On Thu, Sep 26, 2019 at 04:22:38PM +0200, Max Reitz wrote: > To ensure that all blocks touched by the range [offset, offset + count) > are allocated, we need to calculate the block count from the difference > of the range end (rounded up) and the range start (rounded down). > > Before this patch, we just round up the byte count, which may lead to > unaligned ranges not being fully allocated: > > $ touch test_file > $ block_size=$(stat -fc '%S' test_file) > $ fallocate -o $((block_size / 2)) -l $block_size test_file > $ xfs_bmap test_file > test_file: > 0: [0..7]: 1396264..1396271 > 1: [8..15]: hole > > There should not be a hole there. Instead, the first two blocks should > be fully allocated. > > With this patch applied, the result is something like this: > > $ touch test_file > $ block_size=$(stat -fc '%S' test_file) > $ fallocate -o $((block_size / 2)) -l $block_size test_file > $ xfs_bmap test_file > test_file: > 0: [0..15]: 11024..11039 Code looks ok; by any chance do you have an xfstest we could add to the regresion test suite? --D > Signed-off-by: Max Reitz <mreitz@xxxxxxxxxx> > --- > fs/xfs/xfs_bmap_util.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/fs/xfs/xfs_bmap_util.c b/fs/xfs/xfs_bmap_util.c > index 0910cb75b65d..4f443703065e 100644 > --- a/fs/xfs/xfs_bmap_util.c > +++ b/fs/xfs/xfs_bmap_util.c > @@ -864,6 +864,7 @@ xfs_alloc_file_space( > xfs_filblks_t allocatesize_fsb; > xfs_extlen_t extsz, temp; > xfs_fileoff_t startoffset_fsb; > + xfs_fileoff_t endoffset_fsb; > int nimaps; > int quota_flag; > int rt; > @@ -891,7 +892,8 @@ xfs_alloc_file_space( > imapp = &imaps[0]; > nimaps = 1; > startoffset_fsb = XFS_B_TO_FSBT(mp, offset); > - allocatesize_fsb = XFS_B_TO_FSB(mp, count); > + endoffset_fsb = XFS_B_TO_FSB(mp, offset + count); > + allocatesize_fsb = endoffset_fsb - startoffset_fsb; > > /* > * Allocate file space until done or until there is an error > -- > 2.23.0 >
