[PATCH v2 13/29] vfs: make remap_file_range functions take and return bytes completed

Darrick J. Wong
2018-10-19T03:00:28Z

Change the remap_file_range functions to take a number of bytes to
operate upon and return the number of bytes they operated on. This is a
requirement for allowing fs implementations to return short clone/dedupe
results to the user, which will enable us to obey resource limits in a
graceful manner.

A subsequent patch will enable copy_file_range to signal to the
->clone_file_range implementation that it can handle a short length,
which will be returned in the function's return value. For now the
short return is not implemented anywhere so the behavior won't change --
either copy_file_range manages to clone the entire range or it tries an
alternative.

Neither clone ioctl can take advantage of this, alas.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
---
Documentation/filesystems/vfs.txt | 10 ++++----
fs/btrfs/ctree.h | 6 ++---
fs/btrfs/ioctl.c | 13 ++++++----
fs/cifs/cifsfs.c | 6 ++---
fs/ioctl.c | 10 +++++++-
fs/nfs/nfs4file.c | 6 ++---
fs/nfsd/vfs.c | 8 +++++-
fs/ocfs2/file.c | 16 ++++++------
fs/ocfs2/refcounttree.c | 2 +-
fs/ocfs2/refcounttree.h | 2 +-
fs/overlayfs/copy_up.c | 6 ++---
fs/overlayfs/file.c | 12 +++++----
fs/read_write.c | 49 ++++++++++++++++++++-----------------
fs/xfs/xfs_file.c | 9 +++++--
fs/xfs/xfs_reflink.c | 4 ++-
fs/xfs/xfs_reflink.h | 2 +-
include/linux/fs.h | 27 +++++++++++---------
mm/filemap.c | 2 +-
18 files changed, 108 insertions(+), 82 deletions(-)

diff --git a/Documentation/filesystems/vfs.txt b/Documentation/filesystems/vfs.txt
index 6f5babfee27b..1bd2919deaca 100644
--- a/Documentation/filesystems/vfs.txt
+++ b/Documentation/filesystems/vfs.txt
@@ -883,9 +883,9 @@ struct file_operations {
unsigned (*mmap_capabilities)(struct file *);
#endif
ssize_t (*copy_file_range)(struct file *, loff_t, struct file *, loff_t, size_t, unsigned int);
- int (*remap_file_range)(struct file *file_in, loff_t pos_in,
- struct file *file_out, loff_t pos_out,
- u64 len, unsigned int remap_flags);
+ loff_t (*remap_file_range)(struct file *file_in, loff_t pos_in,
+ struct file *file_out, loff_t pos_out,
+ loff_t len, unsigned int remap_flags);
int (*fadvise)(struct file *, loff_t, loff_t, int);
};

@@ -966,8 +966,8 @@ otherwise noted.
implementation should remap len bytes at pos_in of the source file into
the dest file at pos_out. Implementations must handle callers passing
in len == 0; this means "remap to the end of the source file". The
- return value should be zero if all bytes were remapped, or the usual
- negative error code if the remapping did not succeed completely.
+ return value should the number of bytes remapped, or the usual
+ negative error code if errors occurred before any bytes were remapped.
The remap_flags parameter accepts REMAP_FILE_* flags. If
REMAP_FILE_DEDUP is set then the implementation must only remap if the
requested file ranges have identical contents.
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 124a05662fc2..771a961d77ad 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -3247,9 +3247,9 @@ int btrfs_dirty_pages(struct inode *inode, struct page **pages,
size_t num_pages, loff_t pos, size_t write_bytes,
struct extent_state **cached);
int btrfs_fdatawrite_range(struct inode *inode, loff_t start, loff_t end);
-int btrfs_remap_file_range(struct file *file_in, loff_t pos_in,
- struct file *file_out, loff_t pos_out, u64 len,
- unsigned int remap_flags);
+loff_t btrfs_remap_file_range(struct file *file_in, loff_t pos_in,
+ struct file *file_out, loff_t pos_out,
+ loff_t len, unsigned int remap_flags);

/* tree-defrag.c */
int btrfs_defrag_leaves(struct btrfs_trans_handle *trans,
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index bfd99c66723e..b0c513e10977 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -4328,10 +4328,12 @@ static noinline int btrfs_clone_files(struct file *file, struct file *file_src,
return ret;
}

-int btrfs_remap_file_range(struct file *src_file, loff_t off,
- struct file *dst_file, loff_t destoff, u64 len,
+loff_t btrfs_remap_file_range(struct file *src_file, loff_t off,
+ struct file *dst_file, loff_t destoff, loff_t len,
unsigned int remap_flags)
{
+ int ret;
+
if (remap_flags & ~(REMAP_FILE_DEDUP | REMAP_FILE_ADVISORY))
return -EINVAL;

@@ -4349,10 +4351,11 @@ int btrfs_remap_file_range(struct file *src_file, loff_t off,
return -EINVAL;
}

- return btrfs_extent_same(src, off, len, dst, destoff);
+ ret = btrfs_extent_same(src, off, len, dst, destoff);
+ } else {
+ ret = btrfs_clone_files(dst_file, src_file, off, len, destoff);
}
-
- return btrfs_clone_files(dst_file, src_file, off, len, destoff);
+ return ret < 0 ? ret : len;
}

static long btrfs_ioctl_default_subvol(struct file *file, void __user *argp)
diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c
index e8144d0dcde2..5ca71c6c8be2 100644
--- a/fs/cifs/cifsfs.c
+++ b/fs/cifs/cifsfs.c
@@ -975,8 +975,8 @@ const struct inode_operations cifs_symlink_inode_ops = {
.listxattr = cifs_listxattr,
};

-static int cifs_remap_file_range(struct file *src_file, loff_t off,
- struct file *dst_file, loff_t destoff, u64 len,
+static loff_t cifs_remap_file_range(struct file *src_file, loff_t off,
+ struct file *dst_file, loff_t destoff, loff_t len,
unsigned int remap_flags)
{
struct inode *src_inode = file_inode(src_file);
@@ -1029,7 +1029,7 @@ static int cifs_remap_file_range(struct file *src_file, loff_t off,
unlock_two_nondirectories(src_inode, target_inode);
out:
free_xid(xid);
- return rc;
+ return rc < 0 ? rc : len;
}

ssize_t cifs_file_copychunk_range(unsigned int xid,
diff --git a/fs/ioctl.c b/fs/ioctl.c
index 2005529af560..72537b68c272 100644
--- a/fs/ioctl.c
+++ b/fs/ioctl.c
@@ -223,6 +223,7 @@ static long ioctl_file_clone(struct file *dst_file, unsigned long srcfd,
u64 off, u64 olen, u64 destoff)
{
struct fd src_file = fdget(srcfd);
+ loff_t cloned;
int ret;

if (!src_file.file)
@@ -230,7 +231,14 @@ static long ioctl_file_clone(struct file *dst_file, unsigned long srcfd,
ret = -EXDEV;
if (src_file.file->f_path.mnt != dst_file->f_path.mnt)
goto fdput;
- ret = vfs_clone_file_range(src_file.file, off, dst_file, destoff, olen);
+ cloned = vfs_clone_file_range(src_file.file, off, dst_file, destoff,
+ olen);
+ if (cloned < 0)
+ ret = cloned;
+ else if (olen && cloned != olen)
+ ret = -EINVAL;
+ else
+ ret = 0;
fdput:
fdput(src_file);
return ret;
diff --git a/fs/nfs/nfs4file.c b/fs/nfs/nfs4file.c
index ae5780ce41dc..46d691ba04bc 100644
--- a/fs/nfs/nfs4file.c
+++ b/fs/nfs/nfs4file.c
@@ -180,8 +180,8 @@ static long nfs42_fallocate(struct file *filep, int mode, loff_t offset, loff_t
return nfs42_proc_allocate(filep, offset, len);
}

-static int nfs42_remap_file_range(struct file *src_file, loff_t src_off,
- struct file *dst_file, loff_t dst_off, u64 count,
+static loff_t nfs42_remap_file_range(struct file *src_file, loff_t src_off,
+ struct file *dst_file, loff_t dst_off, loff_t count,
unsigned int remap_flags)
{
struct inode *dst_inode = file_inode(dst_file);
@@ -244,7 +244,7 @@ static int nfs42_remap_file_range(struct file *src_file, loff_t src_off,
inode_unlock(src_inode);
}
out:
- return ret;
+ return ret < 0 ? ret : count;
}
#endif /* CONFIG_NFS_V4_2 */

diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index b53e76391e52..ac6cb6101cbe 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -541,8 +541,12 @@ __be32 nfsd4_set_nfs4_label(struct svc_rqst *rqstp, struct svc_fh *fhp,
__be32 nfsd4_clone_file_range(struct file *src, u64 src_pos, struct file *dst,
u64 dst_pos, u64 count)
{
- return nfserrno(vfs_clone_file_range(src, src_pos, dst, dst_pos,
- count));
+ loff_t cloned;
+
+ cloned = vfs_clone_file_range(src, src_pos, dst, dst_pos, count);
+ if (count && cloned != count)
+ cloned = -EINVAL;
+ return nfserrno(cloned < 0 ? cloned : 0);
}

ssize_t nfsd_copy_file_range(struct file *src, u64 src_pos, struct file *dst,
diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c
index 9809b0e5746f..fbaeafe44b5f 100644
--- a/fs/ocfs2/file.c
+++ b/fs/ocfs2/file.c
@@ -2527,18 +2527,18 @@ static loff_t ocfs2_file_llseek(struct file *file, loff_t offset, int whence)
return offset;
}

-static int ocfs2_remap_file_range(struct file *file_in,
- loff_t pos_in,
- struct file *file_out,
- loff_t pos_out,
- u64 len,
- unsigned int remap_flags)
+static loff_t ocfs2_remap_file_range(struct file *file_in, loff_t pos_in,
+ struct file *file_out, loff_t pos_out,
+ loff_t len, unsigned int remap_flags)
{
+ int ret;
+
if (remap_flags & ~(REMAP_FILE_DEDUP | REMAP_FILE_ADVISORY))
return -EINVAL;

- return ocfs2_reflink_remap_range(file_in, pos_in, file_out, pos_out,
- len, remap_flags);
+ ret = ocfs2_reflink_remap_range(file_in, pos_in, file_out, pos_out,
+ len, remap_flags);
+ return ret < 0 ? ret : len;
}

const struct inode_operations ocfs2_file_iops = {
diff --git a/fs/ocfs2/refcounttree.c b/fs/ocfs2/refcounttree.c
index df9781567ec0..6a42c04ac0ab 100644
--- a/fs/ocfs2/refcounttree.c
+++ b/fs/ocfs2/refcounttree.c
@@ -4824,7 +4824,7 @@ int ocfs2_reflink_remap_range(struct file *file_in,
loff_t pos_in,
struct file *file_out,
loff_t pos_out,
- u64 len,
+ loff_t len,
unsigned int remap_flags)
{
struct inode *inode_in = file_inode(file_in);
diff --git a/fs/ocfs2/refcounttree.h b/fs/ocfs2/refcounttree.h
index d2c5f526edff..eb65c1d0843c 100644
--- a/fs/ocfs2/refcounttree.h
+++ b/fs/ocfs2/refcounttree.h
@@ -119,7 +119,7 @@ int ocfs2_reflink_remap_range(struct file *file_in,
loff_t pos_in,
struct file *file_out,
loff_t pos_out,
- u64 len,
+ loff_t len,
unsigned int remap_flags);

#endif /* OCFS2_REFCOUNTTREE_H */
diff --git a/fs/overlayfs/copy_up.c b/fs/overlayfs/copy_up.c
index 1cc797a08a5b..8750b7235516 100644
--- a/fs/overlayfs/copy_up.c
+++ b/fs/overlayfs/copy_up.c
@@ -125,6 +125,7 @@ static int ovl_copy_up_data(struct path *old, struct path *new, loff_t len)
struct file *new_file;
loff_t old_pos = 0;
loff_t new_pos = 0;
+ loff_t cloned;
int error = 0;

if (len == 0)
@@ -141,11 +142,10 @@ static int ovl_copy_up_data(struct path *old, struct path *new, loff_t len)
}

/* Try to use clone_file_range to clone up within the same fs */
- error = do_clone_file_range(old_file, 0, new_file, 0, len);
- if (!error)
+ cloned = do_clone_file_range(old_file, 0, new_file, 0, len);
+ if (cloned == len)
goto out;
/* Couldn't clone, so now we try to copy the data */
- error = 0;

/* FIXME: copy up sparse files efficiently */
while (len) {
diff --git a/fs/overlayfs/file.c b/fs/overlayfs/file.c
index fffb36fd5920..6c3fec6168e9 100644
--- a/fs/overlayfs/file.c
+++ b/fs/overlayfs/file.c
@@ -434,14 +434,14 @@ enum ovl_copyop {
OVL_DEDUPE,
};

-static ssize_t ovl_copyfile(struct file *file_in, loff_t pos_in,
+static loff_t ovl_copyfile(struct file *file_in, loff_t pos_in,
struct file *file_out, loff_t pos_out,
- u64 len, unsigned int flags, enum ovl_copyop op)
+ loff_t len, unsigned int flags, enum ovl_copyop op)
{
struct inode *inode_out = file_inode(file_out);
struct fd real_in, real_out;
const struct cred *old_cred;
- ssize_t ret;
+ loff_t ret;

ret = ovl_real_fdget(file_out, &real_out);
if (ret)
@@ -489,9 +489,9 @@ static ssize_t ovl_copy_file_range(struct file *file_in, loff_t pos_in,
OVL_COPY);
}

-static int ovl_remap_file_range(struct file *file_in, loff_t pos_in,
- struct file *file_out, loff_t pos_out,
- u64 len, unsigned int remap_flags)
+static loff_t ovl_remap_file_range(struct file *file_in, loff_t pos_in,
+ struct file *file_out, loff_t pos_out,
+ loff_t len, unsigned int remap_flags)
{
enum ovl_copyop op;

diff --git a/fs/read_write.c b/fs/read_write.c
index b61bd3fc7154..356641afa487 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -1589,10 +1589,13 @@ ssize_t vfs_copy_file_range(struct file *file_in, loff_t pos_in,
* more efficient if both clone and copy are supported (e.g. NFS).
*/
if (file_in->f_op->remap_file_range) {
- ret = file_in->f_op->remap_file_range(file_in, pos_in,
- file_out, pos_out, len, 0);
- if (ret == 0) {
- ret = len;
+ loff_t cloned;
+
+ cloned = file_in->f_op->remap_file_range(file_in, pos_in,
+ file_out, pos_out,
+ min_t(loff_t, MAX_RW_COUNT, len), 0);
+ if (cloned > 0) {
+ ret = cloned;
goto done;
}
}
@@ -1686,11 +1689,12 @@ SYSCALL_DEFINE6(copy_file_range, int, fd_in, loff_t __user *, off_in,
return ret;
}

-static int remap_verify_area(struct file *file, loff_t pos, u64 len, bool write)
+static int remap_verify_area(struct file *file, loff_t pos, loff_t len,
+ bool write)
{
struct inode *inode = file_inode(file);

- if (unlikely(pos < 0))
+ if (unlikely(pos < 0 || len < 0))
return -EINVAL;

if (unlikely((loff_t) (pos + len) < 0))
@@ -1721,7 +1725,7 @@ static int remap_verify_area(struct file *file, loff_t pos, u64 len, bool write)
static int generic_remap_check_len(struct inode *inode_in,
struct inode *inode_out,
loff_t pos_out,
- u64 *len,
+ loff_t *len,
unsigned int remap_flags)
{
u64 blkmask = i_blocksize(inode_in) - 1;
@@ -1747,7 +1751,7 @@ static int generic_remap_check_len(struct inode *inode_in,
*/
int generic_remap_file_range_prep(struct file *file_in, loff_t pos_in,
struct file *file_out, loff_t pos_out,
- u64 *len, unsigned int remap_flags)
+ loff_t *len, unsigned int remap_flags)
{
struct inode *inode_in = file_inode(file_in);
struct inode *inode_out = file_inode(file_out);
@@ -1843,12 +1847,12 @@ int generic_remap_file_range_prep(struct file *file_in, loff_t pos_in,
}
EXPORT_SYMBOL(generic_remap_file_range_prep);

-int do_clone_file_range(struct file *file_in, loff_t pos_in,
- struct file *file_out, loff_t pos_out, u64 len)
+loff_t do_clone_file_range(struct file *file_in, loff_t pos_in,
+ struct file *file_out, loff_t pos_out, loff_t len)
{
struct inode *inode_in = file_inode(file_in);
struct inode *inode_out = file_inode(file_out);
- int ret;
+ loff_t ret;

if (S_ISDIR(inode_in->i_mode) || S_ISDIR(inode_out->i_mode))
return -EISDIR;
@@ -1881,19 +1885,19 @@ int do_clone_file_range(struct file *file_in, loff_t pos_in,

ret = file_in->f_op->remap_file_range(file_in, pos_in,
file_out, pos_out, len, 0);
- if (!ret) {
- fsnotify_access(file_in);
- fsnotify_modify(file_out);
- }
+ if (ret < 0)
+ return ret;

+ fsnotify_access(file_in);
+ fsnotify_modify(file_out);
return ret;
}
EXPORT_SYMBOL(do_clone_file_range);

-int vfs_clone_file_range(struct file *file_in, loff_t pos_in,
- struct file *file_out, loff_t pos_out, u64 len)
+loff_t vfs_clone_file_range(struct file *file_in, loff_t pos_in,
+ struct file *file_out, loff_t pos_out, loff_t len)
{
- int ret;
+ loff_t ret;

file_start_write(file_out);
ret = do_clone_file_range(file_in, pos_in, file_out, pos_out, len);
@@ -1999,10 +2003,11 @@ int vfs_dedupe_file_range_compare(struct inode *src, loff_t srcoff,
}
EXPORT_SYMBOL(vfs_dedupe_file_range_compare);

-int vfs_dedupe_file_range_one(struct file *src_file, loff_t src_pos,
- struct file *dst_file, loff_t dst_pos, u64 len)
+loff_t vfs_dedupe_file_range_one(struct file *src_file, loff_t src_pos,
+ struct file *dst_file, loff_t dst_pos,
+ loff_t len)
{
- s64 ret;
+ loff_t ret;

ret = mnt_want_write_file(dst_file);
if (ret)
@@ -2051,7 +2056,7 @@ int vfs_dedupe_file_range(struct file *file, struct file_dedupe_range *same)
int i;
int ret;
u16 count = same->dest_count;
- int deduped;
+ loff_t deduped;

if (!(file->f_mode & FMODE_READ))
return -EINVAL;
diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index 20314eb4677a..38fde4e11714 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -919,20 +919,23 @@ xfs_file_fallocate(
return error;
}

-STATIC int
+STATIC loff_t
xfs_file_remap_range(
struct file *file_in,
loff_t pos_in,
struct file *file_out,
loff_t pos_out,
- u64 len,
+ loff_t len,
unsigned int remap_flags)
{
+ int ret;
+
if (remap_flags & ~(REMAP_FILE_DEDUP | REMAP_FILE_ADVISORY))
return -EINVAL;

- return xfs_reflink_remap_range(file_in, pos_in, file_out, pos_out,
+ ret = xfs_reflink_remap_range(file_in, pos_in, file_out, pos_out,
len, remap_flags);
+ return ret < 0 ? ret : len;
}

STATIC int
diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c
index 2d7dd8b28d7c..3dbe5fb7e9c0 100644
--- a/fs/xfs/xfs_reflink.c
+++ b/fs/xfs/xfs_reflink.c
@@ -1296,7 +1296,7 @@ xfs_reflink_remap_prep(
loff_t pos_in,
struct file *file_out,
loff_t pos_out,
- u64 *len,
+ loff_t *len,
unsigned int remap_flags)
{
struct inode *inode_in = file_inode(file_in);
@@ -1387,7 +1387,7 @@ xfs_reflink_remap_range(
loff_t pos_in,
struct file *file_out,
loff_t pos_out,
- u64 len,
+ loff_t len,
unsigned int remap_flags)
{
struct inode *inode_in = file_inode(file_in);
diff --git a/fs/xfs/xfs_reflink.h b/fs/xfs/xfs_reflink.h
index 6f82d628bf17..c3c46c276fe1 100644
--- a/fs/xfs/xfs_reflink.h
+++ b/fs/xfs/xfs_reflink.h
@@ -28,7 +28,7 @@ extern int xfs_reflink_end_cow(struct xfs_inode *ip, xfs_off_t offset,
xfs_off_t count);
extern int xfs_reflink_recover_cow(struct xfs_mount *mp);
extern int xfs_reflink_remap_range(struct file *file_in, loff_t pos_in,
- struct file *file_out, loff_t pos_out, u64 len,
+ struct file *file_out, loff_t pos_out, loff_t len,
unsigned int remap_flags);
extern int xfs_reflink_inode_has_shared_extents(struct xfs_trans *tp,
struct xfs_inode *ip, bool *has_shared);
diff --git a/include/linux/fs.h b/include/linux/fs.h
index c5435ca81132..c72d8c3c065a 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1777,9 +1777,9 @@ struct file_operations {
#endif
ssize_t (*copy_file_range)(struct file *, loff_t, struct file *,
loff_t, size_t, unsigned int);
- int (*remap_file_range)(struct file *file_in, loff_t pos_in,
- struct file *file_out, loff_t pos_out,
- u64 len, unsigned int remap_flags);
+ loff_t (*remap_file_range)(struct file *file_in, loff_t pos_in,
+ struct file *file_out, loff_t pos_out,
+ loff_t len, unsigned int remap_flags);
int (*fadvise)(struct file *, loff_t, loff_t, int);
} __randomize_layout;

@@ -1844,19 +1844,22 @@ extern ssize_t vfs_copy_file_range(struct file *, loff_t , struct file *,
loff_t, size_t, unsigned int);
extern int generic_remap_file_range_prep(struct file *file_in, loff_t pos_in,
struct file *file_out, loff_t pos_out,
- u64 *count, unsigned int remap_flags);
-extern int do_clone_file_range(struct file *file_in, loff_t pos_in,
- struct file *file_out, loff_t pos_out, u64 len);
-extern int vfs_clone_file_range(struct file *file_in, loff_t pos_in,
- struct file *file_out, loff_t pos_out, u64 len);
+ loff_t *count,
+ unsigned int remap_flags);
+extern loff_t do_clone_file_range(struct file *file_in, loff_t pos_in,
+ struct file *file_out, loff_t pos_out,
+ loff_t len);
+extern loff_t vfs_clone_file_range(struct file *file_in, loff_t pos_in,
+ struct file *file_out, loff_t pos_out,
+ loff_t len);
extern int vfs_dedupe_file_range_compare(struct inode *src, loff_t srcoff,
struct inode *dest, loff_t destoff,
loff_t len, bool *is_same);
extern int vfs_dedupe_file_range(struct file *file,
struct file_dedupe_range *same);
-extern int vfs_dedupe_file_range_one(struct file *src_file, loff_t src_pos,
- struct file *dst_file, loff_t dst_pos,
- u64 len);
+extern loff_t vfs_dedupe_file_range_one(struct file *src_file, loff_t src_pos,
+ struct file *dst_file, loff_t dst_pos,
+ loff_t len);

struct super_operations {
@@ -2986,7 +2989,7 @@ extern int generic_file_readonly_mmap(struct file *, struct vm_area_struct *);
extern ssize_t generic_write_checks(struct kiocb *, struct iov_iter *);
extern int generic_remap_checks(struct file *file_in, loff_t pos_in,
struct file *file_out, loff_t pos_out,
- uint64_t *count, unsigned int remap_flags);
+ loff_t *count, unsigned int remap_flags);
extern ssize_t generic_file_read_iter(struct kiocb *, struct iov_iter *);
extern ssize_t __generic_file_write_iter(struct kiocb *, struct iov_iter *);
extern ssize_t generic_file_write_iter(struct kiocb *, struct iov_iter *);
diff --git a/mm/filemap.c b/mm/filemap.c
index fa2d871a1b34..2e4dcebe7253 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -2994,7 +2994,7 @@ EXPORT_SYMBOL(generic_write_checks);
*/
int generic_remap_checks(struct file *file_in, loff_t pos_in,
struct file *file_out, loff_t pos_out,
- uint64_t *req_count, unsigned int remap_flags)
+ loff_t *req_count, unsigned int remap_flags)
{
struct inode *inode_in = file_in->f_mapping->host;
struct inode *inode_out = file_out->f_mapping->host;