fs/freevxfs/vxfs_olt.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (c) 2000-2001 Christoph Hellwig.
   4  */
   5
   6 /*
   7  * Veritas filesystem driver - object location table support.
   8  */
   9 #include <linux/fs.h>
  10 #include <linux/buffer_head.h>
  11 #include <linux/kernel.h>
  12
  13 #include "vxfs.h"
  14 #include "vxfs_olt.h"
  15 #include "vxfs_extern.h"
  16
  17
  18 static inline void
  19 vxfs_get_fshead(struct vxfs_oltfshead *fshp, struct vxfs_sb_info *infp)
  20 {
  21         BUG_ON(infp->vsi_fshino);
  22         infp->vsi_fshino = fs32_to_cpu(infp, fshp->olt_fsino[0]);
  23 }
  24
  25 static inline void
  26 vxfs_get_ilist(struct vxfs_oltilist *ilistp, struct vxfs_sb_info *infp)
  27 {
  28         BUG_ON(infp->vsi_iext);
  29         infp->vsi_iext = fs32_to_cpu(infp, ilistp->olt_iext[0]);
  30 }
  31
  32 static inline u_long
  33 vxfs_oblock(struct super_block *sbp, daddr_t block, u_long bsize)
  34 {
  35         BUG_ON(sbp->s_blocksize % bsize);
  36         return (block * (sbp->s_blocksize / bsize));
  37 }
  38
  39
  40 /**
  41  * vxfs_read_olt - read olt
  42  * @sbp:        superblock of the filesystem
  43  * @bsize:      blocksize of the filesystem
  44  *
  45  * Description:
  46  *   vxfs_read_olt reads the olt of the filesystem described by @sbp
  47  *   into main memory and does some basic setup.
  48  *
  49  * Returns:
  50  *   Zero on success, else a negative error code.
  51  */
  52 int
  53 vxfs_read_olt(struct super_block *sbp, u_long bsize)
  54 {
  55         struct vxfs_sb_info     *infp = VXFS_SBI(sbp);
  56         struct buffer_head      *bp;
  57         struct vxfs_olt         *op;
  58         char                    *oaddr, *eaddr;
  59
  60         bp = sb_bread(sbp, vxfs_oblock(sbp, infp->vsi_oltext, bsize));
  61         if (!bp || !bp->b_data)
  62                 goto fail;
  63
  64         op = (struct vxfs_olt *)bp->b_data;
  65         if (fs32_to_cpu(infp, op->olt_magic) != VXFS_OLT_MAGIC) {
  66                 printk(KERN_NOTICE "vxfs: ivalid olt magic number\n");
  67                 goto fail;
  68         }
  69
  70         /*
  71          * It is in theory possible that vsi_oltsize is > 1.
  72          * I've not seen any such filesystem yet and I'm lazy..  --hch
  73          */
  74         if (infp->vsi_oltsize > 1) {
  75                 printk(KERN_NOTICE "vxfs: oltsize > 1 detected.\n");
  76                 printk(KERN_NOTICE "vxfs: please notify hch@infradead.org\n");
  77                 goto fail;
  78         }
  79
  80         oaddr = bp->b_data + fs32_to_cpu(infp, op->olt_size);
  81         eaddr = bp->b_data + (infp->vsi_oltsize * sbp->s_blocksize);
  82
  83         while (oaddr < eaddr) {
  84                 struct vxfs_oltcommon   *ocp =
  85                         (struct vxfs_oltcommon *)oaddr;
  86
  87                 switch (fs32_to_cpu(infp, ocp->olt_type)) {
  88                 case VXFS_OLT_FSHEAD:
  89                         vxfs_get_fshead((struct vxfs_oltfshead *)oaddr, infp);
  90                         break;
  91                 case VXFS_OLT_ILIST:
  92                         vxfs_get_ilist((struct vxfs_oltilist *)oaddr, infp);
  93                         break;
  94                 }
  95
  96                 oaddr += fs32_to_cpu(infp, ocp->olt_size);
  97         }
  98
  99         brelse(bp);
 100         return (infp->vsi_fshino && infp->vsi_iext) ? 0 : -EINVAL;
 101
 102 fail:
 103         brelse(bp);
 104         return -EINVAL;
 105 }