diff options
| -rw-r--r-- | fs/ext4/super.c | 62 |
1 files changed, 61 insertions, 1 deletions
diff --git a/fs/ext4/super.c b/fs/ext4/super.c index 6edf7deeb2db..bf0cfdffa9d0 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -433,6 +433,57 @@ static time64_t __ext4_get_tstamp(__le32 *lo, __u8 *hi) #define ext4_get_tstamp(es, tstamp) \ __ext4_get_tstamp(&(es)->tstamp, &(es)->tstamp ## _hi) +#define EXT4_SB_REFRESH_INTERVAL_SEC (3600) /* seconds (1 hour) */ +#define EXT4_SB_REFRESH_INTERVAL_KB (16384) /* kilobytes (16MB) */ + +/* + * The ext4_maybe_update_superblock() function checks and updates the + * superblock if needed. + * + * This function is designed to update the on-disk superblock only under + * certain conditions to prevent excessive disk writes and unnecessary + * waking of the disk from sleep. The superblock will be updated if: + * 1. More than an hour has passed since the last superblock update, and + * 2. More than 16MB have been written since the last superblock update. + * + * @sb: The superblock + */ +static void ext4_maybe_update_superblock(struct super_block *sb) +{ + struct ext4_sb_info *sbi = EXT4_SB(sb); + struct ext4_super_block *es = sbi->s_es; + journal_t *journal = sbi->s_journal; + time64_t now; + __u64 last_update; + __u64 lifetime_write_kbytes; + __u64 diff_size; + + if (sb_rdonly(sb) || !(sb->s_flags & SB_ACTIVE) || + !journal || (journal->j_flags & JBD2_UNMOUNT)) + return; + + now = ktime_get_real_seconds(); + last_update = ext4_get_tstamp(es, s_wtime); + + if (likely(now - last_update < EXT4_SB_REFRESH_INTERVAL_SEC)) + return; + + lifetime_write_kbytes = sbi->s_kbytes_written + + ((part_stat_read(sb->s_bdev, sectors[STAT_WRITE]) - + sbi->s_sectors_written_start) >> 1); + + /* Get the number of kilobytes not written to disk to account + * for statistics and compare with a multiple of 16 MB. This + * is used to determine when the next superblock commit should + * occur (i.e. not more often than once per 16MB if there was + * less written in an hour). + */ + diff_size = lifetime_write_kbytes - le64_to_cpu(es->s_kbytes_written); + + if (diff_size > EXT4_SB_REFRESH_INTERVAL_KB) + schedule_work(&EXT4_SB(sb)->s_error_work); +} + /* * The del_gendisk() function uninitializes the disk-specific data * structures, including the bdi structure, without telling anyone @@ -459,6 +510,7 @@ static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn) BUG_ON(txn->t_state == T_FINISHED); ext4_process_freed_data(sb, txn->t_tid); + ext4_maybe_update_superblock(sb); spin_lock(&sbi->s_md_lock); while (!list_empty(&txn->t_private_list)) { @@ -715,6 +767,7 @@ static void flush_stashed_error_work(struct work_struct *work) */ if (!sb_rdonly(sbi->s_sb) && journal) { struct buffer_head *sbh = sbi->s_sbh; + bool call_notify_err; handle = jbd2_journal_start(journal, 1); if (IS_ERR(handle)) goto write_directly; @@ -722,6 +775,10 @@ static void flush_stashed_error_work(struct work_struct *work) jbd2_journal_stop(handle); goto write_directly; } + + if (sbi->s_add_error_count > 0) + call_notify_err = true; + ext4_update_super(sbi->s_sb); if (buffer_write_io_error(sbh) || !buffer_uptodate(sbh)) { ext4_msg(sbi->s_sb, KERN_ERR, "previous I/O error to " @@ -735,7 +792,10 @@ static void flush_stashed_error_work(struct work_struct *work) goto write_directly; } jbd2_journal_stop(handle); - ext4_notify_error_sysfs(sbi); + + if (call_notify_err) + ext4_notify_error_sysfs(sbi); + return; } write_directly: |