exfat: do not zero the extended part

[linux-block.git] / fs / exfat / file.c

diff --git a/fs/exfat/file.c b/fs/exfat/file.c
index 270e2f934124e0edca8923859426a15875615db5..d25a96a148af4cdb966c5d20f720aa944cab10c2 100644 (file)
--- a/fs/exfat/file.c
+++ b/fs/exfat/file.c
@@ -18,32 +18,69 @@
 
 static int exfat_cont_expand(struct inode *inode, loff_t size)
 {
-       struct address_space *mapping = inode->i_mapping;
-       loff_t start = i_size_read(inode), count = size - i_size_read(inode);
-       int err, err2;
+       int ret;
+       unsigned int num_clusters, new_num_clusters, last_clu;
+       struct exfat_inode_info *ei = EXFAT_I(inode);
+       struct super_block *sb = inode->i_sb;
+       struct exfat_sb_info *sbi = EXFAT_SB(sb);
+       struct exfat_chain clu;
 
-       err = generic_cont_expand_simple(inode, size);
-       if (err)
-               return err;
+       ret = inode_newsize_ok(inode, size);
+       if (ret)
+               return ret;
+
+       num_clusters = EXFAT_B_TO_CLU_ROUND_UP(ei->i_size_ondisk, sbi);
+       new_num_clusters = EXFAT_B_TO_CLU_ROUND_UP(size, sbi);
+
+       if (new_num_clusters == num_clusters)
+               goto out;
+
+       exfat_chain_set(&clu, ei->start_clu, num_clusters, ei->flags);
+       ret = exfat_find_last_cluster(sb, &clu, &last_clu);
+       if (ret)
+               return ret;
 
+       clu.dir = (last_clu == EXFAT_EOF_CLUSTER) ?
+                       EXFAT_EOF_CLUSTER : last_clu + 1;
+       clu.size = 0;
+       clu.flags = ei->flags;
+
+       ret = exfat_alloc_cluster(inode, new_num_clusters - num_clusters,
+                       &clu, IS_DIRSYNC(inode));
+       if (ret)
+               return ret;
+
+       /* Append new clusters to chain */
+       if (clu.flags != ei->flags) {
+               exfat_chain_cont_cluster(sb, ei->start_clu, num_clusters);
+               ei->flags = ALLOC_FAT_CHAIN;
+       }
+       if (clu.flags == ALLOC_FAT_CHAIN)
+               if (exfat_ent_set(sb, last_clu, clu.dir))
+                       goto free_clu;
+
+       if (num_clusters == 0)
+               ei->start_clu = clu.dir;
+
+out:
        inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode));
-       EXFAT_I(inode)->valid_size = size;
-       mark_inode_dirty(inode);
+       /* Expanded range not zeroed, do not update valid_size */
+       i_size_write(inode, size);
 
-       if (!IS_SYNC(inode))
-               return 0;
+       ei->i_size_aligned = round_up(size, sb->s_blocksize);
+       ei->i_size_ondisk = ei->i_size_aligned;
+       inode->i_blocks = round_up(size, sbi->cluster_size) >> 9;
 
-       err = filemap_fdatawrite_range(mapping, start, start + count - 1);
-       err2 = sync_mapping_buffers(mapping);
-       if (!err)
-               err = err2;
-       err2 = write_inode_now(inode, 1);
-       if (!err)
-               err = err2;
-       if (err)
-               return err;
+       if (IS_DIRSYNC(inode))
+               return write_inode_now(inode, 1);
+
+       mark_inode_dirty(inode);
+
+       return 0;
 
-       return filemap_fdatawait_range(mapping, start, start + count - 1);
+free_clu:
+       exfat_free_cluster(inode, &clu);
+       return -EIO;
 }
 
 static bool exfat_allow_set_time(struct exfat_sb_info *sbi, struct inode *inode)