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  1. 17 12月, 2018 2 次提交
    • D
      btrfs: dev-replace: open code trivial locking helpers · cb5583dd
      由 David Sterba 提交于 
      The dev-replace locking functions are now trivial wrappers around rw
semaphore that can be used directly everywhere. No functional change.
Signed-off-by: NDavid Sterba <dsterba@suse.com>
      cb5583dd
    • F
      Btrfs: fix deadlock with memory reclaim during scrub · a5fb1142
      由 Filipe Manana 提交于 
      When a transaction commit starts, it attempts to pause scrub and it blocks
until the scrub is paused. So while the transaction is blocked waiting for
scrub to pause, we can not do memory allocation with GFP_KERNEL from scrub,
otherwise we risk getting into a deadlock with reclaim.

Checking for scrub pause requests is done early at the beginning of the
while loop of scrub_stripe() and later in the loop, scrub_extent() and
scrub_raid56_parity() are called, which in turn call scrub_pages() and
scrub_pages_for_parity() respectively. These last two functions do memory
allocations using GFP_KERNEL. Same problem could happen while scrubbing
the super blocks, since it calls scrub_pages().

We also can not have any of the worker tasks, created by the scrub task,
doing GFP_KERNEL allocations, because before pausing, the scrub task waits
for all the worker tasks to complete (also done at scrub_stripe()).

So make sure GFP_NOFS is used for the memory allocations because at any
time a scrub pause request can happen from another task that started to
commit a transaction.

Fixes: 58c4e173 ("btrfs: scrub: use GFP_KERNEL on the submission path")
CC: stable@vger.kernel.org # 4.6+
Reviewed-by: NNikolay Borisov <nborisov@suse.com>
Signed-off-by: NFilipe Manana <fdmanana@suse.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>
      a5fb1142
  3. 15 10月, 2018 2 次提交
  5. 06 8月, 2018 6 次提交
  7. 17 7月, 2018 1 次提交
    • Q
      btrfs: scrub: Don't use inode page cache in scrub_handle_errored_block() · 665d4953
      由 Qu Wenruo 提交于 
      In commit ac0b4145 ("btrfs: scrub: Don't use inode pages for device
replace") we removed the branch of copy_nocow_pages() to avoid
corruption for compressed nodatasum extents.

However above commit only solves the problem in scrub_extent(), if
during scrub_pages() we failed to read some pages,
sctx->no_io_error_seen will be non-zero and we go to fixup function
scrub_handle_errored_block().

In scrub_handle_errored_block(), for sctx without csum (no matter if
we're doing replace or scrub) we go to scrub_fixup_nodatasum() routine,
which does the similar thing with copy_nocow_pages(), but does it
without the extra check in copy_nocow_pages() routine.

So for test cases like btrfs/100, where we emulate read errors during
replace/scrub, we could corrupt compressed extent data again.

This patch will fix it just by avoiding any "optimization" for
nodatasum, just falls back to the normal fixup routine by try read from
any good copy.

This also solves WARN_ON() or dead lock caused by lame backref iteration
in scrub_fixup_nodatasum() routine.

The deadlock or WARN_ON() won't be triggered before commit ac0b4145
("btrfs: scrub: Don't use inode pages for device replace") since
copy_nocow_pages() have better locking and extra check for data extent,
and it's already doing the fixup work by try to read data from any good
copy, so it won't go scrub_fixup_nodatasum() anyway.

This patch disables the faulty code and will be removed completely in a
followup patch.

Fixes: ac0b4145 ("btrfs: scrub: Don't use inode pages for device replace")
Signed-off-by: NQu Wenruo <wqu@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>
      665d4953
  9. 11 6月, 2018 1 次提交
    • Q
      btrfs: scrub: Don't use inode pages for device replace · ac0b4145
      由 Qu Wenruo 提交于 
      [BUG]
Btrfs can create compressed extent without checksum (even though it
shouldn't), and if we then try to replace device containing such extent,
the result device will contain all the uncompressed data instead of the
compressed one.

Test case already submitted to fstests:
https://patchwork.kernel.org/patch/10442353/

[CAUSE]
When handling compressed extent without checksum, device replace will
goe into copy_nocow_pages() function.

In that function, btrfs will get all inodes referring to this data
extents and then use find_or_create_page() to get pages direct from that
inode.

The problem here is, pages directly from inode are always uncompressed.
And for compressed data extent, they mismatch with on-disk data.
Thus this leads to corrupted compressed data extent written to replace
device.

[FIX]
In this attempt, we could just remove the "optimization" branch, and let
unified scrub_pages() to handle it.

Although scrub_pages() won't bother reusing page cache, it will be a
little slower, but it does the correct csum checking and won't cause
such data corruption caused by "optimization".

Note about the fix: this is the minimal fix that can be backported to
older stable trees without conflicts. The whole callchain from
copy_nocow_pages() can be deleted, and will be in followup patches.

Fixes: ff023aac ("Btrfs: add code to scrub to copy read data to another disk")
CC: stable@vger.kernel.org # 4.4+
Reported-by: NJames Harvey <jamespharvey20@gmail.com>
Reviewed-by: NJames Harvey <jamespharvey20@gmail.com>
Signed-off-by: NQu Wenruo <wqu@suse.com>
[ remove code removal, add note why ]
Signed-off-by: NDavid Sterba <dsterba@suse.com>
      ac0b4145
  11. 29 5月, 2018 1 次提交
  13. 12 4月, 2018 1 次提交
  15. 31 3月, 2018 4 次提交
  17. 26 3月, 2018 3 次提交
  19. 22 1月, 2018 8 次提交
  21. 02 11月, 2017 1 次提交
    • Z
      btrfs: add a flag to iterate_inodes_from_logical to find all extent refs for uncompressed extents · c995ab3c
      由 Zygo Blaxell 提交于 
      The LOGICAL_INO ioctl provides a backward mapping from extent bytenr and
offset (encoded as a single logical address) to a list of extent refs.
LOGICAL_INO complements TREE_SEARCH, which provides the forward mapping
(extent ref -> extent bytenr and offset, or logical address).  These are
useful capabilities for programs that manipulate extents and extent
references from userspace (e.g. dedup and defrag utilities).

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

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

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

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

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

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

There is no functional change in this patch.  The new flag is always
false.
Signed-off-by: NZygo Blaxell <ce3g8jdj@umail.furryterror.org>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
[ minor coding style fixes ]
Signed-off-by: NDavid Sterba <dsterba@suse.com>
      c995ab3c
  23. 30 10月, 2017 1 次提交
  25. 24 8月, 2017 1 次提交
    • C
      block: replace bi_bdev with a gendisk pointer and partitions index · 74d46992
      由 Christoph Hellwig 提交于 
      This way we don't need a block_device structure to submit I/O.  The
block_device has different life time rules from the gendisk and
request_queue and is usually only available when the block device node
is open.  Other callers need to explicitly create one (e.g. the lightnvm
passthrough code, or the new nvme multipathing code).

For the actual I/O path all that we need is the gendisk, which exists
once per block device.  But given that the block layer also does
partition remapping we additionally need a partition index, which is
used for said remapping in generic_make_request.

Note that all the block drivers generally want request_queue or
sometimes the gendisk, so this removes a layer of indirection all
over the stack.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>
      74d46992
  27. 21 8月, 2017 4 次提交
  29. 18 8月, 2017 1 次提交
  31. 16 8月, 2017 2 次提交
  33. 30 6月, 2017 1 次提交