5 files changed, 626 insertions, 3 deletions

diff --git a/fs/ubifs/file.c b/fs/ubifs/file.c
index 3d698e2022b..cdcfe95cbfb 100644
--- a/fs/ubifs/file.c
+++ b/fs/ubifs/file.c
@@ -577,8 +577,256 @@ out:
 	return copied;
 }
 
+/**
+ * populate_page - copy data nodes into a page for bulk-read.
+ * @c: UBIFS file-system description object
+ * @page: page
+ * @bu: bulk-read information
+ * @n: next zbranch slot
+ *
+ * This function returns %0 on success and a negative error code on failure.
+ */
+static int populate_page(struct ubifs_info *c, struct page *page,
+			 struct bu_info *bu, int *n)
+{
+	int i = 0, nn = *n, offs = bu->zbranch[0].offs, hole = 1, read = 0;
+	struct inode *inode = page->mapping->host;
+	loff_t i_size = i_size_read(inode);
+	unsigned int page_block;
+	void *addr, *zaddr;
+	pgoff_t end_index;
+
+	dbg_gen("ino %lu, pg %lu, i_size %lld, flags %#lx",
+		inode->i_ino, page->index, i_size, page->flags);
+
+	addr = zaddr = kmap(page);
+
+	end_index = (i_size + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
+	if (!i_size || page->index > end_index) {
+		memset(addr, 0, PAGE_CACHE_SIZE);
+		goto out_hole;
+	}
+
+	page_block = page->index << UBIFS_BLOCKS_PER_PAGE_SHIFT;
+	while (1) {
+		int err, len, out_len, dlen;
+
+		if (nn >= bu->cnt ||
+		    key_block(c, &bu->zbranch[nn].key) != page_block)
+			memset(addr, 0, UBIFS_BLOCK_SIZE);
+		else {
+			struct ubifs_data_node *dn;
+
+			dn = bu->buf + (bu->zbranch[nn].offs - offs);
+
+			ubifs_assert(dn->ch.sqnum >
+				     ubifs_inode(inode)->creat_sqnum);
+
+			len = le32_to_cpu(dn->size);
+			if (len <= 0 || len > UBIFS_BLOCK_SIZE)
+				goto out_err;
+
+			dlen = le32_to_cpu(dn->ch.len) - UBIFS_DATA_NODE_SZ;
+			out_len = UBIFS_BLOCK_SIZE;
+			err = ubifs_decompress(&dn->data, dlen, addr, &out_len,
+					       le16_to_cpu(dn->compr_type));
+			if (err || len != out_len)
+				goto out_err;
+
+			if (len < UBIFS_BLOCK_SIZE)
+				memset(addr + len, 0, UBIFS_BLOCK_SIZE - len);
+
+			nn += 1;
+			hole = 0;
+			read = (i << UBIFS_BLOCK_SHIFT) + len;
+		}
+		if (++i >= UBIFS_BLOCKS_PER_PAGE)
+			break;
+		addr += UBIFS_BLOCK_SIZE;
+		page_block += 1;
+	}
+
+	if (end_index == page->index) {
+		int len = i_size & (PAGE_CACHE_SIZE - 1);
+
+		if (len < read)
+			memset(zaddr + len, 0, read - len);
+	}
+
+out_hole:
+	if (hole) {
+		SetPageChecked(page);
+		dbg_gen("hole");
+	}
+
+	SetPageUptodate(page);
+	ClearPageError(page);
+	flush_dcache_page(page);
+	kunmap(page);
+	*n = nn;
+	return 0;
+
+out_err:
+	ClearPageUptodate(page);
+	SetPageError(page);
+	flush_dcache_page(page);
+	kunmap(page);
+	ubifs_err("bad data node (block %u, inode %lu)",
+		  page_block, inode->i_ino);
+	return -EINVAL;
+}
+
+/**
+ * ubifs_do_bulk_read - do bulk-read.
+ * @c: UBIFS file-system description object
+ * @page1: first page
+ *
+ * This function returns %1 if the bulk-read is done, otherwise %0 is returned.
+ */
+static int ubifs_do_bulk_read(struct ubifs_info *c, struct page *page1)
+{
+	pgoff_t offset = page1->index, end_index;
+	struct address_space *mapping = page1->mapping;
+	struct inode *inode = mapping->host;
+	struct ubifs_inode *ui = ubifs_inode(inode);
+	struct bu_info *bu;
+	int err, page_idx, page_cnt, ret = 0, n = 0;
+	loff_t isize;
+
+	bu = kmalloc(sizeof(struct bu_info), GFP_NOFS);
+	if (!bu)
+		return 0;
+
+	bu->buf_len = c->bulk_read_buf_size;
+	bu->buf = kmalloc(bu->buf_len, GFP_NOFS);
+	if (!bu->buf)
+		goto out_free;
+
+	data_key_init(c, &bu->key, inode->i_ino,
+		      offset << UBIFS_BLOCKS_PER_PAGE_SHIFT);
+
+	err = ubifs_tnc_get_bu_keys(c, bu);
+	if (err)
+		goto out_warn;
+
+	if (bu->eof) {
+		/* Turn off bulk-read at the end of the file */
+		ui->read_in_a_row = 1;
+		ui->bulk_read = 0;
+	}
+
+	page_cnt = bu->blk_cnt >> UBIFS_BLOCKS_PER_PAGE_SHIFT;
+	if (!page_cnt) {
+		/*
+		 * This happens when there are multiple blocks per page and the
+		 * blocks for the first page we are looking for, are not
+		 * together. If all the pages were like this, bulk-read would
+		 * reduce performance, so we turn it off for a while.
+		 */
+		ui->read_in_a_row = 0;
+		ui->bulk_read = 0;
+		goto out_free;
+	}
+
+	if (bu->cnt) {
+		err = ubifs_tnc_bulk_read(c, bu);
+		if (err)
+			goto out_warn;
+	}
+
+	err = populate_page(c, page1, bu, &n);
+	if (err)
+		goto out_warn;
+
+	unlock_page(page1);
+	ret = 1;
+
+	isize = i_size_read(inode);
+	if (isize == 0)
+		goto out_free;
+	end_index = ((isize - 1) >> PAGE_CACHE_SHIFT);
+
+	for (page_idx = 1; page_idx < page_cnt; page_idx++) {
+		pgoff_t page_offset = offset + page_idx;
+		struct page *page;
+
+		if (page_offset > end_index)
+			break;
+		page = find_or_create_page(mapping, page_offset,
+					   GFP_NOFS | __GFP_COLD);
+		if (!page)
+			break;
+		if (!PageUptodate(page))
+			err = populate_page(c, page, bu, &n);
+		unlock_page(page);
+		page_cache_release(page);
+		if (err)
+			break;
+	}
+
+	ui->last_page_read = offset + page_idx - 1;
+
+out_free:
+	kfree(bu->buf);
+	kfree(bu);
+	return ret;
+
+out_warn:
+	ubifs_warn("ignoring error %d and skipping bulk-read", err);
+	goto out_free;
+}
+
+/**
+ * ubifs_bulk_read - determine whether to bulk-read and, if so, do it.
+ * @page: page from which to start bulk-read.
+ *
+ * Some flash media are capable of reading sequentially at faster rates. UBIFS
+ * bulk-read facility is designed to take advantage of that, by reading in one
+ * go consecutive data nodes that are also located consecutively in the same
+ * LEB. This function returns %1 if a bulk-read is done and %0 otherwise.
+ */
+static int ubifs_bulk_read(struct page *page)
+{
+	struct inode *inode = page->mapping->host;
+	struct ubifs_info *c = inode->i_sb->s_fs_info;
+	struct ubifs_inode *ui = ubifs_inode(inode);
+	pgoff_t index = page->index, last_page_read = ui->last_page_read;
+	int ret = 0;
+
+	ui->last_page_read = index;
+
+	if (!c->bulk_read)
+		return 0;
+	/*
+	 * Bulk-read is protected by ui_mutex, but it is an optimization, so
+	 * don't bother if we cannot lock the mutex.
+	 */
+	if (!mutex_trylock(&ui->ui_mutex))
+		return 0;
+	if (index != last_page_read + 1) {
+		/* Turn off bulk-read if we stop reading sequentially */
+		ui->read_in_a_row = 1;
+		if (ui->bulk_read)
+			ui->bulk_read = 0;
+		goto out_unlock;
+	}
+	if (!ui->bulk_read) {
+		ui->read_in_a_row += 1;
+		if (ui->read_in_a_row < 3)
+			goto out_unlock;
+		/* Three reads in a row, so switch on bulk-read */
+		ui->bulk_read = 1;
+	}
+	ret = ubifs_do_bulk_read(c, page);
+out_unlock:
+	mutex_unlock(&ui->ui_mutex);
+	return ret;
+}
+
 static int ubifs_readpage(struct file *file, struct page *page)
 {
+	if (ubifs_bulk_read(page))
+		return 0;
 	do_readpage(page);
 	unlock_page(page);
 	return 0;
diff --git a/fs/ubifs/key.h b/fs/ubifs/key.h
index 8f747600754..9ee65086f62 100644
--- a/fs/ubifs/key.h
+++ b/fs/ubifs/key.h
@@ -484,7 +484,7 @@ static inline void key_copy(const struct ubifs_info *c,
  * @key2: the second key to compare
  *
  * This function compares 2 keys and returns %-1 if @key1 is less than
- * @key2, 0 if the keys are equivalent and %1 if @key1 is greater than @key2.
+ * @key2, %0 if the keys are equivalent and %1 if @key1 is greater than @key2.
  */
 static inline int keys_cmp(const struct ubifs_info *c,
 			   const union ubifs_key *key1,
@@ -503,6 +503,26 @@ static inline int keys_cmp(const struct ubifs_info *c,
 }
 
 /**
+ * keys_eq - determine if keys are equivalent.
+ * @c: UBIFS file-system description object
+ * @key1: the first key to compare
+ * @key2: the second key to compare
+ *
+ * This function compares 2 keys and returns %1 if @key1 is equal to @key2 and
+ * %0 if not.
+ */
+static inline int keys_eq(const struct ubifs_info *c,
+			  const union ubifs_key *key1,
+			  const union ubifs_key *key2)
+{
+	if (key1->u32[0] != key2->u32[0])
+		return 0;
+	if (key1->u32[1] != key2->u32[1])
+		return 0;
+	return 1;
+}
+
+/**
  * is_hash_key - is a key vulnerable to hash collisions.
  * @c: UBIFS file-system description object
  * @key: key
diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c
index d87b0cf5f66..b1c57e8ee85 100644
--- a/fs/ubifs/super.c
+++ b/fs/ubifs/super.c
@@ -401,6 +401,11 @@ static int ubifs_show_options(struct seq_file *s, struct vfsmount *mnt)
 	else if (c->mount_opts.unmount_mode == 1)
 		seq_printf(s, ",norm_unmount");
 
+	if (c->mount_opts.bulk_read == 2)
+		seq_printf(s, ",bulk_read");
+	else if (c->mount_opts.bulk_read == 1)
+		seq_printf(s, ",no_bulk_read");
+
 	return 0;
 }
 
@@ -538,6 +543,18 @@ static int init_constants_early(struct ubifs_info *c)
 	 * calculations when reporting free space.
 	 */
 	c->leb_overhead = c->leb_size % UBIFS_MAX_DATA_NODE_SZ;
+	/* Buffer size for bulk-reads */
+	c->bulk_read_buf_size = UBIFS_MAX_BULK_READ * UBIFS_MAX_DATA_NODE_SZ;
+	if (c->bulk_read_buf_size > c->leb_size)
+		c->bulk_read_buf_size = c->leb_size;
+	if (c->bulk_read_buf_size > 128 * 1024) {
+		/* Check if we can kmalloc more than 128KiB */
+		void *try = kmalloc(c->bulk_read_buf_size, GFP_KERNEL);
+
+		kfree(try);
+		if (!try)
+			c->bulk_read_buf_size = 128 * 1024;
+	}
 	return 0;
 }
 
@@ -840,17 +857,23 @@ static int check_volume_empty(struct ubifs_info *c)
  *
  * Opt_fast_unmount: do not run a journal commit before un-mounting
  * Opt_norm_unmount: run a journal commit before un-mounting
+ * Opt_bulk_read: enable bulk-reads
+ * Opt_no_bulk_read: disable bulk-reads
  * Opt_err: just end of array marker
  */
 enum {
 	Opt_fast_unmount,
 	Opt_norm_unmount,
+	Opt_bulk_read,
+	Opt_no_bulk_read,
 	Opt_err,
 };
 
 static match_table_t tokens = {
 	{Opt_fast_unmount, "fast_unmount"},
 	{Opt_norm_unmount, "norm_unmount"},
+	{Opt_bulk_read, "bulk_read"},
+	{Opt_no_bulk_read, "no_bulk_read"},
 	{Opt_err, NULL},
 };
 
@@ -888,6 +911,14 @@ static int ubifs_parse_options(struct ubifs_info *c, char *options,
 			c->mount_opts.unmount_mode = 1;
 			c->fast_unmount = 0;
 			break;
+		case Opt_bulk_read:
+			c->mount_opts.bulk_read = 2;
+			c->bulk_read = 1;
+			break;
+		case Opt_no_bulk_read:
+			c->mount_opts.bulk_read = 1;
+			c->bulk_read = 0;
+			break;
 		default:
 			ubifs_err("unrecognized mount option \"%s\" "
 				  "or missing value", p);
diff --git a/fs/ubifs/tnc.c b/fs/ubifs/tnc.c
index ba13c92fdf6..d279012d8dd 100644
--- a/fs/ubifs/tnc.c
+++ b/fs/ubifs/tnc.c
@@ -1492,6 +1492,289 @@ out:
 }
 
 /**
+ * ubifs_tnc_get_bu_keys - lookup keys for bulk-read.
+ * @c: UBIFS file-system description object
+ * @bu: bulk-read parameters and results
+ *
+ * Lookup consecutive data node keys for the same inode that reside
+ * consecutively in the same LEB.
+ */
+int ubifs_tnc_get_bu_keys(struct ubifs_info *c, struct bu_info *bu)
+{
+	int n, err = 0, lnum = -1, uninitialized_var(offs);
+	int uninitialized_var(len);
+	unsigned int block = key_block(c, &bu->key);
+	struct ubifs_znode *znode;
+
+	bu->cnt = 0;
+	bu->blk_cnt = 0;
+	bu->eof = 0;
+
+	mutex_lock(&c->tnc_mutex);
+	/* Find first key */
+	err = ubifs_lookup_level0(c, &bu->key, &znode, &n);
+	if (err < 0)
+		goto out;
+	if (err) {
+		/* Key found */
+		len = znode->zbranch[n].len;
+		/* The buffer must be big enough for at least 1 node */
+		if (len > bu->buf_len) {
+			err = -EINVAL;
+			goto out;
+		}
+		/* Add this key */
+		bu->zbranch[bu->cnt++] = znode->zbranch[n];
+		bu->blk_cnt += 1;
+		lnum = znode->zbranch[n].lnum;
+		offs = ALIGN(znode->zbranch[n].offs + len, 8);
+	}
+	while (1) {
+		struct ubifs_zbranch *zbr;
+		union ubifs_key *key;
+		unsigned int next_block;
+
+		/* Find next key */
+		err = tnc_next(c, &znode, &n);
+		if (err)
+			goto out;
+		zbr = &znode->zbranch[n];
+		key = &zbr->key;
+		/* See if there is another data key for this file */
+		if (key_inum(c, key) != key_inum(c, &bu->key) ||
+		    key_type(c, key) != UBIFS_DATA_KEY) {
+			err = -ENOENT;
+			goto out;
+		}
+		if (lnum < 0) {
+			/* First key found */
+			lnum = zbr->lnum;
+			offs = ALIGN(zbr->offs + zbr->len, 8);
+			len = zbr->len;
+			if (len > bu->buf_len) {
+				err = -EINVAL;
+				goto out;
+			}
+		} else {
+			/*
+			 * The data nodes must be in consecutive positions in
+			 * the same LEB.
+			 */
+			if (zbr->lnum != lnum || zbr->offs != offs)
+				goto out;
+			offs += ALIGN(zbr->len, 8);
+			len = ALIGN(len, 8) + zbr->len;
+			/* Must not exceed buffer length */
+			if (len > bu->buf_len)
+				goto out;
+		}
+		/* Allow for holes */
+		next_block = key_block(c, key);
+		bu->blk_cnt += (next_block - block - 1);
+		if (bu->blk_cnt >= UBIFS_MAX_BULK_READ)
+			goto out;
+		block = next_block;
+		/* Add this key */
+		bu->zbranch[bu->cnt++] = *zbr;
+		bu->blk_cnt += 1;
+		/* See if we have room for more */
+		if (bu->cnt >= UBIFS_MAX_BULK_READ)
+			goto out;
+		if (bu->blk_cnt >= UBIFS_MAX_BULK_READ)
+			goto out;
+	}
+out:
+	if (err == -ENOENT) {
+		bu->eof = 1;
+		err = 0;
+	}
+	bu->gc_seq = c->gc_seq;
+	mutex_unlock(&c->tnc_mutex);
+	if (err)
+		return err;
+	/*
+	 * An enormous hole could cause bulk-read to encompass too many
+	 * page cache pages, so limit the number here.
+	 */
+	if (bu->blk_cnt >= UBIFS_MAX_BULK_READ)
+		bu->blk_cnt = UBIFS_MAX_BULK_READ;
+	/*
+	 * Ensure that bulk-read covers a whole number of page cache
+	 * pages.
+	 */
+	if (UBIFS_BLOCKS_PER_PAGE == 1 ||
+	    !(bu->blk_cnt & (UBIFS_BLOCKS_PER_PAGE - 1)))
+		return 0;
+	if (bu->eof) {
+		/* At the end of file we can round up */
+		bu->blk_cnt += UBIFS_BLOCKS_PER_PAGE - 1;
+		return 0;
+	}
+	/* Exclude data nodes that do not make up a whole page cache page */
+	block = key_block(c, &bu->key) + bu->blk_cnt;
+	block &= ~(UBIFS_BLOCKS_PER_PAGE - 1);
+	while (bu->cnt) {
+		if (key_block(c, &bu->zbranch[bu->cnt - 1].key) < block)
+			break;
+		bu->cnt -= 1;
+	}
+	return 0;
+}
+
+/**
+ * read_wbuf - bulk-read from a LEB with a wbuf.
+ * @wbuf: wbuf that may overlap the read
+ * @buf: buffer into which to read
+ * @len: read length
+ * @lnum: LEB number from which to read
+ * @offs: offset from which to read
+ *
+ * This functions returns %0 on success or a negative error code on failure.
+ */
+static int read_wbuf(struct ubifs_wbuf *wbuf, void *buf, int len, int lnum,
+		     int offs)
+{
+	const struct ubifs_info *c = wbuf->c;
+	int rlen, overlap;
+
+	dbg_io("LEB %d:%d, length %d", lnum, offs, len);
+	ubifs_assert(wbuf && lnum >= 0 && lnum < c->leb_cnt && offs >= 0);
+	ubifs_assert(!(offs & 7) && offs < c->leb_size);
+	ubifs_assert(offs + len <= c->leb_size);
+
+	spin_lock(&wbuf->lock);
+	overlap = (lnum == wbuf->lnum && offs + len > wbuf->offs);
+	if (!overlap) {
+		/* We may safely unlock the write-buffer and read the data */
+		spin_unlock(&wbuf->lock);
+		return ubi_read(c->ubi, lnum, buf, offs, len);
+	}
+
+	/* Don't read under wbuf */
+	rlen = wbuf->offs - offs;
+	if (rlen < 0)
+		rlen = 0;
+
+	/* Copy the rest from the write-buffer */
+	memcpy(buf + rlen, wbuf->buf + offs + rlen - wbuf->offs, len - rlen);
+	spin_unlock(&wbuf->lock);
+
+	if (rlen > 0)
+		/* Read everything that goes before write-buffer */
+		return ubi_read(c->ubi, lnum, buf, offs, rlen);
+
+	return 0;
+}
+
+/**
+ * validate_data_node - validate data nodes for bulk-read.
+ * @c: UBIFS file-system description object
+ * @buf: buffer containing data node to validate
+ * @zbr: zbranch of data node to validate
+ *
+ * This functions returns %0 on success or a negative error code on failure.
+ */
+static int validate_data_node(struct ubifs_info *c, void *buf,
+			      struct ubifs_zbranch *zbr)
+{
+	union ubifs_key key1;
+	struct ubifs_ch *ch = buf;
+	int err, len;
+
+	if (ch->node_type != UBIFS_DATA_NODE) {
+		ubifs_err("bad node type (%d but expected %d)",
+			  ch->node_type, UBIFS_DATA_NODE);
+		goto out_err;
+	}
+
+	err = ubifs_check_node(c, buf, zbr->lnum, zbr->offs, 0);
+	if (err) {
+		ubifs_err("expected node type %d", UBIFS_DATA_NODE);
+		goto out;
+	}
+
+	len = le32_to_cpu(ch->len);
+	if (len != zbr->len) {
+		ubifs_err("bad node length %d, expected %d", len, zbr->len);
+		goto out_err;
+	}
+
+	/* Make sure the key of the read node is correct */
+	key_read(c, buf + UBIFS_KEY_OFFSET, &key1);
+	if (!keys_eq(c, &zbr->key, &key1)) {
+		ubifs_err("bad key in node at LEB %d:%d",
+			  zbr->lnum, zbr->offs);
+		dbg_tnc("looked for key %s found node's key %s",
+			DBGKEY(&zbr->key), DBGKEY1(&key1));
+		goto out_err;
+	}
+
+	return 0;
+
+out_err:
+	err = -EINVAL;
+out:
+	ubifs_err("bad node at LEB %d:%d", zbr->lnum, zbr->offs);
+	dbg_dump_node(c, buf);
+	dbg_dump_stack();
+	return err;
+}
+
+/**
+ * ubifs_tnc_bulk_read - read a number of data nodes in one go.
+ * @c: UBIFS file-system description object
+ * @bu: bulk-read parameters and results
+ *
+ * This functions reads and validates the data nodes that were identified by the
+ * 'ubifs_tnc_get_bu_keys()' function. This functions returns %0 on success,
+ * -EAGAIN to indicate a race with GC, or another negative error code on
+ * failure.
+ */
+int ubifs_tnc_bulk_read(struct ubifs_info *c, struct bu_info *bu)
+{
+	int lnum = bu->zbranch[0].lnum, offs = bu->zbranch[0].offs, len, err, i;
+	struct ubifs_wbuf *wbuf;
+	void *buf;
+
+	len = bu->zbranch[bu->cnt - 1].offs;
+	len += bu->zbranch[bu->cnt - 1].len - offs;
+	if (len > bu->buf_len) {
+		ubifs_err("buffer too small %d vs %d", bu->buf_len, len);
+		return -EINVAL;
+	}
+
+	/* Do the read */
+	wbuf = ubifs_get_wbuf(c, lnum);
+	if (wbuf)
+		err = read_wbuf(wbuf, bu->buf, len, lnum, offs);
+	else
+		err = ubi_read(c->ubi, lnum, bu->buf, offs, len);
+
+	/* Check for a race with GC */
+	if (maybe_leb_gced(c, lnum, bu->gc_seq))
+		return -EAGAIN;
+
+	if (err && err != -EBADMSG) {
+		ubifs_err("failed to read from LEB %d:%d, error %d",
+			  lnum, offs, err);
+		dbg_dump_stack();
+		dbg_tnc("key %s", DBGKEY(&bu->key));
+		return err;
+	}
+
+	/* Validate the nodes read */
+	buf = bu->buf;
+	for (i = 0; i < bu->cnt; i++) {
+		err = validate_data_node(c, buf, &bu->zbranch[i]);
+		if (err)
+			return err;
+		buf = buf + ALIGN(bu->zbranch[i].len, 8);
+	}
+
+	return 0;
+}
+
+/**
  * do_lookup_nm- look up a "hashed" node.
  * @c: UBIFS file-system description object
  * @key: node key to lookup
diff --git a/fs/ubifs/ubifs.h b/fs/ubifs/ubifs.h
index ce8654928aa..8513239ea8a 100644
--- a/fs/ubifs/ubifs.h
+++ b/fs/ubifs/ubifs.h
@@ -142,6 +142,9 @@
 /* Maximum expected tree height for use by bottom_up_buf */
 #define BOTTOM_UP_HEIGHT 64
 
+/* Maximum number of data nodes to bulk-read */
+#define UBIFS_MAX_BULK_READ 32
+
 /*
  * Lockdep classes for UBIFS inode @ui_mutex.
  */
@@ -329,8 +332,8 @@ struct ubifs_gced_idx_leb {
  * @dirty: non-zero if the inode is dirty
  * @xattr: non-zero if this is an extended attribute inode
  * @ui_mutex: serializes inode write-back with the rest of VFS operations,
- *            serializes "clean <-> dirty" state changes, protects @dirty,
- *            @ui_size, and @xattr_size
+ *            serializes "clean <-> dirty" state changes, serializes bulk-read,
+ *            protects @dirty, @ui_size, and @xattr_size
  * @ui_lock: protects @synced_i_size
  * @synced_i_size: synchronized size of inode, i.e. the value of inode size
  *                 currently stored on the flash; used only for regular file
@@ -338,6 +341,9 @@ struct ubifs_gced_idx_leb {
  * @ui_size: inode size used by UBIFS when writing to flash
  * @flags: inode flags (@UBIFS_COMPR_FL, etc)
  * @compr_type: default compression type used for this inode
+ * @last_page_read: page number of last page read (for bulk read)
+ * @read_in_a_row: number of consecutive pages read in a row (for bulk read)
+ * @bulk_read: indicates whether bulk-read should be used
  * @data_len: length of the data attached to the inode
  * @data: inode's data
  *
@@ -385,6 +391,9 @@ struct ubifs_inode {
 	loff_t ui_size;
 	int flags;
 	int compr_type;
+	pgoff_t last_page_read;
+	pgoff_t read_in_a_row;
+	int bulk_read;
 	int data_len;
 	void *data;
 };
@@ -744,6 +753,28 @@ struct ubifs_znode {
 };
 
 /**
+ * struct bu_info - bulk-read information
+ * @key: first data node key
+ * @zbranch: zbranches of data nodes to bulk read
+ * @buf: buffer to read into
+ * @buf_len: buffer length
+ * @gc_seq: GC sequence number to detect races with GC
+ * @cnt: number of data nodes for bulk read
+ * @blk_cnt: number of data blocks including holes
+ * @oef: end of file reached
+ */
+struct bu_info {
+	union ubifs_key key;
+	struct ubifs_zbranch zbranch[UBIFS_MAX_BULK_READ];
+	void *buf;
+	int buf_len;
+	int gc_seq;
+	int cnt;
+	int blk_cnt;
+	int eof;
+};
+
+/**
  * struct ubifs_node_range - node length range description data structure.
  * @len: fixed node length
  * @min_len: minimum possible node length
@@ -862,9 +893,11 @@ struct ubifs_orphan {
 /**
  * struct ubifs_mount_opts - UBIFS-specific mount options information.
  * @unmount_mode: selected unmount mode (%0 default, %1 normal, %2 fast)
+ * @bulk_read: enable bulk-reads
  */
 struct ubifs_mount_opts {
 	unsigned int unmount_mode:2;
+	unsigned int bulk_read:2;
 };
 
 /**
@@ -965,6 +998,9 @@ struct ubifs_mount_opts {
  * @old_leb_cnt: count of logical eraseblocks before re-size
  * @ro_media: the underlying UBI volume is read-only
  *
+ * @bulk_read: enable bulk-reads
+ * @bulk_read_buf_size: buffer size for bulk-reads
+ *
  * @dirty_pg_cnt: number of dirty pages (not used)
  * @dirty_zn_cnt: number of dirty znodes
  * @clean_zn_cnt: number of clean znodes
@@ -1205,6 +1241,9 @@ struct ubifs_info {
 	int old_leb_cnt;
 	int ro_media;
 
+	int bulk_read;
+	int bulk_read_buf_size;
+
 	atomic_long_t dirty_pg_cnt;
 	atomic_long_t dirty_zn_cnt;
 	atomic_long_t clean_zn_cnt;
@@ -1490,6 +1529,8 @@ void destroy_old_idx(struct ubifs_info *c);
 int is_idx_node_in_tnc(struct ubifs_info *c, union ubifs_key *key, int level,
 		       int lnum, int offs);
 int insert_old_idx_znode(struct ubifs_info *c, struct ubifs_znode *znode);
+int ubifs_tnc_get_bu_keys(struct ubifs_info *c, struct bu_info *bu);
+int ubifs_tnc_bulk_read(struct ubifs_info *c, struct bu_info *bu);
 
 /* tnc_misc.c */
 struct ubifs_znode *ubifs_tnc_levelorder_next(struct ubifs_znode *zr,