| From dd1b3eb0d784cf77f858a253823b51dc62f142ba Mon Sep 17 00:00:00 2001 |
| From: Arnd Bergmann <arnd@arndb.de> |
| Date: Wed, 2 Nov 2016 14:52:15 +0100 |
| Subject: [PATCH] f2fs: hide a maybe-uninitialized warning |
| MIME-Version: 1.0 |
| Content-Type: text/plain; charset=UTF-8 |
| Content-Transfer-Encoding: 8bit |
| |
| commit 230436b3ef3fd7d4a1da19edf5e87bb2d74e0fc2 upstream. |
| |
| gcc is unsure about the use of last_ofs_in_node, which might happen |
| without a prior initialization: |
| |
| fs/f2fs//git/arm-soc/fs/f2fs/data.c: In function ‘f2fs_map_blocks’: |
| fs/f2fs/data.c:799:54: warning: ‘last_ofs_in_node’ may be used uninitialized in this function [-Wmaybe-uninitialized] |
| if (prealloc && dn.ofs_in_node != last_ofs_in_node + 1) { |
| |
| As pointed out by Chao Yu, the code is actually correct as 'prealloc' |
| is only set if the last_ofs_in_node has been set, the two always |
| get updated together. |
| |
| This initializes last_ofs_in_node to dn.ofs_in_node for each |
| new dnode at the start of the 'next_block' loop, which at that |
| point is a correct initialization as well. I assume that compilers |
| that correctly track the contents of the variables and do not |
| warn about the condition also figure out that they can eliminate |
| the extra assignment here. |
| |
| Fixes: 46008c6d4232 ("f2fs: support in batch multi blocks preallocation") |
| Signed-off-by: Arnd Bergmann <arnd@arndb.de> |
| Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org> |
| Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> |
| |
| diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c |
| index ccb401eebc11..3c60729dcbc6 100644 |
| --- a/fs/f2fs/data.c |
| +++ b/fs/f2fs/data.c |
| @@ -706,7 +706,7 @@ next_dnode: |
| } |
| |
| prealloc = 0; |
| - ofs_in_node = dn.ofs_in_node; |
| + last_ofs_in_node = ofs_in_node = dn.ofs_in_node; |
| end_offset = ADDRS_PER_PAGE(dn.node_page, inode); |
| |
| next_block: |
| -- |
| 2.10.1 |
| |
