예제 #1
0
파일: llite_mmap.c 프로젝트: AK101111/linux
/**
 * Lustre implementation of a vm_operations_struct::fault() method, called by
 * VM to server page fault (both in kernel and user space).
 *
 * \param vma - is virtual area struct related to page fault
 * \param vmf - structure which describe type and address where hit fault
 *
 * \return allocated and filled _locked_ page for address
 * \retval VM_FAULT_ERROR on general error
 * \retval NOPAGE_OOM not have memory for allocate new page
 */
static int ll_fault0(struct vm_area_struct *vma, struct vm_fault *vmf)
{
	struct lu_env	   *env;
	struct cl_io	    *io;
	struct vvp_io	   *vio = NULL;
	struct page	     *vmpage;
	unsigned long	    ra_flags;
	struct cl_env_nest       nest;
	int		      result;
	int		      fault_ret = 0;

	io = ll_fault_io_init(vma, &env,  &nest, vmf->pgoff, &ra_flags);
	if (IS_ERR(io))
		return to_fault_error(PTR_ERR(io));

	result = io->ci_result;
	if (result == 0) {
		vio = vvp_env_io(env);
		vio->u.fault.ft_vma       = vma;
		vio->u.fault.ft_vmpage    = NULL;
		vio->u.fault.ft_vmf = vmf;
		vio->u.fault.ft_flags = 0;
		vio->u.fault.ft_flags_valid = false;

		/* May call ll_readpage() */
		ll_cl_add(vma->vm_file, env, io);

		result = cl_io_loop(env, io);

		ll_cl_remove(vma->vm_file, env);

		/* ft_flags are only valid if we reached
		 * the call to filemap_fault
		 */
		if (vio->u.fault.ft_flags_valid)
			fault_ret = vio->u.fault.ft_flags;

		vmpage = vio->u.fault.ft_vmpage;
		if (result != 0 && vmpage) {
			put_page(vmpage);
			vmf->page = NULL;
		}
	}
	cl_io_fini(env, io);
	cl_env_nested_put(&nest, env);

	vma->vm_flags |= ra_flags;
	if (result != 0 && !(fault_ret & VM_FAULT_RETRY))
		fault_ret |= to_fault_error(result);

	CDEBUG(D_MMAP, "%s fault %d/%d\n",
	       current->comm, fault_ret, result);
	return fault_ret;
}
예제 #2
0
/* Sharing code of page_mkwrite method for rhel5 and rhel6 */
static int ll_page_mkwrite0(struct vm_area_struct *vma, struct page *vmpage,
			    bool *retry)
{
	struct lu_env	   *env;
	struct cl_io	    *io;
	struct vvp_io	   *vio;
	struct cl_env_nest       nest;
	int		      result;
	sigset_t	     set;
	struct inode	     *inode;
	struct ll_inode_info     *lli;

	io = ll_fault_io_init(vma, &env,  &nest, vmpage->index, NULL);
	if (IS_ERR(io)) {
		result = PTR_ERR(io);
		goto out;
	}

	result = io->ci_result;
	if (result < 0)
		goto out_io;

	io->u.ci_fault.ft_mkwrite = 1;
	io->u.ci_fault.ft_writable = 1;

	vio = vvp_env_io(env);
	vio->u.fault.ft_vma    = vma;
	vio->u.fault.ft_vmpage = vmpage;

	set = cfs_block_sigsinv(sigmask(SIGKILL) | sigmask(SIGTERM));

	/* we grab lli_trunc_sem to exclude truncate case.
	 * Otherwise, we could add dirty pages into osc cache
	 * while truncate is on-going.
	 */
	inode = ccc_object_inode(io->ci_obj);
	lli = ll_i2info(inode);
	down_read(&lli->lli_trunc_sem);

	result = cl_io_loop(env, io);

	up_read(&lli->lli_trunc_sem);

	cfs_restore_sigs(set);

	if (result == 0) {
		struct inode *inode = file_inode(vma->vm_file);
		struct ll_inode_info *lli = ll_i2info(inode);

		lock_page(vmpage);
		if (!vmpage->mapping) {
			unlock_page(vmpage);

			/* page was truncated and lock was cancelled, return
			 * ENODATA so that VM_FAULT_NOPAGE will be returned
			 * to handle_mm_fault().
			 */
			if (result == 0)
				result = -ENODATA;
		} else if (!PageDirty(vmpage)) {
			/* race, the page has been cleaned by ptlrpcd after
			 * it was unlocked, it has to be added into dirty
			 * cache again otherwise this soon-to-dirty page won't
			 * consume any grants, even worse if this page is being
			 * transferred because it will break RPC checksum.
			 */
			unlock_page(vmpage);

			CDEBUG(D_MMAP, "Race on page_mkwrite %p/%lu, page has been written out, retry.\n",
			       vmpage, vmpage->index);

			*retry = true;
			result = -EAGAIN;
		}

		if (result == 0) {
			spin_lock(&lli->lli_lock);
			lli->lli_flags |= LLIF_DATA_MODIFIED;
			spin_unlock(&lli->lli_lock);
		}
	}

out_io:
	cl_io_fini(env, io);
	cl_env_nested_put(&nest, env);
out:
	CDEBUG(D_MMAP, "%s mkwrite with %d\n", current->comm, result);
	LASSERT(ergo(result == 0, PageLocked(vmpage)));

	return result;
}
예제 #3
0
/**
 * Lustre implementation of a vm_operations_struct::fault() method, called by
 * VM to server page fault (both in kernel and user space).
 *
 * \param vma - is virtiual area struct related to page fault
 * \param vmf - structure which describe type and address where hit fault
 *
 * \return allocated and filled _locked_ page for address
 * \retval VM_FAULT_ERROR on general error
 * \retval NOPAGE_OOM not have memory for allocate new page
 */
static int ll_fault0(struct vm_area_struct *vma, struct vm_fault *vmf)
{
	struct lu_env           *env;
	struct cl_io            *io;
	struct vvp_io           *vio = NULL;
	struct page             *vmpage;
	unsigned long            ra_flags;
	int                      result = 0;
	int                      fault_ret = 0;
	__u16			 refcheck;
	ENTRY;

	env = cl_env_get(&refcheck);
	if (IS_ERR(env))
		RETURN(PTR_ERR(env));

	if (ll_sbi_has_fast_read(ll_i2sbi(file_inode(vma->vm_file)))) {
		/* do fast fault */
		ll_cl_add(vma->vm_file, env, NULL, LCC_MMAP);
		fault_ret = filemap_fault(vma, vmf);
		ll_cl_remove(vma->vm_file, env);

		/* - If there is no error, then the page was found in cache and
		 *   uptodate;
		 * - If VM_FAULT_RETRY is set, the page existed but failed to
		 *   lock. It will return to kernel and retry;
		 * - Otherwise, it should try normal fault under DLM lock. */
		if ((fault_ret & VM_FAULT_RETRY) ||
		    !(fault_ret & VM_FAULT_ERROR))
			GOTO(out, result = 0);

		fault_ret = 0;
	}

	io = ll_fault_io_init(env, vma, vmf->pgoff, &ra_flags);
	if (IS_ERR(io))
		GOTO(out, result = PTR_ERR(io));

	result = io->ci_result;
	if (result == 0) {
		vio = vvp_env_io(env);
		vio->u.fault.ft_vma       = vma;
		vio->u.fault.ft_vmpage    = NULL;
		vio->u.fault.ft_vmf = vmf;
		vio->u.fault.ft_flags = 0;
		vio->u.fault.ft_flags_valid = 0;

		/* May call ll_readpage() */
		ll_cl_add(vma->vm_file, env, io, LCC_MMAP);

		result = cl_io_loop(env, io);

		ll_cl_remove(vma->vm_file, env);

		/* ft_flags are only valid if we reached
		 * the call to filemap_fault */
		if (vio->u.fault.ft_flags_valid)
			fault_ret = vio->u.fault.ft_flags;

		vmpage = vio->u.fault.ft_vmpage;
		if (result != 0 && vmpage != NULL) {
			put_page(vmpage);
			vmf->page = NULL;
		}
        }
	cl_io_fini(env, io);

	vma->vm_flags |= ra_flags;

out:
	cl_env_put(env, &refcheck);
	if (result != 0 && !(fault_ret & VM_FAULT_RETRY))
		fault_ret |= to_fault_error(result);

	CDEBUG(D_MMAP, "%s fault %d/%d\n", current->comm, fault_ret, result);
	RETURN(fault_ret);
}
예제 #4
0
/* Sharing code of page_mkwrite method for rhel5 and rhel6 */
static int ll_page_mkwrite0(struct vm_area_struct *vma, struct page *vmpage,
                            bool *retry)
{
	struct lu_env           *env;
	struct cl_io            *io;
	struct vvp_io           *vio;
	int                      result;
	__u16			 refcheck;
	sigset_t		 set;
	struct inode             *inode;
	struct ll_inode_info     *lli;
	ENTRY;

	LASSERT(vmpage != NULL);
	env = cl_env_get(&refcheck);
	if (IS_ERR(env))
		RETURN(PTR_ERR(env));

	io = ll_fault_io_init(env, vma, vmpage->index, NULL);
	if (IS_ERR(io))
		GOTO(out, result = PTR_ERR(io));

	result = io->ci_result;
	if (result < 0)
		GOTO(out_io, result);

	io->u.ci_fault.ft_mkwrite = 1;
	io->u.ci_fault.ft_writable = 1;

	vio = vvp_env_io(env);
	vio->u.fault.ft_vma    = vma;
	vio->u.fault.ft_vmpage = vmpage;

	set = cfs_block_sigsinv(sigmask(SIGKILL) | sigmask(SIGTERM));

	inode = vvp_object_inode(io->ci_obj);
	lli = ll_i2info(inode);

	result = cl_io_loop(env, io);

	cfs_restore_sigs(set);

        if (result == 0) {
                lock_page(vmpage);
                if (vmpage->mapping == NULL) {
                        unlock_page(vmpage);

                        /* page was truncated and lock was cancelled, return
                         * ENODATA so that VM_FAULT_NOPAGE will be returned
                         * to handle_mm_fault(). */
                        if (result == 0)
                                result = -ENODATA;
                } else if (!PageDirty(vmpage)) {
                        /* race, the page has been cleaned by ptlrpcd after
                         * it was unlocked, it has to be added into dirty
                         * cache again otherwise this soon-to-dirty page won't
                         * consume any grants, even worse if this page is being
                         * transferred because it will break RPC checksum.
                         */
                        unlock_page(vmpage);

                        CDEBUG(D_MMAP, "Race on page_mkwrite %p/%lu, page has "
                               "been written out, retry.\n",
                               vmpage, vmpage->index);

                        *retry = true;
                        result = -EAGAIN;
                }

		if (result == 0)
			ll_file_set_flag(lli, LLIF_DATA_MODIFIED);
        }
        EXIT;

out_io:
	cl_io_fini(env, io);
out:
	cl_env_put(env, &refcheck);
	CDEBUG(D_MMAP, "%s mkwrite with %d\n", current->comm, result);
	LASSERT(ergo(result == 0, PageLocked(vmpage)));

	return result;
}