diff options
| author | Jan Kara <jack@suse.cz> | 2017-11-01 16:36:45 +0100 |
|---|---|---|
| committer | Dan Williams <dan.j.williams@intel.com> | 2017-11-03 06:26:26 -0700 |
| commit | b8a6176c214cf9aa2679131ed7e4515cddaadc33 (patch) | |
| tree | e9b6ff2b1ee0459854e64f3195a7af7571b62196 /fs/jbd2 | |
| parent | 497f6926d880c57f65bf7c3f1086526fa774c55e (diff) | |
| download | lwn-b8a6176c214cf9aa2679131ed7e4515cddaadc33.tar.gz lwn-b8a6176c214cf9aa2679131ed7e4515cddaadc33.zip | |
ext4: Support for synchronous DAX faults
We return IOMAP_F_DIRTY flag from ext4_iomap_begin() when asked to
prepare blocks for writing and the inode has some uncommitted metadata
changes. In the fault handler ext4_dax_fault() we then detect this case
(through VM_FAULT_NEEDDSYNC return value) and call helper
dax_finish_sync_fault() to flush metadata changes and insert page table
entry. Note that this will also dirty corresponding radix tree entry
which is what we want - fsync(2) will still provide data integrity
guarantees for applications not using userspace flushing. And
applications using userspace flushing can avoid calling fsync(2) and
thus avoid the performance overhead.
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Diffstat (limited to 'fs/jbd2')
| -rw-r--r-- | fs/jbd2/journal.c | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c index 7d5ef3bf3f3e..fa8cde498b4b 100644 --- a/fs/jbd2/journal.c +++ b/fs/jbd2/journal.c @@ -738,6 +738,23 @@ int jbd2_log_wait_commit(journal_t *journal, tid_t tid) return err; } +/* Return 1 when transaction with given tid has already committed. */ +int jbd2_transaction_committed(journal_t *journal, tid_t tid) +{ + int ret = 1; + + read_lock(&journal->j_state_lock); + if (journal->j_running_transaction && + journal->j_running_transaction->t_tid == tid) + ret = 0; + if (journal->j_committing_transaction && + journal->j_committing_transaction->t_tid == tid) + ret = 0; + read_unlock(&journal->j_state_lock); + return ret; +} +EXPORT_SYMBOL(jbd2_transaction_committed); + /* * When this function returns the transaction corresponding to tid * will be completed. If the transaction has currently running, start |