Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  1) // SPDX-License-Identifier: GPL-2.0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  3)  * symlink.c
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  4)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  5)  * Copyright (c) 1999 Al Smith
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  6)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  7)  * Portions derived from work (c) 1995,1996 Christian Vogelgsang.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  8)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  9) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) #include <linux/string.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) #include <linux/pagemap.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) #include <linux/buffer_head.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) #include "efs.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) static int efs_symlink_readpage(struct file *file, struct page *page)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) 	char *link = page_address(page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) 	struct buffer_head * bh;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) 	struct inode * inode = page->mapping->host;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) 	efs_block_t size = inode->i_size;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) 	int err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22)   
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) 	err = -ENAMETOOLONG;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) 	if (size > 2 * EFS_BLOCKSIZE)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) 		goto fail;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26)   
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) 	/* read first 512 bytes of link target */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) 	err = -EIO;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) 	bh = sb_bread(inode->i_sb, efs_bmap(inode, 0));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) 	if (!bh)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) 		goto fail;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) 	memcpy(link, bh->b_data, (size > EFS_BLOCKSIZE) ? EFS_BLOCKSIZE : size);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) 	brelse(bh);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) 	if (size > EFS_BLOCKSIZE) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) 		bh = sb_bread(inode->i_sb, efs_bmap(inode, 1));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) 		if (!bh)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) 			goto fail;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) 		memcpy(link + EFS_BLOCKSIZE, bh->b_data, size - EFS_BLOCKSIZE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) 		brelse(bh);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) 	link[size] = '\0';
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) 	SetPageUptodate(page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) 	unlock_page(page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) fail:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) 	SetPageError(page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) 	unlock_page(page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) 	return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) const struct address_space_operations efs_symlink_aops = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) 	.readpage	= efs_symlink_readpage
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) };