NTFS: Remove address space operations ->prepare_write and ->commit_write in
preparation for the big rewrite of write(2) support in ntfs. Signed-off-by: Anton Altaparmakov <aia21@cantab.net>
This commit is contained in:
parent
29b8990513
commit
29f5f3c141
827
fs/ntfs/aops.c
827
fs/ntfs/aops.c
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@ -1542,830 +1542,6 @@ err_out:
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return err;
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}
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/**
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* ntfs_prepare_nonresident_write -
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*
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*/
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static int ntfs_prepare_nonresident_write(struct page *page,
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unsigned from, unsigned to)
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{
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VCN vcn;
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LCN lcn;
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s64 initialized_size;
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loff_t i_size;
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sector_t block, ablock, iblock;
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struct inode *vi;
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ntfs_inode *ni;
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ntfs_volume *vol;
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runlist_element *rl;
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struct buffer_head *bh, *head, *wait[2], **wait_bh = wait;
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unsigned long flags;
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unsigned int vcn_ofs, block_start, block_end, blocksize;
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int err;
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BOOL is_retry;
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unsigned char blocksize_bits;
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vi = page->mapping->host;
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ni = NTFS_I(vi);
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vol = ni->vol;
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ntfs_debug("Entering for inode 0x%lx, attribute type 0x%x, page index "
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"0x%lx, from = %u, to = %u.", ni->mft_no, ni->type,
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page->index, from, to);
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BUG_ON(!NInoNonResident(ni));
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blocksize_bits = vi->i_blkbits;
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blocksize = 1 << blocksize_bits;
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/*
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* create_empty_buffers() will create uptodate/dirty buffers if the
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* page is uptodate/dirty.
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*/
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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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return -ENOMEM;
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/* The first block in the page. */
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block = (s64)page->index << (PAGE_CACHE_SHIFT - blocksize_bits);
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read_lock_irqsave(&ni->size_lock, flags);
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/*
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* The first out of bounds block for the allocated size. No need to
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* round up as allocated_size is in multiples of cluster size and the
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* minimum cluster size is 512 bytes, which is equal to the smallest
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* blocksize.
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*/
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ablock = ni->allocated_size >> blocksize_bits;
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i_size = i_size_read(vi);
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initialized_size = ni->initialized_size;
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read_unlock_irqrestore(&ni->size_lock, flags);
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/* The last (fully or partially) initialized block. */
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iblock = initialized_size >> blocksize_bits;
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/* Loop through all the buffers in the page. */
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block_start = 0;
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rl = NULL;
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err = 0;
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do {
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block_end = block_start + blocksize;
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/*
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* If buffer @bh is outside the write, just mark it uptodate
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* if the page is uptodate and continue with the next buffer.
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*/
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if (block_end <= from || block_start >= to) {
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if (PageUptodate(page)) {
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if (!buffer_uptodate(bh))
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set_buffer_uptodate(bh);
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}
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continue;
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}
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/*
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* @bh is at least partially being written to.
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* Make sure it is not marked as new.
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*/
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//if (buffer_new(bh))
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// clear_buffer_new(bh);
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if (block >= ablock) {
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// TODO: block is above allocated_size, need to
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// allocate it. Best done in one go to accommodate not
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// only block but all above blocks up to and including:
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// ((page->index << PAGE_CACHE_SHIFT) + to + blocksize
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// - 1) >> blobksize_bits. Obviously will need to round
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// up to next cluster boundary, too. This should be
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// done with a helper function, so it can be reused.
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ntfs_error(vol->sb, "Writing beyond allocated size "
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"is not supported yet. Sorry.");
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err = -EOPNOTSUPP;
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goto err_out;
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// Need to update ablock.
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// Need to set_buffer_new() on all block bhs that are
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// newly allocated.
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}
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/*
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* Now we have enough allocated size to fulfill the whole
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* request, i.e. block < ablock is true.
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*/
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if (unlikely((block >= iblock) &&
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(initialized_size < i_size))) {
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/*
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* If this page is fully outside initialized size, zero
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* out all pages between the current initialized size
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* and the current page. Just use ntfs_readpage() to do
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* the zeroing transparently.
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*/
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if (block > iblock) {
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// TODO:
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// For each page do:
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// - read_cache_page()
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// Again for each page do:
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// - wait_on_page_locked()
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// - Check (PageUptodate(page) &&
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// !PageError(page))
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// Update initialized size in the attribute and
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// in the inode.
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// Again, for each page do:
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// __set_page_dirty_buffers();
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// page_cache_release()
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// We don't need to wait on the writes.
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// Update iblock.
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}
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/*
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* The current page straddles initialized size. Zero
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* all non-uptodate buffers and set them uptodate (and
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* dirty?). Note, there aren't any non-uptodate buffers
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* if the page is uptodate.
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* FIXME: For an uptodate page, the buffers may need to
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* be written out because they were not initialized on
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* disk before.
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*/
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if (!PageUptodate(page)) {
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// TODO:
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// Zero any non-uptodate buffers up to i_size.
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// Set them uptodate and dirty.
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}
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// TODO:
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// Update initialized size in the attribute and in the
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// inode (up to i_size).
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// Update iblock.
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// FIXME: This is inefficient. Try to batch the two
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// size changes to happen in one go.
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ntfs_error(vol->sb, "Writing beyond initialized size "
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"is not supported yet. Sorry.");
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err = -EOPNOTSUPP;
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goto err_out;
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// Do NOT set_buffer_new() BUT DO clear buffer range
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// outside write request range.
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// set_buffer_uptodate() on complete buffers as well as
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// set_buffer_dirty().
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}
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/* Need to map unmapped buffers. */
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if (!buffer_mapped(bh)) {
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/* Unmapped buffer. Need to map it. */
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bh->b_bdev = vol->sb->s_bdev;
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/* Convert block into corresponding vcn and offset. */
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vcn = (VCN)block << blocksize_bits >>
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vol->cluster_size_bits;
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vcn_ofs = ((VCN)block << blocksize_bits) &
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vol->cluster_size_mask;
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is_retry = FALSE;
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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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if (unlikely(lcn < 0)) {
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/*
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* We extended the attribute allocation above.
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* If we hit an ENOENT here it means that the
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* allocation was insufficient which is a bug.
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*/
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BUG_ON(lcn == LCN_ENOENT);
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/* It is a hole, need to instantiate it. */
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if (lcn == LCN_HOLE) {
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// TODO: Instantiate the hole.
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// clear_buffer_new(bh);
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// unmap_underlying_metadata(bh->b_bdev,
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// bh->b_blocknr);
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// For non-uptodate buffers, need to
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// zero out the region outside the
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// request in this bh or all bhs,
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// depending on what we implemented
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// above.
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// Need to flush_dcache_page().
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// Or could use set_buffer_new()
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// instead?
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ntfs_error(vol->sb, "Writing into "
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"sparse regions is "
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"not supported yet. "
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"Sorry.");
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err = -EOPNOTSUPP;
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if (!rl)
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up_read(&ni->runlist.lock);
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goto err_out;
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} else if (!is_retry &&
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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
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* 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);
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if (likely(!err))
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goto lock_retry_remap;
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rl = NULL;
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} else if (!rl)
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up_read(&ni->runlist.lock);
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/*
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* Failed to map the buffer, even after
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* retrying.
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*/
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if (!err)
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err = -EIO;
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bh->b_blocknr = -1;
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ntfs_error(vol->sb, "Failed to write to inode "
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"0x%lx, attribute type 0x%x, "
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"vcn 0x%llx, offset 0x%x "
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"because its location on disk "
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"could not be determined%s "
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"(error code %i).",
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ni->mft_no, ni->type,
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(unsigned long long)vcn,
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vcn_ofs, is_retry ? " even "
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"after retrying" : "", err);
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goto err_out;
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}
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/* We now have a successful remap, i.e. 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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// FIXME: Something analogous to this is needed for
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// each newly allocated block, i.e. BH_New.
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// FIXME: Might need to take this out of the
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// if (!buffer_mapped(bh)) {}, depending on how we
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// implement things during the allocated_size and
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// initialized_size extension code above.
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if (buffer_new(bh)) {
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clear_buffer_new(bh);
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unmap_underlying_metadata(bh->b_bdev,
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bh->b_blocknr);
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if (PageUptodate(page)) {
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set_buffer_uptodate(bh);
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continue;
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}
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/*
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* Page is _not_ uptodate, zero surrounding
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* region. NOTE: This is how we decide if to
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* zero or not!
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*/
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if (block_end > to || block_start < from) {
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void *kaddr;
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kaddr = kmap_atomic(page, KM_USER0);
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if (block_end > to)
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memset(kaddr + to, 0,
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block_end - to);
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if (block_start < from)
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memset(kaddr + block_start, 0,
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from -
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block_start);
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flush_dcache_page(page);
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kunmap_atomic(kaddr, KM_USER0);
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}
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continue;
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}
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}
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/* @bh is mapped, set it uptodate if the page is uptodate. */
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if (PageUptodate(page)) {
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if (!buffer_uptodate(bh))
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set_buffer_uptodate(bh);
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continue;
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}
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/*
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* The page is not uptodate. The buffer is mapped. If it is not
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* uptodate, and it is only partially being written to, we need
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* to read the buffer in before the write, i.e. right now.
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*/
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if (!buffer_uptodate(bh) &&
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(block_start < from || block_end > to)) {
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ll_rw_block(READ, 1, &bh);
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*wait_bh++ = bh;
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}
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} while (block++, block_start = block_end,
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(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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rl = NULL;
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}
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/* If we issued read requests, let them complete. */
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while (wait_bh > wait) {
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wait_on_buffer(*--wait_bh);
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if (!buffer_uptodate(*wait_bh))
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return -EIO;
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}
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ntfs_debug("Done.");
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return 0;
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err_out:
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/*
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* Zero out any newly allocated blocks to avoid exposing stale data.
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* If BH_New is set, we know that the block was newly allocated in the
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* above loop.
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* FIXME: What about initialized_size increments? Have we done all the
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* required zeroing above? If not this error handling is broken, and
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* in particular the if (block_end <= from) check is completely bogus.
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*/
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bh = head;
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block_start = 0;
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is_retry = FALSE;
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do {
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block_end = block_start + blocksize;
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if (block_end <= from)
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continue;
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if (block_start >= to)
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break;
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if (buffer_new(bh)) {
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void *kaddr;
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clear_buffer_new(bh);
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kaddr = kmap_atomic(page, KM_USER0);
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memset(kaddr + block_start, 0, bh->b_size);
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kunmap_atomic(kaddr, KM_USER0);
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set_buffer_uptodate(bh);
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mark_buffer_dirty(bh);
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is_retry = TRUE;
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}
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} while (block_start = block_end, (bh = bh->b_this_page) != head);
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if (is_retry)
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flush_dcache_page(page);
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if (rl)
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up_read(&ni->runlist.lock);
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return err;
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}
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/**
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* ntfs_prepare_write - prepare a page for receiving data
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*
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* This is called from generic_file_write() with i_sem held on the inode
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* (@page->mapping->host). The @page is locked but not kmap()ped. The source
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* data has not yet been copied into the @page.
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*
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* Need to extend the attribute/fill in holes if necessary, create blocks and
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* make partially overwritten blocks uptodate,
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*
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* i_size is not to be modified yet.
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*
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* Return 0 on success or -errno on error.
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*
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* Should be using block_prepare_write() [support for sparse files] or
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* cont_prepare_write() [no support for sparse files]. Cannot do that due to
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* ntfs specifics but can look at them for implementation guidance.
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*
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* Note: In the range, @from is inclusive and @to is exclusive, i.e. @from is
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* the first byte in the page that will be written to and @to is the first byte
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* after the last byte that will be written to.
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*/
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static int ntfs_prepare_write(struct file *file, struct page *page,
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unsigned from, unsigned to)
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{
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s64 new_size;
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loff_t i_size;
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struct inode *vi = page->mapping->host;
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ntfs_inode *base_ni = NULL, *ni = NTFS_I(vi);
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ntfs_volume *vol = ni->vol;
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ntfs_attr_search_ctx *ctx = NULL;
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MFT_RECORD *m = NULL;
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ATTR_RECORD *a;
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u8 *kaddr;
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u32 attr_len;
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int err;
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ntfs_debug("Entering for inode 0x%lx, attribute type 0x%x, page index "
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"0x%lx, from = %u, to = %u.", vi->i_ino, ni->type,
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page->index, from, to);
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BUG_ON(!PageLocked(page));
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BUG_ON(from > PAGE_CACHE_SIZE);
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BUG_ON(to > PAGE_CACHE_SIZE);
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BUG_ON(from > to);
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BUG_ON(NInoMstProtected(ni));
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/*
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* If a previous ntfs_truncate() failed, repeat it and abort if it
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* fails again.
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*/
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if (unlikely(NInoTruncateFailed(ni))) {
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down_write(&vi->i_alloc_sem);
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err = ntfs_truncate(vi);
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up_write(&vi->i_alloc_sem);
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if (err || NInoTruncateFailed(ni)) {
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if (!err)
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err = -EIO;
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goto err_out;
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}
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}
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/* If the attribute is not resident, deal with it elsewhere. */
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if (NInoNonResident(ni)) {
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/*
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* Only unnamed $DATA attributes can be compressed, encrypted,
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* and/or sparse.
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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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ntfs_debug("Denying write access to encrypted "
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"file.");
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return -EACCES;
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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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// TODO: Implement and replace this check with
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// return ntfs_write_compressed_block(page);
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ntfs_error(vi->i_sb, "Writing to compressed "
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"files is not supported yet. "
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"Sorry.");
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return -EOPNOTSUPP;
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}
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// TODO: Implement and remove this check.
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if (NInoSparse(ni)) {
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ntfs_error(vi->i_sb, "Writing to sparse files "
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"is not supported yet. Sorry.");
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return -EOPNOTSUPP;
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}
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}
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/* Normal data stream. */
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return ntfs_prepare_nonresident_write(page, from, to);
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}
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/*
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* Attribute is resident, implying it is not compressed, encrypted, or
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* sparse.
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*/
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BUG_ON(page_has_buffers(page));
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new_size = ((s64)page->index << PAGE_CACHE_SHIFT) + to;
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/* If we do not need to resize the attribute allocation we are done. */
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if (new_size <= i_size_read(vi))
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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 */
|
||||
|
||||
/**
|
||||
|
@ -2377,9 +1553,6 @@ struct address_space_operations ntfs_aops = {
|
|||
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 */
|
||||
};
|
||||
|
||||
|
|
Loading…
Reference in a new issue