f2fs: support RO feature

Given RO feature in superblock, we don't need to check provisioning/reserve
spaces and SSA area.

Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index eaf57b5..8903c43 100644 (file)
--- 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)
 
@@ -4128,6 +4130,7 @@ F2FS_FEATURE_FUNCS(verity, VERITY);
 F2FS_FEATURE_FUNCS(sb_chksum, SB_CHKSUM);
 F2FS_FEATURE_FUNCS(casefold, CASEFOLD);
 F2FS_FEATURE_FUNCS(compression, COMPRESSION);
+F2FS_FEATURE_FUNCS(readonly, RO);
 
 #ifdef CONFIG_BLK_DEV_ZONED
 static inline bool f2fs_blkz_is_seq(struct f2fs_sb_info *sbi, int devi,

diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index 380ef34..54847ee 100644 (file)
--- 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_sb_has_readonly(sbi) &&
+                       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 56f2f2f..3e0e34b 100644 (file)
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -555,7 +555,7 @@ static int parse_options(struct super_block *sb, char *options, bool is_remount)
        int ret;
 
        if (!options)
-               return 0;
+               goto default_check;
 
        while ((p = strsep(&options, ",")) != NULL) {
                int token;
@@ -1090,6 +1090,7 @@ static int parse_options(struct super_block *sb, char *options, bool is_remount)
                        return -EINVAL;
                }
        }
+default_check:
 #ifdef CONFIG_QUOTA
        if (f2fs_check_quota_options(sbi))
                return -EINVAL;
@@ -1162,6 +1163,11 @@ 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_sb_has_readonly(sbi) && !f2fs_readonly(sbi->sb)) {
+               f2fs_err(sbi, "Allow to mount readonly mode only");
+               return -EROFS;
+       }
        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_sb_has_readonly(sbi))
+               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;
@@ -2004,6 +2014,11 @@ static int f2fs_remount(struct super_block *sb, int *flags, char *data)
        if (f2fs_readonly(sb) && (*flags & SB_RDONLY))
                goto skip;
 
+       if (f2fs_sb_has_readonly(sbi) && !(*flags & SB_RDONLY)) {
+               err = -EROFS;
+               goto restore_opts;
+       }
+
 #ifdef CONFIG_QUOTA
        if (!f2fs_readonly(sb) && (*flags & SB_RDONLY)) {
                err = dquot_suspend(sb, -1);
@@ -3137,14 +3152,15 @@ 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_sb_has_readonly(sbi) &&
+                       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_sb_has_readonly(sbi) ? 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) {
@@ -3175,6 +3191,10 @@ 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_sb_has_readonly(sbi))
+                       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])) {
@@ -3185,10 +3205,15 @@ 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_sb_has_readonly(sbi))
+                       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])) {
@@ -3210,7 +3235,7 @@ 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);
 

diff --git a/fs/f2fs/sysfs.c b/fs/f2fs/sysfs.c
index dc71bc9..c579d5d 100644 (file)
--- a/fs/f2fs/sysfs.c
+++ b/fs/f2fs/sysfs.c
@@ -158,6 +158,9 @@ static ssize_t features_show(struct f2fs_attr *a,
        if (f2fs_sb_has_casefold(sbi))
                len += scnprintf(buf + len, PAGE_SIZE - len, "%s%s",
                                len ? ", " : "", "casefold");
+       if (f2fs_sb_has_readonly(sbi))
+               len += scnprintf(buf + len, PAGE_SIZE - len, "%s%s",
+                               len ? ", " : "", "readonly");
        if (f2fs_sb_has_compression(sbi))
                len += scnprintf(buf + len, PAGE_SIZE - len, "%s%s",
                                len ? ", " : "", "compression");
@@ -578,6 +581,7 @@ enum feat_id {
        FEAT_SB_CHECKSUM,
        FEAT_CASEFOLD,
        FEAT_COMPRESSION,
+       FEAT_RO,
        FEAT_TEST_DUMMY_ENCRYPTION_V2,
 };
 
@@ -599,6 +603,7 @@ static ssize_t f2fs_feature_show(struct f2fs_attr *a,
        case FEAT_SB_CHECKSUM:
        case FEAT_CASEFOLD:
        case FEAT_COMPRESSION:
+       case FEAT_RO:
        case FEAT_TEST_DUMMY_ENCRYPTION_V2:
                return sprintf(buf, "supported\n");
        }
@@ -721,12 +726,14 @@ F2FS_FEATURE_RO_ATTR(verity, FEAT_VERITY);
 #endif
 F2FS_FEATURE_RO_ATTR(sb_checksum, FEAT_SB_CHECKSUM);
 F2FS_FEATURE_RO_ATTR(casefold, FEAT_CASEFOLD);
+F2FS_FEATURE_RO_ATTR(readonly, FEAT_RO);
 #ifdef CONFIG_F2FS_FS_COMPRESSION
 F2FS_FEATURE_RO_ATTR(compression, FEAT_COMPRESSION);
 F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, compr_written_block, compr_written_block);
 F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, compr_saved_block, compr_saved_block);
 F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, compr_new_inode, compr_new_inode);
 #endif
+
 /* For ATGC */
 F2FS_RW_ATTR(ATGC_INFO, atgc_management, atgc_candidate_ratio, candidate_ratio);
 F2FS_RW_ATTR(ATGC_INFO, atgc_management, atgc_candidate_count, max_candidate_count);
@@ -830,6 +837,7 @@ static struct attribute *f2fs_feat_attrs[] = {
 #endif
        ATTR_LIST(sb_checksum),
        ATTR_LIST(casefold),
+       ATTR_LIST(readonly),
 #ifdef CONFIG_F2FS_FS_COMPRESSION
        ATTR_LIST(compression),
 #endif