This is a note to let you know that I've just added the patch titled
locks: eliminate BUG() call when there's an unexpected lock on file close
to the 3.14-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
locks-eliminate-bug-call-when-there-s-an-unexpected-lock-on-file-close.patch
and it can be found in the queue-3.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 8c3cac5e6a85f03602ffe09c44f14418699e31ec Mon Sep 17 00:00:00 2001
From: Jeff Layton <jlayton@xxxxxxxxxx>
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@xxxxxxxxxx>
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@xxxxxxxxxxxx>
Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx>
Cc: Markus Blank-Burian <burian@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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;
}
Patches currently in stable-queue which might be from jlayton@xxxxxxxxxx are
queue-3.14/locks-eliminate-bug-call-when-there-s-an-unexpected-lock-on-file-close.patch
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