f2fs: recover superblock at RW remounts

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>

1 files changed, 27 insertions, 9 deletions

diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index ffe4616376ca..f5fbbfdb3d93 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);