Merge branch 'overlayfs-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs (243d5067) · Commits · e / devices / android_kernel_xiaomi_nabu

fs/overlayfs/copy_up.c

+35 −0

Original line number	Original line	Diff line number	Diff line
	@@ -7,6 +7,7 @@
	* the Free Software Foundation.		* the Free Software Foundation.
	*/		*/

			#include <linux/module.h>
	#include <linux/fs.h>		#include <linux/fs.h>
	#include <linux/slab.h>		#include <linux/slab.h>
	#include <linux/file.h>		#include <linux/file.h>
	@@ -16,10 +17,41 @@
	#include <linux/uaccess.h>		#include <linux/uaccess.h>
	#include <linux/sched.h>		#include <linux/sched.h>
	#include <linux/namei.h>		#include <linux/namei.h>
			#include <linux/fdtable.h>
			#include <linux/ratelimit.h>
	#include "overlayfs.h"		#include "overlayfs.h"

	#define OVL_COPY_UP_CHUNK_SIZE (1 << 20)		#define OVL_COPY_UP_CHUNK_SIZE (1 << 20)

			static bool __read_mostly ovl_check_copy_up;
			module_param_named(check_copy_up, ovl_check_copy_up, bool,
			S_IWUSR \| S_IRUGO);
			MODULE_PARM_DESC(ovl_check_copy_up,
			"Warn on copy-up when causing process also has a R/O fd open");

			static int ovl_check_fd(const void data, struct file f, unsigned int fd)
			{
			const struct dentry *dentry = data;

			if (f->f_inode == d_inode(dentry))
			pr_warn_ratelimited("overlayfs: Warning: Copying up %pD, but open R/O on fd %u which will cease to be coherent [pid=%d %s]\n",
			f, fd, current->pid, current->comm);
			return 0;
			}

			/*
			* Check the fds open by this process and warn if something like the following
			* scenario is about to occur:
			*
			* fd1 = open("foo", O_RDONLY);
			* fd2 = open("foo", O_RDWR);
			*/
			static void ovl_do_check_copy_up(struct dentry *dentry)
			{
			if (ovl_check_copy_up)
			iterate_fd(current->files, 0, ovl_check_fd, dentry);
			}

	int ovl_copy_xattr(struct dentry old, struct dentry new)		int ovl_copy_xattr(struct dentry old, struct dentry new)
	{		{
	ssize_t list_size, size, value_size = 0;		ssize_t list_size, size, value_size = 0;
	@@ -235,6 +267,7 @@ static int ovl_copy_up_locked(struct dentry workdir, struct dentry upperdir,

	if (S_ISREG(stat->mode)) {		if (S_ISREG(stat->mode)) {
	struct path upperpath;		struct path upperpath;

	ovl_path_upper(dentry, &upperpath);		ovl_path_upper(dentry, &upperpath);
	BUG_ON(upperpath.dentry != NULL);		BUG_ON(upperpath.dentry != NULL);
	upperpath.dentry = newdentry;		upperpath.dentry = newdentry;
	@@ -309,6 +342,8 @@ int ovl_copy_up_one(struct dentry parent, struct dentry dentry,
	if (WARN_ON(!workdir))		if (WARN_ON(!workdir))
	return -EROFS;		return -EROFS;

			ovl_do_check_copy_up(lowerpath->dentry);

	ovl_path_upper(parent, &parentpath);		ovl_path_upper(parent, &parentpath);
	upperdir = parentpath.dentry;		upperdir = parentpath.dentry;

fs/overlayfs/dir.c

+38 −23

Original line number	Original line	Diff line number	Diff line
	@@ -596,21 +596,25 @@ static int ovl_remove_upper(struct dentry *dentry, bool is_dir)
	{		{
	struct dentry *upperdir = ovl_dentry_upper(dentry->d_parent);		struct dentry *upperdir = ovl_dentry_upper(dentry->d_parent);
	struct inode *dir = upperdir->d_inode;		struct inode *dir = upperdir->d_inode;
	struct dentry *upper = ovl_dentry_upper(dentry);		struct dentry *upper;
	int err;		int err;

	inode_lock_nested(dir, I_MUTEX_PARENT);		inode_lock_nested(dir, I_MUTEX_PARENT);
			upper = lookup_one_len(dentry->d_name.name, upperdir,
			dentry->d_name.len);
			err = PTR_ERR(upper);
			if (IS_ERR(upper))
			goto out_unlock;

	err = -ESTALE;		err = -ESTALE;
	if (upper->d_parent == upperdir) {		if (upper == ovl_dentry_upper(dentry)) {
	/* Don't let d_delete() think it can reset d_inode */
	dget(upper);
	if (is_dir)		if (is_dir)
	err = vfs_rmdir(dir, upper);		err = vfs_rmdir(dir, upper);
	else		else
	err = vfs_unlink(dir, upper, NULL);		err = vfs_unlink(dir, upper, NULL);
	dput(upper);
	ovl_dentry_version_inc(dentry->d_parent);		ovl_dentry_version_inc(dentry->d_parent);
	}		}
			dput(upper);

	/*		/*
	* Keeping this dentry hashed would mean having to release		* Keeping this dentry hashed would mean having to release
	@@ -620,6 +624,7 @@ static int ovl_remove_upper(struct dentry *dentry, bool is_dir)
	*/		*/
	if (!err)		if (!err)
	d_drop(dentry);		d_drop(dentry);
			out_unlock:
	inode_unlock(dir);		inode_unlock(dir);

	return err;		return err;
	@@ -714,7 +719,6 @@ static int ovl_rename2(struct inode olddir, struct dentry old,
	struct dentry *trap;		struct dentry *trap;
	bool old_opaque;		bool old_opaque;
	bool new_opaque;		bool new_opaque;
	bool new_create = false;
	bool cleanup_whiteout = false;		bool cleanup_whiteout = false;
	bool overwrite = !(flags & RENAME_EXCHANGE);		bool overwrite = !(flags & RENAME_EXCHANGE);
	bool is_dir = d_is_dir(old);		bool is_dir = d_is_dir(old);
	@@ -840,29 +844,38 @@ static int ovl_rename2(struct inode olddir, struct dentry old,

	trap = lock_rename(new_upperdir, old_upperdir);		trap = lock_rename(new_upperdir, old_upperdir);

	olddentry = ovl_dentry_upper(old);
	newdentry = ovl_dentry_upper(new);		olddentry = lookup_one_len(old->d_name.name, old_upperdir,
	if (newdentry) {		old->d_name.len);
	if (opaquedir) {		err = PTR_ERR(olddentry);
	newdentry = opaquedir;		if (IS_ERR(olddentry))
	opaquedir = NULL;		goto out_unlock;
	} else {
	dget(newdentry);		err = -ESTALE;
	}		if (olddentry != ovl_dentry_upper(old))
	} else {		goto out_dput_old;
	new_create = true;
	newdentry = lookup_one_len(new->d_name.name, new_upperdir,		newdentry = lookup_one_len(new->d_name.name, new_upperdir,
	new->d_name.len);		new->d_name.len);
	err = PTR_ERR(newdentry);		err = PTR_ERR(newdentry);
	if (IS_ERR(newdentry))		if (IS_ERR(newdentry))
	goto out_unlock;		goto out_dput_old;
	}

	err = -ESTALE;		err = -ESTALE;
	if (olddentry->d_parent != old_upperdir)		if (ovl_dentry_upper(new)) {
			if (opaquedir) {
			if (newdentry != opaquedir)
	goto out_dput;		goto out_dput;
	if (newdentry->d_parent != new_upperdir)		} else {
			if (newdentry != ovl_dentry_upper(new))
	goto out_dput;		goto out_dput;
			}
			} else {
			if (!d_is_negative(newdentry) &&
			(!new_opaque \|\| !ovl_is_whiteout(newdentry)))
			goto out_dput;
			}

	if (olddentry == trap)		if (olddentry == trap)
	goto out_dput;		goto out_dput;
	if (newdentry == trap)		if (newdentry == trap)
	@@ -925,6 +938,8 @@ static int ovl_rename2(struct inode olddir, struct dentry old,

	out_dput:		out_dput:
	dput(newdentry);		dput(newdentry);
			out_dput_old:
			dput(olddentry);
	out_unlock:		out_unlock:
	unlock_rename(new_upperdir, old_upperdir);		unlock_rename(new_upperdir, old_upperdir);
	out_revert_creds:		out_revert_creds:

fs/overlayfs/overlayfs.h

+1 −0

Original line number	Original line	Diff line number	Diff line
	@@ -166,6 +166,7 @@ extern const struct file_operations ovl_dir_operations;
	int ovl_check_empty_dir(struct dentry dentry, struct list_head list);		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_cleanup_whiteouts(struct dentry upper, struct list_head list);
	void ovl_cache_free(struct list_head *list);		void ovl_cache_free(struct list_head *list);
			int ovl_check_d_type_supported(struct path *realpath);

	/* inode.c */		/* inode.c */
	int ovl_setattr(struct dentry dentry, struct iattr attr);		int ovl_setattr(struct dentry dentry, struct iattr attr);

fs/overlayfs/readdir.c

+45 −8

Original line number	Original line	Diff line number	Diff line
	@@ -36,13 +36,14 @@ struct ovl_dir_cache {

	struct ovl_readdir_data {		struct ovl_readdir_data {
	struct dir_context ctx;		struct dir_context ctx;
	bool is_merge;		bool is_lowest;
	struct rb_root root;		struct rb_root root;
	struct list_head *list;		struct list_head *list;
	struct list_head middle;		struct list_head middle;
	struct ovl_cache_entry *first_maybe_whiteout;		struct ovl_cache_entry *first_maybe_whiteout;
	int count;		int count;
	int err;		int err;
			bool d_type_supported;
	};		};

	struct ovl_dir_file {		struct ovl_dir_file {
	@@ -139,7 +140,7 @@ static int ovl_cache_entry_add_rb(struct ovl_readdir_data *rdd,
	return 0;		return 0;
	}		}

	static int ovl_fill_lower(struct ovl_readdir_data *rdd,		static int ovl_fill_lowest(struct ovl_readdir_data *rdd,
	const char *name, int namelen,		const char *name, int namelen,
	loff_t offset, u64 ino, unsigned int d_type)		loff_t offset, u64 ino, unsigned int d_type)
	{		{
	@@ -193,10 +194,10 @@ static int ovl_fill_merge(struct dir_context ctx, const char name,
	container_of(ctx, struct ovl_readdir_data, ctx);		container_of(ctx, struct ovl_readdir_data, ctx);

	rdd->count++;		rdd->count++;
	if (!rdd->is_merge)		if (!rdd->is_lowest)
	return ovl_cache_entry_add_rb(rdd, name, namelen, ino, d_type);		return ovl_cache_entry_add_rb(rdd, name, namelen, ino, d_type);
	else		else
	return ovl_fill_lower(rdd, name, namelen, offset, ino, d_type);		return ovl_fill_lowest(rdd, name, namelen, offset, ino, d_type);
	}		}

	static int ovl_check_whiteouts(struct dentry dir, struct ovl_readdir_data rdd)		static int ovl_check_whiteouts(struct dentry dir, struct ovl_readdir_data rdd)
	@@ -289,7 +290,7 @@ static int ovl_dir_read_merged(struct dentry dentry, struct list_head list)
	.ctx.actor = ovl_fill_merge,		.ctx.actor = ovl_fill_merge,
	.list = list,		.list = list,
	.root = RB_ROOT,		.root = RB_ROOT,
	.is_merge = false,		.is_lowest = false,
	};		};
	int idx, next;		int idx, next;

	@@ -306,7 +307,7 @@ static int ovl_dir_read_merged(struct dentry dentry, struct list_head list)
	* allows offsets to be reasonably constant		* allows offsets to be reasonably constant
	*/		*/
	list_add(&rdd.middle, rdd.list);		list_add(&rdd.middle, rdd.list);
	rdd.is_merge = true;		rdd.is_lowest = true;
	err = ovl_dir_read(&realpath, &rdd);		err = ovl_dir_read(&realpath, &rdd);
	list_del(&rdd.middle);		list_del(&rdd.middle);
	}		}
	@@ -577,3 +578,39 @@ void ovl_cleanup_whiteouts(struct dentry upper, struct list_head list)
	}		}
	inode_unlock(upper->d_inode);		inode_unlock(upper->d_inode);
	}		}

			static int ovl_check_d_type(struct dir_context ctx, const char name,
			int namelen, loff_t offset, u64 ino,
			unsigned int d_type)
			{
			struct ovl_readdir_data *rdd =
			container_of(ctx, struct ovl_readdir_data, ctx);

			/* Even if d_type is not supported, DT_DIR is returned for . and .. */
			if (!strncmp(name, ".", namelen) \|\| !strncmp(name, "..", namelen))
			return 0;

			if (d_type != DT_UNKNOWN)
			rdd->d_type_supported = true;

			return 0;
			}

			/*
			* Returns 1 if d_type is supported, 0 not supported/unknown. Negative values
			* if error is encountered.
			*/
			int ovl_check_d_type_supported(struct path *realpath)
			{
			int err;
			struct ovl_readdir_data rdd = {
			.ctx.actor = ovl_check_d_type,
			.d_type_supported = false,
			};

			err = ovl_dir_read(realpath, &rdd);
			if (err)
			return err;

			return rdd.d_type_supported;
			}

fs/overlayfs/super.c

+17 −1

Original line number	Original line	Diff line number	Diff line
	@@ -936,6 +936,7 @@ static int ovl_fill_super(struct super_block sb, void data, int silent)

	err = -EINVAL;		err = -EINVAL;
	if (!ufs->config.lowerdir) {		if (!ufs->config.lowerdir) {
			if (!silent)
	pr_err("overlayfs: missing 'lowerdir'\n");		pr_err("overlayfs: missing 'lowerdir'\n");
	goto out_free_config;		goto out_free_config;
	}		}
	@@ -1028,6 +1029,21 @@ static int ovl_fill_super(struct super_block sb, void data, int silent)
	sb->s_flags \|= MS_RDONLY;		sb->s_flags \|= MS_RDONLY;
	ufs->workdir = NULL;		ufs->workdir = NULL;
	}		}

			/*
			* Upper should support d_type, else whiteouts are visible.
			* Given workdir and upper are on same fs, we can do
			* iterate_dir() on workdir.
			*/
			err = ovl_check_d_type_supported(&workpath);
			if (err < 0)
			goto out_put_workdir;

			if (!err) {
			pr_err("overlayfs: upper fs needs to support d_type.\n");
			err = -EINVAL;
			goto out_put_workdir;
			}
	}		}

	err = -ENOMEM;		err = -ENOMEM;