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| author | Zheng Bin <zhengbin13@huawei.com> | 2020-05-12 11:48:35 -0700 |
|---|---|---|
| committer | Darrick J. Wong <darrick.wong@oracle.com> | 2020-05-13 15:32:45 -0700 |
| commit | 237aac4624aac5d46b903539e91c8d4567a2bab5 (patch) | |
| tree | ff6c818887afc31ec2259cbb5332ed26c52c4e39 | |
| parent | 3d60548b216b5486a541a06c167df3dfb6df9c2e (diff) | |
| download | linux-stable-237aac4624aac5d46b903539e91c8d4567a2bab5.tar.gz linux-stable-237aac4624aac5d46b903539e91c8d4567a2bab5.tar.bz2 linux-stable-237aac4624aac5d46b903539e91c8d4567a2bab5.zip | |
xfs: ensure f_bfree returned by statfs() is non-negative
Construct an img like this:
dd if=/dev/zero of=xfs.img bs=1M count=20
mkfs.xfs -d agcount=1 xfs.img
xfs_db -x xfs.img
sb 0
write fdblocks 0
agf 0
write freeblks 0
write longest 0
quit
mount it, df -h /mnt(xfs mount point), will show this:
Filesystem Size Used Avail Use% Mounted on
/dev/loop0 17M -64Z -32K 100% /mnt
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Zheng Bin <zhengbin13@huawei.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
| -rw-r--r-- | fs/xfs/xfs_super.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c index e80bd2c4c279..aae469f73efe 100644 --- a/fs/xfs/xfs_super.c +++ b/fs/xfs/xfs_super.c @@ -807,7 +807,8 @@ xfs_fs_statfs( statp->f_blocks = sbp->sb_dblocks - lsize; spin_unlock(&mp->m_sb_lock); - statp->f_bfree = fdblocks - mp->m_alloc_set_aside; + /* make sure statp->f_bfree does not underflow */ + statp->f_bfree = max_t(int64_t, fdblocks - mp->m_alloc_set_aside, 0); statp->f_bavail = statp->f_bfree; fakeinos = XFS_FSB_TO_INO(mp, statp->f_bfree); |