jbd2: clean up jbd2_journal_try_to_free_buffers()

This patch reverts 3f31fddf, which is no longer needed because if a
race between freeing buffer and committing transaction functionality
occurs and dio gets error, currently dio falls back to buffered IO due
to the commit 6ccfa806.

Signed-off-by: Hisashi Hifumi <hifumi.hisashi@oss.ntt.co.jp>
Cc: Mingming Cao <cmm@us.ibm.com>
Acked-by: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
This commit is contained in:
Hisashi Hifumi 2009-06-17 20:08:51 -04:00 committed by Theodore Ts'o
parent 4159175058
commit 536fc240e7

View file

@ -1547,36 +1547,6 @@ out:
return;
}
/*
* jbd2_journal_try_to_free_buffers() could race with
* jbd2_journal_commit_transaction(). The later might still hold the
* reference count to the buffers when inspecting them on
* t_syncdata_list or t_locked_list.
*
* jbd2_journal_try_to_free_buffers() will call this function to
* wait for the current transaction to finish syncing data buffers, before
* try to free that buffer.
*
* Called with journal->j_state_lock hold.
*/
static void jbd2_journal_wait_for_transaction_sync_data(journal_t *journal)
{
transaction_t *transaction;
tid_t tid;
spin_lock(&journal->j_state_lock);
transaction = journal->j_committing_transaction;
if (!transaction) {
spin_unlock(&journal->j_state_lock);
return;
}
tid = transaction->t_tid;
spin_unlock(&journal->j_state_lock);
jbd2_log_wait_commit(journal, tid);
}
/**
* int jbd2_journal_try_to_free_buffers() - try to free page buffers.
* @journal: journal for operation
@ -1649,25 +1619,6 @@ int jbd2_journal_try_to_free_buffers(journal_t *journal,
ret = try_to_free_buffers(page);
/*
* There are a number of places where jbd2_journal_try_to_free_buffers()
* could race with jbd2_journal_commit_transaction(), the later still
* holds the reference to the buffers to free while processing them.
* try_to_free_buffers() failed to free those buffers. Some of the
* caller of releasepage() request page buffers to be dropped, otherwise
* treat the fail-to-free as errors (such as generic_file_direct_IO())
*
* So, if the caller of try_to_release_page() wants the synchronous
* behaviour(i.e make sure buffers are dropped upon return),
* let's wait for the current transaction to finish flush of
* dirty data buffers, then try to free those buffers again,
* with the journal locked.
*/
if (ret == 0 && (gfp_mask & __GFP_WAIT) && (gfp_mask & __GFP_FS)) {
jbd2_journal_wait_for_transaction_sync_data(journal);
ret = try_to_free_buffers(page);
}
busy:
return ret;
}