Introduce a new function, scrub_one_extent(), as a wrapper to check one
mirror-based extent.
It will accept a btrfs_path parameter @path, which must points to a
META/EXTENT_ITEM.
And @start, @len, which must be a subset of META/EXTENT_ITEM.
Signed-off-by: Qu Wenruo <quwen...@cn.fujitsu.com>
---
scrub.c | 148 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 147 insertions(+), 1 deletion(-)
diff --git a/scrub.c b/scrub.c
index e473d168..4302aafa 100644
--- a/scrub.c
+++ b/scrub.c
@@ -441,7 +441,7 @@ static int recover_data_mirror(struct btrfs_fs_info
*fs_info,
num_copies = btrfs_num_copies(&fs_info->mapping_tree, start, len);
for (i = 0; i < num_copies; i++) {
- for_each_set_bit(bit, corrupt_bitmaps[i], BITS_PER_LONG) {
+ for_each_set_bit(bit, corrupt_bitmaps[i], len / sectorsize) {
u64 cur = start + bit * sectorsize;
int good;
@@ -481,3 +481,149 @@ out:
free(buf);
return ret;
}
+
+/* Btrfs only supports up to 2 copies of data, yet */
+#define BTRFS_MAX_COPIES 2
+
+/*
+ * Check all copies of range @start, @len.
+ * Caller must ensure the range is covered by EXTENT_ITEM/METADATA_ITEM
+ * specified by leaf of @path.
+ * And @start, @len must be a subset of the EXTENT_ITEM/METADATA_ITEM.
+ *
+ * Return 0 if the range is all OK or recovered or recoverable.
+ * Return <0 if the range can't be recoverable.
+ */
+static int scrub_one_extent(struct btrfs_fs_info *fs_info,
+ struct btrfs_scrub_progress *scrub_ctx,
+ struct btrfs_path *path, u64 start, u64 len,
+ int write)
+{
+ struct btrfs_key key;
+ struct btrfs_extent_item *ei;
+ struct extent_buffer *leaf = path->nodes[0];
+ u32 sectorsize = fs_info->tree_root->sectorsize;
+ unsigned long *corrupt_bitmaps[BTRFS_MAX_COPIES] = { NULL };
+ int slot = path->slots[0];
+ int num_copies;
+ int meta_corrupted = 0;
+ int meta_good_mirror = 0;
+ int data_bad_mirror = 0;
+ u64 extent_start;
+ u64 extent_len;
+ int metadata = 0;
+ int i;
+ int ret = 0;
+
+ btrfs_item_key_to_cpu(leaf, &key, slot);
+ if (key.type != BTRFS_METADATA_ITEM_KEY &&
+ key.type != BTRFS_EXTENT_ITEM_KEY)
+ goto invalid_arg;
+
+ extent_start = key.objectid;
+ if (key.type == BTRFS_METADATA_ITEM_KEY) {
+ extent_len = fs_info->tree_root->nodesize;
+ metadata = 1;
+ } else {
+ extent_len = key.offset;
+ ei = btrfs_item_ptr(leaf, slot, struct btrfs_extent_item);
+ if (btrfs_extent_flags(leaf, ei) & BTRFS_EXTENT_FLAG_TREE_BLOCK)
+ metadata = 1;
+ }
+ if (start >= extent_start + extent_len ||
+ start + len <= extent_start)
+ goto invalid_arg;
+
+ for (i = 0; i < BTRFS_MAX_COPIES; i++) {
+ corrupt_bitmaps[i] = malloc(
+ calculate_bitmap_len(len / sectorsize));
+ if (!corrupt_bitmaps[i])
+ goto out;
+ }
+ num_copies = btrfs_num_copies(&fs_info->mapping_tree, start, len);
+ for (i = 1; i <= num_copies; i++) {
+ if (metadata) {
+ ret = check_tree_mirror(fs_info, scrub_ctx,
+ NULL, extent_start, i);
+ scrub_ctx->tree_extents_scrubbed++;
+ if (ret < 0)
+ meta_corrupted++;
+ else
+ meta_good_mirror = i;
+ } else {
+ ret = check_data_mirror(fs_info, scrub_ctx, NULL, start,
+ len, i, corrupt_bitmaps[i - 1]);
+ scrub_ctx->data_extents_scrubbed++;
+ }
+ }
+
+ /* Metadata recover and report */
+ if (metadata) {
+ if (!meta_corrupted) {
+ goto out;
+ } else if (meta_corrupted && meta_corrupted < num_copies) {
+ if (write) {
+ ret = recover_tree_mirror(fs_info, scrub_ctx,
+ start, meta_good_mirror);
+ if (ret < 0) {
+ error("failed to recover tree block at
bytenr %llu",
+ start);
+ goto out;
+ }
+ printf("extent %llu len %llu REPAIRED: has
corrupted mirror, repaired\n",
+ start, len);
+ goto out;
+ }
+ printf("extent %llu len %llu RECOVERABLE: has corrupted
mirror, but is recoverable\n",
+ start, len);
+ goto out;
+ } else {
+ error("extent %llu len %llu CORRUPTED: all mirror(s)
corrupted, can't be recovered",
+ start, len);
+ ret = -EIO;
+ goto out;
+ }
+ }
+ /* Data recover and report */
+ for (i = 0; i < num_copies; i++) {
+ if (find_first_bit(corrupt_bitmaps[i], len / sectorsize) >=
+ len / sectorsize)
+ continue;
+ data_bad_mirror = i + 1;
+ }
+ /* All data sectors are good */
+ if (!data_bad_mirror) {
+ ret = 0;
+ goto out;
+ }
+
+ if (check_data_mirror_recoverable(fs_info, start, len,
+ sectorsize, corrupt_bitmaps)) {
+ if (write) {
+ ret = recover_data_mirror(fs_info, scrub_ctx, start,
+ len, corrupt_bitmaps);
+ if (ret < 0) {
+ error("failed to recover data extent at bytenr
%llu len %llu",
+ start, len);
+ goto out;
+ }
+ printf("extent %llu len %llu REPARIED: has corrupted
mirror, repaired\n",
+ start, len);
+ goto out;
+ }
+ printf("extent %llu len %llu RECOVERABLE: has corrupted mirror,
recoverable\n",
+ start, len);
+ goto out;
+ }
+ error("extent %llu len %llu CORRUPTED, all mirror(s) corrupted, can't
be repaired",
+ start, len);
+ ret = -EIO;
+out:
+ for (i = 0; i < BTRFS_MAX_COPIES; i++)
+ kfree(corrupt_bitmaps[i]);
+ return ret;
+
+invalid_arg:
+ error("invalid parameter for %s", __func__);
+ return -EINVAL;
+}
--
2.13.0
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