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authorAl Viro <viro@zeniv.linux.org.uk>2012-08-22 18:42:10 -0400
committerAl Viro <viro@zeniv.linux.org.uk>2012-09-26 21:10:00 -0400
commit864bdb3b6cbd9911222543fef1cfe36f88183f44 (patch)
treebd00e6293592a084ee0fe68e3acb93060f54ae68
parent2be7fd55d44882c9818ed2d1dabc0f0abab5eeed (diff)
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new helper: daemonize_descriptors()
descriptor-related parts of daemonize, done right. As the result we simplify the locking rules for ->files - we hold task_lock in *all* cases when we modify ->files. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
-rw-r--r--fs/file.c6
-rw-r--r--include/linux/fdtable.h1
-rw-r--r--kernel/exit.c4
3 files changed, 8 insertions, 3 deletions
diff --git a/fs/file.c b/fs/file.c
index e6e418122587..15750b80e3ce 100644
--- a/fs/file.c
+++ b/fs/file.c
@@ -519,6 +519,12 @@ struct files_struct init_files = {
.file_lock = __SPIN_LOCK_UNLOCKED(init_task.file_lock),
};
+void daemonize_descriptors(void)
+{
+ atomic_inc(&init_files.count);
+ reset_files_struct(&init_files);
+}
+
/*
* allocate a file descriptor, mark it busy.
*/
diff --git a/include/linux/fdtable.h b/include/linux/fdtable.h
index fb7dacae0522..45052aa814c8 100644
--- a/include/linux/fdtable.h
+++ b/include/linux/fdtable.h
@@ -95,6 +95,7 @@ struct task_struct;
struct files_struct *get_files_struct(struct task_struct *);
void put_files_struct(struct files_struct *fs);
void reset_files_struct(struct files_struct *);
+void daemonize_descriptors(void);
int unshare_files(struct files_struct **);
struct files_struct *dup_fd(struct files_struct *, int *);
void do_close_on_exec(struct files_struct *);
diff --git a/kernel/exit.c b/kernel/exit.c
index 20dfc7617c2e..095113321318 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -457,9 +457,7 @@ void daemonize(const char *name, ...)
/* Become as one with the init task */
daemonize_fs_struct();
- exit_files(current);
- current->files = init_task.files;
- atomic_inc(&current->files->count);
+ daemonize_descriptors();
reparent_to_kthreadd();
}