From 76126e2831580d0df20530f4d6f72189bd4f0b9a Mon Sep 17 00:00:00 2001

From: Paul Eggert <eggert@cs.ucla.edu>

Date: Thu, 18 Jun 2020 22:16:24 -0700

Subject: [PATCH] cp: default to COW

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Likewise for ‘install’.  Proposed in Bug#24400, and long past due.

* NEWS:

* doc/coreutils.texi (cp invocation):

* src/copy.h (enum Reflink_type): Document this.

* src/cp.c (cp_option_init):

* src/install.c (cp_option_init): Implement this.

Upstream-commit: 25725f9d41735d176d73a757430739fb71c7d043

Signed-off-by: Kamil Dudka <kdudka@redhat.com>

---

 doc/coreutils.texi | 19 ++++++++++++-------

 src/copy.h         |  4 ++--

 src/cp.c           |  2 +-

 src/install.c      |  2 +-

 4 files changed, 16 insertions(+), 11 deletions(-)

diff --git a/doc/coreutils.texi b/doc/coreutils.texi

index 02e0c1c..2382a16 100644

--- a/doc/coreutils.texi

+++ b/doc/coreutils.texi

@@ -8854,12 +8854,14 @@ The @var{when} value can be one of the following:

 @table @samp

 @item always

-The default behavior: if the copy-on-write operation is not supported

+If the copy-on-write operation is not supported

 then report the failure for each file and exit with a failure status.

+Plain @option{--reflink} is equivalent to @option{--reflink=when}.

 @item auto

 If the copy-on-write operation is not supported then fall back

 to the standard copy behavior.

+This is the default if no @option{--reflink} option is given.

 @item never

 Disable copy-on-write operation and use the standard copy behavior.

@@ -8868,12 +8870,6 @@ Disable copy-on-write operation and use the standard copy behavior.

 This option is overridden by the @option{--link}, @option{--symbolic-link}

 and @option{--attributes-only} options, thus allowing it to be used

 to configure the default data copying behavior for @command{cp}.

-For example, with the following alias, @command{cp} will use the

-minimum amount of space supported by the file system.

-

-@example

-alias cp='cp --reflink=auto --sparse=always'

-@end example

 @item --remove-destination

 @opindex --remove-destination

@@ -8918,6 +8914,15 @@ This is useful in creating a file for use with the @command{mkswap} command,

 since such a file must not have any holes.

 @end table

+For example, with the following alias, @command{cp} will use the

+minimum amount of space supported by the file system.

+(Older versions of @command{cp} can also benefit from

+@option{--reflink=auto} here.)

+

+@example

+alias cp='cp --sparse=always'

+@end example

+

 @optStripTrailingSlashes

 @item -s

diff --git a/src/copy.h b/src/copy.h

index 874d6f7..a0ad494 100644

--- a/src/copy.h

+++ b/src/copy.h

@@ -46,10 +46,10 @@ enum Sparse_type

 /* Control creation of COW files.  */

 enum Reflink_type

 {

-  /* Default to a standard copy.  */

+  /* Do a standard copy.  */

   REFLINK_NEVER,

-  /* Try a COW copy and fall back to a standard copy.  */

+  /* Try a COW copy and fall back to a standard copy; this is the default.  */

   REFLINK_AUTO,

   /* Require a COW copy and fail if not available.  */

diff --git a/src/cp.c b/src/cp.c

index 0193df8..9e7ad14 100644

--- a/src/cp.c

+++ b/src/cp.c

@@ -796,7 +796,7 @@ cp_option_init (struct cp_options *x)

   x->move_mode = false;

   x->install_mode = false;

   x->one_file_system = false;

-  x->reflink_mode = REFLINK_NEVER;

+  x->reflink_mode = REFLINK_AUTO;

   x->preserve_ownership = false;

   x->preserve_links = false;

diff --git a/src/install.c b/src/install.c

index 4ab44a6..aef16ca 100644

--- a/src/install.c

+++ b/src/install.c

@@ -264,7 +264,7 @@ cp_option_init (struct cp_options *x)

 {

   cp_options_default (x);

   x->copy_as_regular = true;

-  x->reflink_mode = REFLINK_NEVER;

+  x->reflink_mode = REFLINK_AUTO;

   x->dereference = DEREF_ALWAYS;

   x->unlink_dest_before_opening = true;

   x->unlink_dest_after_failed_open = false;

-- 

2.25.4