f2fs: allocate data blocks in advance for f2fs_direct_IO

This patch adds preallocation for data blocks to prepare f2fs_direct_IO.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

1 files changed, 54 insertions, 3 deletions

diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 26e247697e58..985ed023a750 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -592,6 +592,56 @@ static int __allocate_data_block(struct dnode_of_data *dn)
         return 0;
 }
 
+static void __allocate_data_blocks(struct inode *inode, loff_t offset,
+                                                        size_t count)
+{
+        struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+        struct dnode_of_data dn;
+        u64 start = F2FS_BYTES_TO_BLK(offset);
+        u64 len = F2FS_BYTES_TO_BLK(count);
+        bool allocated;
+        u64 end_offset;
+
+        while (len) {
+                f2fs_balance_fs(sbi);
+                f2fs_lock_op(sbi);
+
+                /* When reading holes, we need its node page */
+                set_new_dnode(&dn, inode, NULL, NULL, 0);
+                if (get_dnode_of_data(&dn, start, ALLOC_NODE))
+                        goto out;
+
+                allocated = false;
+                end_offset = ADDRS_PER_PAGE(dn.node_page, F2FS_I(inode));
+
+                while (dn.ofs_in_node < end_offset && len) {
+                        if (dn.data_blkaddr == NULL_ADDR) {
+                                if (__allocate_data_block(&dn))
+                                        goto sync_out;
+                                allocated = true;
+                        }
+                        len--;
+                        start++;
+                        dn.ofs_in_node++;
+                }
+
+                if (allocated)
+                        sync_inode_page(&dn);
+
+                f2fs_put_dnode(&dn);
+                f2fs_unlock_op(sbi);
+        }
+        return;
+
+sync_out:
+        if (allocated)
+                sync_inode_page(&dn);
+        f2fs_put_dnode(&dn);
+out:
+        f2fs_unlock_op(sbi);
+        return;
+}
+
 /*
  * get_data_block() now supported readahead/bmap/rw direct_IO with mapped bh.
  * If original data blocks are allocated, then give them to blockdev.
@@ -617,10 +667,8 @@ static int __get_data_block(struct inode *inode, sector_t iblock,
         if (check_extent_cache(inode, pgofs, bh_result))
                 goto out;
 
-        if (create) {
-                f2fs_balance_fs(F2FS_I_SB(inode));
+        if (create)
                 f2fs_lock_op(F2FS_I_SB(inode));
-        }
 
         /* When reading holes, we need its node page */
         set_new_dnode(&dn, inode, NULL, NULL, 0);
@@ -1108,6 +1156,9 @@ static ssize_t f2fs_direct_IO(int rw, struct kiocb *iocb,
 
         trace_f2fs_direct_IO_enter(inode, offset, count, rw);
 
+        if (rw & WRITE)
+                __allocate_data_blocks(inode, offset, count);
+
         err = blockdev_direct_IO(rw, iocb, inode, iter, offset, get_data_block);
         if (err < 0 && (rw & WRITE))
                 f2fs_write_failed(mapping, offset + count);