Commit c7747faf authored by Al Viro's avatar Al Viro
Browse files

functionfs: switch to simple_remove_by_name() 



No need to return dentry from ffs_sb_create_file() or keep it around
afterwards.

To avoid subtle issues with getting to ffs from epfiles in
ffs_epfiles_destroy(), pass the superblock as explicit argument.
Callers have it anyway.

Reviewed-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent e5bf5ee2

drivers/usb/gadget/function/f_fs.c

+22 −29
Original line number Diff line number Diff line
@@ -160,8 +160,6 @@ struct ffs_epfile { 
	struct ffs_data			*ffs;

	struct ffs_ep			*ep;	/* P: ffs->eps_lock */



	struct dentry			*dentry;



	/*

	 * Buffer for holding data from partial reads which may happen since

	 * we’re rounding user read requests to a multiple of a max packet size.
@@ -271,11 +269,11 @@ struct ffs_desc_helper { 
};



static int  __must_check ffs_epfiles_create(struct ffs_data *ffs);

static void ffs_epfiles_destroy(struct ffs_epfile *epfiles, unsigned count);

static void ffs_epfiles_destroy(struct super_block *sb,

				struct ffs_epfile *epfiles, unsigned count);



static struct dentry *

ffs_sb_create_file(struct super_block *sb, const char *name, void *data,

		   const struct file_operations *fops);

static int ffs_sb_create_file(struct super_block *sb, const char *name,

			      void *data, const struct file_operations *fops);



/* Devices management *******************************************************/
@@ -1894,9 +1892,8 @@ ffs_sb_make_inode(struct super_block *sb, void *data, 
}



/* Create "regular" file */

static struct dentry *ffs_sb_create_file(struct super_block *sb,

					const char *name, void *data,

					const struct file_operations *fops)

static int ffs_sb_create_file(struct super_block *sb, const char *name,

			      void *data, const struct file_operations *fops)

{

	struct ffs_data	*ffs = sb->s_fs_info;

	struct dentry	*dentry;
@@ -1904,16 +1901,16 @@ static struct dentry *ffs_sb_create_file(struct super_block *sb, 


	dentry = d_alloc_name(sb->s_root, name);

	if (!dentry)

		return NULL;

		return -ENOMEM;



	inode = ffs_sb_make_inode(sb, data, fops, NULL, &ffs->file_perms);

	if (!inode) {

		dput(dentry);

		return NULL;

		return -ENOMEM;

	}



	d_add(dentry, inode);

	return dentry;

	return 0;

}



/* Super block */
@@ -1956,10 +1953,7 @@ static int ffs_sb_fill(struct super_block *sb, struct fs_context *fc) 
		return -ENOMEM;



	/* EP0 file */

	if (!ffs_sb_create_file(sb, "ep0", ffs, &ffs_ep0_operations))

		return -ENOMEM;



	return 0;

	return ffs_sb_create_file(sb, "ep0", ffs, &ffs_ep0_operations);

}



enum {
@@ -2196,7 +2190,7 @@ static void ffs_data_closed(struct ffs_data *ffs) 
							flags);



			if (epfiles)

				ffs_epfiles_destroy(epfiles,

				ffs_epfiles_destroy(ffs->sb, epfiles,

						 ffs->eps_count);



			if (ffs->setup_state == FFS_SETUP_PENDING)
@@ -2255,7 +2249,7 @@ static void ffs_data_clear(struct ffs_data *ffs) 
	 * copy of epfile will save us from use-after-free.

	 */

	if (epfiles) {

		ffs_epfiles_destroy(epfiles, ffs->eps_count);

		ffs_epfiles_destroy(ffs->sb, epfiles, ffs->eps_count);

		ffs->epfiles = NULL;

	}
@@ -2352,6 +2346,7 @@ static int ffs_epfiles_create(struct ffs_data *ffs) 
{

	struct ffs_epfile *epfile, *epfiles;

	unsigned i, count;

	int err;



	count = ffs->eps_count;

	epfiles = kcalloc(count, sizeof(*epfiles), GFP_KERNEL);
@@ -2368,12 +2363,11 @@ static int ffs_epfiles_create(struct ffs_data *ffs) 
			sprintf(epfile->name, "ep%02x", ffs->eps_addrmap[i]);

		else

			sprintf(epfile->name, "ep%u", i);

		epfile->dentry = ffs_sb_create_file(ffs->sb, epfile->name,

						 epfile,

						 &ffs_epfile_operations);

		if (!epfile->dentry) {

			ffs_epfiles_destroy(epfiles, i - 1);

			return -ENOMEM;

		err = ffs_sb_create_file(ffs->sb, epfile->name,

					 epfile, &ffs_epfile_operations);

		if (err) {

			ffs_epfiles_destroy(ffs->sb, epfiles, i - 1);

			return err;

		}

	}
@@ -2386,16 +2380,15 @@ static void clear_one(struct dentry *dentry) 
	smp_store_release(&dentry->d_inode->i_private, NULL);

}



static void ffs_epfiles_destroy(struct ffs_epfile *epfiles, unsigned count)

static void ffs_epfiles_destroy(struct super_block *sb,

				struct ffs_epfile *epfiles, unsigned count)

{

	struct ffs_epfile *epfile = epfiles;

	struct dentry *root = sb->s_root;



	for (; count; --count, ++epfile) {

		BUG_ON(mutex_is_locked(&epfile->mutex));

		if (epfile->dentry) {

			simple_recursive_removal(epfile->dentry, clear_one);

			epfile->dentry = NULL;

		}

		simple_remove_by_name(root, epfile->name, clear_one);

	}



	kfree(epfiles);