I noticed while looking at a deadlock that we are always starting a transaction
in cow_file_range().  This isn't really needed since we only need a transaction
if we are doing an inline extent, or if the allocator needs to allocate a chunk.
So push down all the transaction start stuff to be closer to where we actually
need a transaction in all of these cases.  This will hopefully reduce our write
latency when we are committing often.  Thanks,
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

Fix to return error code instead always return 0 from function
btrfs_check_trunc_cache_free_space().
Introduced by commit 7b61cd92
(Btrfs: don't use global block reservation for inode cache truncation)
Signed-off-by: NWei Yongjun <yongjun_wei@trendmicro.com.cn>
Reviewed-by: NMiao Xie <miaox@cn.fujitsu.com>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>

Signed-off-by: NDavid Sterba <dsterba@suse.cz>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>

And change the message level to KERN_INFO.
Signed-off-by: NDavid Sterba <dsterba@suse.cz>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>

Correct spelling typo in various part of drivers
Signed-off-by: NMasanari Iida <standby24x7@gmail.com>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

It is very likely that there are lots of subvolumes/snapshots in the filesystem,
so if we use global block reservation to do inode cache truncation, we may hog
all the free space that is reserved in global rsv. So it is better that we do
the free space reservation for inode cache truncation by ourselves.

Cc: Tsutomu Itoh <t-itoh@jp.fujitsu.com>
Signed-off-by: NMiao Xie <miaox@cn.fujitsu.com>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>

This catches block groups that are too large to properly cache.  We deal with
this case fine, so the warning just confuses users.  Remove the warning.
Thanks,
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>

Big patch, but all it does is add statics to functions which
are in fact static, then remove the associated dead-code fallout.

removed functions:

btrfs_iref_to_path()
__btrfs_lookup_delayed_deletion_item()
__btrfs_search_delayed_insertion_item()
__btrfs_search_delayed_deletion_item()
find_eb_for_page()
btrfs_find_block_group()
range_straddles_pages()
extent_range_uptodate()
btrfs_file_extent_length()
btrfs_scrub_cancel_devid()
btrfs_start_transaction_lflush()

btrfs_print_tree() is left because it is used for debugging.
btrfs_start_transaction_lflush() and btrfs_reada_detach() are
left for symmetry.

ulist.c functions are left, another patch will take care of those.
Signed-off-by: NEric Sandeen <sandeen@redhat.com>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>

So everybody who got hit by my fsync bug will still continue to hit this
BUG_ON() in the free space cache, which is pretty heavy handed.  So I took a
file system that had this bug and fixed up all the BUG_ON()'s and leaks that
popped up when I tried to mount a broken file system like this.  With this patch
we just fail to mount instead of panicing.  Thanks,
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>

With more than one btrfs volume mounted, it can be very difficult to find
out which volume is hitting an error. btrfs_error() will print this, but
it is currently rigged as more of a fatal error handler, while many of
the printk()s are currently for debugging and yet-unhandled cases.

This patch just changes the functions where the device information is
already available. Some cases remain where the root or fs_info is not
passed to the function emitting the error.

This may introduce some confusion with volumes backed by multiple devices
emitting errors referring to the primary device in the set instead of the
one on which the error occurred.

Use btrfs_printk(fs_info, format, ...) rather than writing the device
string every time, and introduce macro wrappers ala XFS for brevity.
Since the function already cannot be used for continuations, print a
newline as part of the btrfs_printk() message rather than at each caller.
Signed-off-by: NSimon Kirby <sim@hostway.ca>
Reviewed-by: NDavid Sterba <dsterba@suse.cz>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>

Argument 'root' is no more used in btrfs_csum_data().
Signed-off-by: NLiu Bo <bo.li.liu@oracle.com>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>

We keep hitting bugs in the tree log replay because btrfs_remove_free_space
doesn't account for some corner case.  So add a bunch of tests to try and fully
test btrfs_remove_free_space since the only time it is called is during tree log
replay.  These tests all finish successfully, so as we find more of these bugs
we need to add to these tests to make sure we don't regress in fixing things.
I've hidden the tests behind a Kconfig option, but they take no time to run so
all btrfs developers should have this turned on all the time.  Thanks,
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>

Dave pointed out that xfstests 273 will tell you that it failed to load the
space cache for a block group when it remounts.  This is because we run out
of space writing out the block group cache.  This is ok and is working as it
should, but let's try to be a bit nicer.  This happens because the block
group was 100mb, but bitmap entries cover 128mb, so we were only getting
extent entries for this block group, which ended up being too many to fit in
the free space cache.  So relax the bitmap size requirements to block groups
that are at least half the size a bitmap will cover or larger, that way we
can still keep the amount of space used in the free space cache low enough
to be able to write it out.  With this patch I no longer fail to write out
the free space cache.  Thanks,
Reported-by: NDavid Sterba <dsterba@suse.cz>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>

This builds on David Woodhouse's original Btrfs raid5/6 implementation.
The code has changed quite a bit, blame Chris Mason for any bugs.

Read/modify/write is done after the higher levels of the filesystem have
prepared a given bio.  This means the higher layers are not responsible
for building full stripes, and they don't need to query for the topology
of the extents that may get allocated during delayed allocation runs.
It also means different files can easily share the same stripe.

But, it does expose us to incorrect parity if we crash or lose power
while doing a read/modify/write cycle.  This will be addressed in a
later commit.

Scrub is unable to repair crc errors on raid5/6 chunks.

Discard does not work on raid5/6 (yet)

The stripe size is fixed at 64KiB per disk.  This will be tunable
in a later commit.
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

A user reported a BUG_ON(ret) that occured during tree log replay.  Ret was
-EAGAIN, so what I think happened is that we removed an extent that covered
a bitmap entry and an extent entry.  We remove the part from the bitmap and
return -EAGAIN and then search for the next piece we want to remove, which
happens to be an entire extent entry, so we just free the sucker and return.
The problem is ret is still set to -EAGAIN so we trip the BUG_ON().  The
user used btrfs-zero-log so I'm not 100% sure this is what happened so I've
added a WARN_ON() to catch the other possibility.  Thanks,
Reported-by: NJan Steffens <jan.steffens@gmail.com>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>

We should use ctl->unit for free space calculation instead of block_group->sectorsize
even though for free space use_bitmap or free space cluster we only have sectorsize assigned to ctl->unit currently. Also, we can keep it consisten in code style.
Signed-off-by: NWang Sheng-Hui <shhuiw@gmail.com>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

io_ctl_map_page is called by many functions in free-space-cache.
In most scenarios, the ->cur is not null, e.g. io_ctl_add_entry.
I think we'd better remove the warn_on here.
Signed-off-by: NWang Sheng-Hui <shhuiw@gmail.com>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

When we find a bitmap free space entry, we may check the previous extent
entry covers the offset or not. But if we find this entry is also a bitmap
entry, we will continue to check the previous entry of the current one by
a while loop. It is unnecessary because it is impossible that the extent
entry which is in front of a bitmap entry can cover the offset of the entry
after that bitmap entry.
Signed-off-by: NMiao Xie <miaox@cn.fujitsu.com>
Reviewed-by: NLiu Bo <bo.li.liu@oracle.com>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

Everytime we write out dirty pages we search for an offset in the tree,
convert the bits in the state, and then when we wait we search for the
offset again and clear the bits.  So for every dirty range in the io tree we
are doing 4 rb searches, which is suboptimal.  With this patch we are only
doing 2 searches for every cycle (modulo weird things happening).  Thanks,
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>

Using for_each_set_bit_from() to simplify the code.

spatch with a semantic match is used to found this.
(http://coccinelle.lip6.fr/)
Signed-off-by: NWei Yongjun <yongjun_wei@trendmicro.com.cn>

If a block group is ro, do not count its entries in when we dump space info.
Signed-off-by: NLiu Bo <liubo2009@cn.fujitsu.com>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>

The tree log stuff can have allocated space that we end up having split
across a bitmap and a real extent.  The free space code does not deal with
this, it assumes that if it finds an extent or bitmap entry that the entire
range must fall within the entry it finds.  This isn't necessarily the case,
so rework the remove function so it can handle this case properly.  This
fixed two panics the user hit, first in the case where the space was
initially in a bitmap and then in an extent entry, and then the reverse
case.  Thanks,
Reported-and-tested-by: NShaun Reich <sreich@kde.org>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>

When we write out the free space cache we will write out everything that is
in our in memory tree, and then we will just walk the pinned extents tree
and write anything we see there.  The problem with this is that during
normal operations the pinned extents will be merged back into the free space
tree normally, and then we can allocate space from the merged areas and
commit them to the tree log.  If we crash and replay the tree log we will
crash again because the tree log will try to free up space from what looks
like 2 seperate but contiguous entries, since one entry is from the original
free space cache and the other was a pinned extent that was merged back.  To
fix this we just need to walk the free space tree after we load it and merge
contiguous entries back together.  This will keep the tree log stuff from
breaking and it will make the allocator behave more nicely.  Thanks,
Signed-off-by: NJosef Bacik <josef@redhat.com>

We noticed that the ordered extent completion doesn't really rely on having
a page and that it could be done independantly of ending the writeback on a
page.  This patch makes us not do the threaded endio stuff for normal
buffered writes and direct writes so we can end page writeback as soon as
possible (in irq context) and only start threads to do the ordered work when
it is actually done.  Compression needs to be reworked some to take
advantage of this as well, but atm it has to do a find_get_page in its endio
handler so it must be done in its own thread.  This makes direct writes
quite a bit faster.  Thanks,
Signed-off-by: NJosef Bacik <josef@redhat.com>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

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: NCalvin Walton <calvin.walton@kepstin.ca>
Signed-off-by: NJosef Bacik <josef@redhat.com>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

 btrfs currently handles most errors with BUG_ON. This patch is a work-in-
 progress but aims to handle most errors other than internal logic
 errors and ENOMEM more gracefully.

 This iteration prevents most crashes but can run into lockups with
 the page lock on occasion when the timing "works out."
Signed-off-by: NJeff Mahoney <jeffm@suse.com>

 lock_extent and unlock_extent are always called with GFP_NOFS, drop the
 argument and use GFP_NOFS consistently.
Signed-off-by: NJeff Mahoney <jeffm@suse.com>

load_free_space_cache() has forgotten to free path.
Signed-off-by: NTsutomu Itoh <t-itoh@jp.fujitsu.com>

Correct spelling "cace" to "cache" in
fs/btrfs/free-space-cache.c
Signed-off-by: NMasanari Iida <standby24x7@gmail.com>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

If we span a long area in a bitmap we could end up taking a lot of time
searching to the next free area if we're searching from the original
window_start, so advance window_start in order to make sure we don't do any
superficial searching.  Thanks,
Signed-off-by: NJosef Bacik <josef@redhat.com>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

We specifically set window_start in the cluster struct to indicate where the
cluster starts in a bitmap, but we've been using min_start to indicate where
we're searching from.  This is usually the start of the blockgroup, so
essentially means we're constantly searching from the start of any bitmap we
find, which completely negates all the trouble we go to in order to setup a
cluster.  So start using window_start to make sure we actually use the area we
found.  Thanks,
Signed-off-by: NJosef Bacik <josef@redhat.com>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

We have only been checking for min_bytes available in bitmap entries, but we
won't successfully setup a bitmap cluster unless it has at least bytes in the
bitmap, so in the common case min_bytes is 4k and we want something like 2MB, so
if there are a bunch of bitmap entries with less than 2mb's in them, we'll
search all them anyway, which is suboptimal.  Fix this check.  Thanks,
Signed-off-by: NJosef Bacik <josef@redhat.com>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

I used these tracepoints when figuring out what the cluster stuff was doing, so
add them to mainline in case we need to profile this stuff again.  Thanks,
Signed-off-by: NJosef Bacik <josef@redhat.com>

There are various bugs in block group trimming:

- It may trim from offset smaller than user-specified offset.
- It may trim beyond user-specified range.
- It may leak free space for extents smaller than specified minlen.
- It may truncate the last trimmed extent thus leak free space.
- With mixed extents+bitmaps, some extents may not be trimmed.
- With mixed extents+bitmaps, some bitmaps may not be trimmed (even
none will be trimmed). Even for those trimmed, not all the free space
in the bitmaps will be trimmed.

I rewrite btrfs_trim_block_group() and break it into two functions.
One is to trim extents only, and the other is to trim bitmaps only.

Before patching:

	# fstrim -v /mnt/
	/mnt/: 1496465408 bytes were trimmed

After patching:

	# fstrim -v /mnt/
	/mnt/: 2193768448 bytes were trimmed

And this matches the total free space:

	# btrfs fi df /mnt
	Data: total=3.58GB, used=1.79GB
	System, DUP: total=8.00MB, used=4.00KB
	System: total=4.00MB, used=0.00
	Metadata, DUP: total=205.12MB, used=97.14MB
	Metadata: total=8.00MB, used=0.00
Signed-off-by: NLi Zefan <lizf@cn.fujitsu.com>

It can return -ENOMEM.
Signed-off-by: NLi Zefan <lizf@cn.fujitsu.com>

If we run into some failure path in io_ctl_prepare_pages(),
io_ctl->pages[] array may have some NULL pointers.
Signed-off-by: NLi Zefan <lizf@cn.fujitsu.com>

I got this while running xfstests:

[24256.836098] block group 317849600 has an wrong amount of free space
[24256.836100] btrfs: failed to load free space cache for block group 317849600

We should clamp the extent returned by find_first_extent_bit(),
so the start of the extent won't smaller than the start of the
block group.
Signed-off-by: NLi Zefan <lizf@cn.fujitsu.com>

Parameterize clusters on minimum total size, minimum chunk size and
minimum contiguous size for at least one chunk, without limits on
cluster, window or gap sizes.  Don't tolerate any fragmentation for
SSD_SPREAD; accept it for metadata, but try to keep data dense.
Signed-off-by: NAlexandre Oliva <oliva@lsd.ic.unicamp.br>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

The patch below removes an extra semicolon.
Signed-off-by: NJustin P. Mattock <justinmattock@gmail.com>
CC: Chris Mason <chris.mason@oracle.com>
CC: linux-btrfs@vger.kernel.org
Signed-off-by: NJiri Kosina <jkosina@suse.cz>