The patch titled
Configure out file locking features
has been added to the -mm tree. Its filename is
configure-out-file-locking-features.patch
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------------------------------------------------------
Subject: Configure out file locking features
From: Thomas Petazzoni <thomas.petazzoni@xxxxxxxxxxxxxxxxxx>
Add the CONFIG_FILE_LOCKING option which allows to remove support for
advisory locks. With this patch enabled, the flock() system call, the
F_GETLK, F_SETLK and F_SETLKW operations of fcntl() and NFS support are
disabled. These features are not necessarly needed on embedded systems.
It allows to save ~11 Kb of kernel code and data:
text data bss dec hex filename
1125436 118764 212992 1457192 163c28 vmlinux.old
1114299 118564 212992 1445855 160fdf vmlinux
-11137 -200 0 -11337 -2C49 +/-
This patch has originally been written by Matt Mackall <mpm@xxxxxxxxxxx>,
and is part of the Linux Tiny project.
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@xxxxxxxxxxxxxxxxxx>
Cc: Matthew Wilcox <willy@xxxxxxxxxx>
Cc: Matt Mackall <mpm@xxxxxxxxxxx>
Cc: "J. Bruce Fields" <bfields@xxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/Kconfig | 2 -
fs/Makefile | 3 +-
fs/proc/proc_misc.c | 4 +++
include/linux/fs.h | 52 ++++++++++++++++++++++++++++++++++++------
init/Kconfig | 8 ++++++
kernel/sys_ni.c | 1
kernel/sysctl.c | 6 ++++
7 files changed, 66 insertions(+), 10 deletions(-)
diff -puN fs/Kconfig~configure-out-file-locking-features fs/Kconfig
--- a/fs/Kconfig~configure-out-file-locking-features
+++ a/fs/Kconfig
@@ -1559,7 +1559,7 @@ if NETWORK_FILESYSTEMS
config NFS_FS
tristate "NFS client support"
- depends on INET
+ depends on INET && FILE_LOCKING
select LOCKD
select SUNRPC
select NFS_ACL_SUPPORT if NFS_V3_ACL
diff -puN fs/Makefile~configure-out-file-locking-features fs/Makefile
--- a/fs/Makefile~configure-out-file-locking-features
+++ a/fs/Makefile
@@ -7,7 +7,7 @@
obj-y := open.o read_write.o file_table.o super.o \
char_dev.o stat.o exec.o pipe.o namei.o fcntl.o \
- ioctl.o readdir.o select.o fifo.o locks.o dcache.o inode.o \
+ ioctl.o readdir.o select.o fifo.o dcache.o inode.o \
attr.o bad_inode.o file.o filesystems.o namespace.o aio.o \
seq_file.o xattr.o libfs.o fs-writeback.o \
pnode.o drop_caches.o splice.o sync.o utimes.o \
@@ -27,6 +27,7 @@ obj-$(CONFIG_ANON_INODES) += anon_inodes
obj-$(CONFIG_SIGNALFD) += signalfd.o
obj-$(CONFIG_TIMERFD) += timerfd.o
obj-$(CONFIG_EVENTFD) += eventfd.o
+obj-$(CONFIG_FILE_LOCKING) += locks.o
obj-$(CONFIG_COMPAT) += compat.o compat_ioctl.o
nfsd-$(CONFIG_NFSD) := nfsctl.o
diff -puN fs/proc/proc_misc.c~configure-out-file-locking-features fs/proc/proc_misc.c
--- a/fs/proc/proc_misc.c~configure-out-file-locking-features
+++ a/fs/proc/proc_misc.c
@@ -677,6 +677,7 @@ static int cmdline_read_proc(char *page,
return proc_calc_metrics(page, start, off, count, eof, len);
}
+#ifdef CONFIG_FILE_LOCKING
static int locks_open(struct inode *inode, struct file *filp)
{
return seq_open(filp, &locks_seq_operations);
@@ -688,6 +689,7 @@ static const struct file_operations proc
.llseek = seq_lseek,
.release = seq_release,
};
+#endif /* CONFIG_FILE_LOCKING */
static int execdomains_read_proc(char *page, char **start, off_t off,
int count, int *eof, void *data)
@@ -881,7 +883,9 @@ void __init proc_misc_init(void)
#ifdef CONFIG_PRINTK
proc_create("kmsg", S_IRUSR, NULL, &proc_kmsg_operations);
#endif
+#ifdef CONFIG_FILE_LOCKING
proc_create("locks", 0, NULL, &proc_locks_operations);
+#endif
proc_create("devices", 0, NULL, &proc_devinfo_operations);
proc_create("cpuinfo", 0, NULL, &proc_cpuinfo_operations);
#ifdef CONFIG_BLOCK
diff -puN include/linux/fs.h~configure-out-file-locking-features include/linux/fs.h
--- a/include/linux/fs.h~configure-out-file-locking-features
+++ a/include/linux/fs.h
@@ -983,6 +983,13 @@ struct file_lock {
#include <linux/fcntl.h>
+extern void send_sigio(struct fown_struct *fown, int fd, int band);
+
+/* fs/sync.c */
+extern int do_sync_mapping_range(struct address_space *mapping, loff_t offset,
+ loff_t endbyte, unsigned int flags);
+
+#ifdef CONFIG_FILE_LOCKING
extern int fcntl_getlk(struct file *, struct flock __user *);
extern int fcntl_setlk(unsigned int, struct file *, unsigned int,
struct flock __user *);
@@ -993,14 +1000,9 @@ extern int fcntl_setlk64(unsigned int, s
struct flock64 __user *);
#endif
-extern void send_sigio(struct fown_struct *fown, int fd, int band);
extern int fcntl_setlease(unsigned int fd, struct file *filp, long arg);
extern int fcntl_getlease(struct file *filp);
-/* fs/sync.c */
-extern int do_sync_mapping_range(struct address_space *mapping, loff_t offset,
- loff_t endbyte, unsigned int flags);
-
/* fs/locks.c */
extern void locks_init_lock(struct file_lock *);
extern void locks_copy_lock(struct file_lock *, struct file_lock *);
@@ -1023,6 +1025,33 @@ extern int lease_modify(struct file_lock
extern int lock_may_read(struct inode *, loff_t start, unsigned long count);
extern int lock_may_write(struct inode *, loff_t start, unsigned long count);
extern struct seq_operations locks_seq_operations;
+#else /* !CONFIG_FILE_LOCKING */
+#define fcntl_getlk(a, b) (-EINVAL)
+#define fcntl_setlk(a, b, c, d) (-EACCES)
+#if BITS_PER_LONG == 32
+#define fcntl_getlk64(a, b) (-EINVAL)
+#define fcntl_setlk64(a, b, c, d) (-EACCES)
+#endif
+#define fcntl_setlease(a, b, c) (0)
+#define fcntl_getlease(a) (0)
+#define locks_init_lock(a)
+#define locks_copy_lock(a, b)
+#define locks_remove_posix(a, b)
+#define locks_remove_flock(a)
+#define posix_test_lock(a, b) (0)
+#define posix_lock_file(a, b) (-ENOLCK)
+#define posix_lock_file_wait(a, b) (-ENOLCK)
+#define posix_unblock_lock(a, b) (-ENOENT)
+#define vfs_test_lock(a, b) (0)
+#define vfs_lock_file(a, b, c, d) (-ENOLCK)
+#define vfs_cancel_lock(a, b) (0)
+#define flock_lock_file_wait(a, b) (-ENOLCK)
+#define __break_lease(a, b) (0)
+#define lease_get_mtime(a, b)
+#define lock_may_read(a, b, c) (1)
+#define lock_may_write(a, b, c) (1)
+#endif /* !CONFIG_FILE_LOCKING */
+
struct fasync_struct {
int magic;
@@ -1554,9 +1583,12 @@ extern int vfs_statfs(struct dentry *, s
/* /sys/fs */
extern struct kobject *fs_kobj;
+extern int rw_verify_area(int, struct file *, loff_t *, size_t);
+
#define FLOCK_VERIFY_READ 1
#define FLOCK_VERIFY_WRITE 2
+#ifdef CONFIG_FILE_LOCKING
extern int locks_mandatory_locked(struct inode *);
extern int locks_mandatory_area(int, struct inode *, struct file *, loff_t, size_t);
@@ -1587,8 +1619,6 @@ static inline int locks_verify_locked(st
return 0;
}
-extern int rw_verify_area(int, struct file *, loff_t *, size_t);
-
static inline int locks_verify_truncate(struct inode *inode,
struct file *filp,
loff_t size)
@@ -1609,6 +1639,14 @@ static inline int break_lease(struct ino
return __break_lease(inode, mode);
return 0;
}
+#else /* !CONFIG_FILE_LOCKING */
+#define locks_mandatory_locked(a) (0)
+#define locks_mandatory_area(a, b, c, d, e) (0)
+#define mandatory_lock(a) (0)
+#define locks_verify_locked(a) (0)
+#define locks_verify_truncate(a, b, c) (0)
+#define break_lease(a, b) (0)
+#endif /* CONFIG_FILE_LOCKING */
/* fs/open.c */
diff -puN init/Kconfig~configure-out-file-locking-features init/Kconfig
--- a/init/Kconfig~configure-out-file-locking-features
+++ a/init/Kconfig
@@ -724,6 +724,14 @@ config SHMEM
option replaces shmem and tmpfs with the much simpler ramfs code,
which may be appropriate on small systems without swap.
+config FILE_LOCKING
+ bool "Enable POSIX file locking API" if EMBEDDED
+ default y
+ help
+ This option enables standard file locking support, required
+ for filesystems like NFS and for the flock() system
+ call. Disabling this option saves about 11k.
+
config VM_EVENT_COUNTERS
default y
bool "Enable VM event counters for /proc/vmstat" if EMBEDDED
diff -puN kernel/sys_ni.c~configure-out-file-locking-features kernel/sys_ni.c
--- a/kernel/sys_ni.c~configure-out-file-locking-features
+++ a/kernel/sys_ni.c
@@ -94,6 +94,7 @@ cond_syscall(compat_sys_set_mempolicy);
cond_syscall(sys_add_key);
cond_syscall(sys_request_key);
cond_syscall(sys_keyctl);
+cond_syscall(sys_flock);
cond_syscall(compat_sys_keyctl);
cond_syscall(compat_sys_socketcall);
cond_syscall(sys_inotify_init);
diff -puN kernel/sysctl.c~configure-out-file-locking-features kernel/sysctl.c
--- a/kernel/sysctl.c~configure-out-file-locking-features
+++ a/kernel/sysctl.c
@@ -98,7 +98,7 @@ static int sixty = 60;
static int neg_one = -1;
#endif
-#ifdef CONFIG_MMU
+#if defined(CONFIG_MMU) && defined(CONFIG_FILE_LOCKING)
static int two = 2;
#endif
@@ -1272,6 +1272,7 @@ static struct ctl_table fs_table[] = {
.extra1 = &minolduid,
.extra2 = &maxolduid,
},
+#ifdef CONFIG_FILE_LOCKING
{
.ctl_name = FS_LEASES,
.procname = "leases-enable",
@@ -1280,6 +1281,7 @@ static struct ctl_table fs_table[] = {
.mode = 0644,
.proc_handler = &proc_dointvec,
},
+#endif
#ifdef CONFIG_DNOTIFY
{
.ctl_name = FS_DIR_NOTIFY,
@@ -1291,6 +1293,7 @@ static struct ctl_table fs_table[] = {
},
#endif
#ifdef CONFIG_MMU
+#ifdef CONFIG_FILE_LOCKING
{
.ctl_name = FS_LEASE_TIME,
.procname = "lease-break-time",
@@ -1302,6 +1305,7 @@ static struct ctl_table fs_table[] = {
.extra1 = &zero,
.extra2 = &two,
},
+#endif /* CONFIG_FILE_LOCKING */
{
.procname = "aio-nr",
.data = &aio_nr,
_
Patches currently in -mm which might be from thomas.petazzoni@xxxxxxxxxxxxxxxxxx are
configure-out-file-locking-features.patch
configure-out-aio-support.patch
configure-out-ethtool-support.patch
configure-out-igmp-support.patch
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