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-rw-r--r--fs/ext4/page-io.c176
1 files changed, 119 insertions, 57 deletions
diff --git a/fs/ext4/page-io.c b/fs/ext4/page-io.c
index dcdeef1..68e896e 100644
--- a/fs/ext4/page-io.c
+++ b/fs/ext4/page-io.c
@@ -71,6 +71,9 @@ void ext4_free_io_end(ext4_io_end_t *io)
int i;
BUG_ON(!io);
+ BUG_ON(!list_empty(&io->list));
+ BUG_ON(io->flag & EXT4_IO_END_UNWRITTEN);
+
if (io->page)
put_page(io->page);
for (i = 0; i < io->num_io_pages; i++)
@@ -81,13 +84,8 @@ void ext4_free_io_end(ext4_io_end_t *io)
kmem_cache_free(io_end_cachep, io);
}
-/*
- * check a range of space and convert unwritten extents to written.
- *
- * Called with inode->i_mutex; we depend on this when we manipulate
- * io->flag, since we could otherwise race with ext4_flush_completed_IO()
- */
-int ext4_end_io_nolock(ext4_io_end_t *io)
+/* check a range of space and convert unwritten extents to written. */
+static int ext4_end_io(ext4_io_end_t *io)
{
struct inode *inode = io->inode;
loff_t offset = io->offset;
@@ -106,63 +104,136 @@ int ext4_end_io_nolock(ext4_io_end_t *io)
"(inode %lu, offset %llu, size %zd, error %d)",
inode->i_ino, offset, size, ret);
}
-
if (io->iocb)
aio_complete(io->iocb, io->result, 0);
if (io->flag & EXT4_IO_END_DIRECT)
inode_dio_done(inode);
/* Wake up anyone waiting on unwritten extent conversion */
- if (atomic_dec_and_test(&EXT4_I(inode)->i_aiodio_unwritten))
+ if (atomic_dec_and_test(&EXT4_I(inode)->i_unwritten))
wake_up_all(ext4_ioend_wq(io->inode));
return ret;
}
-/*
- * work on completed aio dio IO, to convert unwritten extents to extents
- */
-static void ext4_end_io_work(struct work_struct *work)
+static void dump_completed_IO(struct inode *inode)
+{
+#ifdef EXT4FS_DEBUG
+ struct list_head *cur, *before, *after;
+ ext4_io_end_t *io, *io0, *io1;
+ unsigned long flags;
+
+ if (list_empty(&EXT4_I(inode)->i_completed_io_list)) {
+ ext4_debug("inode %lu completed_io list is empty\n",
+ inode->i_ino);
+ return;
+ }
+
+ ext4_debug("Dump inode %lu completed_io list\n", inode->i_ino);
+ list_for_each_entry(io, &EXT4_I(inode)->i_completed_io_list, list) {
+ cur = &io->list;
+ before = cur->prev;
+ io0 = container_of(before, ext4_io_end_t, list);
+ after = cur->next;
+ io1 = container_of(after, ext4_io_end_t, list);
+
+ ext4_debug("io 0x%p from inode %lu,prev 0x%p,next 0x%p\n",
+ io, inode->i_ino, io0, io1);
+ }
+#endif
+}
+
+/* Add the io_end to per-inode completed end_io list. */
+void ext4_add_complete_io(ext4_io_end_t *io_end)
{
- ext4_io_end_t *io = container_of(work, ext4_io_end_t, work);
- struct inode *inode = io->inode;
- struct ext4_inode_info *ei = EXT4_I(inode);
- unsigned long flags;
+ struct ext4_inode_info *ei = EXT4_I(io_end->inode);
+ struct workqueue_struct *wq;
+ unsigned long flags;
+
+ BUG_ON(!(io_end->flag & EXT4_IO_END_UNWRITTEN));
+ wq = EXT4_SB(io_end->inode->i_sb)->dio_unwritten_wq;
spin_lock_irqsave(&ei->i_completed_io_lock, flags);
- if (io->flag & EXT4_IO_END_IN_FSYNC)
- goto requeue;
- if (list_empty(&io->list)) {
- spin_unlock_irqrestore(&ei->i_completed_io_lock, flags);
- goto free;
+ if (list_empty(&ei->i_completed_io_list)) {
+ io_end->flag |= EXT4_IO_END_QUEUED;
+ queue_work(wq, &io_end->work);
}
+ list_add_tail(&io_end->list, &ei->i_completed_io_list);
+ spin_unlock_irqrestore(&ei->i_completed_io_lock, flags);
+}
- if (!mutex_trylock(&inode->i_mutex)) {
- bool was_queued;
-requeue:
- was_queued = !!(io->flag & EXT4_IO_END_QUEUED);
- io->flag |= EXT4_IO_END_QUEUED;
- spin_unlock_irqrestore(&ei->i_completed_io_lock, flags);
- /*
- * Requeue the work instead of waiting so that the work
- * items queued after this can be processed.
- */
- queue_work(EXT4_SB(inode->i_sb)->dio_unwritten_wq, &io->work);
- /*
- * To prevent the ext4-dio-unwritten thread from keeping
- * requeueing end_io requests and occupying cpu for too long,
- * yield the cpu if it sees an end_io request that has already
- * been requeued.
- */
- if (was_queued)
- yield();
- return;
+static int ext4_do_flush_completed_IO(struct inode *inode,
+ ext4_io_end_t *work_io)
+{
+ ext4_io_end_t *io;
+ struct list_head unwritten, complete, to_free;
+ unsigned long flags;
+ struct ext4_inode_info *ei = EXT4_I(inode);
+ int err, ret = 0;
+
+ INIT_LIST_HEAD(&complete);
+ INIT_LIST_HEAD(&to_free);
+
+ spin_lock_irqsave(&ei->i_completed_io_lock, flags);
+ dump_completed_IO(inode);
+ list_replace_init(&ei->i_completed_io_list, &unwritten);
+ spin_unlock_irqrestore(&ei->i_completed_io_lock, flags);
+
+ while (!list_empty(&unwritten)) {
+ io = list_entry(unwritten.next, ext4_io_end_t, list);
+ BUG_ON(!(io->flag & EXT4_IO_END_UNWRITTEN));
+ list_del_init(&io->list);
+
+ err = ext4_end_io(io);
+ if (unlikely(!ret && err))
+ ret = err;
+
+ list_add_tail(&io->list, &complete);
+ }
+ spin_lock_irqsave(&ei->i_completed_io_lock, flags);
+ while (!list_empty(&complete)) {
+ io = list_entry(complete.next, ext4_io_end_t, list);
+ io->flag &= ~EXT4_IO_END_UNWRITTEN;
+ /* end_io context can not be destroyed now because it still
+ * used by queued worker. Worker thread will destroy it later */
+ if (io->flag & EXT4_IO_END_QUEUED)
+ list_del_init(&io->list);
+ else
+ list_move(&io->list, &to_free);
+ }
+ /* If we are called from worker context, it is time to clear queued
+ * flag, and destroy it's end_io if it was converted already */
+ if (work_io) {
+ work_io->flag &= ~EXT4_IO_END_QUEUED;
+ if (!(work_io->flag & EXT4_IO_END_UNWRITTEN))
+ list_add_tail(&work_io->list, &to_free);
}
- list_del_init(&io->list);
spin_unlock_irqrestore(&ei->i_completed_io_lock, flags);
- (void) ext4_end_io_nolock(io);
- mutex_unlock(&inode->i_mutex);
-free:
- ext4_free_io_end(io);
+
+ while (!list_empty(&to_free)) {
+ io = list_entry(to_free.next, ext4_io_end_t, list);
+ list_del_init(&io->list);
+ ext4_free_io_end(io);
+ }
+ return ret;
+}
+
+/*
+ * work on completed aio dio IO, to convert unwritten extents to extents
+ */
+static void ext4_end_io_work(struct work_struct *work)
+{
+ ext4_io_end_t *io = container_of(work, ext4_io_end_t, work);
+ ext4_do_flush_completed_IO(io->inode, io);
+}
+
+int ext4_flush_unwritten_io(struct inode *inode)
+{
+ int ret;
+ WARN_ON_ONCE(!mutex_is_locked(&inode->i_mutex) &&
+ !(inode->i_state & I_FREEING));
+ ret = ext4_do_flush_completed_IO(inode, NULL);
+ ext4_unwritten_wait(inode);
+ return ret;
}
ext4_io_end_t *ext4_init_io_end(struct inode *inode, gfp_t flags)
@@ -195,9 +266,7 @@ static void buffer_io_error(struct buffer_head *bh)
static void ext4_end_bio(struct bio *bio, int error)
{
ext4_io_end_t *io_end = bio->bi_private;
- struct workqueue_struct *wq;
struct inode *inode;
- unsigned long flags;
int i;
sector_t bi_sector = bio->bi_sector;
@@ -255,14 +324,7 @@ static void ext4_end_bio(struct bio *bio, int error)
return;
}
- /* Add the io_end to per-inode completed io list*/
- spin_lock_irqsave(&EXT4_I(inode)->i_completed_io_lock, flags);
- list_add_tail(&io_end->list, &EXT4_I(inode)->i_completed_io_list);
- spin_unlock_irqrestore(&EXT4_I(inode)->i_completed_io_lock, flags);
-
- wq = EXT4_SB(inode->i_sb)->dio_unwritten_wq;
- /* queue the work to convert unwritten extents to written */
- queue_work(wq, &io_end->work);
+ ext4_add_complete_io(io_end);
}
void ext4_io_submit(struct ext4_io_submit *io)
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