On 24-02-15, Sascha Hauer wrote:
> Call reparse_partition_table() when the partition table may have
> changed. We detect this by recording if the block device has been
> written to in the area where the partition table is.
>
> Signed-off-by: Sascha Hauer <s.hauer@xxxxxxxxxxxxxx>
> ---
> common/block.c | 30 ++++++++++++++++++++++++++++--
> include/block.h | 2 ++
> 2 files changed, 30 insertions(+), 2 deletions(-)
>
> diff --git a/common/block.c b/common/block.c
> index 3a4a9fb731..007c8bed12 100644
> --- a/common/block.c
> +++ b/common/block.c
> @@ -284,6 +284,17 @@ static ssize_t block_op_write(struct cdev *cdev, const void *buf, size_t count,
> blkcnt_t blocks;
> int ret;
>
> + /*
> + * When the offset that is written to is within the first two
> + * LBAs then the partition table has changed, reparse the partition
> + * table at close time in this case. A GPT covers more space than
> + * only the first two LBAs, but a CRC of the remaining pieces is
> + * written to LBA1, so LBA1 must change as well when the partioning
> + * is changed.
> + */
> + if (offset < 2 * SECTOR_SIZE)
> + blk->need_reparse = true;
> +
> if (offset & mask) {
> size_t now = BLOCKSIZE(blk) - (offset & mask);
> void *iobuf = block_get(blk, block);
> @@ -335,13 +346,28 @@ static ssize_t block_op_write(struct cdev *cdev, const void *buf, size_t count,
> static int block_op_flush(struct cdev *cdev)
> {
> struct block_device *blk = cdev->priv;
> + int ret;
>
> blk->discard_start = blk->discard_size = 0;
>
> - return writebuffer_flush(blk);
> + ret = writebuffer_flush(blk);
> +
> + return ret;
This change is not required or do I miss something?
Regards,
Marco
> }
>
> -static int block_op_close(struct cdev *cdev) __alias(block_op_flush);
> +static int block_op_close(struct cdev *cdev)
> +{
> + struct block_device *blk = cdev->priv;
> +
> + block_op_flush(cdev);
> +
> + if (blk->need_reparse) {
> + reparse_partition_table(blk);
> + blk->need_reparse = false;
> + }
> +
> + return 0;
> +}
>
> static int block_op_discard_range(struct cdev *cdev, loff_t count, loff_t offset)
> {
> diff --git a/include/block.h b/include/block.h
> index 44037bd74c..aaaa97400f 100644
> --- a/include/block.h
> +++ b/include/block.h
> @@ -33,6 +33,8 @@ struct block_device {
> struct list_head idle_blocks;
>
> struct cdev cdev;
> +
> + bool need_reparse;
> };
>
> extern struct list_head block_device_list;
> --
> 2.39.2
>
>
>
