Hi! I've been seeing fscache complaining about duplicate cookies in 9p: FS-Cache: Duplicate cookie detected FS-Cache: O-cookie c=00000000ba929e80 [p=000000002e706df1 fl=226 nc=0 na=1] FS-Cache: O-cookie d=0000000000000000 n=0000000000000000 FS-Cache: O-key=[8] '0312710100000000' FS-Cache: N-cookie c=00000000274050fe [p=000000002e706df1 fl=2 nc=0 na=1] FS-Cache: N-cookie d=0000000037368b65 n=000000004047ed1f FS-Cache: N-key=[8] '0312710100000000' It's quite easy to reproduce in my environment by running xfstests using the virtme scripts to boot a test kernel. A quick look seems to indicate the warning comes from the v9fs_vfs_atomic_open_dotl() path: [ 383.688975] __fscache_acquire_cookie+0xd1/0x2d0 [ 383.688983] v9fs_cache_inode_get_cookie.part.0+0xd1/0x100 [ 383.688988] ? v9fs_vfs_link+0x160/0x160 [ 383.688994] v9fs_inode_from_fid_dotl+0x141/0x180 [ 383.688998] v9fs_vfs_lookup.part.0+0x1ab/0x1f0 [ 383.689003] ? v9fs_vfs_create+0x80/0x80 [ 383.689007] v9fs_vfs_atomic_open_dotl+0x14f/0x4f0 [ 383.689011] ? do_raw_spin_unlock+0xa3/0x130 [ 383.689016] ? v9fs_inode_from_fid_dotl+0x180/0x180 [ 383.689021] ? __d_lookup_rcu+0x270/0x270 [ 383.689029] ? down_read+0x13b/0x2c0 [ 383.689044] ? rwsem_down_read_slowpath+0x5b0/0x5b0 [ 383.689052] ? __d_lookup+0xb7/0x220 [ 383.689059] path_openat+0xb33/0x15a0 [ 383.689068] ? path_lookupat.isra.0+0x230/0x230 [ 383.689073] ? orc_find.part.0+0x200/0x200 [ 383.689078] ? ftrace_ops_trampoline+0x51/0x80 [ 383.689083] ? __kernel_text_address+0xe/0x30 [ 383.689087] ? unwind_get_return_address+0x2f/0x50 [ 383.689091] ? set_syscall_user_dispatch+0xb0/0xb0 [ 383.689096] ? arch_stack_walk+0x9e/0xf0 [ 383.689101] do_filp_open+0x136/0x1c0 [ 383.689105] ? may_open_dev+0x50/0x50 [ 383.689109] ? simple_attr_release+0x30/0x30 [ 383.689113] ? do_raw_spin_lock+0x119/0x1d0 [ 383.689116] ? rwlock_bug.part.0+0x60/0x60 [ 383.689119] ? do_raw_spin_unlock+0xa3/0x130 [ 383.689123] ? _raw_spin_unlock+0xa/0x10 [ 383.689128] ? alloc_fd+0x12e/0x290 [ 383.689132] do_sys_openat2+0x2f6/0x420 [ 383.689137] ? file_open_root+0x200/0x200 [ 383.689141] ? rwsem_wake.isra.0+0x100/0x100 [ 383.689146] do_sys_open+0x8a/0xe0 [ 383.689150] ? filp_open+0x50/0x50 [ 383.689153] ? asm_exc_page_fault+0x8/0x30 [ 383.689156] ? __x64_sys_openat+0x3e/0x60 [ 383.689159] do_syscall_64+0x45/0x80 [ 383.689163] entry_SYSCALL_64_after_hwframe+0x44/0xae Is this a know issue? Cheers, -- Luis
