[PATCH 03/21] xfs: define locking primitives for realtime groups

Darrick J. Wong
2024-10-11T00:56:28Z

Define helper functions to lock all metadata inodes related to a
realtime group. There's not much to look at now, but this will become
important when we add per-rtgroup metadata files and online fsck code
for them.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
---
fs/xfs/libxfs/xfs_rtgroup.c | 49 +++++++++++++++++++++++++++++++++++++++++++
fs/xfs/libxfs/xfs_rtgroup.h | 16 ++++++++++++++
2 files changed, 65 insertions(+)

diff --git a/fs/xfs/libxfs/xfs_rtgroup.c b/fs/xfs/libxfs/xfs_rtgroup.c
index 37c0330ca379d9..3eedc4a68a3acd 100644
--- a/fs/xfs/libxfs/xfs_rtgroup.c
+++ b/fs/xfs/libxfs/xfs_rtgroup.c
@@ -127,3 +127,52 @@ xfs_rtgroup_extents(
return __xfs_rtgroup_extents(mp, rgno, mp->m_sb.sb_rgcount,
mp->m_sb.sb_rextents);
}
+
+/* Lock metadata inodes associated with this rt group. */
+void
+xfs_rtgroup_lock(
+ struct xfs_rtgroup *rtg,
+ unsigned int rtglock_flags)
+{
+ ASSERT(!(rtglock_flags & ~XFS_RTGLOCK_ALL_FLAGS));
+ ASSERT(!(rtglock_flags & XFS_RTGLOCK_BITMAP_SHARED) ||
+ !(rtglock_flags & XFS_RTGLOCK_BITMAP));
+
+ if (rtglock_flags & XFS_RTGLOCK_BITMAP)
+ xfs_rtbitmap_lock(rtg_mount(rtg));
+ else if (rtglock_flags & XFS_RTGLOCK_BITMAP_SHARED)
+ xfs_rtbitmap_lock_shared(rtg_mount(rtg), XFS_RBMLOCK_BITMAP);
+}
+
+/* Unlock metadata inodes associated with this rt group. */
+void
+xfs_rtgroup_unlock(
+ struct xfs_rtgroup *rtg,
+ unsigned int rtglock_flags)
+{
+ ASSERT(!(rtglock_flags & ~XFS_RTGLOCK_ALL_FLAGS));
+ ASSERT(!(rtglock_flags & XFS_RTGLOCK_BITMAP_SHARED) ||
+ !(rtglock_flags & XFS_RTGLOCK_BITMAP));
+
+ if (rtglock_flags & XFS_RTGLOCK_BITMAP)
+ xfs_rtbitmap_unlock(rtg_mount(rtg));
+ else if (rtglock_flags & XFS_RTGLOCK_BITMAP_SHARED)
+ xfs_rtbitmap_unlock_shared(rtg_mount(rtg), XFS_RBMLOCK_BITMAP);
+}
+
+/*
+ * Join realtime group metadata inodes to the transaction. The ILOCKs will be
+ * released on transaction commit.
+ */
+void
+xfs_rtgroup_trans_join(
+ struct xfs_trans *tp,
+ struct xfs_rtgroup *rtg,
+ unsigned int rtglock_flags)
+{
+ ASSERT(!(rtglock_flags & ~XFS_RTGLOCK_ALL_FLAGS));
+ ASSERT(!(rtglock_flags & XFS_RTGLOCK_BITMAP_SHARED));
+
+ if (rtglock_flags & XFS_RTGLOCK_BITMAP)
+ xfs_rtbitmap_trans_join(tp);
+}
diff --git a/fs/xfs/libxfs/xfs_rtgroup.h b/fs/xfs/libxfs/xfs_rtgroup.h
index a9462aefefd77c..87932fce81fcfe 100644
--- a/fs/xfs/libxfs/xfs_rtgroup.h
+++ b/fs/xfs/libxfs/xfs_rtgroup.h
@@ -189,6 +189,19 @@ int xfs_initialize_rtgroups(struct xfs_mount *mp, xfs_rgnumber_t first_rgno,
xfs_rtxnum_t __xfs_rtgroup_extents(struct xfs_mount *mp, xfs_rgnumber_t rgno,
xfs_rgnumber_t rgcount, xfs_rtbxlen_t rextents);
xfs_rtxnum_t xfs_rtgroup_extents(struct xfs_mount *mp, xfs_rgnumber_t rgno);
+
+/* Lock the rt bitmap inode in exclusive mode */
+#define XFS_RTGLOCK_BITMAP (1U << 0)
+/* Lock the rt bitmap inode in shared mode */
+#define XFS_RTGLOCK_BITMAP_SHARED (1U << 1)
+
+#define XFS_RTGLOCK_ALL_FLAGS (XFS_RTGLOCK_BITMAP | \
+ XFS_RTGLOCK_BITMAP_SHARED)
+
+void xfs_rtgroup_lock(struct xfs_rtgroup *rtg, unsigned int rtglock_flags);
+void xfs_rtgroup_unlock(struct xfs_rtgroup *rtg, unsigned int rtglock_flags);
+void xfs_rtgroup_trans_join(struct xfs_trans *tp, struct xfs_rtgroup *rtg,
+ unsigned int rtglock_flags);
#else
static inline void xfs_free_rtgroups(struct xfs_mount *mp,
xfs_rgnumber_t first_rgno, xfs_rgnumber_t end_rgno)
@@ -203,6 +216,9 @@ static inline int xfs_initialize_rtgroups(struct xfs_mount *mp,
}

# define xfs_rtgroup_extents(mp, rgno) (0)
+# define xfs_rtgroup_lock(rtg, gf) ((void)0)
+# define xfs_rtgroup_unlock(rtg, gf) ((void)0)
+# define xfs_rtgroup_trans_join(tp, rtg, gf) ((void)0)
#endif /* CONFIG_XFS_RT */

#endif /* __LIBXFS_RTGROUP_H */