unsigned max_blocks = bh_result->b_size >> inode->i_blkbits;
int dio_credits;
+ ext4_debug("ext4_get_block_dio_write: inode %lu, create flag %d\n",
+ inode->i_ino, create);
/*
* DIO VFS code passes create = 0 flag for write to
* the middle of file. It does this to avoid block
return ret;
}
-#define DIO_AIO 0x1
-
static void ext4_free_io_end(ext4_io_end_t *io)
{
+ BUG_ON(!io);
+ iput(io->inode);
kfree(io);
}
+static void dump_aio_dio_list(struct inode * inode)
+{
+#ifdef EXT4_DEBUG
+ struct list_head *cur, *before, *after;
+ ext4_io_end_t *io, *io0, *io1;
+
+ if (list_empty(&EXT4_I(inode)->i_aio_dio_complete_list)){
+ ext4_debug("inode %lu aio dio list is empty\n", inode->i_ino);
+ return;
+ }
+
+ ext4_debug("Dump inode %lu aio_dio_completed_IO list \n", inode->i_ino);
+ list_for_each_entry(io, &EXT4_I(inode)->i_aio_dio_complete_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
+}
/*
- * IO write completion for unwritten extents.
- *
* check a range of space and convert unwritten extents to written.
*/
-static void ext4_end_dio_unwritten(struct work_struct *work)
+static int ext4_end_aio_dio_nolock(ext4_io_end_t *io)
{
- ext4_io_end_t *io = container_of(work, ext4_io_end_t, work);
struct inode *inode = io->inode;
loff_t offset = io->offset;
size_t size = io->size;
int ret = 0;
- int aio = io->flag & DIO_AIO;
- if (aio)
- mutex_lock(&inode->i_mutex);
+ ext4_debug("end_aio_dio_onlock: io 0x%p from inode %lu,list->next 0x%p,"
+ "list->prev 0x%p\n",
+ io, inode->i_ino, io->list.next, io->list.prev);
+
+ if (list_empty(&io->list))
+ return ret;
+
+ if (io->flag != DIO_AIO_UNWRITTEN)
+ return ret;
+
if (offset + size <= i_size_read(inode))
ret = ext4_convert_unwritten_extents(inode, offset, size);
- if (ret < 0)
+ if (ret < 0) {
printk(KERN_EMERG "%s: failed to convert unwritten"
- "extents to written extents, error is %d\n",
- __func__, ret);
+ "extents to written extents, error is %d"
+ " io is still on inode %lu aio dio list\n",
+ __func__, ret, inode->i_ino);
+ return ret;
+ }
+
+ /* clear the DIO AIO unwritten flag */
+ io->flag = 0;
+ return ret;
+}
+/*
+ * work on completed aio dio IO, to convert unwritten extents to extents
+ */
+static void ext4_end_aio_dio_work(struct work_struct *work)
+{
+ ext4_io_end_t *io = container_of(work, ext4_io_end_t, work);
+ struct inode *inode = io->inode;
+ int ret = 0;
+
+ mutex_lock(&inode->i_mutex);
+ ret = ext4_end_aio_dio_nolock(io);
+ if (ret >= 0) {
+ if (!list_empty(&io->list))
+ list_del_init(&io->list);
+ ext4_free_io_end(io);
+ }
+ mutex_unlock(&inode->i_mutex);
+}
+/*
+ * This function is called from ext4_sync_file().
+ *
+ * When AIO DIO IO is completed, the work to convert unwritten
+ * extents to written is queued on workqueue but may not get immediately
+ * scheduled. When fsync is called, we need to ensure the
+ * conversion is complete before fsync returns.
+ * The inode keeps track of a list of completed AIO from DIO path
+ * that might needs to do the conversion. This function walks through
+ * the list and convert the related unwritten extents to written.
+ */
+int flush_aio_dio_completed_IO(struct inode *inode)
+{
+ ext4_io_end_t *io;
+ int ret = 0;
+ int ret2 = 0;
- ext4_free_io_end(io);
- if (aio)
- mutex_unlock(&inode->i_mutex);
+ if (list_empty(&EXT4_I(inode)->i_aio_dio_complete_list))
+ return ret;
+
+ dump_aio_dio_list(inode);
+ while (!list_empty(&EXT4_I(inode)->i_aio_dio_complete_list)){
+ io = list_entry(EXT4_I(inode)->i_aio_dio_complete_list.next,
+ ext4_io_end_t, list);
+ /*
+ * Calling ext4_end_aio_dio_nolock() to convert completed
+ * IO to written.
+ *
+ * When ext4_sync_file() is called, run_queue() may already
+ * about to flush the work corresponding to this io structure.
+ * It will be upset if it founds the io structure related
+ * to the work-to-be schedule is freed.
+ *
+ * Thus we need to keep the io structure still valid here after
+ * convertion finished. The io structure has a flag to
+ * avoid double converting from both fsync and background work
+ * queue work.
+ */
+ ret = ext4_end_aio_dio_nolock(io);
+ if (ret < 0)
+ ret2 = ret;
+ else
+ list_del_init(&io->list);
+ }
+ return (ret2 < 0) ? ret2 : 0;
}
-static ext4_io_end_t *ext4_init_io_end (struct inode *inode, unsigned int flag)
+static ext4_io_end_t *ext4_init_io_end (struct inode *inode)
{
ext4_io_end_t *io = NULL;
io = kmalloc(sizeof(*io), GFP_NOFS);
if (io) {
+ igrab(inode);
io->inode = inode;
- io->flag = flag;
+ io->flag = 0;
io->offset = 0;
io->size = 0;
io->error = 0;
- INIT_WORK(&io->work, ext4_end_dio_unwritten);
+ INIT_WORK(&io->work, ext4_end_aio_dio_work);
+ INIT_LIST_HEAD(&io->list);
}
return io;
ext4_io_end_t *io_end = iocb->private;
struct workqueue_struct *wq;
- /* if not hole or unwritten extents, just simple return */
- if (!io_end || !size || !iocb->private)
+ ext_debug("ext4_end_io_dio(): io_end 0x%p"
+ "for inode %lu, iocb 0x%p, offset %llu, size %llu\n",
+ iocb->private, io_end->inode->i_ino, iocb, offset,
+ size);
+ /* if not async direct IO or dio with 0 bytes write, just return */
+ if (!io_end || !size)
return;
+
+ /* if not aio dio with unwritten extents, just free io and return */
+ if (io_end->flag != DIO_AIO_UNWRITTEN){
+ ext4_free_io_end(io_end);
+ iocb->private = NULL;
+ return;
+ }
+
io_end->offset = offset;
io_end->size = size;
wq = EXT4_SB(io_end->inode->i_sb)->dio_unwritten_wq;
- /* We need to convert unwritten extents to written */
+ /* queue the work to convert unwritten extents to written */
queue_work(wq, &io_end->work);
- if (is_sync_kiocb(iocb))
- flush_workqueue(wq);
-
+ /* Add the io_end to per-inode completed aio dio list*/
+ list_add_tail(&io_end->list,
+ &EXT4_I(io_end->inode)->i_aio_dio_complete_list);
iocb->private = NULL;
}
/*
* If those blocks were preallocated, we mark sure they are splited, but
* still keep the range to write as unintialized.
*
- * When end_io call back function called at the last IO complete time,
- * those extents will be converted to written extents.
+ * The unwrritten extents will be converted to written when DIO is completed.
+ * For async direct IO, since the IO may still pending when return, we
+ * set up an end_io call back function, which will do the convertion
+ * when async direct IO completed.
*
* If the O_DIRECT write will extend the file then add this inode to the
* orphan list. So recovery will truncate it back to the original size
loff_t final_size = offset + count;
if (rw == WRITE && final_size <= inode->i_size) {
/*
- * For DIO we fallocate blocks for holes, we fallocate blocks
- * The fallocated extent for hole is marked as uninitialized
+ * We could direct write to holes and fallocate.
+ *
+ * Allocated blocks to fill the hole are marked as uninitialized
* to prevent paralel buffered read to expose the stale data
* before DIO complete the data IO.
- * as for previously fallocated extents, ext4 get_block
+ *
+ * As to previously fallocated extents, ext4 get_block
* will just simply mark the buffer mapped but still
* keep the extents uninitialized.
*
- * At the end of IO, the ext4 end_io callback function
- * will convert those unwritten extents to written,
- *
+ * for non AIO case, we will convert those unwritten extents
+ * to written after return back from blockdev_direct_IO.
+ *
+ * for async DIO, the conversion needs to be defered when
+ * the IO is completed. The ext4 end_io callback function
+ * will be called to take care of the conversion work.
+ * Here for async case, we allocate an io_end structure to
+ * hook to the iocb.
*/
- iocb->private = ext4_init_io_end(inode, !is_sync_kiocb(iocb));
- if (!iocb->private)
- return -ENOMEM;
+ iocb->private = NULL;
+ EXT4_I(inode)->cur_aio_dio = NULL;
+ if (!is_sync_kiocb(iocb)) {
+ iocb->private = ext4_init_io_end(inode);
+ if (!iocb->private)
+ return -ENOMEM;
+ /*
+ * we save the io structure for current async
+ * direct IO, so that later ext4_get_blocks()
+ * could flag the io structure whether there
+ * is a unwritten extents needs to be converted
+ * when IO is completed.
+ */
+ EXT4_I(inode)->cur_aio_dio = iocb->private;
+ }
+
ret = blockdev_direct_IO(rw, iocb, inode,
inode->i_sb->s_bdev, iov,
offset, nr_segs,
ext4_get_block_dio_write,
ext4_end_io_dio);
+ if (iocb->private)
+ EXT4_I(inode)->cur_aio_dio = NULL;
+ /*
+ * The io_end structure takes a reference to the inode,
+ * that structure needs to be destroyed and the
+ * reference to the inode need to be dropped, when IO is
+ * complete, even with 0 byte write, or failed.
+ *
+ * In the successful AIO DIO case, the io_end structure will be
+ * desctroyed and the reference to the inode will be dropped
+ * after the end_io call back function is called.
+ *
+ * In the case there is 0 byte write, or error case, since
+ * VFS direct IO won't invoke the end_io call back function,
+ * we need to free the end_io structure here.
+ */
+ if (ret != -EIOCBQUEUED && ret <= 0 && iocb->private) {
+ ext4_free_io_end(iocb->private);
+ iocb->private = NULL;
+ } else if (ret > 0)
+ /*
+ * for non AIO case, since the IO is already
+ * completed, we could do the convertion right here
+ */
+ ret = ext4_convert_unwritten_extents(inode,
+ offset, ret);
return ret;
}
+
+ /* for write the the end of file case, we fall back to old way */
return ext4_ind_direct_IO(rw, iocb, iov, offset, nr_segs);
}
projects / openwrt / staging / blogic.git / commitdiff