linux-toradex.git/drivers/md/dm-verity-fec.c, branch v4.9.78

dm verity fec: fix bufio leaks

2017-04-12T10:41:12+00:00

commit 86e3e83b443669dd2bcc5c8a83b23e3aa0694c0d upstream.

Buffers read through dm_bufio_read() were not released in all code paths.

Fixes: a739ff3f543a ("dm verity: add support for forward error correction")
Signed-off-by: Sami Tolvanen 
Signed-off-by: Mike Snitzer 
Signed-off-by: Greg Kroah-Hartman

dm verity fec: limit error correction recursion

2017-04-12T10:41:12+00:00

commit f1a880a93baaadb14c10a348fd199f1cdb6bcccd upstream.

If the hash tree itself is sufficiently corrupt in addition to data blocks,
it's possible for error correction to end up in a deep recursive loop,
which eventually causes a kernel panic.  This change limits the
recursion to a reasonable level during a single I/O operation.

Fixes: a739ff3f543a ("dm verity: add support for forward error correction")
Signed-off-by: Sami Tolvanen 
Signed-off-by: Mike Snitzer 
Signed-off-by: Greg Kroah-Hartman

dm verity fec: fix block calculation

2016-07-02T03:29:08+00:00

do_div was replaced with div64_u64 at some point, causing a bug with
block calculation due to incompatible semantics of the two functions.

Signed-off-by: Sami Tolvanen 
Fixes: a739ff3f543a ("dm verity: add support for forward error correction")
Cc: stable@vger.kernel.org # v4.5+
Signed-off-by: Mike Snitzer

dm: rename target's per_bio_data_size to per_io_data_size

2016-02-23T03:34:37+00:00

Request-based DM will also make use of per_bio_data_size.

Signed-off-by: Mike Snitzer

dm verity: add ignore_zero_blocks feature

2015-12-10T15:39:03+00:00

If ignore_zero_blocks is enabled dm-verity will return zeroes for blocks
matching a zero hash without validating the content.

Signed-off-by: Sami Tolvanen 
Signed-off-by: Mike Snitzer

dm verity: add support for forward error correction

2015-12-10T15:39:03+00:00

Add support for correcting corrupted blocks using Reed-Solomon.

This code uses RS(255, N) interleaved across data and hash
blocks. Each error-correcting block covers N bytes evenly
distributed across the combined total data, so that each byte is a
maximum distance away from the others. This makes it possible to
recover from several consecutive corrupted blocks with relatively
small space overhead.

In addition, using verity hashes to locate erasures nearly doubles
the effectiveness of error correction. Being able to detect
corrupted blocks also improves performance, because only corrupted
blocks need to corrected.

For a 2 GiB partition, RS(255, 253) (two parity bytes for each
253-byte block) can correct up to 16 MiB of consecutive corrupted
blocks if erasures can be located, and 8 MiB if they cannot, with
16 MiB space overhead.

Signed-off-by: Sami Tolvanen 
Signed-off-by: Mike Snitzer