qemu/tools/virtiofsd
Misono Tomohiro bdfd667883 virtiofsd: Fix xattr operations
Current virtiofsd has problems about xattr operations and
they does not work properly for directory/symlink/special file.

The fundamental cause is that virtiofsd uses openat() + f...xattr()
systemcalls for xattr operation but we should not open symlink/special
file in the daemon. Therefore the function is restricted.

Fix this problem by:
 1. during setup of each thread, call unshare(CLONE_FS)
 2. in xattr operations (i.e. lo_getxattr), if inode is not a regular
    file or directory, use fchdir(proc_loot_fd) + ...xattr() +
    fchdir(root.fd) instead of openat() + f...xattr()

    (Note: for a regular file/directory openat() + f...xattr()
     is still used for performance reason)

With this patch, xfstests generic/062 passes on virtiofs.

This fix is suggested by Miklos Szeredi and Stefan Hajnoczi.
The original discussion can be found here:
  https://www.redhat.com/archives/virtio-fs/2019-October/msg00046.html

Signed-off-by: Misono Tomohiro <misono.tomohiro@jp.fujitsu.com>
Message-Id: <20200227055927.24566-3-misono.tomohiro@jp.fujitsu.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2020-03-03 15:13:24 +00:00
..
50-qemu-virtiofsd.json.in virtiofsd: add vhost-user.json file 2020-01-23 16:41:36 +00:00
buffer.c virtiofsd: use fuse_buf_writev to replace fuse_buf_write for better performance 2020-01-23 16:41:37 +00:00
fuse_common.h virtiofsd: Parse flag FUSE_WRITE_KILL_PRIV 2020-01-23 16:41:37 +00:00
fuse_i.h virtiofsd: Remove fuse.h and struct fuse_module 2020-02-21 12:53:17 +00:00
fuse_log.c virtiofsd: Fix common header and define for QEMU builds 2020-01-23 16:41:36 +00:00
fuse_log.h virtiofsd: Format imported files to qemu style 2020-01-23 16:41:36 +00:00
fuse_lowlevel.c tools/virtiofsd/fuse_lowlevel: Fix fuse_out_header::error value 2020-02-21 12:53:17 +00:00
fuse_lowlevel.h virtiofsd: Remove fuse_req_getgroups 2020-02-10 17:24:43 +00:00
fuse_misc.h virtiofsd: support nanosecond resolution for file timestamp 2020-01-23 16:41:37 +00:00
fuse_opt.c virtiofsd: Fix common header and define for QEMU builds 2020-01-23 16:41:36 +00:00
fuse_opt.h virtiofsd: Format imported files to qemu style 2020-01-23 16:41:36 +00:00
fuse_signals.c virtiofsd: convert more fprintf and perror to use fuse log infra 2020-01-23 16:41:37 +00:00
fuse_virtio.c virtiofsd: Fix xattr operations 2020-03-03 15:13:24 +00:00
fuse_virtio.h virtiofsd: cleanup allocated resource in se 2020-01-23 16:41:37 +00:00
helper.c virtiofsd: Help message fix for 'seconds' 2020-02-21 12:53:17 +00:00
Makefile.objs virtiofsd: add seccomp whitelist 2020-01-23 16:41:37 +00:00
passthrough_helpers.h virtiofsd: Format imported files to qemu style 2020-01-23 16:41:36 +00:00
passthrough_ll.c virtiofsd: Fix xattr operations 2020-03-03 15:13:24 +00:00
seccomp.c virtiofsd: Fix xattr operations 2020-03-03 15:13:24 +00:00
seccomp.h virtiofsd: add --syslog command-line option 2020-01-23 16:41:37 +00:00