Hi!
On Wed, Jun 28, 2023 at 08:35:34PM -0400, Sweet Tea Dorminy wrote:
> Since extent encryption requires inline encryption, even though we
> expect to use the inlinecrypt software fallback most of the time, we
> need to enumerate all the devices in use by btrfs.
>
> I'm not sure this is the correct list of active devices and it isn't
> tested with any multi-device test yet.
To be honest, I can't say whether this is the correct list either (sorry,
I'm new here!). However, a quick test shows me there's something wrong
with this code because I'm seeing the lockdep splat bellow: mutex_lock()
can't be called here.
It's very easy to reproduce with the fscrypt userspace tool, simply doing
an 'fscrypt lock' in an encrypted directory.
Cheers,
--
Luís
> Signed-off-by: Sweet Tea Dorminy <sweettea-kernel@xxxxxxxxxx>
> ---
> fs/btrfs/fscrypt.c | 30 ++++++++++++++++++++++++++++++
> 1 file changed, 30 insertions(+)
>
> diff --git a/fs/btrfs/fscrypt.c b/fs/btrfs/fscrypt.c
> index 20727d920841..658a67856de6 100644
> --- a/fs/btrfs/fscrypt.c
> +++ b/fs/btrfs/fscrypt.c
> @@ -11,7 +11,9 @@
> #include "ioctl.h"
> #include "messages.h"
> #include "root-tree.h"
> +#include "super.h"
> #include "transaction.h"
> +#include "volumes.h"
> #include "xattr.h"
>
> /*
> @@ -162,9 +164,37 @@ static bool btrfs_fscrypt_empty_dir(struct inode *inode)
> return inode->i_size == BTRFS_EMPTY_DIR_SIZE;
> }
>
> +static struct block_device **btrfs_fscrypt_get_devices(struct super_block *sb,
> + unsigned int *num_devs)
> +{
> + struct btrfs_fs_info *fs_info = btrfs_sb(sb);
> + struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
> + struct block_device **devs;
> + struct btrfs_device *device;
> + int i;
> +
> + devs = kmalloc_array(fs_devices->num_devices, sizeof(*devs),
> + GFP_KERNEL);
> + if (!devs)
> + return ERR_PTR(-ENOMEM);
> +
> + mutex_lock(&fs_devices->device_list_mutex);
> + i = 0;
> + list_for_each_entry(device, &fs_devices->devices, dev_list) {
> + if (test_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state))
> + continue;
> +
> + devs[i++] = device->bdev;
> + }
> + mutex_unlock(&fs_devices->device_list_mutex);
> + *num_devs = i;
> + return devs;
> +}
> +
> const struct fscrypt_operations btrfs_fscrypt_ops = {
> .get_context = btrfs_fscrypt_get_context,
> .set_context = btrfs_fscrypt_set_context,
> .empty_dir = btrfs_fscrypt_empty_dir,
> + .get_devices = btrfs_fscrypt_get_devices,
> .key_prefix = "btrfs:"
> };
> --
> 2.40.1
>
[ 79.809077] =============================
[ 79.810268] [ BUG: Invalid wait context ]
[ 79.811370] 6.4.0-rc7+ #6 Not tainted
[ 79.812451] -----------------------------
[ 79.813561] fscrypt/233 is trying to lock:
[ 79.814576] ffff88812e7b78d8 (&fs_devs->device_list_mutex){+.+.}-{3:3}, at: btrfs_fscrypt_get_devices+0x8a/0x140 [btrfs]
[ 79.817937] other info that might help us debug this:
[ 79.819436] context-{4:4}
[ 79.820227] 1 lock held by fscrypt/233:
[ 79.821335] #0: ffff888111afb7b8 (&tree->lock){++++}-{2:2}, at: btrfs_drop_extent_map_range+0x9f9/0xac0 [btrfs]
[ 79.824674] stack backtrace:
[ 79.825478] CPU: 0 PID: 233 Comm: fscrypt Not tainted 6.4.0-rc7+ #6
[ 79.827186] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.2-3-gd478f380-rebuilt.opensuse.org 04/01/2014
[ 79.829975] Call Trace:
[ 79.830562] <TASK>
[ 79.831051] dump_stack_lvl+0x46/0x80
[ 79.831832] __lock_acquire+0xd05/0x3320
[ 79.832636] ? _raw_spin_unlock_irqrestore+0x2b/0x50
[ 79.833642] ? __stack_depot_save+0x207/0x440
[ 79.834537] ? __pfx___lock_acquire+0x10/0x10
[ 79.835442] ? btrfs_fscrypt_get_devices+0x65/0x140 [btrfs]
[ 79.836836] ? kasan_save_stack+0x2b/0x40
[ 79.837751] ? kasan_save_stack+0x1c/0x40
[ 79.838643] lock_acquire+0x14f/0x390
[ 79.839498] ? btrfs_fscrypt_get_devices+0x8a/0x140 [btrfs]
[ 79.841052] ? __pfx_lock_acquire+0x10/0x10
[ 79.841965] ? entry_SYSCALL_64_after_hwframe+0x72/0xdc
[ 79.843106] ? lock_acquire+0x14f/0x390
[ 79.843928] ? __create_object+0x250/0x620
[ 79.844786] ? __pfx_lock_acquire+0x10/0x10
[ 79.845691] __mutex_lock+0xf2/0x1210
[ 79.846457] ? btrfs_fscrypt_get_devices+0x8a/0x140 [btrfs]
[ 79.847883] ? __kmem_cache_alloc_node+0x154/0x250
[ 79.848822] ? btrfs_fscrypt_get_devices+0x8a/0x140 [btrfs]
[ 79.850214] ? mark_held_locks+0x65/0x90
[ 79.851007] ? __pfx___mutex_lock+0x10/0x10
[ 79.851800] ? lockdep_hardirqs_on_prepare+0x132/0x200
[ 79.852746] ? _raw_spin_unlock_irqrestore+0x2b/0x50
[ 79.853625] ? kasan_set_track+0x21/0x30
[ 79.854366] ? __kasan_kmalloc+0x8b/0x90
[ 79.855109] ? btrfs_fscrypt_get_devices+0x8a/0x140 [btrfs]
[ 79.856319] btrfs_fscrypt_get_devices+0x8a/0x140 [btrfs]
[ 79.857458] fscrypt_get_devices+0x3a/0xc0
[ 79.858137] fscrypt_destroy_inline_crypt_key+0x6c/0xe0
[ 79.859006] ? __pfx_fscrypt_destroy_inline_crypt_key+0x10/0x10
[ 79.860016] ? __pfx_truncate_inode_pages_range+0x10/0x10
[ 79.860849] put_crypt_info+0x13b/0x180
[ 79.861435] fscrypt_free_extent_info+0x11/0x30
[ 79.862175] free_extent_map+0x5a/0xf0 [btrfs]
[ 79.863145] btrfs_drop_extent_map_range+0xa66/0xac0 [btrfs]
[ 79.864221] ? __lockdep_reset_lock+0x80/0xb0
[ 79.864878] ? truncate_inode_pages_final+0x42/0x60
[ 79.865637] ? __pfx_lock_release+0x10/0x10
[ 79.866285] ? do_raw_spin_lock+0x104/0x180
[ 79.866935] ? __pfx_btrfs_drop_extent_map_range+0x10/0x10 [btrfs]
[ 79.868066] ? lockdep_hardirqs_on_prepare+0x132/0x200
[ 79.868798] btrfs_evict_inode+0x14b/0x660 [btrfs]
[ 79.869738] ? __pfx_btrfs_evict_inode+0x10/0x10 [btrfs]
[ 79.870707] ? lock_release+0x1c5/0x380
[ 79.871297] ? evict+0x137/0x2a0
[ 79.871793] ? __pfx_lock_release+0x10/0x10
[ 79.872386] ? __pfx_wake_bit_function+0x10/0x10
[ 79.873070] evict+0x155/0x2a0
[ 79.873532] try_to_lock_encrypted_files+0x211/0x4b0
[ 79.874244] ? __pfx_try_to_lock_encrypted_files+0x10/0x10
[ 79.874981] ? do_remove_key.isra.0+0x2da/0x3e0
[ 79.875636] ? lockdep_hardirqs_on_prepare+0x132/0x200
[ 79.876368] ? up_write+0xfb/0x2d0
[ 79.876833] do_remove_key.isra.0+0x36a/0x3e0
[ 79.877441] ? __pfx_do_remove_key.isra.0+0x10/0x10
[ 79.878111] btrfs_ioctl+0x1cf1/0x4000 [btrfs]
[ 79.878919] ? __pfx_btrfs_ioctl+0x10/0x10 [btrfs]
[ 79.879805] ? __pfx___lock_acquire+0x10/0x10
[ 79.880381] ? mark_held_locks+0x24/0x90
[ 79.880928] ? do_sys_openat2+0xce/0x240
[ 79.881441] ? do_vfs_ioctl+0xb2f/0xca0
[ 79.881948] ? __pfx_do_vfs_ioctl+0x10/0x10
[ 79.882483] ? lock_acquire+0x14f/0x390
[ 79.883007] ? __pfx___fget_files+0x10/0x10
[ 79.883566] ? find_held_lock+0x83/0xa0
[ 79.884062] ? lock_release+0x1c5/0x380
[ 79.884551] ? __fget_files+0x129/0x200
[ 79.885051] ? __pfx_lock_release+0x10/0x10
[ 79.885598] ? map_id_up+0xd7/0x150
[ 79.886037] ? __pfx_map_id_up+0x10/0x10
[ 79.886532] ? __fget_files+0x141/0x200
[ 79.887049] __x64_sys_ioctl+0xc1/0xe0
[ 79.887537] do_syscall_64+0x42/0x90
[ 79.887965] entry_SYSCALL_64_after_hwframe+0x72/0xdc
[ 79.888587] RIP: 0033:0x405e8e
[ 79.888976] Code: 48 89 6c 24 38 48 8d 6c 24 38 e8 0d 00 00 00 48 8b 6c 24 38 48 83 c4 40 c3 cc cc cc 49 89 f2 48 89 fa 48 89 ce 48 89 df 0f 05 <48> 3d 01 f0 ff ff 76 158
[ 79.891248] RSP: 002b:000000c0000ed3f8 EFLAGS: 00000206 ORIG_RAX: 0000000000000010
[ 79.892146] RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000405e8e
[ 79.892967] RDX: 000000c0000ed540 RSI: 00000000c0406618 RDI: 0000000000000003
[ 79.893829] RBP: 000000c0000ed438 R08: 0000000000000000 R09: 0000000000000000
[ 79.894677] R10: 0000000000000000 R11: 0000000000000206 R12: 000000c0000b2b90
[ 79.895503] R13: 0000000000000000 R14: 000000c0000061a0 R15: ffffffffffffffff
[ 79.896329] </TASK>
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