fuse: fix live lock in fuse_iget()
authorAmir Goldstein <amir73il@gmail.com>
Thu, 4 Mar 2021 09:09:12 +0000 (11:09 +0200)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Sat, 20 Mar 2021 09:43:43 +0000 (10:43 +0100)
commitd955f13ea2120269319d6133d0dd82b66d1eeca3
tree09bca80a5ca963432b8ec89e1250da2d12177bd2
parent2d7888b2c4cd531e3c6593ffcb3d5160ebc1f52c
fuse: fix live lock in fuse_iget()

commit 775c5033a0d164622d9d10dd0f0a5531639ed3ed upstream.

Commit 5d069dbe8aaf ("fuse: fix bad inode") replaced make_bad_inode()
in fuse_iget() with a private implementation fuse_make_bad().

The private implementation fails to remove the bad inode from inode
cache, so the retry loop with iget5_locked() finds the same bad inode
and marks it bad forever.

kmsg snip:

[ ] rcu: INFO: rcu_sched self-detected stall on CPU
...
[ ]  ? bit_wait_io+0x50/0x50
[ ]  ? fuse_init_file_inode+0x70/0x70
[ ]  ? find_inode.isra.32+0x60/0xb0
[ ]  ? fuse_init_file_inode+0x70/0x70
[ ]  ilookup5_nowait+0x65/0x90
[ ]  ? fuse_init_file_inode+0x70/0x70
[ ]  ilookup5.part.36+0x2e/0x80
[ ]  ? fuse_init_file_inode+0x70/0x70
[ ]  ? fuse_inode_eq+0x20/0x20
[ ]  iget5_locked+0x21/0x80
[ ]  ? fuse_inode_eq+0x20/0x20
[ ]  fuse_iget+0x96/0x1b0

Fixes: 5d069dbe8aaf ("fuse: fix bad inode")
Cc: stable@vger.kernel.org # 5.10+
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
fs/fuse/fuse_i.h