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Subject[PATCH] aio: add aio_migratepage_helper to get rid of duplicate code
Signed-off-by: Rakesh Pandit <rakesh@tuxera.com>
---
fs/aio.c | 55 +++++++++++++++++++++++--------------------------------
1 file changed, 23 insertions(+), 32 deletions(-)

diff --git a/fs/aio.c b/fs/aio.c
index d3d55dc..20d690a 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -278,32 +278,46 @@ static int aio_set_page_dirty(struct page *page)
}

#if IS_ENABLED(CONFIG_MIGRATION)
-static int aio_migratepage(struct address_space *mapping, struct page *new,
- struct page *old, enum migrate_mode mode)
+static int aio_migratepage_helper(struct address_space *mapping,
+ struct page *new, struct page *old, bool move)
{
struct kioctx *ctx;
unsigned long flags;
- int rc;
-
- rc = 0;
+ int rc = 0;

- /* Make sure the old page hasn't already been changed */
+ /* We can potentially race against kioctx teardown here. Use the
+ * address_space's private data lock to protect the mapping's
+ * private_data.
+ */
spin_lock(&mapping->private_lock);
ctx = mapping->private_data;
if (ctx) {
pgoff_t idx;
spin_lock_irqsave(&ctx->completion_lock, flags);
+ if (move)
+ migrate_page_copy(new, old);
idx = old->index;
if (idx < (pgoff_t)ctx->nr_pages) {
if (ctx->ring_pages[idx] != old)
rc = -EAGAIN;
+ else if (move)
+ ctx->ring_pages[idx] = new;
} else
rc = -EINVAL;
spin_unlock_irqrestore(&ctx->completion_lock, flags);
} else
- rc = -EINVAL;
+ rc = move ? -EBUSY : -EINVAL;
spin_unlock(&mapping->private_lock);
+ return rc;
+}

+static int aio_migratepage(struct address_space *mapping, struct page *new,
+ struct page *old, enum migrate_mode mode)
+{
+ int rc = 0;
+
+ /* Make sure the old page hasn't already been changed */
+ rc = aio_migratepage_helper(mapping, new, old, false);
if (rc != 0)
return rc;

@@ -317,31 +331,8 @@ static int aio_migratepage(struct address_space *mapping, struct page *new,
return rc;
}

- /* We can potentially race against kioctx teardown here. Use the
- * address_space's private data lock to protect the mapping's
- * private_data.
- */
- spin_lock(&mapping->private_lock);
- ctx = mapping->private_data;
- if (ctx) {
- pgoff_t idx;
- spin_lock_irqsave(&ctx->completion_lock, flags);
- migrate_page_copy(new, old);
- idx = old->index;
- if (idx < (pgoff_t)ctx->nr_pages) {
- /* And only do the move if things haven't changed */
- if (ctx->ring_pages[idx] == old)
- ctx->ring_pages[idx] = new;
- else
- rc = -EAGAIN;
- } else
- rc = -EINVAL;
- spin_unlock_irqrestore(&ctx->completion_lock, flags);
- } else
- rc = -EBUSY;
- spin_unlock(&mapping->private_lock);
-
- if (rc == MIGRATEPAGE_SUCCESS)
+ rc = aio_migratepage_helper(mapping, new, old, true);
+ if (rc == 0)
put_page(old);
else
put_page(new);
--
1.8.3.1


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