fs: btrfs: Introduce btrfs_read_extent_inline() and btrfs_read_extent_reg()
These two functions are used to do sector aligned read, which will be
later used to implement btrfs_file_read().
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Marek Behún <marek.behun@nic.cz>
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 4d08b02..4da1b80 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -565,6 +565,42 @@
return ERR_PTR(ret);
}
+int read_extent_data(struct btrfs_fs_info *fs_info, char *data, u64 logical,
+ u64 *len, int mirror)
+{
+ u64 offset = 0;
+ struct btrfs_multi_bio *multi = NULL;
+ struct btrfs_device *device;
+ int ret = 0;
+ u64 max_len = *len;
+
+ ret = btrfs_map_block(fs_info, READ, logical, len, &multi, mirror,
+ NULL);
+ if (ret) {
+ fprintf(stderr, "Couldn't map the block %llu\n",
+ logical + offset);
+ goto err;
+ }
+ device = multi->stripes[0].dev;
+
+ if (*len > max_len)
+ *len = max_len;
+ if (!device->desc || !device->part) {
+ ret = -EIO;
+ goto err;
+ }
+
+ ret = __btrfs_devread(device->desc, device->part, data, *len,
+ multi->stripes[0].physical);
+ if (ret != *len)
+ ret = -EIO;
+ else
+ ret = 0;
+err:
+ kfree(multi);
+ return ret;
+}
+
void btrfs_setup_root(struct btrfs_root *root, struct btrfs_fs_info *fs_info,
u64 objectid)
{