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path: root/fs/overlayfs/namei.c
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Diffstat (limited to 'fs/overlayfs/namei.c')
-rw-r--r--fs/overlayfs/namei.c67
1 files changed, 48 insertions, 19 deletions
diff --git a/fs/overlayfs/namei.c b/fs/overlayfs/namei.c
index 70fcfcc684cc..2dba29eadde6 100644
--- a/fs/overlayfs/namei.c
+++ b/fs/overlayfs/namei.c
@@ -56,6 +56,15 @@ static int ovl_check_redirect(struct dentry *dentry, struct ovl_lookup_data *d,
if (s == next)
goto invalid;
}
+ /*
+ * One of the ancestor path elements in an absolute path
+ * lookup in ovl_lookup_layer() could have been opaque and
+ * that will stop further lookup in lower layers (d->stop=true)
+ * But we have found an absolute redirect in decendant path
+ * element and that should force continue lookup in lower
+ * layers (reset d->stop).
+ */
+ d->stop = false;
} else {
if (strchr(buf, '/') != NULL)
goto invalid;
@@ -171,7 +180,8 @@ invalid:
goto out;
}
-struct dentry *ovl_decode_fh(struct ovl_fh *fh, struct vfsmount *mnt)
+struct dentry *ovl_decode_real_fh(struct ovl_fh *fh, struct vfsmount *mnt,
+ bool connected)
{
struct dentry *real;
int bytes;
@@ -186,7 +196,7 @@ struct dentry *ovl_decode_fh(struct ovl_fh *fh, struct vfsmount *mnt)
bytes = (fh->len - offsetof(struct ovl_fh, fid));
real = exportfs_decode_fh(mnt, (struct fid *)fh->fid,
bytes >> 2, (int)fh->type,
- ovl_acceptable, mnt);
+ connected ? ovl_acceptable : NULL, mnt);
if (IS_ERR(real)) {
/*
* Treat stale file handle to lower file as "origin unknown".
@@ -220,6 +230,7 @@ static int ovl_lookup_single(struct dentry *base, struct ovl_lookup_data *d,
{
struct dentry *this;
int err;
+ bool last_element = !post[0];
this = lookup_one_len_unlocked(name, base, namelen);
if (IS_ERR(this)) {
@@ -245,11 +256,23 @@ static int ovl_lookup_single(struct dentry *base, struct ovl_lookup_data *d,
d->stop = true;
if (d->is_dir)
goto put_and_out;
+
+ /*
+ * NB: handle failure to lookup non-last element when non-dir
+ * redirects become possible
+ */
+ WARN_ON(!last_element);
goto out;
}
- d->is_dir = true;
- if (!d->last && ovl_is_opaquedir(this)) {
- d->stop = d->opaque = true;
+ if (last_element)
+ d->is_dir = true;
+ if (d->last)
+ goto out;
+
+ if (ovl_is_opaquedir(this)) {
+ d->stop = true;
+ if (last_element)
+ d->opaque = true;
goto out;
}
err = ovl_check_redirect(this, d, prelen, post);
@@ -310,14 +333,15 @@ static int ovl_lookup_layer(struct dentry *base, struct ovl_lookup_data *d,
}
-int ovl_check_origin_fh(struct ovl_fs *ofs, struct ovl_fh *fh,
+int ovl_check_origin_fh(struct ovl_fs *ofs, struct ovl_fh *fh, bool connected,
struct dentry *upperdentry, struct ovl_path **stackp)
{
struct dentry *origin = NULL;
int i;
for (i = 0; i < ofs->numlower; i++) {
- origin = ovl_decode_fh(fh, ofs->lower_layers[i].mnt);
+ origin = ovl_decode_real_fh(fh, ofs->lower_layers[i].mnt,
+ connected);
if (origin)
break;
}
@@ -361,7 +385,7 @@ static int ovl_check_origin(struct ovl_fs *ofs, struct dentry *upperdentry,
if (IS_ERR_OR_NULL(fh))
return PTR_ERR(fh);
- err = ovl_check_origin_fh(ofs, fh, upperdentry, stackp);
+ err = ovl_check_origin_fh(ofs, fh, false, upperdentry, stackp);
kfree(fh);
if (err) {
@@ -415,7 +439,7 @@ int ovl_verify_set_fh(struct dentry *dentry, const char *name,
struct ovl_fh *fh;
int err;
- fh = ovl_encode_fh(real, is_upper);
+ fh = ovl_encode_real_fh(real, is_upper);
err = PTR_ERR(fh);
if (IS_ERR(fh))
goto fail;
@@ -451,7 +475,7 @@ struct dentry *ovl_index_upper(struct ovl_fs *ofs, struct dentry *index)
if (IS_ERR_OR_NULL(fh))
return ERR_CAST(fh);
- upper = ovl_decode_fh(fh, ofs->upper_mnt);
+ upper = ovl_decode_real_fh(fh, ofs->upper_mnt, true);
kfree(fh);
if (IS_ERR_OR_NULL(upper))
@@ -558,7 +582,7 @@ int ovl_verify_index(struct ovl_fs *ofs, struct dentry *index)
/* Check if non-dir index is orphan and don't warn before cleaning it */
if (!d_is_dir(index) && d_inode(index)->i_nlink == 1) {
- err = ovl_check_origin_fh(ofs, fh, index, &stack);
+ err = ovl_check_origin_fh(ofs, fh, false, index, &stack);
if (err)
goto fail;
@@ -619,7 +643,7 @@ int ovl_get_index_name(struct dentry *origin, struct qstr *name)
struct ovl_fh *fh;
int err;
- fh = ovl_encode_fh(origin, false);
+ fh = ovl_encode_real_fh(origin, false);
if (IS_ERR(fh))
return PTR_ERR(fh);
@@ -815,7 +839,7 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry,
.is_dir = false,
.opaque = false,
.stop = false,
- .last = !poe->numlower,
+ .last = ofs->config.redirect_follow ? false : !poe->numlower,
.redirect = NULL,
};
@@ -873,7 +897,11 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry,
for (i = 0; !d.stop && i < poe->numlower; i++) {
struct ovl_path lower = poe->lowerstack[i];
- d.last = i == poe->numlower - 1;
+ if (!ofs->config.redirect_follow)
+ d.last = i == poe->numlower - 1;
+ else
+ d.last = lower.layer->idx == roe->numlower;
+
err = ovl_lookup_layer(lower.dentry, &d, &this);
if (err)
goto out_put;
@@ -976,17 +1004,18 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry,
upperdentry = dget(index);
if (upperdentry || ctr) {
- if (ctr)
- origin = stack[0].dentry;
- inode = ovl_get_inode(dentry->d_sb, upperdentry, origin, index,
+ inode = ovl_get_inode(dentry->d_sb, upperdentry, stack, index,
ctr);
err = PTR_ERR(inode);
if (IS_ERR(inode))
goto out_free_oe;
+ /*
+ * NB: handle redirected hard links when non-dir redirects
+ * become possible
+ */
+ WARN_ON(OVL_I(inode)->redirect);
OVL_I(inode)->redirect = upperredirect;
- if (index)
- ovl_set_flag(OVL_INDEX, inode);
}
revert_creds(old_cred);
generated by cgit v1.2.3 (git 2.39.1) at 2025-01-22 02:45:27 +0100