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 - object location table support. 32 */ 33 #include <linux/fs.h> 34 #include <linux/buffer_head.h> 35 #include <linux/kernel.h> 36 37 #include "vxfs.h" 38 #include "vxfs_olt.h" 39 #include "vxfs_extern.h" 40 41 42 static inline void 43 vxfs_get_fshead(struct vxfs_oltfshead *fshp, struct vxfs_sb_info *infp) 44 { 45 BUG_ON(infp->vsi_fshino); 46 infp->vsi_fshino = fs32_to_cpu(infp, fshp->olt_fsino[0]); 47 } 48 49 static inline void 50 vxfs_get_ilist(struct vxfs_oltilist *ilistp, struct vxfs_sb_info *infp) 51 { 52 BUG_ON(infp->vsi_iext); 53 infp->vsi_iext = fs32_to_cpu(infp, ilistp->olt_iext[0]); 54 } 55 56 static inline u_long 57 vxfs_oblock(struct super_block *sbp, daddr_t block, u_long bsize) 58 { 59 BUG_ON(sbp->s_blocksize % bsize); 60 return (block * (sbp->s_blocksize / bsize)); 61 } 62 63 64 /** 65 * vxfs_read_olt - read olt 66 * @sbp: superblock of the filesystem 67 * @bsize: blocksize of the filesystem 68 * 69 * Description: 70 * vxfs_read_olt reads the olt of the filesystem described by @sbp 71 * into main memory and does some basic setup. 72 * 73 * Returns: 74 * Zero on success, else a negative error code. 75 */ 76 int 77 vxfs_read_olt(struct super_block *sbp, u_long bsize) 78 { 79 struct vxfs_sb_info *infp = VXFS_SBI(sbp); 80 struct buffer_head *bp; 81 struct vxfs_olt *op; 82 char *oaddr, *eaddr; 83 84 bp = sb_bread(sbp, vxfs_oblock(sbp, infp->vsi_oltext, bsize)); 85 if (!bp || !bp->b_data) 86 goto fail; 87 88 op = (struct vxfs_olt *)bp->b_data; 89 if (fs32_to_cpu(infp, op->olt_magic) != VXFS_OLT_MAGIC) { 90 printk(KERN_NOTICE "vxfs: ivalid olt magic number\n"); 91 goto fail; 92 } 93 94 /* 95 * It is in theory possible that vsi_oltsize is > 1. 96 * I've not seen any such filesystem yet and I'm lazy.. --hch 97 */ 98 if (infp->vsi_oltsize > 1) { 99 printk(KERN_NOTICE "vxfs: oltsize > 1 detected.\n"); 100 printk(KERN_NOTICE "vxfs: please notify hch@infradead.org\n"); 101 goto fail; 102 } 103 104 oaddr = bp->b_data + fs32_to_cpu(infp, op->olt_size); 105 eaddr = bp->b_data + (infp->vsi_oltsize * sbp->s_blocksize); 106 107 while (oaddr < eaddr) { 108 struct vxfs_oltcommon *ocp = 109 (struct vxfs_oltcommon *)oaddr; 110 111 switch (fs32_to_cpu(infp, ocp->olt_type)) { 112 case VXFS_OLT_FSHEAD: 113 vxfs_get_fshead((struct vxfs_oltfshead *)oaddr, infp); 114 break; 115 case VXFS_OLT_ILIST: 116 vxfs_get_ilist((struct vxfs_oltilist *)oaddr, infp); 117 break; 118 } 119 120 oaddr += fs32_to_cpu(infp, ocp->olt_size); 121 } 122 123 brelse(bp); 124 return (infp->vsi_fshino && infp->vsi_iext) ? 0 : -EINVAL; 125 126 fail: 127 brelse(bp); 128 return -EINVAL; 129 } 130