korg/linux
0
0
Fork 0
mirror of https://mirrors.bfsu.edu.cn/git/linux.git synced 2024-11-16 16:54:20 +08:00
Code Issues Packages Projects Releases Wiki Activity
600f111ef5
linux/fs/ntfs/lcnalloc.c
Thomas Gleixner a1d312de77 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 96 
Based on 1 normalized pattern(s):

  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

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 43 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190520075212.517001706@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-24 17:37:53 +02:00

1001 lines
32 KiB
C
Raw Blame History

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* lcnalloc.c - Cluster (de)allocation code. Part of the Linux-NTFS project.
*
* Copyright (c) 2004-2005 Anton Altaparmakov
*/
#ifdef NTFS_RW
#include <linux/pagemap.h>
#include "lcnalloc.h"
#include "debug.h"
#include "bitmap.h"
#include "inode.h"
#include "volume.h"
#include "attrib.h"
#include "malloc.h"
#include "aops.h"
#include "ntfs.h"
/**
* ntfs_cluster_free_from_rl_nolock - free clusters from runlist
* @vol: mounted ntfs volume on which to free the clusters
* @rl: runlist describing the clusters to free
*
* Free all the clusters described by the runlist @rl on the volume @vol. In
* the case of an error being returned, at least some of the clusters were not
* freed.
*
* Return 0 on success and -errno on error.
*
* Locking: - The volume lcn bitmap must be locked for writing on entry and is
* left locked on return.
*/
int ntfs_cluster_free_from_rl_nolock(ntfs_volume *vol,
const runlist_element *rl)
{
struct inode *lcnbmp_vi = vol->lcnbmp_ino;
int ret = 0;
ntfs_debug("Entering.");
if (!rl)
return 0;
for (; rl->length; rl++) {
int err;
if (rl->lcn < 0)
continue;
err = ntfs_bitmap_clear_run(lcnbmp_vi, rl->lcn, rl->length);
if (unlikely(err && (!ret || ret == -ENOMEM) && ret != err))
ret = err;
}
ntfs_debug("Done.");
return ret;
}
/**
* ntfs_cluster_alloc - allocate clusters on an ntfs volume
* @vol: mounted ntfs volume on which to allocate the clusters
* @start_vcn: vcn to use for the first allocated cluster
* @count: number of clusters to allocate
* @start_lcn: starting lcn at which to allocate the clusters (or -1 if none)
* @zone: zone from which to allocate the clusters
* @is_extension: if 'true', this is an attribute extension
*
* Allocate @count clusters preferably starting at cluster @start_lcn or at the
* current allocator position if @start_lcn is -1, on the mounted ntfs volume
* @vol. @zone is either DATA_ZONE for allocation of normal clusters or
* MFT_ZONE for allocation of clusters for the master file table, i.e. the
* $MFT/$DATA attribute.
*
* @start_vcn specifies the vcn of the first allocated cluster. This makes
* merging the resulting runlist with the old runlist easier.
*
* If @is_extension is 'true', the caller is allocating clusters to extend an
* attribute and if it is 'false', the caller is allocating clusters to fill a
* hole in an attribute. Practically the difference is that if @is_extension
* is 'true' the returned runlist will be terminated with LCN_ENOENT and if
* @is_extension is 'false' the runlist will be terminated with
* LCN_RL_NOT_MAPPED.
*
* You need to check the return value with IS_ERR(). If this is false, the
* function was successful and the return value is a runlist describing the
* allocated cluster(s). If IS_ERR() is true, the function failed and
* PTR_ERR() gives you the error code.
*
* Notes on the allocation algorithm
* =================================
*
* There are two data zones. First is the area between the end of the mft zone
* and the end of the volume, and second is the area between the start of the
* volume and the start of the mft zone. On unmodified/standard NTFS 1.x
* volumes, the second data zone does not exist due to the mft zone being
* expanded to cover the start of the volume in order to reserve space for the
* mft bitmap attribute.
*
* This is not the prettiest function but the complexity stems from the need of
* implementing the mft vs data zoned approach and from the fact that we have
* access to the lcn bitmap in portions of up to 8192 bytes at a time, so we
* need to cope with crossing over boundaries of two buffers. Further, the
* fact that the allocator allows for caller supplied hints as to the location
* of where allocation should begin and the fact that the allocator keeps track
* of where in the data zones the next natural allocation should occur,
* contribute to the complexity of the function. But it should all be
* worthwhile, because this allocator should: 1) be a full implementation of
* the MFT zone approach used by Windows NT, 2) cause reduction in
* fragmentation, and 3) be speedy in allocations (the code is not optimized
* for speed, but the algorithm is, so further speed improvements are probably
* possible).
*
* FIXME: We should be monitoring cluster allocation and increment the MFT zone
* size dynamically but this is something for the future. We will just cause
* heavier fragmentation by not doing it and I am not even sure Windows would
* grow the MFT zone dynamically, so it might even be correct not to do this.
* The overhead in doing dynamic MFT zone expansion would be very large and
* unlikely worth the effort. (AIA)
*
* TODO: I have added in double the required zone position pointer wrap around
* logic which can be optimized to having only one of the two logic sets.
* However, having the double logic will work fine, but if we have only one of
* the sets and we get it wrong somewhere, then we get into trouble, so
* removing the duplicate logic requires _very_ careful consideration of _all_
* possible code paths. So at least for now, I am leaving the double logic -
* better safe than sorry... (AIA)
*
* Locking: - The volume lcn bitmap must be unlocked on entry and is unlocked
* on return.
* - This function takes the volume lcn bitmap lock for writing and
* modifies the bitmap contents.
*/
runlist_element *ntfs_cluster_alloc(ntfs_volume *vol, const VCN start_vcn,
const s64 count, const LCN start_lcn,
const NTFS_CLUSTER_ALLOCATION_ZONES zone,
const bool is_extension)
{
LCN zone_start, zone_end, bmp_pos, bmp_initial_pos, last_read_pos, lcn;
LCN prev_lcn = 0, prev_run_len = 0, mft_zone_size;
s64 clusters;
loff_t i_size;
struct inode *lcnbmp_vi;
runlist_element *rl = NULL;
struct address_space *mapping;
struct page *page = NULL;
u8 *buf, *byte;
int err = 0, rlpos, rlsize, buf_size;
u8 pass, done_zones, search_zone, need_writeback = 0, bit;
ntfs_debug("Entering for start_vcn 0x%llx, count 0x%llx, start_lcn "
"0x%llx, zone %s_ZONE.", (unsigned long long)start_vcn,
(unsigned long long)count,
(unsigned long long)start_lcn,
zone == MFT_ZONE ? "MFT" : "DATA");
BUG_ON(!vol);
lcnbmp_vi = vol->lcnbmp_ino;
BUG_ON(!lcnbmp_vi);
BUG_ON(start_vcn < 0);
BUG_ON(count < 0);
BUG_ON(start_lcn < -1);
BUG_ON(zone < FIRST_ZONE);
BUG_ON(zone > LAST_ZONE);
/* Return NULL if @count is zero. */
if (!count)
return NULL;
/* Take the lcnbmp lock for writing. */
down_write(&vol->lcnbmp_lock);
/*
* If no specific @start_lcn was requested, use the current data zone
* position, otherwise use the requested @start_lcn but make sure it
* lies outside the mft zone. Also set done_zones to 0 (no zones done)
* and pass depending on whether we are starting inside a zone (1) or
* at the beginning of a zone (2). If requesting from the MFT_ZONE,
* we either start at the current position within the mft zone or at
* the specified position. If the latter is out of bounds then we start
* at the beginning of the MFT_ZONE.
*/
done_zones = 0;
pass = 1;
/*
* zone_start and zone_end are the current search range. search_zone
* is 1 for mft zone, 2 for data zone 1 (end of mft zone till end of
* volume) and 4 for data zone 2 (start of volume till start of mft
* zone).
*/
zone_start = start_lcn;
if (zone_start < 0) {
if (zone == DATA_ZONE)
zone_start = vol->data1_zone_pos;
else
zone_start = vol->mft_zone_pos;
if (!zone_start) {
/*
* Zone starts at beginning of volume which means a
* single pass is sufficient.
*/
pass = 2;
}
} else if (zone == DATA_ZONE && zone_start >= vol->mft_zone_start &&
zone_start < vol->mft_zone_end) {
zone_start = vol->mft_zone_end;
/*
* Starting at beginning of data1_zone which means a single
* pass in this zone is sufficient.
*/
pass = 2;
} else if (zone == MFT_ZONE && (zone_start < vol->mft_zone_start ||
zone_start >= vol->mft_zone_end)) {
zone_start = vol->mft_lcn;
if (!vol->mft_zone_end)
zone_start = 0;
/*
* Starting at beginning of volume which means a single pass
* is sufficient.
*/
pass = 2;
}
if (zone == MFT_ZONE) {
zone_end = vol->mft_zone_end;
search_zone = 1;
} else /* if (zone == DATA_ZONE) */ {
/* Skip searching the mft zone. */
done_zones |= 1;
if (zone_start >= vol->mft_zone_end) {
zone_end = vol->nr_clusters;
search_zone = 2;
} else {
zone_end = vol->mft_zone_start;
search_zone = 4;
}
}
/*
* bmp_pos is the current bit position inside the bitmap. We use
* bmp_initial_pos to determine whether or not to do a zone switch.
*/
bmp_pos = bmp_initial_pos = zone_start;
/* Loop until all clusters are allocated, i.e. clusters == 0. */
clusters = count;
rlpos = rlsize = 0;
mapping = lcnbmp_vi->i_mapping;
i_size = i_size_read(lcnbmp_vi);
while (1) {
ntfs_debug("Start of outer while loop: done_zones 0x%x, "
"search_zone %i, pass %i, zone_start 0x%llx, "
"zone_end 0x%llx, bmp_initial_pos 0x%llx, "
"bmp_pos 0x%llx, rlpos %i, rlsize %i.",
done_zones, search_zone, pass,
(unsigned long long)zone_start,
(unsigned long long)zone_end,
(unsigned long long)bmp_initial_pos,
(unsigned long long)bmp_pos, rlpos, rlsize);
/* Loop until we run out of free clusters. */
last_read_pos = bmp_pos >> 3;
ntfs_debug("last_read_pos 0x%llx.",
(unsigned long long)last_read_pos);
if (last_read_pos > i_size) {
ntfs_debug("End of attribute reached. "
"Skipping to zone_pass_done.");
goto zone_pass_done;
}
if (likely(page)) {
if (need_writeback) {
ntfs_debug("Marking page dirty.");
flush_dcache_page(page);
set_page_dirty(page);
need_writeback = 0;
}
ntfs_unmap_page(page);
}
page = ntfs_map_page(mapping, last_read_pos >>
PAGE_SHIFT);
if (IS_ERR(page)) {
err = PTR_ERR(page);
ntfs_error(vol->sb, "Failed to map page.");
goto out;
}
buf_size = last_read_pos & ~PAGE_MASK;
buf = page_address(page) + buf_size;
buf_size = PAGE_SIZE - buf_size;
if (unlikely(last_read_pos + buf_size > i_size))
buf_size = i_size - last_read_pos;
buf_size <<= 3;
lcn = bmp_pos & 7;
bmp_pos &= ~(LCN)7;
ntfs_debug("Before inner while loop: buf_size %i, lcn 0x%llx, "
"bmp_pos 0x%llx, need_writeback %i.", buf_size,
(unsigned long long)lcn,
(unsigned long long)bmp_pos, need_writeback);
while (lcn < buf_size && lcn + bmp_pos < zone_end) {
byte = buf + (lcn >> 3);
ntfs_debug("In inner while loop: buf_size %i, "
"lcn 0x%llx, bmp_pos 0x%llx, "
"need_writeback %i, byte ofs 0x%x, "
"*byte 0x%x.", buf_size,
(unsigned long long)lcn,
(unsigned long long)bmp_pos,
need_writeback,
(unsigned int)(lcn >> 3),
(unsigned int)*byte);
/* Skip full bytes. */
if (*byte == 0xff) {
lcn = (lcn + 8) & ~(LCN)7;
ntfs_debug("Continuing while loop 1.");
continue;
}
bit = 1 << (lcn & 7);
ntfs_debug("bit 0x%x.", bit);
/* If the bit is already set, go onto the next one. */
if (*byte & bit) {
lcn++;
ntfs_debug("Continuing while loop 2.");
continue;
}
/*
* Allocate more memory if needed, including space for
* the terminator element.
* ntfs_malloc_nofs() operates on whole pages only.
*/
if ((rlpos + 2) * sizeof(*rl) > rlsize) {
runlist_element *rl2;
ntfs_debug("Reallocating memory.");
if (!rl)
ntfs_debug("First free bit is at LCN "
"0x%llx.",
(unsigned long long)
(lcn + bmp_pos));
rl2 = ntfs_malloc_nofs(rlsize + (int)PAGE_SIZE);
if (unlikely(!rl2)) {
err = -ENOMEM;
ntfs_error(vol->sb, "Failed to "
"allocate memory.");
goto out;
}
memcpy(rl2, rl, rlsize);
ntfs_free(rl);
rl = rl2;
rlsize += PAGE_SIZE;
ntfs_debug("Reallocated memory, rlsize 0x%x.",
rlsize);
}
/* Allocate the bitmap bit. */
*byte |= bit;
/* We need to write this bitmap page to disk. */
need_writeback = 1;
ntfs_debug("*byte 0x%x, need_writeback is set.",
(unsigned int)*byte);
/*
* Coalesce with previous run if adjacent LCNs.
* Otherwise, append a new run.
*/
ntfs_debug("Adding run (lcn 0x%llx, len 0x%llx), "
"prev_lcn 0x%llx, lcn 0x%llx, "
"bmp_pos 0x%llx, prev_run_len 0x%llx, "
"rlpos %i.",
(unsigned long long)(lcn + bmp_pos),
1ULL, (unsigned long long)prev_lcn,
(unsigned long long)lcn,
(unsigned long long)bmp_pos,
(unsigned long long)prev_run_len,
rlpos);
if (prev_lcn == lcn + bmp_pos - prev_run_len && rlpos) {
ntfs_debug("Coalescing to run (lcn 0x%llx, "
"len 0x%llx).",
(unsigned long long)
rl[rlpos - 1].lcn,
(unsigned long long)
rl[rlpos - 1].length);
rl[rlpos - 1].length = ++prev_run_len;
ntfs_debug("Run now (lcn 0x%llx, len 0x%llx), "
"prev_run_len 0x%llx.",
(unsigned long long)
rl[rlpos - 1].lcn,
(unsigned long long)
rl[rlpos - 1].length,
(unsigned long long)
prev_run_len);
} else {
if (likely(rlpos)) {
ntfs_debug("Adding new run, (previous "
"run lcn 0x%llx, "
"len 0x%llx).",
(unsigned long long)
rl[rlpos - 1].lcn,
(unsigned long long)
rl[rlpos - 1].length);
rl[rlpos].vcn = rl[rlpos - 1].vcn +
prev_run_len;
} else {
ntfs_debug("Adding new run, is first "
"run.");
rl[rlpos].vcn = start_vcn;
}
rl[rlpos].lcn = prev_lcn = lcn + bmp_pos;
rl[rlpos].length = prev_run_len = 1;
rlpos++;
}
/* Done? */
if (!--clusters) {
LCN tc;
/*
* Update the current zone position. Positions
* of already scanned zones have been updated
* during the respective zone switches.
*/
tc = lcn + bmp_pos + 1;
ntfs_debug("Done. Updating current zone "
"position, tc 0x%llx, "
"search_zone %i.",
(unsigned long long)tc,
search_zone);
switch (search_zone) {
case 1:
ntfs_debug("Before checks, "
"vol->mft_zone_pos "
"0x%llx.",
(unsigned long long)
vol->mft_zone_pos);
if (tc >= vol->mft_zone_end) {
vol->mft_zone_pos =
vol->mft_lcn;
if (!vol->mft_zone_end)
vol->mft_zone_pos = 0;
} else if ((bmp_initial_pos >=
vol->mft_zone_pos ||
tc > vol->mft_zone_pos)
&& tc >= vol->mft_lcn)
vol->mft_zone_pos = tc;
ntfs_debug("After checks, "
"vol->mft_zone_pos "
"0x%llx.",
(unsigned long long)
vol->mft_zone_pos);
break;
case 2:
ntfs_debug("Before checks, "
"vol->data1_zone_pos "
"0x%llx.",
(unsigned long long)
vol->data1_zone_pos);
if (tc >= vol->nr_clusters)
vol->data1_zone_pos =
vol->mft_zone_end;
else if ((bmp_initial_pos >=
vol->data1_zone_pos ||
tc > vol->data1_zone_pos)
&& tc >= vol->mft_zone_end)
vol->data1_zone_pos = tc;
ntfs_debug("After checks, "
"vol->data1_zone_pos "
"0x%llx.",
(unsigned long long)
vol->data1_zone_pos);
break;
case 4:
ntfs_debug("Before checks, "
"vol->data2_zone_pos "
"0x%llx.",
(unsigned long long)
vol->data2_zone_pos);
if (tc >= vol->mft_zone_start)
vol->data2_zone_pos = 0;
else if (bmp_initial_pos >=
vol->data2_zone_pos ||
tc > vol->data2_zone_pos)
vol->data2_zone_pos = tc;
ntfs_debug("After checks, "
"vol->data2_zone_pos "
"0x%llx.",
(unsigned long long)
vol->data2_zone_pos);
break;
default:
BUG();
}
ntfs_debug("Finished. Going to out.");
goto out;
}
lcn++;
}
bmp_pos += buf_size;
ntfs_debug("After inner while loop: buf_size 0x%x, lcn "
"0x%llx, bmp_pos 0x%llx, need_writeback %i.",
buf_size, (unsigned long long)lcn,
(unsigned long long)bmp_pos, need_writeback);
if (bmp_pos < zone_end) {
ntfs_debug("Continuing outer while loop, "
"bmp_pos 0x%llx, zone_end 0x%llx.",
(unsigned long long)bmp_pos,
(unsigned long long)zone_end);
continue;
}
zone_pass_done: /* Finished with the current zone pass. */
ntfs_debug("At zone_pass_done, pass %i.", pass);
if (pass == 1) {
/*
* Now do pass 2, scanning the first part of the zone
* we omitted in pass 1.
*/
pass = 2;
zone_end = zone_start;
switch (search_zone) {
case 1: /* mft_zone */
zone_start = vol->mft_zone_start;
break;
case 2: /* data1_zone */
zone_start = vol->mft_zone_end;
break;
case 4: /* data2_zone */
zone_start = 0;
break;
default:
BUG();
}
/* Sanity check. */
if (zone_end < zone_start)
zone_end = zone_start;
bmp_pos = zone_start;
ntfs_debug("Continuing outer while loop, pass 2, "
"zone_start 0x%llx, zone_end 0x%llx, "
"bmp_pos 0x%llx.",
(unsigned long long)zone_start,
(unsigned long long)zone_end,
(unsigned long long)bmp_pos);
continue;
} /* pass == 2 */
done_zones_check:
ntfs_debug("At done_zones_check, search_zone %i, done_zones "
"before 0x%x, done_zones after 0x%x.",
search_zone, done_zones,
done_zones | search_zone);
done_zones |= search_zone;
if (done_zones < 7) {
ntfs_debug("Switching zone.");
/* Now switch to the next zone we haven't done yet. */
pass = 1;
switch (search_zone) {
case 1:
ntfs_debug("Switching from mft zone to data1 "
"zone.");
/* Update mft zone position. */
if (rlpos) {
LCN tc;
ntfs_debug("Before checks, "
"vol->mft_zone_pos "
"0x%llx.",
(unsigned long long)
vol->mft_zone_pos);
tc = rl[rlpos - 1].lcn +
rl[rlpos - 1].length;
if (tc >= vol->mft_zone_end) {
vol->mft_zone_pos =
vol->mft_lcn;
if (!vol->mft_zone_end)
vol->mft_zone_pos = 0;
} else if ((bmp_initial_pos >=
vol->mft_zone_pos ||
tc > vol->mft_zone_pos)
&& tc >= vol->mft_lcn)
vol->mft_zone_pos = tc;
ntfs_debug("After checks, "
"vol->mft_zone_pos "
"0x%llx.",
(unsigned long long)
vol->mft_zone_pos);
}
/* Switch from mft zone to data1 zone. */
switch_to_data1_zone: search_zone = 2;
zone_start = bmp_initial_pos =
vol->data1_zone_pos;
zone_end = vol->nr_clusters;
if (zone_start == vol->mft_zone_end)
pass = 2;
if (zone_start >= zone_end) {
vol->data1_zone_pos = zone_start =
vol->mft_zone_end;
pass = 2;
}
break;
case 2:
ntfs_debug("Switching from data1 zone to "
"data2 zone.");
/* Update data1 zone position. */
if (rlpos) {
LCN tc;
ntfs_debug("Before checks, "
"vol->data1_zone_pos "
"0x%llx.",
(unsigned long long)
vol->data1_zone_pos);
tc = rl[rlpos - 1].lcn +
rl[rlpos - 1].length;
if (tc >= vol->nr_clusters)
vol->data1_zone_pos =
vol->mft_zone_end;
else if ((bmp_initial_pos >=
vol->data1_zone_pos ||
tc > vol->data1_zone_pos)
&& tc >= vol->mft_zone_end)
vol->data1_zone_pos = tc;
ntfs_debug("After checks, "
"vol->data1_zone_pos "
"0x%llx.",
(unsigned long long)
vol->data1_zone_pos);
}
/* Switch from data1 zone to data2 zone. */
search_zone = 4;
zone_start = bmp_initial_pos =
vol->data2_zone_pos;
zone_end = vol->mft_zone_start;
if (!zone_start)
pass = 2;
if (zone_start >= zone_end) {
vol->data2_zone_pos = zone_start =
bmp_initial_pos = 0;
pass = 2;
}
break;
case 4:
ntfs_debug("Switching from data2 zone to "
"data1 zone.");
/* Update data2 zone position. */
if (rlpos) {
LCN tc;
ntfs_debug("Before checks, "
"vol->data2_zone_pos "
"0x%llx.",
(unsigned long long)
vol->data2_zone_pos);
tc = rl[rlpos - 1].lcn +
rl[rlpos - 1].length;
if (tc >= vol->mft_zone_start)
vol->data2_zone_pos = 0;
else if (bmp_initial_pos >=
vol->data2_zone_pos ||
tc > vol->data2_zone_pos)
vol->data2_zone_pos = tc;
ntfs_debug("After checks, "
"vol->data2_zone_pos "
"0x%llx.",
(unsigned long long)
vol->data2_zone_pos);
}
/* Switch from data2 zone to data1 zone. */
goto switch_to_data1_zone;
default:
BUG();
}
ntfs_debug("After zone switch, search_zone %i, "
"pass %i, bmp_initial_pos 0x%llx, "
"zone_start 0x%llx, zone_end 0x%llx.",
search_zone, pass,
(unsigned long long)bmp_initial_pos,
(unsigned long long)zone_start,
(unsigned long long)zone_end);
bmp_pos = zone_start;
if (zone_start == zone_end) {
ntfs_debug("Empty zone, going to "
"done_zones_check.");
/* Empty zone. Don't bother searching it. */
goto done_zones_check;
}
ntfs_debug("Continuing outer while loop.");
continue;
} /* done_zones == 7 */
ntfs_debug("All zones are finished.");
/*
* All zones are finished! If DATA_ZONE, shrink mft zone. If
* MFT_ZONE, we have really run out of space.
*/
mft_zone_size = vol->mft_zone_end - vol->mft_zone_start;
ntfs_debug("vol->mft_zone_start 0x%llx, vol->mft_zone_end "
"0x%llx, mft_zone_size 0x%llx.",
(unsigned long long)vol->mft_zone_start,
(unsigned long long)vol->mft_zone_end,
(unsigned long long)mft_zone_size);
if (zone == MFT_ZONE || mft_zone_size <= 0) {
ntfs_debug("No free clusters left, going to out.");
/* Really no more space left on device. */
err = -ENOSPC;
goto out;
} /* zone == DATA_ZONE && mft_zone_size > 0 */
ntfs_debug("Shrinking mft zone.");
zone_end = vol->mft_zone_end;
mft_zone_size >>= 1;
if (mft_zone_size > 0)
vol->mft_zone_end = vol->mft_zone_start + mft_zone_size;
else /* mft zone and data2 zone no longer exist. */
vol->data2_zone_pos = vol->mft_zone_start =
vol->mft_zone_end = 0;
if (vol->mft_zone_pos >= vol->mft_zone_end) {
vol->mft_zone_pos = vol->mft_lcn;
if (!vol->mft_zone_end)
vol->mft_zone_pos = 0;
}
bmp_pos = zone_start = bmp_initial_pos =
vol->data1_zone_pos = vol->mft_zone_end;
search_zone = 2;
pass = 2;
done_zones &= ~2;
ntfs_debug("After shrinking mft zone, mft_zone_size 0x%llx, "
"vol->mft_zone_start 0x%llx, "
"vol->mft_zone_end 0x%llx, "
"vol->mft_zone_pos 0x%llx, search_zone 2, "
"pass 2, dones_zones 0x%x, zone_start 0x%llx, "
"zone_end 0x%llx, vol->data1_zone_pos 0x%llx, "
"continuing outer while loop.",
(unsigned long long)mft_zone_size,
(unsigned long long)vol->mft_zone_start,
(unsigned long long)vol->mft_zone_end,
(unsigned long long)vol->mft_zone_pos,
done_zones, (unsigned long long)zone_start,
(unsigned long long)zone_end,
(unsigned long long)vol->data1_zone_pos);
}
ntfs_debug("After outer while loop.");
out:
ntfs_debug("At out.");
/* Add runlist terminator element. */
if (likely(rl)) {
rl[rlpos].vcn = rl[rlpos - 1].vcn + rl[rlpos - 1].length;
rl[rlpos].lcn = is_extension ? LCN_ENOENT : LCN_RL_NOT_MAPPED;
rl[rlpos].length = 0;
}
if (likely(page && !IS_ERR(page))) {
if (need_writeback) {
ntfs_debug("Marking page dirty.");
flush_dcache_page(page);
set_page_dirty(page);
need_writeback = 0;
}
ntfs_unmap_page(page);
}
if (likely(!err)) {
up_write(&vol->lcnbmp_lock);
ntfs_debug("Done.");
return rl;
}
ntfs_error(vol->sb, "Failed to allocate clusters, aborting "
"(error %i).", err);
if (rl) {
int err2;
if (err == -ENOSPC)
ntfs_debug("Not enough space to complete allocation, "
"err -ENOSPC, first free lcn 0x%llx, "
"could allocate up to 0x%llx "
"clusters.",
(unsigned long long)rl[0].lcn,
(unsigned long long)(count - clusters));
/* Deallocate all allocated clusters. */
ntfs_debug("Attempting rollback...");
err2 = ntfs_cluster_free_from_rl_nolock(vol, rl);
if (err2) {
ntfs_error(vol->sb, "Failed to rollback (error %i). "
"Leaving inconsistent metadata! "
"Unmount and run chkdsk.", err2);
NVolSetErrors(vol);
}
/* Free the runlist. */
ntfs_free(rl);
} else if (err == -ENOSPC)
ntfs_debug("No space left at all, err = -ENOSPC, first free "
"lcn = 0x%llx.",
(long long)vol->data1_zone_pos);
up_write(&vol->lcnbmp_lock);
return ERR_PTR(err);
}
/**
* __ntfs_cluster_free - free clusters on an ntfs volume
* @ni: ntfs inode whose runlist describes the clusters to free
* @start_vcn: vcn in the runlist of @ni at which to start freeing clusters
* @count: number of clusters to free or -1 for all clusters
* @ctx: active attribute search context if present or NULL if not
* @is_rollback: true if this is a rollback operation
*
* Free @count clusters starting at the cluster @start_vcn in the runlist
* described by the vfs inode @ni.
*
* If @count is -1, all clusters from @start_vcn to the end of the runlist are
* deallocated. Thus, to completely free all clusters in a runlist, use
* @start_vcn = 0 and @count = -1.
*
* If @ctx is specified, it is an active search context of @ni and its base mft
* record. This is needed when __ntfs_cluster_free() encounters unmapped
* runlist fragments and allows their mapping. If you do not have the mft
* record mapped, you can specify @ctx as NULL and __ntfs_cluster_free() will
* perform the necessary mapping and unmapping.
*
* Note, __ntfs_cluster_free() saves the state of @ctx on entry and restores it
* before returning. Thus, @ctx will be left pointing to the same attribute on
* return as on entry. However, the actual pointers in @ctx may point to
* different memory locations on return, so you must remember to reset any
* cached pointers from the @ctx, i.e. after the call to __ntfs_cluster_free(),
* you will probably want to do:
* m = ctx->mrec;
* a = ctx->attr;
* Assuming you cache ctx->attr in a variable @a of type ATTR_RECORD * and that
* you cache ctx->mrec in a variable @m of type MFT_RECORD *.
*
* @is_rollback should always be 'false', it is for internal use to rollback
* errors. You probably want to use ntfs_cluster_free() instead.
*
* Note, __ntfs_cluster_free() does not modify the runlist, so you have to
* remove from the runlist or mark sparse the freed runs later.
*
* Return the number of deallocated clusters (not counting sparse ones) on
* success and -errno on error.
*
* WARNING: If @ctx is supplied, regardless of whether success or failure is
* returned, you need to check IS_ERR(@ctx->mrec) and if 'true' the @ctx
* is no longer valid, i.e. you need to either call
* ntfs_attr_reinit_search_ctx() or ntfs_attr_put_search_ctx() on it.
* In that case PTR_ERR(@ctx->mrec) will give you the error code for
* why the mapping of the old inode failed.
*
* Locking: - The runlist described by @ni must be locked for writing on entry
* and is locked on return. Note the runlist may be modified when
* needed runlist fragments need to be mapped.
* - The volume lcn bitmap must be unlocked on entry and is unlocked
* on return.
* - This function takes the volume lcn bitmap lock for writing and
* modifies the bitmap contents.
* - If @ctx is NULL, the base mft record of @ni must not be mapped on
* entry and it will be left unmapped on return.
* - If @ctx is not NULL, the base mft record must be mapped on entry
* and it will be left mapped on return.
*/
s64 __ntfs_cluster_free(ntfs_inode *ni, const VCN start_vcn, s64 count,
ntfs_attr_search_ctx *ctx, const bool is_rollback)
{
s64 delta, to_free, total_freed, real_freed;
ntfs_volume *vol;
struct inode *lcnbmp_vi;
runlist_element *rl;
int err;
BUG_ON(!ni);
ntfs_debug("Entering for i_ino 0x%lx, start_vcn 0x%llx, count "
"0x%llx.%s", ni->mft_no, (unsigned long long)start_vcn,
(unsigned long long)count,
is_rollback ? " (rollback)" : "");
vol = ni->vol;
lcnbmp_vi = vol->lcnbmp_ino;
BUG_ON(!lcnbmp_vi);
BUG_ON(start_vcn < 0);
BUG_ON(count < -1);
/*
* Lock the lcn bitmap for writing but only if not rolling back. We
* must hold the lock all the way including through rollback otherwise
* rollback is not possible because once we have cleared a bit and
* dropped the lock, anyone could have set the bit again, thus
* allocating the cluster for another use.
*/
if (likely(!is_rollback))
down_write(&vol->lcnbmp_lock);
total_freed = real_freed = 0;
rl = ntfs_attr_find_vcn_nolock(ni, start_vcn, ctx);
if (IS_ERR(rl)) {
if (!is_rollback)
ntfs_error(vol->sb, "Failed to find first runlist "
"element (error %li), aborting.",
PTR_ERR(rl));
err = PTR_ERR(rl);
goto err_out;
}
if (unlikely(rl->lcn < LCN_HOLE)) {
if (!is_rollback)
ntfs_error(vol->sb, "First runlist element has "
"invalid lcn, aborting.");
err = -EIO;
goto err_out;
}
/* Find the starting cluster inside the run that needs freeing. */
delta = start_vcn - rl->vcn;
/* The number of clusters in this run that need freeing. */
to_free = rl->length - delta;
if (count >= 0 && to_free > count)
to_free = count;
if (likely(rl->lcn >= 0)) {
/* Do the actual freeing of the clusters in this run. */
err = ntfs_bitmap_set_bits_in_run(lcnbmp_vi, rl->lcn + delta,
to_free, likely(!is_rollback) ? 0 : 1);
if (unlikely(err)) {
if (!is_rollback)
ntfs_error(vol->sb, "Failed to clear first run "
"(error %i), aborting.", err);
goto err_out;
}
/* We have freed @to_free real clusters. */
real_freed = to_free;
};
/* Go to the next run and adjust the number of clusters left to free. */
++rl;
if (count >= 0)
count -= to_free;
/* Keep track of the total "freed" clusters, including sparse ones. */
total_freed = to_free;
/*
* Loop over the remaining runs, using @count as a capping value, and
* free them.
*/
for (; rl->length && count != 0; ++rl) {
if (unlikely(rl->lcn < LCN_HOLE)) {
VCN vcn;
/* Attempt to map runlist. */
vcn = rl->vcn;
rl = ntfs_attr_find_vcn_nolock(ni, vcn, ctx);
if (IS_ERR(rl)) {
err = PTR_ERR(rl);
if (!is_rollback)
ntfs_error(vol->sb, "Failed to map "
"runlist fragment or "
"failed to find "
"subsequent runlist "
"element.");
goto err_out;
}
if (unlikely(rl->lcn < LCN_HOLE)) {
if (!is_rollback)
ntfs_error(vol->sb, "Runlist element "
"has invalid lcn "
"(0x%llx).",
(unsigned long long)
rl->lcn);
err = -EIO;
goto err_out;
}
}
/* The number of clusters in this run that need freeing. */
to_free = rl->length;
if (count >= 0 && to_free > count)
to_free = count;
if (likely(rl->lcn >= 0)) {
/* Do the actual freeing of the clusters in the run. */
err = ntfs_bitmap_set_bits_in_run(lcnbmp_vi, rl->lcn,
to_free, likely(!is_rollback) ? 0 : 1);
if (unlikely(err)) {
if (!is_rollback)
ntfs_error(vol->sb, "Failed to clear "
"subsequent run.");
goto err_out;
}
/* We have freed @to_free real clusters. */
real_freed += to_free;
}
/* Adjust the number of clusters left to free. */
if (count >= 0)
count -= to_free;
/* Update the total done clusters. */
total_freed += to_free;
}
if (likely(!is_rollback))
up_write(&vol->lcnbmp_lock);
BUG_ON(count > 0);
/* We are done. Return the number of actually freed clusters. */
ntfs_debug("Done.");
return real_freed;
err_out:
if (is_rollback)
return err;
/* If no real clusters were freed, no need to rollback. */
if (!real_freed) {
up_write(&vol->lcnbmp_lock);
return err;
}
/*
* Attempt to rollback and if that succeeds just return the error code.
* If rollback fails, set the volume errors flag, emit an error
* message, and return the error code.
*/
delta = __ntfs_cluster_free(ni, start_vcn, total_freed, ctx, true);
if (delta < 0) {
ntfs_error(vol->sb, "Failed to rollback (error %i). Leaving "
"inconsistent metadata! Unmount and run "
"chkdsk.", (int)delta);
NVolSetErrors(vol);
}
up_write(&vol->lcnbmp_lock);
ntfs_error(vol->sb, "Aborting (error %i).", err);
return err;
}
#endif /* NTFS_RW */
Reference in New Issue View Git Blame Copy Permalink