Commit 7a8e0c8d authored by Martin Schwidefsky's avatar Martin Schwidefsky
Browse files

[S390] Wire up sys_fallocate.



This patch implements support of fallocate system call on s390(x)
platform.  A wrapper is added to address the issue which s390 ABI has with
the arguments of this system call.

Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent cb1863a4
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+10 −0
Original line number Diff line number Diff line
@@ -1710,3 +1710,13 @@ compat_sys_timerfd_wrapper:
sys_eventfd_wrapper:
	llgfr	%r2,%r2			# unsigned int
	jg	sys_eventfd

	.globl	sys_fallocate_wrapper
sys_fallocate_wrapper:
	lgfr	%r2,%r2			# int
	lgfr	%r3,%r3			# int
	sllg	%r4,%r4,32		# get high word of 64bit loff_t
	lr	%r4,%r5			# get low word of 64bit loff_t
	sllg	%r5,%r6,32		# get high word of 64bit loff_t
	l	%r5,164(%r15)		# get low word of 64bit loff_t
	jg	sys_fallocate
+20 −0
Original line number Diff line number Diff line
@@ -265,3 +265,23 @@ s390_fadvise64_64(struct fadvise64_64_args __user *args)
		return -EFAULT;
	return sys_fadvise64_64(a.fd, a.offset, a.len, a.advice);
}

#ifndef CONFIG_64BIT
/*
 * This is a wrapper to call sys_fallocate(). For 31 bit s390 the last
 * 64 bit argument "len" is split into the upper and lower 32 bits. The
 * system call wrapper in the user space loads the value to %r6/%r7.
 * The code in entry.S keeps the values in %r2 - %r6 where they are and
 * stores %r7 to 96(%r15). But the standard C linkage requires that
 * the whole 64 bit value for len is stored on the stack and doesn't
 * use %r6 at all. So s390_fallocate has to convert the arguments from
 *   %r2: fd, %r3: mode, %r4/%r5: offset, %r6/96(%r15)-99(%r15): len
 * to
 *   %r2: fd, %r3: mode, %r4/%r5: offset, 96(%r15)-103(%r15): len
 */
asmlinkage long s390_fallocate(int fd, int mode, loff_t offset,
			       u32 len_high, u32 len_low)
{
	return sys_fallocate(fd, mode, offset, ((u64)len_high << 32) | len_low);
}
#endif
+1 −1
Original line number Diff line number Diff line
@@ -322,7 +322,7 @@ NI_SYSCALL /* 310 sys_move_pages */
SYSCALL(sys_getcpu,sys_getcpu,sys_getcpu_wrapper)
SYSCALL(sys_epoll_pwait,sys_epoll_pwait,compat_sys_epoll_pwait_wrapper)
SYSCALL(sys_utimes,sys_utimes,compat_sys_utimes_wrapper)
NI_SYSCALL							/* 314 sys_fallocate */
SYSCALL(s390_fallocate,sys_fallocate,sys_fallocate_wrapper)
SYSCALL(sys_utimensat,sys_utimensat,compat_sys_utimensat_wrapper)	/* 315 */
SYSCALL(sys_signalfd,sys_signalfd,compat_sys_signalfd_wrapper)
SYSCALL(sys_timerfd,sys_timerfd,compat_sys_timerfd_wrapper)
+1 −1
Original line number Diff line number Diff line
@@ -251,7 +251,7 @@
#define __NR_getcpu		311
#define __NR_epoll_pwait	312
#define __NR_utimes		313
/* Number 314 is reserved for new sys_fallocate */
#define __NR_fallocate		314
#define __NR_utimensat		315
#define __NR_signalfd		316
#define __NR_timerfd		317