---------------------------
+What: filemap_nopage, filemap_populate
+When: April 2007
+Why: These legacy interfaces no longer have any callers in the kernel and
+ any functionality provided can be provided with filemap_fault. The
+ removal schedule is short because they are a big maintainence burden
+ and have some bugs.
+Who: Nick Piggin <npiggin@suse.de>
+
+---------------------------
+
+What: vm_ops.populate, install_page
+When: April 2007
+Why: These legacy interfaces no longer have any callers in the kernel and
+ any functionality provided can be provided with vm_ops.fault.
+Who: Nick Piggin <npiggin@suse.de>
+
+---------------------------
+
+What: vm_ops.nopage
+When: February 2008, provided in-kernel callers have been converted
+Why: This interface is replaced by vm_ops.fault, but it has been around
+ forever, is used by a lot of drivers, and doesn't cost much to
+ maintain.
+Who: Nick Piggin <npiggin@suse.de>
+
+---------------------------
+
What: Interrupt only SA_* flags
When: September 2007
Why: The interrupt related SA_* flags are replaced by IRQF_* to move them
prototypes:
void (*open)(struct vm_area_struct*);
void (*close)(struct vm_area_struct*);
+ struct page *(*fault)(struct vm_area_struct*, struct fault_data *);
struct page *(*nopage)(struct vm_area_struct*, unsigned long, int *);
locking rules:
BKL mmap_sem
open: no yes
close: no yes
+fault: no yes
nopage: no yes
================================================================================
if (file) {
gf = file->private_data;
if (test_bit(GFF_EXLOCK, &gf->f_flags))
- /* gfs2_sharewrite_nopage has grabbed the ip->i_gl already */
+ /* gfs2_sharewrite_fault has grabbed the ip->i_gl already */
goto skip_lock;
}
gfs2_holder_init(ip->i_gl, LM_ST_SHARED, GL_ATIME|LM_FLAG_TRY_1CB, &gh);
else
vma->vm_ops = &gfs2_vm_ops_private;
- vma->vm_flags |= VM_CAN_INVALIDATE;
+ vma->vm_flags |= VM_CAN_INVALIDATE|VM_CAN_NONLINEAR;
gfs2_glock_dq_uninit(&i_gh);
#include "trans.h"
#include "util.h"
-static struct page *gfs2_private_nopage(struct vm_area_struct *area,
- unsigned long address, int *type)
+static struct page *gfs2_private_fault(struct vm_area_struct *vma,
+ struct fault_data *fdata)
{
- struct gfs2_inode *ip = GFS2_I(area->vm_file->f_mapping->host);
+ struct gfs2_inode *ip = GFS2_I(vma->vm_file->f_mapping->host);
set_bit(GIF_PAGED, &ip->i_flags);
- return filemap_nopage(area, address, type);
+ return filemap_fault(vma, fdata);
}
static int alloc_page_backing(struct gfs2_inode *ip, struct page *page)
return error;
}
-static struct page *gfs2_sharewrite_nopage(struct vm_area_struct *area,
- unsigned long address, int *type)
+static struct page *gfs2_sharewrite_fault(struct vm_area_struct *vma,
+ struct fault_data *fdata)
{
- struct file *file = area->vm_file;
+ struct file *file = vma->vm_file;
struct gfs2_file *gf = file->private_data;
struct gfs2_inode *ip = GFS2_I(file->f_mapping->host);
struct gfs2_holder i_gh;
struct page *result = NULL;
- unsigned long index = ((address - area->vm_start) >> PAGE_CACHE_SHIFT) +
- area->vm_pgoff;
int alloc_required;
int error;
set_bit(GIF_PAGED, &ip->i_flags);
set_bit(GIF_SW_PAGED, &ip->i_flags);
- error = gfs2_write_alloc_required(ip, (u64)index << PAGE_CACHE_SHIFT,
- PAGE_CACHE_SIZE, &alloc_required);
- if (error)
+ error = gfs2_write_alloc_required(ip,
+ (u64)fdata->pgoff << PAGE_CACHE_SHIFT,
+ PAGE_CACHE_SIZE, &alloc_required);
+ if (error) {
+ fdata->type = VM_FAULT_OOM; /* XXX: are these right? */
goto out;
+ }
set_bit(GFF_EXLOCK, &gf->f_flags);
- result = filemap_nopage(area, address, type);
+ result = filemap_fault(vma, fdata);
clear_bit(GFF_EXLOCK, &gf->f_flags);
- if (!result || result == NOPAGE_OOM)
+ if (!result)
goto out;
if (alloc_required) {
error = alloc_page_backing(ip, result);
if (error) {
- if (area->vm_flags & VM_CAN_INVALIDATE)
+ if (vma->vm_flags & VM_CAN_INVALIDATE)
unlock_page(result);
page_cache_release(result);
+ fdata->type = VM_FAULT_OOM;
result = NULL;
goto out;
}
}
struct vm_operations_struct gfs2_vm_ops_private = {
- .nopage = gfs2_private_nopage,
+ .fault = gfs2_private_fault,
};
struct vm_operations_struct gfs2_vm_ops_sharewrite = {
- .nopage = gfs2_sharewrite_nopage,
+ .fault = gfs2_sharewrite_fault,
};
/*
* Fill in the supplied page for mmap
*/
-static struct page* ncp_file_mmap_nopage(struct vm_area_struct *area,
- unsigned long address, int *type)
+static struct page* ncp_file_mmap_fault(struct vm_area_struct *area,
+ struct fault_data *fdata)
{
struct file *file = area->vm_file;
struct dentry *dentry = file->f_path.dentry;
page = alloc_page(GFP_HIGHUSER); /* ncpfs has nothing against high pages
as long as recvmsg and memset works on it */
- if (!page)
- return page;
+ if (!page) {
+ fdata->type = VM_FAULT_OOM;
+ return NULL;
+ }
pg_addr = kmap(page);
- address &= PAGE_MASK;
- pos = address - area->vm_start + (area->vm_pgoff << PAGE_SHIFT);
+ pos = fdata->pgoff << PAGE_SHIFT;
count = PAGE_SIZE;
- if (address + PAGE_SIZE > area->vm_end) {
- count = area->vm_end - address;
+ if (fdata->address + PAGE_SIZE > area->vm_end) {
+ WARN_ON(1); /* shouldn't happen? */
+ count = area->vm_end - fdata->address;
}
/* what we can read in one go */
bufsize = NCP_SERVER(inode)->buffer_size;
* fetches from the network, here the analogue of disk.
* -- wli
*/
- if (type)
- *type = VM_FAULT_MAJOR;
+ fdata->type = VM_FAULT_MAJOR;
count_vm_event(PGMAJFAULT);
return page;
}
static struct vm_operations_struct ncp_file_mmap =
{
- .nopage = ncp_file_mmap_nopage,
+ .fault = ncp_file_mmap_fault,
};
* might now be discovering a truncate that hit on another node.
* block_read_full_page->get_block freaks out if it is asked to read
* beyond the end of a file, so we check here. Callers
- * (generic_file_read, fault->nopage) are clever enough to check i_size
+ * (generic_file_read, vm_ops->fault) are clever enough to check i_size
* and notice that the page they just read isn't needed.
*
* XXX sys_readahead() seems to get that wrong?
return sigprocmask(SIG_SETMASK, oldset, NULL);
}
-static struct page *ocfs2_nopage(struct vm_area_struct * area,
- unsigned long address,
- int *type)
+static struct page *ocfs2_fault(struct vm_area_struct *area,
+ struct fault_data *fdata)
{
- struct page *page = NOPAGE_SIGBUS;
+ struct page *page = NULL;
sigset_t blocked, oldset;
int ret;
- mlog_entry("(area=%p, address=%lu, type=%p)\n", area, address,
- type);
+ mlog_entry("(area=%p, page offset=%lu)\n", area, fdata->pgoff);
ret = ocfs2_vm_op_block_sigs(&blocked, &oldset);
if (ret < 0) {
+ fdata->type = VM_FAULT_SIGBUS;
mlog_errno(ret);
goto out;
}
- page = filemap_nopage(area, address, type);
+ page = filemap_fault(area, fdata);
ret = ocfs2_vm_op_unblock_sigs(&oldset);
if (ret < 0)
}
static struct vm_operations_struct ocfs2_file_vm_ops = {
- .nopage = ocfs2_nopage,
+ .fault = ocfs2_fault,
.page_mkwrite = ocfs2_page_mkwrite,
};
ocfs2_meta_unlock(file->f_dentry->d_inode, lock_level);
out:
vma->vm_ops = &ocfs2_file_vm_ops;
- vma->vm_flags |= VM_CAN_INVALIDATE;
+ vma->vm_flags |= VM_CAN_INVALIDATE | VM_CAN_NONLINEAR;
return 0;
}
#ifdef CONFIG_XFS_DMAPI
STATIC struct page *
-xfs_vm_nopage(
- struct vm_area_struct *area,
- unsigned long address,
- int *type)
+xfs_vm_fault(
+ struct vm_area_struct *vma,
+ struct fault_data *fdata)
{
- struct inode *inode = area->vm_file->f_path.dentry->d_inode;
+ struct inode *inode = vma->vm_file->f_path.dentry->d_inode;
bhv_vnode_t *vp = vn_from_inode(inode);
ASSERT_ALWAYS(vp->v_vfsp->vfs_flag & VFS_DMI);
- if (XFS_SEND_MMAP(XFS_VFSTOM(vp->v_vfsp), area, 0))
+ if (XFS_SEND_MMAP(XFS_VFSTOM(vp->v_vfsp), vma, 0)) {
+ fdata->type = VM_FAULT_SIGBUS;
return NULL;
- return filemap_nopage(area, address, type);
+ }
+ return filemap_fault(vma, fdata);
}
#endif /* CONFIG_XFS_DMAPI */
struct vm_area_struct *vma)
{
vma->vm_ops = &xfs_file_vm_ops;
- vma->vm_flags |= VM_CAN_INVALIDATE;
+ vma->vm_flags |= VM_CAN_INVALIDATE | VM_CAN_NONLINEAR;
#ifdef CONFIG_XFS_DMAPI
if (vn_from_inode(filp->f_path.dentry->d_inode)->v_vfsp->vfs_flag & VFS_DMI)
};
static struct vm_operations_struct xfs_file_vm_ops = {
- .nopage = filemap_nopage,
- .populate = filemap_populate,
+ .fault = filemap_fault,
};
#ifdef CONFIG_XFS_DMAPI
static struct vm_operations_struct xfs_dmapi_file_vm_ops = {
- .nopage = xfs_vm_nopage,
- .populate = filemap_populate,
+ .fault = xfs_vm_fault,
#ifdef HAVE_VMOP_MPROTECT
.mprotect = xfs_vm_mprotect,
#endif
* In this case, do_no_page must
* return with the page locked.
*/
+#define VM_CAN_NONLINEAR 0x10000000 /* Has ->fault & does nonlinear pages */
#ifndef VM_STACK_DEFAULT_FLAGS /* arch can override this */
#define VM_STACK_DEFAULT_FLAGS VM_DATA_DEFAULT_FLAGS
*/
extern pgprot_t protection_map[16];
+#define FAULT_FLAG_WRITE 0x01
+#define FAULT_FLAG_NONLINEAR 0x02
+
+/*
+ * fault_data is filled in the the pagefault handler and passed to the
+ * vma's ->fault function. That function is responsible for filling in
+ * 'type', which is the type of fault if a page is returned, or the type
+ * of error if NULL is returned.
+ *
+ * pgoff should be used in favour of address, if possible. If pgoff is
+ * used, one may set VM_CAN_NONLINEAR in the vma->vm_flags to get
+ * nonlinear mapping support.
+ */
+struct fault_data {
+ unsigned long address;
+ pgoff_t pgoff;
+ unsigned int flags;
+ int type;
+};
/*
* These are the virtual MM functions - opening of an area, closing and
struct vm_operations_struct {
void (*open)(struct vm_area_struct * area);
void (*close)(struct vm_area_struct * area);
- struct page * (*nopage)(struct vm_area_struct * area, unsigned long address, int *type);
- unsigned long (*nopfn)(struct vm_area_struct * area, unsigned long address);
- int (*populate)(struct vm_area_struct * area, unsigned long address, unsigned long len, pgprot_t prot, unsigned long pgoff, int nonblock);
+ struct page *(*fault)(struct vm_area_struct *vma,
+ struct fault_data *fdata);
+ struct page *(*nopage)(struct vm_area_struct *area,
+ unsigned long address, int *type);
+ unsigned long (*nopfn)(struct vm_area_struct *area,
+ unsigned long address);
+ int (*populate)(struct vm_area_struct *area, unsigned long address,
+ unsigned long len, pgprot_t prot, unsigned long pgoff,
+ int nonblock);
/* notification that a previously read-only page is about to become
* writable, if an error is returned it will cause a SIGBUS */
*/
#define NOPAGE_SIGBUS (NULL)
#define NOPAGE_OOM ((struct page *) (-1))
-#define NOPAGE_REFAULT ((struct page *) (-2)) /* Return to userspace, rerun */
/*
* Error return values for the *_nopfn functions
loff_t lstart, loff_t lend);
/* generic vm_area_ops exported for stackable file systems */
-extern struct page *filemap_nopage(struct vm_area_struct *, unsigned long, int *);
-extern int filemap_populate(struct vm_area_struct *, unsigned long,
- unsigned long, pgprot_t, unsigned long, int);
+extern struct page *filemap_fault(struct vm_area_struct *, struct fault_data *);
+extern struct page * __deprecated_for_modules
+filemap_nopage(struct vm_area_struct *, unsigned long, int *);
+extern int __deprecated_for_modules filemap_populate(struct vm_area_struct *,
+ unsigned long, unsigned long, pgprot_t, unsigned long, int);
/* mm/page-writeback.c */
int write_one_page(struct page *page, int wait);
mutex_unlock(&shm_ids(ns).mutex);
}
-static struct page *shm_nopage(struct vm_area_struct *vma,
- unsigned long address, int *type)
+static struct page *shm_fault(struct vm_area_struct *vma,
+ struct fault_data *fdata)
{
struct file *file = vma->vm_file;
struct shm_file_data *sfd = shm_file_data(file);
- return sfd->vm_ops->nopage(vma, address, type);
+ return sfd->vm_ops->fault(vma, fdata);
}
#ifdef CONFIG_NUMA
if (ret != 0)
return ret;
sfd->vm_ops = vma->vm_ops;
+ BUG_ON(!sfd->vm_ops->fault);
vma->vm_ops = &shm_vm_ops;
shm_open(vma);
static struct vm_operations_struct shm_vm_ops = {
.open = shm_open, /* callback for a new vm-area open */
.close = shm_close, /* callback for when the vm-area is released */
- .nopage = shm_nopage,
+ .fault = shm_fault,
#if defined(CONFIG_NUMA)
.set_policy = shm_set_policy,
.get_policy = shm_get_policy,
#define MMAP_LOTSAMISS (100)
/**
- * filemap_nopage - read in file data for page fault handling
- * @area: the applicable vm_area
- * @address: target address to read in
- * @type: returned with VM_FAULT_{MINOR,MAJOR} if not %NULL
+ * filemap_fault - read in file data for page fault handling
+ * @vma: user vma (not used)
+ * @fdata: the applicable fault_data
*
- * filemap_nopage() is invoked via the vma operations vector for a
+ * filemap_fault() is invoked via the vma operations vector for a
* mapped memory region to read in file data during a page fault.
*
* The goto's are kind of ugly, but this streamlines the normal case of having
* it in the page cache, and handles the special cases reasonably without
* having a lot of duplicated code.
*/
-struct page *filemap_nopage(struct vm_area_struct *area,
- unsigned long address, int *type)
+struct page *filemap_fault(struct vm_area_struct *vma, struct fault_data *fdata)
{
int error;
- struct file *file = area->vm_file;
+ struct file *file = vma->vm_file;
struct address_space *mapping = file->f_mapping;
struct file_ra_state *ra = &file->f_ra;
struct inode *inode = mapping->host;
struct page *page;
- unsigned long size, pgoff;
- int did_readaround = 0, majmin = VM_FAULT_MINOR;
+ unsigned long size;
+ int did_readaround = 0;
- BUG_ON(!(area->vm_flags & VM_CAN_INVALIDATE));
+ fdata->type = VM_FAULT_MINOR;
- pgoff = ((address-area->vm_start) >> PAGE_CACHE_SHIFT) + area->vm_pgoff;
+ BUG_ON(!(vma->vm_flags & VM_CAN_INVALIDATE));
size = (i_size_read(inode) + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
- if (pgoff >= size)
+ if (fdata->pgoff >= size)
goto outside_data_content;
/* If we don't want any read-ahead, don't bother */
- if (VM_RandomReadHint(area))
+ if (VM_RandomReadHint(vma))
goto no_cached_page;
/*
*
* For sequential accesses, we use the generic readahead logic.
*/
- if (VM_SequentialReadHint(area))
- page_cache_readahead(mapping, ra, file, pgoff, 1);
+ if (VM_SequentialReadHint(vma))
+ page_cache_readahead(mapping, ra, file, fdata->pgoff, 1);
/*
* Do we have something in the page cache already?
*/
retry_find:
- page = find_lock_page(mapping, pgoff);
+ page = find_lock_page(mapping, fdata->pgoff);
if (!page) {
unsigned long ra_pages;
- if (VM_SequentialReadHint(area)) {
- handle_ra_miss(mapping, ra, pgoff);
+ if (VM_SequentialReadHint(vma)) {
+ handle_ra_miss(mapping, ra, fdata->pgoff);
goto no_cached_page;
}
ra->mmap_miss++;
* check did_readaround, as this is an inner loop.
*/
if (!did_readaround) {
- majmin = VM_FAULT_MAJOR;
+ fdata->type = VM_FAULT_MAJOR;
count_vm_event(PGMAJFAULT);
}
did_readaround = 1;
if (ra_pages) {
pgoff_t start = 0;
- if (pgoff > ra_pages / 2)
- start = pgoff - ra_pages / 2;
+ if (fdata->pgoff > ra_pages / 2)
+ start = fdata->pgoff - ra_pages / 2;
do_page_cache_readahead(mapping, file, start, ra_pages);
}
- page = find_lock_page(mapping, pgoff);
+ page = find_lock_page(mapping, fdata->pgoff);
if (!page)
goto no_cached_page;
}
/* Must recheck i_size under page lock */
size = (i_size_read(inode) + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
- if (unlikely(pgoff >= size)) {
+ if (unlikely(fdata->pgoff >= size)) {
unlock_page(page);
goto outside_data_content;
}
* Found the page and have a reference on it.
*/
mark_page_accessed(page);
- if (type)
- *type = majmin;
return page;
outside_data_content:
* An external ptracer can access pages that normally aren't
* accessible..
*/
- if (area->vm_mm == current->mm)
- return NOPAGE_SIGBUS;
+ if (vma->vm_mm == current->mm) {
+ fdata->type = VM_FAULT_SIGBUS;
+ return NULL;
+ }
/* Fall through to the non-read-ahead case */
no_cached_page:
/*
* We're only likely to ever get here if MADV_RANDOM is in
* effect.
*/
- error = page_cache_read(file, pgoff);
+ error = page_cache_read(file, fdata->pgoff);
/*
* The page we want has now been added to the page cache.
* to schedule I/O.
*/
if (error == -ENOMEM)
- return NOPAGE_OOM;
- return NOPAGE_SIGBUS;
+ fdata->type = VM_FAULT_OOM;
+ else
+ fdata->type = VM_FAULT_SIGBUS;
+ return NULL;
page_not_uptodate:
/* IO error path */
if (!did_readaround) {
- majmin = VM_FAULT_MAJOR;
+ fdata->type = VM_FAULT_MAJOR;
count_vm_event(PGMAJFAULT);
}
/* Things didn't work out. Return zero to tell the mm layer so. */
shrink_readahead_size_eio(file, ra);
- return NOPAGE_SIGBUS;
+ fdata->type = VM_FAULT_SIGBUS;
+ return NULL;
+}
+EXPORT_SYMBOL(filemap_fault);
+
+/*
+ * filemap_nopage and filemap_populate are legacy exports that are not used
+ * in tree. Scheduled for removal.
+ */
+struct page *filemap_nopage(struct vm_area_struct *area,
+ unsigned long address, int *type)
+{
+ struct page *page;
+ struct fault_data fdata;
+ fdata.address = address;
+ fdata.pgoff = ((address - area->vm_start) >> PAGE_CACHE_SHIFT)
+ + area->vm_pgoff;
+ fdata.flags = 0;
+
+ page = filemap_fault(area, &fdata);
+ if (type)
+ *type = fdata.type;
+
+ return page;
}
EXPORT_SYMBOL(filemap_nopage);
EXPORT_SYMBOL(filemap_populate);
struct vm_operations_struct generic_file_vm_ops = {
- .nopage = filemap_nopage,
- .populate = filemap_populate,
+ .fault = filemap_fault,
};
/* This is used for a general mmap of a disk file */
return -ENOEXEC;
file_accessed(file);
vma->vm_ops = &generic_file_vm_ops;
- vma->vm_flags |= VM_CAN_INVALIDATE;
+ vma->vm_flags |= VM_CAN_INVALIDATE | VM_CAN_NONLINEAR;
return 0;
}
}
/*
- * xip_nopage() is invoked via the vma operations vector for a
+ * xip_fault() is invoked via the vma operations vector for a
* mapped memory region to read in file data during a page fault.
*
- * This function is derived from filemap_nopage, but used for execute in place
+ * This function is derived from filemap_fault, but used for execute in place
*/
-static struct page *
-xip_file_nopage(struct vm_area_struct * area,
- unsigned long address,
- int *type)
+static struct page *xip_file_fault(struct vm_area_struct *area,
+ struct fault_data *fdata)
{
struct file *file = area->vm_file;
struct address_space *mapping = file->f_mapping;
struct inode *inode = mapping->host;
struct page *page;
- unsigned long size, pgoff, endoff;
+ pgoff_t size;
- pgoff = ((address - area->vm_start) >> PAGE_CACHE_SHIFT)
- + area->vm_pgoff;
- endoff = ((area->vm_end - area->vm_start) >> PAGE_CACHE_SHIFT)
- + area->vm_pgoff;
+ /* XXX: are VM_FAULT_ codes OK? */
size = (i_size_read(inode) + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
- if (pgoff >= size)
- return NOPAGE_SIGBUS;
+ if (fdata->pgoff >= size) {
+ fdata->type = VM_FAULT_SIGBUS;
+ return NULL;
+ }
- page = mapping->a_ops->get_xip_page(mapping, pgoff*(PAGE_SIZE/512), 0);
+ page = mapping->a_ops->get_xip_page(mapping,
+ fdata->pgoff*(PAGE_SIZE/512), 0);
if (!IS_ERR(page))
goto out;
- if (PTR_ERR(page) != -ENODATA)
- return NOPAGE_SIGBUS;
+ if (PTR_ERR(page) != -ENODATA) {
+ fdata->type = VM_FAULT_OOM;
+ return NULL;
+ }
/* sparse block */
if ((area->vm_flags & (VM_WRITE | VM_MAYWRITE)) &&
(area->vm_flags & (VM_SHARED| VM_MAYSHARE)) &&
(!(mapping->host->i_sb->s_flags & MS_RDONLY))) {
/* maybe shared writable, allocate new block */
- page = mapping->a_ops->get_xip_page (mapping,
- pgoff*(PAGE_SIZE/512), 1);
- if (IS_ERR(page))
- return NOPAGE_SIGBUS;
+ page = mapping->a_ops->get_xip_page(mapping,
+ fdata->pgoff*(PAGE_SIZE/512), 1);
+ if (IS_ERR(page)) {
+ fdata->type = VM_FAULT_SIGBUS;
+ return NULL;
+ }
/* unmap page at pgoff from all other vmas */
- __xip_unmap(mapping, pgoff);
+ __xip_unmap(mapping, fdata->pgoff);
} else {
/* not shared and writable, use xip_sparse_page() */
page = xip_sparse_page();
- if (!page)
- return NOPAGE_OOM;
+ if (!page) {
+ fdata->type = VM_FAULT_OOM;
+ return NULL;
+ }
}
out:
+ fdata->type = VM_FAULT_MINOR;
page_cache_get(page);
return page;
}
static struct vm_operations_struct xip_file_vm_ops = {
- .nopage = xip_file_nopage,
+ .fault = xip_file_fault,
};
int xip_file_mmap(struct file * file, struct vm_area_struct * vma)
file_accessed(file);
vma->vm_ops = &xip_file_vm_ops;
+ vma->vm_flags |= VM_CAN_NONLINEAR;
return 0;
}
EXPORT_SYMBOL_GPL(xip_file_mmap);
return err;
}
+static int populate_range(struct mm_struct *mm, struct vm_area_struct *vma,
+ unsigned long addr, unsigned long size, pgoff_t pgoff)
+{
+ int err;
+
+ do {
+ err = install_file_pte(mm, vma, addr, pgoff, vma->vm_page_prot);
+ if (err)
+ return err;
+
+ size -= PAGE_SIZE;
+ addr += PAGE_SIZE;
+ pgoff++;
+ } while (size);
+
+ return 0;
+
+}
+
/***
* sys_remap_file_pages - remap arbitrary pages of a shared backing store
* file within an existing vma.
* the single existing vma. vm_private_data is used as a
* swapout cursor in a VM_NONLINEAR vma.
*/
- if (vma && (vma->vm_flags & VM_SHARED) &&
- (!vma->vm_private_data || (vma->vm_flags & VM_NONLINEAR)) &&
- vma->vm_ops && vma->vm_ops->populate &&
- end > start && start >= vma->vm_start &&
- end <= vma->vm_end) {
-
- /* Must set VM_NONLINEAR before any pages are populated. */
- if (pgoff != linear_page_index(vma, start) &&
- !(vma->vm_flags & VM_NONLINEAR)) {
- if (!has_write_lock) {
- up_read(&mm->mmap_sem);
- down_write(&mm->mmap_sem);
- has_write_lock = 1;
- goto retry;
+ if (!vma || !(vma->vm_flags & VM_SHARED))
+ goto out;
+
+ if (vma->vm_private_data && !(vma->vm_flags & VM_NONLINEAR))
+ goto out;
+
+ if ((!vma->vm_ops || !vma->vm_ops->populate) &&
+ !(vma->vm_flags & VM_CAN_NONLINEAR))
+ goto out;
+
+ if (end <= start || start < vma->vm_start || end > vma->vm_end)
+ goto out;
+
+ /* Must set VM_NONLINEAR before any pages are populated. */
+ if (!(vma->vm_flags & VM_NONLINEAR)) {
+ /* Don't need a nonlinear mapping, exit success */
+ if (pgoff == linear_page_index(vma, start)) {
+ err = 0;
+ goto out;
+ }
+
+ if (!has_write_lock) {
+ up_read(&mm->mmap_sem);
+ down_write(&mm->mmap_sem);
+ has_write_lock = 1;
+ goto retry;
+ }
+ mapping = vma->vm_file->f_mapping;
+ spin_lock(&mapping->i_mmap_lock);
+ flush_dcache_mmap_lock(mapping);
+ vma->vm_flags |= VM_NONLINEAR;
+ vma_prio_tree_remove(vma, &mapping->i_mmap);
+ vma_nonlinear_insert(vma, &mapping->i_mmap_nonlinear);
+ flush_dcache_mmap_unlock(mapping);
+ spin_unlock(&mapping->i_mmap_lock);
+ }
+
+ if (vma->vm_flags & VM_CAN_NONLINEAR) {
+ err = populate_range(mm, vma, start, size, pgoff);
+ if (!err && !(flags & MAP_NONBLOCK)) {
+ if (unlikely(has_write_lock)) {
+ downgrade_write(&mm->mmap_sem);
+ has_write_lock = 0;
}
- mapping = vma->vm_file->f_mapping;
- spin_lock(&mapping->i_mmap_lock);
- flush_dcache_mmap_lock(mapping);
- vma->vm_flags |= VM_NONLINEAR;
- vma_prio_tree_remove(vma, &mapping->i_mmap);
- vma_nonlinear_insert(vma, &mapping->i_mmap_nonlinear);
- flush_dcache_mmap_unlock(mapping);
- spin_unlock(&mapping->i_mmap_lock);
+ make_pages_present(start, start+size);
}
+ } else
+ err = vma->vm_ops->populate(vma, start, size, vma->vm_page_prot,
+ pgoff, flags & MAP_NONBLOCK);
- err = vma->vm_ops->populate(vma, start, size,
- vma->vm_page_prot,
- pgoff, flags & MAP_NONBLOCK);
+ /*
+ * We can't clear VM_NONLINEAR because we'd have to do
+ * it after ->populate completes, and that would prevent
+ * downgrading the lock. (Locks can't be upgraded).
+ */
- /*
- * We can't clear VM_NONLINEAR because we'd have to do
- * it after ->populate completes, and that would prevent
- * downgrading the lock. (Locks can't be upgraded).
- */
- }
+out:
if (likely(!has_write_lock))
up_read(&mm->mmap_sem);
else
if (pages)
foll_flags |= FOLL_GET;
if (!write && !(vma->vm_flags & VM_LOCKED) &&
- (!vma->vm_ops || !vma->vm_ops->nopage))
+ (!vma->vm_ops || (!vma->vm_ops->nopage &&
+ !vma->vm_ops->fault)))
foll_flags |= FOLL_ANON;
do {
}
/*
- * do_no_page() tries to create a new page mapping. It aggressively
+ * __do_fault() tries to create a new page mapping. It aggressively
* tries to share with existing pages, but makes a separate copy if
- * the "write_access" parameter is true in order to avoid the next
- * page fault.
+ * the FAULT_FLAG_WRITE is set in the flags parameter in order to avoid
+ * the next page fault.
*
* As this is called only for pages that do not currently exist, we
* do not need to flush old virtual caches or the TLB.
* but allow concurrent faults), and pte mapped but not yet locked.
* We return with mmap_sem still held, but pte unmapped and unlocked.
*/
-static int do_no_page(struct mm_struct *mm, struct vm_area_struct *vma,
+static int __do_fault(struct mm_struct *mm, struct vm_area_struct *vma,
unsigned long address, pte_t *page_table, pmd_t *pmd,
- int write_access)
+ pgoff_t pgoff, unsigned int flags, pte_t orig_pte)
{
spinlock_t *ptl;
- struct page *page, *nopage_page;
+ struct page *page, *faulted_page;
pte_t entry;
- int ret = VM_FAULT_MINOR;
int anon = 0;
struct page *dirty_page = NULL;
+ struct fault_data fdata;
+
+ fdata.address = address & PAGE_MASK;
+ fdata.pgoff = pgoff;
+ fdata.flags = flags;
pte_unmap(page_table);
BUG_ON(vma->vm_flags & VM_PFNMAP);
- nopage_page = vma->vm_ops->nopage(vma, address & PAGE_MASK, &ret);
- /* no page was available -- either SIGBUS, OOM or REFAULT */
- if (unlikely(nopage_page == NOPAGE_SIGBUS))
- return VM_FAULT_SIGBUS;
- else if (unlikely(nopage_page == NOPAGE_OOM))
- return VM_FAULT_OOM;
- else if (unlikely(nopage_page == NOPAGE_REFAULT))
- return VM_FAULT_MINOR;
+ if (likely(vma->vm_ops->fault)) {
+ fdata.type = -1;
+ faulted_page = vma->vm_ops->fault(vma, &fdata);
+ WARN_ON(fdata.type == -1);
+ if (unlikely(!faulted_page))
+ return fdata.type;
+ } else {
+ /* Legacy ->nopage path */
+ fdata.type = VM_FAULT_MINOR;
+ faulted_page = vma->vm_ops->nopage(vma, address & PAGE_MASK,
+ &fdata.type);
+ /* no page was available -- either SIGBUS or OOM */
+ if (unlikely(faulted_page == NOPAGE_SIGBUS))
+ return VM_FAULT_SIGBUS;
+ else if (unlikely(faulted_page == NOPAGE_OOM))
+ return VM_FAULT_OOM;
+ }
- BUG_ON(vma->vm_flags & VM_CAN_INVALIDATE && !PageLocked(nopage_page));
/*
- * For consistency in subsequent calls, make the nopage_page always
+ * For consistency in subsequent calls, make the faulted_page always
* locked.
*/
if (unlikely(!(vma->vm_flags & VM_CAN_INVALIDATE)))
- lock_page(nopage_page);
+ lock_page(faulted_page);
+ else
+ BUG_ON(!PageLocked(faulted_page));
/*
* Should we do an early C-O-W break?
*/
- page = nopage_page;
- if (write_access) {
+ page = faulted_page;
+ if (flags & FAULT_FLAG_WRITE) {
if (!(vma->vm_flags & VM_SHARED)) {
+ anon = 1;
if (unlikely(anon_vma_prepare(vma))) {
- ret = VM_FAULT_OOM;
- goto out_error;
+ fdata.type = VM_FAULT_OOM;
+ goto out;
}
page = alloc_page_vma(GFP_HIGHUSER_MOVABLE, vma, address);
if (!page) {
- ret = VM_FAULT_OOM;
- goto out_error;
+ fdata.type = VM_FAULT_OOM;
+ goto out;
}
- copy_user_highpage(page, nopage_page, address, vma);
- anon = 1;
+ copy_user_highpage(page, faulted_page, address, vma);
} else {
- /* if the page will be shareable, see if the backing
+ /*
+ * If the page will be shareable, see if the backing
* address space wants to know that the page is about
- * to become writable */
+ * to become writable
+ */
if (vma->vm_ops->page_mkwrite &&
vma->vm_ops->page_mkwrite(vma, page) < 0) {
- ret = VM_FAULT_SIGBUS;
- goto out_error;
+ fdata.type = VM_FAULT_SIGBUS;
+ anon = 1; /* no anon but release faulted_page */
+ goto out;
}
}
+
}
page_table = pte_offset_map_lock(mm, pmd, address, &ptl);
* handle that later.
*/
/* Only go through if we didn't race with anybody else... */
- if (likely(pte_none(*page_table))) {
+ if (likely(pte_same(*page_table, orig_pte))) {
flush_icache_page(vma, page);
entry = mk_pte(page, vma->vm_page_prot);
- if (write_access)
+ if (flags & FAULT_FLAG_WRITE)
entry = maybe_mkwrite(pte_mkdirty(entry), vma);
set_pte_at(mm, address, page_table, entry);
if (anon) {
} else {
inc_mm_counter(mm, file_rss);
page_add_file_rmap(page);
- if (write_access) {
+ if (flags & FAULT_FLAG_WRITE) {
dirty_page = page;
get_page(dirty_page);
}
if (anon)
page_cache_release(page);
else
- anon = 1; /* not anon, but release nopage_page */
+ anon = 1; /* no anon but release faulted_page */
}
pte_unmap_unlock(page_table, ptl);
out:
- unlock_page(nopage_page);
+ unlock_page(faulted_page);
if (anon)
- page_cache_release(nopage_page);
+ page_cache_release(faulted_page);
else if (dirty_page) {
set_page_dirty_balance(dirty_page);
put_page(dirty_page);
}
- return ret;
+ return fdata.type;
+}
-out_error:
- anon = 1; /* relase nopage_page */
- goto out;
+static int do_linear_fault(struct mm_struct *mm, struct vm_area_struct *vma,
+ unsigned long address, pte_t *page_table, pmd_t *pmd,
+ int write_access, pte_t orig_pte)
+{
+ pgoff_t pgoff = (((address & PAGE_MASK)
+ - vma->vm_start) >> PAGE_CACHE_SHIFT) + vma->vm_pgoff;
+ unsigned int flags = (write_access ? FAULT_FLAG_WRITE : 0);
+
+ return __do_fault(mm, vma, address, page_table, pmd, pgoff, flags, orig_pte);
+}
+
+static int do_nonlinear_fault(struct mm_struct *mm, struct vm_area_struct *vma,
+ unsigned long address, pte_t *page_table, pmd_t *pmd,
+ int write_access, pgoff_t pgoff, pte_t orig_pte)
+{
+ unsigned int flags = FAULT_FLAG_NONLINEAR |
+ (write_access ? FAULT_FLAG_WRITE : 0);
+
+ return __do_fault(mm, vma, address, page_table, pmd, pgoff, flags, orig_pte);
}
/*
print_bad_pte(vma, orig_pte, address);
return VM_FAULT_OOM;
}
- /* We can then assume vm->vm_ops && vma->vm_ops->populate */
pgoff = pte_to_pgoff(orig_pte);
+
+ if (vma->vm_ops && vma->vm_ops->fault)
+ return do_nonlinear_fault(mm, vma, address, page_table, pmd,
+ write_access, pgoff, orig_pte);
+
+ /* We can then assume vm->vm_ops && vma->vm_ops->populate */
err = vma->vm_ops->populate(vma, address & PAGE_MASK, PAGE_SIZE,
vma->vm_page_prot, pgoff, 0);
if (err == -ENOMEM)
if (!pte_present(entry)) {
if (pte_none(entry)) {
if (vma->vm_ops) {
- if (vma->vm_ops->nopage)
- return do_no_page(mm, vma, address,
- pte, pmd,
- write_access);
+ if (vma->vm_ops->fault || vma->vm_ops->nopage)
+ return do_linear_fault(mm, vma, address,
+ pte, pmd, write_access, entry);
if (unlikely(vma->vm_ops->nopfn))
return do_no_pfn(mm, vma, address, pte,
pmd, write_access);
mm->locked_vm += len >> PAGE_SHIFT;
make_pages_present(addr, addr + len);
}
- if (flags & MAP_POPULATE) {
- up_write(&mm->mmap_sem);
- sys_remap_file_pages(addr, len, 0,
- pgoff, flags & MAP_NONBLOCK);
- down_write(&mm->mmap_sem);
- }
+ if ((flags & MAP_POPULATE) && !(flags & MAP_NONBLOCK))
+ make_pages_present(addr, addr + len);
return addr;
unmap_and_free_vma:
return 0;
}
-struct page *filemap_nopage(struct vm_area_struct *area,
- unsigned long address, int *type)
+struct page *filemap_fault(struct vm_area_struct *vma, struct fault_data *fdata)
{
BUG();
return NULL;
printk (KERN_EMERG " page->count = %x\n", page_count(page));
printk (KERN_EMERG " page->mapping = %p\n", page->mapping);
print_symbol (KERN_EMERG " vma->vm_ops = %s\n", (unsigned long)vma->vm_ops);
- if (vma->vm_ops)
+ if (vma->vm_ops) {
print_symbol (KERN_EMERG " vma->vm_ops->nopage = %s\n", (unsigned long)vma->vm_ops->nopage);
+ print_symbol (KERN_EMERG " vma->vm_ops->fault = %s\n", (unsigned long)vma->vm_ops->fault);
+ }
if (vma->vm_file && vma->vm_file->f_op)
print_symbol (KERN_EMERG " vma->vm_file->f_op->mmap = %s\n", (unsigned long)vma->vm_file->f_op->mmap);
BUG();
SGP_READ, /* don't exceed i_size, don't allocate page */
SGP_CACHE, /* don't exceed i_size, may allocate page */
SGP_WRITE, /* may exceed i_size, may allocate page */
- SGP_NOPAGE, /* same as SGP_CACHE, return with page locked */
+ SGP_FAULT, /* same as SGP_CACHE, return with page locked */
};
static int shmem_getpage(struct inode *inode, unsigned long idx,
if (idx >= SHMEM_MAX_INDEX)
return -EFBIG;
+
+ if (type)
+ *type = VM_FAULT_MINOR;
+
/*
* Normally, filepage is NULL on entry, and either found
* uptodate immediately, or allocated and zeroed, or read
done:
if (*pagep != filepage) {
*pagep = filepage;
- if (sgp != SGP_NOPAGE)
+ if (sgp != SGP_FAULT)
unlock_page(filepage);
}
return error;
}
-static struct page *shmem_nopage(struct vm_area_struct *vma,
- unsigned long address, int *type)
+static struct page *shmem_fault(struct vm_area_struct *vma,
+ struct fault_data *fdata)
{
struct inode *inode = vma->vm_file->f_path.dentry->d_inode;
struct page *page = NULL;
- unsigned long idx;
int error;
BUG_ON(!(vma->vm_flags & VM_CAN_INVALIDATE));
- idx = (address - vma->vm_start) >> PAGE_SHIFT;
- idx += vma->vm_pgoff;
- idx >>= PAGE_CACHE_SHIFT - PAGE_SHIFT;
- if (((loff_t) idx << PAGE_CACHE_SHIFT) >= i_size_read(inode))
- return NOPAGE_SIGBUS;
+ if (((loff_t)fdata->pgoff << PAGE_CACHE_SHIFT) >= i_size_read(inode)) {
+ fdata->type = VM_FAULT_SIGBUS;
+ return NULL;
+ }
- error = shmem_getpage(inode, idx, &page, SGP_NOPAGE, type);
- if (error)
- return (error == -ENOMEM)? NOPAGE_OOM: NOPAGE_SIGBUS;
+ error = shmem_getpage(inode, fdata->pgoff, &page,
+ SGP_FAULT, &fdata->type);
+ if (error) {
+ fdata->type = ((error == -ENOMEM)?VM_FAULT_OOM:VM_FAULT_SIGBUS);
+ return NULL;
+ }
mark_page_accessed(page);
return page;
}
-static int shmem_populate(struct vm_area_struct *vma,
- unsigned long addr, unsigned long len,
- pgprot_t prot, unsigned long pgoff, int nonblock)
-{
- struct inode *inode = vma->vm_file->f_path.dentry->d_inode;
- struct mm_struct *mm = vma->vm_mm;
- enum sgp_type sgp = nonblock? SGP_QUICK: SGP_CACHE;
- unsigned long size;
-
- size = (i_size_read(inode) + PAGE_SIZE - 1) >> PAGE_SHIFT;
- if (pgoff >= size || pgoff + (len >> PAGE_SHIFT) > size)
- return -EINVAL;
-
- while ((long) len > 0) {
- struct page *page = NULL;
- int err;
- /*
- * Will need changing if PAGE_CACHE_SIZE != PAGE_SIZE
- */
- err = shmem_getpage(inode, pgoff, &page, sgp, NULL);
- if (err)
- return err;
- /* Page may still be null, but only if nonblock was set. */
- if (page) {
- mark_page_accessed(page);
- err = install_page(mm, vma, addr, page, prot);
- if (err) {
- page_cache_release(page);
- return err;
- }
- } else if (vma->vm_flags & VM_NONLINEAR) {
- /* No page was found just because we can't read it in
- * now (being here implies nonblock != 0), but the page
- * may exist, so set the PTE to fault it in later. */
- err = install_file_pte(mm, vma, addr, pgoff, prot);
- if (err)
- return err;
- }
-
- len -= PAGE_SIZE;
- addr += PAGE_SIZE;
- pgoff++;
- }
- return 0;
-}
-
#ifdef CONFIG_NUMA
int shmem_set_policy(struct vm_area_struct *vma, struct mempolicy *new)
{
{
file_accessed(file);
vma->vm_ops = &shmem_vm_ops;
- vma->vm_flags |= VM_CAN_INVALIDATE;
+ vma->vm_flags |= VM_CAN_INVALIDATE | VM_CAN_NONLINEAR;
return 0;
}
};
static struct vm_operations_struct shmem_vm_ops = {
- .nopage = shmem_nopage,
- .populate = shmem_populate,
+ .fault = shmem_fault,
#ifdef CONFIG_NUMA
.set_policy = shmem_set_policy,
.get_policy = shmem_get_policy,
/*
* If truncate cannot remove the fs-private metadata from the page, the page
* becomes anonymous. It will be left on the LRU and may even be mapped into
- * user pagetables if we're racing with filemap_nopage().
+ * user pagetables if we're racing with filemap_fault().
*
* We need to bale out if page->mapping is no longer equal to the original
* mapping. This happens a) when the VM reclaimed the page while we waited on
git.openpandora.org / pandora-kernel.git / commitdiff