/**
* mft.c - NTFS kernel mft record operations. Part of the Linux-NTFS project.
*
* Copyright (c) 2001-2012 Anton Altaparmakov and Tuxera Inc.
* Copyright (c) 2002 Richard Russon
*
* This program/include file is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as published
* by the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program/include file is distributed in the hope that it will be
* useful, but WITHOUT ANY WARRANTY; without even the implied warranty
* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program (in the main directory of the Linux-NTFS
* distribution in the file COPYING); if not, write to the Free Software
* Foundation,Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/buffer_head.h>
#include <linux/slab.h>
#include <linux/swap.h>
#include "attrib.h"
#include "aops.h"
#include "bitmap.h"
#include "debug.h"
#include "dir.h"
#include "lcnalloc.h"
#include "malloc.h"
#include "mft.h"
#include "ntfs.h"
/**
* map_mft_record_page - map the page in which a specific mft record resides
* @ni: ntfs inode whose mft record page to map
*
* This maps the page in which the mft record of the ntfs inode @ni is situated
* and returns a pointer to the mft record within the mapped page.
*
* Return value needs to be checked with IS_ERR() and if that is true PTR_ERR()
* contains the negative error code returned.
*/
static inline MFT_RECORD *map_mft_record_page(ntfs_inode *ni)
{
loff_t i_size;
ntfs_volume *vol = ni->vol;
struct inode *mft_vi = vol->mft_ino;
struct page *page;
unsigned long index, end_index;
unsigned ofs;
BUG_ON(ni->page);
/*
* The index into the page cache and the offset within the page cache
* page of the wanted mft record. FIXME: We need to check for
* overflowing the unsigned long, but I don't think we would ever get
* here if the volume was that big...
*/
index = (u64)ni->mft_no << vol->mft_record_size_bits >>
PAGE_CACHE_SHIFT;
ofs = (ni->mft_no << vol->mft_record_size_bits) & ~PAGE_CACHE_MASK;
i_size = i_size_read(mft_vi);
/* The maximum valid index into the page cache for $MFT's data. */
end_index = i_size >> PAGE_CACHE_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_CACHE_MASK) < ofs +
vol->mft_record_size) {
page = ERR_PTR(-ENOENT);
ntfs_error(vol->sb, "Attempt to read mft record 0x%lx, "
"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 page. */
page = ntfs_map_page(mft_vi->i_mapping, index);
if (likely(!IS_ERR(page))) {
/* Catch multi sector transfer fixup errors. */
if (likely(ntfs_is_mft_recordp((le32*)(page_address(page) +
ofs)))) {
ni->page = page;
ni->page_ofs = ofs;
return page_address(page) + ofs;
}
ntfs_error(vol->sb, "Mft record 0x%lx is corrupt. "
"Run chkdsk.", ni->mft_no);
ntfs_unmap_page(page);
page = ERR_PTR(-EIO);
NVolSetErrors(vol);
}
err_out:
ni->page = NULL;
ni->page_ofs = 0;
return (void*)page;
}
/**
* map_mft_record - map, pin and lock an mft record
* @ni: ntfs inode whose MFT record to map
*
* First, take the mrec_lock mutex. We might now be sleeping, while waiting
* for the mutex if it was already locked by someone else.
*
* The page of the record is mapped using map_mft_record_page() before being
* returned to the caller.
*
* This in turn uses ntfs_map_page() to get the page containing the wanted mft
* record (it in turn calls read_cache_page() which reads it in from disk if
* necessary, increments the use count on the page so that it cannot disappear
* under us and returns a reference to the page cache page).
*
* If read_cache_page() invokes ntfs_readpage() to load the page from disk, it
* sets PG_locked and clears PG_uptodate on the page. Once I/O has completed
* and the post-read mst fixups on each mft record in the page have been
* performed, the page gets PG_uptodate set and PG_locked cleared (this is done
* in our asynchronous I/O completion handler end_buffer_read_mft_async()).
* ntfs_map_page() waits for PG_locked to become clear and checks if
* PG_uptodate is set and returns an error code if not. This provides
* sufficient protection against races when reading/using the page.
*
* However there is the write mapping to think about. Doing the above described
* checking here will be fine, because when initiating the write we will set
* PG_locked and clear PG_uptodate making sure nobody is touching the page
* contents. Doing the locking this way means that the commit to disk code in
* the page cache code paths is automatically sufficiently locked with us as
* we will not touch a page that has been locked or is not uptodate. The only
* locking problem then is them locking the page while we are accessing it.
*
* So that code will end up having to own the mrec_lock of all mft
* records/inodes present in the page before I/O can proceed. In that case we
* wouldn't need to bother with PG_locked and PG_uptodate as nobody will be
* accessing anything without owning the mrec_lock mutex. But we do need to
* use them because of the read_cache_page() invocation and the code becomes so
* much simpler this way that it is well worth it.
*
* The mft record is now ours and we return a pointer to it. You need to check
* the returned pointer with IS_ERR() and if that is true, PTR_ERR() will return
* the error code.
*
* NOTE: Caller is responsible for setting the mft record dirty before calling
* unmap_mft_record(). This is obviously only necessary if the caller really
* modified the mft record...
* Q: Do we want to recycle one of the VFS inode state bits instead?
* A: No, the inode ones mean we want to change the mft record, not we want to
* write it out.
*/
MFT_RECORD *map_mft_record(ntfs_inode *ni)
{
MFT_RECORD *m;
ntfs_debug("Entering for mft_no 0x%lx.", ni->mft_no);
/* Make sure the ntfs inode doesn't go away. */
atomic_inc(&ni->count);
/* Serialize access to this mft record. */
mutex_lock(&ni->mrec_lock);
m = map_mft_record_page(ni);
if (likely(!IS_ERR(m)))
return m;
mutex_unlock(&ni->mrec_lock);
atomic_dec(&ni->count);
ntfs_error(ni->vol->sb, "Failed with error code %lu.", -PTR_ERR(m));
return m;
}
/**
* unmap_mft_record_page - unmap the page in which a specific mft record resides
* @ni: ntfs inode whose mft record page to unmap
*
* This unmaps the page in which the mft record of the ntfs inode @ni is
* situated and returns. This is a NOOP if highmem is not configured.
*
* The unmap happens via ntfs_unmap_page() which in turn decrements the use
* count on the page thus releasing it from the pinned state.
*
* We do not actually unmap the page from memory of course, as that will be
* done by the page cache code itself when memory pressure increases or
* whatever.
*/
static inline void unmap_mft_record_page(ntfs_inode *ni)
{
BUG_ON(!ni->page);
// TODO: If dirty, blah...
ntfs_unmap_page(ni->page);
ni->page = NULL;
ni->page_ofs = 0;
return;
}
/**
* unmap_mft_record - release a mapped mft record
* @ni: ntfs inode whose MFT record to unmap
*
* We release the page mapping and the mrec_lock mutex which unmaps the mft
* record and releases it for others to get hold of. We also release the ntfs
* inode by decrementing the ntfs inode reference count.
*
* 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(ntfs_inode *ni)
{
struct page *page = ni->page;
BUG_ON(!page);
ntfs_debug("Entering for mft_no 0x%lx.", ni->mft_no);
unmap_mft_record_page(ni);
mutex_unlock(&ni->mrec_lock);
atomic_dec(&ni->count);
/*
* If pure ntfs_inode, i.e. no vfs inode attached, we leave it to
* ntfs_clear_extent_inode() in the extent inode case, and to the
* caller in the non-extent, yet pure ntfs inode case, to do the actual
* tear down of all structures and freeing of all allocated memory.
*/
return;
}
/**
* 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 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.
*/
MFT_RECORD *map_extent_mft_record(ntfs_inode *base_ni, MFT_REF mref,
ntfs_inode **ntfs_ino)
{
MFT_RECORD *m;
ntfs_inode *ni = NULL;
ntfs_inode **extent_nis = NULL;
int i;
unsigned long mft_no = MREF(mref);
u16 seq_no = MSEQNO(mref);
bool destroy_ni = false;
ntfs_debug("Mapping extent mft record 0x%lx (base mft record 0x%lx).",
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.
*/
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 (likely(!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;
}
/* 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)) {
mutex_unlock(&base_ni->extent_lock);
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)) {
mutex_unlock(&base_ni->extent_lock);
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_err_out;
}
/* Attach extent inode to base inode, reallocating memory if needed. */
if (!(base_ni->nr_extents & 3)) {
ntfs_inode **tmp;
int new_size = (base_ni->nr_extents + 4) * sizeof(ntfs_inode *);
tmp = kmalloc(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) {
BUG_ON(!base_ni->ext.extent_ntfs_inos);
memcpy(tmp, base_ni->ext.extent_ntfs_inos, new_size -
4 * sizeof(ntfs_inode *));
kfree(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:
unmap_mft_record(ni);
mutex_unlock(&base_ni->extent_lock);
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;
}
#ifdef NTFS_RW
/**
* __mark_mft_record_dirty - set the mft record and the page containing it dirty
* @ni: ntfs inode describing the mapped mft record
*
* Internal function. Users should call mark_mft_record_dirty() instead.
*
* Set the mapped (extent) mft record of the (base or extent) ntfs inode @ni,
* as well as the page containing the mft record, dirty. Also, mark the base
* vfs inode dirty. This ensures that any changes to the mft record are
* written out to disk.
*
* NOTE: We only set I_DIRTY_SYNC and 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(ntfs_inode *ni)
{
ntfs_inode *base_ni;
ntfs_debug("Entering for inode 0x%lx.", ni->mft_no);
BUG_ON(NInoAttr(ni));
mark_ntfs_record_dirty(ni->page, ni->page_ofs);
/* Determine the base vfs inode and mark it dirty, too. */
mutex_lock(&ni->extent_lock);
if (likely(ni->nr_extents >= 0))
base_ni = ni;
else
base_ni = ni->ext.base_ntfs_ino;
mutex_unlock(&ni->extent_lock);
__mark_inode_dirty(VFS_I(base_ni), I_DIRTY_SYNC | I_DIRTY_DATASYNC);
}
static const char *ntfs_please_email = "Please email "
"linux-ntfs-dev@lists.sourceforge.net and say that you saw "
"this message. Thank you.";
/**
* ntfs_sync_mft_mirror_umount - synchronise 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,
* bypassing the page cache and the $MFTMirr inode itself.
*
* This function is only for use at umount time when the mft mirror inode has
* already been disposed off. We BUG() if we are called while the mft mirror
* inode is still attached to the volume.
*
* On success return 0. On error return -errno.
*
* NOTE: This function is not implemented yet as I am not convinced it can
* actually be triggered considering the sequence of commits we do in super.c::
* ntfs_put_super(). But just in case we provide this place holder as the
* alternative would be either to BUG() or to get a NULL pointer dereference
* and Oops.
*/
static int ntfs_sync_mft_mirror_umount(ntfs_volume *vol,
const unsigned long mft_no, MFT_RECORD *m)
{
BUG_ON(vol->mftmirr_ino);
ntfs_error(vol->sb, "Umount time mft mirror syncing is not "
"implemented yet. %s", ntfs_please_email);
return -EOPNOTSUPP;
}
/**
* ntfs_sync_mft_mirror - synchronize an mft record to the mft mirror
* @vol: ntfs volume on which the mft record to synchronize resides
* @mft_no: mft record number of mft record to synchronize
* @m: mapped, mst protected (extent) mft record to synchronize
* @sync: if true, wait for i/o completion
*
* Write the mapped, mst protected (extent) mft record @m with mft record
* number @mft_no to the mft mirror ($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 and ignore the @sync parameter.
*
* TODO: If @sync is false, want to do truly asynchronous i/o, i.e. just
* schedule i/o via ->writepage or do it via kntfsd or whatever.
*/
int ntfs_sync_mft_mirror(ntfs_volume *vol, const unsigned long mft_no,
MFT_RECORD *m, int sync)
{
struct page *page;
unsigned int blocksize = vol->sb->s_blocksize;
int max_bhs = vol->mft_record_size / blocksize;
struct buffer_head *bhs[max_bhs];
struct buffer_head *bh, *head;
u8 *kmirr;
runlist_element *rl;
unsigned int block_start, block_end, m_start, m_end, page_ofs;
int i_bhs, nr_bhs, err = 0;
unsigned char blocksize_bits = vol->sb->s_blocksize_bits;
ntfs_debug("Entering for inode 0x%lx.", mft_no);
BUG_ON(!max_bhs);
if (unlikely(!vol->mftmirr_ino)) {
/* This could happen during umount... */
err = ntfs_sync_mft_mirror_umount(vol, mft_no, m);
if (likely(!err))
return err;
goto err_out;
}
/* Get the page containing the mirror copy of the mft record @m. */
page = ntfs_map_page(vol->mftmirr_ino->i_mapping, mft_no >>
(PAGE_CACHE_SHIFT - vol->mft_record_size_bits));
if (IS_ERR(page)) {
ntfs_error(vol->sb, "Failed to map mft mirror page.");
err = PTR_ERR(page);
goto err_out;
}
lock_page(page);
BUG_ON(!PageUptodate(page));
ClearPageUptodate(page);
/* Offset of the mft mirror record inside the page. */
page_ofs = (mft_no << vol->mft_record_size_bits) & ~PAGE_CACHE_MASK;
/* The address in the page of the mirror copy of the mft record @m. */
kmirr = page_address(page) + page_ofs;
/* Copy the mst protected mft record to the mirror. */
memcpy(kmirr, m, vol->mft_record_size);
/* Create uptodate buffers if not present. */
if (unlikely(!page_has_buffers(page))) {
struct buffer_head *tail;
bh = head = alloc_page_buffers(page, blocksize, 1);
do {
set_buffer_uptodate(bh);
tail = bh;
bh = bh->b_this_page;
} while (bh);
tail->b_this_page = head;
attach_page_buffers(page, head);
}
bh = head = page_buffers(page);
BUG_ON(!bh);
rl = NULL;
nr_bhs = 0;
block_start = 0;
m_start = kmirr - (u8*)page_address(page);
m_end = m_start + vol->mft_record_size;
do {
block_end = block_start + blocksize;
/* If the buffer is outside the mft record, skip it. */
if (block_end <= m_start)
continue;
if (unlikely(block_start >= m_end))
break;
/* Need to map the buffer if it is not mapped already. */
if (unlikely(!buffer_mapped(bh))) {
VCN vcn;
LCN lcn;
unsigned int vcn_ofs;
bh->b_bdev = vol->sb->s_bdev;
/* Obtain the vcn and offset of the current block. */
vcn = ((VCN)mft_no << vol->mft_record_size_bits) +
(block_start - m_start);
vcn_ofs = vcn & vol->cluster_size_mask;
vcn >>= vol->cluster_size_bits;
if (!rl) {
down_read(&NTFS_I(vol->mftmirr_ino)->
runlist.lock);
rl = NTFS_I(vol->mftmirr_ino)->runlist.rl;
/*
* $MFTMirr always has the whole of its runlist
* in memory.
*/
BUG_ON(!rl);
}
/* Seek to element containing target vcn. */
while (rl->length && rl[1].vcn <= vcn)
rl++;
lcn = ntfs_rl_vcn_to_lcn(rl, vcn);
/* For $MFTMirr, only lcn >= 0 is a successful remap. */
if (likely(lcn >= 0)) {
/* Setup buffer head to correct block. */
bh->b_blocknr = ((lcn <<
vol->cluster_size_bits) +
vcn_ofs) >> blocksize_bits;
set_buffer_mapped(bh);
} else {
bh->b_blocknr = -1;
ntfs_error(vol->sb, "Cannot write mft mirror "
"record 0x%lx because its "
"location on disk could not "
"be determined (error code "
"%lli).", mft_no,
(long long)lcn);
err = -EIO;
}
}
BUG_ON(!buffer_uptodate(bh));
BUG_ON(!nr_bhs && (m_start != block_start));
BUG_ON(nr_bhs >= max_bhs);
bhs[nr_bhs++] = bh;
BUG_ON((nr_bhs >= max_bhs) && (m_end != block_end));
} while (block_start = block_end, (bh = bh->b_this_page) != head);
if (unlikely(rl))
up_read(&NTFS_I(vol->mftmirr_ino)->runlist.lock);
if (likely(!err)) {
/* Lock buffers and start synchronous write i/o on them. */
for (i_bhs = 0; i_bhs < nr_bhs; i_bhs++) {
struct buffer_head *tbh = bhs[i_bhs];
if (!trylock_buffer(tbh))
BUG();
BUG_ON(!buffer_uptodate(tbh));
clear_buffer_dirty(tbh);
get_bh(tbh);
tbh->b_end_io = end_buffer_write_sync;
submit_bh(WRITE, tbh);
}
/* Wait on i/o completion of buffers. */
for (i_bhs = 0; i_bhs < nr_bhs; i_bhs++) {
struct buffer_head *tbh = bhs[i_bhs];
wait_on_buffer(tbh);
if (unlikely(!buffer_uptodate(tbh))) {
err = -EIO;
/*
* Set the buffer uptodate so the page and
* buffer states do not become out of sync.
*/
set_buffer_uptodate(tbh);
}
}
} else /* if (unlikely(err)) */ {
/* Clean the buffers. */
for (i_bhs = 0; i_bhs < nr_bhs; i_bhs++)
clear_buffer_dirty(bhs[i_bhs]);
}
/* Current state: all buffers are clean, unlocked, and uptodate. */
/* Remove the mst protection fixups again. */
post_write_mst_fixup((NTFS_RECORD*)kmirr);
flush_dcache_page(page);
SetPageUptodate(page);
unlock_page(page);
ntfs_unmap_page(page);
if (likely(!err)) {
ntfs_debug("Done.");
} else {
ntfs_error(vol->sb, "I/O error while writing mft mirror "
"record 0x%lx!", mft_no);
err_out:
ntfs_error(vol->sb, "Failed to synchronize $MFTMirr (error "
"code %i). Volume will be left marked dirty "
"on umount. Run ntfsfix 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 and the first
* buffer belonging to its mft record is dirty, too. We ignore the dirty state
* of subsequent buffers because we could have raced with
* fs/ntfs/aops.c::mark_ntfs_record_dirty().
*
* On success, clean the mft record and return 0. On error, leave the mft
* record dirty and return -errno.
*
* NOTE: We always perform synchronous i/o and ignore the @sync parameter.
* However, if the mft record has a counterpart in the mft mirror and @sync is
* true, we write the mft record, wait for i/o completion, and only then write
* the mft mirror copy. This ensures that if the system crashes either the mft
* or the mft mirror will contain a self-consistent mft record @m. If @sync is
* false on the other hand, we start i/o on both and then wait for completion
* on them. This provides a speedup but no longer guarantees that you will end
* up with a self-consistent mft record in the case of a crash but if you asked
* for asynchronous writing you probably do not care about that anyway.
*
* TODO: If @sync is false, want to do truly asynchronous i/o, i.e. just
* schedule i/o via ->writepage or do it via kntfsd or whatever.
*/
int write_mft_record_nolock(ntfs_inode *ni, MFT_RECORD *m, int sync)
{
ntfs_volume *vol = ni->vol;
struct page *page = ni->page;
unsigned int blocksize = vol->sb->s_blocksize;
unsigned char blocksize_bits = vol->sb->s_blocksize_bits;
int max_bhs = vol->mft_record_size / blocksize;
struct buffer_head *bhs[max_bhs];
struct buffer_head *bh, *head;
runlist_element *rl;
unsigned int block_start, block_end, m_start, m_end;
int i_bhs, nr_bhs, err = 0;
ntfs_debug("Entering for inode 0x%lx.", ni->mft_no);
BUG_ON(NInoAttr(ni));
BUG_ON(!max_bhs);
BUG_ON(!PageLocked(page));
/*
* If the 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;
bh = head = page_buffers(page);
BUG_ON(!bh);
rl = NULL;
nr_bhs = 0;
block_start = 0;
m_start = ni->page_ofs;
m_end = m_start + vol->mft_record_size;
do {
block_end = block_start + blocksize;
/* If the buffer is outside the mft record, skip it. */
if (block_end <= m_start)
continue;
if (unlikely(block_start >= m_end))
break;
/*
* If this block is not the first one in the record, we ignore
* the buffer's dirty state because we could have raced with a
* parallel mark_ntfs_record_dirty().
*/
if (block_start == m_start) {
/* This block is the first one in the record. */
if (!buffer_dirty(bh)) {
BUG_ON(nr_bhs);
/* Clean records are not written out. */
break;
}
}
/* Need to map the buffer if it is not mapped already. */
if (unlikely(!buffer_mapped(bh))) {
VCN vcn;
LCN lcn;
unsigned int vcn_ofs;
bh->b_bdev = vol->sb->s_bdev;
/* Obtain the vcn and offset of the current block. */
vcn = ((VCN)ni->mft_no << vol->mft_record_size_bits) +
(block_start - m_start);
vcn_ofs = vcn & vol->cluster_size_mask;
vcn >>= vol->cluster_size_bits;
if (!rl) {
down_read(&NTFS_I(vol->mft_ino)->runlist.lock);
rl = NTFS_I(vol->mft_ino)->runlist.rl;
BUG_ON(!rl);
}
/* Seek to element containing target vcn. */
while (rl->length && rl[1].vcn <= vcn)
rl++;
lcn = ntfs_rl_vcn_to_lcn(rl, vcn);
/* For $MFT, only lcn >= 0 is a successful remap. */
if (likely(lcn >= 0)) {
/* Setup buffer head to correct block. */
bh->b_blocknr = ((lcn <<
vol->cluster_size_bits) +
vcn_ofs) >> blocksize_bits;
set_buffer_mapped(bh);
} else {
bh->b_blocknr = -1;
ntfs_error(vol->sb, "Cannot write mft record "
"0x%lx because its location "
"on disk could not be "
"determined (error code %lli).",
ni->mft_no, (long long)lcn);
err = -EIO;
}
}
BUG_ON(!buffer_uptodate(bh));
BUG_ON(!nr_bhs && (m_start != block_start));
BUG_ON(nr_bhs >= max_bhs);
bhs[nr_bhs++] = bh;
BUG_ON((nr_bhs >= max_bhs) && (m_end != block_end));
} while (block_start = block_end, (bh = bh->b_this_page) != head);
if (unlikely(rl))
up_read(&NTFS_I(vol->mft_ino)->runlist.lock);
if (!nr_bhs)
goto done;
if (unlikely(err))
goto cleanup_out;
/* Apply the mst protection fixups. */
err = pre_write_mst_fixup((NTFS_RECORD*)m, vol->mft_record_size);
if (err) {
ntfs_error(vol->sb, "Failed to apply mst fixups!");
goto cleanup_out;
}
flush_dcache_mft_record_page(ni);
/* Lock buffers and start synchronous write i/o on them. */
for (i_bhs = 0; i_bhs < nr_bhs; i_bhs++) {
struct buffer_head *tbh = bhs[i_bhs];
if (!trylock_buffer(tbh))
BUG();
BUG_ON(!buffer_uptodate(tbh));
clear_buffer_dirty(tbh);
get_bh(tbh);
tbh->b_end_io = end_buffer_write_sync;
submit_bh(WRITE, tbh);
}
/* Synchronize the mft mirror now if not @sync. */
if (!sync && ni->mft_no < vol->mftmirr_size)
ntfs_sync_mft_mirror(vol, ni->mft_no, m, sync);
/* Wait on i/o completion of buffers. */
for (i_bhs = 0; i_bhs < nr_bhs; i_bhs++) {
struct buffer_head *tbh = bhs[i_bhs];
wait_on_buffer(tbh);
if (unlikely(!buffer_uptodate(tbh))) {
err = -EIO;
/*
* Set the buffer uptodate so the page and buffer
* states do not become out of sync.
*/
if (PageUptodate(page))
set_buffer_uptodate(tbh);
}
}
/* If @sync, now synchronize the mft mirror. */
if (sync && ni->mft_no < vol->mftmirr_size)
ntfs_sync_mft_mirror(vol, ni->mft_no, m, sync);
/* Remove the mst protection fixups again. */
post_write_mst_fixup((NTFS_RECORD*)m);
flush_dcache_mft_record_page(ni);
if (unlikely(err)) {
/* I/O error during writing. This is really bad! */
ntfs_error(vol->sb, "I/O error while writing mft record "
"0x%lx! 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;
cleanup_out:
/* Clean the buffers. */
for (i_bhs = 0; i_bhs < nr_bhs; i_bhs++)
clear_buffer_dirty(bhs[i_bhs]);
err_out:
/*
* Current state: all buffers are clean, unlocked, and uptodate.
* The caller should mark the base inode as bad so that no more i/o
* happens. ->clear_inode() will still be invoked so all extent inodes
* and other allocated memory will be freed.
*/
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;
}
/**
* 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
*
* 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.
*
* 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 ilookup5() as anyone
* opening/creating such an inode would block when attempting to map the mft
* record in read_cache_page() until we are finished with the write out.
*
* 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. (We know
* the access time update will modify the base mft record because Windows
* chkdsk complains if the standard information attribute is not in the base
* mft record.)
*
* 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 (normally the mft record is
* locked before the page is locked but we already have the page locked here
* when we try to lock the mft record).
*
* 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'.
*
* We now know the mft record is an extent mft record. We check if the inode
* corresponding to its base mft record is in icache and obtain a reference to
* it if it is. If it is not, we can safely write it and return 'true'.
*
* We now have the base inode for the extent mft record. We check if it has an
* ntfs inode for the extent mft record attached and if not it is safe to write
* the extent mft record and we return 'true'.
*
* The ntfs inode for the extent mft record is attached to the base inode so we
* attempt to lock the extent mft record and if we find the lock was already
* taken, it is not safe to write the extent mft record and we return 'false'.
*
* If we manage to obtain the lock we have exclusive access to the extent mft
* record, which also allows us safe writeout of the extent mft record. We
* set the ntfs inode of the extent mft record clean and then set @locked_ni to
* the now locked ntfs inode and return 'true'.
*
* Note, the reason for actually writing dirty mft records here and not just
* relying on the vfs inode dirty code paths is that we can have mft records
* modified without them ever having actual inodes in memory. Also we can have
* dirty mft records with clean ntfs inodes in memory. None of the described
* cases would result in the dirty mft records being written out if we only
* relied on the vfs inode dirty code paths. And these cases can really occur
* during allocation of new mft records and in particular when the
* initialized_size of the $MFT/$DATA attribute is extended and the new space
* is initialized using ntfs_mft_record_format(). The clean inode can then
* appear if the mft record is reused for a new inode before it got written
* out.
*/
bool ntfs_may_write_mft_record(ntfs_volume *vol, const unsigned long mft_no,
const MFT_RECORD *m, ntfs_inode **locked_ni)
{
struct super_block *sb = vol->sb;
struct inode *mft_vi = vol->mft_ino;
struct inode *vi;
ntfs_inode *ni, *eni, **extent_nis;
int i;
ntfs_attr na;
ntfs_debug("Entering for inode 0x%lx.", mft_no);
/*
* Normally we do not return a locked inode so set @locked_ni to NULL.
*/
BUG_ON(!locked_ni);
*locked_ni = 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%lx in icache.", mft_no);
na.mft_no = mft_no;
na.name = NULL;
na.name_len = 0;
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);
BUG_ON(vi != mft_vi);
} else {
/*
* Have to use ilookup5_nowait() since ilookup5() waits for the
* inode lock which causes ntfs to deadlock when a concurrent
* inode write via the inode dirty code paths and the page
* dirty code path of the inode dirty code path when writing
* $MFT occurs.
*/
vi = ilookup5_nowait(sb, mft_no, (test_t)ntfs_test_inode, &na);
}
if (vi) {
ntfs_debug("Base inode 0x%lx 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%lx is dirty, do not write it.",
mft_no);
atomic_dec(&ni->count);
iput(vi);
return false;
}
ntfs_debug("Inode 0x%lx 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%lx is already locked, do "
"not write it.", mft_no);
atomic_dec(&ni->count);
iput(vi);
return false;
}
ntfs_debug("Managed to lock mft record 0x%lx, 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%lx 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%lx 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%lx is a base record, write it.",
mft_no);
return true;
}
/*
* This is an extent mft record. Check if the inode corresponding to
* its base mft record is in icache and obtain a reference to it if it
* is.
*/
na.mft_no = MREF_LE(m->base_mft_record);
ntfs_debug("Mft record 0x%lx is an extent record. Looking for base "
"inode 0x%lx in icache.", mft_no, na.mft_no);
if (!na.mft_no) {
/* Balance the below iput(). */
vi = igrab(mft_vi);
BUG_ON(vi != mft_vi);
} else
vi = ilookup5_nowait(sb, na.mft_no, (test_t)ntfs_test_inode,
&na);
if (!vi) {
/*
* The base inode is not in icache, write this extent mft
* record.
*/
ntfs_debug("Base inode 0x%lx is not in icache, write the "
"extent record.", na.mft_no);
return true;
}
ntfs_debug("Base inode 0x%lx is in icache.", na.mft_no);
/*
* The base inode is in icache. Check if it has the extent inode
* corresponding to this extent mft record attached.
*/
ni = NTFS_I(vi);
mutex_lock(&ni->extent_lock);
if (ni->nr_extents <= 0) {
/*
* The base inode has no attached extent inodes, write this
* extent mft record.
*/
mutex_unlock(&ni->extent_lock);
iput(vi);
ntfs_debug("Base inode 0x%lx has no attached extent inodes, "
"write the extent record.", na.mft_no);
return true;
}
/* Iterate over the attached extent inodes. */
extent_nis = ni->ext.extent_ntfs_inos;
for (eni = NULL, i = 0; i < ni->nr_extents; ++i) {
if (mft_no == extent_nis[i]->mft_no) {
/*
* Found the extent inode corresponding to this extent
* mft record.
*/
eni = extent_nis[i];
break;
}
}
/*
* If the extent inode was not attached to the base inode, write this
* extent mft record.
*/
if (!eni) {
mutex_unlock(&ni->extent_lock);
iput(vi);
ntfs_debug("Extent inode 0x%lx is not attached to its base "
"inode 0x%lx, write the extent record.",
mft_no, na.mft_no);
return true;
}
ntfs_debug("Extent inode 0x%lx is attached to its base inode 0x%lx.",
mft_no, na.mft_no);
/* Take a reference to the extent ntfs inode. */
atomic_inc(&eni->count);
mutex_unlock(&ni->extent_lock);
/*
* Found the extent inode coresponding to this extent mft record.
* Try to take the mft record lock.
*/
if (unlikely(!mutex_trylock(&eni->mrec_lock))) {
atomic_dec(&eni->count);
iput(vi);
ntfs_debug("Extent mft record 0x%lx is already locked, do "
"not write it.", mft_no);
return false;
}
ntfs_debug("Managed to lock extent mft record 0x%lx, write it.",
mft_no);
if (NInoTestClearDirty(eni))
ntfs_debug("Extent inode 0x%lx is dirty, marking it clean.",
mft_no);
/*
* The write has to occur while we hold the mft record lock so return
* the locked extent ntfs inode.
*/
*locked_ni = eni;
return true;
}
static const char *es = " Leaving inconsistent metadata. Unmount and run "
"chkdsk.";
/**
* ntfs_mft_bitmap_find_and_alloc_free_rec_nolock - see name
* @vol: volume on which to search for a free mft record
* @base_ni: open base inode if allocating an extent mft record or NULL
*
* 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 int ntfs_mft_bitmap_find_and_alloc_free_rec_nolock(ntfs_volume *vol,
ntfs_inode *base_ni)
{
s64 pass_end, ll, data_pos, pass_start, ofs, bit;
unsigned long flags;
struct address_space *mftbmp_mapping;
u8 *buf, *byte;
struct page *page;
unsigned int page_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;
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;
pass = 1;
if (!base_ni)
data_pos = vol->mft_data_pos;
else
data_pos = base_ni->mft_no + 1;
if (data_pos < 24)
data_pos = 24;
if (data_pos >= pass_end) {
data_pos = 24;
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,
(long long)pass_start, (long long)pass_end,
(long long)data_pos);
/* Loop until a free mft record is found. */
for (; pass <= 2;) {
/* Cap size to pass_end. */
ofs = data_pos >> 3;
page_ofs = ofs & ~PAGE_CACHE_MASK;
size = PAGE_CACHE_SIZE - page_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) {
page = ntfs_map_page(mftbmp_mapping,
ofs >> PAGE_CACHE_SHIFT);
if (IS_ERR(page)) {
ntfs_error(vol->sb, "Failed to read mft "
"bitmap, aborting.");
return PTR_ERR(page);
}
buf = (u8*)page_address(page) + page_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,
(long long)data_pos, (long long)bit);
for (; bit < size && data_pos + bit < pass_end;
bit &= ~7ull, bit += 8) {
byte = buf + (bit >> 3);
if (*byte == 0xff)
continue;
b = ffz((unsigned long)*byte);
if (b < 8 && b >= (bit & 7)) {
ll = data_pos + (bit & ~7ull) + b;
if (unlikely(ll > (1ll << 32))) {
ntfs_unmap_page(page);
return -ENOSPC;
}
*byte |= 1 << b;
flush_dcache_page(page);
set_page_dirty(page);
ntfs_unmap_page(page);
ntfs_debug("Done. (Found and "
"allocated mft record "
"0x%llx.)",
(long long)ll);
return ll;
}
}
ntfs_debug("After inner for loop: size 0x%x, "
"data_pos 0x%llx, bit 0x%llx", size,
(long long)data_pos, (long long)bit);
data_pos += size;
ntfs_unmap_page(page);
/*
* 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 = pass_start = 24;
ntfs_debug("pass %i, pass_start 0x%llx, pass_end "
"0x%llx.", pass, (long long)pass_start,
(long long)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;
}
/**
* 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(ntfs_volume *vol)
{
LCN lcn;
s64 ll;
unsigned long flags;
struct page *page;
ntfs_inode *mft_ni, *mftbmp_ni;
runlist_element *rl, *rl2 = NULL;
ntfs_attr_search_ctx *ctx = NULL;
MFT_RECORD *mrec;
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;
} status = { 0, 0, 0 };
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,
(ll - 1) >> vol->cluster_size_bits, NULL);
if (unlikely(IS_ERR(rl) || !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;
page = ntfs_map_page(vol->lcnbmp_ino->i_mapping,
ll >> PAGE_CACHE_SHIFT);
if (IS_ERR(page)) {
up_write(&mftbmp_ni->runlist.lock);
ntfs_error(vol->sb, "Failed to read from lcn bitmap.");
return PTR_ERR(page);
}
b = (u8*)page_address(page) + (ll & ~PAGE_CACHE_MASK);
tb = 1 << (lcn & 7ull);
down_write(&vol->lcnbmp_lock);
if (*b != 0xff && !(*b & tb)) {
/* Next cluster is free, allocate it. */
*b |= tb;
flush_dcache_page(page);
set_page_dirty(page);
up_write(&vol->lcnbmp_lock);
ntfs_unmap_page(page);
/* Update the mft bitmap runlist. */
rl->length++;
rl[1].vcn++;
status.added_cluster = 1;
ntfs_debug("Appending one cluster to mft bitmap.");
} else {
up_write(&vol->lcnbmp_lock);
ntfs_unmap_page(page);
/* Allocate a cluster from the DATA_ZONE. */
rl2 = ntfs_cluster_alloc(vol, rl[1].vcn, 1, lcn, DATA_ZONE,
true);
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.rl, rl2);
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);
}
ntfs_free(rl2);
return PTR_ERR(rl);
}
mftbmp_ni->runlist.rl = rl;
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 = sle64_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;
}
BUG_ON(ll < rl2->vcn);
BUG_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);
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)) {
if (ret != -ENOSPC) {
ntfs_error(vol->sb, "Failed to resize attribute "
"record for mft bitmap attribute.");
goto undo_alloc;
}
// TODO: Deal with this by moving this extent to a new mft
// record or by starting a new extent in a new mft record or by
// moving other attributes out of this mft record.
// Note: It will need to be a special mft record and if none of
// those are available it gets rather complicated...
ntfs_error(vol->sb, "Not enough space in this mft record to "
"accommodate extended mft bitmap attribute "
"extent. Cannot handle this yet.");
ret = -EOPNOTSUPP;
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);
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_sle64(rl[1].vcn - 1);
/*
* We now have extended the mft bitmap allocated_size by one cluster.
* Reflect this in the 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.
*/
flush_dcache_mft_record_page(ctx->ntfs_ino);
mark_mft_record_dirty(ctx->ntfs_ino);
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_sle64(mftbmp_ni->allocated_size);
write_unlock_irqrestore(&mftbmp_ni->size_lock, flags);
/* Ensure the changes make it to disk. */
flush_dcache_mft_record_page(ctx->ntfs_ino);
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_sle64(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;
}
/* 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);
}
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)) {
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);
}
flush_dcache_mft_record_page(ctx->ntfs_ino);
mark_mft_record_dirty(ctx->ntfs_ino);
}
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(ntfs_volume *vol)
{
s64 old_data_size, old_initialized_size;
unsigned long flags;
struct inode *mftbmp_vi;
ntfs_inode *mft_ni, *mftbmp_ni;
ntfs_attr_search_ctx *ctx;
MFT_RECORD *mrec;
ATTR_RECORD *a;
int ret;
ntfs_debug("Extending mft bitmap initiailized (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_sle64(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_sle64(mftbmp_ni->initialized_size);
}
write_unlock_irqrestore(&mftbmp_ni->size_lock, flags);
/* Ensure the changes make it to disk. */
flush_dcache_mft_record_page(ctx->ntfs_ino);
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_sle64(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_sle64(old_data_size);
}
write_unlock_irqrestore(&mftbmp_ni->size_lock, flags);
flush_dcache_mft_record_page(ctx->ntfs_ino);
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.",
(long long)mftbmp_ni->allocated_size,
(long long)i_size_read(mftbmp_vi),
(long long)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 one mft record worth
* of clusters.
*
* 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(ntfs_volume *vol)
{
LCN lcn;
VCN old_last_vcn;
s64 min_nr, nr, ll;
unsigned long flags;
ntfs_inode *mft_ni;
runlist_element *rl, *rl2;
ntfs_attr_search_ctx *ctx = NULL;
MFT_RECORD *mrec;
ATTR_RECORD *a = NULL;
int ret, mp_size;
u32 old_alen = 0;
bool mp_rebuilt = false;
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,
(ll - 1) >> vol->cluster_size_bits, NULL);
if (unlikely(IS_ERR(rl) || !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.", (long long)lcn);
/* Minimum allocation is one mft record worth of clusters. */
min_nr = vol->mft_record_size >> vol->cluster_size_bits;
if (!min_nr)
min_nr = 1;
/* 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 + (nr << vol->cluster_size_bits)) >>
vol->mft_record_size_bits >= (1ll << 32))) {
nr = min_nr;
if (unlikely((ll + (nr << vol->cluster_size_bits)) >>
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;
do {
rl2 = ntfs_cluster_alloc(vol, old_last_vcn, nr, lcn, MFT_ZONE,
true);
if (likely(!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.", (long long)nr);
up_write(&mft_ni->runlist.lock);
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.", (long long)nr);
} while (1);
rl = ntfs_runlists_merge(mft_ni->runlist.rl, rl2);
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);
}
ntfs_free(rl2);
return PTR_ERR(rl);
}
mft_ni->runlist.rl = rl;
ntfs_debug("Allocated %lli clusters.", (long long)nr);
/* Find the last run in the new runlist. */
for (; rl[1].length; rl++)
;
/* 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);
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 = sle64_to_cpu(a->data.non_resident.lowest_vcn);
/* 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;
}
BUG_ON(ll < rl2->vcn);
BUG_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);
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;
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)) {
if (ret != -ENOSPC) {
ntfs_error(vol->sb, "Failed to resize attribute "
"record for mft data attribute.");
goto undo_alloc;
}
// TODO: Deal with this by moving this extent to a new mft
// record or by starting a new extent in a new mft record or by
// moving other attributes out of this mft record.
// Note: Use the special reserved mft records and ensure that
// this extent is not required to find the mft record in
// question. If no free special records left we would need to
// move an existing record away, insert ours in its place, and
// then place the moved record into the newly allocated space
// and we would then need to update all references to this mft
// record appropriately. This is rather complicated...
ntfs_error(vol->sb, "Not enough space in this mft record to "
"accommodate extended mft data attribute "
"extent. Cannot handle this yet.");
ret = -EOPNOTSUPP;
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);
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_sle64(rl[1].vcn - 1);
/*
* We now have extended the mft data allocated_size by nr clusters.
* Reflect this in the 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.
*/
flush_dcache_mft_record_page(ctx->ntfs_ino);
mark_mft_record_dirty(ctx->ntfs_ino);
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 += nr << vol->cluster_size_bits;
a->data.non_resident.allocated_size =
cpu_to_sle64(mft_ni->allocated_size);
write_unlock_irqrestore(&mft_ni->size_lock, flags);
/* Ensure the changes make it to disk. */
flush_dcache_mft_record_page(ctx->ntfs_ino);
mark_mft_record_dirty(ctx->ntfs_ino);
ntfs_attr_put_search_ctx(ctx);
unmap_mft_record(mft_ni);
up_write(&mft_ni->runlist.lock);
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 += nr << vol->cluster_size_bits;
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_sle64(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);
}
a = ctx->attr;
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_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)) {
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);
}
flush_dcache_mft_record_page(ctx->ntfs_ino);
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);
}
if (ctx)
ntfs_attr_put_search_ctx(ctx);
if (!IS_ERR(mrec))
unmap_mft_record(mft_ni);
up_write(&mft_ni->runlist.lock);
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 ntfs_volume *vol, const s64 mft_no,
MFT_RECORD *m)
{
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(MFT_RECORD_OLD) + 1) & ~1);
else {
m->usa_ofs = cpu_to_le16((sizeof(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, please email "
"linux-ntfs-dev@lists.sourceforge.net stating "
"that you saw this message and that the "
"modified filesystem created was corrupt. "
"Thank you.");
}
/* 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 = (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 ntfs_volume *vol, const s64 mft_no)
{
loff_t i_size;
struct inode *mft_vi = vol->mft_ino;
struct page *page;
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 = mft_no << vol->mft_record_size_bits >> PAGE_CACHE_SHIFT;
ofs = (mft_no << vol->mft_record_size_bits) & ~PAGE_CACHE_MASK;
/* The maximum valid index into the page cache for $MFT's data. */
i_size = i_size_read(mft_vi);
end_index = i_size >> PAGE_CACHE_SHIFT;
if (unlikely(index >= end_index)) {
if (unlikely(index > end_index || ofs + vol->mft_record_size >=
(i_size & ~PAGE_CACHE_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 page containing the mft record. */
page = ntfs_map_page(mft_vi->i_mapping, index);
if (IS_ERR(page)) {
ntfs_error(vol->sb, "Failed to map page containing mft record "
"to format 0x%llx.", (long long)mft_no);
return PTR_ERR(page);
}
lock_page(page);
BUG_ON(!PageUptodate(page));
ClearPageUptodate(page);
m = (MFT_RECORD*)((u8*)page_address(page) + 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);
SetPageUptodate(page);
unlock_page(page);
ntfs_unmap_page(page);
return err;
}
flush_dcache_page(page);
SetPageUptodate(page);
unlock_page(page);
/*
* 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.
*/
mark_ntfs_record_dirty(page, ofs);
ntfs_unmap_page(page);
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
* @base_ni: [IN] open base inode if allocating an extent mft record or NULL
* @mrec: [OUT] on successful return this is the mapped mft record
*
* 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 anyway and 16
* to 24 are special in that they are used for storing extension mft records
* for the $DATA attribute of $MFT. This is required to avoid the possibility
* of creating a runlist with a circular dependency which once written to disk
* can never be read in again. Windows will only use records 16 to 24 for
* normal files if the volume is completely out of space. We never use them
* which means that when the volume is really out of space we cannot create any
* more files while Windows can still create up to 8 small files. We can start
* doing this at some later time, it does not matter much for now.
*
* 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 a single mft record
* or one cluster, if cluster size is above the mft record size.
*
* No matter how many mft records we allocate, we initialize only the first
* allocated mft record, incrementing mft data size and initialized size
* accordingly, open an ntfs_inode for it and return it to the caller, unless
* there are less than 24 mft records, in which case we allocate and initialize
* mft records until we reach record 24 which we consider as the first free mft
* record for use by 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
* superflous 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 ntfs_inode for the allocated mft record, and we will have
* - returned the 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.
*/
ntfs_inode *ntfs_mft_record_alloc(ntfs_volume *vol, const int mode,
ntfs_inode *base_ni, MFT_RECORD **mrec)
{
s64 ll, bit, old_data_initialized, old_data_size;
unsigned long flags;
struct inode *vi;
struct page *page;
ntfs_inode *mft_ni, *mftbmp_ni, *ni;
ntfs_attr_search_ctx *ctx;
MFT_RECORD *m;
ATTR_RECORD *a;
pgoff_t index;
unsigned int ofs;
int err;
le16 seq_no, usn;
bool record_formatted = false;
if (base_ni) {
ntfs_debug("Entering (allocating an extent mft record for "
"base mft record 0x%llx).",
(long long)base_ni->mft_no);
/* @mode and @base_ni are mutually exclusive. */
BUG_ON(mode);
} else
ntfs_debug("Entering (allocating a base mft record).");
if (mode) {
/* @mode and @base_ni are mutually exclusive. */
BUG_ON(base_ni);
/* We only support creation of normal files and directories. */
if (!S_ISREG(mode) && !S_ISDIR(mode))
return ERR_PTR(-EOPNOTSUPP);
}
BUG_ON(!mrec);
mft_ni = NTFS_I(vol->mft_ino);
mftbmp_ni = NTFS_I(vol->mftbmp_ino);
down_write(&vol->mftbmp_lock);
bit = ntfs_mft_bitmap_find_and_alloc_free_rec_nolock(vol, base_ni);
if (bit >= 0) {
ntfs_debug("Found and allocated free record (#1), bit 0x%llx.",
(long long)bit);
goto have_alloc_rec;
}
if (bit != -ENOSPC) {
up_write(&vol->mftbmp_lock);
return ERR_PTR(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) {
bit = ll;
if (bit < 24)
bit = 24;
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.",
(long long)old_data_size,
(long long)i_size_read(vol->mftbmp_ino),
(long long)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 (unlikely(err)) {
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.",
(long long)mftbmp_ni->allocated_size,
(long long)i_size_read(vol->mftbmp_ino),
(long long)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)) {
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.",
(long long)mftbmp_ni->allocated_size,
(long long)i_size_read(vol->mftbmp_ino),
(long long)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.");
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);
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.
*/
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.",
(long long)mft_ni->allocated_size,
(long long)i_size_read(vol->mft_ino),
(long long)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 (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.",
(long long)mft_ni->allocated_size,
(long long)i_size_read(vol->mft_ino),
(long long)mft_ni->initialized_size);
}
read_unlock_irqrestore(&mft_ni->size_lock, flags);
/*
* 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 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_sle64(mft_ni->initialized_size);
a->data.non_resident.data_size =
cpu_to_sle64(i_size_read(vol->mft_ino));
read_unlock_irqrestore(&mft_ni->size_lock, flags);
/* Ensure the changes make it to disk. */
flush_dcache_mft_record_page(ctx->ntfs_ino);
mark_mft_record_dirty(ctx->ntfs_ino);
ntfs_attr_put_search_ctx(ctx);
unmap_mft_record(mft_ni);
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.",
(long long)mft_ni->allocated_size,
(long long)i_size_read(vol->mft_ino),
(long long)mft_ni->initialized_size);
BUG_ON(i_size_read(vol->mft_ino) > mft_ni->allocated_size);
BUG_ON(mft_ni->initialized_size > i_size_read(vol->mft_ino));
read_unlock_irqrestore(&mft_ni->size_lock, flags);
mft_rec_already_initialized:
/*
* 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.
*/
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 = bit << vol->mft_record_size_bits >> PAGE_CACHE_SHIFT;
ofs = (bit << vol->mft_record_size_bits) & ~PAGE_CACHE_MASK;
/* Read, map, and pin the page containing the mft record. */
page = ntfs_map_page(vol->mft_ino->i_mapping, index);
if (IS_ERR(page)) {
ntfs_error(vol->sb, "Failed to map page containing allocated "
"mft record 0x%llx.", (long long)bit);
err = PTR_ERR(page);
goto undo_mftbmp_alloc;
}
lock_page(page);
BUG_ON(!PageUptodate(page));
ClearPageUptodate(page);
m = (MFT_RECORD*)((u8*)page_address(page) + 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 (ntfs_is_file_record(m->magic) &&
(m->flags & MFT_RECORD_IN_USE)) {
ntfs_error(vol->sb, "Mft record 0x%llx was marked "
"free in mft bitmap but is marked "
"used itself. Corrupt filesystem. "
"Unmount and run chkdsk.",
(long long)bit);
err = -EIO;
SetPageUptodate(page);
unlock_page(page);
ntfs_unmap_page(page);
NVolSetErrors(vol);
goto undo_mftbmp_alloc;
}
/*
* 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;
usn = *(le16*)((u8*)m + le16_to_cpu(m->usa_ofs));
err = ntfs_mft_record_layout(vol, bit, m);
if (unlikely(err)) {
ntfs_error(vol->sb, "Failed to layout allocated mft "
"record 0x%llx.", (long long)bit);
SetPageUptodate(page);
unlock_page(page);
ntfs_unmap_page(page);
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;
}
/* Set the mft record itself in use. */
m->flags |= MFT_RECORD_IN_USE;
if (S_ISDIR(mode))
m->flags |= MFT_RECORD_IS_DIRECTORY;
flush_dcache_page(page);
SetPageUptodate(page);
if (base_ni) {
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, bit, &ni);
if (IS_ERR(m_tmp)) {
ntfs_error(vol->sb, "Failed to map allocated extent "
"mft record 0x%llx.", (long long)bit);
err = PTR_ERR(m_tmp);
/* Set the mft record itself not in use. */
m->flags &= cpu_to_le16(
~le16_to_cpu(MFT_RECORD_IN_USE));
flush_dcache_page(page);
/* Make sure the mft record is written out to disk. */
mark_ntfs_record_dirty(page, ofs);
unlock_page(page);
ntfs_unmap_page(page);
goto undo_mftbmp_alloc;
}
BUG_ON(m != m_tmp);
/*
* 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.
*/
mark_ntfs_record_dirty(page, ofs);
unlock_page(page);
/*
* Need to unmap the page since map_extent_mft_record() mapped
* it as well so we have it mapped twice at the moment.
*/
ntfs_unmap_page(page);
} else {
/*
* Allocate a new VFS inode and set it up. NOTE: @vi->i_nlink
* is set to 1 but the mft record->link_count is 0. The caller
* needs to bear this in mind.
*/
vi = new_inode(vol->sb);
if (unlikely(!vi)) {
err = -ENOMEM;
/* Set the mft record itself not in use. */
m->flags &= cpu_to_le16(
~le16_to_cpu(MFT_RECORD_IN_USE));
flush_dcache_page(page);
/* Make sure the mft record is written out to disk. */
mark_ntfs_record_dirty(page, ofs);
unlock_page(page);
ntfs_unmap_page(page);
goto undo_mftbmp_alloc;
}
vi->i_ino = bit;
/*
* This is for checking whether an inode has changed w.r.t. a
* file so that the file can be updated if necessary (compare
* with f_version).
*/
vi->i_version = 1;
/* The owner and group come from the ntfs volume. */
vi->i_uid = vol->uid;
vi->i_gid = vol->gid;
/* Initialize the ntfs specific part of @vi. */
ntfs_init_big_inode(vi);
ni = NTFS_I(vi);
/*
* Set the appropriate mode, attribute type, and name. For
* directories, also setup the index values to the defaults.
*/
if (S_ISDIR(mode)) {
vi->i_mode = S_IFDIR | S_IRWXUGO;
vi->i_mode &= ~vol->dmask;
NInoSetMstProtected(ni);
ni->type = AT_INDEX_ALLOCATION;
ni->name = I30;
ni->name_len = 4;
ni->itype.index.block_size = 4096;
ni->itype.index.block_size_bits = ntfs_ffs(4096) - 1;
ni->itype.index.collation_rule = COLLATION_FILE_NAME;
if (vol->cluster_size <= ni->itype.index.block_size) {
ni->itype.index.vcn_size = vol->cluster_size;
ni->itype.index.vcn_size_bits =
vol->cluster_size_bits;
} else {
ni->itype.index.vcn_size = vol->sector_size;
ni->itype.index.vcn_size_bits =
vol->sector_size_bits;
}
} else {
vi->i_mode = S_IFREG | S_IRWXUGO;
vi->i_mode &= ~vol->fmask;
ni->type = AT_DATA;
ni->name = NULL;
ni->name_len = 0;
}
if (IS_RDONLY(vi))
vi->i_mode &= ~S_IWUGO;
/* Set the inode times to the current time. */
vi->i_atime = vi->i_mtime = vi->i_ctime =
current_fs_time(vi->i_sb);
/*
* Set the file size to 0, the ntfs inode sizes are set to 0 by
* the call to ntfs_init_big_inode() below.
*/
vi->i_size = 0;
vi->i_blocks = 0;
/* Set the sequence number. */
vi->i_generation = ni->seq_no = le16_to_cpu(m->sequence_number);
/*
* Manually map, pin, and lock the mft record as we already
* have its page mapped and it is very easy to do.
*/
atomic_inc(&ni->count);
mutex_lock(&ni->mrec_lock);
ni->page = page;
ni->page_ofs = ofs;
/*
* 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.
*/
mark_ntfs_record_dirty(page, ofs);
unlock_page(page);
/* Add the inode to the inode hash for the superblock. */
insert_inode_hash(vi);
/* Update the default mft allocation position. */
vol->mft_data_pos = bit + 1;
}
/*
* 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 " : "", (long long)bit);
*mrec = m;
return ni;
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:
down_write(&vol->mftbmp_lock);
undo_mftbmp_alloc_nolock:
if (ntfs_bitmap_clear_bit(vol->mftbmp_ino, bit)) {
ntfs_error(vol->sb, "Failed to clear bit in mft bitmap.%s", es);
NVolSetErrors(vol);
}
up_write(&vol->mftbmp_lock);
err_out:
return ERR_PTR(err);
max_err_out:
ntfs_warning(vol->sb, "Cannot allocate mft record because the maximum "
"number of inodes (2^32) has already been reached.");
up_write(&vol->mftbmp_lock);
return ERR_PTR(-ENOSPC);
}
/**
* ntfs_extent_mft_record_free - free an extent mft record on an ntfs volume
* @ni: ntfs inode of the mapped extent mft record to free
* @m: mapped extent mft record of the ntfs inode @ni
*
* Free the mapped extent mft record @m of the extent ntfs inode @ni.
*
* Note that this function unmaps the mft record and closes and destroys @ni
* internally and hence you cannot use either @ni nor @m any more after this
* function returns success.
*
* On success return 0 and on error return -errno. @ni and @m are still valid
* in this case and have not been freed.
*
* For some errors an error message is displayed and the success code 0 is
* returned and the volume is then left dirty on umount. This makes sense in
* case we could not rollback the changes that were already done since the
* caller no longer wants to reference this mft record so it does not matter to
* the caller if something is wrong with it as long as it is properly detached
* from the base inode.
*/
int ntfs_extent_mft_record_free(ntfs_inode *ni, MFT_RECORD *m)
{
unsigned long mft_no = ni->mft_no;
ntfs_volume *vol = ni->vol;
ntfs_inode *base_ni;
ntfs_inode **extent_nis;
int i, err;
le16 old_seq_no;
u16 seq_no;
BUG_ON(NInoAttr(ni));
BUG_ON(ni->nr_extents != -1);
mutex_lock(&ni->extent_lock);
base_ni = ni->ext.base_ntfs_ino;
mutex_unlock(&ni->extent_lock);
BUG_ON(base_ni->nr_extents <= 0);
ntfs_debug("Entering for extent inode 0x%lx, base inode 0x%lx.\n",
mft_no, base_ni->mft_no);
mutex_lock(&base_ni->extent_lock);
/* Make sure we are holding the only reference to the extent inode. */
if (atomic_read(&ni->count) > 2) {
ntfs_error(vol->sb, "Tried to free busy extent inode 0x%lx, "
"not freeing.", base_ni->mft_no);
mutex_unlock(&base_ni->extent_lock);
return -EBUSY;
}
/* Dissociate the ntfs inode from the base inode. */
extent_nis = base_ni->ext.extent_ntfs_inos;
err = -ENOENT;
for (i = 0; i < base_ni->nr_extents; i++) {
if (ni != extent_nis[i])
continue;
extent_nis += i;
base_ni->nr_extents--;
memmove(extent_nis, extent_nis + 1, (base_ni->nr_extents - i) *
sizeof(ntfs_inode*));
err = 0;
break;
}
mutex_unlock(&base_ni->extent_lock);
if (unlikely(err)) {
ntfs_error(vol->sb, "Extent inode 0x%lx is not attached to "
"its base inode 0x%lx.", mft_no,
base_ni->mft_no);
BUG();
}
/*
* The extent inode is no longer attached to the base inode so no one
* can get a reference to it any more.
*/
/* Mark the mft record as not in use. */
m->flags &= ~MFT_RECORD_IN_USE;
/* Increment the sequence number, skipping zero, if it is not zero. */
old_seq_no = m->sequence_number;
seq_no = le16_to_cpu(old_seq_no);
if (seq_no == 0xffff)
seq_no = 1;
else if (seq_no)
seq_no++;
m->sequence_number = cpu_to_le16(seq_no);
/*
* 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, m, 0);
if (unlikely(err)) {
ntfs_error(vol->sb, "Failed to write mft record 0x%lx, not "
"freeing.", mft_no);
goto rollback;
}
rollback_error:
/* Unmap and throw away the now freed extent inode. */
unmap_extent_mft_record(ni);
ntfs_clear_extent_inode(ni);
/* Clear the bit in the $MFT/$BITMAP corresponding to this record. */
down_write(&vol->mftbmp_lock);
err = ntfs_bitmap_clear_bit(vol->mftbmp_ino, mft_no);
up_write(&vol->mftbmp_lock);
if (unlikely(err)) {
/*
* The extent inode is gone but we failed to deallocate it in
* the mft bitmap. Just emit a warning and leave the volume
* dirty on umount.
*/
ntfs_error(vol->sb, "Failed to clear bit in mft bitmap.%s", es);
NVolSetErrors(vol);
}
return 0;
rollback:
/* Rollback what we did... */
mutex_lock(&base_ni->extent_lock);
extent_nis = base_ni->ext.extent_ntfs_inos;
if (!(base_ni->nr_extents & 3)) {
int new_size = (base_ni->nr_extents + 4) * sizeof(ntfs_inode*);
extent_nis = kmalloc(new_size, GFP_NOFS);
if (unlikely(!extent_nis)) {
ntfs_error(vol->sb, "Failed to allocate internal "
"buffer during rollback.%s", es);
mutex_unlock(&base_ni->extent_lock);
NVolSetErrors(vol);
goto rollback_error;
}
if (base_ni->nr_extents) {
BUG_ON(!base_ni->ext.extent_ntfs_inos);
memcpy(extent_nis, base_ni->ext.extent_ntfs_inos,
new_size - 4 * sizeof(ntfs_inode*));
kfree(base_ni->ext.extent_ntfs_inos);
}
base_ni->ext.extent_ntfs_inos = extent_nis;
}
m->flags |= MFT_RECORD_IN_USE;
m->sequence_number = old_seq_no;
extent_nis[base_ni->nr_extents++] = ni;
mutex_unlock(&base_ni->extent_lock);
mark_mft_record_dirty(ni);
return err;
}
#endif /* NTFS_RW */