From c2ec175c39f62949438354f603f4aa170846aabb Mon Sep 17 00:00:00 2001 From: Nick Piggin Date: Tue, 31 Mar 2009 15:23:21 -0700 Subject: [PATCH] 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: Nick Piggin Cc: Chris Mason Cc: Trond Myklebust Cc: Miklos Szeredi Cc: Steven Whitehouse Cc: Mark Fasheh Cc: Joel Becker Cc: Artem Bityutskiy Cc: Felix Blyakher Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- 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 | 26 ++++++++++++++++++++++---- 16 files changed, 65 insertions(+), 23 deletions(-) diff --git a/Documentation/filesystems/Locking b/Documentation/filesystems/Locking index 4e78ce677843..76efe5b71d7d 100644 --- a/Documentation/filesystems/Locking +++ b/Documentation/filesystems/Locking @@ -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: diff --git a/drivers/video/fb_defio.c b/drivers/video/fb_defio.c index 082026546aee..0a7a6679ee6e 100644 --- a/drivers/video/fb_defio.c +++ b/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; diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index 5e1d4e30e9d8..7dd1b6d0bf32 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -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); diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 7d4f948bc22a..ec5423790bbb 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -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; } diff --git a/fs/buffer.c b/fs/buffer.c index 73abe6d8218c..6d51a3da362c 100644 --- a/fs/buffer.c +++ b/fs/buffer.c @@ -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; } diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h index 6083bb38057b..990c94000924 100644 --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -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 */ diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 71d3ecd5db79..dd82ff390067 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.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; } diff --git a/fs/fuse/file.c b/fs/fuse/file.c index 821d10f719bd..4e340fedf768 100644 --- a/fs/fuse/file.c +++ b/fs/fuse/file.c @@ -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. diff --git a/fs/gfs2/ops_file.c b/fs/gfs2/ops_file.c index 3b9e8de3500b..70b9b8548945 100644 --- a/fs/gfs2/ops_file.c +++ b/fs/gfs2/ops_file.c @@ -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; } diff --git a/fs/nfs/file.c b/fs/nfs/file.c index 90f292b520d2..cec79392e4ba 100644 --- a/fs/nfs/file.c +++ b/fs/nfs/file.c @@ -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; } diff --git a/fs/ocfs2/mmap.c b/fs/ocfs2/mmap.c index eea1d24713ea..b606496b72ec 100644 --- a/fs/ocfs2/mmap.c +++ b/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; } diff --git a/fs/ubifs/file.c b/fs/ubifs/file.c index 93b6de51f261..0ff89fe71e51 100644 --- a/fs/ubifs/file.c +++ b/fs/ubifs/file.c @@ -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; } diff --git a/fs/xfs/linux-2.6/xfs_file.c b/fs/xfs/linux-2.6/xfs_file.c index e14c4e3aea0c..f4e255441574 100644 --- a/fs/xfs/linux-2.6/xfs_file.c +++ b/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 = { diff --git a/include/linux/buffer_head.h b/include/linux/buffer_head.h index f19fd9045ea0..3d7bcde2e332 100644 --- a/include/linux/buffer_head.h +++ b/include/linux/buffer_head.h @@ -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 *); diff --git a/include/linux/mm.h b/include/linux/mm.h index 2223f8dfa568..aeabe953ba4f 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -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 diff --git a/mm/memory.c b/mm/memory.c index 5b4ad5e4f98d..cf6873e91c6a 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -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; } -- 2.20.1