[PATCH v3 2/2] erofs-utils: lib: Add API to get on disk size of an inode

[Kelvin Zhang]

Marginally improve code re-use. It's quite common for users to query for
compressed size of an inode.

Signed-off-by: Kelvin Zhang <zhangkelvin at google.com>
---
 dump/main.c              |  4 ++--
 include/erofs/internal.h | 23 +++++++++++++++++++++++
 2 files changed, 25 insertions(+), 2 deletions(-)

diff --git a/dump/main.c b/dump/main.c
index 71b44b4..4c2c513 100644
--- a/dump/main.c
+++ b/dump/main.c
@@ -175,7 +175,7 @@ static int erofsdump_parse_options_cfg(int argc, char **argv)
 	return 0;
 }
 
-static int erofs_get_occupied_size(struct erofs_inode *inode,
+static int erofsdump_get_occupied_size(struct erofs_inode *inode,
 		erofs_off_t *size)
 {
 	*size = 0;
@@ -291,7 +291,7 @@ static int erofs_read_dirent(struct erofs_dirent *de,
 		return err;
 	}
 
-	err = erofs_get_occupied_size(&inode, &occupied_size);
+	err = erofsdump_get_occupied_size(&inode, &occupied_size);
 	if (err) {
 		erofs_err("get file size failed\n");
 		return err;
diff --git a/include/erofs/internal.h b/include/erofs/internal.h
index 947304f..c64cf36 100644
--- a/include/erofs/internal.h
+++ b/include/erofs/internal.h
@@ -19,6 +19,7 @@ typedef unsigned short umode_t;
 
 #define __packed __attribute__((__packed__))
 
+#include "erofs/print.h"
 #include "erofs_fs.h"
 #include <fcntl.h>
 
@@ -320,6 +321,28 @@ int erofs_pread(struct erofs_inode *inode, char *buf,
 int erofs_map_blocks(struct erofs_inode *inode,
 		struct erofs_map_blocks *map, int flags);
 int erofs_map_dev(struct erofs_sb_info *sbi, struct erofs_map_dev *map);
+
+static inline int erofs_get_occupied_size(const struct erofs_inode *inode,
+					  erofs_off_t *size)
+{
+	*size = 0;
+	switch (inode->datalayout) {
+	case EROFS_INODE_FLAT_INLINE:
+	case EROFS_INODE_FLAT_PLAIN:
+	case EROFS_INODE_CHUNK_BASED:
+		*size = inode->i_size;
+		break;
+	case EROFS_INODE_FLAT_COMPRESSION_LEGACY:
+	case EROFS_INODE_FLAT_COMPRESSION:
+		*size = inode->u.i_blocks * EROFS_BLKSIZ;
+		break;
+	default:
+		erofs_err("unknown datalayout");
+		return -1;
+	}
+	return 0;
+}
+
 /* zmap.c */
 int z_erofs_fill_inode(struct erofs_inode *vi);
 int z_erofs_map_blocks_iter(struct erofs_inode *vi,
-- 
2.34.1.448.ga2b2bfdf31-goog