On Tue, Apr 10, 2018 at 04:45:32PM -0700, Kyle Spiers wrote:
> As part of the effort to remove VLAs from the kernel[1], this changes
> the allocation of the bhs and pages arrays from being on the stack to being
> kcalloc()ed. This also allows for the removal of the explicit zeroing
> of bhs.
>
> https://lkml.org/lkml/2018/3/7/621
Do you even bother reading the feedback given to such patches? I'm just
curious,
> @@ -80,7 +81,9 @@ static loff_t zisofs_uncompress_block(struct inode *inode,
> loff_t block_start,
>
> /* Because zlib is not thread-safe, do all the I/O at the top. */
> blocknum = block_start >> bufshift;
> - memset(bhs, 0, (needblocks + 1) * sizeof(struct buffer_head *));
> + bhs = kcalloc(needblocks + 1, sizeof(*bhs), GFP_KERNEL);
> + if (!bhs)
> + return -ENOMEM;
... because I distinctly remember comments along the lines of "check what
other failure exits look like in there, such as
*errp = -EIO;
return 0;
nearby".
> @@ -330,6 +334,10 @@ static int zisofs_readpage(struct file *file, struct
> page *page)
> full_page = 0;
> pcount = 1;
> }
> + pages = kcalloc(max_t(unsigned int, zisofs_pages_per_cblock, 1),
> + sizeof(*pages), GFP_KERNEL);
> + if (!pages)
> + return -ENOMEM;
> pages[full_page] = page;
What, in your opinion, is going to unlock that page after that failure exit?
