[PATCH 3/4] f2fs: recover superblock at RW remounts

Jaegeuk Kim
2016-03-24T01:32:02Z

This patch adds a sbi flag, SBI_NEED_SB_WRITE, which indicates it needs to
recover superblock when (re)mounting as RW. This is set only when f2fs is
mounted as RO.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
---
fs/f2fs/f2fs.h | 1 +
fs/f2fs/super.c | 36 +++++++++++++++++++++++++++---------
2 files changed, 28 insertions(+), 9 deletions(-)

diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index bbe2cd1..286e917 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -672,6 +672,7 @@ enum {
SBI_IS_CLOSE, /* specify unmounting */
SBI_NEED_FSCK, /* need fsck.f2fs to fix */
SBI_POR_DOING, /* recovery is doing or not */
+ SBI_NEED_SB_WRITE, /* need to recover superblock */
};

enum {
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 742fc48..5718187 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -796,6 +796,15 @@ static int f2fs_remount(struct super_block *sb, int *flags, char *data)
set_sbi_flag(sbi, SBI_IS_DIRTY);
}

+ /* recover superblocks we couldn't write due to previous RO mount */
+ if (!(*flags & MS_RDONLY) && is_sbi_flag_set(sbi, SBI_NEED_SB_WRITE)) {
+ err = f2fs_commit_super(sbi, false);
+ f2fs_msg(sb, KERN_INFO,
+ "Try to recover all the superblocks, ret: %d", err);
+ if (!err)
+ clear_sbi_flag(sbi, SBI_NEED_SB_WRITE);
+ }
+
sync_filesystem(sb);

sbi->mount_opt.opt = 0;
@@ -852,8 +861,9 @@ static int f2fs_remount(struct super_block *sb, int *flags, char *data)
}
skip:
/* Update the POSIXACL Flag */
- sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
+ sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
(test_opt(sbi, POSIX_ACL) ? MS_POSIXACL : 0);
+
return 0;
restore_gc:
if (need_restart_gc) {
@@ -998,11 +1008,12 @@ static int __f2fs_commit_super(struct buffer_head *bh,
return __sync_dirty_buffer(bh, WRITE_FLUSH_FUA);
}

-static inline bool sanity_check_area_boundary(struct super_block *sb,
+static inline bool sanity_check_area_boundary(struct f2fs_sb_info *sbi,
struct buffer_head *bh)
{
struct f2fs_super_block *raw_super = (struct f2fs_super_block *)
(bh->b_data + F2FS_SUPER_OFFSET);
+ struct super_block *sb = sbi->sb;
u32 segment0_blkaddr = le32_to_cpu(raw_super->segment0_blkaddr);
u32 cp_blkaddr = le32_to_cpu(raw_super->cp_blkaddr);
u32 sit_blkaddr = le32_to_cpu(raw_super->sit_blkaddr);
@@ -1081,6 +1092,7 @@ static inline bool sanity_check_area_boundary(struct super_block *sb,
segment0_blkaddr) >> log_blocks_per_seg);

if (f2fs_readonly(sb) || bdev_read_only(sb->s_bdev)) {
+ set_sbi_flag(sbi, SBI_NEED_SB_WRITE);
res = "internally";
} else {
err = __f2fs_commit_super(bh, NULL);
@@ -1098,11 +1110,12 @@ static inline bool sanity_check_area_boundary(struct super_block *sb,
return false;
}

-static int sanity_check_raw_super(struct super_block *sb,
+static int sanity_check_raw_super(struct f2fs_sb_info *sbi,
struct buffer_head *bh)
{
struct f2fs_super_block *raw_super = (struct f2fs_super_block *)
(bh->b_data + F2FS_SUPER_OFFSET);
+ struct super_block *sb = sbi->sb;
unsigned int blocksize;

if (F2FS_SUPER_MAGIC != le32_to_cpu(raw_super->magic)) {
@@ -1169,7 +1182,7 @@ static int sanity_check_raw_super(struct super_block *sb,
}

/* check CP/SIT/NAT/SSA/MAIN_AREA area boundary */
- if (sanity_check_area_boundary(sb, bh))
+ if (sanity_check_area_boundary(sbi, bh))
return 1;

return 0;
@@ -1239,10 +1252,11 @@ static void init_sb_info(struct f2fs_sb_info *sbi)
* to get the first valid one. If any one of them is broken, we pass
* them recovery flag back to the caller.
*/
-static int read_raw_super_block(struct super_block *sb,
+static int read_raw_super_block(struct f2fs_sb_info *sbi,
struct f2fs_super_block **raw_super,
int *valid_super_block, int *recovery)
{
+ struct super_block *sb = sbi->sb;
int block;
struct buffer_head *bh;
struct f2fs_super_block *super;
@@ -1262,7 +1276,7 @@ static int read_raw_super_block(struct super_block *sb,
}

/* sanity checking of raw super */
- if (sanity_check_raw_super(sb, bh)) {
+ if (sanity_check_raw_super(sbi, bh)) {
f2fs_msg(sb, KERN_ERR,
"Can't find valid F2FS filesystem in %dth superblock",
block + 1);
@@ -1298,8 +1312,11 @@ int f2fs_commit_super(struct f2fs_sb_info *sbi, bool recover)
struct buffer_head *bh;
int err;

- if (f2fs_readonly(sbi->sb) || bdev_read_only(sbi->sb->s_bdev))
+ if ((recover && f2fs_readonly(sbi->sb)) ||
+ bdev_read_only(sbi->sb->s_bdev)) {
+ set_sbi_flag(sbi, SBI_NEED_SB_WRITE);
return -EROFS;
+ }

/* write back-up superblock first */
bh = sb_getblk(sbi->sb, sbi->valid_super_block ? 0: 1);
@@ -1343,6 +1360,8 @@ try_onemore:
if (!sbi)
return -ENOMEM;

+ sbi->sb = sb;
+
/* Load the checksum driver */
sbi->s_chksum_driver = crypto_alloc_shash("crc32", 0, 0);
if (IS_ERR(sbi->s_chksum_driver)) {
@@ -1358,7 +1377,7 @@ try_onemore:
goto free_sbi;
}

- err = read_raw_super_block(sb, &raw_super, &valid_super_block,
+ err = read_raw_super_block(sbi, &raw_super, &valid_super_block,
&recovery);
if (err)
goto free_sbi;
@@ -1393,7 +1412,6 @@ try_onemore:
memcpy(sb->s_uuid, raw_super->uuid, sizeof(raw_super->uuid));

/* init f2fs-specific super block info */
- sbi->sb = sb;
sbi->raw_super = raw_super;
sbi->valid_super_block = valid_super_block;
mutex_init(&sbi->gc_mutex);
--
2.6.3