Commit Graph

264329 Commits

Author SHA1 Message Date
Lukas Czerner
f4c697e640 btrfs: return EINVAL if start > total_bytes in fitrim ioctl
We should retirn EINVAL if the start is beyond the end of the file
system in the btrfs_ioctl_fitrim(). Fix that by adding the appropriate
check for it.

Also in the btrfs_trim_fs() it is possible that len+start might overflow
if big values are passed. Fix it by decrementing the len so that start+len
is equal to the file system size in the worst case.

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
2011-10-20 18:10:40 +02:00
Li Zefan
008873eafb Btrfs: honor extent thresh during defragmentation
We won't defrag an extent, if it's bigger than the threshold we
specified and there's no small extent before it, but actually
the code doesn't work this way.

There are three bugs:

- When should_defrag_range() decides we should keep on defragmenting
  an extent, last_len is not incremented. (old bug)

- The length that passes to should_defrag_range() is not the length
  we're going to defrag. (new bug)

- We always defrag 256K bytes data, and a big extent can be part of
  this range. (new bug)

For a file with 4 extents:

        | 4K | 4K | 256K | 256K |

The result of defrag with (the default) 256K extent thresh should be:

        | 264K | 256K |

but with those bugs, we'll get:

        | 520K |

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
2011-10-20 18:10:39 +02:00
Jeff Liu
83c8c9bde0 btrfs: trivial fix, a potential memory leak in btrfs_parse_early_options()
Signed-off-by: Jie Liu <jeff.liu@oracle.com>
2011-10-20 18:10:38 +02:00
Li Zefan
5ca496604b Btrfs: fix wrong max_to_defrag in btrfs_defrag_file()
It's off-by-one, and thus we may skip the last page while defragmenting.

An example case:

  # create /mnt/file with 2 4K file extents
  # btrfs fi defrag /mnt/file
  # sync
  # filefrag /mnt/file
  /mnt/file: 2 extents found

So it's not defragmented.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
2011-10-20 18:10:37 +02:00
Li Zefan
151a31b25e Btrfs: use i_size_read() in btrfs_defrag_file()
Don't use inode->i_size directly, since we're not holding i_mutex.

This also fixes another bug, that i_size can change after it's checked
against 0 and then (i_size - 1) can be negative.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
2011-10-20 18:10:35 +02:00
Li Zefan
cbcc83265d Btrfs: fix defragmentation regression
There's an off-by-one bug:

  # create a file with lots of 4K file extents
  # btrfs fi defrag /mnt/file
  # sync
  # filefrag -v /mnt/file
  Filesystem type is: 9123683e
  File size of /mnt/file is 1228800 (300 blocks, blocksize 4096)
   ext logical physical expected length flags
     0       0     3372              64
     1      64     3136     3435      1
     2      65     3436     3136     64
     3     129     3201     3499      1
     4     130     3500     3201     64
     5     194     3266     3563      1
     6     195     3564     3266     64
     7     259     3331     3627      1
     8     260     3628     3331     40 eof

After this patch:

  ...
  # filefrag -v /mnt/file
  Filesystem type is: 9123683e
  File size of /mnt/file is 1228800 (300 blocks, blocksize 4096)
   ext logical physical expected length flags
     0       0     3372             300 eof
  /mnt/file: 1 extent found

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
2011-10-20 18:10:34 +02:00
Diego Calleja
60ccf82f5b btrfs: fix memory leak in btrfs_defrag_file
kmemleak found this:
unreferenced object 0xffff8801b64af968 (size 512):
  comm "btrfs-cleaner", pid 3317, jiffies 4306810886 (age 903.272s)
  hex dump (first 32 bytes):
    00 82 01 07 00 ea ff ff c0 83 01 07 00 ea ff ff  ................
    80 82 01 07 00 ea ff ff c0 87 01 07 00 ea ff ff  ................
  backtrace:
    [<ffffffff816875cc>] kmemleak_alloc+0x5c/0xc0
    [<ffffffff8114aec3>] kmem_cache_alloc_trace+0x163/0x240
    [<ffffffff8127a290>] btrfs_defrag_file+0xf0/0xb20
    [<ffffffff8125d9a5>] btrfs_run_defrag_inodes+0x165/0x210
    [<ffffffff812479d7>] cleaner_kthread+0x177/0x190
    [<ffffffff81075c7d>] kthread+0x8d/0xa0
    [<ffffffff816af5f4>] kernel_thread_helper+0x4/0x10
    [<ffffffffffffffff>] 0xffffffffffffffff

"pages" is not always freed. Fix it removing the unnecesary additional return.

Signed-off-by: Diego Calleja <diegocg@gmail.com>
2011-10-20 18:10:33 +02:00
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
016fc6a63e Btrfs: don't flush the cache inode before writing it
I noticed we had a little bit of latency when writing out the space cache
inodes.  It's because we flush it before we write anything in case we have dirty
pages already there.  This doesn't matter though since we're just going to
overwrite the space, and there really shouldn't be any dirty pages anyway.  This
makes some of my tests run a little bit faster.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
2011-10-19 15:13:01 -04:00
Josef Bacik
7e355b83ef Btrfs: if we have a lot of pinned space, commit the transaction
Mitch kept hitting a panic because he was getting ENOSPC.  One of my previous
patches makes it so we are much better at not allocating new metadata chunks.
Unfortunately coupled with the overcommit patch this works us into a bit of a
problem if we are removing a bunch of space and end up chewing up all of our
space with pinned extents.  We can allocate chunks fine and overflow is ok, but
the only way to reclaim this space is to commit the transaction.  So if we go to
overcommit, first check and see how much pinned space we have.  If we have more
than 80% of the free space chewed up with pinned extents, just commit the
transaction, this will free up enough space for our reservation and we won't
have this problem anymore.  With this patch Mitch's test doesn't blow up
anymore.  Thanks,

Reported-and-tested-by: Mitch Harder <mitch.harder@sabayonlinux.org>
Signed-off-by: Josef Bacik <josef@redhat.com>
2011-10-19 15:13:00 -04:00
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
3880a1b46d Btrfs: reserve some space for an orphan item when unlinking
In __unlink_start_trans() if we don't have enough room for a reservation we will
check to see if the unlink will free up space.  If it does that's great, but we
will still could add an orphan item, so we need to reserve enough space to add
the orphan item.  Do this and migrate the space the global reserve so it all
works out right.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
2011-10-19 15:12:59 -04:00
Josef Bacik
b24e03db0d Btrfs: release trans metadata bytes before flushing delayed refs
We started setting trans->block_rsv = NULL to allow the delayed refs flushing
stuff to use the right block_rsv and then just made
btrfs_trans_release_metadata() unconditionally use the trans block rsv.  The
problem with this is we need to reserve some space in the transaction and then
migrate it to the global block rsv, so we need to be able to free that out
properly.  So instead just move btrfs_trans_release_metadata() before the
delayed ref flushing and use trans->block_rsv for the freeing.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
2011-10-19 15:12:58 -04:00
Josef Bacik
877da17430 Btrfs: allow shrink_delalloc flush the needed reclaimed pages
Currently we only allow a maximum of 2 megabytes of pages to be flushed at a
time.  This was ok before, but now we have overcommit which will screw us in a
heartbeat if we are quickly filling the disk.  So instead pick either 2
megabytes or the number of pages we need to reclaim to be safe again, which ever
is larger.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
2011-10-19 15:12:58 -04:00
Josef Bacik
f104d04437 Btrfs: wait for ordered extents if we're in trouble when shrinking delalloc
The only way we actually reclaim delalloc space is waiting for the IO to
completely finish.  Usually we kick off a bunch of IO and wait for a little bit
and hope we can make our reservation, and usually this works out pretty well.
With overcommit however we can get seriously underwater if we're filling up the
disk quickly, so we need to be able to force the delalloc shrinker to wait for
the ordered IO to finish to give us a better chance of actually reclaiming
enough space to get our reservation.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
2011-10-19 15:12:57 -04:00
Josef Bacik
bbb495c2ed Btrfs: don't check bytes_pinned to determine if we should commit the transaction
Before the only reason to commit the transaction to recover space in
reserve_metadata_bytes() was if there were enough pinned_bytes to satisfy our
reservation.  But now we have the delayed inode stuff which will hold it's
reservations until we commit the transaction.  So say we max out our reservation
by creating a bunch of files but don't have any pinned bytes we will ENOSPC out
early even though we could commit the transaction and get that space back.  So
now just unconditionally commit the transaction since currently there is no way
to know how much metadata space is being reserved by delayed inode stuff.
Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
2011-10-19 15:12:56 -04:00
Josef Bacik
ed3ee9f44b Btrfs: fix regression in re-setting a large xattr
Recently I changed the xattr stuff to unconditionally set the xattr first in
case the xattr didn't exist yet.  This has introduced a regression when setting
an xattr that already exists with a large value.  If we find the key we are
looking for split_leaf will assume that we're extending that item.  The problem
is the size we pass down to btrfs_search_slot includes the size of the item
already, so if we have the largest xattr we can possibly have plus the size of
the xattr item plus the xattr item that btrfs_search_slot we'd overflow the
leaf.  Thankfully this is not what we're doing, but split_leaf doesn't know this
so it just returns EOVERFLOW.  So in the xattr code we need to check and see if
we got back EOVERFLOW and treat it like EEXIST since that's really what
happened.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
2011-10-19 15:12:56 -04:00
Josef Bacik
e70bea5fe0 Btrfs: fix the amount of space reserved for unlink
Our unlink reservations were a bit much, we were reserving 10 and I only count 8
possible items we're touching, so comment what we're reserving for and fix the
count value.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
2011-10-19 15:12:55 -04:00
Josef Bacik
4b91c14f91 Btrfs: wait for ordered extents if we didn't reclaim enough
I noticed recently that my overcommit patch was causing one of my enospc tests
to fail 25% of the time with early ENOSPC.  This is because my overcommit patch
was letting us go way over board, but it wasn't waiting long enough to let the
delalloc shrinker do it's job.  The problem is we just start writeback and wait
a little bit hoping we flush enough, but we only free up delalloc space by
having the writes complete all the way.  We do this by waiting for ordered
extents, which we do but only if we already free'd enough for the reservation,
which isn't right, we should flush ordered extents if we didn't reclaim enough
in case that will push us over the edge.  With this patch I've not seen a
failure in this enospc test after running it in a loop for an hour.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
2011-10-19 15:12:55 -04:00
Josef Bacik
5b0e95bf60 Btrfs: inline checksums into the disk free space cache
Yeah yeah I know this is how we used to do it and then I changed it, but damnit
I'm changing it back.  The fact is that writing out checksums will modify
metadata, which could cause us to dirty a block group we've already written out,
so we have to truncate it and all of it's checksums and re-write it which will
write new checksums which could dirty a blockg roup that has already been
written and you see where I'm going with this?  This can cause unmount or really
anything that depends on a transaction to commit to take it's sweet damned time
to happen.  So go back to the way it was, only this time we're specifically
setting NODATACOW because we can't go through the COW pathway anyway and we're
doing our own built-in cow'ing by truncating the free space cache.  The other
new thing is once we truncate the old cache and preallocate the new space, we
don't need to do that song and dance at all for the rest of the transaction, we
can just overwrite the existing space with the new cache if the block group
changes for whatever reason, and the NODATACOW will let us do this fine.  So
keep track of which transaction we last cleared our cache in and if we cleared
it in this transaction just say we're all setup and carry on.  This survives
xfstests and stress.sh.

The inode cache will continue to use the normal csum infrastructure since it
only gets written once and there will be no more modifications to the fs tree in
a transaction commit.

Signed-off-by: Josef Bacik <josef@redhat.com>
2011-10-19 15:12:54 -04:00
Josef Bacik
9a82ca659d Btrfs: take overflow into account in reserving space
My overcommit stuff can be a little racy when we're filling up the disk with
fs_mark and we overcommit into things that quickly get used up for data.  So use
num_bytes to see if we have enough available space so we're less likely to
overcommit ourselves out of the ability to make reservations.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
2011-10-19 15:12:53 -04:00
Josef Bacik
549b4fdb8f Btrfs: check the return value of filemap_write_and_wait in the space cache
We need to check the return value of filemap_write_and_wait in the space cache
writeout code.  Also don't set the inode's generation until we're sure nothing
else is going to fail.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
2011-10-19 15:12:53 -04:00
Josef Bacik
a67509c300 Btrfs: add a io_ctl struct and helpers for dealing with the space cache
In writing and reading the space cache we have one big loop that keeps track of
which page we are on and then a bunch of sizeable loops underneath this big loop
to try and read/write out properly.  Especially in the write case this makes
things hugely complicated and hard to follow, and makes our error checking and
recovery equally as complex.  So add a io_ctl struct with a bunch of helpers to
keep track of the pages we have, where we are, if we have enough space etc.
This unifies how we deal with the pages we're writing and keeps all the messy
tracking internal.  This allows us to kill the big loops in both the read and
write case and makes reviewing and chaning the write and read paths much
simpler.  I've run xfstests and stress.sh on this code and it survives.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
2011-10-19 15:12:52 -04:00
Josef Bacik
f75b130e9b Btrfs: don't skip writing out a empty block groups cache
I noticed a slight bug where we will not bother writing out the block group
cache's space cache if it's space tree is empty.  Since it could have a cluster
or pinned extents that need to be written out this is just not a valid test.
Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
2011-10-19 15:12:51 -04:00
Josef Bacik
73bc187680 Btrfs: introduce mount option no_space_cache
Some users have requested this and I've found I needed a way to disable cache
loading without actually clearing the cache, so introduce the no_space_cache
option.  Before we check the super blocks cache generation field and if it was
populated we always turned space caching on.  Now we check this and set the
space cache option on, and then parse the mount options so that if we want it
off it get's turned off.  Then we check the mount option all the places we do
the caching work instead of checking the super's cache generation.  This makes
things more consistent and lets us turn space caching off.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
2011-10-19 15:12:51 -04:00
Josef Bacik
e27425d614 Btrfs: only inherit btrfs specific flags when creating files
Xfstests 79 was failing because we were inheriting the S_APPEND flag when we
weren't supposed to.  There isn't any specific documentation on this so I'm
taking the test as the standard of how things work, and having S_APPEND set on a
directory doesn't mean that S_APPEND gets inherited by its children according to
this test.  So only inherit btrfs specific things.  This will let us set
compress/nocompress on specific directories and everything in the directories
will inherit this flag, same with nodatacow.  With this patch test 79 passes.
Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
2011-10-19 15:12:50 -04:00
Josef Bacik
2bf64758fd Btrfs: allow us to overcommit our enospc reservations
One of the things that kills us is the fact that our ENOSPC reservations are
horribly over the top in most normal cases.  There isn't too much that can be
done about this because when we are completely full we really need them to work
like this so we don't under reserve.  However if there is plenty of unallocated
chunks on the disk we can use that to gauge how much we can overcommit.  So this
patch adds chunk free space accounting so we always know how much unallocated
space we have.  Then if we fail to make a reservation within our allocated
space, check to see if we can overcommit.  In the normal flushing case (like
with delalloc metadata reservations) we'll take the free space and divide it by
2 if our metadata profile is setup for DUP or any of those, and then divide it
by 8 to make sure we don't overcommit too much.  Then if we're in a non-flushing
case (we really need this reservation now!) we only limit ourselves to half of
the free space.  This makes this fio test

[torrent]
filename=torrent-test
rw=randwrite
size=4g
ioengine=sync
directory=/mnt/btrfs-test

go from taking around 45 minutes to 10 seconds on my freshly formatted 3 TiB
file system.  This doesn't seem to break my other enospc tests, but could really
use some more testing as this is a super scary change.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
2011-10-19 15:12:50 -04:00
Josef Bacik
8f6d7f4f45 Btrfs: break out of orphan cleanup if we can't make progress
I noticed while running xfstests 83 that if we didn't have enough space to
delete our inode the orphan cleanup would just loop.  This is because it keeps
finding the same orphan item and keeps trying to kill it but can't because we
don't get an error back from iput for deleting the inode.  So keep track of the
last guy we tried to kill, if it's the same as the one we're trying to kill
currently we know we are having problems and can just error out.  I don't have a
way to test this so look hard and make sure it's right.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
2011-10-19 15:12:49 -04:00
Josef Bacik
726c35fa0e Btrfs: use the global reserve as a backup for deleting inodes
Xfstests 83 really stresses our ENOSPC since it uses a 100mb fs which ends up
with the mixed block group stuff.  Because of this we can run into a situation
where we don't have enough space to delete inodes, or even worse we can't free
the inodes when we next mount the fs which causes the orphan code to lose its
mind.  So if we fail to make our reservation, steal from the global reserve.
The global reserve will end up taking up the entire rest of the free space on
the fs in this worst case so there really is no other option.  With this patch
test 83 doesn't freak out.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
2011-10-19 15:12:48 -04:00
Josef Bacik
1728366efa Btrfs: stop using write_one_page
While looking for a performance regression a user was complaining about, I
noticed that we had a regression with the varmail test of filebench.  This was
introduced by

0d10ee2e6d

which keeps us from calling writepages in writepage.  This is a correct change,
however it happens to help the varmail test because we write out in larger
chunks.  This is largly to do with how we write out dirty pages for each
transaction.  If you run filebench with

load varmail
set $dir=/mnt/btrfs-test
run 60

prior to this patch you would get ~1420 ops/second, but with the patch you get
~1200 ops/second.  This is a 16% decrease.  So since we know the range of dirty
pages we want to write out, don't write out in one page chunks, write out in
ranges.  So to do this we call filemap_fdatawrite_range() on the range of bytes.
Then we convert the DIRTY extents to NEED_WAIT extents.  When we then call
btrfs_wait_marked_extents() we only have to filemap_fdatawait_range() on that
range and clear the NEED_WAIT extents.  This doesn't get us back to our original
speeds, but I've been seeing ~1380 ops/second, which is a <5% regression as
opposed to a >15% regression.  That is acceptable given that the original commit
greatly reduces our latency to begin with.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
2011-10-19 15:12:48 -04:00
Josef Bacik
462d6fac89 Btrfs: introduce convert_extent_bit
If I have a range where I know a certain bit is and I want to set it to another
bit the only option I have is to call set and then clear bit, which will result
in 2 tree searches.  This is inefficient, so introduce convert_extent_bit which
will go through and set the bit I want and clear the old bit I don't want.
Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
2011-10-19 15:12:47 -04:00
Josef Bacik
ef3be45722 Btrfs: check unused against how much space we actually want
There is a bug that may lead to early ENOSPC in our reservation code.  We've
been checking against num_bytes which may be above and beyond what we want to
actually reserve, which could give us a false ENOSPC.  Fix this by making sure
the unused space is above how much we want to reserve and not how much we're
trying to flush.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
2011-10-19 15:12:47 -04:00
Josef Bacik
a8c9e57697 Btrfs: fix orphan cleanup regression
In fixing how we deal with bad inodes, we had a regression in the orphan cleanup
code, since it expects to get a bad inode back.  So fix it to deal with getting
-ESTALE back by deleting the orphan item manually and moving on.  Thanks,

Reported-by: Simon Kirby <sim@hostway.ca>
Signed-off-by: Josef Bacik <josef@redhat.com>
2011-10-19 15:12:46 -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
455757c322 Btrfs: delay iput when deleting a block group
I kept getting warnings from evict because we were calling
btrfs_start_transaction() with a transaction already started when doing a
balance.  This is because we remove a block group which requires a transaction,
and the put the last reference on the cache inode.  Instead of doing this we
need to delay the iput so it is done not within a transaction having started.
This gets rid of our warnings.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
2011-10-19 15:12:45 -04:00
Josef Bacik
9c8d86db9a Btrfs: make sure to unset trans->block_rsv before running delayed refs
Checksums are charged in 2 different ways.  The first case is when we're writing
to the disk, we account for the new checksums with the delalloc block rsv.  In
order for this to work we check if we're allocating a block for the csum root
and if trans->block_rsv == the delalloc block rsv.  But when we're deleting the
csums because of cow, this is charged to the global block rsv, and is done when
we run the delayed refs.  So we need to make sure that trans->block_rsv == NULL
when running the delayed refs.  So set it to NULL and reset it in
should_end_transaction, and set it to NULL in commit_transaction.  This got rid
of the ridiculous amount of warnings I was seeing when trying to do a balance.
Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
2011-10-19 15:12:44 -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
d02c9955de Btrfs: don't get the block_rsv in btrfs_free_tree_block
Since the durable block rsv stuff has been killed there is no need to get the
block_rsv in btrfs_free_tree_block anymore.

Signed-off-by: Josef Bacik <josef@redhat.com>
2011-10-19 15:12:43 -04:00
Josef Bacik
4c13d758b7 Btrfs: use the transactions block_rsv for the csum root
The alloc warnings everybody has been seeing is because we have been reserving
space for csums, but we weren't actually using that space.  So make
get_block_rsv() return the trans->block_rsv if we're modifying the csum root.
Also set the trans->block_rsv to NULL so that if we modify the csum root when
running delayed ref's that comes out of the global reserve like it's supposed
to.  With this patch I'm not seeing those alloc warnings anymore.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
2011-10-19 15:12:42 -04:00
Josef Bacik
c09544e07f Btrfs: handle enospc accounting for free space inodes
Since free space inodes now use normal checksumming we need to make sure to
account for their metadata use.  So reserve metadata space, and then if we fail
to write out the metadata we can just release it, otherwise it will be freed up
when the io completes.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
2011-10-19 15:12:42 -04:00
Josef Bacik
300e4f8a56 Btrfs: put the block group cache after we commit the super
In moving some enospc stuff around I noticed that when we unmount we are often
evicting the free space cache inodes before we do our last commit.  This isn't
bad, but it makes us constantly have to re-read the inodes back.  So instead
don't evict the cache until after we do our last commit, this will make things a
little less crappy and makes a future enospc change work properly.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
2011-10-19 15:12:41 -04:00
Josef Bacik
4a33854257 Btrfs: set truncate block rsv's size
While debugging a different issue I noticed that we were always reserving space
when we tried to use our truncate block rsv's.  This is because they didn't have
a ->size value, so use_block_rsv just assumes there is nothing reserved and it
does a reserve_metadata_bytes.  This is because btrfs_check_block_rsv() doesn't
actually add to the size of the block rsv.  That seems to be the right thing to
do so set ->size to the minimum truncate size we need, since we will always only
refill to that size anyway, and this way everything works out correctly.

Signed-off-by: Josef Bacik <josef@redhat.com>
2011-10-19 15:12:40 -04:00
Josef Bacik
7f70150896 Btrfs: don't increase the block_rsv's size when emergency allocating space
If we have to emergency reserve space we need to not increase the block_rsv
size, otherwise we'll leak space.  Take for instance delalloc, say we reserve
4k, and we use that 4k, and then we have to emergency allocate another 4k, we
bump the size up to 8k, however we've only accounted for 4k in reservations in
all of our supporting logic, so we'll go to free the 4k and end up having a size
of 4k, which will cause us to later not free as much space.  I saw this doing
testing where I wasn't reserving enough space for something but was still
leaking space, very frustrating.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
2011-10-19 15:12:40 -04:00
Josef Bacik
7ed49f187c Btrfs: fix space leak when we fail to make an allocation
When changing back to using a spin_lock to protect the extent counters I decided
that since we would only be dropping our original extent, it was ok to just drop
the extent and return.  However since somebody else could have come in and done
a reservation, we need to do the normal song and dance to clear the reservation
out properly.  So calculate how much space we need to free, and then subtract
what we just attempted to reserve.  If it's more then we know we need to drop
those bytes from the delalloc block rsv.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
2011-10-19 15:12:39 -04:00
Josef Bacik
a9b5fcddce Btrfs: fix call to btrfs_search_slot in free space cache
We are setting ins_len to 1 even tho we are just modifying an item that should
be there already.  This may cause the search stuff to split nodes on the way
down needelessly.  Set this to 0 since we aren't inserting anything.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
2011-10-19 15:12:38 -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
07127184ef Btrfs: reduce the amount of space needed for truncates
With btrfs_truncate_inode_items we always return if we have to go to another
leaf, which makes us do our reservation again.  This means we will only ever
modify one leaf at a time, so we only need 1 items worth of slack space.  Also,
since we are deleting we will not be creating nodes as we go down, if anything
we'll be free'ing them as we merge them together, so make a different
calculation for truncate which will only have the worst case useage of COW'ing
the entire path down to the leaf.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
2011-10-19 15:12:37 -04:00
Josef Bacik
1b9c332b6c Btrfs: only reserve space in fallocate if we have to do a preallocate
Lukas found a problem where if he tries to fallocate over the same region twice
and the first fallocate took up all the space we would fail with ENOSPC.  This
is because we reserve the total space we want to use for fallocate, regardless
of wether or not we will have to actually preallocate.  So instead move the
check into the loop where we actually have to do the preallocate.  Thanks,

Tested-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: Josef Bacik <josef@redhat.com>
2011-10-19 15:12:36 -04:00
Josef Bacik
5e962c7850 Btrfs: kill btrfs_truncate_reserve_metadata
Since we've optimized the truncate path, we no longer require this function.

Signed-off-by: Josef Bacik <josef@redhat.com>
2011-10-19 15:12:36 -04:00
Josef Bacik
907cbcebd4 Btrfs: optimize how we account for space in truncate
Currently we're starting and stopping a transaction for no real reason, so kill
that and just reserve enough space as if we can truncate all in one transaction.
Also use btrfs_block_rsv_check() for our reserve to minimize the amount of space
we may have to allocate for our slack space.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
2011-10-19 15:12:35 -04:00