![Anton Altaparmakov](/assets/img/avatar_default.png)
better code generation and one less sparse warning in fs/ntfs/aops.c. Signed-off-by: Anton Altaparmakov <aia21@cantab.net>
2371 lines
70 KiB
C
2371 lines
70 KiB
C
/**
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* aops.c - NTFS kernel address space operations and page cache handling.
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* Part of the Linux-NTFS project.
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*
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* Copyright (c) 2001-2005 Anton Altaparmakov
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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/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 "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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static DEFINE_SPINLOCK(page_uptodate_lock);
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unsigned long flags;
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struct buffer_head *tmp;
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struct page *page;
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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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ni = NTFS_I(page->mapping->host);
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if (likely(uptodate)) {
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s64 file_ofs, initialized_size;
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set_buffer_uptodate(bh);
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file_ofs = ((s64)page->index << PAGE_CACHE_SHIFT) +
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bh_offset(bh);
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read_lock_irqsave(&ni->size_lock, flags);
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initialized_size = ni->initialized_size;
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read_unlock_irqrestore(&ni->size_lock, flags);
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/* Check for the current buffer head overflowing. */
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if (file_ofs + bh->b_size > initialized_size) {
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char *addr;
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int ofs = 0;
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if (file_ofs < initialized_size)
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ofs = initialized_size - file_ofs;
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addr = kmap_atomic(page, KM_BIO_SRC_IRQ);
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memset(addr + bh_offset(bh) + ofs, 0, bh->b_size - ofs);
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flush_dcache_page(page);
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kunmap_atomic(addr, KM_BIO_SRC_IRQ);
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}
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} else {
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clear_buffer_uptodate(bh);
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ntfs_error(ni->vol->sb, "Buffer I/O error, logical block %llu.",
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(unsigned long long)bh->b_blocknr);
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SetPageError(page);
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}
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spin_lock_irqsave(&page_uptodate_lock, flags);
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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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spin_unlock_irqrestore(&page_uptodate_lock, 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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char *addr;
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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_CACHE_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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addr = kmap_atomic(page, KM_BIO_SRC_IRQ);
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for (i = 0; i < recs; i++)
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post_read_mst_fixup((NTFS_RECORD*)(addr +
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i * rec_size), rec_size);
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flush_dcache_page(page);
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kunmap_atomic(addr, KM_BIO_SRC_IRQ);
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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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spin_unlock_irqrestore(&page_uptodate_lock, 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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VCN vcn;
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LCN lcn;
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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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ni = NTFS_I(page->mapping->host);
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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_bits = VFS_I(ni)->i_blkbits;
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blocksize = 1 << 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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bh = head = page_buffers(page);
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if (unlikely(!bh)) {
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unlock_page(page);
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return -ENOMEM;
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}
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iblock = (s64)page->index << (PAGE_CACHE_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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zblock = (ni->initialized_size + blocksize - 1) >> blocksize_bits;
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read_unlock_irqrestore(&ni->size_lock, flags);
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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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u8 *kaddr;
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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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int err;
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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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lcn = err;
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}
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/* Hard error, zero out region. */
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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 %lli).", 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" : "", (long long)lcn);
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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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kaddr = kmap_atomic(page, KM_USER0);
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memset(kaddr + i * blocksize, 0, blocksize);
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flush_dcache_page(page);
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kunmap_atomic(kaddr, KM_USER0);
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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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/* 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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/* 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(READ, 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
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* even if the mft record is not cached at this point in time, we need to wait
|
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* for it to be read in before we can do the copy.
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*
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* Return 0 on success and -errno on error.
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*/
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static int ntfs_readpage(struct file *file, struct page *page)
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{
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ntfs_inode *ni, *base_ni;
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u8 *kaddr;
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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;
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|
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retry_readpage:
|
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BUG_ON(!PageLocked(page));
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/*
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* This can potentially happen because we clear PageUptodate() during
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* ntfs_writepage() of MstProtected() attributes.
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*/
|
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if (PageUptodate(page)) {
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unlock_page(page);
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return 0;
|
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}
|
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ni = NTFS_I(page->mapping->host);
|
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|
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/* NInoNonResident() == NInoIndexAllocPresent() */
|
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if (NInoNonResident(ni)) {
|
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/*
|
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* Only unnamed $DATA attributes can be compressed or
|
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* encrypted.
|
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*/
|
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if (ni->type == AT_DATA && !ni->name_len) {
|
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/* If file is encrypted, deny access, just like NT4. */
|
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if (NInoEncrypted(ni)) {
|
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err = -EACCES;
|
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goto err_out;
|
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}
|
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/* Compressed data streams are handled in compress.c. */
|
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if (NInoCompressed(ni))
|
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return ntfs_read_compressed_block(page);
|
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}
|
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/* Normal data stream. */
|
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return ntfs_read_block(page);
|
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}
|
|
/*
|
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* Attribute is resident, implying it is not compressed or encrypted.
|
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* 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
|
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* index above 0.
|
|
*/
|
|
if (unlikely(page->index > 0)) {
|
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kaddr = kmap_atomic(page, KM_USER0);
|
|
memset(kaddr, 0, PAGE_CACHE_SIZE);
|
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flush_dcache_page(page);
|
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kunmap_atomic(kaddr, KM_USER0);
|
|
goto done;
|
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}
|
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if (!NInoAttr(ni))
|
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base_ni = ni;
|
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else
|
|
base_ni = ni->ext.base_ntfs_ino;
|
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/* 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;
|
|
read_unlock_irqrestore(&ni->size_lock, flags);
|
|
kaddr = kmap_atomic(page, KM_USER0);
|
|
/* Copy the data to the page. */
|
|
memcpy(kaddr, (u8*)ctx->attr +
|
|
le16_to_cpu(ctx->attr->data.resident.value_offset),
|
|
attr_len);
|
|
/* Zero the remainder of the page. */
|
|
memset(kaddr + attr_len, 0, PAGE_CACHE_SIZE - attr_len);
|
|
flush_dcache_page(page);
|
|
kunmap_atomic(kaddr, KM_USER0);
|
|
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_bits = vi->i_blkbits;
|
|
blocksize = 1 << blocksize_bits;
|
|
|
|
if (!page_has_buffers(page)) {
|
|
BUG_ON(!PageUptodate(page));
|
|
create_empty_buffers(page, blocksize,
|
|
(1 << BH_Uptodate) | (1 << BH_Dirty));
|
|
}
|
|
bh = head = page_buffers(page);
|
|
if (unlikely(!bh)) {
|
|
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
|
|
* buffer's dirty state as-is.
|
|
*/
|
|
redirty_page_for_writepage(wbc, page);
|
|
unlock_page(page);
|
|
return 0;
|
|
}
|
|
|
|
/* NOTE: Different naming scheme to ntfs_read_block()! */
|
|
|
|
/* The first block in the page. */
|
|
block = (s64)page->index << (PAGE_CACHE_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();
|
|
// page_cache_release()
|
|
// 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) {
|
|
// TODO: Instantiate the hole.
|
|
// clear_buffer_new(bh);
|
|
// unmap_underlying_metadata(bh->b_bdev, bh->b_blocknr);
|
|
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;
|
|
lcn = err;
|
|
}
|
|
/* Failed to map the buffer, even after retrying. */
|
|
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 %lli).", ni->mft_no,
|
|
ni->type, (unsigned long long)vcn,
|
|
vcn_ofs, is_retry ? " even after "
|
|
"retrying" : "", (long long)lcn);
|
|
if (!err)
|
|
err = -EIO;
|
|
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() isn't 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 {
|
|
get_bh(bh);
|
|
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. */
|
|
unlock_page(page);
|
|
|
|
/*
|
|
* Submit the prepared buffers for i/o. Note the page is unlocked,
|
|
* and the async write i/o completion handler can end_page_writeback()
|
|
* at any time after the *first* submit_bh(). So the buffers can then
|
|
* disappear...
|
|
*/
|
|
need_end_writeback = TRUE;
|
|
do {
|
|
struct buffer_head *next = bh->b_this_page;
|
|
if (buffer_async_write(bh)) {
|
|
submit_bh(WRITE, bh);
|
|
need_end_writeback = FALSE;
|
|
}
|
|
put_bh(bh);
|
|
bh = next;
|
|
} while (bh != head);
|
|
|
|
/* 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_CACHE_SIZE / rec_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;
|
|
|
|
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_bits = vi->i_blkbits;
|
|
bh_size = 1 << bh_size_bits;
|
|
max_bhs = PAGE_CACHE_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. */
|
|
BUG_ON(!page_has_buffers(page));
|
|
bh = head = page_buffers(page);
|
|
BUG_ON(!bh);
|
|
|
|
rec_size_bits = ni->itype.index.block_size_bits;
|
|
BUG_ON(!(PAGE_CACHE_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_CACHE_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;
|
|
|
|
/* 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;
|
|
/* 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_CACHE_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 (unlikely(test_set_buffer_locked(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(WRITE, 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_CACHE_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. */
|
|
down(&tni->extent_lock);
|
|
if (tni->nr_extents >= 0)
|
|
base_tni = tni;
|
|
else {
|
|
base_tni = tni->ext.base_ntfs_ino;
|
|
BUG_ON(!base_tni);
|
|
}
|
|
up(&tni->extent_lock);
|
|
ntfs_debug("Unlocking %s inode 0x%lx.",
|
|
tni == base_tni ? "base" : "extent",
|
|
tni->mft_no);
|
|
up(&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_CACHE_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_CACHE_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 *kaddr;
|
|
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_CACHE_SIZE - 1) >>
|
|
PAGE_CACHE_SHIFT)) {
|
|
/*
|
|
* The page may have dirty, unmapped buffers. Make them
|
|
* freeable here, so the page does not leak.
|
|
*/
|
|
block_invalidatepage(page, 0);
|
|
unlock_page(page);
|
|
ntfs_debug("Write outside i_size - truncated?");
|
|
return 0;
|
|
}
|
|
/* NInoNonResident() == NInoIndexAllocPresent() */
|
|
if (NInoNonResident(ni)) {
|
|
/*
|
|
* Only unnamed $DATA attributes can be compressed, encrypted,
|
|
* and/or sparse.
|
|
*/
|
|
if (ni->type == AT_DATA && !ni->name_len) {
|
|
/* If file is encrypted, deny access, just like NT4. */
|
|
if (NInoEncrypted(ni)) {
|
|
unlock_page(page);
|
|
ntfs_debug("Denying write access to encrypted "
|
|
"file.");
|
|
return -EACCES;
|
|
}
|
|
/* Compressed data streams are handled in compress.c. */
|
|
if (NInoCompressed(ni)) {
|
|
// TODO: Implement and replace this check 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 (NInoSparse(ni)) {
|
|
unlock_page(page);
|
|
ntfs_error(vi->i_sb, "Writing to sparse files "
|
|
"is not supported yet. Sorry.");
|
|
return -EOPNOTSUPP;
|
|
}
|
|
}
|
|
/* We have to zero every time due to mmap-at-end-of-file. */
|
|
if (page->index >= (i_size >> PAGE_CACHE_SHIFT)) {
|
|
/* The page straddles i_size. */
|
|
unsigned int ofs = i_size & ~PAGE_CACHE_MASK;
|
|
kaddr = kmap_atomic(page, KM_USER0);
|
|
memset(kaddr + ofs, 0, PAGE_CACHE_SIZE - ofs);
|
|
flush_dcache_page(page);
|
|
kunmap_atomic(kaddr, KM_USER0);
|
|
}
|
|
/* Handle mst protected attributes. */
|
|
if (NInoMstProtected(ni))
|
|
return ntfs_write_mst_block(page, wbc);
|
|
/* Normal data stream. */
|
|
return ntfs_write_block(page, wbc);
|
|
}
|
|
/*
|
|
* Attribute is resident, implying it is not compressed, encrypted,
|
|
* sparse, 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.
|
|
*/
|
|
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);
|
|
|
|
/*
|
|
* Here, we don't need to zero the out of bounds area everytime because
|
|
* the below memcpy() already takes care of the mmap-at-end-of-file
|
|
* requirements. If the file is converted to a non-resident one, then
|
|
* the code path use is switched to the non-resident one where the
|
|
* zeroing happens on each ntfs_writepage() invocation.
|
|
*
|
|
* The above also applies nicely when i_size is decreased.
|
|
*
|
|
* When i_size is increased, the memory between the old and new i_size
|
|
* _must_ be zeroed (or overwritten with new data). Otherwise we will
|
|
* expose data to userspace/disk which should never have been exposed.
|
|
*
|
|
* FIXME: Ensure that i_size increases do the zeroing/overwriting and
|
|
* if we cannot guarantee that, then enable the zeroing below. If the
|
|
* zeroing below is enabled, we MUST move the unlock_page() from above
|
|
* to after the kunmap_atomic(), i.e. just before the
|
|
* end_page_writeback().
|
|
* UPDATE: ntfs_prepare/commit_write() do the zeroing on i_size
|
|
* increases for resident attributes so those are ok.
|
|
* TODO: ntfs_truncate(), others?
|
|
*/
|
|
|
|
attr_len = le32_to_cpu(ctx->attr->data.resident.value_length);
|
|
i_size = i_size_read(vi);
|
|
if (unlikely(attr_len > i_size)) {
|
|
attr_len = i_size;
|
|
ctx->attr->data.resident.value_length = cpu_to_le32(attr_len);
|
|
}
|
|
kaddr = kmap_atomic(page, KM_USER0);
|
|
/* Copy the data from the page to the mft record. */
|
|
memcpy((u8*)ctx->attr +
|
|
le16_to_cpu(ctx->attr->data.resident.value_offset),
|
|
kaddr, attr_len);
|
|
flush_dcache_mft_record_page(ctx->ntfs_ino);
|
|
/* Zero out of bounds area in the page cache page. */
|
|
memset(kaddr + attr_len, 0, PAGE_CACHE_SIZE - attr_len);
|
|
flush_dcache_page(page);
|
|
kunmap_atomic(kaddr, KM_USER0);
|
|
|
|
end_page_writeback(page);
|
|
|
|
/* 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);
|
|
make_bad_inode(vi);
|
|
}
|
|
unlock_page(page);
|
|
if (ctx)
|
|
ntfs_attr_put_search_ctx(ctx);
|
|
if (m)
|
|
unmap_mft_record(base_ni);
|
|
return err;
|
|
}
|
|
|
|
/**
|
|
* ntfs_prepare_nonresident_write -
|
|
*
|
|
*/
|
|
static int ntfs_prepare_nonresident_write(struct page *page,
|
|
unsigned from, unsigned to)
|
|
{
|
|
VCN vcn;
|
|
LCN lcn;
|
|
s64 initialized_size;
|
|
loff_t i_size;
|
|
sector_t block, ablock, iblock;
|
|
struct inode *vi;
|
|
ntfs_inode *ni;
|
|
ntfs_volume *vol;
|
|
runlist_element *rl;
|
|
struct buffer_head *bh, *head, *wait[2], **wait_bh = wait;
|
|
unsigned long flags;
|
|
unsigned int vcn_ofs, block_start, block_end, blocksize;
|
|
int err;
|
|
BOOL is_retry;
|
|
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, from = %u, to = %u.", ni->mft_no, ni->type,
|
|
page->index, from, to);
|
|
|
|
BUG_ON(!NInoNonResident(ni));
|
|
|
|
blocksize_bits = vi->i_blkbits;
|
|
blocksize = 1 << blocksize_bits;
|
|
|
|
/*
|
|
* create_empty_buffers() will create uptodate/dirty buffers if the
|
|
* page is uptodate/dirty.
|
|
*/
|
|
if (!page_has_buffers(page))
|
|
create_empty_buffers(page, blocksize, 0);
|
|
bh = head = page_buffers(page);
|
|
if (unlikely(!bh))
|
|
return -ENOMEM;
|
|
|
|
/* The first block in the page. */
|
|
block = (s64)page->index << (PAGE_CACHE_SHIFT - blocksize_bits);
|
|
|
|
read_lock_irqsave(&ni->size_lock, flags);
|
|
/*
|
|
* The first out of bounds block for the allocated size. No need to
|
|
* round up as allocated_size is in multiples of cluster size and the
|
|
* minimum cluster size is 512 bytes, which is equal to the smallest
|
|
* blocksize.
|
|
*/
|
|
ablock = ni->allocated_size >> blocksize_bits;
|
|
i_size = i_size_read(vi);
|
|
initialized_size = ni->initialized_size;
|
|
read_unlock_irqrestore(&ni->size_lock, flags);
|
|
|
|
/* The last (fully or partially) initialized block. */
|
|
iblock = initialized_size >> blocksize_bits;
|
|
|
|
/* Loop through all the buffers in the page. */
|
|
block_start = 0;
|
|
rl = NULL;
|
|
err = 0;
|
|
do {
|
|
block_end = block_start + blocksize;
|
|
/*
|
|
* If buffer @bh is outside the write, just mark it uptodate
|
|
* if the page is uptodate and continue with the next buffer.
|
|
*/
|
|
if (block_end <= from || block_start >= to) {
|
|
if (PageUptodate(page)) {
|
|
if (!buffer_uptodate(bh))
|
|
set_buffer_uptodate(bh);
|
|
}
|
|
continue;
|
|
}
|
|
/*
|
|
* @bh is at least partially being written to.
|
|
* Make sure it is not marked as new.
|
|
*/
|
|
//if (buffer_new(bh))
|
|
// clear_buffer_new(bh);
|
|
|
|
if (block >= ablock) {
|
|
// TODO: block is above allocated_size, need to
|
|
// allocate it. Best done in one go to accommodate not
|
|
// only block but all above blocks up to and including:
|
|
// ((page->index << PAGE_CACHE_SHIFT) + to + blocksize
|
|
// - 1) >> blobksize_bits. Obviously will need to round
|
|
// up to next cluster boundary, too. This should be
|
|
// done with a helper function, so it can be reused.
|
|
ntfs_error(vol->sb, "Writing beyond allocated size "
|
|
"is not supported yet. Sorry.");
|
|
err = -EOPNOTSUPP;
|
|
goto err_out;
|
|
// Need to update ablock.
|
|
// Need to set_buffer_new() on all block bhs that are
|
|
// newly allocated.
|
|
}
|
|
/*
|
|
* Now we have enough allocated size to fulfill the whole
|
|
* request, i.e. block < ablock is true.
|
|
*/
|
|
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();
|
|
// page_cache_release()
|
|
// 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;
|
|
goto err_out;
|
|
// 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().
|
|
}
|
|
|
|
/* Need to map unmapped buffers. */
|
|
if (!buffer_mapped(bh)) {
|
|
/* Unmapped buffer. Need to map it. */
|
|
bh->b_bdev = vol->sb->s_bdev;
|
|
|
|
/* Convert block into corresponding vcn and offset. */
|
|
vcn = (VCN)block << blocksize_bits >>
|
|
vol->cluster_size_bits;
|
|
vcn_ofs = ((VCN)block << blocksize_bits) &
|
|
vol->cluster_size_mask;
|
|
|
|
is_retry = FALSE;
|
|
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;
|
|
if (unlikely(lcn < 0)) {
|
|
/*
|
|
* We extended the attribute allocation above.
|
|
* If we hit an ENOENT here it means that the
|
|
* allocation was insufficient which is a bug.
|
|
*/
|
|
BUG_ON(lcn == LCN_ENOENT);
|
|
|
|
/* It is a hole, need to instantiate it. */
|
|
if (lcn == LCN_HOLE) {
|
|
// TODO: Instantiate the hole.
|
|
// clear_buffer_new(bh);
|
|
// unmap_underlying_metadata(bh->b_bdev,
|
|
// bh->b_blocknr);
|
|
// For non-uptodate buffers, need to
|
|
// zero out the region outside the
|
|
// request in this bh or all bhs,
|
|
// depending on what we implemented
|
|
// above.
|
|
// Need to flush_dcache_page().
|
|
// Or could use set_buffer_new()
|
|
// instead?
|
|
ntfs_error(vol->sb, "Writing into "
|
|
"sparse regions is "
|
|
"not supported yet. "
|
|
"Sorry.");
|
|
err = -EOPNOTSUPP;
|
|
goto err_out;
|
|
} else 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;
|
|
lcn = err;
|
|
}
|
|
/*
|
|
* Failed to map the buffer, even after
|
|
* retrying.
|
|
*/
|
|
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 %lli).",
|
|
ni->mft_no, ni->type,
|
|
(unsigned long long)vcn,
|
|
vcn_ofs, is_retry ? " even "
|
|
"after retrying" : "",
|
|
(long long)lcn);
|
|
if (!err)
|
|
err = -EIO;
|
|
goto err_out;
|
|
}
|
|
/* We now have a successful remap, i.e. lcn >= 0. */
|
|
|
|
/* Setup buffer head to correct block. */
|
|
bh->b_blocknr = ((lcn << vol->cluster_size_bits)
|
|
+ vcn_ofs) >> blocksize_bits;
|
|
set_buffer_mapped(bh);
|
|
|
|
// FIXME: Something analogous to this is needed for
|
|
// each newly allocated block, i.e. BH_New.
|
|
// FIXME: Might need to take this out of the
|
|
// if (!buffer_mapped(bh)) {}, depending on how we
|
|
// implement things during the allocated_size and
|
|
// initialized_size extension code above.
|
|
if (buffer_new(bh)) {
|
|
clear_buffer_new(bh);
|
|
unmap_underlying_metadata(bh->b_bdev,
|
|
bh->b_blocknr);
|
|
if (PageUptodate(page)) {
|
|
set_buffer_uptodate(bh);
|
|
continue;
|
|
}
|
|
/*
|
|
* Page is _not_ uptodate, zero surrounding
|
|
* region. NOTE: This is how we decide if to
|
|
* zero or not!
|
|
*/
|
|
if (block_end > to || block_start < from) {
|
|
void *kaddr;
|
|
|
|
kaddr = kmap_atomic(page, KM_USER0);
|
|
if (block_end > to)
|
|
memset(kaddr + to, 0,
|
|
block_end - to);
|
|
if (block_start < from)
|
|
memset(kaddr + block_start, 0,
|
|
from -
|
|
block_start);
|
|
flush_dcache_page(page);
|
|
kunmap_atomic(kaddr, KM_USER0);
|
|
}
|
|
continue;
|
|
}
|
|
}
|
|
/* @bh is mapped, set it uptodate if the page is uptodate. */
|
|
if (PageUptodate(page)) {
|
|
if (!buffer_uptodate(bh))
|
|
set_buffer_uptodate(bh);
|
|
continue;
|
|
}
|
|
/*
|
|
* The page is not uptodate. The buffer is mapped. If it is not
|
|
* uptodate, and it is only partially being written to, we need
|
|
* to read the buffer in before the write, i.e. right now.
|
|
*/
|
|
if (!buffer_uptodate(bh) &&
|
|
(block_start < from || block_end > to)) {
|
|
ll_rw_block(READ, 1, &bh);
|
|
*wait_bh++ = bh;
|
|
}
|
|
} while (block++, block_start = block_end,
|
|
(bh = bh->b_this_page) != head);
|
|
|
|
/* Release the lock if we took it. */
|
|
if (rl) {
|
|
up_read(&ni->runlist.lock);
|
|
rl = NULL;
|
|
}
|
|
|
|
/* If we issued read requests, let them complete. */
|
|
while (wait_bh > wait) {
|
|
wait_on_buffer(*--wait_bh);
|
|
if (!buffer_uptodate(*wait_bh))
|
|
return -EIO;
|
|
}
|
|
|
|
ntfs_debug("Done.");
|
|
return 0;
|
|
err_out:
|
|
/*
|
|
* Zero out any newly allocated blocks to avoid exposing stale data.
|
|
* If BH_New is set, we know that the block was newly allocated in the
|
|
* above loop.
|
|
* FIXME: What about initialized_size increments? Have we done all the
|
|
* required zeroing above? If not this error handling is broken, and
|
|
* in particular the if (block_end <= from) check is completely bogus.
|
|
*/
|
|
bh = head;
|
|
block_start = 0;
|
|
is_retry = FALSE;
|
|
do {
|
|
block_end = block_start + blocksize;
|
|
if (block_end <= from)
|
|
continue;
|
|
if (block_start >= to)
|
|
break;
|
|
if (buffer_new(bh)) {
|
|
void *kaddr;
|
|
|
|
clear_buffer_new(bh);
|
|
kaddr = kmap_atomic(page, KM_USER0);
|
|
memset(kaddr + block_start, 0, bh->b_size);
|
|
kunmap_atomic(kaddr, KM_USER0);
|
|
set_buffer_uptodate(bh);
|
|
mark_buffer_dirty(bh);
|
|
is_retry = TRUE;
|
|
}
|
|
} while (block_start = block_end, (bh = bh->b_this_page) != head);
|
|
if (is_retry)
|
|
flush_dcache_page(page);
|
|
if (rl)
|
|
up_read(&ni->runlist.lock);
|
|
return err;
|
|
}
|
|
|
|
/**
|
|
* ntfs_prepare_write - prepare a page for receiving data
|
|
*
|
|
* This is called from generic_file_write() with i_sem held on the inode
|
|
* (@page->mapping->host). The @page is locked but not kmap()ped. The source
|
|
* data has not yet been copied into the @page.
|
|
*
|
|
* Need to extend the attribute/fill in holes if necessary, create blocks and
|
|
* make partially overwritten blocks uptodate,
|
|
*
|
|
* i_size is not to be modified yet.
|
|
*
|
|
* Return 0 on success or -errno on error.
|
|
*
|
|
* Should be using block_prepare_write() [support for sparse files] or
|
|
* cont_prepare_write() [no support for sparse files]. Cannot do that due to
|
|
* ntfs specifics but can look at them for implementation guidance.
|
|
*
|
|
* Note: In the range, @from is inclusive and @to is exclusive, i.e. @from is
|
|
* the first byte in the page that will be written to and @to is the first byte
|
|
* after the last byte that will be written to.
|
|
*/
|
|
static int ntfs_prepare_write(struct file *file, struct page *page,
|
|
unsigned from, unsigned to)
|
|
{
|
|
s64 new_size;
|
|
loff_t i_size;
|
|
struct inode *vi = page->mapping->host;
|
|
ntfs_inode *base_ni = NULL, *ni = NTFS_I(vi);
|
|
ntfs_volume *vol = ni->vol;
|
|
ntfs_attr_search_ctx *ctx = NULL;
|
|
MFT_RECORD *m = NULL;
|
|
ATTR_RECORD *a;
|
|
u8 *kaddr;
|
|
u32 attr_len;
|
|
int err;
|
|
|
|
ntfs_debug("Entering for inode 0x%lx, attribute type 0x%x, page index "
|
|
"0x%lx, from = %u, to = %u.", vi->i_ino, ni->type,
|
|
page->index, from, to);
|
|
BUG_ON(!PageLocked(page));
|
|
BUG_ON(from > PAGE_CACHE_SIZE);
|
|
BUG_ON(to > PAGE_CACHE_SIZE);
|
|
BUG_ON(from > to);
|
|
BUG_ON(NInoMstProtected(ni));
|
|
/*
|
|
* If a previous ntfs_truncate() failed, repeat it and abort if it
|
|
* fails again.
|
|
*/
|
|
if (unlikely(NInoTruncateFailed(ni))) {
|
|
down_write(&vi->i_alloc_sem);
|
|
err = ntfs_truncate(vi);
|
|
up_write(&vi->i_alloc_sem);
|
|
if (err || NInoTruncateFailed(ni)) {
|
|
if (!err)
|
|
err = -EIO;
|
|
goto err_out;
|
|
}
|
|
}
|
|
/* If the attribute is not resident, deal with it elsewhere. */
|
|
if (NInoNonResident(ni)) {
|
|
/*
|
|
* Only unnamed $DATA attributes can be compressed, encrypted,
|
|
* and/or sparse.
|
|
*/
|
|
if (ni->type == AT_DATA && !ni->name_len) {
|
|
/* If file is encrypted, deny access, just like NT4. */
|
|
if (NInoEncrypted(ni)) {
|
|
ntfs_debug("Denying write access to encrypted "
|
|
"file.");
|
|
return -EACCES;
|
|
}
|
|
/* Compressed data streams are handled in compress.c. */
|
|
if (NInoCompressed(ni)) {
|
|
// TODO: Implement and replace this check with
|
|
// return ntfs_write_compressed_block(page);
|
|
ntfs_error(vi->i_sb, "Writing to compressed "
|
|
"files is not supported yet. "
|
|
"Sorry.");
|
|
return -EOPNOTSUPP;
|
|
}
|
|
// TODO: Implement and remove this check.
|
|
if (NInoSparse(ni)) {
|
|
ntfs_error(vi->i_sb, "Writing to sparse files "
|
|
"is not supported yet. Sorry.");
|
|
return -EOPNOTSUPP;
|
|
}
|
|
}
|
|
/* Normal data stream. */
|
|
return ntfs_prepare_nonresident_write(page, from, to);
|
|
}
|
|
/*
|
|
* Attribute is resident, implying it is not compressed, encrypted, or
|
|
* sparse.
|
|
*/
|
|
BUG_ON(page_has_buffers(page));
|
|
new_size = ((s64)page->index << PAGE_CACHE_SHIFT) + to;
|
|
/* If we do not need to resize the attribute allocation we are done. */
|
|
if (new_size <= i_size_read(vi))
|
|
goto done;
|
|
/* Map, pin, and lock the (base) mft record. */
|
|
if (!NInoAttr(ni))
|
|
base_ni = ni;
|
|
else
|
|
base_ni = ni->ext.base_ntfs_ino;
|
|
m = map_mft_record(base_ni);
|
|
if (IS_ERR(m)) {
|
|
err = PTR_ERR(m);
|
|
m = NULL;
|
|
ctx = NULL;
|
|
goto err_out;
|
|
}
|
|
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)) {
|
|
if (err == -ENOENT)
|
|
err = -EIO;
|
|
goto err_out;
|
|
}
|
|
m = ctx->mrec;
|
|
a = ctx->attr;
|
|
/* The total length of the attribute value. */
|
|
attr_len = le32_to_cpu(a->data.resident.value_length);
|
|
/* Fix an eventual previous failure of ntfs_commit_write(). */
|
|
i_size = i_size_read(vi);
|
|
if (unlikely(attr_len > i_size)) {
|
|
attr_len = i_size;
|
|
a->data.resident.value_length = cpu_to_le32(attr_len);
|
|
}
|
|
/* If we do not need to resize the attribute allocation we are done. */
|
|
if (new_size <= attr_len)
|
|
goto done_unm;
|
|
/* Check if new size is allowed in $AttrDef. */
|
|
err = ntfs_attr_size_bounds_check(vol, ni->type, new_size);
|
|
if (unlikely(err)) {
|
|
if (err == -ERANGE) {
|
|
ntfs_error(vol->sb, "Write would cause the inode "
|
|
"0x%lx to exceed the maximum size for "
|
|
"its attribute type (0x%x). Aborting "
|
|
"write.", vi->i_ino,
|
|
le32_to_cpu(ni->type));
|
|
} else {
|
|
ntfs_error(vol->sb, "Inode 0x%lx has unknown "
|
|
"attribute type 0x%x. Aborting "
|
|
"write.", vi->i_ino,
|
|
le32_to_cpu(ni->type));
|
|
err = -EIO;
|
|
}
|
|
goto err_out2;
|
|
}
|
|
/*
|
|
* Extend the attribute record to be able to store the new attribute
|
|
* size.
|
|
*/
|
|
if (new_size >= vol->mft_record_size || ntfs_attr_record_resize(m, a,
|
|
le16_to_cpu(a->data.resident.value_offset) +
|
|
new_size)) {
|
|
/* Not enough space in the mft record. */
|
|
ntfs_error(vol->sb, "Not enough space in the mft record for "
|
|
"the resized attribute value. This is not "
|
|
"supported yet. Aborting write.");
|
|
err = -EOPNOTSUPP;
|
|
goto err_out2;
|
|
}
|
|
/*
|
|
* We have enough space in the mft record to fit the write. This
|
|
* implies the attribute is smaller than the mft record and hence the
|
|
* attribute must be in a single page and hence page->index must be 0.
|
|
*/
|
|
BUG_ON(page->index);
|
|
/*
|
|
* If the beginning of the write is past the old size, enlarge the
|
|
* attribute value up to the beginning of the write and fill it with
|
|
* zeroes.
|
|
*/
|
|
if (from > attr_len) {
|
|
memset((u8*)a + le16_to_cpu(a->data.resident.value_offset) +
|
|
attr_len, 0, from - attr_len);
|
|
a->data.resident.value_length = cpu_to_le32(from);
|
|
/* Zero the corresponding area in the page as well. */
|
|
if (PageUptodate(page)) {
|
|
kaddr = kmap_atomic(page, KM_USER0);
|
|
memset(kaddr + attr_len, 0, from - attr_len);
|
|
kunmap_atomic(kaddr, KM_USER0);
|
|
flush_dcache_page(page);
|
|
}
|
|
}
|
|
flush_dcache_mft_record_page(ctx->ntfs_ino);
|
|
mark_mft_record_dirty(ctx->ntfs_ino);
|
|
done_unm:
|
|
ntfs_attr_put_search_ctx(ctx);
|
|
unmap_mft_record(base_ni);
|
|
/*
|
|
* Because resident attributes are handled by memcpy() to/from the
|
|
* corresponding MFT record, and because this form of i/o is byte
|
|
* aligned rather than block aligned, there is no need to bring the
|
|
* page uptodate here as in the non-resident case where we need to
|
|
* bring the buffers straddled by the write uptodate before
|
|
* generic_file_write() does the copying from userspace.
|
|
*
|
|
* We thus defer the uptodate bringing of the page region outside the
|
|
* region written to to ntfs_commit_write(), which makes the code
|
|
* simpler and saves one atomic kmap which is good.
|
|
*/
|
|
done:
|
|
ntfs_debug("Done.");
|
|
return 0;
|
|
err_out:
|
|
if (err == -ENOMEM)
|
|
ntfs_warning(vi->i_sb, "Error allocating memory required to "
|
|
"prepare the write.");
|
|
else {
|
|
ntfs_error(vi->i_sb, "Resident attribute prepare write failed "
|
|
"with error %i.", err);
|
|
NVolSetErrors(vol);
|
|
make_bad_inode(vi);
|
|
}
|
|
err_out2:
|
|
if (ctx)
|
|
ntfs_attr_put_search_ctx(ctx);
|
|
if (m)
|
|
unmap_mft_record(base_ni);
|
|
return err;
|
|
}
|
|
|
|
/**
|
|
* ntfs_commit_nonresident_write -
|
|
*
|
|
*/
|
|
static int ntfs_commit_nonresident_write(struct page *page,
|
|
unsigned from, unsigned to)
|
|
{
|
|
s64 pos = ((s64)page->index << PAGE_CACHE_SHIFT) + to;
|
|
struct inode *vi = page->mapping->host;
|
|
struct buffer_head *bh, *head;
|
|
unsigned int block_start, block_end, blocksize;
|
|
BOOL partial;
|
|
|
|
ntfs_debug("Entering for inode 0x%lx, attribute type 0x%x, page index "
|
|
"0x%lx, from = %u, to = %u.", vi->i_ino,
|
|
NTFS_I(vi)->type, page->index, from, to);
|
|
blocksize = 1 << vi->i_blkbits;
|
|
|
|
// FIXME: We need a whole slew of special cases in here for compressed
|
|
// files for example...
|
|
// For now, we know ntfs_prepare_write() would have failed so we can't
|
|
// get here in any of the cases which we have to special case, so we
|
|
// are just a ripped off, unrolled generic_commit_write().
|
|
|
|
bh = head = page_buffers(page);
|
|
block_start = 0;
|
|
partial = FALSE;
|
|
do {
|
|
block_end = block_start + blocksize;
|
|
if (block_end <= from || block_start >= to) {
|
|
if (!buffer_uptodate(bh))
|
|
partial = TRUE;
|
|
} else {
|
|
set_buffer_uptodate(bh);
|
|
mark_buffer_dirty(bh);
|
|
}
|
|
} while (block_start = block_end, (bh = bh->b_this_page) != head);
|
|
/*
|
|
* If this is a partial write which happened to make all buffers
|
|
* uptodate then we can optimize away a bogus ->readpage() for the next
|
|
* read(). Here we 'discover' whether the page went uptodate as a
|
|
* result of this (potentially partial) write.
|
|
*/
|
|
if (!partial)
|
|
SetPageUptodate(page);
|
|
/*
|
|
* Not convinced about this at all. See disparity comment above. For
|
|
* now we know ntfs_prepare_write() would have failed in the write
|
|
* exceeds i_size case, so this will never trigger which is fine.
|
|
*/
|
|
if (pos > i_size_read(vi)) {
|
|
ntfs_error(vi->i_sb, "Writing beyond the existing file size is "
|
|
"not supported yet. Sorry.");
|
|
return -EOPNOTSUPP;
|
|
// vi->i_size = pos;
|
|
// mark_inode_dirty(vi);
|
|
}
|
|
ntfs_debug("Done.");
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* ntfs_commit_write - commit the received data
|
|
*
|
|
* This is called from generic_file_write() with i_sem held on the inode
|
|
* (@page->mapping->host). The @page is locked but not kmap()ped. The source
|
|
* data has already been copied into the @page. ntfs_prepare_write() has been
|
|
* called before the data copied and it returned success so we can take the
|
|
* results of various BUG checks and some error handling for granted.
|
|
*
|
|
* Need to mark modified blocks dirty so they get written out later when
|
|
* ntfs_writepage() is invoked by the VM.
|
|
*
|
|
* Return 0 on success or -errno on error.
|
|
*
|
|
* Should be using generic_commit_write(). This marks buffers uptodate and
|
|
* dirty, sets the page uptodate if all buffers in the page are uptodate, and
|
|
* updates i_size if the end of io is beyond i_size. In that case, it also
|
|
* marks the inode dirty.
|
|
*
|
|
* Cannot use generic_commit_write() due to ntfs specialities but can look at
|
|
* it for implementation guidance.
|
|
*
|
|
* If things have gone as outlined in ntfs_prepare_write(), then we do not
|
|
* need to do any page content modifications here at all, except in the write
|
|
* to resident attribute case, where we need to do the uptodate bringing here
|
|
* which we combine with the copying into the mft record which means we save
|
|
* one atomic kmap.
|
|
*/
|
|
static int ntfs_commit_write(struct file *file, struct page *page,
|
|
unsigned from, unsigned to)
|
|
{
|
|
struct inode *vi = page->mapping->host;
|
|
ntfs_inode *base_ni, *ni = NTFS_I(vi);
|
|
char *kaddr, *kattr;
|
|
ntfs_attr_search_ctx *ctx;
|
|
MFT_RECORD *m;
|
|
ATTR_RECORD *a;
|
|
u32 attr_len;
|
|
int err;
|
|
|
|
ntfs_debug("Entering for inode 0x%lx, attribute type 0x%x, page index "
|
|
"0x%lx, from = %u, to = %u.", vi->i_ino, ni->type,
|
|
page->index, from, to);
|
|
/* If the attribute is not resident, deal with it elsewhere. */
|
|
if (NInoNonResident(ni)) {
|
|
/* Only unnamed $DATA attributes can be compressed/encrypted. */
|
|
if (ni->type == AT_DATA && !ni->name_len) {
|
|
/* Encrypted files need separate handling. */
|
|
if (NInoEncrypted(ni)) {
|
|
// We never get here at present!
|
|
BUG();
|
|
}
|
|
/* Compressed data streams are handled in compress.c. */
|
|
if (NInoCompressed(ni)) {
|
|
// TODO: Implement this!
|
|
// return ntfs_write_compressed_block(page);
|
|
// We never get here at present!
|
|
BUG();
|
|
}
|
|
}
|
|
/* Normal data stream. */
|
|
return ntfs_commit_nonresident_write(page, from, to);
|
|
}
|
|
/*
|
|
* Attribute is resident, implying it is not compressed, encrypted, or
|
|
* sparse.
|
|
*/
|
|
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;
|
|
}
|
|
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)) {
|
|
if (err == -ENOENT)
|
|
err = -EIO;
|
|
goto err_out;
|
|
}
|
|
a = ctx->attr;
|
|
/* The total length of the attribute value. */
|
|
attr_len = le32_to_cpu(a->data.resident.value_length);
|
|
BUG_ON(from > attr_len);
|
|
kattr = (u8*)a + le16_to_cpu(a->data.resident.value_offset);
|
|
kaddr = kmap_atomic(page, KM_USER0);
|
|
/* Copy the received data from the page to the mft record. */
|
|
memcpy(kattr + from, kaddr + from, to - from);
|
|
/* Update the attribute length if necessary. */
|
|
if (to > attr_len) {
|
|
attr_len = to;
|
|
a->data.resident.value_length = cpu_to_le32(attr_len);
|
|
}
|
|
/*
|
|
* If the page is not uptodate, bring the out of bounds area(s)
|
|
* uptodate by copying data from the mft record to the page.
|
|
*/
|
|
if (!PageUptodate(page)) {
|
|
if (from > 0)
|
|
memcpy(kaddr, kattr, from);
|
|
if (to < attr_len)
|
|
memcpy(kaddr + to, kattr + to, attr_len - to);
|
|
/* Zero the region outside the end of the attribute value. */
|
|
if (attr_len < PAGE_CACHE_SIZE)
|
|
memset(kaddr + attr_len, 0, PAGE_CACHE_SIZE - attr_len);
|
|
/*
|
|
* The probability of not having done any of the above is
|
|
* extremely small, so we just flush unconditionally.
|
|
*/
|
|
flush_dcache_page(page);
|
|
SetPageUptodate(page);
|
|
}
|
|
kunmap_atomic(kaddr, KM_USER0);
|
|
/* Update i_size if necessary. */
|
|
if (i_size_read(vi) < attr_len) {
|
|
unsigned long flags;
|
|
|
|
write_lock_irqsave(&ni->size_lock, flags);
|
|
ni->allocated_size = ni->initialized_size = attr_len;
|
|
i_size_write(vi, attr_len);
|
|
write_unlock_irqrestore(&ni->size_lock, flags);
|
|
}
|
|
/* Mark the mft record dirty, so it gets written back. */
|
|
flush_dcache_mft_record_page(ctx->ntfs_ino);
|
|
mark_mft_record_dirty(ctx->ntfs_ino);
|
|
ntfs_attr_put_search_ctx(ctx);
|
|
unmap_mft_record(base_ni);
|
|
ntfs_debug("Done.");
|
|
return 0;
|
|
err_out:
|
|
if (err == -ENOMEM) {
|
|
ntfs_warning(vi->i_sb, "Error allocating memory required to "
|
|
"commit the write.");
|
|
if (PageUptodate(page)) {
|
|
ntfs_warning(vi->i_sb, "Page is uptodate, setting "
|
|
"dirty so the write will be retried "
|
|
"later on by the VM.");
|
|
/*
|
|
* Put the page on mapping->dirty_pages, but leave its
|
|
* buffers' dirty state as-is.
|
|
*/
|
|
__set_page_dirty_nobuffers(page);
|
|
err = 0;
|
|
} else
|
|
ntfs_error(vi->i_sb, "Page is not uptodate. Written "
|
|
"data has been lost.");
|
|
} else {
|
|
ntfs_error(vi->i_sb, "Resident attribute commit write failed "
|
|
"with error %i.", err);
|
|
NVolSetErrors(ni->vol);
|
|
make_bad_inode(vi);
|
|
}
|
|
if (ctx)
|
|
ntfs_attr_put_search_ctx(ctx);
|
|
if (m)
|
|
unmap_mft_record(base_ni);
|
|
return err;
|
|
}
|
|
|
|
#endif /* NTFS_RW */
|
|
|
|
/**
|
|
* ntfs_aops - general address space operations for inodes and attributes
|
|
*/
|
|
struct address_space_operations ntfs_aops = {
|
|
.readpage = ntfs_readpage, /* Fill page with data. */
|
|
.sync_page = block_sync_page, /* Currently, just unplugs the
|
|
disk request queue. */
|
|
#ifdef NTFS_RW
|
|
.writepage = ntfs_writepage, /* Write dirty page to disk. */
|
|
.prepare_write = ntfs_prepare_write, /* Prepare page and buffers
|
|
ready to receive data. */
|
|
.commit_write = ntfs_commit_write, /* Commit received data. */
|
|
#endif /* NTFS_RW */
|
|
};
|
|
|
|
/**
|
|
* ntfs_mst_aops - general address space operations for mst protecteed inodes
|
|
* and attributes
|
|
*/
|
|
struct address_space_operations ntfs_mst_aops = {
|
|
.readpage = ntfs_readpage, /* Fill page with data. */
|
|
.sync_page = block_sync_page, /* Currently, just unplugs the
|
|
disk request queue. */
|
|
#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 */
|
|
};
|
|
|
|
#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 = 1 << VFS_I(ni)->i_blkbits;
|
|
spin_lock(&mapping->private_lock);
|
|
if (unlikely(!page_has_buffers(page))) {
|
|
spin_unlock(&mapping->private_lock);
|
|
bh = head = alloc_page_buffers(page, bh_size, 1);
|
|
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);
|
|
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 */
|