Define a global enum extents_operation to record extents are pinned,
excluded or new chunk is allocated for extents.
Although global variable is not so graceful, it simplifies codes much.
New function try_avoid_extents_overwrite() will try to mark block
groups full and allocate a new chunk. If it failed because of no space
or wrong used bytes(fsck-tests/004), then try to exclude metadata
blocks.
Signed-off-by: Su Yue <suy.fnst@xxxxxxxxxxxxxx>
---
cmds-check.c | 101 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 101 insertions(+)
diff --git a/cmds-check.c b/cmds-check.c
index 311c8a9f45e8..9042bab93785 100644
--- a/cmds-check.c
+++ b/cmds-check.c
@@ -84,6 +84,15 @@ enum btrfs_check_mode {
static enum btrfs_check_mode check_mode = CHECK_MODE_DEFAULT;
+enum lowmem_extents_operation {
+ EXTENTS_PIN,
+ EXTENTS_EXCLUDE,
+ EXTENTS_MARK_BG_FULL,
+ EXTENTS_NONE
+};
+
+static enum lowmem_extents_operation extents_operation = EXTENTS_NONE;
+
struct extent_backref {
struct rb_node node;
unsigned int is_data:1;
@@ -13517,6 +13526,98 @@ out:
return err;
}
+static void cleanup_excluded_extents(struct btrfs_fs_info *fs_info);
+static int end_avoid_extents_overwrite(struct btrfs_fs_info *fs_info)
+{
+ int ret;
+
+ switch (extents_operation) {
+ case EXTENTS_PIN:
+ ret = btrfs_finish_extent_commit(NULL, fs_info->extent_root,
+ &fs_info->pinned_extents);
+ break;
+ case EXTENTS_EXCLUDE:
+ cleanup_excluded_extents(fs_info);
+ ret = 0;
+ break;
+ case EXTENTS_MARK_BG_FULL:
+ ret = modify_block_groups_cache(fs_info,
+ BTRFS_BLOCK_GROUP_METADATA, 0);
+ break;
+ case EXTENTS_NONE:
+ ret = 0;
+ break;
+ default:
+ ret = -EINVAL;
+ }
+
+ if (!ret)
+ extents_operation = EXTENTS_NONE;
+ return ret;
+}
+
+static int pin_metadata_blocks(struct btrfs_fs_info *fs_info);
+static int exclude_metadata_blocks(struct btrfs_fs_info *fs_info);
+/*
+ * NOTE: Do not call this function during transaction.
+ */
+static int avoid_extents_overwrite(struct btrfs_fs_info *fs_info,
+ enum lowmem_extents_operation op)
+{
+ int ret;
+
+ if (op == extents_operation)
+ return 0;
+
+ switch (op) {
+ case EXTENTS_PIN:
+ ret = pin_metadata_blocks(fs_info);
+ break;
+ case EXTENTS_EXCLUDE:
+ ret = exclude_metadata_blocks(fs_info);
+ break;
+ case EXTENTS_MARK_BG_FULL:
+ ret = force_cow_in_new_chunk(fs_info);
+ break;
+ case EXTENTS_NONE:
+ ret = 0;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ /* extents_operation should be assigned anyway for latter clean up. */
+ extents_operation = op;
+
+ if (ret)
+ end_avoid_extents_overwrite(fs_info);
+ return ret;
+}
+
+static int try_avoid_extents_overwrite(struct btrfs_fs_info *fs_info)
+{
+ int ret;
+ int mixed = btrfs_fs_incompat(fs_info, MIXED_GROUPS);
+
+ if (extents_operation != EXTENTS_NONE)
+ return 0;
+ ret = avoid_extents_overwrite(fs_info, EXTENTS_MARK_BG_FULL);
+
+ /*
+ * If there is no space left to allocate, try to exclude all metadata
+ * blocks. Mix filesystem is unsupported.
+ */
+ if (ret && ret == -ENOSPC && !mixed) {
+ printf(
+ "Try to exclude all metadata blcoks and extents, it may be slow\n");
+ ret = avoid_extents_overwrite(fs_info, EXTENTS_EXCLUDE);
+ }
+
+ if (ret)
+ error("failed to avoid extents overwrite %s", strerror(-ret));
+ return ret;
+}
+
/*
* Low memory usage version check_chunks_and_extents.
*/
--
2.15.1
--
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