Btrfs: autodetect SSD devices
During mount, btrfs will check the queue nonrot flag
for all the devices found in the FS. If they are all
non-rotating, SSD mode is enabled by default.
If the FS was mounted with -o nossd, the non-rotating
flag is ignored.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index b9d8788..5fa7d7d 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -1101,6 +1101,7 @@
#define BTRFS_MOUNT_NOTREELOG (1 << 6)
#define BTRFS_MOUNT_FLUSHONCOMMIT (1 << 7)
#define BTRFS_MOUNT_SSD_SPREAD (1 << 8)
+#define BTRFS_MOUNT_NOSSD (1 << 9)
#define btrfs_clear_opt(o, opt) ((o) &= ~BTRFS_MOUNT_##opt)
#define btrfs_set_opt(o, opt) ((o) |= BTRFS_MOUNT_##opt)
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index e572cf4..f4dfbb7 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -1850,6 +1850,14 @@
if (IS_ERR(fs_info->transaction_kthread))
goto fail_cleaner;
+ if (!btrfs_test_opt(tree_root, SSD) &&
+ !btrfs_test_opt(tree_root, NOSSD) &&
+ !fs_info->fs_devices->rotating) {
+ printk(KERN_INFO "Btrfs detected SSD devices, enabling SSD "
+ "mode\n");
+ btrfs_set_opt(fs_info->mount_opt, SSD);
+ }
+
if (btrfs_super_log_root(disk_super) != 0) {
u64 bytenr = btrfs_super_log_root(disk_super);
@@ -1893,6 +1901,7 @@
fs_info->fs_root = btrfs_read_fs_root_no_name(fs_info, &location);
if (!fs_info->fs_root)
goto fail_trans_kthread;
+
return tree_root;
fail_trans_kthread:
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 7f5b288..3427db2 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -184,6 +184,7 @@
case Opt_nossd:
printk(KERN_INFO "btrfs: not using ssd allocation "
"scheme\n");
+ btrfs_set_opt(info->mount_opt, NOSSD);
btrfs_clear_opt(info->mount_opt, SSD);
btrfs_clear_opt(info->mount_opt, SSD_SPREAD);
break;
@@ -438,6 +439,8 @@
seq_printf(seq, ",thread_pool=%d", info->thread_pool_size);
if (btrfs_test_opt(root, COMPRESS))
seq_puts(seq, ",compress");
+ if (btrfs_test_opt(root, NOSSD))
+ seq_puts(seq, ",nossd");
if (btrfs_test_opt(root, SSD_SPREAD))
seq_puts(seq, ",ssd_spread");
else if (btrfs_test_opt(root, SSD))
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 27d5f37..3f4a593 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -605,6 +605,9 @@
device->in_fs_metadata = 0;
device->mode = flags;
+ if (!blk_queue_nonrot(bdev_get_queue(bdev)))
+ fs_devices->rotating = 1;
+
fs_devices->open_devices++;
if (device->writeable) {
fs_devices->rw_devices++;
@@ -1473,6 +1476,9 @@
root->fs_info->fs_devices->rw_devices++;
root->fs_info->fs_devices->total_rw_bytes += device->total_bytes;
+ if (!blk_queue_nonrot(bdev_get_queue(bdev)))
+ root->fs_info->fs_devices->rotating = 1;
+
total_bytes = btrfs_super_total_bytes(&root->fs_info->super_copy);
btrfs_set_super_total_bytes(&root->fs_info->super_copy,
total_bytes + device->total_bytes);
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index 5c3ff6d..3c1f731 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -107,6 +107,11 @@
int seeding;
int opened;
+
+ /* set when we find or add a device that doesn't have the
+ * nonrot flag set
+ */
+ int rotating;
};
struct btrfs_bio_stripe {