The patch below does not apply to the 6.12-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.12.y git checkout FETCH_HEAD git cherry-pick -x 4b8d867ca6e2fc6d152f629fdaf027053b81765a # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2025020409-duckbill-unbalance-60e9@gregkh' --subject-prefix 'PATCH 6.12.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 4b8d867ca6e2fc6d152f629fdaf027053b81765a Mon Sep 17 00:00:00 2001 From: "Darrick J. Wong" djwong@kernel.org Date: Thu, 12 Dec 2024 14:37:56 -0800 Subject: [PATCH] xfs: don't over-report free space or inodes in statvfs
Emmanual Florac reports a strange occurrence when project quota limits are enabled, free space is lower than the remaining quota, and someone runs statvfs:
# mkfs.xfs -f /dev/sda # mount /dev/sda /mnt -o prjquota # xfs_quota -x -c 'limit -p bhard=2G 55' /mnt # mkdir /mnt/dir # xfs_io -c 'chproj 55' -c 'chattr +P' -c 'stat -vvvv' /mnt/dir # fallocate -l 19g /mnt/a # df /mnt /mnt/dir Filesystem Size Used Avail Use% Mounted on /dev/sda 20G 20G 345M 99% /mnt /dev/sda 2.0G 0 2.0G 0% /mnt
I think the bug here is that xfs_fill_statvfs_from_dquot unconditionally assigns to f_bfree without checking that the filesystem has enough free space to fill the remaining project quota. However, this is a longstanding behavior of xfs so it's unclear what to do here.
Cc: stable@vger.kernel.org # v2.6.18 Fixes: 932f2c323196c2 ("[XFS] statvfs component of directory/project quota support, code originally by Glen.") Reported-by: Emmanuel Florac eflorac@intellique.com Signed-off-by: "Darrick J. Wong" djwong@kernel.org Reviewed-by: Christoph Hellwig hch@lst.de
diff --git a/fs/xfs/xfs_qm_bhv.c b/fs/xfs/xfs_qm_bhv.c index 847ba29630e9..db5b8afd9d1b 100644 --- a/fs/xfs/xfs_qm_bhv.c +++ b/fs/xfs/xfs_qm_bhv.c @@ -32,21 +32,28 @@ xfs_fill_statvfs_from_dquot( limit = blkres->softlimit ? blkres->softlimit : blkres->hardlimit; - if (limit && statp->f_blocks > limit) { - statp->f_blocks = limit; - statp->f_bfree = statp->f_bavail = - (statp->f_blocks > blkres->reserved) ? - (statp->f_blocks - blkres->reserved) : 0; + if (limit) { + uint64_t remaining = 0; + + if (limit > blkres->reserved) + remaining = limit - blkres->reserved; + + statp->f_blocks = min(statp->f_blocks, limit); + statp->f_bfree = min(statp->f_bfree, remaining); + statp->f_bavail = min(statp->f_bavail, remaining); }
limit = dqp->q_ino.softlimit ? dqp->q_ino.softlimit : dqp->q_ino.hardlimit; - if (limit && statp->f_files > limit) { - statp->f_files = limit; - statp->f_ffree = - (statp->f_files > dqp->q_ino.reserved) ? - (statp->f_files - dqp->q_ino.reserved) : 0; + if (limit) { + uint64_t remaining = 0; + + if (limit > dqp->q_ino.reserved) + remaining = limit - dqp->q_ino.reserved; + + statp->f_files = min(statp->f_files, limit); + statp->f_ffree = min(statp->f_ffree, remaining); } }