Commit 34f853b8 authored May 28, 2020 by Gao Xiang

erofs: suppress false positive last_block warning

As Andrew mentioned, some rare specific gcc versions could report
last_block uninitialized warning. Actually last_block doesn't need
to be uninitialized first from its implementation due to bio == NULL
condition. After a bio is allocated, last_block will be assigned
then.

The detailed analysis is in this thread [1]. So let's silence those
confusing gccs simply.

[1] https://lore.kernel.org/r/20200421072839.GA13867@hsiangkao-HP-ZHAN-66-Pro-G1



Cc: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Link: https://lore.kernel.org/r/20200528084844.23359-1-hsiangkao@redhat.com


Signed-off-by: Gao Xiang <hsiangkao@redhat.com>

parent f57a3fe4

fs/erofs/data.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -265,7 +265,7 @@ submit_bio_out:
		*/
		static int erofs_raw_access_readpage(struct file file, struct page page)
		{
		erofs_off_t last_block;
		erofs_off_t uninitialized_var(last_block);
		struct bio *bio;

		trace_erofs_readpage(page, true);
		@@ -285,7 +285,7 @@ static int erofs_raw_access_readpages(struct file *filp,
		struct list_head *pages,
		unsigned int nr_pages)
		{
		erofs_off_t last_block;
		erofs_off_t uninitialized_var(last_block);
		struct bio *bio = NULL;
		gfp_t gfp = readahead_gfp_mask(mapping);
		struct page *page = list_last_entry(pages, struct page, lru);

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