We would like to be able to set type flags during lookup (i.e. INDEX)
instead of deducing them from other state information.
Store the type value in ovl_entry and update the UPPER/MERGE/ORIGIN
flags when needed, so ovl_path_type() just returns the stored value.
Signed-off-by: Amir Goldstein <amir73il@xxxxxxxxx>
---
fs/overlayfs/namei.c | 1 +
fs/overlayfs/overlayfs.h | 1 +
fs/overlayfs/ovl_entry.h | 3 +++
fs/overlayfs/super.c | 1 +
fs/overlayfs/util.c | 20 +++++++++++++++++---
5 files changed, 23 insertions(+), 3 deletions(-)
diff --git a/fs/overlayfs/namei.c b/fs/overlayfs/namei.c
index 400ad20ceb15..6e827a2b1cf0 100644
--- a/fs/overlayfs/namei.c
+++ b/fs/overlayfs/namei.c
@@ -548,6 +548,7 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry,
kfree(stack);
kfree(d.redirect);
dentry->d_fsdata = oe;
+ ovl_update_type(dentry, d.is_dir);
d_add(dentry, inode);
return NULL;
diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h
index 612b6e45c64b..09852c879046 100644
--- a/fs/overlayfs/overlayfs.h
+++ b/fs/overlayfs/overlayfs.h
@@ -199,6 +199,7 @@ struct ovl_entry *ovl_alloc_entry(unsigned int numlower);
bool ovl_dentry_remote(struct dentry *dentry);
bool ovl_dentry_weird(struct dentry *dentry);
enum ovl_path_type ovl_path_type(struct dentry *dentry);
+void ovl_update_type(struct dentry *dentry, bool is_dir);
void ovl_path_upper(struct dentry *dentry, struct path *path);
void ovl_path_lower(struct dentry *dentry, struct path *path);
enum ovl_path_type ovl_path_real(struct dentry *dentry, struct path *path);
diff --git a/fs/overlayfs/ovl_entry.h b/fs/overlayfs/ovl_entry.h
index ddd4b0a874a9..e94fa2638faf 100644
--- a/fs/overlayfs/ovl_entry.h
+++ b/fs/overlayfs/ovl_entry.h
@@ -40,6 +40,8 @@ struct ovl_fs {
struct super_block *same_sb;
};
+enum ovl_path_type;
+
/* private information held for every overlayfs dentry */
struct ovl_entry {
struct dentry *__upperdentry;
@@ -54,6 +56,7 @@ struct ovl_entry {
};
struct rcu_head rcu;
};
+ enum ovl_path_type __type;
unsigned numlower;
struct path lowerstack[];
};
diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c
index a9de7d1893e2..c72d79749652 100644
--- a/fs/overlayfs/super.c
+++ b/fs/overlayfs/super.c
@@ -1105,6 +1105,7 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent)
kfree(stack);
root_dentry->d_fsdata = oe;
+ ovl_update_type(root_dentry, true);
realinode = d_inode(ovl_dentry_real(root_dentry));
ovl_inode_init(d_inode(root_dentry), realinode, !!upperpath.dentry);
diff --git a/fs/overlayfs/util.c b/fs/overlayfs/util.c
index 8e2f308056f1..8e743c76aa03 100644
--- a/fs/overlayfs/util.c
+++ b/fs/overlayfs/util.c
@@ -91,24 +91,37 @@ bool ovl_dentry_weird(struct dentry *dentry)
enum ovl_path_type ovl_path_type(struct dentry *dentry)
{
struct ovl_entry *oe = dentry->d_fsdata;
+
+ return READ_ONCE(oe->__type);
+}
+
+void ovl_update_type(struct dentry *dentry, bool is_dir)
+{
+ struct ovl_entry *oe = dentry->d_fsdata;
enum ovl_path_type type = 0;
+ spin_lock(&dentry->d_lock);
if (oe->__upperdentry) {
type = __OVL_PATH_UPPER;
-
/*
* Non-dir dentry can hold lower dentry of its copy up origin.
*/
if (oe->numlower) {
type |= __OVL_PATH_ORIGIN;
- if (d_is_dir(dentry))
+ if (is_dir)
type |= __OVL_PATH_MERGE;
}
} else {
if (oe->numlower > 1)
type |= __OVL_PATH_MERGE;
}
- return type;
+
+ /*
+ * The UPPER/MERGE/ORIGIN flags can never be cleared during the
+ * lifetime of a dentry, so don't bother masking them out first.
+ */
+ oe->__type |= type;
+ spin_unlock(&dentry->d_lock);
}
void ovl_path_upper(struct dentry *dentry, struct path *path)
@@ -243,6 +256,7 @@ void ovl_dentry_update(struct dentry *dentry, struct dentry *upperdentry)
*/
smp_wmb();
oe->__upperdentry = upperdentry;
+ ovl_update_type(dentry, d_is_dir(dentry));
}
void ovl_inode_init(struct inode *inode, struct inode *realinode, bool is_upper)
--
2.7.4
--
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