Commit Graph

65 Commits

Author SHA1 Message Date
Josef Bacik
660d3f6cde Btrfs: fix how we do delalloc reservations and how we free reservations on error
Running xfstests 269 with some tracing my scripts kept spitting out errors about
releasing bytes that we didn't actually have reserved.  This took me down a huge
rabbit hole and it turns out the way we deal with reserved_extents is wrong,
we need to only be setting it if the reservation succeeds, otherwise the free()
method will come in and unreserve space that isn't actually reserved yet, which
can lead to other warnings and such.  The math was all working out right in the
end, but it caused all sorts of other issues in addition to making my scripts
yell and scream and generally make it impossible for me to track down the
original issue I was looking for.  The other problem is with our error handling
in the reservation code.  There are two cases that we need to deal with

1) We raced with free.  In this case free won't free anything because csum_bytes
is modified before we dro the lock in our reservation path, so free rightly
doesn't release any space because the reservation code may be depending on that
reservation.  However if we fail, we need the reservation side to do the free at
that point since that space is no longer in use.  So as it stands the code was
doing this fine and it worked out, except in case #2

2) We don't race with free.  Nobody comes in and changes anything, and our
reservation fails.  In this case we didn't reserve anything anyway and we just
need to clean up csum_bytes but not free anything.  So we keep track of
csum_bytes before we drop the lock and if it hasn't changed we know we can just
decrement csum_bytes and carry on.

Because of the case where we can race with free()'s since we have to drop our
spin_lock to do the reservation, I'm going to serialize all reservations with
the i_mutex.  We already get this for free in the heavy use paths, truncate and
file write all hold the i_mutex, just needed to add it to page_mkwrite and
various ioctl/balance things.  With this patch my space leak scripts no longer
scream bloody murder.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
2011-12-15 11:04:22 -05:00
Miao Xie
76b9e23d25 Btrfs: fix orphan backref nodes
If the root node of a fs/file tree is in the block group that is
being relocated, but the others are not in the other block groups.
when we create a snapshot for this tree between the relocation tree
creation ends and ->create_reloc_tree is set to 0, Btrfs will create
some backref nodes that are the lowest nodes of the backrefs cache.
But we forget to add them into ->leaves list of the backref cache
and deal with them, and at last, they will triggered BUG_ON().

  kernel BUG at fs/btrfs/relocation.c:239!

This patch fixes it by adding them into ->leaves list of backref cache.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-11-10 20:45:05 -05:00
Yan, Zheng
84850e8d8a btrfs: check file extent backref offset underflow
Offset field in data extent backref can underflow if clone range ioctl
is used. We can reliably detect the underflow because max file size is
limited to 2^63 and max data extent size is limited by block group size.

Signed-off-by: Zheng Yan  <zheng.z.yan@intel.com>
2011-10-20 18:10:31 +02:00
Josef Bacik
36ba022ac0 Btrfs: seperate out btrfs_block_rsv_check out into 2 different functions
Currently btrfs_block_rsv_check does 2 things, it will either refill a block
reserve like in the truncate or refill case, or it will check to see if there is
enough space in the global reserve and possibly refill it.  However because of
overcommit we could be well overcommitting ourselves just to try and refill the
global reserve, when really we should just be committing the transaction.  So
breack this out into btrfs_block_rsv_refill and btrfs_block_rsv_check.  Refill
will try to reserve more metadata if it can and btrfs_block_rsv_check will not,
it will only tell you if the factor of the total space is still reserved.
Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
2011-10-19 15:12:59 -04:00
Josef Bacik
3b16a4e3c3 Btrfs: use the inode's mapping mask for allocating pages
Johannes pointed out we were allocating only kernel pages for doing writes,
which is kind of a big deal if you are on 32bit and have more than a gig of ram.
So fix our allocations to use the mapping's gfp but still clear __GFP_FS so we
don't re-enter.  Thanks,

Reported-by: Johannes Weiner <jweiner@redhat.com>
Signed-off-by: Josef Bacik <josef@redhat.com>
2011-10-19 15:12:45 -04:00
Josef Bacik
4a92b1b8d2 Btrfs: stop passing a trans handle all around the reservation code
The only thing that we need to have a trans handle for is in
reserve_metadata_bytes and thats to know how much flushing we can do.  So
instead of passing it around, just check current->journal_info for a
trans_handle so we know if we can commit a transaction to try and free up space
or not.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
2011-10-19 15:12:44 -04:00
Josef Bacik
482e6dc526 Btrfs: allow callers to specify if flushing can occur for btrfs_block_rsv_check
If you run xfstest 224 it you will get lots of messages about not being able to
delete inodes and that they will be cleaned up next mount.  This is because
btrfs_block_rsv_check was not calling reserve_metadata_bytes with the ability to
flush, so if there was not enough space, it simply failed.  But in truncate and
evict case we could easily flush space to try and get enough space to do our
work, so make btrfs_block_rsv_check take a flush argument to pass down to
reserve_metadata_bytes.  Now xfstests 224 runs fine without all those
complaints.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
2011-10-19 15:12:38 -04:00
Josef Bacik
dabdb6408c Btrfs: kill unused parts of block_rsv
The priority and refill_used flags are not used anymore, and neither is the
usage counter, so just remove them from btrfs_block_rsv.

Signed-off-by: Josef Bacik <josef@redhat.com>
2011-10-19 15:12:34 -04:00
Josef Bacik
37be25bcb6 Btrfs: kill the durable block rsv stuff
This is confusing code and isn't used by anything anymore, so delete it.

Signed-off-by: Josef Bacik <josef@redhat.com>
2011-10-19 15:12:32 -04:00
Chris Mason
ff95acb673 Merge branch 'integration' into for-linus 2011-07-27 16:18:13 -04:00
Josef Bacik
a94733d0bc Btrfs: use find_or_create_page instead of grab_cache_page
grab_cache_page will use mapping_gfp_mask(), which for all inodes is set to
GFP_HIGHUSER_MOVABLE.  So instead use find_or_create_page in all cases where we
need GFP_NOFS so we don't deadlock.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
2011-07-27 12:46:43 -04:00
Linus Torvalds
90a800de0a Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable:
  Btrfs: avoid delayed metadata items during commits
  btrfs: fix uninitialized return value
  btrfs: fix wrong reservation when doing delayed inode operations
  btrfs: Remove unused sysfs code
  btrfs: fix dereference of ERR_PTR value
  Btrfs: fix relocation races
  Btrfs: set no_trans_join after trying to expand the transaction
  Btrfs: protect the pending_snapshots list with trans_lock
  Btrfs: fix path leakage on subvol deletion
  Btrfs: drop the delalloc_bytes check in shrink_delalloc
  Btrfs: check the return value from set_anon_super
2011-06-20 08:58:53 -07:00
Chris Mason
7585717f30 Btrfs: fix relocation races
The recent commit to get rid of our trans_mutex introduced
some races with block group relocation.  The problem is that relocation
needs to do some record keeping about each root, and it was relying
on the transaction mutex to coordinate things in subtle ways.

This fix adds a mutex just for the relocation code and makes sure
it doesn't have a big impact on normal operations.  The race is
really fixed in btrfs_record_root_in_trans, which is where we
step back and wait for the relocation code to finish accounting
setup.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-06-17 13:36:58 -04:00
Linus Torvalds
e6ece70732 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable: (25 commits)
  btrfs: fix uninitialized variable warning
  btrfs: add helper for fs_info->closing
  Btrfs: add mount -o inode_cache
  btrfs: scrub: add explicit plugging
  btrfs: use btrfs_ino to access inode number
  Btrfs: don't save the inode cache if we are deleting this root
  btrfs: false BUG_ON when degraded
  Btrfs: don't save the inode cache in non-FS roots
  Btrfs: make sure we don't overflow the free space cache crc page
  Btrfs: fix uninit variable in the delayed inode code
  btrfs: scrub: don't reuse bios and pages
  Btrfs: leave spinning on lookup and map the leaf
  Btrfs: check for duplicate entries in the free space cache
  Btrfs: don't try to allocate from a block group that doesn't have enough space
  Btrfs: don't always do readahead
  Btrfs: try not to sleep as much when doing slow caching
  Btrfs: kill BTRFS_I(inode)->block_group
  Btrfs: don't look at the extent buffer level 3 times in a row
  Btrfs: map the node block when looking for readahead targets
  Btrfs: set range_start to the right start in count_range_bits
  ...
2011-06-05 06:17:23 +09:00
Chris Mason
ff5714cca9 Merge branch 'for-chris' of
git://git.kernel.org/pub/scm/linux/kernel/git/josef/btrfs-work into for-linus

Conflicts:
	fs/btrfs/disk-io.c
	fs/btrfs/extent-tree.c
	fs/btrfs/free-space-cache.c
	fs/btrfs/inode.c
	fs/btrfs/transaction.c

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-05-28 07:00:39 -04:00
Linus Torvalds
a0c3061093 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable: (58 commits)
  Btrfs: use the device_list_mutex during write_dev_supers
  Btrfs: setup free ino caching in a more asynchronous way
  btrfs scrub: don't coalesce pages that are logically discontiguous
  Btrfs: return -ENOMEM in clear_extent_bit
  Btrfs: add mount -o auto_defrag
  Btrfs: using rcu lock in the reader side of devices list
  Btrfs: drop unnecessary device lock
  Btrfs: fix the race between remove dev and alloc chunk
  Btrfs: fix the race between reading and updating devices
  Btrfs: fix bh leak on __btrfs_open_devices path
  Btrfs: fix unsafe usage of merge_state
  Btrfs: allocate extent state and check the result properly
  fs/btrfs: Add missing btrfs_free_path
  Btrfs: check return value of btrfs_inc_extent_ref()
  Btrfs: return error to caller if read_one_inode() fails
  Btrfs: BUG_ON is deleted from the caller of btrfs_truncate_item & btrfs_extend_item
  Btrfs: return error code to caller when btrfs_del_item fails
  Btrfs: return error code to caller when btrfs_previous_item fails
  btrfs: fix typo 'testeing' -> 'testing'
  btrfs: typo: 'btrfS' -> 'btrfs'
  ...
2011-05-27 13:57:12 -07:00
Josef Bacik
026fd31782 Btrfs: don't always do readahead
Our readahead is sort of sloppy, and really isn't always needed.  For example if
ls is doing a stating ls (which is the default) it's going to stat in non-disk
order, so if say you have a directory with a stupid amount of files, readahead
is going to do nothing but waste time in the case of doing the stat.  Taking the
unconditional readahead out made my test go from 57 minutes to 36 minutes.  This
means that everywhere we do loop through the tree we want to make sure we do set
path->reada properly, so I went through and found all of the places where we
loop through the path and set reada to 1.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
2011-05-23 13:03:14 -04:00
Josef Bacik
a4abeea41a Btrfs: kill trans_mutex
We use trans_mutex for lots of things, here's a basic list

1) To serialize trans_handles joining the currently running transaction
2) To make sure that no new trans handles are started while we are committing
3) To protect the dead_roots list and the transaction lists

Really the serializing trans_handles joining is not too hard, and can really get
bogged down in acquiring a reference to the transaction.  So replace the
trans_mutex with a trans_lock spinlock and use it to do the following

1) Protect fs_info->running_transaction.  All trans handles have to do is check
this, and then take a reference of the transaction and keep on going.
2) Protect the fs_info->trans_list.  This doesn't get used too much, basically
it just holds the current transactions, which will usually just be the currently
committing transaction and the currently running transaction at most.
3) Protect the dead roots list.  This is only ever processed by splicing the
list so this is relatively simple.
4) Protect the fs_info->reloc_ctl stuff.  This is very lightweight and was using
the trans_mutex before, so this is a pretty straightforward change.
5) Protect fs_info->no_trans_join.  Because we don't hold the trans_lock over
the entirety of the commit we need to have a way to block new people from
creating a new transaction while we're doing our work.  So we set no_trans_join
and in join_transaction we test to see if that is set, and if it is we do a
wait_on_commit.
6) Make the transaction use count atomic so we don't need to take locks to
modify it when we're dropping references.
7) Add a commit_lock to the transaction to make sure multiple people trying to
commit the same transaction don't race and commit at the same time.
8) Make open_ioctl_trans an atomic so we don't have to take any locks for ioctl
trans.

I have tested this with xfstests, but obviously it is a pretty hairy change so
lots of testing is greatly appreciated.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
2011-05-23 13:00:57 -04:00
Josef Bacik
7a7eaa40a3 Btrfs: take away the num_items argument from btrfs_join_transaction
I keep forgetting that btrfs_join_transaction() just ignores the num_items
argument, which leads me to sending pointless patches and looking stupid :).  So
just kill the num_items argument from btrfs_join_transaction and
btrfs_start_ioctl_transaction, since neither of them use it.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
2011-05-23 13:00:56 -04:00
Chris Mason
712673339a Merge branch 'for-chris' of git://git.kernel.org/pub/scm/linux/kernel/git/arne/btrfs-unstable-arne into inode_numbers
Conflicts:
	fs/btrfs/Makefile
	fs/btrfs/ctree.h
	fs/btrfs/volumes.h

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-05-23 06:30:52 -04:00
Chris Mason
945d8962ce Merge branch 'cleanups' of git://repo.or.cz/linux-2.6/btrfs-unstable into inode_numbers
Conflicts:
	fs/btrfs/extent-tree.c
	fs/btrfs/free-space-cache.c
	fs/btrfs/inode.c
	fs/btrfs/tree-log.c

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-05-22 12:33:42 -04:00
Chris Mason
0965537308 Merge branch 'ino-alloc' of git://repo.or.cz/linux-btrfs-devel into inode_numbers
Conflicts:
	fs/btrfs/free-space-cache.c

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-05-21 09:27:38 -04:00
Arne Jansen
a2de733c78 btrfs: scrub
This adds an initial implementation for scrub. It works quite
straightforward. The usermode issues an ioctl for each device in the
fs. For each device, it enumerates the allocated device chunks. For
each chunk, the contained extents are enumerated and the data checksums
fetched. The extents are read sequentially and the checksums verified.
If an error occurs (checksum or EIO), a good copy is searched for. If
one is found, the bad copy will be rewritten.
All enumerations happen from the commit roots. During a transaction
commit, the scrubs get paused and afterwards continue from the new
roots.

This commit is based on the series originally posted to linux-btrfs
with some improvements that resulted from comments from David Sterba,
Ilya Dryomov and Jan Schmidt.

Signed-off-by: Arne Jansen <sensille@gmx.net>
2011-05-12 14:45:20 +02:00
Justin P. Mattock
70f23fd66b treewide: fix a few typos in comments
- kenrel -> kernel
- whetehr -> whether
- ttt -> tt
- sss -> ss

Signed-off-by: Justin P. Mattock <justinmattock@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2011-05-10 10:16:21 +02:00
David Sterba
f2a97a9dbd btrfs: remove all unused functions
Remove static and global declarations and/or definitions. Reduces size
of btrfs.ko by ~3.4kB.

  text    data     bss     dec     hex filename
402081    7464     200  409745   64091 btrfs.ko.base
398620    7144     200  405964   631cc btrfs.ko.remove-all

Signed-off-by: David Sterba <dsterba@suse.cz>
2011-05-06 12:34:03 +02:00
David Sterba
b3b4aa74b5 btrfs: drop unused parameter from btrfs_release_path
parameter tree root it's not used since commit
5f39d397df ("Btrfs: Create extent_buffer
interface for large blocksizes")

Signed-off-by: David Sterba <dsterba@suse.cz>
2011-05-02 13:57:22 +02:00
David Sterba
172ddd60a6 btrfs: drop gfp parameter from alloc_extent_map
pass GFP_NOFS directly to kmem_cache_alloc

Signed-off-by: David Sterba <dsterba@suse.cz>
2011-05-02 13:57:21 +02:00
David Sterba
f993c883ad btrfs: drop unused argument from extent_io_tree_init
all callers pass GFP_NOFS, but the GFP mask argument is not used in the
function; GFP_ATOMIC is passed to radix tree initialization and it's the
only correct one, since we're using the preload/insert mechanism of
radix tree.
Let's drop the gfp mask from btrfs function, this will not change
behaviour.

Signed-off-by: David Sterba <dsterba@suse.cz>
2011-05-02 13:57:21 +02:00
David Sterba
c704005d88 btrfs: unify checking of IS_ERR and null
use IS_ERR_OR_NULL when possible, done by this coccinelle script:

@ match @
identifier id;
@@
(
- BUG_ON(IS_ERR(id) || !id);
+ BUG_ON(IS_ERR_OR_NULL(id));
|
- IS_ERR(id) || !id
+ IS_ERR_OR_NULL(id)
|
- !id || IS_ERR(id)
+ IS_ERR_OR_NULL(id)
)

Signed-off-by: David Sterba <dsterba@suse.cz>
2011-05-02 13:57:20 +02:00
Li Zefan
33345d0152 Btrfs: Always use 64bit inode number
There's a potential problem in 32bit system when we exhaust 32bit inode
numbers and start to allocate big inode numbers, because btrfs uses
inode->i_ino in many places.

So here we always use BTRFS_I(inode)->location.objectid, which is an
u64 variable.

There are 2 exceptions that BTRFS_I(inode)->location.objectid !=
inode->i_ino: the btree inode (0 vs 1) and empty subvol dirs (256 vs 2),
and inode->i_ino will be used in those cases.

Another reason to make this change is I'm going to use a special inode
to save free ino cache, and the inode number must be > (u64)-256.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
2011-04-25 16:46:09 +08:00
Li Zefan
581bb05094 Btrfs: Cache free inode numbers in memory
Currently btrfs stores the highest objectid of the fs tree, and it always
returns (highest+1) inode number when we create a file, so inode numbers
won't be reclaimed when we delete files, so we'll run out of inode numbers
as we keep create/delete files in 32bits machines.

This fixes it, and it works similarly to how we cache free space in block
cgroups.

We start a kernel thread to read the file tree. By scanning inode items,
we know which chunks of inode numbers are free, and we cache them in
an rb-tree.

Because we are searching the commit root, we have to carefully handle the
cross-transaction case.

The rb-tree is a hybrid extent+bitmap tree, so if we have too many small
chunks of inode numbers, we'll use bitmaps. Initially we allow 16K ram
of extents, and a bitmap will be used if we exceed this threshold. The
extents threshold is adjusted in runtime.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
2011-04-25 16:46:04 +08:00
Lucas De Marchi
25985edced Fix common misspellings
Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
2011-03-31 11:26:23 -03:00
Tsutomu Itoh
97d9a8a420 Btrfs: check return value of read_tree_block()
This patch is checking return value of read_tree_block(),
and if it is NULL, error processing.

Signed-off-by: Tsutomu Itoh <t-itoh@jp.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-03-28 05:37:37 -04:00
Josef Bacik
66b4ffd110 Btrfs: handle errors in btrfs_orphan_cleanup
If we cannot truncate an inode for some reason we will never delete the orphan
item associated with that inode, which means that we will loop forever in
btrfs_orphan_cleanup.  Instead of doing this just return error so we fail to
mount.  It sucks, but hey it's better than hanging.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
2011-03-17 14:21:26 -04:00
Chris Mason
c87f08ca44 Btrfs: allow balance to explicitly allocate chunks as it relocates
Btrfs device shrinking and balancing ends up reallocating all the blocks
in order to allow COW to move them to new destinations.  It is somewhat
awkward in terms of ENOSPC because most of the enospc code is built
around the idea that some operation on a reference counted tree triggers
allocations in the non-reference counted trees.

This commit changes the balancing code to deal with enospc by trying to
allocate a new chunk.  If that allocation succeeds, we go ahead and
retry whatever failed due to enospc.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-02-16 15:28:47 -05:00
Yan, Zheng
6848ad6461 Btrfs: Fix balance panic
Mark the cloned backref_node as checked in clone_backref_node()

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-02-14 16:00:03 -05:00
Tsutomu Itoh
98d5dc13e7 btrfs: fix return value check of btrfs_start_transaction()
The error check of btrfs_start_transaction() is added, and the mistake
of the error check on several places is corrected.

Signed-off-by: Tsutomu Itoh <t-itoh@jp.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-02-01 07:17:27 -05:00
Tsutomu Itoh
3612b49598 btrfs: fix return value check of btrfs_join_transaction()
The error check of btrfs_join_transaction()/btrfs_join_transaction_nolock()
is added, and the mistake of the error check in several places is
corrected.

For more stable Btrfs, I think that we should reduce BUG_ON().
But, I think that long time is necessary for this.
So, I propose this patch as a short-term solution.

With this patch:
 - To more stable Btrfs, the part that should be corrected is clarified.
 - The panic isn't done by the NULL pointer reference etc. (even if
   BUG_ON() is increased temporarily)
 - The error code is returned in the place where the error can be easily
   returned.

As a long-term plan:
 - BUG_ON() is reduced by using the forced-readonly framework, etc.

Signed-off-by: Tsutomu Itoh <t-itoh@jp.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-01-28 16:40:37 -05:00
Andi Kleen
411fc6bcef Btrfs: Fix variables set but not read (bugs found by gcc 4.6)
These are all the cases where a variable is set, but not
read which are really bugs.

- Couple of incorrect error handling fixed.
- One incorrect use of a allocation policy
- Some other things

Still needs more review.

Found by gcc 4.6's new warnings.

[akpm@linux-foundation.org: fix build.  Might have been bitrot]
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Cc: Chris Mason <chris.mason@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-10-29 15:14:31 -04:00
Chris Mason
6b5b817f10 Merge branch 'bug-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/josef/btrfs-work
Conflicts:
	fs/btrfs/extent-tree.c

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-10-29 09:27:49 -04:00
Josef Bacik
0af3d00bad Btrfs: create special free space cache inode
In order to save free space cache, we need an inode to hold the data, and we
need a special item to point at the right inode for the right block group.  So
first, create a special item that will point to the right inode, and the number
of extent entries we will have and the number of bitmaps we will have.  We
truncate and pre-allocate space everytime to make sure it's uptodate.

This feature will be turned on as soon as you mount with -o space_cache, however
it is safe to boot into old kernels, they will just generate the cache the old
fashion way.  When you boot back into a newer kernel we will notice that we
modified and not the cache and automatically discard the cache.

Signed-off-by: Josef Bacik <josef@redhat.com>
2010-10-28 15:59:09 -04:00
Josef Bacik
8bb8ab2e93 Btrfs: rework how we reserve metadata bytes
With multi-threaded writes we were getting ENOSPC early because somebody would
come in, start flushing delalloc because they couldn't make their reservation,
and in the meantime other threads would come in and use the space that was
getting freed up, so when the original thread went to check to see if they had
space they didn't and they'd return ENOSPC.  So instead if we have some free
space but not enough for our reservation, take the reservation and then start
doing the flushing.  The only time we don't take reservations is when we've
already overcommitted our space, that way we don't have people who come late to
the party way overcommitting ourselves.  This also moves all of the retrying and
flushing code into reserve_metdata_bytes so it's all uniform.  This keeps my
fs_mark test from returning -ENOSPC as soon as it starts and actually lets me
fill up the disk.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
2010-10-22 15:55:01 -04:00
Yan, Zheng
046f264f6b Btrfs: Fix null dereference in relocation.c
Fix a potential null dereference in relocation.c

Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
Acked-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-06-11 15:48:34 -04:00
Yan, Zheng
3fd0a5585e Btrfs: Metadata ENOSPC handling for balance
This patch adds metadata ENOSPC handling for the balance code.
It is consisted by following major changes:

1. Avoid COW tree leave in the phrase of merging tree.

2. Handle interaction with snapshot creation.

3. make the backref cache can live across transactions.

Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-05-25 10:34:54 -04:00
Yan, Zheng
efa5646456 Btrfs: Pre-allocate space for data relocation
Pre-allocate space for data relocation. This can detect ENOPSC
condition caused by fragmentation of free space.

Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-05-25 10:34:53 -04:00
Yan, Zheng
a22285a6a3 Btrfs: Integrate metadata reservation with start_transaction
Besides simplify the code, this change makes sure all metadata
reservation for normal metadata operations are released after
committing transaction.

Changes since V1:

Add code that check if unlink and rmdir will free space.

Add ENOSPC handling for clone ioctl.

Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-05-25 10:34:50 -04:00
Yan, Zheng
f0486c68e4 Btrfs: Introduce contexts for metadata reservation
Introducing metadata reseravtion contexts has two major advantages.
First, it makes metadata reseravtion more traceable. Second, it can
reclaim freed space and re-add them to the itself after transaction
committed.

Besides add btrfs_block_rsv structure and related helper functions,
This patch contains following changes:

Move code that decides if freed tree block should be pinned into
btrfs_free_tree_block().

Make space accounting more accurate, mainly for handling read only
block groups.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-05-25 10:34:50 -04:00
Tejun Heo
5a0e3ad6af include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-30 22:02:32 +09:00
Josef Bacik
2ac55d41b5 Btrfs: cache the extent state everywhere we possibly can V2
This patch just goes through and fixes everybody that does

lock_extent()
blah
unlock_extent()

to use

lock_extent_bits()
blah
unlock_extent_cached()

and pass around a extent_state so we only have to do the searches once per
function.  This gives me about a 3 mb/s boots on my random write test.  I have
not converted some things, like the relocation and ioctl's, since they aren't
heavily used and the relocation stuff is in the middle of being re-written.  I
also changed the clear_extent_bit() to only unset the cached state if we are
clearing EXTENT_LOCKED and related stuff, so we can do things like this

lock_extent_bits()
clear delalloc bits
unlock_extent_cached()

without losing our cached state.  I tested this thoroughly and turned on
LEAK_DEBUG to make sure we weren't leaking extent states, everything worked out
fine.

Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-03-15 11:00:13 -04:00
Josef Bacik
73f73415ca Btrfs: change how we mount subvolumes
This work is in preperation for being able to set a different root as the
default mounting root.

There is currently a problem with how we mount subvolumes.  We cannot currently
mount a subvolume of a subvolume, you can only mount subvolumes/snapshots of the
default subvolume.  So say you take a snapshot of the default subvolume and call
it snap1, and then take a snapshot of snap1 and call it snap2, so now you have

/
/snap1
/snap1/snap2

as your available volumes.  Currently you can only mount / and /snap1,
you cannot mount /snap1/snap2.  To fix this problem instead of passing
subvolid=<name> you must pass in subvolid=<treeid>, where <treeid> is
the tree id that gets spit out via the subvolume listing you get from
the subvolume listing patches (btrfs filesystem list).  This allows us
to mount /, /snap1 and /snap1/snap2 as the root volume.

In addition to the above, we also now read the default dir item in the
tree root to get the root key that it points to.  For now this just
points at what has always been the default subvolme, but later on I plan
to change it to point at whatever root you want to be the new default
root, so you can just set the default mount and not have to mount with
-o subvolid=<treeid>.  I tested this out with the above scenario and it
worked perfectly.  Thanks,

mount -o subvol operates inside the selected subvolid.  For example:

mount -o subvol=snap1,subvolid=256 /dev/xxx /mnt

/mnt will have the snap1 directory for the subvolume with id
256.

mount -o subvol=snap /dev/xxx /mnt

/mnt will be the snap directory of whatever the default subvolume
is.

Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-03-15 10:58:13 -04:00