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authorJan Kara <jack@suse.cz>2011-05-24 11:52:40 -0400
committerTheodore Ts'o <tytso@mit.edu>2011-05-24 11:52:40 -0400
commit81be12c8179c1c397d3f179cdd9b3f7146cf47f1 (patch)
treeb535687e88af17fc6b25329decf28563ed519395
parentb221349fa8b45d13c3650089f0514df7d1eb36c3 (diff)
jbd2: fix sending of data flush on journal commit
In data=ordered mode, it's theoretically possible (however rare) that an inode is filed to transaction's t_inode_list and a flusher thread writes all the data and inode is reclaimed before the transaction starts to commit. In such a case, we could erroneously omit sending a flush to file system device when it is different from the journal device (because data can still be in disk cache only). Fix the problem by setting a flag in a transaction when some inode is added to it and then send disk flush in the commit code when the flag is set. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
-rw-r--r--fs/jbd2/commit.c3
-rw-r--r--fs/jbd2/transaction.c7
-rw-r--r--include/linux/jbd2.h4
3 files changed, 11 insertions, 3 deletions
diff --git a/fs/jbd2/commit.c b/fs/jbd2/commit.c
index 78c299218681..2d5095ecc25f 100644
--- a/fs/jbd2/commit.c
+++ b/fs/jbd2/commit.c
@@ -219,7 +219,6 @@ static int journal_submit_data_buffers(journal_t *journal,
ret = err;
spin_lock(&journal->j_list_lock);
J_ASSERT(jinode->i_transaction == commit_transaction);
- commit_transaction->t_flushed_data_blocks = 1;
clear_bit(__JI_COMMIT_RUNNING, &jinode->i_flags);
smp_mb__after_clear_bit();
wake_up_bit(&jinode->i_flags, __JI_COMMIT_RUNNING);
@@ -683,7 +682,7 @@ start_journal_io:
* then we must flush the file system device before we issue
* the commit record
*/
- if (commit_transaction->t_flushed_data_blocks &&
+ if (commit_transaction->t_need_data_flush &&
(journal->j_fs_dev != journal->j_dev) &&
(journal->j_flags & JBD2_BARRIER))
blkdev_issue_flush(journal->j_fs_dev, GFP_KERNEL, NULL);
diff --git a/fs/jbd2/transaction.c b/fs/jbd2/transaction.c
index 85a055ef93fe..20065c9f2479 100644
--- a/fs/jbd2/transaction.c
+++ b/fs/jbd2/transaction.c
@@ -2147,6 +2147,13 @@ int jbd2_journal_file_inode(handle_t *handle, struct jbd2_inode *jinode)
jinode->i_next_transaction == transaction)
goto done;
+ /*
+ * We only ever set this variable to 1 so the test is safe. Since
+ * t_need_data_flush is likely to be set, we do the test to save some
+ * cacheline bouncing
+ */
+ if (!transaction->t_need_data_flush)
+ transaction->t_need_data_flush = 1;
/* On some different transaction's list - should be
* the committing one */
if (jinode->i_transaction) {
diff --git a/include/linux/jbd2.h b/include/linux/jbd2.h
index a32dcaec04e1..4d57955061f4 100644
--- a/include/linux/jbd2.h
+++ b/include/linux/jbd2.h
@@ -658,7 +658,9 @@ struct transaction_s
* waiting for it to finish.
*/
unsigned int t_synchronous_commit:1;
- unsigned int t_flushed_data_blocks:1;
+
+ /* Disk flush needs to be sent to fs partition [no locking] */
+ int t_need_data_flush;
/*
* For use by the filesystem to store fs-specific data