Commit 54a4d58a authored by Al Viro's avatar Al Viro
Browse files

acct: simplify check_free_space() 



a) file can't be NULL
b) file can't be changed under us
c) all writes are serialized by acct->lock; no need to mess with
spinlock there.

Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent b8f00e6b

kernel/acct.c

+11 −39
Original line number Diff line number Diff line
@@ -93,64 +93,36 @@ static LIST_HEAD(acct_list); 
/*

 * Check the amount of free space and suspend/resume accordingly.

 */

static int check_free_space(struct bsd_acct_struct *acct, struct file *file)

static int check_free_space(struct bsd_acct_struct *acct)

{

	struct kstatfs sbuf;

	int res;

	int act;

	u64 resume;

	u64 suspend;



	spin_lock(&acct_lock);

	res = acct->active;

	if (!file || time_is_before_jiffies(acct->needcheck))

	if (time_is_before_jiffies(acct->needcheck))

		goto out;

	spin_unlock(&acct_lock);



	/* May block */

	if (vfs_statfs(&file->f_path, &sbuf))

		return res;

	suspend = sbuf.f_blocks * SUSPEND;

	resume = sbuf.f_blocks * RESUME;



	do_div(suspend, 100);

	do_div(resume, 100);



	if (sbuf.f_bavail <= suspend)

		act = -1;

	else if (sbuf.f_bavail >= resume)

		act = 1;

	else

		act = 0;



	/*

	 * If some joker switched acct->file under us we'ld better be

	 * silent and _not_ touch anything.

	 */

	spin_lock(&acct_lock);

	if (file != acct->file) {

		if (act)

			res = act > 0;

	if (vfs_statfs(&acct->file->f_path, &sbuf))

		goto out;

	}



	if (acct->active) {

		if (act < 0) {

		u64 suspend = sbuf.f_blocks * SUSPEND;

		do_div(suspend, 100);

		if (sbuf.f_bavail <= suspend) {

			acct->active = 0;

			printk(KERN_INFO "Process accounting paused\n");

		}

	} else {

		if (act > 0) {

		u64 resume = sbuf.f_blocks * RESUME;

		do_div(resume, 100);

		if (sbuf.f_bavail >= resume) {

			acct->active = 1;

			printk(KERN_INFO "Process accounting resumed\n");

		}

	}



	acct->needcheck = jiffies + ACCT_TIMEOUT*HZ;

	res = acct->active;

out:

	spin_unlock(&acct_lock);

	return res;

	return acct->active;

}



static void acct_put(struct bsd_acct_struct *p)
@@ -550,7 +522,7 @@ static void do_acct_process(struct bsd_acct_struct *acct) 
	 * First check to see if there is enough free_space to continue

	 * the process accounting system.

	 */

	if (!check_free_space(acct, file))

	if (!check_free_space(acct))

		goto out;



	fill_ac(&ac);