ovl: consistent d_ino for non-samefs with xino (adbf4f7e) · Commits · 戴 / test

fs/overlayfs/readdir.c

+39 −6

Original line number	Diff line number	Diff line
		@@ -120,6 +120,10 @@ static bool ovl_calc_d_ino(struct ovl_readdir_data *rdd,
		if (!rdd->dentry)
		return false;

		/* Always recalc d_ino when remapping lower inode numbers */
		if (ovl_xino_bits(rdd->dentry->d_sb))
		return true;

		/* Always recalc d_ino for parent */
		if (strcmp(p->name, "..") == 0)
		return true;
		@@ -435,6 +439,19 @@ static struct ovl_dir_cache ovl_cache_get(struct dentry dentry)
		return cache;
		}

		/* Map inode number to lower fs unique range */
		static u64 ovl_remap_lower_ino(u64 ino, int xinobits, int fsid,
		const char *name, int namelen)
		{
		if (ino >> (64 - xinobits)) {
		pr_warn_ratelimited("overlayfs: d_ino too big (%.*s, ino=%llu, xinobits=%d)\n",
		namelen, name, ino, xinobits);
		return ino;
		}

		return ino \| ((u64)fsid) << (64 - xinobits);
		}

		/*
		* Set d_ino for upper entries. Non-upper entries should always report
		* the uppermost real inode ino and should not call this function.
		@@ -452,9 +469,10 @@ static int ovl_cache_update_ino(struct path path, struct ovl_cache_entry p)
		struct dentry *this = NULL;
		enum ovl_path_type type;
		u64 ino = p->real_ino;
		int xinobits = ovl_xino_bits(dir->d_sb);
		int err = 0;

		if (!ovl_same_sb(dir->d_sb))
		if (!ovl_same_sb(dir->d_sb) && !xinobits)
		goto out;

		if (p->name[0] == '.') {
		@@ -491,6 +509,10 @@ get:

		WARN_ON_ONCE(dir->d_sb->s_dev != stat.dev);
		ino = stat.ino;
		} else if (xinobits && !OVL_TYPE_UPPER(type)) {
		ino = ovl_remap_lower_ino(ino, xinobits,
		ovl_layer_lower(this)->fsid,
		p->name, p->len);
		}

		out:
		@@ -618,6 +640,8 @@ struct ovl_readdir_translate {
		struct ovl_dir_cache *cache;
		struct dir_context ctx;
		u64 parent_ino;
		int fsid;
		int xinobits;
		};

		static int ovl_fill_real(struct dir_context ctx, const char name,
		@@ -628,14 +652,17 @@ static int ovl_fill_real(struct dir_context ctx, const char name,
		container_of(ctx, struct ovl_readdir_translate, ctx);
		struct dir_context *orig_ctx = rdt->orig_ctx;

		if (rdt->parent_ino && strcmp(name, "..") == 0)
		if (rdt->parent_ino && strcmp(name, "..") == 0) {
		ino = rdt->parent_ino;
		else if (rdt->cache) {
		} else if (rdt->cache) {
		struct ovl_cache_entry *p;

		p = ovl_cache_entry_find(&rdt->cache->root, name, namelen);
		if (p)
		ino = p->ino;
		} else if (rdt->xinobits) {
		ino = ovl_remap_lower_ino(ino, rdt->xinobits, rdt->fsid,
		name, namelen);
		}

		return orig_ctx->actor(orig_ctx, name, namelen, offset, ino, d_type);
		@@ -646,11 +673,16 @@ 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_layer *lower_layer = ovl_layer_lower(dir);
		struct ovl_readdir_translate rdt = {
		.ctx.actor = ovl_fill_real,
		.orig_ctx = ctx,
		.xinobits = ovl_xino_bits(dir->d_sb),
		};

		if (rdt.xinobits && lower_layer)
		rdt.fsid = lower_layer->fsid;

		if (OVL_TYPE_MERGE(ovl_path_type(dir->d_parent))) {
		struct kstat stat;
		struct path statpath = file->f_path;
		@@ -693,9 +725,10 @@ static int ovl_iterate(struct file file, struct dir_context ctx)
		* dir is impure then need to adjust d_ino for copied up
		* entries.
		*/
		if (ovl_same_sb(dentry->d_sb) &&
		if (ovl_xino_bits(dentry->d_sb) \|\|
		(ovl_same_sb(dentry->d_sb) &&
		(ovl_test_flag(OVL_IMPURE, d_inode(dentry)) \|\|
		OVL_TYPE_MERGE(ovl_path_type(dentry->d_parent)))) {
		OVL_TYPE_MERGE(ovl_path_type(dentry->d_parent))))) {
		return ovl_iterate_real(file, ctx);
		}
		return iterate_dir(od->realfile, ctx);

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