mirror of https://github.com/Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
209 lines
5.2 KiB
209 lines
5.2 KiB
/* |
|
* 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 <linux/bio.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; |
|
udf_pblk_t 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(REQ_OP_READ, REQ_RAHEAD, 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_shared = udf_readdir, |
|
.unlocked_ioctl = udf_ioctl, |
|
.fsync = generic_file_fsync, |
|
};
|
|
|