+#ifdef CONFIG_QUOTA
+
+/* Read data from quotafile - avoid pagecache and such because we cannot afford
+ * acquiring the locks... As quota files are never truncated and quota code
+ * itself serializes the operations (and noone else should touch the files)
+ * we don't have to be afraid of races */
+static ssize_t jfs_quota_read(struct super_block *sb, int type, char *data,
+ size_t len, loff_t off)
+{
+ struct inode *inode = sb_dqopt(sb)->files[type];
+ sector_t blk = off >> sb->s_blocksize_bits;
+ int err = 0;
+ int offset = off & (sb->s_blocksize - 1);
+ int tocopy;
+ size_t toread;
+ struct buffer_head tmp_bh;
+ struct buffer_head *bh;
+ loff_t i_size = i_size_read(inode);
+
+ if (off > i_size)
+ return 0;
+ if (off+len > i_size)
+ len = i_size-off;
+ toread = len;
+ while (toread > 0) {
+ tocopy = sb->s_blocksize - offset < toread ?
+ sb->s_blocksize - offset : toread;
+
+ tmp_bh.b_state = 0;
+ tmp_bh.b_size = 1 << inode->i_blkbits;
+ err = jfs_get_block(inode, blk, &tmp_bh, 0);
+ if (err)
+ return err;
+ if (!buffer_mapped(&tmp_bh)) /* A hole? */
+ memset(data, 0, tocopy);
+ else {
+ bh = sb_bread(sb, tmp_bh.b_blocknr);
+ if (!bh)
+ return -EIO;
+ memcpy(data, bh->b_data+offset, tocopy);
+ brelse(bh);
+ }
+ offset = 0;
+ toread -= tocopy;
+ data += tocopy;
+ blk++;
+ }
+ return len;
+}
+
+/* Write to quotafile */
+static ssize_t jfs_quota_write(struct super_block *sb, int type,
+ const char *data, size_t len, loff_t off)
+{
+ struct inode *inode = sb_dqopt(sb)->files[type];
+ sector_t blk = off >> sb->s_blocksize_bits;
+ int err = 0;
+ int offset = off & (sb->s_blocksize - 1);
+ int tocopy;
+ size_t towrite = len;
+ struct buffer_head tmp_bh;
+ struct buffer_head *bh;
+
+ mutex_lock(&inode->i_mutex);
+ while (towrite > 0) {
+ tocopy = sb->s_blocksize - offset < towrite ?
+ sb->s_blocksize - offset : towrite;
+
+ tmp_bh.b_state = 0;
+ tmp_bh.b_size = 1 << inode->i_blkbits;
+ err = jfs_get_block(inode, blk, &tmp_bh, 1);
+ if (err)
+ goto out;
+ if (offset || tocopy != sb->s_blocksize)
+ bh = sb_bread(sb, tmp_bh.b_blocknr);
+ else
+ bh = sb_getblk(sb, tmp_bh.b_blocknr);
+ if (!bh) {
+ err = -EIO;
+ goto out;
+ }
+ lock_buffer(bh);
+ memcpy(bh->b_data+offset, data, tocopy);
+ flush_dcache_page(bh->b_page);
+ set_buffer_uptodate(bh);
+ mark_buffer_dirty(bh);
+ unlock_buffer(bh);
+ brelse(bh);
+ offset = 0;
+ towrite -= tocopy;
+ data += tocopy;
+ blk++;
+ }
+out:
+ if (len == towrite)
+ return err;
+ if (inode->i_size < off+len-towrite)
+ i_size_write(inode, off+len-towrite);
+ inode->i_version++;
+ inode->i_mtime = inode->i_ctime = CURRENT_TIME;
+ mark_inode_dirty(inode);
+ mutex_unlock(&inode->i_mutex);
+ return len - towrite;
+}
+
+#endif
+