21 files changed, 259 insertions, 125 deletions

diff --git a/fs/Makefile b/fs/Makefile
index 34a1b9dea6dd..da0bbb456d3f 100644
--- a/fs/Makefile
+++ b/fs/Makefile
@@ -104,7 +104,7 @@ obj-$(CONFIG_QNX6FS_FS)		+= qnx6/
 obj-$(CONFIG_AUTOFS4_FS)	+= autofs4/
 obj-$(CONFIG_ADFS_FS)		+= adfs/
 obj-$(CONFIG_FUSE_FS)		+= fuse/
-obj-$(CONFIG_OVERLAYFS_FS)	+= overlayfs/
+obj-$(CONFIG_OVERLAY_FS)	+= overlayfs/
 obj-$(CONFIG_UDF_FS)		+= udf/
 obj-$(CONFIG_SUN_OPENPROMFS)	+= openpromfs/
 obj-$(CONFIG_OMFS_FS)		+= omfs/
diff --git a/fs/aio.c b/fs/aio.c
index 84a751005f5b..14b93159ef83 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -165,6 +165,15 @@ static struct vfsmount *aio_mnt;
 static const struct file_operations aio_ring_fops;
 static const struct address_space_operations aio_ctx_aops;
 
+/* Backing dev info for aio fs.
+ * -no dirty page accounting or writeback happens
+ */
+static struct backing_dev_info aio_fs_backing_dev_info = {
+	.name           = "aiofs",
+	.state          = 0,
+	.capabilities   = BDI_CAP_NO_ACCT_AND_WRITEBACK | BDI_CAP_MAP_COPY,
+};
+
 static struct file *aio_private_file(struct kioctx *ctx, loff_t nr_pages)
 {
 	struct qstr this = QSTR_INIT("[aio]", 5);
@@ -176,6 +185,7 @@ static struct file *aio_private_file(struct kioctx *ctx, loff_t nr_pages)
 
 	inode->i_mapping->a_ops = &aio_ctx_aops;
 	inode->i_mapping->private_data = ctx;
+	inode->i_mapping->backing_dev_info = &aio_fs_backing_dev_info;
 	inode->i_size = PAGE_SIZE * nr_pages;
 
 	path.dentry = d_alloc_pseudo(aio_mnt->mnt_sb, &this);
@@ -220,6 +230,9 @@ static int __init aio_setup(void)
 	if (IS_ERR(aio_mnt))
 		panic("Failed to create aio fs mount.");
 
+	if (bdi_init(&aio_fs_backing_dev_info))
+		panic("Failed to init aio fs backing dev info.");
+
 	kiocb_cachep = KMEM_CACHE(kiocb, SLAB_HWCACHE_ALIGN|SLAB_PANIC);
 	kioctx_cachep = KMEM_CACHE(kioctx,SLAB_HWCACHE_ALIGN|SLAB_PANIC);
 
@@ -281,11 +294,6 @@ static const struct file_operations aio_ring_fops = {
 	.mmap = aio_ring_mmap,
 };
 
-static int aio_set_page_dirty(struct page *page)
-{
-	return 0;
-}
-
 #if IS_ENABLED(CONFIG_MIGRATION)
 static int aio_migratepage(struct address_space *mapping, struct page *new,
 			struct page *old, enum migrate_mode mode)
@@ -357,7 +365,7 @@ out:
 #endif
 
 static const struct address_space_operations aio_ctx_aops = {
-	.set_page_dirty = aio_set_page_dirty,
+	.set_page_dirty = __set_page_dirty_no_writeback,
 #if IS_ENABLED(CONFIG_MIGRATION)
 	.migratepage	= aio_migratepage,
 #endif
@@ -412,7 +420,6 @@ static int aio_setup_ring(struct kioctx *ctx)
 		pr_debug("pid(%d) page[%d]->count=%d\n",
 			 current->pid, i, page_count(page));
 		SetPageUptodate(page);
-		SetPageDirty(page);
 		unlock_page(page);
 
 		ctx->ring_pages[i] = page;
diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c
index d3220d31d3cb..dcd9be32ac57 100644
--- a/fs/btrfs/compression.c
+++ b/fs/btrfs/compression.c
@@ -1011,8 +1011,6 @@ int btrfs_decompress_buf2page(char *buf, unsigned long buf_start,
 		bytes = min(bytes, working_bytes);
 		kaddr = kmap_atomic(page_out);
 		memcpy(kaddr + *pg_offset, buf + buf_offset, bytes);
-		if (*pg_index == (vcnt - 1) && *pg_offset == 0)
-			memset(kaddr + bytes, 0, PAGE_CACHE_SIZE - bytes);
 		kunmap_atomic(kaddr);
 		flush_dcache_page(page_out);
 
@@ -1054,3 +1052,34 @@ int btrfs_decompress_buf2page(char *buf, unsigned long buf_start,
 
 	return 1;
 }
+
+/*
+ * When uncompressing data, we need to make sure and zero any parts of
+ * the biovec that were not filled in by the decompression code.  pg_index
+ * and pg_offset indicate the last page and the last offset of that page
+ * that have been filled in.  This will zero everything remaining in the
+ * biovec.
+ */
+void btrfs_clear_biovec_end(struct bio_vec *bvec, int vcnt,
+				   unsigned long pg_index,
+				   unsigned long pg_offset)
+{
+	while (pg_index < vcnt) {
+		struct page *page = bvec[pg_index].bv_page;
+		unsigned long off = bvec[pg_index].bv_offset;
+		unsigned long len = bvec[pg_index].bv_len;
+
+		if (pg_offset < off)
+			pg_offset = off;
+		if (pg_offset < off + len) {
+			unsigned long bytes = off + len - pg_offset;
+			char *kaddr;
+
+			kaddr = kmap_atomic(page);
+			memset(kaddr + pg_offset, 0, bytes);
+			kunmap_atomic(kaddr);
+		}
+		pg_index++;
+		pg_offset = 0;
+	}
+}
diff --git a/fs/btrfs/compression.h b/fs/btrfs/compression.h
index 0c803b4fbf93..d181f70caae0 100644
--- a/fs/btrfs/compression.h
+++ b/fs/btrfs/compression.h
@@ -45,7 +45,9 @@ int btrfs_submit_compressed_write(struct inode *inode, u64 start,
 				  unsigned long nr_pages);
 int btrfs_submit_compressed_read(struct inode *inode, struct bio *bio,
 				 int mirror_num, unsigned long bio_flags);
-
+void btrfs_clear_biovec_end(struct bio_vec *bvec, int vcnt,
+				   unsigned long pg_index,
+				   unsigned long pg_offset);
 struct btrfs_compress_op {
 	struct list_head *(*alloc_workspace)(void);
 
diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index 19bc6162fb8e..150822ee0a0b 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -80,13 +80,6 @@ noinline void btrfs_clear_path_blocking(struct btrfs_path *p,
 {
 	int i;
 
-#ifdef CONFIG_DEBUG_LOCK_ALLOC
-	/* lockdep really cares that we take all of these spinlocks
-	 * in the right order.  If any of the locks in the path are not
-	 * currently blocking, it is going to complain.  So, make really
-	 * really sure by forcing the path to blocking before we clear
-	 * the path blocking.
-	 */
 	if (held) {
 		btrfs_set_lock_blocking_rw(held, held_rw);
 		if (held_rw == BTRFS_WRITE_LOCK)
@@ -95,7 +88,6 @@ noinline void btrfs_clear_path_blocking(struct btrfs_path *p,
 			held_rw = BTRFS_READ_LOCK_BLOCKING;
 	}
 	btrfs_set_path_blocking(p);
-#endif
 
 	for (i = BTRFS_MAX_LEVEL - 1; i >= 0; i--) {
 		if (p->nodes[i] && p->locks[i]) {
@@ -107,10 +99,8 @@ noinline void btrfs_clear_path_blocking(struct btrfs_path *p,
 		}
 	}
 
-#ifdef CONFIG_DEBUG_LOCK_ALLOC
 	if (held)
 		btrfs_clear_lock_blocking_rw(held, held_rw);
-#endif
 }
 
 /* this also releases the path */
@@ -2893,7 +2883,7 @@ cow_done:
 					}
 					p->locks[level] = BTRFS_WRITE_LOCK;
 				} else {
-					err = btrfs_try_tree_read_lock(b);
+					err = btrfs_tree_read_lock_atomic(b);
 					if (!err) {
 						btrfs_set_path_blocking(p);
 						btrfs_tree_read_lock(b);
@@ -3025,7 +3015,7 @@ again:
 			}
 
 			level = btrfs_header_level(b);
-			err = btrfs_try_tree_read_lock(b);
+			err = btrfs_tree_read_lock_atomic(b);
 			if (!err) {
 				btrfs_set_path_blocking(p);
 				btrfs_tree_read_lock(b);
diff --git a/fs/btrfs/locking.c b/fs/btrfs/locking.c
index 5665d2149249..f8229ef1b46d 100644
--- a/fs/btrfs/locking.c
+++ b/fs/btrfs/locking.c
@@ -128,6 +128,26 @@ again:
 }
 
 /*
+ * take a spinning read lock.
+ * returns 1 if we get the read lock and 0 if we don't
+ * this won't wait for blocking writers
+ */
+int btrfs_tree_read_lock_atomic(struct extent_buffer *eb)
+{
+	if (atomic_read(&eb->blocking_writers))
+		return 0;
+
+	read_lock(&eb->lock);
+	if (atomic_read(&eb->blocking_writers)) {
+		read_unlock(&eb->lock);
+		return 0;
+	}
+	atomic_inc(&eb->read_locks);
+	atomic_inc(&eb->spinning_readers);
+	return 1;
+}
+
+/*
  * returns 1 if we get the read lock and 0 if we don't
  * this won't wait for blocking writers
  */
@@ -158,9 +178,7 @@ int btrfs_try_tree_write_lock(struct extent_buffer *eb)
 	    atomic_read(&eb->blocking_readers))
 		return 0;
 
-	if (!write_trylock(&eb->lock))
-		return 0;
-
+	write_lock(&eb->lock);
 	if (atomic_read(&eb->blocking_writers) ||
 	    atomic_read(&eb->blocking_readers)) {
 		write_unlock(&eb->lock);
diff --git a/fs/btrfs/locking.h b/fs/btrfs/locking.h
index b81e0e9a4894..c44a9d5f5362 100644
--- a/fs/btrfs/locking.h
+++ b/fs/btrfs/locking.h
@@ -35,6 +35,8 @@ void btrfs_clear_lock_blocking_rw(struct extent_buffer *eb, int rw);
 void btrfs_assert_tree_locked(struct extent_buffer *eb);
 int btrfs_try_tree_read_lock(struct extent_buffer *eb);
 int btrfs_try_tree_write_lock(struct extent_buffer *eb);
+int btrfs_tree_read_lock_atomic(struct extent_buffer *eb);
+
 
 static inline void btrfs_tree_unlock_rw(struct extent_buffer *eb, int rw)
 {
diff --git a/fs/btrfs/lzo.c b/fs/btrfs/lzo.c
index 78285f30909e..617553cdb7d3 100644
--- a/fs/btrfs/lzo.c
+++ b/fs/btrfs/lzo.c
@@ -373,6 +373,8 @@ cont:
 	}
 done:
 	kunmap(pages_in[page_in_index]);
+	if (!ret)
+		btrfs_clear_biovec_end(bvec, vcnt, page_out_index, pg_offset);
 	return ret;
 }
 
@@ -410,10 +412,23 @@ static int lzo_decompress(struct list_head *ws, unsigned char *data_in,
 		goto out;
 	}
 
+	/*
+	 * the caller is already checking against PAGE_SIZE, but lets
+	 * move this check closer to the memcpy/memset
+	 */
+	destlen = min_t(unsigned long, destlen, PAGE_SIZE);
 	bytes = min_t(unsigned long, destlen, out_len - start_byte);
 
 	kaddr = kmap_atomic(dest_page);
 	memcpy(kaddr, workspace->buf + start_byte, bytes);
+
+	/*
+	 * btrfs_getblock is doing a zero on the tail of the page too,
+	 * but this will cover anything missing from the decompressed
+	 * data.
+	 */
+	if (bytes < destlen)
+		memset(kaddr+bytes, 0, destlen-bytes);
 	kunmap_atomic(kaddr);
 out:
 	return ret;
diff --git a/fs/btrfs/zlib.c b/fs/btrfs/zlib.c
index 759fa4e2de8f..fb22fd8d8fb8 100644
--- a/fs/btrfs/zlib.c
+++ b/fs/btrfs/zlib.c
@@ -299,6 +299,8 @@ done:
 	zlib_inflateEnd(&workspace->strm);
 	if (data_in)
 		kunmap(pages_in[page_in_index]);
+	if (!ret)
+		btrfs_clear_biovec_end(bvec, vcnt, page_out_index, pg_offset);
 	return ret;
 }
 
@@ -310,10 +312,14 @@ static int zlib_decompress(struct list_head *ws, unsigned char *data_in,
 	struct workspace *workspace = list_entry(ws, struct workspace, list);
 	int ret = 0;
 	int wbits = MAX_WBITS;
-	unsigned long bytes_left = destlen;
+	unsigned long bytes_left;
 	unsigned long total_out = 0;
+	unsigned long pg_offset = 0;
 	char *kaddr;
 
+	destlen = min_t(unsigned long, destlen, PAGE_SIZE);
+	bytes_left = destlen;
+
 	workspace->strm.next_in = data_in;
 	workspace->strm.avail_in = srclen;
 	workspace->strm.total_in = 0;
@@ -341,7 +347,6 @@ static int zlib_decompress(struct list_head *ws, unsigned char *data_in,
 		unsigned long buf_start;
 		unsigned long buf_offset;
 		unsigned long bytes;
-		unsigned long pg_offset = 0;
 
 		ret = zlib_inflate(&workspace->strm, Z_NO_FLUSH);
 		if (ret != Z_OK && ret != Z_STREAM_END)
@@ -384,6 +389,17 @@ next:
 		ret = 0;
 
 	zlib_inflateEnd(&workspace->strm);
+
+	/*
+	 * this should only happen if zlib returned fewer bytes than we
+	 * expected.  btrfs_get_block is responsible for zeroing from the
+	 * end of the inline extent (destlen) to the end of the page
+	 */
+	if (pg_offset < destlen) {
+		kaddr = kmap_atomic(dest_page);
+		memset(kaddr + pg_offset, 0, destlen - pg_offset);
+		kunmap_atomic(kaddr);
+	}
 	return ret;
 }
 
diff --git a/fs/dcache.c b/fs/dcache.c
index 3ffef7f4e5cd..5bc72b07fde2 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -778,6 +778,7 @@ restart:
 			struct dentry *parent = lock_parent(dentry);
 			if (likely(!dentry->d_lockref.count)) {
 				__dentry_kill(dentry);
+				dput(parent);
 				goto restart;
 			}
 			if (parent)
diff --git a/fs/fat/namei_vfat.c b/fs/fat/namei_vfat.c
index 6df8d3d885e5..b8b92c2f9683 100644
--- a/fs/fat/namei_vfat.c
+++ b/fs/fat/namei_vfat.c
@@ -736,7 +736,12 @@ static struct dentry *vfat_lookup(struct inode *dir, struct dentry *dentry,
 	}
 
 	alias = d_find_alias(inode);
-	if (alias && !vfat_d_anon_disconn(alias)) {
+	/*
+	 * Checking "alias->d_parent == dentry->d_parent" to make sure
+	 * FS is not corrupted (especially double linked dir).
+	 */
+	if (alias && alias->d_parent == dentry->d_parent &&
+	    !vfat_d_anon_disconn(alias)) {
 		/*
 		 * This inode has non anonymous-DCACHE_DISCONNECTED
 		 * dentry. This means, the user did ->lookup() by an
@@ -755,12 +760,9 @@ static struct dentry *vfat_lookup(struct inode *dir, struct dentry *dentry,
 
 out:
 	mutex_unlock(&MSDOS_SB(sb)->s_lock);
-	dentry->d_time = dentry->d_parent->d_inode->i_version;
-	dentry = d_splice_alias(inode, dentry);
-	if (dentry)
-		dentry->d_time = dentry->d_parent->d_inode->i_version;
-	return dentry;
-
+	if (!inode)
+		dentry->d_time = dir->i_version;
+	return d_splice_alias(inode, dentry);
 error:
 	mutex_unlock(&MSDOS_SB(sb)->s_lock);
 	return ERR_PTR(err);
@@ -793,7 +795,6 @@ static int vfat_create(struct inode *dir, struct dentry *dentry, umode_t mode,
 	inode->i_mtime = inode->i_atime = inode->i_ctime = ts;
 	/* timestamp is already written, so mark_inode_dirty() is unneeded. */
 
-	dentry->d_time = dentry->d_parent->d_inode->i_version;
 	d_instantiate(dentry, inode);
 out:
 	mutex_unlock(&MSDOS_SB(sb)->s_lock);
@@ -824,6 +825,7 @@ static int vfat_rmdir(struct inode *dir, struct dentry *dentry)
 	clear_nlink(inode);
 	inode->i_mtime = inode->i_atime = CURRENT_TIME_SEC;
 	fat_detach(inode);
+	dentry->d_time = dir->i_version;
 out:
 	mutex_unlock(&MSDOS_SB(sb)->s_lock);
 
@@ -849,6 +851,7 @@ static int vfat_unlink(struct inode *dir, struct dentry *dentry)
 	clear_nlink(inode);
 	inode->i_mtime = inode->i_atime = CURRENT_TIME_SEC;
 	fat_detach(inode);
+	dentry->d_time = dir->i_version;
 out:
 	mutex_unlock(&MSDOS_SB(sb)->s_lock);
 
@@ -889,7 +892,6 @@ static int vfat_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
 	inode->i_mtime = inode->i_atime = inode->i_ctime = ts;
 	/* timestamp is already written, so mark_inode_dirty() is unneeded. */
 
-	dentry->d_time = dentry->d_parent->d_inode->i_version;
 	d_instantiate(dentry, inode);
 
 	mutex_unlock(&MSDOS_SB(sb)->s_lock);
diff --git a/fs/isofs/inode.c b/fs/isofs/inode.c
index fe839b915116..d67a16f2a45d 100644
--- a/fs/isofs/inode.c
+++ b/fs/isofs/inode.c
@@ -174,27 +174,6 @@ struct iso9660_options{
  * Compute the hash for the isofs name corresponding to the dentry.
  */
 static int
-isofs_hash_common(struct qstr *qstr, int ms)
-{
-	const char *name;
-	int len;
-
-	len = qstr->len;
-	name = qstr->name;
-	if (ms) {
-		while (len && name[len-1] == '.')
-			len--;
-	}
-
-	qstr->hash = full_name_hash(name, len);
-
-	return 0;
-}
-
-/*
- * Compute the hash for the isofs name corresponding to the dentry.
- */
-static int
 isofs_hashi_common(struct qstr *qstr, int ms)
 {
 	const char *name;
@@ -263,6 +242,27 @@ isofs_dentry_cmpi(const struct dentry *parent, const struct dentry *dentry,
 }
 
 #ifdef CONFIG_JOLIET
+/*
+ * Compute the hash for the isofs name corresponding to the dentry.
+ */
+static int
+isofs_hash_common(struct qstr *qstr, int ms)
+{
+	const char *name;
+	int len;
+
+	len = qstr->len;
+	name = qstr->name;
+	if (ms) {
+		while (len && name[len-1] == '.')
+			len--;
+	}
+
+	qstr->hash = full_name_hash(name, len);
+
+	return 0;
+}
+
 static int
 isofs_hash_ms(const struct dentry *dentry, struct qstr *qstr)
 {
diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c
index e4dc74713a43..1df94fabe4eb 100644
--- a/fs/jbd2/journal.c
+++ b/fs/jbd2/journal.c
@@ -1853,13 +1853,12 @@ int jbd2_journal_set_features (journal_t *journal, unsigned long compat,
 				journal->j_chksum_driver = NULL;
 				return 0;
 			}
-		}
 
-		/* Precompute checksum seed for all metadata */
-		if (jbd2_journal_has_csum_v2or3(journal))
+			/* Precompute checksum seed for all metadata */
 			journal->j_csum_seed = jbd2_chksum(journal, ~0,
 							   sb->s_uuid,
 							   sizeof(sb->s_uuid));
+		}
 	}
 
 	/* If enabling v1 checksums, downgrade superblock */
diff --git a/fs/nfsd/nfs4callback.c b/fs/nfsd/nfs4callback.c
index ed2b1151b171..7cbdf1b2e4ab 100644
--- a/fs/nfsd/nfs4callback.c
+++ b/fs/nfsd/nfs4callback.c
@@ -774,8 +774,12 @@ static bool nfsd41_cb_get_slot(struct nfs4_client *clp, struct rpc_task *task)
 {
 	if (test_and_set_bit(0, &clp->cl_cb_slot_busy) != 0) {
 		rpc_sleep_on(&clp->cl_cb_waitq, task, NULL);
-		dprintk("%s slot is busy\n", __func__);
-		return false;
+		/* Race breaker */
+		if (test_and_set_bit(0, &clp->cl_cb_slot_busy) != 0) {
+			dprintk("%s slot is busy\n", __func__);
+			return false;
+		}
+		rpc_wake_up_queued_task(&clp->cl_cb_waitq, task);
 	}
 	return true;
 }
diff --git a/fs/nfsd/nfsd.h b/fs/nfsd/nfsd.h
index 747f3b95bd11..33a46a8dfaf7 100644
--- a/fs/nfsd/nfsd.h
+++ b/fs/nfsd/nfsd.h
@@ -335,12 +335,15 @@ void		nfsd_lockd_shutdown(void);
 	(NFSD4_SUPPORTED_ATTRS_WORD2 | FATTR4_WORD2_SUPPATTR_EXCLCREAT)
 
 #ifdef CONFIG_NFSD_V4_SECURITY_LABEL
-#define NFSD4_2_SUPPORTED_ATTRS_WORD2 \
-	(NFSD4_1_SUPPORTED_ATTRS_WORD2 | FATTR4_WORD2_SECURITY_LABEL)
+#define NFSD4_2_SECURITY_ATTRS		FATTR4_WORD2_SECURITY_LABEL
 #else
-#define NFSD4_2_SUPPORTED_ATTRS_WORD2 0
+#define NFSD4_2_SECURITY_ATTRS		0
 #endif
 
+#define NFSD4_2_SUPPORTED_ATTRS_WORD2 \
+	(NFSD4_1_SUPPORTED_ATTRS_WORD2 | \
+	NFSD4_2_SECURITY_ATTRS)
+
 static inline u32 nfsd_suppattrs0(u32 minorversion)
 {
 	return minorversion ? NFSD4_1_SUPPORTED_ATTRS_WORD0
diff --git a/fs/overlayfs/Kconfig b/fs/overlayfs/Kconfig
index e60125976873..34355818a2e0 100644
--- a/fs/overlayfs/Kconfig
+++ b/fs/overlayfs/Kconfig
@@ -1,4 +1,4 @@
-config OVERLAYFS_FS
+config OVERLAY_FS
 	tristate "Overlay filesystem support"
 	help
 	  An overlay filesystem combines two filesystems - an 'upper' filesystem
diff --git a/fs/overlayfs/Makefile b/fs/overlayfs/Makefile
index 8f91889480d0..900daed3e91d 100644
--- a/fs/overlayfs/Makefile
+++ b/fs/overlayfs/Makefile
@@ -2,6 +2,6 @@
 # Makefile for the overlay filesystem.
 #
 
-obj-$(CONFIG_OVERLAYFS_FS) += overlayfs.o
+obj-$(CONFIG_OVERLAY_FS) += overlay.o
 
-overlayfs-objs := super.o inode.o dir.o readdir.o copy_up.o
+overlay-objs := super.o inode.o dir.o readdir.o copy_up.o
diff --git a/fs/overlayfs/dir.c b/fs/overlayfs/dir.c
index 15cd91ad9940..8ffc4b980f1b 100644
--- a/fs/overlayfs/dir.c
+++ b/fs/overlayfs/dir.c
@@ -284,8 +284,7 @@ out:
 	return ERR_PTR(err);
 }
 
-static struct dentry *ovl_check_empty_and_clear(struct dentry *dentry,
-						enum ovl_path_type type)
+static struct dentry *ovl_check_empty_and_clear(struct dentry *dentry)
 {
 	int err;
 	struct dentry *ret = NULL;
@@ -294,8 +293,17 @@ static struct dentry *ovl_check_empty_and_clear(struct dentry *dentry,
 	err = ovl_check_empty_dir(dentry, &list);
 	if (err)
 		ret = ERR_PTR(err);
-	else if (type == OVL_PATH_MERGE)
-		ret = ovl_clear_empty(dentry, &list);
+	else {
+		/*
+		 * If no upperdentry then skip clearing whiteouts.
+		 *
+		 * Can race with copy-up, since we don't hold the upperdir
+		 * mutex.  Doesn't matter, since copy-up can't create a
+		 * non-empty directory from an empty one.
+		 */
+		if (ovl_dentry_upper(dentry))
+			ret = ovl_clear_empty(dentry, &list);
+	}
 
 	ovl_cache_free(&list);
 
@@ -487,8 +495,7 @@ out:
 	return err;
 }
 
-static int ovl_remove_and_whiteout(struct dentry *dentry,
-				   enum ovl_path_type type, bool is_dir)
+static int ovl_remove_and_whiteout(struct dentry *dentry, bool is_dir)
 {
 	struct dentry *workdir = ovl_workdir(dentry);
 	struct inode *wdir = workdir->d_inode;
@@ -500,7 +507,7 @@ static int ovl_remove_and_whiteout(struct dentry *dentry,
 	int err;
 
 	if (is_dir) {
-		opaquedir = ovl_check_empty_and_clear(dentry, type);
+		opaquedir = ovl_check_empty_and_clear(dentry);
 		err = PTR_ERR(opaquedir);
 		if (IS_ERR(opaquedir))
 			goto out;
@@ -515,9 +522,10 @@ static int ovl_remove_and_whiteout(struct dentry *dentry,
 	if (IS_ERR(whiteout))
 		goto out_unlock;
 
-	if (type == OVL_PATH_LOWER) {
+	upper = ovl_dentry_upper(dentry);
+	if (!upper) {
 		upper = lookup_one_len(dentry->d_name.name, upperdir,
-					   dentry->d_name.len);
+				       dentry->d_name.len);
 		err = PTR_ERR(upper);
 		if (IS_ERR(upper))
 			goto kill_whiteout;
@@ -529,7 +537,6 @@ static int ovl_remove_and_whiteout(struct dentry *dentry,
 	} else {
 		int flags = 0;
 
-		upper = ovl_dentry_upper(dentry);
 		if (opaquedir)
 			upper = opaquedir;
 		err = -ESTALE;
@@ -648,7 +655,7 @@ static int ovl_do_remove(struct dentry *dentry, bool is_dir)
 		cap_raise(override_cred->cap_effective, CAP_CHOWN);
 		old_cred = override_creds(override_cred);
 
-		err = ovl_remove_and_whiteout(dentry, type, is_dir);
+		err = ovl_remove_and_whiteout(dentry, is_dir);
 
 		revert_creds(old_cred);
 		put_cred(override_cred);
@@ -781,7 +788,7 @@ static int ovl_rename2(struct inode *olddir, struct dentry *old,
 	}
 
 	if (overwrite && (new_type == OVL_PATH_LOWER || new_type == OVL_PATH_MERGE) && new_is_dir) {
-		opaquedir = ovl_check_empty_and_clear(new, new_type);
+		opaquedir = ovl_check_empty_and_clear(new);
 		err = PTR_ERR(opaquedir);
 		if (IS_ERR(opaquedir)) {
 			opaquedir = NULL;
diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c
index af2d18c9fcee..07d74b24913b 100644
--- a/fs/overlayfs/inode.c
+++ b/fs/overlayfs/inode.c
@@ -235,26 +235,36 @@ out:
 	return err;
 }
 
+static bool ovl_need_xattr_filter(struct dentry *dentry,
+				  enum ovl_path_type type)
+{
+	return type == OVL_PATH_UPPER && S_ISDIR(dentry->d_inode->i_mode);
+}
+
 ssize_t ovl_getxattr(struct dentry *dentry, const char *name,
 		     void *value, size_t size)
 {
-	if (ovl_path_type(dentry->d_parent) == OVL_PATH_MERGE &&
-	    ovl_is_private_xattr(name))
+	struct path realpath;
+	enum ovl_path_type type = ovl_path_real(dentry, &realpath);
+
+	if (ovl_need_xattr_filter(dentry, type) && ovl_is_private_xattr(name))
 		return -ENODATA;
 
-	return vfs_getxattr(ovl_dentry_real(dentry), name, value, size);
+	return vfs_getxattr(realpath.dentry, name, value, size);
 }
 
 ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size)
 {
+	struct path realpath;
+	enum ovl_path_type type = ovl_path_real(dentry, &realpath);
 	ssize_t res;
 	int off;
 
-	res = vfs_listxattr(ovl_dentry_real(dentry), list, size);
+	res = vfs_listxattr(realpath.dentry, list, size);
 	if (res <= 0 || size == 0)
 		return res;
 
-	if (ovl_path_type(dentry->d_parent) != OVL_PATH_MERGE)
+	if (!ovl_need_xattr_filter(dentry, type))
 		return res;
 
 	/* filter out private xattrs */
@@ -279,17 +289,16 @@ int ovl_removexattr(struct dentry *dentry, const char *name)
 {
 	int err;
 	struct path realpath;
-	enum ovl_path_type type;
+	enum ovl_path_type type = ovl_path_real(dentry, &realpath);
 
 	err = ovl_want_write(dentry);
 	if (err)
 		goto out;
 
-	if (ovl_path_type(dentry->d_parent) == OVL_PATH_MERGE &&
-	    ovl_is_private_xattr(name))
+	err = -ENODATA;
+	if (ovl_need_xattr_filter(dentry, type) && ovl_is_private_xattr(name))
 		goto out_drop_write;
 
-	type = ovl_path_real(dentry, &realpath);
 	if (type == OVL_PATH_LOWER) {
 		err = vfs_getxattr(realpath.dentry, name, NULL, 0);
 		if (err < 0)
diff --git a/fs/overlayfs/readdir.c b/fs/overlayfs/readdir.c
index 2a7ef4f8e2a6..ab1e3dcbed95 100644
--- a/fs/overlayfs/readdir.c
+++ b/fs/overlayfs/readdir.c
@@ -274,11 +274,11 @@ static int ovl_dir_mark_whiteouts(struct dentry *dir,
 	return 0;
 }
 
-static inline int ovl_dir_read_merged(struct path *upperpath,
-				      struct path *lowerpath,
-				      struct list_head *list)
+static int ovl_dir_read_merged(struct dentry *dentry, struct list_head *list)
 {
 	int err;
+	struct path lowerpath;
+	struct path upperpath;
 	struct ovl_readdir_data rdd = {
 		.ctx.actor = ovl_fill_merge,
 		.list = list,
@@ -286,25 +286,28 @@ static inline int ovl_dir_read_merged(struct path *upperpath,
 		.is_merge = false,
 	};
 
-	if (upperpath->dentry) {
-		err = ovl_dir_read(upperpath, &rdd);
+	ovl_path_lower(dentry, &lowerpath);
+	ovl_path_upper(dentry, &upperpath);
+
+	if (upperpath.dentry) {
+		err = ovl_dir_read(&upperpath, &rdd);
 		if (err)
 			goto out;
 
-		if (lowerpath->dentry) {
-			err = ovl_dir_mark_whiteouts(upperpath->dentry, &rdd);
+		if (lowerpath.dentry) {
+			err = ovl_dir_mark_whiteouts(upperpath.dentry, &rdd);
 			if (err)
 				goto out;
 		}
 	}
-	if (lowerpath->dentry) {
+	if (lowerpath.dentry) {
 		/*
 		 * Insert lowerpath entries before upperpath ones, this allows
 		 * offsets to be reasonably constant
 		 */
 		list_add(&rdd.middle, rdd.list);
 		rdd.is_merge = true;
-		err = ovl_dir_read(lowerpath, &rdd);
+		err = ovl_dir_read(&lowerpath, &rdd);
 		list_del(&rdd.middle);
 	}
 out:
@@ -329,8 +332,6 @@ static void ovl_seek_cursor(struct ovl_dir_file *od, loff_t pos)
 static struct ovl_dir_cache *ovl_cache_get(struct dentry *dentry)
 {
 	int res;
-	struct path lowerpath;
-	struct path upperpath;
 	struct ovl_dir_cache *cache;
 
 	cache = ovl_dir_cache(dentry);
@@ -347,10 +348,7 @@ static struct ovl_dir_cache *ovl_cache_get(struct dentry *dentry)
 	cache->refcount = 1;
 	INIT_LIST_HEAD(&cache->entries);
 
-	ovl_path_lower(dentry, &lowerpath);
-	ovl_path_upper(dentry, &upperpath);
-
-	res = ovl_dir_read_merged(&upperpath, &lowerpath, &cache->entries);
+	res = ovl_dir_read_merged(dentry, &cache->entries);
 	if (res) {
 		ovl_cache_free(&cache->entries);
 		kfree(cache);
@@ -452,10 +450,10 @@ static int ovl_dir_fsync(struct file *file, loff_t start, loff_t end,
 	/*
 	 * Need to check if we started out being a lower dir, but got copied up
 	 */
-	if (!od->is_upper && ovl_path_type(dentry) == OVL_PATH_MERGE) {
+	if (!od->is_upper && ovl_path_type(dentry) != OVL_PATH_LOWER) {
 		struct inode *inode = file_inode(file);
 
-		realfile =lockless_dereference(od->upperfile);
+		realfile = lockless_dereference(od->upperfile);
 		if (!realfile) {
 			struct path upperpath;
 
@@ -538,14 +536,9 @@ const struct file_operations ovl_dir_operations = {
 int ovl_check_empty_dir(struct dentry *dentry, struct list_head *list)
 {
 	int err;
-	struct path lowerpath;
-	struct path upperpath;
 	struct ovl_cache_entry *p;
 
-	ovl_path_upper(dentry, &upperpath);
-	ovl_path_lower(dentry, &lowerpath);
-
-	err = ovl_dir_read_merged(&upperpath, &lowerpath, list);
+	err = ovl_dir_read_merged(dentry, list);
 	if (err)
 		return err;
 
diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c
index 08b704cebfc4..f16d318b71f8 100644
--- a/fs/overlayfs/super.c
+++ b/fs/overlayfs/super.c
@@ -24,7 +24,7 @@ MODULE_AUTHOR("Miklos Szeredi <miklos@szeredi.hu>");
 MODULE_DESCRIPTION("Overlay filesystem");
 MODULE_LICENSE("GPL");
 
-#define OVERLAYFS_SUPER_MAGIC 0x794c764f
+#define OVERLAYFS_SUPER_MAGIC 0x794c7630
 
 struct ovl_config {
 	char *lowerdir;
@@ -84,12 +84,7 @@ enum ovl_path_type ovl_path_type(struct dentry *dentry)
 
 static struct dentry *ovl_upperdentry_dereference(struct ovl_entry *oe)
 {
-	struct dentry *upperdentry = ACCESS_ONCE(oe->__upperdentry);
-	/*
-	 * Make sure to order reads to upperdentry wrt ovl_dentry_update()
-	 */
-	smp_read_barrier_depends();
-	return upperdentry;
+	return lockless_dereference(oe->__upperdentry);
 }
 
 void ovl_path_upper(struct dentry *dentry, struct path *path)
@@ -462,11 +457,34 @@ static const match_table_t ovl_tokens = {
 	{OPT_ERR,			NULL}
 };
 
+static char *ovl_next_opt(char **s)
+{
+	char *sbegin = *s;
+	char *p;
+
+	if (sbegin == NULL)
+		return NULL;
+
+	for (p = sbegin; *p; p++) {
+		if (*p == '\\') {
+			p++;
+			if (!*p)
+				break;
+		} else if (*p == ',') {
+			*p = '\0';
+			*s = p + 1;
+			return sbegin;
+		}
+	}
+	*s = NULL;
+	return sbegin;
+}
+
 static int ovl_parse_opt(char *opt, struct ovl_config *config)
 {
 	char *p;
 
-	while ((p = strsep(&opt, ",")) != NULL) {
+	while ((p = ovl_next_opt(&opt)) != NULL) {
 		int token;
 		substring_t args[MAX_OPT_ARGS];
 
@@ -554,15 +572,34 @@ out_dput:
 	goto out_unlock;
 }
 
+static void ovl_unescape(char *s)
+{
+	char *d = s;
+
+	for (;; s++, d++) {
+		if (*s == '\\')
+			s++;
+		*d = *s;
+		if (!*s)
+			break;
+	}
+}
+
 static int ovl_mount_dir(const char *name, struct path *path)
 {
 	int err;
+	char *tmp = kstrdup(name, GFP_KERNEL);
+
+	if (!tmp)
+		return -ENOMEM;
 
-	err = kern_path(name, LOOKUP_FOLLOW, path);
+	ovl_unescape(tmp);
+	err = kern_path(tmp, LOOKUP_FOLLOW, path);
 	if (err) {
-		pr_err("overlayfs: failed to resolve '%s': %i\n", name, err);
+		pr_err("overlayfs: failed to resolve '%s': %i\n", tmp, err);
 		err = -EINVAL;
 	}
+	kfree(tmp);
 	return err;
 }
 
@@ -776,11 +813,11 @@ static struct dentry *ovl_mount(struct file_system_type *fs_type, int flags,
 
 static struct file_system_type ovl_fs_type = {
 	.owner		= THIS_MODULE,
-	.name		= "overlayfs",
+	.name		= "overlay",
 	.mount		= ovl_mount,
 	.kill_sb	= kill_anon_super,
 };
-MODULE_ALIAS_FS("overlayfs");
+MODULE_ALIAS_FS("overlay");
 
 static int __init ovl_init(void)
 {