From 2ea98466491b7609ace297647b07c28d99ef3722 Mon Sep 17 00:00:00 2001 From: Amir Goldstein Date: Fri, 23 Sep 2016 11:38:12 +0300 Subject: [PATCH] ovl: use vfs_clone_file_range() for copy up if possible When copying up within the same fs, try to use vfs_clone_file_range(). This is very efficient when lower and upper are on the same fs with file reflink support. If vfs_clone_file_range() fails for any reason, copy up falls back to the regular data copy code. Tested correct behavior when lower and upper are on: 1. same ext4 (copy) 2. same xfs + reflink patches + mkfs.xfs (copy) 3. same xfs + reflink patches + mkfs.xfs -m reflink=1 (reflink) 4. different xfs + reflink patches + mkfs.xfs -m reflink=1 (copy) For comparison, on my laptop, xfstest overlay/001 (copy up of large sparse files) takes less than 1 second in the xfs reflink setup vs. 25 seconds on the rest of the setups. Signed-off-by: Amir Goldstein Signed-off-by: Miklos Szeredi --- fs/overlayfs/copy_up.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/fs/overlayfs/copy_up.c b/fs/overlayfs/copy_up.c index 36795eed40b0..f18c1a616e9e 100644 --- a/fs/overlayfs/copy_up.c +++ b/fs/overlayfs/copy_up.c @@ -153,6 +153,13 @@ static int ovl_copy_up_data(struct path *old, struct path *new, loff_t len) goto out_fput; } + /* Try to use clone_file_range to clone up within the same fs */ + error = vfs_clone_file_range(old_file, 0, new_file, 0, len); + if (!error) + goto out; + /* Couldn't clone, so now we try to copy the data */ + error = 0; + /* FIXME: copy up sparse files efficiently */ while (len) { size_t this_len = OVL_COPY_UP_CHUNK_SIZE; @@ -177,7 +184,7 @@ static int ovl_copy_up_data(struct path *old, struct path *new, loff_t len) len -= bytes; } - +out: if (!error) error = vfs_fsync(new_file, 0); fput(new_file);