f2fs: support in batch fzero in dnode page

This patch tries to speedup fzero_range by making space preallocation and
address removal of blocks in one dnode page as in batch operation.

In virtual machine, with zram driver:

dd if=/dev/zero of=/mnt/f2fs/file bs=1M count=4096
time xfs_io -f /mnt/f2fs/file -c "fzero 0 4096M"

Before:
real	0m3.276s
user	0m0.008s
sys	0m3.260s

After:
real	0m1.568s
user	0m0.000s
sys	0m1.564s

Signed-off-by: Chao Yu <yuchao0@huawei.com>
[Jaegeuk Kim: consider ENOSPC case]
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index f67ca62..a9cb314 100644 (file)
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -997,6 +997,49 @@ static int f2fs_collapse_range(struct inode *inode, loff_t offset, loff_t len)
        return ret;
 }
 
+static int f2fs_do_zero_range(struct dnode_of_data *dn, pgoff_t start,
+                                                               pgoff_t end)
+{
+       struct f2fs_sb_info *sbi = F2FS_I_SB(dn->inode);
+       pgoff_t index = start;
+       unsigned int ofs_in_node = dn->ofs_in_node;
+       blkcnt_t count = 0;
+       int ret;
+
+       for (; index < end; index++, dn->ofs_in_node++) {
+               if (datablock_addr(dn->node_page, dn->ofs_in_node) == NULL_ADDR)
+                       count++;
+       }
+
+       dn->ofs_in_node = ofs_in_node;
+       ret = reserve_new_blocks(dn, count);
+       if (ret)
+               return ret;
+
+       dn->ofs_in_node = ofs_in_node;
+       for (index = start; index < end; index++, dn->ofs_in_node++) {
+               dn->data_blkaddr =
+                               datablock_addr(dn->node_page, dn->ofs_in_node);
+               /*
+                * reserve_new_blocks will not guarantee entire block
+                * allocation.
+                */
+               if (dn->data_blkaddr == NULL_ADDR) {
+                       ret = -ENOSPC;
+                       break;
+               }
+               if (dn->data_blkaddr != NEW_ADDR) {
+                       invalidate_blocks(sbi, dn->data_blkaddr);
+                       dn->data_blkaddr = NEW_ADDR;
+                       set_data_blkaddr(dn);
+               }
+       }
+
+       f2fs_update_extent_cache_range(dn, start, 0, index - start);
+
+       return ret;
+}
+
 static int f2fs_zero_range(struct inode *inode, loff_t offset, loff_t len,
                                                                int mode)
 {
@@ -1047,35 +1090,32 @@ static int f2fs_zero_range(struct inode *inode, loff_t offset, loff_t len,
                                        (loff_t)pg_start << PAGE_SHIFT);
                }
 
-               for (index = pg_start; index < pg_end; index++) {
+               for (index = pg_start; index < pg_end;) {
                        struct dnode_of_data dn;
-                       struct page *ipage;
+                       unsigned int end_offset;
+                       pgoff_t end;
 
                        f2fs_lock_op(sbi);
 
-                       ipage = get_node_page(sbi, inode->i_ino);
-                       if (IS_ERR(ipage)) {
-                               ret = PTR_ERR(ipage);
-                               f2fs_unlock_op(sbi);
-                               goto out;
-                       }
-
-                       set_new_dnode(&dn, inode, ipage, NULL, 0);
-                       ret = f2fs_reserve_block(&dn, index);
+                       set_new_dnode(&dn, inode, NULL, NULL, 0);
+                       ret = get_dnode_of_data(&dn, index, ALLOC_NODE);
                        if (ret) {
                                f2fs_unlock_op(sbi);
                                goto out;
                        }
 
-                       if (dn.data_blkaddr != NEW_ADDR) {
-                               invalidate_blocks(sbi, dn.data_blkaddr);
-                               f2fs_update_data_blkaddr(&dn, NEW_ADDR);
-                       }
+                       end_offset = ADDRS_PER_PAGE(dn.node_page, inode);
+                       end = min(pg_end, end_offset - dn.ofs_in_node + index);
+
+                       ret = f2fs_do_zero_range(&dn, index, end);
                        f2fs_put_dnode(&dn);
                        f2fs_unlock_op(sbi);
+                       if (ret)
+                               goto out;
 
+                       index = end;
                        new_size = max_t(loff_t, new_size,
-                               (loff_t)(index + 1) << PAGE_SHIFT);
+                                       (loff_t)index << PAGE_SHIFT);
                }
 
                if (off_end) {