1015 lines
32 KiB
C
Executable File
1015 lines
32 KiB
C
Executable File
/*
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* lcnalloc.c - Cluster (de)allocation code. Part of the Linux-NTFS project.
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*
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* Copyright (c) 2004-2005 Anton Altaparmakov
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*
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* This program/include file is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as published
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* by the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program/include file is distributed in the hope that it will be
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* useful, but WITHOUT ANY WARRANTY; without even the implied warranty
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* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program (in the main directory of the Linux-NTFS
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* distribution in the file COPYING); if not, write to the Free Software
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* Foundation,Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*/
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#ifdef NTFS_RW
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#include <linux/pagemap.h>
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#include "lcnalloc.h"
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#include "debug.h"
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#include "bitmap.h"
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#include "inode.h"
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#include "volume.h"
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#include "attrib.h"
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#include "malloc.h"
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#include "aops.h"
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#include "ntfs.h"
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/**
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* ntfs_cluster_free_from_rl_nolock - free clusters from runlist
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* @vol: mounted ntfs volume on which to free the clusters
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* @rl: runlist describing the clusters to free
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*
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* Free all the clusters described by the runlist @rl on the volume @vol. In
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* the case of an error being returned, at least some of the clusters were not
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* freed.
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*
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* Return 0 on success and -errno on error.
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*
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* Locking: - The volume lcn bitmap must be locked for writing on entry and is
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* left locked on return.
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*/
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int ntfs_cluster_free_from_rl_nolock(ntfs_volume *vol,
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const runlist_element *rl)
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{
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struct inode *lcnbmp_vi = vol->lcnbmp_ino;
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int ret = 0;
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ntfs_debug("Entering.");
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if (!rl)
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return 0;
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for (; rl->length; rl++) {
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int err;
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if (rl->lcn < 0)
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continue;
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err = ntfs_bitmap_clear_run(lcnbmp_vi, rl->lcn, rl->length);
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if (unlikely(err && (!ret || ret == -ENOMEM) && ret != err))
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ret = err;
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}
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ntfs_debug("Done.");
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return ret;
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}
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/**
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* ntfs_cluster_alloc - allocate clusters on an ntfs volume
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* @vol: mounted ntfs volume on which to allocate the clusters
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* @start_vcn: vcn to use for the first allocated cluster
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* @count: number of clusters to allocate
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* @start_lcn: starting lcn at which to allocate the clusters (or -1 if none)
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* @zone: zone from which to allocate the clusters
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* @is_extension: if 'true', this is an attribute extension
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*
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* Allocate @count clusters preferably starting at cluster @start_lcn or at the
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* current allocator position if @start_lcn is -1, on the mounted ntfs volume
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* @vol. @zone is either DATA_ZONE for allocation of normal clusters or
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* MFT_ZONE for allocation of clusters for the master file table, i.e. the
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* $MFT/$DATA attribute.
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*
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* @start_vcn specifies the vcn of the first allocated cluster. This makes
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* merging the resulting runlist with the old runlist easier.
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*
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* If @is_extension is 'true', the caller is allocating clusters to extend an
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* attribute and if it is 'false', the caller is allocating clusters to fill a
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* hole in an attribute. Practically the difference is that if @is_extension
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* is 'true' the returned runlist will be terminated with LCN_ENOENT and if
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* @is_extension is 'false' the runlist will be terminated with
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* LCN_RL_NOT_MAPPED.
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*
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* You need to check the return value with IS_ERR(). If this is false, the
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* function was successful and the return value is a runlist describing the
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* allocated cluster(s). If IS_ERR() is true, the function failed and
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* PTR_ERR() gives you the error code.
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*
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* Notes on the allocation algorithm
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* =================================
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*
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* There are two data zones. First is the area between the end of the mft zone
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* and the end of the volume, and second is the area between the start of the
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* volume and the start of the mft zone. On unmodified/standard NTFS 1.x
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* volumes, the second data zone does not exist due to the mft zone being
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* expanded to cover the start of the volume in order to reserve space for the
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* mft bitmap attribute.
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*
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* This is not the prettiest function but the complexity stems from the need of
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* implementing the mft vs data zoned approach and from the fact that we have
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* access to the lcn bitmap in portions of up to 8192 bytes at a time, so we
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* need to cope with crossing over boundaries of two buffers. Further, the
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* fact that the allocator allows for caller supplied hints as to the location
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* of where allocation should begin and the fact that the allocator keeps track
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* of where in the data zones the next natural allocation should occur,
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* contribute to the complexity of the function. But it should all be
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* worthwhile, because this allocator should: 1) be a full implementation of
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* the MFT zone approach used by Windows NT, 2) cause reduction in
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* fragmentation, and 3) be speedy in allocations (the code is not optimized
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* for speed, but the algorithm is, so further speed improvements are probably
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* possible).
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*
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* FIXME: We should be monitoring cluster allocation and increment the MFT zone
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* size dynamically but this is something for the future. We will just cause
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* heavier fragmentation by not doing it and I am not even sure Windows would
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* grow the MFT zone dynamically, so it might even be correct not to do this.
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* The overhead in doing dynamic MFT zone expansion would be very large and
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* unlikely worth the effort. (AIA)
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*
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* TODO: I have added in double the required zone position pointer wrap around
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* logic which can be optimized to having only one of the two logic sets.
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* However, having the double logic will work fine, but if we have only one of
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* the sets and we get it wrong somewhere, then we get into trouble, so
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* removing the duplicate logic requires _very_ careful consideration of _all_
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* possible code paths. So at least for now, I am leaving the double logic -
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* better safe than sorry... (AIA)
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*
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* Locking: - The volume lcn bitmap must be unlocked on entry and is unlocked
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* on return.
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* - This function takes the volume lcn bitmap lock for writing and
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* modifies the bitmap contents.
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*/
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runlist_element *ntfs_cluster_alloc(ntfs_volume *vol, const VCN start_vcn,
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const s64 count, const LCN start_lcn,
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const NTFS_CLUSTER_ALLOCATION_ZONES zone,
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const bool is_extension)
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{
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LCN zone_start, zone_end, bmp_pos, bmp_initial_pos, last_read_pos, lcn;
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LCN prev_lcn = 0, prev_run_len = 0, mft_zone_size;
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s64 clusters;
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loff_t i_size;
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struct inode *lcnbmp_vi;
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runlist_element *rl = NULL;
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struct address_space *mapping;
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struct page *page = NULL;
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u8 *buf, *byte;
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int err = 0, rlpos, rlsize, buf_size;
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u8 pass, done_zones, search_zone, need_writeback = 0, bit;
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ntfs_debug("Entering for start_vcn 0x%llx, count 0x%llx, start_lcn "
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"0x%llx, zone %s_ZONE.", (unsigned long long)start_vcn,
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(unsigned long long)count,
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(unsigned long long)start_lcn,
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zone == MFT_ZONE ? "MFT" : "DATA");
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BUG_ON(!vol);
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lcnbmp_vi = vol->lcnbmp_ino;
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BUG_ON(!lcnbmp_vi);
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BUG_ON(start_vcn < 0);
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BUG_ON(count < 0);
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BUG_ON(start_lcn < -1);
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BUG_ON(zone < FIRST_ZONE);
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BUG_ON(zone > LAST_ZONE);
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/* Return NULL if @count is zero. */
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if (!count)
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return NULL;
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/* Take the lcnbmp lock for writing. */
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down_write(&vol->lcnbmp_lock);
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/*
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* If no specific @start_lcn was requested, use the current data zone
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* position, otherwise use the requested @start_lcn but make sure it
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* lies outside the mft zone. Also set done_zones to 0 (no zones done)
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* and pass depending on whether we are starting inside a zone (1) or
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* at the beginning of a zone (2). If requesting from the MFT_ZONE,
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* we either start at the current position within the mft zone or at
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* the specified position. If the latter is out of bounds then we start
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* at the beginning of the MFT_ZONE.
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*/
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done_zones = 0;
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pass = 1;
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/*
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* zone_start and zone_end are the current search range. search_zone
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* is 1 for mft zone, 2 for data zone 1 (end of mft zone till end of
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* volume) and 4 for data zone 2 (start of volume till start of mft
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* zone).
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*/
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zone_start = start_lcn;
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if (zone_start < 0) {
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if (zone == DATA_ZONE)
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zone_start = vol->data1_zone_pos;
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else
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zone_start = vol->mft_zone_pos;
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if (!zone_start) {
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/*
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* Zone starts at beginning of volume which means a
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* single pass is sufficient.
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*/
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pass = 2;
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}
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} else if (zone == DATA_ZONE && zone_start >= vol->mft_zone_start &&
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zone_start < vol->mft_zone_end) {
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zone_start = vol->mft_zone_end;
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/*
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* Starting at beginning of data1_zone which means a single
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* pass in this zone is sufficient.
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*/
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pass = 2;
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} else if (zone == MFT_ZONE && (zone_start < vol->mft_zone_start ||
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zone_start >= vol->mft_zone_end)) {
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zone_start = vol->mft_lcn;
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if (!vol->mft_zone_end)
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zone_start = 0;
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/*
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* Starting at beginning of volume which means a single pass
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* is sufficient.
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*/
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pass = 2;
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}
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if (zone == MFT_ZONE) {
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zone_end = vol->mft_zone_end;
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search_zone = 1;
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} else /* if (zone == DATA_ZONE) */ {
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/* Skip searching the mft zone. */
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done_zones |= 1;
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if (zone_start >= vol->mft_zone_end) {
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zone_end = vol->nr_clusters;
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search_zone = 2;
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} else {
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zone_end = vol->mft_zone_start;
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search_zone = 4;
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}
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}
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/*
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* bmp_pos is the current bit position inside the bitmap. We use
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* bmp_initial_pos to determine whether or not to do a zone switch.
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*/
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bmp_pos = bmp_initial_pos = zone_start;
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/* Loop until all clusters are allocated, i.e. clusters == 0. */
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clusters = count;
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rlpos = rlsize = 0;
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mapping = lcnbmp_vi->i_mapping;
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i_size = i_size_read(lcnbmp_vi);
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while (1) {
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ntfs_debug("Start of outer while loop: done_zones 0x%x, "
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"search_zone %i, pass %i, zone_start 0x%llx, "
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"zone_end 0x%llx, bmp_initial_pos 0x%llx, "
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"bmp_pos 0x%llx, rlpos %i, rlsize %i.",
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done_zones, search_zone, pass,
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(unsigned long long)zone_start,
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(unsigned long long)zone_end,
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(unsigned long long)bmp_initial_pos,
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(unsigned long long)bmp_pos, rlpos, rlsize);
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/* Loop until we run out of free clusters. */
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last_read_pos = bmp_pos >> 3;
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ntfs_debug("last_read_pos 0x%llx.",
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(unsigned long long)last_read_pos);
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if (last_read_pos > i_size) {
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ntfs_debug("End of attribute reached. "
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"Skipping to zone_pass_done.");
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goto zone_pass_done;
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}
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if (likely(page)) {
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if (need_writeback) {
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ntfs_debug("Marking page dirty.");
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flush_dcache_page(page);
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set_page_dirty(page);
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need_writeback = 0;
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}
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ntfs_unmap_page(page);
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}
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page = ntfs_map_page(mapping, last_read_pos >>
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PAGE_CACHE_SHIFT);
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if (IS_ERR(page)) {
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err = PTR_ERR(page);
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ntfs_error(vol->sb, "Failed to map page.");
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goto out;
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}
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buf_size = last_read_pos & ~PAGE_CACHE_MASK;
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buf = page_address(page) + buf_size;
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buf_size = PAGE_CACHE_SIZE - buf_size;
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if (unlikely(last_read_pos + buf_size > i_size))
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buf_size = i_size - last_read_pos;
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buf_size <<= 3;
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lcn = bmp_pos & 7;
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bmp_pos &= ~(LCN)7;
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ntfs_debug("Before inner while loop: buf_size %i, lcn 0x%llx, "
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"bmp_pos 0x%llx, need_writeback %i.", buf_size,
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(unsigned long long)lcn,
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(unsigned long long)bmp_pos, need_writeback);
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while (lcn < buf_size && lcn + bmp_pos < zone_end) {
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byte = buf + (lcn >> 3);
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ntfs_debug("In inner while loop: buf_size %i, "
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"lcn 0x%llx, bmp_pos 0x%llx, "
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"need_writeback %i, byte ofs 0x%x, "
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"*byte 0x%x.", buf_size,
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(unsigned long long)lcn,
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(unsigned long long)bmp_pos,
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need_writeback,
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(unsigned int)(lcn >> 3),
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(unsigned int)*byte);
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/* Skip full bytes. */
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if (*byte == 0xff) {
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lcn = (lcn + 8) & ~(LCN)7;
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ntfs_debug("Continuing while loop 1.");
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continue;
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}
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bit = 1 << (lcn & 7);
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ntfs_debug("bit 0x%x.", bit);
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/* If the bit is already set, go onto the next one. */
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if (*byte & bit) {
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lcn++;
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ntfs_debug("Continuing while loop 2.");
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continue;
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}
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/*
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* Allocate more memory if needed, including space for
|
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* the terminator element.
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* ntfs_malloc_nofs() operates on whole pages only.
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*/
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if ((rlpos + 2) * sizeof(*rl) > rlsize) {
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runlist_element *rl2;
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|
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ntfs_debug("Reallocating memory.");
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if (!rl)
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ntfs_debug("First free bit is at LCN "
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"0x%llx.",
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(unsigned long long)
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(lcn + bmp_pos));
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rl2 = ntfs_malloc_nofs(rlsize + (int)PAGE_SIZE);
|
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if (unlikely(!rl2)) {
|
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err = -ENOMEM;
|
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ntfs_error(vol->sb, "Failed to "
|
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"allocate memory.");
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goto out;
|
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}
|
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memcpy(rl2, rl, rlsize);
|
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ntfs_free(rl);
|
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rl = rl2;
|
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rlsize += PAGE_SIZE;
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ntfs_debug("Reallocated memory, rlsize 0x%x.",
|
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rlsize);
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}
|
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/* Allocate the bitmap bit. */
|
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*byte |= bit;
|
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/* We need to write this bitmap page to disk. */
|
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need_writeback = 1;
|
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ntfs_debug("*byte 0x%x, need_writeback is set.",
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(unsigned int)*byte);
|
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/*
|
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* Coalesce with previous run if adjacent LCNs.
|
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* Otherwise, append a new run.
|
|
*/
|
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ntfs_debug("Adding run (lcn 0x%llx, len 0x%llx), "
|
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"prev_lcn 0x%llx, lcn 0x%llx, "
|
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"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 */
|