From 42ec3d4c02187a18e27ff94b409ec27234bf2ffd Mon Sep 17 00:00:00 2001 From: "Darrick J. Wong" Date: Tue, 30 Oct 2018 10:41:49 +1100 Subject: 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 Reviewed-by: Amir Goldstein Signed-off-by: Dave Chinner --- fs/overlayfs/copy_up.c | 6 +++--- fs/overlayfs/file.c | 12 ++++++------ 2 files changed, 9 insertions(+), 9 deletions(-) (limited to 'fs/overlayfs') 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; -- cgit v1.2.3