aboutsummaryrefslogtreecommitdiffstats
path: root/fs/f2fs/data.c
diff options
context:
space:
mode:
Diffstat (limited to 'fs/f2fs/data.c')
-rw-r--r--fs/f2fs/data.c718
1 files changed, 718 insertions, 0 deletions
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
new file mode 100644
index 00000000000..7bd22a20112
--- /dev/null
+++ b/fs/f2fs/data.c
@@ -0,0 +1,718 @@
+/*
+ * fs/f2fs/data.c
+ *
+ * Copyright (c) 2012 Samsung Electronics Co., Ltd.
+ * http://www.samsung.com/
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/fs.h>
+#include <linux/f2fs_fs.h>
+#include <linux/buffer_head.h>
+#include <linux/mpage.h>
+#include <linux/writeback.h>
+#include <linux/backing-dev.h>
+#include <linux/blkdev.h>
+#include <linux/bio.h>
+#include <linux/prefetch.h>
+
+#include "f2fs.h"
+#include "node.h"
+#include "segment.h"
+
+/*
+ * Lock ordering for the change of data block address:
+ * ->data_page
+ * ->node_page
+ * update block addresses in the node page
+ */
+static void __set_data_blkaddr(struct dnode_of_data *dn, block_t new_addr)
+{
+ struct f2fs_node *rn;
+ __le32 *addr_array;
+ struct page *node_page = dn->node_page;
+ unsigned int ofs_in_node = dn->ofs_in_node;
+
+ wait_on_page_writeback(node_page);
+
+ rn = (struct f2fs_node *)page_address(node_page);
+
+ /* Get physical address of data block */
+ addr_array = blkaddr_in_node(rn);
+ addr_array[ofs_in_node] = cpu_to_le32(new_addr);
+ set_page_dirty(node_page);
+}
+
+int reserve_new_block(struct dnode_of_data *dn)
+{
+ struct f2fs_sb_info *sbi = F2FS_SB(dn->inode->i_sb);
+
+ if (is_inode_flag_set(F2FS_I(dn->inode), FI_NO_ALLOC))
+ return -EPERM;
+ if (!inc_valid_block_count(sbi, dn->inode, 1))
+ return -ENOSPC;
+
+ __set_data_blkaddr(dn, NEW_ADDR);
+ dn->data_blkaddr = NEW_ADDR;
+ sync_inode_page(dn);
+ return 0;
+}
+
+static int check_extent_cache(struct inode *inode, pgoff_t pgofs,
+ struct buffer_head *bh_result)
+{
+ struct f2fs_inode_info *fi = F2FS_I(inode);
+ struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
+ pgoff_t start_fofs, end_fofs;
+ block_t start_blkaddr;
+
+ read_lock(&fi->ext.ext_lock);
+ if (fi->ext.len == 0) {
+ read_unlock(&fi->ext.ext_lock);
+ return 0;
+ }
+
+ sbi->total_hit_ext++;
+ start_fofs = fi->ext.fofs;
+ end_fofs = fi->ext.fofs + fi->ext.len - 1;
+ start_blkaddr = fi->ext.blk_addr;
+
+ if (pgofs >= start_fofs && pgofs <= end_fofs) {
+ unsigned int blkbits = inode->i_sb->s_blocksize_bits;
+ size_t count;
+
+ clear_buffer_new(bh_result);
+ map_bh(bh_result, inode->i_sb,
+ start_blkaddr + pgofs - start_fofs);
+ count = end_fofs - pgofs + 1;
+ if (count < (UINT_MAX >> blkbits))
+ bh_result->b_size = (count << blkbits);
+ else
+ bh_result->b_size = UINT_MAX;
+
+ sbi->read_hit_ext++;
+ read_unlock(&fi->ext.ext_lock);
+ return 1;
+ }
+ read_unlock(&fi->ext.ext_lock);
+ return 0;
+}
+
+void update_extent_cache(block_t blk_addr, struct dnode_of_data *dn)
+{
+ struct f2fs_inode_info *fi = F2FS_I(dn->inode);
+ pgoff_t fofs, start_fofs, end_fofs;
+ block_t start_blkaddr, end_blkaddr;
+
+ BUG_ON(blk_addr == NEW_ADDR);
+ fofs = start_bidx_of_node(ofs_of_node(dn->node_page)) + dn->ofs_in_node;
+
+ /* Update the page address in the parent node */
+ __set_data_blkaddr(dn, blk_addr);
+
+ write_lock(&fi->ext.ext_lock);
+
+ start_fofs = fi->ext.fofs;
+ end_fofs = fi->ext.fofs + fi->ext.len - 1;
+ start_blkaddr = fi->ext.blk_addr;
+ end_blkaddr = fi->ext.blk_addr + fi->ext.len - 1;
+
+ /* Drop and initialize the matched extent */
+ if (fi->ext.len == 1 && fofs == start_fofs)
+ fi->ext.len = 0;
+
+ /* Initial extent */
+ if (fi->ext.len == 0) {
+ if (blk_addr != NULL_ADDR) {
+ fi->ext.fofs = fofs;
+ fi->ext.blk_addr = blk_addr;
+ fi->ext.len = 1;
+ }
+ goto end_update;
+ }
+
+ /* Frone merge */
+ if (fofs == start_fofs - 1 && blk_addr == start_blkaddr - 1) {
+ fi->ext.fofs--;
+ fi->ext.blk_addr--;
+ fi->ext.len++;
+ goto end_update;
+ }
+
+ /* Back merge */
+ if (fofs == end_fofs + 1 && blk_addr == end_blkaddr + 1) {
+ fi->ext.len++;
+ goto end_update;
+ }
+
+ /* Split the existing extent */
+ if (fi->ext.len > 1 &&
+ fofs >= start_fofs && fofs <= end_fofs) {
+ if ((end_fofs - fofs) < (fi->ext.len >> 1)) {
+ fi->ext.len = fofs - start_fofs;
+ } else {
+ fi->ext.fofs = fofs + 1;
+ fi->ext.blk_addr = start_blkaddr +
+ fofs - start_fofs + 1;
+ fi->ext.len -= fofs - start_fofs + 1;
+ }
+ goto end_update;
+ }
+ write_unlock(&fi->ext.ext_lock);
+ return;
+
+end_update:
+ write_unlock(&fi->ext.ext_lock);
+ sync_inode_page(dn);
+ return;
+}
+
+struct page *find_data_page(struct inode *inode, pgoff_t index)
+{
+ struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
+ struct address_space *mapping = inode->i_mapping;
+ struct dnode_of_data dn;
+ struct page *page;
+ int err;
+
+ page = find_get_page(mapping, index);
+ if (page && PageUptodate(page))
+ return page;
+ f2fs_put_page(page, 0);
+
+ set_new_dnode(&dn, inode, NULL, NULL, 0);
+ err = get_dnode_of_data(&dn, index, RDONLY_NODE);
+ if (err)
+ return ERR_PTR(err);
+ f2fs_put_dnode(&dn);
+
+ if (dn.data_blkaddr == NULL_ADDR)
+ return ERR_PTR(-ENOENT);
+
+ /* By fallocate(), there is no cached page, but with NEW_ADDR */
+ if (dn.data_blkaddr == NEW_ADDR)
+ return ERR_PTR(-EINVAL);
+
+ page = grab_cache_page(mapping, index);
+ if (!page)
+ return ERR_PTR(-ENOMEM);
+
+ err = f2fs_readpage(sbi, page, dn.data_blkaddr, READ_SYNC);
+ if (err) {
+ f2fs_put_page(page, 1);
+ return ERR_PTR(err);
+ }
+ unlock_page(page);
+ return page;
+}
+
+/*
+ * If it tries to access a hole, return an error.
+ * Because, the callers, functions in dir.c and GC, should be able to know
+ * whether this page exists or not.
+ */
+struct page *get_lock_data_page(struct inode *inode, pgoff_t index)
+{
+ struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
+ struct address_space *mapping = inode->i_mapping;
+ struct dnode_of_data dn;
+ struct page *page;
+ int err;
+
+ set_new_dnode(&dn, inode, NULL, NULL, 0);
+ err = get_dnode_of_data(&dn, index, RDONLY_NODE);
+ if (err)
+ return ERR_PTR(err);
+ f2fs_put_dnode(&dn);
+
+ if (dn.data_blkaddr == NULL_ADDR)
+ return ERR_PTR(-ENOENT);
+
+ page = grab_cache_page(mapping, index);
+ if (!page)
+ return ERR_PTR(-ENOMEM);
+
+ if (PageUptodate(page))
+ return page;
+
+ BUG_ON(dn.data_blkaddr == NEW_ADDR);
+ BUG_ON(dn.data_blkaddr == NULL_ADDR);
+
+ err = f2fs_readpage(sbi, page, dn.data_blkaddr, READ_SYNC);
+ if (err) {
+ f2fs_put_page(page, 1);
+ return ERR_PTR(err);
+ }
+ return page;
+}
+
+/*
+ * Caller ensures that this data page is never allocated.
+ * A new zero-filled data page is allocated in the page cache.
+ */
+struct page *get_new_data_page(struct inode *inode, pgoff_t index,
+ bool new_i_size)
+{
+ struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
+ struct address_space *mapping = inode->i_mapping;
+ struct page *page;
+ struct dnode_of_data dn;
+ int err;
+
+ set_new_dnode(&dn, inode, NULL, NULL, 0);
+ err = get_dnode_of_data(&dn, index, 0);
+ if (err)
+ return ERR_PTR(err);
+
+ if (dn.data_blkaddr == NULL_ADDR) {
+ if (reserve_new_block(&dn)) {
+ f2fs_put_dnode(&dn);
+ return ERR_PTR(-ENOSPC);
+ }
+ }
+ f2fs_put_dnode(&dn);
+
+ page = grab_cache_page(mapping, index);
+ if (!page)
+ return ERR_PTR(-ENOMEM);
+
+ if (PageUptodate(page))
+ return page;
+
+ if (dn.data_blkaddr == NEW_ADDR) {
+ zero_user_segment(page, 0, PAGE_CACHE_SIZE);
+ } else {
+ err = f2fs_readpage(sbi, page, dn.data_blkaddr, READ_SYNC);
+ if (err) {
+ f2fs_put_page(page, 1);
+ return ERR_PTR(err);
+ }
+ }
+ SetPageUptodate(page);
+
+ if (new_i_size &&
+ i_size_read(inode) < ((index + 1) << PAGE_CACHE_SHIFT)) {
+ i_size_write(inode, ((index + 1) << PAGE_CACHE_SHIFT));
+ mark_inode_dirty_sync(inode);
+ }
+ return page;
+}
+
+static void read_end_io(struct bio *bio, int err)
+{
+ const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
+ struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
+
+ do {
+ struct page *page = bvec->bv_page;
+
+ if (--bvec >= bio->bi_io_vec)
+ prefetchw(&bvec->bv_page->flags);
+
+ if (uptodate) {
+ SetPageUptodate(page);
+ } else {
+ ClearPageUptodate(page);
+ SetPageError(page);
+ }
+ unlock_page(page);
+ } while (bvec >= bio->bi_io_vec);
+ kfree(bio->bi_private);
+ bio_put(bio);
+}
+
+/*
+ * Fill the locked page with data located in the block address.
+ * Read operation is synchronous, and caller must unlock the page.
+ */
+int f2fs_readpage(struct f2fs_sb_info *sbi, struct page *page,
+ block_t blk_addr, int type)
+{
+ struct block_device *bdev = sbi->sb->s_bdev;
+ bool sync = (type == READ_SYNC);
+ struct bio *bio;
+
+ /* This page can be already read by other threads */
+ if (PageUptodate(page)) {
+ if (!sync)
+ unlock_page(page);
+ return 0;
+ }
+
+ down_read(&sbi->bio_sem);
+
+ /* Allocate a new bio */
+ bio = f2fs_bio_alloc(bdev, 1);
+
+ /* Initialize the bio */
+ bio->bi_sector = SECTOR_FROM_BLOCK(sbi, blk_addr);
+ bio->bi_end_io = read_end_io;
+
+ if (bio_add_page(bio, page, PAGE_CACHE_SIZE, 0) < PAGE_CACHE_SIZE) {
+ kfree(bio->bi_private);
+ bio_put(bio);
+ up_read(&sbi->bio_sem);
+ return -EFAULT;
+ }
+
+ submit_bio(type, bio);
+ up_read(&sbi->bio_sem);
+
+ /* wait for read completion if sync */
+ if (sync) {
+ lock_page(page);
+ if (PageError(page))
+ return -EIO;
+ }
+ return 0;
+}
+
+/*
+ * This function should be used by the data read flow only where it
+ * does not check the "create" flag that indicates block allocation.
+ * The reason for this special functionality is to exploit VFS readahead
+ * mechanism.
+ */
+static int get_data_block_ro(struct inode *inode, sector_t iblock,
+ struct buffer_head *bh_result, int create)
+{
+ unsigned int blkbits = inode->i_sb->s_blocksize_bits;
+ unsigned maxblocks = bh_result->b_size >> blkbits;
+ struct dnode_of_data dn;
+ pgoff_t pgofs;
+ int err;
+
+ /* Get the page offset from the block offset(iblock) */
+ pgofs = (pgoff_t)(iblock >> (PAGE_CACHE_SHIFT - blkbits));
+
+ if (check_extent_cache(inode, pgofs, bh_result))
+ return 0;
+
+ /* When reading holes, we need its node page */
+ set_new_dnode(&dn, inode, NULL, NULL, 0);
+ err = get_dnode_of_data(&dn, pgofs, RDONLY_NODE);
+ if (err)
+ return (err == -ENOENT) ? 0 : err;
+
+ /* It does not support data allocation */
+ BUG_ON(create);
+
+ if (dn.data_blkaddr != NEW_ADDR && dn.data_blkaddr != NULL_ADDR) {
+ int i;
+ unsigned int end_offset;
+
+ end_offset = IS_INODE(dn.node_page) ?
+ ADDRS_PER_INODE :
+ ADDRS_PER_BLOCK;
+
+ clear_buffer_new(bh_result);
+
+ /* Give more consecutive addresses for the read ahead */
+ for (i = 0; i < end_offset - dn.ofs_in_node; i++)
+ if (((datablock_addr(dn.node_page,
+ dn.ofs_in_node + i))
+ != (dn.data_blkaddr + i)) || maxblocks == i)
+ break;
+ map_bh(bh_result, inode->i_sb, dn.data_blkaddr);
+ bh_result->b_size = (i << blkbits);
+ }
+ f2fs_put_dnode(&dn);
+ return 0;
+}
+
+static int f2fs_read_data_page(struct file *file, struct page *page)
+{
+ return mpage_readpage(page, get_data_block_ro);
+}
+
+static int f2fs_read_data_pages(struct file *file,
+ struct address_space *mapping,
+ struct list_head *pages, unsigned nr_pages)
+{
+ return mpage_readpages(mapping, pages, nr_pages, get_data_block_ro);
+}
+
+int do_write_data_page(struct page *page)
+{
+ struct inode *inode = page->mapping->host;
+ struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
+ block_t old_blk_addr, new_blk_addr;
+ struct dnode_of_data dn;
+ int err = 0;
+
+ set_new_dnode(&dn, inode, NULL, NULL, 0);
+ err = get_dnode_of_data(&dn, page->index, RDONLY_NODE);
+ if (err)
+ return err;
+
+ old_blk_addr = dn.data_blkaddr;
+
+ /* This page is already truncated */
+ if (old_blk_addr == NULL_ADDR)
+ goto out_writepage;
+
+ set_page_writeback(page);
+
+ /*
+ * If current allocation needs SSR,
+ * it had better in-place writes for updated data.
+ */
+ if (old_blk_addr != NEW_ADDR && !is_cold_data(page) &&
+ need_inplace_update(inode)) {
+ rewrite_data_page(F2FS_SB(inode->i_sb), page,
+ old_blk_addr);
+ } else {
+ write_data_page(inode, page, &dn,
+ old_blk_addr, &new_blk_addr);
+ update_extent_cache(new_blk_addr, &dn);
+ F2FS_I(inode)->data_version =
+ le64_to_cpu(F2FS_CKPT(sbi)->checkpoint_ver);
+ }
+out_writepage:
+ f2fs_put_dnode(&dn);
+ return err;
+}
+
+static int f2fs_write_data_page(struct page *page,
+ struct writeback_control *wbc)
+{
+ struct inode *inode = page->mapping->host;
+ struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
+ loff_t i_size = i_size_read(inode);
+ const pgoff_t end_index = ((unsigned long long) i_size)
+ >> PAGE_CACHE_SHIFT;
+ unsigned offset;
+ int err = 0;
+
+ if (page->index < end_index)
+ goto out;
+
+ /*
+ * If the offset is out-of-range of file size,
+ * this page does not have to be written to disk.
+ */
+ offset = i_size & (PAGE_CACHE_SIZE - 1);
+ if ((page->index >= end_index + 1) || !offset) {
+ if (S_ISDIR(inode->i_mode)) {
+ dec_page_count(sbi, F2FS_DIRTY_DENTS);
+ inode_dec_dirty_dents(inode);
+ }
+ goto unlock_out;
+ }
+
+ zero_user_segment(page, offset, PAGE_CACHE_SIZE);
+out:
+ if (sbi->por_doing)
+ goto redirty_out;
+
+ if (wbc->for_reclaim && !S_ISDIR(inode->i_mode) && !is_cold_data(page))
+ goto redirty_out;
+
+ mutex_lock_op(sbi, DATA_WRITE);
+ if (S_ISDIR(inode->i_mode)) {
+ dec_page_count(sbi, F2FS_DIRTY_DENTS);
+ inode_dec_dirty_dents(inode);
+ }
+ err = do_write_data_page(page);
+ if (err && err != -ENOENT) {
+ wbc->pages_skipped++;
+ set_page_dirty(page);
+ }
+ mutex_unlock_op(sbi, DATA_WRITE);
+
+ if (wbc->for_reclaim)
+ f2fs_submit_bio(sbi, DATA, true);
+
+ if (err == -ENOENT)
+ goto unlock_out;
+
+ clear_cold_data(page);
+ unlock_page(page);
+
+ if (!wbc->for_reclaim && !S_ISDIR(inode->i_mode))
+ f2fs_balance_fs(sbi);
+ return 0;
+
+unlock_out:
+ unlock_page(page);
+ return (err == -ENOENT) ? 0 : err;
+
+redirty_out:
+ wbc->pages_skipped++;
+ set_page_dirty(page);
+ return AOP_WRITEPAGE_ACTIVATE;
+}
+
+#define MAX_DESIRED_PAGES_WP 4096
+
+static int __f2fs_writepage(struct page *page, struct writeback_control *wbc,
+ void *data)
+{
+ struct address_space *mapping = data;
+ int ret = mapping->a_ops->writepage(page, wbc);
+ mapping_set_error(mapping, ret);
+ return ret;
+}
+
+static int f2fs_write_data_pages(struct address_space *mapping,
+ struct writeback_control *wbc)
+{
+ struct inode *inode = mapping->host;
+ struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
+ int ret;
+ long excess_nrtw = 0, desired_nrtw;
+
+ if (wbc->nr_to_write < MAX_DESIRED_PAGES_WP) {
+ desired_nrtw = MAX_DESIRED_PAGES_WP;
+ excess_nrtw = desired_nrtw - wbc->nr_to_write;
+ wbc->nr_to_write = desired_nrtw;
+ }
+
+ if (!S_ISDIR(inode->i_mode))
+ mutex_lock(&sbi->writepages);
+ ret = write_cache_pages(mapping, wbc, __f2fs_writepage, mapping);
+ if (!S_ISDIR(inode->i_mode))
+ mutex_unlock(&sbi->writepages);
+ f2fs_submit_bio(sbi, DATA, (wbc->sync_mode == WB_SYNC_ALL));
+
+ remove_dirty_dir_inode(inode);
+
+ wbc->nr_to_write -= excess_nrtw;
+ return ret;
+}
+
+static int f2fs_write_begin(struct file *file, struct address_space *mapping,
+ loff_t pos, unsigned len, unsigned flags,
+ struct page **pagep, void **fsdata)
+{
+ struct inode *inode = mapping->host;
+ struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
+ struct page *page;
+ pgoff_t index = ((unsigned long long) pos) >> PAGE_CACHE_SHIFT;
+ struct dnode_of_data dn;
+ int err = 0;
+
+ /* for nobh_write_end */
+ *fsdata = NULL;
+
+ f2fs_balance_fs(sbi);
+
+ page = grab_cache_page_write_begin(mapping, index, flags);
+ if (!page)
+ return -ENOMEM;
+ *pagep = page;
+
+ mutex_lock_op(sbi, DATA_NEW);
+
+ set_new_dnode(&dn, inode, NULL, NULL, 0);
+ err = get_dnode_of_data(&dn, index, 0);
+ if (err) {
+ mutex_unlock_op(sbi, DATA_NEW);
+ f2fs_put_page(page, 1);
+ return err;
+ }
+
+ if (dn.data_blkaddr == NULL_ADDR) {
+ err = reserve_new_block(&dn);
+ if (err) {
+ f2fs_put_dnode(&dn);
+ mutex_unlock_op(sbi, DATA_NEW);
+ f2fs_put_page(page, 1);
+ return err;
+ }
+ }
+ f2fs_put_dnode(&dn);
+
+ mutex_unlock_op(sbi, DATA_NEW);
+
+ if ((len == PAGE_CACHE_SIZE) || PageUptodate(page))
+ return 0;
+
+ if ((pos & PAGE_CACHE_MASK) >= i_size_read(inode)) {
+ unsigned start = pos & (PAGE_CACHE_SIZE - 1);
+ unsigned end = start + len;
+
+ /* Reading beyond i_size is simple: memset to zero */
+ zero_user_segments(page, 0, start, end, PAGE_CACHE_SIZE);
+ return 0;
+ }
+
+ if (dn.data_blkaddr == NEW_ADDR) {
+ zero_user_segment(page, 0, PAGE_CACHE_SIZE);
+ } else {
+ err = f2fs_readpage(sbi, page, dn.data_blkaddr, READ_SYNC);
+ if (err) {
+ f2fs_put_page(page, 1);
+ return err;
+ }
+ }
+ SetPageUptodate(page);
+ clear_cold_data(page);
+ return 0;
+}
+
+static ssize_t f2fs_direct_IO(int rw, struct kiocb *iocb,
+ const struct iovec *iov, loff_t offset, unsigned long nr_segs)
+{
+ struct file *file = iocb->ki_filp;
+ struct inode *inode = file->f_mapping->host;
+
+ if (rw == WRITE)
+ return 0;
+
+ /* Needs synchronization with the cleaner */
+ return blockdev_direct_IO(rw, iocb, inode, iov, offset, nr_segs,
+ get_data_block_ro);
+}
+
+static void f2fs_invalidate_data_page(struct page *page, unsigned long offset)
+{
+ struct inode *inode = page->mapping->host;
+ struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
+ if (S_ISDIR(inode->i_mode) && PageDirty(page)) {
+ dec_page_count(sbi, F2FS_DIRTY_DENTS);
+ inode_dec_dirty_dents(inode);
+ }
+ ClearPagePrivate(page);
+}
+
+static int f2fs_release_data_page(struct page *page, gfp_t wait)
+{
+ ClearPagePrivate(page);
+ return 0;
+}
+
+static int f2fs_set_data_page_dirty(struct page *page)
+{
+ struct address_space *mapping = page->mapping;
+ struct inode *inode = mapping->host;
+
+ SetPageUptodate(page);
+ if (!PageDirty(page)) {
+ __set_page_dirty_nobuffers(page);
+ set_dirty_dir_page(inode, page);
+ return 1;
+ }
+ return 0;
+}
+
+static sector_t f2fs_bmap(struct address_space *mapping, sector_t block)
+{
+ return generic_block_bmap(mapping, block, get_data_block_ro);
+}
+
+const struct address_space_operations f2fs_dblock_aops = {
+ .readpage = f2fs_read_data_page,
+ .readpages = f2fs_read_data_pages,
+ .writepage = f2fs_write_data_page,
+ .writepages = f2fs_write_data_pages,
+ .write_begin = f2fs_write_begin,
+ .write_end = nobh_write_end,
+ .set_page_dirty = f2fs_set_data_page_dirty,
+ .invalidatepage = f2fs_invalidate_data_page,
+ .releasepage = f2fs_release_data_page,
+ .direct_IO = f2fs_direct_IO,
+ .bmap = f2fs_bmap,
+};