diff options
Diffstat (limited to 'fs/ntfs3/record.c')
| -rw-r--r-- | fs/ntfs3/record.c | 605 |
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; +} |