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1760 lines
52 KiB
1760 lines
52 KiB
// SPDX-License-Identifier: GPL-2.0-or-later |
|
/** |
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* aops.c - NTFS kernel address space operations and page cache handling. |
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* |
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* Copyright (c) 2001-2014 Anton Altaparmakov and Tuxera Inc. |
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* Copyright (c) 2002 Richard Russon |
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*/ |
|
|
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#include <linux/errno.h> |
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#include <linux/fs.h> |
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#include <linux/gfp.h> |
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#include <linux/mm.h> |
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#include <linux/pagemap.h> |
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#include <linux/swap.h> |
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#include <linux/buffer_head.h> |
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#include <linux/writeback.h> |
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#include <linux/bit_spinlock.h> |
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#include <linux/bio.h> |
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|
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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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/** |
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* ntfs_end_buffer_async_read - async io completion for reading attributes |
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* @bh: buffer head on which io is completed |
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* @uptodate: whether @bh is now uptodate or not |
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* |
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* Asynchronous I/O completion handler for reading pages belonging to the |
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* attribute address space of an inode. The inodes can either be files or |
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* directories or they can be fake inodes describing some attribute. |
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* |
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* If NInoMstProtected(), perform the post read mst fixups when all IO on the |
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* page has been completed and mark the page uptodate or set the error bit on |
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* the page. To determine the size of the records that need fixing up, we |
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* cheat a little bit by setting the index_block_size in ntfs_inode to the ntfs |
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* record size, and index_block_size_bits, to the log(base 2) of the ntfs |
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* record size. |
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*/ |
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static void ntfs_end_buffer_async_read(struct buffer_head *bh, int uptodate) |
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{ |
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unsigned long flags; |
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struct buffer_head *first, *tmp; |
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struct page *page; |
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struct inode *vi; |
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ntfs_inode *ni; |
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int page_uptodate = 1; |
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|
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page = bh->b_page; |
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vi = page->mapping->host; |
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ni = NTFS_I(vi); |
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|
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if (likely(uptodate)) { |
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loff_t i_size; |
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s64 file_ofs, init_size; |
|
|
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set_buffer_uptodate(bh); |
|
|
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file_ofs = ((s64)page->index << PAGE_SHIFT) + |
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bh_offset(bh); |
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read_lock_irqsave(&ni->size_lock, flags); |
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init_size = ni->initialized_size; |
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i_size = i_size_read(vi); |
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read_unlock_irqrestore(&ni->size_lock, flags); |
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if (unlikely(init_size > i_size)) { |
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/* Race with shrinking truncate. */ |
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init_size = i_size; |
|
} |
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/* Check for the current buffer head overflowing. */ |
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if (unlikely(file_ofs + bh->b_size > init_size)) { |
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int ofs; |
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void *kaddr; |
|
|
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ofs = 0; |
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if (file_ofs < init_size) |
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ofs = init_size - file_ofs; |
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kaddr = kmap_atomic(page); |
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memset(kaddr + bh_offset(bh) + ofs, 0, |
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bh->b_size - ofs); |
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flush_dcache_page(page); |
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kunmap_atomic(kaddr); |
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} |
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} else { |
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clear_buffer_uptodate(bh); |
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SetPageError(page); |
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ntfs_error(ni->vol->sb, "Buffer I/O error, logical block " |
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"0x%llx.", (unsigned long long)bh->b_blocknr); |
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} |
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first = page_buffers(page); |
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spin_lock_irqsave(&first->b_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. */ |
|
BUG(); |
|
} |
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tmp = tmp->b_this_page; |
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} while (tmp != bh); |
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spin_unlock_irqrestore(&first->b_uptodate_lock, flags); |
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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 |
|
* rather than per page granularity. |
|
*/ |
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if (!NInoMstProtected(ni)) { |
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if (likely(page_uptodate && !PageError(page))) |
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SetPageUptodate(page); |
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} else { |
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u8 *kaddr; |
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unsigned int i, recs; |
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u32 rec_size; |
|
|
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rec_size = ni->itype.index.block_size; |
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recs = PAGE_SIZE / rec_size; |
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/* Should have been verified before we got here... */ |
|
BUG_ON(!recs); |
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kaddr = kmap_atomic(page); |
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for (i = 0; i < recs; i++) |
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post_read_mst_fixup((NTFS_RECORD*)(kaddr + |
|
i * rec_size), rec_size); |
|
kunmap_atomic(kaddr); |
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flush_dcache_page(page); |
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if (likely(page_uptodate && !PageError(page))) |
|
SetPageUptodate(page); |
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} |
|
unlock_page(page); |
|
return; |
|
still_busy: |
|
spin_unlock_irqrestore(&first->b_uptodate_lock, flags); |
|
return; |
|
} |
|
|
|
/** |
|
* 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) |
|
{ |
|
loff_t i_size; |
|
VCN vcn; |
|
LCN lcn; |
|
s64 init_size; |
|
struct inode *vi; |
|
ntfs_inode *ni; |
|
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; |
|
unsigned char blocksize_bits; |
|
|
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vi = page->mapping->host; |
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ni = NTFS_I(vi); |
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vol = ni->vol; |
|
|
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/* $MFT/$DATA must have its complete runlist in memory at all times. */ |
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BUG_ON(!ni->runlist.rl && !ni->mft_no && !NInoAttr(ni)); |
|
|
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blocksize = vol->sb->s_blocksize; |
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blocksize_bits = vol->sb->s_blocksize_bits; |
|
|
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if (!page_has_buffers(page)) { |
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create_empty_buffers(page, blocksize, 0); |
|
if (unlikely(!page_has_buffers(page))) { |
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unlock_page(page); |
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return -ENOMEM; |
|
} |
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} |
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bh = head = page_buffers(page); |
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BUG_ON(!bh); |
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|
|
/* |
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* We may be racing with truncate. To avoid some of the problems we |
|
* now take a snapshot of the various sizes and use those for the whole |
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* of the function. In case of an extending truncate it just means we |
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* may leave some buffers unmapped which are now allocated. This is |
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* not a problem since these buffers will just get mapped when a write |
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* occurs. In case of a shrinking truncate, we will detect this later |
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* on due to the runlist being incomplete and if the page is being |
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* fully truncated, truncate will throw it away as soon as we unlock |
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* it so no need to worry what we do with it. |
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*/ |
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iblock = (s64)page->index << (PAGE_SHIFT - blocksize_bits); |
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read_lock_irqsave(&ni->size_lock, flags); |
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lblock = (ni->allocated_size + blocksize - 1) >> blocksize_bits; |
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init_size = ni->initialized_size; |
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i_size = i_size_read(vi); |
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read_unlock_irqrestore(&ni->size_lock, flags); |
|
if (unlikely(init_size > i_size)) { |
|
/* Race with shrinking truncate. */ |
|
init_size = i_size; |
|
} |
|
zblock = (init_size + blocksize - 1) >> blocksize_bits; |
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|
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/* Loop through all the buffers in the page. */ |
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rl = NULL; |
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nr = i = 0; |
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do { |
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int err = 0; |
|
|
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if (unlikely(buffer_uptodate(bh))) |
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continue; |
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if (unlikely(buffer_mapped(bh))) { |
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arr[nr++] = bh; |
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continue; |
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} |
|
bh->b_bdev = vol->sb->s_bdev; |
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/* Is the block within the allowed limits? */ |
|
if (iblock < lblock) { |
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bool is_retry = false; |
|
|
|
/* 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; |
|
/* 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; |
|
continue; |
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} |
|
/* Fully non-initialized data block, zero it. */ |
|
goto handle_zblock; |
|
} |
|
/* It is a hole, need to zero it. */ |
|
if (lcn == LCN_HOLE) |
|
goto handle_hole; |
|
/* If first try and runlist unmapped, map and retry. */ |
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if (!is_retry && lcn == LCN_RL_NOT_MAPPED) { |
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is_retry = true; |
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/* |
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* Attempt to map runlist, dropping lock for |
|
* 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); |
|
if (likely(!err)) |
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goto lock_retry_remap; |
|
rl = NULL; |
|
} else if (!rl) |
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up_read(&ni->runlist.lock); |
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/* |
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* If buffer is outside the runlist, treat it as a |
|
* hole. This can happen due to concurrent truncate |
|
* for example. |
|
*/ |
|
if (err == -ENOENT || lcn == LCN_ENOENT) { |
|
err = 0; |
|
goto handle_hole; |
|
} |
|
/* Hard error, zero out region. */ |
|
if (!err) |
|
err = -EIO; |
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bh->b_blocknr = -1; |
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SetPageError(page); |
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ntfs_error(vol->sb, "Failed to read from inode 0x%lx, " |
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"attribute type 0x%x, vcn 0x%llx, " |
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"offset 0x%x because its location on " |
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"disk could not be determined%s " |
|
"(error code %i).", ni->mft_no, |
|
ni->type, (unsigned long long)vcn, |
|
vcn_ofs, is_retry ? " even after " |
|
"retrying" : "", err); |
|
} |
|
/* |
|
* Either iblock was outside lblock limits or |
|
* ntfs_rl_vcn_to_lcn() returned error. Just zero that portion |
|
* of the page and set the buffer uptodate. |
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*/ |
|
handle_hole: |
|
bh->b_blocknr = -1UL; |
|
clear_buffer_mapped(bh); |
|
handle_zblock: |
|
zero_user(page, i * blocksize, blocksize); |
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if (likely(!err)) |
|
set_buffer_uptodate(bh); |
|
} while (i++, iblock++, (bh = bh->b_this_page) != head); |
|
|
|
/* Release the lock if we took it. */ |
|
if (rl) |
|
up_read(&ni->runlist.lock); |
|
|
|
/* Check we have at least one buffer ready for i/o. */ |
|
if (nr) { |
|
struct buffer_head *tbh; |
|
|
|
/* Lock the buffers. */ |
|
for (i = 0; i < nr; i++) { |
|
tbh = arr[i]; |
|
lock_buffer(tbh); |
|
tbh->b_end_io = ntfs_end_buffer_async_read; |
|
set_buffer_async_read(tbh); |
|
} |
|
/* Finally, start i/o on the buffers. */ |
|
for (i = 0; i < nr; i++) { |
|
tbh = arr[i]; |
|
if (likely(!buffer_uptodate(tbh))) |
|
submit_bh(REQ_OP_READ, 0, tbh); |
|
else |
|
ntfs_end_buffer_async_read(tbh, 1); |
|
} |
|
return 0; |
|
} |
|
/* No i/o was scheduled on any of the buffers. */ |
|
if (likely(!PageError(page))) |
|
SetPageUptodate(page); |
|
else /* Signal synchronous i/o error. */ |
|
nr = -EIO; |
|
unlock_page(page); |
|
return nr; |
|
} |
|
|
|
/** |
|
* ntfs_readpage - fill a @page of a @file with data from the device |
|
* @file: open file to which the page @page belongs or NULL |
|
* @page: page cache page to fill with data |
|
* |
|
* For non-resident attributes, ntfs_readpage() fills the @page of the open |
|
* file @file by calling the ntfs version of the generic block_read_full_page() |
|
* function, ntfs_read_block(), which in turn creates and reads in the buffers |
|
* associated with the page asynchronously. |
|
* |
|
* For resident attributes, OTOH, ntfs_readpage() fills @page by copying the |
|
* data from the mft record (which at this stage is most likely in memory) and |
|
* fills the remainder with zeroes. Thus, in this case, I/O is synchronous, as |
|
* even if the mft record is not cached at this point in time, we need to wait |
|
* for it to be read in before we can do the copy. |
|
* |
|
* Return 0 on success and -errno on error. |
|
*/ |
|
static int ntfs_readpage(struct file *file, struct page *page) |
|
{ |
|
loff_t i_size; |
|
struct inode *vi; |
|
ntfs_inode *ni, *base_ni; |
|
u8 *addr; |
|
ntfs_attr_search_ctx *ctx; |
|
MFT_RECORD *mrec; |
|
unsigned long flags; |
|
u32 attr_len; |
|
int err = 0; |
|
|
|
retry_readpage: |
|
BUG_ON(!PageLocked(page)); |
|
vi = page->mapping->host; |
|
i_size = i_size_read(vi); |
|
/* Is the page fully outside i_size? (truncate in progress) */ |
|
if (unlikely(page->index >= (i_size + PAGE_SIZE - 1) >> |
|
PAGE_SHIFT)) { |
|
zero_user(page, 0, PAGE_SIZE); |
|
ntfs_debug("Read outside i_size - truncated?"); |
|
goto done; |
|
} |
|
/* |
|
* This can potentially happen because we clear PageUptodate() during |
|
* ntfs_writepage() of MstProtected() attributes. |
|
*/ |
|
if (PageUptodate(page)) { |
|
unlock_page(page); |
|
return 0; |
|
} |
|
ni = NTFS_I(vi); |
|
/* |
|
* Only $DATA attributes can be encrypted and only unnamed $DATA |
|
* attributes can be compressed. Index root can have the flags set but |
|
* this means to create compressed/encrypted files, not that the |
|
* attribute is compressed/encrypted. Note we need to check for |
|
* AT_INDEX_ALLOCATION since this is the type of both directory and |
|
* index inodes. |
|
*/ |
|
if (ni->type != AT_INDEX_ALLOCATION) { |
|
/* If attribute is encrypted, deny access, just like NT4. */ |
|
if (NInoEncrypted(ni)) { |
|
BUG_ON(ni->type != AT_DATA); |
|
err = -EACCES; |
|
goto err_out; |
|
} |
|
/* Compressed data streams are handled in compress.c. */ |
|
if (NInoNonResident(ni) && NInoCompressed(ni)) { |
|
BUG_ON(ni->type != AT_DATA); |
|
BUG_ON(ni->name_len); |
|
return ntfs_read_compressed_block(page); |
|
} |
|
} |
|
/* NInoNonResident() == NInoIndexAllocPresent() */ |
|
if (NInoNonResident(ni)) { |
|
/* Normal, non-resident data stream. */ |
|
return ntfs_read_block(page); |
|
} |
|
/* |
|
* Attribute is resident, implying it is not compressed or encrypted. |
|
* This also means the attribute is smaller than an mft record and |
|
* hence smaller than a page, so can simply zero out any pages with |
|
* index above 0. Note the attribute can actually be marked compressed |
|
* but if it is resident the actual data is not compressed so we are |
|
* ok to ignore the compressed flag here. |
|
*/ |
|
if (unlikely(page->index > 0)) { |
|
zero_user(page, 0, PAGE_SIZE); |
|
goto done; |
|
} |
|
if (!NInoAttr(ni)) |
|
base_ni = ni; |
|
else |
|
base_ni = ni->ext.base_ntfs_ino; |
|
/* Map, pin, and lock the mft record. */ |
|
mrec = map_mft_record(base_ni); |
|
if (IS_ERR(mrec)) { |
|
err = PTR_ERR(mrec); |
|
goto err_out; |
|
} |
|
/* |
|
* If a parallel write made the attribute non-resident, drop the mft |
|
* record and retry the readpage. |
|
*/ |
|
if (unlikely(NInoNonResident(ni))) { |
|
unmap_mft_record(base_ni); |
|
goto retry_readpage; |
|
} |
|
ctx = ntfs_attr_get_search_ctx(base_ni, mrec); |
|
if (unlikely(!ctx)) { |
|
err = -ENOMEM; |
|
goto unm_err_out; |
|
} |
|
err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len, |
|
CASE_SENSITIVE, 0, NULL, 0, ctx); |
|
if (unlikely(err)) |
|
goto put_unm_err_out; |
|
attr_len = le32_to_cpu(ctx->attr->data.resident.value_length); |
|
read_lock_irqsave(&ni->size_lock, flags); |
|
if (unlikely(attr_len > ni->initialized_size)) |
|
attr_len = ni->initialized_size; |
|
i_size = i_size_read(vi); |
|
read_unlock_irqrestore(&ni->size_lock, flags); |
|
if (unlikely(attr_len > i_size)) { |
|
/* Race with shrinking truncate. */ |
|
attr_len = i_size; |
|
} |
|
addr = kmap_atomic(page); |
|
/* Copy the data to the page. */ |
|
memcpy(addr, (u8*)ctx->attr + |
|
le16_to_cpu(ctx->attr->data.resident.value_offset), |
|
attr_len); |
|
/* Zero the remainder of the page. */ |
|
memset(addr + attr_len, 0, PAGE_SIZE - attr_len); |
|
flush_dcache_page(page); |
|
kunmap_atomic(addr); |
|
put_unm_err_out: |
|
ntfs_attr_put_search_ctx(ctx); |
|
unm_err_out: |
|
unmap_mft_record(base_ni); |
|
done: |
|
SetPageUptodate(page); |
|
err_out: |
|
unlock_page(page); |
|
return err; |
|
} |
|
|
|
#ifdef NTFS_RW |
|
|
|
/** |
|
* ntfs_write_block - write a @page to the backing store |
|
* @page: page cache page to write out |
|
* @wbc: writeback control structure |
|
* |
|
* This function is for writing pages belonging to non-resident, non-mst |
|
* protected attributes to their backing store. |
|
* |
|
* For a page with buffers, map and write the dirty buffers asynchronously |
|
* under page writeback. For a page without buffers, create buffers for the |
|
* page, then proceed as above. |
|
* |
|
* If a page doesn't have buffers the page dirty state is definitive. If a page |
|
* does have buffers, the page dirty state is just a hint, and the buffer dirty |
|
* state is definitive. (A hint which has rules: dirty buffers against a clean |
|
* page is illegal. Other combinations are legal and need to be handled. In |
|
* particular a dirty page containing clean buffers for example.) |
|
* |
|
* Return 0 on success and -errno on error. |
|
* |
|
* Based on ntfs_read_block() and __block_write_full_page(). |
|
*/ |
|
static int ntfs_write_block(struct page *page, struct writeback_control *wbc) |
|
{ |
|
VCN vcn; |
|
LCN lcn; |
|
s64 initialized_size; |
|
loff_t i_size; |
|
sector_t block, dblock, iblock; |
|
struct inode *vi; |
|
ntfs_inode *ni; |
|
ntfs_volume *vol; |
|
runlist_element *rl; |
|
struct buffer_head *bh, *head; |
|
unsigned long flags; |
|
unsigned int blocksize, vcn_ofs; |
|
int err; |
|
bool need_end_writeback; |
|
unsigned char blocksize_bits; |
|
|
|
vi = page->mapping->host; |
|
ni = NTFS_I(vi); |
|
vol = ni->vol; |
|
|
|
ntfs_debug("Entering for inode 0x%lx, attribute type 0x%x, page index " |
|
"0x%lx.", ni->mft_no, ni->type, page->index); |
|
|
|
BUG_ON(!NInoNonResident(ni)); |
|
BUG_ON(NInoMstProtected(ni)); |
|
blocksize = vol->sb->s_blocksize; |
|
blocksize_bits = vol->sb->s_blocksize_bits; |
|
if (!page_has_buffers(page)) { |
|
BUG_ON(!PageUptodate(page)); |
|
create_empty_buffers(page, blocksize, |
|
(1 << BH_Uptodate) | (1 << BH_Dirty)); |
|
if (unlikely(!page_has_buffers(page))) { |
|
ntfs_warning(vol->sb, "Error allocating page " |
|
"buffers. Redirtying page so we try " |
|
"again later."); |
|
/* |
|
* Put the page back on mapping->dirty_pages, but leave |
|
* its buffers' dirty state as-is. |
|
*/ |
|
redirty_page_for_writepage(wbc, page); |
|
unlock_page(page); |
|
return 0; |
|
} |
|
} |
|
bh = head = page_buffers(page); |
|
BUG_ON(!bh); |
|
|
|
/* NOTE: Different naming scheme to ntfs_read_block()! */ |
|
|
|
/* The first block in the page. */ |
|
block = (s64)page->index << (PAGE_SHIFT - blocksize_bits); |
|
|
|
read_lock_irqsave(&ni->size_lock, flags); |
|
i_size = i_size_read(vi); |
|
initialized_size = ni->initialized_size; |
|
read_unlock_irqrestore(&ni->size_lock, flags); |
|
|
|
/* The first out of bounds block for the data size. */ |
|
dblock = (i_size + blocksize - 1) >> blocksize_bits; |
|
|
|
/* The last (fully or partially) initialized block. */ |
|
iblock = initialized_size >> blocksize_bits; |
|
|
|
/* |
|
* Be very careful. We have no exclusion from __set_page_dirty_buffers |
|
* here, and the (potentially unmapped) buffers may become dirty at |
|
* any time. If a buffer becomes dirty here after we've inspected it |
|
* then we just miss that fact, and the page stays dirty. |
|
* |
|
* Buffers outside i_size may be dirtied by __set_page_dirty_buffers; |
|
* handle that here by just cleaning them. |
|
*/ |
|
|
|
/* |
|
* Loop through all the buffers in the page, mapping all the dirty |
|
* buffers to disk addresses and handling any aliases from the |
|
* underlying block device's mapping. |
|
*/ |
|
rl = NULL; |
|
err = 0; |
|
do { |
|
bool is_retry = false; |
|
|
|
if (unlikely(block >= dblock)) { |
|
/* |
|
* Mapped buffers outside i_size will occur, because |
|
* this page can be outside i_size when there is a |
|
* truncate in progress. The contents of such buffers |
|
* were zeroed by ntfs_writepage(). |
|
* |
|
* FIXME: What about the small race window where |
|
* ntfs_writepage() has not done any clearing because |
|
* the page was within i_size but before we get here, |
|
* vmtruncate() modifies i_size? |
|
*/ |
|
clear_buffer_dirty(bh); |
|
set_buffer_uptodate(bh); |
|
continue; |
|
} |
|
|
|
/* Clean buffers are not written out, so no need to map them. */ |
|
if (!buffer_dirty(bh)) |
|
continue; |
|
|
|
/* Make sure we have enough initialized size. */ |
|
if (unlikely((block >= iblock) && |
|
(initialized_size < i_size))) { |
|
/* |
|
* If this page is fully outside initialized size, zero |
|
* out all pages between the current initialized size |
|
* and the current page. Just use ntfs_readpage() to do |
|
* the zeroing transparently. |
|
*/ |
|
if (block > iblock) { |
|
// TODO: |
|
// For each page do: |
|
// - read_cache_page() |
|
// Again for each page do: |
|
// - wait_on_page_locked() |
|
// - Check (PageUptodate(page) && |
|
// !PageError(page)) |
|
// Update initialized size in the attribute and |
|
// in the inode. |
|
// Again, for each page do: |
|
// __set_page_dirty_buffers(); |
|
// put_page() |
|
// We don't need to wait on the writes. |
|
// Update iblock. |
|
} |
|
/* |
|
* The current page straddles initialized size. Zero |
|
* all non-uptodate buffers and set them uptodate (and |
|
* dirty?). Note, there aren't any non-uptodate buffers |
|
* if the page is uptodate. |
|
* FIXME: For an uptodate page, the buffers may need to |
|
* be written out because they were not initialized on |
|
* disk before. |
|
*/ |
|
if (!PageUptodate(page)) { |
|
// TODO: |
|
// Zero any non-uptodate buffers up to i_size. |
|
// Set them uptodate and dirty. |
|
} |
|
// TODO: |
|
// Update initialized size in the attribute and in the |
|
// inode (up to i_size). |
|
// Update iblock. |
|
// FIXME: This is inefficient. Try to batch the two |
|
// size changes to happen in one go. |
|
ntfs_error(vol->sb, "Writing beyond initialized size " |
|
"is not supported yet. Sorry."); |
|
err = -EOPNOTSUPP; |
|
break; |
|
// Do NOT set_buffer_new() BUT DO clear buffer range |
|
// outside write request range. |
|
// set_buffer_uptodate() on complete buffers as well as |
|
// set_buffer_dirty(). |
|
} |
|
|
|
/* No need to map buffers that are already mapped. */ |
|
if (buffer_mapped(bh)) |
|
continue; |
|
|
|
/* Unmapped, dirty buffer. Need to map it. */ |
|
bh->b_bdev = vol->sb->s_bdev; |
|
|
|
/* Convert block into corresponding vcn and offset. */ |
|
vcn = (VCN)block << blocksize_bits; |
|
vcn_ofs = vcn & vol->cluster_size_mask; |
|
vcn >>= vol->cluster_size_bits; |
|
if (!rl) { |
|
lock_retry_remap: |
|
down_read(&ni->runlist.lock); |
|
rl = ni->runlist.rl; |
|
} |
|
if (likely(rl != NULL)) { |
|
/* Seek to element containing target vcn. */ |
|
while (rl->length && rl[1].vcn <= vcn) |
|
rl++; |
|
lcn = ntfs_rl_vcn_to_lcn(rl, vcn); |
|
} else |
|
lcn = LCN_RL_NOT_MAPPED; |
|
/* Successful remap. */ |
|
if (lcn >= 0) { |
|
/* Setup buffer head to point to correct block. */ |
|
bh->b_blocknr = ((lcn << vol->cluster_size_bits) + |
|
vcn_ofs) >> blocksize_bits; |
|
set_buffer_mapped(bh); |
|
continue; |
|
} |
|
/* It is a hole, need to instantiate it. */ |
|
if (lcn == LCN_HOLE) { |
|
u8 *kaddr; |
|
unsigned long *bpos, *bend; |
|
|
|
/* Check if the buffer is zero. */ |
|
kaddr = kmap_atomic(page); |
|
bpos = (unsigned long *)(kaddr + bh_offset(bh)); |
|
bend = (unsigned long *)((u8*)bpos + blocksize); |
|
do { |
|
if (unlikely(*bpos)) |
|
break; |
|
} while (likely(++bpos < bend)); |
|
kunmap_atomic(kaddr); |
|
if (bpos == bend) { |
|
/* |
|
* Buffer is zero and sparse, no need to write |
|
* it. |
|
*/ |
|
bh->b_blocknr = -1; |
|
clear_buffer_dirty(bh); |
|
continue; |
|
} |
|
// TODO: Instantiate the hole. |
|
// clear_buffer_new(bh); |
|
// clean_bdev_bh_alias(bh); |
|
ntfs_error(vol->sb, "Writing into sparse regions is " |
|
"not supported yet. Sorry."); |
|
err = -EOPNOTSUPP; |
|
break; |
|
} |
|
/* If first try and runlist unmapped, map and retry. */ |
|
if (!is_retry && lcn == LCN_RL_NOT_MAPPED) { |
|
is_retry = true; |
|
/* |
|
* Attempt to map runlist, dropping lock for |
|
* the duration. |
|
*/ |
|
up_read(&ni->runlist.lock); |
|
err = ntfs_map_runlist(ni, vcn); |
|
if (likely(!err)) |
|
goto lock_retry_remap; |
|
rl = NULL; |
|
} else if (!rl) |
|
up_read(&ni->runlist.lock); |
|
/* |
|
* If buffer is outside the runlist, truncate has cut it out |
|
* of the runlist. Just clean and clear the buffer and set it |
|
* uptodate so it can get discarded by the VM. |
|
*/ |
|
if (err == -ENOENT || lcn == LCN_ENOENT) { |
|
bh->b_blocknr = -1; |
|
clear_buffer_dirty(bh); |
|
zero_user(page, bh_offset(bh), blocksize); |
|
set_buffer_uptodate(bh); |
|
err = 0; |
|
continue; |
|
} |
|
/* Failed to map the buffer, even after retrying. */ |
|
if (!err) |
|
err = -EIO; |
|
bh->b_blocknr = -1; |
|
ntfs_error(vol->sb, "Failed to write to inode 0x%lx, " |
|
"attribute type 0x%x, vcn 0x%llx, offset 0x%x " |
|
"because its location on disk could not be " |
|
"determined%s (error code %i).", ni->mft_no, |
|
ni->type, (unsigned long long)vcn, |
|
vcn_ofs, is_retry ? " even after " |
|
"retrying" : "", err); |
|
break; |
|
} while (block++, (bh = bh->b_this_page) != head); |
|
|
|
/* Release the lock if we took it. */ |
|
if (rl) |
|
up_read(&ni->runlist.lock); |
|
|
|
/* For the error case, need to reset bh to the beginning. */ |
|
bh = head; |
|
|
|
/* Just an optimization, so ->readpage() is not called later. */ |
|
if (unlikely(!PageUptodate(page))) { |
|
int uptodate = 1; |
|
do { |
|
if (!buffer_uptodate(bh)) { |
|
uptodate = 0; |
|
bh = head; |
|
break; |
|
} |
|
} while ((bh = bh->b_this_page) != head); |
|
if (uptodate) |
|
SetPageUptodate(page); |
|
} |
|
|
|
/* Setup all mapped, dirty buffers for async write i/o. */ |
|
do { |
|
if (buffer_mapped(bh) && buffer_dirty(bh)) { |
|
lock_buffer(bh); |
|
if (test_clear_buffer_dirty(bh)) { |
|
BUG_ON(!buffer_uptodate(bh)); |
|
mark_buffer_async_write(bh); |
|
} else |
|
unlock_buffer(bh); |
|
} else if (unlikely(err)) { |
|
/* |
|
* For the error case. The buffer may have been set |
|
* dirty during attachment to a dirty page. |
|
*/ |
|
if (err != -ENOMEM) |
|
clear_buffer_dirty(bh); |
|
} |
|
} while ((bh = bh->b_this_page) != head); |
|
|
|
if (unlikely(err)) { |
|
// TODO: Remove the -EOPNOTSUPP check later on... |
|
if (unlikely(err == -EOPNOTSUPP)) |
|
err = 0; |
|
else if (err == -ENOMEM) { |
|
ntfs_warning(vol->sb, "Error allocating memory. " |
|
"Redirtying page so we try again " |
|
"later."); |
|
/* |
|
* Put the page back on mapping->dirty_pages, but |
|
* leave its buffer's dirty state as-is. |
|
*/ |
|
redirty_page_for_writepage(wbc, page); |
|
err = 0; |
|
} else |
|
SetPageError(page); |
|
} |
|
|
|
BUG_ON(PageWriteback(page)); |
|
set_page_writeback(page); /* Keeps try_to_free_buffers() away. */ |
|
|
|
/* Submit the prepared buffers for i/o. */ |
|
need_end_writeback = true; |
|
do { |
|
struct buffer_head *next = bh->b_this_page; |
|
if (buffer_async_write(bh)) { |
|
submit_bh(REQ_OP_WRITE, 0, bh); |
|
need_end_writeback = false; |
|
} |
|
bh = next; |
|
} while (bh != head); |
|
unlock_page(page); |
|
|
|
/* If no i/o was started, need to end_page_writeback(). */ |
|
if (unlikely(need_end_writeback)) |
|
end_page_writeback(page); |
|
|
|
ntfs_debug("Done."); |
|
return err; |
|
} |
|
|
|
/** |
|
* ntfs_write_mst_block - write a @page to the backing store |
|
* @page: page cache page to write out |
|
* @wbc: writeback control structure |
|
* |
|
* This function is for writing pages belonging to non-resident, mst protected |
|
* attributes to their backing store. The only supported attributes are index |
|
* allocation and $MFT/$DATA. Both directory inodes and index inodes are |
|
* supported for the index allocation case. |
|
* |
|
* The page must remain locked for the duration of the write because we apply |
|
* the mst fixups, write, and then undo the fixups, so if we were to unlock the |
|
* page before undoing the fixups, any other user of the page will see the |
|
* page contents as corrupt. |
|
* |
|
* We clear the page uptodate flag for the duration of the function to ensure |
|
* exclusion for the $MFT/$DATA case against someone mapping an mft record we |
|
* are about to apply the mst fixups to. |
|
* |
|
* Return 0 on success and -errno on error. |
|
* |
|
* Based on ntfs_write_block(), ntfs_mft_writepage(), and |
|
* write_mft_record_nolock(). |
|
*/ |
|
static int ntfs_write_mst_block(struct page *page, |
|
struct writeback_control *wbc) |
|
{ |
|
sector_t block, dblock, rec_block; |
|
struct inode *vi = page->mapping->host; |
|
ntfs_inode *ni = NTFS_I(vi); |
|
ntfs_volume *vol = ni->vol; |
|
u8 *kaddr; |
|
unsigned int rec_size = ni->itype.index.block_size; |
|
ntfs_inode *locked_nis[PAGE_SIZE / NTFS_BLOCK_SIZE]; |
|
struct buffer_head *bh, *head, *tbh, *rec_start_bh; |
|
struct buffer_head *bhs[MAX_BUF_PER_PAGE]; |
|
runlist_element *rl; |
|
int i, nr_locked_nis, nr_recs, nr_bhs, max_bhs, bhs_per_rec, err, err2; |
|
unsigned bh_size, rec_size_bits; |
|
bool sync, is_mft, page_is_dirty, rec_is_dirty; |
|
unsigned char bh_size_bits; |
|
|
|
if (WARN_ON(rec_size < NTFS_BLOCK_SIZE)) |
|
return -EINVAL; |
|
|
|
ntfs_debug("Entering for inode 0x%lx, attribute type 0x%x, page index " |
|
"0x%lx.", vi->i_ino, ni->type, page->index); |
|
BUG_ON(!NInoNonResident(ni)); |
|
BUG_ON(!NInoMstProtected(ni)); |
|
is_mft = (S_ISREG(vi->i_mode) && !vi->i_ino); |
|
/* |
|
* NOTE: ntfs_write_mst_block() would be called for $MFTMirr if a page |
|
* in its page cache were to be marked dirty. However this should |
|
* never happen with the current driver and considering we do not |
|
* handle this case here we do want to BUG(), at least for now. |
|
*/ |
|
BUG_ON(!(is_mft || S_ISDIR(vi->i_mode) || |
|
(NInoAttr(ni) && ni->type == AT_INDEX_ALLOCATION))); |
|
bh_size = vol->sb->s_blocksize; |
|
bh_size_bits = vol->sb->s_blocksize_bits; |
|
max_bhs = PAGE_SIZE / bh_size; |
|
BUG_ON(!max_bhs); |
|
BUG_ON(max_bhs > MAX_BUF_PER_PAGE); |
|
|
|
/* Were we called for sync purposes? */ |
|
sync = (wbc->sync_mode == WB_SYNC_ALL); |
|
|
|
/* Make sure we have mapped buffers. */ |
|
bh = head = page_buffers(page); |
|
BUG_ON(!bh); |
|
|
|
rec_size_bits = ni->itype.index.block_size_bits; |
|
BUG_ON(!(PAGE_SIZE >> rec_size_bits)); |
|
bhs_per_rec = rec_size >> bh_size_bits; |
|
BUG_ON(!bhs_per_rec); |
|
|
|
/* The first block in the page. */ |
|
rec_block = block = (sector_t)page->index << |
|
(PAGE_SHIFT - bh_size_bits); |
|
|
|
/* The first out of bounds block for the data size. */ |
|
dblock = (i_size_read(vi) + bh_size - 1) >> bh_size_bits; |
|
|
|
rl = NULL; |
|
err = err2 = nr_bhs = nr_recs = nr_locked_nis = 0; |
|
page_is_dirty = rec_is_dirty = false; |
|
rec_start_bh = NULL; |
|
do { |
|
bool is_retry = false; |
|
|
|
if (likely(block < rec_block)) { |
|
if (unlikely(block >= dblock)) { |
|
clear_buffer_dirty(bh); |
|
set_buffer_uptodate(bh); |
|
continue; |
|
} |
|
/* |
|
* This block is not the first one in the record. We |
|
* ignore the buffer's dirty state because we could |
|
* have raced with a parallel mark_ntfs_record_dirty(). |
|
*/ |
|
if (!rec_is_dirty) |
|
continue; |
|
if (unlikely(err2)) { |
|
if (err2 != -ENOMEM) |
|
clear_buffer_dirty(bh); |
|
continue; |
|
} |
|
} else /* if (block == rec_block) */ { |
|
BUG_ON(block > rec_block); |
|
/* This block is the first one in the record. */ |
|
rec_block += bhs_per_rec; |
|
err2 = 0; |
|
if (unlikely(block >= dblock)) { |
|
clear_buffer_dirty(bh); |
|
continue; |
|
} |
|
if (!buffer_dirty(bh)) { |
|
/* Clean records are not written out. */ |
|
rec_is_dirty = false; |
|
continue; |
|
} |
|
rec_is_dirty = true; |
|
rec_start_bh = bh; |
|
} |
|
/* Need to map the buffer if it is not mapped already. */ |
|
if (unlikely(!buffer_mapped(bh))) { |
|
VCN vcn; |
|
LCN lcn; |
|
unsigned int vcn_ofs; |
|
|
|
bh->b_bdev = vol->sb->s_bdev; |
|
/* Obtain the vcn and offset of the current block. */ |
|
vcn = (VCN)block << bh_size_bits; |
|
vcn_ofs = vcn & vol->cluster_size_mask; |
|
vcn >>= vol->cluster_size_bits; |
|
if (!rl) { |
|
lock_retry_remap: |
|
down_read(&ni->runlist.lock); |
|
rl = ni->runlist.rl; |
|
} |
|
if (likely(rl != NULL)) { |
|
/* Seek to element containing target vcn. */ |
|
while (rl->length && rl[1].vcn <= vcn) |
|
rl++; |
|
lcn = ntfs_rl_vcn_to_lcn(rl, vcn); |
|
} else |
|
lcn = LCN_RL_NOT_MAPPED; |
|
/* Successful remap. */ |
|
if (likely(lcn >= 0)) { |
|
/* Setup buffer head to correct block. */ |
|
bh->b_blocknr = ((lcn << |
|
vol->cluster_size_bits) + |
|
vcn_ofs) >> bh_size_bits; |
|
set_buffer_mapped(bh); |
|
} else { |
|
/* |
|
* Remap failed. Retry to map the runlist once |
|
* unless we are working on $MFT which always |
|
* has the whole of its runlist in memory. |
|
*/ |
|
if (!is_mft && !is_retry && |
|
lcn == LCN_RL_NOT_MAPPED) { |
|
is_retry = true; |
|
/* |
|
* Attempt to map runlist, dropping |
|
* lock for the duration. |
|
*/ |
|
up_read(&ni->runlist.lock); |
|
err2 = ntfs_map_runlist(ni, vcn); |
|
if (likely(!err2)) |
|
goto lock_retry_remap; |
|
if (err2 == -ENOMEM) |
|
page_is_dirty = true; |
|
lcn = err2; |
|
} else { |
|
err2 = -EIO; |
|
if (!rl) |
|
up_read(&ni->runlist.lock); |
|
} |
|
/* Hard error. Abort writing this record. */ |
|
if (!err || err == -ENOMEM) |
|
err = err2; |
|
bh->b_blocknr = -1; |
|
ntfs_error(vol->sb, "Cannot write ntfs record " |
|
"0x%llx (inode 0x%lx, " |
|
"attribute type 0x%x) because " |
|
"its location on disk could " |
|
"not be determined (error " |
|
"code %lli).", |
|
(long long)block << |
|
bh_size_bits >> |
|
vol->mft_record_size_bits, |
|
ni->mft_no, ni->type, |
|
(long long)lcn); |
|
/* |
|
* If this is not the first buffer, remove the |
|
* buffers in this record from the list of |
|
* buffers to write and clear their dirty bit |
|
* if not error -ENOMEM. |
|
*/ |
|
if (rec_start_bh != bh) { |
|
while (bhs[--nr_bhs] != rec_start_bh) |
|
; |
|
if (err2 != -ENOMEM) { |
|
do { |
|
clear_buffer_dirty( |
|
rec_start_bh); |
|
} while ((rec_start_bh = |
|
rec_start_bh-> |
|
b_this_page) != |
|
bh); |
|
} |
|
} |
|
continue; |
|
} |
|
} |
|
BUG_ON(!buffer_uptodate(bh)); |
|
BUG_ON(nr_bhs >= max_bhs); |
|
bhs[nr_bhs++] = bh; |
|
} while (block++, (bh = bh->b_this_page) != head); |
|
if (unlikely(rl)) |
|
up_read(&ni->runlist.lock); |
|
/* If there were no dirty buffers, we are done. */ |
|
if (!nr_bhs) |
|
goto done; |
|
/* Map the page so we can access its contents. */ |
|
kaddr = kmap(page); |
|
/* Clear the page uptodate flag whilst the mst fixups are applied. */ |
|
BUG_ON(!PageUptodate(page)); |
|
ClearPageUptodate(page); |
|
for (i = 0; i < nr_bhs; i++) { |
|
unsigned int ofs; |
|
|
|
/* Skip buffers which are not at the beginning of records. */ |
|
if (i % bhs_per_rec) |
|
continue; |
|
tbh = bhs[i]; |
|
ofs = bh_offset(tbh); |
|
if (is_mft) { |
|
ntfs_inode *tni; |
|
unsigned long mft_no; |
|
|
|
/* Get the mft record number. */ |
|
mft_no = (((s64)page->index << PAGE_SHIFT) + ofs) |
|
>> rec_size_bits; |
|
/* Check whether to write this mft record. */ |
|
tni = NULL; |
|
if (!ntfs_may_write_mft_record(vol, mft_no, |
|
(MFT_RECORD*)(kaddr + ofs), &tni)) { |
|
/* |
|
* The record should not be written. This |
|
* means we need to redirty the page before |
|
* returning. |
|
*/ |
|
page_is_dirty = true; |
|
/* |
|
* Remove the buffers in this mft record from |
|
* the list of buffers to write. |
|
*/ |
|
do { |
|
bhs[i] = NULL; |
|
} while (++i % bhs_per_rec); |
|
continue; |
|
} |
|
/* |
|
* The record should be written. If a locked ntfs |
|
* inode was returned, add it to the array of locked |
|
* ntfs inodes. |
|
*/ |
|
if (tni) |
|
locked_nis[nr_locked_nis++] = tni; |
|
} |
|
/* Apply the mst protection fixups. */ |
|
err2 = pre_write_mst_fixup((NTFS_RECORD*)(kaddr + ofs), |
|
rec_size); |
|
if (unlikely(err2)) { |
|
if (!err || err == -ENOMEM) |
|
err = -EIO; |
|
ntfs_error(vol->sb, "Failed to apply mst fixups " |
|
"(inode 0x%lx, attribute type 0x%x, " |
|
"page index 0x%lx, page offset 0x%x)!" |
|
" Unmount and run chkdsk.", vi->i_ino, |
|
ni->type, page->index, ofs); |
|
/* |
|
* Mark all the buffers in this record clean as we do |
|
* not want to write corrupt data to disk. |
|
*/ |
|
do { |
|
clear_buffer_dirty(bhs[i]); |
|
bhs[i] = NULL; |
|
} while (++i % bhs_per_rec); |
|
continue; |
|
} |
|
nr_recs++; |
|
} |
|
/* If no records are to be written out, we are done. */ |
|
if (!nr_recs) |
|
goto unm_done; |
|
flush_dcache_page(page); |
|
/* Lock buffers and start synchronous write i/o on them. */ |
|
for (i = 0; i < nr_bhs; i++) { |
|
tbh = bhs[i]; |
|
if (!tbh) |
|
continue; |
|
if (!trylock_buffer(tbh)) |
|
BUG(); |
|
/* The buffer dirty state is now irrelevant, just clean it. */ |
|
clear_buffer_dirty(tbh); |
|
BUG_ON(!buffer_uptodate(tbh)); |
|
BUG_ON(!buffer_mapped(tbh)); |
|
get_bh(tbh); |
|
tbh->b_end_io = end_buffer_write_sync; |
|
submit_bh(REQ_OP_WRITE, 0, tbh); |
|
} |
|
/* Synchronize the mft mirror now if not @sync. */ |
|
if (is_mft && !sync) |
|
goto do_mirror; |
|
do_wait: |
|
/* Wait on i/o completion of buffers. */ |
|
for (i = 0; i < nr_bhs; i++) { |
|
tbh = bhs[i]; |
|
if (!tbh) |
|
continue; |
|
wait_on_buffer(tbh); |
|
if (unlikely(!buffer_uptodate(tbh))) { |
|
ntfs_error(vol->sb, "I/O error while writing ntfs " |
|
"record buffer (inode 0x%lx, " |
|
"attribute type 0x%x, page index " |
|
"0x%lx, page offset 0x%lx)! Unmount " |
|
"and run chkdsk.", vi->i_ino, ni->type, |
|
page->index, bh_offset(tbh)); |
|
if (!err || err == -ENOMEM) |
|
err = -EIO; |
|
/* |
|
* Set the buffer uptodate so the page and buffer |
|
* states do not become out of sync. |
|
*/ |
|
set_buffer_uptodate(tbh); |
|
} |
|
} |
|
/* If @sync, now synchronize the mft mirror. */ |
|
if (is_mft && sync) { |
|
do_mirror: |
|
for (i = 0; i < nr_bhs; i++) { |
|
unsigned long mft_no; |
|
unsigned int ofs; |
|
|
|
/* |
|
* Skip buffers which are not at the beginning of |
|
* records. |
|
*/ |
|
if (i % bhs_per_rec) |
|
continue; |
|
tbh = bhs[i]; |
|
/* Skip removed buffers (and hence records). */ |
|
if (!tbh) |
|
continue; |
|
ofs = bh_offset(tbh); |
|
/* Get the mft record number. */ |
|
mft_no = (((s64)page->index << PAGE_SHIFT) + ofs) |
|
>> rec_size_bits; |
|
if (mft_no < vol->mftmirr_size) |
|
ntfs_sync_mft_mirror(vol, mft_no, |
|
(MFT_RECORD*)(kaddr + ofs), |
|
sync); |
|
} |
|
if (!sync) |
|
goto do_wait; |
|
} |
|
/* Remove the mst protection fixups again. */ |
|
for (i = 0; i < nr_bhs; i++) { |
|
if (!(i % bhs_per_rec)) { |
|
tbh = bhs[i]; |
|
if (!tbh) |
|
continue; |
|
post_write_mst_fixup((NTFS_RECORD*)(kaddr + |
|
bh_offset(tbh))); |
|
} |
|
} |
|
flush_dcache_page(page); |
|
unm_done: |
|
/* Unlock any locked inodes. */ |
|
while (nr_locked_nis-- > 0) { |
|
ntfs_inode *tni, *base_tni; |
|
|
|
tni = locked_nis[nr_locked_nis]; |
|
/* Get the base inode. */ |
|
mutex_lock(&tni->extent_lock); |
|
if (tni->nr_extents >= 0) |
|
base_tni = tni; |
|
else { |
|
base_tni = tni->ext.base_ntfs_ino; |
|
BUG_ON(!base_tni); |
|
} |
|
mutex_unlock(&tni->extent_lock); |
|
ntfs_debug("Unlocking %s inode 0x%lx.", |
|
tni == base_tni ? "base" : "extent", |
|
tni->mft_no); |
|
mutex_unlock(&tni->mrec_lock); |
|
atomic_dec(&tni->count); |
|
iput(VFS_I(base_tni)); |
|
} |
|
SetPageUptodate(page); |
|
kunmap(page); |
|
done: |
|
if (unlikely(err && err != -ENOMEM)) { |
|
/* |
|
* Set page error if there is only one ntfs record in the page. |
|
* Otherwise we would loose per-record granularity. |
|
*/ |
|
if (ni->itype.index.block_size == PAGE_SIZE) |
|
SetPageError(page); |
|
NVolSetErrors(vol); |
|
} |
|
if (page_is_dirty) { |
|
ntfs_debug("Page still contains one or more dirty ntfs " |
|
"records. Redirtying the page starting at " |
|
"record 0x%lx.", page->index << |
|
(PAGE_SHIFT - rec_size_bits)); |
|
redirty_page_for_writepage(wbc, page); |
|
unlock_page(page); |
|
} else { |
|
/* |
|
* Keep the VM happy. This must be done otherwise the |
|
* radix-tree tag PAGECACHE_TAG_DIRTY remains set even though |
|
* the page is clean. |
|
*/ |
|
BUG_ON(PageWriteback(page)); |
|
set_page_writeback(page); |
|
unlock_page(page); |
|
end_page_writeback(page); |
|
} |
|
if (likely(!err)) |
|
ntfs_debug("Done."); |
|
return err; |
|
} |
|
|
|
/** |
|
* ntfs_writepage - write a @page to the backing store |
|
* @page: page cache page to write out |
|
* @wbc: writeback control structure |
|
* |
|
* This is called from the VM when it wants to have a dirty ntfs page cache |
|
* page cleaned. The VM has already locked the page and marked it clean. |
|
* |
|
* For non-resident attributes, ntfs_writepage() writes the @page by calling |
|
* the ntfs version of the generic block_write_full_page() function, |
|
* ntfs_write_block(), which in turn if necessary creates and writes the |
|
* buffers associated with the page asynchronously. |
|
* |
|
* For resident attributes, OTOH, ntfs_writepage() writes the @page by copying |
|
* the data to the mft record (which at this stage is most likely in memory). |
|
* The mft record is then marked dirty and written out asynchronously via the |
|
* vfs inode dirty code path for the inode the mft record belongs to or via the |
|
* vm page dirty code path for the page the mft record is in. |
|
* |
|
* Based on ntfs_readpage() and fs/buffer.c::block_write_full_page(). |
|
* |
|
* Return 0 on success and -errno on error. |
|
*/ |
|
static int ntfs_writepage(struct page *page, struct writeback_control *wbc) |
|
{ |
|
loff_t i_size; |
|
struct inode *vi = page->mapping->host; |
|
ntfs_inode *base_ni = NULL, *ni = NTFS_I(vi); |
|
char *addr; |
|
ntfs_attr_search_ctx *ctx = NULL; |
|
MFT_RECORD *m = NULL; |
|
u32 attr_len; |
|
int err; |
|
|
|
retry_writepage: |
|
BUG_ON(!PageLocked(page)); |
|
i_size = i_size_read(vi); |
|
/* Is the page fully outside i_size? (truncate in progress) */ |
|
if (unlikely(page->index >= (i_size + PAGE_SIZE - 1) >> |
|
PAGE_SHIFT)) { |
|
/* |
|
* The page may have dirty, unmapped buffers. Make them |
|
* freeable here, so the page does not leak. |
|
*/ |
|
block_invalidatepage(page, 0, PAGE_SIZE); |
|
unlock_page(page); |
|
ntfs_debug("Write outside i_size - truncated?"); |
|
return 0; |
|
} |
|
/* |
|
* Only $DATA attributes can be encrypted and only unnamed $DATA |
|
* attributes can be compressed. Index root can have the flags set but |
|
* this means to create compressed/encrypted files, not that the |
|
* attribute is compressed/encrypted. Note we need to check for |
|
* AT_INDEX_ALLOCATION since this is the type of both directory and |
|
* index inodes. |
|
*/ |
|
if (ni->type != AT_INDEX_ALLOCATION) { |
|
/* If file is encrypted, deny access, just like NT4. */ |
|
if (NInoEncrypted(ni)) { |
|
unlock_page(page); |
|
BUG_ON(ni->type != AT_DATA); |
|
ntfs_debug("Denying write access to encrypted file."); |
|
return -EACCES; |
|
} |
|
/* Compressed data streams are handled in compress.c. */ |
|
if (NInoNonResident(ni) && NInoCompressed(ni)) { |
|
BUG_ON(ni->type != AT_DATA); |
|
BUG_ON(ni->name_len); |
|
// TODO: Implement and replace this with |
|
// return ntfs_write_compressed_block(page); |
|
unlock_page(page); |
|
ntfs_error(vi->i_sb, "Writing to compressed files is " |
|
"not supported yet. Sorry."); |
|
return -EOPNOTSUPP; |
|
} |
|
// TODO: Implement and remove this check. |
|
if (NInoNonResident(ni) && NInoSparse(ni)) { |
|
unlock_page(page); |
|
ntfs_error(vi->i_sb, "Writing to sparse files is not " |
|
"supported yet. Sorry."); |
|
return -EOPNOTSUPP; |
|
} |
|
} |
|
/* NInoNonResident() == NInoIndexAllocPresent() */ |
|
if (NInoNonResident(ni)) { |
|
/* We have to zero every time due to mmap-at-end-of-file. */ |
|
if (page->index >= (i_size >> PAGE_SHIFT)) { |
|
/* The page straddles i_size. */ |
|
unsigned int ofs = i_size & ~PAGE_MASK; |
|
zero_user_segment(page, ofs, PAGE_SIZE); |
|
} |
|
/* Handle mst protected attributes. */ |
|
if (NInoMstProtected(ni)) |
|
return ntfs_write_mst_block(page, wbc); |
|
/* Normal, non-resident data stream. */ |
|
return ntfs_write_block(page, wbc); |
|
} |
|
/* |
|
* Attribute is resident, implying it is not compressed, encrypted, or |
|
* mst protected. This also means the attribute is smaller than an mft |
|
* record and hence smaller than a page, so can simply return error on |
|
* any pages with index above 0. Note the attribute can actually be |
|
* marked compressed but if it is resident the actual data is not |
|
* compressed so we are ok to ignore the compressed flag here. |
|
*/ |
|
BUG_ON(page_has_buffers(page)); |
|
BUG_ON(!PageUptodate(page)); |
|
if (unlikely(page->index > 0)) { |
|
ntfs_error(vi->i_sb, "BUG()! page->index (0x%lx) > 0. " |
|
"Aborting write.", page->index); |
|
BUG_ON(PageWriteback(page)); |
|
set_page_writeback(page); |
|
unlock_page(page); |
|
end_page_writeback(page); |
|
return -EIO; |
|
} |
|
if (!NInoAttr(ni)) |
|
base_ni = ni; |
|
else |
|
base_ni = ni->ext.base_ntfs_ino; |
|
/* Map, pin, and lock the mft record. */ |
|
m = map_mft_record(base_ni); |
|
if (IS_ERR(m)) { |
|
err = PTR_ERR(m); |
|
m = NULL; |
|
ctx = NULL; |
|
goto err_out; |
|
} |
|
/* |
|
* If a parallel write made the attribute non-resident, drop the mft |
|
* record and retry the writepage. |
|
*/ |
|
if (unlikely(NInoNonResident(ni))) { |
|
unmap_mft_record(base_ni); |
|
goto retry_writepage; |
|
} |
|
ctx = ntfs_attr_get_search_ctx(base_ni, m); |
|
if (unlikely(!ctx)) { |
|
err = -ENOMEM; |
|
goto err_out; |
|
} |
|
err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len, |
|
CASE_SENSITIVE, 0, NULL, 0, ctx); |
|
if (unlikely(err)) |
|
goto err_out; |
|
/* |
|
* Keep the VM happy. This must be done otherwise the radix-tree tag |
|
* PAGECACHE_TAG_DIRTY remains set even though the page is clean. |
|
*/ |
|
BUG_ON(PageWriteback(page)); |
|
set_page_writeback(page); |
|
unlock_page(page); |
|
attr_len = le32_to_cpu(ctx->attr->data.resident.value_length); |
|
i_size = i_size_read(vi); |
|
if (unlikely(attr_len > i_size)) { |
|
/* Race with shrinking truncate or a failed truncate. */ |
|
attr_len = i_size; |
|
/* |
|
* If the truncate failed, fix it up now. If a concurrent |
|
* truncate, we do its job, so it does not have to do anything. |
|
*/ |
|
err = ntfs_resident_attr_value_resize(ctx->mrec, ctx->attr, |
|
attr_len); |
|
/* Shrinking cannot fail. */ |
|
BUG_ON(err); |
|
} |
|
addr = kmap_atomic(page); |
|
/* Copy the data from the page to the mft record. */ |
|
memcpy((u8*)ctx->attr + |
|
le16_to_cpu(ctx->attr->data.resident.value_offset), |
|
addr, attr_len); |
|
/* Zero out of bounds area in the page cache page. */ |
|
memset(addr + attr_len, 0, PAGE_SIZE - attr_len); |
|
kunmap_atomic(addr); |
|
flush_dcache_page(page); |
|
flush_dcache_mft_record_page(ctx->ntfs_ino); |
|
/* We are done with the page. */ |
|
end_page_writeback(page); |
|
/* Finally, mark the mft record dirty, so it gets written back. */ |
|
mark_mft_record_dirty(ctx->ntfs_ino); |
|
ntfs_attr_put_search_ctx(ctx); |
|
unmap_mft_record(base_ni); |
|
return 0; |
|
err_out: |
|
if (err == -ENOMEM) { |
|
ntfs_warning(vi->i_sb, "Error allocating memory. Redirtying " |
|
"page so we try again later."); |
|
/* |
|
* Put the page back on mapping->dirty_pages, but leave its |
|
* buffers' dirty state as-is. |
|
*/ |
|
redirty_page_for_writepage(wbc, page); |
|
err = 0; |
|
} else { |
|
ntfs_error(vi->i_sb, "Resident attribute write failed with " |
|
"error %i.", err); |
|
SetPageError(page); |
|
NVolSetErrors(ni->vol); |
|
} |
|
unlock_page(page); |
|
if (ctx) |
|
ntfs_attr_put_search_ctx(ctx); |
|
if (m) |
|
unmap_mft_record(base_ni); |
|
return err; |
|
} |
|
|
|
#endif /* NTFS_RW */ |
|
|
|
/** |
|
* ntfs_bmap - map logical file block to physical device block |
|
* @mapping: address space mapping to which the block to be mapped belongs |
|
* @block: logical block to map to its physical device block |
|
* |
|
* For regular, non-resident files (i.e. not compressed and not encrypted), map |
|
* the logical @block belonging to the file described by the address space |
|
* mapping @mapping to its physical device block. |
|
* |
|
* The size of the block is equal to the @s_blocksize field of the super block |
|
* of the mounted file system which is guaranteed to be smaller than or equal |
|
* to the cluster size thus the block is guaranteed to fit entirely inside the |
|
* cluster which means we do not need to care how many contiguous bytes are |
|
* available after the beginning of the block. |
|
* |
|
* Return the physical device block if the mapping succeeded or 0 if the block |
|
* is sparse or there was an error. |
|
* |
|
* Note: This is a problem if someone tries to run bmap() on $Boot system file |
|
* as that really is in block zero but there is nothing we can do. bmap() is |
|
* just broken in that respect (just like it cannot distinguish sparse from |
|
* not available or error). |
|
*/ |
|
static sector_t ntfs_bmap(struct address_space *mapping, sector_t block) |
|
{ |
|
s64 ofs, size; |
|
loff_t i_size; |
|
LCN lcn; |
|
unsigned long blocksize, flags; |
|
ntfs_inode *ni = NTFS_I(mapping->host); |
|
ntfs_volume *vol = ni->vol; |
|
unsigned delta; |
|
unsigned char blocksize_bits, cluster_size_shift; |
|
|
|
ntfs_debug("Entering for mft_no 0x%lx, logical block 0x%llx.", |
|
ni->mft_no, (unsigned long long)block); |
|
if (ni->type != AT_DATA || !NInoNonResident(ni) || NInoEncrypted(ni)) { |
|
ntfs_error(vol->sb, "BMAP does not make sense for %s " |
|
"attributes, returning 0.", |
|
(ni->type != AT_DATA) ? "non-data" : |
|
(!NInoNonResident(ni) ? "resident" : |
|
"encrypted")); |
|
return 0; |
|
} |
|
/* None of these can happen. */ |
|
BUG_ON(NInoCompressed(ni)); |
|
BUG_ON(NInoMstProtected(ni)); |
|
blocksize = vol->sb->s_blocksize; |
|
blocksize_bits = vol->sb->s_blocksize_bits; |
|
ofs = (s64)block << blocksize_bits; |
|
read_lock_irqsave(&ni->size_lock, flags); |
|
size = ni->initialized_size; |
|
i_size = i_size_read(VFS_I(ni)); |
|
read_unlock_irqrestore(&ni->size_lock, flags); |
|
/* |
|
* If the offset is outside the initialized size or the block straddles |
|
* the initialized size then pretend it is a hole unless the |
|
* initialized size equals the file size. |
|
*/ |
|
if (unlikely(ofs >= size || (ofs + blocksize > size && size < i_size))) |
|
goto hole; |
|
cluster_size_shift = vol->cluster_size_bits; |
|
down_read(&ni->runlist.lock); |
|
lcn = ntfs_attr_vcn_to_lcn_nolock(ni, ofs >> cluster_size_shift, false); |
|
up_read(&ni->runlist.lock); |
|
if (unlikely(lcn < LCN_HOLE)) { |
|
/* |
|
* Step down to an integer to avoid gcc doing a long long |
|
* comparision in the switch when we know @lcn is between |
|
* LCN_HOLE and LCN_EIO (i.e. -1 to -5). |
|
* |
|
* Otherwise older gcc (at least on some architectures) will |
|
* try to use __cmpdi2() which is of course not available in |
|
* the kernel. |
|
*/ |
|
switch ((int)lcn) { |
|
case LCN_ENOENT: |
|
/* |
|
* If the offset is out of bounds then pretend it is a |
|
* hole. |
|
*/ |
|
goto hole; |
|
case LCN_ENOMEM: |
|
ntfs_error(vol->sb, "Not enough memory to complete " |
|
"mapping for inode 0x%lx. " |
|
"Returning 0.", ni->mft_no); |
|
break; |
|
default: |
|
ntfs_error(vol->sb, "Failed to complete mapping for " |
|
"inode 0x%lx. Run chkdsk. " |
|
"Returning 0.", ni->mft_no); |
|
break; |
|
} |
|
return 0; |
|
} |
|
if (lcn < 0) { |
|
/* It is a hole. */ |
|
hole: |
|
ntfs_debug("Done (returning hole)."); |
|
return 0; |
|
} |
|
/* |
|
* The block is really allocated and fullfils all our criteria. |
|
* Convert the cluster to units of block size and return the result. |
|
*/ |
|
delta = ofs & vol->cluster_size_mask; |
|
if (unlikely(sizeof(block) < sizeof(lcn))) { |
|
block = lcn = ((lcn << cluster_size_shift) + delta) >> |
|
blocksize_bits; |
|
/* If the block number was truncated return 0. */ |
|
if (unlikely(block != lcn)) { |
|
ntfs_error(vol->sb, "Physical block 0x%llx is too " |
|
"large to be returned, returning 0.", |
|
(long long)lcn); |
|
return 0; |
|
} |
|
} else |
|
block = ((lcn << cluster_size_shift) + delta) >> |
|
blocksize_bits; |
|
ntfs_debug("Done (returning block 0x%llx).", (unsigned long long)lcn); |
|
return block; |
|
} |
|
|
|
/** |
|
* ntfs_normal_aops - address space operations for normal inodes and attributes |
|
* |
|
* Note these are not used for compressed or mst protected inodes and |
|
* attributes. |
|
*/ |
|
const struct address_space_operations ntfs_normal_aops = { |
|
.readpage = ntfs_readpage, |
|
#ifdef NTFS_RW |
|
.writepage = ntfs_writepage, |
|
.set_page_dirty = __set_page_dirty_buffers, |
|
#endif /* NTFS_RW */ |
|
.bmap = ntfs_bmap, |
|
.migratepage = buffer_migrate_page, |
|
.is_partially_uptodate = block_is_partially_uptodate, |
|
.error_remove_page = generic_error_remove_page, |
|
}; |
|
|
|
/** |
|
* ntfs_compressed_aops - address space operations for compressed inodes |
|
*/ |
|
const struct address_space_operations ntfs_compressed_aops = { |
|
.readpage = ntfs_readpage, |
|
#ifdef NTFS_RW |
|
.writepage = ntfs_writepage, |
|
.set_page_dirty = __set_page_dirty_buffers, |
|
#endif /* NTFS_RW */ |
|
.migratepage = buffer_migrate_page, |
|
.is_partially_uptodate = block_is_partially_uptodate, |
|
.error_remove_page = generic_error_remove_page, |
|
}; |
|
|
|
/** |
|
* ntfs_mst_aops - general address space operations for mst protecteed inodes |
|
* and attributes |
|
*/ |
|
const struct address_space_operations ntfs_mst_aops = { |
|
.readpage = ntfs_readpage, /* Fill page with data. */ |
|
#ifdef NTFS_RW |
|
.writepage = ntfs_writepage, /* Write dirty page to disk. */ |
|
.set_page_dirty = __set_page_dirty_nobuffers, /* Set the page dirty |
|
without touching the buffers |
|
belonging to the page. */ |
|
#endif /* NTFS_RW */ |
|
.migratepage = buffer_migrate_page, |
|
.is_partially_uptodate = block_is_partially_uptodate, |
|
.error_remove_page = generic_error_remove_page, |
|
}; |
|
|
|
#ifdef NTFS_RW |
|
|
|
/** |
|
* mark_ntfs_record_dirty - mark an ntfs record dirty |
|
* @page: page containing the ntfs record to mark dirty |
|
* @ofs: byte offset within @page at which the ntfs record begins |
|
* |
|
* Set the buffers and the page in which the ntfs record is located dirty. |
|
* |
|
* The latter also marks the vfs inode the ntfs record belongs to dirty |
|
* (I_DIRTY_PAGES only). |
|
* |
|
* If the page does not have buffers, we create them and set them uptodate. |
|
* The page may not be locked which is why we need to handle the buffers under |
|
* the mapping->private_lock. Once the buffers are marked dirty we no longer |
|
* need the lock since try_to_free_buffers() does not free dirty buffers. |
|
*/ |
|
void mark_ntfs_record_dirty(struct page *page, const unsigned int ofs) { |
|
struct address_space *mapping = page->mapping; |
|
ntfs_inode *ni = NTFS_I(mapping->host); |
|
struct buffer_head *bh, *head, *buffers_to_free = NULL; |
|
unsigned int end, bh_size, bh_ofs; |
|
|
|
BUG_ON(!PageUptodate(page)); |
|
end = ofs + ni->itype.index.block_size; |
|
bh_size = VFS_I(ni)->i_sb->s_blocksize; |
|
spin_lock(&mapping->private_lock); |
|
if (unlikely(!page_has_buffers(page))) { |
|
spin_unlock(&mapping->private_lock); |
|
bh = head = alloc_page_buffers(page, bh_size, true); |
|
spin_lock(&mapping->private_lock); |
|
if (likely(!page_has_buffers(page))) { |
|
struct buffer_head *tail; |
|
|
|
do { |
|
set_buffer_uptodate(bh); |
|
tail = bh; |
|
bh = bh->b_this_page; |
|
} while (bh); |
|
tail->b_this_page = head; |
|
attach_page_private(page, head); |
|
} else |
|
buffers_to_free = bh; |
|
} |
|
bh = head = page_buffers(page); |
|
BUG_ON(!bh); |
|
do { |
|
bh_ofs = bh_offset(bh); |
|
if (bh_ofs + bh_size <= ofs) |
|
continue; |
|
if (unlikely(bh_ofs >= end)) |
|
break; |
|
set_buffer_dirty(bh); |
|
} while ((bh = bh->b_this_page) != head); |
|
spin_unlock(&mapping->private_lock); |
|
__set_page_dirty_nobuffers(page); |
|
if (unlikely(buffers_to_free)) { |
|
do { |
|
bh = buffers_to_free->b_this_page; |
|
free_buffer_head(buffers_to_free); |
|
buffers_to_free = bh; |
|
} while (buffers_to_free); |
|
} |
|
} |
|
|
|
#endif /* NTFS_RW */
|
|
|