
(leading to the scenario above, of not having more chunks to allocate).
It happens for data and metadata, but not necessarily both. I'm
guessing some thread sets the force_alloc flag on the corresponding
space_info, and then several threads trying to get disk space end up
attempting to allocate a new chunk concurrently. All of them will see
the force_alloc flag and bump their local copy of force up to the level
they see first, and they won't clear it even if another thread succeeds
in allocating a chunk, thus clearing the force flag. Then each thread
that observed the force flag will, on its turn, force the allocation of
a new chunk. And any threads that come in while it does that will see
the force flag still set and pick it up, and so on. This sounds like a
problem to me, but... what should the correct behavior be? Clear
force_flag once we copy it to a local force? Reset force to the
incoming value on every loop? Set the flag to our incoming force if we
have it at first, clear our local flag, and move it from the space_info
when we determined that we are the thread that's going to perform the
allocation?
btrfs: clear chunk_alloc flag on retryable failure
From: Alexandre Oliva <oliva@gnu.org>
If btrfs_alloc_chunk fails with e.g. ENOMEM, we exit do_chunk_alloc
without clearing chunk_alloc in space_info. As a result, any further
calls to do_chunk_alloc on that filesystem will start busy-waiting for
chunk_alloc to be cleared, but it never will be. This patch adjusts
do_chunk_alloc so that it clears this flag in case of an error.
Signed-off-by: Alexandre Oliva <oliva@gnu.org>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
When a subvolume is removed, we remove the root item from the root tree,
while the tree blocks and backrefs remain for a while. When backref walking
comes across one of those orphan tree blocks, it can find a backref for a
no longer existing root. This is all good, we only must tolerate
__resolve_indirect_ref returning an error and continue with the good refs
found.
Reported-by: Alex Lyakas <alex.btrfs@zadarastorage.com>
Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
A user reported hitting the BUG_ON() in btrfs_finished_ordered_io() where we had
csums on a NOCOW extent. This can happen if we have NODATACOW set but not
NODATASUM set, which can happen in two cases, either we mount with -o nodatacow
and then write into preallocated space, or chattr +C a directory and move a file
into that directory. Liu has fixed the move case in a different place, but this
fixes the mount -o nodatacow case. Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
If we remount the fs to close the auto defragment or make the fs R/O,
we should stop the auto defragment.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
When running the 083th case of xfstests on the filesystem with
"compress-force=lzo", the following WARNINGs were triggered.
WARNING: at fs/btrfs/inode.c:7908
WARNING: at fs/btrfs/inode.c:7909
WARNING: at fs/btrfs/inode.c:7911
WARNING: at fs/btrfs/extent-tree.c:4510
WARNING: at fs/btrfs/extent-tree.c:4511
This problem was introduced by the patch "Btrfs: fix deadlock due
to unsubmitted". In this patch, there are two bugs which caused
the above problem.
The 1st one is a off-by-one bug, if the DIO write return 0, it is
also a short write, we need release the reserved space for it. But
we didn't do it in that patch. Fix it by change "ret > 0" to
"ret >= 0".
The 2nd one is ->outstanding_extents was increased twice when
a short write happened. As we know, ->outstanding_extents is
a counter to keep track of the number of extent items we may
use duo to delalloc, when we reserve the free space for a
delalloc write, we assume that the write will introduce just
one extent item, so we increase ->outstanding_extents by 1 at
that time. And then we will increase it every time we split the
write, it is done at the beginning of btrfs_get_blocks_direct().
So when a short write happens, we needn't increase
->outstanding_extents again. But this patch done.
In order to fix the 2nd problem, I re-write the logic for
->outstanding_extents operation. We don't increase it at the
beginning of btrfs_get_blocks_direct(), instead, we just
increase it when the split actually happens.
Reported-by: Mitch Harder <mitch.harder@sabayonlinux.org>
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
This comes from one of btrfs's project ideas,
As we defragment files, we break any sharing from other snapshots.
The balancing code will preserve the sharing, and defrag needs to grow this
as well.
Now we're able to fill the blank with this patch, in which we make full use of
backref walking stuff.
Here is the basic idea,
o set the writeback ranges started by defragment with flag EXTENT_DEFRAG
o at endio, after we finish updating fs tree, we use backref walking to find
all parents of the ranges and re-link them with the new COWed file layout by
adding corresponding backrefs.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
We try to limit the size of a chunk to 10GB, which keeps the unit of
work reasonable during balance and resize operations. The limit checks
were taking into account the number of copies of the data we had but
what they really should be doing is comparing against the logical
size of the chunk we're creating.
This moves the code around a little to use the count of data stripes
from raid5/6.
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Very large fallocate requests are cpu bound and result in extents with a
repeating pattern of ever decreasing size:
$ time fallocate -l 1T file
real 0m13.039s
( an excerpt of the extents from btrfs-debug-tree: )
prealloc data disk byte 1536292564992 nr 397312
prealloc data disk byte 1536292962304 nr 196608
prealloc data disk byte 1536293158912 nr 98304
prealloc data disk byte 1536293257216 nr 49152
prealloc data disk byte 1536293306368 nr 24576
prealloc data disk byte 1536293330944 nr 12288
prealloc data disk byte 1536293343232 nr 8192
prealloc data disk byte 1536293351424 nr 4096
prealloc data disk byte 1536293355520 nr 4096
prealloc data disk byte 1536293359616 nr 4096
The excessive cpu use comes from __btrfs_prealloc_file_range() trying to
allocate the entire remaining size after each extent is allocated.
btrfs_reserve_extent() repeatedly cuts this requested size in half until
it gets down to the size that the allocators can return. We limit the
problem for now by capping each reservation at 256 meg.
The small extents come from a masking bug when decreasing the requested
reservation size. The high 32bits are cleared and the remaining low
bits might happen to reserve a small size. Fix this by using
round_down() which properly casts the mask.
After these fixes huge fallocate requests are fast and result in nice
large extents:
$ time fallocate -l 1T file
real 0m0.082s
prealloc data disk byte 1112425889792 nr 268435456
prealloc data disk byte 1112694325248 nr 268435456
prealloc data disk byte 1112962760704 nr 268435456
Reported-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Zach Brown <zab@redhat.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
__btrfs_close_devices() clones btrfs device structs with
memcpy(). Some of the fields in the clone are reinitialized, but it's
missing to init io_lock. In mainline this goes unnoticed, but on RT it
leaves the plist pointing to the original about to be freed lock
struct.
Initialize io_lock after cloning, so no references to the original
struct are left.
Reported-and-tested-by: Mike Galbraith <efault@gmx.de>
Cc: stable@vger.kernel.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Liu Bo