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![Konstantin Komarov](/assets/img/avatar_default.png)
Added minor refactoring. Added and fixed some comments. In some places, the code has been reformatted to fit into 80 columns. clang-format-12 was used to format code according kernel's .clang-format. Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
593 lines
12 KiB
C
593 lines
12 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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*
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* Copyright (C) 2019-2021 Paragon Software GmbH, All rights reserved.
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*
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*/
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#include <linux/fs.h>
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#include "debug.h"
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#include "ntfs.h"
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#include "ntfs_fs.h"
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static inline int compare_attr(const struct ATTRIB *left, enum ATTR_TYPE type,
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const __le16 *name, u8 name_len,
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const u16 *upcase)
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{
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/* First, compare the type codes. */
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int diff = le32_to_cpu(left->type) - le32_to_cpu(type);
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if (diff)
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return diff;
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/* They have the same type code, so we have to compare the names. */
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return ntfs_cmp_names(attr_name(left), left->name_len, name, name_len,
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upcase, true);
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}
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/*
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* mi_new_attt_id
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*
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* Return: Unused attribute id that is less than mrec->next_attr_id.
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*/
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static __le16 mi_new_attt_id(struct mft_inode *mi)
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{
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u16 free_id, max_id, t16;
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struct MFT_REC *rec = mi->mrec;
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struct ATTRIB *attr;
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__le16 id;
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id = rec->next_attr_id;
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free_id = le16_to_cpu(id);
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if (free_id < 0x7FFF) {
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rec->next_attr_id = cpu_to_le16(free_id + 1);
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return id;
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}
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/* One record can store up to 1024/24 ~= 42 attributes. */
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free_id = 0;
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max_id = 0;
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attr = NULL;
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for (;;) {
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attr = mi_enum_attr(mi, attr);
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if (!attr) {
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rec->next_attr_id = cpu_to_le16(max_id + 1);
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mi->dirty = true;
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return cpu_to_le16(free_id);
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}
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t16 = le16_to_cpu(attr->id);
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if (t16 == free_id) {
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free_id += 1;
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attr = NULL;
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} else if (max_id < t16)
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max_id = t16;
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}
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}
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int mi_get(struct ntfs_sb_info *sbi, CLST rno, struct mft_inode **mi)
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{
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int err;
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struct mft_inode *m = kzalloc(sizeof(struct mft_inode), GFP_NOFS);
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if (!m)
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return -ENOMEM;
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err = mi_init(m, sbi, rno);
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if (err) {
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kfree(m);
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return err;
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}
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err = mi_read(m, false);
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if (err) {
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mi_put(m);
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return err;
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}
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*mi = m;
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return 0;
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}
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void mi_put(struct mft_inode *mi)
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{
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mi_clear(mi);
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kfree(mi);
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}
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int mi_init(struct mft_inode *mi, struct ntfs_sb_info *sbi, CLST rno)
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{
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mi->sbi = sbi;
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mi->rno = rno;
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mi->mrec = kmalloc(sbi->record_size, GFP_NOFS);
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if (!mi->mrec)
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return -ENOMEM;
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return 0;
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}
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/*
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* mi_read - Read MFT data.
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*/
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int mi_read(struct mft_inode *mi, bool is_mft)
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{
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int err;
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struct MFT_REC *rec = mi->mrec;
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struct ntfs_sb_info *sbi = mi->sbi;
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u32 bpr = sbi->record_size;
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u64 vbo = (u64)mi->rno << sbi->record_bits;
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struct ntfs_inode *mft_ni = sbi->mft.ni;
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struct runs_tree *run = mft_ni ? &mft_ni->file.run : NULL;
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struct rw_semaphore *rw_lock = NULL;
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if (is_mounted(sbi)) {
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if (!is_mft) {
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rw_lock = &mft_ni->file.run_lock;
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down_read(rw_lock);
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}
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}
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err = ntfs_read_bh(sbi, run, vbo, &rec->rhdr, bpr, &mi->nb);
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if (rw_lock)
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up_read(rw_lock);
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if (!err)
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goto ok;
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if (err == -E_NTFS_FIXUP) {
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mi->dirty = true;
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goto ok;
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}
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if (err != -ENOENT)
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goto out;
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if (rw_lock) {
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ni_lock(mft_ni);
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down_write(rw_lock);
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}
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err = attr_load_runs_vcn(mft_ni, ATTR_DATA, NULL, 0, &mft_ni->file.run,
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vbo >> sbi->cluster_bits);
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if (rw_lock) {
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up_write(rw_lock);
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ni_unlock(mft_ni);
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}
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if (err)
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goto out;
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if (rw_lock)
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down_read(rw_lock);
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err = ntfs_read_bh(sbi, run, vbo, &rec->rhdr, bpr, &mi->nb);
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if (rw_lock)
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up_read(rw_lock);
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if (err == -E_NTFS_FIXUP) {
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mi->dirty = true;
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goto ok;
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}
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if (err)
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goto out;
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ok:
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/* Check field 'total' only here. */
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if (le32_to_cpu(rec->total) != bpr) {
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err = -EINVAL;
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goto out;
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}
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return 0;
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out:
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return err;
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}
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struct ATTRIB *mi_enum_attr(struct mft_inode *mi, struct ATTRIB *attr)
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{
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const struct MFT_REC *rec = mi->mrec;
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u32 used = le32_to_cpu(rec->used);
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u32 t32, off, asize;
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u16 t16;
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if (!attr) {
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u32 total = le32_to_cpu(rec->total);
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off = le16_to_cpu(rec->attr_off);
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if (used > total)
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return NULL;
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if (off >= used || off < MFTRECORD_FIXUP_OFFSET_1 ||
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!IS_ALIGNED(off, 4)) {
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return NULL;
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}
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/* Skip non-resident records. */
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if (!is_rec_inuse(rec))
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return NULL;
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attr = Add2Ptr(rec, off);
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} else {
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/* Check if input attr inside record. */
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off = PtrOffset(rec, attr);
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if (off >= used)
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return NULL;
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asize = le32_to_cpu(attr->size);
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if (asize < SIZEOF_RESIDENT) {
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/* Impossible 'cause we should not return such attribute. */
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return NULL;
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}
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if (off + asize < off) {
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/* Overflow check. */
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return NULL;
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}
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attr = Add2Ptr(attr, asize);
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off += asize;
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}
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asize = le32_to_cpu(attr->size);
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/* Can we use the first field (attr->type). */
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if (off + 8 > used) {
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static_assert(ALIGN(sizeof(enum ATTR_TYPE), 8) == 8);
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return NULL;
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}
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if (attr->type == ATTR_END) {
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/* End of enumeration. */
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return NULL;
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}
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/* 0x100 is last known attribute for now. */
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t32 = le32_to_cpu(attr->type);
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if ((t32 & 0xf) || (t32 > 0x100))
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return NULL;
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/* Check overflow and boundary. */
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if (off + asize < off || off + asize > used)
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return NULL;
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/* Check size of attribute. */
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if (!attr->non_res) {
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if (asize < SIZEOF_RESIDENT)
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return NULL;
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t16 = le16_to_cpu(attr->res.data_off);
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if (t16 > asize)
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return NULL;
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t32 = le32_to_cpu(attr->res.data_size);
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if (t16 + t32 > asize)
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return NULL;
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t32 = sizeof(short) * attr->name_len;
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if (t32 && le16_to_cpu(attr->name_off) + t32 > t16)
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return NULL;
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return attr;
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}
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/* Check some nonresident fields. */
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if (attr->name_len &&
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le16_to_cpu(attr->name_off) + sizeof(short) * attr->name_len >
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le16_to_cpu(attr->nres.run_off)) {
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return NULL;
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}
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if (attr->nres.svcn || !is_attr_ext(attr)) {
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if (asize + 8 < SIZEOF_NONRESIDENT)
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return NULL;
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if (attr->nres.c_unit)
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return NULL;
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} else if (asize + 8 < SIZEOF_NONRESIDENT_EX)
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return NULL;
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return attr;
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}
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/*
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* mi_find_attr - Find the attribute by type and name and id.
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*/
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struct ATTRIB *mi_find_attr(struct mft_inode *mi, struct ATTRIB *attr,
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enum ATTR_TYPE type, const __le16 *name,
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size_t name_len, const __le16 *id)
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{
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u32 type_in = le32_to_cpu(type);
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u32 atype;
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next_attr:
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attr = mi_enum_attr(mi, attr);
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if (!attr)
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return NULL;
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atype = le32_to_cpu(attr->type);
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if (atype > type_in)
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return NULL;
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if (atype < type_in)
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goto next_attr;
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if (attr->name_len != name_len)
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goto next_attr;
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if (name_len && memcmp(attr_name(attr), name, name_len * sizeof(short)))
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goto next_attr;
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if (id && *id != attr->id)
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goto next_attr;
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return attr;
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}
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int mi_write(struct mft_inode *mi, int wait)
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{
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struct MFT_REC *rec;
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int err;
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struct ntfs_sb_info *sbi;
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if (!mi->dirty)
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return 0;
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sbi = mi->sbi;
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rec = mi->mrec;
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err = ntfs_write_bh(sbi, &rec->rhdr, &mi->nb, wait);
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if (err)
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return err;
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if (mi->rno < sbi->mft.recs_mirr)
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sbi->flags |= NTFS_FLAGS_MFTMIRR;
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mi->dirty = false;
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return 0;
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}
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int mi_format_new(struct mft_inode *mi, struct ntfs_sb_info *sbi, CLST rno,
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__le16 flags, bool is_mft)
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{
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int err;
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u16 seq = 1;
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struct MFT_REC *rec;
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u64 vbo = (u64)rno << sbi->record_bits;
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err = mi_init(mi, sbi, rno);
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if (err)
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return err;
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rec = mi->mrec;
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if (rno == MFT_REC_MFT) {
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;
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} else if (rno < MFT_REC_FREE) {
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seq = rno;
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} else if (rno >= sbi->mft.used) {
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;
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} else if (mi_read(mi, is_mft)) {
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;
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} else if (rec->rhdr.sign == NTFS_FILE_SIGNATURE) {
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/* Record is reused. Update its sequence number. */
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seq = le16_to_cpu(rec->seq) + 1;
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if (!seq)
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seq = 1;
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}
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memcpy(rec, sbi->new_rec, sbi->record_size);
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rec->seq = cpu_to_le16(seq);
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rec->flags = RECORD_FLAG_IN_USE | flags;
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mi->dirty = true;
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if (!mi->nb.nbufs) {
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struct ntfs_inode *ni = sbi->mft.ni;
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bool lock = false;
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if (is_mounted(sbi) && !is_mft) {
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down_read(&ni->file.run_lock);
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lock = true;
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}
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err = ntfs_get_bh(sbi, &ni->file.run, vbo, sbi->record_size,
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&mi->nb);
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if (lock)
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up_read(&ni->file.run_lock);
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}
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return err;
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}
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/*
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* mi_insert_attr - Reserve space for new attribute.
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*
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* Return: Not full constructed attribute or NULL if not possible to create.
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*/
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struct ATTRIB *mi_insert_attr(struct mft_inode *mi, enum ATTR_TYPE type,
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const __le16 *name, u8 name_len, u32 asize,
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u16 name_off)
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{
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size_t tail;
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struct ATTRIB *attr;
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__le16 id;
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struct MFT_REC *rec = mi->mrec;
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struct ntfs_sb_info *sbi = mi->sbi;
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u32 used = le32_to_cpu(rec->used);
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const u16 *upcase = sbi->upcase;
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/* Can we insert mi attribute? */
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if (used + asize > sbi->record_size)
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return NULL;
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/*
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* Scan through the list of attributes to find the point
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* at which we should insert it.
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*/
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attr = NULL;
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while ((attr = mi_enum_attr(mi, attr))) {
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int diff = compare_attr(attr, type, name, name_len, upcase);
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if (diff < 0)
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continue;
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if (!diff && !is_attr_indexed(attr))
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return NULL;
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break;
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}
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if (!attr) {
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/* Append. */
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tail = 8;
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attr = Add2Ptr(rec, used - 8);
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} else {
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/* Insert before 'attr'. */
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tail = used - PtrOffset(rec, attr);
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}
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id = mi_new_attt_id(mi);
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memmove(Add2Ptr(attr, asize), attr, tail);
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memset(attr, 0, asize);
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attr->type = type;
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attr->size = cpu_to_le32(asize);
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attr->name_len = name_len;
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attr->name_off = cpu_to_le16(name_off);
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attr->id = id;
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memmove(Add2Ptr(attr, name_off), name, name_len * sizeof(short));
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rec->used = cpu_to_le32(used + asize);
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mi->dirty = true;
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return attr;
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}
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/*
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* mi_remove_attr - Remove the attribute from record.
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*
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* NOTE: The source attr will point to next attribute.
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*/
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bool mi_remove_attr(struct ntfs_inode *ni, struct mft_inode *mi,
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struct ATTRIB *attr)
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{
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struct MFT_REC *rec = mi->mrec;
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u32 aoff = PtrOffset(rec, attr);
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u32 used = le32_to_cpu(rec->used);
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u32 asize = le32_to_cpu(attr->size);
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if (aoff + asize > used)
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return false;
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if (ni && is_attr_indexed(attr)) {
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le16_add_cpu(&ni->mi.mrec->hard_links, -1);
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ni->mi.dirty = true;
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}
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used -= asize;
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memmove(attr, Add2Ptr(attr, asize), used - aoff);
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rec->used = cpu_to_le32(used);
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mi->dirty = true;
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return true;
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}
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/* bytes = "new attribute size" - "old attribute size" */
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bool mi_resize_attr(struct mft_inode *mi, struct ATTRIB *attr, int bytes)
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{
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struct MFT_REC *rec = mi->mrec;
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u32 aoff = PtrOffset(rec, attr);
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u32 total, used = le32_to_cpu(rec->used);
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u32 nsize, asize = le32_to_cpu(attr->size);
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u32 rsize = le32_to_cpu(attr->res.data_size);
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int tail = (int)(used - aoff - asize);
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int dsize;
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char *next;
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if (tail < 0 || aoff >= used)
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return false;
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if (!bytes)
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return true;
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total = le32_to_cpu(rec->total);
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next = Add2Ptr(attr, asize);
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if (bytes > 0) {
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dsize = ALIGN(bytes, 8);
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if (used + dsize > total)
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return false;
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nsize = asize + dsize;
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/* Move tail */
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memmove(next + dsize, next, tail);
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memset(next, 0, dsize);
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used += dsize;
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rsize += dsize;
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} else {
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dsize = ALIGN(-bytes, 8);
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if (dsize > asize)
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return false;
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nsize = asize - dsize;
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memmove(next - dsize, next, tail);
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used -= dsize;
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rsize -= dsize;
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}
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rec->used = cpu_to_le32(used);
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attr->size = cpu_to_le32(nsize);
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if (!attr->non_res)
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attr->res.data_size = cpu_to_le32(rsize);
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mi->dirty = true;
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return true;
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}
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/*
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* Pack runs in MFT record.
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* If failed record is not changed.
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|
*/
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|
int mi_pack_runs(struct mft_inode *mi, struct ATTRIB *attr,
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struct runs_tree *run, CLST len)
|
|
{
|
|
int err = 0;
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|
struct ntfs_sb_info *sbi = mi->sbi;
|
|
u32 new_run_size;
|
|
CLST plen;
|
|
struct MFT_REC *rec = mi->mrec;
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|
CLST svcn = le64_to_cpu(attr->nres.svcn);
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|
u32 used = le32_to_cpu(rec->used);
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|
u32 aoff = PtrOffset(rec, attr);
|
|
u32 asize = le32_to_cpu(attr->size);
|
|
char *next = Add2Ptr(attr, asize);
|
|
u16 run_off = le16_to_cpu(attr->nres.run_off);
|
|
u32 run_size = asize - run_off;
|
|
u32 tail = used - aoff - asize;
|
|
u32 dsize = sbi->record_size - used;
|
|
|
|
/* Make a maximum gap in current record. */
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|
memmove(next + dsize, next, tail);
|
|
|
|
/* Pack as much as possible. */
|
|
err = run_pack(run, svcn, len, Add2Ptr(attr, run_off), run_size + dsize,
|
|
&plen);
|
|
if (err < 0) {
|
|
memmove(next, next + dsize, tail);
|
|
return err;
|
|
}
|
|
|
|
new_run_size = ALIGN(err, 8);
|
|
|
|
memmove(next + new_run_size - run_size, next + dsize, tail);
|
|
|
|
attr->size = cpu_to_le32(asize + new_run_size - run_size);
|
|
attr->nres.evcn = cpu_to_le64(svcn + plen - 1);
|
|
rec->used = cpu_to_le32(used + new_run_size - run_size);
|
|
mi->dirty = true;
|
|
|
|
return 0;
|
|
}
|