If a cache object gets killed whilst in the process of being set up - for instance if the netfs relinquishes the cookie that the object is associated with - then the object's state machine will transit to the DROP_OBJECT state without necessarily going through the LOOKUP_OBJECT or CREATE_OBJECT states. This is a problem for CacheFiles because cachefiles_drop_object() assumes that object->dentry will be set upon reaching the DROP_OBJECT state and has an ASSERT() to that effect (see the oops below) - but object->dentry doesn't get set until the LOOKUP_OBJECT or CREATE_OBJECT states (and not always then if they fail). To fix this, just make the dentry cleanup in cachefiles_drop_object() conditional on the dentry actually being set and remove the assertion. CacheFiles: Assertion failed ------------[ cut here ]------------ kernel BUG at .../fs/cachefiles/namei.c:425! ... Workqueue: fscache_object fscache_object_work_func [fscache] ... RIP: ... cachefiles_delete_object+0xcd/0x110 [cachefiles] ... Call Trace: [<ffffffffa043280f>] ? cachefiles_drop_object+0xff/0x130 [cachefiles] [<ffffffffa02ac511>] ? fscache_drop_object+0xd1/0x1d0 [fscache] [<ffffffffa02ac697>] ? fscache_object_work_func+0x87/0x210 [fscache] [<ffffffff81080635>] ? process_one_work+0x155/0x450 [<ffffffff81081c44>] ? worker_thread+0x114/0x370 [<ffffffff81081b30>] ? manage_workers.isra.21+0x2c0/0x2c0 [<ffffffff81087fcc>] ? kthread+0xbc/0xe0 [<ffffffff81087f10>] ? flush_kthread_worker+0xa0/0xa0 [<ffffffff8150638c>] ? ret_from_fork+0x7c/0xb0 [<ffffffff81087f10>] ? flush_kthread_worker+0xa0/0xa0 Reported-by: Manuel Schölling <manuel.schoelling@gmx.de> Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Steve Dickson <steved@redhat.com> |
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.. | ||
bind.c | ||
daemon.c | ||
interface.c | ||
internal.h | ||
Kconfig | ||
key.c | ||
main.c | ||
Makefile | ||
namei.c | ||
proc.c | ||
rdwr.c | ||
security.c | ||
xattr.c |