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-rw-r--r--fs/block_dev.c1
-rw-r--r--fs/buffer.c34
-rw-r--r--fs/ext3/inode.c1
-rw-r--r--include/linux/buffer_head.h3
-rw-r--r--include/linux/fs.h1
-rw-r--r--mm/vmscan.c10
6 files changed, 50 insertions, 0 deletions
diff --git a/fs/block_dev.c b/fs/block_dev.c
index 431b6a0..bb43ce0 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -1562,6 +1562,7 @@ static const struct address_space_operations def_blk_aops = {
.writepages = generic_writepages,
.releasepage = blkdev_releasepage,
.direct_IO = blkdev_direct_IO,
+ .is_dirty_writeback = buffer_check_dirty_writeback,
};
const struct file_operations def_blk_fops = {
diff --git a/fs/buffer.c b/fs/buffer.c
index f93392e..4d74335 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -83,6 +83,40 @@ void unlock_buffer(struct buffer_head *bh)
EXPORT_SYMBOL(unlock_buffer);
/*
+ * Returns if the page has dirty or writeback buffers. If all the buffers
+ * are unlocked and clean then the PageDirty information is stale. If
+ * any of the pages are locked, it is assumed they are locked for IO.
+ */
+void buffer_check_dirty_writeback(struct page *page,
+ bool *dirty, bool *writeback)
+{
+ struct buffer_head *head, *bh;
+ *dirty = false;
+ *writeback = false;
+
+ BUG_ON(!PageLocked(page));
+
+ if (!page_has_buffers(page))
+ return;
+
+ if (PageWriteback(page))
+ *writeback = true;
+
+ head = page_buffers(page);
+ bh = head;
+ do {
+ if (buffer_locked(bh))
+ *writeback = true;
+
+ if (buffer_dirty(bh))
+ *dirty = true;
+
+ bh = bh->b_this_page;
+ } while (bh != head);
+}
+EXPORT_SYMBOL(buffer_check_dirty_writeback);
+
+/*
* Block until a buffer comes unlocked. This doesn't stop it
* from becoming locked again - you have to lock it yourself
* if you want to preserve its state.
diff --git a/fs/ext3/inode.c b/fs/ext3/inode.c
index f67668f..2bd8548 100644
--- a/fs/ext3/inode.c
+++ b/fs/ext3/inode.c
@@ -1985,6 +1985,7 @@ static const struct address_space_operations ext3_ordered_aops = {
.direct_IO = ext3_direct_IO,
.migratepage = buffer_migrate_page,
.is_partially_uptodate = block_is_partially_uptodate,
+ .is_dirty_writeback = buffer_check_dirty_writeback,
.error_remove_page = generic_error_remove_page,
};
diff --git a/include/linux/buffer_head.h b/include/linux/buffer_head.h
index f5a3b83..91fa9a9 100644
--- a/include/linux/buffer_head.h
+++ b/include/linux/buffer_head.h
@@ -139,6 +139,9 @@ BUFFER_FNS(Prio, prio)
})
#define page_has_buffers(page) PagePrivate(page)
+void buffer_check_dirty_writeback(struct page *page,
+ bool *dirty, bool *writeback);
+
/*
* Declarations
*/
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 2b82c80..99be011 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -380,6 +380,7 @@ struct address_space_operations {
int (*launder_page) (struct page *);
int (*is_partially_uptodate) (struct page *, read_descriptor_t *,
unsigned long);
+ void (*is_dirty_writeback) (struct page *, bool *, bool *);
int (*error_remove_page)(struct address_space *, struct page *);
/* swapfile support */
diff --git a/mm/vmscan.c b/mm/vmscan.c
index bf47784..c857943 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -673,6 +673,8 @@ static enum page_references page_check_references(struct page *page,
static void page_check_dirty_writeback(struct page *page,
bool *dirty, bool *writeback)
{
+ struct address_space *mapping;
+
/*
* Anonymous pages are not handled by flushers and must be written
* from reclaim context. Do not stall reclaim based on them
@@ -686,6 +688,14 @@ static void page_check_dirty_writeback(struct page *page,
/* By default assume that the page flags are accurate */
*dirty = PageDirty(page);
*writeback = PageWriteback(page);
+
+ /* Verify dirty/writeback state if the filesystem supports it */
+ if (!page_has_private(page))
+ return;
+
+ mapping = page_mapping(page);
+ if (mapping && mapping->a_ops->is_dirty_writeback)
+ mapping->a_ops->is_dirty_writeback(page, dirty, writeback);
}
/*
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