ovl: generalize the lower_layers[] array
Rename lower_layers[] array to layers[], extend its size by one and
initialize layers[0] with upper layer values. Lower layers are now
addressed with index 1..numlower. layers[0] is reserved even with lower
only overlay.
[SzM: replace ofs->numlower with ofs->numlayer, the latter's value is
incremented by one]
Signed-off-by: Amir Goldstein <[email protected]>
Signed-off-by: Miklos Szeredi <[email protected]>
diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c
index cce483a..374a076 100644
--- a/fs/overlayfs/super.c
+++ b/fs/overlayfs/super.c
@@ -224,13 +224,13 @@ static void ovl_free_fs(struct ovl_fs *ofs)
if (ofs->upperdir_locked)
ovl_inuse_unlock(ofs->upper_mnt->mnt_root);
mntput(ofs->upper_mnt);
- for (i = 0; i < ofs->numlower; i++) {
- iput(ofs->lower_layers[i].trap);
- mntput(ofs->lower_layers[i].mnt);
+ for (i = 1; i < ofs->numlayer; i++) {
+ iput(ofs->layers[i].trap);
+ mntput(ofs->layers[i].mnt);
}
for (i = 0; i < ofs->numlowerfs; i++)
free_anon_bdev(ofs->lower_fs[i].pseudo_dev);
- kfree(ofs->lower_layers);
+ kfree(ofs->layers);
kfree(ofs->lower_fs);
kfree(ofs->config.lowerdir);
@@ -1319,16 +1319,16 @@ static int ovl_get_fsid(struct ovl_fs *ofs, const struct path *path)
return ofs->numlowerfs;
}
-static int ovl_get_lower_layers(struct super_block *sb, struct ovl_fs *ofs,
- struct path *stack, unsigned int numlower)
+static int ovl_get_layers(struct super_block *sb, struct ovl_fs *ofs,
+ struct path *stack, unsigned int numlower)
{
int err;
unsigned int i;
err = -ENOMEM;
- ofs->lower_layers = kcalloc(numlower, sizeof(struct ovl_layer),
- GFP_KERNEL);
- if (ofs->lower_layers == NULL)
+ ofs->layers = kcalloc(numlower + 1, sizeof(struct ovl_layer),
+ GFP_KERNEL);
+ if (ofs->layers == NULL)
goto out;
ofs->lower_fs = kcalloc(numlower, sizeof(struct ovl_sb),
@@ -1336,6 +1336,12 @@ static int ovl_get_lower_layers(struct super_block *sb, struct ovl_fs *ofs,
if (ofs->lower_fs == NULL)
goto out;
+ /* idx 0 is reserved for upper fs even with lower only overlay */
+ ofs->layers[0].mnt = ofs->upper_mnt;
+ ofs->layers[0].idx = 0;
+ ofs->layers[0].fsid = 0;
+ ofs->numlayer = 1;
+
for (i = 0; i < numlower; i++) {
struct vfsmount *mnt;
struct inode *trap;
@@ -1369,15 +1375,15 @@ static int ovl_get_lower_layers(struct super_block *sb, struct ovl_fs *ofs,
*/
mnt->mnt_flags |= MNT_READONLY | MNT_NOATIME;
- ofs->lower_layers[ofs->numlower].trap = trap;
- ofs->lower_layers[ofs->numlower].mnt = mnt;
- ofs->lower_layers[ofs->numlower].idx = i + 1;
- ofs->lower_layers[ofs->numlower].fsid = fsid;
+ ofs->layers[ofs->numlayer].trap = trap;
+ ofs->layers[ofs->numlayer].mnt = mnt;
+ ofs->layers[ofs->numlayer].idx = ofs->numlayer;
+ ofs->layers[ofs->numlayer].fsid = fsid;
if (fsid) {
- ofs->lower_layers[ofs->numlower].fs =
+ ofs->layers[ofs->numlayer].fs =
&ofs->lower_fs[fsid - 1];
}
- ofs->numlower++;
+ ofs->numlayer++;
}
/*
@@ -1464,7 +1470,7 @@ static struct ovl_entry *ovl_get_lowerstack(struct super_block *sb,
goto out_err;
}
- err = ovl_get_lower_layers(sb, ofs, stack, numlower);
+ err = ovl_get_layers(sb, ofs, stack, numlower);
if (err)
goto out_err;
@@ -1475,7 +1481,7 @@ static struct ovl_entry *ovl_get_lowerstack(struct super_block *sb,
for (i = 0; i < numlower; i++) {
oe->lowerstack[i].dentry = dget(stack[i].dentry);
- oe->lowerstack[i].layer = &ofs->lower_layers[i];
+ oe->lowerstack[i].layer = &ofs->layers[i+1];
}
if (remote)
@@ -1556,9 +1562,9 @@ static int ovl_check_overlapping_layers(struct super_block *sb,
return err;
}
- for (i = 0; i < ofs->numlower; i++) {
+ for (i = 1; i < ofs->numlayer; i++) {
err = ovl_check_layer(sb, ofs,
- ofs->lower_layers[i].mnt->mnt_root,
+ ofs->layers[i].mnt->mnt_root,
"lowerdir");
if (err)
return err;
