ext4: Remove old legacy block allocator

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

fs/ext4/ext4.h

@@ -539,7 +539,6 @@ do {									       \
 #define EXT4_MOUNT_JOURNAL_CHECKSUM	0x800000 /* Journal checksums */
 #define EXT4_MOUNT_JOURNAL_ASYNC_COMMIT	0x1000000 /* Journal Async Commit */
 #define EXT4_MOUNT_I_VERSION            0x2000000 /* i_version support */
-#define EXT4_MOUNT_MBALLOC		0x4000000 /* Buddy allocation support */
 #define EXT4_MOUNT_DELALLOC		0x8000000 /* Delalloc support */
 /* Compatibility, for having both ext2_fs.h and ext4_fs.h included at once */
 #ifndef _LINUX_EXT2_FS_H
@@ -1002,8 +1001,6 @@ extern ext4_fsblk_t ext4_new_meta_blocks(handle_t *handle, struct inode *inode,
 extern ext4_fsblk_t ext4_new_blocks(handle_t *handle, struct inode *inode,
 					ext4_lblk_t iblock, ext4_fsblk_t goal,
 					unsigned long *count, int *errp);
-extern ext4_fsblk_t ext4_old_new_blocks(handle_t *handle, struct inode *inode,
-			ext4_fsblk_t goal, unsigned long *count, int *errp);
 extern int ext4_claim_free_blocks(struct ext4_sb_info *sbi, s64 nblocks);
 extern ext4_fsblk_t ext4_has_free_blocks(struct ext4_sb_info *sbi,
 					 s64 nblocks);
@@ -1018,8 +1015,6 @@ extern struct ext4_group_desc * ext4_get_group_desc(struct super_block * sb,
 						    ext4_group_t block_group,
 						    struct buffer_head ** bh);
 extern int ext4_should_retry_alloc(struct super_block *sb, int *retries);
-extern void ext4_init_block_alloc_info(struct inode *);
-extern void ext4_rsv_window_add(struct super_block *sb, struct ext4_reserve_window_node *rsv);
 
 /* dir.c */
 extern int ext4_check_dir_entry(const char *, struct inode *,
@@ -1054,7 +1049,7 @@ extern int ext4_mb_release(struct super_block *);
 extern ext4_fsblk_t ext4_mb_new_blocks(handle_t *,
 				struct ext4_allocation_request *, int *);
 extern int ext4_mb_reserve_blocks(struct super_block *, int);
-extern void ext4_mb_discard_inode_preallocations(struct inode *);
+extern void ext4_discard_preallocations(struct inode *);
 extern int __init init_ext4_mballoc(void);
 extern void exit_ext4_mballoc(void);
 extern void ext4_mb_free_blocks(handle_t *, struct inode *,
@@ -1084,7 +1079,6 @@ extern int  ext4_getattr(struct vfsmount *mnt, struct dentry *dentry,
 				struct kstat *stat);
 extern void ext4_delete_inode(struct inode *);
 extern int  ext4_sync_inode(handle_t *, struct inode *);
-extern void ext4_discard_reservation(struct inode *);
 extern void ext4_dirty_inode(struct inode *);
 extern int ext4_change_inode_journal_flag(struct inode *, int);
 extern int ext4_get_inode_loc(struct inode *, struct ext4_iloc *);

fs/ext4/ext4_i.h

@@ -33,38 +33,6 @@ typedef __u32 ext4_lblk_t;
 /* data type for block group number */
 typedef unsigned long ext4_group_t;
 
-struct ext4_reserve_window {
-	ext4_fsblk_t	_rsv_start;	/* First byte reserved */
-	ext4_fsblk_t	_rsv_end;	/* Last byte reserved or 0 */
-};
-
-struct ext4_reserve_window_node {
-	struct rb_node		rsv_node;
-	__u32			rsv_goal_size;
-	__u32			rsv_alloc_hit;
-	struct ext4_reserve_window	rsv_window;
-};
-
-struct ext4_block_alloc_info {
-	/* information about reservation window */
-	struct ext4_reserve_window_node rsv_window_node;
-	/*
-	 * was i_next_alloc_block in ext4_inode_info
-	 * is the logical (file-relative) number of the
-	 * most-recently-allocated block in this file.
-	 * We use this for detecting linearly ascending allocation requests.
-	 */
-	ext4_lblk_t last_alloc_logical_block;
-	/*
-	 * Was i_next_alloc_goal in ext4_inode_info
-	 * is the *physical* companion to i_next_alloc_block.
-	 * it the physical block number of the block which was most-recentl
-	 * allocated to this file.  This give us the goal (target) for the next
-	 * allocation when we detect linearly ascending requests.
-	 */
-	ext4_fsblk_t last_alloc_physical_block;
-};
-
 #define rsv_start rsv_window._rsv_start
 #define rsv_end rsv_window._rsv_end
 
@@ -97,9 +65,6 @@ struct ext4_inode_info {
 	ext4_group_t	i_block_group;
 	__u32	i_state;		/* Dynamic state flags for ext4 */
 
-	/* block reservation info */
-	struct ext4_block_alloc_info *i_block_alloc_info;
-
 	ext4_lblk_t		i_dir_start_lookup;
 #ifdef CONFIG_EXT4DEV_FS_XATTR
 	/*

fs/ext4/ext4_sb.h

@@ -67,7 +67,6 @@ struct ext4_sb_info {
 	/* root of the per fs reservation window tree */
 	spinlock_t s_rsv_window_lock;
 	struct rb_root s_rsv_window_root;
-	struct ext4_reserve_window_node s_rsv_window_head;
 
 	/* Journaling */
 	struct inode *s_journal_inode;

fs/ext4/extents.c

@@ -2697,11 +2697,8 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,
 		goto out2;
 	}
 	/*
-	 * Okay, we need to do block allocation.  Lazily initialize the block
-	 * allocation info here if necessary.
+	 * Okay, we need to do block allocation.
 	 */
-	if (S_ISREG(inode->i_mode) && (!EXT4_I(inode)->i_block_alloc_info))
-		ext4_init_block_alloc_info(inode);
 
 	/* find neighbour allocated blocks */
 	ar.lleft = iblock;
@@ -2761,7 +2758,7 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,
 		/* free data blocks we just allocated */
 		/* not a good idea to call discard here directly,
 		 * but otherwise we'd need to call it every free() */
-		ext4_mb_discard_inode_preallocations(inode);
+		ext4_discard_preallocations(inode);
 		ext4_free_blocks(handle, inode, ext_pblock(&newex),
 					ext4_ext_get_actual_len(&newex), 0);
 		goto out2;
@@ -2825,7 +2822,7 @@ void ext4_ext_truncate(struct inode *inode)
 	down_write(&EXT4_I(inode)->i_data_sem);
 	ext4_ext_invalidate_cache(inode);
 
-	ext4_discard_reservation(inode);
+	ext4_discard_preallocations(inode);
 
 	/*
 	 * TODO: optimization is possible here.

fs/ext4/file.c

@@ -38,7 +38,7 @@ static int ext4_release_file(struct inode *inode, struct file *filp)
 			(atomic_read(&inode->i_writecount) == 1))
 	{
 		down_write(&EXT4_I(inode)->i_data_sem);
-		ext4_discard_reservation(inode);
+		ext4_discard_preallocations(inode);
 		up_write(&EXT4_I(inode)->i_data_sem);
 	}
 	if (is_dx(inode) && filp->private_data)

fs/ext4/ialloc.c

@@ -817,7 +817,6 @@ got:
 		ei->i_flags &= ~EXT4_DIRSYNC_FL;
 	ei->i_file_acl = 0;
 	ei->i_dtime = 0;
-	ei->i_block_alloc_info = NULL;
 	ei->i_block_group = group;
 
 	ext4_set_inode_flags(inode);

fs/ext4/inode.c

@@ -486,18 +486,9 @@ static ext4_fsblk_t ext4_find_near(struct inode *inode, Indirect *ind)
 static ext4_fsblk_t ext4_find_goal(struct inode *inode, ext4_lblk_t block,
 		Indirect *partial)
 {
-	struct ext4_block_alloc_info *block_i;
-
-	block_i =  EXT4_I(inode)->i_block_alloc_info;
-
 	/*
-	 * try the heuristic for sequential allocation,
-	 * failing that at least try to get decent locality.
+	 * XXX need to get goal block from mballoc's data structures
 	 */
-	if (block_i && (block == block_i->last_alloc_logical_block + 1)
-		&& (block_i->last_alloc_physical_block != 0)) {
-		return block_i->last_alloc_physical_block + 1;
-	}
 
 	return ext4_find_near(inode, partial);
 }
@@ -757,10 +748,8 @@ static int ext4_splice_branch(handle_t *handle, struct inode *inode,
 {
 	int i;
 	int err = 0;
-	struct ext4_block_alloc_info *block_i;
 	ext4_fsblk_t current_block;
 
-	block_i = EXT4_I(inode)->i_block_alloc_info;
 	/*
 	 * If we're splicing into a [td]indirect block (as opposed to the
 	 * inode) then we need to get write access to the [td]indirect block
@@ -786,17 +775,6 @@ static int ext4_splice_branch(handle_t *handle, struct inode *inode,
 			*(where->p + i) = cpu_to_le32(current_block++);
 	}
 
-	/*
-	 * update the most recently allocated logical & physical block
-	 * in i_block_alloc_info, to assist find the proper goal block for next
-	 * allocation
-	 */
-	if (block_i) {
-		block_i->last_alloc_logical_block = block + blks - 1;
-		block_i->last_alloc_physical_block =
-				le32_to_cpu(where[num].key) + blks - 1;
-	}
-
 	/* We are done with atomic stuff, now do the rest of housekeeping */
 
 	inode->i_ctime = ext4_current_time(inode);
@@ -914,12 +892,8 @@ int ext4_get_blocks_handle(handle_t *handle, struct inode *inode,
 		goto cleanup;
 
 	/*
-	 * Okay, we need to do block allocation.  Lazily initialize the block
-	 * allocation info here if necessary
+	 * Okay, we need to do block allocation.
 	*/
-	if (S_ISREG(inode->i_mode) && (!ei->i_block_alloc_info))
-		ext4_init_block_alloc_info(inode);
-
 	goal = ext4_find_goal(inode, iblock, partial);
 
 	/* the number of blocks need to allocate for [d,t]indirect blocks */
@@ -3738,7 +3712,7 @@ void ext4_truncate(struct inode *inode)
 	 */
 	down_write(&ei->i_data_sem);
 
-	ext4_discard_reservation(inode);
+	ext4_discard_preallocations(inode);
 
 	/*
 	 * The orphan list entry will now protect us from any crash which
@@ -4071,7 +4045,6 @@ struct inode *ext4_iget(struct super_block *sb, unsigned long ino)
 	ei->i_acl = EXT4_ACL_NOT_CACHED;
 	ei->i_default_acl = EXT4_ACL_NOT_CACHED;
 #endif
-	ei->i_block_alloc_info = NULL;
 
 	ret = __ext4_get_inode_loc(inode, &iloc, 0);
 	if (ret < 0)

fs/ext4/ioctl.c

@@ -23,7 +23,6 @@ long ext4_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 	struct inode *inode = filp->f_dentry->d_inode;
 	struct ext4_inode_info *ei = EXT4_I(inode);
 	unsigned int flags;
-	unsigned short rsv_window_size;
 
 	ext4_debug("cmd = %u, arg = %lu\n", cmd, arg);
 
@@ -190,49 +189,6 @@ setversion_out:
 			return ret;
 		}
 #endif
-	case EXT4_IOC_GETRSVSZ:
-		if (test_opt(inode->i_sb, RESERVATION)
-			&& S_ISREG(inode->i_mode)
-			&& ei->i_block_alloc_info) {
-			rsv_window_size = ei->i_block_alloc_info->rsv_window_node.rsv_goal_size;
-			return put_user(rsv_window_size, (int __user *)arg);
-		}
-		return -ENOTTY;
-	case EXT4_IOC_SETRSVSZ: {
-		int err;
-
-		if (!test_opt(inode->i_sb, RESERVATION) || !S_ISREG(inode->i_mode))
-			return -ENOTTY;
-
-		if (!is_owner_or_cap(inode))
-			return -EACCES;
-
-		if (get_user(rsv_window_size, (int __user *)arg))
-			return -EFAULT;
-
-		err = mnt_want_write(filp->f_path.mnt);
-		if (err)
-			return err;
-
-		if (rsv_window_size > EXT4_MAX_RESERVE_BLOCKS)
-			rsv_window_size = EXT4_MAX_RESERVE_BLOCKS;
-
-		/*
-		 * need to allocate reservation structure for this inode
-		 * before set the window size
-		 */
-		down_write(&ei->i_data_sem);
-		if (!ei->i_block_alloc_info)
-			ext4_init_block_alloc_info(inode);
-
-		if (ei->i_block_alloc_info){
-			struct ext4_reserve_window_node *rsv = &ei->i_block_alloc_info->rsv_window_node;
-			rsv->rsv_goal_size = rsv_window_size;
-		}
-		up_write(&ei->i_data_sem);
-		mnt_drop_write(filp->f_path.mnt);
-		return 0;
-	}
 	case EXT4_IOC_GROUP_EXTEND: {
 		ext4_fsblk_t n_blocks_count;
 		struct super_block *sb = inode->i_sb;

fs/ext4/mballoc.c

@@ -534,9 +534,6 @@ static int __mb_check_buddy(struct ext4_buddy *e4b, char *file,
 	void *buddy;
 	void *buddy2;
 
-	if (!test_opt(sb, MBALLOC))
-		return 0;
-
 	{
 		static int mb_check_counter;
 		if (mb_check_counter++ % 100 != 0)
@@ -2487,19 +2484,14 @@ int ext4_mb_init(struct super_block *sb, int needs_recovery)
 	unsigned max;
 	int ret;
 
-	if (!test_opt(sb, MBALLOC))
-		return 0;
-
 	i = (sb->s_blocksize_bits + 2) * sizeof(unsigned short);
 
 	sbi->s_mb_offsets = kmalloc(i, GFP_KERNEL);
 	if (sbi->s_mb_offsets == NULL) {
-		clear_opt(sbi->s_mount_opt, MBALLOC);
 		return -ENOMEM;
 	}
 	sbi->s_mb_maxs = kmalloc(i, GFP_KERNEL);
 	if (sbi->s_mb_maxs == NULL) {
-		clear_opt(sbi->s_mount_opt, MBALLOC);
 		kfree(sbi->s_mb_maxs);
 		return -ENOMEM;
 	}
@@ -2522,7 +2514,6 @@ int ext4_mb_init(struct super_block *sb, int needs_recovery)
 	/* init file for buddy data */
 	ret = ext4_mb_init_backend(sb);
 	if (ret != 0) {
-		clear_opt(sbi->s_mount_opt, MBALLOC);
 		kfree(sbi->s_mb_offsets);
 		kfree(sbi->s_mb_maxs);
 		return ret;
@@ -2544,7 +2535,6 @@ int ext4_mb_init(struct super_block *sb, int needs_recovery)
 
 	sbi->s_locality_groups = alloc_percpu(struct ext4_locality_group);
 	if (sbi->s_locality_groups == NULL) {
-		clear_opt(sbi->s_mount_opt, MBALLOC);
 		kfree(sbi->s_mb_offsets);
 		kfree(sbi->s_mb_maxs);
 		return -ENOMEM;
@@ -2590,9 +2580,6 @@ int ext4_mb_release(struct super_block *sb)
 	struct ext4_group_info *grinfo;
 	struct ext4_sb_info *sbi = EXT4_SB(sb);
 
-	if (!test_opt(sb, MBALLOC))
-		return 0;
-
 	/* release freed, non-committed blocks */
 	spin_lock(&sbi->s_md_lock);
 	list_splice_init(&sbi->s_closed_transaction,
@@ -3805,7 +3792,7 @@ out:
  *
  * FIXME!! Make sure it is valid at all the call sites
  */
-void ext4_mb_discard_inode_preallocations(struct inode *inode)
+void ext4_discard_preallocations(struct inode *inode)
 {
 	struct ext4_inode_info *ei = EXT4_I(inode);
 	struct super_block *sb = inode->i_sb;
@@ -3817,7 +3804,7 @@ void ext4_mb_discard_inode_preallocations(struct inode *inode)
 	struct ext4_buddy e4b;
 	int err;
 
-	if (!test_opt(sb, MBALLOC) || !S_ISREG(inode->i_mode)) {
+	if (!S_ISREG(inode->i_mode)) {
 		/*BUG_ON(!list_empty(&ei->i_prealloc_list));*/
 		return;
 	}
@@ -4300,11 +4287,6 @@ ext4_fsblk_t ext4_mb_new_blocks(handle_t *handle,
 	sb = ar->inode->i_sb;
 	sbi = EXT4_SB(sb);
 
-	if (!test_opt(sb, MBALLOC)) {
-		block = ext4_old_new_blocks(handle, ar->inode, ar->goal,
-					    &(ar->len), errp);
-		return block;
-	}
 	if (!EXT4_I(ar->inode)->i_delalloc_reserved_flag) {
 		/*
 		 * With delalloc we already reserved the blocks

fs/ext4/resize.c

@@ -870,11 +870,10 @@ int ext4_group_add(struct super_block *sb, struct ext4_new_group_data *input)
 	 * We can allocate memory for mb_alloc based on the new group
 	 * descriptor
 	 */
-	if (test_opt(sb, MBALLOC)) {
-		err = ext4_mb_add_more_groupinfo(sb, input->group, gdp);
-		if (err)
-			goto exit_journal;
-	}
+	err = ext4_mb_add_more_groupinfo(sb, input->group, gdp);
+	if (err)
+		goto exit_journal;
+
 	/*
 	 * Make the new blocks and inodes valid next.  We do this before
 	 * increasing the group count so that once the group is enabled,
@@ -1086,8 +1085,15 @@ int ext4_group_extend(struct super_block *sb, struct ext4_super_block *es,
 	/*
 	 * Mark mballoc pages as not up to date so that they will be updated
 	 * next time they are loaded by ext4_mb_load_buddy.
+	 *
+	 * XXX Bad, Bad, BAD!!!  We should not be overloading the
+	 * Uptodate flag, particularly on thte bitmap bh, as way of
+	 * hinting to ext4_mb_load_buddy() that it needs to be
+	 * overloaded.  A user could take a LVM snapshot, then do an
+	 * on-line fsck, and clear the uptodate flag, and this would
+	 * not be a bug in userspace, but a bug in the kernel.  FIXME!!!
 	 */
-	if (test_opt(sb, MBALLOC)) {
+	{
 		struct ext4_sb_info *sbi = EXT4_SB(sb);
 		struct inode *inode = sbi->s_buddy_cache;
 		int blocks_per_page;

fs/ext4/super.c

@@ -574,7 +574,6 @@ static struct inode *ext4_alloc_inode(struct super_block *sb)
 	ei->i_acl = EXT4_ACL_NOT_CACHED;
 	ei->i_default_acl = EXT4_ACL_NOT_CACHED;
 #endif
-	ei->i_block_alloc_info = NULL;
 	ei->vfs_inode.i_version = 1;
 	ei->vfs_inode.i_data.writeback_index = 0;
 	memset(&ei->i_cached_extent, 0, sizeof(struct ext4_ext_cache));
@@ -633,7 +632,6 @@ static void destroy_inodecache(void)
 
 static void ext4_clear_inode(struct inode *inode)
 {
-	struct ext4_block_alloc_info *rsv = EXT4_I(inode)->i_block_alloc_info;
 #ifdef CONFIG_EXT4DEV_FS_POSIX_ACL
 	if (EXT4_I(inode)->i_acl &&
 			EXT4_I(inode)->i_acl != EXT4_ACL_NOT_CACHED) {
@@ -646,10 +644,7 @@ static void ext4_clear_inode(struct inode *inode)
 		EXT4_I(inode)->i_default_acl = EXT4_ACL_NOT_CACHED;
 	}
 #endif
-	ext4_discard_reservation(inode);
-	EXT4_I(inode)->i_block_alloc_info = NULL;
-	if (unlikely(rsv))
-		kfree(rsv);
+	ext4_discard_preallocations(inode);
 	jbd2_journal_release_jbd_inode(EXT4_SB(inode->i_sb)->s_journal,
 				       &EXT4_I(inode)->jinode);
 }
@@ -760,8 +755,6 @@ static int ext4_show_options(struct seq_file *seq, struct vfsmount *vfs)
 		seq_puts(seq, ",nobh");
 	if (!test_opt(sb, EXTENTS))
 		seq_puts(seq, ",noextents");
-	if (!test_opt(sb, MBALLOC))
-		seq_puts(seq, ",nomballoc");
 	if (test_opt(sb, I_VERSION))
 		seq_puts(seq, ",i_version");
 	if (!test_opt(sb, DELALLOC))
@@ -1373,12 +1366,6 @@ set_qf_format:
 		case Opt_nodelalloc:
 			clear_opt(sbi->s_mount_opt, DELALLOC);
 			break;
-		case Opt_mballoc:
-			set_opt(sbi->s_mount_opt, MBALLOC);
-			break;
-		case Opt_nomballoc:
-			clear_opt(sbi->s_mount_opt, MBALLOC);
-			break;
 		case Opt_stripe:
 			if (match_int(&args[0], &option))
 				return 0;
@@ -2040,11 +2027,6 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
 		ext4_warning(sb, __func__,
 			"extents feature not enabled on this filesystem, "
 			"use tune2fs.\n");
-	/*
-	 * turn on mballoc code by default in ext4 filesystem
-	 * Use -o nomballoc to turn it off
-	 */
-	set_opt(sbi->s_mount_opt, MBALLOC);
 
 	/*
 	 * enable delayed allocation by default
@@ -2301,19 +2283,6 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
 		goto failed_mount3;
 	}
 
-	/* per fileystem reservation list head & lock */
-	spin_lock_init(&sbi->s_rsv_window_lock);
-	sbi->s_rsv_window_root = RB_ROOT;
-	/* Add a single, static dummy reservation to the start of the
-	 * reservation window list --- it gives us a placeholder for
-	 * append-at-start-of-list which makes the allocation logic
-	 * _much_ simpler. */
-	sbi->s_rsv_window_head.rsv_start = EXT4_RESERVE_WINDOW_NOT_ALLOCATED;
-	sbi->s_rsv_window_head.rsv_end = EXT4_RESERVE_WINDOW_NOT_ALLOCATED;
-	sbi->s_rsv_window_head.rsv_alloc_hit = 0;
-	sbi->s_rsv_window_head.rsv_goal_size = 0;
-	ext4_rsv_window_add(sb, &sbi->s_rsv_window_head);
-
 	sbi->s_stripe = ext4_get_stripe_size(sbi);
 
 	/*
@@ -2510,7 +2479,12 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
 		printk(KERN_INFO "EXT4-fs: delayed allocation enabled\n");
 
 	ext4_ext_init(sb);
-	ext4_mb_init(sb, needs_recovery);
+	err = ext4_mb_init(sb, needs_recovery);
+	if (err) {
+		printk(KERN_ERR "EXT4-fs: failed to initalize mballoc (%d)\n",
+		       err);
+		goto failed_mount4;
+	}
 
 	lock_kernel();
 	return 0;