[PATCH 0/7] xfs: Extend per-inode extent counters.

Chandan Babu R
2020-06-06T08:28:13Z

The commit xfs: fix inode fork extent count overflow
(3f8a4f1d876d3e3e49e50b0396eaffcc4ba71b08) mentions that 10 billion
per-inode data fork extents should be possible to create. However the
corresponding on-disk field has an signed 32-bit type. Hence this
patchset extends the on-disk field to 64-bit length out of which only
the first 47-bits are valid.

Also, XFS has a per-inode xattr extent counter which is 16 bits
wide. A workload which
1. Creates 1 million 255-byte sized xattrs,
2. Deletes 50% of these xattrs in an alternating manner,
3. Tries to insert 400,000 new 255-byte sized xattrs
causes the following message to be printed on the console,

XFS (loop0): xfs_iflush_int: detected corrupt incore inode 131, total extents = -19916, nblocks = 102937, ptr ffff9ce33b098c00
XFS (loop0): xfs_do_force_shutdown(0x8) called from line 3739 of file fs/xfs/xfs_inode.c. Return address = ffffffffa4a94173

This indicates that we overflowed the 16-bits wide xattr extent
counter.

I have been informed that there are instances where a single file
has > 100 million hardlinks. With parent pointers being stored in xattr,
we will overflow the 16-bits wide xattr extent counter when large
number of hardlinks are created. Hence this patchset extends the
on-disk field to 32-bit length.

This patchset also includes the previously posted "Fix log reservation
calculation for xattr insert operation" patch as a bug fix. It
replaces the xattr set "mount" and "runtime" reservations with just
one static reservation. Hence we don't need the functionality to
calculate maximum sized 'xattr set' reservation separately anymore.

The patches can also be obtained from
https://github.com/chandanr/linux.git at branch xfs-extend-extent-counters.

Chandan Babu R (7):
xfs: Fix log reservation calculation for xattr insert operation
xfs: Check for per-inode extent count overflow
xfs: Compute maximum height of directory BMBT separately
xfs: Add "Use Dir BMBT height" argument to XFS_BM_MAXLEVELS()
xfs: Use 2^27 as the maximum number of directory extents
xfs: Extend data extent counter to 47 bits
xfs: Extend attr extent counter to 32 bits

fs/xfs/libxfs/xfs_attr.c | 11 +--
fs/xfs/libxfs/xfs_bmap.c | 118 +++++++++++++++++++++++-------
fs/xfs/libxfs/xfs_bmap.h | 3 +-
fs/xfs/libxfs/xfs_bmap_btree.h | 4 +-
fs/xfs/libxfs/xfs_format.h | 49 ++++++++++---
fs/xfs/libxfs/xfs_inode_buf.c | 65 ++++++++++++++---
fs/xfs/libxfs/xfs_inode_buf.h | 2 +
fs/xfs/libxfs/xfs_inode_fork.c | 125 ++++++++++++++++++++++++++++++--
fs/xfs/libxfs/xfs_inode_fork.h | 2 +
fs/xfs/libxfs/xfs_log_format.h | 8 +-
fs/xfs/libxfs/xfs_log_rlimit.c | 29 --------
fs/xfs/libxfs/xfs_trans_resv.c | 75 +++++++++----------
fs/xfs/libxfs/xfs_trans_resv.h | 9 +--
fs/xfs/libxfs/xfs_trans_space.h | 48 ++++++------
fs/xfs/libxfs/xfs_types.h | 11 ++-
fs/xfs/scrub/inode.c | 14 ++--
fs/xfs/xfs_bmap_item.c | 3 +-
fs/xfs/xfs_inode.c | 10 ++-
fs/xfs/xfs_inode_item.c | 10 ++-
fs/xfs/xfs_inode_item_recover.c | 22 +++++-
fs/xfs/xfs_mount.c | 5 +-
fs/xfs/xfs_mount.h | 1 +
fs/xfs/xfs_reflink.c | 4 +-
23 files changed, 451 insertions(+), 177 deletions(-)

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2.20.1