Commit 243d5067 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'overlayfs-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs 

Pull overlayfs updates from Miklos Szeredi:
 "Various fixes and tweaks"

* 'overlayfs-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs:
  ovl: cleanup unused var in rename2
  ovl: rename is_merge to is_lowest
  ovl: fixed coding style warning
  ovl: Ensure upper filesystem supports d_type
  ovl: Warn on copy up if a process has a R/O fd open to the lower file
  ovl: honor flag MS_SILENT at mount
  ovl: verify upper dentry before unlink and rename
parents 9f15dec8 6986c012

fs/overlayfs/copy_up.c

+35 −0
Original line number Diff line number Diff line
@@ -7,6 +7,7 @@ 
 * the Free Software Foundation.

 */



#include <linux/module.h>

#include <linux/fs.h>

#include <linux/slab.h>

#include <linux/file.h>
@@ -16,10 +17,41 @@ 
#include <linux/uaccess.h>

#include <linux/sched.h>

#include <linux/namei.h>

#include <linux/fdtable.h>

#include <linux/ratelimit.h>

#include "overlayfs.h"



#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)

{

	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)) {

		struct path upperpath;



		ovl_path_upper(dentry, &upperpath);

		BUG_ON(upperpath.dentry != NULL);

		upperpath.dentry = newdentry;
@@ -309,6 +342,8 @@ int ovl_copy_up_one(struct dentry *parent, struct dentry *dentry, 
	if (WARN_ON(!workdir))

		return -EROFS;



	ovl_do_check_copy_up(lowerpath->dentry);



	ovl_path_upper(parent, &parentpath);

	upperdir = parentpath.dentry;

fs/overlayfs/dir.c

+38 −23
Original line number 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 inode *dir = upperdir->d_inode;

	struct dentry *upper = ovl_dentry_upper(dentry);

	struct dentry *upper;

	int err;



	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;

	if (upper->d_parent == upperdir) {

		/* Don't let d_delete() think it can reset d_inode */

		dget(upper);

	if (upper == ovl_dentry_upper(dentry)) {

		if (is_dir)

			err = vfs_rmdir(dir, upper);

		else

			err = vfs_unlink(dir, upper, NULL);

		dput(upper);

		ovl_dentry_version_inc(dentry->d_parent);

	}

	dput(upper);



	/*

	 * 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)

		d_drop(dentry);

out_unlock:

	inode_unlock(dir);



	return err;
@@ -714,7 +719,6 @@ static int ovl_rename2(struct inode *olddir, struct dentry *old, 
	struct dentry *trap;

	bool old_opaque;

	bool new_opaque;

	bool new_create = false;

	bool cleanup_whiteout = false;

	bool overwrite = !(flags & RENAME_EXCHANGE);

	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);



	olddentry = ovl_dentry_upper(old);

	newdentry = ovl_dentry_upper(new);

	if (newdentry) {

		if (opaquedir) {

			newdentry = opaquedir;

			opaquedir = NULL;

		} else {

			dget(newdentry);

		}

	} else {

		new_create = true;



	olddentry = lookup_one_len(old->d_name.name, old_upperdir,

				   old->d_name.len);

	err = PTR_ERR(olddentry);

	if (IS_ERR(olddentry))

		goto out_unlock;



	err = -ESTALE;

	if (olddentry != ovl_dentry_upper(old))

		goto out_dput_old;



	newdentry = lookup_one_len(new->d_name.name, new_upperdir,

				   new->d_name.len);

	err = PTR_ERR(newdentry);

	if (IS_ERR(newdentry))

			goto out_unlock;

	}

		goto out_dput_old;



	err = -ESTALE;

	if (olddentry->d_parent != old_upperdir)

	if (ovl_dentry_upper(new)) {

		if (opaquedir) {

			if (newdentry != opaquedir)

				goto out_dput;

	if (newdentry->d_parent != new_upperdir)

		} else {

			if (newdentry != ovl_dentry_upper(new))

				goto out_dput;

		}

	} else {

		if (!d_is_negative(newdentry) &&

		    (!new_opaque || !ovl_is_whiteout(newdentry)))

			goto out_dput;

	}



	if (olddentry == trap)

		goto out_dput;

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


out_dput:

	dput(newdentry);

out_dput_old:

	dput(olddentry);

out_unlock:

	unlock_rename(new_upperdir, old_upperdir);

out_revert_creds:

fs/overlayfs/overlayfs.h

+1 −0
Original line number 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);

void ovl_cleanup_whiteouts(struct dentry *upper, struct list_head *list);

void ovl_cache_free(struct list_head *list);

int ovl_check_d_type_supported(struct path *realpath);



/* inode.c */

int ovl_setattr(struct dentry *dentry, struct iattr *attr);

fs/overlayfs/readdir.c

+45 −8
Original line number Diff line number Diff line
@@ -36,13 +36,14 @@ struct ovl_dir_cache { 


struct ovl_readdir_data {

	struct dir_context ctx;

	bool is_merge;

	bool is_lowest;

	struct rb_root root;

	struct list_head *list;

	struct list_head middle;

	struct ovl_cache_entry *first_maybe_whiteout;

	int count;

	int err;

	bool d_type_supported;

};



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

			   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);



	rdd->count++;

	if (!rdd->is_merge)

	if (!rdd->is_lowest)

		return ovl_cache_entry_add_rb(rdd, name, namelen, ino, d_type);

	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)
@@ -289,7 +290,7 @@ static int ovl_dir_read_merged(struct dentry *dentry, struct list_head *list) 
		.ctx.actor = ovl_fill_merge,

		.list = list,

		.root = RB_ROOT,

		.is_merge = false,

		.is_lowest = false,

	};

	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

			 */

			list_add(&rdd.middle, rdd.list);

			rdd.is_merge = true;

			rdd.is_lowest = true;

			err = ovl_dir_read(&realpath, &rdd);

			list_del(&rdd.middle);

		}
@@ -577,3 +578,39 @@ void ovl_cleanup_whiteouts(struct dentry *upper, struct list_head *list) 
	}

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


	err = -EINVAL;

	if (!ufs->config.lowerdir) {

		if (!silent)

			pr_err("overlayfs: missing 'lowerdir'\n");

		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;

			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;

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