[Devel] [PATCH rh7 2/5] mm: implement ->map_pages for page cache
Andrey Ryabinin
aryabinin at virtuozzo.com
Wed Feb 26 16:49:42 MSK 2020
From: "Kirill A. Shutemov" <kirill.shutemov at linux.intel.com>
filemap_map_pages() is generic implementation of ->map_pages() for
filesystems who uses page cache.
It should be safe to use filemap_map_pages() for ->map_pages() if
filesystem use filemap_fault() for ->fault().
Signed-off-by: Kirill A. Shutemov <kirill.shutemov at linux.intel.com>
Acked-by: Linus Torvalds <torvalds at linux-foundation.org>
Cc: Mel Gorman <mgorman at suse.de>
Cc: Rik van Riel <riel at redhat.com>
Cc: Andi Kleen <ak at linux.intel.com>
Cc: Matthew Wilcox <matthew.r.wilcox at intel.com>
Cc: Dave Hansen <dave.hansen at linux.intel.com>
Cc: Alexander Viro <viro at zeniv.linux.org.uk>
Cc: Dave Chinner <david at fromorbit.com>
Cc: Ning Qu <quning at gmail.com>
Cc: Hugh Dickins <hughd at google.com>
Signed-off-by: Andrew Morton <akpm at linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds at linux-foundation.org>
https://jira.sw.ru/browse/PSBM-101300
(cherry picked from commit f1820361f83d556a7f0a9f629100f3825e594328)
Signed-off-by: Andrey Ryabinin <aryabinin at virtuozzo.com>
---
fs/9p/vfs_file.c | 1 +
fs/btrfs/file.c | 1 +
fs/cifs/file.c | 1 +
fs/ext4/file.c | 1 +
fs/f2fs/file.c | 1 +
fs/fuse/file.c | 1 +
fs/gfs2/file.c | 1 +
fs/nfs/file.c | 1 +
fs/nilfs2/file.c | 1 +
fs/ubifs/file.c | 1 +
fs/xfs/xfs_file.c | 1 +
include/linux/mm.h | 1 +
mm/filemap.c | 74 ++++++++++++++++++++++++++++++++++++++++++++++
mm/nommu.c | 6 ++++
14 files changed, 92 insertions(+)
diff --git a/fs/9p/vfs_file.c b/fs/9p/vfs_file.c
index 1ab222986d8b..b261bb06cd47 100644
--- a/fs/9p/vfs_file.c
+++ b/fs/9p/vfs_file.c
@@ -734,6 +734,7 @@ v9fs_cached_file_write(struct file *filp, const char __user * data,
static const struct vm_operations_struct v9fs_file_vm_ops = {
.fault = filemap_fault,
+ .map_pages = filemap_map_pages,
.page_mkwrite = v9fs_vm_page_mkwrite,
};
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index f3199b4d87de..80dcf423266c 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -2188,6 +2188,7 @@ int btrfs_sync_file(struct file *file, loff_t start, loff_t end, int datasync)
static const struct vm_operations_struct btrfs_file_vm_ops = {
.fault = filemap_fault,
+ .map_pages = filemap_map_pages,
.page_mkwrite = btrfs_page_mkwrite,
};
diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index ccca9c5d9d0f..3f5304f5acf0 100644
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -3398,6 +3398,7 @@ cifs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
static struct vm_operations_struct cifs_file_vm_ops = {
.fault = filemap_fault,
+ .map_pages = filemap_map_pages,
.page_mkwrite = cifs_page_mkwrite,
};
diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index 5acd8ae38db2..509a4ca6c39d 100644
--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c
@@ -349,6 +349,7 @@ static const struct vm_operations_struct ext4_dax_vm_ops = {
static const struct vm_operations_struct ext4_file_vm_ops = {
.fault = ext4_filemap_fault,
.page_mkwrite = ext4_page_mkwrite,
+ .map_pages = filemap_map_pages,
};
static int ext4_file_mmap(struct file *file, struct vm_area_struct *vma)
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index 36a8bec3f5ee..f9b38dc7e897 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -99,6 +99,7 @@ static int f2fs_vm_page_mkwrite(struct vm_area_struct *vma,
static const struct vm_operations_struct f2fs_file_vm_ops = {
.fault = filemap_fault,
+ .map_pages = filemap_map_pages,
.page_mkwrite = f2fs_vm_page_mkwrite,
};
diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index e2e54d5ad571..193c7d3a9cb4 100644
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -2656,6 +2656,7 @@ static int fuse_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
static const struct vm_operations_struct fuse_file_vm_ops = {
.close = fuse_vma_close,
.fault = filemap_fault,
+ .map_pages = filemap_map_pages,
.page_mkwrite = fuse_page_mkwrite,
};
diff --git a/fs/gfs2/file.c b/fs/gfs2/file.c
index a7d368691df0..53a11f484fb4 100644
--- a/fs/gfs2/file.c
+++ b/fs/gfs2/file.c
@@ -506,6 +506,7 @@ static int gfs2_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
static const struct vm_operations_struct gfs2_vm_ops = {
.fault = filemap_fault,
+ .map_pages = filemap_map_pages,
.page_mkwrite = gfs2_page_mkwrite,
};
diff --git a/fs/nfs/file.c b/fs/nfs/file.c
index 7fab5b6cbdef..62ab01623433 100644
--- a/fs/nfs/file.c
+++ b/fs/nfs/file.c
@@ -624,6 +624,7 @@ static int nfs_vm_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
static const struct vm_operations_struct nfs_file_vm_ops = {
.fault = filemap_fault,
+ .map_pages = filemap_map_pages,
.page_mkwrite = nfs_vm_page_mkwrite,
};
diff --git a/fs/nilfs2/file.c b/fs/nilfs2/file.c
index e3ce6c9e2a7b..e0c458b8a168 100644
--- a/fs/nilfs2/file.c
+++ b/fs/nilfs2/file.c
@@ -134,6 +134,7 @@ static int nilfs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
static const struct vm_operations_struct nilfs_file_vm_ops = {
.fault = filemap_fault,
+ .map_pages = filemap_map_pages,
.page_mkwrite = nilfs_page_mkwrite,
};
diff --git a/fs/ubifs/file.c b/fs/ubifs/file.c
index 2dfae9a054c6..09c7e78ea2fc 100644
--- a/fs/ubifs/file.c
+++ b/fs/ubifs/file.c
@@ -1537,6 +1537,7 @@ static int ubifs_vm_page_mkwrite(struct vm_area_struct *vma,
static const struct vm_operations_struct ubifs_file_vm_ops = {
.fault = filemap_fault,
+ .map_pages = filemap_map_pages,
.page_mkwrite = ubifs_vm_page_mkwrite,
};
diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index 891c37fe3992..5c0d38b82bb1 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -1316,6 +1316,7 @@ static const struct vm_operations_struct xfs_file_vm_ops = {
.huge_fault = xfs_filemap_huge_fault,
.page_mkwrite = xfs_filemap_page_mkwrite,
.pfn_mkwrite = xfs_filemap_pfn_mkwrite,
+ .map_pages = filemap_map_pages,
};
STATIC int
diff --git a/include/linux/mm.h b/include/linux/mm.h
index bc4536044e7d..701818b16b1b 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -2156,6 +2156,7 @@ extern void truncate_inode_pages_final(struct address_space *);
/* generic vm_area_ops exported for stackable file systems */
extern int filemap_fault(struct vm_area_struct *, struct vm_fault *);
+extern void filemap_map_pages(struct vm_area_struct *vma, struct vm_fault *vmf);
extern int filemap_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf);
struct path;
diff --git a/mm/filemap.c b/mm/filemap.c
index fd9abfec4b41..2ba7ef844af6 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -35,6 +35,7 @@
#include <linux/hugetlb.h>
#include <linux/memcontrol.h>
#include <linux/cleancache.h>
+#include <linux/rmap.h>
#include "internal.h"
#define CREATE_TRACE_POINTS
@@ -2408,6 +2409,78 @@ int filemap_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
}
EXPORT_SYMBOL(filemap_fault);
+void filemap_map_pages(struct vm_area_struct *vma, struct vm_fault *vmf)
+{
+ struct radix_tree_iter iter;
+ void **slot;
+ struct file *file = vma->vm_file;
+ struct address_space *mapping = file->f_mapping;
+ loff_t size;
+ struct page *page;
+ unsigned long address = (unsigned long) vmf->virtual_address;
+ unsigned long addr;
+ pte_t *pte;
+
+ rcu_read_lock();
+ radix_tree_for_each_slot(slot, &mapping->page_tree, &iter, vmf->pgoff) {
+ if (iter.index > vmf->max_pgoff)
+ break;
+repeat:
+ page = radix_tree_deref_slot(slot);
+ if (unlikely(!page))
+ goto next;
+ if (radix_tree_exception(page)) {
+ if (radix_tree_deref_retry(page))
+ break;
+ else
+ goto next;
+ }
+
+ if (!page_cache_get_speculative(page))
+ goto repeat;
+
+ /* Has the page moved? */
+ if (unlikely(page != *slot)) {
+ page_cache_release(page);
+ goto repeat;
+ }
+
+ if (!PageUptodate(page) ||
+ PageReadahead(page) ||
+ PageHWPoison(page))
+ goto skip;
+ if (!trylock_page(page))
+ goto skip;
+
+ if (page->mapping != mapping || !PageUptodate(page))
+ goto unlock;
+
+ size = i_size_read(mapping->host) + PAGE_CACHE_SIZE - 1;
+ if (page->index >= size >> PAGE_CACHE_SHIFT)
+ goto unlock;
+
+ pte = vmf->pte + page->index - vmf->pgoff;
+ if (!pte_none(*pte))
+ goto unlock;
+
+ if (file->f_ra.mmap_miss > 0)
+ file->f_ra.mmap_miss--;
+ addr = address + (page->index - vmf->pgoff) * PAGE_SIZE;
+ do_set_pte(vma, addr, page, pte, false, false);
+ unlock_page(page);
+ goto next;
+unlock:
+ unlock_page(page);
+skip:
+ page_cache_release(page);
+next:
+ if (iter.index == vmf->max_pgoff)
+ break;
+ }
+ rcu_read_unlock();
+}
+EXPORT_SYMBOL(filemap_map_pages);
+
int filemap_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
{
struct page *page = vmf->page;
@@ -2437,6 +2510,7 @@ EXPORT_SYMBOL(filemap_page_mkwrite);
const struct vm_operations_struct generic_file_vm_ops = {
.fault = filemap_fault,
+ .map_pages = filemap_map_pages,
.page_mkwrite = filemap_page_mkwrite,
};
diff --git a/mm/nommu.c b/mm/nommu.c
index a1c026a88110..0a3cbe94535a 100644
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -2028,6 +2028,12 @@ int filemap_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
}
EXPORT_SYMBOL(filemap_fault);
+void filemap_map_pages(struct vm_area_struct *vma, struct vm_fault *vmf)
+{
+ BUG();
+}
+EXPORT_SYMBOL(filemap_map_pages);
+
static int __access_remote_vm(struct task_struct *tsk, struct mm_struct *mm,
unsigned long addr, void *buf, int len, int write)
{
--
2.24.1
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