Commit e7f52429 authored by Amir Goldstein's avatar Amir Goldstein Committed by Miklos Szeredi
Browse files

ovl: check if upperdir fs supports O_TMPFILE 



This is needed for choosing between concurrent copyup
using O_TMPFILE and legacy copyup using workdir+rename.

Signed-off-by: default avatarAmir Goldstein <amir73il@gmail.com>
Signed-off-by: default avatarMiklos Szeredi <mszeredi@redhat.com>
parent bfe219d3

fs/overlayfs/overlayfs.h

+9 −0
Original line number Diff line number Diff line
@@ -127,6 +127,15 @@ static inline int ovl_do_whiteout(struct inode *dir, struct dentry *dentry) 
	return err;

}



static inline struct dentry *ovl_do_tmpfile(struct dentry *dentry, umode_t mode)

{

	struct dentry *ret = vfs_tmpfile(dentry, mode, 0);

	int err = IS_ERR(ret) ? PTR_ERR(ret) : 0;



	pr_debug("tmpfile(%pd2, 0%o) = %i\n", dentry, mode, err);

	return ret;

}



static inline struct inode *ovl_inode_real(struct inode *inode, bool *is_upper)

{

	unsigned long x = (unsigned long) READ_ONCE(inode->i_private);

fs/overlayfs/ovl_entry.h

+1 −0
Original line number Diff line number Diff line
@@ -27,6 +27,7 @@ struct ovl_fs { 
	struct ovl_config config;

	/* creds of process who forced instantiation of super block */

	const struct cred *creator_cred;

	bool tmpfile;

};



/* private information held for every overlayfs dentry */

fs/overlayfs/super.c

+10 −0
Original line number Diff line number Diff line
@@ -825,6 +825,8 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent) 
		 * creation of workdir in previous step.

		 */

		if (ufs->workdir) {

			struct dentry *temp;



			err = ovl_check_d_type_supported(&workpath);

			if (err < 0)

				goto out_put_workdir;
@@ -836,6 +838,14 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent) 
			 */

			if (!err)

				pr_warn("overlayfs: upper fs needs to support d_type.\n");



			/* Check if upper/work fs supports O_TMPFILE */

			temp = ovl_do_tmpfile(ufs->workdir, S_IFREG | 0);

			ufs->tmpfile = !IS_ERR(temp);

			if (ufs->tmpfile)

				dput(temp);

			else

				pr_warn("overlayfs: upper fs does not support tmpfile.\n");

		}

	}