Re: [PATCH] Change ll_rw_block() calls in JBD

From: Zoltan Menyhart
Date: Wed May 24 2006 - 05:15:22 EST


Yesterday I forgot a small "spin_unlock(&journal->j_list_lock);".

Thanks,

Zoltan

--- linux-2.6.16.16-save/fs/jbd/commit.c 2006-05-19 15:00:50.000000000 +0200
+++ linux-2.6.16.16/fs/jbd/commit.c 2006-05-24 10:43:32.000000000 +0200
@@ -161,6 +161,107 @@
}

/*
+ * Flush data from the "->t_sync_datalist" of the committing transaction.
+ */
+static void write_out_sync_data(journal_t *journal,
+ transaction_t *commit_transaction)
+{
+ struct journal_head *jh;
+ struct buffer_head *bh;
+ int err = 0;
+
+ /*
+ * Whenever we unlock the journal and sleep, things can get removed
+ * from "->t_sync_datalist" by "journal_dirty_data()", so we have
+ * to keep looping back to write_out_data until we *know* that the
+ * list is empty.
+ *
+ * Cleanup any flushed data buffers from the data list. Even in
+ * abort mode, we want to flush this out as soon as possible.
+ */
+write_out_data:
+ cond_resched();
+ spin_lock(&journal->j_list_lock);
+ while ((jh = commit_transaction->t_sync_datalist) != NULL){
+ bh = jh2bh(jh);
+ if (buffer_locked(bh)){ /* Unsafe */
+ BUFFER_TRACE(bh, "locked");
+ if (!inverted_lock(journal, bh)) /* jbd_lock_bh_state */
+ goto write_out_data;
+ /* "bh" may have been unlocked in the mean time */
+ __journal_file_buffer(jh, commit_transaction, BJ_Locked);
+ jbd_unlock_bh_state(bh);
+ } else {
+ /* "bh" may have become locked in the mean time */
+ if (buffer_dirty(bh)){ /* Unsafe */
+ if (test_set_buffer_locked(bh)){
+ BUFFER_TRACE(bh, "locked");
+ /* Put it on the BJ_Locked list */
+ continue;
+ }
+ if (test_clear_buffer_dirty(bh)){
+ BUFFER_TRACE(bh, "start journal wr");
+ spin_unlock(&journal->j_list_lock);
+ get_bh(bh);
+ bh->b_end_io = end_buffer_write_sync;
+ submit_bh(WRITE, bh);
+ /* Put it on the BJ_Locked list */
+ goto write_out_data;
+ }
+ unlock_buffer(bh);
+ } else {
+ /* "bh" may have become dirty in the mean time */
+ /* Just do nothing for this transaction */
+ }
+ BUFFER_TRACE(bh, "writeout complete: unfile");
+ if (!inverted_lock(journal, bh)) /* jbd_lock_bh_state */
+ goto write_out_data;
+ __journal_unfile_buffer(jh);
+ jbd_unlock_bh_state(bh);
+ journal_remove_journal_head(bh);
+ put_bh(bh);
+ }
+ if (lock_need_resched(&journal->j_list_lock)){
+ spin_unlock(&journal->j_list_lock);
+ goto write_out_data;
+ }
+ }
+ /*
+ * Wait for all previously submitted IO to complete.
+ */
+ while (commit_transaction->t_locked_list) {
+ jh = commit_transaction->t_locked_list->b_tprev;
+ bh = jh2bh(jh);
+ get_bh(bh);
+ if (buffer_locked(bh)) {
+ spin_unlock(&journal->j_list_lock);
+ wait_on_buffer(bh);
+ if (unlikely(!buffer_uptodate(bh)))
+ err = -EIO;
+ spin_lock(&journal->j_list_lock);
+ }
+ if (!inverted_lock(journal, bh)) {
+ put_bh(bh);
+ spin_lock(&journal->j_list_lock);
+ continue;
+ }
+ if (buffer_jbd(bh) && jh->b_jlist == BJ_Locked) {
+ __journal_unfile_buffer(jh);
+ jbd_unlock_bh_state(bh);
+ journal_remove_journal_head(bh);
+ put_bh(bh);
+ } else {
+ jbd_unlock_bh_state(bh);
+ }
+ put_bh(bh);
+ cond_resched_lock(&journal->j_list_lock);
+ }
+ spin_unlock(&journal->j_list_lock);
+ if (err)
+ __journal_abort_hard(journal);
+}
+
+/*
* journal_commit_transaction
*
* The primary function for committing a transaction to the log. This
@@ -173,7 +274,7 @@
struct buffer_head **wbuf = journal->j_wbuf;
int bufs;
int flags;
- int err;
+ int err = 0;
unsigned long blocknr;
char *tagp = NULL;
journal_header_t *header;
@@ -313,113 +414,7 @@
* Now start flushing things to disk, in the order they appear
* on the transaction lists. Data blocks go first.
*/
-
- err = 0;
- /*
- * Whenever we unlock the journal and sleep, things can get added
- * onto ->t_sync_datalist, so we have to keep looping back to
- * write_out_data until we *know* that the list is empty.
- */
- bufs = 0;
- /*
- * Cleanup any flushed data buffers from the data list. Even in
- * abort mode, we want to flush this out as soon as possible.
- */
-write_out_data:
- cond_resched();
- spin_lock(&journal->j_list_lock);
-
- while (commit_transaction->t_sync_datalist) {
- struct buffer_head *bh;
-
- jh = commit_transaction->t_sync_datalist;
- commit_transaction->t_sync_datalist = jh->b_tnext;
- bh = jh2bh(jh);
- if (buffer_locked(bh)) {
- BUFFER_TRACE(bh, "locked");
- if (!inverted_lock(journal, bh))
- goto write_out_data;
- __journal_temp_unlink_buffer(jh);
- __journal_file_buffer(jh, commit_transaction,
- BJ_Locked);
- jbd_unlock_bh_state(bh);
- if (lock_need_resched(&journal->j_list_lock)) {
- spin_unlock(&journal->j_list_lock);
- goto write_out_data;
- }
- } else {
- if (buffer_dirty(bh)) {
- BUFFER_TRACE(bh, "start journal writeout");
- get_bh(bh);
- wbuf[bufs++] = bh;
- if (bufs == journal->j_wbufsize) {
- jbd_debug(2, "submit %d writes\n",
- bufs);
- spin_unlock(&journal->j_list_lock);
- ll_rw_block(SWRITE, bufs, wbuf);
- journal_brelse_array(wbuf, bufs);
- bufs = 0;
- goto write_out_data;
- }
- } else {
- BUFFER_TRACE(bh, "writeout complete: unfile");
- if (!inverted_lock(journal, bh))
- goto write_out_data;
- __journal_unfile_buffer(jh);
- jbd_unlock_bh_state(bh);
- journal_remove_journal_head(bh);
- put_bh(bh);
- if (lock_need_resched(&journal->j_list_lock)) {
- spin_unlock(&journal->j_list_lock);
- goto write_out_data;
- }
- }
- }
- }
-
- if (bufs) {
- spin_unlock(&journal->j_list_lock);
- ll_rw_block(SWRITE, bufs, wbuf);
- journal_brelse_array(wbuf, bufs);
- spin_lock(&journal->j_list_lock);
- }
-
- /*
- * Wait for all previously submitted IO to complete.
- */
- while (commit_transaction->t_locked_list) {
- struct buffer_head *bh;
-
- jh = commit_transaction->t_locked_list->b_tprev;
- bh = jh2bh(jh);
- get_bh(bh);
- if (buffer_locked(bh)) {
- spin_unlock(&journal->j_list_lock);
- wait_on_buffer(bh);
- if (unlikely(!buffer_uptodate(bh)))
- err = -EIO;
- spin_lock(&journal->j_list_lock);
- }
- if (!inverted_lock(journal, bh)) {
- put_bh(bh);
- spin_lock(&journal->j_list_lock);
- continue;
- }
- if (buffer_jbd(bh) && jh->b_jlist == BJ_Locked) {
- __journal_unfile_buffer(jh);
- jbd_unlock_bh_state(bh);
- journal_remove_journal_head(bh);
- put_bh(bh);
- } else {
- jbd_unlock_bh_state(bh);
- }
- put_bh(bh);
- cond_resched_lock(&journal->j_list_lock);
- }
- spin_unlock(&journal->j_list_lock);
-
- if (err)
- __journal_abort_hard(journal);
+ write_out_sync_data(journal, commit_transaction);

journal_write_revoke_records(journal, commit_transaction);


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