297 строки
7.2 KiB
C
297 строки
7.2 KiB
C
/*
|
|
* Copyright (c) 2000-2001 Christoph Hellwig.
|
|
* Copyright (c) 2016 Krzysztof Blaszkowski
|
|
* 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 - lookup and other directory related code.
|
|
*/
|
|
#include <linux/fs.h>
|
|
#include <linux/time.h>
|
|
#include <linux/mm.h>
|
|
#include <linux/highmem.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/pagemap.h>
|
|
|
|
#include "vxfs.h"
|
|
#include "vxfs_dir.h"
|
|
#include "vxfs_inode.h"
|
|
#include "vxfs_extern.h"
|
|
|
|
/*
|
|
* Number of VxFS blocks per page.
|
|
*/
|
|
#define VXFS_BLOCK_PER_PAGE(sbp) ((PAGE_SIZE / (sbp)->s_blocksize))
|
|
|
|
|
|
static struct dentry * vxfs_lookup(struct inode *, struct dentry *, unsigned int);
|
|
static int vxfs_readdir(struct file *, struct dir_context *);
|
|
|
|
const struct inode_operations vxfs_dir_inode_ops = {
|
|
.lookup = vxfs_lookup,
|
|
};
|
|
|
|
const struct file_operations vxfs_dir_operations = {
|
|
.llseek = generic_file_llseek,
|
|
.read = generic_read_dir,
|
|
.iterate_shared = vxfs_readdir,
|
|
};
|
|
|
|
|
|
/**
|
|
* vxfs_find_entry - find a mathing directory entry for a dentry
|
|
* @ip: directory inode
|
|
* @dp: dentry for which we want to find a direct
|
|
* @ppp: gets filled with the page the return value sits in
|
|
*
|
|
* Description:
|
|
* vxfs_find_entry finds a &struct vxfs_direct for the VFS directory
|
|
* cache entry @dp. @ppp will be filled with the page the return
|
|
* value resides in.
|
|
*
|
|
* Returns:
|
|
* The wanted direct on success, else a NULL pointer.
|
|
*/
|
|
static struct vxfs_direct *
|
|
vxfs_find_entry(struct inode *ip, struct dentry *dp, struct page **ppp)
|
|
{
|
|
u_long bsize = ip->i_sb->s_blocksize;
|
|
const char *name = dp->d_name.name;
|
|
int namelen = dp->d_name.len;
|
|
loff_t limit = VXFS_DIRROUND(ip->i_size);
|
|
struct vxfs_direct *de_exit = NULL;
|
|
loff_t pos = 0;
|
|
struct vxfs_sb_info *sbi = VXFS_SBI(ip->i_sb);
|
|
|
|
while (pos < limit) {
|
|
struct page *pp;
|
|
char *kaddr;
|
|
int pg_ofs = pos & ~PAGE_MASK;
|
|
|
|
pp = vxfs_get_page(ip->i_mapping, pos >> PAGE_SHIFT);
|
|
if (IS_ERR(pp))
|
|
return NULL;
|
|
kaddr = (char *)page_address(pp);
|
|
|
|
while (pg_ofs < PAGE_SIZE && pos < limit) {
|
|
struct vxfs_direct *de;
|
|
|
|
if ((pos & (bsize - 1)) < 4) {
|
|
struct vxfs_dirblk *dbp =
|
|
(struct vxfs_dirblk *)
|
|
(kaddr + (pos & ~PAGE_MASK));
|
|
int overhead = VXFS_DIRBLKOV(sbi, dbp);
|
|
|
|
pos += overhead;
|
|
pg_ofs += overhead;
|
|
}
|
|
de = (struct vxfs_direct *)(kaddr + pg_ofs);
|
|
|
|
if (!de->d_reclen) {
|
|
pos += bsize - 1;
|
|
pos &= ~(bsize - 1);
|
|
break;
|
|
}
|
|
|
|
pg_ofs += fs16_to_cpu(sbi, de->d_reclen);
|
|
pos += fs16_to_cpu(sbi, de->d_reclen);
|
|
if (!de->d_ino)
|
|
continue;
|
|
|
|
if (namelen != fs16_to_cpu(sbi, de->d_namelen))
|
|
continue;
|
|
if (!memcmp(name, de->d_name, namelen)) {
|
|
*ppp = pp;
|
|
de_exit = de;
|
|
break;
|
|
}
|
|
}
|
|
if (!de_exit)
|
|
vxfs_put_page(pp);
|
|
else
|
|
break;
|
|
}
|
|
|
|
return de_exit;
|
|
}
|
|
|
|
/**
|
|
* vxfs_inode_by_name - find inode number for dentry
|
|
* @dip: directory to search in
|
|
* @dp: dentry we search for
|
|
*
|
|
* Description:
|
|
* vxfs_inode_by_name finds out the inode number of
|
|
* the path component described by @dp in @dip.
|
|
*
|
|
* Returns:
|
|
* The wanted inode number on success, else Zero.
|
|
*/
|
|
static ino_t
|
|
vxfs_inode_by_name(struct inode *dip, struct dentry *dp)
|
|
{
|
|
struct vxfs_direct *de;
|
|
struct page *pp;
|
|
ino_t ino = 0;
|
|
|
|
de = vxfs_find_entry(dip, dp, &pp);
|
|
if (de) {
|
|
ino = fs32_to_cpu(VXFS_SBI(dip->i_sb), de->d_ino);
|
|
kunmap(pp);
|
|
put_page(pp);
|
|
}
|
|
|
|
return (ino);
|
|
}
|
|
|
|
/**
|
|
* vxfs_lookup - lookup pathname component
|
|
* @dip: dir in which we lookup
|
|
* @dp: dentry we lookup
|
|
* @flags: lookup flags
|
|
*
|
|
* Description:
|
|
* vxfs_lookup tries to lookup the pathname component described
|
|
* by @dp in @dip.
|
|
*
|
|
* Returns:
|
|
* A NULL-pointer on success, else a negative error code encoded
|
|
* in the return pointer.
|
|
*/
|
|
static struct dentry *
|
|
vxfs_lookup(struct inode *dip, struct dentry *dp, unsigned int flags)
|
|
{
|
|
struct inode *ip = NULL;
|
|
ino_t ino;
|
|
|
|
if (dp->d_name.len > VXFS_NAMELEN)
|
|
return ERR_PTR(-ENAMETOOLONG);
|
|
|
|
ino = vxfs_inode_by_name(dip, dp);
|
|
if (ino)
|
|
ip = vxfs_iget(dip->i_sb, ino);
|
|
return d_splice_alias(ip, dp);
|
|
}
|
|
|
|
/**
|
|
* vxfs_readdir - read a directory
|
|
* @fp: the directory to read
|
|
* @retp: return buffer
|
|
* @filler: filldir callback
|
|
*
|
|
* Description:
|
|
* vxfs_readdir fills @retp with directory entries from @fp
|
|
* using the VFS supplied callback @filler.
|
|
*
|
|
* Returns:
|
|
* Zero.
|
|
*/
|
|
static int
|
|
vxfs_readdir(struct file *fp, struct dir_context *ctx)
|
|
{
|
|
struct inode *ip = file_inode(fp);
|
|
struct super_block *sbp = ip->i_sb;
|
|
u_long bsize = sbp->s_blocksize;
|
|
loff_t pos, limit;
|
|
struct vxfs_sb_info *sbi = VXFS_SBI(sbp);
|
|
|
|
if (ctx->pos == 0) {
|
|
if (!dir_emit_dot(fp, ctx))
|
|
goto out;
|
|
ctx->pos++;
|
|
}
|
|
if (ctx->pos == 1) {
|
|
if (!dir_emit(ctx, "..", 2, VXFS_INO(ip)->vii_dotdot, DT_DIR))
|
|
goto out;
|
|
ctx->pos++;
|
|
}
|
|
|
|
limit = VXFS_DIRROUND(ip->i_size);
|
|
if (ctx->pos > limit)
|
|
goto out;
|
|
|
|
pos = ctx->pos & ~3L;
|
|
|
|
while (pos < limit) {
|
|
struct page *pp;
|
|
char *kaddr;
|
|
int pg_ofs = pos & ~PAGE_MASK;
|
|
int rc = 0;
|
|
|
|
pp = vxfs_get_page(ip->i_mapping, pos >> PAGE_SHIFT);
|
|
if (IS_ERR(pp))
|
|
return -ENOMEM;
|
|
|
|
kaddr = (char *)page_address(pp);
|
|
|
|
while (pg_ofs < PAGE_SIZE && pos < limit) {
|
|
struct vxfs_direct *de;
|
|
|
|
if ((pos & (bsize - 1)) < 4) {
|
|
struct vxfs_dirblk *dbp =
|
|
(struct vxfs_dirblk *)
|
|
(kaddr + (pos & ~PAGE_MASK));
|
|
int overhead = VXFS_DIRBLKOV(sbi, dbp);
|
|
|
|
pos += overhead;
|
|
pg_ofs += overhead;
|
|
}
|
|
de = (struct vxfs_direct *)(kaddr + pg_ofs);
|
|
|
|
if (!de->d_reclen) {
|
|
pos += bsize - 1;
|
|
pos &= ~(bsize - 1);
|
|
break;
|
|
}
|
|
|
|
pg_ofs += fs16_to_cpu(sbi, de->d_reclen);
|
|
pos += fs16_to_cpu(sbi, de->d_reclen);
|
|
if (!de->d_ino)
|
|
continue;
|
|
|
|
rc = dir_emit(ctx, de->d_name,
|
|
fs16_to_cpu(sbi, de->d_namelen),
|
|
fs32_to_cpu(sbi, de->d_ino),
|
|
DT_UNKNOWN);
|
|
if (!rc) {
|
|
/* the dir entry was not read, fix pos. */
|
|
pos -= fs16_to_cpu(sbi, de->d_reclen);
|
|
break;
|
|
}
|
|
}
|
|
vxfs_put_page(pp);
|
|
if (!rc)
|
|
break;
|
|
}
|
|
|
|
ctx->pos = pos | 2;
|
|
|
|
out:
|
|
return 0;
|
|
}
|