ovl: allow remote upper

No reason to prevent upper layer being a remote filesystem.  Do the
revalidation in that case, just as we already do for lower layers.

This lets virtiofs be used as upper layer, which appears to be a real use
case.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
This commit is contained in:
Miklos Szeredi 2020-03-17 15:04:22 +01:00
parent f428884456
commit bccece1ead
3 changed files with 9 additions and 4 deletions

View File

@ -845,8 +845,7 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry,
if (err)
goto out;
if (upperdentry && (upperdentry->d_flags & DCACHE_OP_REAL ||
unlikely(ovl_dentry_remote(upperdentry)))) {
if (upperdentry && upperdentry->d_flags & DCACHE_OP_REAL) {
dput(upperdentry);
err = -EREMOTE;
goto out;

View File

@ -135,9 +135,14 @@ static int ovl_dentry_revalidate_common(struct dentry *dentry,
unsigned int flags, bool weak)
{
struct ovl_entry *oe = dentry->d_fsdata;
struct dentry *upper;
unsigned int i;
int ret = 1;
upper = ovl_dentry_upper(dentry);
if (upper)
ret = ovl_revalidate_real(upper, flags, weak);
for (i = 0; ret > 0 && i < oe->numlower; i++) {
ret = ovl_revalidate_real(oe->lowerstack[i].dentry, flags,
weak);
@ -747,8 +752,7 @@ static int ovl_mount_dir(const char *name, struct path *path)
ovl_unescape(tmp);
err = ovl_mount_dir_noesc(tmp, path);
if (!err && (ovl_dentry_remote(path->dentry) ||
path->dentry->d_flags & DCACHE_OP_REAL)) {
if (!err && path->dentry->d_flags & DCACHE_OP_REAL) {
pr_err("filesystem on '%s' not supported as upperdir\n",
tmp);
path_put_init(path);

View File

@ -102,6 +102,8 @@ void ovl_dentry_update_reval(struct dentry *dentry, struct dentry *upperdentry,
struct ovl_entry *oe = OVL_E(dentry);
unsigned int i, flags = 0;
if (upperdentry)
flags |= upperdentry->d_flags;
for (i = 0; i < oe->numlower; i++)
flags |= oe->lowerstack[i].dentry->d_flags;