diff options
Diffstat (limited to 'fs/ntfs/mft.c')
| -rw-r--r-- | fs/ntfs/mft.c | 3111 |
1 files changed, 3111 insertions, 0 deletions
diff --git a/fs/ntfs/mft.c b/fs/ntfs/mft.c new file mode 100644 index 000000000..4b7449495 --- /dev/null +++ b/fs/ntfs/mft.c @@ -0,0 +1,3111 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * NTFS kernel mft record operations. + * Part of this file is based on code from the NTFS-3G. + * + * Copyright (c) 2001-2012 Anton Altaparmakov and Tuxera Inc. + * Copyright (c) 2002 Richard Russon + * Copyright (c) 2025 LG Electronics Co., Ltd. + */ + +#include <linux/writeback.h> +#include <linux/bio.h> +#include <linux/iomap.h> + +#include "bitmap.h" +#include "lcnalloc.h" +#include "mft.h" +#include "ntfs.h" + +/* + * ntfs_mft_record_check - Check the consistency of an MFT record + * + * Make sure its general fields are safe, then examine all its + * attributes and apply generic checks to them. + * + * Returns 0 if the checks are successful. If not, return -EIO. + */ +int ntfs_mft_record_check(const struct ntfs_volume *vol, struct mft_record *m, + u64 mft_no) +{ + struct attr_record *a; + struct super_block *sb = vol->sb; + u16 attrs_offset; + u32 bytes_in_use; + + if (!ntfs_is_file_record(m->magic)) { + ntfs_error(sb, "Record %llu has no FILE magic (0x%x)\n", + mft_no, le32_to_cpu(*(__le32 *)m)); + goto err_out; + } + + if (le16_to_cpu(m->usa_ofs) & 0x1 || + (vol->mft_record_size >> NTFS_BLOCK_SIZE_BITS) + 1 != le16_to_cpu(m->usa_count) || + le16_to_cpu(m->usa_ofs) + le16_to_cpu(m->usa_count) * 2 > vol->mft_record_size) { + ntfs_error(sb, "Record %llu has corrupt fix-up values fields\n", + mft_no); + goto err_out; + } + + if (le32_to_cpu(m->bytes_allocated) != vol->mft_record_size) { + ntfs_error(sb, "Record %llu has corrupt allocation size (%u <> %u)\n", + mft_no, vol->mft_record_size, + le32_to_cpu(m->bytes_allocated)); + goto err_out; + } + + if (le32_to_cpu(m->bytes_in_use) > vol->mft_record_size) { + ntfs_error(sb, "Record %llu has corrupt in-use size (%u > %u)\n", + mft_no, le32_to_cpu(m->bytes_in_use), + vol->mft_record_size); + goto err_out; + } + + if (le16_to_cpu(m->attrs_offset) & 7) { + ntfs_error(sb, "Attributes badly aligned in record %llu\n", + mft_no); + goto err_out; + } + + attrs_offset = le16_to_cpu(m->attrs_offset); + bytes_in_use = le32_to_cpu(m->bytes_in_use); + + if (attrs_offset > bytes_in_use || + bytes_in_use - attrs_offset < sizeof_field(struct attr_record, type)) { + ntfs_error(sb, "Record %llu has corrupt attribute offset\n", mft_no); + goto err_out; + } + + a = (struct attr_record *)((char *)m + attrs_offset); + if ((char *)a < (char *)m || (char *)a > (char *)m + vol->mft_record_size) { + ntfs_error(sb, "Record %llu is corrupt\n", mft_no); + goto err_out; + } + + return 0; + +err_out: + return -EIO; +} + +/* + * map_mft_record_folio - map the folio in which a specific mft record resides + * @ni: ntfs inode whose mft record page to map + * + * This maps the folio in which the mft record of the ntfs inode @ni is + * situated. + * + * This allocates a new buffer (@ni->mrec), copies the MFT record data from + * the mapped folio into this buffer, and applies the MST (Multi Sector + * Transfer) fixups on the copy. + * + * The folio is pinned (referenced) in @ni->folio to ensure the data remains + * valid in the page cache, but the returned pointer is the allocated copy. + * + * Return: A pointer to the allocated and fixed-up mft record (@ni->mrec). + * The return value needs to be checked with IS_ERR(). If it is true, + * PTR_ERR() contains the negative error code. + */ +static inline struct mft_record *map_mft_record_folio(struct ntfs_inode *ni) +{ + loff_t i_size; + struct ntfs_volume *vol = ni->vol; + struct inode *mft_vi = vol->mft_ino; + struct folio *folio; + unsigned long index, end_index; + unsigned int ofs; + + WARN_ON(ni->folio); + /* + * The index into the page cache and the offset within the page cache + * page of the wanted mft record. + */ + index = NTFS_MFT_NR_TO_PIDX(vol, ni->mft_no); + ofs = NTFS_MFT_NR_TO_POFS(vol, ni->mft_no); + + i_size = i_size_read(mft_vi); + /* The maximum valid index into the page cache for $MFT's data. */ + end_index = i_size >> PAGE_SHIFT; + + /* If the wanted index is out of bounds the mft record doesn't exist. */ + if (unlikely(index >= end_index)) { + if (index > end_index || (i_size & ~PAGE_MASK) < ofs + + vol->mft_record_size) { + folio = ERR_PTR(-ENOENT); + ntfs_error(vol->sb, + "Attempt to read mft record 0x%llx, which is beyond the end of the mft. This is probably a bug in the ntfs driver.", + ni->mft_no); + goto err_out; + } + } + + /* Read, map, and pin the folio. */ + folio = read_mapping_folio(mft_vi->i_mapping, index, NULL); + if (!IS_ERR(folio)) { + u8 *addr; + + ni->mrec = kmalloc(vol->mft_record_size, GFP_NOFS); + if (!ni->mrec) { + folio_put(folio); + folio = ERR_PTR(-ENOMEM); + goto err_out; + } + + addr = kmap_local_folio(folio, 0); + memcpy(ni->mrec, addr + ofs, vol->mft_record_size); + post_read_mst_fixup((struct ntfs_record *)ni->mrec, vol->mft_record_size); + + /* Catch multi sector transfer fixup errors. */ + if (!ntfs_mft_record_check(vol, (struct mft_record *)ni->mrec, ni->mft_no)) { + kunmap_local(addr); + ni->folio = folio; + ni->folio_ofs = ofs; + return ni->mrec; + } + kunmap_local(addr); + folio_put(folio); + kfree(ni->mrec); + ni->mrec = NULL; + folio = ERR_PTR(-EIO); + NVolSetErrors(vol); + } +err_out: + ni->folio = NULL; + ni->folio_ofs = 0; + return (struct mft_record *)folio; +} + +/* + * map_mft_record - map and pin an mft record + * @ni: ntfs inode whose MFT record to map + * + * This function ensures the MFT record for the given inode is mapped and + * accessible. + * + * It increments the reference count of the ntfs inode. If the record is + * already mapped (@ni->folio is set), it returns the cached record + * immediately. + * + * Otherwise, it calls map_mft_record_folio() to read the folio from disk + * (if necessary via read_mapping_folio), allocate a buffer, and copy the + * record data. + * + * Return: A pointer to the mft record. You need to check the returned + * pointer with IS_ERR(). + */ +struct mft_record *map_mft_record(struct ntfs_inode *ni) +{ + struct mft_record *m; + + if (!ni) + return ERR_PTR(-EINVAL); + + ntfs_debug("Entering for mft_no 0x%llx.", ni->mft_no); + + /* Make sure the ntfs inode doesn't go away. */ + atomic_inc(&ni->count); + + if (ni->folio) + return (struct mft_record *)ni->mrec; + + m = map_mft_record_folio(ni); + if (!IS_ERR(m)) + return m; + + atomic_dec(&ni->count); + if (PTR_ERR(m) != -EINTR && PTR_ERR(m) != -ERESTARTSYS) + ntfs_error(ni->vol->sb, "Failed with error code %lu.", -PTR_ERR(m)); + return m; +} + +/* + * unmap_mft_record - release a reference to a mapped mft record + * @ni: ntfs inode whose MFT record to unmap + * + * This decrements the reference count of the ntfs inode. + * + * It releases the caller's hold on the inode. If the reference count indicates + * that there are still other users (count > 1), the function returns + * immediately, keeping the resources (folio and mrec buffer) pinned for + * those users. + * + * NOTE: If caller has modified the mft record, it is imperative to set the mft + * record dirty BEFORE calling unmap_mft_record(). + */ +void unmap_mft_record(struct ntfs_inode *ni) +{ + struct folio *folio; + + if (!ni) + return; + + ntfs_debug("Entering for mft_no 0x%llx.", ni->mft_no); + + folio = ni->folio; + if (atomic_dec_return(&ni->count) > 1) + return; + WARN_ON(!folio); +} + +/* + * map_extent_mft_record - load an extent inode and attach it to its base + * @base_ni: base ntfs inode + * @mref: mft reference of the extent inode to load + * @ntfs_ino: on successful return, pointer to the struct ntfs_inode structure + * + * Load the extent mft record @mref and attach it to its base inode @base_ni. + * Return the mapped extent mft record if IS_ERR(result) is false. Otherwise + * PTR_ERR(result) gives the negative error code. + * + * On successful return, @ntfs_ino contains a pointer to the ntfs_inode + * structure of the mapped extent inode. + */ +struct mft_record *map_extent_mft_record(struct ntfs_inode *base_ni, u64 mref, + struct ntfs_inode **ntfs_ino) +{ + struct mft_record *m; + struct ntfs_inode *ni = NULL; + struct ntfs_inode **extent_nis = NULL; + int i; + u64 mft_no = MREF(mref); + u16 seq_no = MSEQNO(mref); + bool destroy_ni = false; + + ntfs_debug("Mapping extent mft record 0x%llx (base mft record 0x%llx).", + mft_no, base_ni->mft_no); + /* Make sure the base ntfs inode doesn't go away. */ + atomic_inc(&base_ni->count); + /* + * Check if this extent inode has already been added to the base inode, + * in which case just return it. If not found, add it to the base + * inode before returning it. + */ +retry: + mutex_lock(&base_ni->extent_lock); + if (base_ni->nr_extents > 0) { + extent_nis = base_ni->ext.extent_ntfs_inos; + for (i = 0; i < base_ni->nr_extents; i++) { + if (mft_no != extent_nis[i]->mft_no) + continue; + ni = extent_nis[i]; + /* Make sure the ntfs inode doesn't go away. */ + atomic_inc(&ni->count); + break; + } + } + if (likely(ni != NULL)) { + mutex_unlock(&base_ni->extent_lock); + atomic_dec(&base_ni->count); + /* We found the record; just have to map and return it. */ + m = map_mft_record(ni); + /* map_mft_record() has incremented this on success. */ + atomic_dec(&ni->count); + if (!IS_ERR(m)) { + /* Verify the sequence number. */ + if (likely(le16_to_cpu(m->sequence_number) == seq_no)) { + ntfs_debug("Done 1."); + *ntfs_ino = ni; + return m; + } + unmap_mft_record(ni); + ntfs_error(base_ni->vol->sb, + "Found stale extent mft reference! Corrupt filesystem. Run chkdsk."); + return ERR_PTR(-EIO); + } +map_err_out: + ntfs_error(base_ni->vol->sb, + "Failed to map extent mft record, error code %ld.", + -PTR_ERR(m)); + return m; + } + mutex_unlock(&base_ni->extent_lock); + + /* Record wasn't there. Get a new ntfs inode and initialize it. */ + ni = ntfs_new_extent_inode(base_ni->vol->sb, mft_no); + if (unlikely(!ni)) { + atomic_dec(&base_ni->count); + return ERR_PTR(-ENOMEM); + } + ni->vol = base_ni->vol; + ni->seq_no = seq_no; + ni->nr_extents = -1; + ni->ext.base_ntfs_ino = base_ni; + /* Now map the record. */ + m = map_mft_record(ni); + if (IS_ERR(m)) { + atomic_dec(&base_ni->count); + ntfs_clear_extent_inode(ni); + goto map_err_out; + } + /* Verify the sequence number if it is present. */ + if (seq_no && (le16_to_cpu(m->sequence_number) != seq_no)) { + ntfs_error(base_ni->vol->sb, + "Found stale extent mft reference! Corrupt filesystem. Run chkdsk."); + destroy_ni = true; + m = ERR_PTR(-EIO); + goto unm_nolock_err_out; + } + + mutex_lock(&base_ni->extent_lock); + for (i = 0; i < base_ni->nr_extents; i++) { + if (mft_no == extent_nis[i]->mft_no) { + mutex_unlock(&base_ni->extent_lock); + ntfs_clear_extent_inode(ni); + goto retry; + } + } + /* Attach extent inode to base inode, reallocating memory if needed. */ + if (!(base_ni->nr_extents & 3)) { + struct ntfs_inode **tmp; + int new_size = (base_ni->nr_extents + 4) * sizeof(struct ntfs_inode *); + + tmp = kvzalloc(new_size, GFP_NOFS); + if (unlikely(!tmp)) { + ntfs_error(base_ni->vol->sb, "Failed to allocate internal buffer."); + destroy_ni = true; + m = ERR_PTR(-ENOMEM); + goto unm_err_out; + } + if (base_ni->nr_extents) { + WARN_ON(!base_ni->ext.extent_ntfs_inos); + memcpy(tmp, base_ni->ext.extent_ntfs_inos, new_size - + 4 * sizeof(struct ntfs_inode *)); + kvfree(base_ni->ext.extent_ntfs_inos); + } + base_ni->ext.extent_ntfs_inos = tmp; + } + base_ni->ext.extent_ntfs_inos[base_ni->nr_extents++] = ni; + mutex_unlock(&base_ni->extent_lock); + atomic_dec(&base_ni->count); + ntfs_debug("Done 2."); + *ntfs_ino = ni; + return m; +unm_err_out: + mutex_unlock(&base_ni->extent_lock); +unm_nolock_err_out: + unmap_mft_record(ni); + atomic_dec(&base_ni->count); + /* + * If the extent inode was not attached to the base inode we need to + * release it or we will leak memory. + */ + if (destroy_ni) + ntfs_clear_extent_inode(ni); + return m; +} + +/* + * __mark_mft_record_dirty - mark the base vfs inode dirty + * @ni: ntfs inode describing the mapped mft record + * + * Internal function. Users should call mark_mft_record_dirty() instead. + * + * This function determines the base ntfs inode (in case @ni is an extent + * inode) and marks the corresponding VFS inode dirty. + * + * NOTE: We only set I_DIRTY_DATASYNC (and not I_DIRTY_PAGES) + * on the base vfs inode, because even though file data may have been modified, + * it is dirty in the inode meta data rather than the data page cache of the + * inode, and thus there are no data pages that need writing out. Therefore, a + * full mark_inode_dirty() is overkill. A mark_inode_dirty_sync(), on the + * other hand, is not sufficient, because ->write_inode needs to be called even + * in case of fdatasync. This needs to happen or the file data would not + * necessarily hit the device synchronously, even though the vfs inode has the + * O_SYNC flag set. Also, I_DIRTY_DATASYNC simply "feels" better than just + * I_DIRTY_SYNC, since the file data has not actually hit the block device yet, + * which is not what I_DIRTY_SYNC on its own would suggest. + */ +void __mark_mft_record_dirty(struct ntfs_inode *ni) +{ + struct ntfs_inode *base_ni; + + ntfs_debug("Entering for inode 0x%llx.", ni->mft_no); + WARN_ON(NInoAttr(ni)); + /* Determine the base vfs inode and mark it dirty, too. */ + if (likely(ni->nr_extents >= 0)) + base_ni = ni; + else + base_ni = ni->ext.base_ntfs_ino; + __mark_inode_dirty(VFS_I(base_ni), I_DIRTY_DATASYNC); +} + +/* + * ntfs_bio_end_io - bio completion callback for MFT record writes + * + * Decrements the folio reference count that was incremented before + * submit_bio(). This prevents a race condition where umount could + * evict the inode and release the folio while I/O is still in flight, + * potentially causing data corruption or use-after-free. + */ +static void ntfs_bio_end_io(struct bio *bio) +{ + if (bio->bi_private) + folio_put((struct folio *)bio->bi_private); + bio_put(bio); +} + +/* + * ntfs_sync_mft_mirror - synchronize an mft record to the mft mirror + * @vol: ntfs volume on which the mft record to synchronize resides + * @mft_no: mft record number of mft record to synchronize + * @m: mapped, mst protected (extent) mft record to synchronize + * + * Write the mapped, mst protected (extent) mft record @m with mft record + * number @mft_no to the mft mirror ($MFTMirr) of the ntfs volume @vol. + * + * On success return 0. On error return -errno and set the volume errors flag + * in the ntfs volume @vol. + * + * NOTE: We always perform synchronous i/o. + */ +int ntfs_sync_mft_mirror(struct ntfs_volume *vol, const u64 mft_no, + struct mft_record *m) +{ + u8 *kmirr; + struct folio *folio; + unsigned int folio_ofs; + int err = 0; + struct bio *bio; + + ntfs_debug("Entering for inode 0x%llx.", mft_no); + + if (unlikely(!vol->mftmirr_ino)) { + /* This could happen during umount... */ + err = -EIO; + goto err_out; + } + /* Get the page containing the mirror copy of the mft record @m. */ + folio = read_mapping_folio(vol->mftmirr_ino->i_mapping, + NTFS_MFT_NR_TO_PIDX(vol, mft_no), NULL); + if (IS_ERR(folio)) { + ntfs_error(vol->sb, "Failed to map mft mirror page."); + err = PTR_ERR(folio); + goto err_out; + } + + folio_lock(folio); + folio_clear_uptodate(folio); + /* Offset of the mft mirror record inside the page. */ + folio_ofs = NTFS_MFT_NR_TO_POFS(vol, mft_no); + /* The address in the page of the mirror copy of the mft record @m. */ + kmirr = kmap_local_folio(folio, 0) + folio_ofs; + /* Copy the mst protected mft record to the mirror. */ + memcpy(kmirr, m, vol->mft_record_size); + kunmap_local(kmirr); + + bio = bio_alloc(vol->sb->s_bdev, 1, REQ_OP_WRITE, GFP_NOIO); + bio->bi_iter.bi_sector = + ntfs_bytes_to_bio_sector(NTFS_CLU_TO_B(vol, vol->mftmirr_lcn) + + ((u64)folio->index << PAGE_SHIFT) + + folio_ofs); + + if (bio_add_folio(bio, folio, vol->mft_record_size, folio_ofs)) + err = submit_bio_wait(bio); + else + err = -EIO; + bio_put(bio); + + /* + * The in-memory mirror is now valid because we just memcpy()'d the + * mst-protected mft record into it. Mark the folio uptodate even on + * write error so a subsequent read_mapping_folio() does not refetch + * the stale on-disk mirror and overwrite this copy. The error is + * propagated to the caller via @err. + */ + folio_mark_uptodate(folio); + + folio_unlock(folio); + folio_put(folio); + if (likely(!err)) { + ntfs_debug("Done."); + } else { + ntfs_error(vol->sb, "I/O error while writing mft mirror record 0x%llx!", mft_no); +err_out: + ntfs_error(vol->sb, + "Failed to synchronize $MFTMirr (error code %i). Volume will be left marked dirty on umount. Run chkdsk on the partition after umounting to correct this.", + err); + NVolSetErrors(vol); + } + return err; +} + +/* + * write_mft_record_nolock - write out a mapped (extent) mft record + * @ni: ntfs inode describing the mapped (extent) mft record + * @m: mapped (extent) mft record to write + * @sync: if true, wait for i/o completion + * + * Write the mapped (extent) mft record @m described by the (regular or extent) + * ntfs inode @ni to backing store. If the mft record @m has a counterpart in + * the mft mirror, that is also updated. + * + * We only write the mft record if the ntfs inode @ni is dirty. + * + * On success, clean the mft record and return 0. + * On error (specifically ENOMEM), we redirty the record so it can be retried. + * For other errors, we mark the volume with errors. + */ +int write_mft_record_nolock(struct ntfs_inode *ni, struct mft_record *m, int sync) +{ + struct ntfs_volume *vol = ni->vol; + struct folio *folio = ni->folio; + int err = 0, i = 0; + u8 *kaddr; + struct mft_record *fixup_m; + struct bio *bio; + unsigned int offset = 0, folio_size; + + ntfs_debug("Entering for inode 0x%llx.", ni->mft_no); + + WARN_ON(NInoAttr(ni)); + WARN_ON(!folio_test_locked(folio)); + + /* + * If the struct ntfs_inode is clean no need to do anything. If it is dirty, + * mark it as clean now so that it can be redirtied later on if needed. + * There is no danger of races since the caller is holding the locks + * for the mft record @m and the page it is in. + */ + if (!NInoTestClearDirty(ni)) + goto done; + + kaddr = kmap_local_folio(folio, 0); + fixup_m = (struct mft_record *)(kaddr + ni->folio_ofs); + memcpy(fixup_m, m, vol->mft_record_size); + + /* Apply the mst protection fixups. */ + err = pre_write_mst_fixup((struct ntfs_record *)fixup_m, vol->mft_record_size); + if (err) { + ntfs_error(vol->sb, "Failed to apply mst fixups!"); + goto unmap_err_out; + } + + folio_size = vol->mft_record_size / ni->mft_lcn_count; + while (i < ni->mft_lcn_count) { + unsigned int clu_off; + + clu_off = (unsigned int)((s64)ni->mft_no * vol->mft_record_size + offset) & + vol->cluster_size_mask; + + bio = bio_alloc(vol->sb->s_bdev, 1, REQ_OP_WRITE, GFP_NOIO); + bio->bi_iter.bi_sector = + ntfs_bytes_to_bio_sector(NTFS_CLU_TO_B(vol, ni->mft_lcn[i]) + + clu_off); + + if (!bio_add_folio(bio, folio, folio_size, + ni->folio_ofs + offset)) { + err = -EIO; + goto put_bio_out; + } + + /* Synchronize the mft mirror now if not @sync. */ + if (!sync && ni->mft_no < vol->mftmirr_size) { + int sub_err = ntfs_sync_mft_mirror(vol, ni->mft_no, + fixup_m); + if (unlikely(sub_err) && !err) + err = sub_err; + } + + if (sync) { + int sub_err = submit_bio_wait(bio); + + bio_put(bio); + if (unlikely(sub_err) && !err) + err = sub_err; + } else { + folio_get(folio); + bio->bi_private = folio; + bio->bi_end_io = ntfs_bio_end_io; + submit_bio(bio); + } + offset += vol->cluster_size; + i++; + } + + /* If @sync, now synchronize the mft mirror. */ + if (sync && ni->mft_no < vol->mftmirr_size) { + int sub_err = ntfs_sync_mft_mirror(vol, ni->mft_no, fixup_m); + + if (unlikely(sub_err) && !err) + err = sub_err; + } + kunmap_local(kaddr); + if (unlikely(err)) { + /* I/O error during writing. This is really bad! */ + ntfs_error(vol->sb, + "I/O error while writing mft record 0x%llx! Marking base inode as bad. You should unmount the volume and run chkdsk.", + ni->mft_no); + goto err_out; + } +done: + ntfs_debug("Done."); + return 0; +put_bio_out: + bio_put(bio); +unmap_err_out: + kunmap_local(kaddr); +err_out: + /* + * The caller should mark the base inode as bad so no more I/O + * happens. ->drop_inode() will still be invoked so all extent inodes + * and other allocated memory will be freed. ENOMEM is retried by + * redirtying the mft record below. + */ + if (err == -ENOMEM) { + ntfs_error(vol->sb, + "Not enough memory to write mft record. Redirtying so the write is retried later."); + mark_mft_record_dirty(ni); + err = 0; + } else + NVolSetErrors(vol); + return err; +} + +static int ntfs_test_inode_wb(struct inode *vi, u64 ino, void *data) +{ + struct ntfs_attr *na = data; + + if (!ntfs_test_inode(vi, na)) + return 0; + + /* + * Without this, ntfs_write_mst_block() could call iput_final() + * , and ntfs_evict_big_inode() could try to unlink this inode + * and the contex could be blocked infinitly in map_mft_record(). + */ + if (NInoBeingDeleted(NTFS_I(vi))) { + na->state = NI_BeingDeleted; + return -1; + } + + /* + * This condition can prevent ntfs_write_mst_block() + * from applying/undo fixups while ntfs_create() being + * called + */ + spin_lock(&vi->i_lock); + if (inode_state_read_once(vi) & I_CREATING) { + spin_unlock(&vi->i_lock); + na->state = NI_BeingCreated; + return -1; + } + spin_unlock(&vi->i_lock); + + return igrab(vi) ? 1 : -1; +} + +/* + * ntfs_may_write_mft_record - check if an mft record may be written out + * @vol: [IN] ntfs volume on which the mft record to check resides + * @mft_no: [IN] mft record number of the mft record to check + * @m: [IN] mapped mft record to check + * @locked_ni: [OUT] caller has to unlock this ntfs inode if one is returned + * @ref_vi: [OUT] caller has to drop this vfs inode if one is returned + * + * Check if the mapped (base or extent) mft record @m with mft record number + * @mft_no belonging to the ntfs volume @vol may be written out. If necessary + * and possible the ntfs inode of the mft record is locked and the base vfs + * inode is pinned. The locked ntfs inode is then returned in @locked_ni. The + * caller is responsible for unlocking the ntfs inode and unpinning the base + * vfs inode. + * + * To avoid deadlock when the caller holds a folio lock, if the function + * returns @ref_vi it defers dropping the vfs inode reference by returning + * it in @ref_vi instead of calling iput() directly. The caller must call + * iput() on @ref_vi after releasing the folio lock. + * + * Return 'true' if the mft record may be written out and 'false' if not. + * + * The caller has locked the page and cleared the uptodate flag on it which + * means that we can safely write out any dirty mft records that do not have + * their inodes in icache as determined by find_inode_nowait(). + * + * Here is a description of the tests we perform: + * + * If the inode is found in icache we know the mft record must be a base mft + * record. If it is dirty, we do not write it and return 'false' as the vfs + * inode write paths will result in the access times being updated which would + * cause the base mft record to be redirtied and written out again. + * + * If the inode is in icache and not dirty, we attempt to lock the mft record + * and if we find the lock was already taken, it is not safe to write the mft + * record and we return 'false'. + * + * If we manage to obtain the lock we have exclusive access to the mft record, + * which also allows us safe writeout of the mft record. We then set + * @locked_ni to the locked ntfs inode and return 'true'. + * + * Note we cannot just lock the mft record and sleep while waiting for the lock + * because this would deadlock due to lock reversal. + * + * If the inode is not in icache we need to perform further checks. + * + * If the mft record is not a FILE record or it is a base mft record, we can + * safely write it and return 'true'. + */ +static bool ntfs_may_write_mft_record(struct ntfs_volume *vol, const u64 mft_no, + const struct mft_record *m, struct ntfs_inode **locked_ni, + struct inode **ref_vi) +{ + struct super_block *sb = vol->sb; + struct inode *mft_vi = vol->mft_ino; + struct inode *vi; + struct ntfs_inode *ni; + struct ntfs_attr na = {0}; + + ntfs_debug("Entering for inode 0x%llx.", mft_no); + /* + * Normally we do not return a locked inode so set @locked_ni to NULL. + */ + *locked_ni = NULL; + *ref_vi = NULL; + + /* + * Check if the inode corresponding to this mft record is in the VFS + * inode cache and obtain a reference to it if it is. + */ + ntfs_debug("Looking for inode 0x%llx in icache.", mft_no); + na.mft_no = mft_no; + na.type = AT_UNUSED; + /* + * Optimize inode 0, i.e. $MFT itself, since we have it in memory and + * we get here for it rather often. + */ + if (!mft_no) { + /* Balance the below iput(). */ + vi = igrab(mft_vi); + WARN_ON(vi != mft_vi); + } else { + /* + * Have to use find_inode_nowait() since ilookup5_nowait() + * waits for inode with I_FREEING, which causes ntfs to deadlock + * when inodes are unlinked concurrently + */ + vi = find_inode_nowait(sb, mft_no, ntfs_test_inode_wb, &na); + if (na.state == NI_BeingDeleted || na.state == NI_BeingCreated) + return false; + } + if (vi) { + ntfs_debug("Base inode 0x%llx is in icache.", mft_no); + /* The inode is in icache. */ + ni = NTFS_I(vi); + /* Take a reference to the ntfs inode. */ + atomic_inc(&ni->count); + /* If the inode is dirty, do not write this record. */ + if (NInoDirty(ni)) { + ntfs_debug("Inode 0x%llx is dirty, do not write it.", + mft_no); + atomic_dec(&ni->count); + *ref_vi = vi; + return false; + } + ntfs_debug("Inode 0x%llx is not dirty.", mft_no); + /* The inode is not dirty, try to take the mft record lock. */ + if (unlikely(!mutex_trylock(&ni->mrec_lock))) { + ntfs_debug("Mft record 0x%llx is already locked, do not write it.", mft_no); + atomic_dec(&ni->count); + *ref_vi = vi; + return false; + } + ntfs_debug("Managed to lock mft record 0x%llx, write it.", + mft_no); + /* + * The write has to occur while we hold the mft record lock so + * return the locked ntfs inode. + */ + *locked_ni = ni; + return true; + } + ntfs_debug("Inode 0x%llx is not in icache.", mft_no); + /* The inode is not in icache. */ + /* Write the record if it is not a mft record (type "FILE"). */ + if (!ntfs_is_mft_record(m->magic)) { + ntfs_debug("Mft record 0x%llx is not a FILE record, write it.", + mft_no); + return true; + } + /* Write the mft record if it is a base inode. */ + if (!m->base_mft_record) { + ntfs_debug("Mft record 0x%llx is a base record, write it.", + mft_no); + return true; + } + + ntfs_debug("Mft record 0x%llx is an extent record, skip it.", + mft_no); + return false; +} + +static const char *es = " Leaving inconsistent metadata. Unmount and run chkdsk."; + +#define FIRST_NORMAL_MFT_RECORD 24 +#define MFT_RECORD_RESERVE 4 + +/* + * Records 12-15 are marked in use by Windows but normally have no name + * and no links. Keep them as the last bootstrap option when a volume + * mounted without an in-memory tail reserve needs its first $MFT metadata + * extent. + */ +static bool mft_reserved_is_free(struct ntfs_volume *vol, + struct ntfs_inode *mft_ni, s64 mft_no) +{ + struct attr_record *a; + struct mft_record *m; + struct folio *folio; + void *mapped; + pgoff_t index = NTFS_MFT_NR_TO_PIDX(vol, mft_no); + unsigned int ofs = NTFS_MFT_NR_TO_POFS(vol, mft_no); + u32 attrs_offset, bytes_in_use; + bool available = false, have_std = false; + int i; + + for (i = 0; i < mft_ni->nr_extents; i++) { + if (mft_ni->ext.extent_ntfs_inos[i] && + mft_ni->ext.extent_ntfs_inos[i]->mft_no == mft_no) + return false; + } + m = kmalloc(vol->mft_record_size, GFP_NOFS); + if (!m) + return false; + + folio = read_mapping_folio(vol->mft_ino->i_mapping, index, NULL); + if (IS_ERR(folio)) + goto free_m; + + folio_lock(folio); + mapped = kmap_local_folio(folio, 0); + memcpy(m, (u8 *)mapped + ofs, vol->mft_record_size); + kunmap_local(mapped); + folio_unlock(folio); + folio_put(folio); + if (post_read_mst_fixup((struct ntfs_record *)m, vol->mft_record_size)) + goto free_m; + + if (!ntfs_is_mft_record(m->magic) || + !(m->flags & MFT_RECORD_IN_USE) || m->base_mft_record || + m->link_count) + goto out; + + attrs_offset = le16_to_cpu(m->attrs_offset); + bytes_in_use = le32_to_cpu(m->bytes_in_use); + if (attrs_offset > bytes_in_use || bytes_in_use > vol->mft_record_size || + bytes_in_use - attrs_offset < sizeof(a->type)) + goto out; + + for (a = (struct attr_record *)((u8 *)m + attrs_offset); + (u8 *)a + sizeof(a->type) <= (u8 *)m + bytes_in_use;) { + u32 len; + + if (a->type == AT_END) { + if ((u8 *)a + sizeof(a->type) + sizeof(a->length) > + (u8 *)m + bytes_in_use) + break; + /* Also accept a record emptied by an earlier bootstrap. */ + available = have_std || + (u8 *)a == (u8 *)m + attrs_offset; + break; + } + if (a->type == AT_FILE_NAME) + break; + len = le32_to_cpu(a->length); + if (len < offsetof(struct attr_record, data) || + (u8 *)a + len > (u8 *)m + bytes_in_use) + break; + if (a->type == AT_STANDARD_INFORMATION) { + u32 value_len, value_ofs; + + if (have_std || a->non_resident || + len < offsetof(struct attr_record, + data.resident.reserved) + 1) + break; + value_len = le32_to_cpu(a->data.resident.value_length); + value_ofs = le16_to_cpu(a->data.resident.value_offset); + if (value_ofs > len || value_len > len - value_ofs) + break; + have_std = true; + } + a = (struct attr_record *)((u8 *)a + len); + } +out: + kfree(m); + return available; +free_m: + kfree(m); + return false; +} + +static s64 mft_reserve_end(const u8 *buf, s64 buf_start, s64 buf_end, + s64 start, s64 pass_end, s64 initialized_mft_records) +{ + s64 end = start + 1; + s64 limit = min_t(s64, start + MFT_RECORD_RESERVE, pass_end); + + if (limit > initialized_mft_records) + limit = initialized_mft_records; + if (limit > buf_end) + limit = buf_end; + while (end < limit && + !(buf[(end - buf_start) >> 3] & + (1 << ((end - buf_start) & 7)))) + end++; + return end; +} + +/* + * mft_bitmap_alloc_free_rec - find and allocate a free MFT record + * @vol: volume on which to search for a free mft record + * @base_ni: open base inode if allocating an extent mft record or NULL + * @max_mft_no: first record which must not be allocated, or -1 + * @new_reserve_end: if not NULL, end of a free run starting after the result + * + * Search for a free mft record in the mft bitmap attribute on the ntfs volume + * @vol. + * + * If @base_ni is NULL start the search at the default allocator position. + * + * If @base_ni is not NULL start the search at the mft record after the base + * mft record @base_ni. + * + * Return the free mft record on success and -errno on error. An error code of + * -ENOSPC means that there are no free mft records in the currently + * initialized mft bitmap. + * + * Locking: Caller must hold vol->mftbmp_lock for writing. + */ +static s64 mft_bitmap_alloc_free_rec(struct ntfs_volume *vol, + struct ntfs_inode *base_ni, + s64 max_mft_no, s64 *new_reserve_end) +{ + s64 pass_end, ll, data_pos, pass_start, ofs, bit; + s64 initialized_mft_records; + unsigned long flags; + struct address_space *mftbmp_mapping; + u8 *buf = NULL, *byte; + struct folio *folio; + unsigned int folio_ofs, size; + u8 pass, b; + + ntfs_debug("Searching for free mft record in the currently initialized mft bitmap."); + mftbmp_mapping = vol->mftbmp_ino->i_mapping; + /* + * Set the end of the pass making sure we do not overflow the mft + * bitmap. + */ + read_lock_irqsave(&NTFS_I(vol->mft_ino)->size_lock, flags); + pass_end = NTFS_I(vol->mft_ino)->allocated_size >> + vol->mft_record_size_bits; + initialized_mft_records = NTFS_I(vol->mft_ino)->initialized_size >> + vol->mft_record_size_bits; + read_unlock_irqrestore(&NTFS_I(vol->mft_ino)->size_lock, flags); + read_lock_irqsave(&NTFS_I(vol->mftbmp_ino)->size_lock, flags); + ll = NTFS_I(vol->mftbmp_ino)->initialized_size << 3; + read_unlock_irqrestore(&NTFS_I(vol->mftbmp_ino)->size_lock, flags); + if (pass_end > ll) + pass_end = ll; + if (max_mft_no >= 0 && pass_end > max_mft_no) + pass_end = max_mft_no; + if (base_ni && base_ni->mft_no == FILE_MFT) { + data_pos = FILE_first_user; + pass = 2; + if (data_pos >= pass_end) + return -ENOSPC; + } else { + pass = 1; + if (!base_ni) + data_pos = vol->mft_data_pos; + else + data_pos = base_ni->mft_no + 1; + if (data_pos < FIRST_NORMAL_MFT_RECORD) + data_pos = FIRST_NORMAL_MFT_RECORD; + if (data_pos >= pass_end) { + data_pos = FIRST_NORMAL_MFT_RECORD; + pass = 2; + /* This happens on a freshly formatted volume. */ + if (data_pos >= pass_end) + return -ENOSPC; + } + } + + pass_start = data_pos; + ntfs_debug("Starting bitmap search: pass %u, pass_start 0x%llx, pass_end 0x%llx, data_pos 0x%llx.", + pass, pass_start, pass_end, data_pos); + /* Loop until a free mft record is found. */ + for (; pass <= 2;) { + /* Cap size to pass_end. */ + ofs = data_pos >> 3; + folio_ofs = ofs & ~PAGE_MASK; + size = PAGE_SIZE - folio_ofs; + ll = ((pass_end + 7) >> 3) - ofs; + if (size > ll) + size = ll; + size <<= 3; + /* + * If we are still within the active pass, search the next page + * for a zero bit. + */ + if (size) { + folio = read_mapping_folio(mftbmp_mapping, + ofs >> PAGE_SHIFT, NULL); + if (IS_ERR(folio)) { + ntfs_error(vol->sb, "Failed to read mft bitmap, aborting."); + return PTR_ERR(folio); + } + folio_lock(folio); + buf = (u8 *)kmap_local_folio(folio, 0) + folio_ofs; + bit = data_pos & 7; + data_pos &= ~7ull; + ntfs_debug("Before inner for loop: size 0x%x, data_pos 0x%llx, bit 0x%llx", + size, data_pos, bit); + for (; bit < size && data_pos + bit < pass_end; + bit &= ~7ull, bit += 8) { + byte = buf + (bit >> 3); + if (*byte == 0xff) + continue; + b = bit & 7; + for (; b < 8; b++) { + if (*byte & (1 << b)) + continue; + ll = data_pos + (bit & ~7ull) + b; + if (ll >= pass_end) + break; + /* Keep the dynamic tail reserve for $MFT metadata. */ + if ((!base_ni || base_ni->mft_no != FILE_MFT) && + ll >= vol->mft_record_reserve_pos && + ll < vol->mft_record_reserve_end) + continue; + if (unlikely(ll >= (1ll << 32))) { + folio_unlock(folio); + kunmap_local(buf); + folio_put(folio); + return -ENOSPC; + } + goto found; + } + } + ntfs_debug("After inner for loop: size 0x%x, data_pos 0x%llx, bit 0x%llx", + size, data_pos, bit); + data_pos += size; + folio_unlock(folio); + kunmap_local(buf); + folio_put(folio); + /* + * If the end of the pass has not been reached yet, + * continue searching the mft bitmap for a zero bit. + */ + if (data_pos < pass_end) + continue; + } + /* Do the next pass. */ + if (++pass == 2) { + /* + * Starting the second pass, in which we scan the first + * part of the zone which we omitted earlier. + */ + pass_end = pass_start; + data_pos = FIRST_NORMAL_MFT_RECORD; + pass_start = FIRST_NORMAL_MFT_RECORD; + ntfs_debug("pass %i, pass_start 0x%llx, pass_end 0x%llx.", + pass, pass_start, pass_end); + if (data_pos >= pass_end) + break; + } + } + /* No free mft records in currently initialized mft bitmap. */ + ntfs_debug("Done. (No free mft records left in currently initialized mft bitmap.)"); + return -ENOSPC; +found: + if (new_reserve_end) + *new_reserve_end = mft_reserve_end(buf, data_pos, + data_pos + size, ll, pass_end, + initialized_mft_records); + *byte |= 1 << b; + folio_mark_dirty(folio); + folio_unlock(folio); + kunmap_local(buf); + folio_put(folio); + ntfs_debug("Done. (Found and allocated mft record 0x%llx.)", ll); + return ll; +} + +static int ntfs_mft_attr_extend(struct ntfs_inode *ni, + struct ntfs_inode *locked_ni) +{ + int ret = 0; + struct ntfs_inode *base_ni; + + if (NInoAttr(ni)) + base_ni = ni->ext.base_ntfs_ino; + else + base_ni = ni; + + if (!NInoAttrList(base_ni)) { + ret = ntfs_inode_add_attrlist(base_ni); + if (ret) { + pr_err("Can not add attrlist\n"); + goto out; + } else { + ret = -EAGAIN; + goto out; + } + } + + ret = ntfs_attr_update_mapping_pairs_locked(ni, 0, locked_ni); + if (ret) + pr_err("MP update failed\n"); + +out: + return ret; +} + +/* + * ntfs_mft_bitmap_extend_allocation_nolock - extend mft bitmap by a cluster + * @vol: volume on which to extend the mft bitmap attribute + * + * Extend the mft bitmap attribute on the ntfs volume @vol by one cluster. + * + * Note: Only changes allocated_size, i.e. does not touch initialized_size or + * data_size. + * + * Return 0 on success and -errno on error. + * + * Locking: - Caller must hold vol->mftbmp_lock for writing. + * - This function takes NTFS_I(vol->mftbmp_ino)->runlist.lock for + * writing and releases it before returning. + * - This function takes vol->lcnbmp_lock for writing and releases it + * before returning. + */ +static int ntfs_mft_bitmap_extend_allocation_nolock(struct ntfs_volume *vol) +{ + s64 lcn; + s64 ll; + unsigned long flags; + struct folio *folio; + struct ntfs_inode *mft_ni, *mftbmp_ni; + struct runlist_element *rl, *rl2 = NULL; + struct ntfs_attr_search_ctx *ctx = NULL; + struct mft_record *mrec; + struct attr_record *a = NULL; + int ret, mp_size; + u32 old_alen = 0; + u8 *b, tb; + struct { + u8 added_cluster:1; + u8 added_run:1; + u8 mp_rebuilt:1; + u8 mp_extended:1; + } status = { 0, 0, 0, 0 }; + size_t new_rl_count; + + ntfs_debug("Extending mft bitmap allocation."); + mft_ni = NTFS_I(vol->mft_ino); + mftbmp_ni = NTFS_I(vol->mftbmp_ino); + /* + * Determine the last lcn of the mft bitmap. The allocated size of the + * mft bitmap cannot be zero so we are ok to do this. + */ + down_write(&mftbmp_ni->runlist.lock); + read_lock_irqsave(&mftbmp_ni->size_lock, flags); + ll = mftbmp_ni->allocated_size; + read_unlock_irqrestore(&mftbmp_ni->size_lock, flags); + rl = ntfs_attr_find_vcn_nolock(mftbmp_ni, + NTFS_B_TO_CLU(vol, ll - 1), NULL); + if (IS_ERR(rl) || unlikely(!rl->length || rl->lcn < 0)) { + up_write(&mftbmp_ni->runlist.lock); + ntfs_error(vol->sb, + "Failed to determine last allocated cluster of mft bitmap attribute."); + if (!IS_ERR(rl)) + ret = -EIO; + else + ret = PTR_ERR(rl); + return ret; + } + lcn = rl->lcn + rl->length; + ntfs_debug("Last lcn of mft bitmap attribute is 0x%llx.", + (long long)lcn); + /* + * Attempt to get the cluster following the last allocated cluster by + * hand as it may be in the MFT zone so the allocator would not give it + * to us. + */ + ll = lcn >> 3; + folio = read_mapping_folio(vol->lcnbmp_ino->i_mapping, + ll >> PAGE_SHIFT, NULL); + if (IS_ERR(folio)) { + up_write(&mftbmp_ni->runlist.lock); + ntfs_error(vol->sb, "Failed to read from lcn bitmap."); + return PTR_ERR(folio); + } + + down_write(&vol->lcnbmp_lock); + folio_lock(folio); + b = (u8 *)kmap_local_folio(folio, 0) + (ll & ~PAGE_MASK); + tb = 1 << (lcn & 7ull); + if (*b != 0xff && !(*b & tb)) { + /* Next cluster is free, allocate it. */ + *b |= tb; + folio_mark_dirty(folio); + folio_unlock(folio); + kunmap_local(b); + folio_put(folio); + up_write(&vol->lcnbmp_lock); + /* Update the mft bitmap runlist. */ + rl->length++; + rl[1].vcn++; + status.added_cluster = 1; + ntfs_debug("Appending one cluster to mft bitmap."); + } else { + folio_unlock(folio); + kunmap_local(b); + folio_put(folio); + up_write(&vol->lcnbmp_lock); + /* Allocate a cluster from the DATA_ZONE. */ + rl2 = ntfs_cluster_alloc(vol, rl[1].vcn, 1, lcn, DATA_ZONE, + true, false, false); + if (IS_ERR(rl2)) { + up_write(&mftbmp_ni->runlist.lock); + ntfs_error(vol->sb, + "Failed to allocate a cluster for the mft bitmap."); + return PTR_ERR(rl2); + } + rl = ntfs_runlists_merge(&mftbmp_ni->runlist, rl2, 0, &new_rl_count); + if (IS_ERR(rl)) { + up_write(&mftbmp_ni->runlist.lock); + ntfs_error(vol->sb, "Failed to merge runlists for mft bitmap."); + if (ntfs_cluster_free_from_rl(vol, rl2)) { + ntfs_error(vol->sb, "Failed to deallocate allocated cluster.%s", + es); + NVolSetErrors(vol); + } + kvfree(rl2); + return PTR_ERR(rl); + } + mftbmp_ni->runlist.rl = rl; + mftbmp_ni->runlist.count = new_rl_count; + status.added_run = 1; + ntfs_debug("Adding one run to mft bitmap."); + /* Find the last run in the new runlist. */ + for (; rl[1].length; rl++) + ; + } + /* + * Update the attribute record as well. Note: @rl is the last + * (non-terminator) runlist element of mft bitmap. + */ + mrec = map_mft_record(mft_ni); + if (IS_ERR(mrec)) { + ntfs_error(vol->sb, "Failed to map mft record."); + ret = PTR_ERR(mrec); + goto undo_alloc; + } + ctx = ntfs_attr_get_search_ctx(mft_ni, mrec); + if (unlikely(!ctx)) { + ntfs_error(vol->sb, "Failed to get search context."); + ret = -ENOMEM; + goto undo_alloc; + } + ret = ntfs_attr_lookup(mftbmp_ni->type, mftbmp_ni->name, + mftbmp_ni->name_len, CASE_SENSITIVE, rl[1].vcn, NULL, + 0, ctx); + if (unlikely(ret)) { + ntfs_error(vol->sb, + "Failed to find last attribute extent of mft bitmap attribute."); + if (ret == -ENOENT) + ret = -EIO; + goto undo_alloc; + } + a = ctx->attr; + ll = le64_to_cpu(a->data.non_resident.lowest_vcn); + /* Search back for the previous last allocated cluster of mft bitmap. */ + for (rl2 = rl; rl2 > mftbmp_ni->runlist.rl; rl2--) { + if (ll >= rl2->vcn) + break; + } + WARN_ON(ll < rl2->vcn); + WARN_ON(ll >= rl2->vcn + rl2->length); + /* Get the size for the new mapping pairs array for this extent. */ + mp_size = ntfs_get_size_for_mapping_pairs(vol, rl2, ll, -1, -1); + if (unlikely(mp_size <= 0)) { + ntfs_error(vol->sb, + "Get size for mapping pairs failed for mft bitmap attribute extent."); + ret = mp_size; + if (!ret) + ret = -EIO; + goto undo_alloc; + } + /* Expand the attribute record if necessary. */ + old_alen = le32_to_cpu(a->length); + ret = ntfs_attr_record_resize(ctx->mrec, a, mp_size + + le16_to_cpu(a->data.non_resident.mapping_pairs_offset)); + if (unlikely(ret)) { + ret = ntfs_mft_attr_extend(mftbmp_ni, mftbmp_ni); + if (!ret) + goto extended_ok; + if (ret != -EAGAIN) + status.mp_extended = 1; + goto undo_alloc; + } + status.mp_rebuilt = 1; + /* Generate the mapping pairs array directly into the attr record. */ + ret = ntfs_mapping_pairs_build(vol, (u8 *)a + + le16_to_cpu(a->data.non_resident.mapping_pairs_offset), + mp_size, rl2, ll, -1, NULL, NULL, NULL); + if (unlikely(ret)) { + ntfs_error(vol->sb, + "Failed to build mapping pairs array for mft bitmap attribute."); + goto undo_alloc; + } + /* Update the highest_vcn. */ + a->data.non_resident.highest_vcn = cpu_to_le64(rl[1].vcn - 1); + /* + * We now have extended the mft bitmap allocated_size by one cluster. + * Reflect this in the struct ntfs_inode structure and the attribute record. + */ + if (a->data.non_resident.lowest_vcn) { + /* + * We are not in the first attribute extent, switch to it, but + * first ensure the changes will make it to disk later. + */ + mark_mft_record_dirty(ctx->ntfs_ino); +extended_ok: + ntfs_attr_reinit_search_ctx(ctx); + ret = ntfs_attr_lookup(mftbmp_ni->type, mftbmp_ni->name, + mftbmp_ni->name_len, CASE_SENSITIVE, 0, NULL, + 0, ctx); + if (unlikely(ret)) { + ntfs_error(vol->sb, + "Failed to find first attribute extent of mft bitmap attribute."); + goto restore_undo_alloc; + } + a = ctx->attr; + } + + write_lock_irqsave(&mftbmp_ni->size_lock, flags); + mftbmp_ni->allocated_size += vol->cluster_size; + a->data.non_resident.allocated_size = + cpu_to_le64(mftbmp_ni->allocated_size); + write_unlock_irqrestore(&mftbmp_ni->size_lock, flags); + /* Ensure the changes make it to disk. */ + mark_mft_record_dirty(ctx->ntfs_ino); + ntfs_attr_put_search_ctx(ctx); + unmap_mft_record(mft_ni); + up_write(&mftbmp_ni->runlist.lock); + ntfs_debug("Done."); + return 0; + +restore_undo_alloc: + ntfs_attr_reinit_search_ctx(ctx); + if (ntfs_attr_lookup(mftbmp_ni->type, mftbmp_ni->name, + mftbmp_ni->name_len, CASE_SENSITIVE, rl[1].vcn, NULL, + 0, ctx)) { + ntfs_error(vol->sb, + "Failed to find last attribute extent of mft bitmap attribute.%s", es); + write_lock_irqsave(&mftbmp_ni->size_lock, flags); + mftbmp_ni->allocated_size += vol->cluster_size; + write_unlock_irqrestore(&mftbmp_ni->size_lock, flags); + ntfs_attr_put_search_ctx(ctx); + unmap_mft_record(mft_ni); + up_write(&mftbmp_ni->runlist.lock); + /* + * The only thing that is now wrong is ->allocated_size of the + * base attribute extent which chkdsk should be able to fix. + */ + NVolSetErrors(vol); + return ret; + } + a = ctx->attr; + a->data.non_resident.highest_vcn = cpu_to_le64(rl[1].vcn - 2); +undo_alloc: + if (status.added_cluster) { + /* Truncate the last run in the runlist by one cluster. */ + rl->length--; + rl[1].vcn--; + } else if (status.added_run) { + lcn = rl->lcn; + /* Remove the last run from the runlist. */ + rl->lcn = rl[1].lcn; + rl->length = 0; + mftbmp_ni->runlist.count--; + } + /* Deallocate the cluster. */ + down_write(&vol->lcnbmp_lock); + if (ntfs_bitmap_clear_bit(vol->lcnbmp_ino, lcn)) { + ntfs_error(vol->sb, "Failed to free allocated cluster.%s", es); + NVolSetErrors(vol); + } else + ntfs_inc_free_clusters(vol, 1); + up_write(&vol->lcnbmp_lock); + if (status.mp_rebuilt) { + if (ntfs_mapping_pairs_build(vol, (u8 *)a + le16_to_cpu( + a->data.non_resident.mapping_pairs_offset), + old_alen - le16_to_cpu( + a->data.non_resident.mapping_pairs_offset), + rl2, ll, -1, NULL, NULL, NULL)) { + ntfs_error(vol->sb, "Failed to restore mapping pairs array.%s", es); + NVolSetErrors(vol); + } + if (ntfs_attr_record_resize(ctx->mrec, a, old_alen)) { + ntfs_error(vol->sb, "Failed to restore attribute record.%s", es); + NVolSetErrors(vol); + } + mark_mft_record_dirty(ctx->ntfs_ino); + } else if (status.mp_extended && + ntfs_attr_update_mapping_pairs_locked(mftbmp_ni, 0, + mftbmp_ni)) { + ntfs_error(vol->sb, "Failed to restore mapping pairs.%s", es); + NVolSetErrors(vol); + } + if (ctx) + ntfs_attr_put_search_ctx(ctx); + if (!IS_ERR(mrec)) + unmap_mft_record(mft_ni); + up_write(&mftbmp_ni->runlist.lock); + return ret; +} + +/* + * ntfs_mft_bitmap_extend_initialized_nolock - extend mftbmp initialized data + * @vol: volume on which to extend the mft bitmap attribute + * + * Extend the initialized portion of the mft bitmap attribute on the ntfs + * volume @vol by 8 bytes. + * + * Note: Only changes initialized_size and data_size, i.e. requires that + * allocated_size is big enough to fit the new initialized_size. + * + * Return 0 on success and -error on error. + * + * Locking: Caller must hold vol->mftbmp_lock for writing. + */ +static int ntfs_mft_bitmap_extend_initialized_nolock(struct ntfs_volume *vol) +{ + s64 old_data_size, old_initialized_size; + unsigned long flags; + struct inode *mftbmp_vi; + struct ntfs_inode *mft_ni, *mftbmp_ni; + struct ntfs_attr_search_ctx *ctx; + struct mft_record *mrec; + struct attr_record *a; + int ret; + + ntfs_debug("Extending mft bitmap initialized (and data) size."); + mft_ni = NTFS_I(vol->mft_ino); + mftbmp_vi = vol->mftbmp_ino; + mftbmp_ni = NTFS_I(mftbmp_vi); + /* Get the attribute record. */ + mrec = map_mft_record(mft_ni); + if (IS_ERR(mrec)) { + ntfs_error(vol->sb, "Failed to map mft record."); + return PTR_ERR(mrec); + } + ctx = ntfs_attr_get_search_ctx(mft_ni, mrec); + if (unlikely(!ctx)) { + ntfs_error(vol->sb, "Failed to get search context."); + ret = -ENOMEM; + goto unm_err_out; + } + ret = ntfs_attr_lookup(mftbmp_ni->type, mftbmp_ni->name, + mftbmp_ni->name_len, CASE_SENSITIVE, 0, NULL, 0, ctx); + if (unlikely(ret)) { + ntfs_error(vol->sb, + "Failed to find first attribute extent of mft bitmap attribute."); + if (ret == -ENOENT) + ret = -EIO; + goto put_err_out; + } + a = ctx->attr; + write_lock_irqsave(&mftbmp_ni->size_lock, flags); + old_data_size = i_size_read(mftbmp_vi); + old_initialized_size = mftbmp_ni->initialized_size; + /* + * We can simply update the initialized_size before filling the space + * with zeroes because the caller is holding the mft bitmap lock for + * writing which ensures that no one else is trying to access the data. + */ + mftbmp_ni->initialized_size += 8; + a->data.non_resident.initialized_size = + cpu_to_le64(mftbmp_ni->initialized_size); + if (mftbmp_ni->initialized_size > old_data_size) { + i_size_write(mftbmp_vi, mftbmp_ni->initialized_size); + a->data.non_resident.data_size = + cpu_to_le64(mftbmp_ni->initialized_size); + } + write_unlock_irqrestore(&mftbmp_ni->size_lock, flags); + /* Ensure the changes make it to disk. */ + mark_mft_record_dirty(ctx->ntfs_ino); + ntfs_attr_put_search_ctx(ctx); + unmap_mft_record(mft_ni); + /* Initialize the mft bitmap attribute value with zeroes. */ + ret = ntfs_attr_set(mftbmp_ni, old_initialized_size, 8, 0); + if (likely(!ret)) { + ntfs_debug("Done. (Wrote eight initialized bytes to mft bitmap."); + return 0; + } + ntfs_error(vol->sb, "Failed to write to mft bitmap."); + /* Try to recover from the error. */ + mrec = map_mft_record(mft_ni); + if (IS_ERR(mrec)) { + ntfs_error(vol->sb, "Failed to map mft record.%s", es); + NVolSetErrors(vol); + return ret; + } + ctx = ntfs_attr_get_search_ctx(mft_ni, mrec); + if (unlikely(!ctx)) { + ntfs_error(vol->sb, "Failed to get search context.%s", es); + NVolSetErrors(vol); + goto unm_err_out; + } + if (ntfs_attr_lookup(mftbmp_ni->type, mftbmp_ni->name, + mftbmp_ni->name_len, CASE_SENSITIVE, 0, NULL, 0, ctx)) { + ntfs_error(vol->sb, + "Failed to find first attribute extent of mft bitmap attribute.%s", es); + NVolSetErrors(vol); +put_err_out: + ntfs_attr_put_search_ctx(ctx); +unm_err_out: + unmap_mft_record(mft_ni); + goto err_out; + } + a = ctx->attr; + write_lock_irqsave(&mftbmp_ni->size_lock, flags); + mftbmp_ni->initialized_size = old_initialized_size; + a->data.non_resident.initialized_size = + cpu_to_le64(old_initialized_size); + if (i_size_read(mftbmp_vi) != old_data_size) { + i_size_write(mftbmp_vi, old_data_size); + a->data.non_resident.data_size = cpu_to_le64(old_data_size); + } + write_unlock_irqrestore(&mftbmp_ni->size_lock, flags); + mark_mft_record_dirty(ctx->ntfs_ino); + ntfs_attr_put_search_ctx(ctx); + unmap_mft_record(mft_ni); +#ifdef DEBUG + read_lock_irqsave(&mftbmp_ni->size_lock, flags); + ntfs_debug("Restored status of mftbmp: allocated_size 0x%llx, data_size 0x%llx, initialized_size 0x%llx.", + mftbmp_ni->allocated_size, i_size_read(mftbmp_vi), + mftbmp_ni->initialized_size); + read_unlock_irqrestore(&mftbmp_ni->size_lock, flags); +#endif /* DEBUG */ +err_out: + return ret; +} + +/* + * ntfs_mft_data_extend_allocation_nolock - extend mft data attribute + * @vol: volume on which to extend the mft data attribute + * + * Extend the mft data attribute on the ntfs volume @vol by 16 mft records + * worth of clusters or if not enough space for this by two mft records worth + * of clusters. Keeping at least two new records breaks the recursion between + * extending $MFT and allocating a record for a new $MFT attribute extent. + * + * Note: Only changes allocated_size, i.e. does not touch initialized_size or + * data_size. + * + * Return 0 on success and -errno on error. + * + * Locking: - Caller must hold vol->mftbmp_lock for writing. + * - This function takes NTFS_I(vol->mft_ino)->runlist.lock for + * writing and releases it before returning. + * - This function calls functions which take vol->lcnbmp_lock for + * writing and release it before returning. + */ +static int ntfs_mft_data_extend_allocation_nolock(struct ntfs_volume *vol) +{ + s64 lcn; + s64 old_last_vcn; + s64 min_nr, nr, ll; + unsigned long flags; + struct ntfs_inode *mft_ni; + struct runlist_element *rl, *rl2; + struct ntfs_attr_search_ctx *ctx = NULL; + struct mft_record *mrec; + struct attr_record *a = NULL; + int ret, mp_size; + u32 old_alen = 0; + bool mp_rebuilt = false, mp_extended = false; + size_t new_rl_count; + + ntfs_debug("Extending mft data allocation."); + mft_ni = NTFS_I(vol->mft_ino); + /* + * Determine the preferred allocation location, i.e. the last lcn of + * the mft data attribute. The allocated size of the mft data + * attribute cannot be zero so we are ok to do this. + */ + down_write(&mft_ni->runlist.lock); + read_lock_irqsave(&mft_ni->size_lock, flags); + ll = mft_ni->allocated_size; + read_unlock_irqrestore(&mft_ni->size_lock, flags); + rl = ntfs_attr_find_vcn_nolock(mft_ni, + NTFS_B_TO_CLU(vol, ll - 1), NULL); + if (IS_ERR(rl) || unlikely(!rl->length || rl->lcn < 0)) { + up_write(&mft_ni->runlist.lock); + ntfs_error(vol->sb, + "Failed to determine last allocated cluster of mft data attribute."); + if (!IS_ERR(rl)) + ret = -EIO; + else + ret = PTR_ERR(rl); + return ret; + } + lcn = rl->lcn + rl->length; + ntfs_debug("Last lcn of mft data attribute is 0x%llx.", lcn); + /* Keep room for the allocating record and at least one MFT reserve. */ + min_nr = DIV_ROUND_UP_ULL((u64)vol->mft_record_size * 2, vol->cluster_size); + /* Want to allocate 16 mft records worth of clusters. */ + nr = vol->mft_record_size << 4 >> vol->cluster_size_bits; + if (!nr) + nr = min_nr; + /* Ensure we do not go above 2^32-1 mft records. */ + read_lock_irqsave(&mft_ni->size_lock, flags); + ll = mft_ni->allocated_size; + read_unlock_irqrestore(&mft_ni->size_lock, flags); + if (unlikely((ll + NTFS_CLU_TO_B(vol, nr)) >> + vol->mft_record_size_bits >= (1ll << 32))) { + nr = min_nr; + if (unlikely((ll + NTFS_CLU_TO_B(vol, nr)) >> + vol->mft_record_size_bits >= (1ll << 32))) { + ntfs_warning(vol->sb, + "Cannot allocate mft record because the maximum number of inodes (2^32) has already been reached."); + up_write(&mft_ni->runlist.lock); + return -ENOSPC; + } + } + ntfs_debug("Trying mft data allocation with %s cluster count %lli.", + nr > min_nr ? "default" : "minimal", (long long)nr); + old_last_vcn = rl[1].vcn; + /* + * We can release the mft_ni runlist lock, Because this function is + * the only one that expends $MFT data attribute and is called with + * mft_ni->mrec_lock. + * This is required for the lock order, vol->lcnbmp_lock => + * mft_ni->runlist.lock. + */ + up_write(&mft_ni->runlist.lock); + + do { + rl2 = ntfs_cluster_alloc(vol, old_last_vcn, nr, lcn, MFT_ZONE, + true, false, false); + if (!IS_ERR(rl2)) + break; + if (PTR_ERR(rl2) != -ENOSPC || nr == min_nr) { + ntfs_error(vol->sb, + "Failed to allocate the minimal number of clusters (%lli) for the mft data attribute.", + nr); + return PTR_ERR(rl2); + } + /* + * There is not enough space to do the allocation, but there + * might be enough space to do a minimal allocation so try that + * before failing. + */ + nr = min_nr; + ntfs_debug("Retrying mft data allocation with minimal cluster count %lli.", nr); + } while (1); + + down_write(&mft_ni->runlist.lock); + rl = ntfs_runlists_merge(&mft_ni->runlist, rl2, 0, &new_rl_count); + if (IS_ERR(rl)) { + up_write(&mft_ni->runlist.lock); + ntfs_error(vol->sb, "Failed to merge runlists for mft data attribute."); + if (ntfs_cluster_free_from_rl(vol, rl2)) { + ntfs_error(vol->sb, + "Failed to deallocate clusters from the mft data attribute.%s", es); + NVolSetErrors(vol); + } + kvfree(rl2); + return PTR_ERR(rl); + } + mft_ni->runlist.rl = rl; + mft_ni->runlist.count = new_rl_count; + ntfs_debug("Allocated %lli clusters.", (long long)nr); + /* Find the last run in the new runlist. */ + for (; rl[1].length; rl++) + ; + up_write(&mft_ni->runlist.lock); + + /* Update the attribute record as well. */ + mrec = map_mft_record(mft_ni); + if (IS_ERR(mrec)) { + ntfs_error(vol->sb, "Failed to map mft record."); + ret = PTR_ERR(mrec); + down_write(&mft_ni->runlist.lock); + goto undo_alloc; + } + ctx = ntfs_attr_get_search_ctx(mft_ni, mrec); + if (unlikely(!ctx)) { + ntfs_error(vol->sb, "Failed to get search context."); + ret = -ENOMEM; + goto undo_alloc; + } + ret = ntfs_attr_lookup(mft_ni->type, mft_ni->name, mft_ni->name_len, + CASE_SENSITIVE, rl[1].vcn, NULL, 0, ctx); + if (unlikely(ret)) { + ntfs_error(vol->sb, "Failed to find last attribute extent of mft data attribute."); + if (ret == -ENOENT) + ret = -EIO; + goto undo_alloc; + } + a = ctx->attr; + ll = le64_to_cpu(a->data.non_resident.lowest_vcn); + + down_write(&mft_ni->runlist.lock); + /* Search back for the previous last allocated cluster of mft bitmap. */ + for (rl2 = rl; rl2 > mft_ni->runlist.rl; rl2--) { + if (ll >= rl2->vcn) + break; + } + WARN_ON(ll < rl2->vcn); + WARN_ON(ll >= rl2->vcn + rl2->length); + /* Get the size for the new mapping pairs array for this extent. */ + mp_size = ntfs_get_size_for_mapping_pairs(vol, rl2, ll, -1, -1); + if (unlikely(mp_size <= 0)) { + ntfs_error(vol->sb, + "Get size for mapping pairs failed for mft data attribute extent."); + ret = mp_size; + if (!ret) + ret = -EIO; + up_write(&mft_ni->runlist.lock); + goto undo_alloc; + } + up_write(&mft_ni->runlist.lock); + + /* Expand the attribute record if necessary. */ + old_alen = le32_to_cpu(a->length); + ret = ntfs_attr_record_resize(ctx->mrec, a, mp_size + + le16_to_cpu(a->data.non_resident.mapping_pairs_offset)); + if (unlikely(ret)) { + ret = ntfs_mft_attr_extend(mft_ni, NULL); + if (!ret) + goto extended_ok; + if (ret != -EAGAIN) + mp_extended = true; + goto undo_alloc; + } + mp_rebuilt = true; + /* Generate the mapping pairs array directly into the attr record. */ + ret = ntfs_mapping_pairs_build(vol, (u8 *)a + + le16_to_cpu(a->data.non_resident.mapping_pairs_offset), + mp_size, rl2, ll, -1, NULL, NULL, NULL); + if (unlikely(ret)) { + ntfs_error(vol->sb, "Failed to build mapping pairs array of mft data attribute."); + goto undo_alloc; + } + /* Update the highest_vcn. */ + a->data.non_resident.highest_vcn = cpu_to_le64(rl[1].vcn - 1); + /* + * We now have extended the mft data allocated_size by nr clusters. + * Reflect this in the struct ntfs_inode structure and the attribute record. + * @rl is the last (non-terminator) runlist element of mft data + * attribute. + */ + if (a->data.non_resident.lowest_vcn) { + /* + * We are not in the first attribute extent, switch to it, but + * first ensure the changes will make it to disk later. + */ + mark_mft_record_dirty(ctx->ntfs_ino); +extended_ok: + ntfs_attr_reinit_search_ctx(ctx); + ret = ntfs_attr_lookup(mft_ni->type, mft_ni->name, + mft_ni->name_len, CASE_SENSITIVE, 0, NULL, 0, + ctx); + if (unlikely(ret)) { + ntfs_error(vol->sb, + "Failed to find first attribute extent of mft data attribute."); + goto restore_undo_alloc; + } + a = ctx->attr; + } + + write_lock_irqsave(&mft_ni->size_lock, flags); + mft_ni->allocated_size += NTFS_CLU_TO_B(vol, nr); + a->data.non_resident.allocated_size = + cpu_to_le64(mft_ni->allocated_size); + write_unlock_irqrestore(&mft_ni->size_lock, flags); + /* Ensure the changes make it to disk. */ + mark_mft_record_dirty(ctx->ntfs_ino); + ntfs_attr_put_search_ctx(ctx); + unmap_mft_record(mft_ni); + ntfs_debug("Done."); + return 0; +restore_undo_alloc: + ntfs_attr_reinit_search_ctx(ctx); + if (ntfs_attr_lookup(mft_ni->type, mft_ni->name, mft_ni->name_len, + CASE_SENSITIVE, rl[1].vcn, NULL, 0, ctx)) { + ntfs_error(vol->sb, + "Failed to find last attribute extent of mft data attribute.%s", es); + write_lock_irqsave(&mft_ni->size_lock, flags); + mft_ni->allocated_size += NTFS_CLU_TO_B(vol, nr); + write_unlock_irqrestore(&mft_ni->size_lock, flags); + ntfs_attr_put_search_ctx(ctx); + unmap_mft_record(mft_ni); + up_write(&mft_ni->runlist.lock); + /* + * The only thing that is now wrong is ->allocated_size of the + * base attribute extent which chkdsk should be able to fix. + */ + NVolSetErrors(vol); + return ret; + } + ctx->attr->data.non_resident.highest_vcn = + cpu_to_le64(old_last_vcn - 1); +undo_alloc: + if (ntfs_cluster_free(mft_ni, old_last_vcn, -1, ctx) < 0) { + ntfs_error(vol->sb, "Failed to free clusters from mft data attribute.%s", es); + NVolSetErrors(vol); + } + + if (ntfs_rl_truncate_nolock(vol, &mft_ni->runlist, old_last_vcn)) { + ntfs_error(vol->sb, "Failed to truncate mft data attribute runlist.%s", es); + NVolSetErrors(vol); + } + if (mp_extended && ntfs_attr_update_mapping_pairs(mft_ni, 0)) { + ntfs_error(vol->sb, "Failed to restore mapping pairs.%s", + es); + NVolSetErrors(vol); + } + if (ctx) { + a = ctx->attr; + if (mp_rebuilt && !IS_ERR(ctx->mrec)) { + if (ntfs_mapping_pairs_build(vol, (u8 *)a + le16_to_cpu( + a->data.non_resident.mapping_pairs_offset), + old_alen - le16_to_cpu( + a->data.non_resident.mapping_pairs_offset), + rl2, ll, -1, NULL, NULL, NULL)) { + ntfs_error(vol->sb, "Failed to restore mapping pairs array.%s", es); + NVolSetErrors(vol); + } + if (ntfs_attr_record_resize(ctx->mrec, a, old_alen)) { + ntfs_error(vol->sb, "Failed to restore attribute record.%s", es); + NVolSetErrors(vol); + } + mark_mft_record_dirty(ctx->ntfs_ino); + } else if (IS_ERR(ctx->mrec)) { + ntfs_error(vol->sb, "Failed to restore attribute search context.%s", es); + NVolSetErrors(vol); + } + ntfs_attr_put_search_ctx(ctx); + } + if (!IS_ERR(mrec)) + unmap_mft_record(mft_ni); + return ret; +} + +/* + * ntfs_mft_record_layout - layout an mft record into a memory buffer + * @vol: volume to which the mft record will belong + * @mft_no: mft reference specifying the mft record number + * @m: destination buffer of size >= @vol->mft_record_size bytes + * + * Layout an empty, unused mft record with the mft record number @mft_no into + * the buffer @m. The volume @vol is needed because the mft record structure + * was modified in NTFS 3.1 so we need to know which volume version this mft + * record will be used on. + * + * Return 0 on success and -errno on error. + */ +static int ntfs_mft_record_layout(const struct ntfs_volume *vol, const s64 mft_no, + struct mft_record *m) +{ + struct attr_record *a; + + ntfs_debug("Entering for mft record 0x%llx.", (long long)mft_no); + if (mft_no >= (1ll << 32)) { + ntfs_error(vol->sb, "Mft record number 0x%llx exceeds maximum of 2^32.", + (long long)mft_no); + return -ERANGE; + } + /* Start by clearing the whole mft record to gives us a clean slate. */ + memset(m, 0, vol->mft_record_size); + /* Aligned to 2-byte boundary. */ + if (vol->major_ver < 3 || (vol->major_ver == 3 && !vol->minor_ver)) + m->usa_ofs = cpu_to_le16((sizeof(struct mft_record_old) + 1) & ~1); + else { + m->usa_ofs = cpu_to_le16((sizeof(struct mft_record) + 1) & ~1); + /* + * Set the NTFS 3.1+ specific fields while we know that the + * volume version is 3.1+. + */ + m->reserved = 0; + m->mft_record_number = cpu_to_le32((u32)mft_no); + } + m->magic = magic_FILE; + if (vol->mft_record_size >= NTFS_BLOCK_SIZE) + m->usa_count = cpu_to_le16(vol->mft_record_size / + NTFS_BLOCK_SIZE + 1); + else { + m->usa_count = cpu_to_le16(1); + ntfs_warning(vol->sb, + "Sector size is bigger than mft record size. Setting usa_count to 1. If chkdsk reports this as corruption"); + } + /* Set the update sequence number to 1. */ + *(__le16 *)((u8 *)m + le16_to_cpu(m->usa_ofs)) = cpu_to_le16(1); + m->lsn = 0; + m->sequence_number = cpu_to_le16(1); + m->link_count = 0; + /* + * Place the attributes straight after the update sequence array, + * aligned to 8-byte boundary. + */ + m->attrs_offset = cpu_to_le16((le16_to_cpu(m->usa_ofs) + + (le16_to_cpu(m->usa_count) << 1) + 7) & ~7); + m->flags = 0; + /* + * Using attrs_offset plus eight bytes (for the termination attribute). + * attrs_offset is already aligned to 8-byte boundary, so no need to + * align again. + */ + m->bytes_in_use = cpu_to_le32(le16_to_cpu(m->attrs_offset) + 8); + m->bytes_allocated = cpu_to_le32(vol->mft_record_size); + m->base_mft_record = 0; + m->next_attr_instance = 0; + /* Add the termination attribute. */ + a = (struct attr_record *)((u8 *)m + le16_to_cpu(m->attrs_offset)); + a->type = AT_END; + a->length = 0; + ntfs_debug("Done."); + return 0; +} + +/* + * ntfs_mft_record_format - format an mft record on an ntfs volume + * @vol: volume on which to format the mft record + * @mft_no: mft record number to format + * + * Format the mft record @mft_no in $MFT/$DATA, i.e. lay out an empty, unused + * mft record into the appropriate place of the mft data attribute. This is + * used when extending the mft data attribute. + * + * Return 0 on success and -errno on error. + */ +static int ntfs_mft_record_format(const struct ntfs_volume *vol, const s64 mft_no) +{ + loff_t i_size; + struct inode *mft_vi = vol->mft_ino; + struct folio *folio; + struct mft_record *m; + pgoff_t index, end_index; + unsigned int ofs; + int err; + + ntfs_debug("Entering for mft record 0x%llx.", (long long)mft_no); + /* + * The index into the page cache and the offset within the page cache + * page of the wanted mft record. + */ + index = NTFS_MFT_NR_TO_PIDX(vol, mft_no); + ofs = NTFS_MFT_NR_TO_POFS(vol, mft_no); + /* The maximum valid index into the page cache for $MFT's data. */ + i_size = i_size_read(mft_vi); + end_index = i_size >> PAGE_SHIFT; + if (unlikely(index >= end_index)) { + if (unlikely(index > end_index || + ofs + vol->mft_record_size > (i_size & ~PAGE_MASK))) { + ntfs_error(vol->sb, "Tried to format non-existing mft record 0x%llx.", + (long long)mft_no); + return -ENOENT; + } + } + + /* Read, map, and pin the folio containing the mft record. */ + folio = read_mapping_folio(mft_vi->i_mapping, index, NULL); + if (IS_ERR(folio)) { + ntfs_error(vol->sb, "Failed to map page containing mft record to format 0x%llx.", + (long long)mft_no); + return PTR_ERR(folio); + } + folio_lock(folio); + folio_clear_uptodate(folio); + m = (struct mft_record *)((u8 *)kmap_local_folio(folio, 0) + ofs); + err = ntfs_mft_record_layout(vol, mft_no, m); + if (unlikely(err)) { + ntfs_error(vol->sb, "Failed to layout mft record 0x%llx.", + (long long)mft_no); + folio_mark_uptodate(folio); + folio_unlock(folio); + kunmap_local(m); + folio_put(folio); + return err; + } + pre_write_mst_fixup((struct ntfs_record *)m, vol->mft_record_size); + folio_mark_uptodate(folio); + /* + * Make sure the mft record is written out to disk. We could use + * ilookup5() to check if an inode is in icache and so on but this is + * unnecessary as ntfs_writepage() will write the dirty record anyway. + */ + ntfs_mft_mark_dirty(folio); + folio_unlock(folio); + kunmap_local(m); + folio_put(folio); + ntfs_debug("Done."); + return 0; +} + +/* + * ntfs_mft_record_alloc - allocate an mft record on an ntfs volume + * @vol: [IN] volume on which to allocate the mft record + * @mode: [IN] mode if want a file or directory, i.e. base inode or 0 + * @ni: [OUT] on success, set to the allocated ntfs inode + * @base_ni: [IN] open base inode if allocating an extent mft record or NULL + * @ni_mrec: [OUT] on successful return this is the mapped mft record + * @mft_data_vcn: [IN] lowest VCN of a new $MFT/$DATA extent, or -1 + * + * Allocate an mft record in $MFT/$DATA of an open ntfs volume @vol. + * + * If @base_ni is NULL make the mft record a base mft record, i.e. a file or + * direvctory inode, and allocate it at the default allocator position. In + * this case @mode is the file mode as given to us by the caller. We in + * particular use @mode to distinguish whether a file or a directory is being + * created (S_IFDIR(mode) and S_IFREG(mode), respectively). + * + * If @base_ni is not NULL make the allocated mft record an extent record, + * allocate it starting at the mft record after the base mft record and attach + * the allocated and opened ntfs inode to the base inode @base_ni. In this + * case @mode must be 0 as it is meaningless for extent inodes. + * + * You need to check the return value with IS_ERR(). If false, the function + * was successful and the return value is the now opened ntfs inode of the + * allocated mft record. *@mrec is then set to the allocated, mapped, pinned, + * and locked mft record. If IS_ERR() is true, the function failed and the + * error code is obtained from PTR_ERR(return value). *@mrec is undefined in + * this case. + * + * Allocation strategy: + * + * To find a free mft record, we scan the mft bitmap for a zero bit. To + * optimize this we start scanning at the place specified by @base_ni or if + * @base_ni is NULL we start where we last stopped and we perform wrap around + * when we reach the end. Note, we do not try to allocate mft records below + * number 24 because numbers 0 to 15 are the defined system files and records + * 16 to 23 are kept for metadata compatibility. Records reserved dynamically + * at the initialized MFT tail are skipped by normal allocation and consumed by + * $MFT metadata extent allocation. + * + * When scanning the mft bitmap, we only search up to the last allocated mft + * record. If there are no free records left in the range 24 to number of + * allocated mft records, then we extend the $MFT/$DATA attribute in order to + * create free mft records. We extend the allocated size of $MFT/$DATA by 16 + * records at a time or one cluster, if cluster size is above 16kiB. If there + * is not sufficient space to do this, we try to extend by two mft records or + * one cluster, if a cluster already contains at least two mft records. + * + * When extending the initialized MFT tail, we also initialize up to four + * additional records and reserve them in memory for future $MFT metadata + * extents. If there are less than 24 mft records, records are initialized + * until record 24, which is the first record used for normal files. + * + * If during any stage we overflow the initialized data in the mft bitmap, we + * extend the initialized size (and data size) by 8 bytes, allocating another + * cluster if required. The bitmap data size has to be at least equal to the + * number of mft records in the mft, but it can be bigger, in which case the + * superfluous bits are padded with zeroes. + * + * Thus, when we return successfully (IS_ERR() is false), we will have: + * - initialized / extended the mft bitmap if necessary, + * - initialized / extended the mft data if necessary, + * - set the bit corresponding to the mft record being allocated in the + * mft bitmap, + * - opened an struct ntfs_inode for the allocated mft record, and we will have + * - returned the struct ntfs_inode as well as the allocated mapped, pinned, and + * locked mft record. + * + * On error, the volume will be left in a consistent state and no record will + * be allocated. If rolling back a partial operation fails, we may leave some + * inconsistent metadata in which case we set NVolErrors() so the volume is + * left dirty when unmounted. + * + * Note, this function cannot make use of most of the normal functions, like + * for example for attribute resizing, etc, because when the run list overflows + * the base mft record and an attribute list is used, it is very important that + * the extension mft records used to store the $DATA attribute of $MFT can be + * reached without having to read the information contained inside them, as + * this would make it impossible to find them in the first place after the + * volume is unmounted. $MFT/$BITMAP probably does not need to follow this + * rule because the bitmap is not essential for finding the mft records, but on + * the other hand, handling the bitmap in this special way would make life + * easier because otherwise there might be circular invocations of functions + * when reading the bitmap. + */ +int ntfs_mft_record_alloc(struct ntfs_volume *vol, const int mode, + struct ntfs_inode **ni, struct ntfs_inode *base_ni, + struct mft_record **ni_mrec, const s64 mft_data_vcn) +{ + s64 ll, bit, old_data_initialized, old_data_size; + s64 nr_new_mft_records = 0; + s64 max_mft_no = -1, reserve_start = -1, reserve_end = -1; + s64 candidate_reserve_end = -1; + s64 *reserve_endp; + unsigned long flags; + struct folio *folio; + struct ntfs_inode *mft_ni, *mftbmp_ni; + struct ntfs_attr_search_ctx *ctx; + struct mft_record *m = NULL; + struct attr_record *a; + pgoff_t index; + unsigned int ofs; + int err; + __le16 seq_no, usn; + bool record_formatted = false, from_reserve = false, tail_alloc = false; + bool reserve_created = false; + bool forced_reserved_record = false; + unsigned int memalloc_flags; + + if (base_ni && *ni) + return -EINVAL; + + /* @mode and @base_ni are mutually exclusive. */ + if (mode && base_ni) + return -EINVAL; + if (mft_data_vcn >= 0 && + (!base_ni || base_ni->mft_no != FILE_MFT)) + return -EINVAL; + if (mft_data_vcn >= 0) { + u64 vbo; + + if ((u64)mft_data_vcn > (U64_MAX >> vol->cluster_size_bits)) + return -EOVERFLOW; + vbo = (u64)mft_data_vcn << vol->cluster_size_bits; + /* + * The whole extent record must be reachable without this + * extent, including when an MFT record spans multiple clusters. + */ + max_mft_no = vbo >> vol->mft_record_size_bits; + } + + if (base_ni) + ntfs_debug("Entering (allocating an extent mft record for base mft record 0x%llx).", + (long long)base_ni->mft_no); + else + ntfs_debug("Entering (allocating a base mft record)."); + + memalloc_flags = memalloc_nofs_save(); + + mft_ni = NTFS_I(vol->mft_ino); + if (!base_ni || base_ni->mft_no != FILE_MFT) + mutex_lock(&mft_ni->mrec_lock); + mftbmp_ni = NTFS_I(vol->mftbmp_ino); +search_free_rec: + from_reserve = false; + reserve_created = false; + candidate_reserve_end = -1; + if (!base_ni || base_ni->mft_no != FILE_MFT) + down_write(&vol->mftbmp_lock); + if (base_ni && base_ni->mft_no == FILE_MFT && + vol->mft_record_reserve_pos < vol->mft_record_reserve_end && + (max_mft_no < 0 || vol->mft_record_reserve_pos < max_mft_no)) { + bit = vol->mft_record_reserve_pos; + err = ntfs_bitmap_set_bit(vol->mftbmp_ino, bit); + if (unlikely(err)) { + ntfs_error(vol->sb, + "Failed to allocate reserved MFT record 0x%llx.", + bit); + goto err_out; + } + vol->mft_record_reserve_pos++; + from_reserve = true; + ntfs_debug("Allocated MFT metadata record 0x%llx from tail reserve.", + bit); + goto have_alloc_rec; + } + reserve_endp = vol->mft_record_reserve_pos >= + vol->mft_record_reserve_end ? &candidate_reserve_end : NULL; + bit = mft_bitmap_alloc_free_rec(vol, base_ni, max_mft_no, reserve_endp); + if (bit >= 0) { + if (candidate_reserve_end > bit + 1) { + vol->mft_record_reserve_pos = bit + 1; + vol->mft_record_reserve_end = candidate_reserve_end; + reserve_created = true; + ntfs_debug("Reserved free MFT records [0x%llx, 0x%llx) for metadata.", + bit + 1, candidate_reserve_end); + } + ntfs_debug("Found and allocated free record (#1), bit 0x%llx.", + (long long)bit); + goto have_alloc_rec; + } + if (bit != -ENOSPC) { + if (!base_ni || base_ni->mft_no != FILE_MFT) { + up_write(&vol->mftbmp_lock); + mutex_unlock(&mft_ni->mrec_lock); + } + memalloc_nofs_restore(memalloc_flags); + return bit; + } + + if (base_ni && base_ni->mft_no == FILE_MFT) { + static const u8 bootstrap_records[] = { + FILE_reserved15, FILE_reserved12, FILE_reserved13, + FILE_reserved14, + }; + int i; + + for (i = 0; i < ARRAY_SIZE(bootstrap_records); i++) { + if (max_mft_no >= 0 && bootstrap_records[i] >= max_mft_no) + continue; + if (!mft_reserved_is_free(vol, mft_ni, + bootstrap_records[i])) + continue; + bit = bootstrap_records[i]; + forced_reserved_record = true; + ntfs_debug("Using reserved MFT record %lld to bootstrap metadata extension.", + bit); + goto have_alloc_rec; + } + memalloc_nofs_restore(memalloc_flags); + return bit; + } + + /* + * No free mft records left. If the mft bitmap already covers more + * than the currently used mft records, the next records are all free, + * so we can simply allocate the first unused mft record. + * Note: We also have to make sure that the mft bitmap at least covers + * the first 24 mft records as they are special and whilst they may not + * be in use, we do not allocate from them. + */ + read_lock_irqsave(&mft_ni->size_lock, flags); + ll = mft_ni->initialized_size >> vol->mft_record_size_bits; + read_unlock_irqrestore(&mft_ni->size_lock, flags); + read_lock_irqsave(&mftbmp_ni->size_lock, flags); + old_data_initialized = mftbmp_ni->initialized_size; + read_unlock_irqrestore(&mftbmp_ni->size_lock, flags); + if (old_data_initialized << 3 > ll && + old_data_initialized << 3 > FIRST_NORMAL_MFT_RECORD) { + bit = ll; + if (bit < FIRST_NORMAL_MFT_RECORD) + bit = FIRST_NORMAL_MFT_RECORD; + if (unlikely(bit >= (1ll << 32))) + goto max_err_out; + ntfs_debug("Found free record (#2), bit 0x%llx.", + (long long)bit); + goto found_free_rec; + } + /* + * The mft bitmap needs to be expanded until it covers the first unused + * mft record that we can allocate. + * Note: The smallest mft record we allocate is mft record 24. + */ + bit = old_data_initialized << 3; + if (unlikely(bit >= (1ll << 32))) + goto max_err_out; + read_lock_irqsave(&mftbmp_ni->size_lock, flags); + old_data_size = mftbmp_ni->allocated_size; + ntfs_debug("Status of mftbmp before extension: allocated_size 0x%llx, data_size 0x%llx, initialized_size 0x%llx.", + old_data_size, i_size_read(vol->mftbmp_ino), + old_data_initialized); + read_unlock_irqrestore(&mftbmp_ni->size_lock, flags); + if (old_data_initialized + 8 > old_data_size) { + /* Need to extend bitmap by one more cluster. */ + ntfs_debug("mftbmp: initialized_size + 8 > allocated_size."); + err = ntfs_mft_bitmap_extend_allocation_nolock(vol); + if (err == -EAGAIN) + err = ntfs_mft_bitmap_extend_allocation_nolock(vol); + + if (unlikely(err)) { + if (!base_ni || base_ni->mft_no != FILE_MFT) + up_write(&vol->mftbmp_lock); + goto err_out; + } +#ifdef DEBUG + read_lock_irqsave(&mftbmp_ni->size_lock, flags); + ntfs_debug("Status of mftbmp after allocation extension: allocated_size 0x%llx, data_size 0x%llx, initialized_size 0x%llx.", + mftbmp_ni->allocated_size, + i_size_read(vol->mftbmp_ino), + mftbmp_ni->initialized_size); + read_unlock_irqrestore(&mftbmp_ni->size_lock, flags); +#endif /* DEBUG */ + } + /* + * We now have sufficient allocated space, extend the initialized_size + * as well as the data_size if necessary and fill the new space with + * zeroes. + */ + err = ntfs_mft_bitmap_extend_initialized_nolock(vol); + if (unlikely(err)) { + if (!base_ni || base_ni->mft_no != FILE_MFT) + up_write(&vol->mftbmp_lock); + goto err_out; + } +#ifdef DEBUG + read_lock_irqsave(&mftbmp_ni->size_lock, flags); + ntfs_debug("Status of mftbmp after initialized extension: allocated_size 0x%llx, data_size 0x%llx, initialized_size 0x%llx.", + mftbmp_ni->allocated_size, + i_size_read(vol->mftbmp_ino), + mftbmp_ni->initialized_size); + read_unlock_irqrestore(&mftbmp_ni->size_lock, flags); +#endif /* DEBUG */ + ntfs_debug("Found free record (#3), bit 0x%llx.", (long long)bit); +found_free_rec: + /* @bit is the found free mft record, allocate it in the mft bitmap. */ + ntfs_debug("At found_free_rec."); + err = ntfs_bitmap_set_bit(vol->mftbmp_ino, bit); + if (unlikely(err)) { + ntfs_error(vol->sb, "Failed to allocate bit in mft bitmap."); + if (!base_ni || base_ni->mft_no != FILE_MFT) + up_write(&vol->mftbmp_lock); + goto err_out; + } + ntfs_debug("Set bit 0x%llx in mft bitmap.", (long long)bit); +have_alloc_rec: + /* + * The mft bitmap is now uptodate. Deal with mft data attribute now. + * Note, we keep hold of the mft bitmap lock for writing until all + * modifications to the mft data attribute are complete, too, as they + * will impact decisions for mft bitmap and mft record allocation done + * by a parallel allocation and if the lock is not maintained a + * parallel allocation could allocate the same mft record as this one. + */ + ll = (bit + 1) << vol->mft_record_size_bits; + read_lock_irqsave(&mft_ni->size_lock, flags); + old_data_initialized = mft_ni->initialized_size; + read_unlock_irqrestore(&mft_ni->size_lock, flags); + tail_alloc = (!base_ni || base_ni->mft_no != FILE_MFT) && + bit >= (old_data_initialized >> vol->mft_record_size_bits) && + vol->mft_record_reserve_pos >= vol->mft_record_reserve_end; + if (tail_alloc) + ll = (bit + 2) << vol->mft_record_size_bits; + if (ll <= old_data_initialized) { + ntfs_debug("Allocated mft record already initialized."); + goto mft_rec_already_initialized; + } + ntfs_debug("Initializing allocated mft record."); + /* + * The mft record is outside the initialized data. Extend the mft data + * attribute until it covers the allocated record. The loop is only + * actually traversed more than once when a freshly formatted volume is + * first written to so it optimizes away nicely in the common case. + */ + if (!base_ni || base_ni->mft_no != FILE_MFT) { + read_lock_irqsave(&mft_ni->size_lock, flags); + ntfs_debug("Status of mft data before extension: allocated_size 0x%llx, data_size 0x%llx, initialized_size 0x%llx.", + mft_ni->allocated_size, i_size_read(vol->mft_ino), + mft_ni->initialized_size); + while (ll > mft_ni->allocated_size) { + read_unlock_irqrestore(&mft_ni->size_lock, flags); + err = ntfs_mft_data_extend_allocation_nolock(vol); + if (err == -EAGAIN) + err = ntfs_mft_data_extend_allocation_nolock(vol); + + if (unlikely(err)) { + ntfs_error(vol->sb, "Failed to extend mft data allocation."); + goto undo_mftbmp_alloc_nolock; + } + read_lock_irqsave(&mft_ni->size_lock, flags); + ntfs_debug("Status of mft data after allocation extension: allocated_size 0x%llx, data_size 0x%llx, initialized_size 0x%llx.", + mft_ni->allocated_size, i_size_read(vol->mft_ino), + mft_ni->initialized_size); + } + read_unlock_irqrestore(&mft_ni->size_lock, flags); + if (tail_alloc) { + s64 bitmap_records; + + read_lock_irqsave(&mft_ni->size_lock, flags); + reserve_end = mft_ni->allocated_size >> + vol->mft_record_size_bits; + read_unlock_irqrestore(&mft_ni->size_lock, flags); + read_lock_irqsave(&mftbmp_ni->size_lock, flags); + bitmap_records = mftbmp_ni->initialized_size << 3; + read_unlock_irqrestore(&mftbmp_ni->size_lock, flags); + if (reserve_end > bitmap_records) + reserve_end = bitmap_records; + if (reserve_end > bit + 1 + MFT_RECORD_RESERVE) + reserve_end = bit + 1 + MFT_RECORD_RESERVE; + reserve_start = bit + 1; + if (reserve_end > reserve_start) { + ll = reserve_end << vol->mft_record_size_bits; + } else { + reserve_start = -1; + reserve_end = -1; + ll = (bit + 1) << vol->mft_record_size_bits; + } + } + } else if (ll > mft_ni->allocated_size) { + err = -ENOSPC; + goto undo_mftbmp_alloc_nolock; + } + /* + * Extend mft data initialized size (and data size of course) to reach + * the allocated mft record, formatting the mft records allong the way. + * Note: We only modify the struct ntfs_inode structure as that is all that is + * needed by ntfs_mft_record_format(). We will update the attribute + * record itself in one fell swoop later on. + */ + write_lock_irqsave(&mft_ni->size_lock, flags); + old_data_initialized = mft_ni->initialized_size; + old_data_size = vol->mft_ino->i_size; + while (ll > mft_ni->initialized_size) { + s64 new_initialized_size, mft_no; + + new_initialized_size = mft_ni->initialized_size + + vol->mft_record_size; + mft_no = mft_ni->initialized_size >> vol->mft_record_size_bits; + if (new_initialized_size > i_size_read(vol->mft_ino)) + i_size_write(vol->mft_ino, new_initialized_size); + write_unlock_irqrestore(&mft_ni->size_lock, flags); + ntfs_debug("Initializing mft record 0x%llx.", + (long long)mft_no); + err = ntfs_mft_record_format(vol, mft_no); + if (unlikely(err)) { + ntfs_error(vol->sb, "Failed to format mft record."); + goto undo_data_init; + } + write_lock_irqsave(&mft_ni->size_lock, flags); + mft_ni->initialized_size = new_initialized_size; + } + write_unlock_irqrestore(&mft_ni->size_lock, flags); + record_formatted = true; + /* Update the mft data attribute record to reflect the new sizes. */ + m = map_mft_record(mft_ni); + if (IS_ERR(m)) { + ntfs_error(vol->sb, "Failed to map mft record."); + err = PTR_ERR(m); + goto undo_data_init; + } + ctx = ntfs_attr_get_search_ctx(mft_ni, m); + if (unlikely(!ctx)) { + ntfs_error(vol->sb, "Failed to get search context."); + err = -ENOMEM; + unmap_mft_record(mft_ni); + goto undo_data_init; + } + err = ntfs_attr_lookup(mft_ni->type, mft_ni->name, mft_ni->name_len, + CASE_SENSITIVE, 0, NULL, 0, ctx); + if (unlikely(err)) { + ntfs_error(vol->sb, "Failed to find first attribute extent of mft data attribute."); + ntfs_attr_put_search_ctx(ctx); + unmap_mft_record(mft_ni); + goto undo_data_init; + } + a = ctx->attr; + read_lock_irqsave(&mft_ni->size_lock, flags); + a->data.non_resident.initialized_size = + cpu_to_le64(mft_ni->initialized_size); + a->data.non_resident.data_size = + cpu_to_le64(i_size_read(vol->mft_ino)); + read_unlock_irqrestore(&mft_ni->size_lock, flags); + /* Ensure the changes make it to disk. */ + mark_mft_record_dirty(ctx->ntfs_ino); + ntfs_attr_put_search_ctx(ctx); + unmap_mft_record(mft_ni); + if (reserve_start >= 0 && reserve_end > reserve_start) { + vol->mft_record_reserve_pos = reserve_start; + vol->mft_record_reserve_end = reserve_end; + ntfs_debug("Reserved MFT records [0x%llx, 0x%llx) for metadata.", + reserve_start, reserve_end); + } + read_lock_irqsave(&mft_ni->size_lock, flags); + ntfs_debug("Status of mft data after mft record initialization: allocated_size 0x%llx, data_size 0x%llx, initialized_size 0x%llx.", + mft_ni->allocated_size, i_size_read(vol->mft_ino), + mft_ni->initialized_size); + WARN_ON(i_size_read(vol->mft_ino) > mft_ni->allocated_size); + WARN_ON(mft_ni->initialized_size > i_size_read(vol->mft_ino)); + nr_new_mft_records = (i_size_read(vol->mft_ino) - old_data_size) >> + vol->mft_record_size_bits; + read_unlock_irqrestore(&mft_ni->size_lock, flags); +mft_rec_already_initialized: + /* Account for newly visible MFT records before dropping the lock. */ + if (nr_new_mft_records > 0) + ntfs_inc_free_mft_records(vol, nr_new_mft_records); + /* + * We can finally drop the mft bitmap lock as the mft data attribute + * has been fully updated. The only disparity left is that the + * allocated mft record still needs to be marked as in use to match the + * set bit in the mft bitmap but this is actually not a problem since + * this mft record is not referenced from anywhere yet and the fact + * that it is allocated in the mft bitmap means that no-one will try to + * allocate it either. + */ + if (!base_ni || base_ni->mft_no != FILE_MFT) + up_write(&vol->mftbmp_lock); + /* + * We now have allocated and initialized the mft record. Calculate the + * index of and the offset within the page cache page the record is in. + */ + index = NTFS_MFT_NR_TO_PIDX(vol, bit); + ofs = NTFS_MFT_NR_TO_POFS(vol, bit); + /* Read, map, and pin the folio containing the mft record. */ + folio = read_mapping_folio(vol->mft_ino->i_mapping, index, NULL); + if (IS_ERR(folio)) { + ntfs_error(vol->sb, "Failed to map page containing allocated mft record 0x%llx.", + bit); + err = PTR_ERR(folio); + goto undo_mftbmp_alloc; + } + folio_lock(folio); + folio_clear_uptodate(folio); + m = (struct mft_record *)((u8 *)kmap_local_folio(folio, 0) + ofs); + /* If we just formatted the mft record no need to do it again. */ + if (!record_formatted) { + /* Sanity check that the mft record is really not in use. */ + if (!forced_reserved_record && ntfs_is_file_record(m->magic) && + (m->flags & MFT_RECORD_IN_USE)) { + ntfs_warning(vol->sb, + "Mft record 0x%llx was marked free in mft bitmap but is marked used itself. Unmount and run chkdsk.", + bit); + folio_mark_uptodate(folio); + folio_unlock(folio); + kunmap_local(m); + folio_put(folio); + NVolSetErrors(vol); + goto search_free_rec; + } + /* + * We need to (re-)format the mft record, preserving the + * sequence number if it is not zero as well as the update + * sequence number if it is not zero or -1 (0xffff). This + * means we do not need to care whether or not something went + * wrong with the previous mft record. + */ + seq_no = m->sequence_number; + /* + * The mft record still holds unvalidated, MST-protected on-disk + * bytes, so m->usa_ofs is untrusted here. Only preserve the old + * update sequence number if that offset is in bounds; otherwise + * leave usn zero so it is not restored below. + */ + if (!(le16_to_cpu(m->usa_ofs) & 1) && + le16_to_cpu(m->usa_ofs) + sizeof(usn) <= vol->mft_record_size) + usn = *(__le16 *)((u8 *)m + le16_to_cpu(m->usa_ofs)); + else + usn = 0; + err = ntfs_mft_record_layout(vol, bit, m); + if (unlikely(err)) { + ntfs_error(vol->sb, "Failed to layout allocated mft record 0x%llx.", + bit); + folio_mark_uptodate(folio); + folio_unlock(folio); + kunmap_local(m); + folio_put(folio); + goto undo_mftbmp_alloc; + } + if (seq_no) + m->sequence_number = seq_no; + if (usn && le16_to_cpu(usn) != 0xffff) + *(__le16 *)((u8 *)m + le16_to_cpu(m->usa_ofs)) = usn; + pre_write_mst_fixup((struct ntfs_record *)m, vol->mft_record_size); + } + /* Set the mft record itself in use. */ + m->flags |= MFT_RECORD_IN_USE; + if (S_ISDIR(mode)) + m->flags |= MFT_RECORD_IS_DIRECTORY; + folio_mark_uptodate(folio); + if (base_ni) { + struct mft_record *m_tmp; + + /* + * Setup the base mft record in the extent mft record. This + * completes initialization of the allocated extent mft record + * and we can simply use it with map_extent_mft_record(). + */ + m->base_mft_record = MK_LE_MREF(base_ni->mft_no, + base_ni->seq_no); + /* + * Allocate an extent inode structure for the new mft record, + * attach it to the base inode @base_ni and map, pin, and lock + * its, i.e. the allocated, mft record. + */ + m_tmp = map_extent_mft_record(base_ni, + MK_MREF(bit, le16_to_cpu(m->sequence_number)), + ni); + if (IS_ERR(m_tmp)) { + ntfs_error(vol->sb, "Failed to map allocated extent mft record 0x%llx.", + bit); + err = PTR_ERR(m_tmp); + if (forced_reserved_record) { + m->base_mft_record = 0; + m->flags |= MFT_RECORD_IN_USE; + } else { + /* Set the mft record itself not in use. */ + m->flags &= cpu_to_le16(~le16_to_cpu(MFT_RECORD_IN_USE)); + } + /* Make sure the mft record is written out to disk. */ + ntfs_mft_mark_dirty(folio); + folio_unlock(folio); + kunmap_local(m); + folio_put(folio); + goto undo_mftbmp_alloc; + } + + /* + * Make sure the allocated mft record is written out to disk. + * No need to set the inode dirty because the caller is going + * to do that anyway after finishing with the new extent mft + * record (e.g. at a minimum a new attribute will be added to + * the mft record. + */ + ntfs_mft_mark_dirty(folio); + folio_unlock(folio); + /* + * Need to unmap the page since map_extent_mft_record() mapped + * it as well so we have it mapped twice at the moment. + */ + kunmap_local(m); + folio_put(folio); + } else { + /* + * Manually map, pin, and lock the mft record as we already + * have its page mapped and it is very easy to do. + */ + (*ni)->seq_no = le16_to_cpu(m->sequence_number); + /* + * Make sure the allocated mft record is written out to disk. + * NOTE: We do not set the ntfs inode dirty because this would + * fail in ntfs_write_inode() because the inode does not have a + * standard information attribute yet. Also, there is no need + * to set the inode dirty because the caller is going to do + * that anyway after finishing with the new mft record (e.g. at + * a minimum some new attributes will be added to the mft + * record. + */ + + (*ni)->mrec = kmemdup(m, vol->mft_record_size, GFP_NOFS); + if (!(*ni)->mrec) { + folio_unlock(folio); + kunmap_local(m); + folio_put(folio); + err = -ENOMEM; + goto undo_mftbmp_alloc; + } + + post_read_mst_fixup((struct ntfs_record *)(*ni)->mrec, vol->mft_record_size); + ntfs_mft_mark_dirty(folio); + folio_unlock(folio); + (*ni)->folio = folio; + (*ni)->folio_ofs = ofs; + atomic_inc(&(*ni)->count); + /* Update the default mft allocation position. */ + vol->mft_data_pos = bit + 1; + } + if (!base_ni || base_ni->mft_no != FILE_MFT) + mutex_unlock(&mft_ni->mrec_lock); + memalloc_nofs_restore(memalloc_flags); + + /* + * Return the opened, allocated inode of the allocated mft record as + * well as the mapped, pinned, and locked mft record. + */ + ntfs_debug("Returning opened, allocated %sinode 0x%llx.", + base_ni ? "extent " : "", bit); + (*ni)->mft_no = bit; + if (ni_mrec) + *ni_mrec = (*ni)->mrec; + if (!forced_reserved_record) + ntfs_dec_free_mft_records(vol, 1); + return 0; +undo_data_init: + write_lock_irqsave(&mft_ni->size_lock, flags); + mft_ni->initialized_size = old_data_initialized; + i_size_write(vol->mft_ino, old_data_size); + write_unlock_irqrestore(&mft_ni->size_lock, flags); + goto undo_mftbmp_alloc_nolock; +undo_mftbmp_alloc: + if (!base_ni || base_ni->mft_no != FILE_MFT) + down_write(&vol->mftbmp_lock); +undo_mftbmp_alloc_nolock: + if (!forced_reserved_record && ntfs_bitmap_clear_bit(vol->mftbmp_ino, bit)) { + ntfs_error(vol->sb, "Failed to clear bit in mft bitmap.%s", es); + NVolSetErrors(vol); + } + if ((from_reserve || reserve_created) && + vol->mft_record_reserve_pos == bit + 1) + vol->mft_record_reserve_pos = bit; + if (!base_ni || base_ni->mft_no != FILE_MFT) + up_write(&vol->mftbmp_lock); +err_out: + if (!base_ni || base_ni->mft_no != FILE_MFT) + mutex_unlock(&mft_ni->mrec_lock); + memalloc_nofs_restore(memalloc_flags); + return err; +max_err_out: + ntfs_warning(vol->sb, + "Cannot allocate mft record because the maximum number of inodes (2^32) has already been reached."); + if (!base_ni || base_ni->mft_no != FILE_MFT) { + up_write(&vol->mftbmp_lock); + mutex_unlock(&mft_ni->mrec_lock); + } + memalloc_nofs_restore(memalloc_flags); + return -ENOSPC; +} + +/* + * ntfs_mft_record_free - free an mft record on an ntfs volume + * @vol: volume on which to free the mft record + * @ni: open ntfs inode of the mft record to free + * + * Free the mft record of the open inode @ni on the mounted ntfs volume @vol. + * Note that this function calls ntfs_inode_close() internally and hence you + * cannot use the pointer @ni any more after this function returns success. + * + * On success return 0 and on error return -1 with errno set to the error code. + */ +int ntfs_mft_record_free(struct ntfs_volume *vol, struct ntfs_inode *ni) +{ + u64 mft_no; + int err; + u16 seq_no; + __le16 old_seq_no; + __le64 old_base_mft_record; + struct mft_record *ni_mrec; + unsigned int memalloc_flags; + struct ntfs_inode *base_ni; + bool keep_reserved; + + if (!vol || !ni) + return -EINVAL; + + ntfs_debug("Entering for inode 0x%llx.\n", (long long)ni->mft_no); + + ni_mrec = map_mft_record(ni); + if (IS_ERR(ni_mrec)) + return -EIO; + + /* Cache the mft reference for later. */ + mft_no = ni->mft_no; + if (likely(ni->nr_extents >= 0)) + base_ni = ni; + else + base_ni = ni->ext.base_ntfs_ino; + keep_reserved = mft_no >= FILE_reserved12 && + mft_no <= FILE_reserved15 && + base_ni->mft_no == FILE_MFT; + + old_base_mft_record = ni_mrec->base_mft_record; + if (keep_reserved) { + /* Restore the special, unnamed form used by reserved records. */ + ni_mrec->base_mft_record = 0; + ni_mrec->flags |= MFT_RECORD_IN_USE; + } else { + /* Mark the mft record as not in use. */ + ni_mrec->flags &= ~MFT_RECORD_IN_USE; + } + + /* Increment the sequence number, skipping zero, if it is not zero. */ + old_seq_no = ni_mrec->sequence_number; + seq_no = le16_to_cpu(old_seq_no); + if (seq_no == 0xffff) + seq_no = 1; + else if (seq_no) + seq_no++; + ni_mrec->sequence_number = cpu_to_le16(seq_no); + + down_read(&NTFS_I(vol->mft_ino)->runlist.lock); + err = ntfs_get_block_mft_record(NTFS_I(vol->mft_ino), ni); + up_read(&NTFS_I(vol->mft_ino)->runlist.lock); + if (err) { + unmap_mft_record(ni); + return err; + } + + /* + * Set the ntfs inode dirty and write it out. We do not need to worry + * about the base inode here since whatever caused the extent mft + * record to be freed is guaranteed to do it already. + */ + NInoSetDirty(ni); + err = write_mft_record(ni, ni_mrec, 0); + if (err) + goto sync_rollback; + + if (keep_reserved) { + unmap_mft_record(ni); + return 0; + } + + /* Clear the bit in the $MFT/$BITMAP corresponding to this record. */ + memalloc_flags = memalloc_nofs_save(); + if (base_ni->mft_no != FILE_MFT) + down_write(&vol->mftbmp_lock); + err = ntfs_bitmap_clear_bit(vol->mftbmp_ino, mft_no); + if (!err) + ntfs_inc_free_mft_records(vol, 1); + if (!err && base_ni->mft_no == FILE_MFT && + mft_no + 1 == vol->mft_record_reserve_pos && + mft_no < vol->mft_record_reserve_end) + vol->mft_record_reserve_pos = mft_no; + if (base_ni->mft_no != FILE_MFT) + up_write(&vol->mftbmp_lock); + memalloc_nofs_restore(memalloc_flags); + if (err) + goto bitmap_rollback; + unmap_mft_record(ni); + return 0; + + /* Rollback what we did... */ +bitmap_rollback: + memalloc_flags = memalloc_nofs_save(); + if (base_ni->mft_no != FILE_MFT) + down_write(&vol->mftbmp_lock); + if (ntfs_bitmap_set_bit(vol->mftbmp_ino, mft_no)) + ntfs_error(vol->sb, "ntfs_bitmap_set_bit failed in bitmap_rollback\n"); + if (base_ni->mft_no != FILE_MFT) + up_write(&vol->mftbmp_lock); + memalloc_nofs_restore(memalloc_flags); +sync_rollback: + ntfs_error(vol->sb, + "Eeek! Rollback failed in %s. Leaving inconsistent metadata!\n", __func__); + ni_mrec->flags |= MFT_RECORD_IN_USE; + ni_mrec->sequence_number = old_seq_no; + ni_mrec->base_mft_record = old_base_mft_record; + NInoSetDirty(ni); + write_mft_record(ni, ni_mrec, 0); + unmap_mft_record(ni); + return err; +} + +static s64 lcn_from_index(struct ntfs_volume *vol, struct ntfs_inode *ni, + unsigned long index) +{ + s64 vcn; + s64 lcn; + + vcn = ntfs_pidx_to_cluster(vol, index); + + down_read(&ni->runlist.lock); + lcn = ntfs_attr_vcn_to_lcn_nolock(ni, vcn, false); + up_read(&ni->runlist.lock); + + return lcn; +} + +/* + * ntfs_write_mft_block - Write back a folio containing MFT records + * @folio: The folio to write back (contains one or more MFT records) + * @wbc: Writeback control structure + * + * This function is called as part of the address_space_operations + * .writepages implementation for the $MFT inode (or $MFTMirr). + * It handles writing one folio (normally 4KiB page) worth of MFT records + * to the underlying block device. + * + * Return: 0 on success, or -errno on error. + */ +static int ntfs_write_mft_block(struct folio *folio, struct writeback_control *wbc) +{ + struct address_space *mapping = folio->mapping; + struct inode *vi = mapping->host; + struct ntfs_inode *ni = NTFS_I(vi); + struct ntfs_volume *vol = ni->vol; + u8 *kaddr; + struct ntfs_inode **locked_nis __free(kfree) = kmalloc_objs(struct ntfs_inode *, + PAGE_SIZE / NTFS_BLOCK_SIZE, + GFP_NOFS); + int nr_locked_nis = 0, err = 0, mft_ofs, prev_mft_ofs; + struct inode **ref_inos __free(kfree) = kmalloc_objs(struct inode *, + PAGE_SIZE / NTFS_BLOCK_SIZE, + GFP_NOFS); + int nr_ref_inos = 0; + struct bio *bio = NULL; + u64 mft_no; + struct ntfs_inode *tni; + s64 lcn; + s64 vcn = ntfs_pidx_to_cluster(vol, folio->index); + s64 end_vcn = ntfs_bytes_to_cluster(vol, ni->allocated_size); + unsigned int folio_sz; + loff_t i_size = i_size_read(vi); + + ntfs_debug("Entering for inode 0x%llx, attribute type 0x%x, folio index 0x%lx.", + ni->mft_no, ni->type, folio->index); + + if (!locked_nis || !ref_inos) { + folio_redirty_for_writepage(wbc, folio); + folio_unlock(folio); + return -ENOMEM; + } + + /* We have to zero every time due to mmap-at-end-of-file. */ + if (folio->index >= (i_size >> folio_shift(folio))) + /* The page straddles i_size. */ + folio_zero_segment(folio, + offset_in_folio(folio, i_size), + folio_size(folio)); + + lcn = lcn_from_index(vol, ni, folio->index); + if (lcn <= LCN_HOLE) { + folio_start_writeback(folio); + folio_unlock(folio); + folio_end_writeback(folio); + return -EIO; + } + + /* Map folio so we can access its contents. */ + kaddr = kmap_local_folio(folio, 0); + /* Clear the page uptodate flag whilst the mst fixups are applied. */ + folio_clear_uptodate(folio); + + for (mft_ofs = 0; mft_ofs < PAGE_SIZE && vcn < end_vcn; + mft_ofs += vol->mft_record_size) { + /* Get the mft record number. */ + mft_no = (((s64)folio->index << PAGE_SHIFT) + mft_ofs) >> + vol->mft_record_size_bits; + vcn = ntfs_mft_no_to_cluster(vol, mft_no); + /* Check whether to write this mft record. */ + tni = NULL; + if (ntfs_may_write_mft_record(vol, mft_no, + (struct mft_record *)(kaddr + mft_ofs), + &tni, &ref_inos[nr_ref_inos])) { + unsigned int mft_record_off = 0; + s64 vcn_off = vcn; + s64 rl_len = 0; + + /* + * The record should be written. If a locked ntfs + * inode was returned, add it to the array of locked + * ntfs inodes. + */ + if (tni) + locked_nis[nr_locked_nis++] = tni; + else if (ref_inos[nr_ref_inos]) + nr_ref_inos++; + + if (bio && (mft_ofs != prev_mft_ofs + vol->mft_record_size)) { +flush_bio: + bio->bi_end_io = ntfs_bio_end_io; + submit_bio(bio); + bio = NULL; + } + + if (vol->cluster_size < folio_size(folio)) { + struct runlist_element *rl; + + down_write(&ni->runlist.lock); + rl = ntfs_attr_vcn_to_rl(ni, vcn_off, &lcn); + if (!IS_ERR(rl)) + rl_len = rl->length - (vcn_off - rl->vcn); + up_write(&ni->runlist.lock); + if (IS_ERR(rl) || lcn < 0) { + err = -EIO; + goto unm_done; + } + + if (bio && + (bio_end_sector(bio) >> (vol->cluster_size_bits - 9)) != + lcn) { + bio->bi_end_io = ntfs_bio_end_io; + submit_bio(bio); + bio = NULL; + } + } + + if (!bio) { + unsigned int off; + + off = ((mft_no << vol->mft_record_size_bits) + + mft_record_off) & vol->cluster_size_mask; + + bio = bio_alloc(vol->sb->s_bdev, 1, REQ_OP_WRITE, + GFP_NOIO); + bio->bi_iter.bi_sector = + ntfs_bytes_to_bio_sector( + ntfs_cluster_to_bytes(vol, lcn) + off); + } + + if (vol->cluster_size == NTFS_BLOCK_SIZE && + (mft_record_off || + rl_len == 1 || + mft_ofs + NTFS_BLOCK_SIZE >= PAGE_SIZE)) + folio_sz = NTFS_BLOCK_SIZE; + else + folio_sz = vol->mft_record_size; + if (!bio_add_folio(bio, folio, folio_sz, + mft_ofs + mft_record_off)) { + err = -EIO; + bio_put(bio); + goto unm_done; + } + mft_record_off += folio_sz; + + if (mft_record_off != vol->mft_record_size) { + vcn_off++; + goto flush_bio; + } + prev_mft_ofs = mft_ofs; + + if (mft_no < vol->mftmirr_size) { + int sub_err = ntfs_sync_mft_mirror(vol, mft_no, + (struct mft_record *)(kaddr + mft_ofs)); + + if (unlikely(sub_err) && !err) + err = sub_err; + } + } else if (ref_inos[nr_ref_inos]) + nr_ref_inos++; + } + + if (bio) { + bio->bi_end_io = ntfs_bio_end_io; + submit_bio(bio); + } +unm_done: + folio_mark_uptodate(folio); + kunmap_local(kaddr); + + folio_start_writeback(folio); + folio_unlock(folio); + folio_end_writeback(folio); + + /* Unlock any locked inodes. */ + while (nr_locked_nis-- > 0) { + struct ntfs_inode *base_tni; + + tni = locked_nis[nr_locked_nis]; + mutex_unlock(&tni->mrec_lock); + + /* Get the base inode. */ + mutex_lock(&tni->extent_lock); + if (tni->nr_extents >= 0) + base_tni = tni; + else + base_tni = tni->ext.base_ntfs_ino; + mutex_unlock(&tni->extent_lock); + ntfs_debug("Unlocking %s inode 0x%llx.", + tni == base_tni ? "base" : "extent", + tni->mft_no); + atomic_dec(&tni->count); + iput(VFS_I(base_tni)); + } + + /* Dropping deferred references */ + while (nr_ref_inos-- > 0) { + if (ref_inos[nr_ref_inos]) + iput(ref_inos[nr_ref_inos]); + } + + if (unlikely(err && err != -ENOMEM)) + NVolSetErrors(vol); + if (likely(!err)) + ntfs_debug("Done."); + return err; +} + +/* + * ntfs_mft_writepages - Write back dirty folios for the $MFT inode + * @mapping: address space of the $MFT inode + * @wbc: writeback control + * + * Writeback iterator for MFT records. Iterates over dirty folios and + * delegates actual writing to ntfs_write_mft_block() for each folio. + * Called from the address_space_operations .writepages vector of the + * $MFT inode. + * + * Returns 0 on success, or the first error encountered. + */ +int ntfs_mft_writepages(struct address_space *mapping, + struct writeback_control *wbc) +{ + struct folio *folio = NULL; + int error; + + if (NVolShutdown(NTFS_I(mapping->host)->vol)) + return -EIO; + + while ((folio = writeback_iter(mapping, wbc, folio, &error))) + error = ntfs_write_mft_block(folio, wbc); + return error; +} + +void ntfs_mft_mark_dirty(struct folio *folio) +{ + iomap_dirty_folio(folio->mapping, folio); +} |