From a44c94a7b82a425b73384c104d5cb3dd3caa075e Mon Sep 17 00:00:00 2001 From: Alexander Zarochentsev <zam@namesys.com> Date: Sat, 25 Mar 2006 03:06:59 -0800 Subject: [PATCH] [PATCH] reiserfs: handle trans_id overflow 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 <zam@namesys.com> Signed-off-by: Hans Reiser <reiser@namesys.com> Cc: Chris Mason <mason@suse.com> Cc: Jeff Mahoney <jeffm@suse.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org> --- fs/reiserfs/journal.c | 21 ++++++++++++++++++--- 1 file changed, 18 insertions(+), 3 deletions(-) diff --git a/fs/reiserfs/journal.c b/fs/reiserfs/journal.c index 5a9d2722fa0a..1b73529b8099 100644 --- a/fs/reiserfs/journal.c +++ b/fs/reiserfs/journal.c @@ -2227,6 +2227,9 @@ static int journal_read_transaction(struct super_block *p_s_sb, 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_block *p_s_sb) 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 reiserfs_transaction_handle *th, 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 reiserfs_transaction_handle *th, 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 reiserfs_transaction_handle *th, 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; -- GitLab