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author | Mandy Kirkconnell <alkirkco@sgi.com> | 2006-03-17 17:25:04 +1100 |
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committer | Nathan Scott <nathans@sgi.com> | 2006-03-17 17:25:04 +1100 |
commit | 8867bc9bf0aed7181aa72c7c938c6ce830b75166 (patch) | |
tree | ae2dcc3a986e4e48fd81605f109be44c29362edd /fs/xfs/linux-2.6/xfs_linux.h | |
parent | 524fbf5dd1b25acffe6f8a4ed5f3cce1023cfdb8 (diff) | |
download | linux-8867bc9bf0aed7181aa72c7c938c6ce830b75166.tar.bz2 |
[XFS] There are a few problems with the new
xfs_bmap_search_multi_extents() wrapper function that I introduced in mod
xfs-linux:xfs-kern:207393a. The function was added as a wrapper around
xfs_bmap_do_search_extents() to avoid breaking the top-of-tree CXFS
interface. The idea of the function was basically to extract the target
extent buffer (if muli- level extent allocation mode), then call
xfs_bmap_do_search_extents() with either a pointer to the first extent in
the target buffer or a pointer to the first extent in the file, depending
on which extent mode was being used. However, in addition to locating the
target extent record for block bno, xfs_bmap_do_search_extents() also sets
four parameters needed by the caller: *lastx, *eofp, *gotp, *prevp.
Passing only the target extent buffer to xfs_bmap_do_search_extents()
causes *eofp to be set incorrectly if the extent is at the end of the
target list but there are actually more extents in the next er_extbuf.
Likewise, if the extent is the first one in the buffer but NOT the first
in the file, *prevp is incorrectly set to NULL. Adding the needed
functionality to xfs_bmap_search_multi_extents() to re-set any incorrectly
set fields is redundant and makes the call to xfs_bmap_do_search_extents()
not make much sense when multi-level extent allocation mode is being used.
This mod basically extracts the two functional components from
xfs_bmap_do_search_extents(), with the intent of obsoleting/removing
xfs_bmap_do_search_extents() after the CXFS mult-level in-core extent
changes are checked in. The two components are: 1) The binary search to
locate the target extent record, and 2) Setting the four parameters needed
by the caller (*lastx, *eofp, *gotp, *prevp). Component 1: I created a
new function in xfs_inode.c called xfs_iext_bno_to_ext(), which executes
the binary search to find the target extent record.
xfs_bmap_search_multi_extents() has been modified to call
xfs_iext_bno_to_ext() rather than xfs_bmap_do_search_extents(). Component
2: The parameter setting functionality has been added to
xfs_bmap_search_multi_extents(), eliminating the need for
xfs_bmap_do_search_extents(). These changes make the removal of
xfs_bmap_do_search_extents() trival once the CXFS changes are in place.
They also allow us to maintain the current XFS interface, using the new
search function introduced in mod xfs-linux:xfs-kern:207393a.
SGI-PV: 928864
SGI-Modid: xfs-linux-melb:xfs-kern:207866a
Signed-off-by: Mandy Kirkconnell <alkirkco@sgi.com>
Signed-off-by: Nathan Scott <nathans@sgi.com>
Diffstat (limited to 'fs/xfs/linux-2.6/xfs_linux.h')
0 files changed, 0 insertions, 0 deletions