Commit Graph

8108 Commits

Author SHA1 Message Date
Johannes Thumshirn 65019df8c3 btrfs: resurrect btrfs_crc32c()
Commit 9678c54388 ("btrfs: Remove custom crc32c init code") removed
the btrfs_crc32c() function, because it was a duplicate of the crc32c()
library function we already have in the kernel.

Resurrect it as a shim wrapper over crc32c() to make following
transformations of the checksumming code in btrfs easier.

Also provide a btrfs_crc32_final() to ease following transformations.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-01 13:35:00 +02:00
Johannes Thumshirn 5852c8b961 btrfs: use btrfs_csum_data() instead of directly calling crc32c
btrfsic_test_for_metadata() directly calls the crc32c() library function
for calculating the CRC32C checksum, but then uses btrfs_csum_final() to
invert the result.

To ease further refactoring and development around checksumming in BTRFS
convert to calling btrfs_csum_data(), which is a wrapper around
crc32c().

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-01 13:35:00 +02:00
Qu Wenruo a94d1d0cb3 btrfs: Flush before reflinking any extent to prevent NOCOW write falling back to COW without data reservation
[BUG]
The following script can cause unexpected fsync failure:

  #!/bin/bash

  dev=/dev/test/test
  mnt=/mnt/btrfs

  mkfs.btrfs -f $dev -b 512M > /dev/null
  mount $dev $mnt -o nospace_cache

  # Prealloc one extent
  xfs_io -f -c "falloc 8k 64m" $mnt/file1
  # Fill the remaining data space
  xfs_io -f -c "pwrite 0 -b 4k 512M" $mnt/padding
  sync

  # Write into the prealloc extent
  xfs_io -c "pwrite 1m 16m" $mnt/file1

  # Reflink then fsync, fsync would fail due to ENOSPC
  xfs_io -c "reflink $mnt/file1 8k 0 4k" -c "fsync" $mnt/file1
  umount $dev

The fsync fails with ENOSPC, and the last page of the buffered write is
lost.

[CAUSE]
This is caused by:
- Btrfs' back reference only has extent level granularity
  So write into shared extent must be COWed even only part of the extent
  is shared.

So for above script we have:
- fallocate
  Create a preallocated extent where we can do NOCOW write.

- fill all the remaining data and unallocated space

- buffered write into preallocated space
  As we have not enough space available for data and the extent is not
  shared (yet) we fall into NOCOW mode.

- reflink
  Now part of the large preallocated extent is shared, later write
  into that extent must be COWed.

- fsync triggers writeback
  But now the extent is shared and therefore we must fallback into COW
  mode, which fails with ENOSPC since there's not enough space to
  allocate data extents.

[WORKAROUND]
The workaround is to ensure any buffered write in the related extents
(not just the reflink source range) get flushed before reflink/dedupe,
so that NOCOW writes succeed that happened before reflinking succeed.

The workaround is expensive, we could do it better by only flushing
NOCOW range, but that needs extra accounting for NOCOW range.
For now, fix the possible data loss first.

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-01 13:35:00 +02:00
Nikolay Borisov 5f791ec31f btrfs: Return EAGAIN if we can't start no snpashot write in check_can_nocow
The first thing code does in check_can_nocow is trying to block
concurrent snapshots. If this fails (due to snpashot already being in
progress) the function returns ENOSPC which makes no sense. Instead
return EAGAIN. Despite this return value not being propagated to callers
it's good practice to return the closest in terms of semantics error
code. No functional changes.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-01 13:34:59 +02:00
Nikolay Borisov 0b6f5d408b btrfs: Add comments on locking of several device-related fields
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-01 13:34:59 +02:00
Nikolay Borisov bd80d94efb btrfs: Always use a cached extent_state in btrfs_lock_and_flush_ordered_range
In case no cached_state argument is passed to
btrfs_lock_and_flush_ordered_range use one locally in the function. This
optimises the case when an ordered extent is found since the unlock
function will be able to unlock that state directly without searching
for it again.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-01 13:34:59 +02:00
Nikolay Borisov 23d31bd476 btrfs: Use newly introduced btrfs_lock_and_flush_ordered_range
There several functions which open code
btrfs_lock_and_flush_ordered_range, just replace them with a call to the
function. No functional changes.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-01 13:34:59 +02:00
Nikolay Borisov ffa87214c1 btrfs: add new helper btrfs_lock_and_flush_ordered_range
There is a certain idiom used in multiple places in btrfs' codebase,
dealing with flushing an ordered range. Factor this in a separate
function that can be reused. Future patches will replace the existing
code with that function.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-01 13:34:59 +02:00
Qu Wenruo 1200b51f57 btrfs: remove the incorrect comment on RO fs when btrfs_run_delalloc_range() fails
At the context of btrfs_run_delalloc_range(), we haven't started/joined
a transaction, thus even something went wrong, we can't and won't abort
transaction, thus no way to make the fs RO.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-01 13:34:59 +02:00
Qu Wenruo 480b9b4d84 btrfs: extent-tree: Add trace events for space info numbers update
Add trace event for update_bytes_pinned() and update_bytes_may_use() to
detect underflow better.

The output would be something like (only showing data part):

  ## Buffered write start, 16K total ##
  2255.954 xfs_io/860 btrfs:update_bytes_may_use:(nil)U: type=DATA old=0 diff=4096
  2257.169 sudo/860 btrfs:update_bytes_may_use:(nil)U: type=DATA old=4096 diff=4096
  2257.346 sudo/860 btrfs:update_bytes_may_use:(nil)U: type=DATA old=8192 diff=4096
  2257.542 sudo/860 btrfs:update_bytes_may_use:(nil)U: type=DATA old=12288 diff=4096

  ## Delalloc start ##
  3727.853 kworker/u8:3-e/700 btrfs:update_bytes_may_use:(nil)U: type=DATA old=16384 diff=-16384

  ## Space cache update ##
  3733.132 sudo/862 btrfs:update_bytes_may_use:(nil)U: type=DATA old=0 diff=65536
  3733.169 sudo/862 btrfs:update_bytes_may_use:(nil)U: type=DATA old=65536 diff=-65536
  3739.868 sudo/862 btrfs:update_bytes_may_use:(nil)U: type=DATA old=0 diff=65536
  3739.891 sudo/862 btrfs:update_bytes_may_use:(nil)U: type=DATA old=65536 diff=-65536

These two trace events will allow bcc tool to probe btrfs_space_info
changes and detect underflow with more details (e.g. backtrace for each
update).

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-01 13:34:58 +02:00
Qu Wenruo 0185f364cb btrfs: extent-tree: Add lockdep assert when updating space info
Just add a safe net for btrfs_space_info member updating.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-01 13:34:58 +02:00
David Sterba cff8267228 btrfs: read number of data stripes from map only once
There are several places that call nr_data_stripes, but this value does
not change.

Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-01 13:34:58 +02:00
David Sterba 72ad813157 btrfs: constify map parameter for nr_parity_stripes and nr_data_stripes
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-01 13:34:58 +02:00
David Sterba 158da513b1 btrfs: refactor helper for bg flags to name conversion
The helper lacks the btrfs_ prefix and the parameter is the raw
blockgroup type, so none of the callers has to do the flags -> index
conversion.

Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-01 13:34:58 +02:00
David Sterba e3ecdb3fde btrfs: factor out devs_max setting in __btrfs_alloc_chunk
Merge the repeated code before the if-else block.

Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-01 13:34:57 +02:00
David Sterba 8c3e3582a4 btrfs: use u8 for raid_array members
The raid_attr table is now 7 * 56 = 392 bytes long, consisting of just
small numbers so we don't have to use ints. New size is 7 * 32 = 224,
saving 3 cachelines.

Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-01 13:34:57 +02:00
David Sterba 946c9256c6 btrfs: factor out helper for counting data stripes
Factor the sequence of ifs to a helper, the 'data stripes' here means
the number of stripes without redundancy and parity.

Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-01 13:34:57 +02:00
David Sterba 44b28adafd btrfs: use raid_attr table for btrfs_bg_type_to_factor
The factor is the number of copies.

Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-01 13:34:57 +02:00
David Sterba 6079e12cdb btrfs: use raid_attr table to find profiles for integrity lowering
Replace open coded list of the profiles by selecting them from the
raid_attr table. The criteria are now more explicit, we need profiles
that have more than 1 copy of the data or can reconstruct the data with
a missing device.

Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-01 13:34:57 +02:00
David Sterba 081db89b13 btrfs: use raid_attr to get allowed profiles for balance conversion
Iterate over the table and gather all allowed profiles for a given
number of devices, instead of open coding.

Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-01 13:34:56 +02:00
David Sterba fc9a2ac77c btrfs: use raid_attr in btrfs_chunk_max_errors
The number of tolerated failures is stored in the raid_attr table, use
it.

Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-01 13:34:56 +02:00
David Sterba 9fa02ac75b btrfs: use raid_attr table in get_profile_num_devs
The dev_max constraints are defined in the raid_attr table, use it
instead of open-coding it.

Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-01 13:34:56 +02:00
David Sterba c8bf1b6703 btrfs: remove mapping tree structures indirection
fs_info::mapping_tree is the physical<->logical mapping tree and uses
the same underlying structure as extents, but is embedded to another
structure. There are no other members and this indirection is useless.
No functional change.

Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-01 13:34:56 +02:00
David Sterba 49cc180ca9 btrfs: raid56: allow the exact minimum number of devices for balance convert
The minimum number of devices for RAID5 is 2, though this is only a bit
expensive RAID1, and for RAID6 it's 3, which is a triple copy that works
only 3 devices.

mkfs.btrfs allows that and mounting such filesystem also works, so the
conversion via balance filters is inconsistent with the others and we
should not prevent it.

Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-01 13:34:56 +02:00
David Sterba 0ee5f8ae08 btrfs: fix minimum number of chunk errors for DUP
The list of profiles in btrfs_chunk_max_errors lists DUP as a profile
DUP able to tolerate 1 device missing. Though this profile is special
with 2 copies, it still needs the device, unlike the others.

Looking at the history of changes, thre's no clear reason why DUP is
there, functions were refactored and blocks of code merged to one
helper.

d20983b40e Btrfs: fix writing data into the seed filesystem
  - factor code to a helper

de11cc12df Btrfs: don't pre-allocate btrfs bio
  - unrelated change, DUP still in the list with max errors 1

a236aed14c Btrfs: Deal with failed writes in mirrored configurations
  - introduced the max errors, leaves DUP and RAID1 in the same group

Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-01 13:34:55 +02:00
Liu Bo be9b8dfa9c Btrfs: remove unused variables in __btrfs_unlink_inode
This code was first introduced in 5f39d397df ("Btrfs: Create
extent_buffer interface for large blocksizes") and the function was
named btrfs_unlink_trans. It later got renamed to __btrfs_unlink_inode
and finally commit 16cdcec736 ("btrfs: implement delayed inode items
operation") changed the way inodes are deleted and obviated the need for
those two members.

Signed-off-by: Liu Bo <bo.liu@linux.alibaba.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ replace changelog by Nikolay's version ]
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-01 13:34:55 +02:00
Goldwyn Rodrigues cebf05ca65 btrfs: Remove unused variable mode in btrfs_mount
This is a leftover from 312c89fbca ("btrfs: cleanup btrfs_mount()
using btrfs_mount_root()"), the mode was used for opening devices that's
not done here anymore.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-01 13:34:55 +02:00
Su Yue 8f63a84051 btrfs: switch order of unlocks of space_info and bg in do_trimming()
In function do_trimming(), block_group->lock should be unlocked first,
as the locks should be released in the reverse order. This does not
cause problems but should follow the best practices.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Su Yue <suy.fnst@cn.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ update changelog ]
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-01 13:34:55 +02:00
Qu Wenruo 4c094c33c9 btrfs: tree-checker: Check if the file extent end overflows
Under certain conditions, we could have strange file extent item in log
tree like:

  item 18 key (69599 108 397312) itemoff 15208 itemsize 53
	extent data disk bytenr 0 nr 0
	extent data offset 0 nr 18446744073709547520 ram 18446744073709547520

The num_bytes + ram_bytes overflow 64 bit type.

For num_bytes part, we can detect such overflow along with file offset
(key->offset), as file_offset + num_bytes should never go beyond u64.

For ram_bytes part, it's about the decompressed size of the extent, not
directly related to the size.
In theory it is OK to have a large value, and put extra limitation
on RAM bytes may cause unexpected false alerts.

So in tree-checker, we only check if the file offset and num bytes
overflow.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-01 13:34:55 +02:00
Nikolay Borisov 2ed95d2d59 btrfs: Remove redundant assignment of tgt_device->commit_total_bytes
This is already done in btrfs_init_dev_replace_tgtdev which is the first
phase of device replace, called before doing scrub. During that time
exclusive lock is held. Additionally btrfs_fs_device::commit_total_bytes
is always set based on the size of the underlying block device which
shouldn't change once set. This makes the 2nd assignment of the variable
in the finishing phase redundant.

Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-01 13:34:55 +02:00
Nikolay Borisov f232ab04f6 btrfs: Explicitly reserve space for devreplace item
Part of device replace involves writing an item to the device root
containing information about pending replace operations. Currently space
for this item is not being explicitly reserved so this works thanks to
presence of global reserve. While not fatal it's not a good practice.
Let's be explicit about space requirement of device replace and reserve
space when starting the transaction.

Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-01 13:34:54 +02:00
Nikolay Borisov fa19452a40 btrfs: Streamline replace sem unlock in btrfs_dev_replace_start
There are only 2 branches which goto leave label with need_unlock set
to true. Essentially need_unlock is used as a substitute for directly
calling up_write. Since the branches needing this are only 2 and their
context is not that big it's more clear to just call up_write where
required. No functional changes.

Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-01 13:34:54 +02:00
Nikolay Borisov e1e0eb43ce btrfs: Ensure btrfs_init_dev_replace_tgtdev sees up to date values
btrfs_init_dev_replace_tgtdev reads certain values from the source
device (such as commit_total_bytes) which are updated during transaction
commit. Currently this function is called before committing any pending
transaction, leading to possibly reading outdated values.

Fix this by moving the function below the transaction commit, at this
point the EXCL_OP bit it set hence once transaction is complete the
total size of the device cannot be changed (it's usually changed by
resize/remove ops which are blocked).

Fixes: 9e271ae27e ("Btrfs: kernel operation should come after user input has been verified")
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-01 13:34:54 +02:00
Nikolay Borisov 419684b2c2 btrfs: dev-replace: Remove impossible WARN_ON
This WARN_ON can never trigger because src_device cannot be null.
btrfs_find_device_by_devspec always returns either an error or a valid
pointer to the device. Just remove it.

Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-01 13:34:54 +02:00
Nikolay Borisov b0d9e1ea17 btrfs: Reduce critical section in btrfs_init_dev_replace_tgtdev
There is no point in holding btrfs_fs_devices::device_list_mutex
while initialising fields of the not-yet-published device. Instead,
hold the mutex only when the newly initialised device is being
published. I think holding device_list_mutex here is redundant
altogether, because at this point BTRFS_FS_EXCL_OP is set which
prevents device removal/addition/balance/resize to occur.

Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-01 13:34:54 +02:00
Nikolay Borisov ddb9378469 btrfs: Don't opencode sync_blockdev in btrfs_init_dev_replace_tgtdev
Using sync_blockdev makes it plain obvious what's happening. No
functional changes.

Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-01 13:34:53 +02:00
David Sterba 5911c8fe05 btrfs: fiemap: preallocate ulists for btrfs_check_shared
btrfs_check_shared looks up parents of a given extent and uses ulists
for that. These are allocated and freed repeatedly. Preallocation in the
caller will avoid the overhead and also allow us to use the GFP_KERNEL
as it is happens before the extent locks are taken.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-01 13:34:53 +02:00
David Sterba 9b4e675a99 btrfs: detect fast implementation of crc32c on all architectures
Currently, there's only check for fast crc32c implementation on X86,
based on the CPU flags. This is used to decide if checksumming should be
offloaded to worker threads or can be calculated by the caller.

As there are more architectures that implement a faster version of
crc32c (ARM, SPARC, s390, MIPS, PowerPC), also there are specialized hw
cards.

The detection is based on driver name, all generic C implementations
contain 'generic', while the specialized versions do not. Alternatively
the priority could be used, but this is not currently provided by the
crypto API.

The flag is set per-filesystem at mount time and used for the offloading
decisions.

Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-01 13:34:53 +02:00
Qu Wenruo 78192442d3 btrfs: extent-tree: Refactor add_pinned_bytes() to add|sub_pinned_bytes()
Instead of using @sign to determine whether we're adding or subtracting.
Even it only has 3 callers, it's still (and in fact already caused
problem in the past) confusing to use.

Refactor add_pinned_bytes() to add_pinned_bytes() and sub_pinned_bytes()
to explicitly show what we're doing.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-01 13:34:53 +02:00
Linus Torvalds bed3c0d84e for-5.2-rc5-tag
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Merge tag 'for-5.2-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs fixes from David Sterba:

 - regression where properties stored as xattrs are not properly
   persisted

 - a small readahead fix (the fstests testcase for that fix hangs on
   unpatched kernel, so we'd like get it merged to ease future testing)

 - fix a race during block group creation and deletion

* tag 'for-5.2-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  Btrfs: fix failure to persist compression property xattr deletion on fsync
  btrfs: start readahead also in seed devices
  Btrfs: fix race between block group removal and block group allocation
2019-06-18 11:20:24 -07:00
Filipe Manana 3763771cf6 Btrfs: fix failure to persist compression property xattr deletion on fsync
After the recent series of cleanups in the properties and xattrs modules
that landed in the 5.2 merge window, we ended up with a regression where
after deleting the compression xattr property through the setflags ioctl,
we don't set the BTRFS_INODE_COPY_EVERYTHING flag in the inode anymore.
As a consequence, if the inode was fsync'ed when it had the compression
property set, after deleting the compression property through the setflags
ioctl and fsync'ing again the inode, the log will still contain the
compression xattr, because the inode did not had that bit set, which
made the fsync not delete all xattrs from the log and copy all xattrs
from the subvolume tree to the log tree.

This regression happens due to the fact that that series of cleanups
made btrfs_set_prop() call the old function do_setxattr() (which is now
named btrfs_setxattr()), and not the old version of btrfs_setxattr(),
which is now called btrfs_setxattr_trans().

Fix this by setting the BTRFS_INODE_COPY_EVERYTHING bit in the current
btrfs_setxattr() function and remove it from everywhere else, including
its setup at btrfs_ioctl_setflags(). This is cleaner, avoids similar
regressions in the future, and centralizes the setup of the bit. After
all, the need to setup this bit should only be in the xattrs module,
since it is an implementation of xattrs.

Fixes: 04e6863b19 ("btrfs: split btrfs_setxattr calls regarding transaction")
CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-06-17 16:37:17 +02:00
Naohiro Aota c4e0540d0a btrfs: start readahead also in seed devices
Currently, btrfs does not consult seed devices to start readahead. As a
result, if readahead zone is added to the seed devices, btrfs_reada_wait()
indefinitely wait for the reada_ctl to finish.

You can reproduce the hung by modifying btrfs/163 to have larger initial
file size (e.g. xfs_io pwrite 4M instead of current 256K).

Fixes: 7414a03fbf ("btrfs: initial readahead code and prototypes")
Cc: stable@vger.kernel.org # 3.2+: ce7791ffee1e: Btrfs: fix race between readahead and device replace/removal
Cc: stable@vger.kernel.org # 3.2+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-06-14 17:33:46 +02:00
Filipe Manana 8eaf40c0e2 Btrfs: fix race between block group removal and block group allocation
If a task is removing the block group that currently has the highest start
offset amongst all existing block groups, there is a short time window
where it races with a concurrent block group allocation, resulting in a
transaction abort with an error code of EEXIST.

The following diagram explains the race in detail:

      Task A                                                        Task B

 btrfs_remove_block_group(bg offset X)

   remove_extent_mapping(em offset X)
     -> removes extent map X from the
        tree of extent maps
        (fs_info->mapping_tree), so the
        next call to find_next_chunk()
        will return offset X

                                                   btrfs_alloc_chunk()
                                                     find_next_chunk()
                                                       --> returns offset X

                                                     __btrfs_alloc_chunk(offset X)
                                                       btrfs_make_block_group()
                                                         btrfs_create_block_group_cache()
                                                           --> creates btrfs_block_group_cache
                                                               object with a key corresponding
                                                               to the block group item in the
                                                               extent, the key is:
                                                               (offset X, BTRFS_BLOCK_GROUP_ITEM_KEY, 1G)

                                                         --> adds the btrfs_block_group_cache object
                                                             to the list new_bgs of the transaction
                                                             handle

                                                   btrfs_end_transaction(trans handle)
                                                     __btrfs_end_transaction()
                                                       btrfs_create_pending_block_groups()
                                                         --> sees the new btrfs_block_group_cache
                                                             in the new_bgs list of the transaction
                                                             handle
                                                         --> its call to btrfs_insert_item() fails
                                                             with -EEXIST when attempting to insert
                                                             the block group item key
                                                             (offset X, BTRFS_BLOCK_GROUP_ITEM_KEY, 1G)
                                                             because task A has not removed that key yet
                                                         --> aborts the running transaction with
                                                             error -EEXIST

   btrfs_del_item()
     -> removes the block group's key from
        the extent tree, key is
        (offset X, BTRFS_BLOCK_GROUP_ITEM_KEY, 1G)

A sample transaction abort trace:

  [78912.403537] ------------[ cut here ]------------
  [78912.403811] BTRFS: Transaction aborted (error -17)
  [78912.404082] WARNING: CPU: 2 PID: 20465 at fs/btrfs/extent-tree.c:10551 btrfs_create_pending_block_groups+0x196/0x250 [btrfs]
  (...)
  [78912.405642] CPU: 2 PID: 20465 Comm: btrfs Tainted: G        W         5.0.0-btrfs-next-46 #1
  [78912.405941] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.11.2-0-gf9626ccb91-prebuilt.qemu-project.org 04/01/2014
  [78912.406586] RIP: 0010:btrfs_create_pending_block_groups+0x196/0x250 [btrfs]
  (...)
  [78912.407636] RSP: 0018:ffff9d3d4b7e3b08 EFLAGS: 00010282
  [78912.407997] RAX: 0000000000000000 RBX: ffff90959a3796f0 RCX: 0000000000000006
  [78912.408369] RDX: 0000000000000007 RSI: 0000000000000001 RDI: ffff909636b16860
  [78912.408746] RBP: ffff909626758a58 R08: 0000000000000000 R09: 0000000000000000
  [78912.409144] R10: ffff9095ff462400 R11: 0000000000000000 R12: ffff90959a379588
  [78912.409521] R13: ffff909626758ab0 R14: ffff9095036c0000 R15: ffff9095299e1158
  [78912.409899] FS:  00007f387f16f700(0000) GS:ffff909636b00000(0000) knlGS:0000000000000000
  [78912.410285] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  [78912.410673] CR2: 00007f429fc87cbc CR3: 000000014440a004 CR4: 00000000003606e0
  [78912.411095] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  [78912.411496] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
  [78912.411898] Call Trace:
  [78912.412318]  __btrfs_end_transaction+0x5b/0x1c0 [btrfs]
  [78912.412746]  btrfs_inc_block_group_ro+0xcf/0x160 [btrfs]
  [78912.413179]  scrub_enumerate_chunks+0x188/0x5b0 [btrfs]
  [78912.413622]  ? __mutex_unlock_slowpath+0x100/0x2a0
  [78912.414078]  btrfs_scrub_dev+0x2ef/0x720 [btrfs]
  [78912.414535]  ? __sb_start_write+0xd4/0x1c0
  [78912.414963]  ? mnt_want_write_file+0x24/0x50
  [78912.415403]  btrfs_ioctl+0x17fb/0x3120 [btrfs]
  [78912.415832]  ? lock_acquire+0xa6/0x190
  [78912.416256]  ? do_vfs_ioctl+0xa2/0x6f0
  [78912.416685]  ? btrfs_ioctl_get_supported_features+0x30/0x30 [btrfs]
  [78912.417116]  do_vfs_ioctl+0xa2/0x6f0
  [78912.417534]  ? __fget+0x113/0x200
  [78912.417954]  ksys_ioctl+0x70/0x80
  [78912.418369]  __x64_sys_ioctl+0x16/0x20
  [78912.418812]  do_syscall_64+0x60/0x1b0
  [78912.419231]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
  [78912.419644] RIP: 0033:0x7f3880252dd7
  (...)
  [78912.420957] RSP: 002b:00007f387f16ed68 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
  [78912.421426] RAX: ffffffffffffffda RBX: 000055f5becc1df0 RCX: 00007f3880252dd7
  [78912.421889] RDX: 000055f5becc1df0 RSI: 00000000c400941b RDI: 0000000000000003
  [78912.422354] RBP: 0000000000000000 R08: 00007f387f16f700 R09: 0000000000000000
  [78912.422790] R10: 00007f387f16f700 R11: 0000000000000246 R12: 0000000000000000
  [78912.423202] R13: 00007ffda49c266f R14: 0000000000000000 R15: 00007f388145e040
  [78912.425505] ---[ end trace eb9bfe7c426fc4d3 ]---

Fix this by calling remove_extent_mapping(), at btrfs_remove_block_group(),
only at the very end, after removing the block group item key from the
extent tree (and removing the free space tree entry if we are using the
free space tree feature).

Fixes: 04216820fe ("Btrfs: fix race between fs trimming and block group remove/allocation")
CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-06-12 15:55:42 +02:00
Linus Torvalds 6fa425a265 for-5.2-rc4-tag
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Merge tag 'for-5.2-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs fix from David Sterba:
 "One regression fix to TRIM ioctl.

  The range cannot be used as its meaning can be confusing regarding
  physical and logical addresses. This confusion in code led to
  potential corruptions when the range overlapped data.

  The original patch made it to several stable kernels and was promptly
  reverted, the version for master branch is different due to additional
  changes but the change is effectively the same"

* tag 'for-5.2-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: Always trim all unallocated space in btrfs_trim_free_extents
2019-06-11 15:10:15 -10:00
Nikolay Borisov 8103d10b71 btrfs: Always trim all unallocated space in btrfs_trim_free_extents
This patch removes support for range parameters of FITRIM ioctl when
trimming unallocated space on devices. This is necessary since ranges
passed from user space are generally interpreted as logical addresses,
whereas btrfs_trim_free_extents used to interpret them as device
physical extents. This could result in counter-intuitive behavior for
users so it's best to remove that support altogether.

Additionally, the existing range support had a bug where if an offset
was passed to FITRIM which overflows u64 e.g. -1 (parsed as u64
18446744073709551615) then wrong data was fed into btrfs_issue_discard,
which in turn leads to wrap-around when aligning the passed range and
results in wrong regions being discarded which leads to data corruption.

Fixes: c2d1b3aae3 ("btrfs: Honour FITRIM range constraints during free space trim")
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-06-07 14:52:05 +02:00
Linus Torvalds 318adf8e4b for-5.2-rc2-tag
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Merge tag 'for-5.2-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs fixes from David Sterba:
 "A few more fixes for bugs reported by users, fuzzing tools and
  regressions:

   - fix crashes in relocation:
       + resuming interrupted balance operation does not properly clean
         up orphan trees
       + with enabled qgroups, resuming needs to be more careful about
         block groups due to limited context when updating qgroups

   - fsync and logging fixes found by fuzzing

   - incremental send fixes for no-holes and clone

   - fix spin lock type used in timer function for zstd"

* tag 'for-5.2-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  Btrfs: fix race updating log root item during fsync
  Btrfs: fix wrong ctime and mtime of a directory after log replay
  Btrfs: fix fsync not persisting changed attributes of a directory
  btrfs: qgroup: Check bg while resuming relocation to avoid NULL pointer dereference
  btrfs: reloc: Also queue orphan reloc tree for cleanup to avoid BUG_ON()
  Btrfs: incremental send, fix emission of invalid clone operations
  Btrfs: incremental send, fix file corruption when no-holes feature is enabled
  btrfs: correct zstd workspace manager lock to use spin_lock_bh()
  btrfs: Ensure replaced device doesn't have pending chunk allocation
2019-05-30 20:52:40 -07:00
Filipe Manana 06989c799f Btrfs: fix race updating log root item during fsync
When syncing the log, the final phase of a fsync operation, we need to
either create a log root's item or update the existing item in the log
tree of log roots, and that depends on the current value of the log
root's log_transid - if it's 1 we need to create the log root item,
otherwise it must exist already and we update it. Since there is no
synchronization between updating the log_transid and checking it for
deciding whether the log root's item needs to be created or updated, we
end up with a tiny race window that results in attempts to update the
item to fail because the item was not yet created:

              CPU 1                                    CPU 2

  btrfs_sync_log()

    lock root->log_mutex

    set log root's log_transid to 1

    unlock root->log_mutex

                                               btrfs_sync_log()

                                                 lock root->log_mutex

                                                 sets log root's
                                                 log_transid to 2

                                                 unlock root->log_mutex

    update_log_root()

      sees log root's log_transid
      with a value of 2

        calls btrfs_update_root(),
        which fails with -EUCLEAN
        and causes transaction abort

Until recently the race lead to a BUG_ON at btrfs_update_root(), but after
the recent commit 7ac1e464c4 ("btrfs: Don't panic when we can't find a
root key") we just abort the current transaction.

A sample trace of the BUG_ON() on a SLE12 kernel:

  ------------[ cut here ]------------
  kernel BUG at ../fs/btrfs/root-tree.c:157!
  Oops: Exception in kernel mode, sig: 5 [#1]
  SMP NR_CPUS=2048 NUMA pSeries
  (...)
  Supported: Yes, External
  CPU: 78 PID: 76303 Comm: rtas_errd Tainted: G                 X 4.4.156-94.57-default #1
  task: c00000ffa906d010 ti: c00000ff42b08000 task.ti: c00000ff42b08000
  NIP: d000000036ae5cdc LR: d000000036ae5cd8 CTR: 0000000000000000
  REGS: c00000ff42b0b860 TRAP: 0700   Tainted: G                 X  (4.4.156-94.57-default)
  MSR: 8000000002029033 <SF,VEC,EE,ME,IR,DR,RI,LE>  CR: 22444484  XER: 20000000
  CFAR: d000000036aba66c SOFTE: 1
  GPR00: d000000036ae5cd8 c00000ff42b0bae0 d000000036bda220 0000000000000054
  GPR04: 0000000000000001 0000000000000000 c00007ffff8d37c8 0000000000000000
  GPR08: c000000000e19c00 0000000000000000 0000000000000000 3736343438312079
  GPR12: 3930373337303434 c000000007a3a800 00000000007fffff 0000000000000023
  GPR16: c00000ffa9d26028 c00000ffa9d261f8 0000000000000010 c00000ffa9d2ab28
  GPR20: c00000ff42b0bc48 0000000000000001 c00000ff9f0d9888 0000000000000001
  GPR24: c00000ffa9d26000 c00000ffa9d261e8 c00000ffa9d2a800 c00000ff9f0d9888
  GPR28: c00000ffa9d26028 c00000ffa9d2aa98 0000000000000001 c00000ffa98f5b20
  NIP [d000000036ae5cdc] btrfs_update_root+0x25c/0x4e0 [btrfs]
  LR [d000000036ae5cd8] btrfs_update_root+0x258/0x4e0 [btrfs]
  Call Trace:
  [c00000ff42b0bae0] [d000000036ae5cd8] btrfs_update_root+0x258/0x4e0 [btrfs] (unreliable)
  [c00000ff42b0bba0] [d000000036b53610] btrfs_sync_log+0x2d0/0xc60 [btrfs]
  [c00000ff42b0bce0] [d000000036b1785c] btrfs_sync_file+0x44c/0x4e0 [btrfs]
  [c00000ff42b0bd80] [c00000000032e300] vfs_fsync_range+0x70/0x120
  [c00000ff42b0bdd0] [c00000000032e44c] do_fsync+0x5c/0xb0
  [c00000ff42b0be10] [c00000000032e8dc] SyS_fdatasync+0x2c/0x40
  [c00000ff42b0be30] [c000000000009488] system_call+0x3c/0x100
  Instruction dump:
  7f43d378 4bffebb9 60000000 88d90008 3d220000 e8b90000 3b390009 e87a01f0
  e8898e08 e8f90000 4bfd48e5 60000000 <0fe00000> e95b0060 39200004 394a0ea0
  ---[ end trace 8f2dc8f919cabab8 ]---

So fix this by doing the check of log_transid and updating or creating the
log root's item while holding the root's log_mutex.

Fixes: 7237f18336 ("Btrfs: fix tree logs parallel sync")
CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-05-28 19:26:46 +02:00
Filipe Manana 5338e43abb Btrfs: fix wrong ctime and mtime of a directory after log replay
When replaying a log that contains a new file or directory name that needs
to be added to its parent directory, we end up updating the mtime and the
ctime of the parent directory to the current time after we have set their
values to the correct ones (set at fsync time), efectivelly losing them.

Sample reproducer:

  $ mkfs.btrfs -f /dev/sdb
  $ mount /dev/sdb /mnt

  $ mkdir /mnt/dir
  $ touch /mnt/dir/file

  # fsync of the directory is optional, not needed
  $ xfs_io -c fsync /mnt/dir
  $ xfs_io -c fsync /mnt/dir/file

  $ stat -c %Y /mnt/dir
  1557856079

  <power failure>

  $ sleep 3
  $ mount /dev/sdb /mnt
  $ stat -c %Y /mnt/dir
  1557856082

    --> should have been 1557856079, the mtime is updated to the current
        time when replaying the log

Fix this by not updating the mtime and ctime to the current time at
btrfs_add_link() when we are replaying a log tree.

This could be triggered by my recent fsync fuzz tester for fstests, for
which an fstests patch exists titled "fstests: generic, fsync fuzz tester
with fsstress".

Fixes: e02119d5a7 ("Btrfs: Add a write ahead tree log to optimize synchronous operations")
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-05-28 19:16:16 +02:00
Filipe Manana 60d9f50308 Btrfs: fix fsync not persisting changed attributes of a directory
While logging an inode we follow its ancestors and for each one we mark
it as logged in the current transaction, even if we have not logged it.
As a consequence if we change an attribute of an ancestor, such as the
UID or GID for example, and then explicitly fsync it, we end up not
logging the inode at all despite returning success to user space, which
results in the attribute being lost if a power failure happens after
the fsync.

Sample reproducer:

  $ mkfs.btrfs -f /dev/sdb
  $ mount /dev/sdb /mnt

  $ mkdir /mnt/dir
  $ chown 6007:6007 /mnt/dir

  $ sync

  $ chown 9003:9003 /mnt/dir
  $ touch /mnt/dir/file
  $ xfs_io -c fsync /mnt/dir/file

  # fsync our directory after fsync'ing the new file, should persist the
  # new values for the uid and gid.
  $ xfs_io -c fsync /mnt/dir

  <power failure>

  $ mount /dev/sdb /mnt
  $ stat -c %u:%g /mnt/dir
  6007:6007

    --> should be 9003:9003, the uid and gid were not persisted, despite
        the explicit fsync on the directory prior to the power failure

Fix this by not updating the logged_trans field of ancestor inodes when
logging an inode, since we have not logged them. Let only future calls to
btrfs_log_inode() to mark inodes as logged.

This could be triggered by my recent fsync fuzz tester for fstests, for
which an fstests patch exists titled "fstests: generic, fsync fuzz tester
with fsstress".

Fixes: 12fcfd22fe ("Btrfs: tree logging unlink/rename fixes")
CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-05-28 18:56:50 +02:00
Qu Wenruo 57949d033a btrfs: qgroup: Check bg while resuming relocation to avoid NULL pointer dereference
[BUG]
When mounting a fs with reloc tree and has qgroup enabled, it can cause
NULL pointer dereference at mount time:

  BUG: kernel NULL pointer dereference, address: 00000000000000a8
  #PF: supervisor read access in kernel mode
  #PF: error_code(0x0000) - not-present page
  PGD 0 P4D 0
  Oops: 0000 [#1] PREEMPT SMP NOPTI
  RIP: 0010:btrfs_qgroup_add_swapped_blocks+0x186/0x300 [btrfs]
  Call Trace:
   replace_path.isra.23+0x685/0x900 [btrfs]
   merge_reloc_root+0x26e/0x5f0 [btrfs]
   merge_reloc_roots+0x10a/0x1a0 [btrfs]
   btrfs_recover_relocation+0x3cd/0x420 [btrfs]
   open_ctree+0x1bc8/0x1ed0 [btrfs]
   btrfs_mount_root+0x544/0x680 [btrfs]
   legacy_get_tree+0x34/0x60
   vfs_get_tree+0x2d/0xf0
   fc_mount+0x12/0x40
   vfs_kern_mount.part.12+0x61/0xa0
   vfs_kern_mount+0x13/0x20
   btrfs_mount+0x16f/0x860 [btrfs]
   legacy_get_tree+0x34/0x60
   vfs_get_tree+0x2d/0xf0
   do_mount+0x81f/0xac0
   ksys_mount+0xbf/0xe0
   __x64_sys_mount+0x25/0x30
   do_syscall_64+0x65/0x240
   entry_SYSCALL_64_after_hwframe+0x49/0xbe

[CAUSE]
In btrfs_recover_relocation(), we don't have enough info to determine
which block group we're relocating, but only to merge existing reloc
trees.

Thus in btrfs_recover_relocation(), rc->block_group is NULL.
btrfs_qgroup_add_swapped_blocks() hasn't taken this into consideration,
and causes a NULL pointer dereference.

The bug is introduced by commit 3d0174f78e ("btrfs: qgroup: Only trace
data extents in leaves if we're relocating data block group"), and
later qgroup refactoring still keeps this optimization.

[FIX]
Thankfully in the context of btrfs_recover_relocation(), there is no
other progress can modify tree blocks, thus those swapped tree blocks
pair will never affect qgroup numbers, no matter whatever we set for
block->trace_leaf.

So we only need to check if @bg is NULL before accessing @bg->flags.

Reported-by: Juan Erbes <jerbes@gmail.com>
Link: https://bugzilla.opensuse.org/show_bug.cgi?id=1134806
Fixes: 3d0174f78e ("btrfs: qgroup: Only trace data extents in leaves if we're relocating data block group")
CC: stable@vger.kernel.org # 4.20+
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-05-28 18:54:10 +02:00
Qu Wenruo 30d40577e3 btrfs: reloc: Also queue orphan reloc tree for cleanup to avoid BUG_ON()
[BUG]
When a fs has orphan reloc tree along with unfinished balance:
  ...
        item 16 key (TREE_RELOC ROOT_ITEM FS_TREE) itemoff 12090 itemsize 439
                generation 12 root_dirid 256 bytenr 300400640 level 1 refs 0 <<<
                lastsnap 8 byte_limit 0 bytes_used 1359872 flags 0x0(none)
                uuid 7c48d938-33a3-4aae-ab19-6e5c9d406e46
        item 17 key (BALANCE TEMPORARY_ITEM 0) itemoff 11642 itemsize 448
                temporary item objectid BALANCE offset 0
                balance status flags 14

Then at mount time, we can hit the following kernel BUG_ON():
  BTRFS info (device dm-3): relocating block group 298844160 flags metadata|dup
  ------------[ cut here ]------------
  kernel BUG at fs/btrfs/relocation.c:1413!
  invalid opcode: 0000 [#1] PREEMPT SMP NOPTI
  CPU: 1 PID: 897 Comm: btrfs-balance Tainted: G           O      5.2.0-rc1-custom #15
  RIP: 0010:create_reloc_root+0x1eb/0x200 [btrfs]
  Call Trace:
   btrfs_init_reloc_root+0x96/0xb0 [btrfs]
   record_root_in_trans+0xb2/0xe0 [btrfs]
   btrfs_record_root_in_trans+0x55/0x70 [btrfs]
   select_reloc_root+0x7e/0x230 [btrfs]
   do_relocation+0xc4/0x620 [btrfs]
   relocate_tree_blocks+0x592/0x6a0 [btrfs]
   relocate_block_group+0x47b/0x5d0 [btrfs]
   btrfs_relocate_block_group+0x183/0x2f0 [btrfs]
   btrfs_relocate_chunk+0x4e/0xe0 [btrfs]
   btrfs_balance+0x864/0xfa0 [btrfs]
   balance_kthread+0x3b/0x50 [btrfs]
   kthread+0x123/0x140
   ret_from_fork+0x27/0x50

[CAUSE]
In btrfs, reloc trees are used to record swapped tree blocks during
balance.
Reloc tree either get merged (replace old tree blocks of its parent
subvolume) in next transaction if its ref is 1 (fresh).
Or is already merged and will be cleaned up if its ref is 0 (orphan).

After commit d2311e6985 ("btrfs: relocation: Delay reloc tree deletion
after merge_reloc_roots"), reloc tree cleanup is delayed until one block
group is balanced.

Since fresh reloc roots are recorded during merge, as long as there
is no power loss, those orphan reloc roots converted from fresh ones are
handled without problem.

However when power loss happens, orphan reloc roots can be recorded
on-disk, thus at next mount time, we will have orphan reloc roots from
on-disk data directly, and ignored by clean_dirty_subvols() routine.

Then when background balance starts to balance another block group, and
needs to create new reloc root for the same root, btrfs_insert_item()
returns -EEXIST, and trigger that BUG_ON().

[FIX]
For orphan reloc roots, also queue them to rc->dirty_subvol_roots, so
all reloc roots no matter orphan or not, can be cleaned up properly and
avoid above BUG_ON().

And to cooperate with above change, clean_dirty_subvols() will check if
the queued root is a reloc root or a subvol root.
For a subvol root, do the old work, and for a orphan reloc root, clean it
up.

Fixes: d2311e6985 ("btrfs: relocation: Delay reloc tree deletion after merge_reloc_roots")
CC: stable@vger.kernel.org # 5.1
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-05-28 18:54:10 +02:00
Filipe Manana 3c850b4511 Btrfs: incremental send, fix emission of invalid clone operations
When doing an incremental send we can now issue clone operations with a
source range that ends at the source's file eof and with a destination
range that ends at an offset smaller then the destination's file eof.
If the eof of the source file is not aligned to the sector size of the
filesystem, the receiver will get a -EINVAL error when trying to do the
operation or, on older kernels, silently corrupt the destination file.
The corruption happens on kernels without commit ac765f83f1
("Btrfs: fix data corruption due to cloning of eof block"), while the
failure to clone happens on kernels with that commit.

Example reproducer:

  $ mkfs.btrfs -f /dev/sdb
  $ mount /dev/sdb /mnt/sdb

  $ xfs_io -f -c "pwrite -S 0xb1 0 2M" /mnt/sdb/foo
  $ xfs_io -f -c "pwrite -S 0xc7 0 2M" /mnt/sdb/bar
  $ xfs_io -f -c "pwrite -S 0x4d 0 2M" /mnt/sdb/baz
  $ xfs_io -f -c "pwrite -S 0xe2 0 2M" /mnt/sdb/zoo

  $ btrfs subvolume snapshot -r /mnt/sdb /mnt/sdb/base

  $ btrfs send -f /tmp/base.send /mnt/sdb/base

  $ xfs_io -c "reflink /mnt/sdb/bar 1560K 500K 100K" /mnt/sdb/bar
  $ xfs_io -c "reflink /mnt/sdb/bar 1560K 0 100K" /mnt/sdb/zoo
  $ xfs_io -c "truncate 550K" /mnt/sdb/bar

  $ btrfs subvolume snapshot -r /mnt/sdb /mnt/sdb/incr

  $ btrfs send -f /tmp/incr.send -p /mnt/sdb/base /mnt/sdb/incr

  $ mkfs.btrfs -f /dev/sdc
  $ mount /dev/sdc /mnt/sdc

  $ btrfs receive -f /tmp/base.send /mnt/sdc
  $ btrfs receive -vv -f /tmp/incr.send /mnt/sdc
  (...)
  truncate bar size=563200
  utimes bar
  clone zoo - source=bar source offset=512000 offset=0 length=51200
  ERROR: failed to clone extents to zoo
  Invalid argument

The failure happens because the clone source range ends at the eof of file
bar, 563200, which is not aligned to the filesystems sector size (4Kb in
this case), and the destination range ends at offset 0 + 51200, which is
less then the size of the file zoo (2Mb).

So fix this by detecting such case and instead of issuing a clone
operation for the whole range, do a clone operation for smaller range
that is sector size aligned followed by a write operation for the block
containing the eof. Here we will always be pessimistic and assume the
destination filesystem of the send stream has the largest possible sector
size (64Kb), since we have no way of determining it.

This fixes a recent regression introduced in kernel 5.2-rc1.

Fixes: 040ee6120c ("Btrfs: send, improve clone range")
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-05-28 18:54:10 +02:00
Filipe Manana 6b1f72e5b8 Btrfs: incremental send, fix file corruption when no-holes feature is enabled
When using the no-holes feature, if we have a file with prealloc extents
with a start offset beyond the file's eof, doing an incremental send can
cause corruption of the file due to incorrect hole detection. Such case
requires that the prealloc extent(s) exist in both the parent and send
snapshots, and that a hole is punched into the file that covers all its
extents that do not cross the eof boundary.

Example reproducer:

  $ mkfs.btrfs -f -O no-holes /dev/sdb
  $ mount /dev/sdb /mnt/sdb

  $ xfs_io -f -c "pwrite -S 0xab 0 500K" /mnt/sdb/foobar
  $ xfs_io -c "falloc -k 1200K 800K" /mnt/sdb/foobar

  $ btrfs subvolume snapshot -r /mnt/sdb /mnt/sdb/base

  $ btrfs send -f /tmp/base.snap /mnt/sdb/base

  $ xfs_io -c "fpunch 0 500K" /mnt/sdb/foobar

  $ btrfs subvolume snapshot -r /mnt/sdb /mnt/sdb/incr

  $ btrfs send -p /mnt/sdb/base -f /tmp/incr.snap /mnt/sdb/incr

  $ md5sum /mnt/sdb/incr/foobar
  816df6f64deba63b029ca19d880ee10a   /mnt/sdb/incr/foobar

  $ mkfs.btrfs -f /dev/sdc
  $ mount /dev/sdc /mnt/sdc

  $ btrfs receive -f /tmp/base.snap /mnt/sdc
  $ btrfs receive -f /tmp/incr.snap /mnt/sdc

  $ md5sum /mnt/sdc/incr/foobar
  cf2ef71f4a9e90c2f6013ba3b2257ed2   /mnt/sdc/incr/foobar

    --> Different checksum, because the prealloc extent beyond the
        file's eof confused the hole detection code and it assumed
        a hole starting at offset 0 and ending at the offset of the
        prealloc extent (1200Kb) instead of ending at the offset
        500Kb (the file's size).

Fix this by ensuring we never cross the file's size when issuing the
write operations for a hole.

Fixes: 16e7549f04 ("Btrfs: incompatible format change to remove hole extents")
CC: stable@vger.kernel.org # 3.14+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-05-28 18:54:10 +02:00
Dennis Zhou fee13fe965 btrfs: correct zstd workspace manager lock to use spin_lock_bh()
The btrfs zstd workspace manager uses a background timer to reclaim not
recently used workspaces. I used spin_lock() from this context which
should have been caught with lockdep, but was not. This deadlock was
reported in bugzilla. The fix is to switch the zstd wsm lock to use
spin_lock_bh() from the softirq context.

This happened quite relibably on ppc64, unlike on other architectures.

  [  313.402874] ================================
  [  313.402875] WARNING: inconsistent lock state
  [  313.402879] 5.1.0-rc7 #1 Not tainted
  [  313.402880] --------------------------------
  [  313.402882] inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage.
  [  313.402885] swapper/5/0 [HC0[0]:SC1[1]:HE1:SE0] takes:
  [  313.402888] 0000000080d1120c (&(&wsm.lock)->rlock){+.?.}, at: .zstd_reclaim_timer_fn+0x40/0x230
  [  313.402895] {SOFTIRQ-ON-W} state was registered at:
  [  313.402899]   .lock_acquire+0xd0/0x240
  [  313.402903]   ._raw_spin_lock+0x34/0x60
  [  313.402906]   .zstd_get_workspace+0xd0/0x360
  [  313.402908]   .end_compressed_bio_read+0x3b8/0x540
  [  313.402911]   .bio_endio+0x174/0x2c0
  [  313.402914]   .end_workqueue_fn+0x4c/0x70
  [  313.402917]   .normal_work_helper+0x138/0x7e0
  [  313.402920]   .process_one_work+0x324/0x790
  [  313.402922]   .worker_thread+0x68/0x570
  [  313.402925]   .kthread+0x19c/0x1b0
  [  313.402928]   .ret_from_kernel_thread+0x58/0x78
  [  313.402930] irq event stamp: 2629216
  [  313.402933] hardirqs last  enabled at (2629216): [<c0000000009da738>] ._raw_spin_unlock_irq+0x38/0x60
  [  313.402936] hardirqs last disabled at (2629215): [<c0000000009da4c4>] ._raw_spin_lock_irq+0x24/0x70
  [  313.402939] softirqs last  enabled at (2629212): [<c0000000000af9fc>] .irq_enter+0x8c/0xd0
  [  313.402942] softirqs last disabled at (2629213): [<c0000000000afb58>] .irq_exit+0x118/0x170
  [  313.402944]
		 other info that might help us debug this:
  [  313.402945]  Possible unsafe locking scenario:

  [  313.402947]        CPU0
  [  313.402948]        ----
  [  313.402949]   lock(&(&wsm.lock)->rlock);
  [  313.402951]   <Interrupt>
  [  313.402952]     lock(&(&wsm.lock)->rlock);
  [  313.402954]
		  *** DEADLOCK ***

  [  313.402957] 1 lock held by swapper/5/0:
  [  313.402958]  #0: 000000004b612042 ((&wsm.timer)){+.-.}, at: .call_timer_fn+0x0/0x3c0
  [  313.402963]
		 stack backtrace:
  [  313.402967] CPU: 5 PID: 0 Comm: swapper/5 Not tainted 5.1.0-rc7 #1
  [  313.402968] Call Trace:
  [  313.402972] [c0000007fa262e70] [c0000000009b3294] .dump_stack+0xe0/0x15c (unreliable)
  [  313.402975] [c0000007fa262f10] [c000000000125548] .print_usage_bug+0x348/0x390
  [  313.402978] [c0000007fa262fd0] [c000000000125cb4] .mark_lock+0x724/0x930
  [  313.402981] [c0000007fa263080] [c000000000126c20] .__lock_acquire+0xc90/0x16a0
  [  313.402984] [c0000007fa2631b0] [c000000000128040] .lock_acquire+0xd0/0x240
  [  313.402987] [c0000007fa263280] [c0000000009da2b4] ._raw_spin_lock+0x34/0x60
  [  313.402990] [c0000007fa263300] [c00000000054b0b0] .zstd_reclaim_timer_fn+0x40/0x230
  [  313.402993] [c0000007fa2633d0] [c000000000158b38] .call_timer_fn+0xc8/0x3c0
  [  313.402996] [c0000007fa2634a0] [c000000000158f74] .expire_timers+0x144/0x260
  [  313.402999] [c0000007fa263550] [c000000000159178] .run_timer_softirq+0xe8/0x230
  [  313.403002] [c0000007fa263680] [c0000000009db288] .__do_softirq+0x188/0x5d4
  [  313.403004] [c0000007fa263790] [c0000000000afb58] .irq_exit+0x118/0x170
  [  313.403008] [c0000007fa263800] [c000000000028d88] .timer_interrupt+0x158/0x430
  [  313.403012] [c0000007fa2638b0] [c0000000000091d4] decrementer_common+0x134/0x140
  [  313.403017] --- interrupt: 901 at replay_interrupt_return+0x0/0x4
		     LR = .arch_local_irq_restore.part.0+0x68/0x80
  [  313.403020] [c0000007fa263bb0] [c00000000001a3ac] .arch_local_irq_restore.part.0+0x2c/0x80 (unreliable)
  [  313.403024] [c0000007fa263c30] [c0000000007bbbcc] .cpuidle_enter_state+0xec/0x670
  [  313.403027] [c0000007fa263d00] [c0000000000f5130] .call_cpuidle+0x40/0x90
  [  313.403031] [c0000007fa263d70] [c0000000000f554c] .do_idle+0x2dc/0x3a0
  [  313.403034] [c0000007fa263e30] [c0000000000f59ac] .cpu_startup_entry+0x2c/0x30
  [  313.403037] [c0000007fa263ea0] [c000000000045674] .start_secondary+0x644/0x650
  [  313.403041] [c0000007fa263f90] [c00000000000ad5c] start_secondary_prolog+0x10/0x14

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=203517
Fixes: 3f93aef535 ("btrfs: add zstd compression level support")
CC: stable@vger.kernel.org # 5.1+
Signed-off-by: Dennis Zhou <dennis@kernel.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-05-28 18:54:09 +02:00
Nikolay Borisov debd1c065d btrfs: Ensure replaced device doesn't have pending chunk allocation
Recent FITRIM work, namely bbbf7243d6 ("btrfs: combine device update
operations during transaction commit") combined the way certain
operations are recoded in a transaction. As a result an ASSERT was added
in dev_replace_finish to ensure the new code works correctly.
Unfortunately I got reports that it's possible to trigger the assert,
meaning that during a device replace it's possible to have an unfinished
chunk allocation on the source device.

This is supposed to be prevented by the fact that a transaction is
committed before finishing the replace oepration and alter acquiring the
chunk mutex. This is not sufficient since by the time the transaction is
committed and the chunk mutex acquired it's possible to allocate a chunk
depending on the workload being executed on the replaced device. This
bug has been present ever since device replace was introduced but there
was never code which checks for it.

The correct way to fix is to ensure that there is no pending device
modification operation when the chunk mutex is acquire and if there is
repeat transaction commit. Unfortunately it's not possible to just
exclude the source device from btrfs_fs_devices::dev_alloc_list since
this causes ENOSPC to be hit in transaction commit.

Fixing that in another way would need to add special cases to handle the
last writes and forbid new ones. The looped transaction fix is more
obvious, and can be easily backported. The runtime of dev-replace is
long so there's no noticeable delay caused by that.

Reported-by: David Sterba <dsterba@suse.com>
Fixes: 391cd9df81 ("Btrfs: fix unprotected alloc list insertion during the finishing procedure of replace")
CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-05-28 18:54:00 +02:00
Linus Torvalds f49aa1de98 for-5.2-rc1-tag
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Merge tag 'for-5.2-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs fixes from David Sterba:
 "Notable highlights:

   - fixes for some long-standing bugs in fsync that were quite hard to
     catch but now finaly fixed

   - some fixups to error handling paths that did not properly clean up
     (locking, memory)

   - fix to space reservation for inheriting properties"

* tag 'for-5.2-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  Btrfs: tree-checker: detect file extent items with overlapping ranges
  Btrfs: fix race between ranged fsync and writeback of adjacent ranges
  Btrfs: avoid fallback to transaction commit during fsync of files with holes
  btrfs: extent-tree: Fix a bug that btrfs is unable to add pinned bytes
  btrfs: sysfs: don't leak memory when failing add fsid
  btrfs: sysfs: Fix error path kobject memory leak
  Btrfs: do not abort transaction at btrfs_update_root() after failure to COW path
  btrfs: use the existing reserved items for our first prop for inheritance
  btrfs: don't double unlock on error in btrfs_punch_hole
  btrfs: Check the compression level before getting a workspace
2019-05-20 09:52:35 -07:00
Filipe Manana 4e9845eff5 Btrfs: tree-checker: detect file extent items with overlapping ranges
Having file extent items with ranges that overlap each other is a
serious issue that leads to all sorts of corruptions and crashes (like a
BUG_ON() during the course of __btrfs_drop_extents() when it traims file
extent items). Therefore teach the tree checker to detect such cases.
This is motivated by a recently fixed bug (race between ranged full
fsync and writeback or adjacent ranges).

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-05-16 14:33:51 +02:00
Filipe Manana 0c713cbab6 Btrfs: fix race between ranged fsync and writeback of adjacent ranges
When we do a full fsync (the bit BTRFS_INODE_NEEDS_FULL_SYNC is set in the
inode) that happens to be ranged, which happens during a msync() or writes
for files opened with O_SYNC for example, we can end up with a corrupt log,
due to different file extent items representing ranges that overlap with
each other, or hit some assertion failures.

When doing a ranged fsync we only flush delalloc and wait for ordered
exents within that range. If while we are logging items from our inode
ordered extents for adjacent ranges complete, we end up in a race that can
make us insert the file extent items that overlap with others we logged
previously and the assertion failures.

For example, if tree-log.c:copy_items() receives a leaf that has the
following file extents items, all with a length of 4K and therefore there
is an implicit hole in the range 68K to 72K - 1:

  (257 EXTENT_ITEM 64K), (257 EXTENT_ITEM 72K), (257 EXTENT_ITEM 76K), ...

It copies them to the log tree. However due to the need to detect implicit
holes, it may release the path, in order to look at the previous leaf to
detect an implicit hole, and then later it will search again in the tree
for the first file extent item key, with the goal of locking again the
leaf (which might have changed due to concurrent changes to other inodes).

However when it locks again the leaf containing the first key, the key
corresponding to the extent at offset 72K may not be there anymore since
there is an ordered extent for that range that is finishing (that is,
somewhere in the middle of btrfs_finish_ordered_io()), and it just
removed the file extent item but has not yet replaced it with a new file
extent item, so the part of copy_items() that does hole detection will
decide that there is a hole in the range starting from 68K to 76K - 1,
and therefore insert a file extent item to represent that hole, having
a key offset of 68K. After that we now have a log tree with 2 different
extent items that have overlapping ranges:

 1) The file extent item copied before copy_items() released the path,
    which has a key offset of 72K and a length of 4K, representing the
    file range 72K to 76K - 1.

 2) And a file extent item representing a hole that has a key offset of
    68K and a length of 8K, representing the range 68K to 76K - 1. This
    item was inserted after releasing the path, and overlaps with the
    extent item inserted before.

The overlapping extent items can cause all sorts of unpredictable and
incorrect behaviour, either when replayed or if a fast (non full) fsync
happens later, which can trigger a BUG_ON() when calling
btrfs_set_item_key_safe() through __btrfs_drop_extents(), producing a
trace like the following:

  [61666.783269] ------------[ cut here ]------------
  [61666.783943] kernel BUG at fs/btrfs/ctree.c:3182!
  [61666.784644] invalid opcode: 0000 [#1] PREEMPT SMP
  (...)
  [61666.786253] task: ffff880117b88c40 task.stack: ffffc90008168000
  [61666.786253] RIP: 0010:btrfs_set_item_key_safe+0x7c/0xd2 [btrfs]
  [61666.786253] RSP: 0018:ffffc9000816b958 EFLAGS: 00010246
  [61666.786253] RAX: 0000000000000000 RBX: 000000000000000f RCX: 0000000000030000
  [61666.786253] RDX: 0000000000000000 RSI: ffffc9000816ba4f RDI: ffffc9000816b937
  [61666.786253] RBP: ffffc9000816b998 R08: ffff88011dae2428 R09: 0000000000001000
  [61666.786253] R10: 0000160000000000 R11: 6db6db6db6db6db7 R12: ffff88011dae2418
  [61666.786253] R13: ffffc9000816ba4f R14: ffff8801e10c4118 R15: ffff8801e715c000
  [61666.786253] FS:  00007f6060a18700(0000) GS:ffff88023f5c0000(0000) knlGS:0000000000000000
  [61666.786253] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  [61666.786253] CR2: 00007f6060a28000 CR3: 0000000213e69000 CR4: 00000000000006e0
  [61666.786253] Call Trace:
  [61666.786253]  __btrfs_drop_extents+0x5e3/0xaad [btrfs]
  [61666.786253]  ? time_hardirqs_on+0x9/0x14
  [61666.786253]  btrfs_log_changed_extents+0x294/0x4e0 [btrfs]
  [61666.786253]  ? release_extent_buffer+0x38/0xb4 [btrfs]
  [61666.786253]  btrfs_log_inode+0xb6e/0xcdc [btrfs]
  [61666.786253]  ? lock_acquire+0x131/0x1c5
  [61666.786253]  ? btrfs_log_inode_parent+0xee/0x659 [btrfs]
  [61666.786253]  ? arch_local_irq_save+0x9/0xc
  [61666.786253]  ? btrfs_log_inode_parent+0x1f5/0x659 [btrfs]
  [61666.786253]  btrfs_log_inode_parent+0x223/0x659 [btrfs]
  [61666.786253]  ? arch_local_irq_save+0x9/0xc
  [61666.786253]  ? lockref_get_not_zero+0x2c/0x34
  [61666.786253]  ? rcu_read_unlock+0x3e/0x5d
  [61666.786253]  btrfs_log_dentry_safe+0x60/0x7b [btrfs]
  [61666.786253]  btrfs_sync_file+0x317/0x42c [btrfs]
  [61666.786253]  vfs_fsync_range+0x8c/0x9e
  [61666.786253]  SyS_msync+0x13c/0x1c9
  [61666.786253]  entry_SYSCALL_64_fastpath+0x18/0xad

A sample of a corrupt log tree leaf with overlapping extents I got from
running btrfs/072:

      item 14 key (295 108 200704) itemoff 2599 itemsize 53
              extent data disk bytenr 0 nr 0
              extent data offset 0 nr 458752 ram 458752
      item 15 key (295 108 659456) itemoff 2546 itemsize 53
              extent data disk bytenr 4343541760 nr 770048
              extent data offset 606208 nr 163840 ram 770048
      item 16 key (295 108 663552) itemoff 2493 itemsize 53
              extent data disk bytenr 4343541760 nr 770048
              extent data offset 610304 nr 155648 ram 770048
      item 17 key (295 108 819200) itemoff 2440 itemsize 53
              extent data disk bytenr 4334788608 nr 4096
              extent data offset 0 nr 4096 ram 4096

The file extent item at offset 659456 (item 15) ends at offset 823296
(659456 + 163840) while the next file extent item (item 16) starts at
offset 663552.

Another different problem that the race can trigger is a failure in the
assertions at tree-log.c:copy_items(), which expect that the first file
extent item key we found before releasing the path exists after we have
released path and that the last key we found before releasing the path
also exists after releasing the path:

  $ cat -n fs/btrfs/tree-log.c
  4080          if (need_find_last_extent) {
  4081                  /* btrfs_prev_leaf could return 1 without releasing the path */
  4082                  btrfs_release_path(src_path);
  4083                  ret = btrfs_search_slot(NULL, inode->root, &first_key,
  4084                                  src_path, 0, 0);
  4085                  if (ret < 0)
  4086                          return ret;
  4087                  ASSERT(ret == 0);
  (...)
  4103                  if (i >= btrfs_header_nritems(src_path->nodes[0])) {
  4104                          ret = btrfs_next_leaf(inode->root, src_path);
  4105                          if (ret < 0)
  4106                                  return ret;
  4107                          ASSERT(ret == 0);
  4108                          src = src_path->nodes[0];
  4109                          i = 0;
  4110                          need_find_last_extent = true;
  4111                  }
  (...)

The second assertion implicitly expects that the last key before the path
release still exists, because the surrounding while loop only stops after
we have found that key. When this assertion fails it produces a stack like
this:

  [139590.037075] assertion failed: ret == 0, file: fs/btrfs/tree-log.c, line: 4107
  [139590.037406] ------------[ cut here ]------------
  [139590.037707] kernel BUG at fs/btrfs/ctree.h:3546!
  [139590.038034] invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC PTI
  [139590.038340] CPU: 1 PID: 31841 Comm: fsstress Tainted: G        W         5.0.0-btrfs-next-46 #1
  (...)
  [139590.039354] RIP: 0010:assfail.constprop.24+0x18/0x1a [btrfs]
  (...)
  [139590.040397] RSP: 0018:ffffa27f48f2b9b0 EFLAGS: 00010282
  [139590.040730] RAX: 0000000000000041 RBX: ffff897c635d92c8 RCX: 0000000000000000
  [139590.041105] RDX: 0000000000000000 RSI: ffff897d36a96868 RDI: ffff897d36a96868
  [139590.041470] RBP: ffff897d1b9a0708 R08: 0000000000000000 R09: 0000000000000000
  [139590.041815] R10: 0000000000000008 R11: 0000000000000000 R12: 0000000000000013
  [139590.042159] R13: 0000000000000227 R14: ffff897cffcbba88 R15: 0000000000000001
  [139590.042501] FS:  00007f2efc8dee80(0000) GS:ffff897d36a80000(0000) knlGS:0000000000000000
  [139590.042847] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  [139590.043199] CR2: 00007f8c064935e0 CR3: 0000000232252002 CR4: 00000000003606e0
  [139590.043547] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  [139590.043899] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
  [139590.044250] Call Trace:
  [139590.044631]  copy_items+0xa3f/0x1000 [btrfs]
  [139590.045009]  ? generic_bin_search.constprop.32+0x61/0x200 [btrfs]
  [139590.045396]  btrfs_log_inode+0x7b3/0xd70 [btrfs]
  [139590.045773]  btrfs_log_inode_parent+0x2b3/0xce0 [btrfs]
  [139590.046143]  ? do_raw_spin_unlock+0x49/0xc0
  [139590.046510]  btrfs_log_dentry_safe+0x4a/0x70 [btrfs]
  [139590.046872]  btrfs_sync_file+0x3b6/0x440 [btrfs]
  [139590.047243]  btrfs_file_write_iter+0x45b/0x5c0 [btrfs]
  [139590.047592]  __vfs_write+0x129/0x1c0
  [139590.047932]  vfs_write+0xc2/0x1b0
  [139590.048270]  ksys_write+0x55/0xc0
  [139590.048608]  do_syscall_64+0x60/0x1b0
  [139590.048946]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
  [139590.049287] RIP: 0033:0x7f2efc4be190
  (...)
  [139590.050342] RSP: 002b:00007ffe743243a8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
  [139590.050701] RAX: ffffffffffffffda RBX: 0000000000008d58 RCX: 00007f2efc4be190
  [139590.051067] RDX: 0000000000008d58 RSI: 00005567eca0f370 RDI: 0000000000000003
  [139590.051459] RBP: 0000000000000024 R08: 0000000000000003 R09: 0000000000008d60
  [139590.051863] R10: 0000000000000078 R11: 0000000000000246 R12: 0000000000000003
  [139590.052252] R13: 00000000003d3507 R14: 00005567eca0f370 R15: 0000000000000000
  (...)
  [139590.055128] ---[ end trace 193f35d0215cdeeb ]---

So fix this race between a full ranged fsync and writeback of adjacent
ranges by flushing all delalloc and waiting for all ordered extents to
complete before logging the inode. This is the simplest way to solve the
problem because currently the full fsync path does not deal with ranges
at all (it assumes a full range from 0 to LLONG_MAX) and it always needs
to look at adjacent ranges for hole detection. For use cases of ranged
fsyncs this can make a few fsyncs slower but on the other hand it can
make some following fsyncs to other ranges do less work or no need to do
anything at all. A full fsync is rare anyway and happens only once after
loading/creating an inode and once after less common operations such as a
shrinking truncate.

This is an issue that exists for a long time, and was often triggered by
generic/127, because it does mmap'ed writes and msync (which triggers a
ranged fsync). Adding support for the tree checker to detect overlapping
extents (next patch in the series) and trigger a WARN() when such cases
are found, and then calling btrfs_check_leaf_full() at the end of
btrfs_insert_file_extent() made the issue much easier to detect. Running
btrfs/072 with that change to the tree checker and making fsstress open
files always with O_SYNC made it much easier to trigger the issue (as
triggering it with generic/127 is very rare).

CC: stable@vger.kernel.org # 3.16+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-05-16 14:31:13 +02:00
Filipe Manana ebb929060a Btrfs: avoid fallback to transaction commit during fsync of files with holes
When we are doing a full fsync (bit BTRFS_INODE_NEEDS_FULL_SYNC set) of a
file that has holes and has file extent items spanning two or more leafs,
we can end up falling to back to a full transaction commit due to a logic
bug that leads to failure to insert a duplicate file extent item that is
meant to represent a hole between the last file extent item of a leaf and
the first file extent item in the next leaf. The failure (EEXIST error)
leads to a transaction commit (as most errors when logging an inode do).

For example, we have the two following leafs:

Leaf N:

  -----------------------------------------------
  | ..., ..., ..., (257, FILE_EXTENT_ITEM, 64K) |
  -----------------------------------------------
  The file extent item at the end of leaf N has a length of 4Kb,
  representing the file range from 64K to 68K - 1.

Leaf N + 1:

  -----------------------------------------------
  | (257, FILE_EXTENT_ITEM, 72K), ..., ..., ... |
  -----------------------------------------------
  The file extent item at the first slot of leaf N + 1 has a length of
  4Kb too, representing the file range from 72K to 76K - 1.

During the full fsync path, when we are at tree-log.c:copy_items() with
leaf N as a parameter, after processing the last file extent item, that
represents the extent at offset 64K, we take a look at the first file
extent item at the next leaf (leaf N + 1), and notice there's a 4K hole
between the two extents, and therefore we insert a file extent item
representing that hole, starting at file offset 68K and ending at offset
72K - 1. However we don't update the value of *last_extent, which is used
to represent the end offset (plus 1, non-inclusive end) of the last file
extent item inserted in the log, so it stays with a value of 68K and not
with a value of 72K.

Then, when copy_items() is called for leaf N + 1, because the value of
*last_extent is smaller then the offset of the first extent item in the
leaf (68K < 72K), we look at the last file extent item in the previous
leaf (leaf N) and see it there's a 4K gap between it and our first file
extent item (again, 68K < 72K), so we decide to insert a file extent item
representing the hole, starting at file offset 68K and ending at offset
72K - 1, this insertion will fail with -EEXIST being returned from
btrfs_insert_file_extent() because we already inserted a file extent item
representing a hole for this offset (68K) in the previous call to
copy_items(), when processing leaf N.

The -EEXIST error gets propagated to the fsync callback, btrfs_sync_file(),
which falls back to a full transaction commit.

Fix this by adjusting *last_extent after inserting a hole when we had to
look at the next leaf.

Fixes: 4ee3fad34a ("Btrfs: fix fsync after hole punching when using no-holes feature")
Cc: stable@vger.kernel.org # 4.14+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-05-16 14:31:13 +02:00
Qu Wenruo 14ae4ec1ee btrfs: extent-tree: Fix a bug that btrfs is unable to add pinned bytes
Commit ddf30cf03f ("btrfs: extent-tree: Use btrfs_ref to refactor
add_pinned_bytes()") refactored add_pinned_bytes(), but during that
refactor, there are two callers which add the pinned bytes instead
of subtracting.

That refactor misses those two caller, causing incorrect pinned bytes
calculation and resulting unexpected ENOSPC error.

Fix it by adding a new parameter @sign to restore the original behavior.

Reported-by: kernel test robot <rong.a.chen@intel.com>
Fixes: ddf30cf03f ("btrfs: extent-tree: Use btrfs_ref to refactor add_pinned_bytes()")
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-05-16 14:31:13 +02:00
Tobin C. Harding e32773357d btrfs: sysfs: don't leak memory when failing add fsid
A failed call to kobject_init_and_add() must be followed by a call to
kobject_put().  Currently in the error path when adding fs_devices we
are missing this call.  This could be fixed by calling
btrfs_sysfs_remove_fsid() if btrfs_sysfs_add_fsid() returns an error or
by adding a call to kobject_put() directly in btrfs_sysfs_add_fsid().
Here we choose the second option because it prevents the slightly
unusual error path handling requirements of kobject from leaking out
into btrfs functions.

Add a call to kobject_put() in the error path of kobject_add_and_init().
This causes the release method to be called if kobject_init_and_add()
fails.  open_tree() is the function that calls btrfs_sysfs_add_fsid()
and the error code in this function is already written with the
assumption that the release method is called during the error path of
open_tree() (as seen by the call to btrfs_sysfs_remove_fsid() under the
fail_fsdev_sysfs label).

Cc: stable@vger.kernel.org # v4.4+
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Tobin C. Harding <tobin@kernel.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-05-16 14:31:12 +02:00
Tobin C. Harding 450ff83488 btrfs: sysfs: Fix error path kobject memory leak
If a call to kobject_init_and_add() fails we must call kobject_put()
otherwise we leak memory.

Calling kobject_put() when kobject_init_and_add() fails drops the
refcount back to 0 and calls the ktype release method (which in turn
calls the percpu destroy and kfree).

Add call to kobject_put() in the error path of call to
kobject_init_and_add().

Cc: stable@vger.kernel.org # v4.4+
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Tobin C. Harding <tobin@kernel.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-05-16 14:31:01 +02:00
Filipe Manana 72bd2323ec Btrfs: do not abort transaction at btrfs_update_root() after failure to COW path
Currently when we fail to COW a path at btrfs_update_root() we end up
always aborting the transaction. However all the current callers of
btrfs_update_root() are able to deal with errors returned from it, many do
end up aborting the transaction themselves (directly or not, such as the
transaction commit path), other BUG_ON() or just gracefully cancel whatever
they were doing.

When syncing the fsync log, we call btrfs_update_root() through
tree-log.c:update_log_root(), and if it returns an -ENOSPC error, the log
sync code does not abort the transaction, instead it gracefully handles
the error and returns -EAGAIN to the fsync handler, so that it falls back
to a transaction commit. Any other error different from -ENOSPC, makes the
log sync code abort the transaction.

So remove the transaction abort from btrfs_update_log() when we fail to
COW a path to update the root item, so that if an -ENOSPC failure happens
we avoid aborting the current transaction and have a chance of the fsync
succeeding after falling back to a transaction commit.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=203413
Fixes: 79787eaab4 ("btrfs: replace many BUG_ONs with proper error handling")
Cc: stable@vger.kernel.org # 4.4+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-05-09 11:25:27 +02:00
Josef Bacik d7400ee1b4 btrfs: use the existing reserved items for our first prop for inheritance
We're now reserving an extra items worth of space for property
inheritance.  We only have one property at the moment so this covers us,
but if we add more in the future this will allow us to not get bitten by
the extra space reservation.  If we do add more properties in the future
we should re-visit how we calculate the space reservation needs by the
callers.

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
[ refreshed on top of prop/xattr cleanups ]
Signed-off-by: David Sterba <dsterba@suse.com>
2019-05-09 11:18:14 +02:00
Linus Torvalds 67a2422239 for-5.2/block-20190507
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Merge tag 'for-5.2/block-20190507' of git://git.kernel.dk/linux-block

Pull block updates from Jens Axboe:
 "Nothing major in this series, just fixes and improvements all over the
  map. This contains:

   - Series of fixes for sed-opal (David, Jonas)

   - Fixes and performance tweaks for BFQ (via Paolo)

   - Set of fixes for bcache (via Coly)

   - Set of fixes for md (via Song)

   - Enabling multi-page for passthrough requests (Ming)

   - Queue release fix series (Ming)

   - Device notification improvements (Martin)

   - Propagate underlying device rotational status in loop (Holger)

   - Removal of mtip32xx trim support, which has been disabled for years
     (Christoph)

   - Improvement and cleanup of nvme command handling (Christoph)

   - Add block SPDX tags (Christoph)

   - Cleanup/hardening of bio/bvec iteration (Christoph)

   - A few NVMe pull requests (Christoph)

   - Removal of CONFIG_LBDAF (Christoph)

   - Various little fixes here and there"

* tag 'for-5.2/block-20190507' of git://git.kernel.dk/linux-block: (164 commits)
  block: fix mismerge in bvec_advance
  block: don't drain in-progress dispatch in blk_cleanup_queue()
  blk-mq: move cancel of hctx->run_work into blk_mq_hw_sysfs_release
  blk-mq: always free hctx after request queue is freed
  blk-mq: split blk_mq_alloc_and_init_hctx into two parts
  blk-mq: free hw queue's resource in hctx's release handler
  blk-mq: move cancel of requeue_work into blk_mq_release
  blk-mq: grab .q_usage_counter when queuing request from plug code path
  block: fix function name in comment
  nvmet: protect discovery change log event list iteration
  nvme: mark nvme_core_init and nvme_core_exit static
  nvme: move command size checks to the core
  nvme-fabrics: check more command sizes
  nvme-pci: check more command sizes
  nvme-pci: remove an unneeded variable initialization
  nvme-pci: unquiesce admin queue on shutdown
  nvme-pci: shutdown on timeout during deletion
  nvme-pci: fix psdt field for single segment sgls
  nvme-multipath: don't print ANA group state by default
  nvme-multipath: split bios with the ns_head bio_set before submitting
  ...
2019-05-07 18:14:36 -07:00
Linus Torvalds b4b52b881c Wimplicit-fallthrough patches for 5.2-rc1
Hi Linus,
 
 This is my very first pull-request.  I've been working full-time as
 a kernel developer for more than two years now. During this time I've
 been fixing bugs reported by Coverity all over the tree and, as part
 of my work, I'm also contributing to the KSPP. My work in the kernel
 community has been supervised by Greg KH and Kees Cook.
 
 OK. So, after the quick introduction above, please, pull the following
 patches that mark switch cases where we are expecting to fall through.
 These patches are part of the ongoing efforts to enable -Wimplicit-fallthrough.
 They have been ignored for a long time (most of them more than 3 months,
 even after pinging multiple times), which is the reason why I've created
 this tree. Most of them have been baking in linux-next for a whole development
 cycle. And with Stephen Rothwell's help, we've had linux-next nag-emails
 going out for newly introduced code that triggers -Wimplicit-fallthrough
 to avoid gaining more of these cases while we work to remove the ones
 that are already present.
 
 I'm happy to let you know that we are getting close to completing this
 work.  Currently, there are only 32 of 2311 of these cases left to be
 addressed in linux-next.  I'm auditing every case; I take a look into
 the code and analyze it in order to determine if I'm dealing with an
 actual bug or a false positive, as explained here:
 
 https://lore.kernel.org/lkml/c2fad584-1705-a5f2-d63c-824e9b96cf50@embeddedor.com/
 
 While working on this, I've found and fixed the following missing
 break/return bugs, some of them introduced more than 5 years ago:
 
 84242b82d8
 7850b51b6c
 5e420fe635
 09186e5034
 b5be853181
 7264235ee7
 cc5034a5d2
 479826cc86
 5340f23df8
 df997abeeb
 2f10d82373
 307b00c5e6
 5d25ff7a54
 a7ed5b3e7d
 c24bfa8f21
 ad0eaee619
 9ba8376ce1
 dc586a60a1
 a8e9b186f1
 4e57562b48
 60747828ea
 c5b974bee9
 cc44ba9116
 2c930e3d0a
 
 Once this work is finish, we'll be able to universally enable
 "-Wimplicit-fallthrough" to avoid any of these kinds of bugs from
 entering the kernel again.
 
 Thanks
 
 Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
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Merge tag 'Wimplicit-fallthrough-5.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gustavoars/linux

Pull Wimplicit-fallthrough updates from Gustavo A. R. Silva:
 "Mark switch cases where we are expecting to fall through.

  This is part of the ongoing efforts to enable -Wimplicit-fallthrough.

  Most of them have been baking in linux-next for a whole development
  cycle. And with Stephen Rothwell's help, we've had linux-next
  nag-emails going out for newly introduced code that triggers
  -Wimplicit-fallthrough to avoid gaining more of these cases while we
  work to remove the ones that are already present.

  We are getting close to completing this work. Currently, there are
  only 32 of 2311 of these cases left to be addressed in linux-next. I'm
  auditing every case; I take a look into the code and analyze it in
  order to determine if I'm dealing with an actual bug or a false
  positive, as explained here:

      https://lore.kernel.org/lkml/c2fad584-1705-a5f2-d63c-824e9b96cf50@embeddedor.com/

  While working on this, I've found and fixed the several missing
  break/return bugs, some of them introduced more than 5 years ago.

  Once this work is finished, we'll be able to universally enable
  "-Wimplicit-fallthrough" to avoid any of these kinds of bugs from
  entering the kernel again"

* tag 'Wimplicit-fallthrough-5.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gustavoars/linux: (27 commits)
  memstick: mark expected switch fall-throughs
  drm/nouveau/nvkm: mark expected switch fall-throughs
  NFC: st21nfca: Fix fall-through warnings
  NFC: pn533: mark expected switch fall-throughs
  block: Mark expected switch fall-throughs
  ASN.1: mark expected switch fall-through
  lib/cmdline.c: mark expected switch fall-throughs
  lib: zstd: Mark expected switch fall-throughs
  scsi: sym53c8xx_2: sym_nvram: Mark expected switch fall-through
  scsi: sym53c8xx_2: sym_hipd: mark expected switch fall-throughs
  scsi: ppa: mark expected switch fall-through
  scsi: osst: mark expected switch fall-throughs
  scsi: lpfc: lpfc_scsi: Mark expected switch fall-throughs
  scsi: lpfc: lpfc_nvme: Mark expected switch fall-through
  scsi: lpfc: lpfc_nportdisc: Mark expected switch fall-through
  scsi: lpfc: lpfc_hbadisc: Mark expected switch fall-throughs
  scsi: lpfc: lpfc_els: Mark expected switch fall-throughs
  scsi: lpfc: lpfc_ct: Mark expected switch fall-throughs
  scsi: imm: mark expected switch fall-throughs
  scsi: csiostor: csio_wr: mark expected switch fall-through
  ...
2019-05-07 12:48:10 -07:00
Linus Torvalds 9f2e3a53f7 for-5.2-tag
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Merge tag 'for-5.2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs updates from David Sterba:
 "This time the majority of changes are cleanups, though there's still a
  number of changes of user interest.

  User visible changes:

   - better read time and write checks to catch errors early and before
     writing data to disk (to catch potential memory corruption on data
     that get checksummed)

   - qgroups + metadata relocation: last speed up patch int the series
     to address the slowness, there should be no overhead comparing
     balance with and without qgroups

   - FIEMAP ioctl does not start a transaction unnecessarily, this can
     result in a speed up and less blocking due to IO

   - LOGICAL_INO (v1, v2) does not start transaction unnecessarily, this
     can speed up the mentioned ioctl and scrub as well

   - fsync on files with many (but not too many) hardlinks is faster,
     finer decision if the links should be fsynced individually or
     completely

   - send tries harder to find ranges to clone

   - trim/discard will skip unallocated chunks that haven't been touched
     since the last mount

  Fixes:

   - send flushes delayed allocation before start, otherwise it could
     miss some changes in case of a very recent rw->ro switch of a
     subvolume

   - fix fallocate with qgroups that could lead to space accounting
     underflow, reported as a warning

   - trim/discard ioctl honours the requested range

   - starting send and dedupe on a subvolume at the same time will let
     only one of them succeed, this is to prevent changes that send
     could miss due to dedupe; both operations are restartable

  Core changes:

   - more tree-checker validations, errors reported by fuzzing tools:
      - device item
      - inode item
      - block group profiles

   - tracepoints for extent buffer locking

   - async cow preallocates memory to avoid errors happening too deep in
     the call chain

   - metadata reservations for delalloc reworked to better adapt in
     many-writers/low-space scenarios

   - improved space flushing logic for intense DIO vs buffered workloads

   - lots of cleanups
      - removed unused struct members
      - redundant argument removal
      - properties and xattrs
      - extent buffer locking
      - selftests
      - use common file type conversions
      - many-argument functions reduction"

* tag 'for-5.2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: (227 commits)
  btrfs: Use kvmalloc for allocating compressed path context
  btrfs: Factor out common extent locking code in submit_compressed_extents
  btrfs: Set io_tree only once in submit_compressed_extents
  btrfs: Replace clear_extent_bit with unlock_extent
  btrfs: Make compress_file_range take only struct async_chunk
  btrfs: Remove fs_info from struct async_chunk
  btrfs: Rename async_cow to async_chunk
  btrfs: Preallocate chunks in cow_file_range_async
  btrfs: reserve delalloc metadata differently
  btrfs: track DIO bytes in flight
  btrfs: merge calls of btrfs_setxattr and btrfs_setxattr_trans in btrfs_set_prop
  btrfs: delete unused function btrfs_set_prop_trans
  btrfs: start transaction in xattr_handler_set_prop
  btrfs: drop local copy of inode i_mode
  btrfs: drop old_fsflags in btrfs_ioctl_setflags
  btrfs: modify local copy of btrfs_inode flags
  btrfs: drop useless inode i_flags copy and restore
  btrfs: start transaction in btrfs_ioctl_setflags()
  btrfs: export btrfs_set_prop
  btrfs: refactor btrfs_set_props to validate externally
  ...
2019-05-07 11:34:19 -07:00
Linus Torvalds 168e153d5e Merge branch 'work.icache' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs inode freeing updates from Al Viro:
 "Introduction of separate method for RCU-delayed part of
  ->destroy_inode() (if any).

  Pretty much as posted, except that destroy_inode() stashes
  ->free_inode into the victim (anon-unioned with ->i_fops) before
  scheduling i_callback() and the last two patches (sockfs conversion
  and folding struct socket_wq into struct socket) are excluded - that
  pair should go through netdev once davem reopens his tree"

* 'work.icache' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (58 commits)
  orangefs: make use of ->free_inode()
  shmem: make use of ->free_inode()
  hugetlb: make use of ->free_inode()
  overlayfs: make use of ->free_inode()
  jfs: switch to ->free_inode()
  fuse: switch to ->free_inode()
  ext4: make use of ->free_inode()
  ecryptfs: make use of ->free_inode()
  ceph: use ->free_inode()
  btrfs: use ->free_inode()
  afs: switch to use of ->free_inode()
  dax: make use of ->free_inode()
  ntfs: switch to ->free_inode()
  securityfs: switch to ->free_inode()
  apparmor: switch to ->free_inode()
  rpcpipe: switch to ->free_inode()
  bpf: switch to ->free_inode()
  mqueue: switch to ->free_inode()
  ufs: switch to ->free_inode()
  coda: switch to ->free_inode()
  ...
2019-05-07 10:57:05 -07:00
Linus Torvalds 0968621917 Printk changes for 5.2
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Merge tag 'printk-for-5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk

Pull printk updates from Petr Mladek:

 - Allow state reset of printk_once() calls.

 - Prevent crashes when dereferencing invalid pointers in vsprintf().
   Only the first byte is checked for simplicity.

 - Make vsprintf warnings consistent and inlined.

 - Treewide conversion of obsolete %pf, %pF to %ps, %pF printf
   modifiers.

 - Some clean up of vsprintf and test_printf code.

* tag 'printk-for-5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk:
  lib/vsprintf: Make function pointer_string static
  vsprintf: Limit the length of inlined error messages
  vsprintf: Avoid confusion between invalid address and value
  vsprintf: Prevent crash when dereferencing invalid pointers
  vsprintf: Consolidate handling of unknown pointer specifiers
  vsprintf: Factor out %pO handler as kobject_string()
  vsprintf: Factor out %pV handler as va_format()
  vsprintf: Factor out %p[iI] handler as ip_addr_string()
  vsprintf: Do not check address of well-known strings
  vsprintf: Consistent %pK handling for kptr_restrict == 0
  vsprintf: Shuffle restricted_pointer()
  printk: Tie printk_once / printk_deferred_once into .data.once for reset
  treewide: Switch printk users from %pf and %pF to %ps and %pS, respectively
  lib/test_printf: Switch to bitmap_zalloc()
2019-05-07 09:18:12 -07:00
Linus Torvalds 2c6a392cdd Merge branch 'core-stacktrace-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull stack trace updates from Ingo Molnar:
 "So Thomas looked at the stacktrace code recently and noticed a few
  weirdnesses, and we all know how such stories of crummy kernel code
  meeting German engineering perfection end: a 45-patch series to clean
  it all up! :-)

  Here's the changes in Thomas's words:

   'Struct stack_trace is a sinkhole for input and output parameters
    which is largely pointless for most usage sites. In fact if embedded
    into other data structures it creates indirections and extra storage
    overhead for no benefit.

    Looking at all usage sites makes it clear that they just require an
    interface which is based on a storage array. That array is either on
    stack, global or embedded into some other data structure.

    Some of the stack depot usage sites are outright wrong, but
    fortunately the wrongness just causes more stack being used for
    nothing and does not have functional impact.

    Another oddity is the inconsistent termination of the stack trace
    with ULONG_MAX. It's pointless as the number of entries is what
    determines the length of the stored trace. In fact quite some call
    sites remove the ULONG_MAX marker afterwards with or without nasty
    comments about it. Not all architectures do that and those which do,
    do it inconsistenly either conditional on nr_entries == 0 or
    unconditionally.

    The following series cleans that up by:

      1) Removing the ULONG_MAX termination in the architecture code

      2) Removing the ULONG_MAX fixups at the call sites

      3) Providing plain storage array based interfaces for stacktrace
         and stackdepot.

      4) Cleaning up the mess at the callsites including some related
         cleanups.

      5) Removing the struct stack_trace based interfaces

    This is not changing the struct stack_trace interfaces at the
    architecture level, but it removes the exposure to the generic
    code'"

* 'core-stacktrace-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (45 commits)
  x86/stacktrace: Use common infrastructure
  stacktrace: Provide common infrastructure
  lib/stackdepot: Remove obsolete functions
  stacktrace: Remove obsolete functions
  livepatch: Simplify stack trace retrieval
  tracing: Remove the last struct stack_trace usage
  tracing: Simplify stack trace retrieval
  tracing: Make ftrace_trace_userstack() static and conditional
  tracing: Use percpu stack trace buffer more intelligently
  tracing: Simplify stacktrace retrieval in histograms
  lockdep: Simplify stack trace handling
  lockdep: Remove save argument from check_prev_add()
  lockdep: Remove unused trace argument from print_circular_bug()
  drm: Simplify stacktrace handling
  dm persistent data: Simplify stack trace handling
  dm bufio: Simplify stack trace retrieval
  btrfs: ref-verify: Simplify stack trace retrieval
  dma/debug: Simplify stracktrace retrieval
  fault-inject: Simplify stacktrace retrieval
  mm/page_owner: Simplify stack trace handling
  ...
2019-05-06 13:11:48 -07:00
Josef Bacik 8fca955057 btrfs: don't double unlock on error in btrfs_punch_hole
If we have an error writing out a delalloc range in
btrfs_punch_hole_lock_range we'll unlock the inode and then goto
out_only_mutex, where we will again unlock the inode.  This is bad,
don't do this.

Fixes: f27451f229 ("Btrfs: add support for fallocate's zero range operation")
CC: stable@vger.kernel.org # 4.19+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-05-03 18:21:36 +02:00
Johnny Chang 2b90883c56 btrfs: Check the compression level before getting a workspace
When a file's compression property is set as zlib or zstd but leave
the compression mount option not be set, that means btrfs will try
to compress the file with default compression level. But in
btrfs_compress_pages(), it calls get_workspace() with level = 0.
This will return a workspace with a wrong compression level.
For zlib, the compression level in the workspace will be 0
(that means "store only"). And for zstd, the compression in the
workspace will be 1, not the default level 3.

How to reproduce:
  mkfs -t btrfs /dev/sdb
  mount /dev/sdb /mnt/
  mkdir /mnt/zlib
  btrfs property set /mnt/zlib/ compression zlib
  dd if=/dev/zero of=/mnt/zlib/compression-friendly-file-10M bs=1M count=10
  sync
  btrfs-debugfs -f /mnt/zlib/compression-friendly-file-10M

btrfs-debugfs output:
* before:
  ...
  (258 9961472): ram 524288 disk 1106247680 disk_size 524288
  file: ... extents 20 disk size 10485760 logical size 10485760 ratio 1.00

* after:
 ...
 (258 10354688): ram 131072 disk 14217216 disk_size 4096
 file: ... extents 80 disk size 327680 logical size 10485760 ratio 32.00

The steps for zstd are similar, but need to put a debugging message to
show the level of the return workspace in zstd_get_workspace().

This commit adds a check of the compression level before getting a
workspace by set_level().

CC: stable@vger.kernel.org # 5.1+
Signed-off-by: Johnny Chang <johnnyc@synology.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-05-03 18:21:25 +02:00
Nikolay Borisov b1c16ac978 btrfs: Use kvmalloc for allocating compressed path context
Recent refactoring of cow_file_range_async means it's now possible to
request a rather large physically contiguous memory via kmalloc. The
size is dependent on the number of 512k chunks that the compressed range
consists of. David reported multiple OOM messages on such large
allocations. Fix it by switching to using kvmalloc.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-05-02 13:48:19 +02:00
Nikolay Borisov 7447555fe7 btrfs: Factor out common extent locking code in submit_compressed_extents
Irrespective of whether the compress code fell back to uncompressed or
a compressed extent has to be submitted, the extent range is always
locked. So factor out the common lock_extent call at the beginning of
the loop. No functional changes just removes one duplicate lock_extent
call.

Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-05-02 13:48:19 +02:00
Nikolay Borisov 4336650aff btrfs: Set io_tree only once in submit_compressed_extents
The inode never changes so it's sufficient to dereference it and get
the iotree only once, before the execution of the main loop. No
functional changes, only the size of the function is decreased:

add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-44 (-44)
Function                                     old     new   delta
submit_compressed_extents                   1240    1196     -44
Total: Before=88476, After=88432, chg -0.05%

Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-05-02 13:48:19 +02:00
Nikolay Borisov 69684c5a88 btrfs: Replace clear_extent_bit with unlock_extent
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-05-02 13:48:19 +02:00
Nikolay Borisov 1368c6dac7 btrfs: Make compress_file_range take only struct async_chunk
All context this function needs is held within struct async_chunk.
Currently we not only pass the struct but also every individual member.
This is redundant, simplify it by only passing struct async_chunk and
leaving it to compress_file_range to extract the values it requires.
No functional changes.

Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-05-02 13:48:19 +02:00
Nikolay Borisov c5a68aec4e btrfs: Remove fs_info from struct async_chunk
The associated btrfs_work already contains a reference to the fs_info so
use that instead of passing it via async_chunk. No functional changes.

Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-05-02 13:48:19 +02:00
Nikolay Borisov b5326271e7 btrfs: Rename async_cow to async_chunk
Now that we have an explicit async_chunk struct rename references to
variables of this type to async_chunk. No functional changes.

Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-05-02 13:48:18 +02:00
Nikolay Borisov 97db120451 btrfs: Preallocate chunks in cow_file_range_async
This commit changes the implementation of cow_file_range_async in order
to get rid of the BUG_ON in the middle of the loop. Additionally it
reworks the inner loop in the hopes of making it more understandable.

The idea is to make async_cow be a top-level structured, shared amongst
all chunks being sent for compression. This allows to perform one memory
allocation at the beginning and gracefully fail the IO if there isn't
enough memory. Now, each chunk is going to be described by an
async_chunk struct. It's the responsibility of the final chunk
to actually free the memory.

Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-05-02 13:48:18 +02:00
Josef Bacik c8eaeac7b7 btrfs: reserve delalloc metadata differently
With the per-inode block reserves we started refilling the reserve based
on the calculated size of the outstanding csum bytes and extents for the
inode, including the amount we were adding with the new operation.

However, generic/224 exposed a problem with this approach.  With 1000
files all writing at the same time we ended up with a bunch of bytes
being reserved but unusable.

When you write to a file we reserve space for the csum leaves for those
bytes, the number of extent items required to cover those bytes, and a
single transaction item for updating the inode at ordered extent finish
for that range of bytes.  This is held until the ordered extent finishes
and we release all of the reserved space.

If a second write comes in at this point we would add a single
reservation for the new outstanding extent and however many reservations
for the csum leaves.  At this point we find the delta of how much we
have reserved and how much outstanding size this is and attempt to
reserve this delta.  If the first write finishes it will not release any
space, because the space it had reserved for the initial write is still
needed for the second write.  However some space would have been used,
as we have added csums, extent items, and dirtied the inode.  Our
reserved space would be > 0 but less than the total needed reserved
space.

This is just for a single inode, now consider generic/224.  This has
1000 inodes writing in parallel to a very small file system, 1GiB.  In
my testing this usually means we get about a 120MiB metadata area to
work with, more than enough to allow the writes to continue, but not
enough if all of the inodes are stuck trying to reserve the slack space
while continuing to hold their leftovers from their initial writes.

Fix this by pre-reserved _only_ for the space we are currently trying to
add.  Then once that is successful modify our inodes csum count and
outstanding extents, and then add the newly reserved space to the inodes
block_rsv.  This allows us to actually pass generic/224 without running
out of metadata space.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-05-02 13:47:12 +02:00
Al Viro 26602cab41 btrfs: use ->free_inode()
a lot of stuff remains in ->destroy_inode()

Acked-by: David Sterba <dsterba@suse.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-05-01 22:43:26 -04:00
Linus Torvalds 7e74e235bb gcc-9: don't warn about uninitialized btrfs extent_type variable
The 'extent_type' variable does seem to be reliably initialized, but
it's _very_ non-obvious, since there's a "goto next" case that jumps
over the normal initialization.  That will then always trigger the
"start >= extent_end" test, which will end up never falling through to
the use of that variable.

But the code is certainly not obvious, and the compiler warning looks
reasonable.  Make 'extent_type' an int, and initialize it to an invalid
negative value, which seems to be the common pattern in other places.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-05-01 12:19:20 -07:00
Christoph Hellwig 2b070cfe58 block: remove the i argument to bio_for_each_segment_all
We only have two callers that need the integer loop iterator, and they
can easily maintain it themselves.

Suggested-by: Matthew Wilcox <willy@infradead.org>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Acked-by: David Sterba <dsterba@suse.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Acked-by: Coly Li <colyli@suse.de>
Reviewed-by: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-30 09:26:13 -06:00
Josef Bacik 4297ff84dc btrfs: track DIO bytes in flight
When diagnosing a slowdown of generic/224 I noticed we were not doing
anything when calling into shrink_delalloc().  This is because all
writes in 224 are O_DIRECT, not delalloc, and thus our delalloc_bytes
counter is 0, which short circuits most of the work inside of
shrink_delalloc().  However O_DIRECT writes still consume metadata
resources and generate ordered extents, which we can still wait on.

Fix this by tracking outstanding DIO write bytes, and use this as well
as the delalloc bytes counter to decide if we need to lookup and wait on
any ordered extents.  If we have more DIO writes than delalloc bytes
we'll go ahead and wait on any ordered extents regardless of our flush
state as flushing delalloc is likely to not gain us anything.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
[ use dio instead of odirect in identifiers ]
Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:25:37 +02:00
Anand Jain da9b6ec829 btrfs: merge calls of btrfs_setxattr and btrfs_setxattr_trans in btrfs_set_prop
Since now the trans argument is never NULL in btrfs_set_prop we don't
have to check. So delete it and use btrfs_setxattr that makes use of
that.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:54 +02:00
Anand Jain 717ebdc320 btrfs: delete unused function btrfs_set_prop_trans
The last consumer of btrfs_set_prop_trans() was taken away by the patch
("btrfs: start transaction in xattr_handler_set_prop") so now this
function can be deleted.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:54 +02:00
Anand Jain b3f6a4be13 btrfs: start transaction in xattr_handler_set_prop
btrfs specific extended attributes on the inode are set using
btrfs_xattr_handler_set_prop(), and the required transaction for this
update is started by btrfs_setxattr(). For better visibility of the
transaction start and end, do this in btrfs_xattr_handler_set_prop().
For which this patch copied code of btrfs_setxattr() as it is in the
original, which needs proper error handling.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:54 +02:00
Anand Jain 44e5194b5e btrfs: drop local copy of inode i_mode
There isn't real use of making struct inode::i_mode a local copy, it
saves a dereference one time, not much. Just use it directly.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:53 +02:00
Anand Jain 3c8d8b6357 btrfs: drop old_fsflags in btrfs_ioctl_setflags
btrfs_inode_flags_to_fsflags() is copied into @old_fsflags and used only
once. Instead used it directly.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:53 +02:00
Anand Jain d2b8fcfe43 btrfs: modify local copy of btrfs_inode flags
Instead of updating the binode::flags directly, update a local copy, and
then at the point of no error, store copy it to the binode::flags.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:53 +02:00
Anand Jain 11d3cd5c62 btrfs: drop useless inode i_flags copy and restore
The patch ("btrfs: start transaction in btrfs_ioctl_setflags()") used
btrfs_set_prop() instead of btrfs_set_prop_trans() by which now the
inode::i_flags update functions such as
btrfs_sync_inode_flags_to_i_flags() and btrfs_update_inode() is called
in btrfs_ioctl_setflags() instead of
btrfs_set_prop_trans()->btrfs_setxattr() as earlier. So the
inode::i_flags remains unmodified until the thread has checked all the
conditions. So drop the saved inode::i_flags in out_i_flags.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:53 +02:00
Anand Jain ff9fef559b btrfs: start transaction in btrfs_ioctl_setflags()
Inode attribute can be set through the FS_IOC_SETFLAGS ioctl.  This
flags also includes compression attribute for which we would set/reset
the compression extended attribute. While doing this there is a bit of
duplicate code, the following things happens twice:

- start/end_transaction
- inode_inc_iversion()
- current_time update to inode->i_ctime
- and btrfs_update_inode()

These are updated both at btrfs_ioctl_setflags() and btrfs_set_props()
as well.  This patch merges these two duplicate codes at
btrfs_ioctl_setflags().

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:53 +02:00
Anand Jain cd31af158b btrfs: export btrfs_set_prop
Make btrfs_set_prop() a non-static function, so that it can be called
from btrfs_ioctl_setflags(). We need btrfs_set_prop() instead of
btrfs_set_prop_trans() so that we can use the transaction which is
already started in the current thread.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:53 +02:00
Anand Jain f22125e5d8 btrfs: refactor btrfs_set_props to validate externally
In preparation to merge multiple transactions when setting the
compression flags, split btrfs_set_props() validation part outside of
it.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:52 +02:00
Qu Wenruo 7c15d41016 btrfs: ctree: Dump the leaf before BUG_ON in btrfs_set_item_key_safe
We have a long standing problem with reversed keys that's detected by
btrfs_set_item_key_safe. This is hard to reproduce so we'd like to
capture more information for later analysis.

Let's dump the leaf content before triggering BUG_ON() so that we can
have some clue on what's going wrong.  The output of tree locks should
help us to debug such problem.

Sample stacktrace:

 generic/522             [00:07:05]
 [26946.113381] run fstests generic/522 at 2019-04-16 00:07:05
 [27161.474720] kernel BUG at fs/btrfs/ctree.c:3192!
 [27161.475923] invalid opcode: 0000 [#1] PREEMPT SMP
 [27161.477167] CPU: 0 PID: 15676 Comm: fsx Tainted: G        W         5.1.0-rc5-default+ #562
 [27161.478932] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-0-ga698c89-prebuilt.qemu.org 04/01/2014
 [27161.481099] RIP: 0010:btrfs_set_item_key_safe+0x146/0x1c0 [btrfs]
 [27161.485369] RSP: 0018:ffffb087499e39b0 EFLAGS: 00010286
 [27161.486464] RAX: 00000000ffffffff RBX: ffff941534d80e70 RCX: 0000000000024000
 [27161.487929] RDX: 0000000000013039 RSI: ffffb087499e3aa5 RDI: ffffb087499e39c7
 [27161.489289] RBP: 000000000000000e R08: ffff9414e0f49008 R09: 0000000000001000
 [27161.490807] R10: 0000000000000000 R11: 0000000000000003 R12: ffff9414e0f48e70
 [27161.492305] R13: ffffb087499e3aa5 R14: 0000000000000000 R15: 0000000000071000
 [27161.493845] FS:  00007f8ea58d0b80(0000) GS:ffff94153d400000(0000) knlGS:0000000000000000
 [27161.495608] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 [27161.496717] CR2: 00007f8ea57a9000 CR3: 0000000016a33000 CR4: 00000000000006f0
 [27161.498100] Call Trace:
 [27161.498771]  __btrfs_drop_extents+0x6ec/0xdf0 [btrfs]
 [27161.499872]  btrfs_log_changed_extents.isra.26+0x3a2/0x9e0 [btrfs]
 [27161.501114]  btrfs_log_inode+0x7ff/0xdc0 [btrfs]
 [27161.502114]  ? __mutex_unlock_slowpath+0x4b/0x2b0
 [27161.503172]  btrfs_log_inode_parent+0x237/0x9c0 [btrfs]
 [27161.504348]  btrfs_log_dentry_safe+0x4a/0x70 [btrfs]
 [27161.505374]  btrfs_sync_file+0x1b7/0x480 [btrfs]
 [27161.506371]  __x64_sys_msync+0x180/0x210
 [27161.507208]  do_syscall_64+0x54/0x180
 [27161.507932]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
 [27161.508839] RIP: 0033:0x7f8ea5aa9c61
 [27161.512616] RSP: 002b:00007ffea2a06498 EFLAGS: 00000246 ORIG_RAX: 000000000000001a
 [27161.514161] RAX: ffffffffffffffda RBX: 000000000002a938 RCX: 00007f8ea5aa9c61
 [27161.515376] RDX: 0000000000000004 RSI: 000000000001c9b2 RDI: 00007f8ea578d000
 [27161.516572] RBP: 000000000001c07a R08: fffffffffffffff8 R09: 000000000002a000
 [27161.517883] R10: 00007f8ea57a99b2 R11: 0000000000000246 R12: 0000000000000938
 [27161.519080] R13: 00007f8ea578d000 R14: 000000000001c9b2 R15: 0000000000000000
 [27161.520281] Modules linked in: btrfs libcrc32c xor zstd_decompress zstd_compress xxhash raid6_pq loop [last unloaded: scsi_debug]
 [27161.522272] ---[ end trace d5afec7ccac6a252 ]---
 [27161.523111] RIP: 0010:btrfs_set_item_key_safe+0x146/0x1c0 [btrfs]
 [27161.527253] RSP: 0018:ffffb087499e39b0 EFLAGS: 00010286
 [27161.528192] RAX: 00000000ffffffff RBX: ffff941534d80e70 RCX: 0000000000024000
 [27161.529392] RDX: 0000000000013039 RSI: ffffb087499e3aa5 RDI: ffffb087499e39c7
 [27161.530607] RBP: 000000000000000e R08: ffff9414e0f49008 R09: 0000000000001000
 [27161.531802] R10: 0000000000000000 R11: 0000000000000003 R12: ffff9414e0f48e70
 [27161.533018] R13: ffffb087499e3aa5 R14: 0000000000000000 R15: 0000000000071000
 [27161.534405] FS:  00007f8ea58d0b80(0000) GS:ffff94153d400000(0000) knlGS:0000000000000000
 [27161.536048] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 [27161.537210] CR2: 00007f8ea57a9000 CR3: 0000000016a33000 CR4: 00000000000006f0

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:52 +02:00
Qu Wenruo 02529d7a10 btrfs: tree-checker: Allow error injection for tree-checker
Allowing error injection for btrfs_check_leaf_full() and
btrfs_check_node() is useful to test the failure path of btrfs write
time tree check.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:52 +02:00
Nikolay Borisov 51d470aeaa btrfs: Document btrfs_csum_one_bio
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:52 +02:00
Filipe Manana b8aa330d2a Btrfs: improve performance on fsync of files with multiple hardlinks
Commit 41bd606769 ("Btrfs: fix fsync of files with multiple hard links
in new directories") introduced a path that makes fsync fallback to a full
transaction commit in order to avoid losing hard links and new ancestors
of the fsynced inode. That path is triggered only when the inode has more
than one hard link and either has a new hard link created in the current
transaction or the inode was evicted and reloaded in the current
transaction.

That path ends up getting triggered very often (hundreds of times) during
the course of pgbench benchmarks, resulting in performance drops of about
20%.

This change restores the performance by not triggering the full transaction
commit in those cases, and instead iterate the fs/subvolume tree in search
of all possible new ancestors, for all hard links, to log them.

Reported-by: Zhao Yuhu <zyuhu@suse.com>
Tested-by: James Wang <jnwang@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:52 +02:00
Filipe Manana 62d54f3a7f Btrfs: fix race between send and deduplication that lead to failures and crashes
Send operates on read only trees and expects them to never change while it
is using them. This is part of its initial design, and this expection is
due to two different reasons:

1) When it was introduced, no operations were allowed to modifiy read-only
   subvolumes/snapshots (including defrag for example).

2) It keeps send from having an impact on other filesystem operations.
   Namely send does not need to keep locks on the trees nor needs to hold on
   to transaction handles and delay transaction commits. This ends up being
   a consequence of the former reason.

However the deduplication feature was introduced later (on September 2013,
while send was introduced in July 2012) and it allowed for deduplication
with destination files that belong to read-only trees (subvolumes and
snapshots).

That means that having a send operation (either full or incremental) running
in parallel with a deduplication that has the destination inode in one of
the trees used by the send operation, can result in tree nodes and leaves
getting freed and reused while send is using them. This problem is similar
to the problem solved for the root nodes getting freed and reused when a
snapshot is made against one tree that is currenly being used by a send
operation, fixed in commits [1] and [2]. These commits explain in detail
how the problem happens and the explanation is valid for any node or leaf
that is not the root of a tree as well. This problem was also discussed
and explained recently in a thread [3].

The problem is very easy to reproduce when using send with large trees
(snapshots) and just a few concurrent deduplication operations that target
files in the trees used by send. A stress test case is being sent for
fstests that triggers the issue easily. The most common error to hit is
the send ioctl return -EIO with the following messages in dmesg/syslog:

 [1631617.204075] BTRFS error (device sdc): did not find backref in send_root. inode=63292, offset=0, disk_byte=5228134400 found extent=5228134400
 [1631633.251754] BTRFS error (device sdc): parent transid verify failed on 32243712 wanted 24 found 27

The first one is very easy to hit while the second one happens much less
frequently, except for very large trees (in that test case, snapshots
with 100000 files having large xattrs to get deep and wide trees).
Less frequently, at least one BUG_ON can be hit:

 [1631742.130080] ------------[ cut here ]------------
 [1631742.130625] kernel BUG at fs/btrfs/ctree.c:1806!
 [1631742.131188] invalid opcode: 0000 [#6] SMP DEBUG_PAGEALLOC PTI
 [1631742.131726] CPU: 1 PID: 13394 Comm: btrfs Tainted: G    B D W         5.0.0-rc8-btrfs-next-45 #1
 [1631742.132265] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.11.2-0-gf9626ccb91-prebuilt.qemu-project.org 04/01/2014
 [1631742.133399] RIP: 0010:read_node_slot+0x122/0x130 [btrfs]
 (...)
 [1631742.135061] RSP: 0018:ffffb530021ebaa0 EFLAGS: 00010246
 [1631742.135615] RAX: ffff93ac8912e000 RBX: 000000000000009d RCX: 0000000000000002
 [1631742.136173] RDX: 000000000000009d RSI: ffff93ac564b0d08 RDI: ffff93ad5b48c000
 [1631742.136759] RBP: ffffb530021ebb7d R08: 0000000000000001 R09: ffffb530021ebb7d
 [1631742.137324] R10: ffffb530021eba70 R11: 0000000000000000 R12: ffff93ac87d0a708
 [1631742.137900] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000001
 [1631742.138455] FS:  00007f4cdb1528c0(0000) GS:ffff93ad76a80000(0000) knlGS:0000000000000000
 [1631742.139010] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 [1631742.139568] CR2: 00007f5acb3d0420 CR3: 000000012be3e006 CR4: 00000000003606e0
 [1631742.140131] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
 [1631742.140719] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
 [1631742.141272] Call Trace:
 [1631742.141826]  ? do_raw_spin_unlock+0x49/0xc0
 [1631742.142390]  tree_advance+0x173/0x1d0 [btrfs]
 [1631742.142948]  btrfs_compare_trees+0x268/0x690 [btrfs]
 [1631742.143533]  ? process_extent+0x1070/0x1070 [btrfs]
 [1631742.144088]  btrfs_ioctl_send+0x1037/0x1270 [btrfs]
 [1631742.144645]  _btrfs_ioctl_send+0x80/0x110 [btrfs]
 [1631742.145161]  ? trace_sched_stick_numa+0xe0/0xe0
 [1631742.145685]  btrfs_ioctl+0x13fe/0x3120 [btrfs]
 [1631742.146179]  ? account_entity_enqueue+0xd3/0x100
 [1631742.146662]  ? reweight_entity+0x154/0x1a0
 [1631742.147135]  ? update_curr+0x20/0x2a0
 [1631742.147593]  ? check_preempt_wakeup+0x103/0x250
 [1631742.148053]  ? do_vfs_ioctl+0xa2/0x6f0
 [1631742.148510]  ? btrfs_ioctl_get_supported_features+0x30/0x30 [btrfs]
 [1631742.148942]  do_vfs_ioctl+0xa2/0x6f0
 [1631742.149361]  ? __fget+0x113/0x200
 [1631742.149767]  ksys_ioctl+0x70/0x80
 [1631742.150159]  __x64_sys_ioctl+0x16/0x20
 [1631742.150543]  do_syscall_64+0x60/0x1b0
 [1631742.150931]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
 [1631742.151326] RIP: 0033:0x7f4cd9f5add7
 (...)
 [1631742.152509] RSP: 002b:00007ffe91017708 EFLAGS: 00000202 ORIG_RAX: 0000000000000010
 [1631742.152892] RAX: ffffffffffffffda RBX: 0000000000000105 RCX: 00007f4cd9f5add7
 [1631742.153268] RDX: 00007ffe91017790 RSI: 0000000040489426 RDI: 0000000000000007
 [1631742.153633] RBP: 0000000000000007 R08: 00007f4cd9e79700 R09: 00007f4cd9e79700
 [1631742.153999] R10: 00007f4cd9e799d0 R11: 0000000000000202 R12: 0000000000000003
 [1631742.154365] R13: 0000555dfae53020 R14: 0000000000000000 R15: 0000000000000001
 (...)
 [1631742.156696] ---[ end trace 5dac9f96dcc3fd6b ]---

That BUG_ON happens because while send is using a node, that node is COWed
by a concurrent deduplication, gets freed and gets reused as a leaf (because
a transaction commit happened in between), so when it attempts to read a
slot from the extent buffer, at ctree.c:read_node_slot(), the extent buffer
contents were wiped out and it now matches a leaf (which can even belong to
some other tree now), hitting the BUG_ON(level == 0).

Fix this concurrency issue by not allowing send and deduplication to run
in parallel if both operate on the same readonly trees, returning EAGAIN
to user space and logging an exlicit warning in dmesg/syslog.

[1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=be6821f82c3cc36e026f5afd10249988852b35ea
[2] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=6f2f0b394b54e2b159ef969a0b5274e9bbf82ff2
[3] https://lore.kernel.org/linux-btrfs/CAL3q7H7iqSEEyFaEtpRZw3cp613y+4k2Q8b4W7mweR3tZA05bQ@mail.gmail.com/

CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:52 +02:00