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authorAmir Goldstein <amir73il@gmail.com>2016-09-23 11:38:12 +0300
committerMiklos Szeredi <mszeredi@redhat.com>2016-12-16 11:02:54 +0100
commit2ea98466491b7609ace297647b07c28d99ef3722 (patch)
tree12ffc06a7407573c47653ecc5bbcee4103616709 /fs/overlayfs
parent31c3a7069593b072bd57192b63b62f9a7e994e9a (diff)
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 <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Diffstat (limited to 'fs/overlayfs')
-rw-r--r--fs/overlayfs/copy_up.c9
1 files changed, 8 insertions, 1 deletions
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);