[PATCH] f_count may wrap around

make it atomic_long_t; while we are at it, get rid of useless checks in affs,
hfs and hpfs - ->open() always has it equal to 1, ->release() - to 0.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

drivers/net/ppp_generic.c

@@ -581,12 +581,12 @@ static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 			if (file == ppp->owner)
 				ppp_shutdown_interface(ppp);
 		}
-		if (atomic_read(&file->f_count) <= 2) {
+		if (atomic_long_read(&file->f_count) <= 2) {
 			ppp_release(NULL, file);
 			err = 0;
 		} else
-			printk(KERN_DEBUG "PPPIOCDETACH file->f_count=%d\n",
-			       atomic_read(&file->f_count));
+			printk(KERN_DEBUG "PPPIOCDETACH file->f_count=%ld\n",
+			       atomic_long_read(&file->f_count));
 		unlock_kernel();
 		return err;
 	}

fs/affs/file.c

@@ -46,8 +46,6 @@ const struct inode_operations affs_file_inode_operations = {
 static int
 affs_file_open(struct inode *inode, struct file *filp)
 {
-	if (atomic_read(&filp->f_count) != 1)
-		return 0;
 	pr_debug("AFFS: open(%lu,%d)\n",
 		 inode->i_ino, atomic_read(&AFFS_I(inode)->i_opencnt));
 	atomic_inc(&AFFS_I(inode)->i_opencnt);
@@ -57,8 +55,6 @@ affs_file_open(struct inode *inode, struct file *filp)
 static int
 affs_file_release(struct inode *inode, struct file *filp)
 {
-	if (atomic_read(&filp->f_count) != 0)
-		return 0;
 	pr_debug("AFFS: release(%lu, %d)\n",
 		 inode->i_ino, atomic_read(&AFFS_I(inode)->i_opencnt));
 

fs/aio.c

@@ -512,8 +512,8 @@ static void aio_fput_routine(struct work_struct *data)
  */
 static int __aio_put_req(struct kioctx *ctx, struct kiocb *req)
 {
-	dprintk(KERN_DEBUG "aio_put(%p): f_count=%d\n",
-		req, atomic_read(&req->ki_filp->f_count));
+	dprintk(KERN_DEBUG "aio_put(%p): f_count=%ld\n",
+		req, atomic_long_read(&req->ki_filp->f_count));
 
 	assert_spin_locked(&ctx->ctx_lock);
 
@@ -528,7 +528,7 @@ static int __aio_put_req(struct kioctx *ctx, struct kiocb *req)
 	/* Must be done under the lock to serialise against cancellation.
 	 * Call this aio_fput as it duplicates fput via the fput_work.
 	 */
-	if (unlikely(atomic_dec_and_test(&req->ki_filp->f_count))) {
+	if (unlikely(atomic_long_dec_and_test(&req->ki_filp->f_count))) {
 		get_ioctx(ctx);
 		spin_lock(&fput_lock);
 		list_add(&req->ki_list, &fput_head);

fs/file_table.c

@@ -120,7 +120,7 @@ struct file *get_empty_filp(void)
 
 	tsk = current;
 	INIT_LIST_HEAD(&f->f_u.fu_list);
-	atomic_set(&f->f_count, 1);
+	atomic_long_set(&f->f_count, 1);
 	rwlock_init(&f->f_owner.lock);
 	f->f_uid = tsk->fsuid;
 	f->f_gid = tsk->fsgid;
@@ -219,7 +219,7 @@ EXPORT_SYMBOL(init_file);
 
 void fput(struct file *file)
 {
-	if (atomic_dec_and_test(&file->f_count))
+	if (atomic_long_dec_and_test(&file->f_count))
 		__fput(file);
 }
 
@@ -294,7 +294,7 @@ struct file *fget(unsigned int fd)
 	rcu_read_lock();
 	file = fcheck_files(files, fd);
 	if (file) {
-		if (!atomic_inc_not_zero(&file->f_count)) {
+		if (!atomic_long_inc_not_zero(&file->f_count)) {
 			/* File object ref couldn't be taken */
 			rcu_read_unlock();
 			return NULL;
@@ -326,7 +326,7 @@ struct file *fget_light(unsigned int fd, int *fput_needed)
 		rcu_read_lock();
 		file = fcheck_files(files, fd);
 		if (file) {
-			if (atomic_inc_not_zero(&file->f_count))
+			if (atomic_long_inc_not_zero(&file->f_count))
 				*fput_needed = 1;
 			else
 				/* Didn't get the reference, someone's freed */
@@ -341,7 +341,7 @@ struct file *fget_light(unsigned int fd, int *fput_needed)
 
 void put_filp(struct file *file)
 {
-	if (atomic_dec_and_test(&file->f_count)) {
+	if (atomic_long_dec_and_test(&file->f_count)) {
 		security_file_free(file);
 		file_kill(file);
 		file_free(file);

fs/hfs/inode.c

@@ -522,8 +522,6 @@ static int hfs_file_open(struct inode *inode, struct file *file)
 {
 	if (HFS_IS_RSRC(inode))
 		inode = HFS_I(inode)->rsrc_inode;
-	if (atomic_read(&file->f_count) != 1)
-		return 0;
 	atomic_inc(&HFS_I(inode)->opencnt);
 	return 0;
 }
@@ -534,8 +532,6 @@ static int hfs_file_release(struct inode *inode, struct file *file)
 
 	if (HFS_IS_RSRC(inode))
 		inode = HFS_I(inode)->rsrc_inode;
-	if (atomic_read(&file->f_count) != 0)
-		return 0;
 	if (atomic_dec_and_test(&HFS_I(inode)->opencnt)) {
 		mutex_lock(&inode->i_mutex);
 		hfs_file_truncate(inode);

fs/hfsplus/inode.c

@@ -254,8 +254,6 @@ static int hfsplus_file_open(struct inode *inode, struct file *file)
 {
 	if (HFSPLUS_IS_RSRC(inode))
 		inode = HFSPLUS_I(inode).rsrc_inode;
-	if (atomic_read(&file->f_count) != 1)
-		return 0;
 	atomic_inc(&HFSPLUS_I(inode).opencnt);
 	return 0;
 }
@@ -266,8 +264,6 @@ static int hfsplus_file_release(struct inode *inode, struct file *file)
 
 	if (HFSPLUS_IS_RSRC(inode))
 		inode = HFSPLUS_I(inode).rsrc_inode;
-	if (atomic_read(&file->f_count) != 0)
-		return 0;
 	if (atomic_dec_and_test(&HFSPLUS_I(inode).opencnt)) {
 		mutex_lock(&inode->i_mutex);
 		hfsplus_file_truncate(inode);

include/linux/fs.h

@@ -795,7 +795,7 @@ struct file {
 #define f_dentry	f_path.dentry
 #define f_vfsmnt	f_path.mnt
 	const struct file_operations	*f_op;
-	atomic_t		f_count;
+	atomic_long_t		f_count;
 	unsigned int 		f_flags;
 	mode_t			f_mode;
 	loff_t			f_pos;
@@ -824,8 +824,8 @@ extern spinlock_t files_lock;
 #define file_list_lock() spin_lock(&files_lock);
 #define file_list_unlock() spin_unlock(&files_lock);
 
-#define get_file(x)	atomic_inc(&(x)->f_count)
-#define file_count(x)	atomic_read(&(x)->f_count)
+#define get_file(x)	atomic_long_inc(&(x)->f_count)
+#define file_count(x)	atomic_long_read(&(x)->f_count)
 
 #ifdef CONFIG_DEBUG_WRITECOUNT
 static inline void file_take_write(struct file *f)

include/net/af_unix.h

@@ -51,7 +51,7 @@ struct unix_sock {
         struct sock		*peer;
         struct sock		*other;
 	struct list_head	link;
-        atomic_t                inflight;
+        atomic_long_t           inflight;
         spinlock_t		lock;
 	unsigned int		gc_candidate : 1;
         wait_queue_head_t       peer_wait;

net/sched/sch_atm.c

@@ -162,7 +162,7 @@ static void atm_tc_put(struct Qdisc *sch, unsigned long cl)
 	qdisc_destroy(flow->q);
 	tcf_destroy_chain(&flow->filter_list);
 	if (flow->sock) {
-		pr_debug("atm_tc_put: f_count %d\n",
+		pr_debug("atm_tc_put: f_count %ld\n",
 			file_count(flow->sock->file));
 		flow->vcc->pop = flow->old_pop;
 		sockfd_put(flow->sock);
@@ -259,7 +259,7 @@ static int atm_tc_change(struct Qdisc *sch, u32 classid, u32 parent,
 	sock = sockfd_lookup(fd, &error);
 	if (!sock)
 		return error;	/* f_count++ */
-	pr_debug("atm_tc_change: f_count %d\n", file_count(sock->file));
+	pr_debug("atm_tc_change: f_count %ld\n", file_count(sock->file));
 	if (sock->ops->family != PF_ATMSVC && sock->ops->family != PF_ATMPVC) {
 		error = -EPROTOTYPE;
 		goto err_out;

net/unix/af_unix.c

@@ -603,7 +603,7 @@ static struct sock * unix_create1(struct net *net, struct socket *sock)
 	u->dentry = NULL;
 	u->mnt	  = NULL;
 	spin_lock_init(&u->lock);
-	atomic_set(&u->inflight, 0);
+	atomic_long_set(&u->inflight, 0);
 	INIT_LIST_HEAD(&u->link);
 	mutex_init(&u->readlock); /* single task reading lock */
 	init_waitqueue_head(&u->peer_wait);

net/unix/garbage.c

@@ -127,7 +127,7 @@ void unix_inflight(struct file *fp)
 	if(s) {
 		struct unix_sock *u = unix_sk(s);
 		spin_lock(&unix_gc_lock);
-		if (atomic_inc_return(&u->inflight) == 1) {
+		if (atomic_long_inc_return(&u->inflight) == 1) {
 			BUG_ON(!list_empty(&u->link));
 			list_add_tail(&u->link, &gc_inflight_list);
 		} else {
@@ -145,7 +145,7 @@ void unix_notinflight(struct file *fp)
 		struct unix_sock *u = unix_sk(s);
 		spin_lock(&unix_gc_lock);
 		BUG_ON(list_empty(&u->link));
-		if (atomic_dec_and_test(&u->inflight))
+		if (atomic_long_dec_and_test(&u->inflight))
 			list_del_init(&u->link);
 		unix_tot_inflight--;
 		spin_unlock(&unix_gc_lock);
@@ -237,17 +237,17 @@ static void scan_children(struct sock *x, void (*func)(struct unix_sock *),
 
 static void dec_inflight(struct unix_sock *usk)
 {
-	atomic_dec(&usk->inflight);
+	atomic_long_dec(&usk->inflight);
 }
 
 static void inc_inflight(struct unix_sock *usk)
 {
-	atomic_inc(&usk->inflight);
+	atomic_long_inc(&usk->inflight);
 }
 
 static void inc_inflight_move_tail(struct unix_sock *u)
 {
-	atomic_inc(&u->inflight);
+	atomic_long_inc(&u->inflight);
 	/*
 	 * If this is still a candidate, move it to the end of the
 	 * list, so that it's checked even if it was already passed
@@ -288,11 +288,11 @@ void unix_gc(void)
 	 * before the detach without atomicity guarantees.
 	 */
 	list_for_each_entry_safe(u, next, &gc_inflight_list, link) {
-		int total_refs;
-		int inflight_refs;
+		long total_refs;
+		long inflight_refs;
 
 		total_refs = file_count(u->sk.sk_socket->file);
-		inflight_refs = atomic_read(&u->inflight);
+		inflight_refs = atomic_long_read(&u->inflight);
 
 		BUG_ON(inflight_refs < 1);
 		BUG_ON(total_refs < inflight_refs);
@@ -324,7 +324,7 @@ void unix_gc(void)
 		/* Move cursor to after the current position. */
 		list_move(&cursor, &u->link);
 
-		if (atomic_read(&u->inflight) > 0) {
+		if (atomic_long_read(&u->inflight) > 0) {
 			list_move_tail(&u->link, &gc_inflight_list);
 			u->gc_candidate = 0;
 			scan_children(&u->sk, inc_inflight_move_tail, NULL);