Commit Graph

982 Commits

Author SHA1 Message Date
Linus Torvalds
4ebf662337 Merge git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable
* git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable:
  Btrfs: look for acls during btrfs_read_locked_inode
  Btrfs: fix acl caching
  Btrfs: Fix a bunch of printk() warnings.
  Btrfs: Fix a trivial warning using max() of u64 vs ULL.
  Btrfs: remove unused btrfs_bit_radix slab
  Btrfs: ratelimit IO error printks
  Btrfs: remove #if 0 code
  Btrfs: When shrinking, only update disk size on success
  Btrfs: fix deadlocks and stalls on dead root removal
  Btrfs: fix fallocate deadlock on inode extent lock
  Btrfs: kill btrfs_cache_create
  Btrfs: don't export symbols
  Btrfs: simplify makefile
  Btrfs: try to keep a healthy ratio of metadata vs data block groups
2009-04-27 11:16:33 -07:00
Chris Mason
46a53cca82 Btrfs: look for acls during btrfs_read_locked_inode
This changes btrfs_read_locked_inode() to peek ahead in the btree for acl items.
If it is certain a given inode has no acls, it will set the in memory acl
fields to null to avoid acl lookups completely.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-04-27 13:18:35 -04:00
Chris Mason
7b1a14bbb0 Btrfs: fix acl caching
Linus noticed the btrfs code to cache acls wasn't properly caching
a NULL acl when the inode didn't have any acls.  This meant the common
case of no acls resulted in expensive btree searches every time the
kernel checked permissions (which is quite often).

This is a modified version of Linus' original patch:

Properly set initial acl fields to BTRFS_ACL_NOT_CACHED in the inode.
This forces an acl lookup when permission checks are done.

Fix btrfs_get_acl to avoid lookups and locking when the inode acls fields
are set to null.

Fix btrfs_get_acl to use the right return value from __btrfs_getxattr
when deciding to cache a NULL acl.  It was storing a NULL acl when
__btrfs_getxattr return -ENOENT, but __btrfs_getxattr was actually returning
-ENODATA for this case.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-04-27 13:18:26 -04:00
Joel Becker
21380931eb Btrfs: Fix a bunch of printk() warnings.
Just happened to notice a bunch of %llu vs u64 warnings.  Here's a patch
to cast them all.

Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-04-27 08:37:49 -04:00
Joel Becker
e63b6a6c0f Btrfs: Fix a trivial warning using max() of u64 vs ULL.
A small warning popped up on ia64 because inode-map.c was comparing a
u64 object id with the ULL FIRST_FREE_OBJECTID.  My first thought was
that all the OBJECTID constants should contain the u64 cast because
btrfs code deals entirely in u64s.  But then I saw how large that was,
and figured I'd just fix the max() call.

Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-04-27 08:37:49 -04:00
Chris Mason
45c06543af Btrfs: remove unused btrfs_bit_radix slab
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-04-27 08:37:48 -04:00
Chris Mason
193f284d49 Btrfs: ratelimit IO error printks
Btrfs has printks for various IO errors, including bad checksums and
mismatches between what we expect the block headers to contain and what
we actually find on the disk.

Longer term we need a real reporting mechanism for this, but for now
printk is going to have to do.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-04-27 07:41:47 -04:00
Chris Mason
b7967db75a Btrfs: remove #if 0 code
Btrfs had some old code sitting around under #if 0, this drops it.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-04-27 07:40:52 -04:00
Chris Ball
d6397baee4 Btrfs: When shrinking, only update disk size on success
Previously, we updated a device's size prior to attempting a shrink
operation.  This patch moves the device resizing logic to only happen if
the shrink completes successfully.  In the process, it introduces a new
field to btrfs_device -- disk_total_bytes -- to track the on-disk size.

Signed-off-by: Chris Ball <cjb@laptop.org>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-04-27 07:40:51 -04:00
Chris Mason
59bc5c758e Btrfs: fix deadlocks and stalls on dead root removal
After a transaction commit, the old root of the subvol btrees are sent through
snapshot removal.  This is what actually frees up any blocks replaced by
COW, and anything the old blocks pointed to.

Snapshot deletion will pause when a transaction commit has started, which
helps to avoid a huge amount of delayed reference count updates piling up
as the transaction is trying to close.

But, this pause happens after the snapshot deletion process has asked other
procs on the system to throttle back a bit so that it can make progress.

We don't want to throttle everyone while we're waiting for the transaction
commit, it leads to deadlocks in the user transaction ioctls used by Ceph
and makes things slower in general.

This patch changes things to avoid the throttling while we sleep.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-04-24 15:46:05 -04:00
Chris Mason
e980b50cda Btrfs: fix fallocate deadlock on inode extent lock
The btrfs fallocate call takes an extent lock on the entire range
being fallocated, and then runs through insert_reserved_extent on each
extent as they are allocated.

The problem with this is that btrfs_drop_extents may decide to try
and take the same extent lock fallocate was already holding.  The solution
used here is to push down knowledge of the range that is already locked
going into btrfs_drop_extents.

It turns out that at least one other caller had the same bug.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-04-24 15:46:05 -04:00
Christoph Hellwig
9601e3f633 Btrfs: kill btrfs_cache_create
Just use kmem_cache_create directly.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-04-24 15:46:04 -04:00
Christoph Hellwig
0d4bf11e53 Btrfs: don't export symbols
Currently the extent_map code is only for btrfs so don't export it's
symbols.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-04-24 15:46:04 -04:00
Christoph Hellwig
2ea2544ef5 Btrfs: simplify makefile
Get rid of the hacks for building out of tree, and always use += for
assigning to the object lists.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-04-24 15:46:03 -04:00
Josef Bacik
97e728d435 Btrfs: try to keep a healthy ratio of metadata vs data block groups
This patch makes the chunk allocator keep a good ratio of metadata vs data
block groups.  By default for every 8 data block groups, we'll allocate 1
metadata chunk, or about 12% of the disk will be allocated for metadata.  This
can be changed by specifying the metadata_ratio mount option.

This is simply the number of data block groups that have to be allocated to
force a metadata chunk allocation.  By making sure we allocate metadata chunks
more often, we are less likely to get into situations where the whole disk
has been allocated as data block groups.

Signed-off-by: Josef Bacik <jbacik@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-04-24 15:46:02 -04:00
Linus Torvalds
ccc5ff94c6 Merge git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable
* git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable:
  Btrfs: fix btrfs fallocate oops and deadlock
  Btrfs: use the right node in reada_for_balance
  Btrfs: fix oops on page->mapping->host during writepage
  Btrfs: add a priority queue to the async thread helpers
  Btrfs: use WRITE_SYNC for synchronous writes
2009-04-21 14:12:58 -07:00
Chris Mason
546888da82 Btrfs: fix btrfs fallocate oops and deadlock
Btrfs fallocate was incorrectly starting a transaction with a lock held
on the extent_io tree for the file, which could deadlock.  Strictly
speaking it was using join_transaction which would be safe, but it is better
to move the transaction outside of the lock.

When preallocated extents are overwritten, btrfs_mark_buffer_dirty was
being called on an unlocked buffer.  This was triggering an assertion and
oops because the lock is supposed to be held.

The bug was calling btrfs_mark_buffer_dirty on a leaf after btrfs_del_item had
been run.  btrfs_del_item takes care of dirtying things, so the solution is a
to skip the btrfs_mark_buffer_dirty call in this case.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-04-21 12:45:12 -04:00
Li Zefan
dae7b665cf btrfs: use memdup_user()
Remove open-coded memdup_user().

Note this changes some GFP_NOFS to GFP_KERNEL, since copy_from_user() may
cause pagefault, it's pointless to pass GFP_NOFS to kmalloc().

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-04-20 23:02:50 -04:00
Chris Mason
8c594ea81d Btrfs: use the right node in reada_for_balance
reada_for_balance was using the wrong index into the path node array,
so it wasn't reading the right blocks.  We never directly used the
results of the read done by this function because the btree search is
started over at the end.

This fixes reada_for_balance to reada in the correct node and to
avoid searching past the last slot in the node.  It also makes sure to
hold the parent lock while we are finding the nodes to read.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-04-20 15:53:09 -04:00
Chris Mason
11c8349b4e Btrfs: fix oops on page->mapping->host during writepage
The extent_io writepage call updates the writepage index in the inode
as it makes progress.  But, it was doing the update after unlocking the page,
which isn't legal because page->mapping can't be trusted once the page
is unlocked.

This lead to an oops, especially common with compression turned on.  The
fix here is to update the writeback index before unlocking the page.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-04-20 15:53:09 -04:00
Chris Mason
d313d7a31a Btrfs: add a priority queue to the async thread helpers
Btrfs is using WRITE_SYNC_PLUG to send down synchronous IOs with a
higher priority.  But, the checksumming helper threads prevent it
from being fully effective.

There are two problems.  First, a big queue of pending checksumming
will delay the synchronous IO behind other lower priority writes.  Second,
the checksumming uses an ordered async work queue.  The ordering makes sure
that IOs are sent to the block layer in the same order they are sent
to the checksumming threads.  Usually this gives us less seeky IO.

But, when we start mixing IO priorities, the lower priority IO can delay
the higher priority IO.

This patch solves both problems by adding a high priority list to the async
helper threads, and a new btrfs_set_work_high_prio(), which is used
to make put a new async work item onto the higher priority list.

The ordering is still done on high priority IO, but all of the high
priority bios are ordered separately from the low priority bios.  This
ordering is purely an IO optimization, it is not involved in data
or metadata integrity.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-04-20 15:53:08 -04:00
Chris Mason
ffbd517d5a Btrfs: use WRITE_SYNC for synchronous writes
Part of reducing fsync/O_SYNC/O_DIRECT latencies is using WRITE_SYNC for
writes we plan on waiting on in the near future.  This patch
mirrors recent changes in other filesystems and the generic code to
use WRITE_SYNC when WB_SYNC_ALL is passed and to use WRITE_SYNC for
other latency critical writes.

Btrfs uses async worker threads for checksumming before the write is done,
and then again to actually submit the bios.  The bio submission code just
runs a per-device list of bios that need to be sent down the pipe.

This list is split into low priority and high priority lists so the
WRITE_SYNC IO happens first.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-04-20 15:53:08 -04:00
Linus Torvalds
b983471794 Merge git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable
* git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable:
  Btrfs: BUG to BUG_ON changes
  Btrfs: remove dead code
  Btrfs: remove dead code
  Btrfs: fix typos in comments
  Btrfs: remove unused ftrace include
  Btrfs: fix __ucmpdi2 compile bug on 32 bit builds
  Btrfs: free inode struct when btrfs_new_inode fails
  Btrfs: fix race in worker_loop
  Btrfs: add flushoncommit mount option
  Btrfs: notreelog mount option
  Btrfs: introduce btrfs_show_options
  Btrfs: rework allocation clustering
  Btrfs: Optimize locking in btrfs_next_leaf()
  Btrfs: break up btrfs_search_slot into smaller pieces
  Btrfs: kill the pinned_mutex
  Btrfs: kill the block group alloc mutex
  Btrfs: clean up find_free_extent
  Btrfs: free space cache cleanups
  Btrfs: unplug in the async bio submission threads
  Btrfs: keep processing bios for a given bdev if our proc is batching
2009-04-03 15:14:44 -07:00
Linus Torvalds
8fe74cf053 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6:
  Remove two unneeded exports and make two symbols static in fs/mpage.c
  Cleanup after commit 585d3bc06f
  Trim includes of fdtable.h
  Don't crap into descriptor table in binfmt_som
  Trim includes in binfmt_elf
  Don't mess with descriptor table in load_elf_binary()
  Get rid of indirect include of fs_struct.h
  New helper - current_umask()
  check_unsafe_exec() doesn't care about signal handlers sharing
  New locking/refcounting for fs_struct
  Take fs_struct handling to new file (fs/fs_struct.c)
  Get rid of bumping fs_struct refcount in pivot_root(2)
  Kill unsharing fs_struct in __set_personality()
2009-04-02 21:09:10 -07:00
Stoyan Gaydarov
c293498be6 Btrfs: BUG to BUG_ON changes
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-04-02 17:05:11 -04:00
Dan Carpenter
3e7ad38d20 Btrfs: remove dead code
Remove an unneeded return statement and conditional

Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-04-02 16:46:06 -04:00
Dan Carpenter
ff0a5836ac Btrfs: remove dead code
merge is always NULL at this point.

Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-04-02 16:46:06 -04:00
Wu Fengguang
d4a789474a Btrfs: fix typos in comments
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-04-02 16:46:06 -04:00
Jim Owens
2e966ed22c Btrfs: remove unused ftrace include
Signed-off-by: jim owens <jowens@hp.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-04-02 17:02:55 -04:00
Heiko Carstens
93dbfad7ac Btrfs: fix __ucmpdi2 compile bug on 32 bit builds
We get this on 32 builds:

fs/built-in.o: In function `extent_fiemap':
(.text+0x1019f2): undefined reference to `__ucmpdi2'

Happens because of a switch statement with a 64 bit argument.
Convert this to an if statement to fix this.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-04-03 10:33:45 -04:00
Shen Feng
09771430f3 Btrfs: free inode struct when btrfs_new_inode fails
btrfs_new_inode doesn't call iput to free the inode
when it fails.

Signed-off-by: Shen Feng <shen@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-04-02 16:46:06 -04:00
Amit Gud
b5555f7711 Btrfs: fix race in worker_loop
Need to check kthread_should_stop after schedule_timeout() before calling
schedule(). This causes threads to sleep with potentially no one to wake them
up causing mount(2) to hang in btrfs_stop_workers waiting for threads to stop.

Signed-off-by: Amit Gud <gud@ksu.edu>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-04-02 17:01:27 -04:00
Sage Weil
dccae99995 Btrfs: add flushoncommit mount option
The 'flushoncommit' mount option forces any data dirtied by a write in a
prior transaction to commit as part of the current commit.  This makes
the committed state a fully consistent view of the file system from the
application's perspective (i.e., it includes all completed file system
operations).  This was previously the behavior only when a snapshot is
created.

This is used by Ceph to ensure that completed writes make it to the
platter along with the metadata operations they are bound to (by
BTRFS_IOC_TRANS_{START,END}).

Signed-off-by: Sage Weil <sage@newdream.net>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-04-02 16:59:01 -04:00
Sage Weil
3a5e14048a Btrfs: notreelog mount option
Add a 'notreelog' mount option to disable the tree log (used by fsync,
O_SYNC writes).  This is much slower, but the tree logging produces
inconsistent views into the FS for ceph.

Signed-off-by: Sage Weil <sage@newdream.net>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-04-02 16:49:40 -04:00
Eric Paris
a9572a15a8 Btrfs: introduce btrfs_show_options
btrfs options can change at times other than mount, yet /proc/mounts shows the
options string used when the fs was mounted (an example would be when btrfs
determines that barriers aren't useful and turns them off.)  This patch
instead outputs the actual options in use by btrfs.

Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-04-02 16:46:06 -04:00
Chris Mason
fa9c0d795f Btrfs: rework allocation clustering
Because btrfs is copy-on-write, we end up picking new locations for
blocks very often.  This makes it fairly difficult to maintain perfect
read patterns over time, but we can at least do some optimizations
for writes.

This is done today by remembering the last place we allocated and
trying to find a free space hole big enough to hold more than just one
allocation.  The end result is that we tend to write sequentially to
the drive.

This happens all the time for metadata and it happens for data
when mounted -o ssd.  But, the way we record it is fairly racey
and it tends to fragment the free space over time because we are trying
to allocate fairly large areas at once.

This commit gets rid of the races by adding a free space cluster object
with dedicated locking to make sure that only one process at a time
is out replacing the cluster.

The free space fragmentation is somewhat solved by allowing a cluster
to be comprised of smaller free space extents.  This part definitely
adds some CPU time to the cluster allocations, but it allows the allocator
to consume the small holes left behind by cow.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-04-03 09:47:43 -04:00
Chris Mason
8e73f27501 Btrfs: Optimize locking in btrfs_next_leaf()
btrfs_next_leaf was using blocking locks when it could have been using
faster spinning ones instead.  This adds a few extra checks around
the pieces that block and switches over to spinning locks.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-04-03 10:14:18 -04:00
Chris Mason
c8c42864f6 Btrfs: break up btrfs_search_slot into smaller pieces
btrfs_search_slot was doing too many things at once.  This breaks
it up into more reasonable units.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-04-03 10:14:18 -04:00
Josef Bacik
04018de5d4 Btrfs: kill the pinned_mutex
This patch removes the pinned_mutex.  The extent io map has an internal tree
lock that protects the tree itself, and since we only copy the extent io map
when we are committing the transaction we don't need it there.  We also don't
need it when caching the block group since searching through the tree is also
protected by the internal map spin lock.

Signed-off-by: Josef Bacik <jbacik@redhat.com>
2009-04-03 10:14:18 -04:00
Josef Bacik
6226cb0a5e Btrfs: kill the block group alloc mutex
This patch removes the block group alloc mutex used to protect the free space
tree for allocations and replaces it with a spin lock which is used only to
protect the free space rb tree.  This means we only take the lock when we are
directly manipulating the tree, which makes us a touch faster with
multi-threaded workloads.

This patch also gets rid of btrfs_find_free_space and replaces it with
btrfs_find_space_for_alloc, which takes the number of bytes you want to
allocate, and empty_size, which is used to indicate how much free space should
be at the end of the allocation.

It will return an offset for the allocator to use.  If we don't end up using it
we _must_ call btrfs_add_free_space to put it back.  This is the tradeoff to
kill the alloc_mutex, since we need to make sure nobody else comes along and
takes our space.

Signed-off-by: Josef Bacik <jbacik@redhat.com>
2009-04-03 10:14:18 -04:00
Josef Bacik
2552d17e32 Btrfs: clean up find_free_extent
I've replaced the strange looping constructs with a list_for_each_entry on
space_info->block_groups.  If we have a hint we just jump into the loop with
the block group and start looking for space.  If we don't find anything we
start at the beginning and start looking.  We never come out of the loop with a
ref on the block_group _unless_ we found space to use, then we drop it after we
set the trans block_group.

Signed-off-by: Josef Bacik <jbacik@redhat.com>
2009-04-03 10:14:19 -04:00
Josef Bacik
70cb074345 Btrfs: free space cache cleanups
This patch cleans up the free space cache code a bit.  It better documents the
idiosyncrasies of tree_search_offset and makes the code make a bit more sense.
I took out the info allocation at the start of __btrfs_add_free_space and put it
where it makes more sense.  This was left over cruft from when alloc_mutex
existed.  Also all of the re-searches we do to make sure we inserted properly.

Signed-off-by: Josef Bacik <jbacik@redhat.com>
2009-04-03 10:14:19 -04:00
Chris Mason
bedf762ba3 Btrfs: unplug in the async bio submission threads
Btrfs pages being written get set to writeback, and then may go through
a number of steps before they hit the block layer.  This includes compression,
checksumming and async bio submission.

The end result is that someone who writes a page and then does
wait_on_page_writeback is likely to unplug the queue before the bio they
cared about got there.

We could fix this by marking bios sync, or by doing more frequent unplugs,
but this commit just changes the async bio submission code to unplug
after it has processed all the bios for a device.  The async bio submission
does a fair job of collection bios, so this shouldn't be a huge problem
for reducing merging at the elevator.

For streaming O_DIRECT writes on a 5 drive array, it boosts performance
from 386MB/s to 460MB/s.

Thanks to Hisashi Hifumi for helping with this work.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-04-03 10:32:58 -04:00
Chris Mason
b765ead57d Btrfs: keep processing bios for a given bdev if our proc is batching
Btrfs uses async helper threads to submit write bios so the checksumming
helper threads don't block on the disk.

The submit bio threads may process bios for more than one block device,
so when they find one device congested they try to move on to other
devices instead of blocking in get_request_wait for one device.

This does a pretty good job of keeping multiple devices busy, but the
congested flag has a number of problems.  A congested device may still
give you a request, and other procs that aren't backing off the congested
device may starve you out.

This commit uses the io_context stored in current to decide if our process
has been made a batching process by the block layer.  If so, it keeps
sending IO down for at least one batch.  This helps make sure we do
a good amount of work each time we visit a bdev, and avoids large IO
stalls in multi-device workloads.

It's also very ugly.  A better solution is in the works with Jens Axboe.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-04-03 10:27:10 -04:00
Linus Torvalds
c226fd659f Merge git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable
* git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable:
  Btrfs: try to free metadata pages when we free btree blocks
  Btrfs: add extra flushing for renames and truncates
  Btrfs: make sure btrfs_update_delayed_ref doesn't increase ref_mod
  Btrfs: optimize fsyncs on old files
  Btrfs: tree logging unlink/rename fixes
  Btrfs: Make sure i_nlink doesn't hit zero too soon during log replay
  Btrfs: limit balancing work while flushing delayed refs
  Btrfs: readahead checksums during btrfs_finish_ordered_io
  Btrfs: leave btree locks spinning more often
  Btrfs: Only let very young transactions grow during commit
  Btrfs: Check for a blocking lock before taking the spin
  Btrfs: reduce stack in cow_file_range
  Btrfs: reduce stalls during transaction commit
  Btrfs: process the delayed reference queue in clusters
  Btrfs: try to cleanup delayed refs while freeing extents
  Btrfs: reduce stack usage in some crucial tree balancing functions
  Btrfs: do extent allocation and reference count updates in the background
  Btrfs: don't preallocate metadata blocks during btrfs_search_slot
2009-04-01 10:20:44 -07:00
Nick Piggin
56a76f8275 fs: fix page_mkwrite error cases in core code and btrfs
page_mkwrite is called with neither the page lock nor the ptl held.  This
means a page can be concurrently truncated or invalidated out from
underneath it.  Callers are supposed to prevent truncate races themselves,
however previously the only thing they can do in case they hit one is to
raise a SIGBUS.  A sigbus is wrong for the case that the page has been
invalidated or truncated within i_size (eg.  hole punched).  Callers may
also have to perform memory allocations in this path, where again, SIGBUS
would be wrong.

The previous patch ("mm: page_mkwrite change prototype to match fault")
made it possible to properly specify errors.  Convert the generic buffer.c
code and btrfs to return sane error values (in the case of page removed
from pagecache, VM_FAULT_NOPAGE will cause the fault handler to exit
without doing anything, and the fault will be retried properly).

This fixes core code, and converts btrfs as a template/example.  All other
filesystems defining their own page_mkwrite should be fixed in a similar
manner.

Acked-by: Chris Mason <chris.mason@oracle.com>
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-01 08:59:14 -07:00
Nick Piggin
c2ec175c39 mm: page_mkwrite change prototype to match fault
Change the page_mkwrite prototype to take a struct vm_fault, and return
VM_FAULT_xxx flags.  There should be no functional change.

This makes it possible to return much more detailed error information to
the VM (and also can provide more information eg.  virtual_address to the
driver, which might be important in some special cases).

This is required for a subsequent fix.  And will also make it easier to
merge page_mkwrite() with fault() in future.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <joel.becker@oracle.com>
Cc: Artem Bityutskiy <dedekind@infradead.org>
Cc: Felix Blyakher <felixb@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-01 08:59:14 -07:00
Al Viro
ce3b0f8d5c New helper - current_umask()
current->fs->umask is what most of fs_struct users are doing.
Put that into a helper function.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-03-31 23:00:26 -04:00
Chris Mason
d57e62b897 Btrfs: try to free metadata pages when we free btree blocks
COW means we cycle though blocks fairly quickly, and once we
free an extent on disk, it doesn't make much sense to keep the pages around.

This commit tries to immediately free the page when we free the extent,
which lowers our memory footprint significantly.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-31 14:27:58 -04:00
Chris Mason
5a3f23d515 Btrfs: add extra flushing for renames and truncates
Renames and truncates are both common ways to replace old data with new
data.  The filesystem can make an effort to make sure the new data is
on disk before actually replacing the old data.

This is especially important for rename, which many application use as
though it were atomic for both the data and the metadata involved.  The
current btrfs code will happily replace a file that is fully on disk
with one that was just created and still has pending IO.

If we crash after transaction commit but before the IO is done, we'll end
up replacing a good file with a zero length file.  The solution used
here is to create a list of inodes that need special ordering and force
them to disk before the commit is done.  This is similar to the
ext3 style data=ordering, except it is only done on selected files.

Btrfs is able to get away with this because it does not wait on commits
very often, even for fsync (which use a sub-commit).

For renames, we order the file when it wasn't already
on disk and when it is replacing an existing file.  Larger files
are sent to filemap_flush right away (before the transaction handle is
opened).

For truncates, we order if the file goes from non-zero size down to
zero size.  This is a little different, because at the time of the
truncate the file has no dirty bytes to order.  But, we flag the inode
so that it is added to the ordered list on close (via release method).  We
also immediately add it to the ordered list of the current transaction
so that we can try to flush down any writes the application sneaks in
before commit.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-31 14:27:58 -04:00