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authorDarrick J. Wong <darrick.wong@oracle.com>2018-10-30 10:41:49 +1100
committerDave Chinner <david@fromorbit.com>2018-10-30 10:41:49 +1100
commit42ec3d4c02187a18e27ff94b409ec27234bf2ffd (patch)
treec9db04db8187c370718a43e6067af0e5aa944500 /fs/ioctl.c
parent8dde90bca6fca3736ea20109654bcf6dcf2ecf1d (diff)
downloadlinux-42ec3d4c02187a18e27ff94b409ec27234bf2ffd.tar.bz2
vfs: make remap_file_range functions take and return bytes completed
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> Signed-off-by: Dave Chinner <david@fromorbit.com>
Diffstat (limited to 'fs/ioctl.c')
-rw-r--r--fs/ioctl.c10
1 files changed, 9 insertions, 1 deletions
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;