The function uses the reverse CRC32C table to quickly calculate a
4-byte suffix, that when added to the original data will make it
match desired checksum.
Author: Piotr Pawlow <pp@siedziba.pl>
[ minor adjustments ]
Signed-off-by: David Sterba <dsterba@suse.com>
The table will be used to speed up calculations of CRC32C collisions.
Author: Piotr Pawlow <pp@siedziba.pl>
Signed-off-by: David Sterba <dsterba@suse.com>
Function find_collision sometimes generated file names with non-printable
DEL characters (code 127), for example file name "|5gp!" would be changed
to "U'2<DEL>y" when using "crc-collisions" sanitize mode.
Author: Piotr Pawlow <pp@siedziba.pl>
Signed-off-by: David Sterba <dsterba@suse.com>
Tree blocks are always nodesize. As readahead is only an optimization,
exact size is not required and is only advisory.
Signed-off-by: David Sterba <dsterba@suse.com>
Making the code data-race safe requires that reads *and* writes
happen under a mutex lock, if any of the access are writes. See
Dmitri Vyukov, "Benign data races: what could possibly go wrong?"
for more details.
The fix here was to put most of the main loop of restore_worker
under a mutex lock.
This race was detected using fsck-tests/012-leaf-corruption.
==================
WARNING: ThreadSanitizer: data race
Write of size 4 by main thread:
#0 add_cluster btrfs-progs/image/main.c:1931
#1 restore_metadump btrfs-progs/image/main.c:2566
#2 main btrfs-progs/image/main.c:2859
Previous read of size 4 by thread T6:
#0 restore_worker btrfs-progs/image/main.c:1720
Location is stack of main thread.
Thread T6 (running) created by main thread at:
#0 pthread_create <null>
#1 mdrestore_init btrfs-progs/image/main.c:1868
#2 restore_metadump btrfs-progs/image/main.c:2534
#3 main btrfs-progs/image/main.c:2859
SUMMARY: ThreadSanitizer: data race btrfs-progs/image/main.c:1931 in
add_cluster
Signed-off-by: Adam Buchbinder <abuchbinder@google.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The only reasom read_tree_block() needs a btrfs_root parameter is to get
its node/sector size.
And long ago, I have already introduced a compactible interface,
read_tree_block_fs_info() to pass btrfs_fs_info instead of btrfs_root.
Since we have cleaned up all root->sector/node/stripesize users, we
should be OK to refactor read_tree_block() function.
Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
We correctly build an image from a multiple devices filesystem but when
restoring the image into a single device we were missing updating the
number of devices in the superblock to the value 1 (we already took care
of setting the number of stripes to 1 for each chunk item and setting
the device id for each chunk item to match the device id from the super
block).
This missing update of the number of devices makes it impossible to mount
the restored filesystem on recent kernels, more specifically since the
linux kernel commit 99e3ecfcb9f4ca35192d20a5bea158b81f600062
("Btrfs: add more validation checks for superblock"), that produce the
following message in the dmesg/syslog:
[21097.542047] BTRFS error (device sdi): super_num_devices 2 mismatch with num_devices 1 found here
[21097.543972] BTRFS error (device sdi): failed to read chunk tree: -22
[21097.720360] BTRFS error (device sdi): open_ctree failed
So fix this by updating the number of devices to 1 in the superblock.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
While performing a memcpy, we are copying from uninitialized dst
as opposed to src->data. Though using eb->len is correct, I used
src->len to make it more readable.
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Piotr Pawlow