Merge branch 'misc' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild

[karo-tx-linux.git] / fs / ext4 / page-io.c

diff --git a/fs/ext4/page-io.c b/fs/ext4/page-io.c
index 92f38ee13f8a9efacadcfac2fe8d674d5500aebc..7ce1d0b19c94576892d0d80f016f7db44110ccb7 100644 (file)
--- 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));