From bb20b31dee1a6c329c2f721fbe21c51945cdfc29 Mon Sep 17 00:00:00 2001 From: Heming Zhao via Ocfs2-devel Date: Fri, 29 Apr 2022 14:37:58 -0700 Subject: ocfs2: fix mounting crash if journal is not alloced Patch series "rewrite error handling during mounting stage". This patch (of 5): After commit da5e7c87827e8 ("ocfs2: cleanup journal init and shutdown"), journal init later than before, it makes NULL pointer access in free routine. Crash flow: ocfs2_fill_super + ocfs2_mount_volume | + ocfs2_dlm_init //fail & return, osb->journal is NULL. | + ... | + ocfs2_check_volume //no chance to init osb->journal | + ... + ocfs2_dismount_volume ocfs2_release_system_inodes ... evict ... ocfs2_clear_inode ocfs2_checkpoint_inode ocfs2_ci_fully_checkpointed time_after(journal->j_trans_id, ci->ci_last_trans) + journal is empty, crash! For fixing, there are three solutions: 1> Partly revert commit da5e7c87827e8 For avoiding kernel crash, this make sense for us. We only concerned whether there has any non-system inode access before dlm init. The answer is NO. And all journal replay/recovery handling happen after dlm & journal init done. So this method is not graceful but workable. 2> Add osb->journal check in free inode routine (eg ocfs2_clear_inode) The fix code is special for mounting phase, but it will continue working after mounting stage. In another word, this method adds useless code in normal inode free flow. 3> Do directly free inode in mounting phase This method is brutal/complex and may introduce unsafe code, currently maintainer didn't like. At last, we chose method <1> and did partly reverted job. We reverted journal init codes, and kept cleanup codes flow. Link: https://lkml.kernel.org/r/20220424130952.2436-1-heming.zhao@suse.com Link: https://lkml.kernel.org/r/20220424130952.2436-2-heming.zhao@suse.com Fixes: da5e7c87827e8 ("ocfs2: cleanup journal init and shutdown") Signed-off-by: Heming Zhao Reviewed-by: Joseph Qi Cc: Mark Fasheh Cc: Joel Becker Cc: Junxiao Bi Cc: Changwei Ge Cc: Gang He Cc: Jun Piao Signed-off-by: Andrew Morton --- fs/ocfs2/journal.c | 33 +++++++++++++++++++++++---------- 1 file changed, 23 insertions(+), 10 deletions(-) (limited to 'fs/ocfs2/journal.c') diff --git a/fs/ocfs2/journal.c b/fs/ocfs2/journal.c index 1887a2708709..fa87d89cf754 100644 --- a/fs/ocfs2/journal.c +++ b/fs/ocfs2/journal.c @@ -810,22 +810,20 @@ void ocfs2_set_journal_params(struct ocfs2_super *osb) write_unlock(&journal->j_state_lock); } -int ocfs2_journal_init(struct ocfs2_super *osb, int *dirty) +/* + * alloc & initialize skeleton for journal structure. + * ocfs2_journal_init() will make fs have journal ability. + */ +int ocfs2_journal_alloc(struct ocfs2_super *osb) { - int status = -1; - struct inode *inode = NULL; /* the journal inode */ - journal_t *j_journal = NULL; - struct ocfs2_journal *journal = NULL; - struct ocfs2_dinode *di = NULL; - struct buffer_head *bh = NULL; - int inode_lock = 0; + int status = 0; + struct ocfs2_journal *journal; - /* initialize our journal structure */ journal = kzalloc(sizeof(struct ocfs2_journal), GFP_KERNEL); if (!journal) { mlog(ML_ERROR, "unable to alloc journal\n"); status = -ENOMEM; - goto done; + goto bail; } osb->journal = journal; journal->j_osb = osb; @@ -839,6 +837,21 @@ int ocfs2_journal_init(struct ocfs2_super *osb, int *dirty) INIT_WORK(&journal->j_recovery_work, ocfs2_complete_recovery); journal->j_state = OCFS2_JOURNAL_FREE; +bail: + return status; +} + +int ocfs2_journal_init(struct ocfs2_super *osb, int *dirty) +{ + int status = -1; + struct inode *inode = NULL; /* the journal inode */ + journal_t *j_journal = NULL; + struct ocfs2_journal *journal = osb->journal; + struct ocfs2_dinode *di = NULL; + struct buffer_head *bh = NULL; + int inode_lock = 0; + + BUG_ON(!journal); /* already have the inode for our journal */ inode = ocfs2_get_system_file_inode(osb, JOURNAL_SYSTEM_INODE, osb->slot_num); -- cgit v1.2.3