Commit Graph

6524 Commits

Author SHA1 Message Date
Qu Wenruo
eae8d82529 btrfs: Fix wild memory access in compression level parser
[BUG]
Kernel panic when mounting with "-o compress" mount option.
KASAN will report like:
------
==================================================================
BUG: KASAN: wild-memory-access in strncmp+0x31/0xc0
Read of size 1 at addr d86735fce994f800 by task mount/662
...
Call Trace:
 dump_stack+0xe3/0x175
 kasan_report+0x163/0x370
 __asan_load1+0x47/0x50
 strncmp+0x31/0xc0
 btrfs_compress_str2level+0x20/0x70 [btrfs]
 btrfs_parse_options+0xff4/0x1870 [btrfs]
 open_ctree+0x2679/0x49f0 [btrfs]
 btrfs_mount+0x1b7f/0x1d30 [btrfs]
 mount_fs+0x49/0x190
 vfs_kern_mount.part.29+0xba/0x280
 vfs_kern_mount+0x13/0x20
 btrfs_mount+0x31e/0x1d30 [btrfs]
 mount_fs+0x49/0x190
 vfs_kern_mount.part.29+0xba/0x280
 do_mount+0xaad/0x1a00
 SyS_mount+0x98/0xe0
 entry_SYSCALL_64_fastpath+0x1f/0xbe
------

[Cause]
For 'compress' and 'compress_force' options, its token doesn't expect
any parameter so its args[0] contains uninitialized data.
Accessing args[0] will cause above wild memory access.

[Fix]
For Opt_compress and Opt_compress_force, set compression level to
the default.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ set the default in advance ]
Signed-off-by: David Sterba <dsterba@suse.com>
2017-11-27 17:01:11 +01:00
Josef Bacik
b77000ed55 btrfs: fix deadlock when writing out space cache
If we fail to prepare our pages for whatever reason (out of memory in
our case) we need to make sure to drop the block_group->data_rwsem,
otherwise hilarity ensues.

Signed-off-by: Josef Bacik <jbacik@fb.com>
Reviewed-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ add label and use existing unlocking code ]
Signed-off-by: David Sterba <dsterba@suse.com>
2017-11-27 15:50:07 +01:00
Josef Bacik
8e138e0d92 btrfs: clear space cache inode generation always
We discovered a box that had double allocations, and suspected the space
cache may be to blame.  While auditing the write out path I noticed that
if we've already setup the space cache we will just carry on.  This
means that any error we hit after cache_save_setup before we go to
actually write the cache out we won't reset the inode generation, so
whatever was already written will be considered correct, except it'll be
stale.  Fix this by _always_ resetting the generation on the block group
inode, this way we only ever have valid or invalid cache.

With this patch I was no longer able to reproduce cache corruption with
dm-log-writes and my bpf error injection tool.

Cc: stable@vger.kernel.org
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-11-20 20:43:39 +01:00
Filipe Manana
e3b8a48585 Btrfs: fix reported number of inode blocks after buffered append writes
The patch from commit a7e3b975a0 ("Btrfs: fix reported number of inode
blocks") introduced a regression where if we do a buffered write starting
at position equal to or greater than the file's size and then stat(2) the
file before writeback is triggered, the number of used blocks does not
change (unless there's a prealloc/unwritten extent). Example:

  $ xfs_io -f -c "pwrite -S 0xab 0 64K" foobar
  $ du -h foobar
  0	foobar
  $ sync
  $ du -h foobar
  64K	foobar

The first version of that patch didn't had this regression and the second
version, which was the one committed, was made only to address some
performance regression detected by the intel test robots using fs_mark.

This fixes the regression by setting the new delaloc bit in the range, and
doing it at btrfs_dirty_pages() while setting the regular dealloc bit as
well, so that this way we set both bits at once avoiding navigation of the
inode's io tree twice. Doing it at btrfs_dirty_pages() is also the most
meaninful place, as we should set the new dellaloc bit when if we set the
delalloc bit, which happens only if we copied bytes into the pages at
__btrfs_buffered_write().

This was making some of LTP's du tests fail, which can be quickly run
using a command line like the following:

  $ ./runltp -q -p -l /ltp.log -f commands -s du -d /mnt

Fixes: a7e3b975a0 ("Btrfs: fix reported number of inode blocks")
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-11-15 17:27:46 +01:00
Filipe Manana
f48bf66b66 Btrfs: move definition of the function btrfs_find_new_delalloc_bytes
Move the definition of the function btrfs_find_new_delalloc_bytes() closer
to the function btrfs_dirty_pages(), because in a future commit it will be
used exclusively by btrfs_dirty_pages(). This just moves the function's
definition, with no functional changes at all.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-11-15 17:27:44 +01:00
Liu Bo
56a0e706fc Btrfs: bail out gracefully rather than BUG_ON
If a file's DIR_ITEM key is invalid (due to memory errors) and gets
written to disk, a future lookup_path can end up with kernel panic due
to BUG_ON().

This gets rid of the BUG_ON(), meanwhile output the corrupted key and
return ENOENT if it's invalid.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reported-by: Guillaume Bouchard <bouchard@mercs-eng.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-11-15 14:47:01 +01:00
David Sterba
619c47f3d4 btrfs: dev_alloc_list is not protected by RCU, use normal list_del
The dev_alloc_list list could be protected by various mutexes,
depending on the context. The list tracks devices that can take part of
allocating new chunks, so the closest mutex is chunk_mutex. Adding a new
device from inside the ADD_DEV ioctl will need device_list_mutex and
registering a new device from the ioctl needs uuid_mutex.

All mutexes naturally guarantee exclusivity against the same context.
The device ownership can move between the contexts and the exclusivity
is guaranteed by other means, eg. during the mount with the uuid_mutex.

There's no RCU involved for dev_alloc_list.

Signed-off-by: David Sterba <dsterba@suse.com>
2017-11-15 14:46:12 +01:00
David Sterba
3065ae5b85 btrfs: add missing device::flush_bio puts
This fixes potential bio leaks, in several error paths. Unfortunatelly
the device structure freeing is opencoded in many places and I missed
them when introducing the flush_bio.

Most of the time, devices get freed through call_rcu(..., free_device),
so it at least it's not that easy to hit the leak, but it's still
possible through the path that frees stale devices.

Fixes: e0ae999414 ("btrfs: preallocate device flush bio")
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-11-15 14:45:26 +01:00
Nikolay Borisov
5e9f2ad5b2 btrfs: Fix transaction abort during failure in btrfs_rm_dev_item
btrfs_rm_dev_item calls several function under an active transaction,
however it fails to abort it if an error happens. Fix this by adding
explicit btrfs_abort_transaction/btrfs_end_transaction calls.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-11-15 14:44:44 +01:00
Liu Bo
f82b735936 Btrfs: add write_flags for compression bio
Compression code path has only flaged bios with REQ_OP_WRITE no matter
where the bios come from, but it could be a sync write if fsync starts
this writeback or a normal writeback write if wb kthread starts a
periodic writeback.

It breaks the rule that sync writes and writeback writes need to be
differentiated from each other, because from the POV of block layer,
all bios need to be recognized by these flags in order to do some
management, e.g. throttlling.

This passes writeback_control to compression write path so that it can
send bios with proper flags to block layer.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-11-15 14:44:31 +01:00
Gu JinXiang
d28e649a5c btrfs: Fix bug for misused dev_t when lookup in dev state hash table.
Fix bug of commit 74d46992e0 ("block: replace bi_bdev with a gendisk
pointer and partitions index").

bio_dev(bio) is used to find the dev state in function
__btrfsic_submit_bio. But when dev_state is added to the hashtable, it
is using dev_t of block_device.

bio_dev(bio) returns a dev_t of part0 which is different from dev_t in
block_device(bd_dev). bd_dev in block_device represents the exact
partition.

block_device.bd_dev =
	bio->bi_partno (same as block_device.bd_partno) + bio_dev(bio).

When adding a dev_state into hashtable, we use the exact partition dev_t.
So when looking it up, it should also use the exact partition dev_t.

Reproducer of this bug:

Use MOUNT_OPTIONS="-o check_int" and run btrfs/001 in fstests.
Then there will be WARNING like below.

WARNING:
btrfs: attempt to write superblock which references block M @29523968 (sda7     /1111654400/2) which is never written!

Signed-off-by: Gu JinXiang <gujx@cn.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-11-01 20:45:36 +01:00
Timofey Titovets
19562430c6 Btrfs: heuristic: add Shannon entropy calculation
Byte distribution check in heuristic will filter edge data cases and
some time fail to classify input data.

Let's fix that by adding Shannon entropy calculation, that will cover
classification of most other data types.

As Shannon entropy needs log2 with some precision to work, let's use
ilog2(N) and for increased precision, by do ilog2(pow(N, 4)).

Shannon entropy has been slightly changed to avoid signed numbers and
division.

The calculation is direct by the formula, successor of precalculated
table or chains of if-else.

The accuracy errors of ilog2 are compensated by

@ENTROPY_LVL_ACEPTABLE 70 -> 65
@ENTROPY_LVL_HIGH      85 -> 80

Signed-off-by: Timofey Titovets <nefelim4ag@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ update comments ]
Signed-off-by: David Sterba <dsterba@suse.com>
2017-11-01 20:45:36 +01:00
Timofey Titovets
858177d38d Btrfs: heuristic: add byte core set calculation
Calculate byte core set for data sample:
- sort buckets' numbers in decreasing order
- count how many values cover 90% of the sample

If the core set size is low (<=25%), data are easily compressible.
If the core set size is high (>=80%), data are not compressible.

Signed-off-by: Timofey Titovets <nefelim4ag@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ update comments ]
Signed-off-by: David Sterba <dsterba@suse.com>
2017-11-01 20:45:36 +01:00
Timofey Titovets
a288e92cac Btrfs: heuristic: add byte set calculation
Calculate byte set size for data sample:
- calculate how many unique bytes have been in the sample
- for all bytes count > 0, check if we're still in the low count range
  (~25%), such data are easily compressible, otherwise furhter analysis
  is needed

Signed-off-by: Timofey Titovets <nefelim4ag@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ update comments ]
Signed-off-by: David Sterba <dsterba@suse.com>
2017-11-01 20:45:36 +01:00
Timofey Titovets
1fe4f6fa5a Btrfs: heuristic: add detection of repeated data patterns
Walk over data sample and use memcmp to detect repeated patterns, like
zeros, but a bit more general.

Signed-off-by: Timofey Titovets <nefelim4ag@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ minor coding style fixes ]
Signed-off-by: David Sterba <dsterba@suse.com>
2017-11-01 20:45:36 +01:00
Timofey Titovets
a440d48c7f Btrfs: heuristic: implement sampling logic
Copy sample data from the input data range to sample buffer then
calculate byte value count for that sample into bucket.

Signed-off-by: Timofey Titovets <nefelim4ag@gmail.com>
[ minor comment updates ]
Signed-off-by: David Sterba <dsterba@suse.com>
2017-11-01 20:45:36 +01:00
Timofey Titovets
17b5a6c17e Btrfs: heuristic: add bucket and sample counters and other defines
Add basic defines and structures for data sampling.

Added macros:
 - For future sampling algo
 - For bucket size

Heuristic workspace:
 - Add bucket for storing byte type counters
 - Add sample array for storing partial copy of input data range
 - Add counter for store current sample size to workspace

Signed-off-by: Timofey Titovets <nefelim4ag@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ minor coding style fixes, comments updated ]
Signed-off-by: David Sterba <dsterba@suse.com>
2017-11-01 20:45:36 +01:00
Timofey Titovets
4e439a0b18 Btrfs: compression: separate heuristic/compression workspaces
Compression heuristic itself is not a compression type, as current
infrastructure provides workspaces for several compression types, it's
difficult to just add heuristic workspace.

Just refactor the code to support compression/heuristic workspaces with
maximum code sharing and minimum changes in it.

Signed-off-by: Timofey Titovets <nefelim4ag@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ coding style fixes ]
Signed-off-by: David Sterba <dsterba@suse.com>
2017-11-01 20:45:35 +01:00
Josef Bacik
ddfae63cc8 btrfs: move btrfs_truncate_block out of trans handle
Since we do a delalloc reserve in btrfs_truncate_block we can deadlock
with freeze.  If somebody else is trying to allocate metadata for this
inode and it gets stuck in start_delalloc_inodes because of freeze we
will deadlock.  Be safe and move this outside of a trans handle.  This
also has a side-effect of making sure that we're not leaving stale data
behind in the other_encoding or encryption case.  Not an issue now since
nobody uses it, but it would be a problem in the future.

Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-11-01 20:45:35 +01:00
Josef Bacik
ce8ea7cc6e btrfs: don't call btrfs_start_delalloc_roots in flushoncommit
We're holding the sb_start_intwrite lock at this point, and doing async
filemap_flush of the inodes will result in a deadlock if we freeze the
fs during this operation.  This is because we could do a
btrfs_join_transaction() in the thread we are waiting on which would
block at sb_start_intwrite, and thus deadlock.  Using
writeback_inodes_sb() side steps the problem by not introducing all of
these extra locking dependencies.

Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-11-01 20:45:35 +01:00
Josef Bacik
0e0adbcfdc btrfs: track refs in a rb_tree instead of a list
If we get a significant amount of delayed refs for a single block (think
modifying multiple snapshots) we can end up spending an ungodly amount
of time looping through all of the entries trying to see if they can be
merged.  This is because we only add them to a list, so we have O(2n)
for every ref head.  This doesn't make any sense as we likely have refs
for different roots, and so they cannot be merged.  Tracking in a tree
will allow us to break as soon as we hit an entry that doesn't match,
making our worst case O(n).

With this we can also merge entries more easily.  Before we had to hope
that matching refs were on the ends of our list, but with the tree we
can search down to exact matches and merge them at insert time.

Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-11-01 20:45:35 +01:00
Josef Bacik
1d148e5939 btrfs: add a comp_refs() helper
Instead of open-coding the delayed ref comparisons, add a helper to do
the comparisons generically and use that everywhere.  We compare
sequence numbers last for following patches.

Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-11-01 20:45:35 +01:00
Josef Bacik
c7ad7c8439 btrfs: switch args for comp_*_refs
Make it more consistent, we want the inserted ref to be compared against
what's already in there.  This will make the order go from lowest seq ->
highest seq, which will make us more likely to make forward progress if
there's a seqlock currently held.

Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-11-01 20:45:35 +01:00
Josef Bacik
69fe2d75dd btrfs: make the delalloc block rsv per inode
The way we handle delalloc metadata reservations has gotten
progressively more complicated over the years.  There is so much cruft
and weirdness around keeping the reserved count and outstanding counters
consistent and handling the error cases that it's impossible to
understand.

Fix this by making the delalloc block rsv per-inode.  This way we can
calculate the actual size of the outstanding metadata reservations every
time we make a change, and then reserve the delta based on that amount.
This greatly simplifies the code everywhere, and makes the error
handling in btrfs_delalloc_reserve_metadata far less terrifying.

Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-11-01 20:45:35 +01:00
Josef Bacik
dd48d4072e btrfs: add tracepoints for outstanding extents mods
This is handy for tracing problems with modifying the outstanding
extents counters.

Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-11-01 20:45:35 +01:00
Josef Bacik
8b62f87bad Btrfs: rework outstanding_extents
Right now we do a lot of weird hoops around outstanding_extents in order
to keep the extent count consistent.  This is because we logically
transfer the outstanding_extent count from the initial reservation
through the set_delalloc_bits.  This makes it pretty difficult to get a
handle on how and when we need to mess with outstanding_extents.

Fix this by revamping the rules of how we deal with outstanding_extents.
Now instead everybody that is holding on to a delalloc extent is
required to increase the outstanding extents count for itself.  This
means we'll have something like this

btrfs_delalloc_reserve_metadata	- outstanding_extents = 1
 btrfs_set_extent_delalloc	- outstanding_extents = 2
btrfs_release_delalloc_extents	- outstanding_extents = 1

for an initial file write.  Now take the append write where we extend an
existing delalloc range but still under the maximum extent size

btrfs_delalloc_reserve_metadata - outstanding_extents = 2
  btrfs_set_extent_delalloc
    btrfs_set_bit_hook		- outstanding_extents = 3
    btrfs_merge_extent_hook	- outstanding_extents = 2
btrfs_delalloc_release_extents	- outstanding_extnets = 1

In order to make the ordered extent transition we of course must now
make ordered extents carry their own outstanding_extent reservation, so
for cow_file_range we end up with

btrfs_add_ordered_extent	- outstanding_extents = 2
clear_extent_bit		- outstanding_extents = 1
btrfs_remove_ordered_extent	- outstanding_extents = 0

This makes all manipulations of outstanding_extents much more explicit.
Every successful call to btrfs_delalloc_reserve_metadata _must_ now be
combined with btrfs_release_delalloc_extents, even in the error case, as
that is the only function that actually modifies the
outstanding_extents counter.

The drawback to this is now we are much more likely to have transient
cases where outstanding_extents is much larger than it actually should
be.  This could happen before as we manipulated the delalloc bits, but
now it happens basically at every write.  This may put more pressure on
the ENOSPC flushing code, but I think making this code simpler is worth
the cost.  I have another change coming to mitigate this side-effect
somewhat.

I also added trace points for the counter manipulation.  These were used
by a bpf script I wrote to help track down leak issues.

Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-11-01 20:45:35 +01:00
Zygo Blaxell
b115e3bc81 btrfs: increase output size for LOGICAL_INO_V2 ioctl
Build-server workloads have hundreds of references per file after dedup.
Multiply by a few snapshots and we quickly exhaust the limit of 2730
references per extent that can fit into a 64K buffer.

Raise the limit to 16M to be consistent with other btrfs ioctls
(e.g. TREE_SEARCH_V2, FILE_EXTENT_SAME).

To minimize surprising userspace behavior, apply this change only to
the LOGICAL_INO_V2 ioctl.

Signed-off-by: Zygo Blaxell <ce3g8jdj@umail.furryterror.org>
Reviewed-by: Hans van Kranenburg <hans.van.kranenburg@mendix.com>
Tested-by: Hans van Kranenburg <hans.van.kranenburg@mendix.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-11-01 20:45:35 +01:00
Zygo Blaxell
d24a67b2d9 btrfs: add a flags argument to LOGICAL_INO and call it LOGICAL_INO_V2
Now that check_extent_in_eb()'s extent offset filter can be turned off,
we need a way to do it from userspace.

Add a 'flags' field to the btrfs_logical_ino_args structure to disable
extent offset filtering, taking the place of one of the existing
reserved[] fields.

Previous versions of LOGICAL_INO neglected to check whether any of the
reserved fields have non-zero values.  Assigning meaning to those fields
now may change the behavior of existing programs that left these fields
uninitialized.  The lack of a zero check also means that new programs
have no way to know whether the kernel is honoring the flags field.

To avoid these problems, define a new ioctl LOGICAL_INO_V2.  We can
use the same argument layout as LOGICAL_INO, but shorten the reserved[]
array by one element and turn it into the 'flags' field.  The V2 ioctl
explicitly checks that reserved fields and unsupported flag bits are zero
so that userspace can negotiate future feature bits as they are defined.

Since the memory layouts of the two ioctls' arguments are compatible,
there is no need for a separate function for logical_to_ino_v2 (contrast
with tree_search_v2 vs tree_search where the layout and code are quite
different).  A version parameter and an 'if' statement will suffice.

Now that we have a flags field in logical_ino_args, add a flag
BTRFS_LOGICAL_INO_ARGS_IGNORE_OFFSET to get the behavior we want,
and pass it down the stack to iterate_inodes_from_logical.

Motivation and background, copied from the patchset cover letter:

Suppose we have a file with one extent:

    root@tester:~# zcat /usr/share/doc/cpio/changelog.gz > /test/a
    root@tester:~# sync

Split the extent by overwriting it in the middle:

    root@tester:~# cat /dev/urandom | dd bs=4k seek=2 skip=2 count=1 conv=notrunc of=/test/a

We should now have 3 extent refs to 2 extents, with one block unreachable.
The extent tree looks like:

    root@tester:~# btrfs-debug-tree /dev/vdc -t 2
    [...]
            item 9 key (1103101952 EXTENT_ITEM 73728) itemoff 15942 itemsize 53
                    extent refs 2 gen 29 flags DATA
                    extent data backref root 5 objectid 261 offset 0 count 2
    [...]
            item 11 key (1103175680 EXTENT_ITEM 4096) itemoff 15865 itemsize 53
                    extent refs 1 gen 30 flags DATA
                    extent data backref root 5 objectid 261 offset 8192 count 1
    [...]

and the ref tree looks like:

    root@tester:~# btrfs-debug-tree /dev/vdc -t 5
    [...]
            item 6 key (261 EXTENT_DATA 0) itemoff 15825 itemsize 53
                    extent data disk byte 1103101952 nr 73728
                    extent data offset 0 nr 8192 ram 73728
                    extent compression(none)
            item 7 key (261 EXTENT_DATA 8192) itemoff 15772 itemsize 53
                    extent data disk byte 1103175680 nr 4096
                    extent data offset 0 nr 4096 ram 4096
                    extent compression(none)
            item 8 key (261 EXTENT_DATA 12288) itemoff 15719 itemsize 53
                    extent data disk byte 1103101952 nr 73728
                    extent data offset 12288 nr 61440 ram 73728
                    extent compression(none)
    [...]

There are two references to the same extent with different, non-overlapping
byte offsets:

    [------------------72K extent at 1103101952----------------------]
    [--8K----------------|--4K unreachable----|--60K-----------------]
    ^                                         ^
    |                                         |
    [--8K ref offset 0--][--4K ref offset 0--][--60K ref offset 12K--]
                         |
                         v
                         [-----4K extent-----] at 1103175680

We want to find all of the references to extent bytenr 1103101952.

Without the patch (and without running btrfs-debug-tree), we have to
do it with 18 LOGICAL_INO calls:

    root@tester:~# btrfs ins log 1103101952 -P /test/
    Using LOGICAL_INO
    inode 261 offset 0 root 5

    root@tester:~# for x in $(seq 0 17); do btrfs ins log $((1103101952 + x * 4096)) -P /test/; done 2>&1 | grep inode
    inode 261 offset 0 root 5
    inode 261 offset 4096 root 5   <- same extent ref as offset 0
                                   (offset 8192 returns empty set, not reachable)
    inode 261 offset 12288 root 5
    inode 261 offset 16384 root 5  \
    inode 261 offset 20480 root 5  |
    inode 261 offset 24576 root 5  |
    inode 261 offset 28672 root 5  |
    inode 261 offset 32768 root 5  |
    inode 261 offset 36864 root 5  \
    inode 261 offset 40960 root 5   > all the same extent ref as offset 12288.
    inode 261 offset 45056 root 5  /  More processing required in userspace
    inode 261 offset 49152 root 5  |  to figure out these are all duplicates.
    inode 261 offset 53248 root 5  |
    inode 261 offset 57344 root 5  |
    inode 261 offset 61440 root 5  |
    inode 261 offset 65536 root 5  |
    inode 261 offset 69632 root 5  /

In the worst case the extents are 128MB long, and we have to do 32768
iterations of the loop to find one 4K extent ref.

With the patch, we just use one call to map all refs to the extent at once:
    root@tester:~# btrfs ins log 1103101952 -P /test/
    Using LOGICAL_INO_V2
    inode 261 offset 0 root 5
    inode 261 offset 12288 root 5

The TREE_SEARCH ioctl allows userspace to retrieve the offset and
extent bytenr fields easily once the root, inode and offset are known.
This is sufficient information to build a complete map of the extent
and all of its references.  Userspace can use this information to make
better choices to dedup or defrag.

Signed-off-by: Zygo Blaxell <ce3g8jdj@umail.furryterror.org>
Reviewed-by: Hans van Kranenburg <hans.van.kranenburg@mendix.com>
Tested-by: Hans van Kranenburg <hans.van.kranenburg@mendix.com>
[ copy background and motivation from cover letter ]
Signed-off-by: David Sterba <dsterba@suse.com>
2017-11-01 20:45:35 +01:00
Zygo Blaxell
c995ab3cda btrfs: add a flag to iterate_inodes_from_logical to find all extent refs for uncompressed extents
The LOGICAL_INO ioctl provides a backward mapping from extent bytenr and
offset (encoded as a single logical address) to a list of extent refs.
LOGICAL_INO complements TREE_SEARCH, which provides the forward mapping
(extent ref -> extent bytenr and offset, or logical address).  These are
useful capabilities for programs that manipulate extents and extent
references from userspace (e.g. dedup and defrag utilities).

When the extents are uncompressed (and not encrypted and not other),
check_extent_in_eb performs filtering of the extent refs to remove any
extent refs which do not contain the same extent offset as the 'logical'
parameter's extent offset.  This prevents LOGICAL_INO from returning
references to more than a single block.

To find the set of extent references to an uncompressed extent from [a, b),
userspace has to run a loop like this pseudocode:

	for (i = a; i < b; ++i)
		extent_ref_set += LOGICAL_INO(i);

At each iteration of the loop (up to 32768 iterations for a 128M extent),
data we are interested in is collected in the kernel, then deleted by
the filter in check_extent_in_eb.

When the extents are compressed (or encrypted or other), the 'logical'
parameter must be an extent bytenr (the 'a' parameter in the loop).
No filtering by extent offset is done (or possible?) so the result is
the complete set of extent refs for the entire extent.  This removes
the need for the loop, since we get all the extent refs in one call.

Add an 'ignore_offset' argument to iterate_inodes_from_logical,
[...several levels of function call graph...], and check_extent_in_eb, so
that we can disable the extent offset filtering for uncompressed extents.
This flag can be set by an improved version of the LOGICAL_INO ioctl to
get either behavior as desired.

There is no functional change in this patch.  The new flag is always
false.

Signed-off-by: Zygo Blaxell <ce3g8jdj@umail.furryterror.org>
Reviewed-by: David Sterba <dsterba@suse.com>
[ minor coding style fixes ]
Signed-off-by: David Sterba <dsterba@suse.com>
2017-11-01 20:45:34 +01:00
Nikolay Borisov
eb7b9d6a46 btrfs: send: remove unused code
This code was first introduced in 31db9f7c23 ("Btrfs: introduce
BTRFS_IOC_SEND for btrfs send/receive") and it was not functional, then
it got slightly refactored in e938c8ad54 ("Btrfs: code cleanups for
send/receive"), alas it was still dead. So let's remove it for good!

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-11-01 20:45:34 +01:00
Anand Jain
6dd38f81f9 btrfs: remove BUG_ON in btrfs_rm_dev_replace_free_srcdev()
That was only an extra check to tackle a few bugs around this area, now
its safe to remove it.  Replace it by an ASSERT.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-11-01 20:45:34 +01:00
Adam Borowski
fa4d885a48 btrfs: allow setting zlib compression level via :9
This is bikeshedding, but it seems people are drastically more likely to
understand "zlib:9" as compression level rather than an algorithm
version compared to "zlib9".

Based on feedback on the mailinglist, the ":9" will be the only accepted
syntax. The level must be a single digit. Unrecognized format will
result to the default, for forward compatibility in a similar way the
compression algorithm specifier was relaxed in commit
a7164fa4e0 ("btrfs: prepare for extensions in compression
options").

Signed-off-by: Adam Borowski <kilobyte@angband.pl>
Reviewed-by: David Sterba <dsterba@suse.com>
[ tighten the accepted format ]
Signed-off-by: David Sterba <dsterba@suse.com>
2017-11-01 20:45:34 +01:00
David Sterba
f51d2b5912 btrfs: allow to set compression level for zlib
Preliminary support for setting compression level for zlib, the
following works:

$ mount -o compess=zlib                 # default
$ mount -o compess=zlib0                # same
$ mount -o compess=zlib9                # level 9, slower sync, less data
$ mount -o compess=zlib1                # level 1, faster sync, more data
$ mount -o remount,compress=zlib3	# level set by remount

The compress-force works the same as compress'.  The level is visible in
the same format in /proc/mounts. Level set via file property does not
work yet.

Required patch: "btrfs: prepare for extensions in compression options"

Signed-off-by: David Sterba <dsterba@suse.com>
2017-11-01 20:45:29 +01:00
Nikolay Borisov
d4417e2255 btrfs: Replace opencoded sizes with their symbolic constants
Currently btrfs' code uses a mix of opencoded sizes and defines from sizes.h.
Let's unifiy the code base to always use the symbolic constants. No functional
changes

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-10-30 12:28:01 +01:00
Gu JinXiang
859a58a207 btrfs: Use bd_dev to generate index when dev_state_hashtable add items.
Fix missing change from commit f8f84b2dfd
("btrfs: index check-integrity state hash by a dev_t").

Function btrfsic_dev_state_hashtable_lookup uses dev_t to generate hashval
when look in up a btrfsic_dev_state in hash table. So when we add a
btrfsic_dev_state into the hash table, it should also use dev_t.

Reproducer of this bug:
Use MOUNT_OPTIONS="-o check_int" when running xfstest, device can not be
mounted successfully. So xfstest can not run.

Signed-off-by: Gu JinXiang <gujx@cn.fujitsu.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-10-30 12:28:01 +01:00
Anand Jain
102ed2c5ff btrfs: fix false EIO for missing device
When one of the device is missing, bbio_error() takes care of setting
the error status. And if its only IO that is pending in that stripe, it
fails to check the status of the other IO at %bbio_error before setting
the error %bi_status for the %orig_bio. Fix this by checking if
%bbio->error has exceeded the %bbio->max_errors.

Reproducer as below fdatasync error is seen intermittently.

 mount -o degraded /dev/sdc /btrfs
 dd status=none if=/dev/zero of=$(mktemp /btrfs/XXX) bs=4096 count=1 conv=fdatasync

 dd: fdatasync failed for ‘/btrfs/LSe’: Input/output error

 The reason for the intermittences of the problem is because
 the following conditions have to be met, which depends on timing:
 In btrfs_map_bio()
  - the RAID1 the missing device has to be at %dev_nr = 1
 In bbio_error()
  . before bbio_error() is called the bio of the not-missing
    device at %dev_nr = 0 must be completed so that the below
    condition is true
     if (atomic_dec_and_test(&bbio->stripes_pending)) {

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-10-30 12:28:01 +01:00
Anand Jain
de48373454 btrfs: use need_full_stripe() in __btrfs_map_block()
A cleanup patch, use need_full_stripe() to replace the open code.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: Qu Wenruo <quwenruo.btrfs@gmx.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-10-30 12:28:01 +01:00
Goldwyn Rodrigues
79f015f216 btrfs: cleanup extent locking sequence
Code cleanup for better understanding:
Variable needs_unlock to be called extent_locked to show state as
opposed to action. Changed the type to int, to reduce code in the
critical path.

Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-10-30 12:28:01 +01:00
Anand Jain
2dbe0c7718 btrfs: use BLK_STS defines where needed
At few places we could use BLK_STS_OK and BLK_STS_NOSUPP.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: Satoru Taekeuchi <satoru.takeuchi@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ dropped first hunk btrfs_endio_direct_read ]
Signed-off-by: David Sterba <dsterba@suse.com>
2017-10-30 12:28:01 +01:00
Josef Bacik
bf2681cb94 btrfs: add assertions for releasing trans handle reservations
These are useful for debugging problems where we mess with
trans->block_rsv to make sure we're not screwing something up.

Signed-off-by: Josef Bacik <jbacik@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-10-30 12:28:01 +01:00
Josef Bacik
3b60d436a1 btrfs: remove type argument from comp_tree_refs
We can get this from the ref we've passed in.

Signed-off-by: Josef Bacik <jbacik@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-10-30 12:28:00 +01:00
Josef Bacik
d278850eff btrfs: remove delayed_ref_node from ref_head
This is just excessive information in the ref_head, and makes the code
complicated.  It is a relic from when we had the heads and the refs in
the same tree, which is no longer the case.  With this removal I've
cleaned up a bunch of the cruft around this old assumption as well.

Signed-off-by: Josef Bacik <jbacik@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-10-30 12:28:00 +01:00
Josef Bacik
c1103f7a5d btrfs: move all ref head cleanup to the helper function
We do a couple different cleanup operations on the ref head.  We adjust
counters, we'll free any reserved space if we didn't end up using the
ref, and we clear the pending csum bytes.  Move all these disparate
things into cleanup_ref_head and clean up the logic in
__btrfs_run_delayed_refs so that it handles the !ref case a lot cleaner,
as well as making run_one_delayed_ref() only deal with real refs and not
the ref head.

Signed-off-by: Josef Bacik <jbacik@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-10-30 12:28:00 +01:00
Josef Bacik
1ce7a5ec44 btrfs: move ref_mod modification into the if (ref) logic
We only use this logic if our ref isn't a ref_head, so move it up into
the if (ref) case since we know that this is a normal ref and not a
delayed ref head.

Signed-off-by: Josef Bacik <jbacik@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-10-30 12:28:00 +01:00
Josef Bacik
194ab0bc21 btrfs: breakout empty head cleanup to a helper
Move this code out to a helper function to further simplivy
__btrfs_run_delayed_refs.

Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-10-30 12:28:00 +01:00
Josef Bacik
b00e62507e btrfs: move extent_op cleanup to a helper
Move the extent_op cleanup for an empty head ref to a helper function to
help simplify __btrfs_run_delayed_refs.

Signed-off-by: Josef Bacik <jbacik@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-10-30 12:28:00 +01:00
Josef Bacik
2eadaa22c1 btrfs: add a helper to return a head ref
Simplify the error handling in __btrfs_run_delayed_refs by breaking out
the code used to return a head back to the delayed_refs tree for
processing into a helper function.

Signed-off-by: Josef Bacik <jbacik@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-10-30 12:28:00 +01:00
Josef Bacik
7c777430e8 Btrfs: only check delayed ref usage in should_end_transaction
We were only doing btrfs_check_space_for_delayed_refs() if the metadata
space was full, ie we couldn't allocate chunks.  This assumes we'll be
able to allocate chunks during transaction commit, but since nothing
does a LIMIT flush during the transaction commit this won't actually
happen unless we happen to run shy of actual space.  We already take
into account a full fs in btrfs_check_space_for_delayed_refs() so just
kill this extra check to make sure we're ending the transaction when we
need to.

Signed-off-by: Josef Bacik <jbacik@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-10-30 12:28:00 +01:00
Josef Bacik
fd708b81d9 Btrfs: add a extent ref verify tool
We were having corruption issues that were tied back to problems with
the extent tree.  In order to track them down I built this tool to try
and find the culprit, which was pretty successful.  If you compile with
this tool on it will live verify every ref update that the fs makes and
make sure it is consistent and valid.  I've run this through with
xfstests and haven't gotten any false positives.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ update error messages, add fixup from Dan Carpenter to handle errors
  of read_tree_block ]
Signed-off-by: David Sterba <dsterba@suse.com>
2017-10-30 12:28:00 +01:00
Josef Bacik
84f7d8e624 btrfs: pass root to various extent ref mod functions
We need the actual root for the ref verifier tool to work, so change
these functions to pass the root around instead.  This will be used in
a subsequent patch.

Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-10-30 12:28:00 +01:00