[SRU v2][jammy:hwe-5.17][kinetic:master-next][PATCH 1/2] UBUNTU: SAUCE: for aufs mmap: print the virtual file path
Alexander Mikhalitsyn
alexander.mikhalitsyn at virtuozzo.com
Wed Aug 3 12:00:43 UTC 2022
From: "J. R. Okajima" <hooanon05g at gmail.com>
For details, read the document in later commit.
I don't like this approach, and UnionMount seems to try solving a
similar problem by customizing f_dentry and d_inode. Ideally it is
better to result the same fix, but it may not be so easy because
UnionMount doesn't have its virtual inode/dentry/file objects as it is
not a 'filesystem.'
Signed-off-by: J. R. Okajima <hooanon05g at gmail.com>
(cherry picked from commit f8a27912904bdc40a27f434a9b6d19f56e7fb3b6)
[ https://github.com/sfjro/aufs5-linux ]
This patch is required for proper fix of:
a80dceb9e85 ("UBUNTU: SAUCE: overlayfs: allow with shiftfs as underlay")
Please, refer to bug:
https://bugs.launchpad.net/bugs/1967924
for more details
Rebased to jammy/hwe-5.17 kernel.
Signed-off-by: Alexander Mikhalitsyn <alexander.mikhalitsyn at virtuozzo.com>
---
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 9c336c8e170e..47772df2ffab 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -2191,7 +2191,7 @@ static int map_files_get_link(struct dentry *dentry, struct path *path)
rc = -ENOENT;
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 13452b32e2bd..38acccfef9d4 100644
--- a/fs/proc/nommu.c
+++ b/fs/proc/nommu.c
@@ -40,7 +40,10 @@ 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 f46060eb91b5..2a7c8709acad 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -281,7 +281,10 @@ 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;
@@ -1903,7 +1906,7 @@ 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 mempolicy *pol;
char buffer[64];
diff --git a/fs/proc/task_nommu.c b/fs/proc/task_nommu.c
index a6d21fc0033c..02c2de31196e 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 9cb0ff065e8b..f6ee792b17dd 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1895,6 +1895,28 @@ 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 0f549870da6a..67d02ae46b8f 100644
--- a/include/linux/mm_types.h
+++ b/include/linux/mm_types.h
@@ -344,6 +344,7 @@ 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
@@ -440,6 +441,7 @@ 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) */
#ifdef CONFIG_SWAP
diff --git a/kernel/fork.c b/kernel/fork.c
index 14553058c4b8..89a106e2776b 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -580,7 +580,7 @@ static __latent_entropy int dup_mmap(struct mm_struct *mm,
if (file) {
struct address_space *mapping = file->f_mapping;
- get_file(file);
+ vma_get_file(tmp);
i_mmap_lock_write(mapping);
if (tmp->vm_flags & VM_SHARED)
mapping_allow_writable(mapping);
diff --git a/mm/Makefile b/mm/Makefile
index 70d4309c9ce3..9acff75987df 100644
--- a/mm/Makefile
+++ b/mm/Makefile
@@ -54,7 +54,7 @@ obj-y := filemap.o mempool.o oom_kill.o fadvise.o \
mm_init.o percpu.o slab_common.o \
compaction.o vmacache.o \
interval_tree.o list_lru.o workingset.o \
- debug.o gup.o mmap_lock.o $(mmu-y)
+ prfile.o debug.o gup.o mmap_lock.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 ad8c39d90bf9..f95b595a49b7 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -3395,7 +3395,7 @@ vm_fault_t filemap_page_mkwrite(struct vm_fault *vmf)
vm_fault_t ret = VM_FAULT_LOCKED;
sb_start_pagefault(mapping->host->i_sb);
- file_update_time(vmf->vma->vm_file);
+ vma_file_update_time(vmf->vma);
folio_lock(folio);
if (folio->mapping != mapping) {
folio_unlock(folio);
diff --git a/mm/mmap.c b/mm/mmap.c
index eb39f17cb86e..341711780c06 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -184,7 +184,7 @@ 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;
@@ -953,7 +953,7 @@ 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);
@@ -1879,7 +1879,7 @@ unsigned long mmap_region(struct file *file, unsigned long addr,
return addr;
unmap_and_free_vma:
- fput(vma->vm_file);
+ vma_fput(vma);
vma->vm_file = NULL;
/* Undo any partial mapping done by a device driver. */
@@ -2729,7 +2729,7 @@ 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);
@@ -2748,7 +2748,7 @@ 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));
@@ -2942,7 +2942,7 @@ 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);
@@ -2998,10 +2998,27 @@ SYSCALL_DEFINE5(remap_file_pages, unsigned long, start, unsigned long, size,
if (vma->vm_flags & VM_LOCKED)
flags |= MAP_LOCKED;
- file = get_file(vma->vm_file);
+ vma_get_file(vma);
+ file = vma->vm_file;
+ prfile = vma->vm_prfile;
ret = do_mmap(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:
mmap_write_unlock(mm);
if (populate)
@@ -3283,7 +3300,7 @@ 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 55a9e48a7a02..8dc77ce96335 100644
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -522,7 +522,7 @@ 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 */
@@ -654,7 +654,7 @@ 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);
}
@@ -1174,7 +1174,7 @@ 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;
@@ -1251,10 +1251,10 @@ 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..511543ab1b41
--- /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) 2014-2021 Junjro R. Okajima
+ * Copyright (c) 2014 Ian Campbell
+ */
+
+#include <linux/mm.h>
+#include <linux/file.h>
+#include <linux/fs.h>
+
+/* #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 */
--
2.36.1
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