linux/fs/pstore
Ard Biesheuvel 1756ddea69 pstore: Remove worst-case compression size logic
The worst case compression size used by pstore gives an upper bound for
how much the data might inadvertently *grow* due to encapsulation
overhead if the input is not compressible at all.

Given that pstore records have individual 'compressed' flags, we can
simply store the uncompressed data if compressing it would end up using
more space, making the worst case identical to the uncompressed case.

This means we can just drop all the elaborate logic that reasons about
upper bounds for each individual compression algorithm, and just store
the uncompressed data directly if compression fails for any reason.

Co-developed-by: Kees Cook <keescook@chromium.org>
Tested-by: "Guilherme G. Piccoli" <gpiccoli@igalia.com> # Steam Deck
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Link: https://lore.kernel.org/r/20230712162332.2670437-2-ardb@kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
2023-07-17 16:08:58 -07:00
..
blk.c init: improve the name_to_dev_t interface 2023-06-05 10:56:46 -06:00
ftrace.c pstore/ftrace: Allow immediate recording 2021-11-18 10:29:52 -08:00
inode.c pstore: Add priv field to pstore_record for backend specific use 2022-06-24 20:40:04 +02:00
internal.h pstore: Move kmsg_bytes default into Kconfig 2020-12-01 12:09:17 -08:00
Kconfig pstore: Make sure CONFIG_PSTORE_PMSG selects CONFIG_RT_MUTEXES 2022-12-23 10:33:27 -08:00
Makefile pstore/blk: Introduce backend for block devices 2020-05-30 10:34:03 -07:00
platform.c pstore: Remove worst-case compression size logic 2023-07-17 16:08:58 -07:00
pmsg.c pstore update for v6.4-rc1 2023-04-27 17:03:40 -07:00
ram_core.c pstore/ram: Add check for kstrdup 2023-06-14 11:52:10 -07:00
ram_internal.h pstore/ram: Set freed addresses to NULL 2022-10-19 09:25:39 -07:00
ram.c pstore/ram: Convert to platform remove callback returning void 2023-05-10 14:06:00 -07:00
zone.c pstore/zone: Use GFP_ATOMIC to allocate zone buffer 2022-10-17 13:14:10 -07:00