fs/file: more unsigned file descriptors

Propagate unsignedness for grand total of 149 bytes:

	$ ./scripts/bloat-o-meter ../vmlinux-000 ../obj/vmlinux
	add/remove: 0/0 grow/shrink: 0/10 up/down: 0/-149 (-149)
	function                                     old     new   delta
	set_close_on_exec                             99      98      -1
	put_files_struct                             201     200      -1
	get_close_on_exec                             59      58      -1
	do_prlimit                                   498     497      -1
	do_execveat_common.isra                     1662    1661      -1
	__close_fd                                   178     173      -5
	do_dup2                                      219     204     -15
	seq_show                                     685     660     -25
	__alloc_fd                                   384     357     -27
	dup_fd                                       718     646     -72

It mostly comes from converting "unsigned int" to "long" for bit operations.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

fs/file.c

@@ -23,12 +23,12 @@
 #include <linux/rcupdate.h>
 #include <linux/workqueue.h>
 
-int sysctl_nr_open __read_mostly = 1024*1024;
-int sysctl_nr_open_min = BITS_PER_LONG;
+unsigned int sysctl_nr_open __read_mostly = 1024*1024;
+unsigned int sysctl_nr_open_min = BITS_PER_LONG;
 /* our min() is unusable in constant expressions ;-/ */
 #define __const_min(x, y) ((x) < (y) ? (x) : (y))
-int sysctl_nr_open_max = __const_min(INT_MAX, ~(size_t)0/sizeof(void *)) &
-			 -BITS_PER_LONG;
+unsigned int sysctl_nr_open_max =
+	__const_min(INT_MAX, ~(size_t)0/sizeof(void *)) & -BITS_PER_LONG;
 
 static void *alloc_fdmem(size_t size)
 {
@@ -163,7 +163,7 @@ out:
  * Return <0 error code on error; 1 on successful completion.
  * The files->file_lock should be held on entry, and will be held on exit.
  */
-static int expand_fdtable(struct files_struct *files, int nr)
+static int expand_fdtable(struct files_struct *files, unsigned int nr)
 	__releases(files->file_lock)
 	__acquires(files->file_lock)
 {
@@ -208,7 +208,7 @@ static int expand_fdtable(struct files_struct *files, int nr)
  * expanded and execution may have blocked.
  * The files->file_lock should be held on entry, and will be held on exit.
  */
-static int expand_files(struct files_struct *files, int nr)
+static int expand_files(struct files_struct *files, unsigned int nr)
 	__releases(files->file_lock)
 	__acquires(files->file_lock)
 {
@@ -243,12 +243,12 @@ repeat:
 	return expanded;
 }
 
-static inline void __set_close_on_exec(int fd, struct fdtable *fdt)
+static inline void __set_close_on_exec(unsigned int fd, struct fdtable *fdt)
 {
 	__set_bit(fd, fdt->close_on_exec);
 }
 
-static inline void __clear_close_on_exec(int fd, struct fdtable *fdt)
+static inline void __clear_close_on_exec(unsigned int fd, struct fdtable *fdt)
 {
 	if (test_bit(fd, fdt->close_on_exec))
 		__clear_bit(fd, fdt->close_on_exec);
@@ -268,10 +268,10 @@ static inline void __clear_open_fd(unsigned int fd, struct fdtable *fdt)
 	__clear_bit(fd / BITS_PER_LONG, fdt->full_fds_bits);
 }
 
-static int count_open_files(struct fdtable *fdt)
+static unsigned int count_open_files(struct fdtable *fdt)
 {
-	int size = fdt->max_fds;
-	int i;
+	unsigned int size = fdt->max_fds;
+	unsigned int i;
 
 	/* Find the last open fd */
 	for (i = size / BITS_PER_LONG; i > 0; ) {
@@ -291,7 +291,7 @@ struct files_struct *dup_fd(struct files_struct *oldf, int *errorp)
 {
 	struct files_struct *newf;
 	struct file **old_fds, **new_fds;
-	int open_files, i;
+	unsigned int open_files, i;
 	struct fdtable *old_fdt, *new_fdt;
 
 	*errorp = -ENOMEM;
@@ -391,7 +391,7 @@ static struct fdtable *close_files(struct files_struct * files)
 	 * files structure.
 	 */
 	struct fdtable *fdt = rcu_dereference_raw(files->fdt);
-	int i, j = 0;
+	unsigned int i, j = 0;
 
 	for (;;) {
 		unsigned long set;
@@ -477,11 +477,11 @@ struct files_struct init_files = {
 	.file_lock	= __SPIN_LOCK_UNLOCKED(init_files.file_lock),
 };
 
-static unsigned long find_next_fd(struct fdtable *fdt, unsigned long start)
+static unsigned int find_next_fd(struct fdtable *fdt, unsigned int start)
 {
-	unsigned long maxfd = fdt->max_fds;
-	unsigned long maxbit = maxfd / BITS_PER_LONG;
-	unsigned long bitbit = start / BITS_PER_LONG;
+	unsigned int maxfd = fdt->max_fds;
+	unsigned int maxbit = maxfd / BITS_PER_LONG;
+	unsigned int bitbit = start / BITS_PER_LONG;
 
 	bitbit = find_next_zero_bit(fdt->full_fds_bits, maxbit, bitbit) * BITS_PER_LONG;
 	if (bitbit > maxfd)

include/linux/fdtable.h

@@ -30,12 +30,12 @@ struct fdtable {
 	struct rcu_head rcu;
 };
 
-static inline bool close_on_exec(int fd, const struct fdtable *fdt)
+static inline bool close_on_exec(unsigned int fd, const struct fdtable *fdt)
 {
 	return test_bit(fd, fdt->close_on_exec);
 }
 
-static inline bool fd_is_open(int fd, const struct fdtable *fdt)
+static inline bool fd_is_open(unsigned int fd, const struct fdtable *fdt)
 {
 	return test_bit(fd, fdt->open_fds);
 }
@@ -57,7 +57,7 @@ struct files_struct {
    * written part on a separate cache line in SMP
    */
 	spinlock_t file_lock ____cacheline_aligned_in_smp;
-	int next_fd;
+	unsigned int next_fd;
 	unsigned long close_on_exec_init[1];
 	unsigned long open_fds_init[1];
 	unsigned long full_fds_bits_init[1];

include/linux/fs.h

@@ -63,7 +63,7 @@ extern void __init files_maxfiles_init(void);
 
 extern struct files_stat_struct files_stat;
 extern unsigned long get_max_files(void);
-extern int sysctl_nr_open;
+extern unsigned int sysctl_nr_open;
 extern struct inodes_stat_t inodes_stat;
 extern int leases_enable, lease_break_time;
 extern int sysctl_protected_symlinks;

kernel/sysctl.c

@@ -108,7 +108,7 @@ extern int pid_max_min, pid_max_max;
 extern int percpu_pagelist_fraction;
 extern int compat_log;
 extern int latencytop_enabled;
-extern int sysctl_nr_open_min, sysctl_nr_open_max;
+extern unsigned int sysctl_nr_open_min, sysctl_nr_open_max;
 #ifndef CONFIG_MMU
 extern int sysctl_nr_trim_pages;
 #endif
@@ -1692,7 +1692,7 @@ static struct ctl_table fs_table[] = {
 	{
 		.procname	= "nr_open",
 		.data		= &sysctl_nr_open,
-		.maxlen		= sizeof(int),
+		.maxlen		= sizeof(unsigned int),
 		.mode		= 0644,
 		.proc_handler	= proc_dointvec_minmax,
 		.extra1		= &sysctl_nr_open_min,