fsdax: invalidate pages when CoW

[linux-2.6-microblaze.git] / fs / dax.c

diff --git a/fs/dax.c b/fs/dax.c
index 84fadea..c975d07 100644 (file)
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -1264,6 +1264,15 @@ static s64 dax_zero_iter(struct iomap_iter *iter, bool *did_zero)
        if (srcmap->type == IOMAP_HOLE || srcmap->type == IOMAP_UNWRITTEN)
                return length;
 
+       /*
+        * invalidate the pages whose sharing state is to be changed
+        * because of CoW.
+        */
+       if (iomap->flags & IOMAP_F_SHARED)
+               invalidate_inode_pages2_range(iter->inode->i_mapping,
+                                             pos >> PAGE_SHIFT,
+                                             (pos + length - 1) >> PAGE_SHIFT);
+
        do {
                unsigned offset = offset_in_page(pos);
                unsigned size = min_t(u64, PAGE_SIZE - offset, length);
@@ -1324,12 +1333,13 @@ static loff_t dax_iomap_iter(const struct iomap_iter *iomi,
                struct iov_iter *iter)
 {
        const struct iomap *iomap = &iomi->iomap;
-       const struct iomap *srcmap = &iomi->srcmap;
+       const struct iomap *srcmap = iomap_iter_srcmap(iomi);
        loff_t length = iomap_length(iomi);
        loff_t pos = iomi->pos;
        struct dax_device *dax_dev = iomap->dax_dev;
        loff_t end = pos + length, done = 0;
        bool write = iov_iter_rw(iter) == WRITE;
+       bool cow = write && iomap->flags & IOMAP_F_SHARED;
        ssize_t ret = 0;
        size_t xfer;
        int id;
@@ -1356,7 +1366,7 @@ static loff_t dax_iomap_iter(const struct iomap_iter *iomi,
         * into page tables. We have to tear down these mappings so that data
         * written by write(2) is visible in mmap.
         */
-       if (iomap->flags & IOMAP_F_NEW) {
+       if (iomap->flags & IOMAP_F_NEW || cow) {
                invalidate_inode_pages2_range(iomi->inode->i_mapping,
                                              pos >> PAGE_SHIFT,
                                              (end - 1) >> PAGE_SHIFT);
@@ -1390,8 +1400,7 @@ static loff_t dax_iomap_iter(const struct iomap_iter *iomi,
                        break;
                }
 
-               if (write &&
-                   srcmap->type != IOMAP_HOLE && srcmap->addr != iomap->addr) {
+               if (cow) {
                        ret = dax_iomap_cow_copy(pos, length, PAGE_SIZE, srcmap,
                                                 kaddr);
                        if (ret)