f2fs: introduce f2fs_seek_block to support SEEK_{DATA, HOLE} in llseek (267378d4) · Commits · 戴 / test

fs/f2fs/f2fs.h

+6 −0

Original line number	Diff line number	Diff line
		@@ -1079,6 +1079,12 @@ static inline void f2fs_stop_checkpoint(struct f2fs_sb_info *sbi)
		((is_inode_flag_set(F2FS_I(i), FI_ACL_MODE)) ? \
		(F2FS_I(i)->i_acl_mode) : ((i)->i_mode))

		/* get offset of first page in next direct node */
		#define PGOFS_OF_NEXT_DNODE(pgofs, fi) \
		((pgofs < ADDRS_PER_INODE(fi)) ? ADDRS_PER_INODE(fi) : \
		(pgofs - ADDRS_PER_INODE(fi) + ADDRS_PER_BLOCK) / \
		ADDRS_PER_BLOCK * ADDRS_PER_BLOCK + ADDRS_PER_INODE(fi))

		/*
		* file.c
		*/

fs/f2fs/file.c

+91 −1

Original line number	Diff line number	Diff line
		@@ -194,6 +194,96 @@ out:
		return ret;
		}

		static loff_t f2fs_seek_block(struct file *file, loff_t offset, int whence)
		{
		struct inode *inode = file->f_mapping->host;
		loff_t maxbytes = inode->i_sb->s_maxbytes;
		struct dnode_of_data dn;
		pgoff_t pgofs, end_offset;
		loff_t data_ofs = offset, isize;
		int err = 0;

		mutex_lock(&inode->i_mutex);

		isize = i_size_read(inode);
		if (offset >= isize)
		goto fail;

		/* handle inline data case */
		if (f2fs_has_inline_data(inode)) {
		if (whence == SEEK_HOLE)
		data_ofs = isize;
		goto found;
		}

		pgofs = (pgoff_t)(offset >> PAGE_CACHE_SHIFT);

		for (; data_ofs < isize; data_ofs = pgofs << PAGE_CACHE_SHIFT) {
		set_new_dnode(&dn, inode, NULL, NULL, 0);
		err = get_dnode_of_data(&dn, pgofs, LOOKUP_NODE_RA);
		if (err && err != -ENOENT) {
		goto fail;
		} else if (err == -ENOENT) {
		/* direct node is not exist */
		if (whence == SEEK_DATA) {
		pgofs = PGOFS_OF_NEXT_DNODE(pgofs,
		F2FS_I(inode));
		continue;
		} else {
		goto found;
		}
		}

		end_offset = IS_INODE(dn.node_page) ?
		ADDRS_PER_INODE(F2FS_I(inode)) : ADDRS_PER_BLOCK;

		/* find data/hole in dnode block */
		for (; dn.ofs_in_node < end_offset;
		dn.ofs_in_node++, pgofs++,
		data_ofs = pgofs << PAGE_CACHE_SHIFT) {
		block_t blkaddr;
		blkaddr = datablock_addr(dn.node_page, dn.ofs_in_node);

		if ((whence == SEEK_DATA && blkaddr != NULL_ADDR) \|\|
		(whence == SEEK_HOLE && blkaddr == NULL_ADDR)) {
		f2fs_put_dnode(&dn);
		goto found;
		}
		}
		f2fs_put_dnode(&dn);
		}

		if (whence == SEEK_DATA)
		goto fail;
		else
		data_ofs = isize;
		found:
		mutex_unlock(&inode->i_mutex);
		return vfs_setpos(file, data_ofs, maxbytes);
		fail:
		mutex_unlock(&inode->i_mutex);
		return -ENXIO;
		}

		static loff_t f2fs_llseek(struct file *file, loff_t offset, int whence)
		{
		struct inode *inode = file->f_mapping->host;
		loff_t maxbytes = inode->i_sb->s_maxbytes;

		switch (whence) {
		case SEEK_SET:
		case SEEK_CUR:
		case SEEK_END:
		return generic_file_llseek_size(file, offset, whence,
		maxbytes, i_size_read(inode));
		case SEEK_DATA:
		case SEEK_HOLE:
		return f2fs_seek_block(file, offset, whence);
		}

		return -EINVAL;
		}

		static int f2fs_file_mmap(struct file file, struct vm_area_struct vma)
		{
		file_accessed(file);
		@@ -675,7 +765,7 @@ long f2fs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
		#endif

		const struct file_operations f2fs_file_operations = {
		.llseek = generic_file_llseek,
		.llseek = f2fs_llseek,
		.read = do_sync_read,
		.write = do_sync_write,
		.aio_read = generic_file_aio_read,

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