From: Darrick J. Wong Date: Mon, 25 Nov 2024 21:14:19 +0000 (-0800) Subject: xfs: add a lockdep class key for rtgroup inodes X-Git-Tag: v6.13.0~129 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=abb0172a9a34bf90480e29c4dbe62fe6b922e225;p=thirdparty%2Fxfsprogs-dev.git xfs: add a lockdep class key for rtgroup inodes Source kernel commit: c29237a65c8dbfade3c032763b66d495b8e8cb7a Add a dynamic lockdep class key for rtgroup inodes. This will enable lockdep to deduce inconsistencies in the rtgroup metadata ILOCK locking order. Each class can have 8 subclasses, and for now we will only have 2 inodes per group. This enables rtgroup order and inode order checks when nesting ILOCKs. Signed-off-by: Darrick J. Wong Reviewed-by: Christoph Hellwig --- diff --git a/libxfs/xfs_rtgroup.c b/libxfs/xfs_rtgroup.c index 5c8e269b..ece52626 100644 --- a/libxfs/xfs_rtgroup.c +++ b/libxfs/xfs_rtgroup.c @@ -196,3 +196,55 @@ xfs_rtgroup_trans_join( if (rtglock_flags & XFS_RTGLOCK_BITMAP) xfs_rtbitmap_trans_join(tp); } + +#ifdef CONFIG_PROVE_LOCKING +static struct lock_class_key xfs_rtginode_lock_class; + +static int +xfs_rtginode_ilock_cmp_fn( + const struct lockdep_map *m1, + const struct lockdep_map *m2) +{ + const struct xfs_inode *ip1 = + container_of(m1, struct xfs_inode, i_lock.dep_map); + const struct xfs_inode *ip2 = + container_of(m2, struct xfs_inode, i_lock.dep_map); + + if (ip1->i_projid < ip2->i_projid) + return -1; + if (ip1->i_projid > ip2->i_projid) + return 1; + return 0; +} + +static inline void +xfs_rtginode_ilock_print_fn( + const struct lockdep_map *m) +{ + const struct xfs_inode *ip = + container_of(m, struct xfs_inode, i_lock.dep_map); + + printk(KERN_CONT " rgno=%u", ip->i_projid); +} + +/* + * Most of the time each of the RTG inode locks are only taken one at a time. + * But when committing deferred ops, more than one of a kind can be taken. + * However, deferred rt ops will be committed in rgno order so there is no + * potential for deadlocks. The code here is needed to tell lockdep about this + * order. + */ +static inline void +xfs_rtginode_lockdep_setup( + struct xfs_inode *ip, + xfs_rgnumber_t rgno, + enum xfs_rtg_inodes type) +{ + lockdep_set_class_and_subclass(&ip->i_lock, &xfs_rtginode_lock_class, + type); + lock_set_cmp_fn(&ip->i_lock, xfs_rtginode_ilock_cmp_fn, + xfs_rtginode_ilock_print_fn); +} +#else +#define xfs_rtginode_lockdep_setup(ip, rgno, type) do { } while (0) +#endif /* CONFIG_PROVE_LOCKING */