On Wed, May 3, 2017 at 6:14 PM, Amir Goldstein <amir73il@xxxxxxxxx> wrote: > On Mon, May 1, 2017 at 4:41 PM, Amir Goldstein <amir73il@xxxxxxxxx> wrote: >> Sometimes it is interesting to know if an upper file is pure >> upper or a copy up target, and if it is a copy up target, it >> may be interesting to find the copy up origin. >> >> This will be used to preserve lower inode numbers across copy up. >> >> Store the lower inode file handle in upper inode extended attribute >> overlay.origin on copy up to use it later for these cases. >> Store the lower filesystem uuid along side the file handle, so we can >> validate that we are looking for the origin file in the original fs. >> >> On failure to encode lower file handle, store an invalid 'null' handle, >> so we can always use the overlay.origin xattr to distinguish between >> a copy up and a pure upper inode. >> >> If lower fs does not support NFS export ops or if not all layers are >> on the same fs, don't try to encode a lower file handle and store the >> 'null' handle instead. >> >> Signed-off-by: Amir Goldstein <amir73il@xxxxxxxxx> >> --- > [...] >> @@ -316,6 +417,14 @@ static int ovl_copy_up_locked(struct dentry *workdir, struct dentry *upperdir, >> if (err) >> goto out_cleanup; >> >> + /* >> + * Store identifier of lower inode in upper inode xattr to >> + * allow lookup of the copy up origin inode. >> + */ >> + err = ovl_set_origin(dentry, temp); > > calls setxattr - should be inside the temp->d_inode code block > No. it doesn't - sorry for the noise.
