Btrfs has been pointer tagging bi_private and using bi_bdev
to store the stripe index and mirror number of failed IOs.

As bios bubble back up through the call chain, we use these
to decide if and how to retry our IOs.  They are also used
to count IO failures on a per device basis.

Recently a bio tracepoint was added lead to crashes because
we were abusing bi_bdev.

This commit adds a btrfs bioset, and creates explicit fields
for the mirror number and stripe index.  The plan is to
extend this structure for all of the fields currently in
struct btrfs_bio, which will mean one less kmalloc in
our IO path.
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Reported-by: Tejun Heo <tj@kernel.org>

We've added new checks to make sure the super block crc is correct
during mount.  A fresh filesystem from an older mkfs won't have the
crc set.  This adds a warning when it finds a newly created filesystem
but doesn't fail the mount.
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

The superblock checksum is not verified upon mount. <awkward silence>

Add that check and also reorder existing checks to a more logical
order.

Current mkfs.btrfs does not calculate the correct checksum of
super_block and thus a freshly created filesytem will fail to mount when
this patch is applied.

First transaction commit calculates correct superblock checksum and
saves it to disk.

Reproducer:
$ mfks.btrfs /dev/sda
$ mount /dev/sda /mnt
$ btrfs scrub start /mnt
$ sleep 5
$ btrfs scrub status /mnt
... super:2 ...
Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

The variable was named 'data' in btrfs_reserve_extent and that's the
only function that actually uses it to let btrfs_get_alloc_profile know
what profile we want. Then it's passed down as u64 flags.
Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>

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

1) Right now scrub_stripe() is looping in some unnecessary cases:
* when the found extent item's objectid has been out of the dev extent's range
  but we haven't finish scanning all the range within the dev extent
* when all the items has been processed but we haven't finish scanning all the
  range within the dev extent

In both cases, we can just finish the loop to save costs.

2) Besides, when the found extent item's length is larger than the stripe
len(64k), we don't have to release the path and search again as it'll get at the
same key used in the last loop, we can instead increase the logical cursor in
place till all space of the extent is scanned.

3) And we use 0 as the key's offset to search btree, then get to previous item
to find a smaller item, and again have to move to the next one to get the right
item.  Setting offset=-1 and previous_item() is the correct way.

4) As we won't find any checksum at offset unless this 'offset' is in a data
extent, we can just find checksum when we're really going to scrub an extent.
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>

There's a theoretical possibility of reading stale (or even more
theoretically, freed) data from DEV_INFO ioctl when the device would
disappear between an early mutex unlock and data being copied from the
device structure.
Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>

It's unused since 0b32f4bb.
Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>

Signed-off-by: David Sterba <dsterba@suse.cz>
Reviewed-by: Zach Brown <zab@redhat.com>
Signed-off-by: Josef 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: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>

If you try to mount -o loop a restored file system it will panic if the file
ends up being smaller than the original disk.  This is because we go to try and
get a block for a super that may be past the EOF which makes __getblk return
NULL for a buffer head when we aren't expecting it to.  Fix this by dealing with
this case and just jacking up the errors count.  With this patch we no longer
panic when mounting a restored file system loopback.  Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com>

There were a whole bunch and I was doing it for other things.  I haven't tested
these error paths but at the very least this is better than panicing.  I've only
left 2 BUG_ON()'s since they are logic errors and I want to replace them with a
ASSERT framework that we can compile out for production users.  Thanks,
Signed-off-by: Josef 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: Josef Bacik <jbacik@fusionio.com>

When qgroup tracking is enabled, we do an automatic cycle of the new rescan
mechanism.
Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>

If qgroup tracking is out of sync, a rescan operation can be started. It
iterates the complete extent tree and recalculates all qgroup tracking data.
This is an expensive operation and should not be used unless required.

A filesystem under rescan can still be umounted. The rescan continues on the
next mount.  Status information is provided with a separate ioctl while a
rescan operation is in progress.
Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>

The function is separated into a preparation part and the three accounting
steps mentioned in the qgroups documentation. The goal is to make steps two
and three usable by the rescan functionality. A side effect is that the
function is restructured into readable subunits.
Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>

When running the 208th of xfstests, the fs returned the enospc
error when there was lots of free space in the disk.

By bisect debug, we found it was introduced by commit 96f1bb57.
This commit makes the space check for the global reservation in
can_overcommit() be inconsistent with should_alloc_chunk().
can_overcommit() requires that the free space is 2 times the size
of the global reservation, or we can't do overcommit. And instead,
we need reclaim some reserved space, and if we still don't have
enough free space, we need allocate a new chunk. But unfortunately,
should_alloc_chunk() just requires that the free space is 1 time
the size of the global reservation, that is we would not try to
allocate a new chunk if the free space size is in the middle of
these two requires, and just return the enospc error. Fix it.

Cc: Jim Schutt <jaschut@sandia.gov>
Cc: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>

Sequence numbers for delayed refs have been introduced in the first version
of the qgroup patch set. To solve the problem of find_all_roots on a busy
file system, the tree mod log was introduced. The sequence numbers for that
were simply shared between those two users.

However, at one point in qgroup's quota accounting, there's a statement
accessing the previous sequence number, that's still just doing (seq - 1)
just as it would have to in the very first version.

To satisfy that requirement, this patch makes the sequence number counter 64
bit and splits it into a major part (used for qgroup sequence number
counting) and a minor part (incremented for each tree modification in the
log). This enables us to go exactly one major step backwards, as required
for qgroups, while still incrementing the sequence counter for tree mod log
insertions to keep track of their order. Keeping them in a single variable
means there's no need to change all the code dealing with comparisons of two
sequence numbers.

The sequence number is reset to 0 on commit (not new in this patch), which
ensures we won't overflow the two 32 bit counters.

Without this fix, the qgroup tracking can occasionally go wrong and WARN_ONs
from the tree mod log code may happen.
Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>

Clean up the leak debugging in extent_io.c by moving
the debug code into functions.  This also removes the
list_heads used for debugging from the extent_buffer
and extent_state structures when debug is not enabled.

Since we need a global debug config to do that last
part, implement CONFIG_BTRFS_DEBUG to accommodate.

Thanks to Dave Sterba for the Kconfig bit.
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>

Replace some BUG_ONs with proper handling and take allocated space back to
free space cache for later use.

We don't have to worry about extent maps since they'd be freed in releasepage
path.
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>

It is a rare exception that a new tree is created, like the qgroups
tree. So far these new trees have an all-zero UUID in their root
items. All trees that mkfs.btrfs has created get an UUID during the
first mount when btrfs_read_root_item() rewrites the root_item to
the v2 structure style. These UUID are never used so far, but
anyway, since it is better to have it uniform for all trees, this
commit adds some lines that generate and write an UUID for newly
created trees.
Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>

Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>

fget() returns NULL if error. So, we should check NULL or not.
Signed-off-by: Tsutomu Itoh <t-itoh@jp.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>

Variable 'p' is not used any more. So, remove it.
Signed-off-by: Tsutomu Itoh <t-itoh@jp.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>

I have a broken file system that when it aborts leaves all sorts of accounting
things wrong and gives you lots of WARN_ON()'s other than the abort.  This is
because we're not cleaning up various parts of the file system when we abort.
The first chunks are specific to mount failures, we weren't cleaning up the
block group cached inodes and we weren't cleaning up any transactions that had
been aborted, which leaves a bunch of things laying around.

The second half of this are related to the cleanup parts.  First we don't need
to release space for the dirty pages from the trans_block_rsv, that's all
handled by the trans handles so this is just plain wrong.  The other thing is we
need to pin down extents that were set ->must_insert_reserved for delayed refs.
This isn't so much for the pinning but more for the cleaning up the
cache->reserved counter since we are no longer going to use those reserved
bytes.  With this patch I no longer see a bunch of WARN_ON()'s when I try to
mount this broken file system, just the initial one from the abort.  Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com>

We can just look up the extent_buffers for the range and free stuff that way.
This makes the cleanup a bit cleaner and we can make sure to evict the
extent_buffers pretty quickly by marking them as stale.  Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com>

We need to check the return value of the commit in case something goes wrong,
otherwise we could end up going down the line and doing more stuff (like orphan
cleanup) before we notice we should have errored out.  We need to do this before
we free up the log_tree_root since the caller will handle all of that.  Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com>

This is just obnoxious.  Just print a message, abort the transaction, and return
an error.  Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com>

We can run the tree logging recovery or the orphan cleanup on mount, so we'll
end up looking up a random fs tree in the meantime.  So we need to clean this up
so we don't leave extent buffers hanging around on the cache.  With this patch
we no longer leak extent buffers on failure to mount.  Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com>

This is the same as the fix from commit

Btrfs: fix bad extent logging

but for O_DIRECT.  I missed this when I fixed the problem originally, we were
still using the em for the orig_start and orig_block_len, which would be the
merged extent.  We need to use the actual extent from the on disk file extent
item, which we have to lookup to make sure it's ok to nocow anyway so just pass
in some pointers to hold this info.  Thanks,

Cc: stable@vger.kernel.org
Signed-off-by: Josef Bacik <jbacik@fusionio.com>

We kept leaking extent buffers when mounting a broken file system and it turns
out it's because not everybody uses read_tree_block properly.  You need to check
and make sure the extent_buffer is uptodate before you use it.  This patch fixes
everybody who calls read_tree_block directly to make sure they check that it is
uptodate and free it and return an error if it is not.  With this we no longer
leak EB's when things go horribly wrong.  Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com>

If we fail to load block groups halfway through we can leave extent_state's on
the excluded tree.  This is because we just lookup the supers and add them to
the excluded tree regardless of which block group we are looking at currently.
This is a problem because we remove the excluded extents for the range of the
block group only, so if we don't ever load a block group for one of the excluded
extents we won't ever free it.  This fixes the problem by only adding excluded
extents if it falls in the block group range we care about.  With this patch
we're no longer leaking space when we fail to read all of the block groups.
Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com>

With a users corrupted fs I was getting weird behavior and panics and it turns
out it was because one of his tree blocks had a bogus header level.  So add this
to the sanity checks in the endio handler for tree blocks.  Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com>

This work is done by btrfs_free_path() anyway so there's no need for this
duplicate work.  Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com>

A user sent me a btrfs-image that was panicing because of some corruption.  This
is because we pass in a bogus value to btrfs_num_copies, and it panics.  Instead
just return 1.  We only call btrfs_num_copies to see if there are other copies
to try and read for things, so if we just return 1 it will make the callers exit
out with an appropriate error value.  Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com>

Martin Steigerwald reported a BUG_ON() where we were given a bogus bytenr to
map.  Turns out he is using > PAGESIZE leafsizes.  The readahead stuff is called
every time we do a completion, but we may not have finished reading in all the
pages, so the bytenr we read off the node could be completely bogus.  Fix this
by only calling the readahead hook once all pages have been read in.  Thanks,
Reported-by: Martin Steigerwald <Martin@lichtvoll.de>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>

Martin Steigerwald reported a BUG_ON() in btrfs_map_block where we didn't find
a chunk for a particular block we were trying to map.  This happened because the
block was bogus.  We shouldn't be BUG_ON()'ing in this case, just print a
message and return an error.  This came from reada_add_block and it appears to
deal with an error fine so we should be good there.  Thanks,
Reported-by: Martin Steigerwald <Martin@lichtvoll.de>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>

We need to tag metadata io with REQ_META to avoid priority inversion when using
io throttling cqroups.  Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com>

So I noticed there is an infinite loop in the slow caching code.  If we return 1
when we hit the end of the tree, so we could end up caching the last block group
the slow way and suddenly we're looping forever because we just keep
re-searching and trying again.  Fix this by only doing btrfs_next_leaf() if we
don't need_resched().  Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com>

The locking order for stuff is

__sb_start_write
ordered_mutex

but with sync() we don't do __sb_start_write for some strange reason, which
means that our iput in wait_ordered_extents could start a transaction which does
the __sb_start_write while we're holding the ordered_mutex.  Fix this by using
delayed iput in sync.  Thanks,
Reported-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>