1 /* 2 * symlink.c 3 * 4 * Copyright (c) 1999 Al Smith 5 * 6 * Portions derived from work (c) 1995,1996 Christian Vogelgsang. 7 */ 8 9 #include <linux/string.h> 10 #include <linux/pagemap.h> 11 #include <linux/buffer_head.h> 12 #include <linux/smp_lock.h> 13 #include "efs.h" 14 15 static int efs_symlink_readpage(struct file *file, struct page *page) 16 { 17 char *link = kmap(page); 18 struct buffer_head * bh; 19 struct inode * inode = page->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_notlocked; 26 27 lock_kernel(); 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 unlock_kernel(); 44 SetPageUptodate(page); 45 kunmap(page); 46 unlock_page(page); 47 return 0; 48 fail: 49 unlock_kernel(); 50 fail_notlocked: 51 SetPageError(page); 52 kunmap(page); 53 unlock_page(page); 54 return err; 55 } 56 57 const struct address_space_operations efs_symlink_aops = { 58 .readpage = efs_symlink_readpage 59 }; 60