Right now ovl_inode stores inode pointer for lower inode. This helps
with quickly getting lower inode given overlay inode (ovl_inode_lower()).
Now with metadata only copy-up, we can have metacopy inode in middle
layer as well and inode containing data can be different from ->lower.
I need to be able to open the real file in ovl_open_realfile() and
for that I need to quickly find the lower data inode.
Hence store lower data inode also in ovl_inode. Also provide an
helper ovl_inode_lowerdata() to access this field.
Signed-off-by: Vivek Goyal <vgoyal@xxxxxxxxxx>
---
fs/overlayfs/export.c | 3 ++-
fs/overlayfs/inode.c | 5 +++--
fs/overlayfs/namei.c | 5 ++++-
fs/overlayfs/overlayfs.h | 6 ++++--
fs/overlayfs/ovl_entry.h | 1 +
fs/overlayfs/super.c | 4 +++-
fs/overlayfs/util.c | 10 +++++++++-
7 files changed, 26 insertions(+), 8 deletions(-)
diff --git a/fs/overlayfs/export.c b/fs/overlayfs/export.c
index e1f6546b6c84..d43d926ae68e 100644
--- a/fs/overlayfs/export.c
+++ b/fs/overlayfs/export.c
@@ -305,7 +305,8 @@ static struct dentry *ovl_obtain_alias(struct super_block *sb,
if (d_is_dir(upper ?: lower))
return ERR_PTR(-EIO);
- inode = ovl_get_inode(sb, dget(upper), lowerpath, index, !!lower, NULL);
+ inode = ovl_get_inode(sb, dget(upper), lowerpath, index, !!lower, NULL,
+ NULL);
if (IS_ERR(inode)) {
dput(upper);
return ERR_CAST(inode);
diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c
index 9d17f15480de..a6cd57741a1f 100644
--- a/fs/overlayfs/inode.c
+++ b/fs/overlayfs/inode.c
@@ -802,7 +802,8 @@ static bool ovl_hash_bylower(struct super_block *sb, struct dentry *upper,
struct inode *ovl_get_inode(struct super_block *sb, struct dentry *upperdentry,
struct ovl_path *lowerpath, struct dentry *index,
- unsigned int numlower, char *redirect)
+ unsigned int numlower, char *redirect,
+ struct dentry *lowerdata)
{
struct inode *realinode = upperdentry ? d_inode(upperdentry) : NULL;
struct inode *inode;
@@ -861,7 +862,7 @@ struct inode *ovl_get_inode(struct super_block *sb, struct dentry *upperdentry,
}
}
ovl_fill_inode(inode, realinode->i_mode, realinode->i_rdev, ino, fsid);
- ovl_inode_init(inode, upperdentry, lowerdentry);
+ ovl_inode_init(inode, upperdentry, lowerdentry, lowerdata);
if (upperdentry && ovl_is_impuredir(upperdentry))
ovl_set_flag(OVL_IMPURE, inode);
diff --git a/fs/overlayfs/namei.c b/fs/overlayfs/namei.c
index 682f0d402986..b25e32cf5916 100644
--- a/fs/overlayfs/namei.c
+++ b/fs/overlayfs/namei.c
@@ -1070,8 +1070,11 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry,
upperdentry = dget(index);
if (upperdentry || ctr) {
+ struct dentry *lowerdata = NULL;
+ if (ctr > 1 && !d.is_dir)
+ lowerdata = stack[ctr - 1].dentry;
inode = ovl_get_inode(dentry->d_sb, upperdentry, stack, index,
- ctr, upperredirect);
+ ctr, upperredirect, lowerdata);
err = PTR_ERR(inode);
if (IS_ERR(inode))
goto out_free_oe;
diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h
index 29b28ee50b0f..29c3498a7e61 100644
--- a/fs/overlayfs/overlayfs.h
+++ b/fs/overlayfs/overlayfs.h
@@ -234,6 +234,7 @@ struct dentry *ovl_dentry_real_data(struct dentry *dentry);
struct dentry *ovl_i_dentry_upper(struct inode *inode);
struct inode *ovl_inode_upper(struct inode *inode);
struct inode *ovl_inode_lower(struct inode *inode);
+struct inode *ovl_inode_lowerdata(struct inode *inode);
struct inode *ovl_inode_real(struct inode *inode);
struct ovl_dir_cache *ovl_dir_cache(struct inode *inode);
void ovl_set_dir_cache(struct inode *inode, struct ovl_dir_cache *cache);
@@ -253,7 +254,7 @@ bool ovl_redirect_dir(struct super_block *sb);
const char *ovl_dentry_get_redirect(struct dentry *dentry);
void ovl_dentry_set_redirect(struct dentry *dentry, const char *redirect);
void ovl_inode_init(struct inode *inode, struct dentry *upperdentry,
- struct dentry *lowerdentry);
+ struct dentry *lowerdentry, struct dentry *lowerdata);
void ovl_inode_update(struct inode *inode, struct dentry *upperdentry);
void ovl_dentry_version_inc(struct dentry *dentry, bool impurity);
u64 ovl_dentry_version_get(struct dentry *dentry);
@@ -373,7 +374,8 @@ struct inode *ovl_lookup_inode(struct super_block *sb, struct dentry *real,
bool is_upper);
struct inode *ovl_get_inode(struct super_block *sb, struct dentry *upperdentry,
struct ovl_path *lowerpath, struct dentry *index,
- unsigned int numlower, char *redirect);
+ unsigned int numlower, char *redirect,
+ struct dentry *lowerdata);
static inline void ovl_copyattr(struct inode *from, struct inode *to)
{
to->i_uid = from->i_uid;
diff --git a/fs/overlayfs/ovl_entry.h b/fs/overlayfs/ovl_entry.h
index da65118a0567..83e031e31ff9 100644
--- a/fs/overlayfs/ovl_entry.h
+++ b/fs/overlayfs/ovl_entry.h
@@ -97,6 +97,7 @@ struct ovl_inode {
struct inode vfs_inode;
struct dentry *__upperdentry;
struct inode *lower;
+ struct inode *lowerdata;
/* synchronize copy up and more */
struct mutex lock;
diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c
index 6f5e7ccc3d8f..b81ec9d22ac5 100644
--- a/fs/overlayfs/super.c
+++ b/fs/overlayfs/super.c
@@ -182,6 +182,7 @@ static struct inode *ovl_alloc_inode(struct super_block *sb)
oi->flags = 0;
oi->__upperdentry = NULL;
oi->lower = NULL;
+ oi->lowerdata = NULL;
mutex_init(&oi->lock);
return &oi->vfs_inode;
@@ -200,6 +201,7 @@ static void ovl_destroy_inode(struct inode *inode)
dput(oi->__upperdentry);
iput(oi->lower);
+ iput(oi->lowerdata);
kfree(oi->redirect);
ovl_dir_cache_free(inode);
mutex_destroy(&oi->lock);
@@ -1505,7 +1507,7 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent)
ovl_dentry_set_flag(OVL_E_CONNECTED, root_dentry);
ovl_set_upperdata(d_inode(root_dentry));
ovl_inode_init(d_inode(root_dentry), upperpath.dentry,
- ovl_dentry_lower(root_dentry));
+ ovl_dentry_lower(root_dentry), NULL);
sb->s_root = root_dentry;
diff --git a/fs/overlayfs/util.c b/fs/overlayfs/util.c
index 338de6bdae07..58aa14a02bb0 100644
--- a/fs/overlayfs/util.c
+++ b/fs/overlayfs/util.c
@@ -262,6 +262,12 @@ struct inode *ovl_inode_real(struct inode *inode)
return ovl_inode_upper(inode) ?: ovl_inode_lower(inode);
}
+/* Return inode which containers lower data. Do not return metacopy */
+struct inode *ovl_inode_lowerdata(struct inode *inode)
+{
+ return OVL_I(inode)->lowerdata ?: ovl_inode_lower(inode);
+}
+
struct ovl_dir_cache *ovl_dir_cache(struct inode *inode)
{
@@ -396,7 +402,7 @@ void ovl_dentry_set_redirect(struct dentry *dentry, const char *redirect)
}
void ovl_inode_init(struct inode *inode, struct dentry *upperdentry,
- struct dentry *lowerdentry)
+ struct dentry *lowerdentry, struct dentry *lowerdata)
{
struct inode *realinode = d_inode(upperdentry ?: lowerdentry);
@@ -404,6 +410,8 @@ void ovl_inode_init(struct inode *inode, struct dentry *upperdentry,
OVL_I(inode)->__upperdentry = upperdentry;
if (lowerdentry)
OVL_I(inode)->lower = igrab(d_inode(lowerdentry));
+ if (lowerdata)
+ OVL_I(inode)->lowerdata = igrab(d_inode(lowerdata));
ovl_copyattr(realinode, inode);
ovl_copyflags(realinode, inode);
--
2.13.6
--
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