#include <linux/uio.h>
#include <linux/khugepaged.h>
#include <linux/hugetlb.h>
+#include <linux/frontswap.h>
#include <asm/tlbflush.h> /* for arch/microblaze update_mmu_cache() */
static bool shmem_should_replace_page(struct page *page, gfp_t gfp);
static int shmem_replace_page(struct page **pagep, gfp_t gfp,
struct shmem_inode_info *info, pgoff_t index);
+static int shmem_swapin_page(struct inode *inode, pgoff_t index,
+ struct page **pagep, enum sgp_type sgp,
+ gfp_t gfp, struct vm_area_struct *vma,
+ vm_fault_t *fault_type);
static int shmem_getpage_gfp(struct inode *inode, pgoff_t index,
struct page **pagep, enum sgp_type sgp,
gfp_t gfp, struct vm_area_struct *vma,
clear_inode(inode);
}
-static unsigned long find_swap_entry(struct xarray *xa, void *item)
+extern struct swap_info_struct *swap_info[];
+
+static int shmem_find_swap_entries(struct address_space *mapping,
+ pgoff_t start, unsigned int nr_entries,
+ struct page **entries, pgoff_t *indices,
+ unsigned int type, bool frontswap)
{
- XA_STATE(xas, xa, 0);
- unsigned int checked = 0;
- void *entry;
+ XA_STATE(xas, &mapping->i_pages, start);
+ struct page *page;
+ swp_entry_t entry;
+ unsigned int ret = 0;
+
+ if (!nr_entries)
+ return 0;
rcu_read_lock();
- xas_for_each(&xas, entry, ULONG_MAX) {
- if (xas_retry(&xas, entry))
+ xas_for_each(&xas, page, ULONG_MAX) {
+ if (xas_retry(&xas, page))
continue;
- if (entry == item)
- break;
- checked++;
- if ((checked % XA_CHECK_SCHED) != 0)
+
+ if (!xa_is_value(page))
continue;
- xas_pause(&xas);
- cond_resched_rcu();
+
+ entry = radix_to_swp_entry(page);
+ if (swp_type(entry) != type)
+ continue;
+ if (frontswap &&
+ !frontswap_test(swap_info[type], swp_offset(entry)))
+ continue;
+
+ indices[ret] = xas.xa_index;
+ entries[ret] = page;
+
+ if (need_resched()) {
+ xas_pause(&xas);
+ cond_resched_rcu();
+ }
+ if (++ret == nr_entries)
+ break;
}
rcu_read_unlock();
- return entry ? xas.xa_index : -1;
+ return ret;
}
/*
- * If swap found in inode, free it and move page from swapcache to filecache.
+ * Move the swapped pages for an inode to page cache. Returns the count
+ * of pages swapped in, or the error in case of failure.
*/
-static int shmem_unuse_inode(struct shmem_inode_info *info,
- swp_entry_t swap, struct page **pagep)
+static int shmem_unuse_swap_entries(struct inode *inode, struct pagevec pvec,
+ pgoff_t *indices)
{
- struct address_space *mapping = info->vfs_inode.i_mapping;
- void *radswap;
- pgoff_t index;
- gfp_t gfp;
+ int i = 0;
+ int ret = 0;
int error = 0;
+ struct address_space *mapping = inode->i_mapping;
- radswap = swp_to_radix_entry(swap);
- index = find_swap_entry(&mapping->i_pages, radswap);
- if (index == -1)
- return -EAGAIN; /* tell shmem_unuse we found nothing */
+ for (i = 0; i < pvec.nr; i++) {
+ struct page *page = pvec.pages[i];
- /*
- * Move _head_ to start search for next from here.
- * But be careful: shmem_evict_inode checks list_empty without taking
- * mutex, and there's an instant in list_move_tail when info->swaplist
- * would appear empty, if it were the only one on shmem_swaplist.
- */
- if (shmem_swaplist.next != &info->swaplist)
- list_move_tail(&shmem_swaplist, &info->swaplist);
-
- gfp = mapping_gfp_mask(mapping);
- if (shmem_should_replace_page(*pagep, gfp)) {
- mutex_unlock(&shmem_swaplist_mutex);
- error = shmem_replace_page(pagep, gfp, info, index);
- mutex_lock(&shmem_swaplist_mutex);
- /*
- * We needed to drop mutex to make that restrictive page
- * allocation, but the inode might have been freed while we
- * dropped it: although a racing shmem_evict_inode() cannot
- * complete without emptying the page cache, our page lock
- * on this swapcache page is not enough to prevent that -
- * free_swap_and_cache() of our swap entry will only
- * trylock_page(), removing swap from page cache whatever.
- *
- * We must not proceed to shmem_add_to_page_cache() if the
- * inode has been freed, but of course we cannot rely on
- * inode or mapping or info to check that. However, we can
- * safely check if our swap entry is still in use (and here
- * it can't have got reused for another page): if it's still
- * in use, then the inode cannot have been freed yet, and we
- * can safely proceed (if it's no longer in use, that tells
- * nothing about the inode, but we don't need to unuse swap).
- */
- if (!page_swapcount(*pagep))
- error = -ENOENT;
+ if (!xa_is_value(page))
+ continue;
+ error = shmem_swapin_page(inode, indices[i],
+ &page, SGP_CACHE,
+ mapping_gfp_mask(mapping),
+ NULL, NULL);
+ if (error == 0) {
+ unlock_page(page);
+ put_page(page);
+ ret++;
+ }
+ if (error == -ENOMEM)
+ break;
+ error = 0;
}
+ return error ? error : ret;
+}
- /*
- * We rely on shmem_swaplist_mutex, not only to protect the swaplist,
- * but also to hold up shmem_evict_inode(): so inode cannot be freed
- * beneath us (pagelock doesn't help until the page is in pagecache).
- */
- if (!error)
- error = shmem_add_to_page_cache(*pagep, mapping, index,
- radswap, gfp);
- if (error != -ENOMEM) {
- /*
- * Truncation and eviction use free_swap_and_cache(), which
- * only does trylock page: if we raced, best clean up here.
- */
- delete_from_swap_cache(*pagep);
- set_page_dirty(*pagep);
- if (!error) {
- spin_lock_irq(&info->lock);
- info->swapped--;
- spin_unlock_irq(&info->lock);
- swap_free(swap);
+/*
+ * If swap found in inode, free it and move page from swapcache to filecache.
+ */
+static int shmem_unuse_inode(struct inode *inode, unsigned int type,
+ bool frontswap, unsigned long *fs_pages_to_unuse)
+{
+ struct address_space *mapping = inode->i_mapping;
+ pgoff_t start = 0;
+ struct pagevec pvec;
+ pgoff_t indices[PAGEVEC_SIZE];
+ bool frontswap_partial = (frontswap && *fs_pages_to_unuse > 0);
+ int ret = 0;
+
+ pagevec_init(&pvec);
+ do {
+ unsigned int nr_entries = PAGEVEC_SIZE;
+
+ if (frontswap_partial && *fs_pages_to_unuse < PAGEVEC_SIZE)
+ nr_entries = *fs_pages_to_unuse;
+
+ pvec.nr = shmem_find_swap_entries(mapping, start, nr_entries,
+ pvec.pages, indices,
+ type, frontswap);
+ if (pvec.nr == 0) {
+ ret = 0;
+ break;
}
- }
- return error;
+
+ ret = shmem_unuse_swap_entries(inode, pvec, indices);
+ if (ret < 0)
+ break;
+
+ if (frontswap_partial) {
+ *fs_pages_to_unuse -= ret;
+ if (*fs_pages_to_unuse == 0) {
+ ret = FRONTSWAP_PAGES_UNUSED;
+ break;
+ }
+ }
+
+ start = indices[pvec.nr - 1];
+ } while (true);
+
+ return ret;
}
/*
- * Search through swapped inodes to find and replace swap by page.
+ * Read all the shared memory data that resides in the swap
+ * device 'type' back into memory, so the swap device can be
+ * unused.
*/
-int shmem_unuse(swp_entry_t swap, struct page *page)
+int shmem_unuse(unsigned int type, bool frontswap,
+ unsigned long *fs_pages_to_unuse)
{
- struct list_head *this, *next;
- struct shmem_inode_info *info;
- struct mem_cgroup *memcg;
+ struct shmem_inode_info *info, *next;
+ struct inode *inode;
+ struct inode *prev_inode = NULL;
int error = 0;
- /*
- * There's a faint possibility that swap page was replaced before
- * caller locked it: caller will come back later with the right page.
- */
- if (unlikely(!PageSwapCache(page) || page_private(page) != swap.val))
- goto out;
+ if (list_empty(&shmem_swaplist))
+ return 0;
+
+ mutex_lock(&shmem_swaplist_mutex);
/*
- * Charge page using GFP_KERNEL while we can wait, before taking
- * the shmem_swaplist_mutex which might hold up shmem_writepage().
- * Charged back to the user (not to caller) when swap account is used.
+ * The extra refcount on the inode is necessary to safely dereference
+ * p->next after re-acquiring the lock. New shmem inodes with swap
+ * get added to the end of the list and we will scan them all.
*/
- error = mem_cgroup_try_charge_delay(page, current->mm, GFP_KERNEL,
- &memcg, false);
- if (error)
- goto out;
- /* No memory allocation: swap entry occupies the slot for the page */
- error = -EAGAIN;
-
- mutex_lock(&shmem_swaplist_mutex);
- list_for_each_safe(this, next, &shmem_swaplist) {
- info = list_entry(this, struct shmem_inode_info, swaplist);
- if (info->swapped)
- error = shmem_unuse_inode(info, swap, &page);
- else
+ list_for_each_entry_safe(info, next, &shmem_swaplist, swaplist) {
+ if (!info->swapped) {
list_del_init(&info->swaplist);
+ continue;
+ }
+
+ inode = igrab(&info->vfs_inode);
+ if (!inode)
+ continue;
+
+ mutex_unlock(&shmem_swaplist_mutex);
+ if (prev_inode)
+ iput(prev_inode);
+ prev_inode = inode;
+
+ error = shmem_unuse_inode(inode, type, frontswap,
+ fs_pages_to_unuse);
cond_resched();
- if (error != -EAGAIN)
+
+ mutex_lock(&shmem_swaplist_mutex);
+ next = list_next_entry(info, swaplist);
+ if (!info->swapped)
+ list_del_init(&info->swaplist);
+ if (error)
break;
- /* found nothing in this: move on to search the next */
}
mutex_unlock(&shmem_swaplist_mutex);
- if (error) {
- if (error != -ENOMEM)
- error = 0;
- mem_cgroup_cancel_charge(page, memcg, false);
- } else
- mem_cgroup_commit_charge(page, memcg, true, false);
-out:
- unlock_page(page);
- put_page(page);
+ if (prev_inode)
+ iput(prev_inode);
+
return error;
}
*/
mutex_lock(&shmem_swaplist_mutex);
if (list_empty(&info->swaplist))
- list_add_tail(&info->swaplist, &shmem_swaplist);
+ list_add(&info->swaplist, &shmem_swaplist);
if (add_to_swap_cache(page, swap, GFP_ATOMIC) == 0) {
spin_lock_irq(&info->lock);
return error;
}
+/*
+ * Swap in the page pointed to by *pagep.
+ * Caller has to make sure that *pagep contains a valid swapped page.
+ * Returns 0 and the page in pagep if success. On failure, returns the
+ * the error code and NULL in *pagep.
+ */
+static int shmem_swapin_page(struct inode *inode, pgoff_t index,
+ struct page **pagep, enum sgp_type sgp,
+ gfp_t gfp, struct vm_area_struct *vma,
+ vm_fault_t *fault_type)
+{
+ struct address_space *mapping = inode->i_mapping;
+ struct shmem_inode_info *info = SHMEM_I(inode);
+ struct mm_struct *charge_mm = vma ? vma->vm_mm : current->mm;
+ struct mem_cgroup *memcg;
+ struct page *page;
+ swp_entry_t swap;
+ int error;
+
+ VM_BUG_ON(!*pagep || !xa_is_value(*pagep));
+ swap = radix_to_swp_entry(*pagep);
+ *pagep = NULL;
+
+ /* Look it up and read it in.. */
+ page = lookup_swap_cache(swap, NULL, 0);
+ if (!page) {
+ /* Or update major stats only when swapin succeeds?? */
+ if (fault_type) {
+ *fault_type |= VM_FAULT_MAJOR;
+ count_vm_event(PGMAJFAULT);
+ count_memcg_event_mm(charge_mm, PGMAJFAULT);
+ }
+ /* Here we actually start the io */
+ page = shmem_swapin(swap, gfp, info, index);
+ if (!page) {
+ error = -ENOMEM;
+ goto failed;
+ }
+ }
+
+ /* We have to do this with page locked to prevent races */
+ lock_page(page);
+ if (!PageSwapCache(page) || page_private(page) != swap.val ||
+ !shmem_confirm_swap(mapping, index, swap)) {
+ error = -EEXIST;
+ goto unlock;
+ }
+ if (!PageUptodate(page)) {
+ error = -EIO;
+ goto failed;
+ }
+ wait_on_page_writeback(page);
+
+ if (shmem_should_replace_page(page, gfp)) {
+ error = shmem_replace_page(&page, gfp, info, index);
+ if (error)
+ goto failed;
+ }
+
+ error = mem_cgroup_try_charge_delay(page, charge_mm, gfp, &memcg,
+ false);
+ if (!error) {
+ error = shmem_add_to_page_cache(page, mapping, index,
+ swp_to_radix_entry(swap), gfp);
+ /*
+ * We already confirmed swap under page lock, and make
+ * no memory allocation here, so usually no possibility
+ * of error; but free_swap_and_cache() only trylocks a
+ * page, so it is just possible that the entry has been
+ * truncated or holepunched since swap was confirmed.
+ * shmem_undo_range() will have done some of the
+ * unaccounting, now delete_from_swap_cache() will do
+ * the rest.
+ */
+ if (error) {
+ mem_cgroup_cancel_charge(page, memcg, false);
+ delete_from_swap_cache(page);
+ }
+ }
+ if (error)
+ goto failed;
+
+ mem_cgroup_commit_charge(page, memcg, true, false);
+
+ spin_lock_irq(&info->lock);
+ info->swapped--;
+ shmem_recalc_inode(inode);
+ spin_unlock_irq(&info->lock);
+
+ if (sgp == SGP_WRITE)
+ mark_page_accessed(page);
+
+ delete_from_swap_cache(page);
+ set_page_dirty(page);
+ swap_free(swap);
+
+ *pagep = page;
+ return 0;
+failed:
+ if (!shmem_confirm_swap(mapping, index, swap))
+ error = -EEXIST;
+unlock:
+ if (page) {
+ unlock_page(page);
+ put_page(page);
+ }
+
+ return error;
+}
+
/*
* shmem_getpage_gfp - find page in cache, or get from swap, or allocate
*
struct mm_struct *charge_mm;
struct mem_cgroup *memcg;
struct page *page;
- swp_entry_t swap;
enum sgp_type sgp_huge = sgp;
pgoff_t hindex = index;
int error;
if (sgp == SGP_NOHUGE || sgp == SGP_HUGE)
sgp = SGP_CACHE;
repeat:
- swap.val = 0;
+ if (sgp <= SGP_CACHE &&
+ ((loff_t)index << PAGE_SHIFT) >= i_size_read(inode)) {
+ return -EINVAL;
+ }
+
+ sbinfo = SHMEM_SB(inode->i_sb);
+ charge_mm = vma ? vma->vm_mm : current->mm;
+
page = find_lock_entry(mapping, index);
if (xa_is_value(page)) {
- swap = radix_to_swp_entry(page);
- page = NULL;
- }
+ error = shmem_swapin_page(inode, index, &page,
+ sgp, gfp, vma, fault_type);
+ if (error == -EEXIST)
+ goto repeat;
- if (sgp <= SGP_CACHE &&
- ((loff_t)index << PAGE_SHIFT) >= i_size_read(inode)) {
- error = -EINVAL;
- goto unlock;
+ *pagep = page;
+ return error;
}
if (page && sgp == SGP_WRITE)
put_page(page);
page = NULL;
}
- if (page || (sgp == SGP_READ && !swap.val)) {
+ if (page || sgp == SGP_READ) {
*pagep = page;
return 0;
}
* Fast cache lookup did not find it:
* bring it back from swap or allocate.
*/
- sbinfo = SHMEM_SB(inode->i_sb);
- charge_mm = vma ? vma->vm_mm : current->mm;
-
- if (swap.val) {
- /* Look it up and read it in.. */
- page = lookup_swap_cache(swap, NULL, 0);
- if (!page) {
- /* Or update major stats only when swapin succeeds?? */
- if (fault_type) {
- *fault_type |= VM_FAULT_MAJOR;
- count_vm_event(PGMAJFAULT);
- count_memcg_event_mm(charge_mm, PGMAJFAULT);
- }
- /* Here we actually start the io */
- page = shmem_swapin(swap, gfp, info, index);
- if (!page) {
- error = -ENOMEM;
- goto failed;
- }
- }
-
- /* We have to do this with page locked to prevent races */
- lock_page(page);
- if (!PageSwapCache(page) || page_private(page) != swap.val ||
- !shmem_confirm_swap(mapping, index, swap)) {
- error = -EEXIST; /* try again */
- goto unlock;
- }
- if (!PageUptodate(page)) {
- error = -EIO;
- goto failed;
- }
- wait_on_page_writeback(page);
-
- if (shmem_should_replace_page(page, gfp)) {
- error = shmem_replace_page(&page, gfp, info, index);
- if (error)
- goto failed;
- }
-
- error = mem_cgroup_try_charge_delay(page, charge_mm, gfp, &memcg,
- false);
- if (!error) {
- error = shmem_add_to_page_cache(page, mapping, index,
- swp_to_radix_entry(swap), gfp);
- /*
- * We already confirmed swap under page lock, and make
- * no memory allocation here, so usually no possibility
- * of error; but free_swap_and_cache() only trylocks a
- * page, so it is just possible that the entry has been
- * truncated or holepunched since swap was confirmed.
- * shmem_undo_range() will have done some of the
- * unaccounting, now delete_from_swap_cache() will do
- * the rest.
- * Reset swap.val? No, leave it so "failed" goes back to
- * "repeat": reading a hole and writing should succeed.
- */
- if (error) {
- mem_cgroup_cancel_charge(page, memcg, false);
- delete_from_swap_cache(page);
- }
- }
- if (error)
- goto failed;
-
- mem_cgroup_commit_charge(page, memcg, true, false);
-
- spin_lock_irq(&info->lock);
- info->swapped--;
- shmem_recalc_inode(inode);
- spin_unlock_irq(&info->lock);
-
- if (sgp == SGP_WRITE)
- mark_page_accessed(page);
- delete_from_swap_cache(page);
- set_page_dirty(page);
- swap_free(swap);
-
- } else {
- if (vma && userfaultfd_missing(vma)) {
- *fault_type = handle_userfault(vmf, VM_UFFD_MISSING);
- return 0;
- }
+ if (vma && userfaultfd_missing(vma)) {
+ *fault_type = handle_userfault(vmf, VM_UFFD_MISSING);
+ return 0;
+ }
- /* shmem_symlink() */
- if (mapping->a_ops != &shmem_aops)
- goto alloc_nohuge;
- if (shmem_huge == SHMEM_HUGE_DENY || sgp_huge == SGP_NOHUGE)
- goto alloc_nohuge;
- if (shmem_huge == SHMEM_HUGE_FORCE)
+ /* shmem_symlink() */
+ if (mapping->a_ops != &shmem_aops)
+ goto alloc_nohuge;
+ if (shmem_huge == SHMEM_HUGE_DENY || sgp_huge == SGP_NOHUGE)
+ goto alloc_nohuge;
+ if (shmem_huge == SHMEM_HUGE_FORCE)
+ goto alloc_huge;
+ switch (sbinfo->huge) {
+ loff_t i_size;
+ pgoff_t off;
+ case SHMEM_HUGE_NEVER:
+ goto alloc_nohuge;
+ case SHMEM_HUGE_WITHIN_SIZE:
+ off = round_up(index, HPAGE_PMD_NR);
+ i_size = round_up(i_size_read(inode), PAGE_SIZE);
+ if (i_size >= HPAGE_PMD_SIZE &&
+ i_size >> PAGE_SHIFT >= off)
goto alloc_huge;
- switch (sbinfo->huge) {
- loff_t i_size;
- pgoff_t off;
- case SHMEM_HUGE_NEVER:
- goto alloc_nohuge;
- case SHMEM_HUGE_WITHIN_SIZE:
- off = round_up(index, HPAGE_PMD_NR);
- i_size = round_up(i_size_read(inode), PAGE_SIZE);
- if (i_size >= HPAGE_PMD_SIZE &&
- i_size >> PAGE_SHIFT >= off)
- goto alloc_huge;
- /* fallthrough */
- case SHMEM_HUGE_ADVISE:
- if (sgp_huge == SGP_HUGE)
- goto alloc_huge;
- /* TODO: implement fadvise() hints */
- goto alloc_nohuge;
- }
+ /* fallthrough */
+ case SHMEM_HUGE_ADVISE:
+ if (sgp_huge == SGP_HUGE)
+ goto alloc_huge;
+ /* TODO: implement fadvise() hints */
+ goto alloc_nohuge;
+ }
alloc_huge:
- page = shmem_alloc_and_acct_page(gfp, inode, index, true);
- if (IS_ERR(page)) {
-alloc_nohuge: page = shmem_alloc_and_acct_page(gfp, inode,
- index, false);
- }
- if (IS_ERR(page)) {
- int retry = 5;
- error = PTR_ERR(page);
- page = NULL;
- if (error != -ENOSPC)
- goto failed;
- /*
- * Try to reclaim some spece by splitting a huge page
- * beyond i_size on the filesystem.
- */
- while (retry--) {
- int ret;
- ret = shmem_unused_huge_shrink(sbinfo, NULL, 1);
- if (ret == SHRINK_STOP)
- break;
- if (ret)
- goto alloc_nohuge;
- }
- goto failed;
- }
-
- if (PageTransHuge(page))
- hindex = round_down(index, HPAGE_PMD_NR);
- else
- hindex = index;
+ page = shmem_alloc_and_acct_page(gfp, inode, index, true);
+ if (IS_ERR(page)) {
+alloc_nohuge:
+ page = shmem_alloc_and_acct_page(gfp, inode,
+ index, false);
+ }
+ if (IS_ERR(page)) {
+ int retry = 5;
- if (sgp == SGP_WRITE)
- __SetPageReferenced(page);
+ error = PTR_ERR(page);
+ page = NULL;
+ if (error != -ENOSPC)
+ goto unlock;
+ /*
+ * Try to reclaim some space by splitting a huge page
+ * beyond i_size on the filesystem.
+ */
+ while (retry--) {
+ int ret;
- error = mem_cgroup_try_charge_delay(page, charge_mm, gfp, &memcg,
- PageTransHuge(page));
- if (error)
- goto unacct;
- error = shmem_add_to_page_cache(page, mapping, hindex,
- NULL, gfp & GFP_RECLAIM_MASK);
- if (error) {
- mem_cgroup_cancel_charge(page, memcg,
- PageTransHuge(page));
- goto unacct;
+ ret = shmem_unused_huge_shrink(sbinfo, NULL, 1);
+ if (ret == SHRINK_STOP)
+ break;
+ if (ret)
+ goto alloc_nohuge;
}
- mem_cgroup_commit_charge(page, memcg, false,
- PageTransHuge(page));
- lru_cache_add_anon(page);
+ goto unlock;
+ }
- spin_lock_irq(&info->lock);
- info->alloced += 1 << compound_order(page);
- inode->i_blocks += BLOCKS_PER_PAGE << compound_order(page);
- shmem_recalc_inode(inode);
- spin_unlock_irq(&info->lock);
- alloced = true;
+ if (PageTransHuge(page))
+ hindex = round_down(index, HPAGE_PMD_NR);
+ else
+ hindex = index;
- if (PageTransHuge(page) &&
- DIV_ROUND_UP(i_size_read(inode), PAGE_SIZE) <
- hindex + HPAGE_PMD_NR - 1) {
- /*
- * Part of the huge page is beyond i_size: subject
- * to shrink under memory pressure.
- */
- spin_lock(&sbinfo->shrinklist_lock);
- /*
- * _careful to defend against unlocked access to
- * ->shrink_list in shmem_unused_huge_shrink()
- */
- if (list_empty_careful(&info->shrinklist)) {
- list_add_tail(&info->shrinklist,
- &sbinfo->shrinklist);
- sbinfo->shrinklist_len++;
- }
- spin_unlock(&sbinfo->shrinklist_lock);
- }
+ if (sgp == SGP_WRITE)
+ __SetPageReferenced(page);
+
+ error = mem_cgroup_try_charge_delay(page, charge_mm, gfp, &memcg,
+ PageTransHuge(page));
+ if (error)
+ goto unacct;
+ error = shmem_add_to_page_cache(page, mapping, hindex,
+ NULL, gfp & GFP_RECLAIM_MASK);
+ if (error) {
+ mem_cgroup_cancel_charge(page, memcg,
+ PageTransHuge(page));
+ goto unacct;
+ }
+ mem_cgroup_commit_charge(page, memcg, false,
+ PageTransHuge(page));
+ lru_cache_add_anon(page);
+ spin_lock_irq(&info->lock);
+ info->alloced += 1 << compound_order(page);
+ inode->i_blocks += BLOCKS_PER_PAGE << compound_order(page);
+ shmem_recalc_inode(inode);
+ spin_unlock_irq(&info->lock);
+ alloced = true;
+
+ if (PageTransHuge(page) &&
+ DIV_ROUND_UP(i_size_read(inode), PAGE_SIZE) <
+ hindex + HPAGE_PMD_NR - 1) {
/*
- * Let SGP_FALLOC use the SGP_WRITE optimization on a new page.
+ * Part of the huge page is beyond i_size: subject
+ * to shrink under memory pressure.
*/
- if (sgp == SGP_FALLOC)
- sgp = SGP_WRITE;
-clear:
+ spin_lock(&sbinfo->shrinklist_lock);
/*
- * Let SGP_WRITE caller clear ends if write does not fill page;
- * but SGP_FALLOC on a page fallocated earlier must initialize
- * it now, lest undo on failure cancel our earlier guarantee.
+ * _careful to defend against unlocked access to
+ * ->shrink_list in shmem_unused_huge_shrink()
*/
- if (sgp != SGP_WRITE && !PageUptodate(page)) {
- struct page *head = compound_head(page);
- int i;
+ if (list_empty_careful(&info->shrinklist)) {
+ list_add_tail(&info->shrinklist,
+ &sbinfo->shrinklist);
+ sbinfo->shrinklist_len++;
+ }
+ spin_unlock(&sbinfo->shrinklist_lock);
+ }
- for (i = 0; i < (1 << compound_order(head)); i++) {
- clear_highpage(head + i);
- flush_dcache_page(head + i);
- }
- SetPageUptodate(head);
+ /*
+ * Let SGP_FALLOC use the SGP_WRITE optimization on a new page.
+ */
+ if (sgp == SGP_FALLOC)
+ sgp = SGP_WRITE;
+clear:
+ /*
+ * Let SGP_WRITE caller clear ends if write does not fill page;
+ * but SGP_FALLOC on a page fallocated earlier must initialize
+ * it now, lest undo on failure cancel our earlier guarantee.
+ */
+ if (sgp != SGP_WRITE && !PageUptodate(page)) {
+ struct page *head = compound_head(page);
+ int i;
+
+ for (i = 0; i < (1 << compound_order(head)); i++) {
+ clear_highpage(head + i);
+ flush_dcache_page(head + i);
}
+ SetPageUptodate(head);
}
/* Perhaps the file has been truncated since we checked */
put_page(page);
goto alloc_nohuge;
}
-failed:
- if (swap.val && !shmem_confirm_swap(mapping, index, swap))
- error = -EEXIST;
unlock:
if (page) {
unlock_page(page);
static int shmem_mmap(struct file *file, struct vm_area_struct *vma)
{
+ struct shmem_inode_info *info = SHMEM_I(file_inode(file));
+
+ if (info->seals & F_SEAL_FUTURE_WRITE) {
+ /*
+ * New PROT_WRITE and MAP_SHARED mmaps are not allowed when
+ * "future write" seal active.
+ */
+ if ((vma->vm_flags & VM_SHARED) && (vma->vm_flags & VM_WRITE))
+ return -EPERM;
+
+ /*
+ * Since the F_SEAL_FUTURE_WRITE seals allow for a MAP_SHARED
+ * read-only mapping, take care to not allow mprotect to revert
+ * protections.
+ */
+ vma->vm_flags &= ~(VM_MAYWRITE);
+ }
+
file_accessed(file);
vma->vm_ops = &shmem_vm_ops;
if (IS_ENABLED(CONFIG_TRANSPARENT_HUGE_PAGECACHE) &&
pgoff_t index = pos >> PAGE_SHIFT;
/* i_mutex is held by caller */
- if (unlikely(info->seals & (F_SEAL_WRITE | F_SEAL_GROW))) {
- if (info->seals & F_SEAL_WRITE)
+ if (unlikely(info->seals & (F_SEAL_GROW |
+ F_SEAL_WRITE | F_SEAL_FUTURE_WRITE))) {
+ if (info->seals & (F_SEAL_WRITE | F_SEAL_FUTURE_WRITE))
return -EPERM;
if ((info->seals & F_SEAL_GROW) && pos + len > inode->i_size)
return -EPERM;
DECLARE_WAIT_QUEUE_HEAD_ONSTACK(shmem_falloc_waitq);
/* protected by i_mutex */
- if (info->seals & F_SEAL_WRITE) {
+ if (info->seals & (F_SEAL_WRITE | F_SEAL_FUTURE_WRITE)) {
error = -EPERM;
goto out;
}
return 0;
}
-int shmem_unuse(swp_entry_t swap, struct page *page)
+int shmem_unuse(unsigned int type, bool frontswap,
+ unsigned long *fs_pages_to_unuse)
{
return 0;
}
projects / linux-2.6-block.git / blobdiff