[linux-block.git] / fs / efs / symlink.c

// SPDX-License-Identifier: GPL-2.0
/*
 * symlink.c
 *
 * Copyright (c) 1999 Al Smith
 *
 * Portions derived from work (c) 1995,1996 Christian Vogelgsang.
 */

#include <linux/string.h>
#include <linux/pagemap.h>
#include <linux/buffer_head.h>
#include "efs.h"

static int efs_symlink_read_folio(struct file *file, struct folio *folio)
{
	char *link = folio_address(folio);
	struct buffer_head *bh;
	struct inode *inode = folio->mapping->host;
	efs_block_t size = inode->i_size;
	int err;
  
	err = -ENAMETOOLONG;
	if (size > 2 * EFS_BLOCKSIZE)
		goto fail;
  
	/* read first 512 bytes of link target */
	err = -EIO;
	bh = sb_bread(inode->i_sb, efs_bmap(inode, 0));
	if (!bh)
		goto fail;
	memcpy(link, bh->b_data, (size > EFS_BLOCKSIZE) ? EFS_BLOCKSIZE : size);
	brelse(bh);
	if (size > EFS_BLOCKSIZE) {
		bh = sb_bread(inode->i_sb, efs_bmap(inode, 1));
		if (!bh)
			goto fail;
		memcpy(link + EFS_BLOCKSIZE, bh->b_data, size - EFS_BLOCKSIZE);
		brelse(bh);
	}
	link[size] = '\0';
	err = 0;
fail:
	folio_end_read(folio, err == 0);
	return err;
}

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