driver: implemented and integrated the -t (preserve atime) command-line option.

7 files changed, 98 insertions, 5 deletions

diff --git a/src/driver/tpax_driver_ctx.c b/src/driver/tpax_driver_ctx.c
index 0807379..e8ecb9e 100644
--- a/src/driver/tpax_driver_ctx.c
+++ b/src/driver/tpax_driver_ctx.c
@@ -526,6 +526,10 @@ int tpax_lib_get_driver_ctx(
 					cctx.drvflags &= ~(uintptr_t)TPAX_DRIVER_DIR_MEMBER_RECURSE;
 					break;
 
+				case TAG_PRESERVE_ATIME:
+					cctx.drvflags |= TPAX_DRIVER_PRESERVE_ATIME;
+					break;
+
 				case TAG_STRICT_PATH:
 					cctx.drvflags |= TPAX_DRIVER_STRICT_PATH_INPUT;
 					break;
diff --git a/src/internal/tpax_driver_impl.h b/src/internal/tpax_driver_impl.h
index 1345c32..1e898e9 100644
--- a/src/internal/tpax_driver_impl.h
+++ b/src/internal/tpax_driver_impl.h
@@ -45,6 +45,7 @@ enum app_tags {
 	TAG_NORECURSE,
 	TAG_STRICT_PATH,
 	TAG_PURE_PATH,
+	TAG_PRESERVE_ATIME,
 };
 
 struct tpax_dirent {
diff --git a/src/internal/tpax_ftime_impl.c b/src/internal/tpax_ftime_impl.c
new file mode 100644
index 0000000..19c6d7b
--- /dev/null
+++ b/src/internal/tpax_ftime_impl.c
@@ -0,0 +1,48 @@
+/**************************************************************/
+/*  tpax: a topological pax implementation                    */
+/*  Copyright (C) 2020--2024  SysDeer Technologies, LLC       */
+/*  Released under GPLv2 and GPLv3; see COPYING.TPAX.         */
+/**************************************************************/
+
+#include <time.h>
+#include <sys/time.h>
+#include <sys/stat.h>
+
+#include "tpax_ftime_impl.h"
+#include "tpax_driver_impl.h"
+#include "tpax_visibility_impl.h"
+
+tpax_hidden void tpax_ftime_restore(
+	const struct tpax_driver_ctx *  dctx,
+	int                             fd,
+	const struct stat *             refst)
+{
+	struct timespec ts[2];
+
+	if (dctx->cctx->drvflags & TPAX_DRIVER_PRESERVE_ATIME) {
+		ts[0].tv_sec  = refst->st_atim.tv_sec;
+		ts[0].tv_nsec = refst->st_atim.tv_nsec;
+	} else {
+		ts[0].tv_nsec = UTIME_OMIT;
+	}
+
+	if (dctx->cctx->drvflags & TPAX_DRIVER_PRESERVE_MTIME) {
+		ts[1].tv_sec  = refst->st_mtim.tv_sec;
+		ts[1].tv_nsec = refst->st_mtim.tv_nsec;
+	} else {
+		ts[1].tv_nsec = UTIME_OMIT;
+	}
+
+	if ((ts[0].tv_nsec != UTIME_OMIT) || (ts[1].tv_nsec != UTIME_OMIT)) {
+		futimens(fd,ts);
+	}
+}
+
+tpax_hidden void tpax_ftime_restore_and_close(
+	const struct tpax_driver_ctx *  dctx,
+	int                             fd,
+	const struct stat *             refst)
+{
+	tpax_ftime_restore(dctx,fd,refst);
+	close(fd);
+}
diff --git a/src/internal/tpax_ftime_impl.h b/src/internal/tpax_ftime_impl.h
new file mode 100644
index 0000000..2d0e981
--- /dev/null
+++ b/src/internal/tpax_ftime_impl.h
@@ -0,0 +1,24 @@
+/**************************************************************/
+/*  tpax: a topological pax implementation                    */
+/*  Copyright (C) 2020--2024  SysDeer Technologies, LLC       */
+/*  Released under GPLv2 and GPLv3; see COPYING.TPAX.         */
+/**************************************************************/
+
+#ifndef TPAX_FTIME_IMPL_H
+#define TPAX_FTIME_IMPL_H
+
+#include <time.h>
+#include <sys/time.h>
+#include <sys/stat.h>
+
+#include "tpax_driver_impl.h"
+
+void tpax_ftime_restore(
+	const struct tpax_driver_ctx *,
+	int fd, const struct stat *);
+
+void tpax_ftime_restore_and_close(
+	const struct tpax_driver_ctx *,
+	int fd, const struct stat *);
+
+#endif
diff --git a/src/io/tpax_create_memory_snapshot.c b/src/io/tpax_create_memory_snapshot.c
index 7c3dd7e..6be087f 100644
--- a/src/io/tpax_create_memory_snapshot.c
+++ b/src/io/tpax_create_memory_snapshot.c
@@ -18,6 +18,7 @@
 #include <tpax/tpax_specs.h>
 #include "tpax_driver_impl.h"
 #include "tpax_errinfo_impl.h"
+#include "tpax_ftime_impl.h"
 
 #ifndef ssizeof
 #define ssizeof(x) (ssize_t)(sizeof(x))
@@ -69,11 +70,11 @@ int tpax_io_create_memory_snapshot(
 			nread = read(fd,ch,cap-ch);
 
 		if (nread < 0) {
-			close(fd);
+			tpax_ftime_restore_and_close(dctx,fd,&dstst);
 			return TPAX_SYSTEM_ERROR(dctx);
 
 		} else if (nread == 0) {
-			close(fd);
+			tpax_ftime_restore_and_close(dctx,fd,&dstst);
 			return TPAX_CUSTOM_ERROR(dctx,TPAX_ERR_FLOW_ERROR);
 
 		} else {
@@ -81,6 +82,9 @@ int tpax_io_create_memory_snapshot(
 		}
 	}
 
+	/* preserve last data access time as needed */
+	tpax_ftime_restore(dctx,fd,&dstst);
+
 	/* stat compare */
 	if ((fstat(fd,&dstst)) < 0) {
 		close(fd);
diff --git a/src/io/tpax_create_tmpfs_snapshot.c b/src/io/tpax_create_tmpfs_snapshot.c
index 9891e98..99a1665 100644
--- a/src/io/tpax_create_tmpfs_snapshot.c
+++ b/src/io/tpax_create_tmpfs_snapshot.c
@@ -19,6 +19,7 @@
 #include "tpax_driver_impl.h"
 #include "tpax_tmpfile_impl.h"
 #include "tpax_errinfo_impl.h"
+#include "tpax_ftime_impl.h"
 
 #ifndef ssizeof
 #define ssizeof(x) (ssize_t)(sizeof(x))
@@ -78,12 +79,12 @@ int tpax_io_create_tmpfs_snapshot(
 			nbytes = read(fdsrc,buf,buflen);
 
 		if (nbytes < 0) {
-			close(fdsrc);
+			tpax_ftime_restore_and_close(dctx,fdsrc,&dstst);
 			close(fdtmp);
 			return TPAX_SYSTEM_ERROR(dctx);
 
 		} else if (nbytes == 0) {
-			close(fdsrc);
+			tpax_ftime_restore_and_close(dctx,fdsrc,&dstst);
 			close(fdtmp);
 			return TPAX_CUSTOM_ERROR(dctx,TPAX_ERR_FLOW_ERROR);
 
@@ -98,7 +99,7 @@ int tpax_io_create_tmpfs_snapshot(
 				ret = write(fdtmp,ch,nbytes);
 
 			if (ret < 0) {
-				close(fdsrc);
+				tpax_ftime_restore_and_close(dctx,fdsrc,&dstst);
 				close(fdtmp);
 				return TPAX_SYSTEM_ERROR(dctx);
 
@@ -108,6 +109,9 @@ int tpax_io_create_tmpfs_snapshot(
 		}
 	}
 
+	/* preserve last data access time as needed */
+	tpax_ftime_restore(dctx,fdsrc,&dstst);
+
 	/* stat compare */
 	if ((fstat(fdsrc,&dstst)) < 0) {
 		close(fdsrc);
diff --git a/src/skin/tpax_skin_default.c b/src/skin/tpax_skin_default.c
index a385aac..1684553 100644
--- a/src/skin/tpax_skin_default.c
+++ b/src/skin/tpax_skin_default.c
@@ -58,6 +58,14 @@ const tpax_hidden struct argv_option tpax_default_options[] = {
 			ARGV_OPTION_HYBRID_ONLY,0,0,
 			"do not recurse into directory archive members"},
 
+	{"Wpreserve-atime",
+			't',TAG_PRESERVE_ATIME,ARGV_OPTARG_NONE,
+			ARGV_OPTION_HYBRID_ONLY,0,0,
+			"when user has the necessary permissions, "
+			"set the access time of each file to the access "
+			"time that was reported by fstatat(3) prior to the "
+			"first read operation performed by pax"},
+
 	{"Wstrict-path-input",
 			0,TAG_STRICT_PATH,ARGV_OPTARG_NONE,
 			ARGV_OPTION_HYBRID_ONLY,0,0,