diff options
| author | Darrick J. Wong <djwong@us.ibm.com> | 2012-05-27 07:50:56 -0400 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2012-05-27 07:50:56 -0400 |
| commit | 01b5adcebb977bc61b64167adce6d8260c9da33c (patch) | |
| tree | 2d17de43723163d40ada0d8f51faf1061c324f5f | |
| parent | 25ed6e8a54df904c875365eebedbd19138a47328 (diff) | |
jbd2: Grab a reference to the crc32c driver if necessary
Obtain a reference to the crc32c driver if needed for the v2 checksum.
Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
| -rw-r--r-- | fs/jbd2/Kconfig | 2 | ||||
| -rw-r--r-- | fs/jbd2/journal.c | 25 | ||||
| -rw-r--r-- | include/linux/jbd2.h | 23 |
3 files changed, 50 insertions, 0 deletions
diff --git a/fs/jbd2/Kconfig b/fs/jbd2/Kconfig index f32f346f4b0a..69a48c2944da 100644 --- a/fs/jbd2/Kconfig +++ b/fs/jbd2/Kconfig @@ -1,6 +1,8 @@ config JBD2 tristate select CRC32 + select CRYPTO + select CRYPTO_CRC32C help This is a generic journaling layer for block devices that support both 32-bit and 64-bit block numbers. It is currently used by diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c index 63175f9391ab..f04ab6c4b428 100644 --- a/fs/jbd2/journal.c +++ b/fs/jbd2/journal.c @@ -1438,6 +1438,17 @@ static int journal_get_superblock(journal_t *journal) goto out; } + /* Load the checksum driver */ + if (JBD2_HAS_INCOMPAT_FEATURE(journal, JBD2_FEATURE_INCOMPAT_CSUM_V2)) { + journal->j_chksum_driver = crypto_alloc_shash("crc32c", 0, 0); + if (IS_ERR(journal->j_chksum_driver)) { + printk(KERN_ERR "JBD: Cannot load crc32c driver.\n"); + err = PTR_ERR(journal->j_chksum_driver); + journal->j_chksum_driver = NULL; + goto out; + } + } + set_buffer_verified(bh); return 0; @@ -1591,6 +1602,8 @@ int jbd2_journal_destroy(journal_t *journal) iput(journal->j_inode); if (journal->j_revoke) jbd2_journal_destroy_revoke(journal); + if (journal->j_chksum_driver) + crypto_free_shash(journal->j_chksum_driver); kfree(journal->j_wbuf); kfree(journal); @@ -1707,6 +1720,18 @@ int jbd2_journal_set_features (journal_t *journal, unsigned long compat, sb->s_checksum_type = JBD2_CRC32C_CHKSUM; sb->s_feature_compat &= ~cpu_to_be32(JBD2_FEATURE_COMPAT_CHECKSUM); + + /* Load the checksum driver */ + if (journal->j_chksum_driver == NULL) { + journal->j_chksum_driver = crypto_alloc_shash("crc32c", + 0, 0); + if (IS_ERR(journal->j_chksum_driver)) { + printk(KERN_ERR "JBD: Cannot load crc32c " + "driver.\n"); + journal->j_chksum_driver = NULL; + return 0; + } + } } /* If enabling v1 checksums, downgrade superblock */ diff --git a/include/linux/jbd2.h b/include/linux/jbd2.h index 809c439066c5..71e77dddebf1 100644 --- a/include/linux/jbd2.h +++ b/include/linux/jbd2.h @@ -31,6 +31,7 @@ #include <linux/mutex.h> #include <linux/timer.h> #include <linux/slab.h> +#include <crypto/hash.h> #endif #define journal_oom_retry 1 @@ -965,6 +966,9 @@ struct journal_s * superblock pointer here */ void *j_private; + + /* Reference to checksum algorithm driver via cryptoapi */ + struct crypto_shash *j_chksum_driver; }; /* @@ -1294,6 +1298,25 @@ static inline int jbd_space_needed(journal_t *journal) extern int jbd_blocks_per_page(struct inode *inode); +static inline u32 jbd2_chksum(journal_t *journal, u32 crc, + const void *address, unsigned int length) +{ + struct { + struct shash_desc shash; + char ctx[crypto_shash_descsize(journal->j_chksum_driver)]; + } desc; + int err; + + desc.shash.tfm = journal->j_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__ #define buffer_trace_init(bh) do {} while (0) |