Re: [GIT PULL] ext4 updates for 3.11

From: Jan Kara
Date: Tue Jul 02 2013 - 14:05:01 EST


On Tue 02-07-13 10:18:32, Linus Torvalds wrote:
> Hmm I'm getting this compiler warning:
>
> fs/ext4/inode.c: In function âext4_writepagesâ:
> fs/ext4/inode.c:2219:6: warning: âerrâ may be used uninitialized in
> this function [-Wmaybe-uninitialized]
>
> and I think the compiler is right to warn. The 'err' variable is set
> inside a whilte() and an if() statement, and it is not at all obvious
> that those codepaths are always taken.
>
> Maybe that "map->m_len" is always guaranteed to be nonzero, and the
> "while()" statement could be a "do { } while()" one. But if so, make
> it so, don't write code as if it might never be executed, when the
> return value seems to *depend* on it being executed.
That's caused by my patches (only for certain gcc versions). map->m_len
is guaranteed to be > 0 in the first iteration (the function is called from
under if (map->m_len > 0)). I though Ted silenced that warning but
apparently he did not. The cleanest fix is likely to make a do-while loop
from that one. I'll send Ted a patch for that.

Honza
--
Jan Kara <jack@xxxxxxx>
SUSE Labs, CR
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