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authorArnd Bergmann <arnd@arndb.de>2016-10-18 01:05:34 +0300
committerJan Kara <jack@suse.cz>2016-10-18 12:29:35 +0300
commite952813e210b3addaea063da64ef68c3f30c0aa2 (patch)
tree3bb21ccb56cf2bbce398090b01e58d992f8ca590
parenta2ed0b391dd9c3ef1d64c7c3e370f4a5ffcd324a (diff)
downloadlinux-e952813e210b3addaea063da64ef68c3f30c0aa2.tar.xz
ext2: avoid bogus -Wmaybe-uninitialized warning
On ARM, we get this false-positive warning since the rework of the ext2_get_blocks interface: fs/ext2/inode.c: In function 'ext2_get_block': include/linux/buffer_head.h:340:16: error: 'bno' may be used uninitialized in this function [-Werror=maybe-uninitialized] The calling conventions for this function are rather complex, and it's not surprising that the compiler gets this wrong, I spent a long time trying to understand how it all fits together myself. This change to avoid the warning makes sure the compiler sees that we always set 'bno' pointer whenever we have a positive return code. The transformation is correct because we always arrive at the 'got_it' label with a positive count that gets used as the return value, while any branch to the 'cleanup' label has a negative or zero 'err'. Fixes: 6750ad71986d ("ext2: stop passing buffer_head to ext2_get_blocks") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Dave Chinner <david@fromorbit.com> Signed-off-by: Jan Kara <jack@suse.cz>
-rw-r--r--fs/ext2/inode.c7
1 files changed, 4 insertions, 3 deletions
diff --git a/fs/ext2/inode.c b/fs/ext2/inode.c
index d831e24dc885..41b8b44a391c 100644
--- a/fs/ext2/inode.c
+++ b/fs/ext2/inode.c
@@ -622,7 +622,7 @@ static int ext2_get_blocks(struct inode *inode,
u32 *bno, bool *new, bool *boundary,
int create)
{
- int err = -EIO;
+ int err;
int offsets[4];
Indirect chain[4];
Indirect *partial;
@@ -639,7 +639,7 @@ static int ext2_get_blocks(struct inode *inode,
depth = ext2_block_to_path(inode,iblock,offsets,&blocks_to_boundary);
if (depth == 0)
- return (err);
+ return -EIO;
partial = ext2_get_branch(inode, depth, offsets, chain, &err);
/* Simplest case - block found, no allocation needed */
@@ -761,7 +761,6 @@ static int ext2_get_blocks(struct inode *inode,
ext2_splice_branch(inode, iblock, partial, indirect_blks, count);
mutex_unlock(&ei->truncate_mutex);
got_it:
- *bno = le32_to_cpu(chain[depth-1].key);
if (count > blocks_to_boundary)
*boundary = true;
err = count;
@@ -772,6 +771,8 @@ cleanup:
brelse(partial->bh);
partial--;
}
+ if (err > 0)
+ *bno = le32_to_cpu(chain[depth-1].key);
return err;
}