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    SubjectRe: [PATCH] Introduce a handy list_first_entry macro
    On Tue, Apr 17, 2007 at 03:18:56PM +0400, Pavel Emelianov wrote:
    > There are many places in the kernel where the construction like
    > foo = list_entry(head->next, struct foo_struct, list);
    > are used.
    > The code might look more descriptive and neat if using the macro
    > list_first_entry(head, type, member) \
    > list_entry((head)->next, type, member)

    > - dquot = list_entry(dirty->next, struct dquot, dq_dirty);
    > + dquot = list_first_entry(dirty, struct dquot, dq_dirty);

    I think it's more than just descriptive and neat. A common sneaky bug
    is to accidentally pass &list->next into list_entry() instead of
    list->next. This is easy to do because one is used to typing &list in
    list_empty(), etc. So by following ->next in the macro we make the list
    argument consistent in list_empty() and list_first_entry() and hopefully
    reduce the risk of making that mistake.

    I like it.

    - z
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      Last update: 2007-04-17 19:15    [W:0.019 / U:11.284 seconds]
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