| From 8c3cac5e6a85f03602ffe09c44f14418699e31ec Mon Sep 17 00:00:00 2001 |
| From: Jeff Layton <jlayton@redhat.com> |
| Date: Mon, 3 Feb 2014 12:13:07 -0500 |
| Subject: locks: eliminate BUG() call when there's an unexpected lock on file close |
| |
| From: Jeff Layton <jlayton@redhat.com> |
| |
| commit 8c3cac5e6a85f03602ffe09c44f14418699e31ec upstream. |
| |
| A leftover lock on the list is surely a sign of a problem of some sort, |
| but it's not necessarily a reason to panic the box. Instead, just log a |
| warning with some info about the lock, and then delete it like we would |
| any other lock. |
| |
| In the event that the filesystem declares a ->lock f_op, we may end up |
| leaking something, but that's generally preferable to an immediate |
| panic. |
| |
| Acked-by: J. Bruce Fields <bfields@fieldses.org> |
| Signed-off-by: Jeff Layton <jlayton@redhat.com> |
| Cc: Markus Blank-Burian <burian@muenster.de> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| fs/locks.c | 24 ++++++++++++++++++------ |
| 1 file changed, 18 insertions(+), 6 deletions(-) |
| |
| --- a/fs/locks.c |
| +++ b/fs/locks.c |
| @@ -2235,16 +2235,28 @@ void locks_remove_flock(struct file *fil |
| |
| while ((fl = *before) != NULL) { |
| if (fl->fl_file == filp) { |
| - if (IS_FLOCK(fl)) { |
| - locks_delete_lock(before); |
| - continue; |
| - } |
| if (IS_LEASE(fl)) { |
| lease_modify(before, F_UNLCK); |
| continue; |
| } |
| - /* What? */ |
| - BUG(); |
| + |
| + /* |
| + * There's a leftover lock on the list of a type that |
| + * we didn't expect to see. Most likely a classic |
| + * POSIX lock that ended up not getting released |
| + * properly, or that raced onto the list somehow. Log |
| + * some info about it and then just remove it from |
| + * the list. |
| + */ |
| + WARN(!IS_FLOCK(fl), |
| + "leftover lock: dev=%u:%u ino=%lu type=%hhd flags=0x%x start=%lld end=%lld\n", |
| + MAJOR(inode->i_sb->s_dev), |
| + MINOR(inode->i_sb->s_dev), inode->i_ino, |
| + fl->fl_type, fl->fl_flags, |
| + fl->fl_start, fl->fl_end); |
| + |
| + locks_delete_lock(before); |
| + continue; |
| } |
| before = &fl->fl_next; |
| } |