On Wed, Sep 21, 2016 at 6:09 PM, Miklos Szeredi <miklos@xxxxxxxxxx> wrote: > On Wed, Sep 14, 2016 at 2:43 PM, Amir Goldstein <amir73il@xxxxxxxxx> wrote: >> 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 because >> lower and upper are not on the same fs or if fs has no reflink support, >> 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@xxxxxxxxx> >> --- >> fs/overlayfs/copy_up.c | 12 +++++++++++- >> 1 file changed, 11 insertions(+), 1 deletion(-) >> >> diff --git a/fs/overlayfs/copy_up.c b/fs/overlayfs/copy_up.c >> index 43fdc27..ba039f8 100644 >> --- a/fs/overlayfs/copy_up.c >> +++ b/fs/overlayfs/copy_up.c >> @@ -136,6 +136,16 @@ 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; >> + /* If we can clone but clone failed - abort */ >> + if (error != -EXDEV && error != -EOPNOTSUPP) >> + goto out; > > Would be safer to fall back on any error. > Agreed. Dave, since you suggested the 'softer' fall back, do you have any objections? > Otherwise ACK. > Will you be taking this to your tree? Please note that this patch depends on patch v3 1/4, because vfs_clone_file_range() in current mainline fails to clone from lower to upper due to upper and lower being private mount clones and therefore not the same f_path.mnt. Thanks, Amir. -- To unsubscribe from this list: send the line "unsubscribe linux-unionfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
