btrfs-progs: check: introduce function to check file extent

Introduce a new function check_file_extent() to check file extent,
such as datasum, hole, size.

Signed-off-by: Lu Fengqi <lufq.fnst@cn.fujitsu.com>
Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/cmds-check.c b/cmds-check.c
index dd8926d..620895a 100644 (file)
--- a/cmds-check.c
+++ b/cmds-check.c
@@ -3833,6 +3833,9 @@ out:
 #define INODE_REF_MISSING      (1<<4)  /* INODE_REF/INODE_EXTREF not found */
 #define INODE_ITEM_MISSING     (1<<5)  /* INODE_ITEM not found */
 #define INODE_ITEM_MISMATCH    (1<<6)  /* INODE_ITEM found but not match */
+#define FILE_EXTENT_ERROR      (1<<7)  /* bad FILE_EXTENT */
+#define ODD_CSUM_ITEM          (1<<8)  /* CSUM_ITEM error */
+#define CSUM_ITEM_MISSING      (1<<9)  /* CSUM_ITEM not found */
 
 /*
  * Find DIR_ITEM/DIR_INDEX for the given key and check it with the specified
@@ -4393,6 +4396,100 @@ next:
        return err;
 }
 
+/*
+ * Check file extent datasum/hole, update the size of the file extents,
+ * check and update the last offset of the file extent.
+ *
+ * @root:      the root of fs/file tree.
+ * @fkey:      the key of the file extent.
+ * @nodatasum: INODE_NODATASUM feature.
+ * @size:      the sum of all EXTENT_DATA items size for this inode.
+ * @end:       the offset of the last extent.
+ *
+ * Return 0 if no error occurred.
+ */
+static int check_file_extent(struct btrfs_root *root, struct btrfs_key *fkey,
+                            struct extent_buffer *node, int slot,
+                            unsigned int nodatasum, u64 *size, u64 *end)
+{
+       struct btrfs_file_extent_item *fi;
+       u64 disk_bytenr;
+       u64 disk_num_bytes;
+       u64 extent_num_bytes;
+       u64 found;
+       unsigned int extent_type;
+       unsigned int is_hole;
+       int ret;
+       int err = 0;
+
+       fi = btrfs_item_ptr(node, slot, struct btrfs_file_extent_item);
+
+       extent_type = btrfs_file_extent_type(node, fi);
+       /* Skip if file extent is inline */
+       if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
+               struct btrfs_item *e = btrfs_item_nr(slot);
+               u32 item_inline_len;
+
+               item_inline_len = btrfs_file_extent_inline_item_len(node, e);
+               extent_num_bytes = btrfs_file_extent_inline_len(node, slot, fi);
+               if (extent_num_bytes == 0 ||
+                   extent_num_bytes != item_inline_len)
+                       err |= FILE_EXTENT_ERROR;
+               *size += extent_num_bytes;
+               return err;
+       }
+
+       /* Check extent type */
+       if (extent_type != BTRFS_FILE_EXTENT_REG &&
+                       extent_type != BTRFS_FILE_EXTENT_PREALLOC) {
+               err |= FILE_EXTENT_ERROR;
+               error("root %llu EXTENT_DATA[%llu %llu] type bad",
+                     root->objectid, fkey->objectid, fkey->offset);
+               return err;
+       }
+
+       /* Check REG_EXTENT/PREALLOC_EXTENT */
+       disk_bytenr = btrfs_file_extent_disk_bytenr(node, fi);
+       disk_num_bytes = btrfs_file_extent_disk_num_bytes(node, fi);
+       extent_num_bytes = btrfs_file_extent_num_bytes(node, fi);
+       is_hole = (disk_bytenr == 0) && (disk_num_bytes == 0);
+
+       /* Check EXTENT_DATA datasum */
+       ret = count_csum_range(root, disk_bytenr, disk_num_bytes, &found);
+       if (found > 0 && nodatasum) {
+               err |= ODD_CSUM_ITEM;
+               error("root %llu EXTENT_DATA[%llu %llu] nodatasum shouldn't have datasum",
+                     root->objectid, fkey->objectid, fkey->offset);
+       } else if (extent_type == BTRFS_FILE_EXTENT_REG && !nodatasum &&
+                  !is_hole &&
+                  (ret < 0 || found == 0 || found < disk_num_bytes)) {
+               err |= CSUM_ITEM_MISSING;
+               error("root %llu EXTENT_DATA[%llu %llu] datasum missing",
+                     root->objectid, fkey->objectid, fkey->offset);
+       } else if (extent_type == BTRFS_FILE_EXTENT_PREALLOC && found > 0) {
+               err |= ODD_CSUM_ITEM;
+               error("root %llu EXTENT_DATA[%llu %llu] prealloc shouldn't have datasum",
+                     root->objectid, fkey->objectid, fkey->offset);
+       }
+
+       /* Check EXTENT_DATA hole */
+       if (no_holes && is_hole) {
+               err |= FILE_EXTENT_ERROR;
+               error("root %llu EXTENT_DATA[%llu %llu] shouldn't be hole",
+                     root->objectid, fkey->objectid, fkey->offset);
+       } else if (!no_holes && *end != fkey->offset) {
+               err |= FILE_EXTENT_ERROR;
+               error("root %llu EXTENT_DATA[%llu %llu] interrupt",
+                     root->objectid, fkey->objectid, fkey->offset);
+       }
+
+       *end += extent_num_bytes;
+       if (!is_hole)
+               *size += extent_num_bytes;
+
+       return err;
+}
+
 static int all_backpointers_checked(struct extent_record *rec, int print_errs)
 {
        struct list_head *cur = rec->backrefs.next;