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mm: page_mkwrite change prototype to match fault

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Change the page_mkwrite prototype to take a struct vm_fault, and return
VM_FAULT_xxx flags.  There should be no functional change.

This makes it possible to return much more detailed error information to
the VM (and also can provide more information eg.  virtual_address to the
driver, which might be important in some special cases).

This is required for a subsequent fix.  And will also make it easier to
merge page_mkwrite() with fault() in future.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <joel.becker@oracle.com>
Cc: Artem Bityutskiy <dedekind@infradead.org>
Cc: Felix Blyakher <felixb@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Nick Piggin 2009-03-31 15:23:21 -07:00 committed by Linus Torvalds
parent c2fdf3a9b2
commit c2ec175c39
16 changed files with 65 additions and 23 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
Documentation/filesystems/Locking
View File

@ -505,7 +505,7 @@ prototypes:
void (*open)(struct vm_area_struct*);
void (*close)(struct vm_area_struct*);
int (*fault)(struct vm_area_struct*, struct vm_fault *);
int (*page_mkwrite)(struct vm_area_struct *, struct page *);
int (*page_mkwrite)(struct vm_area_struct *, struct vm_fault *);
int (*access)(struct vm_area_struct *, unsigned long, void*, int, int);
locking rules:

3
drivers/video/fb_defio.c
View File

@ -85,8 +85,9 @@ EXPORT_SYMBOL_GPL(fb_deferred_io_fsync);
/* vm_ops->page_mkwrite handler */
static int fb_deferred_io_mkwrite(struct vm_area_struct *vma,
struct page *page)
struct vm_fault *vmf)
{
struct page *page = vmf->page;
struct fb_info *info = vma->vm_private_data;
struct fb_deferred_io *fbdefio = info->fbdefio;
struct page *cur;

2
fs/btrfs/ctree.h
View File

@ -2060,7 +2060,7 @@ int btrfs_merge_bio_hook(struct page *page, unsigned long offset,
unsigned long btrfs_force_ra(struct address_space *mapping,
struct file_ra_state *ra, struct file *file,
pgoff_t offset, pgoff_t last_index);
int btrfs_page_mkwrite(struct vm_area_struct *vma, struct page *page);
int btrfs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf);
int btrfs_readpage(struct file *file, struct page *page);
void btrfs_delete_inode(struct inode *inode);
void btrfs_put_inode(struct inode *inode);

5
fs/btrfs/inode.c
View File

@ -4292,8 +4292,9 @@ static void btrfs_invalidatepage(struct page *page, unsigned long offset)
* beyond EOF, then the page is guaranteed safe against truncation until we
* unlock the page.
*/
int btrfs_page_mkwrite(struct vm_area_struct *vma, struct page *page)
int btrfs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
{
struct page *page = vmf->page;
struct inode *inode = fdentry(vma->vm_file)->d_inode;
struct btrfs_root *root = BTRFS_I(inode)->root;
struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
@ -4362,6 +4363,8 @@ again:
out_unlock:
unlock_page(page);
out:
if (ret)
ret = VM_FAULT_SIGBUS;
return ret;
}

6
fs/buffer.c
View File

@ -2313,9 +2313,10 @@ int block_commit_write(struct page *page, unsigned from, unsigned to)
* unlock the page.
*/
int
block_page_mkwrite(struct vm_area_struct *vma, struct page *page,
block_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf,
get_block_t get_block)
{
struct page *page = vmf->page;
struct inode *inode = vma->vm_file->f_path.dentry->d_inode;
unsigned long end;
loff_t size;
@ -2340,6 +2341,9 @@ block_page_mkwrite(struct vm_area_struct *vma, struct page *page,
ret = block_commit_write(page, 0, end);
out_unlock:
if (ret)
ret = VM_FAULT_SIGBUS;
unlock_page(page);
return ret;
}

2
fs/ext4/ext4.h
View File

@ -1098,7 +1098,7 @@ extern int ext4_meta_trans_blocks(struct inode *, int nrblocks, int idxblocks);
extern int ext4_chunk_trans_blocks(struct inode *, int nrblocks);
extern int ext4_block_truncate_page(handle_t *handle,
struct address_space *mapping, loff_t from);
extern int ext4_page_mkwrite(struct vm_area_struct *vma, struct page *page);
extern int ext4_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf);
extern qsize_t ext4_get_reserved_space(struct inode *inode);
/* ioctl.c */

5
fs/ext4/inode.c
View File

@ -5146,8 +5146,9 @@ static int ext4_bh_unmapped(handle_t *handle, struct buffer_head *bh)
return !buffer_mapped(bh);
}
int ext4_page_mkwrite(struct vm_area_struct *vma, struct page *page)
int ext4_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
{
struct page *page = vmf->page;
loff_t size;
unsigned long len;
int ret = -EINVAL;
@ -5199,6 +5200,8 @@ int ext4_page_mkwrite(struct vm_area_struct *vma, struct page *page)
goto out_unlock;
ret = 0;
out_unlock:
if (ret)
ret = VM_FAULT_SIGBUS;
up_read(&inode->i_alloc_sem);
return ret;
}

3
fs/fuse/file.c
View File

@ -1234,8 +1234,9 @@ static void fuse_vma_close(struct vm_area_struct *vma)
* - sync(2)
* - try_to_free_pages() with order > PAGE_ALLOC_COSTLY_ORDER
*/
static int fuse_page_mkwrite(struct vm_area_struct *vma, struct page *page)
static int fuse_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
{
struct page *page = vmf->page;
/*
* Don't use page->mapping as it may become NULL from a
* concurrent truncate.

5
fs/gfs2/ops_file.c
View File

@ -337,8 +337,9 @@ static int gfs2_allocate_page_backing(struct page *page)
* blocks allocated on disk to back that page.
*/
static int gfs2_page_mkwrite(struct vm_area_struct *vma, struct page *page)
static int gfs2_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
{
struct page *page = vmf->page;
struct inode *inode = vma->vm_file->f_path.dentry->d_inode;
struct gfs2_inode *ip = GFS2_I(inode);
struct gfs2_sbd *sdp = GFS2_SB(inode);
@ -412,6 +413,8 @@ out_unlock:
gfs2_glock_dq(&gh);
out:
gfs2_holder_uninit(&gh);
if (ret)
ret = VM_FAULT_SIGBUS;
return ret;
}

5
fs/nfs/file.c
View File

@ -451,8 +451,9 @@ const struct address_space_operations nfs_file_aops = {
.launder_page = nfs_launder_page,
};
static int nfs_vm_page_mkwrite(struct vm_area_struct *vma, struct page *page)
static int nfs_vm_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
{
struct page *page = vmf->page;
struct file *filp = vma->vm_file;
struct dentry *dentry = filp->f_path.dentry;
unsigned pagelen;
@ -483,6 +484,8 @@ static int nfs_vm_page_mkwrite(struct vm_area_struct *vma, struct page *page)
ret = pagelen;
out_unlock:
unlock_page(page);
if (ret)
ret = VM_FAULT_SIGBUS;
return ret;
}

6
fs/ocfs2/mmap.c
View File

@ -154,8 +154,9 @@ out:
return ret;
}
static int ocfs2_page_mkwrite(struct vm_area_struct *vma, struct page *page)
static int ocfs2_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
{
struct page *page = vmf->page;
struct inode *inode = vma->vm_file->f_path.dentry->d_inode;
struct buffer_head *di_bh = NULL;
sigset_t blocked, oldset;
@ -196,7 +197,8 @@ out:
ret2 = ocfs2_vm_op_unblock_sigs(&oldset);
if (ret2 < 0)
mlog_errno(ret2);
if (ret)
ret = VM_FAULT_SIGBUS;
return ret;
}

9
fs/ubifs/file.c
View File

@ -1434,8 +1434,9 @@ static int ubifs_releasepage(struct page *page, gfp_t unused_gfp_flags)
* mmap()d file has taken write protection fault and is being made
* writable. UBIFS must ensure page is budgeted for.
*/
static int ubifs_vm_page_mkwrite(struct vm_area_struct *vma, struct page *page)
static int ubifs_vm_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
{
struct page *page = vmf->page;
struct inode *inode = vma->vm_file->f_path.dentry->d_inode;
struct ubifs_info *c = inode->i_sb->s_fs_info;
struct timespec now = ubifs_current_time(inode);
@ -1447,7 +1448,7 @@ static int ubifs_vm_page_mkwrite(struct vm_area_struct *vma, struct page *page)
ubifs_assert(!(inode->i_sb->s_flags & MS_RDONLY));
if (unlikely(c->ro_media))
return -EROFS;
return VM_FAULT_SIGBUS; /* -EROFS */
/*
* We have not locked @page so far so we may budget for changing the
@ -1480,7 +1481,7 @@ static int ubifs_vm_page_mkwrite(struct vm_area_struct *vma, struct page *page)
if (err == -ENOSPC)
ubifs_warn("out of space for mmapped file "
"(inode number %lu)", inode->i_ino);
return err;
return VM_FAULT_SIGBUS;
}
lock_page(page);
@ -1520,6 +1521,8 @@ static int ubifs_vm_page_mkwrite(struct vm_area_struct *vma, struct page *page)
out_unlock:
unlock_page(page);
ubifs_release_budget(c, &req);
if (err)
err = VM_FAULT_SIGBUS;
return err;
}

4
fs/xfs/linux-2.6/xfs_file.c
View File

@ -234,9 +234,9 @@ xfs_file_mmap(
STATIC int
xfs_vm_page_mkwrite(
struct vm_area_struct *vma,
struct page *page)
struct vm_fault *vmf)
{
return block_page_mkwrite(vma, page, xfs_get_blocks);
return block_page_mkwrite(vma, vmf, xfs_get_blocks);
}
const struct file_operations xfs_file_operations = {

2
include/linux/buffer_head.h
View File

@ -216,7 +216,7 @@ int cont_write_begin(struct file *, struct address_space *, loff_t,
get_block_t *, loff_t *);
int generic_cont_expand_simple(struct inode *inode, loff_t size);
int block_commit_write(struct page *page, unsigned from, unsigned to);
int block_page_mkwrite(struct vm_area_struct *vma, struct page *page,
int block_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf,
get_block_t get_block);
void block_sync_page(struct page *);
sector_t generic_block_bmap(struct address_space *, sector_t, get_block_t *);

3
include/linux/mm.h
View File

@ -135,6 +135,7 @@ extern pgprot_t protection_map[16];
#define FAULT_FLAG_WRITE 0x01 /* Fault was a write access */
#define FAULT_FLAG_NONLINEAR 0x02 /* Fault was via a nonlinear mapping */
#define FAULT_FLAG_MKWRITE 0x04 /* Fault was mkwrite of existing pte */
/*
* This interface is used by x86 PAT code to identify a pfn mapping that is
@ -187,7 +188,7 @@ struct vm_operations_struct {
/* notification that a previously read-only page is about to become
* writable, if an error is returned it will cause a SIGBUS */
int (*page_mkwrite)(struct vm_area_struct *vma, struct page *page);
int (*page_mkwrite)(struct vm_area_struct *vma, struct vm_fault *vmf);
/* called by access_process_vm when get_user_pages() fails, typically
* for use by special VMAs that can switch between memory and hardware

26
mm/memory.c
View File

@ -1945,6 +1945,15 @@ static int do_wp_page(struct mm_struct *mm, struct vm_area_struct *vma,
* get_user_pages(.write=1, .force=1).
*/
if (vma->vm_ops && vma->vm_ops->page_mkwrite) {
struct vm_fault vmf;
int tmp;
vmf.virtual_address = (void __user *)(address &
PAGE_MASK);
vmf.pgoff = old_page->index;
vmf.flags = FAULT_FLAG_WRITE|FAULT_FLAG_MKWRITE;
vmf.page = old_page;
/*
* Notify the address space that the page is about to
* become writable so that it can prohibit this or wait
@ -1956,8 +1965,12 @@ static int do_wp_page(struct mm_struct *mm, struct vm_area_struct *vma,
page_cache_get(old_page);
pte_unmap_unlock(page_table, ptl);
if (vma->vm_ops->page_mkwrite(vma, old_page) < 0)
tmp = vma->vm_ops->page_mkwrite(vma, &vmf);
if (unlikely(tmp &
(VM_FAULT_ERROR | VM_FAULT_NOPAGE))) {
ret = tmp;
goto unwritable_page;
}
/*
* Since we dropped the lock we need to revalidate
@ -2106,7 +2119,7 @@ oom:
unwritable_page:
page_cache_release(old_page);
return VM_FAULT_SIGBUS;
return ret;
}
/*
@ -2648,9 +2661,14 @@ static int __do_fault(struct mm_struct *mm, struct vm_area_struct *vma,
* to become writable
*/
if (vma->vm_ops->page_mkwrite) {
int tmp;
unlock_page(page);
if (vma->vm_ops->page_mkwrite(vma, page) < 0) {
ret = VM_FAULT_SIGBUS;
vmf.flags |= FAULT_FLAG_MKWRITE;
tmp = vma->vm_ops->page_mkwrite(vma, &vmf);
if (unlikely(tmp &
(VM_FAULT_ERROR | VM_FAULT_NOPAGE))) {
ret = tmp;
anon = 1; /* no anon but release vmf.page */
goto out_unlocked;
}