/**
* API independent part for page fault initialization.
* \param env - corespondent lu_env to processing
* \param vma - virtual memory area addressed to page fault
* \param index - page index corespondent to fault.
* \parm ra_flags - vma readahead flags.
*
* \return error codes from cl_io_init.
*/
static struct cl_io *
ll_fault_io_init(struct lu_env *env, struct vm_area_struct *vma,
pgoff_t index, unsigned long *ra_flags)
{
struct file *file = vma->vm_file;
struct inode *inode = file_inode(file);
struct cl_io *io;
struct cl_fault_io *fio;
int rc;
ENTRY;
if (ll_file_nolock(file))
RETURN(ERR_PTR(-EOPNOTSUPP));
restart:
io = vvp_env_thread_io(env);
io->ci_obj = ll_i2info(inode)->lli_clob;
LASSERT(io->ci_obj != NULL);
fio = &io->u.ci_fault;
fio->ft_index = index;
fio->ft_executable = vma->vm_flags&VM_EXEC;
/*
* disable VM_SEQ_READ and use VM_RAND_READ to make sure that
* the kernel will not read other pages not covered by ldlm in
* filemap_nopage. we do our readahead in ll_readpage.
*/
if (ra_flags != NULL)
*ra_flags = vma->vm_flags & (VM_RAND_READ|VM_SEQ_READ);
vma->vm_flags &= ~VM_SEQ_READ;
vma->vm_flags |= VM_RAND_READ;
CDEBUG(D_MMAP, "vm_flags: %lx (%lu %d)\n", vma->vm_flags,
fio->ft_index, fio->ft_executable);
rc = cl_io_init(env, io, CIT_FAULT, io->ci_obj);
if (rc == 0) {
struct vvp_io *vio = vvp_env_io(env);
struct ll_file_data *fd = LUSTRE_FPRIVATE(file);
LASSERT(vio->vui_cl.cis_io == io);
/* mmap lock must be MANDATORY it has to cache
* pages. */
io->ci_lockreq = CILR_MANDATORY;
vio->vui_fd = fd;
} else {
LASSERT(rc < 0);
cl_io_fini(env, io);
if (io->ci_need_restart)
goto restart;
io = ERR_PTR(rc);
}
RETURN(io);
}
/**
* API independent part for page fault initialization.
* \param vma - virtual memory area addressed to page fault
* \param env - corespondent lu_env to processing
* \param nest - nested level
* \param index - page index corespondent to fault.
* \parm ra_flags - vma readahead flags.
*
* \return allocated and initialized env for fault operation.
* \retval EINVAL if env can't allocated
* \return other error codes from cl_io_init.
*/
static struct cl_io *
ll_fault_io_init(struct vm_area_struct *vma, struct lu_env **env_ret,
struct cl_env_nest *nest, pgoff_t index,
unsigned long *ra_flags)
{
struct file *file = vma->vm_file;
struct inode *inode = file_inode(file);
struct cl_io *io;
struct cl_fault_io *fio;
struct lu_env *env;
int rc;
*env_ret = NULL;
if (ll_file_nolock(file))
return ERR_PTR(-EOPNOTSUPP);
/*
* page fault can be called when lustre IO is
* already active for the current thread, e.g., when doing read/write
* against user level buffer mapped from Lustre buffer. To avoid
* stomping on existing context, optionally force an allocation of a new
* one.
*/
env = cl_env_nested_get(nest);
if (IS_ERR(env))
return ERR_PTR(-EINVAL);
*env_ret = env;
io = ccc_env_thread_io(env);
io->ci_obj = ll_i2info(inode)->lli_clob;
LASSERT(io->ci_obj);
fio = &io->u.ci_fault;
fio->ft_index = index;
fio->ft_executable = vma->vm_flags&VM_EXEC;
/*
* disable VM_SEQ_READ and use VM_RAND_READ to make sure that
* the kernel will not read other pages not covered by ldlm in
* filemap_nopage. we do our readahead in ll_readpage.
*/
if (ra_flags)
*ra_flags = vma->vm_flags & (VM_RAND_READ|VM_SEQ_READ);
vma->vm_flags &= ~VM_SEQ_READ;
vma->vm_flags |= VM_RAND_READ;
CDEBUG(D_MMAP, "vm_flags: %lx (%lu %d)\n", vma->vm_flags,
fio->ft_index, fio->ft_executable);
rc = cl_io_init(env, io, CIT_FAULT, io->ci_obj);
if (rc == 0) {
struct ccc_io *cio = ccc_env_io(env);
struct ll_file_data *fd = LUSTRE_FPRIVATE(file);
LASSERT(cio->cui_cl.cis_io == io);
/* mmap lock must be MANDATORY it has to cache pages. */
io->ci_lockreq = CILR_MANDATORY;
cio->cui_fd = fd;
} else {
LASSERT(rc < 0);
cl_io_fini(env, io);
cl_env_nested_put(nest, env);
io = ERR_PTR(rc);
}
return io;
}
