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-rw-r--r--fs/ntfs3/record.c605
1 files changed, 605 insertions, 0 deletions
diff --git a/fs/ntfs3/record.c b/fs/ntfs3/record.c
new file mode 100644
index 000000000000..103705c86772
--- /dev/null
+++ b/fs/ntfs3/record.c
@@ -0,0 +1,605 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *
+ * Copyright (C) 2019-2021 Paragon Software GmbH, All rights reserved.
+ *
+ */
+
+#include <linux/blkdev.h>
+#include <linux/buffer_head.h>
+#include <linux/fs.h>
+#include <linux/nls.h>
+
+#include "debug.h"
+#include "ntfs.h"
+#include "ntfs_fs.h"
+
+static inline int compare_attr(const struct ATTRIB *left, enum ATTR_TYPE type,
+ const __le16 *name, u8 name_len,
+ const u16 *upcase)
+{
+ /* First, compare the type codes. */
+ int diff = le32_to_cpu(left->type) - le32_to_cpu(type);
+
+ if (diff)
+ return diff;
+
+ /* They have the same type code, so we have to compare the names. */
+ return ntfs_cmp_names(attr_name(left), left->name_len, name, name_len,
+ upcase, true);
+}
+
+/*
+ * mi_new_attt_id
+ *
+ * Return: Unused attribute id that is less than mrec->next_attr_id.
+ */
+static __le16 mi_new_attt_id(struct mft_inode *mi)
+{
+ u16 free_id, max_id, t16;
+ struct MFT_REC *rec = mi->mrec;
+ struct ATTRIB *attr;
+ __le16 id;
+
+ id = rec->next_attr_id;
+ free_id = le16_to_cpu(id);
+ if (free_id < 0x7FFF) {
+ rec->next_attr_id = cpu_to_le16(free_id + 1);
+ return id;
+ }
+
+ /* One record can store up to 1024/24 ~= 42 attributes. */
+ free_id = 0;
+ max_id = 0;
+
+ attr = NULL;
+
+ for (;;) {
+ attr = mi_enum_attr(mi, attr);
+ if (!attr) {
+ rec->next_attr_id = cpu_to_le16(max_id + 1);
+ mi->dirty = true;
+ return cpu_to_le16(free_id);
+ }
+
+ t16 = le16_to_cpu(attr->id);
+ if (t16 == free_id) {
+ free_id += 1;
+ attr = NULL;
+ } else if (max_id < t16)
+ max_id = t16;
+ }
+}
+
+int mi_get(struct ntfs_sb_info *sbi, CLST rno, struct mft_inode **mi)
+{
+ int err;
+ struct mft_inode *m = kzalloc(sizeof(struct mft_inode), GFP_NOFS);
+
+ if (!m)
+ return -ENOMEM;
+
+ err = mi_init(m, sbi, rno);
+ if (err) {
+ kfree(m);
+ return err;
+ }
+
+ err = mi_read(m, false);
+ if (err) {
+ mi_put(m);
+ return err;
+ }
+
+ *mi = m;
+ return 0;
+}
+
+void mi_put(struct mft_inode *mi)
+{
+ mi_clear(mi);
+ kfree(mi);
+}
+
+int mi_init(struct mft_inode *mi, struct ntfs_sb_info *sbi, CLST rno)
+{
+ mi->sbi = sbi;
+ mi->rno = rno;
+ mi->mrec = kmalloc(sbi->record_size, GFP_NOFS);
+ if (!mi->mrec)
+ return -ENOMEM;
+
+ return 0;
+}
+
+/*
+ * mi_read - Read MFT data.
+ */
+int mi_read(struct mft_inode *mi, bool is_mft)
+{
+ int err;
+ struct MFT_REC *rec = mi->mrec;
+ struct ntfs_sb_info *sbi = mi->sbi;
+ u32 bpr = sbi->record_size;
+ u64 vbo = (u64)mi->rno << sbi->record_bits;
+ struct ntfs_inode *mft_ni = sbi->mft.ni;
+ struct runs_tree *run = mft_ni ? &mft_ni->file.run : NULL;
+ struct rw_semaphore *rw_lock = NULL;
+
+ if (is_mounted(sbi)) {
+ if (!is_mft) {
+ rw_lock = &mft_ni->file.run_lock;
+ down_read(rw_lock);
+ }
+ }
+
+ err = ntfs_read_bh(sbi, run, vbo, &rec->rhdr, bpr, &mi->nb);
+ if (rw_lock)
+ up_read(rw_lock);
+ if (!err)
+ goto ok;
+
+ if (err == -E_NTFS_FIXUP) {
+ mi->dirty = true;
+ goto ok;
+ }
+
+ if (err != -ENOENT)
+ goto out;
+
+ if (rw_lock) {
+ ni_lock(mft_ni);
+ down_write(rw_lock);
+ }
+ err = attr_load_runs_vcn(mft_ni, ATTR_DATA, NULL, 0, &mft_ni->file.run,
+ vbo >> sbi->cluster_bits);
+ if (rw_lock) {
+ up_write(rw_lock);
+ ni_unlock(mft_ni);
+ }
+ if (err)
+ goto out;
+
+ if (rw_lock)
+ down_read(rw_lock);
+ err = ntfs_read_bh(sbi, run, vbo, &rec->rhdr, bpr, &mi->nb);
+ if (rw_lock)
+ up_read(rw_lock);
+
+ if (err == -E_NTFS_FIXUP) {
+ mi->dirty = true;
+ goto ok;
+ }
+ if (err)
+ goto out;
+
+ok:
+ /* Check field 'total' only here. */
+ if (le32_to_cpu(rec->total) != bpr) {
+ err = -EINVAL;
+ goto out;
+ }
+
+ return 0;
+
+out:
+ return err;
+}
+
+struct ATTRIB *mi_enum_attr(struct mft_inode *mi, struct ATTRIB *attr)
+{
+ const struct MFT_REC *rec = mi->mrec;
+ u32 used = le32_to_cpu(rec->used);
+ u32 t32, off, asize;
+ u16 t16;
+
+ if (!attr) {
+ u32 total = le32_to_cpu(rec->total);
+
+ off = le16_to_cpu(rec->attr_off);
+
+ if (used > total)
+ return NULL;
+
+ if (off >= used || off < MFTRECORD_FIXUP_OFFSET_1 ||
+ !IS_ALIGNED(off, 4)) {
+ return NULL;
+ }
+
+ /* Skip non-resident records. */
+ if (!is_rec_inuse(rec))
+ return NULL;
+
+ attr = Add2Ptr(rec, off);
+ } else {
+ /* Check if input attr inside record. */
+ off = PtrOffset(rec, attr);
+ if (off >= used)
+ return NULL;
+
+ asize = le32_to_cpu(attr->size);
+ if (asize < SIZEOF_RESIDENT) {
+ /* Impossible 'cause we should not return such attribute. */
+ return NULL;
+ }
+
+ attr = Add2Ptr(attr, asize);
+ off += asize;
+ }
+
+ asize = le32_to_cpu(attr->size);
+
+ /* Can we use the first field (attr->type). */
+ if (off + 8 > used) {
+ static_assert(ALIGN(sizeof(enum ATTR_TYPE), 8) == 8);
+ return NULL;
+ }
+
+ if (attr->type == ATTR_END) {
+ /* End of enumeration. */
+ return NULL;
+ }
+
+ /* 0x100 is last known attribute for now. */
+ t32 = le32_to_cpu(attr->type);
+ if ((t32 & 0xf) || (t32 > 0x100))
+ return NULL;
+
+ /* Check boundary. */
+ if (off + asize > used)
+ return NULL;
+
+ /* Check size of attribute. */
+ if (!attr->non_res) {
+ if (asize < SIZEOF_RESIDENT)
+ return NULL;
+
+ t16 = le16_to_cpu(attr->res.data_off);
+
+ if (t16 > asize)
+ return NULL;
+
+ t32 = le32_to_cpu(attr->res.data_size);
+ if (t16 + t32 > asize)
+ return NULL;
+
+ return attr;
+ }
+
+ /* Check some nonresident fields. */
+ if (attr->name_len &&
+ le16_to_cpu(attr->name_off) + sizeof(short) * attr->name_len >
+ le16_to_cpu(attr->nres.run_off)) {
+ return NULL;
+ }
+
+ if (attr->nres.svcn || !is_attr_ext(attr)) {
+ if (asize + 8 < SIZEOF_NONRESIDENT)
+ return NULL;
+
+ if (attr->nres.c_unit)
+ return NULL;
+ } else if (asize + 8 < SIZEOF_NONRESIDENT_EX)
+ return NULL;
+
+ return attr;
+}
+
+/*
+ * mi_find_attr - Find the attribute by type and name and id.
+ */
+struct ATTRIB *mi_find_attr(struct mft_inode *mi, struct ATTRIB *attr,
+ enum ATTR_TYPE type, const __le16 *name,
+ size_t name_len, const __le16 *id)
+{
+ u32 type_in = le32_to_cpu(type);
+ u32 atype;
+
+next_attr:
+ attr = mi_enum_attr(mi, attr);
+ if (!attr)
+ return NULL;
+
+ atype = le32_to_cpu(attr->type);
+ if (atype > type_in)
+ return NULL;
+
+ if (atype < type_in)
+ goto next_attr;
+
+ if (attr->name_len != name_len)
+ goto next_attr;
+
+ if (name_len && memcmp(attr_name(attr), name, name_len * sizeof(short)))
+ goto next_attr;
+
+ if (id && *id != attr->id)
+ goto next_attr;
+
+ return attr;
+}
+
+int mi_write(struct mft_inode *mi, int wait)
+{
+ struct MFT_REC *rec;
+ int err;
+ struct ntfs_sb_info *sbi;
+
+ if (!mi->dirty)
+ return 0;
+
+ sbi = mi->sbi;
+ rec = mi->mrec;
+
+ err = ntfs_write_bh(sbi, &rec->rhdr, &mi->nb, wait);
+ if (err)
+ return err;
+
+ if (mi->rno < sbi->mft.recs_mirr)
+ sbi->flags |= NTFS_FLAGS_MFTMIRR;
+
+ mi->dirty = false;
+
+ return 0;
+}
+
+int mi_format_new(struct mft_inode *mi, struct ntfs_sb_info *sbi, CLST rno,
+ __le16 flags, bool is_mft)
+{
+ int err;
+ u16 seq = 1;
+ struct MFT_REC *rec;
+ u64 vbo = (u64)rno << sbi->record_bits;
+
+ err = mi_init(mi, sbi, rno);
+ if (err)
+ return err;
+
+ rec = mi->mrec;
+
+ if (rno == MFT_REC_MFT) {
+ ;
+ } else if (rno < MFT_REC_FREE) {
+ seq = rno;
+ } else if (rno >= sbi->mft.used) {
+ ;
+ } else if (mi_read(mi, is_mft)) {
+ ;
+ } else if (rec->rhdr.sign == NTFS_FILE_SIGNATURE) {
+ /* Record is reused. Update its sequence number. */
+ seq = le16_to_cpu(rec->seq) + 1;
+ if (!seq)
+ seq = 1;
+ }
+
+ memcpy(rec, sbi->new_rec, sbi->record_size);
+
+ rec->seq = cpu_to_le16(seq);
+ rec->flags = RECORD_FLAG_IN_USE | flags;
+
+ mi->dirty = true;
+
+ if (!mi->nb.nbufs) {
+ struct ntfs_inode *ni = sbi->mft.ni;
+ bool lock = false;
+
+ if (is_mounted(sbi) && !is_mft) {
+ down_read(&ni->file.run_lock);
+ lock = true;
+ }
+
+ err = ntfs_get_bh(sbi, &ni->file.run, vbo, sbi->record_size,
+ &mi->nb);
+ if (lock)
+ up_read(&ni->file.run_lock);
+ }
+
+ return err;
+}
+
+/*
+ * mi_mark_free - Mark record as unused and marks it as free in bitmap.
+ */
+void mi_mark_free(struct mft_inode *mi)
+{
+ CLST rno = mi->rno;
+ struct ntfs_sb_info *sbi = mi->sbi;
+
+ if (rno >= MFT_REC_RESERVED && rno < MFT_REC_FREE) {
+ ntfs_clear_mft_tail(sbi, rno, rno + 1);
+ mi->dirty = false;
+ return;
+ }
+
+ if (mi->mrec) {
+ clear_rec_inuse(mi->mrec);
+ mi->dirty = true;
+ mi_write(mi, 0);
+ }
+ ntfs_mark_rec_free(sbi, rno);
+}
+
+/*
+ * mi_insert_attr - Reserve space for new attribute.
+ *
+ * Return: Not full constructed attribute or NULL if not possible to create.
+ */
+struct ATTRIB *mi_insert_attr(struct mft_inode *mi, enum ATTR_TYPE type,
+ const __le16 *name, u8 name_len, u32 asize,
+ u16 name_off)
+{
+ size_t tail;
+ struct ATTRIB *attr;
+ __le16 id;
+ struct MFT_REC *rec = mi->mrec;
+ struct ntfs_sb_info *sbi = mi->sbi;
+ u32 used = le32_to_cpu(rec->used);
+ const u16 *upcase = sbi->upcase;
+ int diff;
+
+ /* Can we insert mi attribute? */
+ if (used + asize > mi->sbi->record_size)
+ return NULL;
+
+ /*
+ * Scan through the list of attributes to find the point
+ * at which we should insert it.
+ */
+ attr = NULL;
+ while ((attr = mi_enum_attr(mi, attr))) {
+ diff = compare_attr(attr, type, name, name_len, upcase);
+ if (diff > 0)
+ break;
+ if (diff < 0)
+ continue;
+
+ if (!is_attr_indexed(attr))
+ return NULL;
+ break;
+ }
+
+ if (!attr) {
+ tail = 8; /* Not used, just to suppress warning. */
+ attr = Add2Ptr(rec, used - 8);
+ } else {
+ tail = used - PtrOffset(rec, attr);
+ }
+
+ id = mi_new_attt_id(mi);
+
+ memmove(Add2Ptr(attr, asize), attr, tail);
+ memset(attr, 0, asize);
+
+ attr->type = type;
+ attr->size = cpu_to_le32(asize);
+ attr->name_len = name_len;
+ attr->name_off = cpu_to_le16(name_off);
+ attr->id = id;
+
+ memmove(Add2Ptr(attr, name_off), name, name_len * sizeof(short));
+ rec->used = cpu_to_le32(used + asize);
+
+ mi->dirty = true;
+
+ return attr;
+}
+
+/*
+ * mi_remove_attr - Remove the attribute from record.
+ *
+ * NOTE: The source attr will point to next attribute.
+ */
+bool mi_remove_attr(struct ntfs_inode *ni, struct mft_inode *mi,
+ struct ATTRIB *attr)
+{
+ struct MFT_REC *rec = mi->mrec;
+ u32 aoff = PtrOffset(rec, attr);
+ u32 used = le32_to_cpu(rec->used);
+ u32 asize = le32_to_cpu(attr->size);
+
+ if (aoff + asize > used)
+ return false;
+
+ if (ni && is_attr_indexed(attr)) {
+ le16_add_cpu(&ni->mi.mrec->hard_links, -1);
+ ni->mi.dirty = true;
+ }
+
+ used -= asize;
+ memmove(attr, Add2Ptr(attr, asize), used - aoff);
+ rec->used = cpu_to_le32(used);
+ mi->dirty = true;
+
+ return true;
+}
+
+/* bytes = "new attribute size" - "old attribute size" */
+bool mi_resize_attr(struct mft_inode *mi, struct ATTRIB *attr, int bytes)
+{
+ struct MFT_REC *rec = mi->mrec;
+ u32 aoff = PtrOffset(rec, attr);
+ u32 total, used = le32_to_cpu(rec->used);
+ u32 nsize, asize = le32_to_cpu(attr->size);
+ u32 rsize = le32_to_cpu(attr->res.data_size);
+ int tail = (int)(used - aoff - asize);
+ int dsize;
+ char *next;
+
+ if (tail < 0 || aoff >= used)
+ return false;
+
+ if (!bytes)
+ return true;
+
+ total = le32_to_cpu(rec->total);
+ next = Add2Ptr(attr, asize);
+
+ if (bytes > 0) {
+ dsize = ALIGN(bytes, 8);
+ if (used + dsize > total)
+ return false;
+ nsize = asize + dsize;
+ /* Move tail */
+ memmove(next + dsize, next, tail);
+ memset(next, 0, dsize);
+ used += dsize;
+ rsize += dsize;
+ } else {
+ dsize = ALIGN(-bytes, 8);
+ if (dsize > asize)
+ return false;
+ nsize = asize - dsize;
+ memmove(next - dsize, next, tail);
+ used -= dsize;
+ rsize -= dsize;
+ }
+
+ rec->used = cpu_to_le32(used);
+ attr->size = cpu_to_le32(nsize);
+ if (!attr->non_res)
+ attr->res.data_size = cpu_to_le32(rsize);
+ mi->dirty = true;
+
+ return true;
+}
+
+int mi_pack_runs(struct mft_inode *mi, struct ATTRIB *attr,
+ struct runs_tree *run, CLST len)
+{
+ int err = 0;
+ struct ntfs_sb_info *sbi = mi->sbi;
+ u32 new_run_size;
+ CLST plen;
+ struct MFT_REC *rec = mi->mrec;
+ CLST svcn = le64_to_cpu(attr->nres.svcn);
+ u32 used = le32_to_cpu(rec->used);
+ 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. */
+ 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;
+}
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.