Commit 83a8836f authored by Gao Xiang's avatar Gao Xiang
Browse files

erofs: add SEEK_{DATA,HOLE} support 



Many userspace programs (including erofs-utils itself) use SEEK_DATA /
SEEK_HOLE to parse hole extents in addition to FIEMAP.

Reviewed-by: default avatarChao Yu <chao@kernel.org>
Signed-off-by: default avatarGao Xiang <hsiangkao@linux.alibaba.com>
Link: https://lore.kernel.org/r/20241011065128.2097377-1-hsiangkao@linux.alibaba.com
parent 59b723cd

fs/erofs/data.c

+25 −1
Original line number Diff line number Diff line
@@ -473,8 +473,32 @@ static int erofs_file_mmap(struct file *file, struct vm_area_struct *vma) 
#define erofs_file_mmap	generic_file_readonly_mmap

#endif



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

{

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

	const struct iomap_ops *ops = &erofs_iomap_ops;



	if (erofs_inode_is_data_compressed(EROFS_I(inode)->datalayout))

#ifdef CONFIG_EROFS_FS_ZIP

		ops = &z_erofs_iomap_report_ops;

#else

		return generic_file_llseek(file, offset, whence);

#endif



	if (whence == SEEK_HOLE)

		offset = iomap_seek_hole(inode, offset, ops);

	else if (whence == SEEK_DATA)

		offset = iomap_seek_data(inode, offset, ops);

	else

		return generic_file_llseek(file, offset, whence);



	if (offset < 0)

		return offset;

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

}



const struct file_operations erofs_file_fops = {

	.llseek		= generic_file_llseek,

	.llseek		= erofs_file_llseek,

	.read_iter	= erofs_file_read_iter,

	.mmap		= erofs_file_mmap,

	.get_unmapped_area = thp_get_unmapped_area,