WSL2-Linux-Kernel/fs/udf/directory.c

243 строки
5.8 KiB
C

/*
* directory.c
*
* PURPOSE
* Directory related functions
*
* 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.
*/
#include "udfdecl.h"
#include "udf_i.h"
#include <linux/fs.h>
#include <linux/string.h>
#include <linux/bio.h>
struct fileIdentDesc *udf_fileident_read(struct inode *dir, loff_t *nf_pos,
struct udf_fileident_bh *fibh,
struct fileIdentDesc *cfi,
struct extent_position *epos,
struct kernel_lb_addr *eloc, uint32_t *elen,
sector_t *offset)
{
struct fileIdentDesc *fi;
int i, num;
udf_pblk_t block;
struct buffer_head *tmp, *bha[16];
struct udf_inode_info *iinfo = UDF_I(dir);
fibh->soffset = fibh->eoffset;
if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) {
fi = udf_get_fileident(iinfo->i_ext.i_data -
(iinfo->i_efe ?
sizeof(struct extendedFileEntry) :
sizeof(struct fileEntry)),
dir->i_sb->s_blocksize,
&(fibh->eoffset));
if (!fi)
return NULL;
*nf_pos += fibh->eoffset - fibh->soffset;
memcpy((uint8_t *)cfi, (uint8_t *)fi,
sizeof(struct fileIdentDesc));
return fi;
}
if (fibh->eoffset == dir->i_sb->s_blocksize) {
uint32_t lextoffset = epos->offset;
unsigned char blocksize_bits = dir->i_sb->s_blocksize_bits;
if (udf_next_aext(dir, epos, eloc, elen, 1) !=
(EXT_RECORDED_ALLOCATED >> 30))
return NULL;
block = udf_get_lb_pblock(dir->i_sb, eloc, *offset);
(*offset)++;
if ((*offset << blocksize_bits) >= *elen)
*offset = 0;
else
epos->offset = lextoffset;
brelse(fibh->sbh);
fibh->sbh = fibh->ebh = udf_tread(dir->i_sb, block);
if (!fibh->sbh)
return NULL;
fibh->soffset = fibh->eoffset = 0;
if (!(*offset & ((16 >> (blocksize_bits - 9)) - 1))) {
i = 16 >> (blocksize_bits - 9);
if (i + *offset > (*elen >> blocksize_bits))
i = (*elen >> blocksize_bits)-*offset;
for (num = 0; i > 0; i--) {
block = udf_get_lb_pblock(dir->i_sb, eloc,
*offset + i);
tmp = udf_tgetblk(dir->i_sb, block);
if (tmp && !buffer_uptodate(tmp) &&
!buffer_locked(tmp))
bha[num++] = tmp;
else
brelse(tmp);
}
if (num) {
ll_rw_block(REQ_OP_READ, REQ_RAHEAD, num, bha);
for (i = 0; i < num; i++)
brelse(bha[i]);
}
}
} else if (fibh->sbh != fibh->ebh) {
brelse(fibh->sbh);
fibh->sbh = fibh->ebh;
}
fi = udf_get_fileident(fibh->sbh->b_data, dir->i_sb->s_blocksize,
&(fibh->eoffset));
if (!fi)
return NULL;
*nf_pos += fibh->eoffset - fibh->soffset;
if (fibh->eoffset <= dir->i_sb->s_blocksize) {
memcpy((uint8_t *)cfi, (uint8_t *)fi,
sizeof(struct fileIdentDesc));
} else if (fibh->eoffset > dir->i_sb->s_blocksize) {
uint32_t lextoffset = epos->offset;
if (udf_next_aext(dir, epos, eloc, elen, 1) !=
(EXT_RECORDED_ALLOCATED >> 30))
return NULL;
block = udf_get_lb_pblock(dir->i_sb, eloc, *offset);
(*offset)++;
if ((*offset << dir->i_sb->s_blocksize_bits) >= *elen)
*offset = 0;
else
epos->offset = lextoffset;
fibh->soffset -= dir->i_sb->s_blocksize;
fibh->eoffset -= dir->i_sb->s_blocksize;
fibh->ebh = udf_tread(dir->i_sb, block);
if (!fibh->ebh)
return NULL;
if (sizeof(struct fileIdentDesc) > -fibh->soffset) {
int fi_len;
memcpy((uint8_t *)cfi, (uint8_t *)fi, -fibh->soffset);
memcpy((uint8_t *)cfi - fibh->soffset,
fibh->ebh->b_data,
sizeof(struct fileIdentDesc) + fibh->soffset);
fi_len = udf_dir_entry_len(cfi);
*nf_pos += fi_len - (fibh->eoffset - fibh->soffset);
fibh->eoffset = fibh->soffset + fi_len;
} else {
memcpy((uint8_t *)cfi, (uint8_t *)fi,
sizeof(struct fileIdentDesc));
}
}
/* Got last entry outside of dir size - fs is corrupted! */
if (*nf_pos > dir->i_size)
return NULL;
return fi;
}
struct fileIdentDesc *udf_get_fileident(void *buffer, int bufsize, int *offset)
{
struct fileIdentDesc *fi;
int lengthThisIdent;
uint8_t *ptr;
int padlen;
if ((!buffer) || (!offset)) {
udf_debug("invalidparms, buffer=%p, offset=%p\n",
buffer, offset);
return NULL;
}
ptr = buffer;
if ((*offset > 0) && (*offset < bufsize))
ptr += *offset;
fi = (struct fileIdentDesc *)ptr;
if (fi->descTag.tagIdent != cpu_to_le16(TAG_IDENT_FID)) {
udf_debug("0x%x != TAG_IDENT_FID\n",
le16_to_cpu(fi->descTag.tagIdent));
udf_debug("offset: %d sizeof: %lu bufsize: %d\n",
*offset, (unsigned long)sizeof(struct fileIdentDesc),
bufsize);
return NULL;
}
if ((*offset + sizeof(struct fileIdentDesc)) > bufsize)
lengthThisIdent = sizeof(struct fileIdentDesc);
else
lengthThisIdent = sizeof(struct fileIdentDesc) +
fi->lengthFileIdent + le16_to_cpu(fi->lengthOfImpUse);
/* we need to figure padding, too! */
padlen = lengthThisIdent % UDF_NAME_PAD;
if (padlen)
lengthThisIdent += (UDF_NAME_PAD - padlen);
*offset = *offset + lengthThisIdent;
return fi;
}
struct short_ad *udf_get_fileshortad(uint8_t *ptr, int maxoffset, uint32_t *offset,
int inc)
{
struct short_ad *sa;
if ((!ptr) || (!offset)) {
pr_err("%s: invalidparms\n", __func__);
return NULL;
}
if ((*offset + sizeof(struct short_ad)) > maxoffset)
return NULL;
else {
sa = (struct short_ad *)ptr;
if (sa->extLength == 0)
return NULL;
}
if (inc)
*offset += sizeof(struct short_ad);
return sa;
}
struct long_ad *udf_get_filelongad(uint8_t *ptr, int maxoffset, uint32_t *offset, int inc)
{
struct long_ad *la;
if ((!ptr) || (!offset)) {
pr_err("%s: invalidparms\n", __func__);
return NULL;
}
if ((*offset + sizeof(struct long_ad)) > maxoffset)
return NULL;
else {
la = (struct long_ad *)ptr;
if (la->extLength == 0)
return NULL;
}
if (inc)
*offset += sizeof(struct long_ad);
return la;
}