On Tue, Jan 26, 2021 at 04:34:02PM +0800, Qu Wenruo wrote:
> This adds the basic RO mount ability for 4K sector size on 64K page
> system.
>
> Currently we only plan to support 4K and 64K page system.
>
> Signed-off-by: Qu Wenruo <[email protected]>
> Signed-off-by: David Sterba <[email protected]>
> ---
> fs/btrfs/disk-io.c | 24 +++++++++++++++++++++---
> fs/btrfs/super.c | 7 +++++++
> 2 files changed, 28 insertions(+), 3 deletions(-)
>
> diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
> index 0b10577ad2bd..d74ee0a396ac 100644
> --- a/fs/btrfs/disk-io.c
> +++ b/fs/btrfs/disk-io.c
> @@ -2483,13 +2483,21 @@ static int validate_super(struct btrfs_fs_info
> *fs_info,
> btrfs_err(fs_info, "invalid sectorsize %llu", sectorsize);
> ret = -EINVAL;
> }
> - /* Only PAGE SIZE is supported yet */
> - if (sectorsize != PAGE_SIZE) {
> +
> + /*
> + * For 4K page size, we only support 4K sector size.
> + * For 64K page size, we support RW for 64K sector size, and RO for
> + * 4K sector size.
> + */
> + if ((SZ_4K == PAGE_SIZE && sectorsize != PAGE_SIZE) ||
> + (SZ_64K == PAGE_SIZE && (sectorsize != SZ_4K &&
I've switched the order here so it reads more naturally as PAGE_SIZE == SZ_...
> + sectorsize != SZ_64K))) {
> btrfs_err(fs_info,
> - "sectorsize %llu not supported yet, only support %lu",
> + "sectorsize %llu not supported yet for page size %lu",
> sectorsize, PAGE_SIZE);
> ret = -EINVAL;
> }
> +
> if (!is_power_of_2(nodesize) || nodesize < sectorsize ||
> nodesize > BTRFS_MAX_METADATA_BLOCKSIZE) {
> btrfs_err(fs_info, "invalid nodesize %llu", nodesize);
> @@ -3248,6 +3256,16 @@ int __cold open_ctree(struct super_block *sb, struct
> btrfs_fs_devices *fs_device
> goto fail_alloc;
> }
>
> + /* For 4K sector size support, it's only read-only yet */
> + if (PAGE_SIZE == SZ_64K && sectorsize == SZ_4K) {
> + if (!sb_rdonly(sb) || btrfs_super_log_root(disk_super)) {
> + btrfs_err(fs_info,
> + "subpage sector size only support RO yet");
Similar to the other message, I've added which sectorsize and page size
don't work.
And s/RO/read-only/. This is for clarity of the messages that are read
by users, while we can use the RO/RW in comments or changelogs.
