Commit Graph

7836 Commits

Author SHA1 Message Date
David Sterba
5ab12d1ff8 btrfs: get fs_info from eb in btree_read_extent_buffer_pages
We can read fs_info from extent buffer and can drop it from the
parameters.

Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:31 +02:00
David Sterba
d0d20b0f5c btrfs: get fs_info from eb in read_node_slot
We can read fs_info from extent buffer and can drop it from the
parameters.

Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:31 +02:00
David Sterba
e902baac65 btrfs: get fs_info from eb in btrfs_leaf_free_space
We can read fs_info from extent buffer and can drop it from the
parameters.

Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:30 +02:00
David Sterba
6a884d7d52 btrfs: get fs_info from eb in clean_tree_block
We can read fs_info from extent buffer and can drop it from the
parameters.

Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:30 +02:00
David Sterba
ed874f0db8 btrfs: get fs_info from eb in tree_mod_log_eb_copy
We can read fs_info from extent buffer and can drop it from the
parameters.

Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:30 +02:00
David Sterba
b0c9b3b05d btrfs: get fs_info from eb in check_tree_block_fsid
We can read fs_info from extent buffer and can drop it from the
parameters.

Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:30 +02:00
David Sterba
bcdc428cfe btrfs: get fs_info from eb in btrfs_exclude_logged_extents
We can read fs_info from extent buffer and can drop it from the
parameters.

Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:30 +02:00
David Sterba
8f881e8c18 btrfs: get fs_info from eb in leaf_data_end
We can read fs_info from extent buffer and can drop it from the
parameters.

Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:30 +02:00
David Sterba
0ab0206328 btrfs: get fs_info from eb in write_one_eb
We can read fs_info from extent buffer and can drop it from the
parameters.

Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:29 +02:00
David Sterba
20a1fbf97e btrfs: get fs_info from eb in repair_eb_io_failure
We can read fs_info from extent buffer and can drop it from the
parameters. As all callsites are updated, add the btrfs_ prefix as the
function is exported.

Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:29 +02:00
David Sterba
9df76fb544 btrfs: get fs_info from eb in lock_extent_buffer_for_io
We can read fs_info from extent buffer and can drop it from the
parameters.

Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:29 +02:00
Phillip Potter
7d157c3d48 btrfs: use common file type conversion
Deduplicate the btrfs file type conversion implementation - file systems
that use the same file types as defined by POSIX do not need to define
their own versions and can use the common helper functions decared in
fs_types.h and implemented in fs_types.c

Common implementation can be found via commit:
bbe7449e25 "fs: common implementation of file type"

Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Phillip Potter <phil@philpotter.co.uk>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:29 +02:00
Goldwyn Rodrigues
7984ae52bb btrfs: Perform locking/unlocking in btrfs_remap_file_range()
Move code to make it more readable, so as locking and unlocking is
done in the same function. The generic checks that are now performed in
the locked section are unaffected.

Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:29 +02:00
Arnd Bergmann
290342f661 btrfs: use BUG() instead of BUG_ON(1)
BUG_ON(1) leads to bogus warnings from clang when
CONFIG_PROFILE_ANNOTATED_BRANCHES is set:

fs/btrfs/volumes.c:5041:3: error: variable 'max_chunk_size' is used uninitialized whenever 'if' condition is false
      [-Werror,-Wsometimes-uninitialized]
                BUG_ON(1);
                ^~~~~~~~~
include/asm-generic/bug.h:61:36: note: expanded from macro 'BUG_ON'
 #define BUG_ON(condition) do { if (unlikely(condition)) BUG(); } while (0)
                                   ^~~~~~~~~~~~~~~~~~~
include/linux/compiler.h:48:23: note: expanded from macro 'unlikely'
 #  define unlikely(x)   (__branch_check__(x, 0, __builtin_constant_p(x)))
                        ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
fs/btrfs/volumes.c:5046:9: note: uninitialized use occurs here
                             max_chunk_size);
                             ^~~~~~~~~~~~~~
include/linux/kernel.h:860:36: note: expanded from macro 'min'
 #define min(x, y)       __careful_cmp(x, y, <)
                                         ^
include/linux/kernel.h:853:17: note: expanded from macro '__careful_cmp'
                __cmp_once(x, y, __UNIQUE_ID(__x), __UNIQUE_ID(__y), op))
                              ^
include/linux/kernel.h:847:25: note: expanded from macro '__cmp_once'
                typeof(y) unique_y = (y);               \
                                      ^
fs/btrfs/volumes.c:5041:3: note: remove the 'if' if its condition is always true
                BUG_ON(1);
                ^
include/asm-generic/bug.h:61:32: note: expanded from macro 'BUG_ON'
 #define BUG_ON(condition) do { if (unlikely(condition)) BUG(); } while (0)
                               ^
fs/btrfs/volumes.c:4993:20: note: initialize the variable 'max_chunk_size' to silence this warning
        u64 max_chunk_size;
                          ^
                           = 0

Change it to BUG() so clang can see that this code path can never
continue.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:28 +02:00
David Sterba
247462a5ac btrfs: move tree block wait and write helpers to tree-log
The wrapper names better describe what's happening so they're not
deleted though they're trivial, but at least moved closer to their place
of use.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:28 +02:00
David Sterba
d4eb671a08 btrfs: remove stale definition of BUFFER_LRU_MAX
Long time ago (2008), the extent buffers were organized in a LRU list
and switched to rb-tree in 6af118ce51 ("Btrfs: Index extent
buffers in an rbtree"). There was one stale macro definition left.

Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:28 +02:00
David Sterba
e4fa7469eb btrfs: tests: unify messages when tests start
- make the messages more visually consistent and use same format
  "running ... test", any error or other warning can be easily spotted

- move some message to the test entry function

- add message to the inode tests

Example output:

[    8.187391] Btrfs loaded, crc32c=crc32c-generic, assert=on, integrity-checker=on, ref-verify=on
[    8.189476] BTRFS: selftest: sectorsize: 4096  nodesize: 4096
[    8.190761] BTRFS: selftest: running btrfs free space cache tests
[    8.192245] BTRFS: selftest: running extent only tests
[    8.193573] BTRFS: selftest: running bitmap only tests
[    8.194876] BTRFS: selftest: running bitmap and extent tests
[    8.196166] BTRFS: selftest: running space stealing from bitmap to extent tests
[    8.198026] BTRFS: selftest: running extent buffer operation tests
[    8.199328] BTRFS: selftest: running btrfs_split_item tests
[    8.200653] BTRFS: selftest: running extent I/O tests
[    8.201808] BTRFS: selftest: running find delalloc tests
[    8.320733] BTRFS: selftest: running extent buffer bitmap tests
[    8.340795] BTRFS: selftest: running inode tests
[    8.341766] BTRFS: selftest: running btrfs_get_extent tests
[    8.342981] BTRFS: selftest: running hole first btrfs_get_extent test
[    8.344342] BTRFS: selftest: running outstanding_extents tests
[    8.345575] BTRFS: selftest: running qgroup tests
[    8.346537] BTRFS: selftest: running qgroup add/remove tests
[    8.347725] BTRFS: selftest: running qgroup multiple refs test
[    8.354982] BTRFS: selftest: running free space tree tests
[    8.372175] BTRFS: selftest: sectorsize: 4096  nodesize: 8192
[    8.373539] BTRFS: selftest: running btrfs free space cache tests
[    8.374989] BTRFS: selftest: running extent only tests
[    8.376236] BTRFS: selftest: running bitmap only tests
[    8.377483] BTRFS: selftest: running bitmap and extent tests
[    8.378854] BTRFS: selftest: running space stealing from bitmap to extent tests
...

Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:28 +02:00
David Sterba
752dbe48e2 btrfs: tests: drop messages when some tests finish
The messages like 'extent I/O tests finished' are redundant, if the test
fails it's quite obvious in the log and hang is also noticeable. No
other then extent_io and free space tree tests print that so make it
consistent.

Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:28 +02:00
David Sterba
3173fd926c btrfs: tests: fix comments about tested extent map ranges
Comments about ranges did not match the code, the correct calculation is
to use start and start+len as the interval boundaries.

Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:28 +02:00
David Sterba
43f7cddc6e btrfs: tests: use SZ_ constants everywhere
There are a few unconverted constants that are not powers of two and
haven't been converted.

Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:27 +02:00
David Sterba
6c30474680 btrfs: tests: use standard error message after extent map allocation failure
Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:27 +02:00
David Sterba
ccfada1f65 btrfs: tests: return error from all extent map test cases
The way the extent map tests handle errors does not conform to the rest
of the suite, where the first failure is reported and then it stops.
Do the same now that we have the errors returned from all the functions.

Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:27 +02:00
David Sterba
7c6f670052 btrfs: tests: return errors from extent map test case 4
Replace asserts with error messages and return errors.

Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:27 +02:00
David Sterba
992dce7494 btrfs: tests: return errors from extent map test case 3
Replace asserts with error messages and return errors.

Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:27 +02:00
David Sterba
e71f2e17e8 btrfs: tests: return errors from extent map test case 2
Replace asserts with error messages and return errors.

Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:27 +02:00
David Sterba
d7de4b0864 btrfs: tests: return errors from extent map test case 1
Replace asserts with error messages and return errors.

Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:26 +02:00
David Sterba
488f673023 btrfs: tests: return errors from extent map tests
The individual testcases for extent maps do not return an error on
allocation failures. This is not a big problem as the allocation don't
fail in general but there are functional tests handled with ASSERTS.
This makes tests dependent on them and it's not reliable.

This patch adds the allocation failure handling and allows for the
conversion of the asserts to proper error handling and reporting.

Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:26 +02:00
David Sterba
7b9586bc2b btrfs: tests: properly initialize fs_info of extent buffer
The fs_info is supposed to be valid, even though it's not used right
now and the test does not crash.

Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:26 +02:00
David Sterba
3199366da7 btrfs: tests: use standard error message after block group allocation failure
Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:26 +02:00
David Sterba
6a060db85d btrfs: tests: use standard error message after inode allocation failure
Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:26 +02:00
David Sterba
770e0cc040 btrfs: tests: use standard error message after path allocation failure
Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:26 +02:00
David Sterba
9e3d9f8462 btrfs: tests: use standard error message after extent buffer allocation failure
Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:25 +02:00
David Sterba
52ab7bca35 btrfs: tests: use standard error message after root allocation failure
Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:25 +02:00
David Sterba
37b2a7bc1e btrfs: tests: use standard error message after fs_info allocation failure
Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:25 +02:00
David Sterba
703de4266f btrfs: tests: add table of most common errors
Allocation of main objects like fs_info or extent buffers is in each
test so let's simplify and unify the error messages to a table and add a
convenience helper.

Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:25 +02:00
David Sterba
efd31fce54 btrfs: tests: print file:line for error messages
For better diagnostics print the file name and line to locate the
errors. Sample output:

[    9.052924] BTRFS: selftest: fs/btrfs/tests/extent-io-tests.c:283 offset bits do not match

Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:25 +02:00
David Sterba
d33d105b85 btrfs: tests: don't leak fs_info in extent_io bitmap tests
The fs_info is not freed at the end of the function and leaks. The
function is called twice so there can be up to 2x sizeof(struct
btrfs_fs_info) of leaked memory.  Fortunatelly this affects only testing
builds, the size could be 16k with several debugging features enabled.

Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:25 +02:00
David Sterba
d46a05edac btrfs: tests: handle fs_info allocation failure in extent_io tests
Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:24 +02:00
Qu Wenruo
75391f0d41 btrfs: disk-io: Show the timing of corrupted tree block explicitly
Just add one extra line to show when the corruption is detected.
Currently only read time detection is possible.

The planned distinguish line would be:

  read time:
    <detailed report>
    block=XXXXX read time tree block corruption detected

  write time:
    <detailed report>
    block=XXXXX write time tree block corruption detected

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:24 +02:00
Josef Bacik
ff612ba784 btrfs: fix panic during relocation after ENOSPC before writeback happens
We've been seeing the following sporadically throughout our fleet

panic: kernel BUG at fs/btrfs/relocation.c:4584!
netversion: 5.0-0
Backtrace:
 #0 [ffffc90003adb880] machine_kexec at ffffffff81041da8
 #1 [ffffc90003adb8c8] __crash_kexec at ffffffff8110396c
 #2 [ffffc90003adb988] crash_kexec at ffffffff811048ad
 #3 [ffffc90003adb9a0] oops_end at ffffffff8101c19a
 #4 [ffffc90003adb9c0] do_trap at ffffffff81019114
 #5 [ffffc90003adba00] do_error_trap at ffffffff810195d0
 #6 [ffffc90003adbab0] invalid_op at ffffffff81a00a9b
    [exception RIP: btrfs_reloc_cow_block+692]
    RIP: ffffffff8143b614  RSP: ffffc90003adbb68  RFLAGS: 00010246
    RAX: fffffffffffffff7  RBX: ffff8806b9c32000  RCX: ffff8806aad00690
    RDX: ffff880850b295e0  RSI: ffff8806b9c32000  RDI: ffff88084f205bd0
    RBP: ffff880849415000   R8: ffffc90003adbbe0   R9: ffff88085ac90000
    R10: ffff8805f7369140  R11: 0000000000000000  R12: ffff880850b295e0
    R13: ffff88084f205bd0  R14: 0000000000000000  R15: 0000000000000000
    ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
 #7 [ffffc90003adbbb0] __btrfs_cow_block at ffffffff813bf1cd
 #8 [ffffc90003adbc28] btrfs_cow_block at ffffffff813bf4b3
 #9 [ffffc90003adbc78] btrfs_search_slot at ffffffff813c2e6c

The way relocation moves data extents is by creating a reloc inode and
preallocating extents in this inode and then copying the data into these
preallocated extents.  Once we've done this for all of our extents,
we'll write out these dirty pages, which marks the extent written, and
goes into btrfs_reloc_cow_block().  From here we get our current
reloc_control, which _should_ match the reloc_control for the current
block group we're relocating.

However if we get an ENOSPC in this path at some point we'll bail out,
never initiating writeback on this inode.  Not a huge deal, unless we
happen to be doing relocation on a different block group, and this block
group is now rc->stage == UPDATE_DATA_PTRS.  This trips the BUG_ON() in
btrfs_reloc_cow_block(), because we expect to be done modifying the data
inode.  We are in fact done modifying the metadata for the data inode
we're currently using, but not the one from the failed block group, and
thus we BUG_ON().

(This happens when writeback finishes for extents from the previous
group, when we are at btrfs_finish_ordered_io() which updates the data
reloc tree (inode item, drops/adds extent items, etc).)

Fix this by writing out the reloc data inode always, and then breaking
out of the loop after that point to keep from tripping this BUG_ON()
later.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
[ add note from Filipe ]
Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:24 +02:00
Nikolay Borisov
6a8d2136ca btrfs: Use less confusing condition for uptodate parameter to btrfs_writepage_endio_finish_ordered
The uptodate parameter of btrfs_writepage_endio_finish_ordered is used
to signal whether an error has occured while writing the given page.
0 signals an error, which is propagated to callees and 1 signifies
success. In end_compressed_bio_write the ->bi_status is checked and
based on it either BLK_STS_OK (0) or BLK_STS_NOTSUPP (1) are used. While
from functional point of view this is ok it's a for the poor reader of
the code, since the block layer values are conflated with the semantics
of the parameter.

Just use plain 0 or 1. 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>
2019-04-29 19:02:24 +02:00
Qu Wenruo
a2a72fbd11 btrfs: extent_io: Handle errors better in extent_writepages()
We can only get <=0 from extent_write_cache_pages, add an ASSERT() for
it just in case.

Then instead of submitting the write bio even if we got some error,
check the return value first.
If we have already hit some error, just clean up the corrupted or
half-baked bio, and return error.

If there is no error so far, then call flush_write_bio() and return the
result.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:24 +02:00
Qu Wenruo
2e3c25136a btrfs: extent_io: add proper error handling to lock_extent_buffer_for_io()
This function needs some extra checks on locked pages and eb.  For error
handling we need to unlock locked pages and the eb.

There is a rare >0 return value branch, where all pages get locked
while write bio is not flushed.

Thankfully it's handled by the only caller, btree_write_cache_pages(),
as later write_one_eb() call will trigger submit_one_bio().  So there
shouldn't be any problem.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:24 +02:00
Qu Wenruo
02c6db4f73 btrfs: extent_io: Handle errors better in extent_write_locked_range()
We can only get @ret <= 0.  Add an ASSERT() for it just in case.

Then, instead of submitting the write bio even we got some error, check
the return value first.

If we have already hit some error, just clean up the corrupted or
half-baked bio, and return error.

If there is no error so far, then call flush_write_bio() and return the
result.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:23 +02:00
Qu Wenruo
e06808be8a btrfs: extent_io: Kill dead condition in extent_write_cache_pages()
Since __extent_writepage() will no longer return >0 value,
(ret == AOP_WRITEPAGE_ACTIVATE) will never be true.

Kill that dead branch.

Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:23 +02:00
Qu Wenruo
2b952eea81 btrfs: extent_io: Handle errors better in btree_write_cache_pages()
In btree_write_cache_pages(), we can only get @ret <= 0.
Add an ASSERT() for it just in case.

Then instead of submitting the write bio even we got some error, check
the return value first.
If we have already hit some error, just clean up the corrupted or
half-baked bio, and return error.

If there is no error so far, then call flush_write_bio() and return the
result.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:23 +02:00
Qu Wenruo
3065976b04 btrfs: extent_io: Handle errors better in extent_write_full_page()
Since now flush_write_bio() could return error, kill the BUG_ON() first.
Then don't call flush_write_bio() unconditionally, instead we check the
return value from __extent_writepage() first.

If __extent_writepage() fails, we do cleanup, and return error without
submitting the possible corrupted or half-baked bio.

If __extent_writepage() successes, then we call flush_write_bio() and
return the result.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:23 +02:00
Qu Wenruo
f4340622e0 btrfs: extent_io: Move the BUG_ON() in flush_write_bio() one level up
We have a BUG_ON() in flush_write_bio() to handle the return value of
submit_one_bio().

Move the BUG_ON() one level up to all its callers.

This patch will introduce temporary variable, @flush_ret to keep code
change minimal in this patch. That variable will be cleaned up when
enhancing the error handling later.

Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:23 +02:00
Qu Wenruo
63489055e4 btrfs: Always output error message when key/level verification fails
We have internal report of strange transaction abort due to EUCLEAN
without any error message.

Since error message inside verify_level_key() is only enabled for
CONFIG_BTRFS_DEBUG, the error message won't be printed on most builds.

This patch will make the error message mandatory, so when problem
happens we know what's causing the problem.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:23 +02:00
Qu Wenruo
448de471cd btrfs: Check the first key and level for cached extent buffer
[BUG]
When reading a file from a fuzzed image, kernel can panic like:

  BTRFS warning (device loop0): csum failed root 5 ino 270 off 0 csum 0x98f94189 expected csum 0x00000000 mirror 1
  assertion failed: !memcmp_extent_buffer(b, &disk_key, offsetof(struct btrfs_leaf, items[0].key), sizeof(disk_key)), file: fs/btrfs/ctree.c, line: 2544
  ------------[ cut here ]------------
  kernel BUG at fs/btrfs/ctree.h:3500!
  invalid opcode: 0000 [#1] PREEMPT SMP NOPTI
  RIP: 0010:btrfs_search_slot.cold.24+0x61/0x63 [btrfs]
  Call Trace:
   btrfs_lookup_csum+0x52/0x150 [btrfs]
   __btrfs_lookup_bio_sums+0x209/0x640 [btrfs]
   btrfs_submit_bio_hook+0x103/0x170 [btrfs]
   submit_one_bio+0x59/0x80 [btrfs]
   extent_read_full_page+0x58/0x80 [btrfs]
   generic_file_read_iter+0x2f6/0x9d0
   __vfs_read+0x14d/0x1a0
   vfs_read+0x8d/0x140
   ksys_read+0x52/0xc0
   do_syscall_64+0x60/0x210
   entry_SYSCALL_64_after_hwframe+0x49/0xbe

[CAUSE]
The fuzzed image has a corrupted leaf whose first key doesn't match its
parent:

  checksum tree key (CSUM_TREE ROOT_ITEM 0)
  node 29741056 level 1 items 14 free 107 generation 19 owner CSUM_TREE
  fs uuid 3381d111-94a3-4ac7-8f39-611bbbdab7e6
  chunk uuid 9af1c3c7-2af5-488b-8553-530bd515f14c
  	...
          key (EXTENT_CSUM EXTENT_CSUM 79691776) block 29761536 gen 19

  leaf 29761536 items 1 free space 1726 generation 19 owner CSUM_TREE
  leaf 29761536 flags 0x1(WRITTEN) backref revision 1
  fs uuid 3381d111-94a3-4ac7-8f39-611bbbdab7e6
  chunk uuid 9af1c3c7-2af5-488b-8553-530bd515f14c
          item 0 key (EXTENT_CSUM EXTENT_CSUM 8798638964736) itemoff 1751 itemsize 2244
                  range start 8798638964736 end 8798641262592 length 2297856

When reading the above tree block, we have extent_buffer->refs = 2 in
the context:

- initial one from __alloc_extent_buffer()
  alloc_extent_buffer()
  |- __alloc_extent_buffer()
     |- atomic_set(&eb->refs, 1)

- one being added to fs_info->buffer_radix
  alloc_extent_buffer()
  |- check_buffer_tree_ref()
     |- atomic_inc(&eb->refs)

So if even we call free_extent_buffer() in read_tree_block or other
similar situation, we only decrease the refs by 1, it doesn't reach 0
and won't be freed right now.

The staled eb and its corrupted content will still be kept cached.

Furthermore, we have several extra cases where we either don't do first
key check or the check is not proper for all callers:

- scrub
  We just don't have first key in this context.

- shared tree block
  One tree block can be shared by several snapshot/subvolume trees.
  In that case, the first key check for one subvolume doesn't apply to
  another.

So for the above reasons, a corrupted extent buffer can sneak into the
buffer cache.

[FIX]
Call verify_level_key in read_block_for_search to do another
verification. For that purpose the function is exported.

Due to above reasons, although we can free corrupted extent buffer from
cache, we still need the check in read_block_for_search(), for scrub and
shared tree blocks.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=202755
Link: https://bugzilla.kernel.org/show_bug.cgi?id=202757
Link: https://bugzilla.kernel.org/show_bug.cgi?id=202759
Link: https://bugzilla.kernel.org/show_bug.cgi?id=202761
Link: https://bugzilla.kernel.org/show_bug.cgi?id=202767
Link: https://bugzilla.kernel.org/show_bug.cgi?id=202769
Reported-by: Yoon Jungyeon <jungyeon@gatech.edu>
CC: stable@vger.kernel.org # 4.19+
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:22 +02:00