Btrfs: add inodes before dropping the extent lock in find_all_leafs

We must build up the inode list with the extent lock held after following
indirect refs.

This also requires an extension to ulists, which allows to modify the stored
aux value in case a key already exists in the list.

Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>

diff --git a/fs/btrfs/backref.c b/fs/btrfs/backref.c
index 0ac47f2834d19c4610dc54eb416ca40e4efaf53a..3f75895c919bcc3b80ae63ab1fca42dcf335f95b 100644 (file)
--- a/fs/btrfs/backref.c
+++ b/fs/btrfs/backref.c
@@ -106,6 +106,7 @@ struct __prelim_ref {
        struct btrfs_key key_for_search;
        int level;
        int count;
+       struct extent_inode_elem *inode_list;
        u64 parent;
        u64 wanted_disk_byte;
 };
@@ -166,6 +167,7 @@ static int __add_prelim_ref(struct list_head *head, u64 root_id,
        else
                memset(&ref->key_for_search, 0, sizeof(ref->key_for_search));
 
+       ref->inode_list = NULL;
        ref->level = level;
        ref->count = count;
        ref->parent = parent;
@@ -181,14 +183,21 @@ static int add_all_parents(struct btrfs_root *root, struct btrfs_path *path,
                                const u64 *extent_item_pos)
 {
        int ret;
-       int slot;
+       int slot = path->slots[level];
        struct extent_buffer *eb = path->nodes[level];
        struct btrfs_file_extent_item *fi;
+       struct extent_inode_elem *eie = NULL;
        u64 disk_byte;
        u64 wanted_objectid = key->objectid;
 
 add_parent:
-       ret = ulist_add(parents, eb->start, 0, GFP_NOFS);
+       if (level == 0 && extent_item_pos) {
+               fi = btrfs_item_ptr(eb, slot, struct btrfs_file_extent_item);
+               ret = check_extent_in_eb(key, eb, fi, *extent_item_pos, &eie);
+               if (ret < 0)
+                       return ret;
+       }
+       ret = ulist_add(parents, eb->start, (unsigned long)eie, GFP_NOFS);
        if (ret < 0)
                return ret;
 
@@ -202,6 +211,7 @@ add_parent:
         * repeat this until we don't find any additional EXTENT_DATA items.
         */
        while (1) {
+               eie = NULL;
                ret = btrfs_next_leaf(root, path);
                if (ret < 0)
                        return ret;
@@ -346,6 +356,8 @@ static int __resolve_indirect_refs(struct btrfs_fs_info *fs_info,
                ULIST_ITER_INIT(&uiter);
                node = ulist_next(parents, &uiter);
                ref->parent = node ? node->val : 0;
+               ref->inode_list =
+                       node ? (struct extent_inode_elem *)node->aux : 0;
 
                /* additional parents require new refs being added here */
                while ((node = ulist_next(parents, &uiter))) {
@@ -356,6 +368,8 @@ static int __resolve_indirect_refs(struct btrfs_fs_info *fs_info,
                        }
                        memcpy(new_ref, ref, sizeof(*ref));
                        new_ref->parent = node->val;
+                       new_ref->inode_list =
+                                       (struct extent_inode_elem *)node->aux;
                        list_add(&new_ref->list, &ref->list);
                }
                ulist_reinit(parents);
@@ -879,7 +893,7 @@ again:
                }
                if (ref->count && ref->parent) {
                        struct extent_inode_elem *eie = NULL;
-                       if (extent_item_pos) {
+                       if (extent_item_pos && !ref->inode_list) {
                                u32 bsz;
                                struct extent_buffer *eb;
                                bsz = btrfs_level_size(fs_info->extent_root,
@@ -889,10 +903,22 @@ again:
                                BUG_ON(!eb);
                                ret = find_extent_in_eb(eb, bytenr,
                                                        *extent_item_pos, &eie);
+                               ref->inode_list = eie;
                                free_extent_buffer(eb);
                        }
-                       ret = ulist_add(refs, ref->parent,
-                                       (unsigned long)eie, GFP_NOFS);
+                       ret = ulist_add_merge(refs, ref->parent,
+                                             (unsigned long)ref->inode_list,
+                                             (unsigned long *)&eie, GFP_NOFS);
+                       if (!ret && extent_item_pos) {
+                               /*
+                                * we've recorded that parent, so we must extend
+                                * its inode list here
+                                */
+                               BUG_ON(!eie);
+                               while (eie->next)
+                                       eie = eie->next;
+                               eie->next = ref->inode_list;
+                       }
                        BUG_ON(ret < 0);
                }
                kfree(ref);

diff --git a/fs/btrfs/ulist.c b/fs/btrfs/ulist.c
index 17e68bdc307c3efa2849d8a1f9adef32833cd513..2ef59400ad6eb38bef17d3967f33fb46dd4287ac 100644 (file)
--- a/fs/btrfs/ulist.c
+++ b/fs/btrfs/ulist.c
@@ -145,12 +145,21 @@ EXPORT_SYMBOL(ulist_free);
  */
 int ulist_add(struct ulist *ulist, u64 val, unsigned long aux,
              unsigned long gfp_mask)
+{
+       return ulist_add_merge(ulist, val, aux, NULL, gfp_mask);
+}
+
+int ulist_add_merge(struct ulist *ulist, u64 val, unsigned long aux,
+                   unsigned long *old_aux, unsigned long gfp_mask)
 {
        int i;
 
        for (i = 0; i < ulist->nnodes; ++i) {
-               if (ulist->nodes[i].val == val)
+               if (ulist->nodes[i].val == val) {
+                       if (old_aux)
+                               *old_aux = ulist->nodes[i].aux;
                        return 0;
+               }
        }
 
        if (ulist->nnodes >= ulist->nodes_alloced) {

diff --git a/fs/btrfs/ulist.h b/fs/btrfs/ulist.h
index 62d2574f775a29ff6d413d59c05f7bf46c31cf7f..f1b1bf00c5a93fb1add21da0e8dd1cbbdd2ba448 100644 (file)
--- a/fs/btrfs/ulist.h
+++ b/fs/btrfs/ulist.h
@@ -67,6 +67,8 @@ struct ulist *ulist_alloc(unsigned long gfp_mask);
 void ulist_free(struct ulist *ulist);
 int ulist_add(struct ulist *ulist, u64 val, unsigned long aux,
              unsigned long gfp_mask);
+int ulist_add_merge(struct ulist *ulist, u64 val, unsigned long aux,
+                   unsigned long *old_aux, unsigned long gfp_mask);
 struct ulist_node *ulist_next(struct ulist *ulist,
                              struct ulist_iterator *uiter);