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authorDarrick J. Wong <darrick.wong@oracle.com>2018-10-30 02:41:49 +0300
committerDave Chinner <david@fromorbit.com>2018-10-30 02:41:49 +0300
commit42ec3d4c02187a18e27ff94b409ec27234bf2ffd (patch)
treec9db04db8187c370718a43e6067af0e5aa944500 /fs/overlayfs
parent8dde90bca6fca3736ea20109654bcf6dcf2ecf1d (diff)
downloadlinux-42ec3d4c02187a18e27ff94b409ec27234bf2ffd.tar.xz
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/overlayfs')
-rw-r--r--fs/overlayfs/copy_up.c6
-rw-r--r--fs/overlayfs/file.c12
2 files changed, 9 insertions, 9 deletions
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;