1 files changed, 162 insertions, 118 deletions

diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 7e44ccaf348f..a0c65adce1ab 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -34,6 +34,7 @@
 #include "disk-io.h"
 #include "transaction.h"
 #include "btrfs_inode.h"
+#include "direct-io.h"
 #include "props.h"
 #include "xattr.h"
 #include "bio.h"
@@ -81,9 +82,9 @@ struct btrfs_fs_context {
 	u32 commit_interval;
 	u32 metadata_ratio;
 	u32 thread_pool_size;
-	unsigned long mount_opt;
+	unsigned long long mount_opt;
 	unsigned long compress_type:4;
-	unsigned int compress_level;
+	int compress_level;
 	refcount_t refs;
 };
 
@@ -119,14 +120,11 @@ enum {
 	Opt_thread_pool,
 	Opt_treelog,
 	Opt_user_subvol_rm_allowed,
+	Opt_norecovery,
 
 	/* Rescue options */
 	Opt_rescue,
 	Opt_usebackuproot,
-	Opt_nologreplay,
-	Opt_ignorebadroots,
-	Opt_ignoredatacsums,
-	Opt_rescue_all,
 
 	/* Debugging options */
 	Opt_enospc_debug,
@@ -177,6 +175,8 @@ enum {
 	Opt_rescue_nologreplay,
 	Opt_rescue_ignorebadroots,
 	Opt_rescue_ignoredatacsums,
+	Opt_rescue_ignoremetacsums,
+	Opt_rescue_ignoresuperflags,
 	Opt_rescue_parameter_all,
 };
 
@@ -186,7 +186,11 @@ static const struct constant_table btrfs_parameter_rescue[] = {
 	{ "ignorebadroots", Opt_rescue_ignorebadroots },
 	{ "ibadroots", Opt_rescue_ignorebadroots },
 	{ "ignoredatacsums", Opt_rescue_ignoredatacsums },
+	{ "ignoremetacsums", Opt_rescue_ignoremetacsums},
+	{ "ignoresuperflags", Opt_rescue_ignoresuperflags},
 	{ "idatacsums", Opt_rescue_ignoredatacsums },
+	{ "imetacsums", Opt_rescue_ignoremetacsums},
+	{ "isuperflags", Opt_rescue_ignoresuperflags},
 	{ "all", Opt_rescue_parameter_all },
 	{}
 };
@@ -241,10 +245,10 @@ static const struct fs_parameter_spec btrfs_fs_parameters[] = {
 
 	/* Rescue options. */
 	fsparam_enum("rescue", Opt_rescue, btrfs_parameter_rescue),
-	/* Deprecated, with alias rescue=nologreplay */
-	__fsparam(NULL, "nologreplay", Opt_nologreplay, fs_param_deprecated, NULL),
 	/* Deprecated, with alias rescue=usebackuproot */
 	__fsparam(NULL, "usebackuproot", Opt_usebackuproot, fs_param_deprecated, NULL),
+	/* For compatibility only, alias for "rescue=nologreplay". */
+	fsparam_flag("norecovery", Opt_norecovery),
 
 	/* Debugging options. */
 	fsparam_flag_no("enospc_debug", Opt_enospc_debug),
@@ -332,6 +336,15 @@ static int btrfs_parse_param(struct fs_context *fc, struct fs_parameter *param)
 		fallthrough;
 	case Opt_compress:
 	case Opt_compress_type:
+		/*
+		 * Provide the same semantics as older kernels that don't use fs
+		 * context, specifying the "compress" option clears
+		 * "force-compress" without the need to pass
+		 * "compress-force=[no|none]" before specifying "compress".
+		 */
+		if (opt != Opt_compress_force && opt != Opt_compress_force_type)
+			btrfs_clear_opt(ctx->mount_opt, FORCE_COMPRESS);
+
 		if (opt == Opt_compress || opt == Opt_compress_force) {
 			ctx->compress_type = BTRFS_COMPRESS_ZLIB;
 			ctx->compress_level = BTRFS_ZLIB_DEFAULT_LEVEL;
@@ -433,9 +446,9 @@ static int btrfs_parse_param(struct fs_context *fc, struct fs_parameter *param)
 		else
 			btrfs_clear_opt(ctx->mount_opt, NOTREELOG);
 		break;
-	case Opt_nologreplay:
-		btrfs_warn(NULL,
-		"'nologreplay' is deprecated, use 'rescue=nologreplay' instead");
+	case Opt_norecovery:
+		btrfs_info(NULL,
+"'norecovery' is for compatibility only, recommended to use 'rescue=nologreplay'");
 		btrfs_set_opt(ctx->mount_opt, NOLOGREPLAY);
 		break;
 	case Opt_flushoncommit:
@@ -548,6 +561,10 @@ static int btrfs_parse_param(struct fs_context *fc, struct fs_parameter *param)
 		break;
 	case Opt_commit_interval:
 		ctx->commit_interval = result.uint_32;
+		if (ctx->commit_interval > BTRFS_WARNING_COMMIT_INTERVAL) {
+			btrfs_warn(NULL, "excessive commit interval %u, use with care",
+				   ctx->commit_interval);
+		}
 		if (ctx->commit_interval == 0)
 			ctx->commit_interval = BTRFS_DEFAULT_COMMIT_INTERVAL;
 		break;
@@ -565,8 +582,16 @@ static int btrfs_parse_param(struct fs_context *fc, struct fs_parameter *param)
 		case Opt_rescue_ignoredatacsums:
 			btrfs_set_opt(ctx->mount_opt, IGNOREDATACSUMS);
 			break;
+		case Opt_rescue_ignoremetacsums:
+			btrfs_set_opt(ctx->mount_opt, IGNOREMETACSUMS);
+			break;
+		case Opt_rescue_ignoresuperflags:
+			btrfs_set_opt(ctx->mount_opt, IGNORESUPERFLAGS);
+			break;
 		case Opt_rescue_parameter_all:
 			btrfs_set_opt(ctx->mount_opt, IGNOREDATACSUMS);
+			btrfs_set_opt(ctx->mount_opt, IGNOREMETACSUMS);
+			btrfs_set_opt(ctx->mount_opt, IGNORESUPERFLAGS);
 			btrfs_set_opt(ctx->mount_opt, IGNOREBADROOTS);
 			btrfs_set_opt(ctx->mount_opt, NOLOGREPLAY);
 			break;
@@ -621,8 +646,8 @@ static void btrfs_clear_oneshot_options(struct btrfs_fs_info *fs_info)
 	btrfs_clear_opt(fs_info->mount_opt, NOSPACECACHE);
 }
 
-static bool check_ro_option(struct btrfs_fs_info *fs_info,
-			    unsigned long mount_opt, unsigned long opt,
+static bool check_ro_option(const struct btrfs_fs_info *fs_info,
+			    unsigned long long mount_opt, unsigned long long opt,
 			    const char *opt_name)
 {
 	if (mount_opt & opt) {
@@ -633,7 +658,8 @@ static bool check_ro_option(struct btrfs_fs_info *fs_info,
 	return false;
 }
 
-bool btrfs_check_options(struct btrfs_fs_info *info, unsigned long *mount_opt,
+bool btrfs_check_options(const struct btrfs_fs_info *info,
+			 unsigned long long *mount_opt,
 			 unsigned long flags)
 {
 	bool ret = true;
@@ -641,7 +667,9 @@ bool btrfs_check_options(struct btrfs_fs_info *info, unsigned long *mount_opt,
 	if (!(flags & SB_RDONLY) &&
 	    (check_ro_option(info, *mount_opt, BTRFS_MOUNT_NOLOGREPLAY, "nologreplay") ||
 	     check_ro_option(info, *mount_opt, BTRFS_MOUNT_IGNOREBADROOTS, "ignorebadroots") ||
-	     check_ro_option(info, *mount_opt, BTRFS_MOUNT_IGNOREDATACSUMS, "ignoredatacsums")))
+	     check_ro_option(info, *mount_opt, BTRFS_MOUNT_IGNOREDATACSUMS, "ignoredatacsums") ||
+	     check_ro_option(info, *mount_opt, BTRFS_MOUNT_IGNOREMETACSUMS, "ignoremetacsums") ||
+	     check_ro_option(info, *mount_opt, BTRFS_MOUNT_IGNORESUPERFLAGS, "ignoresuperflags")))
 		ret = false;
 
 	if (btrfs_fs_compat_ro(info, FREE_SPACE_TREE) &&
@@ -660,8 +688,11 @@ bool btrfs_check_options(struct btrfs_fs_info *info, unsigned long *mount_opt,
 		ret = false;
 
 	if (!test_bit(BTRFS_FS_STATE_REMOUNTING, &info->fs_state)) {
-		if (btrfs_raw_test_opt(*mount_opt, SPACE_CACHE))
+		if (btrfs_raw_test_opt(*mount_opt, SPACE_CACHE)) {
 			btrfs_info(info, "disk space caching is enabled");
+			btrfs_warn(info,
+"space cache v1 is being deprecated and will be removed in a future release, please use -o space_cache=v2");
+		}
 		if (btrfs_raw_test_opt(*mount_opt, FREE_SPACE_TREE))
 			btrfs_info(info, "using free-space-tree");
 	}
@@ -910,10 +941,9 @@ static int get_default_subvol_objectid(struct btrfs_fs_info *fs_info, u64 *objec
 }
 
 static int btrfs_fill_super(struct super_block *sb,
-			    struct btrfs_fs_devices *fs_devices,
-			    void *data)
+			    struct btrfs_fs_devices *fs_devices)
 {
-	struct inode *inode;
+	struct btrfs_inode *inode;
 	struct btrfs_fs_info *fs_info = btrfs_sb(sb);
 	int err;
 
@@ -927,7 +957,7 @@ static int btrfs_fill_super(struct super_block *sb,
 #endif
 	sb->s_xattr = btrfs_xattr_handlers;
 	sb->s_time_gran = 1;
-	sb->s_iflags |= SB_I_CGROUPWB;
+	sb->s_iflags |= SB_I_CGROUPWB | SB_I_ALLOW_HSM;
 
 	err = super_setup_bdi(sb);
 	if (err) {
@@ -935,20 +965,20 @@ static int btrfs_fill_super(struct super_block *sb,
 		return err;
 	}
 
-	err = open_ctree(sb, fs_devices, (char *)data);
+	err = open_ctree(sb, fs_devices);
 	if (err) {
-		btrfs_err(fs_info, "open_ctree failed");
+		btrfs_err(fs_info, "open_ctree failed: %d", err);
 		return err;
 	}
 
-	inode = btrfs_iget(sb, BTRFS_FIRST_FREE_OBJECTID, fs_info->fs_root);
+	inode = btrfs_iget(BTRFS_FIRST_FREE_OBJECTID, fs_info->fs_root);
 	if (IS_ERR(inode)) {
 		err = PTR_ERR(inode);
 		btrfs_handle_fs_error(fs_info, err, NULL);
 		goto fail_close;
 	}
 
-	sb->s_root = d_make_root(inode);
+	sb->s_root = d_make_root(&inode->vfs_inode);
 	if (!sb->s_root) {
 		err = -ENOMEM;
 		goto fail_close;
@@ -975,7 +1005,7 @@ int btrfs_sync_fs(struct super_block *sb, int wait)
 		return 0;
 	}
 
-	btrfs_wait_ordered_roots(fs_info, U64_MAX, 0, (u64)-1);
+	btrfs_wait_ordered_roots(fs_info, U64_MAX, NULL);
 
 	trans = btrfs_attach_transaction_barrier(root);
 	if (IS_ERR(trans)) {
@@ -1057,6 +1087,10 @@ static int btrfs_show_options(struct seq_file *seq, struct dentry *dentry)
 		print_rescue_option(seq, "ignorebadroots", &printed);
 	if (btrfs_test_opt(info, IGNOREDATACSUMS))
 		print_rescue_option(seq, "ignoredatacsums", &printed);
+	if (btrfs_test_opt(info, IGNOREMETACSUMS))
+		print_rescue_option(seq, "ignoremetacsums", &printed);
+	if (btrfs_test_opt(info, IGNORESUPERFLAGS))
+		print_rescue_option(seq, "ignoresuperflags", &printed);
 	if (btrfs_test_opt(info, FLUSHONCOMMIT))
 		seq_puts(seq, ",flushoncommit");
 	if (btrfs_test_opt(info, DISCARD_SYNC))
@@ -1097,13 +1131,11 @@ static int btrfs_show_options(struct seq_file *seq, struct dentry *dentry)
 #endif
 	if (btrfs_test_opt(info, REF_VERIFY))
 		seq_puts(seq, ",ref_verify");
-	seq_printf(seq, ",subvolid=%llu",
-		  BTRFS_I(d_inode(dentry))->root->root_key.objectid);
+	seq_printf(seq, ",subvolid=%llu", btrfs_root_id(BTRFS_I(d_inode(dentry))->root));
 	subvol_name = btrfs_get_subvol_name_from_objectid(info,
-			BTRFS_I(d_inode(dentry))->root->root_key.objectid);
+			btrfs_root_id(BTRFS_I(d_inode(dentry))->root));
 	if (!IS_ERR(subvol_name)) {
-		seq_puts(seq, ",subvol=");
-		seq_escape(seq, subvol_name, " \t\n\\");
+		seq_show_option(seq, "subvol", subvol_name);
 		kfree(subvol_name);
 	}
 	return 0;
@@ -1112,11 +1144,11 @@ static int btrfs_show_options(struct seq_file *seq, struct dentry *dentry)
 /*
  * subvolumes are identified by ino 256
  */
-static inline int is_subvolume_inode(struct inode *inode)
+static inline bool is_subvolume_inode(struct inode *inode)
 {
 	if (inode && inode->i_ino == BTRFS_FIRST_FREE_OBJECTID)
-		return 1;
-	return 0;
+		return true;
+	return false;
 }
 
 static struct dentry *mount_subvol(const char *subvol_name, u64 subvol_objectid,
@@ -1152,7 +1184,7 @@ static struct dentry *mount_subvol(const char *subvol_name, u64 subvol_objectid,
 		struct super_block *s = root->d_sb;
 		struct btrfs_fs_info *fs_info = btrfs_sb(s);
 		struct inode *root_inode = d_inode(root);
-		u64 root_objectid = BTRFS_I(root_inode)->root->root_key.objectid;
+		u64 root_objectid = btrfs_root_id(BTRFS_I(root_inode)->root);
 
 		ret = 0;
 		if (!is_subvolume_inode(root_inode)) {
@@ -1206,7 +1238,7 @@ static void btrfs_resize_thread_pool(struct btrfs_fs_info *fs_info,
 }
 
 static inline void btrfs_remount_begin(struct btrfs_fs_info *fs_info,
-				       unsigned long old_opts, int flags)
+				       unsigned long long old_opts, int flags)
 {
 	if (btrfs_raw_test_opt(old_opts, AUTO_DEFRAG) &&
 	    (!btrfs_raw_test_opt(fs_info->mount_opt, AUTO_DEFRAG) ||
@@ -1220,7 +1252,7 @@ static inline void btrfs_remount_begin(struct btrfs_fs_info *fs_info,
 }
 
 static inline void btrfs_remount_cleanup(struct btrfs_fs_info *fs_info,
-					 unsigned long old_opts)
+					 unsigned long long old_opts)
 {
 	const bool cache_opt = btrfs_test_opt(fs_info, SPACE_CACHE);
 
@@ -1415,6 +1447,8 @@ static void btrfs_emit_options(struct btrfs_fs_info *info,
 	btrfs_info_if_set(info, old, USEBACKUPROOT, "trying to use backup root at mount time");
 	btrfs_info_if_set(info, old, IGNOREBADROOTS, "ignoring bad roots");
 	btrfs_info_if_set(info, old, IGNOREDATACSUMS, "ignoring data csums");
+	btrfs_info_if_set(info, old, IGNOREMETACSUMS, "ignoring meta csums");
+	btrfs_info_if_set(info, old, IGNORESUPERFLAGS, "ignoring unknown super block flags");
 
 	btrfs_info_if_unset(info, old, NODATACOW, "setting datacow");
 	btrfs_info_if_unset(info, old, SSD, "not using ssd optimizations");
@@ -1466,8 +1500,7 @@ static int btrfs_reconfigure(struct fs_context *fc)
 	sync_filesystem(sb);
 	set_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state);
 
-	if (!mount_reconfigure &&
-	    !btrfs_check_options(fs_info, &ctx->mount_opt, fc->sb_flags))
+	if (!btrfs_check_options(fs_info, &ctx->mount_opt, fc->sb_flags))
 		return -EINVAL;
 
 	ret = btrfs_check_features(fs_info, !(fc->sb_flags & SB_RDONLY));
@@ -1774,10 +1807,8 @@ static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf)
 	buf->f_fsid.val[0] = be32_to_cpu(fsid[0]) ^ be32_to_cpu(fsid[2]);
 	buf->f_fsid.val[1] = be32_to_cpu(fsid[1]) ^ be32_to_cpu(fsid[3]);
 	/* Mask in the root object ID too, to disambiguate subvols */
-	buf->f_fsid.val[0] ^=
-		BTRFS_I(d_inode(dentry))->root->root_key.objectid >> 32;
-	buf->f_fsid.val[1] ^=
-		BTRFS_I(d_inode(dentry))->root->root_key.objectid;
+	buf->f_fsid.val[0] ^= btrfs_root_id(BTRFS_I(d_inode(dentry))->root) >> 32;
+	buf->f_fsid.val[1] ^= btrfs_root_id(BTRFS_I(d_inode(dentry))->root);
 
 	return 0;
 }
@@ -1849,18 +1880,21 @@ static int btrfs_get_tree_super(struct fs_context *fc)
 
 	if (sb->s_root) {
 		btrfs_close_devices(fs_devices);
-		if ((fc->sb_flags ^ sb->s_flags) & SB_RDONLY)
-			ret = -EBUSY;
+		/*
+		 * At this stage we may have RO flag mismatch between
+		 * fc->sb_flags and sb->s_flags.  Caller should detect such
+		 * mismatch and reconfigure with sb->s_umount rwsem held if
+		 * needed.
+		 */
 	} else {
 		snprintf(sb->s_id, sizeof(sb->s_id), "%pg", bdev);
 		shrinker_debugfs_rename(sb->s_shrink, "sb-btrfs:%s", sb->s_id);
 		btrfs_sb(sb)->bdev_holder = &btrfs_fs_type;
-		ret = btrfs_fill_super(sb, fs_devices, NULL);
-	}
-
-	if (ret) {
-		deactivate_locked_super(sb);
-		return ret;
+		ret = btrfs_fill_super(sb, fs_devices);
+		if (ret) {
+			deactivate_locked_super(sb);
+			return ret;
+		}
 	}
 
 	btrfs_clear_oneshot_options(fs_info);
@@ -1941,59 +1975,23 @@ error:
  *     fsconfig(FSCONFIG_SET_FLAG, "ro"). This option is seen by the filesystem
  *     in fc->sb_flags.
  *
- * This disambiguation has rather positive consequences.  Mounting a subvolume
- * ro will not also turn the superblock ro. Only the mount for the subvolume
- * will become ro.
- *
- * So, if the superblock creation request comes from the new mount API the
- * caller must have explicitly done:
- *
- *      fsconfig(FSCONFIG_SET_FLAG, "ro")
- *      fsmount/mount_setattr(MOUNT_ATTR_RDONLY)
- *
- * IOW, at some point the caller must have explicitly turned the whole
- * superblock ro and we shouldn't just undo it like we did for the old mount
- * API. In any case, it lets us avoid the hack in the new mount API.
- *
- * Consequently, the remounting hack must only be used for requests originating
- * from the old mount API and should be marked for full deprecation so it can be
- * turned off in a couple of years.
- *
- * The new mount API has no reason to support this hack.
+ * But, currently the util-linux mount command already utilizes the new mount
+ * API and is still setting fsconfig(FSCONFIG_SET_FLAG, "ro") no matter if it's
+ * btrfs or not, setting the whole super block RO.  To make per-subvolume mounting
+ * work with different options work we need to keep backward compatibility.
  */
-static struct vfsmount *btrfs_reconfigure_for_mount(struct fs_context *fc)
+static int btrfs_reconfigure_for_mount(struct fs_context *fc, struct vfsmount *mnt)
 {
-	struct vfsmount *mnt;
-	int ret;
-	const bool ro2rw = !(fc->sb_flags & SB_RDONLY);
-
-	/*
-	 * We got an EBUSY because our SB_RDONLY flag didn't match the existing
-	 * super block, so invert our setting here and retry the mount so we
-	 * can get our vfsmount.
-	 */
-	if (ro2rw)
-		fc->sb_flags |= SB_RDONLY;
-	else
-		fc->sb_flags &= ~SB_RDONLY;
-
-	mnt = fc_mount(fc);
-	if (IS_ERR(mnt))
-		return mnt;
+	int ret = 0;
 
-	if (!fc->oldapi || !ro2rw)
-		return mnt;
+	if (fc->sb_flags & SB_RDONLY)
+		return ret;
 
-	/* We need to convert to rw, call reconfigure. */
-	fc->sb_flags &= ~SB_RDONLY;
 	down_write(&mnt->mnt_sb->s_umount);
-	ret = btrfs_reconfigure(fc);
+	if (!(fc->sb_flags & SB_RDONLY) && (mnt->mnt_sb->s_flags & SB_RDONLY))
+		ret = btrfs_reconfigure(fc);
 	up_write(&mnt->mnt_sb->s_umount);
-	if (ret) {
-		mntput(mnt);
-		return ERR_PTR(ret);
-	}
-	return mnt;
+	return ret;
 }
 
 static int btrfs_get_tree_subvol(struct fs_context *fc)
@@ -2003,6 +2001,7 @@ static int btrfs_get_tree_subvol(struct fs_context *fc)
 	struct fs_context *dup_fc;
 	struct dentry *dentry;
 	struct vfsmount *mnt;
+	int ret = 0;
 
 	/*
 	 * Setup a dummy root and fs_info for test/set super.  This is because
@@ -2045,11 +2044,16 @@ static int btrfs_get_tree_subvol(struct fs_context *fc)
 	fc->security = NULL;
 
 	mnt = fc_mount(dup_fc);
-	if (PTR_ERR_OR_ZERO(mnt) == -EBUSY)
-		mnt = btrfs_reconfigure_for_mount(dup_fc);
-	put_fs_context(dup_fc);
-	if (IS_ERR(mnt))
+	if (IS_ERR(mnt)) {
+		put_fs_context(dup_fc);
 		return PTR_ERR(mnt);
+	}
+	ret = btrfs_reconfigure_for_mount(dup_fc, mnt);
+	put_fs_context(dup_fc);
+	if (ret) {
+		mntput(mnt);
+		return ret;
+	}
 
 	/*
 	 * This free's ->subvol_name, because if it isn't set we have to
@@ -2168,7 +2172,8 @@ static struct file_system_type btrfs_fs_type = {
 	.init_fs_context	= btrfs_init_fs_context,
 	.parameters		= btrfs_fs_parameters,
 	.kill_sb		= btrfs_kill_super,
-	.fs_flags		= FS_REQUIRES_DEV | FS_BINARY_MOUNTDATA | FS_ALLOW_IDMAP,
+	.fs_flags		= FS_REQUIRES_DEV | FS_BINARY_MOUNTDATA |
+				  FS_ALLOW_IDMAP | FS_MGTIME,
  };
 
 MODULE_ALIAS_FS("btrfs");
@@ -2233,7 +2238,10 @@ static long btrfs_control_ioctl(struct file *file, unsigned int cmd,
 		device = btrfs_scan_one_device(vol->name, BLK_OPEN_READ, false);
 		if (IS_ERR_OR_NULL(device)) {
 			mutex_unlock(&uuid_mutex);
-			ret = PTR_ERR(device);
+			if (IS_ERR(device))
+				ret = PTR_ERR(device);
+			else
+				ret = 0;
 			break;
 		}
 		ret = !(device->fs_devices->num_devices ==
@@ -2252,9 +2260,7 @@ out:
 
 static int btrfs_freeze(struct super_block *sb)
 {
-	struct btrfs_trans_handle *trans;
 	struct btrfs_fs_info *fs_info = btrfs_sb(sb);
-	struct btrfs_root *root = fs_info->tree_root;
 
 	set_bit(BTRFS_FS_FROZEN, &fs_info->flags);
 	/*
@@ -2263,14 +2269,7 @@ static int btrfs_freeze(struct super_block *sb)
 	 * we want to avoid on a frozen filesystem), or do the commit
 	 * ourselves.
 	 */
-	trans = btrfs_attach_transaction_barrier(root);
-	if (IS_ERR(trans)) {
-		/* no transaction, don't bother */
-		if (PTR_ERR(trans) == -ENOENT)
-			return 0;
-		return PTR_ERR(trans);
-	}
-	return btrfs_commit_transaction(trans);
+	return btrfs_commit_current_transaction(fs_info->tree_root);
 }
 
 static int check_dev_super(struct btrfs_device *dev)
@@ -2289,7 +2288,7 @@ static int check_dev_super(struct btrfs_device *dev)
 		return 0;
 
 	/* Only need to check the primary super block. */
-	sb = btrfs_read_dev_one_super(dev->bdev, 0, true);
+	sb = btrfs_read_disk_super(dev->bdev, 0, true);
 	if (IS_ERR(sb))
 		return PTR_ERR(sb);
 
@@ -2374,6 +2373,27 @@ static int btrfs_show_devname(struct seq_file *m, struct dentry *root)
 	return 0;
 }
 
+static long btrfs_nr_cached_objects(struct super_block *sb, struct shrink_control *sc)
+{
+	struct btrfs_fs_info *fs_info = btrfs_sb(sb);
+	const s64 nr = percpu_counter_sum_positive(&fs_info->evictable_extent_maps);
+
+	trace_btrfs_extent_map_shrinker_count(fs_info, nr);
+
+	return nr;
+}
+
+static long btrfs_free_cached_objects(struct super_block *sb, struct shrink_control *sc)
+{
+	const long nr_to_scan = min_t(unsigned long, LONG_MAX, sc->nr_to_scan);
+	struct btrfs_fs_info *fs_info = btrfs_sb(sb);
+
+	btrfs_free_extent_maps(fs_info, nr_to_scan);
+
+	/* The extent map shrinker runs asynchronously, so always return 0. */
+	return 0;
+}
+
 static const struct super_operations btrfs_super_ops = {
 	.drop_inode	= btrfs_drop_inode,
 	.evict_inode	= btrfs_evict_inode,
@@ -2387,6 +2407,8 @@ static const struct super_operations btrfs_super_ops = {
 	.statfs		= btrfs_statfs,
 	.freeze_fs	= btrfs_freeze,
 	.unfreeze_fs	= btrfs_unfreeze,
+	.nr_cached_objects = btrfs_nr_cached_objects,
+	.free_cached_objects = btrfs_free_cached_objects,
 };
 
 static const struct file_operations btrfs_ctl_fops = {
@@ -2419,6 +2441,9 @@ static __cold void btrfs_interface_exit(void)
 static int __init btrfs_print_mod_info(void)
 {
 	static const char options[] = ""
+#ifdef CONFIG_BTRFS_EXPERIMENTAL
+			", experimental=on"
+#endif
 #ifdef CONFIG_BTRFS_DEBUG
 			", debug=on"
 #endif
@@ -2439,7 +2464,17 @@ static int __init btrfs_print_mod_info(void)
 			", fsverity=no"
 #endif
 			;
+
+#ifdef CONFIG_BTRFS_EXPERIMENTAL
+	if (btrfs_get_mod_read_policy() == NULL)
+		pr_info("Btrfs loaded%s\n", options);
+	else
+		pr_info("Btrfs loaded%s, read_policy=%s\n",
+			 options, btrfs_get_mod_read_policy());
+#else
 	pr_info("Btrfs loaded%s\n", options);
+#endif
+
 	return 0;
 }
 
@@ -2474,6 +2509,9 @@ static const struct init_sequence mod_init_seq[] = {
 		.init_func = btrfs_init_cachep,
 		.exit_func = btrfs_destroy_cachep,
 	}, {
+		.init_func = btrfs_init_dio,
+		.exit_func = btrfs_destroy_dio,
+	}, {
 		.init_func = btrfs_transaction_init,
 		.exit_func = btrfs_transaction_exit,
 	}, {
@@ -2483,8 +2521,8 @@ static const struct init_sequence mod_init_seq[] = {
 		.init_func = btrfs_free_space_init,
 		.exit_func = btrfs_free_space_exit,
 	}, {
-		.init_func = extent_state_init_cachep,
-		.exit_func = extent_state_free_cachep,
+		.init_func = btrfs_extent_state_init_cachep,
+		.exit_func = btrfs_extent_state_free_cachep,
 	}, {
 		.init_func = extent_buffer_init_cachep,
 		.exit_func = extent_buffer_free_cachep,
@@ -2492,8 +2530,13 @@ static const struct init_sequence mod_init_seq[] = {
 		.init_func = btrfs_bioset_init,
 		.exit_func = btrfs_bioset_exit,
 	}, {
-		.init_func = extent_map_init,
-		.exit_func = extent_map_exit,
+		.init_func = btrfs_extent_map_init,
+		.exit_func = btrfs_extent_map_exit,
+#ifdef CONFIG_BTRFS_EXPERIMENTAL
+	}, {
+		.init_func = btrfs_read_policy_init,
+		.exit_func = NULL,
+#endif
 	}, {
 		.init_func = ordered_data_init,
 		.exit_func = ordered_data_exit,
@@ -2565,6 +2608,7 @@ static int __init init_btrfs_fs(void)
 late_initcall(init_btrfs_fs);
 module_exit(exit_btrfs_fs)
 
+MODULE_DESCRIPTION("B-Tree File System (BTRFS)");
 MODULE_LICENSE("GPL");
 MODULE_SOFTDEP("pre: crc32c");
 MODULE_SOFTDEP("pre: xxhash64");