Using sync() on unpack causes _all_ filesystems to be sync'd, which is
not so great when one of those is a thumb drive, mounted over a
network, or otherwise slow. Remove the sync-instead-of-fsync codepath
to simplify maintenance.

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
---
configure.ac | 1 -
debian/changelog | 4 ++++
m4/dpkg-funcs.m4 | 28 ----------------------------
src/archives.c | 8 --------
4 files changed, 4 insertions(+), 37 deletions(-)

diff --git a/configure.ac b/configure.ac
index b5d9df3..96c6c5e 100644
--- a/configure.ac
+++ b/configure.ac
@@ -77,7 +77,6 @@ DPKG_DECL_SYS_SIGLIST
# Checks for library functions.
DPKG_FUNC_VA_COPY
DPKG_FUNC_C99_SNPRINTF
-DPKG_FUNC_SYNC_SYNC
DPKG_CHECK_DECL([offsetof], [stddef.h])
DPKG_CHECK_DECL([WCOREDUMP], [sys/wait.h])
DPKG_CHECK_DECL([TIOCNOTTY], [sys/ioctl.h])
diff --git a/debian/changelog b/debian/changelog
index 33f9454..e309591 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -23,6 +23,10 @@ dpkg (1.16.0) UNRELEASED; urgency=low
Thanks to Oxan van Leeuwen <oxan@oxanvanleeuwen.nl> who wrote it
as part of the Google Code In program.

+ [ Jonathan Nieder ]
+ * Remove support for use of synchronous sync(2), as it is too much
+ trouble to maintain.
+
[ Updated programs translations ]
* Swedish (Peter Krefting).

diff --git a/m4/dpkg-funcs.m4 b/m4/dpkg-funcs.m4
index 0877a4a..bc5ef6c 100644
--- a/m4/dpkg-funcs.m4
+++ b/m4/dpkg-funcs.m4
@@ -85,34 +85,6 @@ AC_DEFUN([DPKG_MMAP],
])
])

-# DPKG_FUNC_SYNC_SYNC
-# --------------------
-# Define USE_SYNC_SYNC if sync() is synchronous and it has been enabled
-# on configure
-AC_DEFUN([DPKG_FUNC_SYNC_SYNC],
-[
- AC_REQUIRE([AC_CANONICAL_HOST])
-
- AC_MSG_CHECKING([whether sync is synchronous])
- AS_CASE([$host_os],
- [linux-*], [dpkg_cv_sync_sync=yes],
- [dpkg_cv_sync_sync=no])
- AC_MSG_RESULT([$dpkg_cv_sync_sync])
-
- AC_ARG_ENABLE([sync-sync],
- AS_HELP_STRING([--enable-sync-sync],
- [enable usage of synchronous sync(2) if available]),
- [],
- [enable_sync_sync=no])
- AC_MSG_CHECKING([whether to use synchronous sync])
- AS_IF([test "x$dpkg_cv_sync_sync" = "xyes" &&
- test "x$enable_sync_sync" = "xyes"],
- [AC_DEFINE([USE_SYNC_SYNC], 1,
- [Define to 1 if sync(2) is synchronous])],
- [enable_sync_sync=no])
- AC_MSG_RESULT([$enable_sync_sync])
-])# DPKG_FUNC_SYNC_SYNC
-
# DPKG_CHECK_COMPAT_FUNCS(LIST)
# -----------------------
# Check each function and define an automake conditional
diff --git a/src/archives.c b/src/archives.c
index 561a14f..d68f9d6 100644
--- a/src/archives.c
+++ b/src/archives.c
@@ -865,12 +865,6 @@ tar_deferred_extract(struct fileinlist *files, struct pkginfo *pkg)
struct filenamenode *usenode;
const char *usename;

-#if defined(USE_SYNC_SYNC)
- debug(dbg_general, "deferred extract mass sync");
- if (!fc_unsafe_io)
- sync();
-#endif
-
for (cfile = files; cfile; cfile = cfile->next) {
debug(dbg_eachfile, "deferred extract of '%.255s'", cfile->namenode->name);

@@ -882,7 +876,6 @@ tar_deferred_extract(struct fileinlist *files, struct pkginfo *pkg)

setupfnamevbs(usename);

-#if !defined(USE_SYNC_SYNC)
if (cfile->namenode->flags & fnnf_deferred_fsync) {
int fd;

@@ -898,7 +891,6 @@ tar_deferred_extract(struct fileinlist *files, struct pkginfo *pkg)

cfile->namenode->flags &= ~fnnf_deferred_fsync;
}
-#endif

debug(dbg_eachfiledetail, "deferred extract needs rename");

--
1.7.2.3


--
To UNSUBSCRIBE, email to debian-dpkg-REQUEST@lists.debian.org
with a subject of "unsubscribe". Trouble? Contact listmaster@lists.debian.org
Archive: 20101127213810.GB26283@burratino">http://lists.debian.org/20101127213810.GB26283@burratino