[PATCH 4/7] block: reparse partition table when necessary

[Sascha Hauer]

On Thu, Feb 15, 2024 at 01:52:28PM +0100, Marco Felsch wrote:
> 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 at pengutronix.de>
> > ---
> >  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?

Fixed, thanks

Sascha

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