Chirantan Ekbote b696d4feb2 fs: Don't use path-based operations ... There are no *at variants for the xattr syscalls so we were using the path-based variants by reading the /proc/self/fd symlink. While this symlink can track renames it cannot track if the user hard links the file to some other location and then unlinks the original location. In this case the symlink simply shows that the path was deleted even though the fd is still valid. To deal with this, stop using the path-based method. For regular files and directories, we can simply open them and then make the appropriate f{get,set,list,remove}xattr syscall. For non-regular files and directories we can emulate an *at syscall by changing the CWD to /proc and then making the path-based syscall via the self/fd path. Even though the symlink is no longer valid, manipulating the fd via this path still works. BUG=b:168689429 TEST=Create a file, set an xattr, hard link it to a new location, unlink the original, and then verify that {get,set}fattr still works on the new link Change-Id: Ic291f432b96f18e3e7ccbcf27737d5f8fd240a65 Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crosvm/+/2437684 Tested-by: kokoro <noreply+kokoro@google.com> Reviewed-by: Daniel Verkamp <dverkamp@chromium.org> Reviewed-by: Stephen Barber <smbarber@chromium.org> Commit-Queue: Chirantan Ekbote <chirantan@chromium.org>		2020-10-12 15:45:19 +00:00
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9p_device.policy
balloon_device.policy
block_device.policy
common_device.policy
cras_audio_device.policy
fs_device.policy	fs: Don't use path-based operations	2020-10-12 15:45:19 +00:00
gpu_device.policy
input_device.policy
net_device.policy
null_audio_device.policy
pmem_device.policy
rng_device.policy
serial.policy
tpm_device.policy
vhost_net_device.policy
vhost_vsock_device.policy
video_device.policy
wl_device.policy
xhci.policy