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 struct page *page = &folio->page; 18 char *link = page_address(page); 19 struct buffer_head * bh; 20 struct inode * inode = page->mapping->host; 21 efs_block_t size = inode->i_size; 22 int err; 23 24 err = -ENAMETOOLONG; 25 if (size > 2 * EFS_BLOCKSIZE) 26 goto fail; 27 28 /* read first 512 bytes of link target */ 29 err = -EIO; 30 bh = sb_bread(inode->i_sb, efs_bmap(inode, 0)); 31 if (!bh) 32 goto fail; 33 memcpy(link, bh->b_data, (size > EFS_BLOCKSIZE) ? EFS_BLOCKSIZE : size); 34 brelse(bh); 35 if (size > EFS_BLOCKSIZE) { 36 bh = sb_bread(inode->i_sb, efs_bmap(inode, 1)); 37 if (!bh) 38 goto fail; 39 memcpy(link + EFS_BLOCKSIZE, bh->b_data, size - EFS_BLOCKSIZE); 40 brelse(bh); 41 } 42 link[size] = '\0'; 43 SetPageUptodate(page); 44 unlock_page(page); 45 return 0; 46 fail: 47 SetPageError(page); 48 unlock_page(page); 49 return err; 50 } 51 52 const struct address_space_operations efs_symlink_aops = { 53 .read_folio = efs_symlink_read_folio 54 }; 55