fs: add ksys_fallocate() wrapper; remove in-kernel calls to sys_fallocate()
Using the ksys_fallocate() wrapper allows us to get rid of in-kernel
calls to the sys_fallocate() syscall. The ksys_ prefix denotes that this
function is meant as a drop-in replacement for the syscall. In
particular, it uses the same calling convention as sys_fallocate().
This patch is part of a series which removes in-kernel calls to syscalls.
On this basis, the syscall entry path can be streamlined. For details, see
http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
diff --git a/arch/mips/kernel/linux32.c b/arch/mips/kernel/linux32.c
index 91e85e2..0779d47 100644
--- a/arch/mips/kernel/linux32.c
+++ b/arch/mips/kernel/linux32.c
@@ -157,6 +157,6 @@
asmlinkage long sys32_fallocate(int fd, int mode, unsigned offset_a2,
unsigned offset_a3, unsigned len_a4, unsigned len_a5)
{
- return sys_fallocate(fd, mode, merge_64(offset_a2, offset_a3),
- merge_64(len_a4, len_a5));
+ return ksys_fallocate(fd, mode, merge_64(offset_a2, offset_a3),
+ merge_64(len_a4, len_a5));
}
diff --git a/arch/parisc/kernel/sys_parisc.c b/arch/parisc/kernel/sys_parisc.c
index 4f47e83..588fab3 100644
--- a/arch/parisc/kernel/sys_parisc.c
+++ b/arch/parisc/kernel/sys_parisc.c
@@ -367,8 +367,8 @@
asmlinkage long parisc_fallocate(int fd, int mode, u32 offhi, u32 offlo,
u32 lenhi, u32 lenlo)
{
- return sys_fallocate(fd, mode, ((u64)offhi << 32) | offlo,
- ((u64)lenhi << 32) | lenlo);
+ return ksys_fallocate(fd, mode, ((u64)offhi << 32) | offlo,
+ ((u64)lenhi << 32) | lenlo);
}
long parisc_personality(unsigned long personality)
diff --git a/arch/powerpc/kernel/sys_ppc32.c b/arch/powerpc/kernel/sys_ppc32.c
index 36a651e..68f11e1 100644
--- a/arch/powerpc/kernel/sys_ppc32.c
+++ b/arch/powerpc/kernel/sys_ppc32.c
@@ -100,7 +100,7 @@
asmlinkage long compat_sys_fallocate(int fd, int mode, u32 offhi, u32 offlo,
u32 lenhi, u32 lenlo)
{
- return sys_fallocate(fd, mode, ((loff_t)offhi << 32) | offlo,
+ return ksys_fallocate(fd, mode, ((loff_t)offhi << 32) | offlo,
((loff_t)lenhi << 32) | lenlo);
}
diff --git a/arch/s390/kernel/compat_linux.c b/arch/s390/kernel/compat_linux.c
index 71e2c5b..039858f 100644
--- a/arch/s390/kernel/compat_linux.c
+++ b/arch/s390/kernel/compat_linux.c
@@ -516,6 +516,6 @@
COMPAT_SYSCALL_DEFINE6(s390_fallocate, int, fd, int, mode, u32, offhigh, u32, offlow,
u32, lenhigh, u32, lenlow)
{
- return sys_fallocate(fd, mode, ((loff_t)offhigh << 32) + offlow,
- ((u64)lenhigh << 32) + lenlow);
+ return ksys_fallocate(fd, mode, ((loff_t)offhigh << 32) + offlow,
+ ((u64)lenhigh << 32) + lenlow);
}
diff --git a/arch/sparc/kernel/sys_sparc32.c b/arch/sparc/kernel/sys_sparc32.c
index 40c0d2e..4ba62d6 100644
--- a/arch/sparc/kernel/sys_sparc32.c
+++ b/arch/sparc/kernel/sys_sparc32.c
@@ -250,6 +250,6 @@
asmlinkage long compat_sys_fallocate(int fd, int mode, u32 offhi, u32 offlo,
u32 lenhi, u32 lenlo)
{
- return sys_fallocate(fd, mode, ((loff_t)offhi << 32) | offlo,
- ((loff_t)lenhi << 32) | lenlo);
+ return ksys_fallocate(fd, mode, ((loff_t)offhi << 32) | offlo,
+ ((loff_t)lenhi << 32) | lenlo);
}
diff --git a/arch/x86/ia32/sys_ia32.c b/arch/x86/ia32/sys_ia32.c
index c08c25f..df2acb1 100644
--- a/arch/x86/ia32/sys_ia32.c
+++ b/arch/x86/ia32/sys_ia32.c
@@ -226,8 +226,8 @@
unsigned int, offset_lo, unsigned int, offset_hi,
unsigned int, len_lo, unsigned int, len_hi)
{
- return sys_fallocate(fd, mode, ((u64)offset_hi << 32) | offset_lo,
- ((u64)len_hi << 32) | len_lo);
+ return ksys_fallocate(fd, mode, ((u64)offset_hi << 32) | offset_lo,
+ ((u64)len_hi << 32) | len_lo);
}
/*
diff --git a/fs/open.c b/fs/open.c
index 2e816fc..d0e955b 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -333,7 +333,7 @@
}
EXPORT_SYMBOL_GPL(vfs_fallocate);
-SYSCALL_DEFINE4(fallocate, int, fd, int, mode, loff_t, offset, loff_t, len)
+int ksys_fallocate(int fd, int mode, loff_t offset, loff_t len)
{
struct fd f = fdget(fd);
int error = -EBADF;
@@ -345,6 +345,11 @@
return error;
}
+SYSCALL_DEFINE4(fallocate, int, fd, int, mode, loff_t, offset, loff_t, len)
+{
+ return ksys_fallocate(fd, mode, offset, len);
+}
+
/*
* access() needs to use the real uid/gid, not the effective uid/gid.
* We do this by temporarily clearing all FS-related capabilities and
diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index a30e4c2..613b812 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -969,6 +969,7 @@
loff_t pos);
ssize_t ksys_pwrite64(unsigned int fd, const char __user *buf,
size_t count, loff_t pos);
+int ksys_fallocate(int fd, int mode, loff_t offset, loff_t len);
/*
* The following kernel syscall equivalents are just wrappers to fs-internal