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![Linus Torvalds](/assets/img/avatar_default.png)
F_SEAL_EXEC") which permits the setting of the memfd execute bit at memfd creation time, with the option of sealing the state of the X bit. - Peter Xu adds a patch series ("mm/hugetlb: Make huge_pte_offset() thread-safe for pmd unshare") which addresses a rare race condition related to PMD unsharing. - Several folioification patch serieses from Matthew Wilcox, Vishal Moola, Sidhartha Kumar and Lorenzo Stoakes - Johannes Weiner has a series ("mm: push down lock_page_memcg()") which does perform some memcg maintenance and cleanup work. - SeongJae Park has added DAMOS filtering to DAMON, with the series "mm/damon/core: implement damos filter". These filters provide users with finer-grained control over DAMOS's actions. SeongJae has also done some DAMON cleanup work. - Kairui Song adds a series ("Clean up and fixes for swap"). - Vernon Yang contributed the series "Clean up and refinement for maple tree". - Yu Zhao has contributed the "mm: multi-gen LRU: memcg LRU" series. It adds to MGLRU an LRU of memcgs, to improve the scalability of global reclaim. - David Hildenbrand has added some userfaultfd cleanup work in the series "mm: uffd-wp + change_protection() cleanups". - Christoph Hellwig has removed the generic_writepages() library function in the series "remove generic_writepages". - Baolin Wang has performed some maintenance on the compaction code in his series "Some small improvements for compaction". - Sidhartha Kumar is doing some maintenance work on struct page in his series "Get rid of tail page fields". - David Hildenbrand contributed some cleanup, bugfixing and generalization of pte management and of pte debugging in his series "mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE on all architectures with swap PTEs". - Mel Gorman and Neil Brown have removed the __GFP_ATOMIC allocation flag in the series "Discard __GFP_ATOMIC". - Sergey Senozhatsky has improved zsmalloc's memory utilization with his series "zsmalloc: make zspage chain size configurable". - Joey Gouly has added prctl() support for prohibiting the creation of writeable+executable mappings. The previous BPF-based approach had shortcomings. See "mm: In-kernel support for memory-deny-write-execute (MDWE)". - Waiman Long did some kmemleak cleanup and bugfixing in the series "mm/kmemleak: Simplify kmemleak_cond_resched() & fix UAF". - T.J. Alumbaugh has contributed some MGLRU cleanup work in his series "mm: multi-gen LRU: improve". - Jiaqi Yan has provided some enhancements to our memory error statistics reporting, mainly by presenting the statistics on a per-node basis. See the series "Introduce per NUMA node memory error statistics". - Mel Gorman has a second and hopefully final shot at fixing a CPU-hog regression in compaction via his series "Fix excessive CPU usage during compaction". - Christoph Hellwig does some vmalloc maintenance work in the series "cleanup vfree and vunmap". - Christoph Hellwig has removed block_device_operations.rw_page() in ths series "remove ->rw_page". - We get some maple_tree improvements and cleanups in Liam Howlett's series "VMA tree type safety and remove __vma_adjust()". - Suren Baghdasaryan has done some work on the maintainability of our vm_flags handling in the series "introduce vm_flags modifier functions". - Some pagemap cleanup and generalization work in Mike Rapoport's series "mm, arch: add generic implementation of pfn_valid() for FLATMEM" and "fixups for generic implementation of pfn_valid()" - Baoquan He has done some work to make /proc/vmallocinfo and /proc/kcore better represent the real state of things in his series "mm/vmalloc.c: allow vread() to read out vm_map_ram areas". - Jason Gunthorpe rationalized the GUP system's interface to the rest of the kernel in the series "Simplify the external interface for GUP". - SeongJae Park wishes to migrate people from DAMON's debugfs interface over to its sysfs interface. To support this, we'll temporarily be printing warnings when people use the debugfs interface. See the series "mm/damon: deprecate DAMON debugfs interface". - Andrey Konovalov provided the accurately named "lib/stackdepot: fixes and clean-ups" series. - Huang Ying has provided a dramatic reduction in migration's TLB flush IPI rates with the series "migrate_pages(): batch TLB flushing". - Arnd Bergmann has some objtool fixups in "objtool warning fixes". -----BEGIN PGP SIGNATURE----- iHUEABYIAB0WIQTTMBEPP41GrTpTJgfdBJ7gKXxAjgUCY/PoPQAKCRDdBJ7gKXxA jlvpAPsFECUBBl20qSue2zCYWnHC7Yk4q9ytTkPB/MMDrFEN9wD/SNKEm2UoK6/K DmxHkn0LAitGgJRS/W9w81yrgig9tAQ= =MlGs -----END PGP SIGNATURE----- Merge tag 'mm-stable-2023-02-20-13-37' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: - Daniel Verkamp has contributed a memfd series ("mm/memfd: add F_SEAL_EXEC") which permits the setting of the memfd execute bit at memfd creation time, with the option of sealing the state of the X bit. - Peter Xu adds a patch series ("mm/hugetlb: Make huge_pte_offset() thread-safe for pmd unshare") which addresses a rare race condition related to PMD unsharing. - Several folioification patch serieses from Matthew Wilcox, Vishal Moola, Sidhartha Kumar and Lorenzo Stoakes - Johannes Weiner has a series ("mm: push down lock_page_memcg()") which does perform some memcg maintenance and cleanup work. - SeongJae Park has added DAMOS filtering to DAMON, with the series "mm/damon/core: implement damos filter". These filters provide users with finer-grained control over DAMOS's actions. SeongJae has also done some DAMON cleanup work. - Kairui Song adds a series ("Clean up and fixes for swap"). - Vernon Yang contributed the series "Clean up and refinement for maple tree". - Yu Zhao has contributed the "mm: multi-gen LRU: memcg LRU" series. It adds to MGLRU an LRU of memcgs, to improve the scalability of global reclaim. - David Hildenbrand has added some userfaultfd cleanup work in the series "mm: uffd-wp + change_protection() cleanups". - Christoph Hellwig has removed the generic_writepages() library function in the series "remove generic_writepages". - Baolin Wang has performed some maintenance on the compaction code in his series "Some small improvements for compaction". - Sidhartha Kumar is doing some maintenance work on struct page in his series "Get rid of tail page fields". - David Hildenbrand contributed some cleanup, bugfixing and generalization of pte management and of pte debugging in his series "mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE on all architectures with swap PTEs". - Mel Gorman and Neil Brown have removed the __GFP_ATOMIC allocation flag in the series "Discard __GFP_ATOMIC". - Sergey Senozhatsky has improved zsmalloc's memory utilization with his series "zsmalloc: make zspage chain size configurable". - Joey Gouly has added prctl() support for prohibiting the creation of writeable+executable mappings. The previous BPF-based approach had shortcomings. See "mm: In-kernel support for memory-deny-write-execute (MDWE)". - Waiman Long did some kmemleak cleanup and bugfixing in the series "mm/kmemleak: Simplify kmemleak_cond_resched() & fix UAF". - T.J. Alumbaugh has contributed some MGLRU cleanup work in his series "mm: multi-gen LRU: improve". - Jiaqi Yan has provided some enhancements to our memory error statistics reporting, mainly by presenting the statistics on a per-node basis. See the series "Introduce per NUMA node memory error statistics". - Mel Gorman has a second and hopefully final shot at fixing a CPU-hog regression in compaction via his series "Fix excessive CPU usage during compaction". - Christoph Hellwig does some vmalloc maintenance work in the series "cleanup vfree and vunmap". - Christoph Hellwig has removed block_device_operations.rw_page() in ths series "remove ->rw_page". - We get some maple_tree improvements and cleanups in Liam Howlett's series "VMA tree type safety and remove __vma_adjust()". - Suren Baghdasaryan has done some work on the maintainability of our vm_flags handling in the series "introduce vm_flags modifier functions". - Some pagemap cleanup and generalization work in Mike Rapoport's series "mm, arch: add generic implementation of pfn_valid() for FLATMEM" and "fixups for generic implementation of pfn_valid()" - Baoquan He has done some work to make /proc/vmallocinfo and /proc/kcore better represent the real state of things in his series "mm/vmalloc.c: allow vread() to read out vm_map_ram areas". - Jason Gunthorpe rationalized the GUP system's interface to the rest of the kernel in the series "Simplify the external interface for GUP". - SeongJae Park wishes to migrate people from DAMON's debugfs interface over to its sysfs interface. To support this, we'll temporarily be printing warnings when people use the debugfs interface. See the series "mm/damon: deprecate DAMON debugfs interface". - Andrey Konovalov provided the accurately named "lib/stackdepot: fixes and clean-ups" series. - Huang Ying has provided a dramatic reduction in migration's TLB flush IPI rates with the series "migrate_pages(): batch TLB flushing". - Arnd Bergmann has some objtool fixups in "objtool warning fixes". * tag 'mm-stable-2023-02-20-13-37' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (505 commits) include/linux/migrate.h: remove unneeded externs mm/memory_hotplug: cleanup return value handing in do_migrate_range() mm/uffd: fix comment in handling pte markers mm: change to return bool for isolate_movable_page() mm: hugetlb: change to return bool for isolate_hugetlb() mm: change to return bool for isolate_lru_page() mm: change to return bool for folio_isolate_lru() objtool: add UACCESS exceptions for __tsan_volatile_read/write kmsan: disable ftrace in kmsan core code kasan: mark addr_has_metadata __always_inline mm: memcontrol: rename memcg_kmem_enabled() sh: initialize max_mapnr m68k/nommu: add missing definition of ARCH_PFN_OFFSET mm: percpu: fix incorrect size in pcpu_obj_full_size() maple_tree: reduce stack usage with gcc-9 and earlier mm: page_alloc: call panic() when memoryless node allocation fails mm: multi-gen LRU: avoid futile retries migrate_pages: move THP/hugetlb migration support check to simplify code migrate_pages: batch flushing TLB migrate_pages: share more code between _unmap and _move ...
547 lines
13 KiB
C
547 lines
13 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* linux/mm/page_io.c
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*
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* Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
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*
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* Swap reorganised 29.12.95,
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* Asynchronous swapping added 30.12.95. Stephen Tweedie
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* Removed race in async swapping. 14.4.1996. Bruno Haible
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* Add swap of shared pages through the page cache. 20.2.1998. Stephen Tweedie
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* Always use brw_page, life becomes simpler. 12 May 1998 Eric Biederman
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*/
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#include <linux/mm.h>
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#include <linux/kernel_stat.h>
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#include <linux/gfp.h>
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#include <linux/pagemap.h>
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#include <linux/swap.h>
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#include <linux/bio.h>
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#include <linux/swapops.h>
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#include <linux/writeback.h>
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#include <linux/frontswap.h>
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#include <linux/blkdev.h>
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#include <linux/psi.h>
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#include <linux/uio.h>
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#include <linux/sched/task.h>
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#include <linux/delayacct.h>
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#include "swap.h"
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static void __end_swap_bio_write(struct bio *bio)
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{
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struct page *page = bio_first_page_all(bio);
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if (bio->bi_status) {
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SetPageError(page);
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/*
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* We failed to write the page out to swap-space.
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* Re-dirty the page in order to avoid it being reclaimed.
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* Also print a dire warning that things will go BAD (tm)
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* very quickly.
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*
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* Also clear PG_reclaim to avoid folio_rotate_reclaimable()
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*/
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set_page_dirty(page);
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pr_alert_ratelimited("Write-error on swap-device (%u:%u:%llu)\n",
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MAJOR(bio_dev(bio)), MINOR(bio_dev(bio)),
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(unsigned long long)bio->bi_iter.bi_sector);
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ClearPageReclaim(page);
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}
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end_page_writeback(page);
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}
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static void end_swap_bio_write(struct bio *bio)
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{
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__end_swap_bio_write(bio);
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bio_put(bio);
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}
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static void __end_swap_bio_read(struct bio *bio)
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{
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struct page *page = bio_first_page_all(bio);
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if (bio->bi_status) {
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SetPageError(page);
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ClearPageUptodate(page);
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pr_alert_ratelimited("Read-error on swap-device (%u:%u:%llu)\n",
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MAJOR(bio_dev(bio)), MINOR(bio_dev(bio)),
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(unsigned long long)bio->bi_iter.bi_sector);
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} else {
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SetPageUptodate(page);
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}
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unlock_page(page);
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}
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static void end_swap_bio_read(struct bio *bio)
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{
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__end_swap_bio_read(bio);
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bio_put(bio);
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}
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int generic_swapfile_activate(struct swap_info_struct *sis,
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struct file *swap_file,
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sector_t *span)
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{
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struct address_space *mapping = swap_file->f_mapping;
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struct inode *inode = mapping->host;
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unsigned blocks_per_page;
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unsigned long page_no;
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unsigned blkbits;
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sector_t probe_block;
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sector_t last_block;
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sector_t lowest_block = -1;
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sector_t highest_block = 0;
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int nr_extents = 0;
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int ret;
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blkbits = inode->i_blkbits;
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blocks_per_page = PAGE_SIZE >> blkbits;
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/*
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* Map all the blocks into the extent tree. This code doesn't try
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* to be very smart.
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*/
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probe_block = 0;
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page_no = 0;
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last_block = i_size_read(inode) >> blkbits;
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while ((probe_block + blocks_per_page) <= last_block &&
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page_no < sis->max) {
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unsigned block_in_page;
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sector_t first_block;
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cond_resched();
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first_block = probe_block;
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ret = bmap(inode, &first_block);
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if (ret || !first_block)
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goto bad_bmap;
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/*
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* It must be PAGE_SIZE aligned on-disk
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*/
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if (first_block & (blocks_per_page - 1)) {
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probe_block++;
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goto reprobe;
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}
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for (block_in_page = 1; block_in_page < blocks_per_page;
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block_in_page++) {
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sector_t block;
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block = probe_block + block_in_page;
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ret = bmap(inode, &block);
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if (ret || !block)
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goto bad_bmap;
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if (block != first_block + block_in_page) {
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/* Discontiguity */
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probe_block++;
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goto reprobe;
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}
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}
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first_block >>= (PAGE_SHIFT - blkbits);
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if (page_no) { /* exclude the header page */
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if (first_block < lowest_block)
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lowest_block = first_block;
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if (first_block > highest_block)
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highest_block = first_block;
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}
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/*
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* We found a PAGE_SIZE-length, PAGE_SIZE-aligned run of blocks
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*/
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ret = add_swap_extent(sis, page_no, 1, first_block);
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if (ret < 0)
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goto out;
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nr_extents += ret;
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page_no++;
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probe_block += blocks_per_page;
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reprobe:
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continue;
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}
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ret = nr_extents;
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*span = 1 + highest_block - lowest_block;
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if (page_no == 0)
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page_no = 1; /* force Empty message */
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sis->max = page_no;
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sis->pages = page_no - 1;
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sis->highest_bit = page_no - 1;
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out:
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return ret;
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bad_bmap:
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pr_err("swapon: swapfile has holes\n");
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ret = -EINVAL;
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goto out;
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}
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/*
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* We may have stale swap cache pages in memory: notice
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* them here and get rid of the unnecessary final write.
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*/
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int swap_writepage(struct page *page, struct writeback_control *wbc)
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{
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struct folio *folio = page_folio(page);
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int ret;
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if (folio_free_swap(folio)) {
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folio_unlock(folio);
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return 0;
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}
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/*
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* Arch code may have to preserve more data than just the page
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* contents, e.g. memory tags.
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*/
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ret = arch_prepare_to_swap(&folio->page);
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if (ret) {
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folio_mark_dirty(folio);
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folio_unlock(folio);
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return ret;
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}
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if (frontswap_store(&folio->page) == 0) {
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folio_start_writeback(folio);
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folio_unlock(folio);
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folio_end_writeback(folio);
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return 0;
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}
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__swap_writepage(&folio->page, wbc);
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return 0;
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}
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static inline void count_swpout_vm_event(struct page *page)
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{
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#ifdef CONFIG_TRANSPARENT_HUGEPAGE
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if (unlikely(PageTransHuge(page)))
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count_vm_event(THP_SWPOUT);
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#endif
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count_vm_events(PSWPOUT, thp_nr_pages(page));
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}
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#if defined(CONFIG_MEMCG) && defined(CONFIG_BLK_CGROUP)
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static void bio_associate_blkg_from_page(struct bio *bio, struct page *page)
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{
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struct cgroup_subsys_state *css;
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struct mem_cgroup *memcg;
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memcg = page_memcg(page);
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if (!memcg)
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return;
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rcu_read_lock();
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css = cgroup_e_css(memcg->css.cgroup, &io_cgrp_subsys);
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bio_associate_blkg_from_css(bio, css);
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rcu_read_unlock();
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}
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#else
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#define bio_associate_blkg_from_page(bio, page) do { } while (0)
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#endif /* CONFIG_MEMCG && CONFIG_BLK_CGROUP */
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struct swap_iocb {
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struct kiocb iocb;
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struct bio_vec bvec[SWAP_CLUSTER_MAX];
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int pages;
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int len;
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};
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static mempool_t *sio_pool;
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int sio_pool_init(void)
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{
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if (!sio_pool) {
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mempool_t *pool = mempool_create_kmalloc_pool(
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SWAP_CLUSTER_MAX, sizeof(struct swap_iocb));
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if (cmpxchg(&sio_pool, NULL, pool))
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mempool_destroy(pool);
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}
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if (!sio_pool)
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return -ENOMEM;
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return 0;
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}
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static void sio_write_complete(struct kiocb *iocb, long ret)
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{
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struct swap_iocb *sio = container_of(iocb, struct swap_iocb, iocb);
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struct page *page = sio->bvec[0].bv_page;
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int p;
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if (ret != sio->len) {
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/*
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* In the case of swap-over-nfs, this can be a
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* temporary failure if the system has limited
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* memory for allocating transmit buffers.
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* Mark the page dirty and avoid
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* folio_rotate_reclaimable but rate-limit the
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* messages but do not flag PageError like
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* the normal direct-to-bio case as it could
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* be temporary.
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*/
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pr_err_ratelimited("Write error %ld on dio swapfile (%llu)\n",
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ret, page_file_offset(page));
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for (p = 0; p < sio->pages; p++) {
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page = sio->bvec[p].bv_page;
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set_page_dirty(page);
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ClearPageReclaim(page);
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}
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} else {
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for (p = 0; p < sio->pages; p++)
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count_swpout_vm_event(sio->bvec[p].bv_page);
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}
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for (p = 0; p < sio->pages; p++)
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end_page_writeback(sio->bvec[p].bv_page);
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mempool_free(sio, sio_pool);
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}
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static void swap_writepage_fs(struct page *page, struct writeback_control *wbc)
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{
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struct swap_iocb *sio = NULL;
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struct swap_info_struct *sis = page_swap_info(page);
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struct file *swap_file = sis->swap_file;
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loff_t pos = page_file_offset(page);
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set_page_writeback(page);
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unlock_page(page);
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if (wbc->swap_plug)
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sio = *wbc->swap_plug;
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if (sio) {
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if (sio->iocb.ki_filp != swap_file ||
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sio->iocb.ki_pos + sio->len != pos) {
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swap_write_unplug(sio);
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sio = NULL;
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}
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}
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if (!sio) {
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sio = mempool_alloc(sio_pool, GFP_NOIO);
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init_sync_kiocb(&sio->iocb, swap_file);
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sio->iocb.ki_complete = sio_write_complete;
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sio->iocb.ki_pos = pos;
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sio->pages = 0;
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sio->len = 0;
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}
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bvec_set_page(&sio->bvec[sio->pages], page, thp_size(page), 0);
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sio->len += thp_size(page);
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sio->pages += 1;
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if (sio->pages == ARRAY_SIZE(sio->bvec) || !wbc->swap_plug) {
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swap_write_unplug(sio);
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sio = NULL;
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}
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if (wbc->swap_plug)
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*wbc->swap_plug = sio;
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}
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static void swap_writepage_bdev_sync(struct page *page,
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struct writeback_control *wbc, struct swap_info_struct *sis)
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{
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struct bio_vec bv;
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struct bio bio;
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bio_init(&bio, sis->bdev, &bv, 1,
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|
REQ_OP_WRITE | REQ_SWAP | wbc_to_write_flags(wbc));
|
|
bio.bi_iter.bi_sector = swap_page_sector(page);
|
|
bio_add_page(&bio, page, thp_size(page), 0);
|
|
|
|
bio_associate_blkg_from_page(&bio, page);
|
|
count_swpout_vm_event(page);
|
|
|
|
set_page_writeback(page);
|
|
unlock_page(page);
|
|
|
|
submit_bio_wait(&bio);
|
|
__end_swap_bio_write(&bio);
|
|
}
|
|
|
|
static void swap_writepage_bdev_async(struct page *page,
|
|
struct writeback_control *wbc, struct swap_info_struct *sis)
|
|
{
|
|
struct bio *bio;
|
|
|
|
bio = bio_alloc(sis->bdev, 1,
|
|
REQ_OP_WRITE | REQ_SWAP | wbc_to_write_flags(wbc),
|
|
GFP_NOIO);
|
|
bio->bi_iter.bi_sector = swap_page_sector(page);
|
|
bio->bi_end_io = end_swap_bio_write;
|
|
bio_add_page(bio, page, thp_size(page), 0);
|
|
|
|
bio_associate_blkg_from_page(bio, page);
|
|
count_swpout_vm_event(page);
|
|
set_page_writeback(page);
|
|
unlock_page(page);
|
|
submit_bio(bio);
|
|
}
|
|
|
|
void __swap_writepage(struct page *page, struct writeback_control *wbc)
|
|
{
|
|
struct swap_info_struct *sis = page_swap_info(page);
|
|
|
|
VM_BUG_ON_PAGE(!PageSwapCache(page), page);
|
|
/*
|
|
* ->flags can be updated non-atomicially (scan_swap_map_slots),
|
|
* but that will never affect SWP_FS_OPS, so the data_race
|
|
* is safe.
|
|
*/
|
|
if (data_race(sis->flags & SWP_FS_OPS))
|
|
swap_writepage_fs(page, wbc);
|
|
else if (sis->flags & SWP_SYNCHRONOUS_IO)
|
|
swap_writepage_bdev_sync(page, wbc, sis);
|
|
else
|
|
swap_writepage_bdev_async(page, wbc, sis);
|
|
}
|
|
|
|
void swap_write_unplug(struct swap_iocb *sio)
|
|
{
|
|
struct iov_iter from;
|
|
struct address_space *mapping = sio->iocb.ki_filp->f_mapping;
|
|
int ret;
|
|
|
|
iov_iter_bvec(&from, ITER_SOURCE, sio->bvec, sio->pages, sio->len);
|
|
ret = mapping->a_ops->swap_rw(&sio->iocb, &from);
|
|
if (ret != -EIOCBQUEUED)
|
|
sio_write_complete(&sio->iocb, ret);
|
|
}
|
|
|
|
static void sio_read_complete(struct kiocb *iocb, long ret)
|
|
{
|
|
struct swap_iocb *sio = container_of(iocb, struct swap_iocb, iocb);
|
|
int p;
|
|
|
|
if (ret == sio->len) {
|
|
for (p = 0; p < sio->pages; p++) {
|
|
struct page *page = sio->bvec[p].bv_page;
|
|
|
|
SetPageUptodate(page);
|
|
unlock_page(page);
|
|
}
|
|
count_vm_events(PSWPIN, sio->pages);
|
|
} else {
|
|
for (p = 0; p < sio->pages; p++) {
|
|
struct page *page = sio->bvec[p].bv_page;
|
|
|
|
SetPageError(page);
|
|
ClearPageUptodate(page);
|
|
unlock_page(page);
|
|
}
|
|
pr_alert_ratelimited("Read-error on swap-device\n");
|
|
}
|
|
mempool_free(sio, sio_pool);
|
|
}
|
|
|
|
static void swap_readpage_fs(struct page *page,
|
|
struct swap_iocb **plug)
|
|
{
|
|
struct swap_info_struct *sis = page_swap_info(page);
|
|
struct swap_iocb *sio = NULL;
|
|
loff_t pos = page_file_offset(page);
|
|
|
|
if (plug)
|
|
sio = *plug;
|
|
if (sio) {
|
|
if (sio->iocb.ki_filp != sis->swap_file ||
|
|
sio->iocb.ki_pos + sio->len != pos) {
|
|
swap_read_unplug(sio);
|
|
sio = NULL;
|
|
}
|
|
}
|
|
if (!sio) {
|
|
sio = mempool_alloc(sio_pool, GFP_KERNEL);
|
|
init_sync_kiocb(&sio->iocb, sis->swap_file);
|
|
sio->iocb.ki_pos = pos;
|
|
sio->iocb.ki_complete = sio_read_complete;
|
|
sio->pages = 0;
|
|
sio->len = 0;
|
|
}
|
|
bvec_set_page(&sio->bvec[sio->pages], page, thp_size(page), 0);
|
|
sio->len += thp_size(page);
|
|
sio->pages += 1;
|
|
if (sio->pages == ARRAY_SIZE(sio->bvec) || !plug) {
|
|
swap_read_unplug(sio);
|
|
sio = NULL;
|
|
}
|
|
if (plug)
|
|
*plug = sio;
|
|
}
|
|
|
|
static void swap_readpage_bdev_sync(struct page *page,
|
|
struct swap_info_struct *sis)
|
|
{
|
|
struct bio_vec bv;
|
|
struct bio bio;
|
|
|
|
bio_init(&bio, sis->bdev, &bv, 1, REQ_OP_READ);
|
|
bio.bi_iter.bi_sector = swap_page_sector(page);
|
|
bio_add_page(&bio, page, thp_size(page), 0);
|
|
/*
|
|
* Keep this task valid during swap readpage because the oom killer may
|
|
* attempt to access it in the page fault retry time check.
|
|
*/
|
|
get_task_struct(current);
|
|
count_vm_event(PSWPIN);
|
|
submit_bio_wait(&bio);
|
|
__end_swap_bio_read(&bio);
|
|
put_task_struct(current);
|
|
}
|
|
|
|
static void swap_readpage_bdev_async(struct page *page,
|
|
struct swap_info_struct *sis)
|
|
{
|
|
struct bio *bio;
|
|
|
|
bio = bio_alloc(sis->bdev, 1, REQ_OP_READ, GFP_KERNEL);
|
|
bio->bi_iter.bi_sector = swap_page_sector(page);
|
|
bio->bi_end_io = end_swap_bio_read;
|
|
bio_add_page(bio, page, thp_size(page), 0);
|
|
count_vm_event(PSWPIN);
|
|
submit_bio(bio);
|
|
}
|
|
|
|
void swap_readpage(struct page *page, bool synchronous, struct swap_iocb **plug)
|
|
{
|
|
struct swap_info_struct *sis = page_swap_info(page);
|
|
bool workingset = PageWorkingset(page);
|
|
unsigned long pflags;
|
|
bool in_thrashing;
|
|
|
|
VM_BUG_ON_PAGE(!PageSwapCache(page) && !synchronous, page);
|
|
VM_BUG_ON_PAGE(!PageLocked(page), page);
|
|
VM_BUG_ON_PAGE(PageUptodate(page), page);
|
|
|
|
/*
|
|
* Count submission time as memory stall and delay. When the device
|
|
* is congested, or the submitting cgroup IO-throttled, submission
|
|
* can be a significant part of overall IO time.
|
|
*/
|
|
if (workingset) {
|
|
delayacct_thrashing_start(&in_thrashing);
|
|
psi_memstall_enter(&pflags);
|
|
}
|
|
delayacct_swapin_start();
|
|
|
|
if (frontswap_load(page) == 0) {
|
|
SetPageUptodate(page);
|
|
unlock_page(page);
|
|
} else if (data_race(sis->flags & SWP_FS_OPS)) {
|
|
swap_readpage_fs(page, plug);
|
|
} else if (synchronous || (sis->flags & SWP_SYNCHRONOUS_IO)) {
|
|
swap_readpage_bdev_sync(page, sis);
|
|
} else {
|
|
swap_readpage_bdev_async(page, sis);
|
|
}
|
|
|
|
if (workingset) {
|
|
delayacct_thrashing_end(&in_thrashing);
|
|
psi_memstall_leave(&pflags);
|
|
}
|
|
delayacct_swapin_end();
|
|
}
|
|
|
|
void __swap_read_unplug(struct swap_iocb *sio)
|
|
{
|
|
struct iov_iter from;
|
|
struct address_space *mapping = sio->iocb.ki_filp->f_mapping;
|
|
int ret;
|
|
|
|
iov_iter_bvec(&from, ITER_DEST, sio->bvec, sio->pages, sio->len);
|
|
ret = mapping->a_ops->swap_rw(&sio->iocb, &from);
|
|
if (ret != -EIOCBQUEUED)
|
|
sio_read_complete(&sio->iocb, ret);
|
|
}
|