+Implement a JBD per-transaction commit callback. Users can attach arbitrary
+callbacks to a journal handle, which are propagated to the transaction at
+journal handle stop time. The commit callbacks are run when the transaction
+is finished commit, and will be passed a non-zero error code if there was
+a commit error.
+
+Signed-off-by: Andreas Dilger <adilger@sun.com>
+
+
Index: linux-2.6/include/linux/jbd.h
===================================================================
--- linux-2.6.orig/include/linux/jbd.h 2006-07-15 16:08:35.000000000 +0800
+#define HAVE_JOURNAL_CALLBACK_STATUS
+/**
-+ * struct journal_callback - Base structure for callback information.
-+ * @jcb_list: list information for other callbacks attached to the same handle.
-+ * @jcb_func: Function to call with this callback structure.
++ * struct journal_callback - Base structure for callback information
++ * @jcb_list: list information for other callbacks attached to the same handle
++ * @jcb_func: Function to call with this callback structure
+ *
-+ * This struct is a 'seed' structure for a using with your own callback
-+ * structs. If you are using callbacks you must allocate one of these
-+ * or another struct of your own definition which has this struct
-+ * as it's first element and pass it to journal_callback_set().
++ * This struct is a 'seed' structure for a using with your own callback
++ * structs. If you are using callbacks you must allocate one of these
++ * or another struct of your own definition which has this struct
++ * as it's first element and pass it to journal_callback_set().
+ *
-+ * This is used internally by jbd to maintain callback information.
++ * This is used internally by jbd to maintain callback information.
+ *
-+ * See journal_callback_set for more information.
++ * See journal_callback_set for more information.
+ **/
+struct journal_callback {
+ struct list_head jcb_list; /* t_jcb_lock */
+ void (*jcb_func)(struct journal_callback *jcb, int error);
-+ /* user data goes here */
++ /* caller data goes here */
+};
+
struct jbd_revoke_table_s;
===================================================================
--- linux-2.6.orig/fs/jbd/commit.c 2006-07-15 16:08:36.000000000 +0800
+++ linux-2.6/fs/jbd/commit.c 2006-07-15 16:13:01.000000000 +0800
-@@ -708,6 +708,30 @@ wait_for_iobuf:
+@@ -708,6 +708,32 @@ wait_for_iobuf:
transaction can be removed from any checkpoint list it was on
before. */
+ * transaction. It is up to the callback to free any allocated
+ * memory.
+ *
-+ * The spinlocking (t_jcb_lock) here is surely unnecessary...
++ * Locking not strictly required, since this is the only process
++ * touching this transaction anymore, but is done to keep code
++ * checkers happy and has no contention in any case. */
+ */
+ spin_lock(&commit_transaction->t_jcb_lock);
+ if (!list_empty(&commit_transaction->t_jcb)) {
+ struct journal_callback *jcb;
+
+ jcb = list_entry(p, struct journal_callback, jcb_list);
-+ list_del(p);
++ list_del_init(p);
+ spin_unlock(&commit_transaction->t_jcb_lock);
+ jcb->jcb_func(jcb, error);
+ spin_lock(&commit_transaction->t_jcb_lock);
return handle;
}
-@@ -1291,6 +1294,36 @@ drop:
+@@ -1291,6 +1294,35 @@ drop:
}
/**
+ * @jcb: structure with additional information required by func() , and
+ * some space for jbd internal information.
+ *
-+ * The function will be
-+ * called when the transaction that this handle is part of has been
-+ * 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 function will be called when the transaction that this handle is
++ * part of has been 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
+ void (*func)(struct journal_callback *jcb, int error),
+ struct journal_callback *jcb)
+{
++ jcb->jcb_func = func;
+ spin_lock(&handle->h_transaction->t_jcb_lock);
+ list_add_tail(&jcb->jcb_list, &handle->h_jcb);
+ spin_unlock(&handle->h_transaction->t_jcb_lock);
-+ jcb->jcb_func = func;
+}
+
+/**
git://git.whamcloud.com / fs / lustre-release.git / commitdiff