Commit bc80230e authored by Nikolay Borisov's avatar Nikolay Borisov Committed by David Sterba
Browse files

btrfs: Return offset from find_desired_extent 



Instead of using an input pointer parameter as the return value and have
an int as the return type of find_desired_extent, rework the function to
directly return the found offset. Doing that the 'ret' variable in
btrfs_llseek_file can be removed. Additional (subjective) benefit is
that btrfs' llseek function now resemebles those of the other major
filesystems.

Reviewed-by: default avatarJohannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: default avatarNikolay Borisov <nborisov@suse.com>
Reviewed-by: default avatarDavid Sterba <dsterba@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 2034f3b4

fs/btrfs/file.c

+19 −15
Original line number Diff line number Diff line
@@ -3351,7 +3351,8 @@ out: 
	return ret;

}



static int find_desired_extent(struct inode *inode, loff_t *offset, int whence)

static loff_t find_desired_extent(struct inode *inode, loff_t offset,

				  int whence)

{

	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);

	struct extent_map *em = NULL;
@@ -3363,14 +3364,14 @@ static int find_desired_extent(struct inode *inode, loff_t *offset, int whence) 
	u64 len;

	int ret = 0;



	if (i_size == 0 || *offset >= i_size)

	if (i_size == 0 || offset >= i_size)

		return -ENXIO;



	/*

	 * *offset can be negative, in this case we start finding DATA/HOLE from

	 * offset can be negative, in this case we start finding DATA/HOLE from

	 * the very start of the file.

	 */

	start = max_t(loff_t, 0, *offset);

	start = max_t(loff_t, 0, offset);



	lockstart = round_down(start, fs_info->sectorsize);

	lockend = round_up(i_size, fs_info->sectorsize);
@@ -3405,21 +3406,23 @@ static int find_desired_extent(struct inode *inode, loff_t *offset, int whence) 
		cond_resched();

	}

	free_extent_map(em);

	if (!ret) {

	unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,

			     &cached_state);

	if (ret) {

		offset = ret;

	} else {

		if (whence == SEEK_DATA && start >= i_size)

			ret = -ENXIO;

			offset = -ENXIO;

		else

			*offset = min_t(loff_t, start, i_size);

			offset = min_t(loff_t, start, i_size);

	}

	unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,

			     &cached_state);

	return ret;



	return offset;

}



static loff_t btrfs_file_llseek(struct file *file, loff_t offset, int whence)

{

	struct inode *inode = file->f_mapping->host;

	int ret;



	switch (whence) {

	default:
@@ -3427,13 +3430,14 @@ static loff_t btrfs_file_llseek(struct file *file, loff_t offset, int whence) 
	case SEEK_DATA:

	case SEEK_HOLE:

		inode_lock_shared(inode);

		ret = find_desired_extent(inode, &offset, whence);

		offset = find_desired_extent(inode, offset, whence);

		inode_unlock_shared(inode);



		if (ret)

			return ret;

		break;

	}



	if (offset < 0)

		return offset;



	return vfs_setpos(file, offset, inode->i_sb->s_maxbytes);

}

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