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: Mark Fasheh <mark.fasheh@oracle.com>
This commit is contained in:
Mark Fasheh 2006-12-14 13:01:05 -08:00
parent 0333394bff
commit 564f8a3228

View file

@ -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;