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linux-next/fs/freevxfs/vxfs_inode.c
Dmitriy Monakhov 82f703bb8c freevxfs: possible null pointer dereference fix
sb_read may return NULL, so let's explicitly check it.

Signed-off-by: Dmitriy Monakhov <dmonakhov@openvz.org>
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-08 11:14:59 -07:00

342 lines
8.6 KiB
C

/*
* Copyright (c) 2000-2001 Christoph Hellwig.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions, and the following disclaimer,
* without modification.
* 2. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* Alternatively, this software may be distributed under the terms of the
* GNU General Public License ("GPL").
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
* ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
/*
* Veritas filesystem driver - inode routines.
*/
#include <linux/fs.h>
#include <linux/buffer_head.h>
#include <linux/pagemap.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include "vxfs.h"
#include "vxfs_inode.h"
#include "vxfs_extern.h"
extern const struct address_space_operations vxfs_aops;
extern const struct address_space_operations vxfs_immed_aops;
extern const struct inode_operations vxfs_immed_symlink_iops;
struct kmem_cache *vxfs_inode_cachep;
#ifdef DIAGNOSTIC
/*
* Dump inode contents (partially).
*/
void
vxfs_dumpi(struct vxfs_inode_info *vip, ino_t ino)
{
printk(KERN_DEBUG "\n\n");
if (ino)
printk(KERN_DEBUG "dumping vxfs inode %ld\n", ino);
else
printk(KERN_DEBUG "dumping unknown vxfs inode\n");
printk(KERN_DEBUG "---------------------------\n");
printk(KERN_DEBUG "mode is %x\n", vip->vii_mode);
printk(KERN_DEBUG "nlink:%u, uid:%u, gid:%u\n",
vip->vii_nlink, vip->vii_uid, vip->vii_gid);
printk(KERN_DEBUG "size:%Lx, blocks:%u\n",
vip->vii_size, vip->vii_blocks);
printk(KERN_DEBUG "orgtype:%u\n", vip->vii_orgtype);
}
#endif
/**
* vxfs_blkiget - find inode based on extent #
* @sbp: superblock of the filesystem we search in
* @extent: number of the extent to search
* @ino: inode number to search
*
* Description:
* vxfs_blkiget searches inode @ino in the filesystem described by
* @sbp in the extent @extent.
* Returns the matching VxFS inode on success, else a NULL pointer.
*
* NOTE:
* While __vxfs_iget uses the pagecache vxfs_blkiget uses the
* buffercache. This function should not be used outside the
* read_super() method, otherwise the data may be incoherent.
*/
struct vxfs_inode_info *
vxfs_blkiget(struct super_block *sbp, u_long extent, ino_t ino)
{
struct buffer_head *bp;
u_long block, offset;
block = extent + ((ino * VXFS_ISIZE) / sbp->s_blocksize);
offset = ((ino % (sbp->s_blocksize / VXFS_ISIZE)) * VXFS_ISIZE);
bp = sb_bread(sbp, block);
if (bp && buffer_mapped(bp)) {
struct vxfs_inode_info *vip;
struct vxfs_dinode *dip;
if (!(vip = kmem_cache_alloc(vxfs_inode_cachep, GFP_KERNEL)))
goto fail;
dip = (struct vxfs_dinode *)(bp->b_data + offset);
memcpy(vip, dip, sizeof(*vip));
#ifdef DIAGNOSTIC
vxfs_dumpi(vip, ino);
#endif
brelse(bp);
return (vip);
}
fail:
printk(KERN_WARNING "vxfs: unable to read block %ld\n", block);
brelse(bp);
return NULL;
}
/**
* __vxfs_iget - generic find inode facility
* @sbp: VFS superblock
* @ino: inode number
* @ilistp: inode list
*
* Description:
* Search the for inode number @ino in the filesystem
* described by @sbp. Use the specified inode table (@ilistp).
* Returns the matching VxFS inode on success, else a NULL pointer.
*/
static struct vxfs_inode_info *
__vxfs_iget(ino_t ino, struct inode *ilistp)
{
struct page *pp;
u_long offset;
offset = (ino % (PAGE_SIZE / VXFS_ISIZE)) * VXFS_ISIZE;
pp = vxfs_get_page(ilistp->i_mapping, ino * VXFS_ISIZE / PAGE_SIZE);
if (!IS_ERR(pp)) {
struct vxfs_inode_info *vip;
struct vxfs_dinode *dip;
caddr_t kaddr = (char *)page_address(pp);
if (!(vip = kmem_cache_alloc(vxfs_inode_cachep, GFP_KERNEL)))
goto fail;
dip = (struct vxfs_dinode *)(kaddr + offset);
memcpy(vip, dip, sizeof(*vip));
#ifdef DIAGNOSTIC
vxfs_dumpi(vip, ino);
#endif
vxfs_put_page(pp);
return (vip);
}
printk(KERN_WARNING "vxfs: error on page %p\n", pp);
return NULL;
fail:
printk(KERN_WARNING "vxfs: unable to read inode %ld\n", (unsigned long)ino);
vxfs_put_page(pp);
return NULL;
}
/**
* vxfs_stiget - find inode using the structural inode list
* @sbp: VFS superblock
* @ino: inode #
*
* Description:
* Find inode @ino in the filesystem described by @sbp using
* the structural inode list.
* Returns the matching VxFS inode on success, else a NULL pointer.
*/
struct vxfs_inode_info *
vxfs_stiget(struct super_block *sbp, ino_t ino)
{
return __vxfs_iget(ino, VXFS_SBI(sbp)->vsi_stilist);
}
/**
* vxfs_transmod - mode for a VxFS inode
* @vip: VxFS inode
*
* Description:
* vxfs_transmod returns a Linux mode_t for a given
* VxFS inode structure.
*/
static __inline__ mode_t
vxfs_transmod(struct vxfs_inode_info *vip)
{
mode_t ret = vip->vii_mode & ~VXFS_TYPE_MASK;
if (VXFS_ISFIFO(vip))
ret |= S_IFIFO;
if (VXFS_ISCHR(vip))
ret |= S_IFCHR;
if (VXFS_ISDIR(vip))
ret |= S_IFDIR;
if (VXFS_ISBLK(vip))
ret |= S_IFBLK;
if (VXFS_ISLNK(vip))
ret |= S_IFLNK;
if (VXFS_ISREG(vip))
ret |= S_IFREG;
if (VXFS_ISSOC(vip))
ret |= S_IFSOCK;
return (ret);
}
/**
* vxfs_iinit- helper to fill inode fields
* @ip: VFS inode
* @vip: VxFS inode
*
* Description:
* vxfs_instino is a helper function to fill in all relevant
* fields in @ip from @vip.
*/
static void
vxfs_iinit(struct inode *ip, struct vxfs_inode_info *vip)
{
ip->i_mode = vxfs_transmod(vip);
ip->i_uid = (uid_t)vip->vii_uid;
ip->i_gid = (gid_t)vip->vii_gid;
ip->i_nlink = vip->vii_nlink;
ip->i_size = vip->vii_size;
ip->i_atime.tv_sec = vip->vii_atime;
ip->i_ctime.tv_sec = vip->vii_ctime;
ip->i_mtime.tv_sec = vip->vii_mtime;
ip->i_atime.tv_nsec = 0;
ip->i_ctime.tv_nsec = 0;
ip->i_mtime.tv_nsec = 0;
ip->i_blocks = vip->vii_blocks;
ip->i_generation = vip->vii_gen;
ip->i_private = vip;
}
/**
* vxfs_get_fake_inode - get fake inode structure
* @sbp: filesystem superblock
* @vip: fspriv inode
*
* Description:
* vxfs_fake_inode gets a fake inode (not in the inode hash) for a
* superblock, vxfs_inode pair.
* Returns the filled VFS inode.
*/
struct inode *
vxfs_get_fake_inode(struct super_block *sbp, struct vxfs_inode_info *vip)
{
struct inode *ip = NULL;
if ((ip = new_inode(sbp))) {
vxfs_iinit(ip, vip);
ip->i_mapping->a_ops = &vxfs_aops;
}
return (ip);
}
/**
* vxfs_put_fake_inode - free faked inode
* *ip: VFS inode
*
* Description:
* vxfs_put_fake_inode frees all data asssociated with @ip.
*/
void
vxfs_put_fake_inode(struct inode *ip)
{
iput(ip);
}
/**
* vxfs_read_inode - fill in inode information
* @ip: inode pointer to fill
*
* Description:
* vxfs_read_inode reads the disk inode for @ip and fills
* in all relevant fields in @ip.
*/
void
vxfs_read_inode(struct inode *ip)
{
struct super_block *sbp = ip->i_sb;
struct vxfs_inode_info *vip;
const struct address_space_operations *aops;
ino_t ino = ip->i_ino;
if (!(vip = __vxfs_iget(ino, VXFS_SBI(sbp)->vsi_ilist)))
return;
vxfs_iinit(ip, vip);
if (VXFS_ISIMMED(vip))
aops = &vxfs_immed_aops;
else
aops = &vxfs_aops;
if (S_ISREG(ip->i_mode)) {
ip->i_fop = &generic_ro_fops;
ip->i_mapping->a_ops = aops;
} else if (S_ISDIR(ip->i_mode)) {
ip->i_op = &vxfs_dir_inode_ops;
ip->i_fop = &vxfs_dir_operations;
ip->i_mapping->a_ops = aops;
} else if (S_ISLNK(ip->i_mode)) {
if (!VXFS_ISIMMED(vip)) {
ip->i_op = &page_symlink_inode_operations;
ip->i_mapping->a_ops = &vxfs_aops;
} else
ip->i_op = &vxfs_immed_symlink_iops;
} else
init_special_inode(ip, ip->i_mode, old_decode_dev(vip->vii_rdev));
return;
}
/**
* vxfs_clear_inode - remove inode from main memory
* @ip: inode to discard.
*
* Description:
* vxfs_clear_inode() is called on the final iput and frees the private
* inode area.
*/
void
vxfs_clear_inode(struct inode *ip)
{
kmem_cache_free(vxfs_inode_cachep, ip->i_private);
}