From: Jan Kara <jack@xxxxxxx>
Date: Wed, 21 May 2008 17:48:42 +0200
Subject: [PATCH] jbd2: Implement data=ordered mode handling via inodes
This patch adds necessary framework into JBD2 to be able to track inodes
with each transaction and write-out their dirty data during transaction
commit time.
Signed-off-by: Jan Kara <jack@xxxxxxx>
---
fs/jbd2/commit.c | 90 +++++++++++++++++++++++++++++++++++++++++++++++++
fs/jbd2/journal.c | 52 ++++++++++++++++++++++++++++
fs/jbd2/transaction.c | 86 ++++++++++++++++++++++++++++++++++++++++++++++
include/linux/jbd2.h | 42 +++++++++++++++++++++++
4 files changed, 270 insertions(+), 0 deletions(-)
Index: linux-2.6-linus/fs/jbd2/commit.c
===================================================================
--- linux-2.6-linus.orig/fs/jbd2/commit.c
+++ linux-2.6-linus/fs/jbd2/commit.c
@@ -354,6 +354,81 @@ write_out_data:
journal_do_submit_data(wbuf, bufs);
}
+/*
+ * Submit all the data buffers of inode associated with the transaction to
+ * disk.
+ *
+ * We are in a committing transaction. Therefore no new inode can be added to
+ * our inode list. We use JI_COMMIT_RUNNING flag to protect inode we currently
+ * operate on from being released while we write out pages.
+ */
+static int journal_submit_inode_data_buffers(journal_t *journal,
+ transaction_t *commit_transaction)
+{
+ struct jbd2_inode *jinode;
+ int err, ret = 0;
+ struct address_space *mapping;
+
+ spin_lock(&journal->j_list_lock);
+ list_for_each_entry(jinode, &commit_transaction->t_inode_list, i_list) {
+ mapping = jinode->i_vfs_inode->i_mapping;
+ jinode->i_flags |= JI_COMMIT_RUNNING;
+ spin_unlock(&journal->j_list_lock);
+ err = filemap_fdatawrite_range(mapping, 0,
+ i_size_read(jinode->i_vfs_inode));
+ if (!ret)
+ ret = err;
+ spin_lock(&journal->j_list_lock);
+ J_ASSERT(jinode->i_transaction == commit_transaction);
+ jinode->i_flags &= ~JI_COMMIT_RUNNING;
+ wake_up_bit(&jinode->i_flags, __JI_COMMIT_RUNNING);
+ }
+ spin_unlock(&journal->j_list_lock);
+ return ret;
+}
+
+/*
+ * Wait for data submitted for writeout, refile inodes to proper
+ * transaction if needed.
+ *
+ */
+static int journal_finish_inode_data_buffers(journal_t *journal,
+ transaction_t *commit_transaction)
+{
+ struct jbd2_inode *jinode, *next_i;
+ int err, ret = 0;
+
+ /* For locking, see the comment in journal_submit_inode_data_buffers() */
+ spin_lock(&journal->j_list_lock);
+ list_for_each_entry(jinode, &commit_transaction->t_inode_list, i_list) {
+ jinode->i_flags |= JI_COMMIT_RUNNING;
+ spin_unlock(&journal->j_list_lock);
+ err = filemap_fdatawait(jinode->i_vfs_inode->i_mapping);
+ if (!ret)
+ ret = err;
+ spin_lock(&journal->j_list_lock);
+ jinode->i_flags &= ~JI_COMMIT_RUNNING;
+ wake_up_bit(&jinode->i_flags, __JI_COMMIT_RUNNING);
+ }
+
+ /* Now refile inode to proper lists */
+ list_for_each_entry_safe(jinode, next_i,
+ &commit_transaction->t_inode_list, i_list) {
+ list_del(&jinode->i_list);
+ if (jinode->i_next_transaction) {
+ jinode->i_transaction = jinode->i_next_transaction;
+ jinode->i_next_transaction = NULL;
+ list_add(&jinode->i_list,
+ &jinode->i_transaction->t_inode_list);
+ } else {
+ jinode->i_transaction = NULL;
+ }
+ }
+ spin_unlock(&journal->j_list_lock);
+
+ return ret;
+}
+
static __u32 jbd2_checksum_data(__u32 crc32_sum, struct buffer_head *bh)
{
struct page *page = bh->b_page;
@@ -528,6 +603,9 @@ void jbd2_journal_commit_transaction(jou
*/
err = 0;
journal_submit_data_buffers(journal, commit_transaction);
+ err = journal_submit_inode_data_buffers(journal, commit_transaction);
+ if (err)
+ jbd2_journal_abort(journal, err);
/*
* Wait for all previously submitted IO to complete if commit
@@ -759,6 +837,17 @@ start_journal_io:
__jbd2_journal_abort_hard(journal);
}
+ /*
+ * This is the right place to wait for data buffers both for ASYNC
+ * and !ASYNC commit. If commit is ASYNC, we need to wait only after
+ * the commit block went to disk (which happens above). If commit is
+ * SYNC, we need to wait for data buffers before we start writing
+ * commit block, which happens below in such setting.
+ */
+ err = journal_finish_inode_data_buffers(journal, commit_transaction);
+ if (err)
+ jbd2_journal_abort(journal, err);
+
/* Lo and behold: we have just managed to send a transaction to
the log. Before we can commit it, wait for the IO so far to
complete. Control buffers being written are on the
@@ -879,6 +968,7 @@ wait_for_iobuf:
jbd_debug(3, "JBD: commit phase 7\n");
J_ASSERT(commit_transaction->t_sync_datalist == NULL);
+ J_ASSERT(list_empty(&commit_transaction->t_inode_list));
J_ASSERT(commit_transaction->t_buffers == NULL);
J_ASSERT(commit_transaction->t_checkpoint_list == NULL);
J_ASSERT(commit_transaction->t_iobuf_list == NULL);
Index: linux-2.6-linus/fs/jbd2/journal.c
===================================================================
--- linux-2.6-linus.orig/fs/jbd2/journal.c
+++ linux-2.6-linus/fs/jbd2/journal.c
@@ -82,6 +82,10 @@ EXPORT_SYMBOL(jbd2_journal_blocks_per_pa
EXPORT_SYMBOL(jbd2_journal_invalidatepage);
EXPORT_SYMBOL(jbd2_journal_try_to_free_buffers);
EXPORT_SYMBOL(jbd2_journal_force_commit);
+EXPORT_SYMBOL(jbd2_journal_file_inode);
+EXPORT_SYMBOL(jbd2_journal_init_jbd_inode);
+EXPORT_SYMBOL(jbd2_journal_release_jbd_inode);
+EXPORT_SYMBOL(jbd2_journal_begin_ordered_truncate);
static int journal_convert_superblock_v1(journal_t *, journal_superblock_t *);
static void __journal_abort_soft (journal_t *journal, int errno);
@@ -2195,6 +2199,54 @@ void jbd2_journal_put_journal_head(struc
}
/*
+ * Initialize jbd inode head
+ */
+void jbd2_journal_init_jbd_inode(struct jbd2_inode *jinode, struct inode *inode)
+{
+ jinode->i_transaction = NULL;
+ jinode->i_next_transaction = NULL;
+ jinode->i_vfs_inode = inode;
+ jinode->i_flags = 0;
+ INIT_LIST_HEAD(&jinode->i_list);
+}
+
+/*
+ * Function to be called before we start removing inode from memory (i.e.,
+ * clear_inode() is a fine place to be called from). It removes inode from
+ * transaction's lists.
+ */
+void jbd2_journal_release_jbd_inode(journal_t *journal,
+ struct jbd2_inode *jinode)
+{
+ int writeout = 0;
+
+ if (!journal)
+ return;
+restart:
+ spin_lock(&journal->j_list_lock);
+ /* Is commit writing out inode - we have to wait */
+ if (jinode->i_flags & JI_COMMIT_RUNNING) {
+ wait_queue_head_t *wq;
+ DEFINE_WAIT_BIT(wait, &jinode->i_flags, __JI_COMMIT_RUNNING);
+ wq = bit_waitqueue(&jinode->i_flags, __JI_COMMIT_RUNNING);
+ prepare_to_wait(wq, &wait.wait, TASK_UNINTERRUPTIBLE);
+ spin_unlock(&journal->j_list_lock);
+ schedule();
+ finish_wait(wq, &wait.wait);
+ goto restart;
+ }
+
+ /* Do we need to wait for data writeback? */
+ if (journal->j_committing_transaction == jinode->i_transaction)
+ writeout = 1;
+ if (jinode->i_transaction) {
+ list_del(&jinode->i_list);
+ jinode->i_transaction = NULL;
+ }
+ spin_unlock(&journal->j_list_lock);
+}
+
+/*
* debugfs tunables
*/
#ifdef CONFIG_JBD2_DEBUG
Index: linux-2.6-linus/fs/jbd2/transaction.c
===================================================================
--- linux-2.6-linus.orig/fs/jbd2/transaction.c
+++ linux-2.6-linus/fs/jbd2/transaction.c
@@ -51,6 +51,7 @@ jbd2_get_transaction(journal_t *journal,
transaction->t_tid = journal->j_transaction_sequence++;
transaction->t_expires = jiffies + journal->j_commit_interval;
spin_lock_init(&transaction->t_handle_lock);
+ INIT_LIST_HEAD(&transaction->t_inode_list);
/* Set up the commit timer for the new transaction. */
journal->j_commit_timer.expires = round_jiffies(transaction->t_expires);
@@ -2195,3 +2196,88 @@ void jbd2_journal_refile_buffer(journal_
spin_unlock(&journal->j_list_lock);
__brelse(bh);
}
+
+/*
+ * File inode in the inode list of the handle's transaction
+ */
+int jbd2_journal_file_inode(handle_t *handle, struct jbd2_inode *jinode)
+{
+ transaction_t *transaction = handle->h_transaction;
+ journal_t *journal = transaction->t_journal;
+
+ if (is_handle_aborted(handle))
+ return -EIO;
+
+ jbd_debug(4, "Adding inode %lu, tid:%d\n", jinode->i_vfs_inode->i_ino,
+ transaction->t_tid);
+
+ /*
+ * First check whether inode isn't already on the transaction's
+ * lists without taking the lock. Note that this check is safe
+ * without the lock as we cannot race with somebody removing inode
+ * from the transaction. The reason is that we remove inode from the
+ * transaction only in journal_release_jbd_inode() and when we commit
+ * the transaction. We are guarded from the first case by holding
+ * a reference to the inode. We are safe against the second case
+ * because if jinode->i_transaction == transaction, commit code
+ * cannot touch the transaction because we hold reference to it,
+ * and if jinode->i_next_transaction == transaction, commit code
+ * will only file the inode where we want it.
+ */
+ if (jinode->i_transaction == transaction ||
+ jinode->i_next_transaction == transaction)
+ return 0;
+
+ spin_lock(&journal->j_list_lock);
+
+ if (jinode->i_transaction == transaction ||
+ jinode->i_next_transaction == transaction)
+ goto done;
+
+ /* On some different transaction's list - should be
+ * the committing one */
+ if (jinode->i_transaction) {
+ J_ASSERT(jinode->i_next_transaction == NULL);
+ J_ASSERT(jinode->i_transaction ==
+ journal->j_committing_transaction);
+ jinode->i_next_transaction = transaction;
+ goto done;
+ }
+ /* Not on any transaction list... */
+ J_ASSERT(!jinode->i_next_transaction);
+ jinode->i_transaction = transaction;
+ list_add(&jinode->i_list, &transaction->t_inode_list);
+done:
+ spin_unlock(&journal->j_list_lock);
+
+ return 0;
+}
+
+/*
+ * This function must be called when inode is journaled in ordered mode
+ * before truncation happens. It starts writeout of truncated part in
+ * case it is in the committing transaction so that we stand to ordered
+ * mode consistency guarantees.
+ */
+int jbd2_journal_begin_ordered_truncate(struct jbd2_inode *inode,
+ loff_t new_size)
+{
+ journal_t *journal;
+ transaction_t *commit_trans;
+ int ret = 0;
+
+ if (!inode->i_transaction && !inode->i_next_transaction)
+ goto out;
+ journal = inode->i_transaction->t_journal;
+ spin_lock(&journal->j_state_lock);
+ commit_trans = journal->j_committing_transaction;
+ spin_unlock(&journal->j_state_lock);
+ if (inode->i_transaction == commit_trans) {
+ ret = filemap_fdatawrite_range(inode->i_vfs_inode->i_mapping,
+ new_size, LLONG_MAX);
+ if (ret)
+ jbd2_journal_abort(journal, ret);
+ }
+out:
+ return ret;
+}
Index: linux-2.6-linus/include/linux/jbd2.h
===================================================================
--- linux-2.6-linus.orig/include/linux/jbd2.h
+++ linux-2.6-linus/include/linux/jbd2.h
@@ -381,6 +381,38 @@ static inline void jbd_unlock_bh_journal
bit_spin_unlock(BH_JournalHead, &bh->b_state);
}
+/* Flags in jbd_inode->i_flags */
+#define __JI_COMMIT_RUNNING 0
+/* Commit of the inode data in progress. We use this flag to protect us from
+ * concurrent deletion of inode. We cannot use reference to inode for this
+ * since we cannot afford doing last iput() on behalf of kjournald
+ */
+#define JI_COMMIT_RUNNING (1 << __JI_COMMIT_RUNNING)
+
+/**
+ * struct jbd_inode is the structure linking inodes in ordered mode
+ * present in a transaction so that we can sync them during commit.
+ */
+struct jbd2_inode {
+ /* Which transaction does this inode belong to? Either the running
+ * transaction or the committing one. [j_list_lock] */
+ transaction_t *i_transaction;
+
+ /* Pointer to the running transaction modifying inode's data in case
+ * there is already a committing transaction touching it. [j_list_lock] */
+ transaction_t *i_next_transaction;
+
+ /* List of inodes in the i_transaction [j_list_lock] */
+ struct list_head i_list;
+
+ /* VFS inode this inode belongs to [constant during the lifetime
+ * of the structure] */
+ struct inode *i_vfs_inode;
+
+ /* Flags of inode [j_list_lock] */
+ unsigned int i_flags;
+};
+
struct jbd2_revoke_table_s;
/**
@@ -567,6 +599,12 @@ struct transaction_s
struct journal_head *t_log_list;
/*
+ * List of inodes whose data we've modified in data=ordered mode.
+ * [j_list_lock]
+ */
+ struct list_head t_inode_list;
+
+ /*
* Protects info related to handles
*/
spinlock_t t_handle_lock;
@@ -1043,6 +1081,10 @@ extern void jbd2_journal_ack_err (
extern int jbd2_journal_clear_err (journal_t *);
extern int jbd2_journal_bmap(journal_t *, unsigned long, unsigned long long *);
extern int jbd2_journal_force_commit(journal_t *);
+extern int jbd2_journal_file_inode(handle_t *handle, struct jbd2_inode *inode);
+extern int jbd2_journal_begin_ordered_truncate(struct jbd2_inode *inode, loff_t new_size);
+extern void jbd2_journal_init_jbd_inode(struct jbd2_inode *jinode, struct inode *inode);
+extern void jbd2_journal_release_jbd_inode(journal_t *journal, struct jbd2_inode *jinode);
/*
* journal_head management
--
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