1 files changed, 25 insertions, 41 deletions

diff --git a/fs/ext4/page-io.c b/fs/ext4/page-io.c
index 92f38ee13f8..7ce1d0b19c9 100644
--- a/fs/ext4/page-io.c
+++ b/fs/ext4/page-io.c
@@ -70,7 +70,6 @@ static void put_io_page(struct ext4_io_page *io_page)
 void ext4_free_io_end(ext4_io_end_t *io)
 {
         int i;
-        wait_queue_head_t *wq;
 
         BUG_ON(!io);
         if (io->page)
@@ -78,56 +77,43 @@ void ext4_free_io_end(ext4_io_end_t *io)
         for (i = 0; i < io->num_io_pages; i++)
                 put_io_page(io->pages[i]);
         io->num_io_pages = 0;
-        wq = ext4_ioend_wq(io->inode);
-        if (atomic_dec_and_test(&EXT4_I(io->inode)->i_ioend_count) &&
-            waitqueue_active(wq))
-                wake_up_all(wq);
+        if (atomic_dec_and_test(&EXT4_I(io->inode)->i_ioend_count))
+                wake_up_all(ext4_ioend_wq(io->inode));
         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)
 {
         struct inode *inode = io->inode;
         loff_t offset = io->offset;
         ssize_t size = io->size;
-        wait_queue_head_t *wq;
         int ret = 0;
 
         ext4_debug("ext4_end_io_nolock: 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 & EXT4_IO_END_UNWRITTEN))
-                return ret;
-
         ret = ext4_convert_unwritten_extents(inode, offset, size);
         if (ret < 0) {
-                printk(KERN_EMERG "%s: failed to convert unwritten "
-                        "extents to written extents, error is %d "
-                        "io is still on inode %lu aio dio list\n",
-                       __func__, ret, inode->i_ino);
-                return ret;
+                ext4_msg(inode->i_sb, KERN_EMERG,
+                         "failed to convert unwritten extents to written "
+                         "extents -- potential data loss!  "
+                         "(inode %lu, offset %llu, size %zd, error %d)",
+                         inode->i_ino, offset, size, ret);
         }
 
         if (io->iocb)
                 aio_complete(io->iocb, io->result, 0);
-        /* clear the DIO AIO unwritten flag */
-        if (io->flag & EXT4_IO_END_UNWRITTEN) {
-                io->flag &= ~EXT4_IO_END_UNWRITTEN;
-                /* Wake up anyone waiting on unwritten extent conversion */
-                wq = ext4_ioend_wq(io->inode);
-                if (atomic_dec_and_test(&EXT4_I(inode)->i_aiodio_unwritten) &&
-                    waitqueue_active(wq)) {
-                        wake_up_all(wq);
-                }
-        }
 
+        /* Wake up anyone waiting on unwritten extent conversion */
+        if (atomic_dec_and_test(&EXT4_I(inode)->i_aiodio_unwritten))
+                wake_up_all(ext4_ioend_wq(io->inode));
         return ret;
 }
 
@@ -140,9 +126,15 @@ static void ext4_end_io_work(struct work_struct *work)
         struct inode            *inode = io->inode;
         struct ext4_inode_info  *ei = EXT4_I(inode);
         unsigned long           flags;
-        int                     ret;
+
+        spin_lock_irqsave(&ei->i_completed_io_lock, flags);
+        if (list_empty(&io->list)) {
+                spin_unlock_irqrestore(&ei->i_completed_io_lock, flags);
+                goto free;
+        }
 
         if (!mutex_trylock(&inode->i_mutex)) {
+                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.
@@ -159,17 +151,11 @@ static void ext4_end_io_work(struct work_struct *work)
                 io->flag |= EXT4_IO_END_QUEUED;
                 return;
         }
-        ret = ext4_end_io_nolock(io);
-        if (ret < 0) {
-                mutex_unlock(&inode->i_mutex);
-                return;
-        }
-
-        spin_lock_irqsave(&ei->i_completed_io_lock, flags);
-        if (!list_empty(&io->list))
-                list_del_init(&io->list);
+        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);
 }
 
@@ -350,10 +336,8 @@ submit_and_retry:
         if ((io_end->num_io_pages >= MAX_IO_PAGES) &&
             (io_end->pages[io_end->num_io_pages-1] != io_page))
                 goto submit_and_retry;
-        if (buffer_uninit(bh) && !(io_end->flag & EXT4_IO_END_UNWRITTEN)) {
-                io_end->flag |= EXT4_IO_END_UNWRITTEN;
-                atomic_inc(&EXT4_I(inode)->i_aiodio_unwritten);
-        }
+        if (buffer_uninit(bh))
+                ext4_set_io_unwritten_flag(inode, io_end);
         io->io_end->size += bh->b_size;
         io->io_next_block++;
         ret = bio_add_page(io->io_bio, bh->b_page, bh->b_size, bh_offset(bh));