From 0bb3eb3ee8674d5d20ad3c0c0767e18787bbd761 Mon Sep 17 00:00:00 2001 From: Qu Wenruo Date: Tue, 26 Jan 2021 16:34:02 +0800 Subject: btrfs: allow read-only mount of 4K sector size fs on 64K page system 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. Reviewed-by: Josef Bacik Signed-off-by: Qu Wenruo Reviewed-by: David Sterba Signed-off-by: David Sterba --- fs/btrfs/disk-io.c | 25 ++++++++++++++++++++++--- fs/btrfs/super.c | 7 +++++++ 2 files changed, 29 insertions(+), 3 deletions(-) diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index d34c6d61928f..71fab77873a5 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 read-write for 64K sector size, and + * read-only for 4K sector size. + */ + if ((PAGE_SIZE == SZ_4K && sectorsize != PAGE_SIZE) || + (PAGE_SIZE == SZ_64K && (sectorsize != SZ_4K && + sectorsize != SZ_64K))) { btrfs_err(fs_info, - "sectorsize %llu not supported yet, only support %lu", + "sectorsize %llu not yet supported 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 +3256,17 @@ 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 */ + if (PAGE_SIZE == SZ_64K && sectorsize == SZ_4K) { + if (!sb_rdonly(sb) || btrfs_super_log_root(disk_super)) { + btrfs_err(fs_info, + "subpage sectorsize %u only supported read-only for page size %lu", + sectorsize, PAGE_SIZE); + err = -EINVAL; + goto fail_alloc; + } + } + ret = btrfs_init_workqueues(fs_info, fs_devices); if (ret) { err = ret; diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c index 919ed5c357e9..f8435641b912 100644 --- a/fs/btrfs/super.c +++ b/fs/btrfs/super.c @@ -2027,6 +2027,13 @@ static int btrfs_remount(struct super_block *sb, int *flags, char *data) ret = -EINVAL; goto restore; } + if (fs_info->sectorsize < PAGE_SIZE) { + btrfs_warn(fs_info, + "read-write mount is not yet allowed for sectorsize %u page size %lu", + fs_info->sectorsize, PAGE_SIZE); + ret = -EINVAL; + goto restore; + } /* * NOTE: when remounting with a change that does writes, don't -- cgit v1.2.3-58-ga151