Allow completely skipping ->revalidate() on a per-dentry bases, in case the
underlying layers used for a dentry do not themselves have ->revalidate().
E.g. negative overlay dentry has no underlying layers, hence revalidate is
unnecessary. Or if lower layer is remote but overlay dentry is pure-upper,
then can skip revalidate.
The following places need to update whether the dentry needs revalidate or
not:
- fill-super (root dentry)
- lookup
- create
- fh_to_dentry
Signed-off-by: Miklos Szeredi <mszeredi@xxxxxxxxxx>
---
fs/overlayfs/dir.c | 3 +++
fs/overlayfs/export.c | 2 ++
fs/overlayfs/namei.c | 3 +++
fs/overlayfs/overlayfs.h | 3 ++-
fs/overlayfs/super.c | 23 +++++++----------------
fs/overlayfs/util.c | 15 ++++++++++++---
6 files changed, 29 insertions(+), 20 deletions(-)
diff --git a/fs/overlayfs/dir.c b/fs/overlayfs/dir.c
index 8e57d5372b8f..b3471ef51440 100644
--- a/fs/overlayfs/dir.c
+++ b/fs/overlayfs/dir.c
@@ -243,6 +243,9 @@ 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);
+
if (!hardlink) {
/*
* ovl_obtain_alias() can be called after ovl_create_real()
diff --git a/fs/overlayfs/export.c b/fs/overlayfs/export.c
index 6f54d70cef27..a58b3d9b06b9 100644
--- a/fs/overlayfs/export.c
+++ b/fs/overlayfs/export.c
@@ -324,6 +324,8 @@ 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);
return d_instantiate_anon(dentry, inode);
diff --git a/fs/overlayfs/namei.c b/fs/overlayfs/namei.c
index a5b998a93a24..76e61cc27822 100644
--- a/fs/overlayfs/namei.c
+++ b/fs/overlayfs/namei.c
@@ -1077,6 +1077,9 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry,
goto out_free_oe;
}
+ ovl_dentry_update_reval(dentry, upperdentry,
+ DCACHE_OP_REVALIDATE | DCACHE_OP_WEAK_REVALIDATE);
+
revert_creds(old_cred);
if (origin_path) {
dput(origin_path->dentry);
diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h
index 3623d28aa4fa..68124a4f8f9b 100644
--- a/fs/overlayfs/overlayfs.h
+++ b/fs/overlayfs/overlayfs.h
@@ -229,7 +229,8 @@ struct dentry *ovl_indexdir(struct super_block *sb);
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);
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 7e294bf719ff..26d4153240a8 100644
--- a/fs/overlayfs/super.c
+++ b/fs/overlayfs/super.c
@@ -158,11 +158,6 @@ static int ovl_dentry_weak_revalidate(struct dentry *dentry, unsigned int flags)
static const struct dentry_operations ovl_dentry_operations = {
.d_release = ovl_dentry_release,
.d_real = ovl_d_real,
-};
-
-static const struct dentry_operations ovl_reval_dentry_operations = {
- .d_release = ovl_dentry_release,
- .d_real = ovl_d_real,
.d_revalidate = ovl_dentry_revalidate,
.d_weak_revalidate = ovl_dentry_weak_revalidate,
};
@@ -779,7 +774,7 @@ static int ovl_check_namelen(struct path *path, struct ovl_fs *ofs,
}
static int ovl_lower_dir(const char *name, struct path *path,
- struct ovl_fs *ofs, int *stack_depth, bool *remote)
+ struct ovl_fs *ofs, int *stack_depth)
{
int fh_type;
int err;
@@ -794,9 +789,6 @@ static int ovl_lower_dir(const char *name, struct path *path,
*stack_depth = max(*stack_depth, path->mnt->mnt_sb->s_stack_depth);
- if (ovl_dentry_remote(path->dentry))
- *remote = true;
-
/*
* The inodes index feature and NFS export need to encode and decode
* file handles, so they require that all layers support them.
@@ -1439,7 +1431,6 @@ static struct ovl_entry *ovl_get_lowerstack(struct super_block *sb,
char *lowertmp, *lower;
struct path *stack = NULL;
unsigned int stacklen, numlower = 0, i;
- bool remote = false;
struct ovl_entry *oe;
err = -ENOMEM;
@@ -1471,7 +1462,7 @@ static struct ovl_entry *ovl_get_lowerstack(struct super_block *sb,
lower = lowertmp;
for (numlower = 0; numlower < stacklen; numlower++) {
err = ovl_lower_dir(lower, &stack[numlower], ofs,
- &sb->s_stack_depth, &remote);
+ &sb->s_stack_depth);
if (err)
goto out_err;
@@ -1499,11 +1490,6 @@ static struct ovl_entry *ovl_get_lowerstack(struct super_block *sb,
oe->lowerstack[i].layer = &ofs->layers[i+1];
}
- if (remote)
- sb->s_d_op = &ovl_reval_dentry_operations;
- else
- sb->s_d_op = &ovl_dentry_operations;
-
out:
for (i = 0; i < numlower; i++)
path_put(&stack[i]);
@@ -1597,6 +1583,8 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent)
struct cred *cred;
int err;
+ sb->s_d_op = &ovl_dentry_operations;
+
err = -ENOMEM;
ofs = kzalloc(sizeof(struct ovl_fs), GFP_KERNEL);
if (!ofs)
@@ -1724,6 +1712,9 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent)
ovl_inode_init(d_inode(root_dentry), upperpath.dentry,
ovl_dentry_lower(root_dentry), NULL);
+ ovl_dentry_update_reval(root_dentry, upperpath.dentry,
+ DCACHE_OP_WEAK_REVALIDATE);
+
sb->s_root = root_dentry;
return 0;
diff --git a/fs/overlayfs/util.c b/fs/overlayfs/util.c
index 67cd2866aaa2..3ad8fb291f7d 100644
--- a/fs/overlayfs/util.c
+++ b/fs/overlayfs/util.c
@@ -90,10 +90,19 @@ struct ovl_entry *ovl_alloc_entry(unsigned int numlower)
return oe;
}
-bool ovl_dentry_remote(struct dentry *dentry)
+void ovl_dentry_update_reval(struct dentry *dentry, struct dentry *upperdentry,
+ unsigned int mask)
{
- return dentry->d_flags &
- (DCACHE_OP_REVALIDATE | DCACHE_OP_WEAK_REVALIDATE);
+ struct ovl_entry *oe = OVL_E(dentry);
+ unsigned int i, flags = 0;
+
+ for (i = 0; i < oe->numlower; i++)
+ flags |= oe->lowerstack[i].dentry->d_flags;
+
+ spin_lock(&dentry->d_lock);
+ dentry->d_flags &= ~mask;
+ dentry->d_flags |= flags & mask;
+ spin_unlock(&dentry->d_lock);
}
bool ovl_dentry_weird(struct dentry *dentry)
--
2.21.1
