On 07 Apr 2022 at 07:28, Darrick J. Wong wrote: > On Thu, Apr 07, 2022 at 11:05:44AM +1000, Dave Chinner wrote: >> On Wed, Apr 06, 2022 at 11:48:56AM +0530, Chandan Babu R wrote: >> > This commit defines new macros to represent maximum extent counts allowed by >> > filesystems which have support for large per-inode extent counters. >> > >> > Reviewed-by: Darrick J. Wong <djwong@xxxxxxxxxx> >> > Signed-off-by: Chandan Babu R <chandan.babu@xxxxxxxxxx> >> > --- >> > fs/xfs/libxfs/xfs_bmap.c | 9 ++++----- >> > fs/xfs/libxfs/xfs_bmap_btree.c | 3 ++- >> > fs/xfs/libxfs/xfs_format.h | 24 ++++++++++++++++++++++-- >> > fs/xfs/libxfs/xfs_inode_buf.c | 4 +++- >> > fs/xfs/libxfs/xfs_inode_fork.c | 3 ++- >> > fs/xfs/libxfs/xfs_inode_fork.h | 21 +++++++++++++++++---- >> > 6 files changed, 50 insertions(+), 14 deletions(-) >> > >> > diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c >> > index b317226fb4ba..1254d4d4821e 100644 >> > --- a/fs/xfs/libxfs/xfs_bmap.c >> > +++ b/fs/xfs/libxfs/xfs_bmap.c >> > @@ -61,10 +61,8 @@ xfs_bmap_compute_maxlevels( >> > int sz; /* root block size */ >> > >> > /* >> > - * The maximum number of extents in a file, hence the maximum number of >> > - * leaf entries, is controlled by the size of the on-disk extent count, >> > - * either a signed 32-bit number for the data fork, or a signed 16-bit >> > - * number for the attr fork. >> > + * The maximum number of extents in a fork, hence the maximum number of >> > + * leaf entries, is controlled by the size of the on-disk extent count. >> > * >> > * Note that we can no longer assume that if we are in ATTR1 that the >> > * fork offset of all the inodes will be >> > @@ -74,7 +72,8 @@ xfs_bmap_compute_maxlevels( >> > * ATTR2 we have to assume the worst case scenario of a minimum size >> > * available. >> > */ >> > - maxleafents = xfs_iext_max_nextents(whichfork); >> > + maxleafents = xfs_iext_max_nextents(xfs_has_large_extent_counts(mp), >> > + whichfork); >> > if (whichfork == XFS_DATA_FORK) >> > sz = XFS_BMDR_SPACE_CALC(MINDBTPTRS); >> > else >> >> Just to confirm, the large extent count feature bit can only be >> added when the filesystem is unmounted? > > Yes, because we (currently) don't support /any/ online feature upgrades. > IIRC Chandan said that you'd have to be careful about validating the min > log size requirements are still met because the tx reservation sizes can > change with the taller bmbts. > Yes, taller BMBT trees causes transaction reservation values to change. This in turn causes a change in log size calculations. -- chandan
