From 6a835b93050494f7fd7eca69ca8043a64890fe78 Mon Sep 17 00:00:00 2001 From: adilger Date: Wed, 24 Apr 2002 21:09:30 +0000 Subject: [PATCH] Add callbacks from the JBD (journal) to allow async notification of when a handle has been committed to disk. --- lustre/patches/patch-2.4.18 | 206 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 206 insertions(+) diff --git a/lustre/patches/patch-2.4.18 b/lustre/patches/patch-2.4.18 index c604d12..93e371a 100644 --- a/lustre/patches/patch-2.4.18 +++ b/lustre/patches/patch-2.4.18 @@ -126,3 +126,209 @@ if (IDE_CONTROL_REG) OUT_BYTE(drive->ctl,IDE_CONTROL_REG); OUT_BYTE(0x00, IDE_FEATURE_REG); +--- lum/include/linux/jbd.h.orig Tue Apr 16 14:27:25 2002 ++++ lum/include/linux/jbd.h Wed Apr 24 05:19:00 2002 +@@ -249,6 +249,12 @@ + return bh->b_private; + } + ++struct journal_callback { ++ struct list_head jcb_list; ++ void (*jcb_func)(void *); ++ /* user data goes here */ ++}; ++ + struct jbd_revoke_table_s; + + /* The handle_t type represents a single atomic update being performed +@@ -279,6 +285,12 @@ + operations */ + int h_err; + ++ /* List of application registered callbacks for this handle. ++ * The function(s) will be called after the transaction that ++ * this handle is part of has been committed to disk. ++ */ ++ struct list_head h_jcb; ++ + /* Flags */ + unsigned int h_sync: 1; /* sync-on-close */ + unsigned int h_jdata: 1; /* force data journaling */ +@@ -398,6 +410,10 @@ + + /* How many handles used this transaction? */ + int t_handle_count; ++ ++ /* List of registered callback functions for this transaction. ++ * Called when the transaction is committed. */ ++ struct list_head t_jcb; + }; + + +@@ -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 *), ++ 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 +@@ -475,7 +475,7 @@ + transaction's t_log_list queue, and metadata buffers are on + the t_iobuf_list queue. + +- Wait for the transactions in reverse order. That way we are ++ Wait for the buffers in reverse order. That way we are + less likely to be woken up until all IOs have completed, and + so we incur less scheduling load. + */ +@@ -602,6 +602,21 @@ + } + lock_journal(journal); + ++ /* Call any callbacks that had been registered for handles in this ++ * transaction. It is up to the callback to free any allocated ++ * memory. ++ */ ++ { ++ struct list_head *p, *n; ++ 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); ++ } ++ } ++ + /* 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 +--- 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 @@ + #endif + EXPORT_SYMBOL(journal_flush); + EXPORT_SYMBOL(journal_revoke); ++EXPORT_SYMBOL(journal_callback_set); + + EXPORT_SYMBOL(journal_init_dev); + EXPORT_SYMBOL(journal_init_inode); +--- lum/fs/jbd/transaction.c.orig Fri Apr 12 10:27:52 2002 ++++ lum/fs/jbd/transaction.c Wed Apr 24 05:31:14 2002 +@@ -57,6 +57,7 @@ + transaction->t_state = T_RUNNING; + transaction->t_tid = journal->j_transaction_sequence++; + transaction->t_expires = jiffies + journal->j_commit_interval; ++ INIT_LIST_HEAD(&transaction->t_jcb); + + /* Set up the commit timer for the new transaction. */ + J_ASSERT (!journal->j_commit_timer_active); +@@ -201,6 +202,20 @@ + return 0; + } + ++/* Allocate a new handle. This should probably be in a slab... */ ++static handle_t *get_handle(int nblocks) ++{ ++ handle_t *handle = jbd_kmalloc(sizeof (handle_t), GFP_NOFS); ++ if (!handle) ++ return NULL; ++ memset(handle, 0, sizeof (handle_t)); ++ handle->h_buffer_credits = nblocks; ++ handle->h_ref = 1; ++ INIT_LIST_HEAD(&handle->h_jcb); ++ ++ return handle; ++} ++ + /* + * Obtain a new handle. + * +@@ -227,14 +242,11 @@ + handle->h_ref++; + return handle; + } +- +- handle = jbd_kmalloc(sizeof (handle_t), GFP_NOFS); ++ ++ handle = get_handle(nblocks); + if (!handle) + return ERR_PTR(-ENOMEM); +- memset (handle, 0, sizeof (handle_t)); + +- handle->h_buffer_credits = nblocks; +- handle->h_ref = 1; + current->journal_info = handle; + + err = start_this_handle(journal, handle); +@@ -333,14 +345,11 @@ + + if (is_journal_aborted(journal)) + return ERR_PTR(-EIO); +- +- handle = jbd_kmalloc(sizeof (handle_t), GFP_NOFS); ++ ++ handle = get_handle(nblocks); + if (!handle) + return ERR_PTR(-ENOMEM); +- memset (handle, 0, sizeof (handle_t)); + +- handle->h_buffer_credits = nblocks; +- handle->h_ref = 1; + current->journal_info = handle; + + err = try_start_this_handle(journal, handle); +@@ -1328,6 +1337,27 @@ + #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. ++ * ++ * 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. ++ */ ++void journal_callback_set(handle_t *handle, void (*func)(void *), void *cb_data) ++{ ++ struct journal_callback *jcb = cb_data; ++ ++ list_add(&jcb->jcb_list, &handle->h_jcb); ++ jcb->jcb_func = func; ++} ++ ++/* + * All done for a particular handle. + * + * There is not much action needed here. We just return any remaining +@@ -1393,7 +1423,11 @@ + 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 + * going! We also want to force a commit if the current + * transaction is occupying too much of the log, or if the -- 1.8.3.1