[PATCH 6.4 425/800] ovl: update of dentry revalidate flags after copy up

Greg Kroah-Hartman
2023-07-16T20:13:06Z

From: Amir Goldstein <amir73il@gmail.com>

[ Upstream commit b07d5cc93e1b28df47a72c519d09d0a836043613 ]

After copy up, we may need to update d_flags if upper dentry is on a
remote fs and lower dentries are not.

Add helpers to allow incremental update of the revalidate flags.

Fixes: bccece1ead36 ("ovl: allow remote upper")
Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/overlayfs/copy_up.c | 2 ++
fs/overlayfs/dir.c | 3 +--
fs/overlayfs/export.c | 3 +--
fs/overlayfs/namei.c | 3 +--
fs/overlayfs/overlayfs.h | 6 ++++--
fs/overlayfs/super.c | 2 +-
fs/overlayfs/util.c | 24 ++++++++++++++++++++----
7 files changed, 30 insertions(+), 13 deletions(-)

diff --git a/fs/overlayfs/copy_up.c b/fs/overlayfs/copy_up.c
index f658cc8ea4920..95dce240ba17a 100644
--- a/fs/overlayfs/copy_up.c
+++ b/fs/overlayfs/copy_up.c
@@ -575,6 +575,7 @@ static int ovl_link_up(struct ovl_copy_up_ctx *c)
/* Restore timestamps on parent (best effort) */
ovl_set_timestamps(ofs, upperdir, &c->pstat);
ovl_dentry_set_upper_alias(c->dentry);
+ ovl_dentry_update_reval(c->dentry, upper);
}
}
inode_unlock(udir);
@@ -894,6 +895,7 @@ static int ovl_do_copy_up(struct ovl_copy_up_ctx *c)
inode_unlock(udir);

ovl_dentry_set_upper_alias(c->dentry);
+ ovl_dentry_update_reval(c->dentry, ovl_dentry_upper(c->dentry));
}

out:
diff --git a/fs/overlayfs/dir.c b/fs/overlayfs/dir.c
index fc25fb95d5fc0..9be52d8013c83 100644
--- a/fs/overlayfs/dir.c
+++ b/fs/overlayfs/dir.c
@@ -269,8 +269,7 @@ static int ovl_instantiate(struct dentry *dentry, struct inode *inode,

ovl_dir_modified(dentry->d_parent, false);
ovl_dentry_set_upper_alias(dentry);
- ovl_dentry_update_reval(dentry, newdentry,
- DCACHE_OP_REVALIDATE | DCACHE_OP_WEAK_REVALIDATE);
+ ovl_dentry_init_reval(dentry, newdentry);

if (!hardlink) {
/*
diff --git a/fs/overlayfs/export.c b/fs/overlayfs/export.c
index defd4e231ad2c..5c36fb3a7bab1 100644
--- a/fs/overlayfs/export.c
+++ b/fs/overlayfs/export.c
@@ -326,8 +326,7 @@ static struct dentry *ovl_obtain_alias(struct super_block *sb,
if (upper_alias)
ovl_dentry_set_upper_alias(dentry);

- ovl_dentry_update_reval(dentry, upper,
- DCACHE_OP_REVALIDATE | DCACHE_OP_WEAK_REVALIDATE);
+ ovl_dentry_init_reval(dentry, upper);

return d_instantiate_anon(dentry, inode);

diff --git a/fs/overlayfs/namei.c b/fs/overlayfs/namei.c
index cfb3420b7df0e..100a492d2b2a6 100644
--- a/fs/overlayfs/namei.c
+++ b/fs/overlayfs/namei.c
@@ -1122,8 +1122,7 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry,
ovl_set_flag(OVL_UPPERDATA, inode);
}

- ovl_dentry_update_reval(dentry, upperdentry,
- DCACHE_OP_REVALIDATE | DCACHE_OP_WEAK_REVALIDATE);
+ ovl_dentry_init_reval(dentry, upperdentry);

revert_creds(old_cred);
if (origin_path) {
diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h
index 4d0b278f5630e..e100c55bb924a 100644
--- a/fs/overlayfs/overlayfs.h
+++ b/fs/overlayfs/overlayfs.h
@@ -375,8 +375,10 @@ bool ovl_index_all(struct super_block *sb);
bool ovl_verify_lower(struct super_block *sb);
struct ovl_entry *ovl_alloc_entry(unsigned int numlower);
bool ovl_dentry_remote(struct dentry *dentry);
-void ovl_dentry_update_reval(struct dentry *dentry, struct dentry *upperdentry,
- unsigned int mask);
+void ovl_dentry_update_reval(struct dentry *dentry, struct dentry *realdentry);
+void ovl_dentry_init_reval(struct dentry *dentry, struct dentry *upperdentry);
+void ovl_dentry_init_flags(struct dentry *dentry, struct dentry *upperdentry,
+ unsigned int mask);
bool ovl_dentry_weird(struct dentry *dentry);
enum ovl_path_type ovl_path_type(struct dentry *dentry);
void ovl_path_upper(struct dentry *dentry, struct path *path);
diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c
index f97ad8b40dbbd..ae1058fbfb5b2 100644
--- a/fs/overlayfs/super.c
+++ b/fs/overlayfs/super.c
@@ -1877,7 +1877,7 @@ static struct dentry *ovl_get_root(struct super_block *sb,
ovl_dentry_set_flag(OVL_E_CONNECTED, root);
ovl_set_upperdata(d_inode(root));
ovl_inode_init(d_inode(root), &oip, ino, fsid);
- ovl_dentry_update_reval(root, upperdentry, DCACHE_OP_WEAK_REVALIDATE);
+ ovl_dentry_init_flags(root, upperdentry, DCACHE_OP_WEAK_REVALIDATE);

return root;
}
diff --git a/fs/overlayfs/util.c b/fs/overlayfs/util.c
index 923d66d131c16..6a0652bd51f24 100644
--- a/fs/overlayfs/util.c
+++ b/fs/overlayfs/util.c
@@ -94,14 +94,30 @@ struct ovl_entry *ovl_alloc_entry(unsigned int numlower)
return oe;
}

+#define OVL_D_REVALIDATE (DCACHE_OP_REVALIDATE | DCACHE_OP_WEAK_REVALIDATE)
+
bool ovl_dentry_remote(struct dentry *dentry)
{
- return dentry->d_flags &
- (DCACHE_OP_REVALIDATE | DCACHE_OP_WEAK_REVALIDATE);
+ return dentry->d_flags & OVL_D_REVALIDATE;
+}
+
+void ovl_dentry_update_reval(struct dentry *dentry, struct dentry *realdentry)
+{
+ if (!ovl_dentry_remote(realdentry))
+ return;
+
+ spin_lock(&dentry->d_lock);
+ dentry->d_flags |= realdentry->d_flags & OVL_D_REVALIDATE;
+ spin_unlock(&dentry->d_lock);
+}
+
+void ovl_dentry_init_reval(struct dentry *dentry, struct dentry *upperdentry)
+{
+ return ovl_dentry_init_flags(dentry, upperdentry, OVL_D_REVALIDATE);
}

-void ovl_dentry_update_reval(struct dentry *dentry, struct dentry *upperdentry,
- unsigned int mask)
+void ovl_dentry_init_flags(struct dentry *dentry, struct dentry *upperdentry,
+ unsigned int mask)
{
struct ovl_entry *oe = OVL_E(dentry);
unsigned int i, flags = 0;
--
2.39.2