Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit fa0d3fce authored by Ross Zwisler's avatar Ross Zwisler Committed by Dave Chinner
Browse files

dax: remove buffer_size_valid() 



Now that ext4 properly sets bh.b_size when we call get_block() for a hole,
rely on that value and remove the buffer_size_valid() sanity check.

Signed-off-by: default avatarRoss Zwisler <ross.zwisler@linux.intel.com>
Reviewed-by: default avatarJan Kara <jack@suse.cz>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarDave Chinner <david@fromorbit.com>
parent 547edce3

fs/dax.c

+1 −21
Original line number Diff line number Diff line
@@ -123,19 +123,6 @@ static bool buffer_written(struct buffer_head *bh) 
	return buffer_mapped(bh) && !buffer_unwritten(bh);

}



/*

 * When ext4 encounters a hole, it returns without modifying the buffer_head

 * which means that we can't trust b_size.  To cope with this, we set b_state

 * to 0 before calling get_block and, if any bit is set, we know we can trust

 * b_size.  Unfortunate, really, since ext4 knows precisely how long a hole is

 * and would save us time calling get_block repeatedly.

 */

static bool buffer_size_valid(struct buffer_head *bh)

{

	return bh->b_state != 0;

}





static sector_t to_sector(const struct buffer_head *bh,

		const struct inode *inode)

{
@@ -177,8 +164,6 @@ static ssize_t dax_io(struct inode *inode, struct iov_iter *iter, 
				rc = get_block(inode, block, bh, rw == WRITE);

				if (rc)

					break;

				if (!buffer_size_valid(bh))

					bh->b_size = 1 << blkbits;

				bh_max = pos - first + bh->b_size;

				bdev = bh->b_bdev;

				/*
@@ -1012,12 +997,7 @@ int dax_pmd_fault(struct vm_area_struct *vma, unsigned long address, 


	bdev = bh.b_bdev;



	/*

	 * If the filesystem isn't willing to tell us the length of a hole,

	 * just fall back to PTEs.  Calling get_block 512 times in a loop

	 * would be silly.

	 */

	if (!buffer_size_valid(&bh) || bh.b_size < PMD_SIZE) {

	if (bh.b_size < PMD_SIZE) {

		dax_pmd_dbg(&bh, address, "allocated block too small");

		return VM_FAULT_FALLBACK;

	}