From: Heming Zhao via Ocfs2-devel ocfs2-devel@oss.oracle.com
[ Upstream commit bb20b31dee1a6c329c2f721fbe21c51945cdfc29 ]
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 heming.zhao@suse.com Reviewed-by: Joseph Qi joseph.qi@linux.alibaba.com Cc: Mark Fasheh mark@fasheh.com Cc: Joel Becker jlbec@evilplan.org Cc: Junxiao Bi junxiao.bi@oracle.com Cc: Changwei Ge gechangwei@live.cn Cc: Gang He ghe@suse.com Cc: Jun Piao piaojun@huawei.com Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- fs/ocfs2/inode.c | 4 ++-- fs/ocfs2/journal.c | 33 +++++++++++++++++++++++---------- fs/ocfs2/journal.h | 2 ++ fs/ocfs2/super.c | 15 +++++++++++++++ 4 files changed, 42 insertions(+), 12 deletions(-)
diff --git a/fs/ocfs2/inode.c b/fs/ocfs2/inode.c index 6c2411c2afcf..fb090dac21d2 100644 --- a/fs/ocfs2/inode.c +++ b/fs/ocfs2/inode.c @@ -125,6 +125,7 @@ struct inode *ocfs2_iget(struct ocfs2_super *osb, u64 blkno, unsigned flags, struct inode *inode = NULL; struct super_block *sb = osb->sb; struct ocfs2_find_inode_args args; + journal_t *journal = osb->journal->j_journal;
trace_ocfs2_iget_begin((unsigned long long)blkno, flags, sysfile_type); @@ -171,11 +172,10 @@ struct inode *ocfs2_iget(struct ocfs2_super *osb, u64 blkno, unsigned flags, * part of the transaction - the inode could have been reclaimed and * now it is reread from disk. */ - if (osb->journal) { + if (journal) { transaction_t *transaction; tid_t tid; struct ocfs2_inode_info *oi = OCFS2_I(inode); - journal_t *journal = osb->journal->j_journal;
read_lock(&journal->j_state_lock); if (journal->j_running_transaction) 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); diff --git a/fs/ocfs2/journal.h b/fs/ocfs2/journal.h index 8dcb2f2cadbc..969d0aa28718 100644 --- a/fs/ocfs2/journal.h +++ b/fs/ocfs2/journal.h @@ -154,6 +154,7 @@ int ocfs2_compute_replay_slots(struct ocfs2_super *osb); * Journal Control: * Initialize, Load, Shutdown, Wipe a journal. * + * ocfs2_journal_alloc - Initialize skeleton for journal structure. * ocfs2_journal_init - Initialize journal structures in the OSB. * ocfs2_journal_load - Load the given journal off disk. Replay it if * there's transactions still in there. @@ -167,6 +168,7 @@ int ocfs2_compute_replay_slots(struct ocfs2_super *osb); * ocfs2_start_checkpoint - Kick the commit thread to do a checkpoint. */ void ocfs2_set_journal_params(struct ocfs2_super *osb); +int ocfs2_journal_alloc(struct ocfs2_super *osb); int ocfs2_journal_init(struct ocfs2_super *osb, int *dirty); void ocfs2_journal_shutdown(struct ocfs2_super *osb); int ocfs2_journal_wipe(struct ocfs2_journal *journal, diff --git a/fs/ocfs2/super.c b/fs/ocfs2/super.c index 8bde30fa5387..4a3d625772fc 100644 --- a/fs/ocfs2/super.c +++ b/fs/ocfs2/super.c @@ -2195,6 +2195,15 @@ static int ocfs2_initialize_super(struct super_block *sb,
get_random_bytes(&osb->s_next_generation, sizeof(u32));
+ /* + * FIXME + * This should be done in ocfs2_journal_init(), but any inode + * writes back operation will cause the filesystem to crash. + */ + status = ocfs2_journal_alloc(osb); + if (status < 0) + goto bail; + INIT_WORK(&osb->dquot_drop_work, ocfs2_drop_dquot_refs); init_llist_head(&osb->dquot_drop_list);
@@ -2483,6 +2492,12 @@ static void ocfs2_delete_osb(struct ocfs2_super *osb)
kfree(osb->osb_orphan_wipes); kfree(osb->slot_recovery_generations); + /* FIXME + * This belongs in journal shutdown, but because we have to + * allocate osb->journal at the middle of ocfs2_initialize_super(), + * we free it here. + */ + kfree(osb->journal); kfree(osb->local_alloc_copy); kfree(osb->uuid_str); kfree(osb->vol_label);