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path: root/fs/btrfs/extent_map.c
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Diffstat (limited to 'fs/btrfs/extent_map.c')
-rw-r--r--fs/btrfs/extent_map.c23
1 files changed, 16 insertions, 7 deletions
diff --git a/fs/btrfs/extent_map.c b/fs/btrfs/extent_map.c
index 2834ca5768e..a4a7a1a8da9 100644
--- a/fs/btrfs/extent_map.c
+++ b/fs/btrfs/extent_map.c
@@ -174,6 +174,14 @@ static int mergable_maps(struct extent_map *prev, struct extent_map *next)
test_bit(EXTENT_FLAG_LOGGING, &next->flags))
return 0;
+ /*
+ * We don't want to merge stuff that hasn't been written to the log yet
+ * since it may not reflect exactly what is on disk, and that would be
+ * bad.
+ */
+ if (!list_empty(&prev->list) || !list_empty(&next->list))
+ return 0;
+
if (extent_map_end(prev) == next->start &&
prev->flags == next->flags &&
prev->bdev == next->bdev &&
@@ -209,9 +217,7 @@ static void try_merge_map(struct extent_map_tree *tree, struct extent_map *em)
em->mod_len = (em->mod_len + em->mod_start) - merge->mod_start;
em->mod_start = merge->mod_start;
em->generation = max(em->generation, merge->generation);
- list_move(&em->list, &tree->modified_extents);
- list_del_init(&merge->list);
rb_erase(&merge->rb_node, &tree->map);
free_extent_map(merge);
}
@@ -227,7 +233,6 @@ static void try_merge_map(struct extent_map_tree *tree, struct extent_map *em)
merge->in_tree = 0;
em->mod_len = (merge->mod_start + merge->mod_len) - em->mod_start;
em->generation = max(em->generation, merge->generation);
- list_del_init(&merge->list);
free_extent_map(merge);
}
}
@@ -302,7 +307,7 @@ void clear_em_logging(struct extent_map_tree *tree, struct extent_map *em)
* reference dropped if the merge attempt was successful.
*/
int add_extent_mapping(struct extent_map_tree *tree,
- struct extent_map *em)
+ struct extent_map *em, int modified)
{
int ret = 0;
struct rb_node *rb;
@@ -324,7 +329,10 @@ int add_extent_mapping(struct extent_map_tree *tree,
em->mod_start = em->start;
em->mod_len = em->len;
- try_merge_map(tree, em);
+ if (modified)
+ list_move(&em->list, &tree->modified_extents);
+ else
+ try_merge_map(tree, em);
out:
return ret;
}
@@ -337,8 +345,9 @@ static u64 range_end(u64 start, u64 len)
return start + len;
}
-struct extent_map *__lookup_extent_mapping(struct extent_map_tree *tree,
- u64 start, u64 len, int strict)
+static struct extent_map *
+__lookup_extent_mapping(struct extent_map_tree *tree,
+ u64 start, u64 len, int strict)
{
struct extent_map *em;
struct rb_node *rb_node;