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Diffstat (limited to 'kernel/acct.c')
-rw-r--r--kernel/acct.c24
1 files changed, 19 insertions, 5 deletions
diff --git a/kernel/acct.c b/kernel/acct.c
index a7993a6cb604..2e6cf818021d 100644
--- a/kernel/acct.c
+++ b/kernel/acct.c
@@ -154,7 +154,6 @@ static void close_work(struct work_struct *work)
{
struct bsd_acct_struct *acct = container_of(work, struct bsd_acct_struct, work);
struct file *file = acct->file;
- mnt_unpin(file->f_path.mnt);
if (file->f_op->flush)
file->f_op->flush(file, NULL);
__fput_sync(file);
@@ -196,9 +195,10 @@ static void acct_pin_kill(struct fs_pin *pin)
static int acct_on(struct filename *pathname)
{
struct file *file;
- struct vfsmount *mnt;
+ struct vfsmount *mnt, *internal;
struct pid_namespace *ns = task_active_pid_ns(current);
struct bsd_acct_struct *acct, *old;
+ int err;
acct = kzalloc(sizeof(struct bsd_acct_struct), GFP_KERNEL);
if (!acct)
@@ -222,6 +222,21 @@ static int acct_on(struct filename *pathname)
filp_close(file, NULL);
return -EIO;
}
+ internal = mnt_clone_internal(&file->f_path);
+ if (IS_ERR(internal)) {
+ kfree(acct);
+ filp_close(file, NULL);
+ return PTR_ERR(internal);
+ }
+ err = mnt_want_write(internal);
+ if (err) {
+ mntput(internal);
+ kfree(acct);
+ filp_close(file, NULL);
+ return err;
+ }
+ mnt = file->f_path.mnt;
+ file->f_path.mnt = internal;
atomic_long_set(&acct->pin.count, 1);
acct->pin.kill = acct_pin_kill;
@@ -229,8 +244,6 @@ static int acct_on(struct filename *pathname)
acct->needcheck = jiffies;
acct->ns = ns;
mutex_init(&acct->lock);
- mnt = file->f_path.mnt;
- mnt_pin(mnt);
mutex_lock_nested(&acct->lock, 1); /* nobody has seen it yet */
pin_insert(&acct->pin, mnt);
@@ -240,7 +253,8 @@ static int acct_on(struct filename *pathname)
else
ns->bacct = acct;
mutex_unlock(&acct->lock);
- mntput(mnt); /* it's pinned, now give up active reference */
+ mnt_drop_write(mnt);
+ mntput(mnt);
return 0;
}