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 }; 51