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fs: Add fsync on/off support

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[efremov: change permissions from 0755 to 0644]
Signed-off-by: djb77 <dwayne.bakewell@gmail.com>
Signed-off-by: Denis Efremov <efremov@linux.com>
This commit is contained in:
franciscofranco 2017-09-17 02:48:54 +02:00 committed by prashantpaddune
parent 2a285456a4
commit 248a47bf83
1 changed files with 31 additions and 2 deletions
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33
fs/sync.c
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@ -7,6 +7,7 @@
#include <linux/fs.h>
#include <linux/slab.h>
#include <linux/export.h>
#include <linux/module.h>
#include <linux/namei.h>
#include <linux/sched.h>
#include <linux/writeback.h>
@ -17,6 +18,9 @@
#include <linux/backing-dev.h>
#include "internal.h"
bool fsync_enabled = true;
module_param(fsync_enabled, bool, 0644);
#define VALID_FLAGS (SYNC_FILE_RANGE_WAIT_BEFORE|SYNC_FILE_RANGE_WRITE| \
SYNC_FILE_RANGE_WAIT_AFTER)
@ -403,10 +407,15 @@ void emergency_sync(void)
*/
SYSCALL_DEFINE1(syncfs, int, fd)
{
struct fd f = fdget(fd);
struct fd f;
struct super_block *sb;
int ret;
if (!fsync_enabled)
return 0;
f = fdget(fd);
if (!f.file)
return -EBADF;
sb = f.file->f_path.dentry->d_sb;
@ -434,6 +443,9 @@ int vfs_fsync_range(struct file *file, loff_t start, loff_t end, int datasync)
{
struct inode *inode = file->f_mapping->host;
if (!fsync_enabled)
return 0;
if (!file->f_op->fsync)
return -EINVAL;
if (!datasync && (inode->i_state & I_DIRTY_TIME)) {
@ -456,15 +468,23 @@ EXPORT_SYMBOL(vfs_fsync_range);
*/
int vfs_fsync(struct file *file, int datasync)
{
if (!fsync_enabled)
return 0;
return vfs_fsync_range(file, 0, LLONG_MAX, datasync);
}
EXPORT_SYMBOL(vfs_fsync);
static int do_fsync(unsigned int fd, int datasync)
{
struct fd f = fdget(fd);
struct fd f;
int ret = -EBADF;
if (!fsync_enabled)
return 0;
f = fdget(fd);
if (f.file) {
ret = vfs_fsync(f.file, datasync);
fdput(f);
@ -475,11 +495,17 @@ static int do_fsync(unsigned int fd, int datasync)
SYSCALL_DEFINE1(fsync, unsigned int, fd)
{
if (!fsync_enabled)
return 0;
return do_fsync(fd, 0);
}
SYSCALL_DEFINE1(fdatasync, unsigned int, fd)
{
if (!fsync_enabled)
return 0;
return do_fsync(fd, 1);
}
@ -539,6 +565,9 @@ SYSCALL_DEFINE4(sync_file_range, int, fd, loff_t, offset, loff_t, nbytes,
loff_t endbyte; /* inclusive */
umode_t i_mode;
if (!fsync_enabled)
return 0;
ret = -EINVAL;
if (flags & ~VALID_FLAGS)
goto out;