diff options
| author | Girish Shilamkar <girish@clusterfs.com> | 2008-01-28 23:58:27 -0500 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2008-01-28 23:58:27 -0500 |
| commit | 818d276ceb83aa9fdebb5e0a53188290312de987 (patch) | |
| tree | de3fb4ffadd72caea2876c5232ce76cd14b3646e /fs/jbd2/journal.c | |
| parent | 8e85fb3f305b24b79c6d9cb7a56d22b062335ad3 (diff) | |
| download | linux-818d276ceb83aa9fdebb5e0a53188290312de987.tar.gz | |
ext4: Add the journal checksum feature
The journal checksum feature adds two new flags i.e JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT and JBD2_FEATURE_COMPAT_CHECKSUM. JBD2_FEATURE_CHECKSUM flag indicates that the commit block contains the checksum for the blocks described by the descriptor blocks. Due to checksums, writing of the commit record no longer needs to be synchronous. Now commit record can be sent to disk without waiting for descriptor blocks to be written to disk. This behavior is controlled using JBD2_FEATURE_ASYNC_COMMIT flag. Older kernels/e2fsck should not be able to recover the journal with _ASYNC_COMMIT hence it is made incompat. The commit header has been extended to hold the checksum along with the type of the checksum. For recovery in pass scan checksums are verified to ensure the sanity and completeness(in case of _ASYNC_COMMIT) of every transaction. Signed-off-by: Andreas Dilger <adilger@clusterfs.com> Signed-off-by: Girish Shilamkar <girish@clusterfs.com> Signed-off-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com> Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Diffstat (limited to 'fs/jbd2/journal.c')
| -rw-r--r-- | fs/jbd2/journal.c | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c index 3667c91bc786..59ba2494dcaf 100644 --- a/fs/jbd2/journal.c +++ b/fs/jbd2/journal.c @@ -1578,6 +1578,32 @@ int jbd2_journal_set_features (journal_t *journal, unsigned long compat, return 1; } +/* + * jbd2_journal_clear_features () - Clear a given journal feature in the + * superblock + * @journal: Journal to act on. + * @compat: bitmask of compatible features + * @ro: bitmask of features that force read-only mount + * @incompat: bitmask of incompatible features + * + * Clear a given journal feature as present on the + * superblock. + */ +void jbd2_journal_clear_features(journal_t *journal, unsigned long compat, + unsigned long ro, unsigned long incompat) +{ + journal_superblock_t *sb; + + jbd_debug(1, "Clear features 0x%lx/0x%lx/0x%lx\n", + compat, ro, incompat); + + sb = journal->j_superblock; + + sb->s_feature_compat &= ~cpu_to_be32(compat); + sb->s_feature_ro_compat &= ~cpu_to_be32(ro); + sb->s_feature_incompat &= ~cpu_to_be32(incompat); +} +EXPORT_SYMBOL(jbd2_journal_clear_features); /** * int jbd2_journal_update_format () - Update on-disk journal structure. |