/**
* Estimates lock value for the purpose of managing the lock cache during
* memory shortages.
*
* Locks for memory mapped files are almost infinitely precious, others are
* junk. "Mapped locks" are heavy, but not infinitely heavy, so that they are
* ordered within themselves by weights assigned from other layers.
*/
static unsigned long vvp_lock_weigh(const struct lu_env *env,
const struct cl_lock_slice *slice)
{
struct ccc_object *cob = cl2ccc(slice->cls_obj);
return atomic_read(&cob->cob_mmap_cnt) > 0 ? ~0UL >> 2 : 0;
}
static void slp_transient_page_fini(const struct lu_env *env,
struct cl_page_slice *slice)
{
struct ccc_page *cp = cl2ccc_page(slice);
struct cl_page *clp = slice->cpl_page;
struct ccc_object *clobj = cl2ccc(clp->cp_obj);
slp_page_fini_common(cp);
clobj->cob_transient_pages--;
}
static int slp_page_init(const struct lu_env *env, struct cl_object *obj,
struct cl_page *page, struct page *vmpage)
{
struct ccc_page *cpg = cl_object_page_slice(obj, page);
CLOBINVRNT(env, obj, ccc_object_invariant(obj));
cpg->cpg_page = vmpage;
if (page->cp_type == CPT_CACHEABLE) {
LBUG();
} else {
struct ccc_object *clobj = cl2ccc(obj);
cl_page_slice_add(page, &cpg->cpg_cl, obj,
&slp_transient_page_ops);
clobj->cob_transient_pages++;
}
return 0;
}
/** Queues DONE_WRITING if
* - done writing is allowed;
* - inode has no no dirty pages; */
void ll_queue_done_writing(struct inode *inode, unsigned long flags)
{
struct ll_inode_info *lli = ll_i2info(inode);
struct ccc_object *club = cl2ccc(ll_i2info(inode)->lli_clob);
ENTRY;
spin_lock(&lli->lli_lock);
lli->lli_flags |= flags;
if ((lli->lli_flags & LLIF_DONE_WRITING) &&
cfs_list_empty(&club->cob_pending_list)) {
struct ll_close_queue *lcq = ll_i2sbi(inode)->ll_lcq;
if (lli->lli_flags & LLIF_MDS_SIZE_LOCK)
CWARN("ino %lu/%u(flags %u) som valid it just after "
"recovery\n",
inode->i_ino, inode->i_generation,
lli->lli_flags);
/* DONE_WRITING is allowed and inode has no dirty page. */
spin_lock(&lcq->lcq_lock);
LASSERT(cfs_list_empty(&lli->lli_close_list));
CDEBUG(D_INODE, "adding inode %lu/%u to close list\n",
inode->i_ino, inode->i_generation);
cfs_list_add_tail(&lli->lli_close_list, &lcq->lcq_head);
/* Avoid a concurrent insertion into the close thread queue:
* an inode is already in the close thread, open(), write(),
* close() happen, epoch is closed as the inode is marked as
* LLIF_EPOCH_PENDING. When pages are written inode should not
* be inserted into the queue again, clear this flag to avoid
* it. */
lli->lli_flags &= ~LLIF_DONE_WRITING;
cfs_waitq_signal(&lcq->lcq_waitq);
spin_unlock(&lcq->lcq_lock);
}
spin_unlock(&lli->lli_lock);
EXIT;
}
/** Closes ioepoch and packs Size-on-MDS attribute if needed into @op_data. */
void ll_ioepoch_close(struct inode *inode, struct md_op_data *op_data,
struct obd_client_handle **och, unsigned long flags)
{
struct ll_inode_info *lli = ll_i2info(inode);
struct ccc_object *club = cl2ccc(ll_i2info(inode)->lli_clob);
spin_lock(&lli->lli_lock);
if (!(list_empty(&club->cob_pending_list))) {
if (!(lli->lli_flags & LLIF_EPOCH_PENDING)) {
LASSERT(*och != NULL);
LASSERT(lli->lli_pending_och == NULL);
/* Inode is dirty and there is no pending write done
* request yet, DONE_WRITE is to be sent later. */
lli->lli_flags |= LLIF_EPOCH_PENDING;
lli->lli_pending_och = *och;
spin_unlock(&lli->lli_lock);
inode = igrab(inode);
LASSERT(inode);
GOTO(out, 0);
}
if (flags & LLIF_DONE_WRITING) {
/* Some pages are still dirty, it is early to send
* DONE_WRITE. Wait untill all pages will be flushed
* and try DONE_WRITE again later. */
LASSERT(!(lli->lli_flags & LLIF_DONE_WRITING));
lli->lli_flags |= LLIF_DONE_WRITING;
spin_unlock(&lli->lli_lock);
inode = igrab(inode);
LASSERT(inode);
GOTO(out, 0);
}
}
CDEBUG(D_INODE, "Epoch "LPU64" closed on "DFID"\n",
ll_i2info(inode)->lli_ioepoch, PFID(&lli->lli_fid));
op_data->op_flags |= MF_EPOCH_CLOSE;
if (flags & LLIF_DONE_WRITING) {
LASSERT(lli->lli_flags & LLIF_SOM_DIRTY);
LASSERT(!(lli->lli_flags & LLIF_DONE_WRITING));
*och = lli->lli_pending_och;
lli->lli_pending_och = NULL;
lli->lli_flags &= ~LLIF_EPOCH_PENDING;
} else {
/* Pack Size-on-MDS inode attributes only if they has changed */
if (!(lli->lli_flags & LLIF_SOM_DIRTY)) {
spin_unlock(&lli->lli_lock);
GOTO(out, 0);
}
/* There is a pending DONE_WRITE -- close epoch with no
* attribute change. */
if (lli->lli_flags & LLIF_EPOCH_PENDING) {
spin_unlock(&lli->lli_lock);
GOTO(out, 0);
}
}
LASSERT(list_empty(&club->cob_pending_list));
lli->lli_flags &= ~LLIF_SOM_DIRTY;
spin_unlock(&lli->lli_lock);
ll_done_writing_attr(inode, op_data);
out:
return;
}
static int vvp_io_commit_write(const struct lu_env *env,
const struct cl_io_slice *ios,
const struct cl_page_slice *slice,
unsigned from, unsigned to)
{
struct cl_object *obj = slice->cpl_obj;
struct cl_io *io = ios->cis_io;
struct ccc_page *cp = cl2ccc_page(slice);
struct cl_page *pg = slice->cpl_page;
struct inode *inode = ccc_object_inode(obj);
struct ll_sb_info *sbi = ll_i2sbi(inode);
struct ll_inode_info *lli = ll_i2info(inode);
struct page *vmpage = cp->cpg_page;
int result;
int tallyop;
loff_t size;
ENTRY;
LINVRNT(cl_page_is_vmlocked(env, pg));
LASSERT(vmpage->mapping->host == inode);
LU_OBJECT_HEADER(D_INODE, env, &obj->co_lu, "commiting page write\n");
CL_PAGE_HEADER(D_PAGE, env, pg, "committing: [%d, %d]\n", from, to);
/*
* queue a write for some time in the future the first time we
* dirty the page.
*
* This is different from what other file systems do: they usually
* just mark page (and some of its buffers) dirty and rely on
* balance_dirty_pages() to start a write-back. Lustre wants write-back
* to be started earlier for the following reasons:
*
* (1) with a large number of clients we need to limit the amount
* of cached data on the clients a lot;
*
* (2) large compute jobs generally want compute-only then io-only
* and the IO should complete as quickly as possible;
*
* (3) IO is batched up to the RPC size and is async until the
* client max cache is hit
* (/proc/fs/lustre/osc/OSC.../max_dirty_mb)
*
*/
if (!PageDirty(vmpage)) {
tallyop = LPROC_LL_DIRTY_MISSES;
result = cl_page_cache_add(env, io, pg, CRT_WRITE);
if (result == 0) {
/* page was added into cache successfully. */
set_page_dirty(vmpage);
vvp_write_pending(cl2ccc(obj), cp);
} else if (result == -EDQUOT) {
pgoff_t last_index = i_size_read(inode) >> PAGE_CACHE_SHIFT;
bool need_clip = true;
/*
* Client ran out of disk space grant. Possible
* strategies are:
*
* (a) do a sync write, renewing grant;
*
* (b) stop writing on this stripe, switch to the
* next one.
*
* (b) is a part of "parallel io" design that is the
* ultimate goal. (a) is what "old" client did, and
* what the new code continues to do for the time
* being.
*/
if (last_index > pg->cp_index) {
to = PAGE_CACHE_SIZE;
need_clip = false;
} else if (last_index == pg->cp_index) {
int size_to = i_size_read(inode) & ~CFS_PAGE_MASK;
if (to < size_to)
to = size_to;
}
if (need_clip)
cl_page_clip(env, pg, 0, to);
result = vvp_page_sync_io(env, io, pg, cp, CRT_WRITE);
if (result)
CERROR("Write page %lu of inode %p failed %d\n",
pg->cp_index, inode, result);
}
static int vvp_io_fault_start(const struct lu_env *env,
const struct cl_io_slice *ios)
{
struct vvp_io *vio = cl2vvp_io(env, ios);
struct cl_io *io = ios->cis_io;
struct cl_object *obj = io->ci_obj;
struct inode *inode = ccc_object_inode(obj);
struct cl_fault_io *fio = &io->u.ci_fault;
struct vvp_fault_io *cfio = &vio->u.fault;
loff_t offset;
int result = 0;
struct page *vmpage = NULL;
struct cl_page *page;
loff_t size;
pgoff_t last; /* last page in a file data region */
if (fio->ft_executable &&
LTIME_S(inode->i_mtime) != vio->u.fault.ft_mtime)
CWARN("binary "DFID
" changed while waiting for the page fault lock\n",
PFID(lu_object_fid(&obj->co_lu)));
/* offset of the last byte on the page */
offset = cl_offset(obj, fio->ft_index + 1) - 1;
LASSERT(cl_index(obj, offset) == fio->ft_index);
result = ccc_prep_size(env, obj, io, 0, offset + 1, NULL);
if (result != 0)
return result;
/* must return locked page */
if (fio->ft_mkwrite) {
LASSERT(cfio->ft_vmpage != NULL);
lock_page(cfio->ft_vmpage);
} else {
result = vvp_io_kernel_fault(cfio);
if (result != 0)
return result;
}
vmpage = cfio->ft_vmpage;
LASSERT(PageLocked(vmpage));
if (OBD_FAIL_CHECK(OBD_FAIL_LLITE_FAULT_TRUNC_RACE))
ll_invalidate_page(vmpage);
size = i_size_read(inode);
/* Though we have already held a cl_lock upon this page, but
* it still can be truncated locally. */
if (unlikely((vmpage->mapping != inode->i_mapping) ||
(page_offset(vmpage) > size))) {
CDEBUG(D_PAGE, "llite: fault and truncate race happened!\n");
/* return +1 to stop cl_io_loop() and ll_fault() will catch
* and retry. */
GOTO(out, result = +1);
}
if (fio->ft_mkwrite ) {
pgoff_t last_index;
/*
* Capture the size while holding the lli_trunc_sem from above
* we want to make sure that we complete the mkwrite action
* while holding this lock. We need to make sure that we are
* not past the end of the file.
*/
last_index = cl_index(obj, size - 1);
if (last_index < fio->ft_index) {
CDEBUG(D_PAGE,
"llite: mkwrite and truncate race happened: "
"%p: 0x%lx 0x%lx\n",
vmpage->mapping,fio->ft_index,last_index);
/*
* We need to return if we are
* passed the end of the file. This will propagate
* up the call stack to ll_page_mkwrite where
* we will return VM_FAULT_NOPAGE. Any non-negative
* value returned here will be silently
* converted to 0. If the vmpage->mapping is null
* the error code would be converted back to ENODATA
* in ll_page_mkwrite0. Thus we return -ENODATA
* to handle both cases
*/
GOTO(out, result = -ENODATA);
}
}
page = cl_page_find(env, obj, fio->ft_index, vmpage, CPT_CACHEABLE);
if (IS_ERR(page))
GOTO(out, result = PTR_ERR(page));
/* if page is going to be written, we should add this page into cache
* earlier. */
if (fio->ft_mkwrite) {
wait_on_page_writeback(vmpage);
if (set_page_dirty(vmpage)) {
struct ccc_page *cp;
/* vvp_page_assume() calls wait_on_page_writeback(). */
cl_page_assume(env, io, page);
cp = cl2ccc_page(cl_page_at(page, &vvp_device_type));
vvp_write_pending(cl2ccc(obj), cp);
/* Do not set Dirty bit here so that in case IO is
* started before the page is really made dirty, we
* still have chance to detect it. */
result = cl_page_cache_add(env, io, page, CRT_WRITE);
LASSERT(cl_page_is_owned(page, io));
vmpage = NULL;
if (result < 0) {
cl_page_unmap(env, io, page);
cl_page_discard(env, io, page);
cl_page_disown(env, io, page);
cl_page_put(env, page);
/* we're in big trouble, what can we do now? */
if (result == -EDQUOT)
result = -ENOSPC;
GOTO(out, result);
} else
cl_page_disown(env, io, page);
}
}
last = cl_index(obj, size - 1);
/*
* The ft_index is only used in the case of
* a mkwrite action. We need to check
* our assertions are correct, since
* we should have caught this above
*/
LASSERT(!fio->ft_mkwrite || fio->ft_index <= last);
if (fio->ft_index == last)
/*
* Last page is mapped partially.
*/
fio->ft_nob = size - cl_offset(obj, fio->ft_index);
else
fio->ft_nob = cl_page_size(obj);
lu_ref_add(&page->cp_reference, "fault", io);
fio->ft_page = page;
EXIT;
out:
/* return unlocked vmpage to avoid deadlocking */
if (vmpage != NULL)
unlock_page(vmpage);
cfio->fault.ft_flags &= ~VM_FAULT_LOCKED;
return result;
}
