@@ -67,7 +67,7 @@ btrfsck: $(objects) btrfsck.o
$(CC) $(CFLAGS) -o btrfsck btrfsck.o $(objects) $(LDFLAGS) $(LIBS)
mkfs.btrfs: $(objects) mkfs.o
- $(CC) $(CFLAGS) -o mkfs.btrfs $(objects) mkfs.o $(LDFLAGS) $(LIBS)
+ $(CC) $(CFLAGS) -o mkfs.btrfs $(objects) mkfs.o $(LDFLAGS) $(LIBS) -lblkid
btrfs-debug-tree: $(objects) debug-tree.o
$(CC) $(CFLAGS) -o btrfs-debug-tree $(objects) debug-tree.o $(LDFLAGS) $(LIBS)
@@ -47,7 +47,10 @@ Specify a label for the filesystem.
.TP
\fB\-m\fR, \fB\-\-metadata \fIprofile\fR
Specify how metadata must be spanned across the devices specified. Valid
-values are raid0, raid1, raid10 or single.
+values are raid0, raid1, raid10, single or dup. Single device will have dup
+set by default except in the case of SSDs which will default to single. This is
+because SSDs can remap blocks internally so duplicate blocks could end up in the
+same erase block which negates the benefits of doing metadata duplication.
.TP
\fB\-M\fR, \fB\-\-mixed\fR
Mix data and metadata chunks together for more efficient space
@@ -39,6 +39,7 @@
#include <linux/fs.h>
#include <ctype.h>
#include <attr/xattr.h>
+#include <blkid/blkid.h>
#include "ctree.h"
#include "disk-io.h"
#include "volumes.h"
@@ -204,7 +205,7 @@ static int create_one_raid_group(struct btrfs_trans_handle *trans,
static int create_raid_groups(struct btrfs_trans_handle *trans,
struct btrfs_root *root, u64 data_profile,
int data_profile_opt, u64 metadata_profile,
- int metadata_profile_opt, int mixed)
+ int metadata_profile_opt, int mixed, int ssd)
{
u64 num_devices = btrfs_super_num_devices(&root->fs_info->super_copy);
u64 allowed;
@@ -215,8 +216,12 @@ static int create_raid_groups(struct btrfs_trans_handle *trans,
* For mixed groups defaults are single/single.
*/
if (!metadata_profile_opt && !mixed) {
+ if (num_devices == 1 && ssd)
+ printf("Detected a SSD, turning off metadata "
+ "duplication. Mkfs with -m dup if you want to "
+ "force metadata duplication.\n");
metadata_profile = (num_devices > 1) ?
- BTRFS_BLOCK_GROUP_RAID1 : BTRFS_BLOCK_GROUP_DUP;
+ BTRFS_BLOCK_GROUP_RAID1 : (ssd) ? 0: BTRFS_BLOCK_GROUP_DUP;
}
if (!data_profile_opt && !mixed) {
data_profile = (num_devices > 1) ?
@@ -1186,6 +1191,54 @@ static int check_leaf_or_node_size(u32 size, u32 sectorsize)
return 0;
}
+static int is_ssd(const char *file)
+{
+ char *devname;
+ blkid_probe probe;
+ char *dev;
+ char path[PATH_MAX];
+ dev_t disk;
+ int fd;
+ char rotational;
+
+ probe = blkid_new_probe_from_filename(file);
+ if (!probe)
+ return 0;
+
+ /*
+ * We want to use blkid_devno_to_wholedisk() but it's broken for some
+ * reason on F17 at least so we'll do this trickery
+ */
+ disk = blkid_probe_get_wholedisk_devno(probe);
+ if (!disk)
+ return 0;
+
+ devname = blkid_devno_to_devname(disk);
+ if (!devname)
+ return 0;
+
+ dev = strrchr(devname, '/');
+ dev++;
+
+ snprintf(path, PATH_MAX, "/sys/block/%s/queue/rotational", dev);
+
+ free(devname);
+ blkid_free_probe(probe);
+
+ fd = open(path, O_RDONLY);
+ if (fd < 0) {
+ return 0;
+ }
+
+ if (read(fd, &rotational, sizeof(char)) < sizeof(char)) {
+ close(fd);
+ return 0;
+ }
+ close(fd);
+
+ return !atoi((const char *)&rotational);
+}
+
int main(int ac, char **av)
{
char *file;
@@ -1212,6 +1265,7 @@ int main(int ac, char **av)
int data_profile_opt = 0;
int metadata_profile_opt = 0;
int nodiscard = 0;
+ int ssd = 0;
char *source_dir = NULL;
int source_dir_set = 0;
@@ -1331,6 +1385,9 @@ int main(int ac, char **av)
exit(1);
}
}
+
+ ssd = is_ssd(file);
+
if (mixed) {
if (metadata_profile != data_profile) {
fprintf(stderr, "With mixed block groups data and metadata "
@@ -1416,7 +1473,7 @@ raid_groups:
if (!source_dir_set) {
ret = create_raid_groups(trans, root, data_profile,
data_profile_opt, metadata_profile,
- metadata_profile_opt, mixed);
+ metadata_profile_opt, mixed, ssd);
BUG_ON(ret);
}