iomap: rework unshare flag

Instead of another internal flags namespace inside of buffered-io.c,
just pass a UNSHARE hint in the main iomap flags field.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>

diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c
index d6d1fd0..a0ef7eb 100644 (file)
--- a/fs/iomap/buffered-io.c
+++ b/fs/iomap/buffered-io.c
@@ -508,10 +508,6 @@ iomap_migrate_page(struct address_space *mapping, struct page *newpage,
 EXPORT_SYMBOL_GPL(iomap_migrate_page);
 #endif /* CONFIG_MIGRATION */
 
-enum {
-       IOMAP_WRITE_F_UNSHARE           = (1 << 0),
-};
-
 static void
 iomap_write_failed(struct inode *inode, loff_t pos, unsigned len)
 {
@@ -541,7 +537,7 @@ iomap_read_page_sync(loff_t block_start, struct page *page, unsigned poff,
 }
 
 static int __iomap_write_begin(struct iomap_iter *iter, loff_t pos,
-               unsigned len, int flags, struct page *page)
+               unsigned len, struct page *page)
 {
        struct iomap *srcmap = iomap_iter_srcmap(iter);
        struct iomap_page *iop = iomap_page_create(iter->inode, page);
@@ -560,13 +556,13 @@ static int __iomap_write_begin(struct iomap_iter *iter, loff_t pos,
                if (plen == 0)
                        break;
 
-               if (!(flags & IOMAP_WRITE_F_UNSHARE) &&
+               if (!(iter->flags & IOMAP_UNSHARE) &&
                    (from <= poff || from >= poff + plen) &&
                    (to <= poff || to >= poff + plen))
                        continue;
 
                if (iomap_block_needs_zeroing(iter, block_start)) {
-                       if (WARN_ON_ONCE(flags & IOMAP_WRITE_F_UNSHARE))
+                       if (WARN_ON_ONCE(iter->flags & IOMAP_UNSHARE))
                                return -EIO;
                        zero_user_segments(page, poff, from, to, poff + plen);
                } else {
@@ -596,7 +592,7 @@ static int iomap_write_begin_inline(struct iomap_iter *iter,
 }
 
 static int iomap_write_begin(struct iomap_iter *iter, loff_t pos, unsigned len,
-               unsigned flags, struct page **pagep)
+               struct page **pagep)
 {
        const struct iomap_page_ops *page_ops = iter->iomap.page_ops;
        struct iomap *srcmap = iomap_iter_srcmap(iter);
@@ -628,7 +624,7 @@ static int iomap_write_begin(struct iomap_iter *iter, loff_t pos, unsigned len,
        else if (srcmap->flags & IOMAP_F_BUFFER_HEAD)
                status = __block_write_begin_int(page, pos, len, NULL, srcmap);
        else
-               status = __iomap_write_begin(iter, pos, len, flags, page);
+               status = __iomap_write_begin(iter, pos, len, page);
 
        if (unlikely(status))
                goto out_unlock;
@@ -759,7 +755,7 @@ again:
                        break;
                }
 
-               status = iomap_write_begin(iter, pos, bytes, 0, &page);
+               status = iomap_write_begin(iter, pos, bytes, &page);
                if (unlikely(status))
                        break;
 
@@ -836,8 +832,7 @@ static loff_t iomap_unshare_iter(struct iomap_iter *iter)
                unsigned long bytes = min_t(loff_t, PAGE_SIZE - offset, length);
                struct page *page;
 
-               status = iomap_write_begin(iter, pos, bytes,
-                               IOMAP_WRITE_F_UNSHARE, &page);
+               status = iomap_write_begin(iter, pos, bytes, &page);
                if (unlikely(status))
                        return status;
 
@@ -865,7 +860,7 @@ iomap_file_unshare(struct inode *inode, loff_t pos, loff_t len,
                .inode          = inode,
                .pos            = pos,
                .len            = len,
-               .flags          = IOMAP_WRITE,
+               .flags          = IOMAP_WRITE | IOMAP_UNSHARE,
        };
        int ret;
 
@@ -882,7 +877,7 @@ static s64 __iomap_zero_iter(struct iomap_iter *iter, loff_t pos, u64 length)
        unsigned offset = offset_in_page(pos);
        unsigned bytes = min_t(u64, PAGE_SIZE - offset, length);
 
-       status = iomap_write_begin(iter, pos, bytes, 0, &page);
+       status = iomap_write_begin(iter, pos, bytes, &page);
        if (status)
                return status;
 

diff --git a/include/linux/iomap.h b/include/linux/iomap.h
index 6784a8b..f53c40e 100644 (file)
--- a/include/linux/iomap.h
+++ b/include/linux/iomap.h
@@ -140,6 +140,7 @@ struct iomap_page_ops {
 #define IOMAP_DIRECT           (1 << 4) /* direct I/O */
 #define IOMAP_NOWAIT           (1 << 5) /* do not block */
 #define IOMAP_OVERWRITE_ONLY   (1 << 6) /* only pure overwrites allowed */
+#define IOMAP_UNSHARE          (1 << 7) /* unshare_file_range */
 
 struct iomap_ops {
        /*