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-rw-r--r--fs/overlayfs/dir.c11
-rw-r--r--fs/overlayfs/overlayfs.h8
-rw-r--r--fs/overlayfs/readdir.c267
-rw-r--r--fs/overlayfs/super.c1
-rw-r--r--fs/overlayfs/util.c24
5 files changed, 266 insertions, 45 deletions
diff --git a/fs/overlayfs/dir.c b/fs/overlayfs/dir.c
index 48b70e6490f3..9cb0c80e5967 100644
--- a/fs/overlayfs/dir.c
+++ b/fs/overlayfs/dir.c
@@ -155,7 +155,7 @@ static int ovl_set_opaque(struct dentry *dentry, struct dentry *upperdentry)
static void ovl_instantiate(struct dentry *dentry, struct inode *inode,
struct dentry *newdentry, bool hardlink)
{
- ovl_dentry_version_inc(dentry->d_parent);
+ ovl_dentry_version_inc(dentry->d_parent, false);
ovl_dentry_set_upper_alias(dentry);
if (!hardlink) {
ovl_inode_update(inode, newdentry);
@@ -692,7 +692,7 @@ static int ovl_remove_and_whiteout(struct dentry *dentry, bool is_dir)
if (flags)
ovl_cleanup(wdir, upper);
- ovl_dentry_version_inc(dentry->d_parent);
+ ovl_dentry_version_inc(dentry->d_parent, true);
out_d_drop:
d_drop(dentry);
dput(whiteout);
@@ -742,7 +742,7 @@ static int ovl_remove_upper(struct dentry *dentry, bool is_dir)
err = vfs_rmdir(dir, upper);
else
err = vfs_unlink(dir, upper, NULL);
- ovl_dentry_version_inc(dentry->d_parent);
+ ovl_dentry_version_inc(dentry->d_parent, ovl_type_origin(dentry));
/*
* Keeping this dentry hashed would mean having to release
@@ -1089,8 +1089,9 @@ static int ovl_rename(struct inode *olddir, struct dentry *old,
drop_nlink(d_inode(new));
}
- ovl_dentry_version_inc(old->d_parent);
- ovl_dentry_version_inc(new->d_parent);
+ ovl_dentry_version_inc(old->d_parent,
+ !overwrite && ovl_type_origin(new));
+ ovl_dentry_version_inc(new->d_parent, ovl_type_origin(old));
out_dput:
dput(newdentry);
diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h
index e927a62c97ae..d4e8c1a08fb0 100644
--- a/fs/overlayfs/overlayfs.h
+++ b/fs/overlayfs/overlayfs.h
@@ -204,8 +204,8 @@ 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_real(struct inode *inode);
-struct ovl_dir_cache *ovl_dir_cache(struct dentry *dentry);
-void ovl_set_dir_cache(struct dentry *dentry, struct ovl_dir_cache *cache);
+struct ovl_dir_cache *ovl_dir_cache(struct inode *inode);
+void ovl_set_dir_cache(struct inode *inode, struct ovl_dir_cache *cache);
bool ovl_dentry_is_opaque(struct dentry *dentry);
bool ovl_dentry_is_whiteout(struct dentry *dentry);
void ovl_dentry_set_opaque(struct dentry *dentry);
@@ -217,7 +217,7 @@ void ovl_dentry_set_redirect(struct dentry *dentry, const char *redirect);
void ovl_inode_init(struct inode *inode, struct dentry *upperdentry,
struct dentry *lowerdentry);
void ovl_inode_update(struct inode *inode, struct dentry *upperdentry);
-void ovl_dentry_version_inc(struct dentry *dentry);
+void ovl_dentry_version_inc(struct dentry *dentry, bool impurity);
u64 ovl_dentry_version_get(struct dentry *dentry);
bool ovl_is_whiteout(struct dentry *dentry);
struct file *ovl_path_open(struct path *path, int flags);
@@ -229,6 +229,7 @@ int ovl_check_setxattr(struct dentry *dentry, struct dentry *upperdentry,
int xerr);
int ovl_set_impure(struct dentry *dentry, struct dentry *upperdentry);
void ovl_set_flag(unsigned long flag, struct inode *inode);
+void ovl_clear_flag(unsigned long flag, struct inode *inode);
bool ovl_test_flag(unsigned long flag, struct inode *inode);
bool ovl_inuse_trylock(struct dentry *dentry);
void ovl_inuse_unlock(struct dentry *dentry);
@@ -256,6 +257,7 @@ extern const struct file_operations ovl_dir_operations;
int ovl_check_empty_dir(struct dentry *dentry, struct list_head *list);
void ovl_cleanup_whiteouts(struct dentry *upper, struct list_head *list);
void ovl_cache_free(struct list_head *list);
+void ovl_dir_cache_free(struct inode *inode);
int ovl_check_d_type_supported(struct path *realpath);
void ovl_workdir_cleanup(struct inode *dir, struct vfsmount *mnt,
struct dentry *dentry, int level);
diff --git a/fs/overlayfs/readdir.c b/fs/overlayfs/readdir.c
index 2aab37054027..3e27e455a502 100644
--- a/fs/overlayfs/readdir.c
+++ b/fs/overlayfs/readdir.c
@@ -34,13 +34,14 @@ struct ovl_dir_cache {
long refcount;
u64 version;
struct list_head entries;
+ struct rb_root root;
};
struct ovl_readdir_data {
struct dir_context ctx;
struct dentry *dentry;
bool is_lowest;
- struct rb_root root;
+ struct rb_root *root;
struct list_head *list;
struct list_head middle;
struct ovl_cache_entry *first_maybe_whiteout;
@@ -61,7 +62,33 @@ struct ovl_dir_file {
static struct ovl_cache_entry *ovl_cache_entry_from_node(struct rb_node *n)
{
- return container_of(n, struct ovl_cache_entry, node);
+ return rb_entry(n, struct ovl_cache_entry, node);
+}
+
+static bool ovl_cache_entry_find_link(const char *name, int len,
+ struct rb_node ***link,
+ struct rb_node **parent)
+{
+ bool found = false;
+ struct rb_node **newp = *link;
+
+ while (!found && *newp) {
+ int cmp;
+ struct ovl_cache_entry *tmp;
+
+ *parent = *newp;
+ tmp = ovl_cache_entry_from_node(*newp);
+ cmp = strncmp(name, tmp->name, len);
+ if (cmp > 0)
+ newp = &tmp->node.rb_right;
+ else if (cmp < 0 || len < tmp->len)
+ newp = &tmp->node.rb_left;
+ else
+ found = true;
+ }
+ *link = newp;
+
+ return found;
}
static struct ovl_cache_entry *ovl_cache_entry_find(struct rb_root *root,
@@ -144,24 +171,12 @@ static int ovl_cache_entry_add_rb(struct ovl_readdir_data *rdd,
const char *name, int len, u64 ino,
unsigned int d_type)
{
- struct rb_node **newp = &rdd->root.rb_node;
+ struct rb_node **newp = &rdd->root->rb_node;
struct rb_node *parent = NULL;
struct ovl_cache_entry *p;
- while (*newp) {
- int cmp;
- struct ovl_cache_entry *tmp;
-
- parent = *newp;
- tmp = ovl_cache_entry_from_node(*newp);
- cmp = strncmp(name, tmp->name, len);
- if (cmp > 0)
- newp = &tmp->node.rb_right;
- else if (cmp < 0 || len < tmp->len)
- newp = &tmp->node.rb_left;
- else
- return 0;
- }
+ if (ovl_cache_entry_find_link(name, len, &newp, &parent))
+ return 0;
p = ovl_cache_entry_new(rdd, name, len, ino, d_type);
if (p == NULL) {
@@ -171,7 +186,7 @@ static int ovl_cache_entry_add_rb(struct ovl_readdir_data *rdd,
list_add_tail(&p->l_node, rdd->list);
rb_link_node(&p->node, parent, newp);
- rb_insert_color(&p->node, &rdd->root);
+ rb_insert_color(&p->node, rdd->root);
return 0;
}
@@ -182,7 +197,7 @@ static int ovl_fill_lowest(struct ovl_readdir_data *rdd,
{
struct ovl_cache_entry *p;
- p = ovl_cache_entry_find(&rdd->root, name, namelen);
+ p = ovl_cache_entry_find(rdd->root, name, namelen);
if (p) {
list_move_tail(&p->l_node, &rdd->middle);
} else {
@@ -207,6 +222,16 @@ void ovl_cache_free(struct list_head *list)
INIT_LIST_HEAD(list);
}
+void ovl_dir_cache_free(struct inode *inode)
+{
+ struct ovl_dir_cache *cache = ovl_dir_cache(inode);
+
+ if (cache) {
+ ovl_cache_free(&cache->entries);
+ kfree(cache);
+ }
+}
+
static void ovl_cache_put(struct ovl_dir_file *od, struct dentry *dentry)
{
struct ovl_dir_cache *cache = od->cache;
@@ -214,8 +239,8 @@ static void ovl_cache_put(struct ovl_dir_file *od, struct dentry *dentry)
WARN_ON(cache->refcount <= 0);
cache->refcount--;
if (!cache->refcount) {
- if (ovl_dir_cache(dentry) == cache)
- ovl_set_dir_cache(dentry, NULL);
+ if (ovl_dir_cache(d_inode(dentry)) == cache)
+ ovl_set_dir_cache(d_inode(dentry), NULL);
ovl_cache_free(&cache->entries);
kfree(cache);
@@ -308,7 +333,8 @@ static void ovl_dir_reset(struct file *file)
od->is_real = false;
}
-static int ovl_dir_read_merged(struct dentry *dentry, struct list_head *list)
+static int ovl_dir_read_merged(struct dentry *dentry, struct list_head *list,
+ struct rb_root *root)
{
int err;
struct path realpath;
@@ -316,7 +342,7 @@ static int ovl_dir_read_merged(struct dentry *dentry, struct list_head *list)
.ctx.actor = ovl_fill_merge,
.dentry = dentry,
.list = list,
- .root = RB_ROOT,
+ .root = root,
.is_lowest = false,
};
int idx, next;
@@ -362,12 +388,13 @@ static struct ovl_dir_cache *ovl_cache_get(struct dentry *dentry)
int res;
struct ovl_dir_cache *cache;
- cache = ovl_dir_cache(dentry);
+ cache = ovl_dir_cache(d_inode(dentry));
if (cache && ovl_dentry_version_get(dentry) == cache->version) {
+ WARN_ON(!cache->refcount);
cache->refcount++;
return cache;
}
- ovl_set_dir_cache(dentry, NULL);
+ ovl_set_dir_cache(d_inode(dentry), NULL);
cache = kzalloc(sizeof(struct ovl_dir_cache), GFP_KERNEL);
if (!cache)
@@ -375,8 +402,9 @@ static struct ovl_dir_cache *ovl_cache_get(struct dentry *dentry)
cache->refcount = 1;
INIT_LIST_HEAD(&cache->entries);
+ cache->root = RB_ROOT;
- res = ovl_dir_read_merged(dentry, &cache->entries);
+ res = ovl_dir_read_merged(dentry, &cache->entries, &cache->root);
if (res) {
ovl_cache_free(&cache->entries);
kfree(cache);
@@ -384,7 +412,7 @@ static struct ovl_dir_cache *ovl_cache_get(struct dentry *dentry)
}
cache->version = ovl_dentry_version_get(dentry);
- ovl_set_dir_cache(dentry, cache);
+ ovl_set_dir_cache(d_inode(dentry), cache);
return cache;
}
@@ -458,6 +486,169 @@ fail:
goto out;
}
+static int ovl_fill_plain(struct dir_context *ctx, const char *name,
+ int namelen, loff_t offset, u64 ino,
+ unsigned int d_type)
+{
+ struct ovl_cache_entry *p;
+ struct ovl_readdir_data *rdd =
+ container_of(ctx, struct ovl_readdir_data, ctx);
+
+ rdd->count++;
+ p = ovl_cache_entry_new(rdd, name, namelen, ino, d_type);
+ if (p == NULL) {
+ rdd->err = -ENOMEM;
+ return -ENOMEM;
+ }
+ list_add_tail(&p->l_node, rdd->list);
+
+ return 0;
+}
+
+static int ovl_dir_read_impure(struct path *path, struct list_head *list,
+ struct rb_root *root)
+{
+ int err;
+ struct path realpath;
+ struct ovl_cache_entry *p, *n;
+ struct ovl_readdir_data rdd = {
+ .ctx.actor = ovl_fill_plain,
+ .list = list,
+ .root = root,
+ };
+
+ INIT_LIST_HEAD(list);
+ *root = RB_ROOT;
+ ovl_path_upper(path->dentry, &realpath);
+
+ err = ovl_dir_read(&realpath, &rdd);
+ if (err)
+ return err;
+
+ list_for_each_entry_safe(p, n, list, l_node) {
+ if (strcmp(p->name, ".") != 0 &&
+ strcmp(p->name, "..") != 0) {
+ err = ovl_cache_update_ino(path, p);
+ if (err)
+ return err;
+ }
+ if (p->ino == p->real_ino) {
+ list_del(&p->l_node);
+ kfree(p);
+ } else {
+ struct rb_node **newp = &root->rb_node;
+ struct rb_node *parent = NULL;
+
+ if (WARN_ON(ovl_cache_entry_find_link(p->name, p->len,
+ &newp, &parent)))
+ return -EIO;
+
+ rb_link_node(&p->node, parent, newp);
+ rb_insert_color(&p->node, root);
+ }
+ }
+ return 0;
+}
+
+static struct ovl_dir_cache *ovl_cache_get_impure(struct path *path)
+{
+ int res;
+ struct dentry *dentry = path->dentry;
+ struct ovl_dir_cache *cache;
+
+ cache = ovl_dir_cache(d_inode(dentry));
+ if (cache && ovl_dentry_version_get(dentry) == cache->version)
+ return cache;
+
+ /* Impure cache is not refcounted, free it here */
+ ovl_dir_cache_free(d_inode(dentry));
+ ovl_set_dir_cache(d_inode(dentry), NULL);
+
+ cache = kzalloc(sizeof(struct ovl_dir_cache), GFP_KERNEL);
+ if (!cache)
+ return ERR_PTR(-ENOMEM);
+
+ res = ovl_dir_read_impure(path, &cache->entries, &cache->root);
+ if (res) {
+ ovl_cache_free(&cache->entries);
+ kfree(cache);
+ return ERR_PTR(res);
+ }
+ if (list_empty(&cache->entries)) {
+ /* Good oportunity to get rid of an unnecessary "impure" flag */
+ ovl_do_removexattr(ovl_dentry_upper(dentry), OVL_XATTR_IMPURE);
+ ovl_clear_flag(OVL_IMPURE, d_inode(dentry));
+ kfree(cache);
+ return NULL;
+ }
+
+ cache->version = ovl_dentry_version_get(dentry);
+ ovl_set_dir_cache(d_inode(dentry), cache);
+
+ return cache;
+}
+
+struct ovl_readdir_translate {
+ struct dir_context *orig_ctx;
+ struct ovl_dir_cache *cache;
+ struct dir_context ctx;
+ u64 parent_ino;
+};
+
+static int ovl_fill_real(struct dir_context *ctx, const char *name,
+ int namelen, loff_t offset, u64 ino,
+ unsigned int d_type)
+{
+ struct ovl_readdir_translate *rdt =
+ container_of(ctx, struct ovl_readdir_translate, ctx);
+ struct dir_context *orig_ctx = rdt->orig_ctx;
+
+ if (rdt->parent_ino && strcmp(name, "..") == 0)
+ ino = rdt->parent_ino;
+ else if (rdt->cache) {
+ struct ovl_cache_entry *p;
+
+ p = ovl_cache_entry_find(&rdt->cache->root, name, namelen);
+ if (p)
+ ino = p->ino;
+ }
+
+ return orig_ctx->actor(orig_ctx, name, namelen, offset, ino, d_type);
+}
+
+static int ovl_iterate_real(struct file *file, struct dir_context *ctx)
+{
+ int err;
+ struct ovl_dir_file *od = file->private_data;
+ struct dentry *dir = file->f_path.dentry;
+ struct ovl_readdir_translate rdt = {
+ .ctx.actor = ovl_fill_real,
+ .orig_ctx = ctx,
+ };
+
+ if (OVL_TYPE_MERGE(ovl_path_type(dir->d_parent))) {
+ struct kstat stat;
+ struct path statpath = file->f_path;
+
+ statpath.dentry = dir->d_parent;
+ err = vfs_getattr(&statpath, &stat, STATX_INO, 0);
+ if (err)
+ return err;
+
+ WARN_ON_ONCE(dir->d_sb->s_dev != stat.dev);
+ rdt.parent_ino = stat.ino;
+ }
+
+ if (ovl_test_flag(OVL_IMPURE, d_inode(dir))) {
+ rdt.cache = ovl_cache_get_impure(&file->f_path);
+ if (IS_ERR(rdt.cache))
+ return PTR_ERR(rdt.cache);
+ }
+
+ return iterate_dir(od->realfile, &rdt.ctx);
+}
+
+
static int ovl_iterate(struct file *file, struct dir_context *ctx)
{
struct ovl_dir_file *od = file->private_data;
@@ -468,8 +659,19 @@ static int ovl_iterate(struct file *file, struct dir_context *ctx)
if (!ctx->pos)
ovl_dir_reset(file);
- if (od->is_real)
+ if (od->is_real) {
+ /*
+ * If parent is merge, then need to adjust d_ino for '..', if
+ * dir is impure then need to adjust d_ino for copied up
+ * entries.
+ */
+ if (ovl_same_sb(dentry->d_sb) &&
+ (ovl_test_flag(OVL_IMPURE, d_inode(dentry)) ||
+ OVL_TYPE_MERGE(ovl_path_type(dentry->d_parent)))) {
+ return ovl_iterate_real(file, ctx);
+ }
return iterate_dir(od->realfile, ctx);
+ }
if (!od->cache) {
struct ovl_dir_cache *cache;
@@ -634,8 +836,9 @@ int ovl_check_empty_dir(struct dentry *dentry, struct list_head *list)
{
int err;
struct ovl_cache_entry *p;
+ struct rb_root root = RB_ROOT;
- err = ovl_dir_read_merged(dentry, list);
+ err = ovl_dir_read_merged(dentry, list, &root);
if (err)
return err;
@@ -724,12 +927,13 @@ static void ovl_workdir_cleanup_recurse(struct path *path, int level)
int err;
struct inode *dir = path->dentry->d_inode;
LIST_HEAD(list);
+ struct rb_root root = RB_ROOT;
struct ovl_cache_entry *p;
struct ovl_readdir_data rdd = {
.ctx.actor = ovl_fill_merge,
.dentry = NULL,
.list = &list,
- .root = RB_ROOT,
+ .root = &root,
.is_lowest = false,
};
@@ -787,12 +991,13 @@ int ovl_indexdir_cleanup(struct dentry *dentry, struct vfsmount *mnt,
struct inode *dir = dentry->d_inode;
struct path path = { .mnt = mnt, .dentry = dentry };
LIST_HEAD(list);
+ struct rb_root root = RB_ROOT;
struct ovl_cache_entry *p;
struct ovl_readdir_data rdd = {
.ctx.actor = ovl_fill_merge,
.dentry = NULL,
.list = &list,
- .root = RB_ROOT,
+ .root = &root,
.is_lowest = false,
};
diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c
index d86e89f97201..40d49390feb9 100644
--- a/fs/overlayfs/super.c
+++ b/fs/overlayfs/super.c
@@ -198,6 +198,7 @@ static void ovl_destroy_inode(struct inode *inode)
dput(oi->__upperdentry);
kfree(oi->redirect);
+ ovl_dir_cache_free(inode);
mutex_destroy(&oi->lock);
call_rcu(&inode->i_rcu, ovl_i_callback);
diff --git a/fs/overlayfs/util.c b/fs/overlayfs/util.c
index f46ad75dc96a..117794582f9f 100644
--- a/fs/overlayfs/util.c
+++ b/fs/overlayfs/util.c
@@ -180,14 +180,14 @@ struct inode *ovl_inode_real(struct inode *inode)
}
-struct ovl_dir_cache *ovl_dir_cache(struct dentry *dentry)
+struct ovl_dir_cache *ovl_dir_cache(struct inode *inode)
{
- return OVL_I(d_inode(dentry))->cache;
+ return OVL_I(inode)->cache;
}
-void ovl_set_dir_cache(struct dentry *dentry, struct ovl_dir_cache *cache)
+void ovl_set_dir_cache(struct inode *inode, struct ovl_dir_cache *cache)
{
- OVL_I(d_inode(dentry))->cache = cache;
+ OVL_I(inode)->cache = cache;
}
bool ovl_dentry_is_opaque(struct dentry *dentry)
@@ -275,12 +275,19 @@ void ovl_inode_update(struct inode *inode, struct dentry *upperdentry)
}
}
-void ovl_dentry_version_inc(struct dentry *dentry)
+void ovl_dentry_version_inc(struct dentry *dentry, bool impurity)
{
struct inode *inode = d_inode(dentry);
WARN_ON(!inode_is_locked(inode));
- OVL_I(inode)->version++;
+ /*
+ * Version is used by readdir code to keep cache consistent. For merge
+ * dirs all changes need to be noted. For non-merge dirs, cache only
+ * contains impure (ones which have been copied up and have origins)
+ * entries, so only need to note changes to impure entries.
+ */
+ if (OVL_TYPE_MERGE(ovl_path_type(dentry)) || impurity)
+ OVL_I(inode)->version++;
}
u64 ovl_dentry_version_get(struct dentry *dentry)
@@ -382,6 +389,11 @@ void ovl_set_flag(unsigned long flag, struct inode *inode)
set_bit(flag, &OVL_I(inode)->flags);
}
+void ovl_clear_flag(unsigned long flag, struct inode *inode)
+{
+ clear_bit(flag, &OVL_I(inode)->flags);
+}
+
bool ovl_test_flag(unsigned long flag, struct inode *inode)
{
return test_bit(flag, &OVL_I(inode)->flags);
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.