1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * linux/fs/ext4/symlink.c 4 * 5 * Only fast symlinks left here - the rest is done by generic code. AV, 1999 6 * 7 * Copyright (C) 1992, 1993, 1994, 1995 8 * Remy Card (card@masi.ibp.fr) 9 * Laboratoire MASI - Institut Blaise Pascal 10 * Universite Pierre et Marie Curie (Paris VI) 11 * 12 * from 13 * 14 * linux/fs/minix/symlink.c 15 * 16 * Copyright (C) 1991, 1992 Linus Torvalds 17 * 18 * ext4 symlink handling code 19 */ 20 21 #include <linux/fs.h> 22 #include <linux/namei.h> 23 #include "ext4.h" 24 #include "xattr.h" 25 26 static const char *ext4_encrypted_get_link(struct dentry *dentry, 27 struct inode *inode, 28 struct delayed_call *done) 29 { 30 struct page *cpage = NULL; 31 const void *caddr; 32 unsigned int max_size; 33 const char *paddr; 34 35 if (!dentry) 36 return ERR_PTR(-ECHILD); 37 38 if (ext4_inode_is_fast_symlink(inode)) { 39 caddr = EXT4_I(inode)->i_data; 40 max_size = sizeof(EXT4_I(inode)->i_data); 41 } else { 42 cpage = read_mapping_page(inode->i_mapping, 0, NULL); 43 if (IS_ERR(cpage)) 44 return ERR_CAST(cpage); 45 caddr = page_address(cpage); 46 max_size = inode->i_sb->s_blocksize; 47 } 48 49 paddr = fscrypt_get_symlink(inode, caddr, max_size, done); 50 if (cpage) 51 put_page(cpage); 52 return paddr; 53 } 54 55 static int ext4_encrypted_symlink_getattr(struct user_namespace *mnt_userns, 56 const struct path *path, 57 struct kstat *stat, u32 request_mask, 58 unsigned int query_flags) 59 { 60 ext4_getattr(mnt_userns, path, stat, request_mask, query_flags); 61 62 return fscrypt_symlink_getattr(path, stat); 63 } 64 65 const struct inode_operations ext4_encrypted_symlink_inode_operations = { 66 .get_link = ext4_encrypted_get_link, 67 .setattr = ext4_setattr, 68 .getattr = ext4_encrypted_symlink_getattr, 69 .listxattr = ext4_listxattr, 70 }; 71 72 const struct inode_operations ext4_symlink_inode_operations = { 73 .get_link = page_get_link, 74 .setattr = ext4_setattr, 75 .getattr = ext4_getattr, 76 .listxattr = ext4_listxattr, 77 }; 78 79 const struct inode_operations ext4_fast_symlink_inode_operations = { 80 .get_link = simple_get_link, 81 .setattr = ext4_setattr, 82 .getattr = ext4_getattr, 83 .listxattr = ext4_listxattr, 84 }; 85