zte's code,first commit
Change-Id: I9a04da59e459a9bc0d67f101f700d9d7dc8d681b
diff --git a/ap/os/linux/linux-3.4.x/fs/bfs/file.c b/ap/os/linux/linux-3.4.x/fs/bfs/file.c
new file mode 100644
index 0000000..f20e8a7
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/fs/bfs/file.c
@@ -0,0 +1,194 @@
+/*
+ * fs/bfs/file.c
+ * BFS file operations.
+ * Copyright (C) 1999,2000 Tigran Aivazian <tigran@veritas.com>
+ *
+ * Make the file block allocation algorithm understand the size
+ * of the underlying block device.
+ * Copyright (C) 2007 Dmitri Vorobiev <dmitri.vorobiev@gmail.com>
+ *
+ */
+
+#include <linux/fs.h>
+#include <linux/buffer_head.h>
+#include "bfs.h"
+
+#undef DEBUG
+
+#ifdef DEBUG
+#define dprintf(x...) printf(x)
+#else
+#define dprintf(x...)
+#endif
+
+const struct file_operations bfs_file_operations = {
+ .llseek = generic_file_llseek,
+ .read = do_sync_read,
+ .aio_read = generic_file_aio_read,
+ .write = do_sync_write,
+ .aio_write = generic_file_aio_write,
+ .mmap = generic_file_mmap,
+ .splice_read = generic_file_splice_read,
+};
+
+static int bfs_move_block(unsigned long from, unsigned long to,
+ struct super_block *sb)
+{
+ struct buffer_head *bh, *new;
+
+ bh = sb_bread(sb, from);
+ if (!bh)
+ return -EIO;
+ new = sb_getblk(sb, to);
+ memcpy(new->b_data, bh->b_data, bh->b_size);
+ mark_buffer_dirty(new);
+ bforget(bh);
+ brelse(new);
+ return 0;
+}
+
+static int bfs_move_blocks(struct super_block *sb, unsigned long start,
+ unsigned long end, unsigned long where)
+{
+ unsigned long i;
+
+ dprintf("%08lx-%08lx->%08lx\n", start, end, where);
+ for (i = start; i <= end; i++)
+ if(bfs_move_block(i, where + i, sb)) {
+ dprintf("failed to move block %08lx -> %08lx\n", i,
+ where + i);
+ return -EIO;
+ }
+ return 0;
+}
+
+static int bfs_get_block(struct inode *inode, sector_t block,
+ struct buffer_head *bh_result, int create)
+{
+ unsigned long phys;
+ int err;
+ struct super_block *sb = inode->i_sb;
+ struct bfs_sb_info *info = BFS_SB(sb);
+ struct bfs_inode_info *bi = BFS_I(inode);
+
+ phys = bi->i_sblock + block;
+ if (!create) {
+ if (phys <= bi->i_eblock) {
+ dprintf("c=%d, b=%08lx, phys=%09lx (granted)\n",
+ create, (unsigned long)block, phys);
+ map_bh(bh_result, sb, phys);
+ }
+ return 0;
+ }
+
+ /*
+ * If the file is not empty and the requested block is within the
+ * range of blocks allocated for this file, we can grant it.
+ */
+ if (bi->i_sblock && (phys <= bi->i_eblock)) {
+ dprintf("c=%d, b=%08lx, phys=%08lx (interim block granted)\n",
+ create, (unsigned long)block, phys);
+ map_bh(bh_result, sb, phys);
+ return 0;
+ }
+
+ /* The file will be extended, so let's see if there is enough space. */
+ if (phys >= info->si_blocks)
+ return -ENOSPC;
+
+ /* The rest has to be protected against itself. */
+ mutex_lock(&info->bfs_lock);
+
+ /*
+ * If the last data block for this file is the last allocated
+ * block, we can extend the file trivially, without moving it
+ * anywhere.
+ */
+ if (bi->i_eblock == info->si_lf_eblk) {
+ dprintf("c=%d, b=%08lx, phys=%08lx (simple extension)\n",
+ create, (unsigned long)block, phys);
+ map_bh(bh_result, sb, phys);
+ info->si_freeb -= phys - bi->i_eblock;
+ info->si_lf_eblk = bi->i_eblock = phys;
+ mark_inode_dirty(inode);
+ err = 0;
+ goto out;
+ }
+
+ /* Ok, we have to move this entire file to the next free block. */
+ phys = info->si_lf_eblk + 1;
+ if (phys + block >= info->si_blocks) {
+ err = -ENOSPC;
+ goto out;
+ }
+
+ if (bi->i_sblock) {
+ err = bfs_move_blocks(inode->i_sb, bi->i_sblock,
+ bi->i_eblock, phys);
+ if (err) {
+ dprintf("failed to move ino=%08lx -> fs corruption\n",
+ inode->i_ino);
+ goto out;
+ }
+ } else
+ err = 0;
+
+ dprintf("c=%d, b=%08lx, phys=%08lx (moved)\n",
+ create, (unsigned long)block, phys);
+ bi->i_sblock = phys;
+ phys += block;
+ info->si_lf_eblk = bi->i_eblock = phys;
+
+ /*
+ * This assumes nothing can write the inode back while we are here
+ * and thus update inode->i_blocks! (XXX)
+ */
+ info->si_freeb -= bi->i_eblock - bi->i_sblock + 1 - inode->i_blocks;
+ mark_inode_dirty(inode);
+ map_bh(bh_result, sb, phys);
+out:
+ mutex_unlock(&info->bfs_lock);
+ return err;
+}
+
+static int bfs_writepage(struct page *page, struct writeback_control *wbc)
+{
+ return block_write_full_page(page, bfs_get_block, wbc);
+}
+
+static int bfs_readpage(struct file *file, struct page *page)
+{
+ return block_read_full_page(page, bfs_get_block);
+}
+
+static int bfs_write_begin(struct file *file, struct address_space *mapping,
+ loff_t pos, unsigned len, unsigned flags,
+ struct page **pagep, void **fsdata)
+{
+ int ret;
+
+ ret = block_write_begin(mapping, pos, len, flags, pagep,
+ bfs_get_block);
+ if (unlikely(ret)) {
+ loff_t isize = mapping->host->i_size;
+ if (pos + len > isize)
+ vmtruncate(mapping->host, isize);
+ }
+
+ return ret;
+}
+
+static sector_t bfs_bmap(struct address_space *mapping, sector_t block)
+{
+ return generic_block_bmap(mapping, block, bfs_get_block);
+}
+
+const struct address_space_operations bfs_aops = {
+ .readpage = bfs_readpage,
+ .writepage = bfs_writepage,
+ .write_begin = bfs_write_begin,
+ .write_end = generic_write_end,
+ .bmap = bfs_bmap,
+};
+
+const struct inode_operations bfs_file_inops;