Commit f3a15685 authored by Amir Goldstein's avatar Amir Goldstein Committed by Miklos Szeredi
Browse files

ovl: mark upper merge dir with type origin entries "impure" 



An upper dir is marked "impure" to let ovl_iterate() know that this
directory may contain non pure upper entries whose d_ino may need to be
read from the origin inode.

We already mark a non-merge dir "impure" when moving a non-pure child
entry inside it, to let ovl_iterate() know not to iterate the non-merge
dir directly.

Mark also a merge dir "impure" when moving a non-pure child entry inside
it and when copying up a child entry inside it.

This can be used to optimize ovl_iterate() to perform a "pure merge" of
upper and lower directories, merging the content of the directories,
without having to read d_ino from origin inodes.

Signed-off-by: default avatarAmir Goldstein <amir73il@gmail.com>
Signed-off-by: default avatarMiklos Szeredi <mszeredi@redhat.com>
parent ee1d6d37

fs/overlayfs/copy_up.c

+5 −0
Original line number Diff line number Diff line
@@ -459,6 +459,11 @@ static int ovl_copy_up_one(struct dentry *parent, struct dentry *dentry, 
	ovl_path_upper(parent, &parentpath);

	upperdir = parentpath.dentry;



	/* Mark parent "impure" because it may now contain non-pure upper */

	err = ovl_set_impure(parent, upperdir);

	if (err)

		return err;



	err = vfs_getattr(&parentpath, &pstat,

			  STATX_ATIME | STATX_MTIME, AT_STATX_SYNC_AS_STAT);

	if (err)

fs/overlayfs/dir.c

+5 −26
Original line number Diff line number Diff line
@@ -149,22 +149,6 @@ static int ovl_set_opaque(struct dentry *dentry, struct dentry *upperdentry) 
	return ovl_set_opaque_xerr(dentry, upperdentry, -EIO);

}



static int ovl_set_impure(struct dentry *dentry, struct dentry *upperdentry)

{

	int err;



	/*

	 * Do not fail when upper doesn't support xattrs.

	 * Upper inodes won't have origin nor redirect xattr anyway.

	 */

	err = ovl_check_setxattr(dentry, upperdentry, OVL_XATTR_IMPURE,

				 "y", 1, 0);

	if (!err)

		ovl_dentry_set_impure(dentry);



	return err;

}



/* Common operations required to be done after creation of file on upper */

static void ovl_instantiate(struct dentry *dentry, struct inode *inode,

			    struct dentry *newdentry, bool hardlink)
@@ -976,21 +960,16 @@ static int ovl_rename(struct inode *olddir, struct dentry *old, 
	if (!samedir) {

		/*

		 * When moving a merge dir or non-dir with copy up origin into

		 * a non-merge upper dir (a.k.a pure upper dir), we are making

		 * the target parent dir "impure". ovl_iterate() iterates pure

		 * upper dirs directly, because there is no need to filter out

		 * whiteouts and merge dir content with lower dir. But for the

		 * case of an "impure" upper dir, ovl_iterate() cannot iterate

		 * the real directory directly, because it looks for the inode

		 * numbers to fill d_ino in the entries origin inode.

		 * a new parent, we are marking the new parent dir "impure".

		 * When ovl_iterate() iterates an "impure" upper dir, it will

		 * lookup the origin inodes of the entries to fill d_ino.

		 */

		if (ovl_type_origin(old) && !ovl_type_merge(new->d_parent)) {

		if (ovl_type_origin(old)) {

			err = ovl_set_impure(new->d_parent, new_upperdir);

			if (err)

				goto out_revert_creds;

		}

		if (!overwrite && ovl_type_origin(new) &&

		    !ovl_type_merge(old->d_parent)) {

		if (!overwrite && ovl_type_origin(new)) {

			err = ovl_set_impure(old->d_parent, old_upperdir);

			if (err)

				goto out_revert_creds;

fs/overlayfs/namei.c

+0 −20
Original line number Diff line number Diff line
@@ -167,31 +167,11 @@ invalid: 
	goto out;

}



static bool ovl_check_dir_xattr(struct dentry *dentry, const char *name)

{

	int res;

	char val;



	if (!d_is_dir(dentry))

		return false;



	res = vfs_getxattr(dentry, name, &val, 1);

	if (res == 1 && val == 'y')

		return true;



	return false;

}



static bool ovl_is_opaquedir(struct dentry *dentry)

{

	return ovl_check_dir_xattr(dentry, OVL_XATTR_OPAQUE);

}



static bool ovl_is_impuredir(struct dentry *dentry)

{

	return ovl_check_dir_xattr(dentry, OVL_XATTR_IMPURE);

}



static int ovl_lookup_single(struct dentry *base, struct ovl_lookup_data *d,

			     const char *name, unsigned int namelen,

			     size_t prelen, const char *post,

fs/overlayfs/overlayfs.h

+11 −4
Original line number Diff line number Diff line
@@ -207,7 +207,6 @@ bool ovl_dentry_is_opaque(struct dentry *dentry); 
bool ovl_dentry_is_impure(struct dentry *dentry);

bool ovl_dentry_is_whiteout(struct dentry *dentry);

void ovl_dentry_set_opaque(struct dentry *dentry);

void ovl_dentry_set_impure(struct dentry *dentry);

bool ovl_redirect_dir(struct super_block *sb);

const char *ovl_dentry_get_redirect(struct dentry *dentry);

void ovl_dentry_set_redirect(struct dentry *dentry, const char *redirect);
@@ -221,6 +220,17 @@ bool ovl_is_whiteout(struct dentry *dentry); 
struct file *ovl_path_open(struct path *path, int flags);

int ovl_copy_up_start(struct dentry *dentry);

void ovl_copy_up_end(struct dentry *dentry);

bool ovl_check_dir_xattr(struct dentry *dentry, const char *name);

int ovl_check_setxattr(struct dentry *dentry, struct dentry *upperdentry,

		       const char *name, const void *value, size_t size,

		       int xerr);

int ovl_set_impure(struct dentry *dentry, struct dentry *upperdentry);



static inline bool ovl_is_impuredir(struct dentry *dentry)

{

	return ovl_check_dir_xattr(dentry, OVL_XATTR_IMPURE);

}





/* namei.c */

int ovl_path_next(int idx, struct dentry *dentry, struct path *path);
@@ -281,6 +291,3 @@ int ovl_copy_up(struct dentry *dentry); 
int ovl_copy_up_flags(struct dentry *dentry, int flags);

int ovl_copy_xattr(struct dentry *old, struct dentry *new);

int ovl_set_attr(struct dentry *upper, struct kstat *stat);
 
int ovl_check_setxattr(struct dentry *dentry, struct dentry *upperdentry,

		       const char *name, const void *value, size_t size,

		       int xerr);

fs/overlayfs/super.c

+4 −1
Original line number Diff line number Diff line
@@ -974,7 +974,10 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent) 
	path_put(&workpath);

	kfree(lowertmp);



	if (upperpath.dentry) {

		oe->__upperdentry = upperpath.dentry;

		oe->impure = ovl_is_impuredir(upperpath.dentry);

	}

	for (i = 0; i < numlower; i++) {

		oe->lowerstack[i].dentry = stack[i].dentry;

		oe->lowerstack[i].mnt = ufs->lower_mnt[i];

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