Commit 564f8a32 authored by Mark Fasheh's avatar Mark Fasheh
Browse files

ocfs2: Allow direct I/O read past end of file 



ocfs2_direct_IO_get_blocks() was incorrectly returning -EIO for a direct I/O
read whose start block was past the end of the file allocation tree. Fix
things so that we return a hole instead. do_direct_IO() will then notice
that the range start is past eof and return a short read.

While there, remove the unused vbo_max variable.

Signed-off-by: default avatarMark Fasheh <mark.fasheh@oracle.com>
parent 0333394b

fs/ocfs2/aops.c

+17 −7
Original line number Diff line number Diff line
@@ -540,8 +540,7 @@ static int ocfs2_direct_IO_get_blocks(struct inode *inode, sector_t iblock, 
				     struct buffer_head *bh_result, int create)

{

	int ret;

	u64 vbo_max; /* file offset, max_blocks from iblock */

	u64 p_blkno;

	u64 p_blkno, inode_blocks;

	int contig_blocks;

	unsigned char blocksize_bits = inode->i_sb->s_blocksize_bits;

	unsigned long max_blocks = bh_result->b_size >> inode->i_blkbits;
@@ -550,12 +549,23 @@ static int ocfs2_direct_IO_get_blocks(struct inode *inode, sector_t iblock, 
	 * nicely aligned and of the right size, so there's no need

	 * for us to check any of that. */



	vbo_max = ((u64)iblock + max_blocks) << blocksize_bits;



	spin_lock(&OCFS2_I(inode)->ip_lock);

	if ((iblock + max_blocks) >

	    ocfs2_clusters_to_blocks(inode->i_sb,

				     OCFS2_I(inode)->ip_clusters)) {

	inode_blocks = ocfs2_clusters_to_blocks(inode->i_sb,

						OCFS2_I(inode)->ip_clusters);



	/*

	 * For a read which begins past the end of file, we return a hole.

	 */

	if (!create && (iblock >= inode_blocks)) {

		spin_unlock(&OCFS2_I(inode)->ip_lock);

		ret = 0;

		goto bail;

	}



	/*

	 * Any write past EOF is not allowed because we'd be extending.

	 */

	if (create && (iblock + max_blocks) > inode_blocks) {

		spin_unlock(&OCFS2_I(inode)->ip_lock);

		ret = -EIO;

		goto bail;

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