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![Jens Axboe](/assets/img/avatar_default.png)
If bio_iov_iter_get_pages() is called on an iov_iter that is flagged with NO_REF, then we don't need to add a page reference for the pages that we add. Add BIO_NO_PAGE_REF to track this in the bio, so IO completion knows not to drop a reference to these pages. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2189 lines
55 KiB
C
2189 lines
55 KiB
C
/*
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* Copyright (C) 2010 Red Hat, Inc.
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* Copyright (c) 2016-2018 Christoph Hellwig.
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms and conditions of the GNU General Public License,
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* version 2, as published by the Free Software Foundation.
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*
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* This program is distributed in the hope it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
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* more details.
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*/
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#include <linux/module.h>
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#include <linux/compiler.h>
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#include <linux/fs.h>
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#include <linux/iomap.h>
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#include <linux/uaccess.h>
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#include <linux/gfp.h>
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#include <linux/migrate.h>
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#include <linux/mm.h>
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#include <linux/mm_inline.h>
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#include <linux/swap.h>
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#include <linux/pagemap.h>
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#include <linux/pagevec.h>
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#include <linux/file.h>
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#include <linux/uio.h>
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#include <linux/backing-dev.h>
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#include <linux/buffer_head.h>
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#include <linux/task_io_accounting_ops.h>
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#include <linux/dax.h>
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#include <linux/sched/signal.h>
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#include "internal.h"
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/*
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* Execute a iomap write on a segment of the mapping that spans a
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* contiguous range of pages that have identical block mapping state.
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*
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* This avoids the need to map pages individually, do individual allocations
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* for each page and most importantly avoid the need for filesystem specific
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* locking per page. Instead, all the operations are amortised over the entire
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* range of pages. It is assumed that the filesystems will lock whatever
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* resources they require in the iomap_begin call, and release them in the
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* iomap_end call.
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*/
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loff_t
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iomap_apply(struct inode *inode, loff_t pos, loff_t length, unsigned flags,
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const struct iomap_ops *ops, void *data, iomap_actor_t actor)
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{
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struct iomap iomap = { 0 };
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loff_t written = 0, ret;
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/*
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* Need to map a range from start position for length bytes. This can
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* span multiple pages - it is only guaranteed to return a range of a
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* single type of pages (e.g. all into a hole, all mapped or all
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* unwritten). Failure at this point has nothing to undo.
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*
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* If allocation is required for this range, reserve the space now so
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* that the allocation is guaranteed to succeed later on. Once we copy
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* the data into the page cache pages, then we cannot fail otherwise we
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* expose transient stale data. If the reserve fails, we can safely
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* back out at this point as there is nothing to undo.
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*/
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ret = ops->iomap_begin(inode, pos, length, flags, &iomap);
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if (ret)
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return ret;
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if (WARN_ON(iomap.offset > pos))
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return -EIO;
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if (WARN_ON(iomap.length == 0))
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return -EIO;
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/*
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* Cut down the length to the one actually provided by the filesystem,
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* as it might not be able to give us the whole size that we requested.
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*/
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if (iomap.offset + iomap.length < pos + length)
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length = iomap.offset + iomap.length - pos;
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/*
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* Now that we have guaranteed that the space allocation will succeed.
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* we can do the copy-in page by page without having to worry about
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* failures exposing transient data.
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*/
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written = actor(inode, pos, length, data, &iomap);
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/*
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* Now the data has been copied, commit the range we've copied. This
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* should not fail unless the filesystem has had a fatal error.
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*/
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if (ops->iomap_end) {
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ret = ops->iomap_end(inode, pos, length,
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written > 0 ? written : 0,
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flags, &iomap);
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}
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return written ? written : ret;
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}
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static sector_t
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iomap_sector(struct iomap *iomap, loff_t pos)
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{
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return (iomap->addr + pos - iomap->offset) >> SECTOR_SHIFT;
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}
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static struct iomap_page *
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iomap_page_create(struct inode *inode, struct page *page)
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{
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struct iomap_page *iop = to_iomap_page(page);
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if (iop || i_blocksize(inode) == PAGE_SIZE)
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return iop;
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iop = kmalloc(sizeof(*iop), GFP_NOFS | __GFP_NOFAIL);
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atomic_set(&iop->read_count, 0);
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atomic_set(&iop->write_count, 0);
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bitmap_zero(iop->uptodate, PAGE_SIZE / SECTOR_SIZE);
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/*
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* migrate_page_move_mapping() assumes that pages with private data have
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* their count elevated by 1.
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*/
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get_page(page);
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set_page_private(page, (unsigned long)iop);
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SetPagePrivate(page);
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return iop;
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}
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static void
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iomap_page_release(struct page *page)
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{
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struct iomap_page *iop = to_iomap_page(page);
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if (!iop)
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return;
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WARN_ON_ONCE(atomic_read(&iop->read_count));
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WARN_ON_ONCE(atomic_read(&iop->write_count));
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ClearPagePrivate(page);
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set_page_private(page, 0);
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put_page(page);
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kfree(iop);
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}
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/*
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* Calculate the range inside the page that we actually need to read.
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*/
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static void
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iomap_adjust_read_range(struct inode *inode, struct iomap_page *iop,
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loff_t *pos, loff_t length, unsigned *offp, unsigned *lenp)
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{
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loff_t orig_pos = *pos;
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loff_t isize = i_size_read(inode);
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unsigned block_bits = inode->i_blkbits;
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unsigned block_size = (1 << block_bits);
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unsigned poff = offset_in_page(*pos);
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unsigned plen = min_t(loff_t, PAGE_SIZE - poff, length);
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unsigned first = poff >> block_bits;
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unsigned last = (poff + plen - 1) >> block_bits;
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/*
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* If the block size is smaller than the page size we need to check the
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* per-block uptodate status and adjust the offset and length if needed
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* to avoid reading in already uptodate ranges.
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*/
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if (iop) {
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unsigned int i;
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/* move forward for each leading block marked uptodate */
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for (i = first; i <= last; i++) {
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if (!test_bit(i, iop->uptodate))
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break;
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*pos += block_size;
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poff += block_size;
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plen -= block_size;
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first++;
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}
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/* truncate len if we find any trailing uptodate block(s) */
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for ( ; i <= last; i++) {
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if (test_bit(i, iop->uptodate)) {
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plen -= (last - i + 1) * block_size;
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last = i - 1;
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break;
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}
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}
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}
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/*
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* If the extent spans the block that contains the i_size we need to
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* handle both halves separately so that we properly zero data in the
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* page cache for blocks that are entirely outside of i_size.
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*/
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if (orig_pos <= isize && orig_pos + length > isize) {
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unsigned end = offset_in_page(isize - 1) >> block_bits;
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if (first <= end && last > end)
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plen -= (last - end) * block_size;
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}
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*offp = poff;
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*lenp = plen;
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}
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static void
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iomap_set_range_uptodate(struct page *page, unsigned off, unsigned len)
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{
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struct iomap_page *iop = to_iomap_page(page);
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struct inode *inode = page->mapping->host;
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unsigned first = off >> inode->i_blkbits;
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unsigned last = (off + len - 1) >> inode->i_blkbits;
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unsigned int i;
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bool uptodate = true;
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if (iop) {
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for (i = 0; i < PAGE_SIZE / i_blocksize(inode); i++) {
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if (i >= first && i <= last)
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set_bit(i, iop->uptodate);
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else if (!test_bit(i, iop->uptodate))
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uptodate = false;
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}
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}
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if (uptodate && !PageError(page))
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SetPageUptodate(page);
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}
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static void
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iomap_read_finish(struct iomap_page *iop, struct page *page)
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{
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if (!iop || atomic_dec_and_test(&iop->read_count))
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unlock_page(page);
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}
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static void
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iomap_read_page_end_io(struct bio_vec *bvec, int error)
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{
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struct page *page = bvec->bv_page;
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struct iomap_page *iop = to_iomap_page(page);
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if (unlikely(error)) {
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ClearPageUptodate(page);
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SetPageError(page);
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} else {
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iomap_set_range_uptodate(page, bvec->bv_offset, bvec->bv_len);
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}
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iomap_read_finish(iop, page);
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}
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static void
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iomap_read_inline_data(struct inode *inode, struct page *page,
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struct iomap *iomap)
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{
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size_t size = i_size_read(inode);
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void *addr;
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if (PageUptodate(page))
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return;
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BUG_ON(page->index);
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BUG_ON(size > PAGE_SIZE - offset_in_page(iomap->inline_data));
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addr = kmap_atomic(page);
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memcpy(addr, iomap->inline_data, size);
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memset(addr + size, 0, PAGE_SIZE - size);
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kunmap_atomic(addr);
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SetPageUptodate(page);
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}
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static void
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iomap_read_end_io(struct bio *bio)
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{
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int error = blk_status_to_errno(bio->bi_status);
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struct bio_vec *bvec;
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int i;
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struct bvec_iter_all iter_all;
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bio_for_each_segment_all(bvec, bio, i, iter_all)
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iomap_read_page_end_io(bvec, error);
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bio_put(bio);
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}
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struct iomap_readpage_ctx {
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struct page *cur_page;
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bool cur_page_in_bio;
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bool is_readahead;
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struct bio *bio;
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struct list_head *pages;
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};
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static loff_t
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iomap_readpage_actor(struct inode *inode, loff_t pos, loff_t length, void *data,
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struct iomap *iomap)
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{
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struct iomap_readpage_ctx *ctx = data;
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struct page *page = ctx->cur_page;
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struct iomap_page *iop = iomap_page_create(inode, page);
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bool is_contig = false;
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loff_t orig_pos = pos;
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unsigned poff, plen;
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sector_t sector;
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if (iomap->type == IOMAP_INLINE) {
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WARN_ON_ONCE(pos);
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iomap_read_inline_data(inode, page, iomap);
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return PAGE_SIZE;
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}
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/* zero post-eof blocks as the page may be mapped */
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iomap_adjust_read_range(inode, iop, &pos, length, &poff, &plen);
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if (plen == 0)
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goto done;
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if (iomap->type != IOMAP_MAPPED || pos >= i_size_read(inode)) {
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zero_user(page, poff, plen);
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iomap_set_range_uptodate(page, poff, plen);
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goto done;
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}
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ctx->cur_page_in_bio = true;
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/*
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* Try to merge into a previous segment if we can.
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*/
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sector = iomap_sector(iomap, pos);
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if (ctx->bio && bio_end_sector(ctx->bio) == sector) {
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if (__bio_try_merge_page(ctx->bio, page, plen, poff, true))
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goto done;
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is_contig = true;
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}
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/*
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* If we start a new segment we need to increase the read count, and we
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* need to do so before submitting any previous full bio to make sure
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* that we don't prematurely unlock the page.
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*/
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if (iop)
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atomic_inc(&iop->read_count);
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if (!ctx->bio || !is_contig || bio_full(ctx->bio)) {
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gfp_t gfp = mapping_gfp_constraint(page->mapping, GFP_KERNEL);
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int nr_vecs = (length + PAGE_SIZE - 1) >> PAGE_SHIFT;
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if (ctx->bio)
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submit_bio(ctx->bio);
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if (ctx->is_readahead) /* same as readahead_gfp_mask */
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gfp |= __GFP_NORETRY | __GFP_NOWARN;
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ctx->bio = bio_alloc(gfp, min(BIO_MAX_PAGES, nr_vecs));
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ctx->bio->bi_opf = REQ_OP_READ;
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if (ctx->is_readahead)
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ctx->bio->bi_opf |= REQ_RAHEAD;
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ctx->bio->bi_iter.bi_sector = sector;
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bio_set_dev(ctx->bio, iomap->bdev);
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ctx->bio->bi_end_io = iomap_read_end_io;
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}
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bio_add_page(ctx->bio, page, plen, poff);
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done:
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/*
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* Move the caller beyond our range so that it keeps making progress.
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* For that we have to include any leading non-uptodate ranges, but
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* we can skip trailing ones as they will be handled in the next
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* iteration.
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*/
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return pos - orig_pos + plen;
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}
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int
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iomap_readpage(struct page *page, const struct iomap_ops *ops)
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{
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struct iomap_readpage_ctx ctx = { .cur_page = page };
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struct inode *inode = page->mapping->host;
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unsigned poff;
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loff_t ret;
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for (poff = 0; poff < PAGE_SIZE; poff += ret) {
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ret = iomap_apply(inode, page_offset(page) + poff,
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PAGE_SIZE - poff, 0, ops, &ctx,
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iomap_readpage_actor);
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if (ret <= 0) {
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WARN_ON_ONCE(ret == 0);
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SetPageError(page);
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break;
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}
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}
|
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|
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if (ctx.bio) {
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submit_bio(ctx.bio);
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WARN_ON_ONCE(!ctx.cur_page_in_bio);
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} else {
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WARN_ON_ONCE(ctx.cur_page_in_bio);
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unlock_page(page);
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}
|
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|
|
/*
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* Just like mpage_readpages and block_read_full_page we always
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* return 0 and just mark the page as PageError on errors. This
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* should be cleaned up all through the stack eventually.
|
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*/
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return 0;
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}
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EXPORT_SYMBOL_GPL(iomap_readpage);
|
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|
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static struct page *
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iomap_next_page(struct inode *inode, struct list_head *pages, loff_t pos,
|
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loff_t length, loff_t *done)
|
|
{
|
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while (!list_empty(pages)) {
|
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struct page *page = lru_to_page(pages);
|
|
|
|
if (page_offset(page) >= (u64)pos + length)
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break;
|
|
|
|
list_del(&page->lru);
|
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if (!add_to_page_cache_lru(page, inode->i_mapping, page->index,
|
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GFP_NOFS))
|
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return page;
|
|
|
|
/*
|
|
* If we already have a page in the page cache at index we are
|
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* done. Upper layers don't care if it is uptodate after the
|
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* readpages call itself as every page gets checked again once
|
|
* actually needed.
|
|
*/
|
|
*done += PAGE_SIZE;
|
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put_page(page);
|
|
}
|
|
|
|
return NULL;
|
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}
|
|
|
|
static loff_t
|
|
iomap_readpages_actor(struct inode *inode, loff_t pos, loff_t length,
|
|
void *data, struct iomap *iomap)
|
|
{
|
|
struct iomap_readpage_ctx *ctx = data;
|
|
loff_t done, ret;
|
|
|
|
for (done = 0; done < length; done += ret) {
|
|
if (ctx->cur_page && offset_in_page(pos + done) == 0) {
|
|
if (!ctx->cur_page_in_bio)
|
|
unlock_page(ctx->cur_page);
|
|
put_page(ctx->cur_page);
|
|
ctx->cur_page = NULL;
|
|
}
|
|
if (!ctx->cur_page) {
|
|
ctx->cur_page = iomap_next_page(inode, ctx->pages,
|
|
pos, length, &done);
|
|
if (!ctx->cur_page)
|
|
break;
|
|
ctx->cur_page_in_bio = false;
|
|
}
|
|
ret = iomap_readpage_actor(inode, pos + done, length - done,
|
|
ctx, iomap);
|
|
}
|
|
|
|
return done;
|
|
}
|
|
|
|
int
|
|
iomap_readpages(struct address_space *mapping, struct list_head *pages,
|
|
unsigned nr_pages, const struct iomap_ops *ops)
|
|
{
|
|
struct iomap_readpage_ctx ctx = {
|
|
.pages = pages,
|
|
.is_readahead = true,
|
|
};
|
|
loff_t pos = page_offset(list_entry(pages->prev, struct page, lru));
|
|
loff_t last = page_offset(list_entry(pages->next, struct page, lru));
|
|
loff_t length = last - pos + PAGE_SIZE, ret = 0;
|
|
|
|
while (length > 0) {
|
|
ret = iomap_apply(mapping->host, pos, length, 0, ops,
|
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&ctx, iomap_readpages_actor);
|
|
if (ret <= 0) {
|
|
WARN_ON_ONCE(ret == 0);
|
|
goto done;
|
|
}
|
|
pos += ret;
|
|
length -= ret;
|
|
}
|
|
ret = 0;
|
|
done:
|
|
if (ctx.bio)
|
|
submit_bio(ctx.bio);
|
|
if (ctx.cur_page) {
|
|
if (!ctx.cur_page_in_bio)
|
|
unlock_page(ctx.cur_page);
|
|
put_page(ctx.cur_page);
|
|
}
|
|
|
|
/*
|
|
* Check that we didn't lose a page due to the arcance calling
|
|
* conventions..
|
|
*/
|
|
WARN_ON_ONCE(!ret && !list_empty(ctx.pages));
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(iomap_readpages);
|
|
|
|
/*
|
|
* iomap_is_partially_uptodate checks whether blocks within a page are
|
|
* uptodate or not.
|
|
*
|
|
* Returns true if all blocks which correspond to a file portion
|
|
* we want to read within the page are uptodate.
|
|
*/
|
|
int
|
|
iomap_is_partially_uptodate(struct page *page, unsigned long from,
|
|
unsigned long count)
|
|
{
|
|
struct iomap_page *iop = to_iomap_page(page);
|
|
struct inode *inode = page->mapping->host;
|
|
unsigned len, first, last;
|
|
unsigned i;
|
|
|
|
/* Limit range to one page */
|
|
len = min_t(unsigned, PAGE_SIZE - from, count);
|
|
|
|
/* First and last blocks in range within page */
|
|
first = from >> inode->i_blkbits;
|
|
last = (from + len - 1) >> inode->i_blkbits;
|
|
|
|
if (iop) {
|
|
for (i = first; i <= last; i++)
|
|
if (!test_bit(i, iop->uptodate))
|
|
return 0;
|
|
return 1;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(iomap_is_partially_uptodate);
|
|
|
|
int
|
|
iomap_releasepage(struct page *page, gfp_t gfp_mask)
|
|
{
|
|
/*
|
|
* mm accommodates an old ext3 case where clean pages might not have had
|
|
* the dirty bit cleared. Thus, it can send actual dirty pages to
|
|
* ->releasepage() via shrink_active_list(), skip those here.
|
|
*/
|
|
if (PageDirty(page) || PageWriteback(page))
|
|
return 0;
|
|
iomap_page_release(page);
|
|
return 1;
|
|
}
|
|
EXPORT_SYMBOL_GPL(iomap_releasepage);
|
|
|
|
void
|
|
iomap_invalidatepage(struct page *page, unsigned int offset, unsigned int len)
|
|
{
|
|
/*
|
|
* If we are invalidating the entire page, clear the dirty state from it
|
|
* and release it to avoid unnecessary buildup of the LRU.
|
|
*/
|
|
if (offset == 0 && len == PAGE_SIZE) {
|
|
WARN_ON_ONCE(PageWriteback(page));
|
|
cancel_dirty_page(page);
|
|
iomap_page_release(page);
|
|
}
|
|
}
|
|
EXPORT_SYMBOL_GPL(iomap_invalidatepage);
|
|
|
|
#ifdef CONFIG_MIGRATION
|
|
int
|
|
iomap_migrate_page(struct address_space *mapping, struct page *newpage,
|
|
struct page *page, enum migrate_mode mode)
|
|
{
|
|
int ret;
|
|
|
|
ret = migrate_page_move_mapping(mapping, newpage, page, mode, 0);
|
|
if (ret != MIGRATEPAGE_SUCCESS)
|
|
return ret;
|
|
|
|
if (page_has_private(page)) {
|
|
ClearPagePrivate(page);
|
|
get_page(newpage);
|
|
set_page_private(newpage, page_private(page));
|
|
set_page_private(page, 0);
|
|
put_page(page);
|
|
SetPagePrivate(newpage);
|
|
}
|
|
|
|
if (mode != MIGRATE_SYNC_NO_COPY)
|
|
migrate_page_copy(newpage, page);
|
|
else
|
|
migrate_page_states(newpage, page);
|
|
return MIGRATEPAGE_SUCCESS;
|
|
}
|
|
EXPORT_SYMBOL_GPL(iomap_migrate_page);
|
|
#endif /* CONFIG_MIGRATION */
|
|
|
|
static void
|
|
iomap_write_failed(struct inode *inode, loff_t pos, unsigned len)
|
|
{
|
|
loff_t i_size = i_size_read(inode);
|
|
|
|
/*
|
|
* Only truncate newly allocated pages beyoned EOF, even if the
|
|
* write started inside the existing inode size.
|
|
*/
|
|
if (pos + len > i_size)
|
|
truncate_pagecache_range(inode, max(pos, i_size), pos + len);
|
|
}
|
|
|
|
static int
|
|
iomap_read_page_sync(struct inode *inode, loff_t block_start, struct page *page,
|
|
unsigned poff, unsigned plen, unsigned from, unsigned to,
|
|
struct iomap *iomap)
|
|
{
|
|
struct bio_vec bvec;
|
|
struct bio bio;
|
|
|
|
if (iomap->type != IOMAP_MAPPED || block_start >= i_size_read(inode)) {
|
|
zero_user_segments(page, poff, from, to, poff + plen);
|
|
iomap_set_range_uptodate(page, poff, plen);
|
|
return 0;
|
|
}
|
|
|
|
bio_init(&bio, &bvec, 1);
|
|
bio.bi_opf = REQ_OP_READ;
|
|
bio.bi_iter.bi_sector = iomap_sector(iomap, block_start);
|
|
bio_set_dev(&bio, iomap->bdev);
|
|
__bio_add_page(&bio, page, plen, poff);
|
|
return submit_bio_wait(&bio);
|
|
}
|
|
|
|
static int
|
|
__iomap_write_begin(struct inode *inode, loff_t pos, unsigned len,
|
|
struct page *page, struct iomap *iomap)
|
|
{
|
|
struct iomap_page *iop = iomap_page_create(inode, page);
|
|
loff_t block_size = i_blocksize(inode);
|
|
loff_t block_start = pos & ~(block_size - 1);
|
|
loff_t block_end = (pos + len + block_size - 1) & ~(block_size - 1);
|
|
unsigned from = offset_in_page(pos), to = from + len, poff, plen;
|
|
int status = 0;
|
|
|
|
if (PageUptodate(page))
|
|
return 0;
|
|
|
|
do {
|
|
iomap_adjust_read_range(inode, iop, &block_start,
|
|
block_end - block_start, &poff, &plen);
|
|
if (plen == 0)
|
|
break;
|
|
|
|
if ((from > poff && from < poff + plen) ||
|
|
(to > poff && to < poff + plen)) {
|
|
status = iomap_read_page_sync(inode, block_start, page,
|
|
poff, plen, from, to, iomap);
|
|
if (status)
|
|
break;
|
|
}
|
|
|
|
} while ((block_start += plen) < block_end);
|
|
|
|
return status;
|
|
}
|
|
|
|
static int
|
|
iomap_write_begin(struct inode *inode, loff_t pos, unsigned len, unsigned flags,
|
|
struct page **pagep, struct iomap *iomap)
|
|
{
|
|
pgoff_t index = pos >> PAGE_SHIFT;
|
|
struct page *page;
|
|
int status = 0;
|
|
|
|
BUG_ON(pos + len > iomap->offset + iomap->length);
|
|
|
|
if (fatal_signal_pending(current))
|
|
return -EINTR;
|
|
|
|
page = grab_cache_page_write_begin(inode->i_mapping, index, flags);
|
|
if (!page)
|
|
return -ENOMEM;
|
|
|
|
if (iomap->type == IOMAP_INLINE)
|
|
iomap_read_inline_data(inode, page, iomap);
|
|
else if (iomap->flags & IOMAP_F_BUFFER_HEAD)
|
|
status = __block_write_begin_int(page, pos, len, NULL, iomap);
|
|
else
|
|
status = __iomap_write_begin(inode, pos, len, page, iomap);
|
|
if (unlikely(status)) {
|
|
unlock_page(page);
|
|
put_page(page);
|
|
page = NULL;
|
|
|
|
iomap_write_failed(inode, pos, len);
|
|
}
|
|
|
|
*pagep = page;
|
|
return status;
|
|
}
|
|
|
|
int
|
|
iomap_set_page_dirty(struct page *page)
|
|
{
|
|
struct address_space *mapping = page_mapping(page);
|
|
int newly_dirty;
|
|
|
|
if (unlikely(!mapping))
|
|
return !TestSetPageDirty(page);
|
|
|
|
/*
|
|
* Lock out page->mem_cgroup migration to keep PageDirty
|
|
* synchronized with per-memcg dirty page counters.
|
|
*/
|
|
lock_page_memcg(page);
|
|
newly_dirty = !TestSetPageDirty(page);
|
|
if (newly_dirty)
|
|
__set_page_dirty(page, mapping, 0);
|
|
unlock_page_memcg(page);
|
|
|
|
if (newly_dirty)
|
|
__mark_inode_dirty(mapping->host, I_DIRTY_PAGES);
|
|
return newly_dirty;
|
|
}
|
|
EXPORT_SYMBOL_GPL(iomap_set_page_dirty);
|
|
|
|
static int
|
|
__iomap_write_end(struct inode *inode, loff_t pos, unsigned len,
|
|
unsigned copied, struct page *page, struct iomap *iomap)
|
|
{
|
|
flush_dcache_page(page);
|
|
|
|
/*
|
|
* The blocks that were entirely written will now be uptodate, so we
|
|
* don't have to worry about a readpage reading them and overwriting a
|
|
* partial write. However if we have encountered a short write and only
|
|
* partially written into a block, it will not be marked uptodate, so a
|
|
* readpage might come in and destroy our partial write.
|
|
*
|
|
* Do the simplest thing, and just treat any short write to a non
|
|
* uptodate page as a zero-length write, and force the caller to redo
|
|
* the whole thing.
|
|
*/
|
|
if (unlikely(copied < len && !PageUptodate(page))) {
|
|
copied = 0;
|
|
} else {
|
|
iomap_set_range_uptodate(page, offset_in_page(pos), len);
|
|
iomap_set_page_dirty(page);
|
|
}
|
|
return __generic_write_end(inode, pos, copied, page);
|
|
}
|
|
|
|
static int
|
|
iomap_write_end_inline(struct inode *inode, struct page *page,
|
|
struct iomap *iomap, loff_t pos, unsigned copied)
|
|
{
|
|
void *addr;
|
|
|
|
WARN_ON_ONCE(!PageUptodate(page));
|
|
BUG_ON(pos + copied > PAGE_SIZE - offset_in_page(iomap->inline_data));
|
|
|
|
addr = kmap_atomic(page);
|
|
memcpy(iomap->inline_data + pos, addr + pos, copied);
|
|
kunmap_atomic(addr);
|
|
|
|
mark_inode_dirty(inode);
|
|
__generic_write_end(inode, pos, copied, page);
|
|
return copied;
|
|
}
|
|
|
|
static int
|
|
iomap_write_end(struct inode *inode, loff_t pos, unsigned len,
|
|
unsigned copied, struct page *page, struct iomap *iomap)
|
|
{
|
|
int ret;
|
|
|
|
if (iomap->type == IOMAP_INLINE) {
|
|
ret = iomap_write_end_inline(inode, page, iomap, pos, copied);
|
|
} else if (iomap->flags & IOMAP_F_BUFFER_HEAD) {
|
|
ret = generic_write_end(NULL, inode->i_mapping, pos, len,
|
|
copied, page, NULL);
|
|
} else {
|
|
ret = __iomap_write_end(inode, pos, len, copied, page, iomap);
|
|
}
|
|
|
|
if (iomap->page_done)
|
|
iomap->page_done(inode, pos, copied, page, iomap);
|
|
|
|
if (ret < len)
|
|
iomap_write_failed(inode, pos, len);
|
|
return ret;
|
|
}
|
|
|
|
static loff_t
|
|
iomap_write_actor(struct inode *inode, loff_t pos, loff_t length, void *data,
|
|
struct iomap *iomap)
|
|
{
|
|
struct iov_iter *i = data;
|
|
long status = 0;
|
|
ssize_t written = 0;
|
|
unsigned int flags = AOP_FLAG_NOFS;
|
|
|
|
do {
|
|
struct page *page;
|
|
unsigned long offset; /* Offset into pagecache page */
|
|
unsigned long bytes; /* Bytes to write to page */
|
|
size_t copied; /* Bytes copied from user */
|
|
|
|
offset = offset_in_page(pos);
|
|
bytes = min_t(unsigned long, PAGE_SIZE - offset,
|
|
iov_iter_count(i));
|
|
again:
|
|
if (bytes > length)
|
|
bytes = length;
|
|
|
|
/*
|
|
* Bring in the user page that we will copy from _first_.
|
|
* Otherwise there's a nasty deadlock on copying from the
|
|
* same page as we're writing to, without it being marked
|
|
* up-to-date.
|
|
*
|
|
* Not only is this an optimisation, but it is also required
|
|
* to check that the address is actually valid, when atomic
|
|
* usercopies are used, below.
|
|
*/
|
|
if (unlikely(iov_iter_fault_in_readable(i, bytes))) {
|
|
status = -EFAULT;
|
|
break;
|
|
}
|
|
|
|
status = iomap_write_begin(inode, pos, bytes, flags, &page,
|
|
iomap);
|
|
if (unlikely(status))
|
|
break;
|
|
|
|
if (mapping_writably_mapped(inode->i_mapping))
|
|
flush_dcache_page(page);
|
|
|
|
copied = iov_iter_copy_from_user_atomic(page, i, offset, bytes);
|
|
|
|
flush_dcache_page(page);
|
|
|
|
status = iomap_write_end(inode, pos, bytes, copied, page,
|
|
iomap);
|
|
if (unlikely(status < 0))
|
|
break;
|
|
copied = status;
|
|
|
|
cond_resched();
|
|
|
|
iov_iter_advance(i, copied);
|
|
if (unlikely(copied == 0)) {
|
|
/*
|
|
* If we were unable to copy any data at all, we must
|
|
* fall back to a single segment length write.
|
|
*
|
|
* If we didn't fallback here, we could livelock
|
|
* because not all segments in the iov can be copied at
|
|
* once without a pagefault.
|
|
*/
|
|
bytes = min_t(unsigned long, PAGE_SIZE - offset,
|
|
iov_iter_single_seg_count(i));
|
|
goto again;
|
|
}
|
|
pos += copied;
|
|
written += copied;
|
|
length -= copied;
|
|
|
|
balance_dirty_pages_ratelimited(inode->i_mapping);
|
|
} while (iov_iter_count(i) && length);
|
|
|
|
return written ? written : status;
|
|
}
|
|
|
|
ssize_t
|
|
iomap_file_buffered_write(struct kiocb *iocb, struct iov_iter *iter,
|
|
const struct iomap_ops *ops)
|
|
{
|
|
struct inode *inode = iocb->ki_filp->f_mapping->host;
|
|
loff_t pos = iocb->ki_pos, ret = 0, written = 0;
|
|
|
|
while (iov_iter_count(iter)) {
|
|
ret = iomap_apply(inode, pos, iov_iter_count(iter),
|
|
IOMAP_WRITE, ops, iter, iomap_write_actor);
|
|
if (ret <= 0)
|
|
break;
|
|
pos += ret;
|
|
written += ret;
|
|
}
|
|
|
|
return written ? written : ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(iomap_file_buffered_write);
|
|
|
|
static struct page *
|
|
__iomap_read_page(struct inode *inode, loff_t offset)
|
|
{
|
|
struct address_space *mapping = inode->i_mapping;
|
|
struct page *page;
|
|
|
|
page = read_mapping_page(mapping, offset >> PAGE_SHIFT, NULL);
|
|
if (IS_ERR(page))
|
|
return page;
|
|
if (!PageUptodate(page)) {
|
|
put_page(page);
|
|
return ERR_PTR(-EIO);
|
|
}
|
|
return page;
|
|
}
|
|
|
|
static loff_t
|
|
iomap_dirty_actor(struct inode *inode, loff_t pos, loff_t length, void *data,
|
|
struct iomap *iomap)
|
|
{
|
|
long status = 0;
|
|
ssize_t written = 0;
|
|
|
|
do {
|
|
struct page *page, *rpage;
|
|
unsigned long offset; /* Offset into pagecache page */
|
|
unsigned long bytes; /* Bytes to write to page */
|
|
|
|
offset = offset_in_page(pos);
|
|
bytes = min_t(loff_t, PAGE_SIZE - offset, length);
|
|
|
|
rpage = __iomap_read_page(inode, pos);
|
|
if (IS_ERR(rpage))
|
|
return PTR_ERR(rpage);
|
|
|
|
status = iomap_write_begin(inode, pos, bytes,
|
|
AOP_FLAG_NOFS, &page, iomap);
|
|
put_page(rpage);
|
|
if (unlikely(status))
|
|
return status;
|
|
|
|
WARN_ON_ONCE(!PageUptodate(page));
|
|
|
|
status = iomap_write_end(inode, pos, bytes, bytes, page, iomap);
|
|
if (unlikely(status <= 0)) {
|
|
if (WARN_ON_ONCE(status == 0))
|
|
return -EIO;
|
|
return status;
|
|
}
|
|
|
|
cond_resched();
|
|
|
|
pos += status;
|
|
written += status;
|
|
length -= status;
|
|
|
|
balance_dirty_pages_ratelimited(inode->i_mapping);
|
|
} while (length);
|
|
|
|
return written;
|
|
}
|
|
|
|
int
|
|
iomap_file_dirty(struct inode *inode, loff_t pos, loff_t len,
|
|
const struct iomap_ops *ops)
|
|
{
|
|
loff_t ret;
|
|
|
|
while (len) {
|
|
ret = iomap_apply(inode, pos, len, IOMAP_WRITE, ops, NULL,
|
|
iomap_dirty_actor);
|
|
if (ret <= 0)
|
|
return ret;
|
|
pos += ret;
|
|
len -= ret;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(iomap_file_dirty);
|
|
|
|
static int iomap_zero(struct inode *inode, loff_t pos, unsigned offset,
|
|
unsigned bytes, struct iomap *iomap)
|
|
{
|
|
struct page *page;
|
|
int status;
|
|
|
|
status = iomap_write_begin(inode, pos, bytes, AOP_FLAG_NOFS, &page,
|
|
iomap);
|
|
if (status)
|
|
return status;
|
|
|
|
zero_user(page, offset, bytes);
|
|
mark_page_accessed(page);
|
|
|
|
return iomap_write_end(inode, pos, bytes, bytes, page, iomap);
|
|
}
|
|
|
|
static int iomap_dax_zero(loff_t pos, unsigned offset, unsigned bytes,
|
|
struct iomap *iomap)
|
|
{
|
|
return __dax_zero_page_range(iomap->bdev, iomap->dax_dev,
|
|
iomap_sector(iomap, pos & PAGE_MASK), offset, bytes);
|
|
}
|
|
|
|
static loff_t
|
|
iomap_zero_range_actor(struct inode *inode, loff_t pos, loff_t count,
|
|
void *data, struct iomap *iomap)
|
|
{
|
|
bool *did_zero = data;
|
|
loff_t written = 0;
|
|
int status;
|
|
|
|
/* already zeroed? we're done. */
|
|
if (iomap->type == IOMAP_HOLE || iomap->type == IOMAP_UNWRITTEN)
|
|
return count;
|
|
|
|
do {
|
|
unsigned offset, bytes;
|
|
|
|
offset = offset_in_page(pos);
|
|
bytes = min_t(loff_t, PAGE_SIZE - offset, count);
|
|
|
|
if (IS_DAX(inode))
|
|
status = iomap_dax_zero(pos, offset, bytes, iomap);
|
|
else
|
|
status = iomap_zero(inode, pos, offset, bytes, iomap);
|
|
if (status < 0)
|
|
return status;
|
|
|
|
pos += bytes;
|
|
count -= bytes;
|
|
written += bytes;
|
|
if (did_zero)
|
|
*did_zero = true;
|
|
} while (count > 0);
|
|
|
|
return written;
|
|
}
|
|
|
|
int
|
|
iomap_zero_range(struct inode *inode, loff_t pos, loff_t len, bool *did_zero,
|
|
const struct iomap_ops *ops)
|
|
{
|
|
loff_t ret;
|
|
|
|
while (len > 0) {
|
|
ret = iomap_apply(inode, pos, len, IOMAP_ZERO,
|
|
ops, did_zero, iomap_zero_range_actor);
|
|
if (ret <= 0)
|
|
return ret;
|
|
|
|
pos += ret;
|
|
len -= ret;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(iomap_zero_range);
|
|
|
|
int
|
|
iomap_truncate_page(struct inode *inode, loff_t pos, bool *did_zero,
|
|
const struct iomap_ops *ops)
|
|
{
|
|
unsigned int blocksize = i_blocksize(inode);
|
|
unsigned int off = pos & (blocksize - 1);
|
|
|
|
/* Block boundary? Nothing to do */
|
|
if (!off)
|
|
return 0;
|
|
return iomap_zero_range(inode, pos, blocksize - off, did_zero, ops);
|
|
}
|
|
EXPORT_SYMBOL_GPL(iomap_truncate_page);
|
|
|
|
static loff_t
|
|
iomap_page_mkwrite_actor(struct inode *inode, loff_t pos, loff_t length,
|
|
void *data, struct iomap *iomap)
|
|
{
|
|
struct page *page = data;
|
|
int ret;
|
|
|
|
if (iomap->flags & IOMAP_F_BUFFER_HEAD) {
|
|
ret = __block_write_begin_int(page, pos, length, NULL, iomap);
|
|
if (ret)
|
|
return ret;
|
|
block_commit_write(page, 0, length);
|
|
} else {
|
|
WARN_ON_ONCE(!PageUptodate(page));
|
|
iomap_page_create(inode, page);
|
|
set_page_dirty(page);
|
|
}
|
|
|
|
return length;
|
|
}
|
|
|
|
vm_fault_t iomap_page_mkwrite(struct vm_fault *vmf, const struct iomap_ops *ops)
|
|
{
|
|
struct page *page = vmf->page;
|
|
struct inode *inode = file_inode(vmf->vma->vm_file);
|
|
unsigned long length;
|
|
loff_t offset, size;
|
|
ssize_t ret;
|
|
|
|
lock_page(page);
|
|
size = i_size_read(inode);
|
|
if ((page->mapping != inode->i_mapping) ||
|
|
(page_offset(page) > size)) {
|
|
/* We overload EFAULT to mean page got truncated */
|
|
ret = -EFAULT;
|
|
goto out_unlock;
|
|
}
|
|
|
|
/* page is wholly or partially inside EOF */
|
|
if (((page->index + 1) << PAGE_SHIFT) > size)
|
|
length = offset_in_page(size);
|
|
else
|
|
length = PAGE_SIZE;
|
|
|
|
offset = page_offset(page);
|
|
while (length > 0) {
|
|
ret = iomap_apply(inode, offset, length,
|
|
IOMAP_WRITE | IOMAP_FAULT, ops, page,
|
|
iomap_page_mkwrite_actor);
|
|
if (unlikely(ret <= 0))
|
|
goto out_unlock;
|
|
offset += ret;
|
|
length -= ret;
|
|
}
|
|
|
|
wait_for_stable_page(page);
|
|
return VM_FAULT_LOCKED;
|
|
out_unlock:
|
|
unlock_page(page);
|
|
return block_page_mkwrite_return(ret);
|
|
}
|
|
EXPORT_SYMBOL_GPL(iomap_page_mkwrite);
|
|
|
|
struct fiemap_ctx {
|
|
struct fiemap_extent_info *fi;
|
|
struct iomap prev;
|
|
};
|
|
|
|
static int iomap_to_fiemap(struct fiemap_extent_info *fi,
|
|
struct iomap *iomap, u32 flags)
|
|
{
|
|
switch (iomap->type) {
|
|
case IOMAP_HOLE:
|
|
/* skip holes */
|
|
return 0;
|
|
case IOMAP_DELALLOC:
|
|
flags |= FIEMAP_EXTENT_DELALLOC | FIEMAP_EXTENT_UNKNOWN;
|
|
break;
|
|
case IOMAP_MAPPED:
|
|
break;
|
|
case IOMAP_UNWRITTEN:
|
|
flags |= FIEMAP_EXTENT_UNWRITTEN;
|
|
break;
|
|
case IOMAP_INLINE:
|
|
flags |= FIEMAP_EXTENT_DATA_INLINE;
|
|
break;
|
|
}
|
|
|
|
if (iomap->flags & IOMAP_F_MERGED)
|
|
flags |= FIEMAP_EXTENT_MERGED;
|
|
if (iomap->flags & IOMAP_F_SHARED)
|
|
flags |= FIEMAP_EXTENT_SHARED;
|
|
|
|
return fiemap_fill_next_extent(fi, iomap->offset,
|
|
iomap->addr != IOMAP_NULL_ADDR ? iomap->addr : 0,
|
|
iomap->length, flags);
|
|
}
|
|
|
|
static loff_t
|
|
iomap_fiemap_actor(struct inode *inode, loff_t pos, loff_t length, void *data,
|
|
struct iomap *iomap)
|
|
{
|
|
struct fiemap_ctx *ctx = data;
|
|
loff_t ret = length;
|
|
|
|
if (iomap->type == IOMAP_HOLE)
|
|
return length;
|
|
|
|
ret = iomap_to_fiemap(ctx->fi, &ctx->prev, 0);
|
|
ctx->prev = *iomap;
|
|
switch (ret) {
|
|
case 0: /* success */
|
|
return length;
|
|
case 1: /* extent array full */
|
|
return 0;
|
|
default:
|
|
return ret;
|
|
}
|
|
}
|
|
|
|
int iomap_fiemap(struct inode *inode, struct fiemap_extent_info *fi,
|
|
loff_t start, loff_t len, const struct iomap_ops *ops)
|
|
{
|
|
struct fiemap_ctx ctx;
|
|
loff_t ret;
|
|
|
|
memset(&ctx, 0, sizeof(ctx));
|
|
ctx.fi = fi;
|
|
ctx.prev.type = IOMAP_HOLE;
|
|
|
|
ret = fiemap_check_flags(fi, FIEMAP_FLAG_SYNC);
|
|
if (ret)
|
|
return ret;
|
|
|
|
if (fi->fi_flags & FIEMAP_FLAG_SYNC) {
|
|
ret = filemap_write_and_wait(inode->i_mapping);
|
|
if (ret)
|
|
return ret;
|
|
}
|
|
|
|
while (len > 0) {
|
|
ret = iomap_apply(inode, start, len, IOMAP_REPORT, ops, &ctx,
|
|
iomap_fiemap_actor);
|
|
/* inode with no (attribute) mapping will give ENOENT */
|
|
if (ret == -ENOENT)
|
|
break;
|
|
if (ret < 0)
|
|
return ret;
|
|
if (ret == 0)
|
|
break;
|
|
|
|
start += ret;
|
|
len -= ret;
|
|
}
|
|
|
|
if (ctx.prev.type != IOMAP_HOLE) {
|
|
ret = iomap_to_fiemap(fi, &ctx.prev, FIEMAP_EXTENT_LAST);
|
|
if (ret < 0)
|
|
return ret;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(iomap_fiemap);
|
|
|
|
/*
|
|
* Seek for SEEK_DATA / SEEK_HOLE within @page, starting at @lastoff.
|
|
* Returns true if found and updates @lastoff to the offset in file.
|
|
*/
|
|
static bool
|
|
page_seek_hole_data(struct inode *inode, struct page *page, loff_t *lastoff,
|
|
int whence)
|
|
{
|
|
const struct address_space_operations *ops = inode->i_mapping->a_ops;
|
|
unsigned int bsize = i_blocksize(inode), off;
|
|
bool seek_data = whence == SEEK_DATA;
|
|
loff_t poff = page_offset(page);
|
|
|
|
if (WARN_ON_ONCE(*lastoff >= poff + PAGE_SIZE))
|
|
return false;
|
|
|
|
if (*lastoff < poff) {
|
|
/*
|
|
* Last offset smaller than the start of the page means we found
|
|
* a hole:
|
|
*/
|
|
if (whence == SEEK_HOLE)
|
|
return true;
|
|
*lastoff = poff;
|
|
}
|
|
|
|
/*
|
|
* Just check the page unless we can and should check block ranges:
|
|
*/
|
|
if (bsize == PAGE_SIZE || !ops->is_partially_uptodate)
|
|
return PageUptodate(page) == seek_data;
|
|
|
|
lock_page(page);
|
|
if (unlikely(page->mapping != inode->i_mapping))
|
|
goto out_unlock_not_found;
|
|
|
|
for (off = 0; off < PAGE_SIZE; off += bsize) {
|
|
if (offset_in_page(*lastoff) >= off + bsize)
|
|
continue;
|
|
if (ops->is_partially_uptodate(page, off, bsize) == seek_data) {
|
|
unlock_page(page);
|
|
return true;
|
|
}
|
|
*lastoff = poff + off + bsize;
|
|
}
|
|
|
|
out_unlock_not_found:
|
|
unlock_page(page);
|
|
return false;
|
|
}
|
|
|
|
/*
|
|
* Seek for SEEK_DATA / SEEK_HOLE in the page cache.
|
|
*
|
|
* Within unwritten extents, the page cache determines which parts are holes
|
|
* and which are data: uptodate buffer heads count as data; everything else
|
|
* counts as a hole.
|
|
*
|
|
* Returns the resulting offset on successs, and -ENOENT otherwise.
|
|
*/
|
|
static loff_t
|
|
page_cache_seek_hole_data(struct inode *inode, loff_t offset, loff_t length,
|
|
int whence)
|
|
{
|
|
pgoff_t index = offset >> PAGE_SHIFT;
|
|
pgoff_t end = DIV_ROUND_UP(offset + length, PAGE_SIZE);
|
|
loff_t lastoff = offset;
|
|
struct pagevec pvec;
|
|
|
|
if (length <= 0)
|
|
return -ENOENT;
|
|
|
|
pagevec_init(&pvec);
|
|
|
|
do {
|
|
unsigned nr_pages, i;
|
|
|
|
nr_pages = pagevec_lookup_range(&pvec, inode->i_mapping, &index,
|
|
end - 1);
|
|
if (nr_pages == 0)
|
|
break;
|
|
|
|
for (i = 0; i < nr_pages; i++) {
|
|
struct page *page = pvec.pages[i];
|
|
|
|
if (page_seek_hole_data(inode, page, &lastoff, whence))
|
|
goto check_range;
|
|
lastoff = page_offset(page) + PAGE_SIZE;
|
|
}
|
|
pagevec_release(&pvec);
|
|
} while (index < end);
|
|
|
|
/* When no page at lastoff and we are not done, we found a hole. */
|
|
if (whence != SEEK_HOLE)
|
|
goto not_found;
|
|
|
|
check_range:
|
|
if (lastoff < offset + length)
|
|
goto out;
|
|
not_found:
|
|
lastoff = -ENOENT;
|
|
out:
|
|
pagevec_release(&pvec);
|
|
return lastoff;
|
|
}
|
|
|
|
|
|
static loff_t
|
|
iomap_seek_hole_actor(struct inode *inode, loff_t offset, loff_t length,
|
|
void *data, struct iomap *iomap)
|
|
{
|
|
switch (iomap->type) {
|
|
case IOMAP_UNWRITTEN:
|
|
offset = page_cache_seek_hole_data(inode, offset, length,
|
|
SEEK_HOLE);
|
|
if (offset < 0)
|
|
return length;
|
|
/* fall through */
|
|
case IOMAP_HOLE:
|
|
*(loff_t *)data = offset;
|
|
return 0;
|
|
default:
|
|
return length;
|
|
}
|
|
}
|
|
|
|
loff_t
|
|
iomap_seek_hole(struct inode *inode, loff_t offset, const struct iomap_ops *ops)
|
|
{
|
|
loff_t size = i_size_read(inode);
|
|
loff_t length = size - offset;
|
|
loff_t ret;
|
|
|
|
/* Nothing to be found before or beyond the end of the file. */
|
|
if (offset < 0 || offset >= size)
|
|
return -ENXIO;
|
|
|
|
while (length > 0) {
|
|
ret = iomap_apply(inode, offset, length, IOMAP_REPORT, ops,
|
|
&offset, iomap_seek_hole_actor);
|
|
if (ret < 0)
|
|
return ret;
|
|
if (ret == 0)
|
|
break;
|
|
|
|
offset += ret;
|
|
length -= ret;
|
|
}
|
|
|
|
return offset;
|
|
}
|
|
EXPORT_SYMBOL_GPL(iomap_seek_hole);
|
|
|
|
static loff_t
|
|
iomap_seek_data_actor(struct inode *inode, loff_t offset, loff_t length,
|
|
void *data, struct iomap *iomap)
|
|
{
|
|
switch (iomap->type) {
|
|
case IOMAP_HOLE:
|
|
return length;
|
|
case IOMAP_UNWRITTEN:
|
|
offset = page_cache_seek_hole_data(inode, offset, length,
|
|
SEEK_DATA);
|
|
if (offset < 0)
|
|
return length;
|
|
/*FALLTHRU*/
|
|
default:
|
|
*(loff_t *)data = offset;
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
loff_t
|
|
iomap_seek_data(struct inode *inode, loff_t offset, const struct iomap_ops *ops)
|
|
{
|
|
loff_t size = i_size_read(inode);
|
|
loff_t length = size - offset;
|
|
loff_t ret;
|
|
|
|
/* Nothing to be found before or beyond the end of the file. */
|
|
if (offset < 0 || offset >= size)
|
|
return -ENXIO;
|
|
|
|
while (length > 0) {
|
|
ret = iomap_apply(inode, offset, length, IOMAP_REPORT, ops,
|
|
&offset, iomap_seek_data_actor);
|
|
if (ret < 0)
|
|
return ret;
|
|
if (ret == 0)
|
|
break;
|
|
|
|
offset += ret;
|
|
length -= ret;
|
|
}
|
|
|
|
if (length <= 0)
|
|
return -ENXIO;
|
|
return offset;
|
|
}
|
|
EXPORT_SYMBOL_GPL(iomap_seek_data);
|
|
|
|
/*
|
|
* Private flags for iomap_dio, must not overlap with the public ones in
|
|
* iomap.h:
|
|
*/
|
|
#define IOMAP_DIO_WRITE_FUA (1 << 28)
|
|
#define IOMAP_DIO_NEED_SYNC (1 << 29)
|
|
#define IOMAP_DIO_WRITE (1 << 30)
|
|
#define IOMAP_DIO_DIRTY (1 << 31)
|
|
|
|
struct iomap_dio {
|
|
struct kiocb *iocb;
|
|
iomap_dio_end_io_t *end_io;
|
|
loff_t i_size;
|
|
loff_t size;
|
|
atomic_t ref;
|
|
unsigned flags;
|
|
int error;
|
|
bool wait_for_completion;
|
|
|
|
union {
|
|
/* used during submission and for synchronous completion: */
|
|
struct {
|
|
struct iov_iter *iter;
|
|
struct task_struct *waiter;
|
|
struct request_queue *last_queue;
|
|
blk_qc_t cookie;
|
|
} submit;
|
|
|
|
/* used for aio completion: */
|
|
struct {
|
|
struct work_struct work;
|
|
} aio;
|
|
};
|
|
};
|
|
|
|
int iomap_dio_iopoll(struct kiocb *kiocb, bool spin)
|
|
{
|
|
struct request_queue *q = READ_ONCE(kiocb->private);
|
|
|
|
if (!q)
|
|
return 0;
|
|
return blk_poll(q, READ_ONCE(kiocb->ki_cookie), spin);
|
|
}
|
|
EXPORT_SYMBOL_GPL(iomap_dio_iopoll);
|
|
|
|
static void iomap_dio_submit_bio(struct iomap_dio *dio, struct iomap *iomap,
|
|
struct bio *bio)
|
|
{
|
|
atomic_inc(&dio->ref);
|
|
|
|
if (dio->iocb->ki_flags & IOCB_HIPRI)
|
|
bio_set_polled(bio, dio->iocb);
|
|
|
|
dio->submit.last_queue = bdev_get_queue(iomap->bdev);
|
|
dio->submit.cookie = submit_bio(bio);
|
|
}
|
|
|
|
static ssize_t iomap_dio_complete(struct iomap_dio *dio)
|
|
{
|
|
struct kiocb *iocb = dio->iocb;
|
|
struct inode *inode = file_inode(iocb->ki_filp);
|
|
loff_t offset = iocb->ki_pos;
|
|
ssize_t ret;
|
|
|
|
if (dio->end_io) {
|
|
ret = dio->end_io(iocb,
|
|
dio->error ? dio->error : dio->size,
|
|
dio->flags);
|
|
} else {
|
|
ret = dio->error;
|
|
}
|
|
|
|
if (likely(!ret)) {
|
|
ret = dio->size;
|
|
/* check for short read */
|
|
if (offset + ret > dio->i_size &&
|
|
!(dio->flags & IOMAP_DIO_WRITE))
|
|
ret = dio->i_size - offset;
|
|
iocb->ki_pos += ret;
|
|
}
|
|
|
|
/*
|
|
* Try again to invalidate clean pages which might have been cached by
|
|
* non-direct readahead, or faulted in by get_user_pages() if the source
|
|
* of the write was an mmap'ed region of the file we're writing. Either
|
|
* one is a pretty crazy thing to do, so we don't support it 100%. If
|
|
* this invalidation fails, tough, the write still worked...
|
|
*
|
|
* And this page cache invalidation has to be after dio->end_io(), as
|
|
* some filesystems convert unwritten extents to real allocations in
|
|
* end_io() when necessary, otherwise a racing buffer read would cache
|
|
* zeros from unwritten extents.
|
|
*/
|
|
if (!dio->error &&
|
|
(dio->flags & IOMAP_DIO_WRITE) && inode->i_mapping->nrpages) {
|
|
int err;
|
|
err = invalidate_inode_pages2_range(inode->i_mapping,
|
|
offset >> PAGE_SHIFT,
|
|
(offset + dio->size - 1) >> PAGE_SHIFT);
|
|
if (err)
|
|
dio_warn_stale_pagecache(iocb->ki_filp);
|
|
}
|
|
|
|
/*
|
|
* If this is a DSYNC write, make sure we push it to stable storage now
|
|
* that we've written data.
|
|
*/
|
|
if (ret > 0 && (dio->flags & IOMAP_DIO_NEED_SYNC))
|
|
ret = generic_write_sync(iocb, ret);
|
|
|
|
inode_dio_end(file_inode(iocb->ki_filp));
|
|
kfree(dio);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static void iomap_dio_complete_work(struct work_struct *work)
|
|
{
|
|
struct iomap_dio *dio = container_of(work, struct iomap_dio, aio.work);
|
|
struct kiocb *iocb = dio->iocb;
|
|
|
|
iocb->ki_complete(iocb, iomap_dio_complete(dio), 0);
|
|
}
|
|
|
|
/*
|
|
* Set an error in the dio if none is set yet. We have to use cmpxchg
|
|
* as the submission context and the completion context(s) can race to
|
|
* update the error.
|
|
*/
|
|
static inline void iomap_dio_set_error(struct iomap_dio *dio, int ret)
|
|
{
|
|
cmpxchg(&dio->error, 0, ret);
|
|
}
|
|
|
|
static void iomap_dio_bio_end_io(struct bio *bio)
|
|
{
|
|
struct iomap_dio *dio = bio->bi_private;
|
|
bool should_dirty = (dio->flags & IOMAP_DIO_DIRTY);
|
|
|
|
if (bio->bi_status)
|
|
iomap_dio_set_error(dio, blk_status_to_errno(bio->bi_status));
|
|
|
|
if (atomic_dec_and_test(&dio->ref)) {
|
|
if (dio->wait_for_completion) {
|
|
struct task_struct *waiter = dio->submit.waiter;
|
|
WRITE_ONCE(dio->submit.waiter, NULL);
|
|
blk_wake_io_task(waiter);
|
|
} else if (dio->flags & IOMAP_DIO_WRITE) {
|
|
struct inode *inode = file_inode(dio->iocb->ki_filp);
|
|
|
|
INIT_WORK(&dio->aio.work, iomap_dio_complete_work);
|
|
queue_work(inode->i_sb->s_dio_done_wq, &dio->aio.work);
|
|
} else {
|
|
iomap_dio_complete_work(&dio->aio.work);
|
|
}
|
|
}
|
|
|
|
if (should_dirty) {
|
|
bio_check_pages_dirty(bio);
|
|
} else {
|
|
if (!bio_flagged(bio, BIO_NO_PAGE_REF)) {
|
|
struct bvec_iter_all iter_all;
|
|
struct bio_vec *bvec;
|
|
int i;
|
|
|
|
bio_for_each_segment_all(bvec, bio, i, iter_all)
|
|
put_page(bvec->bv_page);
|
|
}
|
|
bio_put(bio);
|
|
}
|
|
}
|
|
|
|
static void
|
|
iomap_dio_zero(struct iomap_dio *dio, struct iomap *iomap, loff_t pos,
|
|
unsigned len)
|
|
{
|
|
struct page *page = ZERO_PAGE(0);
|
|
int flags = REQ_SYNC | REQ_IDLE;
|
|
struct bio *bio;
|
|
|
|
bio = bio_alloc(GFP_KERNEL, 1);
|
|
bio_set_dev(bio, iomap->bdev);
|
|
bio->bi_iter.bi_sector = iomap_sector(iomap, pos);
|
|
bio->bi_private = dio;
|
|
bio->bi_end_io = iomap_dio_bio_end_io;
|
|
|
|
get_page(page);
|
|
__bio_add_page(bio, page, len, 0);
|
|
bio_set_op_attrs(bio, REQ_OP_WRITE, flags);
|
|
iomap_dio_submit_bio(dio, iomap, bio);
|
|
}
|
|
|
|
static loff_t
|
|
iomap_dio_bio_actor(struct inode *inode, loff_t pos, loff_t length,
|
|
struct iomap_dio *dio, struct iomap *iomap)
|
|
{
|
|
unsigned int blkbits = blksize_bits(bdev_logical_block_size(iomap->bdev));
|
|
unsigned int fs_block_size = i_blocksize(inode), pad;
|
|
unsigned int align = iov_iter_alignment(dio->submit.iter);
|
|
struct iov_iter iter;
|
|
struct bio *bio;
|
|
bool need_zeroout = false;
|
|
bool use_fua = false;
|
|
int nr_pages, ret = 0;
|
|
size_t copied = 0;
|
|
|
|
if ((pos | length | align) & ((1 << blkbits) - 1))
|
|
return -EINVAL;
|
|
|
|
if (iomap->type == IOMAP_UNWRITTEN) {
|
|
dio->flags |= IOMAP_DIO_UNWRITTEN;
|
|
need_zeroout = true;
|
|
}
|
|
|
|
if (iomap->flags & IOMAP_F_SHARED)
|
|
dio->flags |= IOMAP_DIO_COW;
|
|
|
|
if (iomap->flags & IOMAP_F_NEW) {
|
|
need_zeroout = true;
|
|
} else if (iomap->type == IOMAP_MAPPED) {
|
|
/*
|
|
* Use a FUA write if we need datasync semantics, this is a pure
|
|
* data IO that doesn't require any metadata updates (including
|
|
* after IO completion such as unwritten extent conversion) and
|
|
* the underlying device supports FUA. This allows us to avoid
|
|
* cache flushes on IO completion.
|
|
*/
|
|
if (!(iomap->flags & (IOMAP_F_SHARED|IOMAP_F_DIRTY)) &&
|
|
(dio->flags & IOMAP_DIO_WRITE_FUA) &&
|
|
blk_queue_fua(bdev_get_queue(iomap->bdev)))
|
|
use_fua = true;
|
|
}
|
|
|
|
/*
|
|
* Operate on a partial iter trimmed to the extent we were called for.
|
|
* We'll update the iter in the dio once we're done with this extent.
|
|
*/
|
|
iter = *dio->submit.iter;
|
|
iov_iter_truncate(&iter, length);
|
|
|
|
nr_pages = iov_iter_npages(&iter, BIO_MAX_PAGES);
|
|
if (nr_pages <= 0)
|
|
return nr_pages;
|
|
|
|
if (need_zeroout) {
|
|
/* zero out from the start of the block to the write offset */
|
|
pad = pos & (fs_block_size - 1);
|
|
if (pad)
|
|
iomap_dio_zero(dio, iomap, pos - pad, pad);
|
|
}
|
|
|
|
do {
|
|
size_t n;
|
|
if (dio->error) {
|
|
iov_iter_revert(dio->submit.iter, copied);
|
|
return 0;
|
|
}
|
|
|
|
bio = bio_alloc(GFP_KERNEL, nr_pages);
|
|
bio_set_dev(bio, iomap->bdev);
|
|
bio->bi_iter.bi_sector = iomap_sector(iomap, pos);
|
|
bio->bi_write_hint = dio->iocb->ki_hint;
|
|
bio->bi_ioprio = dio->iocb->ki_ioprio;
|
|
bio->bi_private = dio;
|
|
bio->bi_end_io = iomap_dio_bio_end_io;
|
|
|
|
ret = bio_iov_iter_get_pages(bio, &iter);
|
|
if (unlikely(ret)) {
|
|
/*
|
|
* We have to stop part way through an IO. We must fall
|
|
* through to the sub-block tail zeroing here, otherwise
|
|
* this short IO may expose stale data in the tail of
|
|
* the block we haven't written data to.
|
|
*/
|
|
bio_put(bio);
|
|
goto zero_tail;
|
|
}
|
|
|
|
n = bio->bi_iter.bi_size;
|
|
if (dio->flags & IOMAP_DIO_WRITE) {
|
|
bio->bi_opf = REQ_OP_WRITE | REQ_SYNC | REQ_IDLE;
|
|
if (use_fua)
|
|
bio->bi_opf |= REQ_FUA;
|
|
else
|
|
dio->flags &= ~IOMAP_DIO_WRITE_FUA;
|
|
task_io_account_write(n);
|
|
} else {
|
|
bio->bi_opf = REQ_OP_READ;
|
|
if (dio->flags & IOMAP_DIO_DIRTY)
|
|
bio_set_pages_dirty(bio);
|
|
}
|
|
|
|
iov_iter_advance(dio->submit.iter, n);
|
|
|
|
dio->size += n;
|
|
pos += n;
|
|
copied += n;
|
|
|
|
nr_pages = iov_iter_npages(&iter, BIO_MAX_PAGES);
|
|
iomap_dio_submit_bio(dio, iomap, bio);
|
|
} while (nr_pages);
|
|
|
|
/*
|
|
* We need to zeroout the tail of a sub-block write if the extent type
|
|
* requires zeroing or the write extends beyond EOF. If we don't zero
|
|
* the block tail in the latter case, we can expose stale data via mmap
|
|
* reads of the EOF block.
|
|
*/
|
|
zero_tail:
|
|
if (need_zeroout ||
|
|
((dio->flags & IOMAP_DIO_WRITE) && pos >= i_size_read(inode))) {
|
|
/* zero out from the end of the write to the end of the block */
|
|
pad = pos & (fs_block_size - 1);
|
|
if (pad)
|
|
iomap_dio_zero(dio, iomap, pos, fs_block_size - pad);
|
|
}
|
|
return copied ? copied : ret;
|
|
}
|
|
|
|
static loff_t
|
|
iomap_dio_hole_actor(loff_t length, struct iomap_dio *dio)
|
|
{
|
|
length = iov_iter_zero(length, dio->submit.iter);
|
|
dio->size += length;
|
|
return length;
|
|
}
|
|
|
|
static loff_t
|
|
iomap_dio_inline_actor(struct inode *inode, loff_t pos, loff_t length,
|
|
struct iomap_dio *dio, struct iomap *iomap)
|
|
{
|
|
struct iov_iter *iter = dio->submit.iter;
|
|
size_t copied;
|
|
|
|
BUG_ON(pos + length > PAGE_SIZE - offset_in_page(iomap->inline_data));
|
|
|
|
if (dio->flags & IOMAP_DIO_WRITE) {
|
|
loff_t size = inode->i_size;
|
|
|
|
if (pos > size)
|
|
memset(iomap->inline_data + size, 0, pos - size);
|
|
copied = copy_from_iter(iomap->inline_data + pos, length, iter);
|
|
if (copied) {
|
|
if (pos + copied > size)
|
|
i_size_write(inode, pos + copied);
|
|
mark_inode_dirty(inode);
|
|
}
|
|
} else {
|
|
copied = copy_to_iter(iomap->inline_data + pos, length, iter);
|
|
}
|
|
dio->size += copied;
|
|
return copied;
|
|
}
|
|
|
|
static loff_t
|
|
iomap_dio_actor(struct inode *inode, loff_t pos, loff_t length,
|
|
void *data, struct iomap *iomap)
|
|
{
|
|
struct iomap_dio *dio = data;
|
|
|
|
switch (iomap->type) {
|
|
case IOMAP_HOLE:
|
|
if (WARN_ON_ONCE(dio->flags & IOMAP_DIO_WRITE))
|
|
return -EIO;
|
|
return iomap_dio_hole_actor(length, dio);
|
|
case IOMAP_UNWRITTEN:
|
|
if (!(dio->flags & IOMAP_DIO_WRITE))
|
|
return iomap_dio_hole_actor(length, dio);
|
|
return iomap_dio_bio_actor(inode, pos, length, dio, iomap);
|
|
case IOMAP_MAPPED:
|
|
return iomap_dio_bio_actor(inode, pos, length, dio, iomap);
|
|
case IOMAP_INLINE:
|
|
return iomap_dio_inline_actor(inode, pos, length, dio, iomap);
|
|
default:
|
|
WARN_ON_ONCE(1);
|
|
return -EIO;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* iomap_dio_rw() always completes O_[D]SYNC writes regardless of whether the IO
|
|
* is being issued as AIO or not. This allows us to optimise pure data writes
|
|
* to use REQ_FUA rather than requiring generic_write_sync() to issue a
|
|
* REQ_FLUSH post write. This is slightly tricky because a single request here
|
|
* can be mapped into multiple disjoint IOs and only a subset of the IOs issued
|
|
* may be pure data writes. In that case, we still need to do a full data sync
|
|
* completion.
|
|
*/
|
|
ssize_t
|
|
iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter,
|
|
const struct iomap_ops *ops, iomap_dio_end_io_t end_io)
|
|
{
|
|
struct address_space *mapping = iocb->ki_filp->f_mapping;
|
|
struct inode *inode = file_inode(iocb->ki_filp);
|
|
size_t count = iov_iter_count(iter);
|
|
loff_t pos = iocb->ki_pos, start = pos;
|
|
loff_t end = iocb->ki_pos + count - 1, ret = 0;
|
|
unsigned int flags = IOMAP_DIRECT;
|
|
bool wait_for_completion = is_sync_kiocb(iocb);
|
|
struct blk_plug plug;
|
|
struct iomap_dio *dio;
|
|
|
|
lockdep_assert_held(&inode->i_rwsem);
|
|
|
|
if (!count)
|
|
return 0;
|
|
|
|
dio = kmalloc(sizeof(*dio), GFP_KERNEL);
|
|
if (!dio)
|
|
return -ENOMEM;
|
|
|
|
dio->iocb = iocb;
|
|
atomic_set(&dio->ref, 1);
|
|
dio->size = 0;
|
|
dio->i_size = i_size_read(inode);
|
|
dio->end_io = end_io;
|
|
dio->error = 0;
|
|
dio->flags = 0;
|
|
|
|
dio->submit.iter = iter;
|
|
dio->submit.waiter = current;
|
|
dio->submit.cookie = BLK_QC_T_NONE;
|
|
dio->submit.last_queue = NULL;
|
|
|
|
if (iov_iter_rw(iter) == READ) {
|
|
if (pos >= dio->i_size)
|
|
goto out_free_dio;
|
|
|
|
if (iter_is_iovec(iter) && iov_iter_rw(iter) == READ)
|
|
dio->flags |= IOMAP_DIO_DIRTY;
|
|
} else {
|
|
flags |= IOMAP_WRITE;
|
|
dio->flags |= IOMAP_DIO_WRITE;
|
|
|
|
/* for data sync or sync, we need sync completion processing */
|
|
if (iocb->ki_flags & IOCB_DSYNC)
|
|
dio->flags |= IOMAP_DIO_NEED_SYNC;
|
|
|
|
/*
|
|
* For datasync only writes, we optimistically try using FUA for
|
|
* this IO. Any non-FUA write that occurs will clear this flag,
|
|
* hence we know before completion whether a cache flush is
|
|
* necessary.
|
|
*/
|
|
if ((iocb->ki_flags & (IOCB_DSYNC | IOCB_SYNC)) == IOCB_DSYNC)
|
|
dio->flags |= IOMAP_DIO_WRITE_FUA;
|
|
}
|
|
|
|
if (iocb->ki_flags & IOCB_NOWAIT) {
|
|
if (filemap_range_has_page(mapping, start, end)) {
|
|
ret = -EAGAIN;
|
|
goto out_free_dio;
|
|
}
|
|
flags |= IOMAP_NOWAIT;
|
|
}
|
|
|
|
ret = filemap_write_and_wait_range(mapping, start, end);
|
|
if (ret)
|
|
goto out_free_dio;
|
|
|
|
/*
|
|
* Try to invalidate cache pages for the range we're direct
|
|
* writing. If this invalidation fails, tough, the write will
|
|
* still work, but racing two incompatible write paths is a
|
|
* pretty crazy thing to do, so we don't support it 100%.
|
|
*/
|
|
ret = invalidate_inode_pages2_range(mapping,
|
|
start >> PAGE_SHIFT, end >> PAGE_SHIFT);
|
|
if (ret)
|
|
dio_warn_stale_pagecache(iocb->ki_filp);
|
|
ret = 0;
|
|
|
|
if (iov_iter_rw(iter) == WRITE && !wait_for_completion &&
|
|
!inode->i_sb->s_dio_done_wq) {
|
|
ret = sb_init_dio_done_wq(inode->i_sb);
|
|
if (ret < 0)
|
|
goto out_free_dio;
|
|
}
|
|
|
|
inode_dio_begin(inode);
|
|
|
|
blk_start_plug(&plug);
|
|
do {
|
|
ret = iomap_apply(inode, pos, count, flags, ops, dio,
|
|
iomap_dio_actor);
|
|
if (ret <= 0) {
|
|
/* magic error code to fall back to buffered I/O */
|
|
if (ret == -ENOTBLK) {
|
|
wait_for_completion = true;
|
|
ret = 0;
|
|
}
|
|
break;
|
|
}
|
|
pos += ret;
|
|
|
|
if (iov_iter_rw(iter) == READ && pos >= dio->i_size)
|
|
break;
|
|
} while ((count = iov_iter_count(iter)) > 0);
|
|
blk_finish_plug(&plug);
|
|
|
|
if (ret < 0)
|
|
iomap_dio_set_error(dio, ret);
|
|
|
|
/*
|
|
* If all the writes we issued were FUA, we don't need to flush the
|
|
* cache on IO completion. Clear the sync flag for this case.
|
|
*/
|
|
if (dio->flags & IOMAP_DIO_WRITE_FUA)
|
|
dio->flags &= ~IOMAP_DIO_NEED_SYNC;
|
|
|
|
WRITE_ONCE(iocb->ki_cookie, dio->submit.cookie);
|
|
WRITE_ONCE(iocb->private, dio->submit.last_queue);
|
|
|
|
/*
|
|
* We are about to drop our additional submission reference, which
|
|
* might be the last reference to the dio. There are three three
|
|
* different ways we can progress here:
|
|
*
|
|
* (a) If this is the last reference we will always complete and free
|
|
* the dio ourselves.
|
|
* (b) If this is not the last reference, and we serve an asynchronous
|
|
* iocb, we must never touch the dio after the decrement, the
|
|
* I/O completion handler will complete and free it.
|
|
* (c) If this is not the last reference, but we serve a synchronous
|
|
* iocb, the I/O completion handler will wake us up on the drop
|
|
* of the final reference, and we will complete and free it here
|
|
* after we got woken by the I/O completion handler.
|
|
*/
|
|
dio->wait_for_completion = wait_for_completion;
|
|
if (!atomic_dec_and_test(&dio->ref)) {
|
|
if (!wait_for_completion)
|
|
return -EIOCBQUEUED;
|
|
|
|
for (;;) {
|
|
set_current_state(TASK_UNINTERRUPTIBLE);
|
|
if (!READ_ONCE(dio->submit.waiter))
|
|
break;
|
|
|
|
if (!(iocb->ki_flags & IOCB_HIPRI) ||
|
|
!dio->submit.last_queue ||
|
|
!blk_poll(dio->submit.last_queue,
|
|
dio->submit.cookie, true))
|
|
io_schedule();
|
|
}
|
|
__set_current_state(TASK_RUNNING);
|
|
}
|
|
|
|
return iomap_dio_complete(dio);
|
|
|
|
out_free_dio:
|
|
kfree(dio);
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(iomap_dio_rw);
|
|
|
|
/* Swapfile activation */
|
|
|
|
#ifdef CONFIG_SWAP
|
|
struct iomap_swapfile_info {
|
|
struct iomap iomap; /* accumulated iomap */
|
|
struct swap_info_struct *sis;
|
|
uint64_t lowest_ppage; /* lowest physical addr seen (pages) */
|
|
uint64_t highest_ppage; /* highest physical addr seen (pages) */
|
|
unsigned long nr_pages; /* number of pages collected */
|
|
int nr_extents; /* extent count */
|
|
};
|
|
|
|
/*
|
|
* Collect physical extents for this swap file. Physical extents reported to
|
|
* the swap code must be trimmed to align to a page boundary. The logical
|
|
* offset within the file is irrelevant since the swapfile code maps logical
|
|
* page numbers of the swap device to the physical page-aligned extents.
|
|
*/
|
|
static int iomap_swapfile_add_extent(struct iomap_swapfile_info *isi)
|
|
{
|
|
struct iomap *iomap = &isi->iomap;
|
|
unsigned long nr_pages;
|
|
uint64_t first_ppage;
|
|
uint64_t first_ppage_reported;
|
|
uint64_t next_ppage;
|
|
int error;
|
|
|
|
/*
|
|
* Round the start up and the end down so that the physical
|
|
* extent aligns to a page boundary.
|
|
*/
|
|
first_ppage = ALIGN(iomap->addr, PAGE_SIZE) >> PAGE_SHIFT;
|
|
next_ppage = ALIGN_DOWN(iomap->addr + iomap->length, PAGE_SIZE) >>
|
|
PAGE_SHIFT;
|
|
|
|
/* Skip too-short physical extents. */
|
|
if (first_ppage >= next_ppage)
|
|
return 0;
|
|
nr_pages = next_ppage - first_ppage;
|
|
|
|
/*
|
|
* Calculate how much swap space we're adding; the first page contains
|
|
* the swap header and doesn't count. The mm still wants that first
|
|
* page fed to add_swap_extent, however.
|
|
*/
|
|
first_ppage_reported = first_ppage;
|
|
if (iomap->offset == 0)
|
|
first_ppage_reported++;
|
|
if (isi->lowest_ppage > first_ppage_reported)
|
|
isi->lowest_ppage = first_ppage_reported;
|
|
if (isi->highest_ppage < (next_ppage - 1))
|
|
isi->highest_ppage = next_ppage - 1;
|
|
|
|
/* Add extent, set up for the next call. */
|
|
error = add_swap_extent(isi->sis, isi->nr_pages, nr_pages, first_ppage);
|
|
if (error < 0)
|
|
return error;
|
|
isi->nr_extents += error;
|
|
isi->nr_pages += nr_pages;
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Accumulate iomaps for this swap file. We have to accumulate iomaps because
|
|
* swap only cares about contiguous page-aligned physical extents and makes no
|
|
* distinction between written and unwritten extents.
|
|
*/
|
|
static loff_t iomap_swapfile_activate_actor(struct inode *inode, loff_t pos,
|
|
loff_t count, void *data, struct iomap *iomap)
|
|
{
|
|
struct iomap_swapfile_info *isi = data;
|
|
int error;
|
|
|
|
switch (iomap->type) {
|
|
case IOMAP_MAPPED:
|
|
case IOMAP_UNWRITTEN:
|
|
/* Only real or unwritten extents. */
|
|
break;
|
|
case IOMAP_INLINE:
|
|
/* No inline data. */
|
|
pr_err("swapon: file is inline\n");
|
|
return -EINVAL;
|
|
default:
|
|
pr_err("swapon: file has unallocated extents\n");
|
|
return -EINVAL;
|
|
}
|
|
|
|
/* No uncommitted metadata or shared blocks. */
|
|
if (iomap->flags & IOMAP_F_DIRTY) {
|
|
pr_err("swapon: file is not committed\n");
|
|
return -EINVAL;
|
|
}
|
|
if (iomap->flags & IOMAP_F_SHARED) {
|
|
pr_err("swapon: file has shared extents\n");
|
|
return -EINVAL;
|
|
}
|
|
|
|
/* Only one bdev per swap file. */
|
|
if (iomap->bdev != isi->sis->bdev) {
|
|
pr_err("swapon: file is on multiple devices\n");
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (isi->iomap.length == 0) {
|
|
/* No accumulated extent, so just store it. */
|
|
memcpy(&isi->iomap, iomap, sizeof(isi->iomap));
|
|
} else if (isi->iomap.addr + isi->iomap.length == iomap->addr) {
|
|
/* Append this to the accumulated extent. */
|
|
isi->iomap.length += iomap->length;
|
|
} else {
|
|
/* Otherwise, add the retained iomap and store this one. */
|
|
error = iomap_swapfile_add_extent(isi);
|
|
if (error)
|
|
return error;
|
|
memcpy(&isi->iomap, iomap, sizeof(isi->iomap));
|
|
}
|
|
return count;
|
|
}
|
|
|
|
/*
|
|
* Iterate a swap file's iomaps to construct physical extents that can be
|
|
* passed to the swapfile subsystem.
|
|
*/
|
|
int iomap_swapfile_activate(struct swap_info_struct *sis,
|
|
struct file *swap_file, sector_t *pagespan,
|
|
const struct iomap_ops *ops)
|
|
{
|
|
struct iomap_swapfile_info isi = {
|
|
.sis = sis,
|
|
.lowest_ppage = (sector_t)-1ULL,
|
|
};
|
|
struct address_space *mapping = swap_file->f_mapping;
|
|
struct inode *inode = mapping->host;
|
|
loff_t pos = 0;
|
|
loff_t len = ALIGN_DOWN(i_size_read(inode), PAGE_SIZE);
|
|
loff_t ret;
|
|
|
|
/*
|
|
* Persist all file mapping metadata so that we won't have any
|
|
* IOMAP_F_DIRTY iomaps.
|
|
*/
|
|
ret = vfs_fsync(swap_file, 1);
|
|
if (ret)
|
|
return ret;
|
|
|
|
while (len > 0) {
|
|
ret = iomap_apply(inode, pos, len, IOMAP_REPORT,
|
|
ops, &isi, iomap_swapfile_activate_actor);
|
|
if (ret <= 0)
|
|
return ret;
|
|
|
|
pos += ret;
|
|
len -= ret;
|
|
}
|
|
|
|
if (isi.iomap.length) {
|
|
ret = iomap_swapfile_add_extent(&isi);
|
|
if (ret)
|
|
return ret;
|
|
}
|
|
|
|
*pagespan = 1 + isi.highest_ppage - isi.lowest_ppage;
|
|
sis->max = isi.nr_pages;
|
|
sis->pages = isi.nr_pages - 1;
|
|
sis->highest_bit = isi.nr_pages - 1;
|
|
return isi.nr_extents;
|
|
}
|
|
EXPORT_SYMBOL_GPL(iomap_swapfile_activate);
|
|
#endif /* CONFIG_SWAP */
|
|
|
|
static loff_t
|
|
iomap_bmap_actor(struct inode *inode, loff_t pos, loff_t length,
|
|
void *data, struct iomap *iomap)
|
|
{
|
|
sector_t *bno = data, addr;
|
|
|
|
if (iomap->type == IOMAP_MAPPED) {
|
|
addr = (pos - iomap->offset + iomap->addr) >> inode->i_blkbits;
|
|
if (addr > INT_MAX)
|
|
WARN(1, "would truncate bmap result\n");
|
|
else
|
|
*bno = addr;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/* legacy ->bmap interface. 0 is the error return (!) */
|
|
sector_t
|
|
iomap_bmap(struct address_space *mapping, sector_t bno,
|
|
const struct iomap_ops *ops)
|
|
{
|
|
struct inode *inode = mapping->host;
|
|
loff_t pos = bno << inode->i_blkbits;
|
|
unsigned blocksize = i_blocksize(inode);
|
|
|
|
if (filemap_write_and_wait(mapping))
|
|
return 0;
|
|
|
|
bno = 0;
|
|
iomap_apply(inode, pos, blocksize, 0, ops, &bno, iomap_bmap_actor);
|
|
return bno;
|
|
}
|
|
EXPORT_SYMBOL_GPL(iomap_bmap);
|