Configure out file locking features
This patch adds 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@selenic.com>, and is part of the Linux Tiny project.
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Matt Mackall <mpm@selenic.com>
Cc: matthew@wil.cx
Cc: linux-fsdevel@vger.kernel.org
Cc: mpm@selenic.com
Cc: akpm@linux-foundation.org
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
diff --git a/fs/Kconfig b/fs/Kconfig
index abccb5d..c6ae4d48 100644
--- a/fs/Kconfig
+++ b/fs/Kconfig
@@ -419,6 +419,14 @@
bool
default n
+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.
+
source "fs/xfs/Kconfig"
source "fs/gfs2/Kconfig"
diff --git a/fs/Makefile b/fs/Makefile
index a1482a5..4b86d43 100644
--- a/fs/Makefile
+++ b/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-$(CONFIG_SIGNALFD) += signalfd.o
obj-$(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 --git a/fs/proc/proc_misc.c b/fs/proc/proc_misc.c
index 29e20c6..1aabbe2 100644
--- a/fs/proc/proc_misc.c
+++ b/fs/proc/proc_misc.c
@@ -684,6 +684,7 @@
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);
@@ -695,6 +696,7 @@
.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)
@@ -888,7 +890,9 @@
#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