Merge tag 'f2fs-for-5.6' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs

Pull f2fs updates from Jaegeuk Kim:
 "In this series, we've implemented transparent compression
  experimentally. It supports LZO and LZ4, but will add more later as we
  investigate in the field more.

  At this point, the feature doesn't expose compressed space to user
  directly in order to guarantee potential data updates later to the
  space. Instead, the main goal is to reduce data writes to flash disk
  as much as possible, resulting in extending disk life time as well as
  relaxing IO congestion.

  Alternatively, we're also considering to add ioctl() to reclaim
  compressed space and show it to user after putting the immutable bit.

  Enhancements:
   - add compression support
   - avoid unnecessary locks in quota ops
   - harden power-cut scenario for zoned block devices
   - use private bio_set to avoid IO congestion
   - replace GC mutex with rwsem to serialize callers

  Bug fixes:
   - fix dentry consistency and memory corruption in rename()'s error case
   - fix wrong swap extent reports
   - fix casefolding bugs
   - change lock coverage to avoid deadlock
   - avoid GFP_KERNEL under f2fs_lock_op

  And, we've cleaned up sysfs entries to prepare no debugfs"

* tag 'f2fs-for-5.6' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs: (31 commits)
  f2fs: fix race conditions in ->d_compare() and ->d_hash()
  f2fs: fix dcache lookup of !casefolded directories
  f2fs: Add f2fs stats to sysfs
  f2fs: delete duplicate information on sysfs nodes
  f2fs: change to use rwsem for gc_mutex
  f2fs: update f2fs document regarding to fsync_mode
  f2fs: add a way to turn off ipu bio cache
  f2fs: code cleanup for f2fs_statfs_project()
  f2fs: fix miscounted block limit in f2fs_statfs_project()
  f2fs: show the CP_PAUSE reason in checkpoint traces
  f2fs: fix deadlock allocating bio_post_read_ctx from mempool
  f2fs: remove unneeded check for error allocating bio_post_read_ctx
  f2fs: convert inline_dir early before starting rename
  f2fs: fix memleak of kobject
  f2fs: fix to add swap extent correctly
  f2fs: run fsck when getting bad inode during GC
  f2fs: support data compression
  f2fs: free sysfs kobject
  f2fs: declare nested quota_sem and remove unnecessary sems
  f2fs: don't put new_page twice in f2fs_rename
  ...

1 files changed, 1176 insertions, 0 deletions

diff --git a/fs/f2fs/compress.c b/fs/f2fs/compress.c
new file mode 100644
index 000000000000..d8a64be90a50
--- /dev/null
+++ b/fs/f2fs/compress.c
@@ -0,0 +1,1176 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * f2fs compress support
+ *
+ * Copyright (c) 2019 Chao Yu <chao@kernel.org>
+ */
+
+#include <linux/fs.h>
+#include <linux/f2fs_fs.h>
+#include <linux/writeback.h>
+#include <linux/backing-dev.h>
+#include <linux/lzo.h>
+#include <linux/lz4.h>
+
+#include "f2fs.h"
+#include "node.h"
+#include <trace/events/f2fs.h>
+
+struct f2fs_compress_ops {
+	int (*init_compress_ctx)(struct compress_ctx *cc);
+	void (*destroy_compress_ctx)(struct compress_ctx *cc);
+	int (*compress_pages)(struct compress_ctx *cc);
+	int (*decompress_pages)(struct decompress_io_ctx *dic);
+};
+
+static unsigned int offset_in_cluster(struct compress_ctx *cc, pgoff_t index)
+{
+	return index & (cc->cluster_size - 1);
+}
+
+static pgoff_t cluster_idx(struct compress_ctx *cc, pgoff_t index)
+{
+	return index >> cc->log_cluster_size;
+}
+
+static pgoff_t start_idx_of_cluster(struct compress_ctx *cc)
+{
+	return cc->cluster_idx << cc->log_cluster_size;
+}
+
+bool f2fs_is_compressed_page(struct page *page)
+{
+	if (!PagePrivate(page))
+		return false;
+	if (!page_private(page))
+		return false;
+	if (IS_ATOMIC_WRITTEN_PAGE(page) || IS_DUMMY_WRITTEN_PAGE(page))
+		return false;
+	f2fs_bug_on(F2FS_M_SB(page->mapping),
+		*((u32 *)page_private(page)) != F2FS_COMPRESSED_PAGE_MAGIC);
+	return true;
+}
+
+static void f2fs_set_compressed_page(struct page *page,
+		struct inode *inode, pgoff_t index, void *data, refcount_t *r)
+{
+	SetPagePrivate(page);
+	set_page_private(page, (unsigned long)data);
+
+	/* i_crypto_info and iv index */
+	page->index = index;
+	page->mapping = inode->i_mapping;
+	if (r)
+		refcount_inc(r);
+}
+
+static void f2fs_put_compressed_page(struct page *page)
+{
+	set_page_private(page, (unsigned long)NULL);
+	ClearPagePrivate(page);
+	page->mapping = NULL;
+	unlock_page(page);
+	put_page(page);
+}
+
+static void f2fs_drop_rpages(struct compress_ctx *cc, int len, bool unlock)
+{
+	int i;
+
+	for (i = 0; i < len; i++) {
+		if (!cc->rpages[i])
+			continue;
+		if (unlock)
+			unlock_page(cc->rpages[i]);
+		else
+			put_page(cc->rpages[i]);
+	}
+}
+
+static void f2fs_put_rpages(struct compress_ctx *cc)
+{
+	f2fs_drop_rpages(cc, cc->cluster_size, false);
+}
+
+static void f2fs_unlock_rpages(struct compress_ctx *cc, int len)
+{
+	f2fs_drop_rpages(cc, len, true);
+}
+
+static void f2fs_put_rpages_mapping(struct compress_ctx *cc,
+				struct address_space *mapping,
+				pgoff_t start, int len)
+{
+	int i;
+
+	for (i = 0; i < len; i++) {
+		struct page *page = find_get_page(mapping, start + i);
+
+		put_page(page);
+		put_page(page);
+	}
+}
+
+static void f2fs_put_rpages_wbc(struct compress_ctx *cc,
+		struct writeback_control *wbc, bool redirty, int unlock)
+{
+	unsigned int i;
+
+	for (i = 0; i < cc->cluster_size; i++) {
+		if (!cc->rpages[i])
+			continue;
+		if (redirty)
+			redirty_page_for_writepage(wbc, cc->rpages[i]);
+		f2fs_put_page(cc->rpages[i], unlock);
+	}
+}
+
+struct page *f2fs_compress_control_page(struct page *page)
+{
+	return ((struct compress_io_ctx *)page_private(page))->rpages[0];
+}
+
+int f2fs_init_compress_ctx(struct compress_ctx *cc)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(cc->inode);
+
+	if (cc->nr_rpages)
+		return 0;
+
+	cc->rpages = f2fs_kzalloc(sbi, sizeof(struct page *) <<
+					cc->log_cluster_size, GFP_NOFS);
+	return cc->rpages ? 0 : -ENOMEM;
+}
+
+void f2fs_destroy_compress_ctx(struct compress_ctx *cc)
+{
+	kfree(cc->rpages);
+	cc->rpages = NULL;
+	cc->nr_rpages = 0;
+	cc->nr_cpages = 0;
+	cc->cluster_idx = NULL_CLUSTER;
+}
+
+void f2fs_compress_ctx_add_page(struct compress_ctx *cc, struct page *page)
+{
+	unsigned int cluster_ofs;
+
+	if (!f2fs_cluster_can_merge_page(cc, page->index))
+		f2fs_bug_on(F2FS_I_SB(cc->inode), 1);
+
+	cluster_ofs = offset_in_cluster(cc, page->index);
+	cc->rpages[cluster_ofs] = page;
+	cc->nr_rpages++;
+	cc->cluster_idx = cluster_idx(cc, page->index);
+}
+
+#ifdef CONFIG_F2FS_FS_LZO
+static int lzo_init_compress_ctx(struct compress_ctx *cc)
+{
+	cc->private = f2fs_kvmalloc(F2FS_I_SB(cc->inode),
+				LZO1X_MEM_COMPRESS, GFP_NOFS);
+	if (!cc->private)
+		return -ENOMEM;
+
+	cc->clen = lzo1x_worst_compress(PAGE_SIZE << cc->log_cluster_size);
+	return 0;
+}
+
+static void lzo_destroy_compress_ctx(struct compress_ctx *cc)
+{
+	kvfree(cc->private);
+	cc->private = NULL;
+}
+
+static int lzo_compress_pages(struct compress_ctx *cc)
+{
+	int ret;
+
+	ret = lzo1x_1_compress(cc->rbuf, cc->rlen, cc->cbuf->cdata,
+					&cc->clen, cc->private);
+	if (ret != LZO_E_OK) {
+		printk_ratelimited("%sF2FS-fs (%s): lzo compress failed, ret:%d\n",
+				KERN_ERR, F2FS_I_SB(cc->inode)->sb->s_id, ret);
+		return -EIO;
+	}
+	return 0;
+}
+
+static int lzo_decompress_pages(struct decompress_io_ctx *dic)
+{
+	int ret;
+
+	ret = lzo1x_decompress_safe(dic->cbuf->cdata, dic->clen,
+						dic->rbuf, &dic->rlen);
+	if (ret != LZO_E_OK) {
+		printk_ratelimited("%sF2FS-fs (%s): lzo decompress failed, ret:%d\n",
+				KERN_ERR, F2FS_I_SB(dic->inode)->sb->s_id, ret);
+		return -EIO;
+	}
+
+	if (dic->rlen != PAGE_SIZE << dic->log_cluster_size) {
+		printk_ratelimited("%sF2FS-fs (%s): lzo invalid rlen:%zu, "
+					"expected:%lu\n", KERN_ERR,
+					F2FS_I_SB(dic->inode)->sb->s_id,
+					dic->rlen,
+					PAGE_SIZE << dic->log_cluster_size);
+		return -EIO;
+	}
+	return 0;
+}
+
+static const struct f2fs_compress_ops f2fs_lzo_ops = {
+	.init_compress_ctx	= lzo_init_compress_ctx,
+	.destroy_compress_ctx	= lzo_destroy_compress_ctx,
+	.compress_pages		= lzo_compress_pages,
+	.decompress_pages	= lzo_decompress_pages,
+};
+#endif
+
+#ifdef CONFIG_F2FS_FS_LZ4
+static int lz4_init_compress_ctx(struct compress_ctx *cc)
+{
+	cc->private = f2fs_kvmalloc(F2FS_I_SB(cc->inode),
+				LZ4_MEM_COMPRESS, GFP_NOFS);
+	if (!cc->private)
+		return -ENOMEM;
+
+	cc->clen = LZ4_compressBound(PAGE_SIZE << cc->log_cluster_size);
+	return 0;
+}
+
+static void lz4_destroy_compress_ctx(struct compress_ctx *cc)
+{
+	kvfree(cc->private);
+	cc->private = NULL;
+}
+
+static int lz4_compress_pages(struct compress_ctx *cc)
+{
+	int len;
+
+	len = LZ4_compress_default(cc->rbuf, cc->cbuf->cdata, cc->rlen,
+						cc->clen, cc->private);
+	if (!len) {
+		printk_ratelimited("%sF2FS-fs (%s): lz4 compress failed\n",
+				KERN_ERR, F2FS_I_SB(cc->inode)->sb->s_id);
+		return -EIO;
+	}
+	cc->clen = len;
+	return 0;
+}
+
+static int lz4_decompress_pages(struct decompress_io_ctx *dic)
+{
+	int ret;
+
+	ret = LZ4_decompress_safe(dic->cbuf->cdata, dic->rbuf,
+						dic->clen, dic->rlen);
+	if (ret < 0) {
+		printk_ratelimited("%sF2FS-fs (%s): lz4 decompress failed, ret:%d\n",
+				KERN_ERR, F2FS_I_SB(dic->inode)->sb->s_id, ret);
+		return -EIO;
+	}
+
+	if (ret != PAGE_SIZE << dic->log_cluster_size) {
+		printk_ratelimited("%sF2FS-fs (%s): lz4 invalid rlen:%zu, "
+					"expected:%lu\n", KERN_ERR,
+					F2FS_I_SB(dic->inode)->sb->s_id,
+					dic->rlen,
+					PAGE_SIZE << dic->log_cluster_size);
+		return -EIO;
+	}
+	return 0;
+}
+
+static const struct f2fs_compress_ops f2fs_lz4_ops = {
+	.init_compress_ctx	= lz4_init_compress_ctx,
+	.destroy_compress_ctx	= lz4_destroy_compress_ctx,
+	.compress_pages		= lz4_compress_pages,
+	.decompress_pages	= lz4_decompress_pages,
+};
+#endif
+
+static const struct f2fs_compress_ops *f2fs_cops[COMPRESS_MAX] = {
+#ifdef CONFIG_F2FS_FS_LZO
+	&f2fs_lzo_ops,
+#else
+	NULL,
+#endif
+#ifdef CONFIG_F2FS_FS_LZ4
+	&f2fs_lz4_ops,
+#else
+	NULL,
+#endif
+};
+
+bool f2fs_is_compress_backend_ready(struct inode *inode)
+{
+	if (!f2fs_compressed_file(inode))
+		return true;
+	return f2fs_cops[F2FS_I(inode)->i_compress_algorithm];
+}
+
+static struct page *f2fs_grab_page(void)
+{
+	struct page *page;
+
+	page = alloc_page(GFP_NOFS);
+	if (!page)
+		return NULL;
+	lock_page(page);
+	return page;
+}
+
+static int f2fs_compress_pages(struct compress_ctx *cc)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(cc->inode);
+	struct f2fs_inode_info *fi = F2FS_I(cc->inode);
+	const struct f2fs_compress_ops *cops =
+				f2fs_cops[fi->i_compress_algorithm];
+	unsigned int max_len, nr_cpages;
+	int i, ret;
+
+	trace_f2fs_compress_pages_start(cc->inode, cc->cluster_idx,
+				cc->cluster_size, fi->i_compress_algorithm);
+
+	ret = cops->init_compress_ctx(cc);
+	if (ret)
+		goto out;
+
+	max_len = COMPRESS_HEADER_SIZE + cc->clen;
+	cc->nr_cpages = DIV_ROUND_UP(max_len, PAGE_SIZE);
+
+	cc->cpages = f2fs_kzalloc(sbi, sizeof(struct page *) *
+					cc->nr_cpages, GFP_NOFS);
+	if (!cc->cpages) {
+		ret = -ENOMEM;
+		goto destroy_compress_ctx;
+	}
+
+	for (i = 0; i < cc->nr_cpages; i++) {
+		cc->cpages[i] = f2fs_grab_page();
+		if (!cc->cpages[i]) {
+			ret = -ENOMEM;
+			goto out_free_cpages;
+		}
+	}
+
+	cc->rbuf = vmap(cc->rpages, cc->cluster_size, VM_MAP, PAGE_KERNEL_RO);
+	if (!cc->rbuf) {
+		ret = -ENOMEM;
+		goto out_free_cpages;
+	}
+
+	cc->cbuf = vmap(cc->cpages, cc->nr_cpages, VM_MAP, PAGE_KERNEL);
+	if (!cc->cbuf) {
+		ret = -ENOMEM;
+		goto out_vunmap_rbuf;
+	}
+
+	ret = cops->compress_pages(cc);
+	if (ret)
+		goto out_vunmap_cbuf;
+
+	max_len = PAGE_SIZE * (cc->cluster_size - 1) - COMPRESS_HEADER_SIZE;
+
+	if (cc->clen > max_len) {
+		ret = -EAGAIN;
+		goto out_vunmap_cbuf;
+	}
+
+	cc->cbuf->clen = cpu_to_le32(cc->clen);
+	cc->cbuf->chksum = cpu_to_le32(0);
+
+	for (i = 0; i < COMPRESS_DATA_RESERVED_SIZE; i++)
+		cc->cbuf->reserved[i] = cpu_to_le32(0);
+
+	vunmap(cc->cbuf);
+	vunmap(cc->rbuf);
+
+	nr_cpages = DIV_ROUND_UP(cc->clen + COMPRESS_HEADER_SIZE, PAGE_SIZE);
+
+	for (i = nr_cpages; i < cc->nr_cpages; i++) {
+		f2fs_put_compressed_page(cc->cpages[i]);
+		cc->cpages[i] = NULL;
+	}
+
+	cc->nr_cpages = nr_cpages;
+
+	trace_f2fs_compress_pages_end(cc->inode, cc->cluster_idx,
+							cc->clen, ret);
+	return 0;
+
+out_vunmap_cbuf:
+	vunmap(cc->cbuf);
+out_vunmap_rbuf:
+	vunmap(cc->rbuf);
+out_free_cpages:
+	for (i = 0; i < cc->nr_cpages; i++) {
+		if (cc->cpages[i])
+			f2fs_put_compressed_page(cc->cpages[i]);
+	}
+	kfree(cc->cpages);
+	cc->cpages = NULL;
+destroy_compress_ctx:
+	cops->destroy_compress_ctx(cc);
+out:
+	trace_f2fs_compress_pages_end(cc->inode, cc->cluster_idx,
+							cc->clen, ret);
+	return ret;
+}
+
+void f2fs_decompress_pages(struct bio *bio, struct page *page, bool verity)
+{
+	struct decompress_io_ctx *dic =
+			(struct decompress_io_ctx *)page_private(page);
+	struct f2fs_sb_info *sbi = F2FS_I_SB(dic->inode);
+	struct f2fs_inode_info *fi= F2FS_I(dic->inode);
+	const struct f2fs_compress_ops *cops =
+			f2fs_cops[fi->i_compress_algorithm];
+	int ret;
+
+	dec_page_count(sbi, F2FS_RD_DATA);
+
+	if (bio->bi_status || PageError(page))
+		dic->failed = true;
+
+	if (refcount_dec_not_one(&dic->ref))
+		return;
+
+	trace_f2fs_decompress_pages_start(dic->inode, dic->cluster_idx,
+				dic->cluster_size, fi->i_compress_algorithm);
+
+	/* submit partial compressed pages */
+	if (dic->failed) {
+		ret = -EIO;
+		goto out_free_dic;
+	}
+
+	dic->rbuf = vmap(dic->tpages, dic->cluster_size, VM_MAP, PAGE_KERNEL);
+	if (!dic->rbuf) {
+		ret = -ENOMEM;
+		goto out_free_dic;
+	}
+
+	dic->cbuf = vmap(dic->cpages, dic->nr_cpages, VM_MAP, PAGE_KERNEL_RO);
+	if (!dic->cbuf) {
+		ret = -ENOMEM;
+		goto out_vunmap_rbuf;
+	}
+
+	dic->clen = le32_to_cpu(dic->cbuf->clen);
+	dic->rlen = PAGE_SIZE << dic->log_cluster_size;
+
+	if (dic->clen > PAGE_SIZE * dic->nr_cpages - COMPRESS_HEADER_SIZE) {
+		ret = -EFSCORRUPTED;
+		goto out_vunmap_cbuf;
+	}
+
+	ret = cops->decompress_pages(dic);
+
+out_vunmap_cbuf:
+	vunmap(dic->cbuf);
+out_vunmap_rbuf:
+	vunmap(dic->rbuf);
+out_free_dic:
+	if (!verity)
+		f2fs_decompress_end_io(dic->rpages, dic->cluster_size,
+								ret, false);
+
+	trace_f2fs_decompress_pages_end(dic->inode, dic->cluster_idx,
+							dic->clen, ret);
+	if (!verity)
+		f2fs_free_dic(dic);
+}
+
+static bool is_page_in_cluster(struct compress_ctx *cc, pgoff_t index)
+{
+	if (cc->cluster_idx == NULL_CLUSTER)
+		return true;
+	return cc->cluster_idx == cluster_idx(cc, index);
+}
+
+bool f2fs_cluster_is_empty(struct compress_ctx *cc)
+{
+	return cc->nr_rpages == 0;
+}
+
+static bool f2fs_cluster_is_full(struct compress_ctx *cc)
+{
+	return cc->cluster_size == cc->nr_rpages;
+}
+
+bool f2fs_cluster_can_merge_page(struct compress_ctx *cc, pgoff_t index)
+{
+	if (f2fs_cluster_is_empty(cc))
+		return true;
+	return is_page_in_cluster(cc, index);
+}
+
+static bool __cluster_may_compress(struct compress_ctx *cc)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(cc->inode);
+	loff_t i_size = i_size_read(cc->inode);
+	unsigned nr_pages = DIV_ROUND_UP(i_size, PAGE_SIZE);
+	int i;
+
+	for (i = 0; i < cc->cluster_size; i++) {
+		struct page *page = cc->rpages[i];
+
+		f2fs_bug_on(sbi, !page);
+
+		if (unlikely(f2fs_cp_error(sbi)))
+			return false;
+		if (unlikely(is_sbi_flag_set(sbi, SBI_POR_DOING)))
+			return false;
+
+		/* beyond EOF */
+		if (page->index >= nr_pages)
+			return false;
+	}
+	return true;
+}
+
+/* return # of compressed block addresses */
+static int f2fs_compressed_blocks(struct compress_ctx *cc)
+{
+	struct dnode_of_data dn;
+	int ret;
+
+	set_new_dnode(&dn, cc->inode, NULL, NULL, 0);
+	ret = f2fs_get_dnode_of_data(&dn, start_idx_of_cluster(cc),
+							LOOKUP_NODE);
+	if (ret) {
+		if (ret == -ENOENT)
+			ret = 0;
+		goto fail;
+	}
+
+	if (dn.data_blkaddr == COMPRESS_ADDR) {
+		int i;
+
+		ret = 1;
+		for (i = 1; i < cc->cluster_size; i++) {
+			block_t blkaddr;
+
+			blkaddr = datablock_addr(dn.inode,
+					dn.node_page, dn.ofs_in_node + i);
+			if (blkaddr != NULL_ADDR)
+				ret++;
+		}
+	}
+fail:
+	f2fs_put_dnode(&dn);
+	return ret;
+}
+
+int f2fs_is_compressed_cluster(struct inode *inode, pgoff_t index)
+{
+	struct compress_ctx cc = {
+		.inode = inode,
+		.log_cluster_size = F2FS_I(inode)->i_log_cluster_size,
+		.cluster_size = F2FS_I(inode)->i_cluster_size,
+		.cluster_idx = index >> F2FS_I(inode)->i_log_cluster_size,
+	};
+
+	return f2fs_compressed_blocks(&cc);
+}
+
+static bool cluster_may_compress(struct compress_ctx *cc)
+{
+	if (!f2fs_compressed_file(cc->inode))
+		return false;
+	if (f2fs_is_atomic_file(cc->inode))
+		return false;
+	if (f2fs_is_mmap_file(cc->inode))
+		return false;
+	if (!f2fs_cluster_is_full(cc))
+		return false;
+	return __cluster_may_compress(cc);
+}
+
+static void set_cluster_writeback(struct compress_ctx *cc)
+{
+	int i;
+
+	for (i = 0; i < cc->cluster_size; i++) {
+		if (cc->rpages[i])
+			set_page_writeback(cc->rpages[i]);
+	}
+}
+
+static void set_cluster_dirty(struct compress_ctx *cc)
+{
+	int i;
+
+	for (i = 0; i < cc->cluster_size; i++)
+		if (cc->rpages[i])
+			set_page_dirty(cc->rpages[i]);
+}
+
+static int prepare_compress_overwrite(struct compress_ctx *cc,
+		struct page **pagep, pgoff_t index, void **fsdata)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(cc->inode);
+	struct address_space *mapping = cc->inode->i_mapping;
+	struct page *page;
+	struct dnode_of_data dn;
+	sector_t last_block_in_bio;
+	unsigned fgp_flag = FGP_LOCK | FGP_WRITE | FGP_CREAT;
+	pgoff_t start_idx = start_idx_of_cluster(cc);
+	int i, ret;
+	bool prealloc;
+
+retry:
+	ret = f2fs_compressed_blocks(cc);
+	if (ret <= 0)
+		return ret;
+
+	/* compressed case */
+	prealloc = (ret < cc->cluster_size);
+
+	ret = f2fs_init_compress_ctx(cc);
+	if (ret)
+		return ret;
+
+	/* keep page reference to avoid page reclaim */
+	for (i = 0; i < cc->cluster_size; i++) {
+		page = f2fs_pagecache_get_page(mapping, start_idx + i,
+							fgp_flag, GFP_NOFS);
+		if (!page) {
+			ret = -ENOMEM;
+			goto unlock_pages;
+		}
+
+		if (PageUptodate(page))
+			unlock_page(page);
+		else
+			f2fs_compress_ctx_add_page(cc, page);
+	}
+
+	if (!f2fs_cluster_is_empty(cc)) {
+		struct bio *bio = NULL;
+
+		ret = f2fs_read_multi_pages(cc, &bio, cc->cluster_size,
+						&last_block_in_bio, false);
+		f2fs_destroy_compress_ctx(cc);
+		if (ret)
+			goto release_pages;
+		if (bio)
+			f2fs_submit_bio(sbi, bio, DATA);
+
+		ret = f2fs_init_compress_ctx(cc);
+		if (ret)
+			goto release_pages;
+	}
+
+	for (i = 0; i < cc->cluster_size; i++) {
+		f2fs_bug_on(sbi, cc->rpages[i]);
+
+		page = find_lock_page(mapping, start_idx + i);
+		f2fs_bug_on(sbi, !page);
+
+		f2fs_wait_on_page_writeback(page, DATA, true, true);
+
+		f2fs_compress_ctx_add_page(cc, page);
+		f2fs_put_page(page, 0);
+
+		if (!PageUptodate(page)) {
+			f2fs_unlock_rpages(cc, i + 1);
+			f2fs_put_rpages_mapping(cc, mapping, start_idx,
+					cc->cluster_size);
+			f2fs_destroy_compress_ctx(cc);
+			goto retry;
+		}
+	}
+
+	if (prealloc) {
+		__do_map_lock(sbi, F2FS_GET_BLOCK_PRE_AIO, true);
+
+		set_new_dnode(&dn, cc->inode, NULL, NULL, 0);
+
+		for (i = cc->cluster_size - 1; i > 0; i--) {
+			ret = f2fs_get_block(&dn, start_idx + i);
+			if (ret) {
+				i = cc->cluster_size;
+				break;
+			}
+
+			if (dn.data_blkaddr != NEW_ADDR)
+				break;
+		}
+
+		__do_map_lock(sbi, F2FS_GET_BLOCK_PRE_AIO, false);
+	}
+
+	if (likely(!ret)) {
+		*fsdata = cc->rpages;
+		*pagep = cc->rpages[offset_in_cluster(cc, index)];
+		return cc->cluster_size;
+	}
+
+unlock_pages:
+	f2fs_unlock_rpages(cc, i);
+release_pages:
+	f2fs_put_rpages_mapping(cc, mapping, start_idx, i);
+	f2fs_destroy_compress_ctx(cc);
+	return ret;
+}
+
+int f2fs_prepare_compress_overwrite(struct inode *inode,
+		struct page **pagep, pgoff_t index, void **fsdata)
+{
+	struct compress_ctx cc = {
+		.inode = inode,
+		.log_cluster_size = F2FS_I(inode)->i_log_cluster_size,
+		.cluster_size = F2FS_I(inode)->i_cluster_size,
+		.cluster_idx = index >> F2FS_I(inode)->i_log_cluster_size,
+		.rpages = NULL,
+		.nr_rpages = 0,
+	};
+
+	return prepare_compress_overwrite(&cc, pagep, index, fsdata);
+}
+
+bool f2fs_compress_write_end(struct inode *inode, void *fsdata,
+					pgoff_t index, unsigned copied)
+
+{
+	struct compress_ctx cc = {
+		.log_cluster_size = F2FS_I(inode)->i_log_cluster_size,
+		.cluster_size = F2FS_I(inode)->i_cluster_size,
+		.rpages = fsdata,
+	};
+	bool first_index = (index == cc.rpages[0]->index);
+
+	if (copied)
+		set_cluster_dirty(&cc);
+
+	f2fs_put_rpages_wbc(&cc, NULL, false, 1);
+	f2fs_destroy_compress_ctx(&cc);
+
+	return first_index;
+}
+
+static int f2fs_write_compressed_pages(struct compress_ctx *cc,
+					int *submitted,
+					struct writeback_control *wbc,
+					enum iostat_type io_type)
+{
+	struct inode *inode = cc->inode;
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	struct f2fs_inode_info *fi = F2FS_I(inode);
+	struct f2fs_io_info fio = {
+		.sbi = sbi,
+		.ino = cc->inode->i_ino,
+		.type = DATA,
+		.op = REQ_OP_WRITE,
+		.op_flags = wbc_to_write_flags(wbc),
+		.old_blkaddr = NEW_ADDR,
+		.page = NULL,
+		.encrypted_page = NULL,
+		.compressed_page = NULL,
+		.submitted = false,
+		.need_lock = LOCK_RETRY,
+		.io_type = io_type,
+		.io_wbc = wbc,
+		.encrypted = f2fs_encrypted_file(cc->inode),
+	};
+	struct dnode_of_data dn;
+	struct node_info ni;
+	struct compress_io_ctx *cic;
+	pgoff_t start_idx = start_idx_of_cluster(cc);
+	unsigned int last_index = cc->cluster_size - 1;
+	loff_t psize;
+	int i, err;
+
+	set_new_dnode(&dn, cc->inode, NULL, NULL, 0);
+
+	f2fs_lock_op(sbi);
+
+	err = f2fs_get_dnode_of_data(&dn, start_idx, LOOKUP_NODE);
+	if (err)
+		goto out_unlock_op;
+
+	for (i = 0; i < cc->cluster_size; i++) {
+		if (datablock_addr(dn.inode, dn.node_page,
+					dn.ofs_in_node + i) == NULL_ADDR)
+			goto out_put_dnode;
+	}
+
+	psize = (loff_t)(cc->rpages[last_index]->index + 1) << PAGE_SHIFT;
+
+	err = f2fs_get_node_info(fio.sbi, dn.nid, &ni);
+	if (err)
+		goto out_put_dnode;
+
+	fio.version = ni.version;
+
+	cic = f2fs_kzalloc(sbi, sizeof(struct compress_io_ctx), GFP_NOFS);
+	if (!cic)
+		goto out_put_dnode;
+
+	cic->magic = F2FS_COMPRESSED_PAGE_MAGIC;
+	cic->inode = inode;
+	refcount_set(&cic->ref, 1);
+	cic->rpages = f2fs_kzalloc(sbi, sizeof(struct page *) <<
+			cc->log_cluster_size, GFP_NOFS);
+	if (!cic->rpages)
+		goto out_put_cic;
+
+	cic->nr_rpages = cc->cluster_size;
+
+	for (i = 0; i < cc->nr_cpages; i++) {
+		f2fs_set_compressed_page(cc->cpages[i], inode,
+					cc->rpages[i + 1]->index,
+					cic, i ? &cic->ref : NULL);
+		fio.compressed_page = cc->cpages[i];
+		if (fio.encrypted) {
+			fio.page = cc->rpages[i + 1];
+			err = f2fs_encrypt_one_page(&fio);
+			if (err)
+				goto out_destroy_crypt;
+			cc->cpages[i] = fio.encrypted_page;
+		}
+	}
+
+	set_cluster_writeback(cc);
+
+	for (i = 0; i < cc->cluster_size; i++)
+		cic->rpages[i] = cc->rpages[i];
+
+	for (i = 0; i < cc->cluster_size; i++, dn.ofs_in_node++) {
+		block_t blkaddr;
+
+		blkaddr = datablock_addr(dn.inode, dn.node_page,
+							dn.ofs_in_node);
+		fio.page = cic->rpages[i];
+		fio.old_blkaddr = blkaddr;
+
+		/* cluster header */
+		if (i == 0) {
+			if (blkaddr == COMPRESS_ADDR)
+				fio.compr_blocks++;
+			if (__is_valid_data_blkaddr(blkaddr))
+				f2fs_invalidate_blocks(sbi, blkaddr);
+			f2fs_update_data_blkaddr(&dn, COMPRESS_ADDR);
+			goto unlock_continue;
+		}
+
+		if (fio.compr_blocks && __is_valid_data_blkaddr(blkaddr))
+			fio.compr_blocks++;
+
+		if (i > cc->nr_cpages) {
+			if (__is_valid_data_blkaddr(blkaddr)) {
+				f2fs_invalidate_blocks(sbi, blkaddr);
+				f2fs_update_data_blkaddr(&dn, NEW_ADDR);
+			}
+			goto unlock_continue;
+		}
+
+		f2fs_bug_on(fio.sbi, blkaddr == NULL_ADDR);
+
+		if (fio.encrypted)
+			fio.encrypted_page = cc->cpages[i - 1];
+		else
+			fio.compressed_page = cc->cpages[i - 1];
+
+		cc->cpages[i - 1] = NULL;
+		f2fs_outplace_write_data(&dn, &fio);
+		(*submitted)++;
+unlock_continue:
+		inode_dec_dirty_pages(cc->inode);
+		unlock_page(fio.page);
+	}
+
+	if (fio.compr_blocks)
+		f2fs_i_compr_blocks_update(inode, fio.compr_blocks - 1, false);
+	f2fs_i_compr_blocks_update(inode, cc->nr_cpages, true);
+
+	set_inode_flag(cc->inode, FI_APPEND_WRITE);
+	if (cc->cluster_idx == 0)
+		set_inode_flag(inode, FI_FIRST_BLOCK_WRITTEN);
+
+	f2fs_put_dnode(&dn);
+	f2fs_unlock_op(sbi);
+
+	down_write(&fi->i_sem);
+	if (fi->last_disk_size < psize)
+		fi->last_disk_size = psize;
+	up_write(&fi->i_sem);
+
+	f2fs_put_rpages(cc);
+	f2fs_destroy_compress_ctx(cc);
+	return 0;
+
+out_destroy_crypt:
+	kfree(cic->rpages);
+
+	for (--i; i >= 0; i--)
+		fscrypt_finalize_bounce_page(&cc->cpages[i]);
+	for (i = 0; i < cc->nr_cpages; i++) {
+		if (!cc->cpages[i])
+			continue;
+		f2fs_put_page(cc->cpages[i], 1);
+	}
+out_put_cic:
+	kfree(cic);
+out_put_dnode:
+	f2fs_put_dnode(&dn);
+out_unlock_op:
+	f2fs_unlock_op(sbi);
+	return -EAGAIN;
+}
+
+void f2fs_compress_write_end_io(struct bio *bio, struct page *page)
+{
+	struct f2fs_sb_info *sbi = bio->bi_private;
+	struct compress_io_ctx *cic =
+			(struct compress_io_ctx *)page_private(page);
+	int i;
+
+	if (unlikely(bio->bi_status))
+		mapping_set_error(cic->inode->i_mapping, -EIO);
+
+	f2fs_put_compressed_page(page);
+
+	dec_page_count(sbi, F2FS_WB_DATA);
+
+	if (refcount_dec_not_one(&cic->ref))
+		return;
+
+	for (i = 0; i < cic->nr_rpages; i++) {
+		WARN_ON(!cic->rpages[i]);
+		clear_cold_data(cic->rpages[i]);
+		end_page_writeback(cic->rpages[i]);
+	}
+
+	kfree(cic->rpages);
+	kfree(cic);
+}
+
+static int f2fs_write_raw_pages(struct compress_ctx *cc,
+					int *submitted,
+					struct writeback_control *wbc,
+					enum iostat_type io_type)
+{
+	struct address_space *mapping = cc->inode->i_mapping;
+	int _submitted, compr_blocks, ret;
+	int i = -1, err = 0;
+
+	compr_blocks = f2fs_compressed_blocks(cc);
+	if (compr_blocks < 0) {
+		err = compr_blocks;
+		goto out_err;
+	}
+
+	for (i = 0; i < cc->cluster_size; i++) {
+		if (!cc->rpages[i])
+			continue;
+retry_write:
+		if (cc->rpages[i]->mapping != mapping) {
+			unlock_page(cc->rpages[i]);
+			continue;
+		}
+
+		BUG_ON(!PageLocked(cc->rpages[i]));
+
+		ret = f2fs_write_single_data_page(cc->rpages[i], &_submitted,
+						NULL, NULL, wbc, io_type,
+						compr_blocks);
+		if (ret) {
+			if (ret == AOP_WRITEPAGE_ACTIVATE) {
+				unlock_page(cc->rpages[i]);
+				ret = 0;
+			} else if (ret == -EAGAIN) {
+				ret = 0;
+				cond_resched();
+				congestion_wait(BLK_RW_ASYNC, HZ/50);
+				lock_page(cc->rpages[i]);
+				clear_page_dirty_for_io(cc->rpages[i]);
+				goto retry_write;
+			}
+			err = ret;
+			goto out_fail;
+		}
+
+		*submitted += _submitted;
+	}
+	return 0;
+
+out_fail:
+	/* TODO: revoke partially updated block addresses */
+	BUG_ON(compr_blocks);
+out_err:
+	for (++i; i < cc->cluster_size; i++) {
+		if (!cc->rpages[i])
+			continue;
+		redirty_page_for_writepage(wbc, cc->rpages[i]);
+		unlock_page(cc->rpages[i]);
+	}
+	return err;
+}
+
+int f2fs_write_multi_pages(struct compress_ctx *cc,
+					int *submitted,
+					struct writeback_control *wbc,
+					enum iostat_type io_type)
+{
+	struct f2fs_inode_info *fi = F2FS_I(cc->inode);
+	const struct f2fs_compress_ops *cops =
+			f2fs_cops[fi->i_compress_algorithm];
+	int err;
+
+	*submitted = 0;
+	if (cluster_may_compress(cc)) {
+		err = f2fs_compress_pages(cc);
+		if (err == -EAGAIN) {
+			goto write;
+		} else if (err) {
+			f2fs_put_rpages_wbc(cc, wbc, true, 1);
+			goto destroy_out;
+		}
+
+		err = f2fs_write_compressed_pages(cc, submitted,
+							wbc, io_type);
+		cops->destroy_compress_ctx(cc);
+		if (!err)
+			return 0;
+		f2fs_bug_on(F2FS_I_SB(cc->inode), err != -EAGAIN);
+	}
+write:
+	f2fs_bug_on(F2FS_I_SB(cc->inode), *submitted);
+
+	err = f2fs_write_raw_pages(cc, submitted, wbc, io_type);
+	f2fs_put_rpages_wbc(cc, wbc, false, 0);
+destroy_out:
+	f2fs_destroy_compress_ctx(cc);
+	return err;
+}
+
+struct decompress_io_ctx *f2fs_alloc_dic(struct compress_ctx *cc)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(cc->inode);
+	struct decompress_io_ctx *dic;
+	pgoff_t start_idx = start_idx_of_cluster(cc);
+	int i;
+
+	dic = f2fs_kzalloc(sbi, sizeof(struct decompress_io_ctx), GFP_NOFS);
+	if (!dic)
+		return ERR_PTR(-ENOMEM);
+
+	dic->rpages = f2fs_kzalloc(sbi, sizeof(struct page *) <<
+			cc->log_cluster_size, GFP_NOFS);
+	if (!dic->rpages) {
+		kfree(dic);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	dic->magic = F2FS_COMPRESSED_PAGE_MAGIC;
+	dic->inode = cc->inode;
+	refcount_set(&dic->ref, 1);
+	dic->cluster_idx = cc->cluster_idx;
+	dic->cluster_size = cc->cluster_size;
+	dic->log_cluster_size = cc->log_cluster_size;
+	dic->nr_cpages = cc->nr_cpages;
+	dic->failed = false;
+
+	for (i = 0; i < dic->cluster_size; i++)
+		dic->rpages[i] = cc->rpages[i];
+	dic->nr_rpages = cc->cluster_size;
+
+	dic->cpages = f2fs_kzalloc(sbi, sizeof(struct page *) *
+					dic->nr_cpages, GFP_NOFS);
+	if (!dic->cpages)
+		goto out_free;
+
+	for (i = 0; i < dic->nr_cpages; i++) {
+		struct page *page;
+
+		page = f2fs_grab_page();
+		if (!page)
+			goto out_free;
+
+		f2fs_set_compressed_page(page, cc->inode,
+					start_idx + i + 1,
+					dic, i ? &dic->ref : NULL);
+		dic->cpages[i] = page;
+	}
+
+	dic->tpages = f2fs_kzalloc(sbi, sizeof(struct page *) *
+					dic->cluster_size, GFP_NOFS);
+	if (!dic->tpages)
+		goto out_free;
+
+	for (i = 0; i < dic->cluster_size; i++) {
+		if (cc->rpages[i])
+			continue;
+
+		dic->tpages[i] = f2fs_grab_page();
+		if (!dic->tpages[i])
+			goto out_free;
+	}
+
+	for (i = 0; i < dic->cluster_size; i++) {
+		if (dic->tpages[i])
+			continue;
+		dic->tpages[i] = cc->rpages[i];
+	}
+
+	return dic;
+
+out_free:
+	f2fs_free_dic(dic);
+	return ERR_PTR(-ENOMEM);
+}
+
+void f2fs_free_dic(struct decompress_io_ctx *dic)
+{
+	int i;
+
+	if (dic->tpages) {
+		for (i = 0; i < dic->cluster_size; i++) {
+			if (dic->rpages[i])
+				continue;
+			f2fs_put_page(dic->tpages[i], 1);
+		}
+		kfree(dic->tpages);
+	}
+
+	if (dic->cpages) {
+		for (i = 0; i < dic->nr_cpages; i++) {
+			if (!dic->cpages[i])
+				continue;
+			f2fs_put_compressed_page(dic->cpages[i]);
+		}
+		kfree(dic->cpages);
+	}
+
+	kfree(dic->rpages);
+	kfree(dic);
+}
+
+void f2fs_decompress_end_io(struct page **rpages,
+			unsigned int cluster_size, bool err, bool verity)
+{
+	int i;
+
+	for (i = 0; i < cluster_size; i++) {
+		struct page *rpage = rpages[i];
+
+		if (!rpage)
+			continue;
+
+		if (err || PageError(rpage)) {
+			ClearPageUptodate(rpage);
+			ClearPageError(rpage);
+		} else {
+			if (!verity || fsverity_verify_page(rpage))
+				SetPageUptodate(rpage);
+			else
+				SetPageError(rpage);
+		}
+		unlock_page(rpage);
+	}
+}