Using CLOCK_REALTIME time_t timestamps breaks on 32-bit systems in 2038, and gives surprising results with a concurrent settimeofday().
This changes the reiserfs journal timestamps to use ktime_get_seconds() instead, which makes it use a 64-bit CLOCK_MONOTONIC stamp. In the procfs output, the monotonic timestamp needs to be converted back to CLOCK_REALTIME to keep the existing ABI. Reviewed-by: Jan Kara <[email protected]> Signed-off-by: Arnd Bergmann <[email protected]> --- v2: I split out the conversion from monotonic to real time into a separate function for readability, though I decided against making it a global function. I looked at almost all uses of CLOCK_REALTIME in the kernel several times and don't remember any other file that would benefit from making it a generic helper, and it can be slightly inaccurate because of the double rounding. --- fs/reiserfs/journal.c | 22 +++++++++++----------- fs/reiserfs/procfs.c | 11 +++++++++-- fs/reiserfs/reiserfs.h | 2 +- 3 files changed, 21 insertions(+), 14 deletions(-) diff --git a/fs/reiserfs/journal.c b/fs/reiserfs/journal.c index 1e7f733b2a12..e809da912c00 100644 --- a/fs/reiserfs/journal.c +++ b/fs/reiserfs/journal.c @@ -2381,7 +2381,7 @@ static int journal_read(struct super_block *sb) struct reiserfs_journal_desc *desc; unsigned int oldest_trans_id = 0; unsigned int oldest_invalid_trans_id = 0; - time_t start; + time64_t start; unsigned long oldest_start = 0; unsigned long cur_dblock = 0; unsigned long newest_mount_id = 9; @@ -2395,7 +2395,7 @@ static int journal_read(struct super_block *sb) cur_dblock = SB_ONDISK_JOURNAL_1st_BLOCK(sb); reiserfs_info(sb, "checking transaction log (%pg)\n", journal->j_dev_bd); - start = get_seconds(); + start = ktime_get_seconds(); /* * step 1, read in the journal header block. Check the transaction @@ -2556,7 +2556,7 @@ static int journal_read(struct super_block *sb) if (replay_count > 0) { reiserfs_info(sb, "replayed %d transactions in %lu seconds\n", - replay_count, get_seconds() - start); + replay_count, ktime_get_seconds() - start); } /* needed to satisfy the locking in _update_journal_header_block */ reiserfs_write_lock(sb); @@ -2914,7 +2914,7 @@ int journal_transaction_should_end(struct reiserfs_transaction_handle *th, int new_alloc) { struct reiserfs_journal *journal = SB_JOURNAL(th->t_super); - time_t now = get_seconds(); + time64_t now = ktime_get_seconds(); /* cannot restart while nested */ BUG_ON(!th->t_trans_id); if (th->t_refcount > 1) @@ -3023,7 +3023,7 @@ static int do_journal_begin_r(struct reiserfs_transaction_handle *th, struct super_block *sb, unsigned long nblocks, int join) { - time_t now = get_seconds(); + time64_t now = ktime_get_seconds(); unsigned int old_trans_id; struct reiserfs_journal *journal = SB_JOURNAL(sb); struct reiserfs_transaction_handle myth; @@ -3056,7 +3056,7 @@ static int do_journal_begin_r(struct reiserfs_transaction_handle *th, PROC_INFO_INC(sb, journal.journal_relock_writers); goto relock; } - now = get_seconds(); + now = ktime_get_seconds(); /* * if there is no room in the journal OR @@ -3119,7 +3119,7 @@ static int do_journal_begin_r(struct reiserfs_transaction_handle *th, } /* we are the first writer, set trans_id */ if (journal->j_trans_start_time == 0) { - journal->j_trans_start_time = get_seconds(); + journal->j_trans_start_time = ktime_get_seconds(); } atomic_inc(&journal->j_wcount); journal->j_len_alloc += nblocks; @@ -3559,11 +3559,11 @@ static void flush_async_commits(struct work_struct *work) */ void reiserfs_flush_old_commits(struct super_block *sb) { - time_t now; + time64_t now; struct reiserfs_transaction_handle th; struct reiserfs_journal *journal = SB_JOURNAL(sb); - now = get_seconds(); + now = ktime_get_seconds(); /* * safety check so we don't flush while we are replaying the log during * mount @@ -3613,7 +3613,7 @@ void reiserfs_flush_old_commits(struct super_block *sb) static int check_journal_end(struct reiserfs_transaction_handle *th, int flags) { - time_t now; + time64_t now; int flush = flags & FLUSH_ALL; int commit_now = flags & COMMIT_NOW; int wait_on_commit = flags & WAIT; @@ -3694,7 +3694,7 @@ static int check_journal_end(struct reiserfs_transaction_handle *th, int flags) } /* deal with old transactions where we are the last writers */ - now = get_seconds(); + now = ktime_get_seconds(); if ((now - journal->j_trans_start_time) > journal->j_max_trans_age) { commit_now = 1; journal->j_next_async_flush = 1; diff --git a/fs/reiserfs/procfs.c b/fs/reiserfs/procfs.c index e39b3910d24d..f2cf3441fdfc 100644 --- a/fs/reiserfs/procfs.c +++ b/fs/reiserfs/procfs.c @@ -297,6 +297,13 @@ static int show_oidmap(struct seq_file *m, void *unused) return 0; } +static time64_t ktime_mono_to_real_seconds(time64_t mono) +{ + ktime_t kt = ktime_set(mono, NSEC_PER_SEC/2); + + return ktime_divns(ktime_mono_to_real(kt), NSEC_PER_SEC); +} + static int show_journal(struct seq_file *m, void *unused) { struct super_block *sb = m->private; @@ -325,7 +332,7 @@ static int show_journal(struct seq_file *m, void *unused) "j_bcount: \t%lu\n" "j_first_unflushed_offset: \t%lu\n" "j_last_flush_trans_id: \t%u\n" - "j_trans_start_time: \t%li\n" + "j_trans_start_time: \t%lli\n" "j_list_bitmap_index: \t%i\n" "j_must_wait: \t%i\n" "j_next_full_flush: \t%i\n" @@ -366,7 +373,7 @@ static int show_journal(struct seq_file *m, void *unused) JF(j_bcount), JF(j_first_unflushed_offset), JF(j_last_flush_trans_id), - JF(j_trans_start_time), + ktime_mono_to_real_seconds(JF(j_trans_start_time)), JF(j_list_bitmap_index), JF(j_must_wait), JF(j_next_full_flush), diff --git a/fs/reiserfs/reiserfs.h b/fs/reiserfs/reiserfs.h index 1536ebbaf6ab..d0fc829bd760 100644 --- a/fs/reiserfs/reiserfs.h +++ b/fs/reiserfs/reiserfs.h @@ -330,7 +330,7 @@ struct reiserfs_journal { struct buffer_head *j_header_bh; - time_t j_trans_start_time; /* time this transaction started */ + time64_t j_trans_start_time; /* time this transaction started */ struct mutex j_mutex; struct mutex j_flush_mutex; -- 2.9.0 _______________________________________________ Y2038 mailing list [email protected] https://lists.linaro.org/mailman/listinfo/y2038
