Re: [PATCH v2 1/4] kernfs: kvmalloc xattr value instead of kmalloc
From: Joe Perches <joe@perches.com>
Date: 2020-03-06 08:51:30
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On Thu, 2020-03-05 at 13:16 -0800, Daniel Xu wrote:
It's not really necessary to have contiguous physical memory for xattr values. We no longer need to worry about higher order allocations failing with kvmalloc, especially because the xattr size limit is at 64K.
So why use vmalloc memory at all?
quoted hunk ↗ jump to hunk
diff --git a/fs/xattr.c b/fs/xattr.c
']
quoted hunk ↗ jump to hunk
@@ -817,7 +817,7 @@ struct simple_xattr *simple_xattr_alloc(const void *value, size_t size) if (len < sizeof(*new_xattr)) return NULL; - new_xattr = kmalloc(len, GFP_KERNEL); + new_xattr = kvmalloc(len, GFP_KERNEL);
Why is this sensible? vmalloc memory is a much more limited resource. Also, it seems as if the function should set new_xattr->name to NULL before the return.