ext4: validate that metadata blocks do not overlap superblock
[pandora-kernel.git] / fs / ext4 / super.c
index 3858767..7266a2e 100644 (file)
@@ -463,9 +463,13 @@ static void ext4_handle_error(struct super_block *sb)
                ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
                sb->s_flags |= MS_RDONLY;
        }
-       if (test_opt(sb, ERRORS_PANIC))
+       if (test_opt(sb, ERRORS_PANIC)) {
+               if (EXT4_SB(sb)->s_journal &&
+                 !(EXT4_SB(sb)->s_journal->j_flags & JBD2_REC_ERR))
+                       return;
                panic("EXT4-fs (device %s): panic forced after error\n",
                        sb->s_id);
+       }
 }
 
 void __ext4_error(struct super_block *sb, const char *function,
@@ -480,6 +484,7 @@ void __ext4_error(struct super_block *sb, const char *function,
        printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
               sb->s_id, function, line, current->comm, &vaf);
        va_end(args);
+       save_error_info(sb, function, line);
 
        ext4_handle_error(sb);
 }
@@ -627,8 +632,12 @@ void __ext4_abort(struct super_block *sb, const char *function,
                        jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
                save_error_info(sb, function, line);
        }
-       if (test_opt(sb, ERRORS_PANIC))
+       if (test_opt(sb, ERRORS_PANIC)) {
+               if (EXT4_SB(sb)->s_journal &&
+                 !(EXT4_SB(sb)->s_journal->j_flags & JBD2_REC_ERR))
+                       return;
                panic("EXT4-fs panic from previous error\n");
+       }
 }
 
 void ext4_msg(struct super_block *sb, const char *prefix, const char *fmt, ...)
@@ -818,7 +827,7 @@ static void ext4_put_super(struct super_block *sb)
                        ext4_abort(sb, "Couldn't clean up the journal");
        }
 
-       del_timer(&sbi->s_err_report);
+       del_timer_sync(&sbi->s_err_report);
        ext4_release_system_zone(sb);
        ext4_mb_release(sb);
        ext4_ext_release(sb);
@@ -856,6 +865,7 @@ static void ext4_put_super(struct super_block *sb)
                dump_orphan_list(sb, sbi);
        J_ASSERT(list_empty(&sbi->s_orphan));
 
+       sync_blockdev(sb->s_bdev);
        invalidate_bdev(sb->s_bdev);
        if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
                /*
@@ -903,6 +913,7 @@ static struct inode *ext4_alloc_inode(struct super_block *sb)
        ei->i_reserved_meta_blocks = 0;
        ei->i_allocated_meta_blocks = 0;
        ei->i_da_metadata_calc_len = 0;
+       ei->i_da_metadata_calc_last_lblock = 0;
        spin_lock_init(&(ei->i_block_reservation_lock));
 #ifdef CONFIG_QUOTA
        ei->i_reserved_quota = 0;
@@ -1015,10 +1026,10 @@ static inline void ext4_show_quota_options(struct seq_file *seq,
        }
 
        if (sbi->s_qf_names[USRQUOTA])
-               seq_printf(seq, ",usrjquota=%s", sbi->s_qf_names[USRQUOTA]);
+               seq_show_option(seq, "usrjquota", sbi->s_qf_names[USRQUOTA]);
 
        if (sbi->s_qf_names[GRPQUOTA])
-               seq_printf(seq, ",grpjquota=%s", sbi->s_qf_names[GRPQUOTA]);
+               seq_show_option(seq, "grpjquota", sbi->s_qf_names[GRPQUOTA]);
 
        if (test_opt(sb, USRQUOTA))
                seq_puts(seq, ",usrquota");
@@ -1096,7 +1107,7 @@ static int ext4_show_options(struct seq_file *seq, struct vfsmount *vfs)
        }
        if (sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME) {
                seq_printf(seq, ",max_batch_time=%u",
-                          (unsigned) sbi->s_min_batch_time);
+                          (unsigned) sbi->s_max_batch_time);
        }
 
        /*
@@ -1155,9 +1166,9 @@ static int ext4_show_options(struct seq_file *seq, struct vfsmount *vfs)
                seq_puts(seq, ",block_validity");
 
        if (!test_opt(sb, INIT_INODE_TABLE))
-               seq_puts(seq, ",noinit_inode_table");
+               seq_puts(seq, ",noinit_itable");
        else if (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)
-               seq_printf(seq, ",init_inode_table=%u",
+               seq_printf(seq, ",init_itable=%u",
                           (unsigned) sbi->s_li_wait_mult);
 
        ext4_show_quota_options(seq, sb);
@@ -1183,7 +1194,7 @@ static struct inode *ext4_nfs_get_inode(struct super_block *sb,
         * Currently we don't know the generation for parent directory, so
         * a generation of 0 means "accept any"
         */
-       inode = ext4_iget(sb, ino);
+       inode = ext4_iget_normal(sb, ino);
        if (IS_ERR(inode))
                return ERR_CAST(inode);
        if (generation && inode->i_generation != generation) {
@@ -1333,8 +1344,7 @@ enum {
        Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
        Opt_inode_readahead_blks, Opt_journal_ioprio,
        Opt_dioread_nolock, Opt_dioread_lock,
-       Opt_discard, Opt_nodiscard,
-       Opt_init_inode_table, Opt_noinit_inode_table,
+       Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
 };
 
 static const match_table_t tokens = {
@@ -1407,9 +1417,9 @@ static const match_table_t tokens = {
        {Opt_dioread_lock, "dioread_lock"},
        {Opt_discard, "discard"},
        {Opt_nodiscard, "nodiscard"},
-       {Opt_init_inode_table, "init_itable=%u"},
-       {Opt_init_inode_table, "init_itable"},
-       {Opt_noinit_inode_table, "noinit_itable"},
+       {Opt_init_itable, "init_itable=%u"},
+       {Opt_init_itable, "init_itable"},
+       {Opt_noinit_itable, "noinit_itable"},
        {Opt_err, NULL},
 };
 
@@ -1662,8 +1672,6 @@ static int parse_options(char *options, struct super_block *sb,
                                return 0;
                        if (option < 0)
                                return 0;
-                       if (option == 0)
-                               option = EXT4_DEF_MAX_BATCH_TIME;
                        sbi->s_max_batch_time = option;
                        break;
                case Opt_min_batch_time:
@@ -1892,7 +1900,7 @@ set_qf_format:
                case Opt_dioread_lock:
                        clear_opt(sb, DIOREAD_NOLOCK);
                        break;
-               case Opt_init_inode_table:
+               case Opt_init_itable:
                        set_opt(sb, INIT_INODE_TABLE);
                        if (args[0].from) {
                                if (match_int(&args[0], &option))
@@ -1903,7 +1911,7 @@ set_qf_format:
                                return 0;
                        sbi->s_li_wait_mult = option;
                        break;
-               case Opt_noinit_inode_table:
+               case Opt_noinit_itable:
                        clear_opt(sb, INIT_INODE_TABLE);
                        break;
                default:
@@ -1932,15 +1940,18 @@ set_qf_format:
                                        "not specified");
                        return 0;
                }
-       } else {
-               if (sbi->s_jquota_fmt) {
-                       ext4_msg(sb, KERN_ERR, "journaled quota format "
-                                       "specified with no journaling "
-                                       "enabled");
+       }
+#endif
+       if (test_opt(sb, DIOREAD_NOLOCK)) {
+               int blocksize =
+                       BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
+
+               if (blocksize < PAGE_CACHE_SIZE) {
+                       ext4_msg(sb, KERN_ERR, "can't mount with "
+                                "dioread_nolock if block size != PAGE_SIZE");
                        return 0;
                }
        }
-#endif
        return 1;
 }
 
@@ -2007,17 +2018,16 @@ static int ext4_fill_flex_info(struct super_block *sb)
        struct ext4_group_desc *gdp = NULL;
        ext4_group_t flex_group_count;
        ext4_group_t flex_group;
-       int groups_per_flex = 0;
+       unsigned int groups_per_flex = 0;
        size_t size;
        int i;
 
        sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
-       groups_per_flex = 1 << sbi->s_log_groups_per_flex;
-
-       if (groups_per_flex < 2) {
+       if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
                sbi->s_log_groups_per_flex = 0;
                return 1;
        }
+       groups_per_flex = 1 << sbi->s_log_groups_per_flex;
 
        /* We allocate both existing and potentially added groups */
        flex_group_count = ((sbi->s_groups_count + groups_per_flex - 1) +
@@ -2037,8 +2047,8 @@ static int ext4_fill_flex_info(struct super_block *sb)
                flex_group = ext4_flex_group(sbi, i);
                atomic_add(ext4_free_inodes_count(sb, gdp),
                           &sbi->s_flex_groups[flex_group].free_inodes);
-               atomic_add(ext4_free_group_clusters(sb, gdp),
-                          &sbi->s_flex_groups[flex_group].free_clusters);
+               atomic64_add(ext4_free_group_clusters(sb, gdp),
+                            &sbi->s_flex_groups[flex_group].free_clusters);
                atomic_add(ext4_used_dirs_count(sb, gdp),
                           &sbi->s_flex_groups[flex_group].used_dirs);
        }
@@ -2087,6 +2097,7 @@ int ext4_group_desc_csum_verify(struct ext4_sb_info *sbi, __u32 block_group,
 
 /* Called at mount-time, super-block is locked */
 static int ext4_check_descriptors(struct super_block *sb,
+                                 ext4_fsblk_t sb_block,
                                  ext4_group_t *first_not_zeroed)
 {
        struct ext4_sb_info *sbi = EXT4_SB(sb);
@@ -2117,6 +2128,11 @@ static int ext4_check_descriptors(struct super_block *sb,
                        grp = i;
 
                block_bitmap = ext4_block_bitmap(sb, gdp);
+               if (block_bitmap == sb_block) {
+                       ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
+                                "Block bitmap for group %u overlaps "
+                                "superblock", i);
+               }
                if (block_bitmap < first_block || block_bitmap > last_block) {
                        ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
                               "Block bitmap for group %u not in group "
@@ -2124,6 +2140,11 @@ static int ext4_check_descriptors(struct super_block *sb,
                        return 0;
                }
                inode_bitmap = ext4_inode_bitmap(sb, gdp);
+               if (inode_bitmap == sb_block) {
+                       ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
+                                "Inode bitmap for group %u overlaps "
+                                "superblock", i);
+               }
                if (inode_bitmap < first_block || inode_bitmap > last_block) {
                        ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
                               "Inode bitmap for group %u not in group "
@@ -2131,6 +2152,11 @@ static int ext4_check_descriptors(struct super_block *sb,
                        return 0;
                }
                inode_table = ext4_inode_table(sb, gdp);
+               if (inode_table == sb_block) {
+                       ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
+                                "Inode table for group %u overlaps "
+                                "superblock", i);
+               }
                if (inode_table < first_block ||
                    inode_table + sbi->s_itb_per_group - 1 > last_block) {
                        ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
@@ -2236,6 +2262,16 @@ static void ext4_orphan_cleanup(struct super_block *sb,
        while (es->s_last_orphan) {
                struct inode *inode;
 
+               /*
+                * We may have encountered an error during cleanup; if
+                * so, skip the rest.
+                */
+               if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
+                       jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
+                       es->s_last_orphan = 0;
+                       break;
+               }
+
                inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
                if (IS_ERR(inode)) {
                        es->s_last_orphan = 0;
@@ -2250,7 +2286,9 @@ static void ext4_orphan_cleanup(struct super_block *sb,
                                __func__, inode->i_ino, inode->i_size);
                        jbd_debug(2, "truncating inode %lu to %lld bytes\n",
                                  inode->i_ino, inode->i_size);
+                       mutex_lock(&inode->i_mutex);
                        ext4_truncate(inode);
+                       mutex_unlock(&inode->i_mutex);
                        nr_truncates++;
                } else {
                        ext4_msg(sb, KERN_DEBUG,
@@ -2506,18 +2544,6 @@ static ssize_t lifetime_write_kbytes_show(struct ext4_attr *a,
                          EXT4_SB(sb)->s_sectors_written_start) >> 1)));
 }
 
-static ssize_t extent_cache_hits_show(struct ext4_attr *a,
-                                     struct ext4_sb_info *sbi, char *buf)
-{
-       return snprintf(buf, PAGE_SIZE, "%lu\n", sbi->extent_cache_hits);
-}
-
-static ssize_t extent_cache_misses_show(struct ext4_attr *a,
-                                       struct ext4_sb_info *sbi, char *buf)
-{
-       return snprintf(buf, PAGE_SIZE, "%lu\n", sbi->extent_cache_misses);
-}
-
 static ssize_t inode_readahead_blks_store(struct ext4_attr *a,
                                          struct ext4_sb_info *sbi,
                                          const char *buf, size_t count)
@@ -2575,8 +2601,6 @@ static struct ext4_attr ext4_attr_##name = __ATTR(name, mode, show, store)
 EXT4_RO_ATTR(delayed_allocation_blocks);
 EXT4_RO_ATTR(session_write_kbytes);
 EXT4_RO_ATTR(lifetime_write_kbytes);
-EXT4_RO_ATTR(extent_cache_hits);
-EXT4_RO_ATTR(extent_cache_misses);
 EXT4_ATTR_OFFSET(inode_readahead_blks, 0644, sbi_ui_show,
                 inode_readahead_blks_store, s_inode_readahead_blks);
 EXT4_RW_ATTR_SBI_UI(inode_goal, s_inode_goal);
@@ -2592,8 +2616,6 @@ static struct attribute *ext4_attrs[] = {
        ATTR_LIST(delayed_allocation_blocks),
        ATTR_LIST(session_write_kbytes),
        ATTR_LIST(lifetime_write_kbytes),
-       ATTR_LIST(extent_cache_hits),
-       ATTR_LIST(extent_cache_misses),
        ATTR_LIST(inode_readahead_blks),
        ATTR_LIST(inode_goal),
        ATTR_LIST(mb_stats),
@@ -2730,10 +2752,11 @@ static void print_daily_error_info(unsigned long arg)
        es = sbi->s_es;
 
        if (es->s_error_count)
-               ext4_msg(sb, KERN_NOTICE, "error count: %u",
+               /* fsck newer than v1.41.13 is needed to clean this condition. */
+               ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
                         le32_to_cpu(es->s_error_count));
        if (es->s_first_error_time) {
-               printk(KERN_NOTICE "EXT4-fs (%s): initial error at %u: %.*s:%d",
+               printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %u: %.*s:%d",
                       sb->s_id, le32_to_cpu(es->s_first_error_time),
                       (int) sizeof(es->s_first_error_func),
                       es->s_first_error_func,
@@ -2747,7 +2770,7 @@ static void print_daily_error_info(unsigned long arg)
                printk("\n");
        }
        if (es->s_last_error_time) {
-               printk(KERN_NOTICE "EXT4-fs (%s): last error at %u: %.*s:%d",
+               printk(KERN_NOTICE "EXT4-fs (%s): last error at time %u: %.*s:%d",
                       sb->s_id, le32_to_cpu(es->s_last_error_time),
                       (int) sizeof(es->s_last_error_func),
                       es->s_last_error_func,
@@ -3100,6 +3123,118 @@ static void ext4_destroy_lazyinit_thread(void)
        kthread_stop(ext4_lazyinit_task);
 }
 
+/*
+ * Note: calculating the overhead so we can be compatible with
+ * historical BSD practice is quite difficult in the face of
+ * clusters/bigalloc.  This is because multiple metadata blocks from
+ * different block group can end up in the same allocation cluster.
+ * Calculating the exact overhead in the face of clustered allocation
+ * requires either O(all block bitmaps) in memory or O(number of block
+ * groups**2) in time.  We will still calculate the superblock for
+ * older file systems --- and if we come across with a bigalloc file
+ * system with zero in s_overhead_clusters the estimate will be close to
+ * correct especially for very large cluster sizes --- but for newer
+ * file systems, it's better to calculate this figure once at mkfs
+ * time, and store it in the superblock.  If the superblock value is
+ * present (even for non-bigalloc file systems), we will use it.
+ */
+static int count_overhead(struct super_block *sb, ext4_group_t grp,
+                         char *buf)
+{
+       struct ext4_sb_info     *sbi = EXT4_SB(sb);
+       struct ext4_group_desc  *gdp;
+       ext4_fsblk_t            first_block, last_block, b;
+       ext4_group_t            i, ngroups = ext4_get_groups_count(sb);
+       int                     s, j, count = 0;
+
+       if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_BIGALLOC))
+               return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
+                       sbi->s_itb_per_group + 2);
+
+       first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
+               (grp * EXT4_BLOCKS_PER_GROUP(sb));
+       last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
+       for (i = 0; i < ngroups; i++) {
+               gdp = ext4_get_group_desc(sb, i, NULL);
+               b = ext4_block_bitmap(sb, gdp);
+               if (b >= first_block && b <= last_block) {
+                       ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
+                       count++;
+               }
+               b = ext4_inode_bitmap(sb, gdp);
+               if (b >= first_block && b <= last_block) {
+                       ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
+                       count++;
+               }
+               b = ext4_inode_table(sb, gdp);
+               if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
+                       for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
+                               int c = EXT4_B2C(sbi, b - first_block);
+                               ext4_set_bit(c, buf);
+                               count++;
+                       }
+               if (i != grp)
+                       continue;
+               s = 0;
+               if (ext4_bg_has_super(sb, grp)) {
+                       ext4_set_bit(s++, buf);
+                       count++;
+               }
+               for (j = ext4_bg_num_gdb(sb, grp); j > 0; j--) {
+                       ext4_set_bit(EXT4_B2C(sbi, s++), buf);
+                       count++;
+               }
+       }
+       if (!count)
+               return 0;
+       return EXT4_CLUSTERS_PER_GROUP(sb) -
+               ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
+}
+
+/*
+ * Compute the overhead and stash it in sbi->s_overhead
+ */
+int ext4_calculate_overhead(struct super_block *sb)
+{
+       struct ext4_sb_info *sbi = EXT4_SB(sb);
+       struct ext4_super_block *es = sbi->s_es;
+       ext4_group_t i, ngroups = ext4_get_groups_count(sb);
+       ext4_fsblk_t overhead = 0;
+       char *buf = (char *) get_zeroed_page(GFP_KERNEL);
+
+       memset(buf, 0, PAGE_SIZE);
+       if (!buf)
+               return -ENOMEM;
+
+       /*
+        * Compute the overhead (FS structures).  This is constant
+        * for a given filesystem unless the number of block groups
+        * changes so we cache the previous value until it does.
+        */
+
+       /*
+        * All of the blocks before first_data_block are overhead
+        */
+       overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
+
+       /*
+        * Add the overhead found in each block group
+        */
+       for (i = 0; i < ngroups; i++) {
+               int blks;
+
+               blks = count_overhead(sb, i, buf);
+               overhead += blks;
+               if (blks)
+                       memset(buf, 0, PAGE_SIZE);
+               cond_resched();
+       }
+       sbi->s_overhead = overhead;
+       smp_wmb();
+       free_page((unsigned long) buf);
+       return 0;
+}
+
 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
 {
        char *orig_data = kstrdup(data, GFP_KERNEL);
@@ -3264,22 +3399,13 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
                }
                if (test_opt(sb, DIOREAD_NOLOCK)) {
                        ext4_msg(sb, KERN_ERR, "can't mount with "
-                                "both data=journal and delalloc");
+                                "both data=journal and dioread_nolock");
                        goto failed_mount;
                }
                if (test_opt(sb, DELALLOC))
                        clear_opt(sb, DELALLOC);
        }
 
-       blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
-       if (test_opt(sb, DIOREAD_NOLOCK)) {
-               if (blocksize < PAGE_SIZE) {
-                       ext4_msg(sb, KERN_ERR, "can't mount with "
-                                "dioread_nolock if block size != PAGE_SIZE");
-                       goto failed_mount;
-               }
-       }
-
        sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
                (test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
 
@@ -3321,6 +3447,7 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
        if (!ext4_feature_set_ok(sb, (sb->s_flags & MS_RDONLY)))
                goto failed_mount;
 
+       blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
        if (blocksize < EXT4_MIN_BLOCK_SIZE ||
            blocksize > EXT4_MAX_BLOCK_SIZE) {
                ext4_msg(sb, KERN_ERR,
@@ -3328,6 +3455,13 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
                goto failed_mount;
        }
 
+       if (le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) > (blocksize / 4)) {
+               ext4_msg(sb, KERN_ERR,
+                        "Number of reserved GDT blocks insanely large: %d",
+                        le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks));
+               goto failed_mount;
+       }
+
        if (sb->s_blocksize != blocksize) {
                /* Validate the filesystem blocksize */
                if (!sb_set_blocksize(sb, blocksize)) {
@@ -3556,7 +3690,7 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
                        goto failed_mount2;
                }
        }
-       if (!ext4_check_descriptors(sb, &first_not_zeroed)) {
+       if (!ext4_check_descriptors(sb, logical_sb_block, &first_not_zeroed)) {
                ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
                goto failed_mount2;
        }
@@ -3711,6 +3845,18 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
        percpu_counter_set(&sbi->s_dirtyclusters_counter, 0);
 
 no_journal:
+       /*
+        * Get the # of file system overhead blocks from the
+        * superblock if present.
+        */
+       if (es->s_overhead_clusters)
+               sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
+       else {
+               ret = ext4_calculate_overhead(sb);
+               if (ret)
+                       goto failed_mount_wq;
+       }
+
        /*
         * The maximum number of concurrent works can be high and
         * concurrency isn't really necessary.  Limit it to 1.
@@ -3745,7 +3891,8 @@ no_journal:
                goto failed_mount4;
        }
 
-       ext4_setup_super(sb, es, sb->s_flags & MS_RDONLY);
+       if (ext4_setup_super(sb, es, sb->s_flags & MS_RDONLY))
+               sb->s_flags |= MS_RDONLY;
 
        /* determine the minimum size of new large inodes, if present */
        if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
@@ -3848,7 +3995,7 @@ failed_mount_wq:
                sbi->s_journal = NULL;
        }
 failed_mount3:
-       del_timer(&sbi->s_err_report);
+       del_timer_sync(&sbi->s_err_report);
        if (sbi->s_flex_groups)
                ext4_kvfree(sbi->s_flex_groups);
        percpu_counter_destroy(&sbi->s_freeclusters_counter);
@@ -4426,6 +4573,21 @@ static int ext4_remount(struct super_block *sb, int *flags, char *data)
                goto restore_opts;
        }
 
+       if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
+               if (test_opt2(sb, EXPLICIT_DELALLOC)) {
+                       ext4_msg(sb, KERN_ERR, "can't mount with "
+                                "both data=journal and delalloc");
+                       err = -EINVAL;
+                       goto restore_opts;
+               }
+               if (test_opt(sb, DIOREAD_NOLOCK)) {
+                       ext4_msg(sb, KERN_ERR, "can't mount with "
+                                "both data=journal and dioread_nolock");
+                       err = -EINVAL;
+                       goto restore_opts;
+               }
+       }
+
        if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
                ext4_abort(sb, "Abort forced by user");
 
@@ -4543,7 +4705,7 @@ static int ext4_remount(struct super_block *sb, int *flags, char *data)
        }
 
        ext4_setup_system_zone(sb);
-       if (sbi->s_journal == NULL)
+       if (sbi->s_journal == NULL && !(old_sb_flags & MS_RDONLY))
                ext4_commit_super(sb, 1);
 
 #ifdef CONFIG_QUOTA
@@ -4584,67 +4746,21 @@ restore_opts:
        return err;
 }
 
-/*
- * Note: calculating the overhead so we can be compatible with
- * historical BSD practice is quite difficult in the face of
- * clusters/bigalloc.  This is because multiple metadata blocks from
- * different block group can end up in the same allocation cluster.
- * Calculating the exact overhead in the face of clustered allocation
- * requires either O(all block bitmaps) in memory or O(number of block
- * groups**2) in time.  We will still calculate the superblock for
- * older file systems --- and if we come across with a bigalloc file
- * system with zero in s_overhead_clusters the estimate will be close to
- * correct especially for very large cluster sizes --- but for newer
- * file systems, it's better to calculate this figure once at mkfs
- * time, and store it in the superblock.  If the superblock value is
- * present (even for non-bigalloc file systems), we will use it.
- */
 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
 {
        struct super_block *sb = dentry->d_sb;
        struct ext4_sb_info *sbi = EXT4_SB(sb);
        struct ext4_super_block *es = sbi->s_es;
-       struct ext4_group_desc *gdp;
+       ext4_fsblk_t overhead = 0;
        u64 fsid;
        s64 bfree;
 
-       if (test_opt(sb, MINIX_DF)) {
-               sbi->s_overhead_last = 0;
-       } else if (es->s_overhead_clusters) {
-               sbi->s_overhead_last = le32_to_cpu(es->s_overhead_clusters);
-       } else if (sbi->s_blocks_last != ext4_blocks_count(es)) {
-               ext4_group_t i, ngroups = ext4_get_groups_count(sb);
-               ext4_fsblk_t overhead = 0;
-
-               /*
-                * Compute the overhead (FS structures).  This is constant
-                * for a given filesystem unless the number of block groups
-                * changes so we cache the previous value until it does.
-                */
-
-               /*
-                * All of the blocks before first_data_block are
-                * overhead
-                */
-               overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
-
-               /*
-                * Add the overhead found in each block group
-                */
-               for (i = 0; i < ngroups; i++) {
-                       gdp = ext4_get_group_desc(sb, i, NULL);
-                       overhead += ext4_num_overhead_clusters(sb, i, gdp);
-                       cond_resched();
-               }
-               sbi->s_overhead_last = overhead;
-               smp_wmb();
-               sbi->s_blocks_last = ext4_blocks_count(es);
-       }
+       if (!test_opt(sb, MINIX_DF))
+               overhead = sbi->s_overhead;
 
        buf->f_type = EXT4_SUPER_MAGIC;
        buf->f_bsize = sb->s_blocksize;
-       buf->f_blocks = (ext4_blocks_count(es) -
-                        EXT4_C2B(sbi, sbi->s_overhead_last));
+       buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, sbi->s_overhead);
        bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
                percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
        /* prevent underflow in case that few free space is available */