linux/fs/udf/dir.c
Jan Kara 066b9cded0 udf: Use separate buffer for copying split names
Code in udf_find_entry() and udf_readdir() used the same buffer for
storing filename that was split among blocks and for the resulting
filename in utf8. This worked because udf_get_filename() first
internally copied the name into a different buffer and only then
performed a conversion into the destination buffer. However we want to
get rid of intermediate buffers so use separate buffer for converted
name and name split between blocks so that we don't have the same source
and destination buffer when converting split names.

Signed-off-by: Jan Kara <jack@suse.cz>
2016-02-09 13:05:23 +01:00

209 lines
5.1 KiB
C

/*
* dir.c
*
* PURPOSE
* Directory handling routines for the OSTA-UDF(tm) filesystem.
*
* COPYRIGHT
* This file is distributed under the terms of the GNU General Public
* License (GPL). Copies of the GPL can be obtained from:
* ftp://prep.ai.mit.edu/pub/gnu/GPL
* Each contributing author retains all rights to their own work.
*
* (C) 1998-2004 Ben Fennema
*
* HISTORY
*
* 10/05/98 dgb Split directory operations into its own file
* Implemented directory reads via do_udf_readdir
* 10/06/98 Made directory operations work!
* 11/17/98 Rewrote directory to support ICBTAG_FLAG_AD_LONG
* 11/25/98 blf Rewrote directory handling (readdir+lookup) to support reading
* across blocks.
* 12/12/98 Split out the lookup code to namei.c. bulk of directory
* code now in directory.c:udf_fileident_read.
*/
#include "udfdecl.h"
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include "udf_i.h"
#include "udf_sb.h"
static int udf_readdir(struct file *file, struct dir_context *ctx)
{
struct inode *dir = file_inode(file);
struct udf_inode_info *iinfo = UDF_I(dir);
struct udf_fileident_bh fibh = { .sbh = NULL, .ebh = NULL};
struct fileIdentDesc *fi = NULL;
struct fileIdentDesc cfi;
int block, iblock;
loff_t nf_pos;
int flen;
unsigned char *fname = NULL, *copy_name = NULL;
unsigned char *nameptr;
uint16_t liu;
uint8_t lfi;
loff_t size = udf_ext0_offset(dir) + dir->i_size;
struct buffer_head *tmp, *bha[16];
struct kernel_lb_addr eloc;
uint32_t elen;
sector_t offset;
int i, num, ret = 0;
struct extent_position epos = { NULL, 0, {0, 0} };
struct super_block *sb = dir->i_sb;
if (ctx->pos == 0) {
if (!dir_emit_dot(file, ctx))
return 0;
ctx->pos = 1;
}
nf_pos = (ctx->pos - 1) << 2;
if (nf_pos >= size)
goto out;
fname = kmalloc(UDF_NAME_LEN, GFP_NOFS);
if (!fname) {
ret = -ENOMEM;
goto out;
}
if (nf_pos == 0)
nf_pos = udf_ext0_offset(dir);
fibh.soffset = fibh.eoffset = nf_pos & (sb->s_blocksize - 1);
if (iinfo->i_alloc_type != ICBTAG_FLAG_AD_IN_ICB) {
if (inode_bmap(dir, nf_pos >> sb->s_blocksize_bits,
&epos, &eloc, &elen, &offset)
!= (EXT_RECORDED_ALLOCATED >> 30)) {
ret = -ENOENT;
goto out;
}
block = udf_get_lb_pblock(sb, &eloc, offset);
if ((++offset << sb->s_blocksize_bits) < elen) {
if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
epos.offset -= sizeof(struct short_ad);
else if (iinfo->i_alloc_type ==
ICBTAG_FLAG_AD_LONG)
epos.offset -= sizeof(struct long_ad);
} else {
offset = 0;
}
if (!(fibh.sbh = fibh.ebh = udf_tread(sb, block))) {
ret = -EIO;
goto out;
}
if (!(offset & ((16 >> (sb->s_blocksize_bits - 9)) - 1))) {
i = 16 >> (sb->s_blocksize_bits - 9);
if (i + offset > (elen >> sb->s_blocksize_bits))
i = (elen >> sb->s_blocksize_bits) - offset;
for (num = 0; i > 0; i--) {
block = udf_get_lb_pblock(sb, &eloc, offset + i);
tmp = udf_tgetblk(sb, block);
if (tmp && !buffer_uptodate(tmp) && !buffer_locked(tmp))
bha[num++] = tmp;
else
brelse(tmp);
}
if (num) {
ll_rw_block(READA, num, bha);
for (i = 0; i < num; i++)
brelse(bha[i]);
}
}
}
while (nf_pos < size) {
struct kernel_lb_addr tloc;
ctx->pos = (nf_pos >> 2) + 1;
fi = udf_fileident_read(dir, &nf_pos, &fibh, &cfi, &epos, &eloc,
&elen, &offset);
if (!fi)
goto out;
liu = le16_to_cpu(cfi.lengthOfImpUse);
lfi = cfi.lengthFileIdent;
if (fibh.sbh == fibh.ebh) {
nameptr = fi->fileIdent + liu;
} else {
int poffset; /* Unpaded ending offset */
poffset = fibh.soffset + sizeof(struct fileIdentDesc) + liu + lfi;
if (poffset >= lfi) {
nameptr = (char *)(fibh.ebh->b_data + poffset - lfi);
} else {
if (!copy_name) {
copy_name = kmalloc(UDF_NAME_LEN,
GFP_NOFS);
if (!copy_name) {
ret = -ENOMEM;
goto out;
}
}
nameptr = copy_name;
memcpy(nameptr, fi->fileIdent + liu,
lfi - poffset);
memcpy(nameptr + lfi - poffset,
fibh.ebh->b_data, poffset);
}
}
if ((cfi.fileCharacteristics & FID_FILE_CHAR_DELETED) != 0) {
if (!UDF_QUERY_FLAG(sb, UDF_FLAG_UNDELETE))
continue;
}
if ((cfi.fileCharacteristics & FID_FILE_CHAR_HIDDEN) != 0) {
if (!UDF_QUERY_FLAG(sb, UDF_FLAG_UNHIDE))
continue;
}
if (cfi.fileCharacteristics & FID_FILE_CHAR_PARENT) {
if (!dir_emit_dotdot(file, ctx))
goto out;
continue;
}
flen = udf_get_filename(sb, nameptr, lfi, fname, UDF_NAME_LEN);
if (flen < 0)
continue;
tloc = lelb_to_cpu(cfi.icb.extLocation);
iblock = udf_get_lb_pblock(sb, &tloc, 0);
if (!dir_emit(ctx, fname, flen, iblock, DT_UNKNOWN))
goto out;
} /* end while */
ctx->pos = (nf_pos >> 2) + 1;
out:
if (fibh.sbh != fibh.ebh)
brelse(fibh.ebh);
brelse(fibh.sbh);
brelse(epos.bh);
kfree(fname);
kfree(copy_name);
return ret;
}
/* readdir and lookup functions */
const struct file_operations udf_dir_operations = {
.llseek = generic_file_llseek,
.read = generic_read_dir,
.iterate = udf_readdir,
.unlocked_ioctl = udf_ioctl,
.fsync = generic_file_fsync,
};