From: Christoph Hellwig Date: Wed, 28 Apr 2010 12:28:59 +0000 (+0000) Subject: xfs: clean up mapping size calculation in __xfs_get_blocks X-Git-Url: http://drtracing.org/?a=commitdiff_plain;h=2b8f12b7e438fa6ba4a0f8f861871be0beb3a3e6;p=deliverable%2Flinux.git xfs: clean up mapping size calculation in __xfs_get_blocks Signed-off-by: Christoph Hellwig Signed-off-by: Alex Elder --- diff --git a/fs/xfs/linux-2.6/xfs_aops.c b/fs/xfs/linux-2.6/xfs_aops.c index 6feecd279470..1d51bdde5748 100644 --- a/fs/xfs/linux-2.6/xfs_aops.c +++ b/fs/xfs/linux-2.6/xfs_aops.c @@ -1536,16 +1536,23 @@ __xfs_get_blocks( } } + /* + * If this is O_DIRECT or the mpage code calling tell them how large + * the mapping is, so that we can avoid repeated get_blocks calls. + */ if (direct || size > (1 << inode->i_blkbits)) { - struct xfs_mount *mp = XFS_I(inode)->i_mount; - xfs_off_t iomap_offset = XFS_FSB_TO_B(mp, imap.br_startoff); - xfs_off_t iomap_delta = offset - iomap_offset; - xfs_off_t iomap_bsize = XFS_FSB_TO_B(mp, imap.br_blockcount); - - ASSERT(iomap_bsize - iomap_delta > 0); - offset = min_t(xfs_off_t, - iomap_bsize - iomap_delta, size); - bh_result->b_size = (ssize_t)min_t(xfs_off_t, LONG_MAX, offset); + xfs_off_t mapping_size; + + mapping_size = imap.br_startoff + imap.br_blockcount - iblock; + mapping_size <<= inode->i_blkbits; + + ASSERT(mapping_size > 0); + if (mapping_size > size) + mapping_size = size; + if (mapping_size > LONG_MAX) + mapping_size = LONG_MAX; + + bh_result->b_size = mapping_size; } return 0;