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authorDarrick J. Wong <djwong@us.ibm.com>2012-04-29 18:27:10 -0400
committerTheodore Ts'o <tytso@mit.edu>2012-04-29 18:27:10 -0400
commit0441984a3398970ab4820410b9cf4ff85bf3a6b0 (patch)
tree23c22fad52554003b39d35e6dee7729df3e0797d /fs/ext4/ext4.h
parentd25425f8e0ed01fc0167c043aee7e619fc3f6ab2 (diff)
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.h23
1 files changed, 23 insertions, 0 deletions
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 61dd739b64f..f19192bde09 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 */