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  1. 18 12月, 2020 1 次提交
    • E
      btrfs: correctly calculate item size used when item key collision happens · 9a664971
      由 ethanwu 提交于 
      Item key collision is allowed for some item types, like dir item and
inode refs, but the overall item size is limited by the nodesize.

item size(ins_len) passed from btrfs_insert_empty_items to
btrfs_search_slot already contains size of btrfs_item.

When btrfs_search_slot reaches leaf, we'll see if we need to split leaf.
The check incorrectly reports that split leaf is required, because
it treats the space required by the newly inserted item as
btrfs_item + item data. But in item key collision case, only item data
is actually needed, the newly inserted item could merge into the existing
one. No new btrfs_item will be inserted.

And split_leaf return EOVERFLOW from following code:

  if (extend && data_size + btrfs_item_size_nr(l, slot) +
      sizeof(struct btrfs_item) > BTRFS_LEAF_DATA_SIZE(fs_info))
      return -EOVERFLOW;

In most cases, when callers receive EOVERFLOW, they either return
this error or handle in different ways. For example, in normal dir item
creation the userspace will get errno EOVERFLOW; in inode ref case
INODE_EXTREF is used instead.

However, this is not the case for rename. To avoid the unrecoverable
situation in rename, btrfs_check_dir_item_collision is called in
early phase of rename. In this function, when item key collision is
detected leaf space is checked:

  data_size = sizeof(*di) + name_len;
  if (data_size + btrfs_item_size_nr(leaf, slot) +
      sizeof(struct btrfs_item) > BTRFS_LEAF_DATA_SIZE(root->fs_info))

the sizeof(struct btrfs_item) + btrfs_item_size_nr(leaf, slot) here
refers to existing item size, the condition here correctly calculates
the needed size for collision case rather than the wrong case above.

The consequence of inconsistent condition check between
btrfs_check_dir_item_collision and btrfs_search_slot when item key
collision happens is that we might pass check here but fail
later at btrfs_search_slot. Rename fails and volume is forced readonly

  [436149.586170] ------------[ cut here ]------------
  [436149.586173] BTRFS: Transaction aborted (error -75)
  [436149.586196] WARNING: CPU: 0 PID: 16733 at fs/btrfs/inode.c:9870 btrfs_rename2+0x1938/0x1b70 [btrfs]
  [436149.586227] CPU: 0 PID: 16733 Comm: python Tainted: G      D           4.18.0-rc5+ #1
  [436149.586228] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 04/05/2016
  [436149.586238] RIP: 0010:btrfs_rename2+0x1938/0x1b70 [btrfs]
  [436149.586254] RSP: 0018:ffffa327043a7ce0 EFLAGS: 00010286
  [436149.586255] RAX: 0000000000000000 RBX: ffff8d8a17d13340 RCX: 0000000000000006
  [436149.586256] RDX: 0000000000000007 RSI: 0000000000000096 RDI: ffff8d8a7fc164b0
  [436149.586257] RBP: ffffa327043a7da0 R08: 0000000000000560 R09: 7265282064657472
  [436149.586258] R10: 0000000000000000 R11: 6361736e61725420 R12: ffff8d8a0d4c8b08
  [436149.586258] R13: ffff8d8a17d13340 R14: ffff8d8a33e0a540 R15: 00000000000001fe
  [436149.586260] FS:  00007fa313933740(0000) GS:ffff8d8a7fc00000(0000) knlGS:0000000000000000
  [436149.586261] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  [436149.586262] CR2: 000055d8d9c9a720 CR3: 000000007aae0003 CR4: 00000000003606f0
  [436149.586295] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  [436149.586296] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
  [436149.586296] Call Trace:
  [436149.586311]  vfs_rename+0x383/0x920
  [436149.586313]  ? vfs_rename+0x383/0x920
  [436149.586315]  do_renameat2+0x4ca/0x590
  [436149.586317]  __x64_sys_rename+0x20/0x30
  [436149.586324]  do_syscall_64+0x5a/0x120
  [436149.586330]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
  [436149.586332] RIP: 0033:0x7fa3133b1d37
  [436149.586348] RSP: 002b:00007fffd3e43908 EFLAGS: 00000246 ORIG_RAX: 0000000000000052
  [436149.586349] RAX: ffffffffffffffda RBX: 00007fa3133b1d30 RCX: 00007fa3133b1d37
  [436149.586350] RDX: 000055d8da06b5e0 RSI: 000055d8da225d60 RDI: 000055d8da2c4da0
  [436149.586351] RBP: 000055d8da2252f0 R08: 00007fa313782000 R09: 00000000000177e0
  [436149.586351] R10: 000055d8da010680 R11: 0000000000000246 R12: 00007fa313840b00

Thanks to Hans van Kranenburg for information about crc32 hash collision
tools, I was able to reproduce the dir item collision with following
python script.
https://github.com/wutzuchieh/misc_tools/blob/master/crc32_forge.py Run
it under a btrfs volume will trigger the abort transaction.  It simply
creates files and rename them to forged names that leads to
hash collision.

There are two ways to fix this. One is to simply revert the patch
878f2d2c ("Btrfs: fix max dir item size calculation") to make the
condition consistent although that patch is correct about the size.

The other way is to handle the leaf space check correctly when
collision happens. I prefer the second one since it correct leaf
space check in collision case. This fix will not account
sizeof(struct btrfs_item) when the item already exists.
There are two places where ins_len doesn't contain
sizeof(struct btrfs_item), however.

  1. extent-tree.c: lookup_inline_extent_backref
  2. file-item.c: btrfs_csum_file_blocks

to make the logic of btrfs_search_slot more clear, we add a flag
search_for_extension in btrfs_path.

This flag indicates that ins_len passed to btrfs_search_slot doesn't
contain sizeof(struct btrfs_item). When key exists, btrfs_search_slot
will use the actual size needed to calculate the required leaf space.

CC: stable@vger.kernel.org # 4.4+
Reviewed-by: NFilipe Manana <fdmanana@suse.com>
Signed-off-by: Nethanwu <ethanwu@synology.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>
      9a664971
  3. 10 12月, 2020 1 次提交
    • Q
      btrfs: handle sectorsize < PAGE_SIZE case for extent buffer accessors · 884b07d0
      由 Qu Wenruo 提交于 
      To support sectorsize < PAGE_SIZE case, we need to take extra care of
extent buffer accessors.

Since sectorsize is smaller than PAGE_SIZE, one page can contain
multiple tree blocks, we must use eb->start to determine the real offset
to read/write for extent buffer accessors.

This patch introduces two helpers to do this:

- get_eb_page_index()
  This is to calculate the index to access extent_buffer::pages.
  It's just a simple wrapper around "start >> PAGE_SHIFT".

  For sectorsize == PAGE_SIZE case, nothing is changed.
  For sectorsize < PAGE_SIZE case, we always get index as 0, and
  the existing page shift also works.

- get_eb_offset_in_page()
  This is to calculate the offset to access extent_buffer::pages.
  This needs to take extent_buffer::start into consideration.

  For sectorsize == PAGE_SIZE case, extent_buffer::start is always
  aligned to PAGE_SIZE, thus adding extent_buffer::start to
  offset_in_page() won't change the result.
  For sectorsize < PAGE_SIZE case, adding extent_buffer::start gives
  us the correct offset to access.

This patch will touch the following parts to cover all extent buffer
accessors:

- BTRFS_SETGET_HEADER_FUNCS()
- read_extent_buffer()
- read_extent_buffer_to_user()
- memcmp_extent_buffer()
- write_extent_buffer_chunk_tree_uuid()
- write_extent_buffer_fsid()
- write_extent_buffer()
- memzero_extent_buffer()
- copy_extent_buffer_full()
- copy_extent_buffer()
- memcpy_extent_buffer()
- memmove_extent_buffer()
- btrfs_get_token_##bits()
- btrfs_get_##bits()
- btrfs_set_token_##bits()
- btrfs_set_##bits()
- generic_bin_search()
Signed-off-by: NGoldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: NQu Wenruo <wqu@suse.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>
      884b07d0
  5. 08 12月, 2020 12 次提交
  7. 07 10月, 2020 16 次提交
    • J
      btrfs: cleanup cow block on error · 572c83ac
      由 Josef Bacik 提交于 
      In fstest btrfs/064 a transaction abort in __btrfs_cow_block could lead
to a system lockup. It gets stuck trying to write back inodes, and the
write back thread was trying to lock an extent buffer:

  $ cat /proc/2143497/stack
  [<0>] __btrfs_tree_lock+0x108/0x250
  [<0>] lock_extent_buffer_for_io+0x35e/0x3a0
  [<0>] btree_write_cache_pages+0x15a/0x3b0
  [<0>] do_writepages+0x28/0xb0
  [<0>] __writeback_single_inode+0x54/0x5c0
  [<0>] writeback_sb_inodes+0x1e8/0x510
  [<0>] wb_writeback+0xcc/0x440
  [<0>] wb_workfn+0xd7/0x650
  [<0>] process_one_work+0x236/0x560
  [<0>] worker_thread+0x55/0x3c0
  [<0>] kthread+0x13a/0x150
  [<0>] ret_from_fork+0x1f/0x30

This is because we got an error while COWing a block, specifically here

        if (test_bit(BTRFS_ROOT_SHAREABLE, &root->state)) {
                ret = btrfs_reloc_cow_block(trans, root, buf, cow);
                if (ret) {
                        btrfs_abort_transaction(trans, ret);
                        return ret;
                }
        }

  [16402.241552] BTRFS: Transaction aborted (error -2)
  [16402.242362] WARNING: CPU: 1 PID: 2563188 at fs/btrfs/ctree.c:1074 __btrfs_cow_block+0x376/0x540
  [16402.249469] CPU: 1 PID: 2563188 Comm: fsstress Not tainted 5.9.0-rc6+ #8
  [16402.249936] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-2.fc32 04/01/2014
  [16402.250525] RIP: 0010:__btrfs_cow_block+0x376/0x540
  [16402.252417] RSP: 0018:ffff9cca40e578b0 EFLAGS: 00010282
  [16402.252787] RAX: 0000000000000025 RBX: 0000000000000002 RCX: ffff9132bbd19388
  [16402.253278] RDX: 00000000ffffffd8 RSI: 0000000000000027 RDI: ffff9132bbd19380
  [16402.254063] RBP: ffff9132b41a49c0 R08: 0000000000000000 R09: 0000000000000000
  [16402.254887] R10: 0000000000000000 R11: ffff91324758b080 R12: ffff91326ef17ce0
  [16402.255694] R13: ffff91325fc0f000 R14: ffff91326ef176b0 R15: ffff9132815e2000
  [16402.256321] FS:  00007f542c6d7b80(0000) GS:ffff9132bbd00000(0000) knlGS:0000000000000000
  [16402.256973] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  [16402.257374] CR2: 00007f127b83f250 CR3: 0000000133480002 CR4: 0000000000370ee0
  [16402.257867] Call Trace:
  [16402.258072]  btrfs_cow_block+0x109/0x230
  [16402.258356]  btrfs_search_slot+0x530/0x9d0
  [16402.258655]  btrfs_lookup_file_extent+0x37/0x40
  [16402.259155]  __btrfs_drop_extents+0x13c/0xd60
  [16402.259628]  ? btrfs_block_rsv_migrate+0x4f/0xb0
  [16402.259949]  btrfs_replace_file_extents+0x190/0x820
  [16402.260873]  btrfs_clone+0x9ae/0xc00
  [16402.261139]  btrfs_extent_same_range+0x66/0x90
  [16402.261771]  btrfs_remap_file_range+0x353/0x3b1
  [16402.262333]  vfs_dedupe_file_range_one.part.0+0xd5/0x140
  [16402.262821]  vfs_dedupe_file_range+0x189/0x220
  [16402.263150]  do_vfs_ioctl+0x552/0x700
  [16402.263662]  __x64_sys_ioctl+0x62/0xb0
  [16402.264023]  do_syscall_64+0x33/0x40
  [16402.264364]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
  [16402.264862] RIP: 0033:0x7f542c7d15cb
  [16402.266901] RSP: 002b:00007ffd35944ea8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
  [16402.267627] RAX: ffffffffffffffda RBX: 00000000009d1968 RCX: 00007f542c7d15cb
  [16402.268298] RDX: 00000000009d2490 RSI: 00000000c0189436 RDI: 0000000000000003
  [16402.268958] RBP: 00000000009d2520 R08: 0000000000000036 R09: 00000000009d2e64
  [16402.269726] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000002
  [16402.270659] R13: 000000000001f000 R14: 00000000009d1970 R15: 00000000009d2e80
  [16402.271498] irq event stamp: 0
  [16402.271846] hardirqs last  enabled at (0): [<0000000000000000>] 0x0
  [16402.272497] hardirqs last disabled at (0): [<ffffffff910dbf59>] copy_process+0x6b9/0x1ba0
  [16402.273343] softirqs last  enabled at (0): [<ffffffff910dbf59>] copy_process+0x6b9/0x1ba0
  [16402.273905] softirqs last disabled at (0): [<0000000000000000>] 0x0
  [16402.274338] ---[ end trace 737874a5a41a8236 ]---
  [16402.274669] BTRFS: error (device dm-9) in __btrfs_cow_block:1074: errno=-2 No such entry
  [16402.276179] BTRFS info (device dm-9): forced readonly
  [16402.277046] BTRFS: error (device dm-9) in btrfs_replace_file_extents:2723: errno=-2 No such entry
  [16402.278744] BTRFS: error (device dm-9) in __btrfs_cow_block:1074: errno=-2 No such entry
  [16402.279968] BTRFS: error (device dm-9) in __btrfs_cow_block:1074: errno=-2 No such entry
  [16402.280582] BTRFS info (device dm-9): balance: ended with status: -30

The problem here is that as soon as we allocate the new block it is
locked and marked dirty in the btree inode.  This means that we could
attempt to writeback this block and need to lock the extent buffer.
However we're not unlocking it here and thus we deadlock.

Fix this by unlocking the cow block if we have any errors inside of
__btrfs_cow_block, and also free it so we do not leak it.

CC: stable@vger.kernel.org # 4.4+
Reviewed-by: NFilipe Manana <fdmanana@suse.com>
Signed-off-by: NJosef Bacik <josef@toxicpanda.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>
      572c83ac
    • N
      btrfs: improve error message in setup_items_for_insert · 7269ddd2
      由 Nikolay Borisov 提交于 
      Reword and update formats to match variable types.
Reviewed-by: NJosef Bacik <josef@toxicpanda.com>
Reviewed-by: NJohannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: NNikolay Borisov <nborisov@suse.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
[ update formats ]
Signed-off-by: NDavid Sterba <dsterba@suse.com>
      7269ddd2
    • N
      btrfs: add kerneldoc for setup_items_for_insert · da9ffb24
      由 Nikolay Borisov 提交于 
      Reviewed-by: NJosef Bacik <josef@toxicpanda.com>
Reviewed-by: NJohannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: NNikolay Borisov <nborisov@suse.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>
      da9ffb24
    • N
      btrfs: sink total_data parameter in setup_items_for_insert · fc0d82e1
      由 Nikolay Borisov 提交于 
      That parameter can easily be derived based on the "data_size" and "nr"
parameters exploit this fact to simply the function's signature. No
functional changes.
Reviewed-by: NJosef Bacik <josef@toxicpanda.com>
Reviewed-by: NJohannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: NNikolay Borisov <nborisov@suse.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>
      fc0d82e1
    • N
      btrfs: eliminate total_size parameter from setup_items_for_insert · 3dc9dc89
      由 Nikolay Borisov 提交于 
      The value of this argument can be derived from the total_data as it's
simply the value of the data size + size of btrfs_items being touched.
Move the parameter calculation inside the function. This results in a
simpler interface and also a minor size reduction:

./scripts/bloat-o-meter ctree.original fs/btrfs/ctree.o
add/remove: 0/0 grow/shrink: 0/3 up/down: 0/-34 (-34)
Function                                     old     new   delta
btrfs_duplicate_item                         260     259      -1
setup_items_for_insert                      1200    1190     -10
btrfs_insert_empty_items                     177     154     -23
Reviewed-by: NJosef Bacik <josef@toxicpanda.com>
Reviewed-by: NJohannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: NNikolay Borisov <nborisov@suse.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>
      3dc9dc89
    • N
      btrfs: re-arrange statements in setup_items_for_insert · fc0716c2
      由 Nikolay Borisov 提交于 
      Rearrange statements calculating the offset of the newly added items so
that the calculation has to be done only once. No functional change.
Reviewed-by: NJosef Bacik <josef@toxicpanda.com>
Reviewed-by: NJohannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: NNikolay Borisov <nborisov@suse.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>
      fc0716c2
    • J
      btrfs: use BTRFS_NESTED_NEW_ROOT for double splits · ca9d473a
      由 Josef Bacik 提交于 
      I've made this change separate since it requires both of the newly added
NESTED flags and I didn't want to slip it into one of those changes.

If we do a double split of a node we can end up doing a
BTRFS_NESTED_SPLIT on level 0, which throws lockdep off because it
appears as a double lock.  Since we're maxed out on subclasses, use
BTRFS_NESTED_NEW_ROOT if we had to do a double split.  This is OK
because we won't have to do a double split if we had to insert a new
root, and the new root would be at a higher level anyway.
Signed-off-by: NJosef Bacik <josef@toxicpanda.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>
      ca9d473a
    • J
      btrfs: introduce BTRFS_NESTING_NEW_ROOT for adding new roots · cf6f34aa
      由 Josef Bacik 提交于 
      The way we add new roots is confusing from a locking perspective for
lockdep.  We generally have the rule that we lock things in order from
highest level to lowest, but in the case of adding a new level to the
tree we actually allocate a new block for the root, which makes the
locking go in reverse.  A similar issue exists for snapshotting, we cow
the original root for the root of a new tree, however they're at the
same level.  Address this by using BTRFS_NESTING_NEW_ROOT for these
operations.
Signed-off-by: NJosef Bacik <josef@toxicpanda.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>
      cf6f34aa
    • J
      btrfs: introduce BTRFS_NESTING_SPLIT for split blocks · 4dff97e6
      由 Josef Bacik 提交于 
      If we are splitting a leaf/node, we could do something like the
following

lock(leaf)  BTRFS_NESTING_NORMAL
  lock(left) BTRFS_NESTING_LEFT + BTRFS_NESTING_COW
    push from leaf -> left
      reset path to point to left
        split left
          allocate new block, lock block BTRFS_NESTING_SPLIT

at the new block point we need to have a different nesting level,
because we have already used either BTRFS_NESTING_LEFT or
BTRFS_NESTING_RIGHT when pushing items from the original leaf into the
adjacent leaves.
Signed-off-by: NJosef Bacik <josef@toxicpanda.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>
      4dff97e6
    • J
      btrfs: introduce BTRFS_NESTING_LEFT/RIGHT_COW · bf59a5a2
      由 Josef Bacik 提交于 
      For similar reasons as BTRFS_NESTING_COW, we need
BTRFS_NESTING_LEFT/RIGHT_COW.  The pattern is this

lock leaf -> BTRFS_NESTING_NORMAL
  cow leaf -> BTRFS_NESTING_COW
    split leaf
      lock left -> BTRFS_NESTING_LEFT
        cow left -> BTRFS_NESTING_LEFT_COW

We need this in order to indicate to lockdep that these locks are
discrete and are being taken in a safe order.
Signed-off-by: NJosef Bacik <josef@toxicpanda.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>
      bf59a5a2
    • J
      btrfs: introduce BTRFS_NESTING_LEFT/BTRFS_NESTING_RIGHT · bf77467a
      由 Josef Bacik 提交于 
      Our lockdep maps are based on rootid+level, however in some cases we
will lock adjacent blocks on the same level, namely in searching forward
or in split/balance.  Because of this lockdep will complain, so we need
a separate subclass to indicate to lockdep that these are different
locks.

lock leaf -> BTRFS_NESTING_NORMAL
  cow leaf -> BTRFS_NESTING_COW
    split leaf
       lock left -> BTRFS_NESTING_LEFT
       lock right -> BTRFS_NESTING_RIGHT

The above graph illustrates the need for this new nesting subclass.
Signed-off-by: NJosef Bacik <josef@toxicpanda.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>
      bf77467a
    • J
      btrfs: introduce BTRFS_NESTING_COW for cow'ing blocks · 9631e4cc
      由 Josef Bacik 提交于 
      When we COW a block we are holding a lock on the original block, and
then we lock the new COW block.  Because our lockdep maps are based on
root + level, this will make lockdep complain.  We need a way to
indicate a subclass for locking the COW'ed block, so plumb through our
btrfs_lock_nesting from btrfs_cow_block down to the btrfs_init_buffer,
and then introduce BTRFS_NESTING_COW to be used for cow'ing blocks.

The reason I've added all this extra infrastructure is because there
will be need of different nesting classes in follow up patches.
Signed-off-by: NJosef Bacik <josef@toxicpanda.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>
      9631e4cc
    • J
      btrfs: add nesting tags to the locking helpers · fd7ba1c1
      由 Josef Bacik 提交于 
      We will need these when we switch to an rwsem, so plumb in the
infrastructure here to use later on.  I violate the 80 character limit
some here because it'll be cleaned up later.
Signed-off-by: NJosef Bacik <josef@toxicpanda.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>
      fd7ba1c1
    • J
      btrfs: introduce btrfs_path::recurse · 51899412
      由 Josef Bacik 提交于 
      Our current tree locking stuff allows us to recurse with read locks if
we're already holding the write lock.  This is necessary for the space
cache inode, as we could be holding a lock on the root_tree root when we
need to cache a block group, and thus need to be able to read down the
root_tree to read in the inode cache.

We can get away with this in our current locking, but we won't be able
to with a rwsem.  Handle this by purposefully annotating the places
where we require recursion, so that in the future we can maybe come up
with a way to avoid the recursion.  In the case of the free space inode,
this will be superseded by the free space tree.
Signed-off-by: NJosef Bacik <josef@toxicpanda.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>
      51899412
    • Q
      btrfs: ctree: check key order before merging tree blocks · d16c702f
      由 Qu Wenruo 提交于 
      [BUG]
With a crafted image, btrfs can panic at btrfs_del_csums():

  kernel BUG at fs/btrfs/ctree.c:3188!
  invalid opcode: 0000 [#1] SMP PTI
  CPU: 0 PID: 1156 Comm: btrfs-transacti Not tainted 5.0.0-rc8+ #9
  RIP: 0010:btrfs_set_item_key_safe+0x16c/0x180
  RSP: 0018:ffff976141257ab8 EFLAGS: 00010202
  RAX: 0000000000000001 RBX: ffff898a6b890930 RCX: 0000000004b70000
  RDX: 0000000000000000 RSI: ffff976141257bae RDI: ffff976141257acf
  RBP: ffff976141257b10 R08: 0000000000001000 R09: ffff9761412579a8
  R10: 0000000000000000 R11: 0000000000000000 R12: ffff976141257abe
  R13: 0000000000000003 R14: ffff898a6a8be578 R15: ffff976141257bae
  FS: 0000000000000000(0000) GS:ffff898a77a00000(0000) knlGS:0000000000000000
  CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 00007f779d9cd624 CR3: 000000022b2b4006 CR4: 00000000000206f0
  Call Trace:
  truncate_one_csum+0xac/0xf0
  btrfs_del_csums+0x24f/0x3a0
  __btrfs_free_extent.isra.72+0x5a7/0xbe0
  __btrfs_run_delayed_refs+0x539/0x1120
  btrfs_run_delayed_refs+0xdb/0x1b0
  btrfs_commit_transaction+0x52/0x950
  ? start_transaction+0x94/0x450
  transaction_kthread+0x163/0x190
  kthread+0x105/0x140
  ? btrfs_cleanup_transaction+0x560/0x560
  ? kthread_destroy_worker+0x50/0x50
  ret_from_fork+0x35/0x40
  Modules linked in:
  ---[ end trace 93bf9db00e6c374e ]---

[CAUSE]
This crafted image has a tricky key order corruption:

  checksum tree key (CSUM_TREE ROOT_ITEM 0)
  node 29741056 level 1 items 14 free 107 generation 19 owner CSUM_TREE
          ...
          key (EXTENT_CSUM EXTENT_CSUM 73785344) block 29757440 gen 19
          key (EXTENT_CSUM EXTENT_CSUM 77594624) block 29753344 gen 19
          ...

  leaf 29757440 items 5 free space 150 generation 19 owner CSUM_TREE
          item 0 key (EXTENT_CSUM EXTENT_CSUM 73785344) itemoff 2323 itemsize 1672
                  range start 73785344 end 75497472 length 1712128
          item 1 key (EXTENT_CSUM EXTENT_CSUM 75497472) itemoff 2319 itemsize 4
                  range start 75497472 end 75501568 length 4096
          item 2 key (EXTENT_CSUM EXTENT_CSUM 75501568) itemoff 579 itemsize 1740
                  range start 75501568 end 77283328 length 1781760
          item 3 key (EXTENT_CSUM EXTENT_CSUM 77283328) itemoff 575 itemsize 4
                  range start 77283328 end 77287424 length 4096
          item 4 key (EXTENT_CSUM EXTENT_CSUM 4120596480) itemoff 275 itemsize 300 <<<
                  range start 4120596480 end 4120903680 length 307200
  leaf 29753344 items 3 free space 1936 generation 19 owner CSUM_TREE
          item 0 key (18446744073457893366 EXTENT_CSUM 77594624) itemoff 2323 itemsize 1672
                  range start 77594624 end 79306752 length 1712128
          ...

Note the item 4 key of leaf 29757440, which is obviously too large, and
even larger than the first key of the next leaf.

However it still follows the key order in that tree block, thus tree
checker is unable to detect it at read time, since tree checker can only
work inside one leaf, thus such complex corruption can't be detected in
advance.

[FIX]
The next time to detect such problem is at tree block merge time,
which is in push_node_left(), balance_node_right(), push_leaf_left() or
push_leaf_right().

Now we check if the key order of the right-most key of the left node is
larger than the left-most key of the right node.

By this we don't need to call the full tree-checker, while still keeping
the key order correct as key order in each node is already checked by
tree checker thus we only need to check the above two slots.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=202833Reviewed-by: NNikolay Borisov <nborisov@suse.com>
Reviewed-by: NJosef Bacik <josef@toxicpanda.com>
Signed-off-by: NQu Wenruo <wqu@suse.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>
      d16c702f
    • R
      btrfs: delete duplicated words + other fixes in comments · 260db43c
      由 Randy Dunlap 提交于 
      Delete repeated words in fs/btrfs/.
{to, the, a, and old}
and change "into 2 part" to "into 2 parts".
Reviewed-by: NNikolay Borisov <nborisov@suse.com>
Signed-off-by: NRandy Dunlap <rdunlap@infradead.org>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>
      260db43c
  9. 27 8月, 2020 1 次提交
  11. 20 8月, 2020 1 次提交
  13. 27 7月, 2020 1 次提交
    • D
      btrfs: add little-endian optimized key helpers · ce6ef5ab
      由 David Sterba 提交于 
      The CPU and on-disk keys are mapped to two different structures because
of the endianness. There's an intermediate buffer used to do the
conversion, but this is not necessary when CPU and on-disk endianness
match.

Add optimized versions of helpers that take disk_key and use the buffer
directly for CPU keys or drop the intermediate buffer and conversion.

This saves a lot of stack space accross many functions and removes about
6K of generated binary code:

   text    data     bss     dec     hex filename
1090439   17468   14912 1122819  112203 pre/btrfs.ko
1084613   17456   14912 1116981  110b35 post/btrfs.ko

Delta: -5826
Reviewed-by: NJohannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: NNikolay Borisov <nborisov@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>
      ce6ef5ab
  15. 02 7月, 2020 1 次提交
  17. 28 5月, 2020 2 次提交
  19. 25 5月, 2020 4 次提交