Commit df2825e9 authored by David Sterba's avatar David Sterba
Browse files

btrfs: always pass readahead state to defrag 



Defrag ioctl passes readahead from the file, but autodefrag does not
have a file so the readahead state is allocated when needed.

The autodefrag loop in cleaner thread iterates over inodes so we can
simply provide an on-stack readahead state and will not need to allocate
it in btrfs_defrag_file(). The size is 32 bytes which is acceptable.

Reviewed-by: default avatarQu Wenruo <wqu@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 11e3107d

fs/btrfs/defrag.c

+11 −21
Original line number Diff line number Diff line
@@ -219,7 +219,8 @@ void btrfs_cleanup_defrag_inodes(struct btrfs_fs_info *fs_info) 
#define BTRFS_DEFRAG_BATCH	1024



static int btrfs_run_defrag_inode(struct btrfs_fs_info *fs_info,

				  struct inode_defrag *defrag)

				  struct inode_defrag *defrag,

				  struct file_ra_state *ra)

{

	struct btrfs_root *inode_root;

	struct inode *inode;
@@ -258,9 +259,10 @@ static int btrfs_run_defrag_inode(struct btrfs_fs_info *fs_info, 
	range.len = (u64)-1;

	range.start = cur;

	range.extent_thresh = defrag->extent_thresh;

	file_ra_state_init(ra, inode->i_mapping);



	sb_start_write(fs_info->sb);

	ret = btrfs_defrag_file(inode, NULL, &range, defrag->transid,

	ret = btrfs_defrag_file(inode, ra, &range, defrag->transid,

				       BTRFS_DEFRAG_BATCH);

	sb_end_write(fs_info->sb);

	iput(inode);
@@ -287,6 +289,8 @@ int btrfs_run_defrag_inodes(struct btrfs_fs_info *fs_info) 


	atomic_inc(&fs_info->defrag_running);

	while (1) {

		struct file_ra_state ra = { 0 };



		/* Pause the auto defragger. */

		if (test_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state))

			break;
@@ -309,7 +313,7 @@ int btrfs_run_defrag_inodes(struct btrfs_fs_info *fs_info) 
		first_ino = defrag->ino + 1;

		root_objectid = defrag->root;



		btrfs_run_defrag_inode(fs_info, defrag);

		btrfs_run_defrag_inode(fs_info, defrag, &ra);

	}

	atomic_dec(&fs_info->defrag_running);
@@ -1302,7 +1306,6 @@ static int defrag_one_cluster(struct btrfs_inode *inode, 
		if (entry->start + range_len <= *last_scanned_ret)

			continue;



		if (ra)

		page_cache_sync_readahead(inode->vfs_inode.i_mapping,

				ra, NULL, entry->start >> PAGE_SHIFT,

				((entry->start + range_len - 1) >> PAGE_SHIFT) -
@@ -1335,7 +1338,7 @@ static int defrag_one_cluster(struct btrfs_inode *inode, 
 * Entry point to file defragmentation.

 *

 * @inode:	   inode to be defragged

 * @ra:		   readahead state (can be NUL)

 * @ra:		   readahead state

 * @range:	   defrag options including range and flags

 * @newer_than:	   minimum transid to defrag

 * @max_to_defrag: max number of sectors to be defragged, if 0, the whole inode
@@ -1357,12 +1360,13 @@ int btrfs_defrag_file(struct inode *inode, struct file_ra_state *ra, 
	u64 cur;

	u64 last_byte;

	bool do_compress = (range->flags & BTRFS_DEFRAG_RANGE_COMPRESS);

	bool ra_allocated = false;

	int compress_type = BTRFS_COMPRESS_ZLIB;

	int ret = 0;

	u32 extent_thresh = range->extent_thresh;

	pgoff_t start_index;



	ASSERT(ra);



	if (isize == 0)

		return 0;
@@ -1391,18 +1395,6 @@ int btrfs_defrag_file(struct inode *inode, struct file_ra_state *ra, 
	cur = round_down(range->start, fs_info->sectorsize);

	last_byte = round_up(last_byte, fs_info->sectorsize) - 1;



	/*

	 * If we were not given a ra, allocate a readahead context. As

	 * readahead is just an optimization, defrag will work without it so

	 * we don't error out.

	 */

	if (!ra) {

		ra_allocated = true;

		ra = kzalloc(sizeof(*ra), GFP_KERNEL);

		if (ra)

			file_ra_state_init(ra, inode->i_mapping);

	}



	/*

	 * Make writeback start from the beginning of the range, so that the

	 * defrag range can be written sequentially.
@@ -1457,8 +1449,6 @@ int btrfs_defrag_file(struct inode *inode, struct file_ra_state *ra, 
		cond_resched();

	}



	if (ra_allocated)

		kfree(ra);

	/*

	 * Update range.start for autodefrag, this will indicate where to start

	 * in next run.