On Mon, May 07, 2018 at 09:59:00PM +0300, Amir Goldstein wrote:
> On Mon, May 7, 2018 at 8:40 PM, Vivek Goyal <vgoyal@xxxxxxxxxx> wrote:
> > 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>
>
> Reviewed-by: Amir Goldstein <amir73il@xxxxxxxxx>
>
> After fixing some nits below
Here is the new version of patch.
Subject: ovl: Store lower data inode in ovl_inode
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>
Reviewed-by: Amir Goldstein <amir73il@xxxxxxxxx>
---
fs/overlayfs/inode.c | 2 +-
fs/overlayfs/namei.c | 2 ++
fs/overlayfs/overlayfs.h | 3 ++-
fs/overlayfs/ovl_entry.h | 6 +++++-
fs/overlayfs/super.c | 8 ++++++--
fs/overlayfs/util.c | 10 +++++++++-
6 files changed, 25 insertions(+), 6 deletions(-)
Index: rhvgoyal-linux/fs/overlayfs/ovl_entry.h
===================================================================
--- rhvgoyal-linux.orig/fs/overlayfs/ovl_entry.h 2018-05-07 16:48:20.399350785 -0400
+++ rhvgoyal-linux/fs/overlayfs/ovl_entry.h 2018-05-07 16:55:48.911350785 -0400
@@ -90,7 +90,10 @@ static inline struct ovl_entry *OVL_E(st
}
struct ovl_inode {
- struct ovl_dir_cache *cache;
+ union {
+ struct ovl_dir_cache *cache; /* directory */
+ struct inode *lowerdata; /* regular file */
+ };
const char *redirect;
u64 version;
unsigned long flags;
@@ -108,6 +111,7 @@ struct ovl_inode_params {
struct dentry *index;
unsigned int numlower;
char *redirect;
+ struct dentry *lowerdata;
};
static inline struct ovl_inode *OVL_I(struct inode *inode)
Index: rhvgoyal-linux/fs/overlayfs/inode.c
===================================================================
--- rhvgoyal-linux.orig/fs/overlayfs/inode.c 2018-05-07 16:48:20.400350785 -0400
+++ rhvgoyal-linux/fs/overlayfs/inode.c 2018-05-07 16:55:01.997350785 -0400
@@ -856,7 +856,7 @@ struct inode *ovl_get_inode(struct super
}
}
ovl_fill_inode(inode, realinode->i_mode, realinode->i_rdev, ino, fsid);
- ovl_inode_init(inode, upperdentry, lowerdentry);
+ ovl_inode_init(inode, upperdentry, lowerdentry, oip->lowerdata);
if (upperdentry && ovl_is_impuredir(upperdentry))
ovl_set_flag(OVL_IMPURE, inode);
Index: rhvgoyal-linux/fs/overlayfs/util.c
===================================================================
--- rhvgoyal-linux.orig/fs/overlayfs/util.c 2018-05-07 16:48:20.402350785 -0400
+++ rhvgoyal-linux/fs/overlayfs/util.c 2018-05-07 16:55:02.683350785 -0400
@@ -262,6 +262,12 @@ struct inode *ovl_inode_real(struct inod
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 dent
}
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,
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);
Index: rhvgoyal-linux/fs/overlayfs/overlayfs.h
===================================================================
--- rhvgoyal-linux.orig/fs/overlayfs/overlayfs.h 2018-05-07 16:48:20.403350785 -0400
+++ rhvgoyal-linux/fs/overlayfs/overlayfs.h 2018-05-07 16:55:02.683350785 -0400
@@ -234,6 +234,7 @@ struct dentry *ovl_dentry_realdata(struc
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
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_dir_modified(struct dentry *dentry, bool impurity);
u64 ovl_dentry_version_get(struct dentry *dentry);
Index: rhvgoyal-linux/fs/overlayfs/super.c
===================================================================
--- rhvgoyal-linux.orig/fs/overlayfs/super.c 2018-05-07 16:48:20.405350785 -0400
+++ rhvgoyal-linux/fs/overlayfs/super.c 2018-05-07 16:55:02.443350785 -0400
@@ -187,6 +187,7 @@ static struct inode *ovl_alloc_inode(str
oi->flags = 0;
oi->__upperdentry = NULL;
oi->lower = NULL;
+ oi->lowerdata = NULL;
mutex_init(&oi->lock);
return &oi->vfs_inode;
@@ -205,8 +206,11 @@ static void ovl_destroy_inode(struct ino
dput(oi->__upperdentry);
iput(oi->lower);
+ if (S_ISDIR(inode->i_mode))
+ ovl_dir_cache_free(inode);
+ else
+ iput(oi->lowerdata);
kfree(oi->redirect);
- ovl_dir_cache_free(inode);
mutex_destroy(&oi->lock);
call_rcu(&inode->i_rcu, ovl_i_callback);
@@ -1510,7 +1514,7 @@ static int ovl_fill_super(struct super_b
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;
Index: rhvgoyal-linux/fs/overlayfs/namei.c
===================================================================
--- rhvgoyal-linux.orig/fs/overlayfs/namei.c 2018-05-07 16:48:23.302350785 -0400
+++ rhvgoyal-linux/fs/overlayfs/namei.c 2018-05-07 16:55:02.379350785 -0400
@@ -1082,6 +1082,8 @@ struct dentry *ovl_lookup(struct inode *
.index = index,
.numlower = ctr,
.redirect = upperredirect,
+ .lowerdata = (ctr > 1 && !d.is_dir) ?
+ stack[ctr - 1].dentry : NULL,
};
inode = ovl_get_inode(dentry->d_sb, &oip);
--
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