Commit Graph

2362 Commits

Author SHA1 Message Date
Linus Torvalds
659e45d8a0 Merge branch 'for-linus-min' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs
Pull the minimal btrfs branch from Chris Mason:
 "We have a use-after-free in there, along with errors when mount -o
  discard is enabled, and a BUG_ON(we should compile with UP more
  often)."

* 'for-linus-min' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  Btrfs: use commit root when loading free space cache
  Btrfs: fix use-after-free in __btrfs_end_transaction
  Btrfs: check return value of bio_alloc() properly
  Btrfs: remove lock assert from get_restripe_target()
  Btrfs: fix eof while discarding extents
  Btrfs: fix uninit variable in repair_eb_io_failure
  Revert "Btrfs: increase the global block reserve estimates"
2012-04-13 19:41:27 -07:00
Josef Bacik
d53ba47484 Btrfs: use commit root when loading free space cache
A user reported that booting his box up with btrfs root on 3.4 was way
slower than on 3.3 because I removed the ideal caching code.  It turns out
that we don't load the free space cache if we're in a commit for deadlock
reasons, but since we're reading the cache and it hasn't changed yet we are
safe reading the inode and free space item from the commit root, so do that
and remove all of the deadlock checks so we don't unnecessarily skip loading
the free space cache.  The user reported this fixed the slowness.  Thanks,

Tested-by: Calvin Walton <calvin.walton@kepstin.ca>
Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2012-04-12 20:54:01 -04:00
Dave Jones
4edc2ca388 Btrfs: fix use-after-free in __btrfs_end_transaction
49b25e0540 introduced a use-after-free bug
that caused spurious -EIO's to be returned.

Do the check before we free the transaction.

Cc: David Sterba <dsterba@suse.cz>
Cc: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Dave Jones <davej@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2012-04-12 16:03:56 -04:00
Tsutomu Itoh
e627ee7bcd Btrfs: check return value of bio_alloc() properly
bio_alloc() has the possibility of returning NULL.
So, it is necessary to check the return value.

Signed-off-by: Tsutomu Itoh <t-itoh@jp.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2012-04-12 16:03:56 -04:00
Ilya Dryomov
c6664b42c4 Btrfs: remove lock assert from get_restripe_target()
This fixes a regression introduced by fc67c450.  spin_is_locked() always
returns 0 on UP kernels, which caused assert in get_restripe_target() to
be fired on every call from btrfs_reduce_alloc_profile() on UP systems.
Remove it completely for now, it's not clear if it's going to be needed
in future.

Reported-by: Bobby Powers <bobbypowers@gmail.com>
Reported-by: Mitch Harder <mitch.harder@sabayonlinux.org>
Tested-by: Mitch Harder <mitch.harder@sabayonlinux.org>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2012-04-12 16:03:56 -04:00
Liu Bo
b89203f74b Btrfs: fix eof while discarding extents
We miscalculate the length of extents we're discarding, and it leads to
an eof of device.

Reported-by: Daniel Blueman <daniel@quora.org>
Signed-off-by: Liu Bo <liubo2009@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2012-04-12 16:03:56 -04:00
Chris Mason
d95603b262 Btrfs: fix uninit variable in repair_eb_io_failure
We'd have to be passing bogus extent buffers for this uninit variable to
actually be used, but set it to zero just in case.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2012-04-12 15:55:15 -04:00
Chris Mason
8e62c2de6e Revert "Btrfs: increase the global block reserve estimates"
This reverts commit 5500cdbe14.

We've had a number of complaints of early enospc that bisect down
to this patch.  We'll hae to fix the reservations differently.

CC: stable@kernel.org
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2012-04-12 13:46:48 -04:00
Linus Torvalds
9613bebb22 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs
Pull btrfs fixes and features from Chris Mason:
 "We've merged in the error handling patches from SuSE.  These are
  already shipping in the sles kernel, and they give btrfs the ability
  to abort transactions and go readonly on errors.  It involves a lot of
  churn as they clarify BUG_ONs, and remove the ones we now properly
  deal with.

  Josef reworked the way our metadata interacts with the page cache.
  page->private now points to the btrfs extent_buffer object, which
  makes everything faster.  He changed it so we write an whole extent
  buffer at a time instead of allowing individual pages to go down,,
  which will be important for the raid5/6 code (for the 3.5 merge
  window ;)

  Josef also made us more aggressive about dropping pages for metadata
  blocks that were freed due to COW.  Overall, our metadata caching is
  much faster now.

  We've integrated my patch for metadata bigger than the page size.
  This allows metadata blocks up to 64KB in size.  In practice 16K and
  32K seem to work best.  For workloads with lots of metadata, this cuts
  down the size of the extent allocation tree dramatically and fragments
  much less.

  Scrub was updated to support the larger block sizes, which ended up
  being a fairly large change (thanks Stefan Behrens).

  We also have an assortment of fixes and updates, especially to the
  balancing code (Ilya Dryomov), the back ref walker (Jan Schmidt) and
  the defragging code (Liu Bo)."

Fixed up trivial conflicts in fs/btrfs/scrub.c that were just due to
removal of the second argument to k[un]map_atomic() in commit
7ac687d9e0.

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (75 commits)
  Btrfs: update the checks for mixed block groups with big metadata blocks
  Btrfs: update to the right index of defragment
  Btrfs: do not bother to defrag an extent if it is a big real extent
  Btrfs: add a check to decide if we should defrag the range
  Btrfs: fix recursive defragment with autodefrag option
  Btrfs: fix the mismatch of page->mapping
  Btrfs: fix race between direct io and autodefrag
  Btrfs: fix deadlock during allocating chunks
  Btrfs: show useful info in space reservation tracepoint
  Btrfs: don't use crc items bigger than 4KB
  Btrfs: flush out and clean up any block device pages during mount
  btrfs: disallow unequal data/metadata blocksize for mixed block groups
  Btrfs: enhance superblock sanity checks
  Btrfs: change scrub to support big blocks
  Btrfs: minor cleanup in scrub
  Btrfs: introduce common define for max number of mirrors
  Btrfs: fix infinite loop in btrfs_shrink_device()
  Btrfs: fix memory leak in resolver code
  Btrfs: allow dup for data chunks in mixed mode
  Btrfs: validate target profiles only if we are going to use them
  ...
2012-03-30 12:44:29 -07:00
Chris Mason
bc3f116fec Btrfs: update the checks for mixed block groups with big metadata blocks
Dave Sterba had put in patches to look for mixed data/metadata groups
with metadata bigger than 4KB.  But these ended up in the wrong place
and it wasn't testing the feature flag correctly.

This updates the tests to make sure our sizes are matching

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2012-03-29 17:02:47 -04:00
Liu Bo
e1f041e14c Btrfs: update to the right index of defragment
When we use autodefrag, we forget to update the index which indicates
the last page we've dirty.  And we'll set dirty flags on a same set of
pages again and again.

Signed-off-by: Liu Bo <liubo2009@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2012-03-29 09:57:45 -04:00
Liu Bo
66c2689226 Btrfs: do not bother to defrag an extent if it is a big real extent
$ mkfs.btrfs /dev/sdb7
$ mount /dev/sdb7 /mnt/btrfs/ -oautodefrag
$ dd if=/dev/zero of=/mnt/btrfs/foobar bs=4k count=10 oflag=direct 2>/dev/null
$ filefrag -v /mnt/btrfs/foobar
Filesystem type is: 9123683e
File size of /mnt/btrfs/foobar is 40960 (10 blocks, blocksize 4096)
 ext logical physical expected length flags
   0       0     3072              10 eof
/mnt/btrfs/foobar: 1 extent found

Now we have a big real extent [0, 40960), but autodefrag will still defrag it.

$ sync
$ filefrag -v /mnt/btrfs/foobar
Filesystem type is: 9123683e
File size of /mnt/btrfs/foobar is 40960 (10 blocks, blocksize 4096)
 ext logical physical expected length flags
   0       0     3082              10 eof
/mnt/btrfs/foobar: 1 extent found

So if we already find a big real extent, we're ok about that, just skip it.

Signed-off-by: Liu Bo <liubo2009@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2012-03-29 09:57:45 -04:00
Liu Bo
17ce6ef8d7 Btrfs: add a check to decide if we should defrag the range
If our file's layout is as follows:
| hole | data1 | hole | data2 |

we do not need to defrag this file, because this file has holes and
cannot be merged into one extent.

Signed-off-by: Liu Bo <liubo2009@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2012-03-29 09:57:45 -04:00
Liu Bo
4cb13e5d6e Btrfs: fix recursive defragment with autodefrag option
$ mkfs.btrfs disk
$ mount disk /mnt -o autodefrag
$ dd if=/dev/zero of=/mnt/foobar bs=4k count=10 2>/dev/null && sync
$ for i in `seq 9 -2 0`; do dd if=/dev/zero of=/mnt/foobar bs=4k count=1 \
  seek=$i conv=notrunc 2> /dev/null; done && sync

then we'll get to defrag "foobar" again and again.
So does option "-o autodefrag,compress".

Reasons:
When the cleaner kthread gets to fetch inodes from the defrag tree and defrag
them, it will dirty pages and submit them, this will comes to another DATA COW
where the processing inode will be inserted to the defrag tree again.

This patch sets a rule for COW code, i.e. insert an inode when we're really
going to make some defragments.

Signed-off-by: Liu Bo <liubo2009@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2012-03-29 09:57:45 -04:00
Liu Bo
1f12bd0632 Btrfs: fix the mismatch of page->mapping
commit 600a45e1d5
(Btrfs: fix deadlock on page lock when doing auto-defragment)
fixes the deadlock on page, but it also introduces another bug.

A page may have been truncated after unlock & lock.
So we need to find it again to get the right one.

And since we've held i_mutex lock, inode size remains unchanged and
we can drop isize overflow checks.

Signed-off-by: Liu Bo <liubo2009@cn.fujitsu.com>
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2012-03-29 09:57:44 -04:00
Liu Bo
ecb8bea87d Btrfs: fix race between direct io and autodefrag
The bug is from running xfstests 209 with autodefrag.

The race is as follows:
       t1                       t2(autodefrag)
   direct IO
     invalidate pagecache
     dio(old data)             add_inode_defrag
     invalidate pagecache
   endio

   direct IO
     invalidate pagecache
                                run_defrag
                                  readpage(old data)
                                  set page dirty (old data)
     dio(new data, rewrite)
     invalidate pagecache (*)
     endio

t2(autodefrag) will get old data into pagecache via readpage and set
pagecache dirty.  Meanwhile, invalidate pagecache(*) will fail due to
dirty flags in pages.  So the old data may be flushed into disk by
flush thread, which will lead to data loss.

And so does the case of user defragment progs.

The patch fixes this race by holding i_mutex when we readpage and set page dirty.

Signed-off-by: Liu Bo <liubo2009@cn.fujitsu.com>
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2012-03-29 09:57:44 -04:00
Liu Bo
15d1ff8111 Btrfs: fix deadlock during allocating chunks
This deadlock comes from xfstests 251.

We'll hold the chunk_mutex throughout the whole of a chunk allocation.
But if we find that we've used up system chunk space, we need to allocate a
new system chunk, but this will lead to a recursion of chunk allocation and end
up with a deadlock on chunk_mutex.
So instead we need to allocate the system chunk first if we find we're in ENOSPC.

Signed-off-by: Liu Bo <liubo2009@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2012-03-29 09:57:44 -04:00
Liu Bo
2bcc0328c3 Btrfs: show useful info in space reservation tracepoint
o For space info, the type of space info is useful for debug.
o For transaction handle, its transid is useful.

Signed-off-by: Liu Bo <liubo2009@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2012-03-29 09:57:44 -04:00
Chris Mason
7ca4be45a0 Btrfs: don't use crc items bigger than 4KB
With the big metadata blocks, we can have crc items
that are much bigger than a page.  There are a few
places that we try to kmalloc memory to hold the
items during a split.

Items bigger than 4KB don't really have a huge benefit
in efficiency, but they do trigger larger order allocations.
This commits changes the csums to make sure they stay under
4KB.  This is not a format change, just a #define to limit
huge items.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2012-03-28 20:34:10 -04:00
Chris Mason
3c4bb26b21 Btrfs: flush out and clean up any block device pages during mount
Btrfs puts the filesystem metadata into its own address space, and
somehow the block device address space isn't getting onto disk properly
before a mount.  The end result is that a loop of mkfs and mounting the
filesystem will sometimes find stale or incorrect data.

This commit should fix it by sprinkling fdatawrites and invalidate_bdev
calls around.  This is a short term measure to make sure it is fixed.
The block devices really should be flushed and cleaned up higher in the
stack.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2012-03-28 20:33:58 -04:00
Chris Mason
98961a7e43 Merge git://git.jan-o-sch.net/btrfs-unstable into for-linus
Conflicts:
	fs/btrfs/transaction.c

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2012-03-28 20:33:40 -04:00
Chris Mason
1c691b330a Merge branch 'for-chris' of git://github.com/idryomov/btrfs-unstable into for-linus 2012-03-28 20:32:46 -04:00
Chris Mason
1d4284bd6e Merge branch 'error-handling' into for-linus
Conflicts:
	fs/btrfs/ctree.c
	fs/btrfs/disk-io.c
	fs/btrfs/extent-tree.c
	fs/btrfs/extent_io.c
	fs/btrfs/extent_io.h
	fs/btrfs/inode.c
	fs/btrfs/scrub.c

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2012-03-28 20:31:37 -04:00
David Sterba
65139ed992 btrfs: disallow unequal data/metadata blocksize for mixed block groups
With support for bigger metadata blocks, we must avoid mounting a
filesystem with different block size for mixed block groups, this causes
corruption (found by xfstests/083).

Signed-off-by: David Sterba <dsterba@suse.cz>
2012-03-28 20:30:28 -04:00
David Sterba
fcd1f065da Btrfs: enhance superblock sanity checks
Validate checksum algorithm during mount and prevent BUG_ON later in
btrfs_super_csum_size.

Signed-off-by: David Sterba <dsterba@suse.cz>
2012-03-28 20:30:28 -04:00
Stefan Behrens
b5d67f64f9 Btrfs: change scrub to support big blocks
Scrub used to be coded for nodesize == leafsize == sectorsize == PAGE_SIZE.
This is now changed to support sizes for nodesize and leafsize which are
N * PAGE_SIZE.

Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2012-03-27 14:21:27 -04:00
Stefan Behrens
1623edebee Btrfs: minor cleanup in scrub
Just a minor cleanup commit in preparation for the big block changes.

Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2012-03-27 14:21:26 -04:00
Stefan Behrens
94598ba8d8 Btrfs: introduce common define for max number of mirrors
Readahead already has a define for the max number of mirrors. Scrub
needs such a define now, the rest of the code will need something
like this soon. Therefore the define was added to ctree.h and removed
from the readahead code.

Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2012-03-27 14:21:26 -04:00
Ilya Dryomov
213e64da90 Btrfs: fix infinite loop in btrfs_shrink_device()
If relocate of block group 0 fails with ENOSPC we end up infinitely
looping because key.offset -= 1 statement in that case brings us back to
where we started.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2012-03-27 17:09:18 +03:00
Ilya Dryomov
5eb56d2520 Btrfs: fix memory leak in resolver code
init_ipath() allocates btrfs_data_container which is never freed.  Free
it in free_ipath() and nuke the comment for init_data_container() - we
can safely free it with kfree().

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2012-03-27 17:09:18 +03:00
Ilya Dryomov
e4837f8f3b Btrfs: allow dup for data chunks in mixed mode
Generally we don't allow dup for data, but mixed chunks are special and
people seem to think this has its use cases.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2012-03-27 17:09:17 +03:00
Ilya Dryomov
6728b198de Btrfs: validate target profiles only if we are going to use them
Do not run sanity checks on all target profiles unless they all will be
used.  This came up because alloc_profile_is_valid() is now more strict
than it used to be.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2012-03-27 17:09:17 +03:00
Ilya Dryomov
4a5e98f5d6 Btrfs: improve the logic in btrfs_can_relocate()
Currently if we don't have enough space allocated we go ahead and loop
though devices in the hopes of finding enough space for a chunk of the
*same* type as the one we are trying to relocate.  The problem with that
is that if we are trying to restripe the chunk its target type can be
more relaxed than the current one (eg require less devices or less
space).  So, when restriping, run checks against the target profile
instead of the current one.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2012-03-27 17:09:17 +03:00
Ilya Dryomov
7738a53a3a Btrfs: add __get_block_group_index() helper
Add __get_block_group_index() helper to be able to derive block group
index from an arbitary set of flags.  Implement get_block_group_index()
in terms of it.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2012-03-27 17:09:17 +03:00
Ilya Dryomov
fc67c45083 Btrfs: add get_restripe_target() helper
Add get_restripe_target() helper and switch everybody to use it.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2012-03-27 17:09:17 +03:00
Ilya Dryomov
0c460c0d70 Btrfs: move alloc_profile_is_valid() to volumes.c
Header file is not a good place to define functions.  This also moves a
call to alloc_profile_is_valid() down the stack and removes a redundant
check from __btrfs_alloc_chunk() - alloc_profile_is_valid() takes it
into account.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2012-03-27 17:09:17 +03:00
Ilya Dryomov
e8920a640b Btrfs: make profile_is_valid() check more strict
"0" is a valid value for an on-disk chunk profile, but it is not a valid
extended profile.  (We have a separate bit for single chunks in extended
case)

Also rename it to alloc_profile_is_valid() for clarity.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2012-03-27 17:09:17 +03:00
Ilya Dryomov
899c81eac8 Btrfs: add wrappers for working with alloc profiles
Add functions to abstract the conversion between chunk and extended
allocation profile formats and switch everybody to use them.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2012-03-27 17:09:16 +03:00
Ilya Dryomov
e3176ca276 Btrfs: stop silently switching single chunks to raid0 on balance
This has been causing a lot of confusion for quite a while now and a lot
of users were surprised by this (some of them were even stuck in a
ENOSPC situation which they couldn't easily get out of).  The addition
of restriper gives users a clear choice between raid0 and drive concat
setup so there's absolutely no excuse for us to keep doing this.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2012-03-27 17:09:16 +03:00
Jan Schmidt
7a3ae2f8c8 Btrfs: fix regression in scrub path resolving
In commit 4692cf58 we introduced new backref walking code for btrfs. This
assumes we're searching live roots, which requires a transaction context.
While scrubbing, however, we must not join a transaction because this could
deadlock with the commit path. Additionally, what scrub really wants to do
is resolving a logical address in the commit root it's currently checking.

This patch adds support for logical to path resolving on commit roots and
makes scrub use that.

Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
2012-03-27 14:51:21 +02:00
Jan Schmidt
103e976616 Btrfs: check return value of btrfs_cow_block()
The two helper functions commit_cowonly_roots() and
create_pending_snapshot() failed to check the return value from
btrfs_cow_block(), which could at least in theory fail with -ENOSPC from
btrfs_alloc_free_block(). This commit adds the missing checks.

Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
2012-03-27 14:51:20 +02:00
Jan Schmidt
e565d4b962 Btrfs: actually call btrfs_init_lockdep
btrfs_init_lockdep only makes our lockdep class names look prettier, thus
it did never hurt we forgot to actually call it. This turns our lockdep
identifier strings from lockdep auto-set #[id] into really pretty
"btrfs-fs-01" or "btrfs-csum-03".

Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
2012-03-27 14:51:17 +02:00
Josef Bacik
ea46679408 Btrfs: deal with read errors on extent buffers differently
Since we need to read and write extent buffers in their entirety we can't use
the normal bio_readpage_error stuff since it only works on a per page basis.  So
instead make it so that if we see an io error in endio we just mark the eb as
having an IO error and then in btree_read_extent_buffer_pages we will manually
try other mirrors and then overwrite the bad mirror if we find a good copy.
This works with larger than page size blocks.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2012-03-26 21:57:36 -04:00
Chris Mason
f3f266ab1b Btrfs: don't use threaded IO completion helpers for metadata writes
The metadata write IO completion code is now simple enough that we
don't need the threaded helpers anymore.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2012-03-26 17:04:24 -04:00
Chris Mason
f7c79f30cb Btrfs: adjust the write_lock_level as we unlock
btrfs_search_slot sometimes needs write locks on high levels of
the tree.  It remembers the highest level that needs a write lock
and will use that for all future searches through the tree in a given
call.

But, very often we'll just cow the top level or the level below and we
won't really need write locks on the root again after that.  This patch
changes things to adjust the write lock requirement as it unlocks
levels.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2012-03-26 17:04:24 -04:00
Chris Mason
a098d8e8ee Btrfs: loop waiting on writeback
lock_extent_buffer_for_io needs to loop around and make sure the
writeback bits are not set.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2012-03-26 17:04:23 -04:00
Chris Mason
cfed81a04e Btrfs: add the ability to cache a pointer into the eb
This cuts down on the CPU time used by map_private_extent_buffer

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2012-03-26 17:04:23 -04:00
Josef Bacik
0b32f4bbb4 Btrfs: ensure an entire eb is written at once
This patch simplifies how we track our extent buffers.  Previously we could exit
writepages with only having written half of an extent buffer, which meant we had
to track the state of the pages and the state of the extent buffers differently.
Now we only read in entire extent buffers and write out entire extent buffers,
this allows us to simply set bits in our bflags to indicate the state of the eb
and we no longer have to do things like track uptodate with our iotree.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2012-03-26 17:04:23 -04:00
Josef Bacik
5df4235ea1 Btrfs: introduce mark_extent_buffer_accessed
Because an eb can have multiple pages we need to make sure that all pages within
the eb are markes as accessed, since releasepage can be called against any page
in the eb.  This will keep us from possibly evicting hot eb's when we're doing
larger than pagesize eb's.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
2012-03-26 16:51:09 -04:00
Josef Bacik
3083ee2e18 Btrfs: introduce free_extent_buffer_stale
Because btrfs cow's we can end up with extent buffers that are no longer
necessary just sitting around in memory.  So instead of evicting these pages, we
could end up evicting things we actually care about.  Thus we have
free_extent_buffer_stale for use when we are freeing tree blocks.  This will
make it so that the ref for the eb being in the radix tree is dropped as soon as
possible and then is freed when the refcount hits 0 instead of waiting to be
released by releasepage.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
2012-03-26 16:51:08 -04:00