From: Chandan Babu R <chandanrlinux@gmail.com>
To: linux-xfs@vger.kernel.org
Cc: Chandan Babu R <chandanrlinux@gmail.com>,
darrick.wong@oracle.com, david@fromorbit.com, hch@infradead.org
Subject: [PATCH V3 00/10] Bail out if transaction can cause extent count to overflow
Date: Thu, 20 Aug 2020 11:13:39 +0530 [thread overview]
Message-ID: <20200820054349.5525-1-chandanrlinux@gmail.com> (raw)
XFS does not check for possible overflow of per-inode extent counter
fields when adding extents to either data or attr fork.
For e.g.
1. Insert 5 million xattrs (each having a value size of 255 bytes) and
then delete 50% of them in an alternating manner.
2. On a 4k block sized XFS filesystem instance, the above causes 98511
extents to be created in the attr fork of the inode.
xfsaild/loop0 2008 [003] 1475.127209: probe:xfs_inode_to_disk: (ffffffffa43fb6b0) if_nextents=98511 i_ino=131
3. The incore inode fork extent counter is a signed 32-bit
quantity. However, the on-disk extent counter is an unsigned 16-bit
quantity and hence cannot hold 98511 extents.
4. The following incorrect value is stored in the xattr extent counter,
# xfs_db -f -c 'inode 131' -c 'print core.naextents' /dev/loop0
core.naextents = -32561
This patchset adds a new helper function
(i.e. xfs_iext_count_may_overflow()) to check for overflow of the
per-inode data and xattr extent counters and invokes it before
starting an fs operation (e.g. creating a new directory entry). With
this patchset applied, XFS detects counter overflows and returns with
an error rather than causing a silent corruption.
The patchset has been tested by executing xfstests with the following
mkfs.xfs options,
1. -m crc=0 -b size=1k
2. -m crc=0 -b size=4k
3. -m crc=0 -b size=512
4. -m rmapbt=1,reflink=1 -b size=1k
5. -m rmapbt=1,reflink=1 -b size=4k
The patches can also be obtained from
https://github.com/chandanr/linux.git at branch xfs-reserve-extent-count-v3.
Changelog:
V2 -> V3:
1. Move the definition of xfs_iext_count_may_overflow() from
libxfs/xfs_trans_resv.c to libxfs/xfs_inode_fork.c. Also, I tried
to make xfs_iext_count_may_overflow() an inline function by
placing the definition in libxfs/xfs_inode_fork.h. However this
required that the definition of 'struct xfs_inode' be available,
since xfs_iext_count_may_overflow() uses a 'struct xfs_inode *'
type variable.
2. Handle XFS_COW_FORK within xfs_iext_count_may_overflow() by
returning a success value.
3. Rename XFS_IEXT_ADD_CNT to XFS_IEXT_ADD_NOSPLIT_CNT. Thanks to
Darrick for the suggesting the new name.
4. Expand comments to make use of 80 columns.
V1 -> V2:
1. Rename helper function from xfs_trans_resv_ext_cnt() to
xfs_iext_count_may_overflow().
2. Define and use macros to represent fs operations and the
corresponding increase in extent count.
3. Split the patches based on the fs operation being performed.
Chandan Babu R (10):
xfs: Add helper for checking per-inode extent count overflow
xfs: Check for extent overflow when trivally adding a new extent
xfs: Check for extent overflow when deleting an extent
xfs: Check for extent overflow when adding/removing xattrs
xfs: Check for extent overflow when adding/removing dir entries
xfs: Check for extent overflow when writing to unwritten extent
xfs: Check for extent overflow when inserting a hole
xfs: Check for extent overflow when moving extent from cow to data
fork
xfs: Check for extent overflow when remapping an extent
xfs: Check for extent overflow when swapping extents
fs/xfs/libxfs/xfs_attr.c | 13 ++++++
fs/xfs/libxfs/xfs_bmap.c | 6 +++
fs/xfs/libxfs/xfs_inode_fork.c | 23 +++++++++++
fs/xfs/libxfs/xfs_inode_fork.h | 75 ++++++++++++++++++++++++++++++++++
fs/xfs/xfs_bmap_item.c | 4 ++
fs/xfs/xfs_bmap_util.c | 30 ++++++++++++++
fs/xfs/xfs_dquot.c | 8 +++-
fs/xfs/xfs_inode.c | 27 ++++++++++++
fs/xfs/xfs_iomap.c | 10 +++++
fs/xfs/xfs_reflink.c | 10 +++++
fs/xfs/xfs_rtalloc.c | 5 +++
fs/xfs/xfs_symlink.c | 5 +++
12 files changed, 215 insertions(+), 1 deletion(-)
--
2.28.0
next reply other threads:[~2020-08-20 5:44 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-20 5:43 Chandan Babu R [this message]
2020-08-20 5:43 ` [PATCH V3 01/10] xfs: Add helper for checking per-inode extent count overflow Chandan Babu R
2020-08-31 16:08 ` Darrick J. Wong
2020-08-31 16:44 ` Darrick J. Wong
2020-09-01 9:44 ` Chandan Babu R
2020-08-20 5:43 ` [PATCH V3 02/10] xfs: Check for extent overflow when trivally adding a new extent Chandan Babu R
2020-08-31 16:12 ` Darrick J. Wong
2020-08-20 5:43 ` [PATCH V3 03/10] xfs: Check for extent overflow when deleting an extent Chandan Babu R
2020-08-31 16:34 ` Darrick J. Wong
2020-09-01 9:44 ` Chandan Babu R
2020-08-20 5:43 ` [PATCH V3 04/10] xfs: Check for extent overflow when adding/removing xattrs Chandan Babu R
2020-08-31 16:37 ` Darrick J. Wong
2020-09-01 9:44 ` Chandan Babu R
2020-08-20 5:43 ` [PATCH V3 05/10] xfs: Check for extent overflow when adding/removing dir entries Chandan Babu R
2020-08-31 16:41 ` Darrick J. Wong
2020-08-20 5:43 ` [PATCH V3 06/10] xfs: Check for extent overflow when writing to unwritten extent Chandan Babu R
2020-08-31 16:45 ` Darrick J. Wong
2020-08-20 5:43 ` [PATCH V3 07/10] xfs: Check for extent overflow when inserting a hole Chandan Babu R
2020-08-31 16:46 ` Darrick J. Wong
2020-09-01 9:44 ` Chandan Babu R
2020-08-20 5:43 ` [PATCH V3 08/10] xfs: Check for extent overflow when moving extent from cow to data fork Chandan Babu R
2020-08-31 16:29 ` Darrick J. Wong
2020-09-01 9:45 ` Chandan Babu R
2020-08-20 5:43 ` [PATCH V3 09/10] xfs: Check for extent overflow when remapping an extent Chandan Babu R
2020-08-31 16:23 ` Darrick J. Wong
2020-09-01 9:45 ` Chandan Babu R
2020-08-20 5:43 ` [PATCH V3 10/10] xfs: Check for extent overflow when swapping extents Chandan Babu R
2020-08-31 16:20 ` Darrick J. Wong
2020-09-01 9:45 ` Chandan Babu R
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