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ac4ecf968a
In the quest to remove all stack VLA usage from the kernel[1], this uses the maximum size needed on the stack and adds a sanity check for robustness: index.block_size cannot be larger than PAGE_SIZE nor less than NTFS_BLOCK_SIZE. [1] https://lkml.kernel.org/r/CA+55aFzCG-zNmZwX4A2FQpadafLfEzK6CC=qPXydAacU1RqZWA@mail.gmail.com Link: http://lkml.kernel.org/r/20180626172909.41453-2-keescook@chromium.org Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Anton Altaparmakov <anton@tuxera.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1778 lines
52 KiB
C
1778 lines
52 KiB
C
/**
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* aops.c - NTFS kernel address space operations and page cache handling.
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*
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* Copyright (c) 2001-2014 Anton Altaparmakov and Tuxera Inc.
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* Copyright (c) 2002 Richard Russon
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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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#include <linux/errno.h>
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#include <linux/fs.h>
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#include <linux/gfp.h>
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#include <linux/mm.h>
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#include <linux/pagemap.h>
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#include <linux/swap.h>
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#include <linux/buffer_head.h>
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#include <linux/writeback.h>
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#include <linux/bit_spinlock.h>
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#include <linux/bio.h>
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#include "aops.h"
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#include "attrib.h"
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#include "debug.h"
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#include "inode.h"
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#include "mft.h"
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#include "runlist.h"
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#include "types.h"
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#include "ntfs.h"
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/**
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* ntfs_end_buffer_async_read - async io completion for reading attributes
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* @bh: buffer head on which io is completed
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* @uptodate: whether @bh is now uptodate or not
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*
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* Asynchronous I/O completion handler for reading pages belonging to the
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* attribute address space of an inode. The inodes can either be files or
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* directories or they can be fake inodes describing some attribute.
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*
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* If NInoMstProtected(), perform the post read mst fixups when all IO on the
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* page has been completed and mark the page uptodate or set the error bit on
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* the page. To determine the size of the records that need fixing up, we
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* cheat a little bit by setting the index_block_size in ntfs_inode to the ntfs
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* record size, and index_block_size_bits, to the log(base 2) of the ntfs
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* record size.
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*/
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static void ntfs_end_buffer_async_read(struct buffer_head *bh, int uptodate)
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{
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unsigned long flags;
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struct buffer_head *first, *tmp;
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struct page *page;
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struct inode *vi;
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ntfs_inode *ni;
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int page_uptodate = 1;
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page = bh->b_page;
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vi = page->mapping->host;
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ni = NTFS_I(vi);
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if (likely(uptodate)) {
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loff_t i_size;
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s64 file_ofs, init_size;
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set_buffer_uptodate(bh);
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file_ofs = ((s64)page->index << PAGE_SHIFT) +
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bh_offset(bh);
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read_lock_irqsave(&ni->size_lock, flags);
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init_size = ni->initialized_size;
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i_size = i_size_read(vi);
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read_unlock_irqrestore(&ni->size_lock, flags);
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if (unlikely(init_size > i_size)) {
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/* Race with shrinking truncate. */
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init_size = i_size;
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}
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/* Check for the current buffer head overflowing. */
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if (unlikely(file_ofs + bh->b_size > init_size)) {
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int ofs;
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void *kaddr;
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ofs = 0;
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if (file_ofs < init_size)
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ofs = init_size - file_ofs;
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kaddr = kmap_atomic(page);
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memset(kaddr + bh_offset(bh) + ofs, 0,
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bh->b_size - ofs);
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flush_dcache_page(page);
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kunmap_atomic(kaddr);
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}
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} else {
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clear_buffer_uptodate(bh);
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SetPageError(page);
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ntfs_error(ni->vol->sb, "Buffer I/O error, logical block "
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"0x%llx.", (unsigned long long)bh->b_blocknr);
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}
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first = page_buffers(page);
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local_irq_save(flags);
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bit_spin_lock(BH_Uptodate_Lock, &first->b_state);
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clear_buffer_async_read(bh);
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unlock_buffer(bh);
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tmp = bh;
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do {
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if (!buffer_uptodate(tmp))
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page_uptodate = 0;
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if (buffer_async_read(tmp)) {
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if (likely(buffer_locked(tmp)))
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goto still_busy;
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/* Async buffers must be locked. */
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BUG();
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}
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tmp = tmp->b_this_page;
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} while (tmp != bh);
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bit_spin_unlock(BH_Uptodate_Lock, &first->b_state);
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local_irq_restore(flags);
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/*
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* If none of the buffers had errors then we can set the page uptodate,
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* but we first have to perform the post read mst fixups, if the
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* attribute is mst protected, i.e. if NInoMstProteced(ni) is true.
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* Note we ignore fixup errors as those are detected when
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* map_mft_record() is called which gives us per record granularity
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* rather than per page granularity.
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*/
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if (!NInoMstProtected(ni)) {
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if (likely(page_uptodate && !PageError(page)))
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SetPageUptodate(page);
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} else {
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u8 *kaddr;
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unsigned int i, recs;
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u32 rec_size;
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rec_size = ni->itype.index.block_size;
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recs = PAGE_SIZE / rec_size;
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/* Should have been verified before we got here... */
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BUG_ON(!recs);
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kaddr = kmap_atomic(page);
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for (i = 0; i < recs; i++)
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post_read_mst_fixup((NTFS_RECORD*)(kaddr +
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i * rec_size), rec_size);
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kunmap_atomic(kaddr);
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flush_dcache_page(page);
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if (likely(page_uptodate && !PageError(page)))
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SetPageUptodate(page);
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}
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unlock_page(page);
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return;
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still_busy:
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bit_spin_unlock(BH_Uptodate_Lock, &first->b_state);
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local_irq_restore(flags);
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return;
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}
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/**
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* ntfs_read_block - fill a @page of an address space with data
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* @page: page cache page to fill with data
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*
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* Fill the page @page of the address space belonging to the @page->host inode.
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* We read each buffer asynchronously and when all buffers are read in, our io
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* completion handler ntfs_end_buffer_read_async(), if required, automatically
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* applies the mst fixups to the page before finally marking it uptodate and
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* unlocking it.
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*
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* We only enforce allocated_size limit because i_size is checked for in
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* generic_file_read().
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*
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* Return 0 on success and -errno on error.
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*
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* Contains an adapted version of fs/buffer.c::block_read_full_page().
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*/
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static int ntfs_read_block(struct page *page)
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{
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loff_t i_size;
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VCN vcn;
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LCN lcn;
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s64 init_size;
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struct inode *vi;
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ntfs_inode *ni;
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ntfs_volume *vol;
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runlist_element *rl;
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struct buffer_head *bh, *head, *arr[MAX_BUF_PER_PAGE];
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sector_t iblock, lblock, zblock;
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unsigned long flags;
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unsigned int blocksize, vcn_ofs;
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int i, nr;
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unsigned char blocksize_bits;
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vi = page->mapping->host;
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ni = NTFS_I(vi);
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vol = ni->vol;
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/* $MFT/$DATA must have its complete runlist in memory at all times. */
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BUG_ON(!ni->runlist.rl && !ni->mft_no && !NInoAttr(ni));
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blocksize = vol->sb->s_blocksize;
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blocksize_bits = vol->sb->s_blocksize_bits;
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if (!page_has_buffers(page)) {
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create_empty_buffers(page, blocksize, 0);
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if (unlikely(!page_has_buffers(page))) {
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unlock_page(page);
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return -ENOMEM;
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}
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}
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bh = head = page_buffers(page);
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BUG_ON(!bh);
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/*
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* We may be racing with truncate. To avoid some of the problems we
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* now take a snapshot of the various sizes and use those for the whole
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* of the function. In case of an extending truncate it just means we
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* may leave some buffers unmapped which are now allocated. This is
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* not a problem since these buffers will just get mapped when a write
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* occurs. In case of a shrinking truncate, we will detect this later
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* on due to the runlist being incomplete and if the page is being
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* fully truncated, truncate will throw it away as soon as we unlock
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* it so no need to worry what we do with it.
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*/
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iblock = (s64)page->index << (PAGE_SHIFT - blocksize_bits);
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read_lock_irqsave(&ni->size_lock, flags);
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lblock = (ni->allocated_size + blocksize - 1) >> blocksize_bits;
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init_size = ni->initialized_size;
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i_size = i_size_read(vi);
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read_unlock_irqrestore(&ni->size_lock, flags);
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if (unlikely(init_size > i_size)) {
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/* Race with shrinking truncate. */
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init_size = i_size;
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}
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zblock = (init_size + blocksize - 1) >> blocksize_bits;
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/* Loop through all the buffers in the page. */
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rl = NULL;
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nr = i = 0;
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do {
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int err = 0;
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if (unlikely(buffer_uptodate(bh)))
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continue;
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if (unlikely(buffer_mapped(bh))) {
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arr[nr++] = bh;
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continue;
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}
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bh->b_bdev = vol->sb->s_bdev;
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/* Is the block within the allowed limits? */
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if (iblock < lblock) {
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bool is_retry = false;
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/* Convert iblock into corresponding vcn and offset. */
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vcn = (VCN)iblock << blocksize_bits >>
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vol->cluster_size_bits;
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vcn_ofs = ((VCN)iblock << blocksize_bits) &
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vol->cluster_size_mask;
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if (!rl) {
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lock_retry_remap:
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down_read(&ni->runlist.lock);
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rl = ni->runlist.rl;
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}
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if (likely(rl != NULL)) {
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/* Seek to element containing target vcn. */
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while (rl->length && rl[1].vcn <= vcn)
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rl++;
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lcn = ntfs_rl_vcn_to_lcn(rl, vcn);
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} else
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lcn = LCN_RL_NOT_MAPPED;
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/* Successful remap. */
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if (lcn >= 0) {
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/* Setup buffer head to correct block. */
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bh->b_blocknr = ((lcn << vol->cluster_size_bits)
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+ vcn_ofs) >> blocksize_bits;
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set_buffer_mapped(bh);
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/* Only read initialized data blocks. */
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if (iblock < zblock) {
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arr[nr++] = bh;
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continue;
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}
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/* Fully non-initialized data block, zero it. */
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goto handle_zblock;
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}
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/* It is a hole, need to zero it. */
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if (lcn == LCN_HOLE)
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goto handle_hole;
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/* If first try and runlist unmapped, map and retry. */
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if (!is_retry && lcn == LCN_RL_NOT_MAPPED) {
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is_retry = true;
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/*
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* Attempt to map runlist, dropping lock for
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* the duration.
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*/
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up_read(&ni->runlist.lock);
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err = ntfs_map_runlist(ni, vcn);
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if (likely(!err))
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goto lock_retry_remap;
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rl = NULL;
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} else if (!rl)
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up_read(&ni->runlist.lock);
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/*
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* If buffer is outside the runlist, treat it as a
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* hole. This can happen due to concurrent truncate
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* for example.
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*/
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if (err == -ENOENT || lcn == LCN_ENOENT) {
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err = 0;
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goto handle_hole;
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}
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/* Hard error, zero out region. */
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if (!err)
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err = -EIO;
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bh->b_blocknr = -1;
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SetPageError(page);
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ntfs_error(vol->sb, "Failed to read from inode 0x%lx, "
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"attribute type 0x%x, vcn 0x%llx, "
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"offset 0x%x because its location on "
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"disk could not be determined%s "
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"(error code %i).", ni->mft_no,
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ni->type, (unsigned long long)vcn,
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vcn_ofs, is_retry ? " even after "
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"retrying" : "", err);
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}
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/*
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* Either iblock was outside lblock limits or
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* ntfs_rl_vcn_to_lcn() returned error. Just zero that portion
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* of the page and set the buffer uptodate.
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*/
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handle_hole:
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bh->b_blocknr = -1UL;
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clear_buffer_mapped(bh);
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handle_zblock:
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zero_user(page, i * blocksize, blocksize);
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if (likely(!err))
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set_buffer_uptodate(bh);
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} while (i++, iblock++, (bh = bh->b_this_page) != head);
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/* Release the lock if we took it. */
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if (rl)
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up_read(&ni->runlist.lock);
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|
|
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/* Check we have at least one buffer ready for i/o. */
|
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if (nr) {
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struct buffer_head *tbh;
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|
|
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/* Lock the buffers. */
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for (i = 0; i < nr; i++) {
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tbh = arr[i];
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lock_buffer(tbh);
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tbh->b_end_io = ntfs_end_buffer_async_read;
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set_buffer_async_read(tbh);
|
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}
|
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/* Finally, start i/o on the buffers. */
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for (i = 0; i < nr; i++) {
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tbh = arr[i];
|
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if (likely(!buffer_uptodate(tbh)))
|
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submit_bh(REQ_OP_READ, 0, tbh);
|
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else
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ntfs_end_buffer_async_read(tbh, 1);
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}
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return 0;
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}
|
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/* No i/o was scheduled on any of the buffers. */
|
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if (likely(!PageError(page)))
|
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SetPageUptodate(page);
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else /* Signal synchronous i/o error. */
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nr = -EIO;
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unlock_page(page);
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return nr;
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}
|
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|
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/**
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* ntfs_readpage - fill a @page of a @file with data from the device
|
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* @file: open file to which the page @page belongs or NULL
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* @page: page cache page to fill with data
|
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*
|
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* For non-resident attributes, ntfs_readpage() fills the @page of the open
|
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* file @file by calling the ntfs version of the generic block_read_full_page()
|
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* function, ntfs_read_block(), which in turn creates and reads in the buffers
|
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* associated with the page asynchronously.
|
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*
|
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* For resident attributes, OTOH, ntfs_readpage() fills @page by copying the
|
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* data from the mft record (which at this stage is most likely in memory) and
|
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* fills the remainder with zeroes. Thus, in this case, I/O is synchronous, as
|
|
* even if the mft record is not cached at this point in time, we need to wait
|
|
* for it to be read in before we can do the copy.
|
|
*
|
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* Return 0 on success and -errno on error.
|
|
*/
|
|
static int ntfs_readpage(struct file *file, struct page *page)
|
|
{
|
|
loff_t i_size;
|
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struct inode *vi;
|
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ntfs_inode *ni, *base_ni;
|
|
u8 *addr;
|
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ntfs_attr_search_ctx *ctx;
|
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MFT_RECORD *mrec;
|
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unsigned long flags;
|
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u32 attr_len;
|
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int err = 0;
|
|
|
|
retry_readpage:
|
|
BUG_ON(!PageLocked(page));
|
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vi = page->mapping->host;
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i_size = i_size_read(vi);
|
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/* Is the page fully outside i_size? (truncate in progress) */
|
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if (unlikely(page->index >= (i_size + PAGE_SIZE - 1) >>
|
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PAGE_SHIFT)) {
|
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zero_user(page, 0, PAGE_SIZE);
|
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ntfs_debug("Read outside i_size - truncated?");
|
|
goto done;
|
|
}
|
|
/*
|
|
* This can potentially happen because we clear PageUptodate() during
|
|
* ntfs_writepage() of MstProtected() attributes.
|
|
*/
|
|
if (PageUptodate(page)) {
|
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unlock_page(page);
|
|
return 0;
|
|
}
|
|
ni = NTFS_I(vi);
|
|
/*
|
|
* Only $DATA attributes can be encrypted and only unnamed $DATA
|
|
* attributes can be compressed. Index root can have the flags set but
|
|
* this means to create compressed/encrypted files, not that the
|
|
* attribute is compressed/encrypted. Note we need to check for
|
|
* AT_INDEX_ALLOCATION since this is the type of both directory and
|
|
* index inodes.
|
|
*/
|
|
if (ni->type != AT_INDEX_ALLOCATION) {
|
|
/* If attribute is encrypted, deny access, just like NT4. */
|
|
if (NInoEncrypted(ni)) {
|
|
BUG_ON(ni->type != AT_DATA);
|
|
err = -EACCES;
|
|
goto err_out;
|
|
}
|
|
/* Compressed data streams are handled in compress.c. */
|
|
if (NInoNonResident(ni) && NInoCompressed(ni)) {
|
|
BUG_ON(ni->type != AT_DATA);
|
|
BUG_ON(ni->name_len);
|
|
return ntfs_read_compressed_block(page);
|
|
}
|
|
}
|
|
/* NInoNonResident() == NInoIndexAllocPresent() */
|
|
if (NInoNonResident(ni)) {
|
|
/* Normal, non-resident data stream. */
|
|
return ntfs_read_block(page);
|
|
}
|
|
/*
|
|
* Attribute is resident, implying it is not compressed or encrypted.
|
|
* This also means the attribute is smaller than an mft record and
|
|
* hence smaller than a page, so can simply zero out any pages with
|
|
* index above 0. Note the attribute can actually be marked compressed
|
|
* but if it is resident the actual data is not compressed so we are
|
|
* ok to ignore the compressed flag here.
|
|
*/
|
|
if (unlikely(page->index > 0)) {
|
|
zero_user(page, 0, PAGE_SIZE);
|
|
goto done;
|
|
}
|
|
if (!NInoAttr(ni))
|
|
base_ni = ni;
|
|
else
|
|
base_ni = ni->ext.base_ntfs_ino;
|
|
/* Map, pin, and lock the mft record. */
|
|
mrec = map_mft_record(base_ni);
|
|
if (IS_ERR(mrec)) {
|
|
err = PTR_ERR(mrec);
|
|
goto err_out;
|
|
}
|
|
/*
|
|
* If a parallel write made the attribute non-resident, drop the mft
|
|
* record and retry the readpage.
|
|
*/
|
|
if (unlikely(NInoNonResident(ni))) {
|
|
unmap_mft_record(base_ni);
|
|
goto retry_readpage;
|
|
}
|
|
ctx = ntfs_attr_get_search_ctx(base_ni, mrec);
|
|
if (unlikely(!ctx)) {
|
|
err = -ENOMEM;
|
|
goto unm_err_out;
|
|
}
|
|
err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len,
|
|
CASE_SENSITIVE, 0, NULL, 0, ctx);
|
|
if (unlikely(err))
|
|
goto put_unm_err_out;
|
|
attr_len = le32_to_cpu(ctx->attr->data.resident.value_length);
|
|
read_lock_irqsave(&ni->size_lock, flags);
|
|
if (unlikely(attr_len > ni->initialized_size))
|
|
attr_len = ni->initialized_size;
|
|
i_size = i_size_read(vi);
|
|
read_unlock_irqrestore(&ni->size_lock, flags);
|
|
if (unlikely(attr_len > i_size)) {
|
|
/* Race with shrinking truncate. */
|
|
attr_len = i_size;
|
|
}
|
|
addr = kmap_atomic(page);
|
|
/* Copy the data to the page. */
|
|
memcpy(addr, (u8*)ctx->attr +
|
|
le16_to_cpu(ctx->attr->data.resident.value_offset),
|
|
attr_len);
|
|
/* Zero the remainder of the page. */
|
|
memset(addr + attr_len, 0, PAGE_SIZE - attr_len);
|
|
flush_dcache_page(page);
|
|
kunmap_atomic(addr);
|
|
put_unm_err_out:
|
|
ntfs_attr_put_search_ctx(ctx);
|
|
unm_err_out:
|
|
unmap_mft_record(base_ni);
|
|
done:
|
|
SetPageUptodate(page);
|
|
err_out:
|
|
unlock_page(page);
|
|
return err;
|
|
}
|
|
|
|
#ifdef NTFS_RW
|
|
|
|
/**
|
|
* ntfs_write_block - write a @page to the backing store
|
|
* @page: page cache page to write out
|
|
* @wbc: writeback control structure
|
|
*
|
|
* This function is for writing pages belonging to non-resident, non-mst
|
|
* protected attributes to their backing store.
|
|
*
|
|
* For a page with buffers, map and write the dirty buffers asynchronously
|
|
* under page writeback. For a page without buffers, create buffers for the
|
|
* page, then proceed as above.
|
|
*
|
|
* If a page doesn't have buffers the page dirty state is definitive. If a page
|
|
* does have buffers, the page dirty state is just a hint, and the buffer dirty
|
|
* state is definitive. (A hint which has rules: dirty buffers against a clean
|
|
* page is illegal. Other combinations are legal and need to be handled. In
|
|
* particular a dirty page containing clean buffers for example.)
|
|
*
|
|
* Return 0 on success and -errno on error.
|
|
*
|
|
* Based on ntfs_read_block() and __block_write_full_page().
|
|
*/
|
|
static int ntfs_write_block(struct page *page, struct writeback_control *wbc)
|
|
{
|
|
VCN vcn;
|
|
LCN lcn;
|
|
s64 initialized_size;
|
|
loff_t i_size;
|
|
sector_t block, dblock, iblock;
|
|
struct inode *vi;
|
|
ntfs_inode *ni;
|
|
ntfs_volume *vol;
|
|
runlist_element *rl;
|
|
struct buffer_head *bh, *head;
|
|
unsigned long flags;
|
|
unsigned int blocksize, vcn_ofs;
|
|
int err;
|
|
bool need_end_writeback;
|
|
unsigned char blocksize_bits;
|
|
|
|
vi = page->mapping->host;
|
|
ni = NTFS_I(vi);
|
|
vol = ni->vol;
|
|
|
|
ntfs_debug("Entering for inode 0x%lx, attribute type 0x%x, page index "
|
|
"0x%lx.", ni->mft_no, ni->type, page->index);
|
|
|
|
BUG_ON(!NInoNonResident(ni));
|
|
BUG_ON(NInoMstProtected(ni));
|
|
blocksize = vol->sb->s_blocksize;
|
|
blocksize_bits = vol->sb->s_blocksize_bits;
|
|
if (!page_has_buffers(page)) {
|
|
BUG_ON(!PageUptodate(page));
|
|
create_empty_buffers(page, blocksize,
|
|
(1 << BH_Uptodate) | (1 << BH_Dirty));
|
|
if (unlikely(!page_has_buffers(page))) {
|
|
ntfs_warning(vol->sb, "Error allocating page "
|
|
"buffers. Redirtying page so we try "
|
|
"again later.");
|
|
/*
|
|
* Put the page back on mapping->dirty_pages, but leave
|
|
* its buffers' dirty state as-is.
|
|
*/
|
|
redirty_page_for_writepage(wbc, page);
|
|
unlock_page(page);
|
|
return 0;
|
|
}
|
|
}
|
|
bh = head = page_buffers(page);
|
|
BUG_ON(!bh);
|
|
|
|
/* NOTE: Different naming scheme to ntfs_read_block()! */
|
|
|
|
/* The first block in the page. */
|
|
block = (s64)page->index << (PAGE_SHIFT - blocksize_bits);
|
|
|
|
read_lock_irqsave(&ni->size_lock, flags);
|
|
i_size = i_size_read(vi);
|
|
initialized_size = ni->initialized_size;
|
|
read_unlock_irqrestore(&ni->size_lock, flags);
|
|
|
|
/* The first out of bounds block for the data size. */
|
|
dblock = (i_size + blocksize - 1) >> blocksize_bits;
|
|
|
|
/* The last (fully or partially) initialized block. */
|
|
iblock = initialized_size >> blocksize_bits;
|
|
|
|
/*
|
|
* Be very careful. We have no exclusion from __set_page_dirty_buffers
|
|
* here, and the (potentially unmapped) buffers may become dirty at
|
|
* any time. If a buffer becomes dirty here after we've inspected it
|
|
* then we just miss that fact, and the page stays dirty.
|
|
*
|
|
* Buffers outside i_size may be dirtied by __set_page_dirty_buffers;
|
|
* handle that here by just cleaning them.
|
|
*/
|
|
|
|
/*
|
|
* Loop through all the buffers in the page, mapping all the dirty
|
|
* buffers to disk addresses and handling any aliases from the
|
|
* underlying block device's mapping.
|
|
*/
|
|
rl = NULL;
|
|
err = 0;
|
|
do {
|
|
bool is_retry = false;
|
|
|
|
if (unlikely(block >= dblock)) {
|
|
/*
|
|
* Mapped buffers outside i_size will occur, because
|
|
* this page can be outside i_size when there is a
|
|
* truncate in progress. The contents of such buffers
|
|
* were zeroed by ntfs_writepage().
|
|
*
|
|
* FIXME: What about the small race window where
|
|
* ntfs_writepage() has not done any clearing because
|
|
* the page was within i_size but before we get here,
|
|
* vmtruncate() modifies i_size?
|
|
*/
|
|
clear_buffer_dirty(bh);
|
|
set_buffer_uptodate(bh);
|
|
continue;
|
|
}
|
|
|
|
/* Clean buffers are not written out, so no need to map them. */
|
|
if (!buffer_dirty(bh))
|
|
continue;
|
|
|
|
/* Make sure we have enough initialized size. */
|
|
if (unlikely((block >= iblock) &&
|
|
(initialized_size < i_size))) {
|
|
/*
|
|
* If this page is fully outside initialized size, zero
|
|
* out all pages between the current initialized size
|
|
* and the current page. Just use ntfs_readpage() to do
|
|
* the zeroing transparently.
|
|
*/
|
|
if (block > iblock) {
|
|
// TODO:
|
|
// For each page do:
|
|
// - read_cache_page()
|
|
// Again for each page do:
|
|
// - wait_on_page_locked()
|
|
// - Check (PageUptodate(page) &&
|
|
// !PageError(page))
|
|
// Update initialized size in the attribute and
|
|
// in the inode.
|
|
// Again, for each page do:
|
|
// __set_page_dirty_buffers();
|
|
// put_page()
|
|
// We don't need to wait on the writes.
|
|
// Update iblock.
|
|
}
|
|
/*
|
|
* The current page straddles initialized size. Zero
|
|
* all non-uptodate buffers and set them uptodate (and
|
|
* dirty?). Note, there aren't any non-uptodate buffers
|
|
* if the page is uptodate.
|
|
* FIXME: For an uptodate page, the buffers may need to
|
|
* be written out because they were not initialized on
|
|
* disk before.
|
|
*/
|
|
if (!PageUptodate(page)) {
|
|
// TODO:
|
|
// Zero any non-uptodate buffers up to i_size.
|
|
// Set them uptodate and dirty.
|
|
}
|
|
// TODO:
|
|
// Update initialized size in the attribute and in the
|
|
// inode (up to i_size).
|
|
// Update iblock.
|
|
// FIXME: This is inefficient. Try to batch the two
|
|
// size changes to happen in one go.
|
|
ntfs_error(vol->sb, "Writing beyond initialized size "
|
|
"is not supported yet. Sorry.");
|
|
err = -EOPNOTSUPP;
|
|
break;
|
|
// Do NOT set_buffer_new() BUT DO clear buffer range
|
|
// outside write request range.
|
|
// set_buffer_uptodate() on complete buffers as well as
|
|
// set_buffer_dirty().
|
|
}
|
|
|
|
/* No need to map buffers that are already mapped. */
|
|
if (buffer_mapped(bh))
|
|
continue;
|
|
|
|
/* Unmapped, dirty buffer. Need to map it. */
|
|
bh->b_bdev = vol->sb->s_bdev;
|
|
|
|
/* Convert block into corresponding vcn and offset. */
|
|
vcn = (VCN)block << blocksize_bits;
|
|
vcn_ofs = vcn & vol->cluster_size_mask;
|
|
vcn >>= vol->cluster_size_bits;
|
|
if (!rl) {
|
|
lock_retry_remap:
|
|
down_read(&ni->runlist.lock);
|
|
rl = ni->runlist.rl;
|
|
}
|
|
if (likely(rl != NULL)) {
|
|
/* Seek to element containing target vcn. */
|
|
while (rl->length && rl[1].vcn <= vcn)
|
|
rl++;
|
|
lcn = ntfs_rl_vcn_to_lcn(rl, vcn);
|
|
} else
|
|
lcn = LCN_RL_NOT_MAPPED;
|
|
/* Successful remap. */
|
|
if (lcn >= 0) {
|
|
/* Setup buffer head to point to correct block. */
|
|
bh->b_blocknr = ((lcn << vol->cluster_size_bits) +
|
|
vcn_ofs) >> blocksize_bits;
|
|
set_buffer_mapped(bh);
|
|
continue;
|
|
}
|
|
/* It is a hole, need to instantiate it. */
|
|
if (lcn == LCN_HOLE) {
|
|
u8 *kaddr;
|
|
unsigned long *bpos, *bend;
|
|
|
|
/* Check if the buffer is zero. */
|
|
kaddr = kmap_atomic(page);
|
|
bpos = (unsigned long *)(kaddr + bh_offset(bh));
|
|
bend = (unsigned long *)((u8*)bpos + blocksize);
|
|
do {
|
|
if (unlikely(*bpos))
|
|
break;
|
|
} while (likely(++bpos < bend));
|
|
kunmap_atomic(kaddr);
|
|
if (bpos == bend) {
|
|
/*
|
|
* Buffer is zero and sparse, no need to write
|
|
* it.
|
|
*/
|
|
bh->b_blocknr = -1;
|
|
clear_buffer_dirty(bh);
|
|
continue;
|
|
}
|
|
// TODO: Instantiate the hole.
|
|
// clear_buffer_new(bh);
|
|
// clean_bdev_bh_alias(bh);
|
|
ntfs_error(vol->sb, "Writing into sparse regions is "
|
|
"not supported yet. Sorry.");
|
|
err = -EOPNOTSUPP;
|
|
break;
|
|
}
|
|
/* If first try and runlist unmapped, map and retry. */
|
|
if (!is_retry && lcn == LCN_RL_NOT_MAPPED) {
|
|
is_retry = true;
|
|
/*
|
|
* Attempt to map runlist, dropping lock for
|
|
* the duration.
|
|
*/
|
|
up_read(&ni->runlist.lock);
|
|
err = ntfs_map_runlist(ni, vcn);
|
|
if (likely(!err))
|
|
goto lock_retry_remap;
|
|
rl = NULL;
|
|
} else if (!rl)
|
|
up_read(&ni->runlist.lock);
|
|
/*
|
|
* If buffer is outside the runlist, truncate has cut it out
|
|
* of the runlist. Just clean and clear the buffer and set it
|
|
* uptodate so it can get discarded by the VM.
|
|
*/
|
|
if (err == -ENOENT || lcn == LCN_ENOENT) {
|
|
bh->b_blocknr = -1;
|
|
clear_buffer_dirty(bh);
|
|
zero_user(page, bh_offset(bh), blocksize);
|
|
set_buffer_uptodate(bh);
|
|
err = 0;
|
|
continue;
|
|
}
|
|
/* Failed to map the buffer, even after retrying. */
|
|
if (!err)
|
|
err = -EIO;
|
|
bh->b_blocknr = -1;
|
|
ntfs_error(vol->sb, "Failed to write to inode 0x%lx, "
|
|
"attribute type 0x%x, vcn 0x%llx, offset 0x%x "
|
|
"because its location on disk could not be "
|
|
"determined%s (error code %i).", ni->mft_no,
|
|
ni->type, (unsigned long long)vcn,
|
|
vcn_ofs, is_retry ? " even after "
|
|
"retrying" : "", err);
|
|
break;
|
|
} while (block++, (bh = bh->b_this_page) != head);
|
|
|
|
/* Release the lock if we took it. */
|
|
if (rl)
|
|
up_read(&ni->runlist.lock);
|
|
|
|
/* For the error case, need to reset bh to the beginning. */
|
|
bh = head;
|
|
|
|
/* Just an optimization, so ->readpage() is not called later. */
|
|
if (unlikely(!PageUptodate(page))) {
|
|
int uptodate = 1;
|
|
do {
|
|
if (!buffer_uptodate(bh)) {
|
|
uptodate = 0;
|
|
bh = head;
|
|
break;
|
|
}
|
|
} while ((bh = bh->b_this_page) != head);
|
|
if (uptodate)
|
|
SetPageUptodate(page);
|
|
}
|
|
|
|
/* Setup all mapped, dirty buffers for async write i/o. */
|
|
do {
|
|
if (buffer_mapped(bh) && buffer_dirty(bh)) {
|
|
lock_buffer(bh);
|
|
if (test_clear_buffer_dirty(bh)) {
|
|
BUG_ON(!buffer_uptodate(bh));
|
|
mark_buffer_async_write(bh);
|
|
} else
|
|
unlock_buffer(bh);
|
|
} else if (unlikely(err)) {
|
|
/*
|
|
* For the error case. The buffer may have been set
|
|
* dirty during attachment to a dirty page.
|
|
*/
|
|
if (err != -ENOMEM)
|
|
clear_buffer_dirty(bh);
|
|
}
|
|
} while ((bh = bh->b_this_page) != head);
|
|
|
|
if (unlikely(err)) {
|
|
// TODO: Remove the -EOPNOTSUPP check later on...
|
|
if (unlikely(err == -EOPNOTSUPP))
|
|
err = 0;
|
|
else if (err == -ENOMEM) {
|
|
ntfs_warning(vol->sb, "Error allocating memory. "
|
|
"Redirtying page so we try again "
|
|
"later.");
|
|
/*
|
|
* Put the page back on mapping->dirty_pages, but
|
|
* leave its buffer's dirty state as-is.
|
|
*/
|
|
redirty_page_for_writepage(wbc, page);
|
|
err = 0;
|
|
} else
|
|
SetPageError(page);
|
|
}
|
|
|
|
BUG_ON(PageWriteback(page));
|
|
set_page_writeback(page); /* Keeps try_to_free_buffers() away. */
|
|
|
|
/* Submit the prepared buffers for i/o. */
|
|
need_end_writeback = true;
|
|
do {
|
|
struct buffer_head *next = bh->b_this_page;
|
|
if (buffer_async_write(bh)) {
|
|
submit_bh(REQ_OP_WRITE, 0, bh);
|
|
need_end_writeback = false;
|
|
}
|
|
bh = next;
|
|
} while (bh != head);
|
|
unlock_page(page);
|
|
|
|
/* If no i/o was started, need to end_page_writeback(). */
|
|
if (unlikely(need_end_writeback))
|
|
end_page_writeback(page);
|
|
|
|
ntfs_debug("Done.");
|
|
return err;
|
|
}
|
|
|
|
/**
|
|
* ntfs_write_mst_block - write a @page to the backing store
|
|
* @page: page cache page to write out
|
|
* @wbc: writeback control structure
|
|
*
|
|
* This function is for writing pages belonging to non-resident, mst protected
|
|
* attributes to their backing store. The only supported attributes are index
|
|
* allocation and $MFT/$DATA. Both directory inodes and index inodes are
|
|
* supported for the index allocation case.
|
|
*
|
|
* The page must remain locked for the duration of the write because we apply
|
|
* the mst fixups, write, and then undo the fixups, so if we were to unlock the
|
|
* page before undoing the fixups, any other user of the page will see the
|
|
* page contents as corrupt.
|
|
*
|
|
* We clear the page uptodate flag for the duration of the function to ensure
|
|
* exclusion for the $MFT/$DATA case against someone mapping an mft record we
|
|
* are about to apply the mst fixups to.
|
|
*
|
|
* Return 0 on success and -errno on error.
|
|
*
|
|
* Based on ntfs_write_block(), ntfs_mft_writepage(), and
|
|
* write_mft_record_nolock().
|
|
*/
|
|
static int ntfs_write_mst_block(struct page *page,
|
|
struct writeback_control *wbc)
|
|
{
|
|
sector_t block, dblock, rec_block;
|
|
struct inode *vi = page->mapping->host;
|
|
ntfs_inode *ni = NTFS_I(vi);
|
|
ntfs_volume *vol = ni->vol;
|
|
u8 *kaddr;
|
|
unsigned int rec_size = ni->itype.index.block_size;
|
|
ntfs_inode *locked_nis[PAGE_SIZE / NTFS_BLOCK_SIZE];
|
|
struct buffer_head *bh, *head, *tbh, *rec_start_bh;
|
|
struct buffer_head *bhs[MAX_BUF_PER_PAGE];
|
|
runlist_element *rl;
|
|
int i, nr_locked_nis, nr_recs, nr_bhs, max_bhs, bhs_per_rec, err, err2;
|
|
unsigned bh_size, rec_size_bits;
|
|
bool sync, is_mft, page_is_dirty, rec_is_dirty;
|
|
unsigned char bh_size_bits;
|
|
|
|
if (WARN_ON(rec_size < NTFS_BLOCK_SIZE))
|
|
return -EINVAL;
|
|
|
|
ntfs_debug("Entering for inode 0x%lx, attribute type 0x%x, page index "
|
|
"0x%lx.", vi->i_ino, ni->type, page->index);
|
|
BUG_ON(!NInoNonResident(ni));
|
|
BUG_ON(!NInoMstProtected(ni));
|
|
is_mft = (S_ISREG(vi->i_mode) && !vi->i_ino);
|
|
/*
|
|
* NOTE: ntfs_write_mst_block() would be called for $MFTMirr if a page
|
|
* in its page cache were to be marked dirty. However this should
|
|
* never happen with the current driver and considering we do not
|
|
* handle this case here we do want to BUG(), at least for now.
|
|
*/
|
|
BUG_ON(!(is_mft || S_ISDIR(vi->i_mode) ||
|
|
(NInoAttr(ni) && ni->type == AT_INDEX_ALLOCATION)));
|
|
bh_size = vol->sb->s_blocksize;
|
|
bh_size_bits = vol->sb->s_blocksize_bits;
|
|
max_bhs = PAGE_SIZE / bh_size;
|
|
BUG_ON(!max_bhs);
|
|
BUG_ON(max_bhs > MAX_BUF_PER_PAGE);
|
|
|
|
/* Were we called for sync purposes? */
|
|
sync = (wbc->sync_mode == WB_SYNC_ALL);
|
|
|
|
/* Make sure we have mapped buffers. */
|
|
bh = head = page_buffers(page);
|
|
BUG_ON(!bh);
|
|
|
|
rec_size_bits = ni->itype.index.block_size_bits;
|
|
BUG_ON(!(PAGE_SIZE >> rec_size_bits));
|
|
bhs_per_rec = rec_size >> bh_size_bits;
|
|
BUG_ON(!bhs_per_rec);
|
|
|
|
/* The first block in the page. */
|
|
rec_block = block = (sector_t)page->index <<
|
|
(PAGE_SHIFT - bh_size_bits);
|
|
|
|
/* The first out of bounds block for the data size. */
|
|
dblock = (i_size_read(vi) + bh_size - 1) >> bh_size_bits;
|
|
|
|
rl = NULL;
|
|
err = err2 = nr_bhs = nr_recs = nr_locked_nis = 0;
|
|
page_is_dirty = rec_is_dirty = false;
|
|
rec_start_bh = NULL;
|
|
do {
|
|
bool is_retry = false;
|
|
|
|
if (likely(block < rec_block)) {
|
|
if (unlikely(block >= dblock)) {
|
|
clear_buffer_dirty(bh);
|
|
set_buffer_uptodate(bh);
|
|
continue;
|
|
}
|
|
/*
|
|
* 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 (!rec_is_dirty)
|
|
continue;
|
|
if (unlikely(err2)) {
|
|
if (err2 != -ENOMEM)
|
|
clear_buffer_dirty(bh);
|
|
continue;
|
|
}
|
|
} else /* if (block == rec_block) */ {
|
|
BUG_ON(block > rec_block);
|
|
/* This block is the first one in the record. */
|
|
rec_block += bhs_per_rec;
|
|
err2 = 0;
|
|
if (unlikely(block >= dblock)) {
|
|
clear_buffer_dirty(bh);
|
|
continue;
|
|
}
|
|
if (!buffer_dirty(bh)) {
|
|
/* Clean records are not written out. */
|
|
rec_is_dirty = false;
|
|
continue;
|
|
}
|
|
rec_is_dirty = true;
|
|
rec_start_bh = bh;
|
|
}
|
|
/* 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)block << bh_size_bits;
|
|
vcn_ofs = vcn & vol->cluster_size_mask;
|
|
vcn >>= vol->cluster_size_bits;
|
|
if (!rl) {
|
|
lock_retry_remap:
|
|
down_read(&ni->runlist.lock);
|
|
rl = ni->runlist.rl;
|
|
}
|
|
if (likely(rl != NULL)) {
|
|
/* Seek to element containing target vcn. */
|
|
while (rl->length && rl[1].vcn <= vcn)
|
|
rl++;
|
|
lcn = ntfs_rl_vcn_to_lcn(rl, vcn);
|
|
} else
|
|
lcn = LCN_RL_NOT_MAPPED;
|
|
/* Successful remap. */
|
|
if (likely(lcn >= 0)) {
|
|
/* Setup buffer head to correct block. */
|
|
bh->b_blocknr = ((lcn <<
|
|
vol->cluster_size_bits) +
|
|
vcn_ofs) >> bh_size_bits;
|
|
set_buffer_mapped(bh);
|
|
} else {
|
|
/*
|
|
* Remap failed. Retry to map the runlist once
|
|
* unless we are working on $MFT which always
|
|
* has the whole of its runlist in memory.
|
|
*/
|
|
if (!is_mft && !is_retry &&
|
|
lcn == LCN_RL_NOT_MAPPED) {
|
|
is_retry = true;
|
|
/*
|
|
* Attempt to map runlist, dropping
|
|
* lock for the duration.
|
|
*/
|
|
up_read(&ni->runlist.lock);
|
|
err2 = ntfs_map_runlist(ni, vcn);
|
|
if (likely(!err2))
|
|
goto lock_retry_remap;
|
|
if (err2 == -ENOMEM)
|
|
page_is_dirty = true;
|
|
lcn = err2;
|
|
} else {
|
|
err2 = -EIO;
|
|
if (!rl)
|
|
up_read(&ni->runlist.lock);
|
|
}
|
|
/* Hard error. Abort writing this record. */
|
|
if (!err || err == -ENOMEM)
|
|
err = err2;
|
|
bh->b_blocknr = -1;
|
|
ntfs_error(vol->sb, "Cannot write ntfs record "
|
|
"0x%llx (inode 0x%lx, "
|
|
"attribute type 0x%x) because "
|
|
"its location on disk could "
|
|
"not be determined (error "
|
|
"code %lli).",
|
|
(long long)block <<
|
|
bh_size_bits >>
|
|
vol->mft_record_size_bits,
|
|
ni->mft_no, ni->type,
|
|
(long long)lcn);
|
|
/*
|
|
* If this is not the first buffer, remove the
|
|
* buffers in this record from the list of
|
|
* buffers to write and clear their dirty bit
|
|
* if not error -ENOMEM.
|
|
*/
|
|
if (rec_start_bh != bh) {
|
|
while (bhs[--nr_bhs] != rec_start_bh)
|
|
;
|
|
if (err2 != -ENOMEM) {
|
|
do {
|
|
clear_buffer_dirty(
|
|
rec_start_bh);
|
|
} while ((rec_start_bh =
|
|
rec_start_bh->
|
|
b_this_page) !=
|
|
bh);
|
|
}
|
|
}
|
|
continue;
|
|
}
|
|
}
|
|
BUG_ON(!buffer_uptodate(bh));
|
|
BUG_ON(nr_bhs >= max_bhs);
|
|
bhs[nr_bhs++] = bh;
|
|
} while (block++, (bh = bh->b_this_page) != head);
|
|
if (unlikely(rl))
|
|
up_read(&ni->runlist.lock);
|
|
/* If there were no dirty buffers, we are done. */
|
|
if (!nr_bhs)
|
|
goto done;
|
|
/* Map the page so we can access its contents. */
|
|
kaddr = kmap(page);
|
|
/* Clear the page uptodate flag whilst the mst fixups are applied. */
|
|
BUG_ON(!PageUptodate(page));
|
|
ClearPageUptodate(page);
|
|
for (i = 0; i < nr_bhs; i++) {
|
|
unsigned int ofs;
|
|
|
|
/* Skip buffers which are not at the beginning of records. */
|
|
if (i % bhs_per_rec)
|
|
continue;
|
|
tbh = bhs[i];
|
|
ofs = bh_offset(tbh);
|
|
if (is_mft) {
|
|
ntfs_inode *tni;
|
|
unsigned long mft_no;
|
|
|
|
/* Get the mft record number. */
|
|
mft_no = (((s64)page->index << PAGE_SHIFT) + ofs)
|
|
>> rec_size_bits;
|
|
/* Check whether to write this mft record. */
|
|
tni = NULL;
|
|
if (!ntfs_may_write_mft_record(vol, mft_no,
|
|
(MFT_RECORD*)(kaddr + ofs), &tni)) {
|
|
/*
|
|
* The record should not be written. This
|
|
* means we need to redirty the page before
|
|
* returning.
|
|
*/
|
|
page_is_dirty = true;
|
|
/*
|
|
* Remove the buffers in this mft record from
|
|
* the list of buffers to write.
|
|
*/
|
|
do {
|
|
bhs[i] = NULL;
|
|
} while (++i % bhs_per_rec);
|
|
continue;
|
|
}
|
|
/*
|
|
* The record should be written. If a locked ntfs
|
|
* inode was returned, add it to the array of locked
|
|
* ntfs inodes.
|
|
*/
|
|
if (tni)
|
|
locked_nis[nr_locked_nis++] = tni;
|
|
}
|
|
/* Apply the mst protection fixups. */
|
|
err2 = pre_write_mst_fixup((NTFS_RECORD*)(kaddr + ofs),
|
|
rec_size);
|
|
if (unlikely(err2)) {
|
|
if (!err || err == -ENOMEM)
|
|
err = -EIO;
|
|
ntfs_error(vol->sb, "Failed to apply mst fixups "
|
|
"(inode 0x%lx, attribute type 0x%x, "
|
|
"page index 0x%lx, page offset 0x%x)!"
|
|
" Unmount and run chkdsk.", vi->i_ino,
|
|
ni->type, page->index, ofs);
|
|
/*
|
|
* Mark all the buffers in this record clean as we do
|
|
* not want to write corrupt data to disk.
|
|
*/
|
|
do {
|
|
clear_buffer_dirty(bhs[i]);
|
|
bhs[i] = NULL;
|
|
} while (++i % bhs_per_rec);
|
|
continue;
|
|
}
|
|
nr_recs++;
|
|
}
|
|
/* If no records are to be written out, we are done. */
|
|
if (!nr_recs)
|
|
goto unm_done;
|
|
flush_dcache_page(page);
|
|
/* Lock buffers and start synchronous write i/o on them. */
|
|
for (i = 0; i < nr_bhs; i++) {
|
|
tbh = bhs[i];
|
|
if (!tbh)
|
|
continue;
|
|
if (!trylock_buffer(tbh))
|
|
BUG();
|
|
/* The buffer dirty state is now irrelevant, just clean it. */
|
|
clear_buffer_dirty(tbh);
|
|
BUG_ON(!buffer_uptodate(tbh));
|
|
BUG_ON(!buffer_mapped(tbh));
|
|
get_bh(tbh);
|
|
tbh->b_end_io = end_buffer_write_sync;
|
|
submit_bh(REQ_OP_WRITE, 0, tbh);
|
|
}
|
|
/* Synchronize the mft mirror now if not @sync. */
|
|
if (is_mft && !sync)
|
|
goto do_mirror;
|
|
do_wait:
|
|
/* Wait on i/o completion of buffers. */
|
|
for (i = 0; i < nr_bhs; i++) {
|
|
tbh = bhs[i];
|
|
if (!tbh)
|
|
continue;
|
|
wait_on_buffer(tbh);
|
|
if (unlikely(!buffer_uptodate(tbh))) {
|
|
ntfs_error(vol->sb, "I/O error while writing ntfs "
|
|
"record buffer (inode 0x%lx, "
|
|
"attribute type 0x%x, page index "
|
|
"0x%lx, page offset 0x%lx)! Unmount "
|
|
"and run chkdsk.", vi->i_ino, ni->type,
|
|
page->index, bh_offset(tbh));
|
|
if (!err || err == -ENOMEM)
|
|
err = -EIO;
|
|
/*
|
|
* Set the buffer uptodate so the page and buffer
|
|
* states do not become out of sync.
|
|
*/
|
|
set_buffer_uptodate(tbh);
|
|
}
|
|
}
|
|
/* If @sync, now synchronize the mft mirror. */
|
|
if (is_mft && sync) {
|
|
do_mirror:
|
|
for (i = 0; i < nr_bhs; i++) {
|
|
unsigned long mft_no;
|
|
unsigned int ofs;
|
|
|
|
/*
|
|
* Skip buffers which are not at the beginning of
|
|
* records.
|
|
*/
|
|
if (i % bhs_per_rec)
|
|
continue;
|
|
tbh = bhs[i];
|
|
/* Skip removed buffers (and hence records). */
|
|
if (!tbh)
|
|
continue;
|
|
ofs = bh_offset(tbh);
|
|
/* Get the mft record number. */
|
|
mft_no = (((s64)page->index << PAGE_SHIFT) + ofs)
|
|
>> rec_size_bits;
|
|
if (mft_no < vol->mftmirr_size)
|
|
ntfs_sync_mft_mirror(vol, mft_no,
|
|
(MFT_RECORD*)(kaddr + ofs),
|
|
sync);
|
|
}
|
|
if (!sync)
|
|
goto do_wait;
|
|
}
|
|
/* Remove the mst protection fixups again. */
|
|
for (i = 0; i < nr_bhs; i++) {
|
|
if (!(i % bhs_per_rec)) {
|
|
tbh = bhs[i];
|
|
if (!tbh)
|
|
continue;
|
|
post_write_mst_fixup((NTFS_RECORD*)(kaddr +
|
|
bh_offset(tbh)));
|
|
}
|
|
}
|
|
flush_dcache_page(page);
|
|
unm_done:
|
|
/* Unlock any locked inodes. */
|
|
while (nr_locked_nis-- > 0) {
|
|
ntfs_inode *tni, *base_tni;
|
|
|
|
tni = locked_nis[nr_locked_nis];
|
|
/* Get the base inode. */
|
|
mutex_lock(&tni->extent_lock);
|
|
if (tni->nr_extents >= 0)
|
|
base_tni = tni;
|
|
else {
|
|
base_tni = tni->ext.base_ntfs_ino;
|
|
BUG_ON(!base_tni);
|
|
}
|
|
mutex_unlock(&tni->extent_lock);
|
|
ntfs_debug("Unlocking %s inode 0x%lx.",
|
|
tni == base_tni ? "base" : "extent",
|
|
tni->mft_no);
|
|
mutex_unlock(&tni->mrec_lock);
|
|
atomic_dec(&tni->count);
|
|
iput(VFS_I(base_tni));
|
|
}
|
|
SetPageUptodate(page);
|
|
kunmap(page);
|
|
done:
|
|
if (unlikely(err && err != -ENOMEM)) {
|
|
/*
|
|
* Set page error if there is only one ntfs record in the page.
|
|
* Otherwise we would loose per-record granularity.
|
|
*/
|
|
if (ni->itype.index.block_size == PAGE_SIZE)
|
|
SetPageError(page);
|
|
NVolSetErrors(vol);
|
|
}
|
|
if (page_is_dirty) {
|
|
ntfs_debug("Page still contains one or more dirty ntfs "
|
|
"records. Redirtying the page starting at "
|
|
"record 0x%lx.", page->index <<
|
|
(PAGE_SHIFT - rec_size_bits));
|
|
redirty_page_for_writepage(wbc, page);
|
|
unlock_page(page);
|
|
} else {
|
|
/*
|
|
* Keep the VM happy. This must be done otherwise the
|
|
* radix-tree tag PAGECACHE_TAG_DIRTY remains set even though
|
|
* the page is clean.
|
|
*/
|
|
BUG_ON(PageWriteback(page));
|
|
set_page_writeback(page);
|
|
unlock_page(page);
|
|
end_page_writeback(page);
|
|
}
|
|
if (likely(!err))
|
|
ntfs_debug("Done.");
|
|
return err;
|
|
}
|
|
|
|
/**
|
|
* ntfs_writepage - write a @page to the backing store
|
|
* @page: page cache page to write out
|
|
* @wbc: writeback control structure
|
|
*
|
|
* This is called from the VM when it wants to have a dirty ntfs page cache
|
|
* page cleaned. The VM has already locked the page and marked it clean.
|
|
*
|
|
* For non-resident attributes, ntfs_writepage() writes the @page by calling
|
|
* the ntfs version of the generic block_write_full_page() function,
|
|
* ntfs_write_block(), which in turn if necessary creates and writes the
|
|
* buffers associated with the page asynchronously.
|
|
*
|
|
* For resident attributes, OTOH, ntfs_writepage() writes the @page by copying
|
|
* the data to the mft record (which at this stage is most likely in memory).
|
|
* The mft record is then marked dirty and written out asynchronously via the
|
|
* vfs inode dirty code path for the inode the mft record belongs to or via the
|
|
* vm page dirty code path for the page the mft record is in.
|
|
*
|
|
* Based on ntfs_readpage() and fs/buffer.c::block_write_full_page().
|
|
*
|
|
* Return 0 on success and -errno on error.
|
|
*/
|
|
static int ntfs_writepage(struct page *page, struct writeback_control *wbc)
|
|
{
|
|
loff_t i_size;
|
|
struct inode *vi = page->mapping->host;
|
|
ntfs_inode *base_ni = NULL, *ni = NTFS_I(vi);
|
|
char *addr;
|
|
ntfs_attr_search_ctx *ctx = NULL;
|
|
MFT_RECORD *m = NULL;
|
|
u32 attr_len;
|
|
int err;
|
|
|
|
retry_writepage:
|
|
BUG_ON(!PageLocked(page));
|
|
i_size = i_size_read(vi);
|
|
/* Is the page fully outside i_size? (truncate in progress) */
|
|
if (unlikely(page->index >= (i_size + PAGE_SIZE - 1) >>
|
|
PAGE_SHIFT)) {
|
|
/*
|
|
* The page may have dirty, unmapped buffers. Make them
|
|
* freeable here, so the page does not leak.
|
|
*/
|
|
block_invalidatepage(page, 0, PAGE_SIZE);
|
|
unlock_page(page);
|
|
ntfs_debug("Write outside i_size - truncated?");
|
|
return 0;
|
|
}
|
|
/*
|
|
* Only $DATA attributes can be encrypted and only unnamed $DATA
|
|
* attributes can be compressed. Index root can have the flags set but
|
|
* this means to create compressed/encrypted files, not that the
|
|
* attribute is compressed/encrypted. Note we need to check for
|
|
* AT_INDEX_ALLOCATION since this is the type of both directory and
|
|
* index inodes.
|
|
*/
|
|
if (ni->type != AT_INDEX_ALLOCATION) {
|
|
/* If file is encrypted, deny access, just like NT4. */
|
|
if (NInoEncrypted(ni)) {
|
|
unlock_page(page);
|
|
BUG_ON(ni->type != AT_DATA);
|
|
ntfs_debug("Denying write access to encrypted file.");
|
|
return -EACCES;
|
|
}
|
|
/* Compressed data streams are handled in compress.c. */
|
|
if (NInoNonResident(ni) && NInoCompressed(ni)) {
|
|
BUG_ON(ni->type != AT_DATA);
|
|
BUG_ON(ni->name_len);
|
|
// TODO: Implement and replace this with
|
|
// return ntfs_write_compressed_block(page);
|
|
unlock_page(page);
|
|
ntfs_error(vi->i_sb, "Writing to compressed files is "
|
|
"not supported yet. Sorry.");
|
|
return -EOPNOTSUPP;
|
|
}
|
|
// TODO: Implement and remove this check.
|
|
if (NInoNonResident(ni) && NInoSparse(ni)) {
|
|
unlock_page(page);
|
|
ntfs_error(vi->i_sb, "Writing to sparse files is not "
|
|
"supported yet. Sorry.");
|
|
return -EOPNOTSUPP;
|
|
}
|
|
}
|
|
/* NInoNonResident() == NInoIndexAllocPresent() */
|
|
if (NInoNonResident(ni)) {
|
|
/* We have to zero every time due to mmap-at-end-of-file. */
|
|
if (page->index >= (i_size >> PAGE_SHIFT)) {
|
|
/* The page straddles i_size. */
|
|
unsigned int ofs = i_size & ~PAGE_MASK;
|
|
zero_user_segment(page, ofs, PAGE_SIZE);
|
|
}
|
|
/* Handle mst protected attributes. */
|
|
if (NInoMstProtected(ni))
|
|
return ntfs_write_mst_block(page, wbc);
|
|
/* Normal, non-resident data stream. */
|
|
return ntfs_write_block(page, wbc);
|
|
}
|
|
/*
|
|
* Attribute is resident, implying it is not compressed, encrypted, or
|
|
* mst protected. This also means the attribute is smaller than an mft
|
|
* record and hence smaller than a page, so can simply return error on
|
|
* any pages with index above 0. Note the attribute can actually be
|
|
* marked compressed but if it is resident the actual data is not
|
|
* compressed so we are ok to ignore the compressed flag here.
|
|
*/
|
|
BUG_ON(page_has_buffers(page));
|
|
BUG_ON(!PageUptodate(page));
|
|
if (unlikely(page->index > 0)) {
|
|
ntfs_error(vi->i_sb, "BUG()! page->index (0x%lx) > 0. "
|
|
"Aborting write.", page->index);
|
|
BUG_ON(PageWriteback(page));
|
|
set_page_writeback(page);
|
|
unlock_page(page);
|
|
end_page_writeback(page);
|
|
return -EIO;
|
|
}
|
|
if (!NInoAttr(ni))
|
|
base_ni = ni;
|
|
else
|
|
base_ni = ni->ext.base_ntfs_ino;
|
|
/* Map, pin, and lock the mft record. */
|
|
m = map_mft_record(base_ni);
|
|
if (IS_ERR(m)) {
|
|
err = PTR_ERR(m);
|
|
m = NULL;
|
|
ctx = NULL;
|
|
goto err_out;
|
|
}
|
|
/*
|
|
* If a parallel write made the attribute non-resident, drop the mft
|
|
* record and retry the writepage.
|
|
*/
|
|
if (unlikely(NInoNonResident(ni))) {
|
|
unmap_mft_record(base_ni);
|
|
goto retry_writepage;
|
|
}
|
|
ctx = ntfs_attr_get_search_ctx(base_ni, m);
|
|
if (unlikely(!ctx)) {
|
|
err = -ENOMEM;
|
|
goto err_out;
|
|
}
|
|
err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len,
|
|
CASE_SENSITIVE, 0, NULL, 0, ctx);
|
|
if (unlikely(err))
|
|
goto err_out;
|
|
/*
|
|
* Keep the VM happy. This must be done otherwise the radix-tree tag
|
|
* PAGECACHE_TAG_DIRTY remains set even though the page is clean.
|
|
*/
|
|
BUG_ON(PageWriteback(page));
|
|
set_page_writeback(page);
|
|
unlock_page(page);
|
|
attr_len = le32_to_cpu(ctx->attr->data.resident.value_length);
|
|
i_size = i_size_read(vi);
|
|
if (unlikely(attr_len > i_size)) {
|
|
/* Race with shrinking truncate or a failed truncate. */
|
|
attr_len = i_size;
|
|
/*
|
|
* If the truncate failed, fix it up now. If a concurrent
|
|
* truncate, we do its job, so it does not have to do anything.
|
|
*/
|
|
err = ntfs_resident_attr_value_resize(ctx->mrec, ctx->attr,
|
|
attr_len);
|
|
/* Shrinking cannot fail. */
|
|
BUG_ON(err);
|
|
}
|
|
addr = kmap_atomic(page);
|
|
/* Copy the data from the page to the mft record. */
|
|
memcpy((u8*)ctx->attr +
|
|
le16_to_cpu(ctx->attr->data.resident.value_offset),
|
|
addr, attr_len);
|
|
/* Zero out of bounds area in the page cache page. */
|
|
memset(addr + attr_len, 0, PAGE_SIZE - attr_len);
|
|
kunmap_atomic(addr);
|
|
flush_dcache_page(page);
|
|
flush_dcache_mft_record_page(ctx->ntfs_ino);
|
|
/* We are done with the page. */
|
|
end_page_writeback(page);
|
|
/* Finally, mark the mft record dirty, so it gets written back. */
|
|
mark_mft_record_dirty(ctx->ntfs_ino);
|
|
ntfs_attr_put_search_ctx(ctx);
|
|
unmap_mft_record(base_ni);
|
|
return 0;
|
|
err_out:
|
|
if (err == -ENOMEM) {
|
|
ntfs_warning(vi->i_sb, "Error allocating memory. Redirtying "
|
|
"page so we try again later.");
|
|
/*
|
|
* Put the page back on mapping->dirty_pages, but leave its
|
|
* buffers' dirty state as-is.
|
|
*/
|
|
redirty_page_for_writepage(wbc, page);
|
|
err = 0;
|
|
} else {
|
|
ntfs_error(vi->i_sb, "Resident attribute write failed with "
|
|
"error %i.", err);
|
|
SetPageError(page);
|
|
NVolSetErrors(ni->vol);
|
|
}
|
|
unlock_page(page);
|
|
if (ctx)
|
|
ntfs_attr_put_search_ctx(ctx);
|
|
if (m)
|
|
unmap_mft_record(base_ni);
|
|
return err;
|
|
}
|
|
|
|
#endif /* NTFS_RW */
|
|
|
|
/**
|
|
* ntfs_bmap - map logical file block to physical device block
|
|
* @mapping: address space mapping to which the block to be mapped belongs
|
|
* @block: logical block to map to its physical device block
|
|
*
|
|
* For regular, non-resident files (i.e. not compressed and not encrypted), map
|
|
* the logical @block belonging to the file described by the address space
|
|
* mapping @mapping to its physical device block.
|
|
*
|
|
* The size of the block is equal to the @s_blocksize field of the super block
|
|
* of the mounted file system which is guaranteed to be smaller than or equal
|
|
* to the cluster size thus the block is guaranteed to fit entirely inside the
|
|
* cluster which means we do not need to care how many contiguous bytes are
|
|
* available after the beginning of the block.
|
|
*
|
|
* Return the physical device block if the mapping succeeded or 0 if the block
|
|
* is sparse or there was an error.
|
|
*
|
|
* Note: This is a problem if someone tries to run bmap() on $Boot system file
|
|
* as that really is in block zero but there is nothing we can do. bmap() is
|
|
* just broken in that respect (just like it cannot distinguish sparse from
|
|
* not available or error).
|
|
*/
|
|
static sector_t ntfs_bmap(struct address_space *mapping, sector_t block)
|
|
{
|
|
s64 ofs, size;
|
|
loff_t i_size;
|
|
LCN lcn;
|
|
unsigned long blocksize, flags;
|
|
ntfs_inode *ni = NTFS_I(mapping->host);
|
|
ntfs_volume *vol = ni->vol;
|
|
unsigned delta;
|
|
unsigned char blocksize_bits, cluster_size_shift;
|
|
|
|
ntfs_debug("Entering for mft_no 0x%lx, logical block 0x%llx.",
|
|
ni->mft_no, (unsigned long long)block);
|
|
if (ni->type != AT_DATA || !NInoNonResident(ni) || NInoEncrypted(ni)) {
|
|
ntfs_error(vol->sb, "BMAP does not make sense for %s "
|
|
"attributes, returning 0.",
|
|
(ni->type != AT_DATA) ? "non-data" :
|
|
(!NInoNonResident(ni) ? "resident" :
|
|
"encrypted"));
|
|
return 0;
|
|
}
|
|
/* None of these can happen. */
|
|
BUG_ON(NInoCompressed(ni));
|
|
BUG_ON(NInoMstProtected(ni));
|
|
blocksize = vol->sb->s_blocksize;
|
|
blocksize_bits = vol->sb->s_blocksize_bits;
|
|
ofs = (s64)block << blocksize_bits;
|
|
read_lock_irqsave(&ni->size_lock, flags);
|
|
size = ni->initialized_size;
|
|
i_size = i_size_read(VFS_I(ni));
|
|
read_unlock_irqrestore(&ni->size_lock, flags);
|
|
/*
|
|
* If the offset is outside the initialized size or the block straddles
|
|
* the initialized size then pretend it is a hole unless the
|
|
* initialized size equals the file size.
|
|
*/
|
|
if (unlikely(ofs >= size || (ofs + blocksize > size && size < i_size)))
|
|
goto hole;
|
|
cluster_size_shift = vol->cluster_size_bits;
|
|
down_read(&ni->runlist.lock);
|
|
lcn = ntfs_attr_vcn_to_lcn_nolock(ni, ofs >> cluster_size_shift, false);
|
|
up_read(&ni->runlist.lock);
|
|
if (unlikely(lcn < LCN_HOLE)) {
|
|
/*
|
|
* Step down to an integer to avoid gcc doing a long long
|
|
* comparision in the switch when we know @lcn is between
|
|
* LCN_HOLE and LCN_EIO (i.e. -1 to -5).
|
|
*
|
|
* Otherwise older gcc (at least on some architectures) will
|
|
* try to use __cmpdi2() which is of course not available in
|
|
* the kernel.
|
|
*/
|
|
switch ((int)lcn) {
|
|
case LCN_ENOENT:
|
|
/*
|
|
* If the offset is out of bounds then pretend it is a
|
|
* hole.
|
|
*/
|
|
goto hole;
|
|
case LCN_ENOMEM:
|
|
ntfs_error(vol->sb, "Not enough memory to complete "
|
|
"mapping for inode 0x%lx. "
|
|
"Returning 0.", ni->mft_no);
|
|
break;
|
|
default:
|
|
ntfs_error(vol->sb, "Failed to complete mapping for "
|
|
"inode 0x%lx. Run chkdsk. "
|
|
"Returning 0.", ni->mft_no);
|
|
break;
|
|
}
|
|
return 0;
|
|
}
|
|
if (lcn < 0) {
|
|
/* It is a hole. */
|
|
hole:
|
|
ntfs_debug("Done (returning hole).");
|
|
return 0;
|
|
}
|
|
/*
|
|
* The block is really allocated and fullfils all our criteria.
|
|
* Convert the cluster to units of block size and return the result.
|
|
*/
|
|
delta = ofs & vol->cluster_size_mask;
|
|
if (unlikely(sizeof(block) < sizeof(lcn))) {
|
|
block = lcn = ((lcn << cluster_size_shift) + delta) >>
|
|
blocksize_bits;
|
|
/* If the block number was truncated return 0. */
|
|
if (unlikely(block != lcn)) {
|
|
ntfs_error(vol->sb, "Physical block 0x%llx is too "
|
|
"large to be returned, returning 0.",
|
|
(long long)lcn);
|
|
return 0;
|
|
}
|
|
} else
|
|
block = ((lcn << cluster_size_shift) + delta) >>
|
|
blocksize_bits;
|
|
ntfs_debug("Done (returning block 0x%llx).", (unsigned long long)lcn);
|
|
return block;
|
|
}
|
|
|
|
/**
|
|
* ntfs_normal_aops - address space operations for normal inodes and attributes
|
|
*
|
|
* Note these are not used for compressed or mst protected inodes and
|
|
* attributes.
|
|
*/
|
|
const struct address_space_operations ntfs_normal_aops = {
|
|
.readpage = ntfs_readpage,
|
|
#ifdef NTFS_RW
|
|
.writepage = ntfs_writepage,
|
|
.set_page_dirty = __set_page_dirty_buffers,
|
|
#endif /* NTFS_RW */
|
|
.bmap = ntfs_bmap,
|
|
.migratepage = buffer_migrate_page,
|
|
.is_partially_uptodate = block_is_partially_uptodate,
|
|
.error_remove_page = generic_error_remove_page,
|
|
};
|
|
|
|
/**
|
|
* ntfs_compressed_aops - address space operations for compressed inodes
|
|
*/
|
|
const struct address_space_operations ntfs_compressed_aops = {
|
|
.readpage = ntfs_readpage,
|
|
#ifdef NTFS_RW
|
|
.writepage = ntfs_writepage,
|
|
.set_page_dirty = __set_page_dirty_buffers,
|
|
#endif /* NTFS_RW */
|
|
.migratepage = buffer_migrate_page,
|
|
.is_partially_uptodate = block_is_partially_uptodate,
|
|
.error_remove_page = generic_error_remove_page,
|
|
};
|
|
|
|
/**
|
|
* ntfs_mst_aops - general address space operations for mst protecteed inodes
|
|
* and attributes
|
|
*/
|
|
const struct address_space_operations ntfs_mst_aops = {
|
|
.readpage = ntfs_readpage, /* Fill page with data. */
|
|
#ifdef NTFS_RW
|
|
.writepage = ntfs_writepage, /* Write dirty page to disk. */
|
|
.set_page_dirty = __set_page_dirty_nobuffers, /* Set the page dirty
|
|
without touching the buffers
|
|
belonging to the page. */
|
|
#endif /* NTFS_RW */
|
|
.migratepage = buffer_migrate_page,
|
|
.is_partially_uptodate = block_is_partially_uptodate,
|
|
.error_remove_page = generic_error_remove_page,
|
|
};
|
|
|
|
#ifdef NTFS_RW
|
|
|
|
/**
|
|
* mark_ntfs_record_dirty - mark an ntfs record dirty
|
|
* @page: page containing the ntfs record to mark dirty
|
|
* @ofs: byte offset within @page at which the ntfs record begins
|
|
*
|
|
* Set the buffers and the page in which the ntfs record is located dirty.
|
|
*
|
|
* The latter also marks the vfs inode the ntfs record belongs to dirty
|
|
* (I_DIRTY_PAGES only).
|
|
*
|
|
* If the page does not have buffers, we create them and set them uptodate.
|
|
* The page may not be locked which is why we need to handle the buffers under
|
|
* the mapping->private_lock. Once the buffers are marked dirty we no longer
|
|
* need the lock since try_to_free_buffers() does not free dirty buffers.
|
|
*/
|
|
void mark_ntfs_record_dirty(struct page *page, const unsigned int ofs) {
|
|
struct address_space *mapping = page->mapping;
|
|
ntfs_inode *ni = NTFS_I(mapping->host);
|
|
struct buffer_head *bh, *head, *buffers_to_free = NULL;
|
|
unsigned int end, bh_size, bh_ofs;
|
|
|
|
BUG_ON(!PageUptodate(page));
|
|
end = ofs + ni->itype.index.block_size;
|
|
bh_size = VFS_I(ni)->i_sb->s_blocksize;
|
|
spin_lock(&mapping->private_lock);
|
|
if (unlikely(!page_has_buffers(page))) {
|
|
spin_unlock(&mapping->private_lock);
|
|
bh = head = alloc_page_buffers(page, bh_size, true);
|
|
spin_lock(&mapping->private_lock);
|
|
if (likely(!page_has_buffers(page))) {
|
|
struct buffer_head *tail;
|
|
|
|
do {
|
|
set_buffer_uptodate(bh);
|
|
tail = bh;
|
|
bh = bh->b_this_page;
|
|
} while (bh);
|
|
tail->b_this_page = head;
|
|
attach_page_buffers(page, head);
|
|
} else
|
|
buffers_to_free = bh;
|
|
}
|
|
bh = head = page_buffers(page);
|
|
BUG_ON(!bh);
|
|
do {
|
|
bh_ofs = bh_offset(bh);
|
|
if (bh_ofs + bh_size <= ofs)
|
|
continue;
|
|
if (unlikely(bh_ofs >= end))
|
|
break;
|
|
set_buffer_dirty(bh);
|
|
} while ((bh = bh->b_this_page) != head);
|
|
spin_unlock(&mapping->private_lock);
|
|
__set_page_dirty_nobuffers(page);
|
|
if (unlikely(buffers_to_free)) {
|
|
do {
|
|
bh = buffers_to_free->b_this_page;
|
|
free_buffer_head(buffers_to_free);
|
|
buffers_to_free = bh;
|
|
} while (buffers_to_free);
|
|
}
|
|
}
|
|
|
|
#endif /* NTFS_RW */
|