diff options
| -rw-r--r-- | NEWS | 4 | ||||
| -rw-r--r-- | src/copy.c | 80 | ||||
| -rw-r--r-- | tests/Makefile.am | 5 | ||||
| -rwxr-xr-x | tests/cp/fiemap-empty | 89 |
4 files changed, 162 insertions, 16 deletions
@@ -40,6 +40,10 @@ GNU coreutils NEWS -*- outline -*- The sync in only needed on Linux kernels before 2.6.38. [The sync was introduced in coreutils-8.10] + cp now copies empty extents efficiently, when doing a FIEMAP copy. + It no longer reads the zero bytes from the input, and also can efficiently + create a hole in the output file when --sparse=always is specified. + df now aligns columns consistently, and no longer wraps entries with longer device identifiers, over two lines. diff --git a/src/copy.c b/src/copy.c index e839f973f..05f92b3ee 100644 --- a/src/copy.c +++ b/src/copy.c @@ -39,6 +39,7 @@ #include "extent-scan.h" #include "error.h" #include "fcntl--.h" +#include "fiemap.h" #include "file-set.h" #include "filemode.h" #include "filenamecat.h" @@ -330,11 +331,28 @@ extent_copy (int src_fd, int dest_fd, char *buf, size_t buf_size, } unsigned int i; - for (i = 0; i < scan.ei_count; i++) + bool empty_extent = false; + for (i = 0; i < scan.ei_count || empty_extent; i++) { - off_t ext_start = scan.ext_info[i].ext_logical; - uint64_t ext_len = scan.ext_info[i].ext_length; - uint64_t hole_size = ext_start - last_ext_start - last_ext_len; + off_t ext_start; + uint64_t ext_len; + uint64_t hole_size; + + if (i < scan.ei_count) + { + ext_start = scan.ext_info[i].ext_logical; + ext_len = scan.ext_info[i].ext_length; + } + else /* empty extent at EOF. */ + { + i--; + ext_start = last_ext_start + scan.ext_info[i].ext_length; + ext_len = 0; + } + + hole_size = ext_start - last_ext_start - last_ext_len; + + wrote_hole_at_eof = false; if (hole_size) { @@ -346,38 +364,72 @@ extent_copy (int src_fd, int dest_fd, char *buf, size_t buf_size, return false; } - if (sparse_mode != SPARSE_NEVER) + if ((empty_extent && sparse_mode == SPARSE_ALWAYS) + || (!empty_extent && sparse_mode != SPARSE_NEVER)) { if (lseek (dest_fd, ext_start, SEEK_SET) < 0) { error (0, errno, _("cannot lseek %s"), quote (dst_name)); goto fail; } + wrote_hole_at_eof = true; } else { /* When not inducing holes and when there is a hole between the end of the previous extent and the beginning of the current one, write zeros to the destination file. */ - if (! write_zeros (dest_fd, hole_size)) + off_t nzeros = hole_size; + if (empty_extent) + nzeros = MIN (src_total_size - dest_pos, hole_size); + + if (! write_zeros (dest_fd, nzeros)) { error (0, errno, _("%s: write failed"), quote (dst_name)); goto fail; } + + dest_pos = MIN (src_total_size, ext_start); } } last_ext_start = ext_start; - last_ext_len = ext_len; - off_t n_read; - if ( ! sparse_copy (src_fd, dest_fd, buf, buf_size, - sparse_mode == SPARSE_ALWAYS, src_name, dst_name, - ext_len, &n_read, - &wrote_hole_at_eof)) - return false; + /* Treat an unwritten but allocated extent much like a hole. + I.E. don't read, but don't convert to a hole in the destination, + unless SPARSE_ALWAYS. */ + if (scan.ext_info[i].ext_flags & FIEMAP_EXTENT_UNWRITTEN) + { + empty_extent = true; + last_ext_len = 0; + if (ext_len == 0) /* The last extent is empty and processed. */ + empty_extent = false; + } + else + { + off_t n_read; + empty_extent = false; + last_ext_len = ext_len; + + if ( ! sparse_copy (src_fd, dest_fd, buf, buf_size, + sparse_mode == SPARSE_ALWAYS, + src_name, dst_name, ext_len, &n_read, + &wrote_hole_at_eof)) + return false; - dest_pos = ext_start + n_read; + dest_pos = ext_start + n_read; + } + + /* If the file ends with unwritten extents not accounted for in the + size, then skip processing them, and the associated redundant + read() calls which will always return 0. We will need to + remove this when we add fallocate() so that we can maintain + extents beyond the apparent size. */ + if (dest_pos == src_total_size) + { + scan.hit_final_extent = true; + break; + } } /* Release the space allocated to scan->ext_info. */ diff --git a/tests/Makefile.am b/tests/Makefile.am index e7f3fffb1..685eb52b9 100644 --- a/tests/Makefile.am +++ b/tests/Makefile.am @@ -321,8 +321,9 @@ TESTS = \ cp/dir-vs-file \ cp/existing-perm-race \ cp/fail-perm \ - cp/fiemap-perf \ - cp/fiemap-2 \ + cp/fiemap-empty \ + cp/fiemap-perf \ + cp/fiemap-2 \ cp/file-perm-race \ cp/into-self \ cp/link \ diff --git a/tests/cp/fiemap-empty b/tests/cp/fiemap-empty new file mode 100755 index 000000000..f1ed71c71 --- /dev/null +++ b/tests/cp/fiemap-empty @@ -0,0 +1,89 @@ +#!/bin/sh +# Test cp reads unwritten extents efficiently + +# Copyright (C) 2011 Free Software Foundation, Inc. + +# This program is free software: you can redistribute it and/or modify +# it under the terms of the GNU General Public License as published by +# the Free Software Foundation, either version 3 of the License, or +# (at your option) any later version. + +# This program is distributed in the hope that it will be useful, +# but WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +# GNU General Public License for more details. + +# You should have received a copy of the GNU General Public License +# along with this program. If not, see <http://www.gnu.org/licenses/>. + +. "${srcdir=.}/init.sh"; path_prepend_ ../src +print_ver_ cp + +touch fiemap_chk +fiemap_capable_ fiemap_chk || + skip_test_ 'this file system lacks FIEMAP support' +rm fiemap_chk + +# TODO: rather than requiring `fallocate`, possible add +# this functionality to truncate --alloc +fallocate --help >/dev/null || skip_test_ 'The fallocate utility is required' +fallocate -l 1 -n falloc.test || + skip_test_ 'this file system lacks FALLOCATE support' +rm falloc.test + +fallocate -l 600000000 space.test || + skip_test_ 'this test needs at least 600MB free space' + +# Disable this test on old BTRFS (e.g. Fedora 14) +# which reports ordinary extents for unwritten ones. +filefrag space.test || skip_test_ 'the `filefrag` utility is missing' +filefrag -v space.test | grep -F 'unwritten' > /dev/null || + skip_test_ 'this file system does not report empty extents as "unwritten"' + +rm space.test + +# Ensure we read a large empty file quickly +fallocate -l 300000000 empty.big || framework_failure +timeout 3 cp --sparse=always empty.big cp.test || fail=1 +test $(stat -c %s empty.big) = $(stat -c %s cp.test) || fail=1 +rm empty.big cp.test + +# Ensure we handle extents beyond file size correctly. +# Note until we support fallocate, we will not maintain +# the file allocation. Ammend this test when fallocate is supported +fallocate -l 10000000 -n unwritten.withdata || framework_failure +dd count=10 if=/dev/urandom conv=notrunc iflag=fullblock of=unwritten.withdata +cp unwritten.withdata cp.test || fail=1 +test $(stat -c %s unwritten.withdata) = $(stat -c %s cp.test) || fail=1 +cmp unwritten.withdata cp.test || fail=1 +rm unwritten.withdata cp.test + +# The following to generate unaccounted extents followed by a hole, is not +# supported by ext4 at least. The ftruncate discards all extents not +# accounted for in the size. +# fallocate -l 10000000 -n unacc.withholes +# dd count=10 if=/dev/urandom conv=notrunc iflag=fullblock of=unacc.withholes +# truncate -s20000000 unacc.withholes + +# Ensure we handle a hole after empty extents correctly. +# Since all extents are accounted for in the size, +# we can maintain the allocation independently from +# fallocate() support. +fallocate -l 10000000 empty.withholes +truncate -s 20000000 empty.withholes +sectors_per_block=$(expr $(stat -c %o .) / 512) +cp empty.withholes cp.test || fail=1 +test $(stat -c %s empty.withholes) = $(stat -c %s cp.test) || fail=1 +# These are usually equal but can vary by an IO block due to alignment +alloc_diff=$(expr $(stat -c %b empty.withholes) - $(stat -c %b cp.test)) +alloc_diff=$(echo $alloc_diff | tr -d -- -) # abs() +test $alloc_diff -le $sectors_per_block || fail=1 +# Again with SPARSE_ALWAYS +cp --sparse=always empty.withholes cp.test || fail=1 +test $(stat -c %s empty.withholes) = $(stat -c %s cp.test) || fail=1 +# cp.test should take 0 space, but allowing for some systems +# that store default extended attributes in data blocks +test $(stat -c %b cp.test) -le $sectors_per_block || fail=1 +rm empty.withholes cp.test + +Exit $fail |