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>

1 files changed, 22 insertions, 3 deletions

diff --git a/fs/btrfs/check-integrity.c b/fs/btrfs/check-integrity.c
index 7f6cc359e440..ed7618389327 100644
--- 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;