| Message ID | m1pqdxvroc.fsf_-_@fess.ebiederm.org |
|---|---|
| State | Not Applicable, archived |
| Delegated to: | David Miller |
| Headers | show |
On Wed, 2012-02-01 at 19:29 -0800, Eric W. Biederman wrote: > Document get_subdir and that find_subdir alwasy takes a reference. > > Suggested-by: Lucian Adrian Grijincu <lucian.grijincu@gmail.com> > Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> > --- > fs/proc/proc_sysctl.c | 16 ++++++++++++++++ > 1 files changed, 16 insertions(+), 0 deletions(-) > > diff --git a/fs/proc/proc_sysctl.c b/fs/proc/proc_sysctl.c > index 722ec11..e5601dc 100644 > --- a/fs/proc/proc_sysctl.c > +++ b/fs/proc/proc_sysctl.c > @@ -73,6 +73,7 @@ static int namecmp(const char *name1, int len1, const char *name2, int len2) > return cmp; > } > > +/* Called under sysctl_lock */ > static struct ctl_table *find_entry(struct ctl_table_header **phead, > struct ctl_dir *dir, const char *name, int namelen) > { > @@ -864,6 +865,18 @@ static struct ctl_dir *new_dir(struct ctl_table_set *set, > return new; > } > > +/** > + * get_subdir - find or create a subdir with the specified name. > + * @dir: Directory to create the subdirectory in > + * @name: The name of the subdirectory to find or create > + * @namelen: The length of name > + * > + * Takes a directory with an elevated reference count so we know that > + * if we drop the lock the directory will not go away. Upon success > + * the reference is moved from @dir to the returned subdirectory. > + * Upon error an error code is returned and the reference on @dir is > + * simply dropped. > + */ > static struct ctl_dir *get_subdir(struct ctl_dir *dir, > const char *name, int namelen) [...] Should static functions really have kernel-doc? (Aside from static inlines defined in a header.) This can pollute the documentation namespace. Ben.
diff --git a/fs/proc/proc_sysctl.c b/fs/proc/proc_sysctl.c index 722ec11..e5601dc 100644 --- a/fs/proc/proc_sysctl.c +++ b/fs/proc/proc_sysctl.c @@ -73,6 +73,7 @@ static int namecmp(const char *name1, int len1, const char *name2, int len2) return cmp; } +/* Called under sysctl_lock */ static struct ctl_table *find_entry(struct ctl_table_header **phead, struct ctl_dir *dir, const char *name, int namelen) { @@ -864,6 +865,18 @@ static struct ctl_dir *new_dir(struct ctl_table_set *set, return new; } +/** + * get_subdir - find or create a subdir with the specified name. + * @dir: Directory to create the subdirectory in + * @name: The name of the subdirectory to find or create + * @namelen: The length of name + * + * Takes a directory with an elevated reference count so we know that + * if we drop the lock the directory will not go away. Upon success + * the reference is moved from @dir to the returned subdirectory. + * Upon error an error code is returned and the reference on @dir is + * simply dropped. + */ static struct ctl_dir *get_subdir(struct ctl_dir *dir, const char *name, int namelen) { @@ -885,12 +898,14 @@ static struct ctl_dir *get_subdir(struct ctl_dir *dir, if (!new) goto failed; + /* Was the subdir added while we dropped the lock? */ subdir = find_subdir(dir, name, namelen); if (!IS_ERR(subdir)) goto found; if (PTR_ERR(subdir) != -ENOENT) goto failed; + /* Nope. Use the our freshly made directory entry. */ err = insert_header(dir, &new->header); subdir = ERR_PTR(err); if (err) @@ -1190,6 +1205,7 @@ struct ctl_table_header *__register_sysctl_table( spin_lock(&sysctl_lock); dir = &set->dir; + /* Reference moved down the diretory tree get_subdir */ dir->header.nreg++; spin_unlock(&sysctl_lock);
Document get_subdir and that find_subdir alwasy takes a reference. Suggested-by: Lucian Adrian Grijincu <lucian.grijincu@gmail.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> --- fs/proc/proc_sysctl.c | 16 ++++++++++++++++ 1 files changed, 16 insertions(+), 0 deletions(-)