Btrfs: Add mount option to enforce a max extent size (c59f8951) · Commits · 戴 / test

fs/btrfs/ctree.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -322,6 +322,7 @@ struct btrfs_fs_info {
		u64 generation;
		u64 last_trans_committed;
		unsigned long mount_opt;
		u64 max_extent;
		struct btrfs_transaction *running_transaction;
		struct btrfs_super_block super_copy;
		struct extent_buffer *sb_buffer;

fs/btrfs/disk-io.c

+1 −0

Original line number	Diff line number	Diff line
		@@ -569,6 +569,7 @@ struct btrfs_root open_ctree(struct super_block sb)
		fs_info->extent_root = extent_root;
		fs_info->sb = sb;
		fs_info->mount_opt = 0;
		fs_info->max_extent = (u64)-1;
		fs_info->btree_inode = new_inode(sb);
		fs_info->btree_inode->i_ino = 1;
		fs_info->btree_inode->i_nlink = 1;

fs/btrfs/inode.c

+18 −10

Original line number	Diff line number	Diff line
		@@ -78,6 +78,7 @@ static int cow_file_range(struct inode *inode, u64 start, u64 end)
		struct btrfs_trans_handle *trans;
		u64 alloc_hint = 0;
		u64 num_bytes;
		u64 cur_alloc_size;
		u64 blocksize = root->sectorsize;
		struct btrfs_key ins;
		int ret;
		@@ -94,8 +95,11 @@ static int cow_file_range(struct inode *inode, u64 start, u64 end)
		if (alloc_hint == EXTENT_MAP_INLINE)
		goto out;

		ret = btrfs_alloc_extent(trans, root, num_bytes,
		root->root_key.objectid, trans->transid,
		while(num_bytes > 0) {
		cur_alloc_size = min(num_bytes, root->fs_info->max_extent);
		ret = btrfs_alloc_extent(trans, root, cur_alloc_size,
		root->root_key.objectid,
		trans->transid,
		inode->i_ino, start, 0,
		alloc_hint, (u64)-1, &ins, 1);
		if (ret) {
		@@ -105,6 +109,10 @@ static int cow_file_range(struct inode *inode, u64 start, u64 end)
		ret = btrfs_insert_file_extent(trans, root, inode->i_ino,
		start, ins.objectid, ins.offset,
		ins.offset);
		num_bytes -= cur_alloc_size;
		alloc_hint = ins.objectid + ins.offset;
		start += cur_alloc_size;
		}
		out:
		btrfs_end_transaction(trans, root);
		return ret;

fs/btrfs/super.c

+45 −1

Original line number	Diff line number	Diff line
		@@ -34,6 +34,7 @@
		#include <linux/statfs.h>
		#include <linux/compat.h>
		#include <linux/parser.h>
		#include <linux/ctype.h>
		#include "ctree.h"
		#include "disk-io.h"
		#include "transaction.h"
		@@ -61,16 +62,42 @@ static void btrfs_put_super (struct super_block * sb)
		}

		enum {
		Opt_subvol, Opt_nodatasum, Opt_nodatacow, Opt_err,
		Opt_subvol, Opt_nodatasum, Opt_nodatacow, Opt_max_extent, Opt_err,
		};

		static match_table_t tokens = {
		{Opt_subvol, "subvol=%s"},
		{Opt_nodatasum, "nodatasum"},
		{Opt_nodatacow, "nodatacow"},
		{Opt_max_extent, "max_extent=%s"},
		{Opt_err, NULL}
		};

		static unsigned long parse_size(char *str)
		{
		unsigned long res;
		int mult = 1;
		char *end;
		char last;

		res = simple_strtoul(str, &end, 10);

		last = end[0];
		if (isalpha(last)) {
		last = tolower(last);
		switch (last) {
		case 'g':
		mult *= 1024;
		case 'm':
		mult *= 1024;
		case 'k':
		mult *= 1024;
		}
		res = res * mult;
		}
		return res;
		}

		static int parse_options (char * options,
		struct btrfs_root *root,
		char **subvol_name)
		@@ -118,6 +145,21 @@ static int parse_options (char * options,
		btrfs_set_opt(info->mount_opt, NODATASUM);
		}
		break;
		case Opt_max_extent:
		if (info) {
		char *num = match_strdup(&args[0]);
		if (num) {
		info->max_extent = parse_size(num);
		kfree(num);

		info->max_extent = max_t(u64,
		info->max_extent,
		root->sectorsize);
		printk("btrfs: max_extent at %Lu\n",
		info->max_extent);
		}
		}
		break;
		default:
		break;
		}
		@@ -329,6 +371,8 @@ static int btrfs_get_sb(struct file_system_type *fs_type,
		ret = btrfs_get_sb_bdev(fs_type, flags, dev_name, data,
		btrfs_fill_super, mnt,
		subvol_name ? subvol_name : "default");
		if (subvol_name)
		kfree(subvol_name);
		return ret;
		}

Admin message