diff options
| author | Darrick J. Wong <djwong@us.ibm.com> | 2012-04-29 18:27:10 -0400 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2012-04-29 18:27:10 -0400 |
| commit | 0441984a3398970ab4820410b9cf4ff85bf3a6b0 (patch) | |
| tree | 23c22fad52554003b39d35e6dee7729df3e0797d /fs/ext4/ext4.h | |
| parent | d25425f8e0ed01fc0167c043aee7e619fc3f6ab2 (diff) | |
| download | lwn-0441984a3398970ab4820410b9cf4ff85bf3a6b0.tar.gz lwn-0441984a3398970ab4820410b9cf4ff85bf3a6b0.zip | |
ext4: load the crc32c driver if necessary
Obtain a reference to the cryptoapi and crc32c if we mount a
filesystem with metadata checksumming enabled.
Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Diffstat (limited to 'fs/ext4/ext4.h')
| -rw-r--r-- | fs/ext4/ext4.h | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h index 61dd739b64f0..f19192bde094 100644 --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -29,6 +29,7 @@ #include <linux/wait.h> #include <linux/blockgroup_lock.h> #include <linux/percpu_counter.h> +#include <crypto/hash.h> #ifdef __KERNEL__ #include <linux/compat.h> #endif @@ -1276,6 +1277,9 @@ struct ext4_sb_info { /* record the last minlen when FITRIM is called. */ atomic_t s_last_trim_minblks; + + /* Reference to checksum algorithm driver via cryptoapi */ + struct crypto_shash *s_chksum_driver; }; static inline struct ext4_sb_info *EXT4_SB(struct super_block *sb) @@ -1639,6 +1643,25 @@ static inline __le16 ext4_rec_len_to_disk(unsigned len, unsigned blocksize) #define DX_HASH_HALF_MD4_UNSIGNED 4 #define DX_HASH_TEA_UNSIGNED 5 +static inline u32 ext4_chksum(struct ext4_sb_info *sbi, u32 crc, + const void *address, unsigned int length) +{ + struct { + struct shash_desc shash; + char ctx[crypto_shash_descsize(sbi->s_chksum_driver)]; + } desc; + int err; + + desc.shash.tfm = sbi->s_chksum_driver; + desc.shash.flags = 0; + *(u32 *)desc.ctx = crc; + + err = crypto_shash_update(&desc.shash, address, length); + BUG_ON(err); + + return *(u32 *)desc.ctx; +} + #ifdef __KERNEL__ /* hash info structure used by the directory hash */ |