• Amir Goldstein's avatar
    ovl: do not try to reconnect a disconnected origin dentry · 8a22efa1
    Amir Goldstein authored
    On lookup of non directory, we try to decode the origin file handle
    stored in upper inode. The origin file handle is supposed to be decoded
    to a disconnected non-dir dentry, which is fine, because we only need
    the lower inode of a copy up origin.
    
    However, if the origin file handle somehow turns out to be a directory
    we pay the expensive cost of reconnecting the directory dentry, only to
    get a mismatch file type and drop the dentry.
    
    Optimize this case by explicitly opting out of reconnecting the dentry.
    Opting-out of reconnect is done by passing a NULL acceptable callback
    to exportfs_decode_fh().
    
    While the case described above is a strange corner case that does not
    really need to be optimized, the API added for this optimization will
    be used by a following patch to optimize a more common case of decoding
    an overlayfs file handle.
    Signed-off-by: Amir Goldstein's avatarAmir Goldstein <amir73il@gmail.com>
    Signed-off-by: default avatarMiklos Szeredi <mszeredi@redhat.com>
    8a22efa1
expfs.c 14.1 KB