Add support for atomic open(O_TRUNC)

5 files changed, 92 insertions, 84 deletions

diff --git a/lib/fuse.c b/lib/fuse.c
index a15b5c2..3cc57e4 100644
--- a/lib/fuse.c
+++ b/lib/fuse.c
@@ -2915,21 +2915,21 @@ static const struct fuse_opt fuse_lib_opts[] = {
 static void fuse_lib_help(void)
 {
 	fprintf(stderr,
-"    -o hard_remove	    immediate removal (don't hide files)\n"
-"    -o use_ino		    let filesystem set inode numbers\n"
-"    -o readdir_ino	    try to fill in d_ino in readdir\n"
-"    -o direct_io	    use direct I/O\n"
-"    -o kernel_cache	    cache files in kernel\n"
-"    -o [no]auto_cache	    enable caching based on modification times\n"
-"    -o umask=M		    set file permissions (octal)\n"
-"    -o uid=N		    set file owner\n"
-"    -o gid=N		    set file group\n"
-"    -o entry_timeout=T	    cache timeout for names (1.0s)\n"
+"    -o hard_remove         immediate removal (don't hide files)\n"
+"    -o use_ino             let filesystem set inode numbers\n"
+"    -o readdir_ino         try to fill in d_ino in readdir\n"
+"    -o direct_io           use direct I/O\n"
+"    -o kernel_cache        cache files in kernel\n"
+"    -o [no]auto_cache      enable caching based on modification times\n"
+"    -o umask=M             set file permissions (octal)\n"
+"    -o uid=N               set file owner\n"
+"    -o gid=N               set file group\n"
+"    -o entry_timeout=T     cache timeout for names (1.0s)\n"
 "    -o negative_timeout=T  cache timeout for deleted names (0.0s)\n"
-"    -o attr_timeout=T	    cache timeout for attributes (1.0s)\n"
+"    -o attr_timeout=T      cache timeout for attributes (1.0s)\n"
 "    -o ac_attr_timeout=T   auto cache timeout for attributes (attr_timeout)\n"
-"    -o intr		    allow requests to be interrupted\n"
-"    -o intr_signal=NUM	    signal to send on interrupt (%i)\n"
+"    -o intr                allow requests to be interrupted\n"
+"    -o intr_signal=NUM     signal to send on interrupt (%i)\n"
 "    -o modules=M1[:M2...]  names of modules to push onto filesystem stack\n"
 "\n", FUSE_DEFAULT_INTR_SIGNAL);
 }
diff --git a/lib/fuse_lowlevel.c b/lib/fuse_lowlevel.c
index d1ef7b2..75906b9 100644
--- a/lib/fuse_lowlevel.c
+++ b/lib/fuse_lowlevel.c
@@ -1008,9 +1008,12 @@ static void do_init(fuse_req_t req, fuse_ino_t nodeid, const void *inarg)
 			f->conn.async_read = arg->flags & FUSE_ASYNC_READ;
 		if (arg->max_readahead < f->conn.max_readahead)
 			f->conn.max_readahead = arg->max_readahead;
+		if (f->conn.atomic_o_trunc)
+			f->conn.atomic_o_trunc = arg->flags & FUSE_ATOMIC_O_TRUNC;
 	} else {
 		f->conn.async_read = 0;
 		f->conn.max_readahead = 0;
+		f->conn.atomic_o_trunc = 0;
 	}
 
 	if (bufsize < FUSE_MIN_READ_BUFFER) {
@@ -1034,6 +1037,8 @@ static void do_init(fuse_req_t req, fuse_ino_t nodeid, const void *inarg)
 		outarg.flags |= FUSE_ASYNC_READ;
 	if (f->op.getlk && f->op.setlk)
 		outarg.flags |= FUSE_POSIX_LOCKS;
+	if (f->conn.atomic_o_trunc)
+		outarg.flags |= FUSE_ATOMIC_O_TRUNC;
 	outarg.max_readahead = f->conn.max_readahead;
 	outarg.max_write = f->conn.max_write;
 
@@ -1214,6 +1219,7 @@ static struct fuse_opt fuse_ll_opts[] = {
 	{ "max_readahead=%u", offsetof(struct fuse_ll, conn.max_readahead), 0 },
 	{ "async_read", offsetof(struct fuse_ll, conn.async_read), 1 },
 	{ "sync_read", offsetof(struct fuse_ll, conn.async_read), 0 },
+	{ "atomic_o_trunc", offsetof(struct fuse_ll, conn.atomic_o_trunc), 1},
 	FUSE_OPT_KEY("max_read=", FUSE_OPT_KEY_DISCARD),
 	FUSE_OPT_KEY("-h", KEY_HELP),
 	FUSE_OPT_KEY("--help", KEY_HELP),
@@ -1231,10 +1237,11 @@ static void fuse_ll_version(void)
 static void fuse_ll_help(void)
 {
 	fprintf(stderr,
-"    -o max_write=N	    set maximum size of write requests\n"
-"    -o max_readahead=N	    set maximum readahead\n"
-"    -o async_read	    perform reads asynchronously (default)\n"
-"    -o sync_read	    perform reads synchronously\n");
+"    -o max_write=N         set maximum size of write requests\n"
+"    -o max_readahead=N     set maximum readahead\n"
+"    -o async_read          perform reads asynchronously (default)\n"
+"    -o sync_read           perform reads synchronously\n"
+"    -o atomic_o_trunc      enable atomic open+truncate support\n");
 }
 
 static int fuse_ll_opt_proc(void *data, const char *arg, int key,
@@ -1306,6 +1313,7 @@ struct fuse_session *fuse_lowlevel_new_common(struct fuse_args *args,
 	f->conn.async_read = 1;
 	f->conn.max_write = UINT_MAX;
 	f->conn.max_readahead = UINT_MAX;
+	f->conn.atomic_o_trunc = 0;
 	list_init_req(&f->list);
 	list_init_req(&f->interrupts);
 	fuse_mutex_init(&f->lock);
diff --git a/lib/helper.c b/lib/helper.c
index a175ee9..4e7945c 100644
--- a/lib/helper.c
+++ b/lib/helper.c
@@ -37,22 +37,22 @@ struct helper_opts {
 #define FUSE_HELPER_OPT(t, p) { t, offsetof(struct helper_opts, p), 1 }
 
 static const struct fuse_opt fuse_helper_opts[] = {
-	FUSE_HELPER_OPT("-d",	       foreground),
-	FUSE_HELPER_OPT("debug",       foreground),
-	FUSE_HELPER_OPT("-f",	       foreground),
-	FUSE_HELPER_OPT("-s",	       singlethread),
-	FUSE_HELPER_OPT("fsname=",     nodefault_subtype),
-	FUSE_HELPER_OPT("subtype=",    nodefault_subtype),
-
-	FUSE_OPT_KEY("-h",	    KEY_HELP),
-	FUSE_OPT_KEY("--help",	    KEY_HELP),
-	FUSE_OPT_KEY("-ho",	    KEY_HELP_NOHEADER),
-	FUSE_OPT_KEY("-V",	    KEY_VERSION),
-	FUSE_OPT_KEY("--version",   KEY_VERSION),
-	FUSE_OPT_KEY("-d",	    FUSE_OPT_KEY_KEEP),
-	FUSE_OPT_KEY("debug",	    FUSE_OPT_KEY_KEEP),
-	FUSE_OPT_KEY("fsname=",	    FUSE_OPT_KEY_KEEP),
-	FUSE_OPT_KEY("subtype=",    FUSE_OPT_KEY_KEEP),
+	FUSE_HELPER_OPT("-d",		foreground),
+	FUSE_HELPER_OPT("debug",	foreground),
+	FUSE_HELPER_OPT("-f",		foreground),
+	FUSE_HELPER_OPT("-s",		singlethread),
+	FUSE_HELPER_OPT("fsname=",	nodefault_subtype),
+	FUSE_HELPER_OPT("subtype=",	nodefault_subtype),
+
+	FUSE_OPT_KEY("-h",		KEY_HELP),
+	FUSE_OPT_KEY("--help",		KEY_HELP),
+	FUSE_OPT_KEY("-ho",		KEY_HELP_NOHEADER),
+	FUSE_OPT_KEY("-V",		KEY_VERSION),
+	FUSE_OPT_KEY("--version",	KEY_VERSION),
+	FUSE_OPT_KEY("-d",		FUSE_OPT_KEY_KEEP),
+	FUSE_OPT_KEY("debug",		FUSE_OPT_KEY_KEEP),
+	FUSE_OPT_KEY("fsname=",		FUSE_OPT_KEY_KEEP),
+	FUSE_OPT_KEY("subtype=",	FUSE_OPT_KEY_KEEP),
 	FUSE_OPT_END
 };
 
@@ -62,9 +62,9 @@ static void usage(const char *progname)
 		"usage: %s mountpoint [options]\n\n", progname);
 	fprintf(stderr,
 		"general options:\n"
-		"    -o opt,[opt...]	    mount options\n"
-		"    -h	  --help	    print help\n"
-		"    -V	  --version	    print version\n"
+		"    -o opt,[opt...]        mount options\n"
+		"    -h   --help            print help\n"
+		"    -V   --version         print version\n"
 		"\n");
 }
 
@@ -72,9 +72,9 @@ static void helper_help(void)
 {
 	fprintf(stderr,
 		"FUSE options:\n"
-		"    -d	  -o debug	    enable debug output (implies -f)\n"
-		"    -f			    foreground operation\n"
-		"    -s			    disable multi-threaded operation\n"
+		"    -d   -o debug          enable debug output (implies -f)\n"
+		"    -f                     foreground operation\n"
+		"    -s                     disable multi-threaded operation\n"
 		"\n"
 		);
 }
diff --git a/lib/mount.c b/lib/mount.c
index 14fbfb5..ed5f56d 100644
--- a/lib/mount.c
+++ b/lib/mount.c
@@ -66,56 +66,56 @@ struct mount_opts {
 #define FUSE_MOUNT_OPT(t, p) { t, offsetof(struct mount_opts, p), 1 }
 
 static const struct fuse_opt fuse_mount_opts[] = {
-	FUSE_MOUNT_OPT("allow_other",	    allow_other),
-	FUSE_MOUNT_OPT("allow_root",	    allow_root),
-	FUSE_MOUNT_OPT("nonempty",	    nonempty),
-	FUSE_MOUNT_OPT("blkdev",	    blkdev),
-	FUSE_MOUNT_OPT("fsname=%s",	    fsname),
-	FUSE_MOUNT_OPT("subtype=%s",	    subtype),
-	FUSE_OPT_KEY("allow_other",	    KEY_KERN_OPT),
-	FUSE_OPT_KEY("allow_root",	    KEY_ALLOW_ROOT),
-	FUSE_OPT_KEY("nonempty",	    KEY_FUSERMOUNT_OPT),
-	FUSE_OPT_KEY("blkdev",		    KEY_FUSERMOUNT_OPT),
-	FUSE_OPT_KEY("fsname=",		    KEY_FUSERMOUNT_OPT),
-	FUSE_OPT_KEY("subtype=",	    KEY_SUBTYPE_OPT),
-	FUSE_OPT_KEY("large_read",	    KEY_KERN_OPT),
-	FUSE_OPT_KEY("blksize=",	    KEY_KERN_OPT),
-	FUSE_OPT_KEY("default_permissions", KEY_KERN_OPT),
-	FUSE_OPT_KEY("max_read=",	    KEY_KERN_OPT),
-	FUSE_OPT_KEY("max_read=",	    FUSE_OPT_KEY_KEEP),
-	FUSE_OPT_KEY("user=",		    KEY_MTAB_OPT),
-	FUSE_OPT_KEY("-r",		    KEY_RO),
-	FUSE_OPT_KEY("ro",		    KEY_KERN_FLAG),
-	FUSE_OPT_KEY("rw",		    KEY_KERN_FLAG),
-	FUSE_OPT_KEY("suid",		    KEY_KERN_FLAG),
-	FUSE_OPT_KEY("nosuid",		    KEY_KERN_FLAG),
-	FUSE_OPT_KEY("dev",		    KEY_KERN_FLAG),
-	FUSE_OPT_KEY("nodev",		    KEY_KERN_FLAG),
-	FUSE_OPT_KEY("exec",		    KEY_KERN_FLAG),
-	FUSE_OPT_KEY("noexec",		    KEY_KERN_FLAG),
-	FUSE_OPT_KEY("async",		    KEY_KERN_FLAG),
-	FUSE_OPT_KEY("sync",		    KEY_KERN_FLAG),
-	FUSE_OPT_KEY("dirsync",		    KEY_KERN_FLAG),
-	FUSE_OPT_KEY("atime",		    KEY_KERN_FLAG),
-	FUSE_OPT_KEY("noatime",		    KEY_KERN_FLAG),
-	FUSE_OPT_KEY("-h",		    KEY_HELP),
-	FUSE_OPT_KEY("--help",		    KEY_HELP),
-	FUSE_OPT_KEY("-V",		    KEY_VERSION),
-	FUSE_OPT_KEY("--version",	    KEY_VERSION),
+	FUSE_MOUNT_OPT("allow_other",		allow_other),
+	FUSE_MOUNT_OPT("allow_root",		allow_root),
+	FUSE_MOUNT_OPT("nonempty",		nonempty),
+	FUSE_MOUNT_OPT("blkdev",		blkdev),
+	FUSE_MOUNT_OPT("fsname=%s",		fsname),
+	FUSE_MOUNT_OPT("subtype=%s",		subtype),
+	FUSE_OPT_KEY("allow_other",		KEY_KERN_OPT),
+	FUSE_OPT_KEY("allow_root",		KEY_ALLOW_ROOT),
+	FUSE_OPT_KEY("nonempty",		KEY_FUSERMOUNT_OPT),
+	FUSE_OPT_KEY("blkdev",			KEY_FUSERMOUNT_OPT),
+	FUSE_OPT_KEY("fsname=",			KEY_FUSERMOUNT_OPT),
+	FUSE_OPT_KEY("subtype=",		KEY_SUBTYPE_OPT),
+	FUSE_OPT_KEY("large_read",		KEY_KERN_OPT),
+	FUSE_OPT_KEY("blksize=",		KEY_KERN_OPT),
+	FUSE_OPT_KEY("default_permissions",	KEY_KERN_OPT),
+	FUSE_OPT_KEY("max_read=",		KEY_KERN_OPT),
+	FUSE_OPT_KEY("max_read=",		FUSE_OPT_KEY_KEEP),
+	FUSE_OPT_KEY("user=",			KEY_MTAB_OPT),
+	FUSE_OPT_KEY("-r",			KEY_RO),
+	FUSE_OPT_KEY("ro",			KEY_KERN_FLAG),
+	FUSE_OPT_KEY("rw",			KEY_KERN_FLAG),
+	FUSE_OPT_KEY("suid",			KEY_KERN_FLAG),
+	FUSE_OPT_KEY("nosuid",			KEY_KERN_FLAG),
+	FUSE_OPT_KEY("dev",			KEY_KERN_FLAG),
+	FUSE_OPT_KEY("nodev",			KEY_KERN_FLAG),
+	FUSE_OPT_KEY("exec",			KEY_KERN_FLAG),
+	FUSE_OPT_KEY("noexec",			KEY_KERN_FLAG),
+	FUSE_OPT_KEY("async",			KEY_KERN_FLAG),
+	FUSE_OPT_KEY("sync",			KEY_KERN_FLAG),
+	FUSE_OPT_KEY("dirsync",			KEY_KERN_FLAG),
+	FUSE_OPT_KEY("atime",			KEY_KERN_FLAG),
+	FUSE_OPT_KEY("noatime",			KEY_KERN_FLAG),
+	FUSE_OPT_KEY("-h",			KEY_HELP),
+	FUSE_OPT_KEY("--help",			KEY_HELP),
+	FUSE_OPT_KEY("-V",			KEY_VERSION),
+	FUSE_OPT_KEY("--version",		KEY_VERSION),
 	FUSE_OPT_END
 };
 
 static void mount_help(void)
 {
 	fprintf(stderr,
-"    -o allow_other	    allow access to other users\n"
-"    -o allow_root	    allow access to root\n"
-"    -o nonempty	    allow mounts over non-empty file/dir\n"
+"    -o allow_other         allow access to other users\n"
+"    -o allow_root          allow access to root\n"
+"    -o nonempty            allow mounts over non-empty file/dir\n"
 "    -o default_permissions enable permission checking by kernel\n"
-"    -o fsname=NAME	    set filesystem name\n"
-"    -o subtype=NAME	    set filesystem type\n"
-"    -o large_read	    issue large read requests (2.4 only)\n"
-"    -o max_read=N	    set maximum size of read requests\n"
+"    -o fsname=NAME         set filesystem name\n"
+"    -o subtype=NAME        set filesystem type\n"
+"    -o large_read          issue large read requests (2.4 only)\n"
+"    -o max_read=N          set maximum size of read requests\n"
 "\n");
 }
 
diff --git a/lib/mount_bsd.c b/lib/mount_bsd.c
index cf19a7b..62443ac 100644
--- a/lib/mount_bsd.c
+++ b/lib/mount_bsd.c
@@ -102,7 +102,7 @@ static const struct fuse_opt fuse_mount_opts[] = {
 static void mount_help(void)
 {
 	fprintf(stderr,
-		"    -o allow_root	    allow access to root\n"
+		"    -o allow_root          allow access to root\n"
 		);
 	system(FUSERMOUNT_PROG " --help");
 	fputc('\n', stderr);
@@ -156,7 +156,7 @@ void fuse_unmount_compat22(const char *mountpoint)
 		"exec 2>/dev/null; "
 		"/usr/bin/fstat " FUSE_DEV_TRUNK "* | "
 		"/usr/bin/awk 'BEGIN{ getline; if (! ($3 == \"PID\" && $10 == \"NAME\")) exit 1; }; "
-		"	       { if ($3 == %d) print $10; }' | "
+		"              { if ($3 == %d) print $10; }' | "
 		"/usr/bin/sort | "
 		"/usr/bin/uniq | "
 		"/usr/bin/awk '{ i += 1; if (i > 1){ exit 1; }; printf; }; END{ if (i == 0) exit 1; }'";