return ovl_check_dir_xattr(dentry, OVL_XATTR_OPAQUE);
}
+static struct dentry *ovl_lookup_positive_unlocked(const char *name,
+ struct dentry *base, int len,
+ bool drop_negative)
+{
+ struct dentry *ret = lookup_one_len_unlocked(name, base, len);
+
+ if (!IS_ERR(ret) && d_flags_negative(smp_load_acquire(&ret->d_flags))) {
+ if (drop_negative && ret->d_lockref.count == 1) {
+ spin_lock(&ret->d_lock);
+ /* Recheck condition under lock */
+ if (d_is_negative(ret) && ret->d_lockref.count == 1)
+ __d_drop(ret);
+ spin_unlock(&ret->d_lock);
+ }
+ dput(ret);
+ ret = ERR_PTR(-ENOENT);
+ }
+ return ret;
+}
+
static int ovl_lookup_single(struct dentry *base, struct ovl_lookup_data *d,
const char *name, unsigned int namelen,
size_t prelen, const char *post,
- struct dentry **ret)
+ struct dentry **ret, bool drop_negative)
{
struct dentry *this;
int err;
bool last_element = !post[0];
- this = lookup_positive_unlocked(name, base, namelen);
+ this = ovl_lookup_positive_unlocked(name, base, namelen, drop_negative);
if (IS_ERR(this)) {
err = PTR_ERR(this);
this = NULL;
}
static int ovl_lookup_layer(struct dentry *base, struct ovl_lookup_data *d,
- struct dentry **ret)
+ struct dentry **ret, bool drop_negative)
{
/* Counting down from the end, since the prefix can change */
size_t rem = d->name.len - 1;
if (d->name.name[0] != '/')
return ovl_lookup_single(base, d, d->name.name, d->name.len,
- 0, "", ret);
+ 0, "", ret, drop_negative);
while (!IS_ERR_OR_NULL(base) && d_can_lookup(base)) {
const char *s = d->name.name + d->name.len - rem;
return -EIO;
err = ovl_lookup_single(base, d, s, thislen,
- d->name.len - rem, next, &base);
+ d->name.len - rem, next, &base,
+ drop_negative);
dput(dentry);
if (err)
return err;
}
static int ovl_check_origin(struct ovl_fs *ofs, struct dentry *upperdentry,
- struct ovl_path **stackp, unsigned int *ctrp)
+ struct ovl_path **stackp)
{
struct ovl_fh *fh = ovl_get_fh(upperdentry, OVL_XATTR_ORIGIN);
int err;
return err;
}
- if (WARN_ON(*ctrp))
- return -EIO;
-
- *ctrp = 1;
return 0;
}
if (IS_ERR_OR_NULL(fh))
return ERR_CAST(fh);
- upper = ovl_decode_real_fh(fh, ofs->upper_mnt, true);
+ upper = ovl_decode_real_fh(fh, ovl_upper_mnt(ofs), true);
kfree(fh);
if (IS_ERR_OR_NULL(upper))
return upper;
}
-/* Is this a leftover from create/whiteout of directory index entry? */
-static bool ovl_is_temp_index(struct dentry *index)
-{
- return index->d_name.name[0] == '#';
-}
-
/*
* Verify that an index entry name matches the origin file handle stored in
* OVL_XATTR_ORIGIN and that origin file handle can be decoded to lower path.
if (!d_inode(index))
return 0;
- /* Cleanup leftover from index create/cleanup attempt */
- err = -ESTALE;
- if (ovl_is_temp_index(index))
- goto fail;
-
err = -EINVAL;
if (index->d_name.len < sizeof(struct ovl_fb)*2)
goto fail;
struct dentry *this;
unsigned int i;
int err;
- bool metacopy = false;
+ bool uppermetacopy = false;
struct ovl_lookup_data d = {
.sb = dentry->d_sb,
.name = dentry->d_name,
old_cred = ovl_override_creds(dentry->d_sb);
upperdir = ovl_dentry_upper(dentry->d_parent);
if (upperdir) {
- err = ovl_lookup_layer(upperdir, &d, &upperdentry);
+ err = ovl_lookup_layer(upperdir, &d, &upperdentry, true);
if (err)
goto out;
goto out;
}
if (upperdentry && !d.is_dir) {
- unsigned int origin_ctr = 0;
-
/*
* Lookup copy up origin by decoding origin file handle.
* We may get a disconnected dentry, which is fine,
* number - it's the same as if we held a reference
* to a dentry in lower layer that was moved under us.
*/
- err = ovl_check_origin(ofs, upperdentry, &origin_path,
- &origin_ctr);
+ err = ovl_check_origin(ofs, upperdentry, &origin_path);
if (err)
goto out_put_upper;
if (d.metacopy)
- metacopy = true;
+ uppermetacopy = true;
}
if (d.redirect) {
else
d.last = lower.layer->idx == roe->numlower;
- err = ovl_lookup_layer(lower.dentry, &d, &this);
+ err = ovl_lookup_layer(lower.dentry, &d, &this, false);
if (err)
goto out_put;
if (!this)
continue;
+ if ((uppermetacopy || d.metacopy) && !ofs->config.metacopy) {
+ err = -EPERM;
+ pr_warn_ratelimited("refusing to follow metacopy origin for (%pd2)\n", dentry);
+ goto out_put;
+ }
+
/*
* If no origin fh is stored in upper of a merge dir, store fh
* of lower dir and set upper parent "impure".
origin = this;
}
- if (d.metacopy)
- metacopy = true;
- /*
- * Do not store intermediate metacopy dentries in chain,
- * except top most lower metacopy dentry
- */
if (d.metacopy && ctr) {
+ /*
+ * Do not store intermediate metacopy dentries in
+ * lower chain, except top most lower metacopy dentry.
+ * Continue the loop so that if there is an absolute
+ * redirect on this dentry, poe can be reset to roe.
+ */
dput(this);
- continue;
+ this = NULL;
+ } else {
+ stack[ctr].dentry = this;
+ stack[ctr].layer = lower.layer;
+ ctr++;
}
- stack[ctr].dentry = this;
- stack[ctr].layer = lower.layer;
- ctr++;
-
/*
* Following redirects can have security consequences: it's like
* a symlink into the lower layer without the permission checks.
}
}
- if (metacopy) {
- /*
- * Found a metacopy dentry but did not find corresponding
- * data dentry
- */
- if (d.metacopy) {
- err = -EIO;
- goto out_put;
- }
-
- err = -EPERM;
- if (!ofs->config.metacopy) {
- pr_warn_ratelimited("refusing to follow metacopy origin for (%pd2)\n",
- dentry);
- goto out_put;
- }
+ /*
+ * For regular non-metacopy upper dentries, there is no lower
+ * path based lookup, hence ctr will be zero. If a dentry is found
+ * using ORIGIN xattr on upper, install it in stack.
+ *
+ * For metacopy dentry, path based lookup will find lower dentries.
+ * Just make sure a corresponding data dentry has been found.
+ */
+ if (d.metacopy || (uppermetacopy && !ctr)) {
+ err = -EIO;
+ goto out_put;
} else if (!d.is_dir && upperdentry && !ctr && origin_path) {
if (WARN_ON(stack != NULL)) {
err = -EIO;
}
stack = origin_path;
ctr = 1;
+ origin = origin_path->dentry;
origin_path = NULL;
}
/*
- * Lookup index by lower inode and verify it matches upper inode.
- * We only trust dir index if we verified that lower dir matches
- * origin, otherwise dir index entries may be inconsistent and we
- * ignore them.
+ * Always lookup index if there is no-upperdentry.
*
- * For non-dir upper metacopy dentry, we already set "origin" if we
- * verified that lower matched upper origin. If upper origin was
- * not present (because lower layer did not support fh encode/decode),
- * or indexing is not enabled, do not set "origin" and skip looking up
- * index. This case should be handled in same way as a non-dir upper
- * without ORIGIN is handled.
+ * For the case of upperdentry, we have set origin by now if it
+ * needed to be set. There are basically three cases.
+ *
+ * For directories, lookup index by lower inode and verify it matches
+ * upper inode. We only trust dir index if we verified that lower dir
+ * matches origin, otherwise dir index entries may be inconsistent
+ * and we ignore them.
+ *
+ * For regular upper, we already set origin if upper had ORIGIN
+ * xattr. There is no verification though as there is no path
+ * based dentry lookup in lower in this case.
+ *
+ * For metacopy upper, we set a verified origin already if index
+ * is enabled and if upper had an ORIGIN xattr.
*
- * Always lookup index of non-dir non-metacopy and non-upper.
*/
- if (ctr && (!upperdentry || (!d.is_dir && !metacopy)))
+ if (!upperdentry && ctr)
origin = stack[0].dentry;
if (origin && ovl_indexdir(dentry->d_sb) &&
upperredirect = NULL;
goto out_free_oe;
}
+ err = ovl_check_metacopy_xattr(upperdentry);
+ if (err < 0)
+ goto out_free_oe;
+ uppermetacopy = err;
}
if (upperdentry || ctr) {
err = PTR_ERR(inode);
if (IS_ERR(inode))
goto out_free_oe;
+ if (upperdentry && !uppermetacopy)
+ ovl_set_flag(OVL_UPPERDATA, inode);
}
ovl_dentry_update_reval(dentry, upperdentry,
projects / linux-2.6-microblaze.git / blobdiff