From: adilger <adilger>
Date: Thu, 23 May 2002 22:57:14 +0000 (+0000)
Subject: Hopefully final version of journal commit callback patch.  Stephen agreed
X-Git-Tag: 0.4.2~251
X-Git-Url: https://git.whamcloud.com/gitweb?a=commitdiff_plain;h=6a49f0b71a84e7bb8da3d766eb6b90239716d61d;p=fs%2Flustre-release.git

Hopefully final version of journal commit callback patch.  Stephen agreed
with this one and should include it into CVS/release at some point.  This
includes a status for the callback function, because the callbacks need to
always be called (to clean up memory), but the actual operations may have
had an error for some reason (no memory, IO, etc).
---

diff --git a/lustre/patches/patch-2.4.18 b/lustre/patches/patch-2.4.18
index 645d64b..3cac795 100644
--- a/lustre/patches/patch-2.4.18
+++ b/lustre/patches/patch-2.4.18
@@ -169,10 +169,10 @@ diff -Nur linux-2.4.18/include/linux/limits.h linux-2.4.18ea/include/linux/limit
  	return bh->b_private;
  }
  
-+#define HAVE_JOURNAL_CALLBACK
++#define HAVE_JOURNAL_CALLBACK_STATUS
 +struct journal_callback {
 +	struct list_head jcb_list;
-+	void (*jcb_func)(void *);
++	void (*jcb_func)(void *cb_data, int error);
 +	/* user data goes here */
 +};
 +
@@ -203,26 +203,17 @@ diff -Nur linux-2.4.18/include/linux/limits.h linux-2.4.18ea/include/linux/limit
  };
  
  
-@@ -547,7 +563,7 @@
- #define JFS_FLUSHED	0x008	/* The journal superblock has been flushed */
- #define JFS_LOADED	0x010	/* The journal superblock has been loaded */
- 
--/* 
-+/*
-  * Function declarations for the journaling transaction and buffer
-  * management
-  */
 @@ -646,6 +662,8 @@
  extern int	 journal_try_to_free_buffers(journal_t *, struct page *, int);
  extern int	 journal_stop(handle_t *);
  extern int	 journal_flush (journal_t *);
-+extern void	 journal_callback_set(handle_t *handle, void (*func)(void *),
++extern void	 journal_callback_set(handle_t *handle, void (*fn)(void *, int),
 +				      void *cb_data);
  
  extern void	 journal_lock_updates (journal_t *);
  extern void	 journal_unlock_updates (journal_t *);
 --- lum/fs/jbd/commit.c.orig	Fri Apr 12 10:27:52 2002
-+++ lum/fs/jbd/commit.c	Wed Apr 24 05:18:07 2002
++++ lum/fs/jbd/commit.c	Thu May 23 16:53:16 2002
 @@ -475,7 +475,7 @@
             transaction's t_log_list queue, and metadata buffers are on
             the t_iobuf_list queue.
@@ -232,28 +223,64 @@ diff -Nur linux-2.4.18/include/linux/limits.h linux-2.4.18ea/include/linux/limit
  	   less likely to be woken up until all IOs have completed, and
  	   so we incur less scheduling load.
  	*/
-@@ -602,6 +602,21 @@
+@@ -566,8 +566,10 @@
+ 
+ 	jbd_debug(3, "JBD: commit phase 6\n");
+ 
+-	if (is_journal_aborted(journal))
++	if (is_journal_aborted(journal)) {
++		unlock_journal(journal);
+ 		goto skip_commit;
++	}
+ 
+ 	/* Done it all: now write the commit record.  We should have
+ 	 * cleaned up our previous buffers by now, so if we are in abort
+@@ -577,9 +579,10 @@
+ 	descriptor = journal_get_descriptor_buffer(journal);
+ 	if (!descriptor) {
+ 		__journal_abort_hard(journal);
++		unlock_journal(journal);
+ 		goto skip_commit;
+ 	}
+-	
++
+ 	/* AKPM: buglet - add `i' to tmp! */
+ 	for (i = 0; i < jh2bh(descriptor)->b_size; i += 512) {
+ 		journal_header_t *tmp =
+@@ -600,7 +603,6 @@
+ 		put_bh(bh);		/* One for getblk() */
+ 		journal_unlock_journal_head(descriptor);
  	}
- 	lock_journal(journal);
+-	lock_journal(journal);
+ 
+ 	/* End of a transaction!  Finally, we can do checkpoint
+            processing: any buffers committed as a result of this
+@@ -609,6 +611,25 @@
+ 
+ skip_commit:
  
 +	/* Call any callbacks that had been registered for handles in this
 +	 * transaction.  It is up to the callback to free any allocated
 +	 * memory.
 +	 */
-+	{
++	if (!list_empty(&commit_transaction->t_jcb)) {
 +		struct list_head *p, *n;
++		int error = is_journal_aborted(journal);
++
 +		list_for_each_safe(p, n, &commit_transaction->t_jcb) {
 +			struct journal_callback *jcb;
 +
 +			jcb = list_entry(p, struct journal_callback, jcb_list);
 +			list_del(p);
-+			jcb->jcb_func(jcb);
++			jcb->jcb_func(jcb, error);
 +		}
 +	}
 +
- 	/* End of a transaction!  Finally, we can do checkpoint
-            processing: any buffers committed as a result of this
-            transaction can be removed from any checkpoint list it was on
++	lock_journal(journal);
++
+ 	jbd_debug(3, "JBD: commit phase 7\n");
+ 
+ 	J_ASSERT(commit_transaction->t_sync_datalist == NULL);
 --- lum/fs/jbd/journal.c.orig	Fri Apr 12 10:27:52 2002
 +++ lum/fs/jbd/journal.c	Wed Apr 24 05:18:49 2002
 @@ -58,6 +58,7 @@
@@ -329,23 +356,25 @@ diff -Nur linux-2.4.18/include/linux/limits.h linux-2.4.18ea/include/linux/limit
  	current->journal_info = handle;
  
  	err = try_start_this_handle(journal, handle);
-@@ -1328,6 +1337,27 @@
+@@ -1328,6 +1337,28 @@
  #endif
  
  /*
 + * Register a callback function for this handle.  The function will be
 + * called when the transaction that this handle is part of has been
-+ * committed to disk.  There is no guarantee of ordering between handles
-+ * within a single transaction, nor between callbacks registered on the
-+ * same handle.
++ * committed to disk with the original callback data struct and the
++ * error status of the journal as parameters.  There is no guarantee of
++ * ordering between handles within a single transaction, nor between
++ * callbacks registered on the same handle.
 + *
 + * The caller is responsible for allocating the journal_callback struct.
 + * This is to allow the caller to add as much extra data to the callback
 + * as needed, but reduce the overhead of multiple allocations.  The caller
-+ * should use the journal_callback_size() function to reserve enough space
-+ * for the JBD-private part of the callback struct.
++ * allocated struct must start with a struct journal_callback at offset 0,
++ * and has the caller-specific data afterwards.
 + */
-+void journal_callback_set(handle_t *handle, void (*func)(void *), void *cb_data)
++void journal_callback_set(handle_t *handle, void (*func)(void *, int),
++			  void *cb_data)
 +{
 +	struct journal_callback *jcb = cb_data;
 +
@@ -357,14 +386,13 @@ diff -Nur linux-2.4.18/include/linux/limits.h linux-2.4.18ea/include/linux/limit
   * All done for a particular handle.
   *
   * There is not much action needed here.  We just return any remaining
-@@ -1393,7 +1423,11 @@
+@@ -1393,7 +1423,10 @@
  			wake_up(&journal->j_wait_transaction_locked);
  	}
  
 -	/* 
 +	/* Move callbacks from the handle to the transaction. */
 +	list_splice(&handle->h_jcb, &transaction->t_jcb);
-+	INIT_LIST_HEAD(&handle->h_jcb);
 +
 +	/*
  	 * If the handle is marked SYNC, we need to set another commit