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iomap: move the swapfile code into a separate file
Move the swapfile activation code into a separate file so that we can group related functions in a single file instead of having a single enormous source file. Signed-off-by: Darrick J. Wong <[email protected]> Reviewed-by: Christoph Hellwig <[email protected]>
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| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,180 @@ | ||
| // SPDX-License-Identifier: GPL-2.0 | ||
| /* | ||
| * Copyright (C) 2018 Oracle. All Rights Reserved. | ||
| * Author: Darrick J. Wong <[email protected]> | ||
| */ | ||
| #include <linux/module.h> | ||
| #include <linux/compiler.h> | ||
| #include <linux/fs.h> | ||
| #include <linux/iomap.h> | ||
| #include <linux/swap.h> | ||
|
|
||
| #include "../internal.h" | ||
|
|
||
| /* Swapfile activation */ | ||
|
|
||
| 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); |