libfuse: add flags to ->rename()

See renameat2() system call in linux-3.15 and later kernels.

10 files changed, 97 insertions, 20 deletions

diff --git a/ChangeLog b/ChangeLog
index a5f611d..bde75cc 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -14,6 +14,9 @@
 
 	* libfuse: allow setting ctime in ->setattr()
 
+	* libfuse: add flags to ->rename().  See renameat2() system call
+	in linux-3.15 and later kernels.
+
 2014-03-26  Miklos Szeredi <miklos@szeredi.hu>
 
 	* Initilaize stat buffer passed to ->getattr() and ->fgetattr() to
diff --git a/example/fusexmp.c b/example/fusexmp.c
index fe20f57..eae3562 100755
--- a/example/fusexmp.c
+++ b/example/fusexmp.c
@@ -172,10 +172,13 @@ static int xmp_symlink(const char *from, const char *to)
 	return 0;
 }
 
-static int xmp_rename(const char *from, const char *to)
+static int xmp_rename(const char *from, const char *to, unsigned int flags)
 {
 	int res;
 
+	if (flags)
+		return -EINVAL;
+
 	res = rename(from, to);
 	if (res == -1)
 		return -errno;
diff --git a/example/fusexmp_fh.c b/example/fusexmp_fh.c
index 531438f..84fce3f 100755
--- a/example/fusexmp_fh.c
+++ b/example/fusexmp_fh.c
@@ -242,10 +242,14 @@ static int xmp_symlink(const char *from, const char *to)
 	return 0;
 }
 
-static int xmp_rename(const char *from, const char *to)
+static int xmp_rename(const char *from, const char *to, unsigned int flags)
 {
 	int res;
 
+	/* When we have renameat2() in libc, then we can implement flags */
+	if (flags)
+		return -EINVAL;
+
 	res = rename(from, to);
 	if (res == -1)
 		return -errno;
diff --git a/include/fuse.h b/include/fuse.h
index edece77..bf86bda 100644
--- a/include/fuse.h
+++ b/include/fuse.h
@@ -162,7 +162,7 @@ struct fuse_operations {
 	int (*symlink) (const char *, const char *);
 
 	/** Rename a file */
-	int (*rename) (const char *, const char *);
+	int (*rename) (const char *, const char *, unsigned int);
 
 	/** Create a hard link to a file */
 	int (*link) (const char *, const char *);
@@ -808,7 +808,7 @@ int fuse_fs_getattr(struct fuse_fs *fs, const char *path, struct stat *buf);
 int fuse_fs_fgetattr(struct fuse_fs *fs, const char *path, struct stat *buf,
 		     struct fuse_file_info *fi);
 int fuse_fs_rename(struct fuse_fs *fs, const char *oldpath,
-		   const char *newpath);
+		   const char *newpath, unsigned int flags);
 int fuse_fs_unlink(struct fuse_fs *fs, const char *path);
 int fuse_fs_rmdir(struct fuse_fs *fs, const char *path);
 int fuse_fs_symlink(struct fuse_fs *fs, const char *linkname,
diff --git a/include/fuse_kernel.h b/include/fuse_kernel.h
index e86a21a..40b5ca8 100644
--- a/include/fuse_kernel.h
+++ b/include/fuse_kernel.h
@@ -100,6 +100,7 @@
  *  - add reserved space to fuse_init_out
  *  - add FATTR_CTIME
  *  - add ctime and ctimensec to fuse_setattr_in
+ *  - add FUSE_RENAME2 request
  */
 
 #ifndef _LINUX_FUSE_H
@@ -353,6 +354,7 @@ enum fuse_opcode {
 	FUSE_BATCH_FORGET  = 42,
 	FUSE_FALLOCATE     = 43,
 	FUSE_READDIRPLUS   = 44,
+	FUSE_RENAME2       = 45,
 
 	/* CUSE specific operations */
 	CUSE_INIT          = 4096,
@@ -431,6 +433,12 @@ struct fuse_rename_in {
 	uint64_t	newdir;
 };
 
+struct fuse_rename2_in {
+	uint64_t	newdir;
+	uint32_t	flags;
+	uint32_t	padding;
+};
+
 struct fuse_link_in {
 	uint64_t	oldnodeid;
 };
diff --git a/include/fuse_lowlevel.h b/include/fuse_lowlevel.h
index 8eef9b9..b31868f 100644
--- a/include/fuse_lowlevel.h
+++ b/include/fuse_lowlevel.h
@@ -393,7 +393,8 @@ struct fuse_lowlevel_ops {
 	 * @param newname new name
 	 */
 	void (*rename) (fuse_req_t req, fuse_ino_t parent, const char *name,
-			fuse_ino_t newparent, const char *newname);
+			fuse_ino_t newparent, const char *newname,
+			unsigned int flags);
 
 	/**
 	 * Create a hard link
diff --git a/lib/fuse.c b/lib/fuse.c
index ca6d3cd..77da446 100644
--- a/lib/fuse.c
+++ b/lib/fuse.c
@@ -43,6 +43,10 @@
 #undef FUSE_NODE_SLAB
 #endif
 
+#ifndef RENAME_EXCHANGE
+#define RENAME_EXCHANGE		(1 << 1)	/* Exchange source and dest */
+#endif
+
 #define FUSE_DEFAULT_INTR_SIGNAL SIGUSR1
 
 #define FUSE_UNKNOWN_INO 0xffffffff
@@ -1414,6 +1418,37 @@ out:
 	return err;
 }
 
+static int exchange_node(struct fuse *f, fuse_ino_t olddir, const char *oldname,
+			 fuse_ino_t newdir, const char *newname)
+{
+	struct node *oldnode;
+	struct node *newnode;
+	int err;
+
+	pthread_mutex_lock(&f->lock);
+	oldnode  = lookup_node(f, olddir, oldname);
+	newnode	 = lookup_node(f, newdir, newname);
+
+	if (oldnode)
+		unhash_name(f, oldnode);
+	if (newnode)
+		unhash_name(f, newnode);
+
+	err = -ENOMEM;
+	if (oldnode) {
+		if (hash_name(f, oldnode, newdir, newname) == -1)
+			goto out;
+	}
+	if (newnode) {
+		if (hash_name(f, newnode, olddir, oldname) == -1)
+			goto out;
+	}
+	err = 0;
+out:
+	pthread_mutex_unlock(&f->lock);
+	return err;
+}
+
 static void set_stat(struct fuse *f, fuse_ino_t nodeid, struct stat *stbuf)
 {
 	if (!f->conf.use_ino)
@@ -1533,14 +1568,15 @@ int fuse_fs_fgetattr(struct fuse_fs *fs, const char *path, struct stat *buf,
 }
 
 int fuse_fs_rename(struct fuse_fs *fs, const char *oldpath,
-		   const char *newpath)
+		   const char *newpath, unsigned int flags)
 {
 	fuse_get_context()->private_data = fs->user_data;
 	if (fs->op.rename) {
 		if (fs->debug)
-			fprintf(stderr, "rename %s %s\n", oldpath, newpath);
+			fprintf(stderr, "rename %s %s 0x%x\n", oldpath, newpath,
+				flags);
 
-		return fs->op.rename(oldpath, newpath);
+		return fs->op.rename(oldpath, newpath, flags);
 	} else {
 		return -ENOSYS;
 	}
@@ -2298,7 +2334,7 @@ static int hide_node(struct fuse *f, const char *oldpath,
 
 	newpath = hidden_name(f, dir, oldname, newname, sizeof(newname));
 	if (newpath) {
-		err = fuse_fs_rename(f->fs, oldpath, newpath);
+		err = fuse_fs_rename(f->fs, oldpath, newpath, 0);
 		if (!err)
 			err = rename_node(f, dir, oldname, dir, newname, 1);
 		free(newpath);
@@ -2912,7 +2948,7 @@ static void fuse_lib_symlink(fuse_req_t req, const char *linkname,
 
 static void fuse_lib_rename(fuse_req_t req, fuse_ino_t olddir,
 			    const char *oldname, fuse_ino_t newdir,
-			    const char *newname)
+			    const char *newname, unsigned int flags)
 {
 	struct fuse *f = req_fuse_prepare(req);
 	char *oldpath;
@@ -2927,13 +2963,20 @@ static void fuse_lib_rename(fuse_req_t req, fuse_ino_t olddir,
 		struct fuse_intr_data d;
 		err = 0;
 		fuse_prepare_interrupt(f, req, &d);
-		if (!f->conf.hard_remove && is_open(f, newdir, newname))
+		if (!f->conf.hard_remove && !(flags & RENAME_EXCHANGE) &&
+		    is_open(f, newdir, newname))
 			err = hide_node(f, newpath, newdir, newname);
 		if (!err) {
-			err = fuse_fs_rename(f->fs, oldpath, newpath);
-			if (!err)
-				err = rename_node(f, olddir, oldname, newdir,
-						  newname, 0);
+			err = fuse_fs_rename(f->fs, oldpath, newpath, flags);
+			if (!err) {
+				if (flags & RENAME_EXCHANGE) {
+					err = exchange_node(f, olddir, oldname,
+							    newdir, newname);
+				} else {
+					err = rename_node(f, olddir, oldname,
+							  newdir, newname, 0);
+				}
+			}
 		}
 		fuse_finish_interrupt(f, req, &d);
 		free_path2(f, olddir, newdir, wnode1, wnode2, oldpath, newpath);
diff --git a/lib/fuse_lowlevel.c b/lib/fuse_lowlevel.c
index 9131811..1911863 100755
--- a/lib/fuse_lowlevel.c
+++ b/lib/fuse_lowlevel.c
@@ -1270,7 +1270,21 @@ static void do_rename(fuse_req_t req, fuse_ino_t nodeid, const void *inarg)
 	char *newname = oldname + strlen(oldname) + 1;
 
 	if (req->f->op.rename)
-		req->f->op.rename(req, nodeid, oldname, arg->newdir, newname);
+		req->f->op.rename(req, nodeid, oldname, arg->newdir, newname,
+				  0);
+	else
+		fuse_reply_err(req, ENOSYS);
+}
+
+static void do_rename2(fuse_req_t req, fuse_ino_t nodeid, const void *inarg)
+{
+	struct fuse_rename2_in *arg = (struct fuse_rename2_in *) inarg;
+	char *oldname = PARAM(arg);
+	char *newname = oldname + strlen(oldname) + 1;
+
+	if (req->f->op.rename)
+		req->f->op.rename(req, nodeid, oldname, arg->newdir, newname,
+				  arg->flags);
 	else
 		fuse_reply_err(req, ENOSYS);
 }
@@ -2431,6 +2445,7 @@ static struct {
 	[FUSE_NOTIFY_REPLY] = { (void *) 1,    "NOTIFY_REPLY" },
 	[FUSE_BATCH_FORGET] = { do_batch_forget, "BATCH_FORGET" },
 	[FUSE_READDIRPLUS] = { do_readdirplus,	"READDIRPLUS"},
+	[FUSE_RENAME2]     = { do_rename2,      "RENAME2"    },
 	[CUSE_INIT]	   = { cuse_lowlevel_init, "CUSE_INIT"   },
 };
 
diff --git a/lib/modules/iconv.c b/lib/modules/iconv.c
index 7d96c17..174e2b9 100644
--- a/lib/modules/iconv.c
+++ b/lib/modules/iconv.c
@@ -281,7 +281,7 @@ static int iconv_symlink(const char *from, const char *to)
 	return err;
 }
 
-static int iconv_rename(const char *from, const char *to)
+static int iconv_rename(const char *from, const char *to, unsigned int flags)
 {
 	struct iconv *ic = iconv_get();
 	char *newfrom;
@@ -290,7 +290,7 @@ static int iconv_rename(const char *from, const char *to)
 	if (!err) {
 		err = iconv_convpath(ic, to, &newto, 0);
 		if (!err) {
-			err = fuse_fs_rename(ic->next, newfrom, newto);
+			err = fuse_fs_rename(ic->next, newfrom, newto, flags);
 			free(newto);
 		}
 		free(newfrom);
diff --git a/lib/modules/subdir.c b/lib/modules/subdir.c
index 05eccdf..a039b3c 100644
--- a/lib/modules/subdir.c
+++ b/lib/modules/subdir.c
@@ -267,7 +267,7 @@ static int subdir_symlink(const char *from, const char *path)
 	return err;
 }
 
-static int subdir_rename(const char *from, const char *to)
+static int subdir_rename(const char *from, const char *to, unsigned int flags)
 {
 	struct subdir *d = subdir_get();
 	char *newfrom;
@@ -276,7 +276,7 @@ static int subdir_rename(const char *from, const char *to)
 	if (!err) {
 		err = subdir_addpath(d, to, &newto);
 		if (!err) {
-			err = fuse_fs_rename(d->next, newfrom, newto);
+			err = fuse_fs_rename(d->next, newfrom, newto, flags);
 			free(newto);
 		}
 		free(newfrom);