Re: [PATCH 04/13] sysfs: Simplify sysfs_chmod_file semantics

From: Serge E. Hallyn
Date: Tue Nov 03 2009 - 21:43:44 EST


Quoting Eric W. Biederman (ebiederm@xxxxxxxxxxxx):
> From: Eric W. Biederman <ebiederm@xxxxxxxxxxxx>
>
> Currently every caller of sysfs_chmod_file happens at either
> file creation time to set a non-default mode or in response
> to a specific user requested space change in policy. Making
> timestamps of when the chmod happens and notification of
> a file changing mode uninteresting.

But these changes can occur by togging values in sysfs files
(i.e. f71805f.c), right? Is this (specifically not doing inotify)
definately uncontroversial?

I can't exactly picture an admin sitting there watching
nautilus for a sysfs file to become writeable, but could
imagine some site's automation getting hung... Or am I way
off base?

> Remove the unnecessary time stamp and filesystem change
> notification, and removes the last of the explicit inotify
> and donitfy support from sysfs.
>
> Acked-by: Tejun Heo <tj@xxxxxxxxxx>
> Signed-off-by: Eric W. Biederman <ebiederm@xxxxxxxxxxxxxxxxxx>
> ---
> fs/sysfs/file.c | 10 +---------
> 1 files changed, 1 insertions(+), 9 deletions(-)
>
> diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c
> index f5ea468..faa1a80 100644
> --- a/fs/sysfs/file.c
> +++ b/fs/sysfs/file.c
> @@ -604,17 +604,9 @@ int sysfs_chmod_file(struct kobject *kobj, struct attribute *attr, mode_t mode)
> mutex_lock(&inode->i_mutex);
>
> newattrs.ia_mode = (mode & S_IALLUGO) | (inode->i_mode & ~S_IALLUGO);
> - newattrs.ia_valid = ATTR_MODE | ATTR_CTIME;
> - newattrs.ia_ctime = current_fs_time(inode->i_sb);
> + newattrs.ia_valid = ATTR_MODE;
> rc = sysfs_setattr(victim, &newattrs);
>
> - if (rc == 0) {
> - fsnotify_change(victim, newattrs.ia_valid);
> - mutex_lock(&sysfs_mutex);
> - victim_sd->s_mode = newattrs.ia_mode;
> - mutex_unlock(&sysfs_mutex);
> - }
> -
> mutex_unlock(&inode->i_mutex);
> out:
> dput(victim);
> --
> 1.6.5.2.143.g8cc62
>
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