On Wed, Sep 21, 2016 at 7:01 PM, Amir Goldstein <amir73il@xxxxxxxxx> wrote: > 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? Sure I can take it. > > 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. Right. I didn't do a thorough audit of ->clone_file_range() implementations, but 1/4 is probably OK. Thanks, Miklos -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
