inode.c

EM85XX读NTFS修正代码包

/*
 * inode.c
 *
 * Copyright (C) 1995-1999 Martin von L鰓is
 * Copyright (C) 1996 Albert D. Cahalan
 * Copyright (C) 1996-1997 R間is Duchesne
 * Copyright (C) 1998 Joseph Malicki
 * Copyright (C) 1999 Steve Dodd
 * Copyright (C) 2000-2001 Anton Altaparmakov (AIA)
 */
#include "ntfstypes.h"
#include "ntfsendian.h"
#include "struct.h"
#include "inode.h"
#include <linux/errno.h>
#include "macros.h"
#include "attr.h"
#include "super.h"
#include "dir.h"
#include "support.h"
#include "util.h"
#include <linux/ntfs_fs.h>
#include <linux/smp_lock.h>

typedef struct {
	int recno;
	unsigned char *record;
} ntfs_mft_record;

typedef struct {
	int size;
	int count;
	ntfs_mft_record *records;
} ntfs_disk_inode;

static void ntfs_fill_mft_header(ntfs_u8 *mft, int rec_size, int seq_no,
		int links, int flags)
{
	int fixup_ofs = 0x2a;
	int fixup_cnt = rec_size / NTFS_SECTOR_SIZE + 1;
	int attr_ofs = (fixup_ofs + 2 * fixup_cnt + 7) & ~7;

	NTFS_PUTU32(mft + 0x00, 0x454c4946);	/* FILE */
	NTFS_PUTU16(mft + 0x04, fixup_ofs);	/* Offset to fixup. */
	NTFS_PUTU16(mft + 0x06, fixup_cnt);	/* Number of fixups. */
	NTFS_PUTU64(mft + 0x08, 0);		/* Logical sequence number. */
	NTFS_PUTU16(mft + 0x10, seq_no);	/* Sequence number. */
	NTFS_PUTU16(mft + 0x12, links);		/* Hard link count. */
	NTFS_PUTU16(mft + 0x14, attr_ofs);	/* Offset to attributes. */
	NTFS_PUTU16(mft + 0x16, flags);		/* Flags: 1 = In use,
							  2 = Directory. */
	NTFS_PUTU32(mft + 0x18, attr_ofs + 8);	/* Bytes in use. */
	NTFS_PUTU32(mft + 0x1c, rec_size);	/* Total allocated size. */
	NTFS_PUTU64(mft + 0x20, 0);		/* Base mft record. */
	NTFS_PUTU16(mft + 0x28, 0);		/* Next attr instance. */
	NTFS_PUTU16(mft + fixup_ofs, 1);	/* Fixup word. */
	NTFS_PUTU32(mft + attr_ofs, (__u32)-1);	/* End of attributes marker. */
}

/*
 * Search in an inode an attribute by type and name. 
 * FIXME: Check that when attributes are inserted all attribute list
 * attributes are expanded otherwise need to modify this function to deal
 * with attribute lists. (AIA)
 */
ntfs_attribute *ntfs_find_attr(ntfs_inode *ino, int type, char *name)
{
	int i;
	
	if (!ino) {
		ntfs_error("ntfs_find_attr: NO INODE!\n");
		return 0;
	}
	for (i = 0; i < ino->attr_count; i++) {
		if (type < ino->attrs[i].type)
			return 0;
		if (type == ino->attrs[i].type) {
			if (!name) {
				if (!ino->attrs[i].name)
					return ino->attrs + i;
			} else if (ino->attrs[i].name &&
				   !ntfs_ua_strncmp(ino->attrs[i].name, name,
						    strlen(name)))
				return ino->attrs + i;
		}
	}
	return 0;
}

/*
 * Insert all attributes from the record mftno of the MFT in the inode ino.
 * If mftno is a base mft record we abort as soon as we find the attribute
 * list, but only on the first pass. We will get called later when the attribute
 * list attribute is being parsed so we need to distinguish the two cases.
 * FIXME: We should be performing structural consistency checks. (AIA)
 * Return 0 on success or -errno on error.
 */
static int ntfs_insert_mft_attributes(ntfs_inode* ino, char *mft, int mftno)
{
	int i, error, type, len, present = 0;
	char *it;

	/* Check for duplicate extension record. */
	for(i = 0; i < ino->record_count; i++)
		if (ino->records[i] == mftno) {
			if (i)
				return 0;
			present = 1;
			break;
		}
	if (!present) {
		/* (re-)allocate space if necessary. */
		if (ino->record_count % 8 == 0)	{
			int *new;

			new = ntfs_malloc((ino->record_count + 8) *
								sizeof(int));
			if (!new)
				return -ENOMEM;
			if (ino->records) {
				for (i = 0; i < ino->record_count; i++)
					new[i] = ino->records[i];
				ntfs_free(ino->records);
			}
			ino->records = new;
		}
		ino->records[ino->record_count] = mftno;
		ino->record_count++;
	}
	it = mft + NTFS_GETU16(mft + 0x14); /* mft->attrs_offset */
	do {
		type = NTFS_GETU32(it);
		len = NTFS_GETU32(it + 4);
		if (type != -1) {
			error = ntfs_insert_attribute(ino, it);
			if (error)
				return error;
		}
		/* If we have just processed the attribute list and this is
		 * the first time we are parsing this (base) mft record then we
		 * are done so that the attribute list gets parsed before the
		 * entries in the base mft record. Otherwise we run into
		 * problems with encountering attributes out of order and when
		 * this happens with different attribute extents we die. )-:
		 * This way we are ok as the attribute list is always sorted
		 * fully and correctly. (-: */
		if (type == 0x20 && !present)
			return 0;
		it += len;
	} while (type != -1); /* Attribute listing ends with type -1. */
	return 0;
}

/*
 * Insert a single specific attribute from the record mftno of the MFT in the
 * inode ino. We disregard the attribute list assuming we have already parsed
 * it.
 * FIXME: We should be performing structural consistency checks. (AIA)
 * Return 0 on success or -errno on error.
 */
static int ntfs_insert_mft_attribute(ntfs_inode* ino, int mftno,
		ntfs_u8 *attr)
{
	int i, error, present = 0;

	/* Check for duplicate extension record. */
	for(i = 0; i < ino->record_count; i++)
		if (ino->records[i] == mftno) {
			present = 1;
			break;
		}
	if (!present) {
		/* (re-)allocate space if necessary. */
		if (ino->record_count % 8 == 0)	{
			int *new;

			new = ntfs_malloc((ino->record_count + 8) *
								sizeof(int));
			if (!new)
				return -ENOMEM;
			if (ino->records) {
				for (i = 0; i < ino->record_count; i++)
					new[i] = ino->records[i];
				ntfs_free(ino->records);
			}
			ino->records = new;
		}
		ino->records[ino->record_count] = mftno;
		ino->record_count++;
	}
	if (NTFS_GETU32(attr) == -1) {
		ntfs_debug(DEBUG_FILE3, "ntfs_insert_mft_attribute: attribute "
				"type is -1.\n");
		return 0;
	}
	error = ntfs_insert_attribute(ino, attr);
	if (error)
		return error;
	return 0;
}

/* Read and insert all the attributes of an 'attribute list' attribute.
 * Return the number of remaining bytes in *plen. */
static int parse_attributes(ntfs_inode *ino, ntfs_u8 *alist, int *plen)
{
	ntfs_u8 *mft, *attr;
	int mftno, l, error;
	int last_mft = -1;
	int len = *plen;
	int tries = 0;
	
	if (!ino->attr) {
		ntfs_error("parse_attributes: called on inode 0x%x without a "
				"loaded base mft record.\n", ino->i_number);
		return -EINVAL;
	}
	mft = ntfs_malloc(ino->vol->mft_record_size);
	if (!mft)
		return -ENOMEM;
	while (len > 8)	{
		l = NTFS_GETU16(alist + 4);
		if (l > len)
			break;
	        /* Process an attribute description. */
		mftno = NTFS_GETU32(alist + 0x10); 
			/* FIXME: The mft reference (alist + 0x10) is __s64.
			* - Not a problem unless we encounter a huge partition.
			* - Should be consistency checking the sequence numbers
			*   though! This should maybe happen in 
			*   ntfs_read_mft_record() itself and a hotfix could
			*   then occur there or the user notified to run
			*   ntfsck. (AIA) */
		if (mftno != ino->i_number && mftno != last_mft) {
continue_after_loading_mft_data:
			last_mft = mftno;
			error = ntfs_read_mft_record(ino->vol, mftno, mft);
			if (error) {
				if (error == -EINVAL && !tries)
					goto force_load_mft_data;
failed_reading_mft_data:
				ntfs_debug(DEBUG_FILE3, "parse_attributes: "
					"ntfs_read_mft_record(mftno = 0x%x) "
					"failed\n", mftno);
				ntfs_free(mft);
				return error;
			}
		}
		attr = ntfs_find_attr_in_mft_rec(
				ino->vol,		/* ntfs volume */
				mftno == ino->i_number ?/* mft record is: */
					ino->attr:	/*   base record */
					mft,		/*   extension record */
				NTFS_GETU32(alist + 0),	/* type */
				(wchar_t*)(alist + alist[7]),	/* name */
				alist[6], 		/* name length */
				1,			/* ignore case */
				NTFS_GETU16(alist + 24)	/* instance number */
				);
		if (!attr) {
			ntfs_error("parse_attributes: mft records 0x%x and/or "
				       "0x%x corrupt!\n", ino->i_number, mftno);
			ntfs_free(mft);
			return -EINVAL; /* FIXME: Better error code? (AIA) */
		}
		error = ntfs_insert_mft_attribute(ino, mftno, attr);
		if (error) {
			ntfs_debug(DEBUG_FILE3, "parse_attributes: "
				"ntfs_insert_mft_attribute(mftno 0x%x, "
				"attribute type 0x%x) failed\n", mftno,
				NTFS_GETU32(alist + 0));
			ntfs_free(mft);
			return error;
		}
		len -= l;
		alist += l;
	}
	ntfs_free(mft);
	*plen = len;
	return 0;
force_load_mft_data:
{
	ntfs_u8 *mft2, *attr2;
	int mftno2;
	int last_mft2 = last_mft;
	int len2 = len;
	int error2;
	int found2 = 0;
	ntfs_u8 *alist2 = alist;
	/*
	 * We only get here if $DATA wasn't found in $MFT which only happens
	 * on volume mount when $MFT has an attribute list and there are
	 * attributes before $DATA which are inside extent mft records. So
	 * we just skip forward to the $DATA attribute and read that. Then we
	 * restart which is safe as an attribute will not be inserted twice.
	 *
	 * This still will not fix the case where the attribute list is non-
	 * resident, larger than 1024 bytes, and the $DATA attribute list entry
	 * is not in the first 1024 bytes. FIXME: This should be implemented
	 * somehow! Perhaps by passing special error code up to
	 * ntfs_load_attributes() so it keeps going trying to get to $DATA
	 * regardless. Then it would have to restart just like we do here.
	 */
	mft2 = ntfs_malloc(ino->vol->mft_record_size);
	if (!mft2) {
		ntfs_free(mft);
		return -ENOMEM;
	}
	ntfs_memcpy(mft2, mft, ino->vol->mft_record_size);
	while (len2 > 8) {
		l = NTFS_GETU16(alist2 + 4);
		if (l > len2)
			break;
		if (NTFS_GETU32(alist2 + 0x0) < ino->vol->at_data) {
			len2 -= l;
			alist2 += l;
			continue;
		}
		if (NTFS_GETU32(alist2 + 0x0) > ino->vol->at_data) {
			if (found2)
				break;
			/* Uh-oh! It really isn't there! */
			ntfs_error("Either the $MFT is corrupt or, equally "
					"likely, the $MFT is too complex for "
					"the current driver to handle. Please "
					"email the ntfs maintainer that you "
					"saw this message. Thank you.\n");
			goto failed_reading_mft_data;
		}
	        /* Process attribute description. */
		mftno2 = NTFS_GETU32(alist2 + 0x10); 
		if (mftno2 != ino->i_number && mftno2 != last_mft2) {
			last_mft2 = mftno2;
			error2 = ntfs_read_mft_record(ino->vol, mftno2, mft2);
			if (error2) {
				ntfs_debug(DEBUG_FILE3, "parse_attributes: "
					"ntfs_read_mft_record(mftno2 = 0x%x) "
					"failed\n", mftno2);
				ntfs_free(mft2);
				goto failed_reading_mft_data;
			}
		}
		attr2 = ntfs_find_attr_in_mft_rec(
				ino->vol,		 /* ntfs volume */
				mftno2 == ino->i_number ?/* mft record is: */
					ino->attr:	 /*  base record */
					mft2,		 /*  extension record */
				NTFS_GETU32(alist2 + 0),	/* type */
				(wchar_t*)(alist2 + alist2[7]),	/* name */
				alist2[6], 		 /* name length */
				1,			 /* ignore case */
				NTFS_GETU16(alist2 + 24) /* instance number */
				);
		if (!attr2) {
			ntfs_error("parse_attributes: mft records 0x%x and/or "
				       "0x%x corrupt!\n", ino->i_number,
				       mftno2);
			ntfs_free(mft2);
			goto failed_reading_mft_data;
		}
		error2 = ntfs_insert_mft_attribute(ino, mftno2, attr2);
		if (error2) {
			ntfs_debug(DEBUG_FILE3, "parse_attributes: "
				"ntfs_insert_mft_attribute(mftno2 0x%x, "
				"attribute2 type 0x%x) failed\n", mftno2,
				NTFS_GETU32(alist2 + 0));
			ntfs_free(mft2);
			goto failed_reading_mft_data;
		}
		len2 -= l;
		alist2 += l;
		found2 = 1;
	}
	ntfs_free(mft2);
	tries = 1;
	goto continue_after_loading_mft_data;
}
}

static void ntfs_load_attributes(ntfs_inode *ino)
{
	ntfs_attribute *alist;
	int datasize;
	int offset, len, delta;
	char *buf;
	ntfs_volume *vol = ino->vol;
	
	ntfs_debug(DEBUG_FILE2, "load_attributes 0x%x 1\n", ino->i_number);
	if (ntfs_insert_mft_attributes(ino, ino->attr, ino->i_number))
		return;
	ntfs_debug(DEBUG_FILE2, "load_attributes 0x%x 2\n", ino->i_number);
	alist = ntfs_find_attr(ino, vol->at_attribute_list, 0);
	ntfs_debug(DEBUG_FILE2, "load_attributes 0x%x 3\n", ino->i_number);
	if (!alist)
		return;
	ntfs_debug(DEBUG_FILE2, "load_attributes 0x%x 4\n", ino->i_number);
	datasize = alist->size;
	ntfs_debug(DEBUG_FILE2, "load_attributes 0x%x: alist->size = 0x%x\n",
			ino->i_number, alist->size);
	if (alist->resident) {
		parse_attributes(ino, alist->d.data, &datasize);
		return;
	}
	ntfs_debug(DEBUG_FILE2, "load_attributes 0x%x 5\n", ino->i_number);
	buf = ntfs_malloc(1024);
	if (!buf)    /* FIXME: Should be passing error code to caller. (AIA) */
		return;
	delta = 0;
	for (offset = 0; datasize; datasize -= len, offset += len) {
		ntfs_io io;
		
		io.fn_put = ntfs_put;