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authorLiu Bo <bo.li.liu@oracle.com>2018-01-05 12:51:10 -0700
committerDavid Sterba <dsterba@suse.com>2018-01-22 16:08:21 +0100
commit7b4df058b051fb67db61ea371f7d278131cb6e7b (patch)
treeae12edbe7dc44fbe99ad4aaa4c3b7fb8739a97a9 /fs/btrfs
parent18e83ac75bfe67009c4ddcdd581bba8eb16f4030 (diff)
Btrfs: add helper for em merge logic
This is a prepare work for the following extent map selftest, which runs tests against em merge logic. Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Reviewed-by: Josef Bacik <jbacik@fb.com> Signed-off-by: David Sterba <dsterba@suse.com>
Diffstat (limited to 'fs/btrfs')
-rw-r--r--fs/btrfs/ctree.h2
-rw-r--r--fs/btrfs/inode.c80
2 files changed, 48 insertions, 34 deletions
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 1a462ab85c49..1e05fc7e0e35 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -3143,6 +3143,8 @@ struct btrfs_delalloc_work *btrfs_alloc_delalloc_work(struct inode *inode,
int delay_iput);
void btrfs_wait_and_free_delalloc_work(struct btrfs_delalloc_work *work);
+int btrfs_add_extent_mapping(struct extent_map_tree *em_tree,
+ struct extent_map **em_in, u64 start, u64 len);
struct extent_map *btrfs_get_extent_fiemap(struct btrfs_inode *inode,
struct page *page, size_t pg_offset, u64 start,
u64 len, int create);
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 4ab713bd4139..c6a05ee3d74b 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -6925,6 +6925,51 @@ static noinline int uncompress_inline(struct btrfs_path *path,
return ret;
}
+int btrfs_add_extent_mapping(struct extent_map_tree *em_tree,
+ struct extent_map **em_in, u64 start, u64 len)
+{
+ int ret;
+ struct extent_map *em = *em_in;
+
+ ret = add_extent_mapping(em_tree, em, 0);
+ /* it is possible that someone inserted the extent into the tree
+ * while we had the lock dropped. It is also possible that
+ * an overlapping map exists in the tree
+ */
+ if (ret == -EEXIST) {
+ struct extent_map *existing;
+
+ ret = 0;
+
+ existing = search_extent_mapping(em_tree, start, len);
+ /*
+ * existing will always be non-NULL, since there must be
+ * extent causing the -EEXIST.
+ */
+ if (start >= existing->start &&
+ start < extent_map_end(existing)) {
+ free_extent_map(em);
+ *em_in = existing;
+ ret = 0;
+ } else {
+ /*
+ * The existing extent map is the one nearest to
+ * the [start, start + len) range which overlaps
+ */
+ ret = merge_extent_mapping(em_tree, existing,
+ em, start);
+ free_extent_map(existing);
+ if (ret) {
+ free_extent_map(em);
+ *em_in = NULL;
+ }
+ }
+ }
+
+ ASSERT(ret == 0 || ret == -EEXIST);
+ return ret;
+}
+
/*
* a bit scary, this does extent mapping from logical file offset to the disk.
* the ugly parts come from merging extents from the disk with the in-ram
@@ -7138,40 +7183,7 @@ insert:
err = 0;
write_lock(&em_tree->lock);
- ret = add_extent_mapping(em_tree, em, 0);
- /* it is possible that someone inserted the extent into the tree
- * while we had the lock dropped. It is also possible that
- * an overlapping map exists in the tree
- */
- if (ret == -EEXIST) {
- struct extent_map *existing;
-
- ret = 0;
-
- existing = search_extent_mapping(em_tree, start, len);
- /*
- * existing will always be non-NULL, since there must be
- * extent causing the -EEXIST.
- */
- if (start >= existing->start &&
- start < extent_map_end(existing)) {
- free_extent_map(em);
- em = existing;
- err = 0;
- } else {
- /*
- * The existing extent map is the one nearest to
- * the [start, start + len) range which overlaps
- */
- err = merge_extent_mapping(em_tree, existing,
- em, start);
- free_extent_map(existing);
- if (err) {
- free_extent_map(em);
- em = NULL;
- }
- }
- }
+ err = btrfs_add_extent_mapping(em_tree, &em, start, len);
write_unlock(&em_tree->lock);
out: