Merge branch 'for-linus-4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/mason...

[cascardo/linux.git] / fs / btrfs / inode.c

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index e28f3d4..151b7c7 100644 (file)
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -5717,6 +5717,7 @@ static int btrfs_real_readdir(struct file *file, struct dir_context *ctx)
        char *name_ptr;
        int name_len;
        int is_curr = 0;        /* ctx->pos points to the current index? */
+       bool emitted;
 
        /* FIXME, use a real flag for deciding about the key type */
        if (root->fs_info->tree_root == root)
@@ -5745,6 +5746,7 @@ static int btrfs_real_readdir(struct file *file, struct dir_context *ctx)
        if (ret < 0)
                goto err;
 
+       emitted = false;
        while (1) {
                leaf = path->nodes[0];
                slot = path->slots[0];
@@ -5824,6 +5826,7 @@ skip:
 
                        if (over)
                                goto nopos;
+                       emitted = true;
                        di_len = btrfs_dir_name_len(leaf, di) +
                                 btrfs_dir_data_len(leaf, di) + sizeof(*di);
                        di_cur += di_len;
@@ -5836,11 +5839,20 @@ next:
        if (key_type == BTRFS_DIR_INDEX_KEY) {
                if (is_curr)
                        ctx->pos++;
-               ret = btrfs_readdir_delayed_dir_index(ctx, &ins_list);
+               ret = btrfs_readdir_delayed_dir_index(ctx, &ins_list, &emitted);
                if (ret)
                        goto nopos;
        }
 
+       /*
+        * If we haven't emitted any dir entry, we must not touch ctx->pos as
+        * it was was set to the termination value in previous call. We assume
+        * that "." and ".." were emitted if we reach this point and set the
+        * termination value as well for an empty directory.
+        */
+       if (ctx->pos > 2 && !emitted)
+               goto nopos;
+
        /* Reached end of directory/root. Bump pos past the last item. */
        ctx->pos++;
 
@@ -7116,21 +7128,41 @@ static struct extent_map *btrfs_new_extent_direct(struct inode *inode,
        if (ret)
                return ERR_PTR(ret);
 
-       em = create_pinned_em(inode, start, ins.offset, start, ins.objectid,
-                             ins.offset, ins.offset, ins.offset, 0);
-       if (IS_ERR(em)) {
-               btrfs_free_reserved_extent(root, ins.objectid, ins.offset, 1);
-               return em;
-       }
-
+       /*
+        * Create the ordered extent before the extent map. This is to avoid
+        * races with the fast fsync path that would lead to it logging file
+        * extent items that point to disk extents that were not yet written to.
+        * The fast fsync path collects ordered extents into a local list and
+        * then collects all the new extent maps, so we must create the ordered
+        * extent first and make sure the fast fsync path collects any new
+        * ordered extents after collecting new extent maps as well.
+        * The fsync path simply can not rely on inode_dio_wait() because it
+        * causes deadlock with AIO.
+        */
        ret = btrfs_add_ordered_extent_dio(inode, start, ins.objectid,
                                           ins.offset, ins.offset, 0);
        if (ret) {
                btrfs_free_reserved_extent(root, ins.objectid, ins.offset, 1);
-               free_extent_map(em);
                return ERR_PTR(ret);
        }
 
+       em = create_pinned_em(inode, start, ins.offset, start, ins.objectid,
+                             ins.offset, ins.offset, ins.offset, 0);
+       if (IS_ERR(em)) {
+               struct btrfs_ordered_extent *oe;
+
+               btrfs_free_reserved_extent(root, ins.objectid, ins.offset, 1);
+               oe = btrfs_lookup_ordered_extent(inode, start);
+               ASSERT(oe);
+               if (WARN_ON(!oe))
+                       return em;
+               set_bit(BTRFS_ORDERED_IOERR, &oe->flags);
+               set_bit(BTRFS_ORDERED_IO_DONE, &oe->flags);
+               btrfs_remove_ordered_extent(inode, oe);
+               /* Once for our lookup and once for the ordered extents tree. */
+               btrfs_put_ordered_extent(oe);
+               btrfs_put_ordered_extent(oe);
+       }
        return em;
 }