On Fri, 24 Jun 2011 10:48:08 +0900
"FJCL) 荻野 大輔" <ogino.daisuke@xxxxxxxxxxxxxx> wrote:
> From: Daisuke Ohino <ogino.daisuke@xxxxxxxxxxxxxx>
>
> opening the proc entry may return EINVAL if the entry is being removed, for
> example open("/proc/bus/pci/XX/YY") during the corresponding device is being
> hot-removed. The return value is inappropriate and should return ENOENT.
>
> This return value comes from proc_reg_open().
>
> fs/proc/inode.c:
> -----------------------------------------------------------
> static int proc_reg_open(struct inode *inode, struct file *file)
> {
> (snip)
> if (!pde->proc_fops) {
> spin_unlock(&pde->pde_unload_lock);
> kfree(pdeo);
> return -EINVAL;
> }
> (snip)
> -----------------------------------------------------------
>
> pde->proc_fops is NULL iff the proc entry is being removed. It
> is set by remove_proc_entry().
>
> -----------------------------------------------------------
> void remove_proc_entry(const char *name, struct proc_dir_entry*parent)
> {
> (snip)
> /*
> * Stop accepting new callers into module. If you're
> * dynamically allocating ->proc_fops, save a pointer somewhere.
> */
> de->proc_fops = NULL;
> (snip)
> -----------------------------------------------------------
>
> But POSIX says:
>
> -----------------------------------------------------------
> [EINVAL]
> The implementation does not support synchronized I/O for this file.
> -----------------------------------------------------------
>
> Since removing proc entry is apparently not related to synchronized I/O,
> this function should return ENOENT in this case.
>
> Signed-off-by: Daisuke Ogino <ogino.daisuke@xxxxxxxxxxxxxx>
It makes sense to me.
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
Add fsdevel to CC.
> ---
> fs/proc/inode.c | 2 +-
> 1 files changed, 1 insertions(+), 1 deletions(-)
>
> diff --git a/fs/proc/inode.c b/fs/proc/inode.c
> index 74b48cf..7ed72d6 100644
> --- a/fs/proc/inode.c
> +++ b/fs/proc/inode.c
> @@ -319,7 +319,7 @@ static int proc_reg_open(struct inode *inode, struct file *file)
> if (!pde->proc_fops) {
> spin_unlock(&pde->pde_unload_lock);
> kfree(pdeo);
> - return -EINVAL;
> + return -ENOENT;
> }
> pde->pde_users++;
> open = pde->proc_fops->open;
> --
>
> Since I don't subscribe LKML, please Cc me if you have any comment.
>
> Thanks,
> Daisuke
>
>
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