From: "Darrick J. Wong" <djwong@us.ibm.com>
To: Andreas Dilger <adilger.kernel@dilger.ca>,
Theodore Tso <tytso@mit.edu>,
"Darrick J. Wong" <djwong@us.ibm.com>
Cc: Sunil Mushran <sunil.mushran@oracle.com>,
Martin K Petersen <martin.petersen@oracle.com>,
Greg Freemyer <greg.freemyer@gmail.com>,
Amir Goldstein <amir73il@gmail.com>,
linux-kernel <linux-kernel@vger.kernel.org>,
Andi Kleen <andi@firstfloor.org>, Mingming Cao <cmm@us.ibm.com>,
Joel Becker <jlbec@evilplan.org>,
linux-fsdevel <linux-fsdevel@vger.kernel.org>,
linux-ext4@vger.kernel.org, Coly Li <colyli@gmail.com>
Subject: [PATCH 17/23] jbd2: Grab a reference to the crc32c driver only when necessary
Date: Tue, 13 Dec 2011 16:48:11 -0800 [thread overview]
Message-ID: <20111214004811.28243.62143.stgit@elm3c44.beaverton.ibm.com> (raw)
In-Reply-To: <20111214004613.28243.54122.stgit@elm3c44.beaverton.ibm.com>
Obtain a reference to the crc32c driver only when the journal needs it for
checksum v2.
Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
---
fs/jbd2/Kconfig | 2 ++
fs/jbd2/journal.c | 25 +++++++++++++++++++++++++
include/linux/jbd2.h | 23 +++++++++++++++++++++++
3 files changed, 50 insertions(+), 0 deletions(-)
diff --git a/fs/jbd2/Kconfig b/fs/jbd2/Kconfig
index f32f346..69a48c2 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 300b46f..bb7f03f 100644
--- a/fs/jbd2/journal.c
+++ b/fs/jbd2/journal.c
@@ -1284,6 +1284,17 @@ 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;
@@ -1440,6 +1451,8 @@ 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);
@@ -1556,6 +1569,18 @@ 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 ecd9b45..5b2abf9 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;
};
/*
@@ -1283,6 +1287,25 @@ 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)
next prev parent reply other threads:[~2011-12-14 0:48 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-12-14 0:46 [PATCH v2.2 00/23] ext4: Add metadata checksumming Darrick J. Wong
2011-12-14 0:46 ` [PATCH 01/23] ext4: Create a new BH_Verified flag to avoid unnecessary metadata validation Darrick J. Wong
2011-12-14 0:46 ` [PATCH 03/23] ext4: Record the checksum algorithm in use in the superblock Darrick J. Wong
2011-12-14 0:46 ` [PATCH 04/23] ext4: Only call out to crc32c if necessary Darrick J. Wong
2011-12-14 0:47 ` [PATCH 13/23] ext4: Add new feature to make block group checksums use metadata_csum algorithm Darrick J. Wong
2011-12-14 0:47 ` [PATCH 14/23] ext4: Add checksums to the MMP block Darrick J. Wong
2011-12-14 0:47 ` [PATCH 15/23] jbd2: Change disk layout for metadata checksumming Darrick J. Wong
2011-12-14 0:48 ` [PATCH 16/23] jbd2: Enable journal clients to enable v2 checksumming Darrick J. Wong
2011-12-14 0:48 ` Darrick J. Wong [this message]
2011-12-14 0:48 ` [PATCH 18/23] jbd2: Update structure definitions and flags to support extended checksumming Darrick J. Wong
2011-12-14 0:48 ` [PATCH 19/23] jbd2: Checksum revocation blocks Darrick J. Wong
2011-12-14 0:48 ` [PATCH 20/23] jbd2: Checksum descriptor blocks Darrick J. Wong
2011-12-14 0:48 ` [PATCH 21/23] jbd2: Checksum commit blocks Darrick J. Wong
2011-12-14 0:48 ` [PATCH 22/23] jbd2: Checksum data blocks that are stored in the journal Darrick J. Wong
2011-12-14 0:48 ` [PATCH 23/23] ext4/jbd2: Add metadata checksumming to the list of supported features Darrick J. Wong
2011-12-14 1:10 ` [PATCH v2.2 00/23] ext4: Add metadata checksumming Darrick J. Wong
2011-12-14 1:31 ` Darrick J. Wong
2012-01-06 18:46 ` Andreas Dilger
2012-01-06 18:57 ` Darrick J. Wong
2012-01-07 8:27 [PATCH v2.3 " Darrick J. Wong
2012-01-07 8:29 ` [PATCH 17/23] jbd2: Grab a reference to the crc32c driver only when necessary Darrick J. Wong
2012-03-06 20:47 [PATCH v3 00/23] ext4: Add metadata checksumming Darrick J. Wong
2012-03-06 20:49 ` [PATCH 17/23] jbd2: Grab a reference to the crc32c driver only when necessary Darrick J. Wong
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