1 /* 2 * Copyright (c) 2000-2001 Christoph Hellwig. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions, and the following disclaimer, 10 * without modification. 11 * 2. The name of the author may not be used to endorse or promote products 12 * derived from this software without specific prior written permission. 13 * 14 * Alternatively, this software may be distributed under the terms of the 15 * GNU General Public License ("GPL"). 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR 21 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 */ 29 30 /* 31 * Veritas filesystem driver - support for 'immed' inodes. 32 */ 33 #include <linux/fs.h> 34 #include <linux/pagemap.h> 35 #include <linux/namei.h> 36 37 #include "vxfs.h" 38 #include "vxfs_extern.h" 39 #include "vxfs_inode.h" 40 41 42 static void * vxfs_immed_follow_link(struct dentry *, struct nameidata *); 43 44 static int vxfs_immed_readpage(struct file *, struct page *); 45 46 /* 47 * Inode operations for immed symlinks. 48 * 49 * Unliked all other operations we do not go through the pagecache, 50 * but do all work directly on the inode. 51 */ 52 const struct inode_operations vxfs_immed_symlink_iops = { 53 .readlink = generic_readlink, 54 .follow_link = vxfs_immed_follow_link, 55 }; 56 57 /* 58 * Address space operations for immed files and directories. 59 */ 60 const struct address_space_operations vxfs_immed_aops = { 61 .readpage = vxfs_immed_readpage, 62 }; 63 64 /** 65 * vxfs_immed_follow_link - follow immed symlink 66 * @dp: dentry for the link 67 * @np: pathname lookup data for the current path walk 68 * 69 * Description: 70 * vxfs_immed_follow_link restarts the pathname lookup with 71 * the data obtained from @dp. 72 * 73 * Returns: 74 * Zero on success, else a negative error code. 75 */ 76 static void * 77 vxfs_immed_follow_link(struct dentry *dp, struct nameidata *np) 78 { 79 struct vxfs_inode_info *vip = VXFS_INO(dp->d_inode); 80 nd_set_link(np, vip->vii_immed.vi_immed); 81 return NULL; 82 } 83 84 /** 85 * vxfs_immed_readpage - read part of an immed inode into pagecache 86 * @file: file context (unused) 87 * @page: page frame to fill in. 88 * 89 * Description: 90 * vxfs_immed_readpage reads a part of the immed area of the 91 * file that hosts @pp into the pagecache. 92 * 93 * Returns: 94 * Zero on success, else a negative error code. 95 * 96 * Locking status: 97 * @page is locked and will be unlocked. 98 */ 99 static int 100 vxfs_immed_readpage(struct file *fp, struct page *pp) 101 { 102 struct vxfs_inode_info *vip = VXFS_INO(pp->mapping->host); 103 u_int64_t offset = (u_int64_t)pp->index << PAGE_CACHE_SHIFT; 104 caddr_t kaddr; 105 106 kaddr = kmap(pp); 107 memcpy(kaddr, vip->vii_immed.vi_immed + offset, PAGE_CACHE_SIZE); 108 kunmap(pp); 109 110 flush_dcache_page(pp); 111 SetPageUptodate(pp); 112 unlock_page(pp); 113 114 return 0; 115 } 116