Commit c289811c authored by Chris Mason's avatar Chris Mason
Browse files

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: default avatarChris Mason <chris.mason@oracle.com>
parent 451d7585

fs/btrfs/ctree.h

+1 −0
Original line number Diff line number Diff line
@@ -1101,6 +1101,7 @@ struct btrfs_root { 
#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)

fs/btrfs/disk-io.c

+9 −0
Original line number Diff line number Diff line
@@ -1850,6 +1850,14 @@ struct btrfs_root *open_ctree(struct super_block *sb, 
	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 @@ struct btrfs_root *open_ctree(struct super_block *sb, 
	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:

fs/btrfs/super.c

+3 −0
Original line number Diff line number Diff line
@@ -184,6 +184,7 @@ int btrfs_parse_options(struct btrfs_root *root, char *options) 
		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 @@ static int btrfs_show_options(struct seq_file *seq, struct vfsmount *vfs) 
		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))

fs/btrfs/volumes.c

+6 −0
Original line number Diff line number Diff line
@@ -605,6 +605,9 @@ static int __btrfs_open_devices(struct btrfs_fs_devices *fs_devices, 
		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 @@ int btrfs_init_new_device(struct btrfs_root *root, char *device_path) 
	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);

fs/btrfs/volumes.h

+5 −0
Original line number Diff line number Diff line
@@ -107,6 +107,11 @@ struct btrfs_fs_devices { 
	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 {

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