Commit c2ec175c authored by Nick Piggin's avatar Nick Piggin Committed by Linus Torvalds
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mm: page_mkwrite change prototype to match fault



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: default avatarNick 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: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent c2fdf3a9
......@@ -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:
......
......@@ -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;
......
......@@ -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);
......
......@@ -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;
}
......
......@@ -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;
}
......
......@@ -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 */
......
......@@ -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;
}
......@@ -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.
......
......@@ -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;
}
......
......@@ -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;
}
......
......@@ -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;
}
......
......@@ -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;
}
......
......@@ -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 = {
......
......@@ -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 *);
......
......@@ -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
......
......@@ -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;
}
......
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