Almost everywhere where JBD removes a buffer from the transaction lists the
caller then nulls out jh->b_transaction. Sometimes, the caller does that
without holding the locks which are defined to protect b_transaction. This
makes me queazy.
So change things so that __journal_unfile_buffer() nulls out b_transaction
inside both j_list_lock and jbd_lock_bh_state().
It cleans things up a bit, too.
---
25-akpm/fs/jbd/commit.c | 14 ++------------
25-akpm/fs/jbd/transaction.c | 13 ++++---------
2 files changed, 6 insertions(+), 21 deletions(-)
diff -puN fs/jbd/commit.c~jbd-b_transaction-zeroing-cleanup fs/jbd/commit.c
--- 25/fs/jbd/commit.c~jbd-b_transaction-zeroing-cleanup 2004-04-05 21:10:45.366713744 -0700
+++ 25-akpm/fs/jbd/commit.c 2004-04-05 21:10:45.371712984 -0700
@@ -259,7 +259,8 @@ write_out_data:
if (!inverted_lock(journal, bh))
goto write_out_data;
__journal_unfile_buffer(jh);
- __journal_file_buffer(jh, jh->b_transaction, BJ_Locked);
+ __journal_file_buffer(jh, commit_transaction,
+ BJ_Locked);
jbd_unlock_bh_state(bh);
if (need_resched()) {
spin_unlock(&journal->j_list_lock);
@@ -284,7 +285,6 @@ write_out_data:
if (!inverted_lock(journal, bh))
goto write_out_data;
__journal_unfile_buffer(jh);
- jh->b_transaction = NULL;
jbd_unlock_bh_state(bh);
journal_remove_journal_head(bh);
put_bh(bh);
@@ -326,7 +326,6 @@ write_out_data:
}
if (buffer_jbd(bh) && jh->b_jlist == BJ_Locked) {
__journal_unfile_buffer(jh);
- jh->b_transaction = NULL;
jbd_unlock_bh_state(bh);
journal_remove_journal_head(bh);
put_bh(bh);
@@ -555,13 +554,6 @@ wait_for_iobuf:
journal_unfile_buffer(journal, jh);
/*
- * akpm: don't put back a buffer_head with stale pointers
- * dangling around.
- */
- J_ASSERT_JH(jh, jh->b_transaction != NULL);
- jh->b_transaction = NULL;
-
- /*
* ->t_iobuf_list should contain only dummy buffer_heads
* which were created by journal_write_metadata_buffer().
*/
@@ -613,7 +605,6 @@ wait_for_iobuf:
BUFFER_TRACE(bh, "ph5: control buffer writeout done: unfile");
clear_buffer_jwrite(bh);
journal_unfile_buffer(journal, jh);
- jh->b_transaction = NULL;
journal_put_journal_head(jh);
__brelse(bh); /* One for getblk */
/* AKPM: bforget here */
@@ -766,7 +757,6 @@ skip_commit: /* The journal should be un
J_ASSERT_BH(bh, !buffer_dirty(bh));
J_ASSERT_JH(jh, jh->b_next_transaction == NULL);
__journal_unfile_buffer(jh);
- jh->b_transaction = 0;
jbd_unlock_bh_state(bh);
journal_remove_journal_head(bh); /* needs a brelse */
release_buffer_page(bh);
diff -puN fs/jbd/transaction.c~jbd-b_transaction-zeroing-cleanup fs/jbd/transaction.c
--- 25/fs/jbd/transaction.c~jbd-b_transaction-zeroing-cleanup 2004-04-05 21:10:45.367713592 -0700
+++ 25-akpm/fs/jbd/transaction.c 2004-04-05 21:10:45.373712680 -0700
@@ -1019,7 +1019,6 @@ int journal_dirty_data(handle_t *handle,
if (jh->b_transaction != NULL) {
JBUFFER_TRACE(jh, "unfile from commit");
__journal_unfile_buffer(jh);
- jh->b_transaction = NULL;
}
/* The buffer will be refiled below */
@@ -1034,7 +1033,6 @@ int journal_dirty_data(handle_t *handle,
JBUFFER_TRACE(jh, "not on correct data list: unfile");
J_ASSERT_JH(jh, jh->b_jlist != BJ_Shadow);
__journal_unfile_buffer(jh);
- jh->b_transaction = NULL;
JBUFFER_TRACE(jh, "file as data");
__journal_file_buffer(jh, handle->h_transaction,
BJ_SyncData);
@@ -1205,7 +1203,6 @@ void journal_forget(handle_t *handle, st
J_ASSERT_JH(jh, !jh->b_committed_data);
__journal_unfile_buffer(jh);
- jh->b_transaction = 0;
/*
* We are no longer going to journal this buffer.
@@ -1493,7 +1490,7 @@ void __journal_unfile_buffer(struct jour
switch (jh->b_jlist) {
case BJ_None:
- return;
+ goto out;
case BJ_SyncData:
list = &transaction->t_sync_datalist;
break;
@@ -1526,6 +1523,8 @@ void __journal_unfile_buffer(struct jour
jh->b_jlist = BJ_None;
if (test_clear_buffer_jbddirty(bh))
mark_buffer_dirty(bh); /* Expose it to the VM */
+out:
+ jh->b_transaction = NULL;
}
void journal_unfile_buffer(journal_t *journal, struct journal_head *jh)
@@ -1561,7 +1560,6 @@ __journal_try_to_free_buffer(journal_t *
/* A written-back ordered data buffer */
JBUFFER_TRACE(jh, "release data");
__journal_unfile_buffer(jh);
- jh->b_transaction = 0;
journal_remove_journal_head(bh);
__brelse(bh);
}
@@ -1667,7 +1665,6 @@ static int __dispose_buffer(struct journ
struct buffer_head *bh = jh2bh(jh);
__journal_unfile_buffer(jh);
- jh->b_transaction = 0;
if (jh->b_cp_transaction) {
JBUFFER_TRACE(jh, "on running+cp transaction");
@@ -1936,8 +1933,7 @@ void __journal_file_buffer(struct journa
if (jh->b_transaction)
__journal_unfile_buffer(jh);
- else
- jh->b_transaction = transaction;
+ jh->b_transaction = transaction;
switch (jlist) {
case BJ_None:
@@ -2010,7 +2006,6 @@ void __journal_refile_buffer(struct jour
/* If the buffer is now unused, just drop it. */
if (jh->b_next_transaction == NULL) {
__journal_unfile_buffer(jh);
- jh->b_transaction = NULL;
return;
}
_