tmpfs: take control of its truncate_range

[sfrench/cifs-2.6.git] / mm / truncate.c

diff --git a/mm/truncate.c b/mm/truncate.c
index a9566752913596152022f5d22983cb4f2cb4d2cf..29a9b8a5a31a800e874e3a2622e25321a84d37af 100644 (file)
--- a/mm/truncate.c
+++ b/mm/truncate.c
@@ -19,6 +19,7 @@
 #include <linux/task_io_accounting_ops.h>
 #include <linux/buffer_head.h> /* grr. try_to_release_page,
                                   do_invalidatepage */
+#include <linux/cleancache.h>
 #include "internal.h"
 
 
@@ -51,6 +52,7 @@ void do_invalidatepage(struct page *page, unsigned long offset)
 static inline void truncate_partial_page(struct page *page, unsigned partial)
 {
        zero_user_segment(page, partial, PAGE_CACHE_SIZE);
+       cleancache_flush_page(page->mapping, page);
        if (page_has_private(page))
                do_invalidatepage(page, partial);
 }
@@ -214,6 +216,7 @@ void truncate_inode_pages_range(struct address_space *mapping,
        pgoff_t next;
        int i;
 
+       cleancache_flush_inode(mapping);
        if (mapping->nrpages == 0)
                return;
 
@@ -291,6 +294,7 @@ void truncate_inode_pages_range(struct address_space *mapping,
                pagevec_release(&pvec);
                mem_cgroup_uncharge_end();
        }
+       cleancache_flush_inode(mapping);
 }
 EXPORT_SYMBOL(truncate_inode_pages_range);
 
@@ -440,6 +444,7 @@ int invalidate_inode_pages2_range(struct address_space *mapping,
        int did_range_unmap = 0;
        int wrapped = 0;
 
+       cleancache_flush_inode(mapping);
        pagevec_init(&pvec, 0);
        next = start;
        while (next <= end && !wrapped &&
@@ -498,6 +503,7 @@ int invalidate_inode_pages2_range(struct address_space *mapping,
                mem_cgroup_uncharge_end();
                cond_resched();
        }
+       cleancache_flush_inode(mapping);
        return ret;
 }
 EXPORT_SYMBOL_GPL(invalidate_inode_pages2_range);
@@ -597,3 +603,27 @@ int vmtruncate(struct inode *inode, loff_t offset)
        return 0;
 }
 EXPORT_SYMBOL(vmtruncate);
+
+int vmtruncate_range(struct inode *inode, loff_t offset, loff_t end)
+{
+       struct address_space *mapping = inode->i_mapping;
+
+       /*
+        * If the underlying filesystem is not going to provide
+        * a way to truncate a range of blocks (punch a hole) -
+        * we should return failure right now.
+        */
+       if (!inode->i_op->truncate_range)
+               return -ENOSYS;
+
+       mutex_lock(&inode->i_mutex);
+       down_write(&inode->i_alloc_sem);
+       unmap_mapping_range(mapping, offset, (end - offset), 1);
+       inode->i_op->truncate_range(inode, offset, end);
+       /* unmap again to remove racily COWed private pages */
+       unmap_mapping_range(mapping, offset, (end - offset), 1);
+       up_write(&inode->i_alloc_sem);
+       mutex_unlock(&inode->i_mutex);
+
+       return 0;
+}