From e4da1b16e29f6fe6b34de9b9b0f97141fb2e1855 Mon Sep 17 00:00:00 2001 From: Dave Chinner Date: Wed, 29 Sep 2021 16:48:03 -0400 Subject: [PATCH] xfsprogs: introduce liburcu support The upcoming buffer cache rework/kerenl sync-up requires atomic variables. I could use C++11 atomics build into GCC, but they are a pain to work with and shoe-horn into the kernel atomic variable API. Much easier is to introduce a dependency on liburcu - the userspace RCU library. This provides atomic variables that very closely match the kernel atomic variable API, and it provides a very similar memory model and memory barrier support to the kernel. And we get RCU support that has an identical interface to the kernel and works the same way. Hence kernel code written with RCU algorithms and atomic variables will just slot straight into the userspace xfsprogs code without us having to think about whether the lockless algorithms will work in userspace or not. This reduces glue and hoop jumping, and gets us a step closer to having the entire userspace libxfs code MT safe. Signed-off-by: Dave Chinner [chandan.babu@oracle.com: Add m4 macros to detect availability of liburcu] Signed-off-by: Chandan Babu R [sandeen: use dchinner's m4 macros] Reviewed-by: Eric Sandeen Signed-off-by: Eric Sandeen --- configure.ac | 3 +++ copy/Makefile | 3 ++- copy/xfs_copy.c | 3 +++ db/Makefile | 3 ++- debian/control | 2 +- growfs/Makefile | 3 ++- include/builddefs.in | 4 +++- include/platform_defs.h.in | 1 + libfrog/workqueue.c | 3 +++ libxfs/init.c | 3 +++ libxfs/libxfs_priv.h | 3 +-- logprint/Makefile | 3 ++- m4/Makefile | 1 + m4/package_urcu.m4 | 22 ++++++++++++++++++++++ mdrestore/Makefile | 3 ++- mkfs/Makefile | 2 +- repair/Makefile | 2 +- repair/prefetch.c | 9 +++++++-- repair/progress.c | 4 +++- scrub/Makefile | 3 ++- scrub/progress.c | 2 ++ 21 files changed, 67 insertions(+), 15 deletions(-) create mode 100644 m4/package_urcu.m4 diff --git a/configure.ac b/configure.ac index 568717451..9725a4ff1 100644 --- a/configure.ac +++ b/configure.ac @@ -154,6 +154,9 @@ AC_PACKAGE_NEED_UUIDCOMPARE AC_PACKAGE_NEED_PTHREAD_H AC_PACKAGE_NEED_PTHREADMUTEXINIT +AC_PACKAGE_NEED_URCU_H +AC_PACKAGE_NEED_RCU_INIT + AC_HAVE_FADVISE AC_HAVE_MADVISE AC_HAVE_MINCORE diff --git a/copy/Makefile b/copy/Makefile index 449b235fa..1b00cd0d5 100644 --- a/copy/Makefile +++ b/copy/Makefile @@ -9,7 +9,8 @@ LTCOMMAND = xfs_copy CFILES = xfs_copy.c HFILES = xfs_copy.h -LLDLIBS = $(LIBXFS) $(LIBXLOG) $(LIBFROG) $(LIBUUID) $(LIBPTHREAD) $(LIBRT) +LLDLIBS = $(LIBXFS) $(LIBXLOG) $(LIBFROG) $(LIBUUID) $(LIBPTHREAD) $(LIBRT) \ + $(LIBURCU) LTDEPENDENCIES = $(LIBXFS) $(LIBXLOG) $(LIBFROG) LLDFLAGS = -static-libtool-libs diff --git a/copy/xfs_copy.c b/copy/xfs_copy.c index fc7d225fe..f5eff9697 100644 --- a/copy/xfs_copy.c +++ b/copy/xfs_copy.c @@ -110,6 +110,7 @@ do_message(int flags, int code, const char *fmt, ...) fprintf(stderr, _("Aborting XFS copy -- logfile error -- reason: %s\n"), strerror(errno)); + rcu_unregister_thread(); pthread_exit(NULL); } } @@ -224,6 +225,7 @@ begin_reader(void *arg) { thread_args *args = arg; + rcu_register_thread(); for (;;) { pthread_mutex_lock(&args->wait); if (do_write(args, NULL)) @@ -243,6 +245,7 @@ handle_error: if (--glob_masks.num_working == 0) pthread_mutex_unlock(&mainwait); pthread_mutex_unlock(&glob_masks.mutex); + rcu_unregister_thread(); pthread_exit(NULL); return NULL; } diff --git a/db/Makefile b/db/Makefile index beafb1058..5c0178982 100644 --- a/db/Makefile +++ b/db/Makefile @@ -18,7 +18,8 @@ CFILES = $(HFILES:.h=.c) btdump.c btheight.c convert.c info.c namei.c \ timelimit.c LSRCFILES = xfs_admin.sh xfs_ncheck.sh xfs_metadump.sh -LLDLIBS = $(LIBXFS) $(LIBXLOG) $(LIBFROG) $(LIBUUID) $(LIBRT) $(LIBPTHREAD) +LLDLIBS = $(LIBXFS) $(LIBXLOG) $(LIBFROG) $(LIBUUID) $(LIBRT) $(LIBPTHREAD) \ + $(LIBURCU) LTDEPENDENCIES = $(LIBXFS) $(LIBXLOG) $(LIBFROG) LLDFLAGS += -static-libtool-libs diff --git a/debian/control b/debian/control index e4ec897cc..71c081675 100644 --- a/debian/control +++ b/debian/control @@ -3,7 +3,7 @@ Section: admin Priority: optional Maintainer: XFS Development Team Uploaders: Nathan Scott , Anibal Monsalve Salazar , Bastian Germann -Build-Depends: libinih-dev (>= 53), uuid-dev, dh-autoreconf, debhelper (>= 5), gettext, libtool, libedit-dev, libblkid-dev (>= 2.17), linux-libc-dev, libdevmapper-dev, libattr1-dev, libicu-dev, pkg-config +Build-Depends: libinih-dev (>= 53), uuid-dev, dh-autoreconf, debhelper (>= 5), gettext, libtool, libedit-dev, libblkid-dev (>= 2.17), linux-libc-dev, libdevmapper-dev, libattr1-dev, libicu-dev, pkg-config, liburcu-dev Standards-Version: 4.0.0 Homepage: https://xfs.wiki.kernel.org/ diff --git a/growfs/Makefile b/growfs/Makefile index a107d348a..08601de77 100644 --- a/growfs/Makefile +++ b/growfs/Makefile @@ -9,7 +9,8 @@ LTCOMMAND = xfs_growfs CFILES = xfs_growfs.c -LLDLIBS = $(LIBXFS) $(LIBXCMD) $(LIBFROG) $(LIBUUID) $(LIBRT) $(LIBPTHREAD) +LLDLIBS = $(LIBXFS) $(LIBXCMD) $(LIBFROG) $(LIBUUID) $(LIBRT) $(LIBPTHREAD) \ + $(LIBURCU) ifeq ($(ENABLE_EDITLINE),yes) LLDLIBS += $(LIBEDITLINE) $(LIBTERMCAP) diff --git a/include/builddefs.in b/include/builddefs.in index e8f447f92..78eddf4a9 100644 --- a/include/builddefs.in +++ b/include/builddefs.in @@ -22,6 +22,7 @@ LDFLAGS = LIBRT = @librt@ LIBUUID = @libuuid@ +LIBURCU = @liburcu@ LIBPTHREAD = @libpthread@ LIBTERMCAP = @libtermcap@ LIBEDITLINE = @libeditline@ @@ -125,7 +126,8 @@ CROND_DIR = @crond_dir@ GCCFLAGS = -funsigned-char -fno-strict-aliasing -Wall # -Wbitwise -Wno-transparent-union -Wno-old-initializer -Wno-decl -PCFLAGS = -D_GNU_SOURCE $(GCCFLAGS) +# _LGPL_SOURCE is for liburcu to work correctly with GPL/LGPL programs +PCFLAGS = -D_LGPL_SOURCE -D_GNU_SOURCE $(GCCFLAGS) ifeq ($(HAVE_UMODE_T),yes) PCFLAGS += -DHAVE_UMODE_T endif diff --git a/include/platform_defs.h.in b/include/platform_defs.h.in index 539bdbecf..7c6b3ada0 100644 --- a/include/platform_defs.h.in +++ b/include/platform_defs.h.in @@ -23,6 +23,7 @@ #include #include #include +#include typedef struct filldir filldir_t; diff --git a/libfrog/workqueue.c b/libfrog/workqueue.c index 8c1a163e1..702a53e2f 100644 --- a/libfrog/workqueue.c +++ b/libfrog/workqueue.c @@ -11,6 +11,7 @@ #include #include #include +#include #include "workqueue.h" /* Main processing thread */ @@ -24,6 +25,7 @@ workqueue_thread(void *arg) * Loop pulling work from the passed in work queue. * Check for notification to exit after every chunk of work. */ + rcu_register_thread(); while (1) { pthread_mutex_lock(&wq->lock); @@ -60,6 +62,7 @@ workqueue_thread(void *arg) (wi->function)(wi->queue, wi->index, wi->arg); free(wi); } + rcu_unregister_thread(); return NULL; } diff --git a/libxfs/init.c b/libxfs/init.c index 1ec837911..b06faf8ac 100644 --- a/libxfs/init.c +++ b/libxfs/init.c @@ -310,6 +310,8 @@ libxfs_init(libxfs_init_t *a) fd = -1; flags = (a->isreadonly | a->isdirect); + rcu_init(); + rcu_register_thread(); radix_tree_init(); if (a->volname) { @@ -1023,6 +1025,7 @@ libxfs_destroy( libxfs_bcache_free(); cache_destroy(libxfs_bcache); leaked = destroy_zones(); + rcu_unregister_thread(); if (getenv("LIBXFS_LEAK_CHECK") && leaked) exit(1); } diff --git a/libxfs/libxfs_priv.h b/libxfs/libxfs_priv.h index 7181a8589..db90e173f 100644 --- a/libxfs/libxfs_priv.h +++ b/libxfs/libxfs_priv.h @@ -210,8 +210,7 @@ enum ce { CE_DEBUG, CE_CONT, CE_NOTE, CE_WARN, CE_ALERT, CE_PANIC }; #define spin_unlock(a) ((void) 0) #define likely(x) (x) #define unlikely(x) (x) -#define rcu_read_lock() ((void) 0) -#define rcu_read_unlock() ((void) 0) + /* Need to be able to handle this bare or in control flow */ static inline bool WARN_ON(bool expr) { return (expr); diff --git a/logprint/Makefile b/logprint/Makefile index 758504b39..cdedbd0db 100644 --- a/logprint/Makefile +++ b/logprint/Makefile @@ -12,7 +12,8 @@ CFILES = logprint.c \ log_copy.c log_dump.c log_misc.c \ log_print_all.c log_print_trans.c log_redo.c -LLDLIBS = $(LIBXFS) $(LIBXLOG) $(LIBFROG) $(LIBUUID) $(LIBRT) $(LIBPTHREAD) +LLDLIBS = $(LIBXFS) $(LIBXLOG) $(LIBFROG) $(LIBUUID) $(LIBRT) $(LIBPTHREAD) \ + $(LIBURCU) LTDEPENDENCIES = $(LIBXFS) $(LIBXLOG) $(LIBFROG) LLDFLAGS = -static-libtool-libs diff --git a/m4/Makefile b/m4/Makefile index c6c73dc9b..731205303 100644 --- a/m4/Makefile +++ b/m4/Makefile @@ -24,6 +24,7 @@ LSRCFILES = \ package_services.m4 \ package_types.m4 \ package_icu.m4 \ + package_urcu.m4 \ package_utilies.m4 \ package_uuiddev.m4 \ multilib.m4 \ diff --git a/m4/package_urcu.m4 b/m4/package_urcu.m4 new file mode 100644 index 000000000..f0337f341 --- /dev/null +++ b/m4/package_urcu.m4 @@ -0,0 +1,22 @@ +AC_DEFUN([AC_PACKAGE_NEED_URCU_H], + [ AC_CHECK_HEADERS(urcu.h) + if test $ac_cv_header_urcu_h = no; then + AC_CHECK_HEADERS(urcu.h,, [ + echo + echo 'FATAL ERROR: could not find a valid urcu header.' + exit 1]) + fi + ]) + +AC_DEFUN([AC_PACKAGE_NEED_RCU_INIT], + [ AC_MSG_CHECKING([for liburcu]) + AC_TRY_COMPILE([ +#define _GNU_SOURCE +#include + ], [ + rcu_init(); + ], liburcu=-lurcu + AC_MSG_RESULT(yes), + AC_MSG_RESULT(no)) + AC_SUBST(liburcu) + ]) diff --git a/mdrestore/Makefile b/mdrestore/Makefile index d946955b0..8f28ddab3 100644 --- a/mdrestore/Makefile +++ b/mdrestore/Makefile @@ -8,7 +8,8 @@ include $(TOPDIR)/include/builddefs LTCOMMAND = xfs_mdrestore CFILES = xfs_mdrestore.c -LLDLIBS = $(LIBXFS) $(LIBFROG) $(LIBRT) $(LIBPTHREAD) $(LIBUUID) +LLDLIBS = $(LIBXFS) $(LIBFROG) $(LIBRT) $(LIBPTHREAD) $(LIBUUID) \ + $(LIBURCU) LTDEPENDENCIES = $(LIBXFS) $(LIBFROG) LLDFLAGS = -static diff --git a/mkfs/Makefile b/mkfs/Makefile index b8805f7e1..811ba9dbe 100644 --- a/mkfs/Makefile +++ b/mkfs/Makefile @@ -11,7 +11,7 @@ HFILES = CFILES = proto.c xfs_mkfs.c LLDLIBS += $(LIBXFS) $(LIBXCMD) $(LIBFROG) $(LIBRT) $(LIBPTHREAD) $(LIBBLKID) \ - $(LIBUUID) $(LIBINIH) + $(LIBUUID) $(LIBINIH) $(LIBURCU) LTDEPENDENCIES += $(LIBXFS) $(LIBXCMD) $(LIBFROG) LLDFLAGS = -static-libtool-libs diff --git a/repair/Makefile b/repair/Makefile index 5f0764d1c..47536ca1c 100644 --- a/repair/Makefile +++ b/repair/Makefile @@ -72,7 +72,7 @@ CFILES = \ xfs_repair.c LLDLIBS = $(LIBXFS) $(LIBXLOG) $(LIBXCMD) $(LIBFROG) $(LIBUUID) $(LIBRT) \ - $(LIBPTHREAD) $(LIBBLKID) + $(LIBPTHREAD) $(LIBBLKID) $(LIBURCU) LTDEPENDENCIES = $(LIBXFS) $(LIBXLOG) $(LIBXCMD) $(LIBFROG) LLDFLAGS = -static-libtool-libs diff --git a/repair/prefetch.c b/repair/prefetch.c index 48affa186..22a0c0c90 100644 --- a/repair/prefetch.c +++ b/repair/prefetch.c @@ -660,6 +660,7 @@ pf_io_worker( if (buf == NULL) return NULL; + rcu_register_thread(); pthread_mutex_lock(&args->lock); while (!args->queuing_done || !btree_is_empty(args->io_queue)) { pftrace("waiting to start prefetch I/O for AG %d", args->agno); @@ -682,6 +683,7 @@ pf_io_worker( free(buf); pftrace("finished prefetch I/O for AG %d", args->agno); + rcu_unregister_thread(); return NULL; } @@ -726,6 +728,8 @@ pf_queuing_worker( struct xfs_ino_geometry *igeo = M_IGEO(mp); unsigned long long cluster_mask; + rcu_register_thread(); + cluster_mask = (1ULL << igeo->inodes_per_cluster) - 1; for (i = 0; i < PF_THREAD_COUNT; i++) { @@ -739,7 +743,7 @@ pf_queuing_worker( args->io_threads[i] = 0; if (i == 0) { pf_skip_prefetch_thread(args); - return NULL; + goto out; } /* * since we have at least one I/O thread, use them for @@ -779,7 +783,6 @@ pf_queuing_worker( * Start processing as well, in case everything so * far was already prefetched and the queue is empty. */ - pf_start_io_workers(args); pf_start_processing(args); sem_wait(&args->ra_count); @@ -841,6 +844,8 @@ pf_queuing_worker( if (next_args) pf_create_prefetch_thread(next_args); +out: + rcu_unregister_thread(); return NULL; } diff --git a/repair/progress.c b/repair/progress.c index e5a9c1efa..f6c4d9884 100644 --- a/repair/progress.c +++ b/repair/progress.c @@ -182,6 +182,7 @@ progress_rpt_thread (void *p) do_error (_("progress_rpt: cannot malloc progress msg buffer\n")); running = 1; + rcu_register_thread(); /* * Specify a repeating timer that fires each MSG_INTERVAL seconds. @@ -286,7 +287,8 @@ progress_rpt_thread (void *p) do_warn(_("cannot delete timer\n")); free (msgbuf); - return (NULL); + rcu_unregister_thread(); + return NULL; } int diff --git a/scrub/Makefile b/scrub/Makefile index 47c887eb7..849e3afd5 100644 --- a/scrub/Makefile +++ b/scrub/Makefile @@ -71,7 +71,8 @@ spacemap.c \ vfs.c \ xfs_scrub.c -LLDLIBS += $(LIBHANDLE) $(LIBFROG) $(LIBPTHREAD) $(LIBICU_LIBS) $(LIBRT) +LLDLIBS += $(LIBHANDLE) $(LIBFROG) $(LIBPTHREAD) $(LIBICU_LIBS) $(LIBRT) \ + $(LIBURCU) LTDEPENDENCIES += $(LIBHANDLE) $(LIBFROG) LLDFLAGS = -static diff --git a/scrub/progress.c b/scrub/progress.c index 15247b7c6..a3d096f98 100644 --- a/scrub/progress.c +++ b/scrub/progress.c @@ -116,6 +116,7 @@ progress_report_thread(void *arg) struct timespec abstime; int ret; + rcu_register_thread(); pthread_mutex_lock(&pt.lock); while (1) { uint64_t progress_val; @@ -139,6 +140,7 @@ progress_report_thread(void *arg) progress_report(progress_val); } pthread_mutex_unlock(&pt.lock); + rcu_unregister_thread(); return NULL; } -- 2.39.2