From 03cb793b26834ddca170ba87057c8f883772dd45 Mon Sep 17 00:00:00 2001 From: Christian Marangi <ansuelsmth@gmail.com> Date: Thu, 3 Oct 2024 00:11:41 +0200 Subject: [PATCH 1/5] block: add support for defining read-only partitions Add support for defining read-only partitions and complete support for it in the cmdline partition parser as the additional "ro" after a partition is scanned but never actually applied. Signed-off-by: Christian Marangi <ansuelsmth@gmail.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20241002221306.4403-2-ansuelsmth@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk> --- block/blk.h | 1 + block/partitions/cmdline.c | 3 +++ block/partitions/core.c | 3 +++ 3 files changed, 7 insertions(+) --- a/block/blk.h +++ b/block/blk.h @@ -424,6 +424,7 @@ void blk_free_ext_minor(unsigned int min #define ADDPART_FLAG_NONE 0 #define ADDPART_FLAG_RAID 1 #define ADDPART_FLAG_WHOLEDISK 2 +#define ADDPART_FLAG_READONLY 4 int bdev_add_partition(struct gendisk *disk, int partno, sector_t start, sector_t length); int bdev_del_partition(struct gendisk *disk, int partno); --- a/block/partitions/cmdline.c +++ b/block/partitions/cmdline.c @@ -237,6 +237,9 @@ static int add_part(int slot, struct cmd put_partition(state, slot, subpart->from >> 9, subpart->size >> 9); + if (subpart->flags & PF_RDONLY) + state->parts[slot].flags |= ADDPART_FLAG_READONLY; + info = &state->parts[slot].info; strscpy(info->volname, subpart->name, sizeof(info->volname)); --- a/block/partitions/core.c +++ b/block/partitions/core.c @@ -392,6 +392,9 @@ static struct block_device *add_partitio goto out_del; } + if (flags & ADDPART_FLAG_READONLY) + bdev->bd_read_only = true; + /* everything is up and running, commence */ err = xa_insert(&disk->part_tbl, partno, bdev, GFP_KERNEL); if (err)