From: Alexander Zarochentsev Reiserfs does not handle transaction ID overflow correctly. Transaction ID == 0 causes reiserfs to crash. The patch fixes all places where the transaction ID is incremented. Signed-off-by: Alexander Zarochentsev Signed-off-by: Hans Reiser Cc: Chris Mason Cc: Jeff Mahoney Signed-off-by: Andrew Morton --- fs/reiserfs/journal.c | 21 ++++++++++++++++++--- 1 files changed, 18 insertions(+), 3 deletions(-) diff -puN fs/reiserfs/journal.c~reiserfs-handle-trans_id-overflow fs/reiserfs/journal.c --- 25/fs/reiserfs/journal.c~reiserfs-handle-trans_id-overflow Thu Mar 2 15:25:30 2006 +++ 25-akpm/fs/reiserfs/journal.c Thu Mar 2 15:25:30 2006 @@ -2227,6 +2227,9 @@ static int journal_read_transaction(stru journal->j_start = cur_dblock - SB_ONDISK_JOURNAL_1st_BLOCK(p_s_sb); journal->j_last_flush_trans_id = trans_id; journal->j_trans_id = trans_id + 1; + /* check for trans_id overflow */ + if (journal->j_trans_id == 0) + journal->j_trans_id = 10; brelse(c_bh); brelse(d_bh); kfree(log_blocks); @@ -2450,6 +2453,9 @@ static int journal_read(struct super_blo journal->j_start = le32_to_cpu(jh->j_first_unflushed_offset); journal->j_trans_id = le32_to_cpu(jh->j_last_flush_trans_id) + 1; + /* check for trans_id overflow */ + if (journal->j_trans_id == 0) + journal->j_trans_id = 10; journal->j_last_flush_trans_id = le32_to_cpu(jh->j_last_flush_trans_id); journal->j_mount_id = le32_to_cpu(jh->j_mount_id) + 1; @@ -3873,8 +3879,8 @@ static int do_journal_end(struct reiserf int cur_write_start = 0; /* start index of current log write */ int old_start; int i; - int flush = flags & FLUSH_ALL; - int wait_on_commit = flags & WAIT; + int flush; + int wait_on_commit; struct reiserfs_journal_list *jl, *temp_jl; struct list_head *entry, *safe; unsigned long jindex; @@ -3884,6 +3890,13 @@ static int do_journal_end(struct reiserf BUG_ON(th->t_refcount > 1); BUG_ON(!th->t_trans_id); + /* protect flush_older_commits from doing mistakes if the + transaction ID counter gets overflowed. */ + if (th->t_trans_id == ~0UL) + flags |= FLUSH_ALL | COMMIT_NOW | WAIT; + flush = flags & FLUSH_ALL; + wait_on_commit = flags & WAIT; + put_fs_excl(); current->journal_info = th->t_handle_save; reiserfs_check_lock_depth(p_s_sb, "journal end"); @@ -4105,7 +4118,9 @@ static int do_journal_end(struct reiserf journal->j_first = NULL; journal->j_len = 0; journal->j_trans_start_time = 0; - journal->j_trans_id++; + /* check for trans_id overflow */ + if (++journal->j_trans_id == 0) + journal->j_trans_id = 10; journal->j_current_jl->j_trans_id = journal->j_trans_id; journal->j_must_wait = 0; journal->j_len_alloc = 0; _