[mirror_ubuntu-bionic-kernel.git] / fs / sync.c

/*
 * High-level sync()-related operations
 */

#include <linux/kernel.h>
#include <linux/file.h>
#include <linux/fs.h>
#include <linux/slab.h>
#include <linux/export.h>
#include <linux/namei.h>
#include <linux/sched.h>
#include <linux/writeback.h>
#include <linux/syscalls.h>
#include <linux/linkage.h>
#include <linux/pagemap.h>
#include <linux/quotaops.h>
#include <linux/backing-dev.h>
#include "internal.h"

#define VALID_FLAGS (SYNC_FILE_RANGE_WAIT_BEFORE|SYNC_FILE_RANGE_WRITE| \
			SYNC_FILE_RANGE_WAIT_AFTER)

/*
 * Do the filesystem syncing work. For simple filesystems
 * writeback_inodes_sb(sb) just dirties buffers with inodes so we have to
 * submit IO for these buffers via __sync_blockdev(). This also speeds up the
 * wait == 1 case since in that case write_inode() functions do
 * sync_dirty_buffer() and thus effectively write one block at a time.
 */
static int __sync_filesystem(struct super_block *sb, int wait)
{
	if (wait)
		sync_inodes_sb(sb);
	else
		writeback_inodes_sb(sb, WB_REASON_SYNC);

	if (sb->s_op->sync_fs)
		sb->s_op->sync_fs(sb, wait);
	return __sync_blockdev(sb->s_bdev, wait);
}

/*
 * Write out and wait upon all dirty data associated with this
 * superblock.  Filesystem data as well as the underlying block
 * device.  Takes the superblock lock.
 */
int sync_filesystem(struct super_block *sb)
{
	int ret;

	/*
	 * We need to be protected against the filesystem going from
	 * r/o to r/w or vice versa.
	 */
	WARN_ON(!rwsem_is_locked(&sb->s_umount));

	/*
	 * No point in syncing out anything if the filesystem is read-only.
	 */
	if (sb->s_flags & MS_RDONLY)
		return 0;

	ret = __sync_filesystem(sb, 0);
	if (ret < 0)
		return ret;
	return __sync_filesystem(sb, 1);
}
EXPORT_SYMBOL_GPL(sync_filesystem);

static void sync_one_sb(struct super_block *sb, void *arg)
{
	if (!(sb->s_flags & MS_RDONLY))
		__sync_filesystem(sb, *(int *)arg);
}
/*
 * Sync all the data for all the filesystems (called by sys_sync() and
 * emergency sync)
 */
static void sync_filesystems(int wait)
{
	iterate_supers(sync_one_sb, &wait);
}

/*
 * sync everything.  Start out by waking pdflush, because that writes back
 * all queues in parallel.
 */
SYSCALL_DEFINE0(sync)
{
	wakeup_flusher_threads(0, WB_REASON_SYNC);
	sync_filesystems(0);
	sync_filesystems(1);
	if (unlikely(laptop_mode))
		laptop_sync_completion();
	return 0;
}

static void do_sync_work(struct work_struct *work)
{
	/*
	 * Sync twice to reduce the possibility we skipped some inodes / pages
	 * because they were temporarily locked
	 */
	sync_filesystems(0);
	sync_filesystems(0);
	printk("Emergency Sync complete\n");
	kfree(work);
}

void emergency_sync(void)
{
	struct work_struct *work;

	work = kmalloc(sizeof(*work), GFP_ATOMIC);
	if (work) {
		INIT_WORK(work, do_sync_work);
		schedule_work(work);
	}
}

/*
 * sync a single super
 */
SYSCALL_DEFINE1(syncfs, int, fd)
{
	struct file *file;
	struct super_block *sb;
	int ret;
	int fput_needed;

	file = fget_light(fd, &fput_needed);
	if (!file)
		return -EBADF;
	sb = file->f_dentry->d_sb;

	down_read(&sb->s_umount);
	ret = sync_filesystem(sb);
	up_read(&sb->s_umount);

	fput_light(file, fput_needed);
	return ret;
}

/**
 * vfs_fsync_range - helper to sync a range of data & metadata to disk
 * @file:		file to sync
 * @start:		offset in bytes of the beginning of data range to sync
 * @end:		offset in bytes of the end of data range (inclusive)
 * @datasync:		perform only datasync
 *
 * Write back data in range @start..@end and metadata for @file to disk.  If
 * @datasync is set only metadata needed to access modified file data is
 * written.
 */
int vfs_fsync_range(struct file *file, loff_t start, loff_t end, int datasync)
{
	if (!file->f_op || !file->f_op->fsync)
		return -EINVAL;
	return file->f_op->fsync(file, start, end, datasync);
}
EXPORT_SYMBOL(vfs_fsync_range);

/**
 * vfs_fsync - perform a fsync or fdatasync on a file
 * @file:		file to sync
 * @datasync:		only perform a fdatasync operation
 *
 * Write back data and metadata for @file to disk.  If @datasync is
 * set only metadata needed to access modified file data is written.
 */
int vfs_fsync(struct file *file, int datasync)
{
	return vfs_fsync_range(file, 0, LLONG_MAX, datasync);
}
EXPORT_SYMBOL(vfs_fsync);

static int do_fsync(unsigned int fd, int datasync)
{
	struct file *file;
	int ret = -EBADF;
	int fput_needed;

	file = fget_light(fd, &fput_needed);
	if (file) {
		ret = vfs_fsync(file, datasync);
		fput_light(file, fput_needed);
	}
	return ret;
}

SYSCALL_DEFINE1(fsync, unsigned int, fd)
{
	return do_fsync(fd, 0);
}

SYSCALL_DEFINE1(fdatasync, unsigned int, fd)
{
	return do_fsync(fd, 1);
}

/**
 * generic_write_sync - perform syncing after a write if file / inode is sync
 * @file:	file to which the write happened
 * @pos:	offset where the write started
 * @count:	length of the write
 *
 * This is just a simple wrapper about our general syncing function.
 */
int generic_write_sync(struct file *file, loff_t pos, loff_t count)
{
	if (!(file->f_flags & O_DSYNC) && !IS_SYNC(file->f_mapping->host))
		return 0;
	return vfs_fsync_range(file, pos, pos + count - 1,
			       (file->f_flags & __O_SYNC) ? 0 : 1);
}
EXPORT_SYMBOL(generic_write_sync);

/*
 * sys_sync_file_range() permits finely controlled syncing over a segment of
 * a file in the range offset .. (offset+nbytes-1) inclusive.  If nbytes is
 * zero then sys_sync_file_range() will operate from offset out to EOF.
 *
 * The flag bits are:
 *
 * SYNC_FILE_RANGE_WAIT_BEFORE: wait upon writeout of all pages in the range
 * before performing the write.
 *
 * SYNC_FILE_RANGE_WRITE: initiate writeout of all those dirty pages in the
 * range which are not presently under writeback. Note that this may block for
 * significant periods due to exhaustion of disk request structures.
 *
 * SYNC_FILE_RANGE_WAIT_AFTER: wait upon writeout of all pages in the range
 * after performing the write.
 *
 * Useful combinations of the flag bits are:
 *
 * SYNC_FILE_RANGE_WAIT_BEFORE|SYNC_FILE_RANGE_WRITE: ensures that all pages
 * in the range which were dirty on entry to sys_sync_file_range() are placed
 * under writeout.  This is a start-write-for-data-integrity operation.
 *
 * SYNC_FILE_RANGE_WRITE: start writeout of all dirty pages in the range which
 * are not presently under writeout.  This is an asynchronous flush-to-disk
 * operation.  Not suitable for data integrity operations.
 *
 * SYNC_FILE_RANGE_WAIT_BEFORE (or SYNC_FILE_RANGE_WAIT_AFTER): wait for
 * completion of writeout of all pages in the range.  This will be used after an
 * earlier SYNC_FILE_RANGE_WAIT_BEFORE|SYNC_FILE_RANGE_WRITE operation to wait
 * for that operation to complete and to return the result.
 *
 * SYNC_FILE_RANGE_WAIT_BEFORE|SYNC_FILE_RANGE_WRITE|SYNC_FILE_RANGE_WAIT_AFTER:
 * a traditional sync() operation.  This is a write-for-data-integrity operation
 * which will ensure that all pages in the range which were dirty on entry to
 * sys_sync_file_range() are committed to disk.
 *
 *
 * SYNC_FILE_RANGE_WAIT_BEFORE and SYNC_FILE_RANGE_WAIT_AFTER will detect any
 * I/O errors or ENOSPC conditions and will return those to the caller, after
 * clearing the EIO and ENOSPC flags in the address_space.
 *
 * It should be noted that none of these operations write out the file's
 * metadata.  So unless the application is strictly performing overwrites of
 * already-instantiated disk blocks, there are no guarantees here that the data
 * will be available after a crash.
 */
SYSCALL_DEFINE(sync_file_range)(int fd, loff_t offset, loff_t nbytes,
				unsigned int flags)
{
	int ret;
	struct file *file;
	struct address_space *mapping;
	loff_t endbyte;			/* inclusive */
	int fput_needed;
	umode_t i_mode;

	ret = -EINVAL;
	if (flags & ~VALID_FLAGS)
		goto out;

	endbyte = offset + nbytes;

	if ((s64)offset < 0)
		goto out;
	if ((s64)endbyte < 0)
		goto out;
	if (endbyte < offset)
		goto out;

	if (sizeof(pgoff_t) == 4) {
		if (offset >= (0x100000000ULL << PAGE_CACHE_SHIFT)) {
			/*
			 * The range starts outside a 32 bit machine's
			 * pagecache addressing capabilities.  Let it "succeed"
			 */
			ret = 0;
			goto out;
		}
		if (endbyte >= (0x100000000ULL << PAGE_CACHE_SHIFT)) {
			/*
			 * Out to EOF
			 */
			nbytes = 0;
		}
	}

	if (nbytes == 0)
		endbyte = LLONG_MAX;
	else
		endbyte--;		/* inclusive */

	ret = -EBADF;
	file = fget_light(fd, &fput_needed);
	if (!file)
		goto out;

	i_mode = file->f_path.dentry->d_inode->i_mode;
	ret = -ESPIPE;
	if (!S_ISREG(i_mode) && !S_ISBLK(i_mode) && !S_ISDIR(i_mode) &&
			!S_ISLNK(i_mode))
		goto out_put;

	mapping = file->f_mapping;
	if (!mapping) {
		ret = -EINVAL;
		goto out_put;
	}

	ret = 0;
	if (flags & SYNC_FILE_RANGE_WAIT_BEFORE) {
		ret = filemap_fdatawait_range(mapping, offset, endbyte);
		if (ret < 0)
			goto out_put;
	}

	if (flags & SYNC_FILE_RANGE_WRITE) {
		ret = filemap_fdatawrite_range(mapping, offset, endbyte);
		if (ret < 0)
			goto out_put;
	}

	if (flags & SYNC_FILE_RANGE_WAIT_AFTER)
		ret = filemap_fdatawait_range(mapping, offset, endbyte);

out_put:
	fput_light(file, fput_needed);
out:
	return ret;
}
#ifdef CONFIG_HAVE_SYSCALL_WRAPPERS
asmlinkage long SyS_sync_file_range(long fd, loff_t offset, loff_t nbytes,
				    long flags)
{
	return SYSC_sync_file_range((int) fd, offset, nbytes,
				    (unsigned int) flags);
}
SYSCALL_ALIAS(sys_sync_file_range, SyS_sync_file_range);
#endif

/* It would be nice if people remember that not all the world's an i386
   when they introduce new system calls */
SYSCALL_DEFINE(sync_file_range2)(int fd, unsigned int flags,
				 loff_t offset, loff_t nbytes)
{
	return sys_sync_file_range(fd, offset, nbytes, flags);
}
#ifdef CONFIG_HAVE_SYSCALL_WRAPPERS
asmlinkage long SyS_sync_file_range2(long fd, long flags,
				     loff_t offset, loff_t nbytes)
{
	return SYSC_sync_file_range2((int) fd, (unsigned int) flags,
				     offset, nbytes);
}
SYSCALL_ALIAS(sys_sync_file_range2, SyS_sync_file_range2);
#endif
Commit	Line	Data
f79e2abb AM	1	/*
	2	* High-level sync()-related operations
	3	*/
	4
	5	#include <linux/kernel.h>
	6	#include <linux/file.h>
	7	#include <linux/fs.h>
5a0e3ad6	8	#include <linux/slab.h>
630d9c47	9	#include <linux/export.h>
b7ed78f5	10	#include <linux/namei.h>
914e2637	11	#include <linux/sched.h>
f79e2abb AM	12	#include <linux/writeback.h>
	13	#include <linux/syscalls.h>
	14	#include <linux/linkage.h>
	15	#include <linux/pagemap.h>
cf9a2ae8	16	#include <linux/quotaops.h>
5129a469	17	#include <linux/backing-dev.h>
5a3e5cb8	18	#include "internal.h"
f79e2abb AM	19
	20	#define VALID_FLAGS (SYNC_FILE_RANGE_WAIT_BEFORE\|SYNC_FILE_RANGE_WRITE\| \
	21	SYNC_FILE_RANGE_WAIT_AFTER)
	22
c15c54f5	23	/*
d8a8559c JA	24	* Do the filesystem syncing work. For simple filesystems
	25	* writeback_inodes_sb(sb) just dirties buffers with inodes so we have to
	26	* submit IO for these buffers via __sync_blockdev(). This also speeds up the
	27	* wait == 1 case since in that case write_inode() functions do
	28	* sync_dirty_buffer() and thus effectively write one block at a time.
c15c54f5	29	*/
60b0680f	30	static int __sync_filesystem(struct super_block *sb, int wait)
c15c54f5	31	{
5fb324ad	32	if (wait)
d8a8559c	33	sync_inodes_sb(sb);
5fb324ad	34	else
0e175a18	35	writeback_inodes_sb(sb, WB_REASON_SYNC);
5fb324ad	36
c15c54f5 JK	37	if (sb->s_op->sync_fs)
	38	sb->s_op->sync_fs(sb, wait);
	39	return __sync_blockdev(sb->s_bdev, wait);
	40	}
	41
	42	/*
	43	* Write out and wait upon all dirty data associated with this
	44	* superblock. Filesystem data as well as the underlying block
	45	* device. Takes the superblock lock.
	46	*/
60b0680f	47	int sync_filesystem(struct super_block *sb)
c15c54f5 JK	48	{
	49	int ret;
	50
5af7926f CH	51	/*
	52	* We need to be protected against the filesystem going from
	53	* r/o to r/w or vice versa.
	54	*/
	55	WARN_ON(!rwsem_is_locked(&sb->s_umount));
	56
	57	/*
	58	* No point in syncing out anything if the filesystem is read-only.
	59	*/
	60	if (sb->s_flags & MS_RDONLY)
	61	return 0;
	62
60b0680f	63	ret = __sync_filesystem(sb, 0);
c15c54f5 JK	64	if (ret < 0)
c15c54f5 JK	65	return ret;
60b0680f	66	return __sync_filesystem(sb, 1);
c15c54f5	67	}
60b0680f	68	EXPORT_SYMBOL_GPL(sync_filesystem);
c15c54f5	69
01a05b33 AV	70	static void sync_one_sb(struct super_block sb, void arg)
01a05b33 AV	71	{
95f28604	72	if (!(sb->s_flags & MS_RDONLY))
01a05b33 AV	73	__sync_filesystem(sb, (int )arg);
01a05b33 AV	74	}
c15c54f5 JK	75	/*
	76	* Sync all the data for all the filesystems (called by sys_sync() and
	77	* emergency sync)
c15c54f5 JK	78	*/
	79	static void sync_filesystems(int wait)
	80	{
01a05b33	81	iterate_supers(sync_one_sb, &wait);
c15c54f5 JK	82	}
c15c54f5 JK	83
3beab0b4 ZY	84	/*
	85	* sync everything. Start out by waking pdflush, because that writes back
	86	* all queues in parallel.
	87	*/
5cee5815	88	SYSCALL_DEFINE0(sync)
cf9a2ae8	89	{
0e175a18	90	wakeup_flusher_threads(0, WB_REASON_SYNC);
5cee5815 JK	91	sync_filesystems(0);
5cee5815 JK	92	sync_filesystems(1);
cf9a2ae8 DH	93	if (unlikely(laptop_mode))
cf9a2ae8 DH	94	laptop_sync_completion();
cf9a2ae8 DH	95	return 0;
	96	}
	97
a2a9537a JA	98	static void do_sync_work(struct work_struct *work)
a2a9537a JA	99	{
5cee5815 JK	100	/*
	101	* Sync twice to reduce the possibility we skipped some inodes / pages
	102	* because they were temporarily locked
	103	*/
	104	sync_filesystems(0);
	105	sync_filesystems(0);
	106	printk("Emergency Sync complete\n");
a2a9537a JA	107	kfree(work);
	108	}
	109
cf9a2ae8 DH	110	void emergency_sync(void)
cf9a2ae8 DH	111	{
a2a9537a JA	112	struct work_struct *work;
	113
	114	work = kmalloc(sizeof(*work), GFP_ATOMIC);
	115	if (work) {
	116	INIT_WORK(work, do_sync_work);
	117	schedule_work(work);
	118	}
cf9a2ae8 DH	119	}
cf9a2ae8 DH	120
b7ed78f5 SW	121	/*
	122	* sync a single super
	123	*/
	124	SYSCALL_DEFINE1(syncfs, int, fd)
	125	{
	126	struct file *file;
	127	struct super_block *sb;
	128	int ret;
	129	int fput_needed;
	130
	131	file = fget_light(fd, &fput_needed);
	132	if (!file)
	133	return -EBADF;
	134	sb = file->f_dentry->d_sb;
	135
	136	down_read(&sb->s_umount);
	137	ret = sync_filesystem(sb);
	138	up_read(&sb->s_umount);
	139
	140	fput_light(file, fput_needed);
	141	return ret;
	142	}
	143
4c728ef5	144	/**
148f948b	145	* vfs_fsync_range - helper to sync a range of data & metadata to disk
4c728ef5	146	* @file: file to sync
148f948b JK	147	* @start: offset in bytes of the beginning of data range to sync
	148	* @end: offset in bytes of the end of data range (inclusive)
	149	* @datasync: perform only datasync
4c728ef5	150	*
148f948b JK	151	* Write back data in range @start..@end and metadata for @file to disk. If
	152	* @datasync is set only metadata needed to access modified file data is
	153	* written.
4c728ef5	154	*/
8018ab05	155	int vfs_fsync_range(struct file *file, loff_t start, loff_t end, int datasync)
cf9a2ae8	156	{
02c24a82 JB	157	if (!file->f_op \|\| !file->f_op->fsync)
	158	return -EINVAL;
	159	return file->f_op->fsync(file, start, end, datasync);
cf9a2ae8	160	}
148f948b JK	161	EXPORT_SYMBOL(vfs_fsync_range);
	162
	163	/**
	164	* vfs_fsync - perform a fsync or fdatasync on a file
	165	* @file: file to sync
148f948b JK	166	* @datasync: only perform a fdatasync operation
	167	*
	168	* Write back data and metadata for @file to disk. If @datasync is
	169	* set only metadata needed to access modified file data is written.
148f948b	170	*/
8018ab05	171	int vfs_fsync(struct file *file, int datasync)
148f948b	172	{
8018ab05	173	return vfs_fsync_range(file, 0, LLONG_MAX, datasync);
148f948b	174	}
4c728ef5	175	EXPORT_SYMBOL(vfs_fsync);
cf9a2ae8	176
4c728ef5	177	static int do_fsync(unsigned int fd, int datasync)
cf9a2ae8 DH	178	{
	179	struct file *file;
	180	int ret = -EBADF;
c2bd6c11	181	int fput_needed;
cf9a2ae8	182
c2bd6c11	183	file = fget_light(fd, &fput_needed);
cf9a2ae8	184	if (file) {
8018ab05	185	ret = vfs_fsync(file, datasync);
c2bd6c11	186	fput_light(file, fput_needed);
cf9a2ae8 DH	187	}
	188	return ret;
	189	}
	190
a5f8fa9e	191	SYSCALL_DEFINE1(fsync, unsigned int, fd)
cf9a2ae8	192	{
4c728ef5	193	return do_fsync(fd, 0);
cf9a2ae8 DH	194	}
cf9a2ae8 DH	195
a5f8fa9e	196	SYSCALL_DEFINE1(fdatasync, unsigned int, fd)
cf9a2ae8	197	{
4c728ef5	198	return do_fsync(fd, 1);
cf9a2ae8 DH	199	}
cf9a2ae8 DH	200
148f948b JK	201	/**
	202	* generic_write_sync - perform syncing after a write if file / inode is sync
	203	* @file: file to which the write happened
	204	* @pos: offset where the write started
	205	* @count: length of the write
	206	*
	207	* This is just a simple wrapper about our general syncing function.
	208	*/
	209	int generic_write_sync(struct file *file, loff_t pos, loff_t count)
	210	{
6b2f3d1f	211	if (!(file->f_flags & O_DSYNC) && !IS_SYNC(file->f_mapping->host))
148f948b	212	return 0;
8018ab05	213	return vfs_fsync_range(file, pos, pos + count - 1,
6b2f3d1f	214	(file->f_flags & __O_SYNC) ? 0 : 1);
148f948b JK	215	}
	216	EXPORT_SYMBOL(generic_write_sync);
	217
f79e2abb AM	218	/*
	219	* sys_sync_file_range() permits finely controlled syncing over a segment of
	220	* a file in the range offset .. (offset+nbytes-1) inclusive. If nbytes is
	221	* zero then sys_sync_file_range() will operate from offset out to EOF.
	222	*
	223	* The flag bits are:
	224	*
	225	* SYNC_FILE_RANGE_WAIT_BEFORE: wait upon writeout of all pages in the range
	226	* before performing the write.
	227	*
	228	* SYNC_FILE_RANGE_WRITE: initiate writeout of all those dirty pages in the
cce77081 PM	229	* range which are not presently under writeback. Note that this may block for
cce77081 PM	230	* significant periods due to exhaustion of disk request structures.
f79e2abb AM	231	*
	232	* SYNC_FILE_RANGE_WAIT_AFTER: wait upon writeout of all pages in the range
	233	* after performing the write.
	234	*
	235	* Useful combinations of the flag bits are:
	236	*
	237	* SYNC_FILE_RANGE_WAIT_BEFORE\|SYNC_FILE_RANGE_WRITE: ensures that all pages
	238	* in the range which were dirty on entry to sys_sync_file_range() are placed
	239	* under writeout. This is a start-write-for-data-integrity operation.
	240	*
	241	* SYNC_FILE_RANGE_WRITE: start writeout of all dirty pages in the range which
	242	* are not presently under writeout. This is an asynchronous flush-to-disk
	243	* operation. Not suitable for data integrity operations.
	244	*
	245	* SYNC_FILE_RANGE_WAIT_BEFORE (or SYNC_FILE_RANGE_WAIT_AFTER): wait for
	246	* completion of writeout of all pages in the range. This will be used after an
	247	* earlier SYNC_FILE_RANGE_WAIT_BEFORE\|SYNC_FILE_RANGE_WRITE operation to wait
	248	* for that operation to complete and to return the result.
	249	*
	250	* SYNC_FILE_RANGE_WAIT_BEFORE\|SYNC_FILE_RANGE_WRITE\|SYNC_FILE_RANGE_WAIT_AFTER:
	251	* a traditional sync() operation. This is a write-for-data-integrity operation
	252	* which will ensure that all pages in the range which were dirty on entry to
	253	* sys_sync_file_range() are committed to disk.
	254	*
	255	*
	256	* SYNC_FILE_RANGE_WAIT_BEFORE and SYNC_FILE_RANGE_WAIT_AFTER will detect any
	257	* I/O errors or ENOSPC conditions and will return those to the caller, after
	258	* clearing the EIO and ENOSPC flags in the address_space.
	259	*
	260	* It should be noted that none of these operations write out the file's
	261	* metadata. So unless the application is strictly performing overwrites of
	262	* already-instantiated disk blocks, there are no guarantees here that the data
	263	* will be available after a crash.
	264	*/
6673e0c3 HC	265	SYSCALL_DEFINE(sync_file_range)(int fd, loff_t offset, loff_t nbytes,
6673e0c3 HC	266	unsigned int flags)
f79e2abb AM	267	{
	268	int ret;
	269	struct file *file;
7a0ad10c	270	struct address_space *mapping;
f79e2abb AM	271	loff_t endbyte; /* inclusive */
	272	int fput_needed;
	273	umode_t i_mode;
	274
	275	ret = -EINVAL;
	276	if (flags & ~VALID_FLAGS)
	277	goto out;
	278
	279	endbyte = offset + nbytes;
	280
	281	if ((s64)offset < 0)
	282	goto out;
	283	if ((s64)endbyte < 0)
	284	goto out;
	285	if (endbyte < offset)
	286	goto out;
	287
	288	if (sizeof(pgoff_t) == 4) {
	289	if (offset >= (0x100000000ULL << PAGE_CACHE_SHIFT)) {
	290	/*
	291	* The range starts outside a 32 bit machine's
	292	* pagecache addressing capabilities. Let it "succeed"
	293	*/
	294	ret = 0;
	295	goto out;
	296	}
	297	if (endbyte >= (0x100000000ULL << PAGE_CACHE_SHIFT)) {
	298	/*
	299	* Out to EOF
	300	*/
	301	nbytes = 0;
	302	}
	303	}
	304
	305	if (nbytes == 0)
111ebb6e	306	endbyte = LLONG_MAX;
f79e2abb AM	307	else
	308	endbyte--; /* inclusive */
	309
	310	ret = -EBADF;
	311	file = fget_light(fd, &fput_needed);
	312	if (!file)
	313	goto out;
	314
0f7fc9e4	315	i_mode = file->f_path.dentry->d_inode->i_mode;
f79e2abb AM	316	ret = -ESPIPE;
	317	if (!S_ISREG(i_mode) && !S_ISBLK(i_mode) && !S_ISDIR(i_mode) &&
	318	!S_ISLNK(i_mode))
	319	goto out_put;
	320
7a0ad10c CH	321	mapping = file->f_mapping;
	322	if (!mapping) {
	323	ret = -EINVAL;
	324	goto out_put;
	325	}
	326
	327	ret = 0;
	328	if (flags & SYNC_FILE_RANGE_WAIT_BEFORE) {
	329	ret = filemap_fdatawait_range(mapping, offset, endbyte);
	330	if (ret < 0)
	331	goto out_put;
	332	}
	333
	334	if (flags & SYNC_FILE_RANGE_WRITE) {
	335	ret = filemap_fdatawrite_range(mapping, offset, endbyte);
	336	if (ret < 0)
	337	goto out_put;
	338	}
	339
	340	if (flags & SYNC_FILE_RANGE_WAIT_AFTER)
	341	ret = filemap_fdatawait_range(mapping, offset, endbyte);
	342
f79e2abb AM	343	out_put:
	344	fput_light(file, fput_needed);
	345	out:
	346	return ret;
	347	}
6673e0c3 HC	348	#ifdef CONFIG_HAVE_SYSCALL_WRAPPERS
	349	asmlinkage long SyS_sync_file_range(long fd, loff_t offset, loff_t nbytes,
	350	long flags)
	351	{
	352	return SYSC_sync_file_range((int) fd, offset, nbytes,
	353	(unsigned int) flags);
	354	}
	355	SYSCALL_ALIAS(sys_sync_file_range, SyS_sync_file_range);
	356	#endif
f79e2abb	357
edd5cd4a DW	358	/* It would be nice if people remember that not all the world's an i386
edd5cd4a DW	359	when they introduce new system calls */
6673e0c3 HC	360	SYSCALL_DEFINE(sync_file_range2)(int fd, unsigned int flags,
6673e0c3 HC	361	loff_t offset, loff_t nbytes)
edd5cd4a DW	362	{
	363	return sys_sync_file_range(fd, offset, nbytes, flags);
	364	}
6673e0c3 HC	365	#ifdef CONFIG_HAVE_SYSCALL_WRAPPERS
	366	asmlinkage long SyS_sync_file_range2(long fd, long flags,
	367	loff_t offset, loff_t nbytes)
	368	{
	369	return SYSC_sync_file_range2((int) fd, (unsigned int) flags,
	370	offset, nbytes);
	371	}
	372	SYSCALL_ALIAS(sys_sync_file_range2, SyS_sync_file_range2);
	373	#endif