[mirror_ubuntu-zesty-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/module.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/buffer_head.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)
{
	/*
	 * This should be safe, as we require bdi backing to actually
	 * write out data in the first place
	 */
	if (sb->s_bdi == &noop_backing_dev_info)
		return 0;

	if (sb->s_qcop && sb->s_qcop->quota_sync)
		sb->s_qcop->quota_sync(sb, -1, wait);

	if (wait)
		sync_inodes_sb(sb);
	else
		writeback_inodes_sb(sb);

	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);
	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;

	file = fget(fd);
	if (file) {
		ret = vfs_fsync(file, datasync);
		fput(file);
	}
	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>
f79e2abb	9	#include <linux/module.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 DH	16	#include <linux/quotaops.h>
cf9a2ae8 DH	17	#include <linux/buffer_head.h>
5129a469	18	#include <linux/backing-dev.h>
5a3e5cb8	19	#include "internal.h"
f79e2abb AM	20
	21	#define VALID_FLAGS (SYNC_FILE_RANGE_WAIT_BEFORE\|SYNC_FILE_RANGE_WRITE\| \
	22	SYNC_FILE_RANGE_WAIT_AFTER)
	23
c15c54f5	24	/*
d8a8559c JA	25	* Do the filesystem syncing work. For simple filesystems
	26	* writeback_inodes_sb(sb) just dirties buffers with inodes so we have to
	27	* submit IO for these buffers via __sync_blockdev(). This also speeds up the
	28	* wait == 1 case since in that case write_inode() functions do
	29	* sync_dirty_buffer() and thus effectively write one block at a time.
c15c54f5	30	*/
60b0680f	31	static int __sync_filesystem(struct super_block *sb, int wait)
c15c54f5	32	{
32a88aa1 JA	33	/*
	34	* This should be safe, as we require bdi backing to actually
	35	* write out data in the first place
	36	*/
95f28604	37	if (sb->s_bdi == &noop_backing_dev_info)
32a88aa1 JA	38	return 0;
32a88aa1 JA	39
5fb324ad CH	40	if (sb->s_qcop && sb->s_qcop->quota_sync)
	41	sb->s_qcop->quota_sync(sb, -1, wait);
	42
	43	if (wait)
d8a8559c	44	sync_inodes_sb(sb);
5fb324ad	45	else
0e3c9a22	46	writeback_inodes_sb(sb);
5fb324ad	47
c15c54f5 JK	48	if (sb->s_op->sync_fs)
	49	sb->s_op->sync_fs(sb, wait);
	50	return __sync_blockdev(sb->s_bdev, wait);
	51	}
	52
	53	/*
	54	* Write out and wait upon all dirty data associated with this
	55	* superblock. Filesystem data as well as the underlying block
	56	* device. Takes the superblock lock.
	57	*/
60b0680f	58	int sync_filesystem(struct super_block *sb)
c15c54f5 JK	59	{
	60	int ret;
	61
5af7926f CH	62	/*
	63	* We need to be protected against the filesystem going from
	64	* r/o to r/w or vice versa.
	65	*/
	66	WARN_ON(!rwsem_is_locked(&sb->s_umount));
	67
	68	/*
	69	* No point in syncing out anything if the filesystem is read-only.
	70	*/
	71	if (sb->s_flags & MS_RDONLY)
	72	return 0;
	73
60b0680f	74	ret = __sync_filesystem(sb, 0);
c15c54f5 JK	75	if (ret < 0)
c15c54f5 JK	76	return ret;
60b0680f	77	return __sync_filesystem(sb, 1);
c15c54f5	78	}
60b0680f	79	EXPORT_SYMBOL_GPL(sync_filesystem);
c15c54f5	80
01a05b33 AV	81	static void sync_one_sb(struct super_block sb, void arg)
01a05b33 AV	82	{
95f28604	83	if (!(sb->s_flags & MS_RDONLY))
01a05b33 AV	84	__sync_filesystem(sb, (int )arg);
01a05b33 AV	85	}
c15c54f5 JK	86	/*
	87	* Sync all the data for all the filesystems (called by sys_sync() and
	88	* emergency sync)
c15c54f5 JK	89	*/
	90	static void sync_filesystems(int wait)
	91	{
01a05b33	92	iterate_supers(sync_one_sb, &wait);
c15c54f5 JK	93	}
c15c54f5 JK	94
3beab0b4 ZY	95	/*
	96	* sync everything. Start out by waking pdflush, because that writes back
	97	* all queues in parallel.
	98	*/
5cee5815	99	SYSCALL_DEFINE0(sync)
cf9a2ae8	100	{
03ba3782	101	wakeup_flusher_threads(0);
5cee5815 JK	102	sync_filesystems(0);
5cee5815 JK	103	sync_filesystems(1);
cf9a2ae8 DH	104	if (unlikely(laptop_mode))
cf9a2ae8 DH	105	laptop_sync_completion();
cf9a2ae8 DH	106	return 0;
	107	}
	108
a2a9537a JA	109	static void do_sync_work(struct work_struct *work)
a2a9537a JA	110	{
5cee5815 JK	111	/*
	112	* Sync twice to reduce the possibility we skipped some inodes / pages
	113	* because they were temporarily locked
	114	*/
	115	sync_filesystems(0);
	116	sync_filesystems(0);
	117	printk("Emergency Sync complete\n");
a2a9537a JA	118	kfree(work);
	119	}
	120
cf9a2ae8 DH	121	void emergency_sync(void)
cf9a2ae8 DH	122	{
a2a9537a JA	123	struct work_struct *work;
	124
	125	work = kmalloc(sizeof(*work), GFP_ATOMIC);
	126	if (work) {
	127	INIT_WORK(work, do_sync_work);
	128	schedule_work(work);
	129	}
cf9a2ae8 DH	130	}
cf9a2ae8 DH	131
b7ed78f5 SW	132	/*
	133	* sync a single super
	134	*/
	135	SYSCALL_DEFINE1(syncfs, int, fd)
	136	{
	137	struct file *file;
	138	struct super_block *sb;
	139	int ret;
	140	int fput_needed;
	141
	142	file = fget_light(fd, &fput_needed);
	143	if (!file)
	144	return -EBADF;
	145	sb = file->f_dentry->d_sb;
	146
	147	down_read(&sb->s_umount);
	148	ret = sync_filesystem(sb);
	149	up_read(&sb->s_umount);
	150
	151	fput_light(file, fput_needed);
	152	return ret;
	153	}
	154
4c728ef5	155	/**
148f948b	156	* vfs_fsync_range - helper to sync a range of data & metadata to disk
4c728ef5	157	* @file: file to sync
148f948b JK	158	* @start: offset in bytes of the beginning of data range to sync
	159	* @end: offset in bytes of the end of data range (inclusive)
	160	* @datasync: perform only datasync
4c728ef5	161	*
148f948b JK	162	* Write back data in range @start..@end and metadata for @file to disk. If
	163	* @datasync is set only metadata needed to access modified file data is
	164	* written.
4c728ef5	165	*/
8018ab05	166	int vfs_fsync_range(struct file *file, loff_t start, loff_t end, int datasync)
cf9a2ae8	167	{
02c24a82 JB	168	if (!file->f_op \|\| !file->f_op->fsync)
	169	return -EINVAL;
	170	return file->f_op->fsync(file, start, end, datasync);
cf9a2ae8	171	}
148f948b JK	172	EXPORT_SYMBOL(vfs_fsync_range);
	173
	174	/**
	175	* vfs_fsync - perform a fsync or fdatasync on a file
	176	* @file: file to sync
148f948b JK	177	* @datasync: only perform a fdatasync operation
	178	*
	179	* Write back data and metadata for @file to disk. If @datasync is
	180	* set only metadata needed to access modified file data is written.
148f948b	181	*/
8018ab05	182	int vfs_fsync(struct file *file, int datasync)
148f948b	183	{
8018ab05	184	return vfs_fsync_range(file, 0, LLONG_MAX, datasync);
148f948b	185	}
4c728ef5	186	EXPORT_SYMBOL(vfs_fsync);
cf9a2ae8	187
4c728ef5	188	static int do_fsync(unsigned int fd, int datasync)
cf9a2ae8 DH	189	{
	190	struct file *file;
	191	int ret = -EBADF;
	192
	193	file = fget(fd);
	194	if (file) {
8018ab05	195	ret = vfs_fsync(file, datasync);
cf9a2ae8 DH	196	fput(file);
	197	}
	198	return ret;
	199	}
	200
a5f8fa9e	201	SYSCALL_DEFINE1(fsync, unsigned int, fd)
cf9a2ae8	202	{
4c728ef5	203	return do_fsync(fd, 0);
cf9a2ae8 DH	204	}
cf9a2ae8 DH	205
a5f8fa9e	206	SYSCALL_DEFINE1(fdatasync, unsigned int, fd)
cf9a2ae8	207	{
4c728ef5	208	return do_fsync(fd, 1);
cf9a2ae8 DH	209	}
cf9a2ae8 DH	210
148f948b JK	211	/**
	212	* generic_write_sync - perform syncing after a write if file / inode is sync
	213	* @file: file to which the write happened
	214	* @pos: offset where the write started
	215	* @count: length of the write
	216	*
	217	* This is just a simple wrapper about our general syncing function.
	218	*/
	219	int generic_write_sync(struct file *file, loff_t pos, loff_t count)
	220	{
6b2f3d1f	221	if (!(file->f_flags & O_DSYNC) && !IS_SYNC(file->f_mapping->host))
148f948b	222	return 0;
8018ab05	223	return vfs_fsync_range(file, pos, pos + count - 1,
6b2f3d1f	224	(file->f_flags & __O_SYNC) ? 0 : 1);
148f948b JK	225	}
	226	EXPORT_SYMBOL(generic_write_sync);
	227
f79e2abb AM	228	/*
	229	* sys_sync_file_range() permits finely controlled syncing over a segment of
	230	* a file in the range offset .. (offset+nbytes-1) inclusive. If nbytes is
	231	* zero then sys_sync_file_range() will operate from offset out to EOF.
	232	*
	233	* The flag bits are:
	234	*
	235	* SYNC_FILE_RANGE_WAIT_BEFORE: wait upon writeout of all pages in the range
	236	* before performing the write.
	237	*
	238	* SYNC_FILE_RANGE_WRITE: initiate writeout of all those dirty pages in the
cce77081 PM	239	* range which are not presently under writeback. Note that this may block for
cce77081 PM	240	* significant periods due to exhaustion of disk request structures.
f79e2abb AM	241	*
	242	* SYNC_FILE_RANGE_WAIT_AFTER: wait upon writeout of all pages in the range
	243	* after performing the write.
	244	*
	245	* Useful combinations of the flag bits are:
	246	*
	247	* SYNC_FILE_RANGE_WAIT_BEFORE\|SYNC_FILE_RANGE_WRITE: ensures that all pages
	248	* in the range which were dirty on entry to sys_sync_file_range() are placed
	249	* under writeout. This is a start-write-for-data-integrity operation.
	250	*
	251	* SYNC_FILE_RANGE_WRITE: start writeout of all dirty pages in the range which
	252	* are not presently under writeout. This is an asynchronous flush-to-disk
	253	* operation. Not suitable for data integrity operations.
	254	*
	255	* SYNC_FILE_RANGE_WAIT_BEFORE (or SYNC_FILE_RANGE_WAIT_AFTER): wait for
	256	* completion of writeout of all pages in the range. This will be used after an
	257	* earlier SYNC_FILE_RANGE_WAIT_BEFORE\|SYNC_FILE_RANGE_WRITE operation to wait
	258	* for that operation to complete and to return the result.
	259	*
	260	* SYNC_FILE_RANGE_WAIT_BEFORE\|SYNC_FILE_RANGE_WRITE\|SYNC_FILE_RANGE_WAIT_AFTER:
	261	* a traditional sync() operation. This is a write-for-data-integrity operation
	262	* which will ensure that all pages in the range which were dirty on entry to
	263	* sys_sync_file_range() are committed to disk.
	264	*
	265	*
	266	* SYNC_FILE_RANGE_WAIT_BEFORE and SYNC_FILE_RANGE_WAIT_AFTER will detect any
	267	* I/O errors or ENOSPC conditions and will return those to the caller, after
	268	* clearing the EIO and ENOSPC flags in the address_space.
	269	*
	270	* It should be noted that none of these operations write out the file's
	271	* metadata. So unless the application is strictly performing overwrites of
	272	* already-instantiated disk blocks, there are no guarantees here that the data
	273	* will be available after a crash.
	274	*/
6673e0c3 HC	275	SYSCALL_DEFINE(sync_file_range)(int fd, loff_t offset, loff_t nbytes,
6673e0c3 HC	276	unsigned int flags)
f79e2abb AM	277	{
	278	int ret;
	279	struct file *file;
7a0ad10c	280	struct address_space *mapping;
f79e2abb AM	281	loff_t endbyte; /* inclusive */
	282	int fput_needed;
	283	umode_t i_mode;
	284
	285	ret = -EINVAL;
	286	if (flags & ~VALID_FLAGS)
	287	goto out;
	288
	289	endbyte = offset + nbytes;
	290
	291	if ((s64)offset < 0)
	292	goto out;
	293	if ((s64)endbyte < 0)
	294	goto out;
	295	if (endbyte < offset)
	296	goto out;
	297
	298	if (sizeof(pgoff_t) == 4) {
	299	if (offset >= (0x100000000ULL << PAGE_CACHE_SHIFT)) {
	300	/*
	301	* The range starts outside a 32 bit machine's
	302	* pagecache addressing capabilities. Let it "succeed"
	303	*/
	304	ret = 0;
	305	goto out;
	306	}
	307	if (endbyte >= (0x100000000ULL << PAGE_CACHE_SHIFT)) {
	308	/*
	309	* Out to EOF
	310	*/
	311	nbytes = 0;
	312	}
	313	}
	314
	315	if (nbytes == 0)
111ebb6e	316	endbyte = LLONG_MAX;
f79e2abb AM	317	else
	318	endbyte--; /* inclusive */
	319
	320	ret = -EBADF;
	321	file = fget_light(fd, &fput_needed);
	322	if (!file)
	323	goto out;
	324
0f7fc9e4	325	i_mode = file->f_path.dentry->d_inode->i_mode;
f79e2abb AM	326	ret = -ESPIPE;
	327	if (!S_ISREG(i_mode) && !S_ISBLK(i_mode) && !S_ISDIR(i_mode) &&
	328	!S_ISLNK(i_mode))
	329	goto out_put;
	330
7a0ad10c CH	331	mapping = file->f_mapping;
	332	if (!mapping) {
	333	ret = -EINVAL;
	334	goto out_put;
	335	}
	336
	337	ret = 0;
	338	if (flags & SYNC_FILE_RANGE_WAIT_BEFORE) {
	339	ret = filemap_fdatawait_range(mapping, offset, endbyte);
	340	if (ret < 0)
	341	goto out_put;
	342	}
	343
	344	if (flags & SYNC_FILE_RANGE_WRITE) {
	345	ret = filemap_fdatawrite_range(mapping, offset, endbyte);
	346	if (ret < 0)
	347	goto out_put;
	348	}
	349
	350	if (flags & SYNC_FILE_RANGE_WAIT_AFTER)
	351	ret = filemap_fdatawait_range(mapping, offset, endbyte);
	352
f79e2abb AM	353	out_put:
	354	fput_light(file, fput_needed);
	355	out:
	356	return ret;
	357	}
6673e0c3 HC	358	#ifdef CONFIG_HAVE_SYSCALL_WRAPPERS
	359	asmlinkage long SyS_sync_file_range(long fd, loff_t offset, loff_t nbytes,
	360	long flags)
	361	{
	362	return SYSC_sync_file_range((int) fd, offset, nbytes,
	363	(unsigned int) flags);
	364	}
	365	SYSCALL_ALIAS(sys_sync_file_range, SyS_sync_file_range);
	366	#endif
f79e2abb	367
edd5cd4a DW	368	/* It would be nice if people remember that not all the world's an i386
edd5cd4a DW	369	when they introduce new system calls */
6673e0c3 HC	370	SYSCALL_DEFINE(sync_file_range2)(int fd, unsigned int flags,
6673e0c3 HC	371	loff_t offset, loff_t nbytes)
edd5cd4a DW	372	{
	373	return sys_sync_file_range(fd, offset, nbytes, flags);
	374	}
6673e0c3 HC	375	#ifdef CONFIG_HAVE_SYSCALL_WRAPPERS
	376	asmlinkage long SyS_sync_file_range2(long fd, long flags,
	377	loff_t offset, loff_t nbytes)
	378	{
	379	return SYSC_sync_file_range2((int) fd, (unsigned int) flags,
	380	offset, nbytes);
	381	}
	382	SYSCALL_ALIAS(sys_sync_file_range2, SyS_sync_file_range2);
	383	#endif