Hi,
Looks good to me from a GFS2 standpoint,
Steve.
On Tue, Mar 03, 2009 at 11:38:38AM +0100, Nick Piggin wrote:
>
> Change the page_mkwrite prototype to take a struct vm_fault, and return
> VM_FAULT_xxx flags. Same as ->fault handler. Should be no change in
> behaviour.
>
> 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.
>
> ---
> Documentation/filesystems/Locking | 2 +-
> drivers/video/fb_defio.c | 3 ++-
> fs/btrfs/ctree.h | 2 +-
> fs/btrfs/inode.c | 5 ++++-
> fs/buffer.c | 6 +++++-
> fs/ext4/ext4.h | 2 +-
> fs/ext4/inode.c | 5 ++++-
> fs/fuse/file.c | 3 ++-
> fs/gfs2/ops_file.c | 5 ++++-
> fs/nfs/file.c | 5 ++++-
> fs/ocfs2/mmap.c | 6 ++++--
> fs/ubifs/file.c | 9 ++++++---
> fs/xfs/linux-2.6/xfs_file.c | 4 ++--
> include/linux/buffer_head.h | 2 +-
> include/linux/mm.h | 3 ++-
> mm/memory.c | 25 +++++++++++++++++++++----
> 16 files changed, 64 insertions(+), 23 deletions(-)
>
> Index: linux-2.6/Documentation/filesystems/Locking
> ===================================================================
> --- linux-2.6.orig/Documentation/filesystems/Locking
> +++ linux-2.6/Documentation/filesystems/Locking
> @@ -502,7 +502,7 @@ 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:
> Index: linux-2.6/fs/btrfs/ctree.h
> ===================================================================
> --- linux-2.6.orig/fs/btrfs/ctree.h
> +++ linux-2.6/fs/btrfs/ctree.h
> @@ -2051,7 +2051,7 @@ int btrfs_merge_bio_hook(struct page *pa
> 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);
> Index: linux-2.6/fs/btrfs/inode.c
> ===================================================================
> --- linux-2.6.orig/fs/btrfs/inode.c
> +++ linux-2.6/fs/btrfs/inode.c
> @@ -4292,8 +4292,9 @@ static void btrfs_invalidatepage(struct
> * 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;
> }
>
> Index: linux-2.6/fs/buffer.c
> ===================================================================
> --- linux-2.6.orig/fs/buffer.c
> +++ linux-2.6/fs/buffer.c
> @@ -2466,9 +2466,10 @@ int block_commit_write(struct page *page
> * 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;
> @@ -2493,6 +2494,9 @@ block_page_mkwrite(struct vm_area_struct
> ret = block_commit_write(page, 0, end);
>
> out_unlock:
> + if (ret)
> + ret = VM_FAULT_SIGBUS;
> +
> unlock_page(page);
> return ret;
> }
> Index: linux-2.6/fs/ext4/ext4.h
> ===================================================================
> --- linux-2.6.orig/fs/ext4/ext4.h
> +++ linux-2.6/fs/ext4/ext4.h
> @@ -1097,7 +1097,7 @@ extern int ext4_meta_trans_blocks(struct
> 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);
>
> /* ioctl.c */
> extern long ext4_ioctl(struct file *, unsigned int, unsigned long);
> Index: linux-2.6/fs/ext4/inode.c
> ===================================================================
> --- linux-2.6.orig/fs/ext4/inode.c
> +++ linux-2.6/fs/ext4/inode.c
> @@ -5116,8 +5116,9 @@ static int ext4_bh_unmapped(handle_t *ha
> 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;
> @@ -5169,6 +5170,8 @@ int ext4_page_mkwrite(struct vm_area_str
> goto out_unlock;
> ret = 0;
> out_unlock:
> + if (ret)
> + ret = VM_FAULT_SIGBUS;
> up_read(&inode->i_alloc_sem);
> return ret;
> }
> Index: linux-2.6/fs/fuse/file.c
> ===================================================================
> --- linux-2.6.orig/fs/fuse/file.c
> +++ linux-2.6/fs/fuse/file.c
> @@ -1234,8 +1234,9 @@ static void fuse_vma_close(struct vm_are
> * - 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.
> Index: linux-2.6/fs/gfs2/ops_file.c
> ===================================================================
> --- linux-2.6.orig/fs/gfs2/ops_file.c
> +++ linux-2.6/fs/gfs2/ops_file.c
> @@ -336,8 +336,9 @@ static int gfs2_allocate_page_backing(st
> * 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);
> @@ -409,6 +410,8 @@ out_unlock:
> gfs2_glock_dq(&gh);
> out:
> gfs2_holder_uninit(&gh);
> + if (ret)
> + ret = VM_FAULT_SIGBUS;
> return ret;
> }
>
> Index: linux-2.6/fs/nfs/file.c
> ===================================================================
> --- linux-2.6.orig/fs/nfs/file.c
> +++ linux-2.6/fs/nfs/file.c
> @@ -451,8 +451,9 @@ const struct address_space_operations nf
> .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
> ret = pagelen;
> out_unlock:
> unlock_page(page);
> + if (ret)
> + ret = VM_FAULT_SIGBUS;
> return ret;
> }
>
> Index: linux-2.6/fs/ocfs2/mmap.c
> ===================================================================
> --- linux-2.6.orig/fs/ocfs2/mmap.c
> +++ linux-2.6/fs/ocfs2/mmap.c
> @@ -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;
> }
>
> Index: linux-2.6/fs/ubifs/file.c
> ===================================================================
> --- linux-2.6.orig/fs/ubifs/file.c
> +++ linux-2.6/fs/ubifs/file.c
> @@ -1434,8 +1434,9 @@ static int ubifs_releasepage(struct page
> * 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
> 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
> 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
> out_unlock:
> unlock_page(page);
> ubifs_release_budget(c, &req);
> + if (err)
> + err = VM_FAULT_SIGBUS;
> return err;
> }
>
> Index: linux-2.6/fs/xfs/linux-2.6/xfs_file.c
> ===================================================================
> --- linux-2.6.orig/fs/xfs/linux-2.6/xfs_file.c
> +++ linux-2.6/fs/xfs/linux-2.6/xfs_file.c
> @@ -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 = {
> Index: linux-2.6/include/linux/buffer_head.h
> ===================================================================
> --- linux-2.6.orig/include/linux/buffer_head.h
> +++ linux-2.6/include/linux/buffer_head.h
> @@ -223,7 +223,7 @@ int cont_write_begin(struct file *, stru
> 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 *);
> Index: linux-2.6/include/linux/mm.h
> ===================================================================
> --- linux-2.6.orig/include/linux/mm.h
> +++ linux-2.6/include/linux/mm.h
> @@ -134,6 +134,7 @@ 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
> @@ -186,7 +187,7 @@ 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
> Index: linux-2.6/mm/memory.c
> ===================================================================
> --- linux-2.6.orig/mm/memory.c
> +++ linux-2.6/mm/memory.c
> @@ -1938,6 +1938,14 @@ static int do_wp_page(struct mm_struct *
> * 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
> @@ -1949,8 +1957,12 @@ static int do_wp_page(struct mm_struct *
> 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
> @@ -2099,7 +2111,7 @@ oom:
>
> unwritable_page:
> page_cache_release(old_page);
> - return VM_FAULT_SIGBUS;
> + return ret;
> }
>
> /*
> @@ -2643,9 +2655,14 @@ static int __do_fault(struct mm_struct *
> * 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;
> }
> Index: linux-2.6/drivers/video/fb_defio.c
> ===================================================================
> --- linux-2.6.orig/drivers/video/fb_defio.c
> +++ linux-2.6/drivers/video/fb_defio.c
> @@ -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;
> --
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