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| author | Xue jiufei <xuejiufei@huawei.com> | 2014-06-05 01:06:13 +0200 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-06-05 01:53:54 +0200 |
| commit | a9e9acaeb0a981a6dfa54b32dd756103aeefa6a7 (patch) | |
| tree | 132b64a3d1e5c79a76c903a58f4f335869f87f5f /fs/ocfs2 | |
| parent | fs/ocfs2/ioctl.c: add static to local functions (diff) | |
| download | linux-a9e9acaeb0a981a6dfa54b32dd756103aeefa6a7.tar.xz linux-a9e9acaeb0a981a6dfa54b32dd756103aeefa6a7.zip | |
ocfs2: fix umount hang while shutting down truncate log
Revert commit 75f82eaa502c ("ocfs2: fix NULL pointer dereference when
dismount and ocfs2rec simultaneously") because it may cause a umount
hang while shutting down the truncate log.
fix NULL pointer dereference when dismount and ocfs2rec simultaneously
The situation is as followes:
ocfs2_dismout_volume
-> ocfs2_recovery_exit
-> free osb->recovery_map
-> ocfs2_truncate_shutdown
-> lock global bitmap inode
-> ocfs2_wait_for_recovery
-> check whether osb->recovery_map->rm_used is zero
Because osb->recovery_map is already freed, rm_used can be any other
values, so it may yield umount hang.
To prevent NULL pointer dereference while getting sys_root_inode, we use
a osb_tl_disable flag to disable schedule osb_truncate_log_wq after
truncate log shutdown.
Signed-off-by: joyce.xue <xuejiufei@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/ocfs2')
| -rw-r--r-- | fs/ocfs2/alloc.c | 6 | ||||
| -rw-r--r-- | fs/ocfs2/ocfs2.h | 1 |
2 files changed, 6 insertions, 1 deletions
diff --git a/fs/ocfs2/alloc.c b/fs/ocfs2/alloc.c index b4deb5f750d9..9d8fcf2f3b94 100644 --- a/fs/ocfs2/alloc.c +++ b/fs/ocfs2/alloc.c @@ -6046,7 +6046,8 @@ static void ocfs2_truncate_log_worker(struct work_struct *work) void ocfs2_schedule_truncate_log_flush(struct ocfs2_super *osb, int cancel) { - if (osb->osb_tl_inode) { + if (osb->osb_tl_inode && + atomic_read(&osb->osb_tl_disable) == 0) { /* We want to push off log flushes while truncates are * still running. */ if (cancel) @@ -6223,6 +6224,8 @@ void ocfs2_truncate_log_shutdown(struct ocfs2_super *osb) int status; struct inode *tl_inode = osb->osb_tl_inode; + atomic_set(&osb->osb_tl_disable, 1); + if (tl_inode) { cancel_delayed_work(&osb->osb_truncate_log_wq); flush_workqueue(ocfs2_wq); @@ -6254,6 +6257,7 @@ int ocfs2_truncate_log_init(struct ocfs2_super *osb) * until we're sure all is well. */ INIT_DELAYED_WORK(&osb->osb_truncate_log_wq, ocfs2_truncate_log_worker); + atomic_set(&osb->osb_tl_disable, 0); osb->osb_tl_bh = tl_bh; osb->osb_tl_inode = tl_inode; diff --git a/fs/ocfs2/ocfs2.h b/fs/ocfs2/ocfs2.h index 8d64a97a9d5e..bbec539230fd 100644 --- a/fs/ocfs2/ocfs2.h +++ b/fs/ocfs2/ocfs2.h @@ -422,6 +422,7 @@ struct ocfs2_super struct inode *osb_tl_inode; struct buffer_head *osb_tl_bh; struct delayed_work osb_truncate_log_wq; + atomic_t osb_tl_disable; /* * How many clusters in our truncate log. * It must be protected by osb_tl_inode->i_mutex. |