Re: [f2fs-dev] [PATCH 2/2 v5] f2fs: support RO feature

Jaegeuk Kim
2021-06-03T16:09:03Z

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

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
---
Change log from v4:
- use f2fs_sb_has_readonly

fs/f2fs/f2fs.h | 3 +++
fs/f2fs/segment.c | 4 ++++
fs/f2fs/super.c | 37 +++++++++++++++++++++++++++++++------
fs/f2fs/sysfs.c | 8 ++++++++
4 files changed, 46 insertions(+), 6 deletions(-)

diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index eaf57b5f3c4b..8903c43091f8 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)

@@ -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 380ef34e1a59..54847eebc5ca 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_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 2fa59c674cd9..df8ac902886d 100644
--- 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;
@@ -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_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);
@@ -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_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) {
@@ -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_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])) {
@@ -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_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])) {
@@ -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);

diff --git a/fs/f2fs/sysfs.c b/fs/f2fs/sysfs.c
index dc71bc968c72..c579d5d3a916 100644
--- 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
--
2.32.0.rc0.204.g9fa02ecfa5-goog