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author | Darrick J. Wong <darrick.wong@oracle.com> | 2018-10-30 10:41:49 +1100 |
---|---|---|
committer | Dave Chinner <david@fromorbit.com> | 2018-10-30 10:41:49 +1100 |
commit | 42ec3d4c02187a18e27ff94b409ec27234bf2ffd (patch) | |
tree | c9db04db8187c370718a43e6067af0e5aa944500 /fs/ioctl.c | |
parent | 8dde90bca6fca3736ea20109654bcf6dcf2ecf1d (diff) | |
download | linux-stable-42ec3d4c02187a18e27ff94b409ec27234bf2ffd.tar.gz linux-stable-42ec3d4c02187a18e27ff94b409ec27234bf2ffd.tar.bz2 linux-stable-42ec3d4c02187a18e27ff94b409ec27234bf2ffd.zip |
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.c | 10 |
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; |