[PATCH 1/5] fallocate() implementation in i86, x86_64 and powerpc

Amit K. Arora
2007-04-26T18:03:34Z

This patch implements the fallocate() system call and adds support for
i386, x86_64 and powerpc.

NOTE: It is based on 2.6.21 kernel version.

Signed-off-by: Amit Arora <aarora@in.ibm.com>
---
arch/i386/kernel/syscall_table.S | 1
arch/powerpc/kernel/sys_ppc32.c | 7 ++++++
arch/x86_64/kernel/functionlist | 1
fs/open.c | 41 +++++++++++++++++++++++++++++++++++++++
include/asm-i386/unistd.h | 3 +-
include/asm-powerpc/systbl.h | 1
include/asm-powerpc/unistd.h | 3 +-
include/asm-x86_64/unistd.h | 4 ++-
include/linux/fs.h | 7 ++++++
include/linux/syscalls.h | 1
10 files changed, 66 insertions(+), 3 deletions(-)

Index: linux-2.6.21/arch/i386/kernel/syscall_table.S
===================================================================
--- linux-2.6.21.orig/arch/i386/kernel/syscall_table.S
+++ linux-2.6.21/arch/i386/kernel/syscall_table.S
@@ -319,3 +319,4 @@ ENTRY(sys_call_table)
.long sys_move_pages
.long sys_getcpu
.long sys_epoll_pwait
+ .long sys_fallocate /* 320 */
Index: linux-2.6.21/arch/x86_64/kernel/functionlist
===================================================================
--- linux-2.6.21.orig/arch/x86_64/kernel/functionlist
+++ linux-2.6.21/arch/x86_64/kernel/functionlist
@@ -931,6 +931,7 @@
*(.text.sys_getitimer)
*(.text.sys_getgroups)
*(.text.sys_ftruncate)
+*(.text.sys_fallocate)
*(.text.sysfs_lookup)
*(.text.sys_exit_group)
*(.text.stub_fork)
Index: linux-2.6.21/fs/open.c
===================================================================
--- linux-2.6.21.orig/fs/open.c
+++ linux-2.6.21/fs/open.c
@@ -350,6 +350,47 @@ asmlinkage long sys_ftruncate64(unsigned
}
#endif

+asmlinkage long sys_fallocate(int fd, int mode, loff_t offset, loff_t len)
+{
+ struct file *file;
+ struct inode *inode;
+ long ret = -EINVAL;
+
+ if (len == 0 || offset < 0)
+ goto out;
+
+ ret = -EBADF;
+ file = fget(fd);
+ if (!file)
+ goto out;
+ if (!(file->f_mode & FMODE_WRITE))
+ goto out_fput;
+
+ inode = file->f_path.dentry->d_inode;
+
+ ret = -ESPIPE;
+ if (S_ISFIFO(inode->i_mode))
+ goto out_fput;
+
+ ret = -ENODEV;
+ if (!S_ISREG(inode->i_mode))
+ goto out_fput;
+
+ ret = -EFBIG;
+ if (offset + len > inode->i_sb->s_maxbytes)
+ goto out_fput;
+
+ if (inode->i_op && inode->i_op->fallocate)
+ ret = inode->i_op->fallocate(inode, mode, offset, len);
+ else
+ ret = -ENOSYS;
+out_fput:
+ fput(file);
+out:
+ return ret;
+}
+EXPORT_SYMBOL(sys_fallocate);
+
/*
* access() needs to use the real uid/gid, not the effective uid/gid.
* We do this by temporarily clearing all FS-related capabilities and
Index: linux-2.6.21/include/asm-i386/unistd.h
===================================================================
--- linux-2.6.21.orig/include/asm-i386/unistd.h
+++ linux-2.6.21/include/asm-i386/unistd.h
@@ -325,10 +325,11 @@
#define __NR_move_pages 317
#define __NR_getcpu 318
#define __NR_epoll_pwait 319
+#define __NR_fallocate 320

#ifdef __KERNEL__

-#define NR_syscalls 320
+#define NR_syscalls 321

#define __ARCH_WANT_IPC_PARSE_VERSION
#define __ARCH_WANT_OLD_READDIR
Index: linux-2.6.21/include/asm-powerpc/systbl.h
===================================================================
--- linux-2.6.21.orig/include/asm-powerpc/systbl.h
+++ linux-2.6.21/include/asm-powerpc/systbl.h
@@ -307,3 +307,4 @@ COMPAT_SYS_SPU(set_robust_list)
COMPAT_SYS_SPU(move_pages)
SYSCALL_SPU(getcpu)
COMPAT_SYS(epoll_pwait)
+COMPAT_SYS(fallocate)
Index: linux-2.6.21/include/asm-powerpc/unistd.h
===================================================================
--- linux-2.6.21.orig/include/asm-powerpc/unistd.h
+++ linux-2.6.21/include/asm-powerpc/unistd.h
@@ -326,10 +326,11 @@
#define __NR_move_pages 301
#define __NR_getcpu 302
#define __NR_epoll_pwait 303
+#define __NR_fallocate 304

#ifdef __KERNEL__

-#define __NR_syscalls 304
+#define __NR_syscalls 305

#define __NR__exit __NR_exit
#define NR_syscalls __NR_syscalls
Index: linux-2.6.21/include/asm-x86_64/unistd.h
===================================================================
--- linux-2.6.21.orig/include/asm-x86_64/unistd.h
+++ linux-2.6.21/include/asm-x86_64/unistd.h
@@ -619,8 +619,10 @@ __SYSCALL(__NR_sync_file_range, sys_sync
__SYSCALL(__NR_vmsplice, sys_vmsplice)
#define __NR_move_pages 279
__SYSCALL(__NR_move_pages, sys_move_pages)
+#define __NR_fallocate 280
+__SYSCALL(__NR_fallocate, sys_fallocate)

-#define __NR_syscall_max __NR_move_pages
+#define __NR_syscall_max __NR_fallocate

#ifndef __NO_STUBS
#define __ARCH_WANT_OLD_READDIR
Index: linux-2.6.21/include/linux/fs.h
===================================================================
--- linux-2.6.21.orig/include/linux/fs.h
+++ linux-2.6.21/include/linux/fs.h
@@ -264,6 +264,12 @@ extern int dir_notify_enable;
#define SYNC_FILE_RANGE_WRITE 2
#define SYNC_FILE_RANGE_WAIT_AFTER 4

+/*
+ * fallocate() modes
+ */
+#define FA_ALLOCATE 0x1
+#define FA_DEALLOCATE 0x2
+
#ifdef __KERNEL__

#include <linux/linkage.h>
@@ -1125,6 +1131,7 @@ struct inode_operations {
ssize_t (*listxattr) (struct dentry *, char *, size_t);
int (*removexattr) (struct dentry *, const char *);
void (*truncate_range)(struct inode *, loff_t, loff_t);
+ long (*fallocate)(struct inode *, int, loff_t, loff_t);
};

struct seq_file;
Index: linux-2.6.21/include/linux/syscalls.h
===================================================================
--- linux-2.6.21.orig/include/linux/syscalls.h
+++ linux-2.6.21/include/linux/syscalls.h
@@ -602,6 +602,7 @@ asmlinkage long sys_get_robust_list(int
asmlinkage long sys_set_robust_list(struct robust_list_head __user *head,
size_t len);
asmlinkage long sys_getcpu(unsigned __user *cpu, unsigned __user *node, struct getcpu_cache __user *cache);
+asmlinkage long sys_fallocate(int fd, int mode, loff_t offset, loff_t len);

int kernel_execve(const char *filename, char *const argv[], char *const envp[]);

Index: linux-2.6.21/arch/powerpc/kernel/sys_ppc32.c
===================================================================
--- linux-2.6.21.orig/arch/powerpc/kernel/sys_ppc32.c
+++ linux-2.6.21/arch/powerpc/kernel/sys_ppc32.c
@@ -777,6 +777,13 @@ asmlinkage int compat_sys_truncate64(con
return sys_truncate(path, (high << 32) | low);
}

+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);
+}
+
asmlinkage int compat_sys_ftruncate64(unsigned int fd, u32 reg4, unsigned long high,
unsigned long low)
{