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 @@ static int ovl_cache_update_ino(struct path *path, struct ovl_cache_entry *p) 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);