Commit graph

48 commits

Author SHA1 Message Date
Josef Bacik
09a2a8f96e Btrfs: fix bad extent logging
A user sent me a btrfs-image of a file system that was panicing on mount during
the log recovery.  I had originally thought these problems were from a bug in
the free space cache code, but that was just a symptom of the problem.  The
problem is if your application does something like this

[prealloc][prealloc][prealloc]

the internal extent maps will merge those all together into one extent map, even
though on disk they are 3 separate extents.  So if you go to write into one of
these ranges the extent map will be right since we use the physical extent when
doing the write, but when we log the extents they will use the wrong sizes for
the remainder prealloc space.  If this doesn't happen to trip up the free space
cache (which it won't in a lot of cases) then you will get bogus entries in your
extent tree which will screw stuff up later.  The data and such will still work,
but everything else is broken.  This patch fixes this by not allowing extents
that are on the modified list to be merged.  This has the side effect that we
are no longer adding everything to the modified list all the time, which means
we now have to call btrfs_drop_extents every time we log an extent into the
tree.  So this allows me to drop all this speciality code I was using to get
around calling btrfs_drop_extents.  With this patch the testcase I've created no
longer creates a bogus file system after replaying the log.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2013-05-06 15:54:34 -04:00
Josef Bacik
cc95bef635 Btrfs: log ram bytes properly
When logging changed extents I was logging ram_bytes as the current length,
which isn't correct, it's supposed to be the ram bytes of the original extent.
This is for compression where even if we split the extent we need to know the
ram bytes so when we uncompress the extent we know how big it will be.  This was
still working out right with compression for some reason but I think we were
getting lucky.  It was definitely off for prealloc which is why I noticed it,
btrfsck was complaining about it.  With this patch btrfsck no longer complains
after a log replay.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2013-05-06 15:54:33 -04:00
Josef Bacik
201a903894 Btrfs: do not allow logged extents to be merged or removed
We drop the extent map tree lock while we're logging extents, so somebody
could come in and merge another extent into this one and screw up our
logging, or they could even remove us from the list which would keep us from
logging the extent or freeing our ref on it, so we need to make sure to not
clear LOGGING until after the extent is logged, and then we can merge it to
adjacent extents.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2013-01-24 12:49:48 -05:00
Josef Bacik
b11e234d21 Btrfs: do not mark ems as prealloc if we are writing to them
We are going to use EM's to log extents in the future, so we need to not
mark them as prealloc if they aren't actually prealloc extents.  Instead
mark them with FILLING so we know to ammend mod_start/mod_len and that way
we don't confuse the extent logging code.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
2012-12-16 20:46:23 -05:00
Josef Bacik
b493968096 Btrfs: keep track of the extents original block length
If we've written to a prealloc extent we need to know the original block len
for the extent.  We can't figure this out currently since ->block_len is
just set to the extent length.  So introduce ->orig_block_len so that we
know how many bytes were in the original extent for proper extent logging
that future patches will need.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
2012-12-16 20:46:23 -05:00
Josef Bacik
ff44c6e36d Btrfs: do not hold the write_lock on the extent tree while logging
Dave Sterba pointed out a sleeping while atomic bug while doing fsync.  This
is because I'm an idiot and didn't realize that rwlock's were spin locks, so
we've been holding this thing while doing allocations and such which is not
good.  This patch fixes this by dropping the write lock before we do
anything heavy and re-acquire it when it is done.  We also need to take a
ref on the em's in case their corresponding pages are evicted and mark them
as being logged so that releasepage does not remove them and doesn't remove
them from our local list.  Thanks,

Reported-by: Dave Sterba <dave@jikos.cz>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2012-10-04 09:39:58 -04:00
Liu Bo
4e2f84e63d Btrfs: improve fsync by filtering extents that we want
This is based on Josef's "Btrfs: turbo charge fsync".

The above Josef's patch performs very good in random sync write test,
because we won't have too much extents to merge.

However, it does not performs good on the test:
dd if=/dev/zero of=foobar bs=4k count=12500 oflag=sync

The reason is when we do sequencial sync write, we need to merge the
current extent just with the previous one, so that we can get accumulated
extents to log:

A(4k) --> AA(8k) --> AAA(12k) --> AAAA(16k) ...

So we'll have to flush more and more checksum into log tree, which is the
bottleneck according to my tests.

But we can avoid this by telling fsync the real extents that are needed
to be logged.

With this, I did the above dd sync write test (size=50m),

         w/o (orig)   w/ (josef's)   w/ (this)
SATA      104KB/s       109KB/s       121KB/s
ramdisk   1.5MB/s       1.5MB/s       10.7MB/s (613%)

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
2012-10-01 15:19:05 -04:00
Josef Bacik
5dc562c541 Btrfs: turbo charge fsync
At least for the vm workload.  Currently on fsync we will

1) Truncate all items in the log tree for the given inode if they exist

and

2) Copy all items for a given inode into the log

The problem with this is that for things like VMs you can have lots of
extents from the fragmented writing behavior, and worst yet you may have
only modified a few extents, not the entire thing.  This patch fixes this
problem by tracking which transid modified our extent, and then when we do
the tree logging we find all of the extents we've modified in our current
transaction, sort them and commit them.  We also only truncate up to the
xattrs of the inode and copy that stuff in normally, and then just drop any
extents in the range we have that exist in the log already.  Here are some
numbers of a 50 meg fio job that does random writes and fsync()s after every
write

		Original	Patched
SATA drive	82KB/s		140KB/s
Fusion drive	431KB/s		2532KB/s

So around 2-6 times faster depending on your hardware.  There are a few
corner cases, for example if you truncate at all we have to do it the old
way since there is no way to be sure what is in the log is ok.  This
probably could be done smarter, but if you write-fsync-truncate-write-fsync
you deserve what you get.  All this work is in RAM of course so if your
inode gets evicted from cache and you read it in and fsync it we'll do it
the slow way if we are still in the same transaction that we last modified
the inode in.

The biggest cool part of this is that it requires no changes to the recovery
code, so if you fsync with this patch and crash and load an old kernel, it
will run the recovery and be a-ok.  I have tested this pretty thoroughly
with an fsync tester and everything comes back fine, as well as xfstests.
Thanks,

Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2012-10-01 15:19:03 -04:00
David Sterba
c08782dacd btrfs: fix structs where bitfields and spinlock/atomic share 8B word
On ia64, powerpc64 and sparc64 the bitfield is modified through a RMW cycle and current
gcc rewrites the adjacent 4B word, which in case of a spinlock or atomic has
disaterous effect.

https://lkml.org/lkml/2012/2/1/220

Signed-off-by: David Sterba <dsterba@suse.cz>
2012-02-15 16:40:25 +01:00
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
a8067e022a btrfs: drop unused parameter from extent_map_tree_init
the GFP flags are not stored anywhere and all allocations are done via
alloc_extent_map(GFP_NOFS).

Signed-off-by: David Sterba <dsterba@suse.cz>
2011-05-02 13:57:21 +02:00
Li Zefan
261507a02c btrfs: Allow to add new compression algorithm
Make the code aware of compression type, instead of always assuming
zlib compression.

Also make the zlib workspace function as common code for all
compression types.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
2010-12-22 23:15:45 +08:00
Chris Mason
b917b7c3be Btrfs: search for an allocation hint while filling file COW
The allocator has some nice knobs for sending hints about where
to try and allocate new blocks, but when we're doing file allocations
we're not sending any hint at all.

This commit adds a simple extent map search to see if we can
quickly and easily find a hint for the allocator.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-09-18 16:08:52 -04:00
Chris Mason
a1ed835e1a Btrfs: Fix extent replacment race
Data COW means that whenever we write to a file, we replace any old
extent pointers with new ones.  There was a window where a readpage
might find the old extent pointers on disk and cache them in the
extent_map tree in ram in the middle of a given write replacing them.

Even though both the readpage and the write had their respective bytes
in the file locked, the extent readpage inserts may cover more bytes than
it had locked down.

This commit closes the race by keeping the new extent pinned in the extent
map tree until after the on-disk btree is properly setup with the new
extent pointers.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-09-11 13:31:07 -04:00
Chris Mason
890871be85 Btrfs: switch extent_map to a rw lock
There are two main users of the extent_map tree.  The
first is regular file inodes, where it is evenly spread
between readers and writers.

The second is the chunk allocation tree, which maps blocks from
logical addresses to phyiscal ones, and it is 99.99% reads.

The mapping tree is a point of lock contention during heavy IO
workloads, so this commit switches things to a rw lock.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-09-11 13:31:05 -04:00
Yan Zheng
ff5b7ee33d Btrfs: Fix csum error for compressed data
The decompress code doesn't take the logical offset in extent
pointer into account. If the logical offset isn't zero, data
will be decompressed into wrong pages.

The solution used here is to record the starting offset of the extent
in the file separately from the logical start of the extent_map struct.
This allows us to avoid problems inserting overlapping extents.

Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
2008-11-10 07:34:43 -05:00
Yan Zheng
d899e05215 Btrfs: Add fallocate support v2
This patch updates btrfs-progs for fallocate support.

fallocate is a little different in Btrfs because we need to tell the
COW system that a given preallocated extent doesn't need to be
cow'd as long as there are no snapshots of it.  This leverages the
-o nodatacow checks.
 
Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
2008-10-30 14:25:28 -04:00
Yan Zheng
9036c10208 Btrfs: update hole handling v2
This patch splits the hole insertion code out of btrfs_setattr
into btrfs_cont_expand and updates btrfs_get_extent to properly
handle the case that file extent items are not continuous.

Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
2008-10-30 14:19:41 -04:00
Chris Mason
c8b978188c Btrfs: Add zlib compression support
This is a large change for adding compression on reading and writing,
both for inline and regular extents.  It does some fairly large
surgery to the writeback paths.

Compression is off by default and enabled by mount -o compress.  Even
when the -o compress mount option is not used, it is possible to read
compressed extents off the disk.

If compression for a given set of pages fails to make them smaller, the
file is flagged to avoid future compression attempts later.

* While finding delalloc extents, the pages are locked before being sent down
to the delalloc handler.  This allows the delalloc handler to do complex things
such as cleaning the pages, marking them writeback and starting IO on their
behalf.

* Inline extents are inserted at delalloc time now.  This allows us to compress
the data before inserting the inline extent, and it allows us to insert
an inline extent that spans multiple pages.

* All of the in-memory extent representations (extent_map.c, ordered-data.c etc)
are changed to record both an in-memory size and an on disk size, as well
as a flag for compression.

From a disk format point of view, the extent pointers in the file are changed
to record the on disk size of a given extent and some encoding flags.
Space in the disk format is allocated for compression encoding, as well
as encryption and a generic 'other' field.  Neither the encryption or the
'other' field are currently used.

In order to limit the amount of data read for a single random read in the
file, the size of a compressed extent is limited to 128k.  This is a
software only limit, the disk format supports u64 sized compressed extents.

In order to limit the ram consumed while processing extents, the uncompressed
size of a compressed extent is limited to 256k.  This is a software only limit
and will be subject to tuning later.

Checksumming is still done on compressed extents, and it is done on the
uncompressed version of the data.  This way additional encodings can be
layered on without having to figure out which encoding to checksum.

Compression happens at delalloc time, which is basically singled threaded because
it is usually done by a single pdflush thread.  This makes it tricky to
spread the compression load across all the cpus on the box.  We'll have to
look at parallel pdflush walks of dirty inodes at a later time.

Decompression is hooked into readpages and it does spread across CPUs nicely.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-10-29 14:49:59 -04:00
Chris Mason
f421950f86 Btrfs: Fix some data=ordered related data corruptions
Stress testing was showing data checksum errors, most of which were caused
by a lookup bug in the extent_map tree.  The tree was caching the last
pointer returned, and searches would check the last pointer first.

But, search callers also expect the search to return the very first
matching extent in the range, which wasn't always true with the last
pointer usage.

For now, the code to cache the last return value is just removed.  It is
easy to fix, but I think lookups are rare enough that it isn't required anymore.

This commit also replaces do_sync_mapping_range with a local copy of the
related functions.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:05 -04:00
Chris Mason
7f3c74fb83 Btrfs: Keep extent mappings in ram until pending ordered extents are done
It was possible for stale mappings from disk to be used instead of the
new pending ordered extent.  This adds a flag to the extent map struct
to keep it pinned until the pending ordered extent is actually on disk.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:05 -04:00
Chris Mason
d1310b2e0c Btrfs: Split the extent_map code into two parts
There is now extent_map for mapping offsets in the file to disk and
extent_io for state tracking, IO submission and extent_bufers.

The new extent_map code shifts from [start,end] pairs to [start,len], and
pushes the locking out into the caller.  This allows a few performance
optimizations and is easier to use.

A number of extent_map usage bugs were fixed, mostly with failing
to remove extent_map entries when changing the file.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:03:59 -04:00
Chris Mason
1832a6d5ee Btrfs: Implement basic support for -ENOSPC
This is intended to prevent accidentally filling the drive.  A determined
user can still make things oops.

It includes some accounting of the current bytes under delayed allocation,
but this will change as things get optimized

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:03:58 -04:00
Christian Hesse
17636e03f4 Btrfs: section mismatch warnings
--Boundary-00=_CcOWHFYK4T+JwSj
Content-Type: text/plain;
  charset="iso-8859-1"
Content-Transfer-Encoding: 7bit
Content-Disposition: inline

Hello everybody,

compiling btrfs into the kernel results in section mismatch warnings. __exit
functions are called where they are not allowed to. The attached patch fixes
this for me. Not sure if it is correct though.

Signed-off-by: Christian Hesse <mail@earthworm.de>
--
Regards,
Chris

--Boundary-00=_CcOWHFYK4T+JwSj
Content-Type: text/x-diff; charset="iso-8859-1";
	name="btrfs-section_mismatches.patch"
Content-Transfer-Encoding: 7bit
Content-Disposition: attachment;
	filename="btrfs-section_mismatches.patch"

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:03:58 -04:00
Chris Mason
ca6646264b Btrfs: Add efficient dirty accounting to the extent_map tree
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:03:58 -04:00
Chris Mason
793955bca6 Btrfs: Limit btree writeback to prevent seeks
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:03:58 -04:00
Wyatt Banks
2f4cbe6442 Btrfs: Return value checking in module init
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:03:58 -04:00
Chris Mason
3ab2fb5a8c Btrfs: Add readpages support
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:03:57 -04:00
Chris Mason
b293f02e14 Btrfs: Add writepages support
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:03:57 -04:00
Chris Mason
179e29e488 Btrfs: Fix a number of inline extent problems that Yan Zheng reported.
The fixes do a number of things:

1) Most btrfs_drop_extent callers will try to leave the inline extents in
place.  It can truncate bytes off the beginning of the inline extent if
required.

2) writepage can now update the inline extent, allowing mmap writes to
go directly into the inline extent.

3) btrfs_truncate_in_transaction truncates inline extents

4) extent_map.c fixed to not merge inline extent mappings and hole
mappings together

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:03:57 -04:00
Chris Mason
19c00ddcc3 Btrfs: Add back metadata checksumming
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:03:56 -04:00
Chris Mason
810191ff30 Btrfs: extent_map optimizations to cut down on CPU usage
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:03:56 -04:00
Chris Mason
4dc119046d Btrfs: Add an extent buffer LRU to reduce radix tree hits
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:03:56 -04:00
Chris Mason
6b80053d02 Btrfs: Add back the online defragging code
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:03:56 -04:00
Chris Mason
09e71a3263 Btrfs: Use an array of pages in the extent buffers to reduce the cost of find_get_page
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:03:56 -04:00
Chris Mason
db94535db7 Btrfs: Allow tree blocks larger than the page size
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:03:56 -04:00
Chris Mason
1a5bc167f6 Btrfs: Change the remaining radix trees used by extent-tree.c to extent_map trees
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:03:56 -04:00
Chris Mason
96b5179d0d Btrfs: Stop using radix trees for the block group cache
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:03:56 -04:00
Chris Mason
f510cfecfc Btrfs: Fix extent_buffer and extent_state leaks
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:03:56 -04:00
Chris Mason
6d36dcd48f Btrfs: Avoid memcpy where possible in extent_buffers
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:03:56 -04:00
Chris Mason
479965d66e Btrfs: Optimizations for the extent_buffer code
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:03:56 -04:00
Chris Mason
5f39d397df Btrfs: Create extent_buffer interface for large blocksizes
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:03:56 -04:00
Christoph Hellwig
b3cfa35a49 Btrfs: factor page private preparations into a helper
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:03:56 -04:00
Christoph Hellwig
0e2752a72c Btrfs: [PATCH] extent_map: add writepage_end_io hook
XFS updates the ondisk inode size only after the data I/O has finished,
so it needs a hook when the writepage end_bio handler has finished.

Might not be worth applying as-is as the per-page callback is very
ineffcient.  What XFS really wants is a callback when writeout of a
whole extent has completed.  This delayed i_size updates scheme might
be worthwile for btrfs aswell, btw.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2007-09-10 20:02:33 -04:00
Christoph Hellwig
d396c6f554 Btrfs: [PATCH] extent_map: provide generic bmap
generic_bmap is completely trivial, while the extent to bh mapping in
btrfs is rather complex.  So provide a extent_bmap instead that takes
a get_extent callback and can be used by filesystem using the extent_map
code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2007-09-10 20:02:30 -04:00
Chris Mason
07157aacb1 Btrfs: Add file data csums back in via hooks in the extent map code
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2007-08-30 08:50:51 -04:00
Chris Mason
b888db2bd7 Btrfs: Add delayed allocation to the extent based page tree code
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2007-08-27 16:49:44 -04:00
Chris Mason
a52d9a8033 Btrfs: Extent based page cache code. This uses an rbtree of extents and tests
instead of buffer heads.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2007-08-27 16:49:44 -04:00