[PATCH] autofs4: tree race fix
For tree mount maps, a call to chdir or chroot, to a directory above the
moint point directories at a certain time during the expire results in the
expire incorrectly thinking the tree is not busy. This patch adds a check
to see if the filesystem above the tree mount points is busy and also locks
the filesystem during the tree mount expire to prevent the race.
Signed-off-by: Ian Kent <raven@themaw.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/fs/autofs4/inode.c b/fs/autofs4/inode.c
index a525607..4bb14cc 100644
--- a/fs/autofs4/inode.c
+++ b/fs/autofs4/inode.c
@@ -206,6 +206,7 @@
sbi->version = 0;
sbi->sub_version = 0;
init_MUTEX(&sbi->wq_sem);
+ spin_lock_init(&sbi->fs_lock);
sbi->queues = NULL;
s->s_blocksize = 1024;
s->s_blocksize_bits = 10;
