When pstore was refactored to use the crypto compress API in: commit cb3bee0369bc ("pstore: Use crypto compress API") nearly all the pstore-specific compression routines were replaced with the existing crypto compression API. One case remained: calculating the "worst case" compression sizes ahead of time so it could have a buffer preallocated for doing compression (which was called "zbufsize"). To make pstore fully algorithm-agnostic, the compression API needs to grow this functionality. This adds the interface to support querying the "worst case" estimate, with a new "zbufsize" routine that each compressor can implement. This series adds the interface, updates each compressor, and refactors pstore. (Though note, this is based on v4.18-rc2, and pstore will be gaining zstd support during the v4.19 merge window, so the last patch in this series will need to be coordinated, but I left it to show how things would look right now.) -Kees Kees Cook (9): crypto: add zbufsize() interface crypto, 842: implement zbufsize() crypto, null: Implement zbufsize() crypto, lzo: Implement zbufsize() crypto, deflate: Implement zbufsize() crypto, zstd: Implement zbufsize() crypto, lz4: Implement zbufsize() crypto, lz4hc: Implement zbufsize() pstore: Use crypto_comp_zbufsize() crypto/842.c | 17 ++- crypto/compress.c | 9 ++ crypto/crypto_null.c | 10 +- crypto/deflate.c | 48 +++++++- crypto/lz4.c | 22 +++- crypto/lz4hc.c | 22 +++- crypto/lzo.c | 22 +++- crypto/zstd.c | 22 +++- fs/pstore/Kconfig | 91 +++++---------- fs/pstore/inode.c | 2 - fs/pstore/internal.h | 3 - fs/pstore/platform.c | 171 ++++++---------------------- include/crypto/internal/scompress.h | 11 ++ include/linux/crypto.h | 12 ++ include/linux/sw842.h | 9 ++ 15 files changed, 257 insertions(+), 214 deletions(-) -- 2.17.1