Btrfs: fix runtime warning in check-integrity check data mode

If a file_extent_item was located at the very end of a leaf and there was
not enough space to hold a full item, but there was enough space to hold
one of type BTRFS_FILE_EXTENT_INLINE or PREALLOC, and it was only such a
short item, a warning was printed anyway. This check is now fixed.

Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de>

diff --git a/fs/btrfs/check-integrity.c b/fs/btrfs/check-integrity.c
index 7f6cc359e4401363bd8276b03c9352fe1bcbc7eb..ed7618389327f7ad403a61f723915ab23f719fac 100644 (file)
--- a/fs/btrfs/check-integrity.c
+++ b/fs/btrfs/check-integrity.c
@@ -1428,6 +1428,28 @@ static int btrfsic_handle_extent_data(
 
        file_extent_item_offset = offsetof(struct btrfs_leaf, items) +
                                  item_offset;
+       if (file_extent_item_offset +
+           offsetof(struct btrfs_file_extent_item, disk_num_bytes) >
+           block_ctx->len) {
+               printk(KERN_INFO
+                      "btrfsic: file item out of bounce at logical %llu, dev %s\n",
+                      block_ctx->start, block_ctx->dev->name);
+               return -1;
+       }
+
+       btrfsic_read_from_block_data(block_ctx, &file_extent_item,
+               file_extent_item_offset,
+               offsetof(struct btrfs_file_extent_item, disk_num_bytes));
+       if (BTRFS_FILE_EXTENT_REG != file_extent_item.type ||
+           ((u64)0) == le64_to_cpu(file_extent_item.disk_bytenr)) {
+               if (state->print_mask & BTRFSIC_PRINT_MASK_VERY_VERBOSE)
+                       printk(KERN_INFO "extent_data: type %u, disk_bytenr = %llu\n",
+                              file_extent_item.type,
+                              (unsigned long long)
+                              le64_to_cpu(file_extent_item.disk_bytenr));
+               return 0;
+       }
+
        if (file_extent_item_offset + sizeof(struct btrfs_file_extent_item) >
            block_ctx->len) {
                printk(KERN_INFO
@@ -1452,9 +1474,6 @@ static int btrfsic_handle_extent_data(
                       le64_to_cpu(file_extent_item.disk_bytenr),
                       (unsigned long long)le64_to_cpu(file_extent_item.offset),
                       (unsigned long long)num_bytes);
-       if (BTRFS_FILE_EXTENT_REG != file_extent_item.type ||
-           ((u64)0) == le64_to_cpu(file_extent_item.disk_bytenr))
-               return 0;
        while (num_bytes > 0) {
                u32 chunk_len;
                int num_copies;