Commit 6a63209f authored by Josef Bacik's avatar Josef Bacik Committed by Chris Mason
Browse files

Btrfs: add better -ENOSPC handling 



This is a step in the direction of better -ENOSPC handling.  Instead of
checking the global bytes counter we check the space_info bytes counters to
make sure we have enough space.

If we don't we go ahead and try to allocate a new chunk, and then if that fails
we return -ENOSPC.  This patch adds two counters to btrfs_space_info,
bytes_delalloc and bytes_may_use.

bytes_delalloc account for extents we've actually setup for delalloc and will
be allocated at some point down the line. 

bytes_may_use is to keep track of how many bytes we may use for delalloc at
some point.  When we actually set the extent_bit for the delalloc bytes we
subtract the reserved bytes from the bytes_may_use counter.  This keeps us from
not actually being able to allocate space for any delalloc bytes.

Signed-off-by: default avatarJosef Bacik <jbacik@redhat.com>
parent 2cfbd50b

fs/btrfs/btrfs_inode.h

+8 −0
Original line number Diff line number Diff line
@@ -66,6 +66,9 @@ struct btrfs_inode { 
	 */

	struct list_head delalloc_inodes;



	/* the space_info for where this inode's data allocations are done */

	struct btrfs_space_info *space_info;



	/* full 64 bit generation number, struct vfs_inode doesn't have a big

	 * enough field for this.

	 */
@@ -94,6 +97,11 @@ struct btrfs_inode { 
	 */

	u64 delalloc_bytes;



	/* total number of bytes that may be used for this inode for

	 * delalloc

	 */

	u64 reserved_bytes;



	/*

	 * the size of the file stored in the metadata on disk.  data=ordered

	 * means the in-memory i_size might be larger than the size on disk

fs/btrfs/ctree.h

+31 −9
Original line number Diff line number Diff line
@@ -596,13 +596,27 @@ struct btrfs_block_group_item { 


struct btrfs_space_info {

	u64 flags;

	u64 total_bytes;

	u64 bytes_used;

	u64 bytes_pinned;

	u64 bytes_reserved;

	u64 bytes_readonly;

	int full;

	int force_alloc;



	u64 total_bytes;	/* total bytes in the space */

	u64 bytes_used;		/* total bytes used on disk */

	u64 bytes_pinned;	/* total bytes pinned, will be freed when the

				   transaction finishes */

	u64 bytes_reserved;	/* total bytes the allocator has reserved for

				   current allocations */

	u64 bytes_readonly;	/* total bytes that are read only */



	/* delalloc accounting */

	u64 bytes_delalloc;	/* number of bytes reserved for allocation,

				   this space is not necessarily reserved yet

				   by the allocator */

	u64 bytes_may_use;	/* number of bytes that may be used for

				   delalloc */



	int full;		/* indicates that we cannot allocate any more

				   chunks for this space */

	int force_alloc;	/* set if we need to force a chunk alloc for

				   this space */



	struct list_head list;



	/* for block groups in our same type */
@@ -1782,6 +1796,16 @@ int btrfs_add_dead_reloc_root(struct btrfs_root *root); 
int btrfs_cleanup_reloc_trees(struct btrfs_root *root);

int btrfs_reloc_clone_csums(struct inode *inode, u64 file_pos, u64 len);

u64 btrfs_reduce_alloc_profile(struct btrfs_root *root, u64 flags);

void btrfs_set_inode_space_info(struct btrfs_root *root, struct inode *ionde);

int btrfs_check_metadata_free_space(struct btrfs_root *root);

int btrfs_check_data_free_space(struct btrfs_root *root, struct inode *inode,

				u64 bytes);

void btrfs_free_reserved_data_space(struct btrfs_root *root,

				    struct inode *inode, u64 bytes);

void btrfs_delalloc_reserve_space(struct btrfs_root *root, struct inode *inode,

				 u64 bytes);

void btrfs_delalloc_free_space(struct btrfs_root *root, struct inode *inode,

			      u64 bytes);

/* ctree.c */

int btrfs_previous_item(struct btrfs_root *root,

			struct btrfs_path *path, u64 min_objectid,
@@ -2027,8 +2051,6 @@ int btrfs_merge_bio_hook(struct page *page, unsigned long offset, 
unsigned long btrfs_force_ra(struct address_space *mapping,

			      struct file_ra_state *ra, struct file *file,

			      pgoff_t offset, pgoff_t last_index);

int btrfs_check_free_space(struct btrfs_root *root, u64 num_required,

			   int for_del);

int btrfs_page_mkwrite(struct vm_area_struct *vma, struct page *page);

int btrfs_readpage(struct file *file, struct page *page);

void btrfs_delete_inode(struct inode *inode);

fs/btrfs/extent-tree.c

+200 −15
Original line number Diff line number Diff line
@@ -60,6 +60,10 @@ static int update_block_group(struct btrfs_trans_handle *trans, 
			      u64 bytenr, u64 num_bytes, int alloc,

			      int mark_free);



static int do_chunk_alloc(struct btrfs_trans_handle *trans,

			  struct btrfs_root *extent_root, u64 alloc_bytes,

			  u64 flags, int force);



static int block_group_bits(struct btrfs_block_group_cache *cache, u64 bits)

{

	return (cache->flags & bits) == bits;
@@ -1909,6 +1913,7 @@ static int update_space_info(struct btrfs_fs_info *info, u64 flags, 
	found->bytes_pinned = 0;

	found->bytes_reserved = 0;

	found->bytes_readonly = 0;

	found->bytes_delalloc = 0;

	found->full = 0;

	found->force_alloc = 0;

	*space_info = found;
@@ -1972,6 +1977,196 @@ u64 btrfs_reduce_alloc_profile(struct btrfs_root *root, u64 flags) 
	return flags;

}



static u64 btrfs_get_alloc_profile(struct btrfs_root *root, u64 data)

{

	struct btrfs_fs_info *info = root->fs_info;

	u64 alloc_profile;



	if (data) {

		alloc_profile = info->avail_data_alloc_bits &

			info->data_alloc_profile;

		data = BTRFS_BLOCK_GROUP_DATA | alloc_profile;

	} else if (root == root->fs_info->chunk_root) {

		alloc_profile = info->avail_system_alloc_bits &

			info->system_alloc_profile;

		data = BTRFS_BLOCK_GROUP_SYSTEM | alloc_profile;

	} else {

		alloc_profile = info->avail_metadata_alloc_bits &

			info->metadata_alloc_profile;

		data = BTRFS_BLOCK_GROUP_METADATA | alloc_profile;

	}



	return btrfs_reduce_alloc_profile(root, data);

}



void btrfs_set_inode_space_info(struct btrfs_root *root, struct inode *inode)

{

	u64 alloc_target;



	alloc_target = btrfs_get_alloc_profile(root, 1);

	BTRFS_I(inode)->space_info = __find_space_info(root->fs_info,

						       alloc_target);

}



/*

 * for now this just makes sure we have at least 5% of our metadata space free

 * for use.

 */

int btrfs_check_metadata_free_space(struct btrfs_root *root)

{

	struct btrfs_fs_info *info = root->fs_info;

	struct btrfs_space_info *meta_sinfo;

	u64 alloc_target, thresh;



	/* get the space info for where the metadata will live */

	alloc_target = btrfs_get_alloc_profile(root, 0);

	meta_sinfo = __find_space_info(info, alloc_target);



	/*

	 * if the metadata area isn't maxed out then there is no sense in

	 * checking how much is used, since we can always allocate a new chunk

	 */

	if (!meta_sinfo->full)

		return 0;



	spin_lock(&meta_sinfo->lock);

	thresh = meta_sinfo->total_bytes * 95;



	do_div(thresh, 100);



	if (meta_sinfo->bytes_used + meta_sinfo->bytes_reserved +

	    meta_sinfo->bytes_pinned + meta_sinfo->bytes_readonly > thresh) {

		spin_unlock(&meta_sinfo->lock);

		return -ENOSPC;

	}

	spin_unlock(&meta_sinfo->lock);



	return 0;

}



/*

 * This will check the space that the inode allocates from to make sure we have

 * enough space for bytes.

 */

int btrfs_check_data_free_space(struct btrfs_root *root, struct inode *inode,

				u64 bytes)

{

	struct btrfs_space_info *data_sinfo;

	int ret = 0;



	/* make sure bytes are sectorsize aligned */

	bytes = (bytes + root->sectorsize - 1) & ~((u64)root->sectorsize - 1);



	data_sinfo = BTRFS_I(inode)->space_info;

again:

	/* make sure we have enough space to handle the data first */

	spin_lock(&data_sinfo->lock);

	if (data_sinfo->total_bytes - data_sinfo->bytes_used -

	    data_sinfo->bytes_delalloc - data_sinfo->bytes_reserved -

	    data_sinfo->bytes_pinned - data_sinfo->bytes_readonly -

	    data_sinfo->bytes_may_use < bytes) {

		/*

		 * if we don't have enough free bytes in this space then we need

		 * to alloc a new chunk.

		 */

		if (!data_sinfo->full) {

			u64 alloc_target;

			struct btrfs_trans_handle *trans;



			data_sinfo->force_alloc = 1;

			spin_unlock(&data_sinfo->lock);



			alloc_target = btrfs_get_alloc_profile(root, 1);

			trans = btrfs_start_transaction(root, 1);

			if (!trans)

				return -ENOMEM;



			ret = do_chunk_alloc(trans, root->fs_info->extent_root,

					     bytes + 2 * 1024 * 1024,

					     alloc_target, 0);

			btrfs_end_transaction(trans, root);

			if (ret)

				return ret;

			goto again;

		}

		spin_unlock(&data_sinfo->lock);

		printk(KERN_ERR "no space left, need %llu, %llu delalloc bytes"

		       ", %llu bytes_used, %llu bytes_reserved, "

		       "%llu bytes_pinned, %llu bytes_readonly, %llu may use"

		       "%llu total\n", bytes, data_sinfo->bytes_delalloc,

		       data_sinfo->bytes_used, data_sinfo->bytes_reserved,

		       data_sinfo->bytes_pinned, data_sinfo->bytes_readonly,

		       data_sinfo->bytes_may_use, data_sinfo->total_bytes);

		return -ENOSPC;

	}

	data_sinfo->bytes_may_use += bytes;

	BTRFS_I(inode)->reserved_bytes += bytes;

	spin_unlock(&data_sinfo->lock);



	return btrfs_check_metadata_free_space(root);

}



/*

 * if there was an error for whatever reason after calling

 * btrfs_check_data_free_space, call this so we can cleanup the counters.

 */

void btrfs_free_reserved_data_space(struct btrfs_root *root,

				    struct inode *inode, u64 bytes)

{

	struct btrfs_space_info *data_sinfo;



	/* make sure bytes are sectorsize aligned */

	bytes = (bytes + root->sectorsize - 1) & ~((u64)root->sectorsize - 1);



	data_sinfo = BTRFS_I(inode)->space_info;

	spin_lock(&data_sinfo->lock);

	data_sinfo->bytes_may_use -= bytes;

	BTRFS_I(inode)->reserved_bytes -= bytes;

	spin_unlock(&data_sinfo->lock);

}



/* called when we are adding a delalloc extent to the inode's io_tree */

void btrfs_delalloc_reserve_space(struct btrfs_root *root, struct inode *inode,

				  u64 bytes)

{

	struct btrfs_space_info *data_sinfo;



	/* get the space info for where this inode will be storing its data */

	data_sinfo = BTRFS_I(inode)->space_info;



	/* make sure we have enough space to handle the data first */

	spin_lock(&data_sinfo->lock);

	data_sinfo->bytes_delalloc += bytes;



	/*

	 * we are adding a delalloc extent without calling

	 * btrfs_check_data_free_space first.  This happens on a weird

	 * writepage condition, but shouldn't hurt our accounting

	 */

	if (unlikely(bytes > BTRFS_I(inode)->reserved_bytes)) {

		data_sinfo->bytes_may_use -= BTRFS_I(inode)->reserved_bytes;

		BTRFS_I(inode)->reserved_bytes = 0;

	} else {

		data_sinfo->bytes_may_use -= bytes;

		BTRFS_I(inode)->reserved_bytes -= bytes;

	}



	spin_unlock(&data_sinfo->lock);

}



/* called when we are clearing an delalloc extent from the inode's io_tree */

void btrfs_delalloc_free_space(struct btrfs_root *root, struct inode *inode,

			      u64 bytes)

{

	struct btrfs_space_info *info;



	info = BTRFS_I(inode)->space_info;



	spin_lock(&info->lock);

	info->bytes_delalloc -= bytes;

	spin_unlock(&info->lock);

}



static int do_chunk_alloc(struct btrfs_trans_handle *trans,

			  struct btrfs_root *extent_root, u64 alloc_bytes,

			  u64 flags, int force)
@@ -3105,6 +3300,10 @@ static void dump_space_info(struct btrfs_space_info *info, u64 bytes) 
	       (unsigned long long)(info->total_bytes - info->bytes_used -

				    info->bytes_pinned - info->bytes_reserved),

	       (info->full) ? "" : "not ");

	printk(KERN_INFO "space_info total=%llu, pinned=%llu, delalloc=%llu,"

	       " may_use=%llu, used=%llu\n", info->total_bytes,

	       info->bytes_pinned, info->bytes_delalloc, info->bytes_may_use,

	       info->bytes_used);



	down_read(&info->groups_sem);

	list_for_each_entry(cache, &info->block_groups, list) {
@@ -3131,24 +3330,10 @@ static int __btrfs_reserve_extent(struct btrfs_trans_handle *trans, 
{

	int ret;

	u64 search_start = 0;

	u64 alloc_profile;

	struct btrfs_fs_info *info = root->fs_info;



	if (data) {

		alloc_profile = info->avail_data_alloc_bits &

			info->data_alloc_profile;

		data = BTRFS_BLOCK_GROUP_DATA | alloc_profile;

	} else if (root == root->fs_info->chunk_root) {

		alloc_profile = info->avail_system_alloc_bits &

			info->system_alloc_profile;

		data = BTRFS_BLOCK_GROUP_SYSTEM | alloc_profile;

	} else {

		alloc_profile = info->avail_metadata_alloc_bits &

			info->metadata_alloc_profile;

		data = BTRFS_BLOCK_GROUP_METADATA | alloc_profile;

	}

	data = btrfs_get_alloc_profile(root, data);

again:

	data = btrfs_reduce_alloc_profile(root, data);

	/*

	 * the only place that sets empty_size is btrfs_realloc_node, which

	 * is not called recursively on allocations

fs/btrfs/file.c

+13 −3
Original line number Diff line number Diff line
@@ -1091,19 +1091,24 @@ static ssize_t btrfs_file_write(struct file *file, const char __user *buf, 
		WARN_ON(num_pages > nrptrs);

		memset(pages, 0, sizeof(struct page *) * nrptrs);



		ret = btrfs_check_free_space(root, write_bytes, 0);

		ret = btrfs_check_data_free_space(root, inode, write_bytes);

		if (ret)

			goto out;



		ret = prepare_pages(root, file, pages, num_pages,

				    pos, first_index, last_index,

				    write_bytes);

		if (ret)

		if (ret) {

			btrfs_free_reserved_data_space(root, inode,

						       write_bytes);

			goto out;

		}



		ret = btrfs_copy_from_user(pos, num_pages,

					   write_bytes, pages, buf);

		if (ret) {

			btrfs_free_reserved_data_space(root, inode,

						       write_bytes);

			btrfs_drop_pages(pages, num_pages);

			goto out;

		}
@@ -1111,8 +1116,11 @@ static ssize_t btrfs_file_write(struct file *file, const char __user *buf, 
		ret = dirty_and_release_pages(NULL, root, file, pages,

					      num_pages, pos, write_bytes);

		btrfs_drop_pages(pages, num_pages);

		if (ret)

		if (ret) {

			btrfs_free_reserved_data_space(root, inode,

						       write_bytes);

			goto out;

		}



		if (will_write) {

			btrfs_fdatawrite_range(inode->i_mapping, pos,
@@ -1136,6 +1144,8 @@ static ssize_t btrfs_file_write(struct file *file, const char __user *buf, 
	}

out:

	mutex_unlock(&inode->i_mutex);

	if (ret)

		err = ret;



out_nolock:

	kfree(pages);

fs/btrfs/inode.c

+16 −46
Original line number Diff line number Diff line
@@ -101,34 +101,6 @@ static int btrfs_init_inode_security(struct inode *inode, struct inode *dir) 
	return err;

}



/*

 * a very lame attempt at stopping writes when the FS is 85% full.  There

 * are countless ways this is incorrect, but it is better than nothing.

 */

int btrfs_check_free_space(struct btrfs_root *root, u64 num_required,

			   int for_del)

{

	u64 total;

	u64 used;

	u64 thresh;

	int ret = 0;



	spin_lock(&root->fs_info->delalloc_lock);

	total = btrfs_super_total_bytes(&root->fs_info->super_copy);

	used = btrfs_super_bytes_used(&root->fs_info->super_copy);

	if (for_del)

		thresh = total * 90;

	else

		thresh = total * 85;



	do_div(thresh, 100);



	if (used + root->fs_info->delalloc_bytes + num_required > thresh)

		ret = -ENOSPC;

	spin_unlock(&root->fs_info->delalloc_lock);

	return ret;

}



/*

 * this does all the hard work for inserting an inline extent into

 * the btree.  The caller should have done a btrfs_drop_extents so that
@@ -1190,6 +1162,7 @@ static int btrfs_set_bit_hook(struct inode *inode, u64 start, u64 end, 
	 */

	if (!(old & EXTENT_DELALLOC) && (bits & EXTENT_DELALLOC)) {

		struct btrfs_root *root = BTRFS_I(inode)->root;

		btrfs_delalloc_reserve_space(root, inode, end - start + 1);

		spin_lock(&root->fs_info->delalloc_lock);

		BTRFS_I(inode)->delalloc_bytes += end - start + 1;

		root->fs_info->delalloc_bytes += end - start + 1;
@@ -1223,9 +1196,12 @@ static int btrfs_clear_bit_hook(struct inode *inode, u64 start, u64 end, 
			       (unsigned long long)end - start + 1,

			       (unsigned long long)

			       root->fs_info->delalloc_bytes);

			btrfs_delalloc_free_space(root, inode, (u64)-1);

			root->fs_info->delalloc_bytes = 0;

			BTRFS_I(inode)->delalloc_bytes = 0;

		} else {

			btrfs_delalloc_free_space(root, inode,

						  end - start + 1);

			root->fs_info->delalloc_bytes -= end - start + 1;

			BTRFS_I(inode)->delalloc_bytes -= end - start + 1;

		}
@@ -2245,10 +2221,6 @@ static int btrfs_unlink(struct inode *dir, struct dentry *dentry) 


	root = BTRFS_I(dir)->root;



	ret = btrfs_check_free_space(root, 1, 1);

	if (ret)

		goto fail;



	trans = btrfs_start_transaction(root, 1);



	btrfs_set_trans_block_group(trans, dir);
@@ -2261,7 +2233,6 @@ static int btrfs_unlink(struct inode *dir, struct dentry *dentry) 
	nr = trans->blocks_used;



	btrfs_end_transaction_throttle(trans, root);

fail:

	btrfs_btree_balance_dirty(root, nr);

	return ret;

}
@@ -2284,10 +2255,6 @@ static int btrfs_rmdir(struct inode *dir, struct dentry *dentry) 
		return -ENOTEMPTY;

	}



	ret = btrfs_check_free_space(root, 1, 1);

	if (ret)

		goto fail;



	trans = btrfs_start_transaction(root, 1);

	btrfs_set_trans_block_group(trans, dir);
@@ -2304,7 +2271,6 @@ static int btrfs_rmdir(struct inode *dir, struct dentry *dentry) 
fail_trans:

	nr = trans->blocks_used;

	ret = btrfs_end_transaction_throttle(trans, root);

fail:

	btrfs_btree_balance_dirty(root, nr);



	if (ret && !err)
@@ -2818,7 +2784,7 @@ int btrfs_cont_expand(struct inode *inode, loff_t size) 
	if (size <= hole_start)

		return 0;



	err = btrfs_check_free_space(root, 1, 0);

	err = btrfs_check_metadata_free_space(root);

	if (err)

		return err;
@@ -3014,6 +2980,7 @@ static noinline void init_btrfs_i(struct inode *inode) 
	bi->last_trans = 0;

	bi->logged_trans = 0;

	bi->delalloc_bytes = 0;

	bi->reserved_bytes = 0;

	bi->disk_i_size = 0;

	bi->flags = 0;

	bi->index_cnt = (u64)-1;
@@ -3035,6 +3002,7 @@ static int btrfs_init_locked_inode(struct inode *inode, void *p) 
	inode->i_ino = args->ino;

	init_btrfs_i(inode);

	BTRFS_I(inode)->root = args->root;

	btrfs_set_inode_space_info(args->root, inode);

	return 0;

}
@@ -3455,6 +3423,7 @@ static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans, 
	BTRFS_I(inode)->index_cnt = 2;

	BTRFS_I(inode)->root = root;

	BTRFS_I(inode)->generation = trans->transid;

	btrfs_set_inode_space_info(root, inode);



	if (mode & S_IFDIR)

		owner = 0;
@@ -3602,7 +3571,7 @@ static int btrfs_mknod(struct inode *dir, struct dentry *dentry, 
	if (!new_valid_dev(rdev))

		return -EINVAL;



	err = btrfs_check_free_space(root, 1, 0);

	err = btrfs_check_metadata_free_space(root);

	if (err)

		goto fail;
@@ -3665,7 +3634,7 @@ static int btrfs_create(struct inode *dir, struct dentry *dentry, 
	u64 objectid;

	u64 index = 0;



	err = btrfs_check_free_space(root, 1, 0);

	err = btrfs_check_metadata_free_space(root);

	if (err)

		goto fail;

	trans = btrfs_start_transaction(root, 1);
@@ -3733,7 +3702,7 @@ static int btrfs_link(struct dentry *old_dentry, struct inode *dir, 
		return -ENOENT;



	btrfs_inc_nlink(inode);

	err = btrfs_check_free_space(root, 1, 0);

	err = btrfs_check_metadata_free_space(root);

	if (err)

		goto fail;

	err = btrfs_set_inode_index(dir, &index);
@@ -3779,7 +3748,7 @@ static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, int mode) 
	u64 index = 0;

	unsigned long nr = 1;



	err = btrfs_check_free_space(root, 1, 0);

	err = btrfs_check_metadata_free_space(root);

	if (err)

		goto out_unlock;
@@ -4336,7 +4305,7 @@ int btrfs_page_mkwrite(struct vm_area_struct *vma, struct page *page) 
	u64 page_start;

	u64 page_end;



	ret = btrfs_check_free_space(root, PAGE_CACHE_SIZE, 0);

	ret = btrfs_check_data_free_space(root, inode, PAGE_CACHE_SIZE);

	if (ret)

		goto out;
@@ -4349,6 +4318,7 @@ again: 


	if ((page->mapping != inode->i_mapping) ||

	    (page_start >= size)) {

		btrfs_free_reserved_data_space(root, inode, PAGE_CACHE_SIZE);

		/* page got truncated out from underneath us */

		goto out_unlock;

	}
@@ -4631,7 +4601,7 @@ static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry, 
	if (old_inode->i_ino == BTRFS_FIRST_FREE_OBJECTID)

		return -EXDEV;



	ret = btrfs_check_free_space(root, 1, 0);

	ret = btrfs_check_metadata_free_space(root);

	if (ret)

		goto out_unlock;
@@ -4749,7 +4719,7 @@ static int btrfs_symlink(struct inode *dir, struct dentry *dentry, 
	if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(root))

		return -ENAMETOOLONG;



	err = btrfs_check_free_space(root, 1, 0);

	err = btrfs_check_metadata_free_space(root);

	if (err)

		goto out_fail;

CRA Git | Maintained and supported by SUSTech CRA and CCSE