libfstools: use container_of for volume private data

Signed-off-by: Felix Fietkau <nbd@nbd.name>

5 files changed, 59 insertions, 64 deletions

diff --git a/libfstools/libfstools.h b/libfstools/libfstools.h
index 31d9f9e..ec760f4 100644
--- a/libfstools/libfstools.h
+++ b/libfstools/libfstools.h
@@ -17,6 +17,7 @@
 #include <libubox/list.h>
 #include <libubox/blob.h>
 #include <libubox/ulog.h>
+#include <libubox/utils.h>
 
 struct volume;
 
diff --git a/libfstools/mtd.c b/libfstools/mtd.c
index 156d166..a1811c3 100644
--- a/libfstools/mtd.c
+++ b/libfstools/mtd.c
@@ -27,7 +27,8 @@
 
 #define PATH_MAX		256
 
-struct mtd_priv {
+struct mtd_volume {
+	struct volume v;
 	int	fd;
 	int	idx;
 	char	*chr;
@@ -60,10 +61,8 @@ static int mtd_open(const char *mtd, int block)
 	return open(mtd, flags);
 }
 
-static void mtd_volume_close(struct volume *v)
+static void mtd_volume_close(struct mtd_volume *p)
 {
-	struct mtd_priv *p = (struct mtd_priv*) v->priv;
-
 	if (!p->fd)
 		return;
 
@@ -71,9 +70,9 @@ static void mtd_volume_close(struct volume *v)
 	p->fd = 0;
 }
 
-static int mtd_volume_load(struct volume *v)
+static int mtd_volume_load(struct mtd_volume *p)
 {
-	struct mtd_priv *p = (struct mtd_priv*) v->priv;
+	struct volume *v = &p->v;
 	struct mtd_info_user mtdInfo;
 	struct erase_info_user mtdLockInfo;
 
@@ -91,7 +90,7 @@ static int mtd_volume_load(struct volume *v)
 	}
 
 	if (ioctl(p->fd, MEMGETINFO, &mtdInfo)) {
-		mtd_volume_close(v);
+		mtd_volume_close(p);
 		ULOG_ERR("Could not get MTD device info from %s\n", p->chr);
 		return -1;
 	}
@@ -148,20 +147,21 @@ static char* mtd_find_index(char *name)
 	return index;
 }
 
-static int mtd_volume_find(struct volume *v, char *name)
+static struct volume *mtd_volume_find(char *name)
 {
 	char *idx = mtd_find_index(name);
-	struct mtd_priv *p;
+	struct mtd_volume *p;
+	struct volume *v;
 	char buffer[32];
 
 	if (!idx)
-		return -1;
+		return NULL;
 
-	p = calloc(1, sizeof(struct mtd_priv));
+	p = calloc(1, sizeof(struct mtd_volume));
 	if (!p)
-		return -1;
+		return NULL;
 
-	v->priv = p;
+	v = &p->v;
 	v->name = strdup(name);
 	v->drv = &mtd_driver;
 	p->idx = atoi(idx);
@@ -172,22 +172,23 @@ static int mtd_volume_find(struct volume *v, char *name)
 	snprintf(buffer, sizeof(buffer), "/dev/mtd%s", idx);
 	p->chr = strdup(buffer);
 
-	if (mtd_volume_load(v)) {
+	if (mtd_volume_load(p)) {
 		ULOG_ERR("reading %s failed\n", v->name);
-		return -1;
+		free(p);
+		return NULL;
 	}
 
-	return 0;
+	return v;
 }
 
 static int mtd_volume_identify(struct volume *v)
 {
-	struct mtd_priv *p = (struct mtd_priv*) v->priv;
+	struct mtd_volume *p = container_of(v, struct mtd_volume, v);;
 	__u32 deadc0de;
 	__u16 jffs2;
 	size_t sz;
 
-	if (mtd_volume_load(v)) {
+	if (mtd_volume_load(p)) {
 		ULOG_ERR("reading %s failed\n", v->name);
 		return -1;
 	}
@@ -221,11 +222,11 @@ static int mtd_volume_identify(struct volume *v)
 
 static int mtd_volume_erase(struct volume *v, int offset, int len)
 {
-	struct mtd_priv *p = (struct mtd_priv*) v->priv;
+	struct mtd_volume *p = container_of(v, struct mtd_volume, v);;
 	struct erase_info_user eiu;
 	int first_block, num_blocks;
 
-	if (mtd_volume_load(v))
+	if (mtd_volume_load(p))
 		return -1;
 
 	if (offset % v->block_size || len % v->block_size) {
@@ -246,26 +247,28 @@ static int mtd_volume_erase(struct volume *v, int offset, int len)
 			ULOG_ERR("Failed to erase block at 0x%x\n", eiu.start);
 	}
 
-	mtd_volume_close(v);
+	mtd_volume_close(p);
 
 	return 0;
 }
 
 static int mtd_volume_erase_all(struct volume *v)
 {
+	struct mtd_volume *p = container_of(v, struct mtd_volume, v);;
+
 	mtd_volume_erase(v, 0, v->size);
-	mtd_volume_close(v);
+	mtd_volume_close(p);
 
 	return 0;
 }
 
 static int mtd_volume_init(struct volume *v)
 {
-	struct mtd_priv *p = (struct mtd_priv*) v->priv;
+	struct mtd_volume *p = container_of(v, struct mtd_volume, v);;
 	struct mtd_info_user mtdinfo;
 	int ret;
 
-	if (mtd_volume_load(v))
+	if (mtd_volume_load(p))
 		return -1;
 
 	ret = ioctl(p->fd, MEMGETINFO, &mtdinfo);
@@ -284,9 +287,9 @@ static int mtd_volume_init(struct volume *v)
 
 static int mtd_volume_read(struct volume *v, void *buf, int offset, int length)
 {
-	struct mtd_priv *p = (struct mtd_priv*) v->priv;
+	struct mtd_volume *p = container_of(v, struct mtd_volume, v);;
 
-	if (mtd_volume_load(v))
+	if (mtd_volume_load(p))
 		return -1;
 
 	if (lseek(p->fd, offset, SEEK_SET) == (off_t) -1) {
@@ -304,9 +307,9 @@ static int mtd_volume_read(struct volume *v, void *buf, int offset, int length)
 
 static int mtd_volume_write(struct volume *v, void *buf, int offset, int length)
 {
-	struct mtd_priv *p = (struct mtd_priv*) v->priv;
+	struct mtd_volume *p = container_of(v, struct mtd_volume, v);;
 
-	if (mtd_volume_load(v))
+	if (mtd_volume_load(p))
 		return -1;
 
 	if (lseek(p->fd, offset, SEEK_SET) == (off_t) -1) {
diff --git a/libfstools/ubi.c b/libfstools/ubi.c
index c1dce46..f9d6e0a 100644
--- a/libfstools/ubi.c
+++ b/libfstools/ubi.c
@@ -26,7 +26,8 @@
  * from sysfs */
 const char *const ubi_dir_name = "/sys/devices/virtual/ubi";
 
-struct ubi_priv {
+struct ubi_volume {
+	struct volume v;
 	int		ubi_num;
 	int		ubi_volid;
 };
@@ -98,12 +99,10 @@ test_open(char *filename)
 
 static int ubi_volume_init(struct volume *v)
 {
+	struct ubi_volume *p = container_of(v, struct ubi_volume, v);
 	char voldir[BUFLEN], voldev[BUFLEN], *volname;
-	struct ubi_priv *p;
 	unsigned int volsize;
 
-	p = (struct ubi_priv*)v->priv;
-
 	snprintf(voldir, sizeof(voldir), "%s/ubi%u/ubi%u_%u",
 		ubi_dir_name, p->ubi_num, p->ubi_num, p->ubi_volid);
 
@@ -125,10 +124,10 @@ static int ubi_volume_init(struct volume *v)
 	return 0;
 }
 
-static int ubi_volume_match(struct volume *v, char *name, int ubi_num, int volid)
+static struct volume *ubi_volume_match(char *name, int ubi_num, int volid)
 {
 	char voldir[BUFLEN], volblkdev[BUFLEN], *volname;
-	struct ubi_priv *p;
+	struct ubi_volume *p;
 
 	snprintf(voldir, sizeof(voldir), "%s/ubi%u/ubi%u_%u",
 		ubi_dir_name, ubi_num, ubi_num, volid);
@@ -138,38 +137,37 @@ static int ubi_volume_match(struct volume *v, char *name, int ubi_num, int volid
 
 	/* skip if ubiblock device exists */
 	if (test_open(volblkdev))
-		return -1;
+		return NULL;
 
 	/* todo: skip existing gluebi device for legacy support */
 
 	volname = read_string_from_file(voldir, "name");
 	if (!volname) {
 		ULOG_ERR("Couldn't read %s/name\n", voldir);
-		return -1;
+		return NULL;
 	}
 
 	if (strncmp(name, volname, strlen(volname) + 1))
-		return -1;
+		return NULL;
 
-	p = calloc(1, sizeof(struct ubi_priv));
+	p = calloc(1, sizeof(struct ubi_volume));
 	if (!p)
-		return -1;
+		return NULL;
 
-	v->priv = p;
-	v->drv = &ubi_driver;
+	p->v.drv = &ubi_driver;
 	p->ubi_num = ubi_num;
 	p->ubi_volid = volid;
 
-	return 0;
+	return &p->v;
 }
 
-static int ubi_part_match(struct volume *v, char *name, unsigned int ubi_num)
+static struct volume *ubi_part_match(char *name, unsigned int ubi_num)
 {
 	DIR *ubi_dir;
 	struct dirent *ubi_dirent;
 	unsigned int volid;
 	char devdir[BUFLEN];
-	int ret = -1;
+	struct volume *ret = NULL;
 
 	snprintf(devdir, sizeof(devdir), "%s/ubi%u",
 		ubi_dir_name, ubi_num);
@@ -185,22 +183,21 @@ static int ubi_part_match(struct volume *v, char *name, unsigned int ubi_num)
 		if (sscanf(ubi_dirent->d_name, "ubi%*u_%u", &volid) != 1)
 			continue;
 
-		if (!ubi_volume_match(v, name, ubi_num, volid)) {
-			ret = 0;
+		ret = ubi_volume_match(name, ubi_num, volid);
+		if (ret)
 			break;
-		}
 	}
 	closedir(ubi_dir);
 
 	return ret;
 }
 
-static int ubi_volume_find(struct volume *v, char *name)
+static struct volume *ubi_volume_find(char *name)
 {
+	struct volume *ret = NULL;
 	DIR *ubi_dir;
 	struct dirent *ubi_dirent;
 	unsigned int ubi_num;
-	int ret = -1;
 
 	if (find_filesystem("ubifs"))
 		return ret;
@@ -216,10 +213,9 @@ static int ubi_volume_find(struct volume *v, char *name)
 			continue;
 
 		sscanf(ubi_dirent->d_name, "ubi%u", &ubi_num);
-		if (!ubi_part_match(v, name, ubi_num)) {
-			ret = 0;
+		ret = ubi_part_match(name, ubi_num);
+		if (ret)
 			break;
-		};
 	}
 	closedir(ubi_dir);
 	return ret;
diff --git a/libfstools/volume.c b/libfstools/volume.c
index 8f920e0..0d293d5 100644
--- a/libfstools/volume.c
+++ b/libfstools/volume.c
@@ -28,20 +28,16 @@ volume_register_driver(struct driver *d)
 
 struct volume* volume_find(char *name)
 {
-	struct volume *v = malloc(sizeof(struct volume));
+	struct volume *v;
 	struct driver *d;
 
-	if (!v)
-		return NULL;
-
 	list_for_each_entry(d, &drivers, list) {
-		memset(v, 0, sizeof(struct volume));
-
-		if (d->find && !d->find(v, name))
-			return v;
+		if (d->find) {
+			v = d->find(name);
+			if (v)
+				return v;
+		}
 	}
 
-	free(v);
-
 	return NULL;
 }
diff --git a/libfstools/volume.h b/libfstools/volume.h
index 9c679f7..fdd97d1 100644
--- a/libfstools/volume.h
+++ b/libfstools/volume.h
@@ -21,7 +21,7 @@ struct volume;
 typedef int (*volume_probe_t)(void);
 typedef int (*volume_init_t)(struct volume *v);
 typedef void (*volume_stop_t)(struct volume *v);
-typedef int (*volume_find_t)(struct volume *v, char *name);
+typedef struct volume *(*volume_find_t)(char *name);
 typedef int (*volume_identify_t)(struct volume *v);
 typedef int (*volume_read_t)(struct volume *v, void *buf, int offset, int length);
 typedef int (*volume_write_t)(struct volume *v, void *buf, int offset, int length);
@@ -51,7 +51,6 @@ enum {
 
 struct volume {
 	struct driver	*drv;
-	void		*priv;
 	char		*name;
 	char		*blk;