libroot: generate a name for nameless volumes

Generate a name indicating the volume size and filesystem.

Remove code that was doing that or similar things in various
filesystems.

Change-Id: I6b993735e58cdfaf1f19af575e918614c7fe5679
Reviewed-on: https://review.haiku-os.org/c/haiku/+/5381
Tested-by: Commit checker robot <no-reply+buildbot@haiku-os.org>
Reviewed-by: Jessica Hamilton <jessica.l.hamilton@gmail.com>
Reviewed-by: John Scipione <jscipione@gmail.com>

src/add-ons/kernel/file_systems/ext2/Volume.cpp

@@ -109,10 +109,8 @@ Volume::HasExtendedAttributes() const
 const char*
 Volume::Name() const
 {
-	if (fSuperBlock.name[0])
-		return fSuperBlock.name;
-
-	return fName;
+	// The name may be empty, in that case, userspace will generate one.
+	return fSuperBlock.name;
 }
 
 
@@ -333,26 +331,6 @@ Volume::Mount(const char* deviceName, uint32 flags)
 	// all went fine
 	opener.Keep();
 
-	if (!fSuperBlock.name[0]) {
-		// generate a more or less descriptive volume name
-		off_t divisor = 1ULL << 40;
-		char unit = 'T';
-		if (diskSize < divisor) {
-			divisor = 1UL << 30;
-			unit = 'G';
-			if (diskSize < divisor) {
-				divisor = 1UL << 20;
-				unit = 'M';
-			}
-		}
-
-		double size = double((10 * diskSize + divisor - 1) / divisor);
-			// %g in the kernel does not support precision...
-
-		snprintf(fName, sizeof(fName), "%g %cB Ext2 Volume",
-			size / 10, unit);
-	}
-
 	return B_OK;
 }
 

src/add-ons/kernel/file_systems/ext2/Volume.h

@@ -166,7 +166,6 @@ private:
 			fs_volume*			fFSVolume;
 			int					fDevice;
 			ext2_super_block	fSuperBlock;
-			char				fName[32];
 
 			BlockAllocator*		fBlockAllocator;
 			InodeAllocator		fInodeAllocator;

src/add-ons/kernel/file_systems/fat/dosfs.cpp

@@ -710,7 +710,7 @@ dosfs_identify_partition(int fd, partition_data *partition, void **_cookie)
 	if (buf[0x15] != 0xf0 && buf[0x15] < 0xf8)
 		return -1;
 
-	strcpy(name, "no name");
+	name[0] = 0;
 	sectors_per_fat = read16(buf, 0x16);
 	if (sectors_per_fat == 0) {
 		total_sectors = read32(buf, 0x20);
@@ -995,8 +995,10 @@ dosfs_read_fs_stat(fs_volume *_vol, struct fs_info * fss)
 
 	if (vol->vol_entry > -2)
 		strlcpy(fss->volume_name, vol->vol_label, sizeof(fss->volume_name));
-	else
-		strcpy(fss->volume_name, "no name");
+	else {
+		// No name defined, let userspace decide of one
+		fss->volume_name[0] = 0;
+	}
 
 	sanitize_name(fss->volume_name, 12);
 

src/system/kernel/lib/Jamfile

@@ -21,7 +21,7 @@ local posixSources = [ FDirName $(librootSources) posix ] ;
 local sources =
 	driver_settings.cpp
 	find_directory.cpp
-	fs_info.c
+	fs_info.cpp
 	system_revision.c
 	wait_for_objects.cpp
 	;

src/system/libroot/os/Jamfile

@@ -24,7 +24,7 @@ for architectureObject in [ MultiArchSubDirSetup ] {
 			find_paths.cpp
 			fs_attr.cpp
 			fs_index.c
-			fs_info.c
+			fs_info.cpp
 			fs_query.cpp
 			fs_volume.c
 			image.cpp

src/system/libroot/os/fs_info.cpp

@@ -6,9 +6,10 @@
 
 #include <fs_info.h>
 
-#include <stdlib.h>
-#include <fcntl.h>
 #include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
 
 #include <errno_private.h>
 #include <syscalls.h>
@@ -40,6 +41,28 @@ fs_stat_dev(dev_t device, fs_info *info)
 {
 	status_t status = _kern_read_fs_info(device, info);
 
+	if (info != NULL) {
+		if (info->volume_name[0] == 0) {
+			// Give a default name to unnamed volumes
+			off_t divisor = 1ULL << 40;
+			off_t diskSize = info->total_blocks * info->block_size;
+
+			char unit = 'T';
+			if (diskSize < divisor) {
+				divisor = 1UL << 30;
+				unit = 'G';
+				if (diskSize < divisor) {
+					divisor = 1UL << 20;
+					unit = 'M';
+				}
+			}
+
+			double size = double((10 * diskSize + divisor - 1) / divisor);
+
+			sprintf(info->volume_name, "%g %ciB %s volume", size / 10, unit, info->fsh_name);
+		}
+	}
+
 	RETURN_AND_SET_ERRNO(status);
 }