error = add_to_page_cache_locked(page, mapping, idx, GFP_NOWAIT);
/* which does mem_cgroup_uncharge_cache_page on error */
- if (error == -EEXIST) {
- struct page *filepage = find_get_page(mapping, idx);
- error = 1;
- if (filepage) {
- /*
- * There might be a more uptodate page coming down
- * from a stacked writepage: forget our swappage if so.
- */
- if (PageUptodate(filepage))
- error = 0;
- page_cache_release(filepage);
- }
- }
- if (!error) {
+ if (error != -ENOMEM) {
delete_from_swap_cache(page);
set_page_dirty(page);
info->flags |= SHMEM_PAGEIN;
/*
* shmem_backing_dev_info's capabilities prevent regular writeback or
* sync from ever calling shmem_writepage; but a stacking filesystem
- * may use the ->writepage of its underlying filesystem, in which case
+ * might use ->writepage of its underlying filesystem, in which case
* tmpfs should write out to swap only in response to memory pressure,
- * and not for the writeback threads or sync. However, in those cases,
- * we do still want to check if there's a redundant swappage to be
- * discarded.
+ * and not for the writeback threads or sync.
*/
- if (wbc->for_reclaim)
- swap = get_swap_page();
- else
- swap.val = 0;
+ if (!wbc->for_reclaim) {
+ WARN_ON_ONCE(1); /* Still happens? Tell us about it! */
+ goto redirty;
+ }
+ swap = get_swap_page();
+ if (!swap.val)
+ goto redirty;
/*
* Add inode to shmem_unuse()'s list of swapped-out inodes,
* we've taken the spinlock, because shmem_unuse_inode() will
* prune a !swapped inode from the swaplist under both locks.
*/
- if (swap.val) {
- mutex_lock(&shmem_swaplist_mutex);
- if (list_empty(&info->swaplist))
- list_add_tail(&info->swaplist, &shmem_swaplist);
- }
+ mutex_lock(&shmem_swaplist_mutex);
+ if (list_empty(&info->swaplist))
+ list_add_tail(&info->swaplist, &shmem_swaplist);
spin_lock(&info->lock);
- if (swap.val)
- mutex_unlock(&shmem_swaplist_mutex);
+ mutex_unlock(&shmem_swaplist_mutex);
if (index >= info->next_index) {
BUG_ON(!(info->flags & SHMEM_TRUNCATE));
}
entry = shmem_swp_entry(info, index, NULL);
if (entry->val) {
- /*
- * The more uptodate page coming down from a stacked
- * writepage should replace our old swappage.
- */
+ WARN_ON_ONCE(1); /* Still happens? Tell us about it! */
free_swap_and_cache(*entry);
shmem_swp_set(info, entry, 0);
}
shmem_recalc_inode(inode);
- if (swap.val && add_to_swap_cache(page, swap, GFP_ATOMIC) == 0) {
+ if (add_to_swap_cache(page, swap, GFP_ATOMIC) == 0) {
delete_from_page_cache(page);
shmem_swp_set(info, entry, swap.val);
shmem_swp_unmap(entry);
struct address_space *mapping = inode->i_mapping;
struct shmem_inode_info *info = SHMEM_I(inode);
struct shmem_sb_info *sbinfo;
- struct page *filepage;
- struct page *swappage;
+ struct page *page;
struct page *prealloc_page = NULL;
swp_entry_t *entry;
swp_entry_t swap;
int error;
+ int ret;
if (idx >= SHMEM_MAX_INDEX)
return -EFBIG;
repeat:
- filepage = find_lock_page(mapping, idx);
- if (filepage && PageUptodate(filepage))
- goto done;
- if (!filepage) {
+ page = find_lock_page(mapping, idx);
+ if (page) {
/*
- * Try to preload while we can wait, to not make a habit of
- * draining atomic reserves; but don't latch on to this cpu.
+ * Once we can get the page lock, it must be uptodate:
+ * if there were an error in reading back from swap,
+ * the page would not be inserted into the filecache.
*/
- error = radix_tree_preload(gfp & GFP_RECLAIM_MASK);
- if (error)
- goto failed;
- radix_tree_preload_end();
- if (sgp != SGP_READ && !prealloc_page) {
- prealloc_page = shmem_alloc_page(gfp, info, idx);
- if (prealloc_page) {
- SetPageSwapBacked(prealloc_page);
- if (mem_cgroup_cache_charge(prealloc_page,
- current->mm, GFP_KERNEL)) {
- page_cache_release(prealloc_page);
- prealloc_page = NULL;
- }
+ BUG_ON(!PageUptodate(page));
+ goto done;
+ }
+
+ /*
+ * Try to preload while we can wait, to not make a habit of
+ * draining atomic reserves; but don't latch on to this cpu.
+ */
+ error = radix_tree_preload(gfp & GFP_RECLAIM_MASK);
+ if (error)
+ goto out;
+ radix_tree_preload_end();
+
+ if (sgp != SGP_READ && !prealloc_page) {
+ prealloc_page = shmem_alloc_page(gfp, info, idx);
+ if (prealloc_page) {
+ SetPageSwapBacked(prealloc_page);
+ if (mem_cgroup_cache_charge(prealloc_page,
+ current->mm, GFP_KERNEL)) {
+ page_cache_release(prealloc_page);
+ prealloc_page = NULL;
}
}
}
- error = 0;
spin_lock(&info->lock);
shmem_recalc_inode(inode);
if (IS_ERR(entry)) {
spin_unlock(&info->lock);
error = PTR_ERR(entry);
- goto failed;
+ goto out;
}
swap = *entry;
if (swap.val) {
/* Look it up and read it in.. */
- swappage = lookup_swap_cache(swap);
- if (!swappage) {
+ page = lookup_swap_cache(swap);
+ if (!page) {
shmem_swp_unmap(entry);
spin_unlock(&info->lock);
/* here we actually do the io */
if (fault_type)
*fault_type |= VM_FAULT_MAJOR;
- swappage = shmem_swapin(swap, gfp, info, idx);
- if (!swappage) {
+ page = shmem_swapin(swap, gfp, info, idx);
+ if (!page) {
spin_lock(&info->lock);
entry = shmem_swp_alloc(info, idx, sgp, gfp);
if (IS_ERR(entry))
}
spin_unlock(&info->lock);
if (error)
- goto failed;
+ goto out;
goto repeat;
}
- wait_on_page_locked(swappage);
- page_cache_release(swappage);
+ wait_on_page_locked(page);
+ page_cache_release(page);
goto repeat;
}
/* We have to do this with page locked to prevent races */
- if (!trylock_page(swappage)) {
+ if (!trylock_page(page)) {
shmem_swp_unmap(entry);
spin_unlock(&info->lock);
- wait_on_page_locked(swappage);
- page_cache_release(swappage);
+ wait_on_page_locked(page);
+ page_cache_release(page);
goto repeat;
}
- if (PageWriteback(swappage)) {
+ if (PageWriteback(page)) {
shmem_swp_unmap(entry);
spin_unlock(&info->lock);
- wait_on_page_writeback(swappage);
- unlock_page(swappage);
- page_cache_release(swappage);
+ wait_on_page_writeback(page);
+ unlock_page(page);
+ page_cache_release(page);
goto repeat;
}
- if (!PageUptodate(swappage)) {
+ if (!PageUptodate(page)) {
shmem_swp_unmap(entry);
spin_unlock(&info->lock);
- unlock_page(swappage);
- page_cache_release(swappage);
+ unlock_page(page);
+ page_cache_release(page);
error = -EIO;
- goto failed;
+ goto out;
}
- if (filepage) {
- shmem_swp_set(info, entry, 0);
- shmem_swp_unmap(entry);
- delete_from_swap_cache(swappage);
- spin_unlock(&info->lock);
- copy_highpage(filepage, swappage);
- unlock_page(swappage);
- page_cache_release(swappage);
- flush_dcache_page(filepage);
- SetPageUptodate(filepage);
- set_page_dirty(filepage);
- swap_free(swap);
- } else if (!(error = add_to_page_cache_locked(swappage, mapping,
- idx, GFP_NOWAIT))) {
- info->flags |= SHMEM_PAGEIN;
- shmem_swp_set(info, entry, 0);
- shmem_swp_unmap(entry);
- delete_from_swap_cache(swappage);
- spin_unlock(&info->lock);
- filepage = swappage;
- set_page_dirty(filepage);
- swap_free(swap);
- } else {
+ error = add_to_page_cache_locked(page, mapping,
+ idx, GFP_NOWAIT);
+ if (error) {
shmem_swp_unmap(entry);
spin_unlock(&info->lock);
if (error == -ENOMEM) {
* call memcg's OOM if needed.
*/
error = mem_cgroup_shmem_charge_fallback(
- swappage,
- current->mm,
- gfp);
+ page, current->mm, gfp);
if (error) {
- unlock_page(swappage);
- page_cache_release(swappage);
- goto failed;
+ unlock_page(page);
+ page_cache_release(page);
+ goto out;
}
}
- unlock_page(swappage);
- page_cache_release(swappage);
+ unlock_page(page);
+ page_cache_release(page);
goto repeat;
}
- } else if (sgp == SGP_READ && !filepage) {
+
+ info->flags |= SHMEM_PAGEIN;
+ shmem_swp_set(info, entry, 0);
+ shmem_swp_unmap(entry);
+ delete_from_swap_cache(page);
+ spin_unlock(&info->lock);
+ set_page_dirty(page);
+ swap_free(swap);
+
+ } else if (sgp == SGP_READ) {
shmem_swp_unmap(entry);
- filepage = find_get_page(mapping, idx);
- if (filepage &&
- (!PageUptodate(filepage) || !trylock_page(filepage))) {
+ page = find_get_page(mapping, idx);
+ if (page && !trylock_page(page)) {
spin_unlock(&info->lock);
- wait_on_page_locked(filepage);
- page_cache_release(filepage);
- filepage = NULL;
+ wait_on_page_locked(page);
+ page_cache_release(page);
goto repeat;
}
spin_unlock(&info->lock);
} else if (shmem_acct_block(info->flags))
goto nospace;
- if (!filepage) {
- int ret;
-
- filepage = prealloc_page;
- prealloc_page = NULL;
+ page = prealloc_page;
+ prealloc_page = NULL;
- entry = shmem_swp_alloc(info, idx, sgp, gfp);
- if (IS_ERR(entry))
- error = PTR_ERR(entry);
- else {
- swap = *entry;
- shmem_swp_unmap(entry);
- }
- ret = error || swap.val;
- if (ret)
- mem_cgroup_uncharge_cache_page(filepage);
- else
- ret = add_to_page_cache_lru(filepage, mapping,
+ entry = shmem_swp_alloc(info, idx, sgp, gfp);
+ if (IS_ERR(entry))
+ error = PTR_ERR(entry);
+ else {
+ swap = *entry;
+ shmem_swp_unmap(entry);
+ }
+ ret = error || swap.val;
+ if (ret)
+ mem_cgroup_uncharge_cache_page(page);
+ else
+ ret = add_to_page_cache_lru(page, mapping,
idx, GFP_NOWAIT);
- /*
- * At add_to_page_cache_lru() failure, uncharge will
- * be done automatically.
- */
- if (ret) {
- shmem_unacct_blocks(info->flags, 1);
- shmem_free_blocks(inode, 1);
- spin_unlock(&info->lock);
- page_cache_release(filepage);
- filepage = NULL;
- if (error)
- goto failed;
- goto repeat;
- }
- info->flags |= SHMEM_PAGEIN;
+ /*
+ * At add_to_page_cache_lru() failure,
+ * uncharge will be done automatically.
+ */
+ if (ret) {
+ shmem_unacct_blocks(info->flags, 1);
+ shmem_free_blocks(inode, 1);
+ spin_unlock(&info->lock);
+ page_cache_release(page);
+ if (error)
+ goto out;
+ goto repeat;
}
+ info->flags |= SHMEM_PAGEIN;
info->alloced++;
spin_unlock(&info->lock);
- clear_highpage(filepage);
- flush_dcache_page(filepage);
- SetPageUptodate(filepage);
+ clear_highpage(page);
+ flush_dcache_page(page);
+ SetPageUptodate(page);
if (sgp == SGP_DIRTY)
- set_page_dirty(filepage);
+ set_page_dirty(page);
+
} else {
spin_unlock(&info->lock);
error = -ENOMEM;
goto out;
}
done:
- *pagep = filepage;
+ *pagep = page;
error = 0;
out:
if (prealloc_page) {
* but must also avoid reporting a spurious ENOSPC while working on a
* full tmpfs.
*/
- if (!filepage) {
- struct page *page = find_get_page(mapping, idx);
- if (page) {
- spin_unlock(&info->lock);
- page_cache_release(page);
- goto repeat;
- }
- }
+ page = find_get_page(mapping, idx);
spin_unlock(&info->lock);
- error = -ENOSPC;
-failed:
- if (filepage) {
- unlock_page(filepage);
- page_cache_release(filepage);
+ if (page) {
+ page_cache_release(page);
+ goto repeat;
}
+ error = -ENOSPC;
goto out;
}
.listxattr = shmem_listxattr,
.removexattr = shmem_removexattr,
#endif
-#ifdef CONFIG_TMPFS_POSIX_ACL
- .check_acl = generic_check_acl,
-#endif
-
};
static const struct inode_operations shmem_dir_inode_operations = {
#endif
#ifdef CONFIG_TMPFS_POSIX_ACL
.setattr = shmem_setattr,
- .check_acl = generic_check_acl,
#endif
};
#endif
#ifdef CONFIG_TMPFS_POSIX_ACL
.setattr = shmem_setattr,
- .check_acl = generic_check_acl,
#endif
};
git.openpandora.org / pandora-kernel.git / blobdiff