Commit 94375f9d authored by Amir Goldstein's avatar Amir Goldstein Committed by Miklos Szeredi
Browse files

ovl: generalize the lower_layers[] array 



Rename lower_layers[] array to layers[], extend its size by one and
initialize layers[0] with upper layer values.  Lower layers are now
addressed with index 1..numlower.  layers[0] is reserved even with lower
only overlay.

[SzM: replace ofs->numlower with ofs->numlayer, the latter's value is
incremented by one]

Signed-off-by: default avatarAmir Goldstein <amir73il@gmail.com>
Signed-off-by: default avatarMiklos Szeredi <mszeredi@redhat.com>
parent b504c654

fs/overlayfs/export.c

+2 −4
Original line number Diff line number Diff line
@@ -424,7 +424,6 @@ static struct dentry *ovl_lookup_real_inode(struct super_block *sb, 
					    struct ovl_layer *layer)

{

	struct ovl_fs *ofs = sb->s_fs_info;

	struct ovl_layer upper_layer = { .mnt = ofs->upper_mnt };

	struct dentry *index = NULL;

	struct dentry *this = NULL;

	struct inode *inode;
@@ -466,7 +465,7 @@ static struct dentry *ovl_lookup_real_inode(struct super_block *sb, 
		 * recursive call walks back from indexed upper to the topmost

		 * connected/hashed upper parent (or up to root).

		 */

		this = ovl_lookup_real(sb, upper, &upper_layer);

		this = ovl_lookup_real(sb, upper, &ofs->layers[0]);

		dput(upper);

	}
@@ -646,8 +645,7 @@ static struct dentry *ovl_get_dentry(struct super_block *sb, 
				     struct dentry *index)

{

	struct ovl_fs *ofs = sb->s_fs_info;

	struct ovl_layer upper_layer = { .mnt = ofs->upper_mnt };

	struct ovl_layer *layer = upper ? &upper_layer : lowerpath->layer;

	struct ovl_layer *layer = upper ? &ofs->layers[0] : lowerpath->layer;

	struct dentry *real = upper ?: (index ?: lowerpath->dentry);



	/*

fs/overlayfs/namei.c

+6 −6
Original line number Diff line number Diff line
@@ -322,16 +322,16 @@ int ovl_check_origin_fh(struct ovl_fs *ofs, struct ovl_fh *fh, bool connected, 
	struct dentry *origin = NULL;

	int i;



	for (i = 0; i < ofs->numlower; i++) {

	for (i = 1; i < ofs->numlayer; i++) {

		/*

		 * If lower fs uuid is not unique among lower fs we cannot match

		 * fh->uuid to layer.

		 */

		if (ofs->lower_layers[i].fsid &&

		    ofs->lower_layers[i].fs->bad_uuid)

		if (ofs->layers[i].fsid &&

		    ofs->layers[i].fs->bad_uuid)

			continue;



		origin = ovl_decode_real_fh(fh, ofs->lower_layers[i].mnt,

		origin = ovl_decode_real_fh(fh, ofs->layers[i].mnt,

					    connected);

		if (origin)

			break;
@@ -354,7 +354,7 @@ int ovl_check_origin_fh(struct ovl_fs *ofs, struct ovl_fh *fh, bool connected, 
	}

	**stackp = (struct ovl_path){

		.dentry = origin,

		.layer = &ofs->lower_layers[i]

		.layer = &ofs->layers[i]

	};



	return 0;
@@ -885,7 +885,7 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry, 


	if (!d.stop && poe->numlower) {

		err = -ENOMEM;

		stack = kcalloc(ofs->numlower, sizeof(struct ovl_path),

		stack = kcalloc(ofs->numlayer - 1, sizeof(struct ovl_path),

				GFP_KERNEL);

		if (!stack)

			goto out_put_upper;

fs/overlayfs/ovl_entry.h

+2 −2
Original line number Diff line number Diff line
@@ -45,10 +45,10 @@ struct ovl_path { 
/* private information held for overlayfs's superblock */

struct ovl_fs {

	struct vfsmount *upper_mnt;

	unsigned int numlower;

	unsigned int numlayer;

	/* Number of unique lower sb that differ from upper sb */

	unsigned int numlowerfs;

	struct ovl_layer *lower_layers;

	struct ovl_layer *layers;

	struct ovl_sb *lower_fs;

	/* workbasedir is the path at workdir= mount option */

	struct dentry *workbasedir;

fs/overlayfs/super.c

+25 −19
Original line number Diff line number Diff line
@@ -224,13 +224,13 @@ static void ovl_free_fs(struct ovl_fs *ofs) 
	if (ofs->upperdir_locked)

		ovl_inuse_unlock(ofs->upper_mnt->mnt_root);

	mntput(ofs->upper_mnt);

	for (i = 0; i < ofs->numlower; i++) {

		iput(ofs->lower_layers[i].trap);

		mntput(ofs->lower_layers[i].mnt);

	for (i = 1; i < ofs->numlayer; i++) {

		iput(ofs->layers[i].trap);

		mntput(ofs->layers[i].mnt);

	}

	for (i = 0; i < ofs->numlowerfs; i++)

		free_anon_bdev(ofs->lower_fs[i].pseudo_dev);

	kfree(ofs->lower_layers);

	kfree(ofs->layers);

	kfree(ofs->lower_fs);



	kfree(ofs->config.lowerdir);
@@ -1319,16 +1319,16 @@ static int ovl_get_fsid(struct ovl_fs *ofs, const struct path *path) 
	return ofs->numlowerfs;

}



static int ovl_get_lower_layers(struct super_block *sb, struct ovl_fs *ofs,

static int ovl_get_layers(struct super_block *sb, struct ovl_fs *ofs,

			  struct path *stack, unsigned int numlower)

{

	int err;

	unsigned int i;



	err = -ENOMEM;

	ofs->lower_layers = kcalloc(numlower, sizeof(struct ovl_layer),

	ofs->layers = kcalloc(numlower + 1, sizeof(struct ovl_layer),

			      GFP_KERNEL);

	if (ofs->lower_layers == NULL)

	if (ofs->layers == NULL)

		goto out;



	ofs->lower_fs = kcalloc(numlower, sizeof(struct ovl_sb),
@@ -1336,6 +1336,12 @@ static int ovl_get_lower_layers(struct super_block *sb, struct ovl_fs *ofs, 
	if (ofs->lower_fs == NULL)

		goto out;



	/* idx 0 is reserved for upper fs even with lower only overlay */

	ofs->layers[0].mnt = ofs->upper_mnt;

	ofs->layers[0].idx = 0;

	ofs->layers[0].fsid = 0;

	ofs->numlayer = 1;



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

		struct vfsmount *mnt;

		struct inode *trap;
@@ -1369,15 +1375,15 @@ static int ovl_get_lower_layers(struct super_block *sb, struct ovl_fs *ofs, 
		 */

		mnt->mnt_flags |= MNT_READONLY | MNT_NOATIME;



		ofs->lower_layers[ofs->numlower].trap = trap;

		ofs->lower_layers[ofs->numlower].mnt = mnt;

		ofs->lower_layers[ofs->numlower].idx = i + 1;

		ofs->lower_layers[ofs->numlower].fsid = fsid;

		ofs->layers[ofs->numlayer].trap = trap;

		ofs->layers[ofs->numlayer].mnt = mnt;

		ofs->layers[ofs->numlayer].idx = ofs->numlayer;

		ofs->layers[ofs->numlayer].fsid = fsid;

		if (fsid) {

			ofs->lower_layers[ofs->numlower].fs =

			ofs->layers[ofs->numlayer].fs =

				&ofs->lower_fs[fsid - 1];

		}

		ofs->numlower++;

		ofs->numlayer++;

	}



	/*
@@ -1464,7 +1470,7 @@ static struct ovl_entry *ovl_get_lowerstack(struct super_block *sb, 
		goto out_err;

	}



	err = ovl_get_lower_layers(sb, ofs, stack, numlower);

	err = ovl_get_layers(sb, ofs, stack, numlower);

	if (err)

		goto out_err;
@@ -1475,7 +1481,7 @@ static struct ovl_entry *ovl_get_lowerstack(struct super_block *sb, 


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

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

		oe->lowerstack[i].layer = &ofs->lower_layers[i];

		oe->lowerstack[i].layer = &ofs->layers[i+1];

	}



	if (remote)
@@ -1556,9 +1562,9 @@ static int ovl_check_overlapping_layers(struct super_block *sb, 
			return err;

	}



	for (i = 0; i < ofs->numlower; i++) {

	for (i = 1; i < ofs->numlayer; i++) {

		err = ovl_check_layer(sb, ofs,

				      ofs->lower_layers[i].mnt->mnt_root,

				      ofs->layers[i].mnt->mnt_root,

				      "lowerdir");

		if (err)

			return err;

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