On 10.10.2017 10:51, Qu Wenruo wrote:
> Along with the fix introduced, also introduce check for them.
> Unlike normal check funtions, some of the check is optional, and even if
> the image failed to pass optional check, kernel can still run fine.
> (But may cause noisy kernel warning)
>
> So some check, mainly for alignment, will not cause btrfs check to fail,
> but only to output warning and how to fix it.
>
> Signed-off-by: Qu Wenruo <quwenruo.btrfs@xxxxxxx>
> ---
> cmds-check.c | 73 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 73 insertions(+)
>
> diff --git a/cmds-check.c b/cmds-check.c
> index fdb6d832eee1..23dd3b51102b 100644
> --- a/cmds-check.c
> +++ b/cmds-check.c
> @@ -9879,6 +9879,67 @@ static int check_device_used(struct device_record *dev_rec,
> }
> }
>
> +/*
> + * Extra (optional) check for dev_item size
> + *
> + * To avoid possible kernel warning for v4.14 kernel.
> + * It's not a deadly problem, just to info v4.14 kernel user.
> + * So it won't change the return value.
> + */
> +static void check_dev_size_alignment(u64 devid, u64 total_bytes,
> + u32 sectorsize)
> +{
> + if (!IS_ALIGNED(total_bytes, sectorsize)) {
> + warning("unaligned total_bytes detected for devid %llu, have %llu should be aligned to %u",
> + devid, total_bytes, sectorsize);
> + warning("this is OK for older kernel (<4.14), but may cause kernel warning for newer kernel (>=4.14)");
> + warning("this can be fixed by 'btrfs check --fix-dev-size'");
> + }
> +}
> +
> +/*
> + * Unlike device size alignment check above, some super total_bytes check
> + * failure can lead to unmountable fs for kernel >=v4.6.
> + *
> + * So this function will return the error for fatal super total_bytes problem.
> + */
> +static int check_super_size(struct btrfs_fs_info *fs_info)
> +{
> + struct btrfs_device *dev;
> + struct list_head *dev_list = &fs_info->fs_devices->devices;
> + u64 total_bytes = 0;
> + u64 super_bytes = btrfs_super_total_bytes(fs_info->super_copy);
> +
> + list_for_each_entry(dev, dev_list, dev_list)
> + total_bytes += dev->total_bytes;
> +
> + /* Important check, which can cause unmountable fs */
> + if (super_bytes < total_bytes) {
> + error("super total bytes %llu smaller than real devices size %llu",
> + super_bytes, total_bytes);
> + error("this fs will not be mountable for newer kernels (>=v4.6)");
> + error("this can be fixed by 'btrfs check --fix-dev-size'");
> + return 1;
> + }
> +
> + /*
> + * Optional check, just to make everything aligned and match with
> + * each other.
> + *
> + * For btrfs-image restored fs, we don't need to check it anyway.
> + */
> + if (btrfs_super_flags(fs_info->super_copy) &
> + (BTRFS_SUPER_FLAG_METADUMP | BTRFS_SUPER_FLAG_METADUMP_V2))
> + return 0;
> + if (!IS_ALIGNED(super_bytes, fs_info->sectorsize) ||
> + !IS_ALIGNED(total_bytes, fs_info->sectorsize) ||
> + super_bytes != total_bytes) {
> + warning("minor unaligned/mismatch device size detected");
> + warning("recommended to use 'btrfs check --fix-dev-size' to fix it");
> + }
> + return 0;
> +}
nit: Make the function return bool and perhaps rename it to
"is_super_size_aligned" or something like that ?
> +
> /* check btrfs_dev_item -> btrfs_dev_extent */
> static int check_devices(struct rb_root *dev_cache,
> struct device_extent_tree *dev_extent_cache)
> @@ -9896,6 +9957,11 @@ static int check_devices(struct rb_root *dev_cache,
> if (err)
> ret = err;
>
> + if (!IS_ALIGNED(dev_rec->total_byte, global_info->sectorsize)) {
> + }
> +
> + check_dev_size_alignment(dev_rec->devid, dev_rec->total_byte,
> + global_info->sectorsize);
> dev_node = rb_next(dev_node);
Something funny is going on here, the body of the if is empty, perhaps
those function have to be inside?
> }
> list_for_each_entry(dext_rec, &dev_extent_cache->no_device_orphans,
> @@ -11141,6 +11207,7 @@ static int check_dev_item(struct btrfs_fs_info *fs_info,
> struct btrfs_path path;
> struct btrfs_key key;
> struct btrfs_dev_extent *ptr;
> + u64 total_bytes;
> u64 dev_id;
> u64 used;
> u64 total = 0;
> @@ -11149,6 +11216,7 @@ static int check_dev_item(struct btrfs_fs_info *fs_info,
> dev_item = btrfs_item_ptr(eb, slot, struct btrfs_dev_item);
> dev_id = btrfs_device_id(eb, dev_item);
> used = btrfs_device_bytes_used(eb, dev_item);
> + total_bytes = btrfs_device_total_bytes(eb, dev_item);
>
> key.objectid = dev_id;
> key.type = BTRFS_DEV_EXTENT_KEY;
> @@ -11193,6 +11261,8 @@ next:
> BTRFS_DEV_EXTENT_KEY, dev_id);
> return ACCOUNTING_MISMATCH;
> }
> + check_dev_size_alignment(dev_id, total_bytes, fs_info->sectorsize);
> +
> return 0;
> }
>
> @@ -13471,6 +13541,9 @@ int cmd_check(int argc, char **argv)
> error(
> "errors found in extent allocation tree or chunk allocation");
>
> + /* Only re-check super size after we checked and repaired the fs */
> + err |= check_super_size(info);
> +
> ret = repair_root_items(info);
> err |= !!ret;
> if (ret < 0) {
>
--
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