From aef8130125f0bf3d741f77b7132a9ac4c8094cbe Mon Sep 17 00:00:00 2001 From: Bruce Ashfield Date: Wed, 3 Jul 2019 10:55:03 -0400 Subject: [PATCH 3/5] aufs5: mmap support Application of; aufs5-mmap.patch Signed-off-by: Bruce Ashfield --- fs/proc/base.c | 2 +- fs/proc/nommu.c | 5 ++- fs/proc/task_mmu.c | 7 +++- fs/proc/task_nommu.c | 5 ++- include/linux/mm.h | 22 ++++++++++ include/linux/mm_types.h | 2 + kernel/fork.c | 2 +- mm/Makefile | 2 +- mm/filemap.c | 2 +- mm/mmap.c | 33 +++++++++++---- mm/nommu.c | 10 ++--- mm/prfile.c | 86 ++++++++++++++++++++++++++++++++++++++++ 12 files changed, 157 insertions(+), 21 deletions(-) create mode 100644 mm/prfile.c diff --git a/fs/proc/base.c b/fs/proc/base.c index 255f6754c70d..2c009be14898 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -2014,7 +2014,7 @@ static int map_files_get_link(struct dentry *dentry, struct path *path) down_read(&mm->mmap_sem); vma = find_exact_vma(mm, vm_start, vm_end); if (vma && vma->vm_file) { - *path = vma->vm_file->f_path; + *path = vma_pr_or_file(vma)->f_path; path_get(path); rc = 0; } diff --git a/fs/proc/nommu.c b/fs/proc/nommu.c index 14c2badb8fd9..65afe5287e43 100644 --- a/fs/proc/nommu.c +++ b/fs/proc/nommu.c @@ -41,7 +41,10 @@ static int nommu_region_show(struct seq_file *m, struct vm_region *region) file = region->vm_file; if (file) { - struct inode *inode = file_inode(region->vm_file); + struct inode *inode; + + file = vmr_pr_or_file(region); + inode = file_inode(file); dev = inode->i_sb->s_dev; ino = inode->i_ino; } diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index 01d4eb0e6bd1..fedfaa012768 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -305,7 +305,10 @@ show_map_vma(struct seq_file *m, struct vm_area_struct *vma) const char *name = NULL; if (file) { - struct inode *inode = file_inode(vma->vm_file); + struct inode *inode; + + file = vma_pr_or_file(vma); + inode = file_inode(file); dev = inode->i_sb->s_dev; ino = inode->i_ino; pgoff = ((loff_t)vma->vm_pgoff) << PAGE_SHIFT; @@ -1761,7 +1764,7 @@ static int show_numa_map(struct seq_file *m, void *v) struct proc_maps_private *proc_priv = &numa_priv->proc_maps; struct vm_area_struct *vma = v; struct numa_maps *md = &numa_priv->md; - struct file *file = vma->vm_file; + struct file *file = vma_pr_or_file(vma); struct mm_struct *mm = vma->vm_mm; struct mm_walk walk = { .hugetlb_entry = gather_hugetlb_stats, diff --git a/fs/proc/task_nommu.c b/fs/proc/task_nommu.c index 36bf0f2e102e..8df6cbc58756 100644 --- a/fs/proc/task_nommu.c +++ b/fs/proc/task_nommu.c @@ -155,7 +155,10 @@ static int nommu_vma_show(struct seq_file *m, struct vm_area_struct *vma) file = vma->vm_file; if (file) { - struct inode *inode = file_inode(vma->vm_file); + struct inode *inode; + + file = vma_pr_or_file(vma); + inode = file_inode(file); dev = inode->i_sb->s_dev; ino = inode->i_ino; pgoff = (loff_t)vma->vm_pgoff << PAGE_SHIFT; diff --git a/include/linux/mm.h b/include/linux/mm.h index dd0b5f4e1e45..22030c24191e 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1553,6 +1553,28 @@ static inline void unmap_shared_mapping_range(struct address_space *mapping, unmap_mapping_range(mapping, holebegin, holelen, 0); } +extern void vma_do_file_update_time(struct vm_area_struct *, const char[], int); +extern struct file *vma_do_pr_or_file(struct vm_area_struct *, const char[], + int); +extern void vma_do_get_file(struct vm_area_struct *, const char[], int); +extern void vma_do_fput(struct vm_area_struct *, const char[], int); + +#define vma_file_update_time(vma) vma_do_file_update_time(vma, __func__, \ + __LINE__) +#define vma_pr_or_file(vma) vma_do_pr_or_file(vma, __func__, \ + __LINE__) +#define vma_get_file(vma) vma_do_get_file(vma, __func__, __LINE__) +#define vma_fput(vma) vma_do_fput(vma, __func__, __LINE__) + +#ifndef CONFIG_MMU +extern struct file *vmr_do_pr_or_file(struct vm_region *, const char[], int); +extern void vmr_do_fput(struct vm_region *, const char[], int); + +#define vmr_pr_or_file(region) vmr_do_pr_or_file(region, __func__, \ + __LINE__) +#define vmr_fput(region) vmr_do_fput(region, __func__, __LINE__) +#endif /* !CONFIG_MMU */ + extern int access_process_vm(struct task_struct *tsk, unsigned long addr, void *buf, int len, unsigned int gup_flags); extern int access_remote_vm(struct mm_struct *mm, unsigned long addr, diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h index 8ec38b11b361..d3f5492a2611 100644 --- a/include/linux/mm_types.h +++ b/include/linux/mm_types.h @@ -253,6 +253,7 @@ struct vm_region { unsigned long vm_top; /* region allocated to here */ unsigned long vm_pgoff; /* the offset in vm_file corresponding to vm_start */ struct file *vm_file; /* the backing file or NULL */ + struct file *vm_prfile; /* the virtual backing file or NULL */ int vm_usage; /* region usage count (access under nommu_region_sem) */ bool vm_icache_flushed : 1; /* true if the icache has been flushed for @@ -327,6 +328,7 @@ struct vm_area_struct { unsigned long vm_pgoff; /* Offset (within vm_file) in PAGE_SIZE units */ struct file * vm_file; /* File we map to (can be NULL). */ + struct file *vm_prfile; /* shadow of vm_file */ void * vm_private_data; /* was vm_pte (shared mem) */ atomic_long_t swap_readahead_info; diff --git a/kernel/fork.c b/kernel/fork.c index 61667909ce83..d444b5dae73e 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -553,7 +553,7 @@ static __latent_entropy int dup_mmap(struct mm_struct *mm, struct inode *inode = file_inode(file); struct address_space *mapping = file->f_mapping; - get_file(file); + vma_get_file(tmp); if (tmp->vm_flags & VM_DENYWRITE) atomic_dec(&inode->i_writecount); i_mmap_lock_write(mapping); diff --git a/mm/Makefile b/mm/Makefile index ac5e5ba78874..5decb22d13a0 100644 --- a/mm/Makefile +++ b/mm/Makefile @@ -39,7 +39,7 @@ obj-y := filemap.o mempool.o oom_kill.o fadvise.o \ mm_init.o mmu_context.o percpu.o slab_common.o \ compaction.o vmacache.o \ interval_tree.o list_lru.o workingset.o \ - debug.o $(mmu-y) + prfile.o debug.o $(mmu-y) # Give 'page_alloc' its own module-parameter namespace page-alloc-y := page_alloc.o diff --git a/mm/filemap.c b/mm/filemap.c index df2006ba0cfa..d5221dedfe56 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -2671,7 +2671,7 @@ vm_fault_t filemap_page_mkwrite(struct vm_fault *vmf) vm_fault_t ret = VM_FAULT_LOCKED; sb_start_pagefault(inode->i_sb); - file_update_time(vmf->vma->vm_file); + vma_file_update_time(vmf->vma); lock_page(page); if (page->mapping != inode->i_mapping) { unlock_page(page); diff --git a/mm/mmap.c b/mm/mmap.c index 7e8c3e8ae75f..d8a903f61262 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -182,7 +182,7 @@ static struct vm_area_struct *remove_vma(struct vm_area_struct *vma) if (vma->vm_ops && vma->vm_ops->close) vma->vm_ops->close(vma); if (vma->vm_file) - fput(vma->vm_file); + vma_fput(vma); mpol_put(vma_policy(vma)); vm_area_free(vma); return next; @@ -931,7 +931,7 @@ int __vma_adjust(struct vm_area_struct *vma, unsigned long start, if (remove_next) { if (file) { uprobe_munmap(next, next->vm_start, next->vm_end); - fput(file); + vma_fput(vma); } if (next->anon_vma) anon_vma_merge(vma, next); @@ -1847,8 +1847,8 @@ unsigned long mmap_region(struct file *file, unsigned long addr, return addr; unmap_and_free_vma: + vma_fput(vma); vma->vm_file = NULL; - fput(file); /* Undo any partial mapping done by a device driver. */ unmap_region(mm, vma, prev, vma->vm_start, vma->vm_end); @@ -2680,7 +2680,7 @@ int __split_vma(struct mm_struct *mm, struct vm_area_struct *vma, goto out_free_mpol; if (new->vm_file) - get_file(new->vm_file); + vma_get_file(new); if (new->vm_ops && new->vm_ops->open) new->vm_ops->open(new); @@ -2699,7 +2699,7 @@ int __split_vma(struct mm_struct *mm, struct vm_area_struct *vma, if (new->vm_ops && new->vm_ops->close) new->vm_ops->close(new); if (new->vm_file) - fput(new->vm_file); + vma_fput(new); unlink_anon_vmas(new); out_free_mpol: mpol_put(vma_policy(new)); @@ -2890,7 +2890,7 @@ SYSCALL_DEFINE5(remap_file_pages, unsigned long, start, unsigned long, size, struct vm_area_struct *vma; unsigned long populate = 0; unsigned long ret = -EINVAL; - struct file *file; + struct file *file, *prfile; pr_warn_once("%s (%d) uses deprecated remap_file_pages() syscall. See Documentation/vm/remap_file_pages.rst.\n", current->comm, current->pid); @@ -2965,10 +2965,27 @@ SYSCALL_DEFINE5(remap_file_pages, unsigned long, start, unsigned long, size, } } - file = get_file(vma->vm_file); + vma_get_file(vma); + file = vma->vm_file; + prfile = vma->vm_prfile; ret = do_mmap_pgoff(vma->vm_file, start, size, prot, flags, pgoff, &populate, NULL); + if (!IS_ERR_VALUE(ret) && file && prfile) { + struct vm_area_struct *new_vma; + + new_vma = find_vma(mm, ret); + if (!new_vma->vm_prfile) + new_vma->vm_prfile = prfile; + if (new_vma != vma) + get_file(prfile); + } + /* + * two fput()s instead of vma_fput(vma), + * coz vma may not be available anymore. + */ fput(file); + if (prfile) + fput(prfile); out: up_write(&mm->mmap_sem); if (populate) @@ -3258,7 +3275,7 @@ struct vm_area_struct *copy_vma(struct vm_area_struct **vmap, if (anon_vma_clone(new_vma, vma)) goto out_free_mempol; if (new_vma->vm_file) - get_file(new_vma->vm_file); + vma_get_file(new_vma); if (new_vma->vm_ops && new_vma->vm_ops->open) new_vma->vm_ops->open(new_vma); vma_link(mm, new_vma, prev, rb_link, rb_parent); diff --git a/mm/nommu.c b/mm/nommu.c index d8c02fbe03b5..22dae8b7216a 100644 --- a/mm/nommu.c +++ b/mm/nommu.c @@ -640,7 +640,7 @@ static void __put_nommu_region(struct vm_region *region) up_write(&nommu_region_sem); if (region->vm_file) - fput(region->vm_file); + vmr_fput(region); /* IO memory and memory shared directly out of the pagecache * from ramfs/tmpfs mustn't be released here */ @@ -778,7 +778,7 @@ static void delete_vma(struct mm_struct *mm, struct vm_area_struct *vma) if (vma->vm_ops && vma->vm_ops->close) vma->vm_ops->close(vma); if (vma->vm_file) - fput(vma->vm_file); + vma_fput(vma); put_nommu_region(vma->vm_region); vm_area_free(vma); } @@ -1301,7 +1301,7 @@ unsigned long do_mmap(struct file *file, goto error_just_free; } } - fput(region->vm_file); + vmr_fput(region); kmem_cache_free(vm_region_jar, region); region = pregion; result = start; @@ -1376,10 +1376,10 @@ unsigned long do_mmap(struct file *file, up_write(&nommu_region_sem); error: if (region->vm_file) - fput(region->vm_file); + vmr_fput(region); kmem_cache_free(vm_region_jar, region); if (vma->vm_file) - fput(vma->vm_file); + vma_fput(vma); vm_area_free(vma); return ret; diff --git a/mm/prfile.c b/mm/prfile.c new file mode 100644 index 000000000000..024cdcfae1b1 --- /dev/null +++ b/mm/prfile.c @@ -0,0 +1,86 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Mainly for aufs which mmap(2) different file and wants to print different + * path in /proc/PID/maps. + * Call these functions via macros defined in linux/mm.h. + * + * See Documentation/filesystems/aufs/design/06mmap.txt + * + * Copyright (c) 2014-2019 Junjro R. Okajima + * Copyright (c) 2014 Ian Campbell + */ + +#include +#include +#include + +/* #define PRFILE_TRACE */ +static inline void prfile_trace(struct file *f, struct file *pr, + const char func[], int line, const char func2[]) +{ +#ifdef PRFILE_TRACE + if (pr) + pr_info("%s:%d: %s, %pD2\n", func, line, func2, f); +#endif +} + +void vma_do_file_update_time(struct vm_area_struct *vma, const char func[], + int line) +{ + struct file *f = vma->vm_file, *pr = vma->vm_prfile; + + prfile_trace(f, pr, func, line, __func__); + file_update_time(f); + if (f && pr) + file_update_time(pr); +} + +struct file *vma_do_pr_or_file(struct vm_area_struct *vma, const char func[], + int line) +{ + struct file *f = vma->vm_file, *pr = vma->vm_prfile; + + prfile_trace(f, pr, func, line, __func__); + return (f && pr) ? pr : f; +} + +void vma_do_get_file(struct vm_area_struct *vma, const char func[], int line) +{ + struct file *f = vma->vm_file, *pr = vma->vm_prfile; + + prfile_trace(f, pr, func, line, __func__); + get_file(f); + if (f && pr) + get_file(pr); +} + +void vma_do_fput(struct vm_area_struct *vma, const char func[], int line) +{ + struct file *f = vma->vm_file, *pr = vma->vm_prfile; + + prfile_trace(f, pr, func, line, __func__); + fput(f); + if (f && pr) + fput(pr); +} + +#ifndef CONFIG_MMU +struct file *vmr_do_pr_or_file(struct vm_region *region, const char func[], + int line) +{ + struct file *f = region->vm_file, *pr = region->vm_prfile; + + prfile_trace(f, pr, func, line, __func__); + return (f && pr) ? pr : f; +} + +void vmr_do_fput(struct vm_region *region, const char func[], int line) +{ + struct file *f = region->vm_file, *pr = region->vm_prfile; + + prfile_trace(f, pr, func, line, __func__); + fput(f); + if (f && pr) + fput(pr); +} +#endif /* !CONFIG_MMU */ -- 2.19.1