Re: [f2fs-dev] [PATCH 2/2 v2] f2fs: support RO feature

From: Jaegeuk Kim
Date: Wed May 26 2021 - 10:06:23 EST


On 05/26, Jaegeuk Kim wrote:
> Given RO feature in superblock, we don't need to check provisioning/reserve
> spaces and SSA area.
>
> Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>
> ---
> fs/f2fs/f2fs.h | 2 ++
> fs/f2fs/segment.c | 4 ++++
> fs/f2fs/super.c | 35 ++++++++++++++++++++++++++++++-----
> 3 files changed, 36 insertions(+), 5 deletions(-)
>
> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
> index eaf57b5f3c4b..9ad502f92529 100644
> --- a/fs/f2fs/f2fs.h
> +++ b/fs/f2fs/f2fs.h
> @@ -168,6 +168,7 @@ struct f2fs_mount_info {
> #define F2FS_FEATURE_SB_CHKSUM 0x0800
> #define F2FS_FEATURE_CASEFOLD 0x1000
> #define F2FS_FEATURE_COMPRESSION 0x2000
> +#define F2FS_FEATURE_RO 0x4000
>
> #define __F2FS_HAS_FEATURE(raw_super, mask) \
> ((raw_super->feature & cpu_to_le32(mask)) != 0)
> @@ -940,6 +941,7 @@ static inline void set_new_dnode(struct dnode_of_data *dn, struct inode *inode,
> #define NR_CURSEG_DATA_TYPE (3)
> #define NR_CURSEG_NODE_TYPE (3)
> #define NR_CURSEG_INMEM_TYPE (2)
> +#define NR_CURSEG_RO_TYPE (2)
> #define NR_CURSEG_PERSIST_TYPE (NR_CURSEG_DATA_TYPE + NR_CURSEG_NODE_TYPE)
> #define NR_CURSEG_TYPE (NR_CURSEG_INMEM_TYPE + NR_CURSEG_PERSIST_TYPE)
>
> diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
> index 8668df7870d0..02e0c38be7eb 100644
> --- a/fs/f2fs/segment.c
> +++ b/fs/f2fs/segment.c
> @@ -4683,6 +4683,10 @@ static int sanity_check_curseg(struct f2fs_sb_info *sbi)
> struct seg_entry *se = get_seg_entry(sbi, curseg->segno);
> unsigned int blkofs = curseg->next_blkoff;
>
> + if (F2FS_HAS_FEATURE(sbi, F2FS_FEATURE_RO) &&
> + i != CURSEG_HOT_DATA && i != CURSEG_HOT_NODE)
> + continue;
> +
> sanity_check_seg_type(sbi, curseg->seg_type);
>
> if (f2fs_test_bit(blkofs, se->cur_valid_map))
> diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
> index e70aca8f97bd..7769ed789b38 100644
> --- a/fs/f2fs/super.c
> +++ b/fs/f2fs/super.c
> @@ -1162,6 +1162,12 @@ static int parse_options(struct super_block *sb, char *options, bool is_remount)
> */
> if (F2FS_OPTION(sbi).active_logs != NR_CURSEG_TYPE)
> F2FS_OPTION(sbi).whint_mode = WHINT_MODE_OFF;
> +
> + if (F2FS_HAS_FEATURE(sbi, F2FS_FEATURE_RO) && !f2fs_readonly(sbi->sb)) {
> + f2fs_info(sbi, "Allow to mount readonly mode only");
> + err = -EINVAL;
> + goto free_options;

Fixed:
if (F2FS_HAS_FEATURE(sbi, F2FS_FEATURE_RO) && !f2fs_readonly(sbi->sb)) {
f2fs_err(sbi, "Allow to mount readonly mode only");
return EINVAL;
}

> + }
> return 0;
> }
>
> @@ -1819,7 +1825,11 @@ static int f2fs_show_options(struct seq_file *seq, struct dentry *root)
> static void default_options(struct f2fs_sb_info *sbi)
> {
> /* init some FS parameters */
> - F2FS_OPTION(sbi).active_logs = NR_CURSEG_PERSIST_TYPE;
> + if (F2FS_HAS_FEATURE(sbi, F2FS_FEATURE_RO))
> + F2FS_OPTION(sbi).active_logs = NR_CURSEG_RO_TYPE;
> + else
> + F2FS_OPTION(sbi).active_logs = NR_CURSEG_PERSIST_TYPE;
> +
> F2FS_OPTION(sbi).inline_xattr_size = DEFAULT_INLINE_XATTR_ADDRS;
> F2FS_OPTION(sbi).whint_mode = WHINT_MODE_OFF;
> F2FS_OPTION(sbi).alloc_mode = ALLOC_MODE_DEFAULT;
> @@ -2001,6 +2011,11 @@ static int f2fs_remount(struct super_block *sb, int *flags, char *data)
> if (f2fs_readonly(sb) && (*flags & SB_RDONLY))
> goto skip;
>
> + if (F2FS_HAS_FEATURE(sbi, F2FS_FEATURE_RO) && !(*flags & SB_RDONLY)) {
> + err = -EROFS;
> + goto restore_opts;
> + }
> +
> #ifdef CONFIG_QUOTA
> if (!f2fs_readonly(sb) && (*flags & SB_RDONLY)) {
> err = dquot_suspend(sb, -1);
> @@ -3134,14 +3149,15 @@ int f2fs_sanity_check_ckpt(struct f2fs_sb_info *sbi)
> ovp_segments = le32_to_cpu(ckpt->overprov_segment_count);
> reserved_segments = le32_to_cpu(ckpt->rsvd_segment_count);
>
> - if (unlikely(fsmeta < F2FS_MIN_META_SEGMENTS ||
> + if (!F2FS_HAS_FEATURE(sbi, F2FS_FEATURE_RO) &&
> + unlikely(fsmeta < F2FS_MIN_META_SEGMENTS ||
> ovp_segments == 0 || reserved_segments == 0)) {
> f2fs_err(sbi, "Wrong layout: check mkfs.f2fs version");
> return 1;
> }
> -
> user_block_count = le64_to_cpu(ckpt->user_block_count);
> - segment_count_main = le32_to_cpu(raw_super->segment_count_main);
> + segment_count_main = le32_to_cpu(raw_super->segment_count_main) +
> + F2FS_HAS_FEATURE(sbi, F2FS_FEATURE_RO) ? 1 : 0;
> log_blocks_per_seg = le32_to_cpu(raw_super->log_blocks_per_seg);
> if (!user_block_count || user_block_count >=
> segment_count_main << log_blocks_per_seg) {
> @@ -3172,6 +3188,10 @@ int f2fs_sanity_check_ckpt(struct f2fs_sb_info *sbi)
> if (le32_to_cpu(ckpt->cur_node_segno[i]) >= main_segs ||
> le16_to_cpu(ckpt->cur_node_blkoff[i]) >= blocks_per_seg)
> return 1;
> +
> + if (F2FS_HAS_FEATURE(sbi, F2FS_FEATURE_RO))
> + goto check_data;
> +
> for (j = i + 1; j < NR_CURSEG_NODE_TYPE; j++) {
> if (le32_to_cpu(ckpt->cur_node_segno[i]) ==
> le32_to_cpu(ckpt->cur_node_segno[j])) {
> @@ -3182,10 +3202,15 @@ int f2fs_sanity_check_ckpt(struct f2fs_sb_info *sbi)
> }
> }
> }
> +check_data:
> for (i = 0; i < NR_CURSEG_DATA_TYPE; i++) {
> if (le32_to_cpu(ckpt->cur_data_segno[i]) >= main_segs ||
> le16_to_cpu(ckpt->cur_data_blkoff[i]) >= blocks_per_seg)
> return 1;
> +
> + if (F2FS_HAS_FEATURE(sbi, F2FS_FEATURE_RO))
> + goto skip_cross;
> +
> for (j = i + 1; j < NR_CURSEG_DATA_TYPE; j++) {
> if (le32_to_cpu(ckpt->cur_data_segno[i]) ==
> le32_to_cpu(ckpt->cur_data_segno[j])) {
> @@ -3207,7 +3232,7 @@ int f2fs_sanity_check_ckpt(struct f2fs_sb_info *sbi)
> }
> }
> }
> -
> +skip_cross:
> sit_bitmap_size = le32_to_cpu(ckpt->sit_ver_bitmap_bytesize);
> nat_bitmap_size = le32_to_cpu(ckpt->nat_ver_bitmap_bytesize);
>
> --
> 2.32.0.rc0.204.g9fa02ecfa5-goog
>
>
>
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