Thanks for the bug report. Although this part of the code is messy and
needs a revamp, in the meantime I installed the attached into the master
branch on Savannah; please give it a try.From b7fc76269bbc830bf96320cd5cca3cfd90d33f68 Mon Sep 17 00:00:00 2001
From: Paul Eggert <egg...@cs.ucla.edu>
Date: Thu, 21 Aug 2025 16:02:10 -0600
Subject: [PATCH] cp: always punch holes that we make
Problem reported by Jeremy Allison <https://bugs.gnu.org/79267>.
* src/copy.c (create_hole, sparse_copy): Omit arg PUNCH_HOLES,
as we always punch holes now. All uses changed.
(lseek_copy): When calling sparse_copy, scan for holes when
sparse_mode == SPARSE_AUTO, as that means we are making holes.
(copy_reg): Always punch any hole made at end.
---
src/copy.c | 21 ++++++++-------------
1 file changed, 8 insertions(+), 13 deletions(-)
diff --git a/src/copy.c b/src/copy.c
index 77f0c561e..e328bd886 100644
--- a/src/copy.c
+++ b/src/copy.c
@@ -253,12 +253,11 @@ punch_hole (int fd, off_t offset, off_t length)
}
/* Create a hole at the end of the file with descriptor FD and name NAME.
- If PUNCH_HOLES, avoid preallocation if requested.
The hole is of size SIZE. Assume FD is already at file end,
and advance FD past the newly-created hole. */
static bool
-create_hole (int fd, char const *name, bool punch_holes, off_t size)
+create_hole (int fd, char const *name, off_t size)
{
off_t file_end = lseek (fd, size, SEEK_CUR);
@@ -272,7 +271,7 @@ create_hole (int fd, char const *name, bool punch_holes, off_t size)
I.e., a previous write() may have preallocated extra space
that the seek above will not discard. A subsequent write() could
then make this allocation permanent. */
- if (punch_holes && punch_hole (fd, file_end - size, size) < 0)
+ if (punch_hole (fd, file_end - size, size) < 0)
{
error (0, errno, _("error deallocating %s"), quoteaf (name));
return false;
@@ -311,7 +310,6 @@ is_CLONENOTSUP (int err)
honoring the MAKE_HOLES setting and using the BUF_SIZE-byte buffer
*ABUF for temporary storage, allocating it lazily if *ABUF is null.
For best results, *ABUF should be well-aligned.
- If PUNCH_HOLES, punch holes in the output.
Copy no more than MAX_N_READ bytes.
If HOLE_SIZE, look for holes in the input; *HOLE_SIZE contains
the size of the current hole so far, and update *HOLE_SIZE
@@ -322,7 +320,7 @@ is_CLONENOTSUP (int err)
print a diagnostic and return false upon error. */
static bool
sparse_copy (int src_fd, int dest_fd, char **abuf, size_t buf_size,
- bool punch_holes, bool allow_reflink,
+ bool allow_reflink,
char const *src_name, char const *dst_name,
uintmax_t max_n_read, off_t *hole_size, off_t *total_n_read)
{
@@ -437,7 +435,7 @@ sparse_copy (int src_fd, int dest_fd, char **abuf, size_t buf_size,
psize += csize;
else if (prev_hole)
{
- if (! create_hole (dest_fd, dst_name, punch_holes, psize))
+ if (! create_hole (dest_fd, dst_name, psize))
return false;
pbuf = cbuf;
psize = csize;
@@ -591,9 +589,7 @@ lseek_copy (int src_fd, int dest_fd, char **abuf, size_t buf_size,
*hole_size += ext_hole_size;
else if (sparse_mode != SPARSE_NEVER)
{
- if (! create_hole (dest_fd, dst_name,
- sparse_mode == SPARSE_ALWAYS,
- ext_hole_size))
+ if (! create_hole (dest_fd, dst_name, ext_hole_size))
return false;
}
else
@@ -619,9 +615,9 @@ lseek_copy (int src_fd, int dest_fd, char **abuf, size_t buf_size,
is conservative and may miss some holes. */
off_t n_read;
if ( ! sparse_copy (src_fd, dest_fd, abuf, buf_size,
- true, allow_reflink, src_name, dst_name,
+ allow_reflink, src_name, dst_name,
ext_len,
- sparse_mode == SPARSE_ALWAYS ? hole_size : nullptr,
+ sparse_mode != SPARSE_NEVER ? hole_size : nullptr,
&n_read))
return false;
@@ -1576,7 +1572,6 @@ copy_reg (char const *src_name, char const *dst_name,
:
#endif
sparse_copy (source_desc, dest_desc, &buf, buf_size,
- x->sparse_mode == SPARSE_ALWAYS,
x->reflink_mode != REFLINK_NEVER,
src_name, dst_name, UINTMAX_MAX,
make_holes ? &hole_size : nullptr, &n_read)))
@@ -1594,7 +1589,7 @@ copy_reg (char const *src_name, char const *dst_name,
return_val = false;
goto close_src_and_dst_desc;
}
- if (x->sparse_mode == SPARSE_ALWAYS
+ if (make_holes
&& punch_hole (dest_desc, n_read - hole_size, hole_size) < 0)
{
error (0, errno, _("error deallocating %s"), quoteaf (dst_name));
--
2.50.1
