[PATCH] FS-Cache: Remove unneeded null checks

From: David Howells
Date: Tue Jun 01 2010 - 15:59:13 EST


From: Dan Carpenter <error27@xxxxxxxxx>

fscache_write_op() makes unnecessary checks of the page variable to see if it
is NULL. It can't be NULL at those points as the kernel would already have
crashed a little higher up where we examined page->index.

Furthermore, unless radix_tree_gang_lookup_tag() can return 1 but no page, a
NULL pointer crash should not be encountered there as we can only get there if
r_t_g_l_t() returned 1.

Signed-off-by: Dan Carpenter <error27@xxxxxxxxx>
Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
---

fs/fscache/page.c | 36 ++++++++++++++++--------------------
1 files changed, 16 insertions(+), 20 deletions(-)

diff --git a/fs/fscache/page.c b/fs/fscache/page.c
index 9461617..5b9b00a 100644
--- a/fs/fscache/page.c
+++ b/fs/fscache/page.c
@@ -710,30 +710,26 @@ static void fscache_write_op(struct fscache_operation *_op)
goto superseded;
}

- if (page) {
- radix_tree_tag_set(&cookie->stores, page->index,
- FSCACHE_COOKIE_STORING_TAG);
- radix_tree_tag_clear(&cookie->stores, page->index,
- FSCACHE_COOKIE_PENDING_TAG);
- }
+ radix_tree_tag_set(&cookie->stores, page->index,
+ FSCACHE_COOKIE_STORING_TAG);
+ radix_tree_tag_clear(&cookie->stores, page->index,
+ FSCACHE_COOKIE_PENDING_TAG);

spin_unlock(&cookie->stores_lock);
spin_unlock(&object->lock);

- if (page) {
- fscache_set_op_state(&op->op, "Store");
- fscache_stat(&fscache_n_store_pages);
- fscache_stat(&fscache_n_cop_write_page);
- ret = object->cache->ops->write_page(op, page);
- fscache_stat_d(&fscache_n_cop_write_page);
- fscache_set_op_state(&op->op, "EndWrite");
- fscache_end_page_write(object, page);
- if (ret < 0) {
- fscache_set_op_state(&op->op, "Abort");
- fscache_abort_object(object);
- } else {
- fscache_enqueue_operation(&op->op);
- }
+ fscache_set_op_state(&op->op, "Store");
+ fscache_stat(&fscache_n_store_pages);
+ fscache_stat(&fscache_n_cop_write_page);
+ ret = object->cache->ops->write_page(op, page);
+ fscache_stat_d(&fscache_n_cop_write_page);
+ fscache_set_op_state(&op->op, "EndWrite");
+ fscache_end_page_write(object, page);
+ if (ret < 0) {
+ fscache_set_op_state(&op->op, "Abort");
+ fscache_abort_object(object);
+ } else {
+ fscache_enqueue_operation(&op->op);
}

_leave("");

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