sfrench/cifs-2.6.git
2 years agoBtrfs: send, improve clone range
Robbie Ko [Fri, 29 Mar 2019 10:03:27 +0000 (18:03 +0800)]
Btrfs: send, improve clone range

Improve clone_range in two scenarios.

1. Remove the limit of inode size when find clone inodes We can do
   partial clone, so there is no need to limit the size of the candidate
   inode.  When clone a range, we clone the legal range only by bytenr,
   offset, len, inode size.

2. In the scenarios of rewrite or clone_range, data_offset rarely
   matches exactly, so the chance of a clone is missed.

e.g.
    1. Write a 1M file
        dd if=/dev/zero of=1M bs=1M count=1

    2. Clone 1M file
       cp --reflink 1M clone

    3. Rewrite 4k on the clone file
       dd if=/dev/zero of=clone bs=4k count=1 conv=notrunc

    The disk layout is as follows:
    item 16 key (257 EXTENT_DATA 0) itemoff 15353 itemsize 53
extent data disk byte 1103101952 nr 1048576
extent data offset 0 nr 1048576 ram 1048576
extent compression(none)
    ...
    item 22 key (258 EXTENT_DATA 0) itemoff 14959 itemsize 53
extent data disk byte 1104150528 nr 4096
extent data offset 0 nr 4096 ram 4096
extent compression(none)
    item 23 key (258 EXTENT_DATA 4096) itemoff 14906 itemsize 53
extent data disk byte 1103101952 nr 1048576
extent data offset 4096 nr 1044480 ram 1048576
extent compression(none)

When send, inode 258 file offset 4096~1048576 (item 23) has a chance to
clone_range, but because data_offset does not match inode 257 (item 16),
it causes missed clone and can only transfer actual data.

Improve the problem by judging whether the current data_offset has
overlap with the file extent item, and if so, adjusting offset and
extent_len so that we can clone correctly.

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Robbie Ko <robbieko@synology.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2 years agobtrfs: prop: open code btrfs_set_prop in inherit_prop
Anand Jain [Tue, 2 Apr 2019 10:07:41 +0000 (18:07 +0800)]
btrfs: prop: open code btrfs_set_prop in inherit_prop

When an inode inherits property from its parent, we call btrfs_set_prop().
btrfs_set_prop() does an elaborate checks, which is not required in the
context of inheriting a property. Instead just open-code only the required
items from btrfs_set_prop() and then call btrfs_setxattr() directly. So
now the only user of btrfs_set_prop() is gone, (except for the wraper
function btrfs_set_prop_trans()).

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2 years agobtrfs: drop unused parameter in mount_subvol
Anand Jain [Fri, 29 Mar 2019 06:03:17 +0000 (14:03 +0800)]
btrfs: drop unused parameter in mount_subvol

@device_name in mount_subvol() is not used, drop it.  Also see:
5bedc48a8f9e ("btrfs: drop unused parameters from mount_subvol").

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2 years agobtrfs: tree-checker: get fs_info from eb in check_inode_item
David Sterba [Wed, 20 Mar 2019 15:22:58 +0000 (16:22 +0100)]
btrfs: tree-checker: get fs_info from eb in check_inode_item

We can read fs_info from extent buffer and can drop it from the
parameters.

Signed-off-by: David Sterba <dsterba@suse.com>
2 years agobtrfs: tree-checker: get fs_info from eb in check_dev_item
David Sterba [Wed, 20 Mar 2019 15:22:58 +0000 (16:22 +0100)]
btrfs: tree-checker: get fs_info from eb in check_dev_item

We can read fs_info from extent buffer and can drop it from the
parameters.

Signed-off-by: David Sterba <dsterba@suse.com>
2 years agobtrfs: tree-checker: get fs_info from eb in dev_item_err
David Sterba [Wed, 20 Mar 2019 15:22:58 +0000 (16:22 +0100)]
btrfs: tree-checker: get fs_info from eb in dev_item_err

We can read fs_info from extent buffer and can drop it from the
parameters.

Signed-off-by: David Sterba <dsterba@suse.com>
2 years agobtrfs: tree-checker: get fs_info from eb in chunk_err
David Sterba [Wed, 20 Mar 2019 15:22:58 +0000 (16:22 +0100)]
btrfs: tree-checker: get fs_info from eb in chunk_err

We can read fs_info from extent buffer and can drop it from the
parameters.

Signed-off-by: David Sterba <dsterba@suse.com>
2 years agobtrfs: tree-checker: get fs_info from eb in check_leaf
David Sterba [Wed, 20 Mar 2019 15:22:58 +0000 (16:22 +0100)]
btrfs: tree-checker: get fs_info from eb in check_leaf

We can read fs_info from extent buffer and can drop it from the
parameters.

Signed-off-by: David Sterba <dsterba@suse.com>
2 years agobtrfs: tree-checker: get fs_info from eb in check_leaf_item
David Sterba [Wed, 20 Mar 2019 15:22:00 +0000 (16:22 +0100)]
btrfs: tree-checker: get fs_info from eb in check_leaf_item

We can read fs_info from extent buffer and can drop it from the
parameters.

Signed-off-by: David Sterba <dsterba@suse.com>
2 years agobtrfs: tree-checker: get fs_info from eb in check_extent_data_item
David Sterba [Wed, 20 Mar 2019 15:21:10 +0000 (16:21 +0100)]
btrfs: tree-checker: get fs_info from eb in check_extent_data_item

We can read fs_info from extent buffer and can drop it from the
parameters.

Signed-off-by: David Sterba <dsterba@suse.com>
2 years agobtrfs: tree-checker: get fs_info from eb in check_block_group_item
David Sterba [Wed, 20 Mar 2019 15:19:31 +0000 (16:19 +0100)]
btrfs: tree-checker: get fs_info from eb in check_block_group_item

We can read fs_info from extent buffer and can drop it from the
parameters.

Signed-off-by: David Sterba <dsterba@suse.com>
2 years agobtrfs: tree-checker: get fs_info from eb in block_group_err
David Sterba [Wed, 20 Mar 2019 15:18:57 +0000 (16:18 +0100)]
btrfs: tree-checker: get fs_info from eb in block_group_err

We can read fs_info from extent buffer and can drop it from the
parameters.

Signed-off-by: David Sterba <dsterba@suse.com>
2 years agobtrfs: tree-checker: get fs_info from eb in check_dir_item
David Sterba [Wed, 20 Mar 2019 15:17:46 +0000 (16:17 +0100)]
btrfs: tree-checker: get fs_info from eb in check_dir_item

We can read fs_info from extent buffer and can drop it from the
parameters.

Signed-off-by: David Sterba <dsterba@suse.com>
2 years agobtrfs: tree-checker: get fs_info from eb in dir_item_err
David Sterba [Wed, 20 Mar 2019 15:07:27 +0000 (16:07 +0100)]
btrfs: tree-checker: get fs_info from eb in dir_item_err

We can read fs_info from extent buffer and can drop it from the
parameters.

Signed-off-by: David Sterba <dsterba@suse.com>
2 years agobtrfs: tree-checker: get fs_info from eb in check_csum_item
David Sterba [Wed, 20 Mar 2019 15:02:56 +0000 (16:02 +0100)]
btrfs: tree-checker: get fs_info from eb in check_csum_item

We can read fs_info from extent buffer and can drop it from the
parameters.

Signed-off-by: David Sterba <dsterba@suse.com>
2 years agobtrfs: tree-checker: get fs_info from eb in file_extent_err
David Sterba [Wed, 20 Mar 2019 14:32:46 +0000 (15:32 +0100)]
btrfs: tree-checker: get fs_info from eb in file_extent_err

We can read fs_info from extent buffer and can drop it from the
parameters.

Signed-off-by: David Sterba <dsterba@suse.com>
2 years agobtrfs: tree-checker: get fs_info from eb in generic_err
David Sterba [Wed, 20 Mar 2019 14:31:28 +0000 (15:31 +0100)]
btrfs: tree-checker: get fs_info from eb in generic_err

We can read fs_info from extent buffer and can drop it from the
parameters.

Signed-off-by: David Sterba <dsterba@suse.com>
2 years agobtrfs: inode: Verify inode mode to avoid NULL pointer dereference
Qu Wenruo [Wed, 13 Mar 2019 05:55:11 +0000 (13:55 +0800)]
btrfs: inode: Verify inode mode to avoid NULL pointer dereference

[BUG]
When accessing a file on a crafted image, btrfs can crash in block layer:

  BUG: unable to handle kernel NULL pointer dereference at 0000000000000008
  PGD 136501067 P4D 136501067 PUD 124519067 PMD 0
  CPU: 3 PID: 0 Comm: swapper/3 Not tainted 5.0.0-rc8-default #252
  RIP: 0010:end_bio_extent_readpage+0x144/0x700
  Call Trace:
   <IRQ>
   blk_update_request+0x8f/0x350
   blk_mq_end_request+0x1a/0x120
   blk_done_softirq+0x99/0xc0
   __do_softirq+0xc7/0x467
   irq_exit+0xd1/0xe0
   call_function_single_interrupt+0xf/0x20
   </IRQ>
  RIP: 0010:default_idle+0x1e/0x170

[CAUSE]
The crafted image has a tricky corruption, the INODE_ITEM has a
different type against its parent dir:

        item 20 key (268 INODE_ITEM 0) itemoff 2808 itemsize 160
                generation 13 transid 13 size 1048576 nbytes 1048576
                block group 0 mode 121644 links 1 uid 0 gid 0 rdev 0
                sequence 9 flags 0x0(none)

This mode number 0120000 means it's a symlink.

But the dir item think it's still a regular file:

        item 8 key (264 DIR_INDEX 5) itemoff 3707 itemsize 32
                location key (268 INODE_ITEM 0) type FILE
                transid 13 data_len 0 name_len 2
                name: f4
        item 40 key (264 DIR_ITEM 51821248) itemoff 1573 itemsize 32
                location key (268 INODE_ITEM 0) type FILE
                transid 13 data_len 0 name_len 2
                name: f4

For symlink, we don't set BTRFS_I(inode)->io_tree.ops and leave it
empty, as symlink is only designed to have inlined extent, all handled
by tree block read.  Thus no need to trigger btrfs_submit_bio_hook() for
inline file extent.

However end_bio_extent_readpage() expects tree->ops populated, as it's
reading regular data extent.  This causes NULL pointer dereference.

[FIX]
This patch fixes the problem in two ways:

- Verify inode mode against its dir item when looking up inode
  So in btrfs_lookup_dentry() if we find inode mode mismatch with dir
  item, we error out so that corrupted inode will not be accessed.

- Verify inode mode when getting extent mapping
  Only regular file should have regular or preallocated extent.
  If we found regular/preallocated file extent for symlink or
  the rest, we error out before submitting the read bio.

With this fix that crafted image can be rejected gracefully:

  BTRFS critical (device loop0): inode mode mismatch with dir: inode mode=0121644 btrfs type=7 dir type=1

Reported-by: Yoon Jungyeon <jungyeon@gatech.edu>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=202763
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2 years agobtrfs: tree-checker: Verify inode item
Qu Wenruo [Wed, 13 Mar 2019 06:31:35 +0000 (14:31 +0800)]
btrfs: tree-checker: Verify inode item

There is a report in kernel bugzilla about mismatch file type in dir
item and inode item.

This inspires us to check inode mode in inode item.

This patch will check the following members:

- inode key objectid
  Should be ROOT_DIR_DIR or [256, (u64)-256] or FREE_INO.

- inode key offset
  Should be 0

- inode item generation
- inode item transid
  No newer than sb generation + 1.
  The +1 is for log tree.

- inode item mode
  No unknown bits.
  No invalid S_IF* bit.
  NOTE: S_IFMT check is not enough, need to check every know type.

- inode item nlink
  Dir should have no more link than 1.

- inode item flags

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>
2 years agobtrfs: tree-checker: Enhance chunk checker to validate chunk profile
Qu Wenruo [Wed, 13 Mar 2019 04:17:50 +0000 (12:17 +0800)]
btrfs: tree-checker: Enhance chunk checker to validate chunk profile

Btrfs-progs already have a comprehensive type checker, to ensure there
is only 0 (SINGLE profile) or 1 (DUP/RAID0/1/5/6/10) bit set for chunk
profile bits.

Do the same work for kernel.

Reported-by: Yoon Jungyeon <jungyeon@gatech.edu>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=202765
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>
2 years agobtrfs: tree-checker: Verify dev item
Qu Wenruo [Fri, 8 Mar 2019 06:20:03 +0000 (14:20 +0800)]
btrfs: tree-checker: Verify dev item

[BUG]
For fuzzed image whose DEV_ITEM has invalid total_bytes as 0, then
kernel will just panic:
  BUG: unable to handle kernel NULL pointer dereference at 0000000000000098
  #PF error: [normal kernel read fault]
  PGD 800000022b2bd067 P4D 800000022b2bd067 PUD 22b2bc067 PMD 0
  Oops: 0000 [#1] SMP PTI
  CPU: 0 PID: 1106 Comm: mount Not tainted 5.0.0-rc8+ #9
  RIP: 0010:btrfs_verify_dev_extents+0x2a5/0x5a0
  Call Trace:
   open_ctree+0x160d/0x2149
   btrfs_mount_root+0x5b2/0x680

[CAUSE]
If device extent verification finds a deivce with 0 total_bytes, then it
assumes it's a seed dummy, then search for seed devices.

But in this case, there is no seed device at all, causing NULL pointer.

[FIX]
Since this is caused by fuzzed image, let's go the tree-check way, just
add a new verification for device item.

Reported-by: Yoon Jungyeon <jungyeon@gatech.edu>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=202691
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: David Sterba <dsterba@suse.com>
2 years agobtrfs: tree-checker: Check chunk item at tree block read time
Qu Wenruo [Wed, 20 Mar 2019 05:42:33 +0000 (13:42 +0800)]
btrfs: tree-checker: Check chunk item at tree block read time

Since we have btrfs_check_chunk_valid() in tree-checker, let's do
chunk item verification in tree-checker too.

Since the tree-checker is run at endio time, if one chunk leaf fails
chunk verification, we can still retry the other copy, making btrfs more
robust to fuzzed image as we may still get a good chunk item.

Also since we have done chunk verification in tree block read time, skip
the btrfs_check_chunk_valid() call in read_one_chunk() if we're reading
chunk items from leaf.

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>
2 years agobtrfs: tree-checker: Make btrfs_check_chunk_valid() return EUCLEAN instead of EIO
Qu Wenruo [Wed, 20 Mar 2019 05:39:14 +0000 (13:39 +0800)]
btrfs: tree-checker: Make btrfs_check_chunk_valid() return EUCLEAN instead of EIO

To follow the standard behavior of tree-checker.

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>
2 years agobtrfs: tree-checker: Make chunk item checker messages more readable
Qu Wenruo [Wed, 20 Mar 2019 05:36:06 +0000 (13:36 +0800)]
btrfs: tree-checker: Make chunk item checker messages more readable

Old error message would be something like:
  BTRFS error (device dm-3): invalid chunk num_stipres: 0

New error message would be:
  Btrfs critical (device dm-3): corrupt superblock syschunk array: chunk_start=2097152, invalid chunk num_stripes: 0
Or
  Btrfs critical (device dm-3): corrupt leaf: root=3 block=8388608 slot=3 chunk_start=2097152, invalid chunk num_stripes: 0

And for certain error message, also output expected value.

The error message levels are changed from error to critical.

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>
2 years agobtrfs: Move btrfs_check_chunk_valid() to tree-check.[ch] and export it
Qu Wenruo [Wed, 20 Mar 2019 05:16:42 +0000 (13:16 +0800)]
btrfs: Move btrfs_check_chunk_valid() to tree-check.[ch] and export it

By function, chunk item verification is more suitable to be done inside
tree-checker.

So move btrfs_check_chunk_valid() to tree-checker.c and export it.

And since it's now moved to tree-checker, also add a better comment for
what this function is doing.

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>
2 years agobtrfs: qgroup: remove obsolete fs_info members
David Sterba [Wed, 27 Mar 2019 15:55:26 +0000 (16:55 +0100)]
btrfs: qgroup: remove obsolete fs_info members

The commit fcebe4562dec ("Btrfs: rework qgroup accounting") reworked
qgroups and added some new structures. Another rework of qgroup
mechanics e69bcee37692 ("btrfs: qgroup: Cleanup the old
ref_node-oriented mechanism.") stopped using them and left uncleaned.

Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2 years agobtrfs: get fs_info from eb in btrfs_verify_level_key
David Sterba [Wed, 20 Mar 2019 13:58:13 +0000 (14:58 +0100)]
btrfs: get fs_info from eb in btrfs_verify_level_key

We can read fs_info from extent buffer and can drop it from the
parameters.

Signed-off-by: David Sterba <dsterba@suse.com>
2 years agobtrfs: get fs_info from eb in btree_read_extent_buffer_pages
David Sterba [Wed, 20 Mar 2019 13:56:39 +0000 (14:56 +0100)]
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>
2 years agobtrfs: get fs_info from eb in read_node_slot
David Sterba [Wed, 20 Mar 2019 13:54:01 +0000 (14:54 +0100)]
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>
2 years agobtrfs: get fs_info from eb in btrfs_leaf_free_space
David Sterba [Wed, 20 Mar 2019 13:36:46 +0000 (14:36 +0100)]
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>
2 years agobtrfs: get fs_info from eb in clean_tree_block
David Sterba [Wed, 20 Mar 2019 13:30:02 +0000 (14:30 +0100)]
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>
2 years agobtrfs: get fs_info from eb in tree_mod_log_eb_copy
David Sterba [Wed, 20 Mar 2019 13:22:04 +0000 (14:22 +0100)]
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>
2 years agobtrfs: get fs_info from eb in check_tree_block_fsid
David Sterba [Wed, 20 Mar 2019 12:12:00 +0000 (13:12 +0100)]
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>
2 years agobtrfs: get fs_info from eb in btrfs_exclude_logged_extents
David Sterba [Wed, 20 Mar 2019 11:14:33 +0000 (12:14 +0100)]
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>
2 years agobtrfs: get fs_info from eb in leaf_data_end
David Sterba [Wed, 20 Mar 2019 10:33:10 +0000 (11:33 +0100)]
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>
2 years agobtrfs: get fs_info from eb in write_one_eb
David Sterba [Wed, 20 Mar 2019 10:27:57 +0000 (11:27 +0100)]
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>
2 years agobtrfs: get fs_info from eb in repair_eb_io_failure
David Sterba [Wed, 20 Mar 2019 10:23:44 +0000 (11:23 +0100)]
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>
2 years agobtrfs: get fs_info from eb in lock_extent_buffer_for_io
David Sterba [Wed, 20 Mar 2019 10:21:41 +0000 (11:21 +0100)]
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>
2 years agobtrfs: use common file type conversion
Phillip Potter [Tue, 26 Mar 2019 21:39:34 +0000 (21:39 +0000)]
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:
bbe7449e2599 "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>
2 years agobtrfs: Perform locking/unlocking in btrfs_remap_file_range()
Goldwyn Rodrigues [Mon, 25 Feb 2019 19:07:44 +0000 (13:07 -0600)]
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>
2 years agobtrfs: use BUG() instead of BUG_ON(1)
Arnd Bergmann [Mon, 25 Mar 2019 13:02:25 +0000 (14:02 +0100)]
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>
2 years agobtrfs: move tree block wait and write helpers to tree-log
David Sterba [Thu, 21 Mar 2019 19:21:05 +0000 (20:21 +0100)]
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>
2 years agobtrfs: remove stale definition of BUFFER_LRU_MAX
David Sterba [Thu, 21 Mar 2019 19:20:48 +0000 (20:20 +0100)]
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 6af118ce51b52ced ("Btrfs: Index extent
buffers in an rbtree"). There was one stale macro definition left.

Signed-off-by: David Sterba <dsterba@suse.com>
2 years agobtrfs: tests: unify messages when tests start
David Sterba [Mon, 18 Mar 2019 13:06:55 +0000 (14:06 +0100)]
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>
2 years agobtrfs: tests: drop messages when some tests finish
David Sterba [Mon, 18 Mar 2019 12:54:36 +0000 (13:54 +0100)]
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>
2 years agobtrfs: tests: fix comments about tested extent map ranges
David Sterba [Mon, 18 Mar 2019 13:19:33 +0000 (14:19 +0100)]
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>
2 years agobtrfs: tests: use SZ_ constants everywhere
David Sterba [Mon, 18 Mar 2019 13:14:35 +0000 (14:14 +0100)]
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>
2 years agobtrfs: tests: use standard error message after extent map allocation failure
David Sterba [Fri, 15 Mar 2019 16:28:46 +0000 (17:28 +0100)]
btrfs: tests: use standard error message after extent map allocation failure

Signed-off-by: David Sterba <dsterba@suse.com>
2 years agobtrfs: tests: return error from all extent map test cases
David Sterba [Mon, 18 Mar 2019 14:05:27 +0000 (15:05 +0100)]
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>
2 years agobtrfs: tests: return errors from extent map test case 4
David Sterba [Fri, 15 Mar 2019 17:41:06 +0000 (18:41 +0100)]
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>
2 years agobtrfs: tests: return errors from extent map test case 3
David Sterba [Fri, 15 Mar 2019 17:41:06 +0000 (18:41 +0100)]
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>
2 years agobtrfs: tests: return errors from extent map test case 2
David Sterba [Fri, 15 Mar 2019 17:41:06 +0000 (18:41 +0100)]
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>
2 years agobtrfs: tests: return errors from extent map test case 1
David Sterba [Fri, 15 Mar 2019 17:41:06 +0000 (18:41 +0100)]
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>
2 years agobtrfs: tests: return errors from extent map tests
David Sterba [Fri, 15 Mar 2019 17:06:16 +0000 (18:06 +0100)]
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>
2 years agobtrfs: tests: properly initialize fs_info of extent buffer
David Sterba [Fri, 15 Mar 2019 16:42:07 +0000 (17:42 +0100)]
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>
2 years agobtrfs: tests: use standard error message after block group allocation failure
David Sterba [Fri, 15 Mar 2019 16:28:46 +0000 (17:28 +0100)]
btrfs: tests: use standard error message after block group allocation failure

Signed-off-by: David Sterba <dsterba@suse.com>
2 years agobtrfs: tests: use standard error message after inode allocation failure
David Sterba [Fri, 15 Mar 2019 16:28:46 +0000 (17:28 +0100)]
btrfs: tests: use standard error message after inode allocation failure

Signed-off-by: David Sterba <dsterba@suse.com>
2 years agobtrfs: tests: use standard error message after path allocation failure
David Sterba [Fri, 15 Mar 2019 16:28:46 +0000 (17:28 +0100)]
btrfs: tests: use standard error message after path allocation failure

Signed-off-by: David Sterba <dsterba@suse.com>
2 years agobtrfs: tests: use standard error message after extent buffer allocation failure
David Sterba [Fri, 15 Mar 2019 16:28:46 +0000 (17:28 +0100)]
btrfs: tests: use standard error message after extent buffer allocation failure

Signed-off-by: David Sterba <dsterba@suse.com>
2 years agobtrfs: tests: use standard error message after root allocation failure
David Sterba [Fri, 15 Mar 2019 16:28:46 +0000 (17:28 +0100)]
btrfs: tests: use standard error message after root allocation failure

Signed-off-by: David Sterba <dsterba@suse.com>
2 years agobtrfs: tests: use standard error message after fs_info allocation failure
David Sterba [Fri, 15 Mar 2019 16:28:46 +0000 (17:28 +0100)]
btrfs: tests: use standard error message after fs_info allocation failure

Signed-off-by: David Sterba <dsterba@suse.com>
2 years agobtrfs: tests: add table of most common errors
David Sterba [Fri, 15 Mar 2019 16:23:30 +0000 (17:23 +0100)]
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>
2 years agobtrfs: tests: print file:line for error messages
David Sterba [Fri, 15 Mar 2019 16:03:55 +0000 (17:03 +0100)]
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>
2 years agobtrfs: tests: don't leak fs_info in extent_io bitmap tests
David Sterba [Fri, 15 Mar 2019 15:46:55 +0000 (16:46 +0100)]
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>
2 years agobtrfs: tests: handle fs_info allocation failure in extent_io tests
David Sterba [Fri, 15 Mar 2019 15:43:11 +0000 (16:43 +0100)]
btrfs: tests: handle fs_info allocation failure in extent_io tests

Signed-off-by: David Sterba <dsterba@suse.com>
2 years agobtrfs: disk-io: Show the timing of corrupted tree block explicitly
Qu Wenruo [Wed, 20 Mar 2019 06:27:40 +0000 (14:27 +0800)]
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>
2 years agobtrfs: fix panic during relocation after ENOSPC before writeback happens
Josef Bacik [Mon, 25 Feb 2019 16:14:45 +0000 (11:14 -0500)]
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>
2 years agobtrfs: Use less confusing condition for uptodate parameter to btrfs_writepage_endio_f...
Nikolay Borisov [Wed, 20 Mar 2019 19:53:16 +0000 (21:53 +0200)]
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>
2 years agobtrfs: extent_io: Handle errors better in extent_writepages()
Qu Wenruo [Wed, 20 Mar 2019 06:27:48 +0000 (14:27 +0800)]
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>
2 years agobtrfs: extent_io: add proper error handling to lock_extent_buffer_for_io()
Qu Wenruo [Wed, 20 Mar 2019 06:27:46 +0000 (14:27 +0800)]
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>
2 years agobtrfs: extent_io: Handle errors better in extent_write_locked_range()
Qu Wenruo [Wed, 20 Mar 2019 06:27:45 +0000 (14:27 +0800)]
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>
2 years agobtrfs: extent_io: Kill dead condition in extent_write_cache_pages()
Qu Wenruo [Wed, 20 Mar 2019 06:27:44 +0000 (14:27 +0800)]
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>
2 years agobtrfs: extent_io: Handle errors better in btree_write_cache_pages()
Qu Wenruo [Wed, 20 Mar 2019 06:27:43 +0000 (14:27 +0800)]
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>
2 years agobtrfs: extent_io: Handle errors better in extent_write_full_page()
Qu Wenruo [Wed, 20 Mar 2019 06:27:42 +0000 (14:27 +0800)]
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>
2 years agobtrfs: extent_io: Move the BUG_ON() in flush_write_bio() one level up
Qu Wenruo [Wed, 20 Mar 2019 06:27:41 +0000 (14:27 +0800)]
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>
2 years agobtrfs: Always output error message when key/level verification fails
Qu Wenruo [Wed, 20 Mar 2019 06:27:39 +0000 (14:27 +0800)]
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>
2 years agobtrfs: Check the first key and level for cached extent buffer
Qu Wenruo [Tue, 12 Mar 2019 09:10:40 +0000 (17:10 +0800)]
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>
2 years agobtrfs: Correctly free extent buffer in case btree_read_extent_buffer_pages fails
Nikolay Borisov [Thu, 14 Mar 2019 07:52:35 +0000 (09:52 +0200)]
btrfs: Correctly free extent buffer in case btree_read_extent_buffer_pages fails

If a an eb fails to be read for whatever reason - it's corrupted on disk
and parent transid/key validations fail or IO for eb pages fail then
this buffer must be removed from the buffer cache. Currently the code
calls free_extent_buffer if an error occurs. Unfortunately this doesn't
achieve the desired behavior since btrfs_find_create_tree_block returns
with eb->refs == 2.

On the other hand free_extent_buffer will only decrement the refs once
leaving it added to the buffer cache radix tree.  This enables later
code to look up the buffer from the cache and utilize it potentially
leading to a crash.

The correct way to free the buffer is call free_extent_buffer_stale.
This function will correctly call atomic_dec explicitly for the buffer
and subsequently call release_extent_buffer which will decrement the
final reference thus correctly remove the invalid buffer from buffer
cache. This change affects only newly allocated buffers since they have
eb->refs == 2.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=202755
Reported-by: Jungyeon <jungyeon@gatech.edu>
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>
2 years agobtrfs: Make btrfs_(set|clear)_header_flag return void
Qu Wenruo [Tue, 19 Mar 2019 06:04:17 +0000 (14:04 +0800)]
btrfs: Make btrfs_(set|clear)_header_flag return void

From the introduction of btrfs_(set|clear)_header_flag, there is no
usage of its return value.  So just make it return void.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2 years agobtrfs: reloc: Fix NULL pointer dereference due to expanded reloc_root lifespan
Qu Wenruo [Mon, 18 Mar 2019 02:48:19 +0000 (10:48 +0800)]
btrfs: reloc: Fix NULL pointer dereference due to expanded reloc_root lifespan

Commit d2311e698578 ("btrfs: relocation: Delay reloc tree deletion after
merge_reloc_roots()") expands the life span of root->reloc_root.

This breaks certain checs of fs_info->reloc_ctl.  Before that commit, if
we have a root with valid reloc_root, then it's ensured to have
fs_info->reloc_ctl.

But now since reloc_root doesn't always mean a valid fs_info->reloc_ctl,
such check is unreliable and can cause the following NULL pointer
dereference:

  BUG: unable to handle kernel NULL pointer dereference at 00000000000005c1
  IP: btrfs_reloc_pre_snapshot+0x20/0x50 [btrfs]
  PGD 0 P4D 0
  Oops: 0000 [#1] SMP PTI
  CPU: 0 PID: 10379 Comm: snapperd Not tainted
  Call Trace:
   create_pending_snapshot+0xd7/0xfc0 [btrfs]
   create_pending_snapshots+0x8e/0xb0 [btrfs]
   btrfs_commit_transaction+0x2ac/0x8f0 [btrfs]
   btrfs_mksubvol+0x561/0x570 [btrfs]
   btrfs_ioctl_snap_create_transid+0x189/0x190 [btrfs]
   btrfs_ioctl_snap_create_v2+0x102/0x150 [btrfs]
   btrfs_ioctl+0x5c9/0x1e60 [btrfs]
   do_vfs_ioctl+0x90/0x5f0
   SyS_ioctl+0x74/0x80
   do_syscall_64+0x7b/0x150
   entry_SYSCALL_64_after_hwframe+0x3d/0xa2
  RIP: 0033:0x7fd7cdab8467

Fix it by explicitly checking fs_info->reloc_ctl other than using the
implied root->reloc_root.

Fixes: d2311e698578 ("btrfs: relocation: Delay reloc tree deletion after merge_reloc_roots")
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2 years agobtrfs: Remove unused -EIO assignment in end_bio_extent_readpage
Nikolay Borisov [Mon, 18 Mar 2019 15:45:18 +0000 (17:45 +0200)]
btrfs: Remove unused -EIO assignment in end_bio_extent_readpage

In case we hit the error case for a metadata buffer in
end_bio_extent_readpage then 'ret' won't really be checked before it's
written again to. This means the -EIO in this case will never be
checked, just remove it.

Fixes-coverity-id: 1442513
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2 years agobtrfs: Exploit the fact that pages passed to extent_readpages are always contiguous
Nikolay Borisov [Mon, 11 Mar 2019 07:55:38 +0000 (09:55 +0200)]
btrfs: Exploit the fact that pages passed to extent_readpages are always contiguous

Currently extent_readpages (called from btrfs_readpages) will always
call __extent_readpages which tries to create contiguous range of pages
and call __do_contiguous_readpages when such contiguous range is
created.

It turns out this is unnecessary due to the fact that generic MM code
always calls filesystem's ->readpages callback (btrfs_readpages in
this case) with already contiguous pages. Armed with this knowledge it's
possible to simplify extent_readpages by eliminating the call to
__extent_readpages and directly calling contiguous_readpages.

The only edge case that needs to be handled is when
add_to_page_cache_lru fails. This is easy as all that is needed is to
submit whatever is the number of pages successfully added to the lru.
This can happen when the page is already in the range, so it does not
need to be read again, and we can't do anything else in case of other
errors.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2 years agobtrfs: switch extent_buffer::lock_nested to bool
David Sterba [Fri, 24 Aug 2018 14:31:17 +0000 (16:31 +0200)]
btrfs: switch extent_buffer::lock_nested to bool

The member is tracking simple status of the lock, we can use bool for
that and make some room for further space reduction in the structure.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: David Sterba <dsterba@suse.com>
2 years agobtrfs: use assertion helpers for extent buffer write lock counters
David Sterba [Fri, 24 Aug 2018 14:24:26 +0000 (16:24 +0200)]
btrfs: use assertion helpers for extent buffer write lock counters

Use the helpers where open coded. On non-debug builds, the warnings will
not trigger and extent_buffer::write_locks become unused and can be
moved to the appropriate section, saving a few bytes.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: David Sterba <dsterba@suse.com>
2 years agobtrfs: add assertion helpers for extent buffer write lock counters
David Sterba [Fri, 24 Aug 2018 14:20:02 +0000 (16:20 +0200)]
btrfs: add assertion helpers for extent buffer write lock counters

The write_locks are a simple counter to track locking balance and used
to assert tree locks.  Add helpers to make it conditionally work only in
DEBUG builds.  Will be used in followup patches.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: David Sterba <dsterba@suse.com>
2 years agobtrfs: use assertion helpers for extent buffer read lock counters
David Sterba [Fri, 24 Aug 2018 14:15:51 +0000 (16:15 +0200)]
btrfs: use assertion helpers for extent buffer read lock counters

Use the helpers where open coded. On non-debug builds, the warnings will
not trigger and extent_buffer::read_locks become unused and can be
moved to the appropriate section, saving a few bytes.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: David Sterba <dsterba@suse.com>
2 years agobtrfs: add assertion helpers for extent buffer read lock counters
David Sterba [Fri, 24 Aug 2018 14:13:41 +0000 (16:13 +0200)]
btrfs: add assertion helpers for extent buffer read lock counters

The read_locks are a simple counter to track locking balance and used to
assert tree locks.  Add helpers to make it conditionally work only in
DEBUG builds.  Will be used in followup patches.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: David Sterba <dsterba@suse.com>
2 years agobtrfs: use assertion helpers for spinning readers
David Sterba [Fri, 24 Aug 2018 13:57:38 +0000 (15:57 +0200)]
btrfs: use assertion helpers for spinning readers

Use the helpers where open coded. On non-debug builds, the warnings will
not trigger and extent_buffer::spining_readers become unused and can be
moved to the appropriate section, saving a few bytes.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: David Sterba <dsterba@suse.com>
2 years agobtrfs: add assertion helpers for spinning readers
David Sterba [Fri, 24 Aug 2018 13:53:42 +0000 (15:53 +0200)]
btrfs: add assertion helpers for spinning readers

Add helpers for conditional DEBUG build to assert that the extent buffer
spinning_readers constraints are met. Will be used in followup patches.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: David Sterba <dsterba@suse.com>
2 years agobtrfs: use assertion helpers for spinning writers
David Sterba [Fri, 24 Aug 2018 12:56:28 +0000 (14:56 +0200)]
btrfs: use assertion helpers for spinning writers

Use the helpers where open coded. On non-debug builds, the warnings will
not trigger and extent_buffer::spining_writers become unused and can be
moved to the appropriate section, saving a few bytes.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: David Sterba <dsterba@suse.com>
2 years agobtrfs: add assertion helpers for spinning writers
David Sterba [Fri, 24 Aug 2018 12:45:20 +0000 (14:45 +0200)]
btrfs: add assertion helpers for spinning writers

Add helpers for conditional DEBUG build to assert that the extent buffer
spinning_writers constraints are met. Will be used in followup patches.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: David Sterba <dsterba@suse.com>
2 years agobtrfs: Remove EXTENT_IOBITS
Nikolay Borisov [Thu, 14 Mar 2019 13:28:31 +0000 (15:28 +0200)]
btrfs: Remove EXTENT_IOBITS

This flag just became synonymous to EXTENT_LOCKED, so just remove it and
used EXTENT_LOCKED directly. 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>
2 years agobtrfs: Remove EXTENT_WRITEBACK
Nikolay Borisov [Thu, 14 Mar 2019 13:28:30 +0000 (15:28 +0200)]
btrfs: Remove EXTENT_WRITEBACK

This flag was introduced in a52d9a8033c4 ("Btrfs: Extent based page
cache code.") and subsequently it's usage effectively was removed by
1edbb734b4e0 ("Btrfs: reduce CPU usage in the extent_state tree") and
f2a97a9dbd86 ("btrfs: remove all unused functions"). Just remove it,
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>
2 years agobtrfs: Turn an 'else if' into an 'else' in btrfs_uuid_tree_add
Nathan Chancellor [Thu, 7 Mar 2019 16:35:15 +0000 (09:35 -0700)]
btrfs: Turn an 'else if' into an 'else' in btrfs_uuid_tree_add

When building with -Wsometimes-uninitialized, Clang warns:

fs/btrfs/uuid-tree.c:129:13: warning: variable 'eb' is used uninitialized whenever 'if' condition is false [-Wsometimes-uninitialized]
fs/btrfs/uuid-tree.c:129:13: warning: variable 'offset' is used uninitialized whenever 'if' condition is false [-Wsometimes-uninitialized]

Clang can't tell that all cases are covered with this final else if.
Just turn it into an else so that it is clear.

Link: https://github.com/ClangBuiltLinux/linux/issues/385
Suggested-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2 years agobtrfs: refactor btrfs_set_prop and add btrfs_set_prop_trans
Anand Jain [Fri, 1 Mar 2019 04:34:50 +0000 (12:34 +0800)]
btrfs: refactor btrfs_set_prop and add btrfs_set_prop_trans

btrfs_set_prop() takes transaction pointer as the first argument,
however in ioctl.c for the purpose of setting the compression property,
we call btrfs_set_prop() with NULL transaction pointer. Down in
the call chain  btrfs_setxattr() starts transaction to update the
attribute and also to update the inode.

So for clarity, create btrfs_set_prop_trans() with no transaction
pointer as argument, in preparation to start transaction here instead of
doing it down the call chain at btrfs_setxattr().

Also now the btrfs_set_prop() is a static function.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2 years agobtrfs: rename fs_info argument to fs_private
Anand Jain [Fri, 1 Mar 2019 04:34:49 +0000 (12:34 +0800)]
btrfs: rename fs_info argument to fs_private

fs_info is commonly used to represent struct fs_info *, rename
to fs_private to avoid confusion.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2 years agobtrfs: drop redundant forward declaration in props.c
Anand Jain [Fri, 1 Mar 2019 04:34:48 +0000 (12:34 +0800)]
btrfs: drop redundant forward declaration in props.c

Drop forward declaration of the functions:

- prop_compression_validate
- prop_compression_apply
- prop_compression_extract

No functional changes.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2 years agobtrfs: merge _btrfs_set_prop helpers
Anand Jain [Fri, 1 Mar 2019 04:34:47 +0000 (12:34 +0800)]
btrfs: merge _btrfs_set_prop helpers

btrfs_set_prop() is a redirect to __btrfs_set_prop() with the
transaction handle equal to NULL.  __btrfs_set_prop() in turn passes
this to do_setxattr() which then transaction is actually created.

Instead merge  __btrfs_set_prop() to btrfs_set_prop(), and update the
caller with NULL argument.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2 years agobtrfs: reduce kmap_atomic time for checksumming
Johannes Thumshirn [Thu, 7 Mar 2019 16:14:00 +0000 (17:14 +0100)]
btrfs: reduce kmap_atomic time for checksumming

Since commit c40a3d38aff4 ("Btrfs: Compute and look up csums based on
sectorsized blocks") we do a kmap_atomic() on the contents of a bvec.
The code before c40a3d38aff4 had the kmap region just around the
checksumming too.

kmap_atomic() in turn does a preempt_disable() and pagefault_disable(),
so we shouldn't map the data for too long. Reduce the time the bvec's
page is mapped to when we actually need it.

Performance wise it doesn't seem to make a huge difference with a 2 vcpu VM
on a /dev/zram device:

       vanilla      patched      delta
write  17.4MiB/s    17.8MiB/s +0.4MiB/s (+2%)
read   40.6MiB/s    41.5MiB/s   +0.9MiB/s (+2%)

The following fio job profile was used in the comparision:

[global]
ioengine=libaio
direct=1
sync=1
norandommap
time_based
runtime=10m
size=100m
group_reporting
numjobs=2

[test]
filename=/mnt/test/fio
rw=randrw
rwmixread=70

Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2 years agobtrfs: tracepoints: Add trace events for extent_io_tree
Qu Wenruo [Fri, 1 Mar 2019 02:48:00 +0000 (10:48 +0800)]
btrfs: tracepoints: Add trace events for extent_io_tree

Although btrfs heavily relies on extent_io_tree, we don't really have
any good trace events for them.

This patch will add the folowing trace events:
- trace_btrfs_set_extent_bit()
- trace_btrfs_clear_extent_bit()
- trace_btrfs_convert_extent_bit()

Since selftests could create temporary extent_io_tree without fs_info,
modify TP_fast_assign_fsid() to accept NULL as fs_info.  NULL fs_info
will lead to all zero fsid.

The output would be:
  btrfs_set_extent_bit: <FDID>: io_tree=INODE_IO ino=1 root=1 start=22036480 len=4096 set_bits=LOCKED
  btrfs_set_extent_bit: <FSID>: io_tree=INODE_IO ino=1 root=1 start=22040576 len=4096 set_bits=LOCKED
  btrfs_set_extent_bit: <FSID>: io_tree=INODE_IO ino=1 root=1 start=22044672 len=4096 set_bits=LOCKED
  btrfs_set_extent_bit: <FSID>: io_tree=INODE_IO ino=1 root=1 start=22048768 len=4096 set_bits=LOCKED
  btrfs_clear_extent_bit: <FSID>: io_tree=INODE_IO ino=1 root=1 start=22036480 len=16384 clear_bits=LOCKED
  ^^^ Extent buffer 22036480 read from disk, the locking progress

  btrfs_set_extent_bit: <FSID>: io_tree=TRANS_DIRTY_PAGES ino=1 root=1 start=30425088 len=16384 set_bits=DIRTY
  btrfs_set_extent_bit: <FSID>: io_tree=TRANS_DIRTY_PAGES ino=1 root=1 start=30441472 len=16384 set_bits=DIRTY
  ^^^ 2 new tree blocks allocated in one transaction

  btrfs_set_extent_bit: <FSID>: io_tree=FREED_EXTENTS0 ino=0 root=0 start=30523392 len=16384 set_bits=DIRTY
  btrfs_set_extent_bit: <FSID>: io_tree=FREED_EXTENTS0 ino=0 root=0 start=30556160 len=16384 set_bits=DIRTY
  ^^^ 2 old tree blocks get pinned down

There is one point which need attention:
1) Those trace events can be pretty heavy:
   The following workload would generate over 400 trace events.

mkfs.btrfs -f $dev
start_trace
mount $dev $mnt -o enospc_debug
sync
touch $mnt/file1
touch $mnt/file2
touch $mnt/file3
xfs_io -f -c "pwrite 0 16k" $mnt/file4
umount $mnt
end_trace

   It's not recommended to use them in real world environment.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ rename enums ]
Signed-off-by: David Sterba <dsterba@suse.com>