[PATCH 03/13] xfs: factor the xfs_iunlink functions

Dave Chinner
2020-08-12T09:26:03Z

From: Dave Chinner <dchinner@redhat.com>

Prep work that separates the locking that protects the unlinked list
from the actual operations being performed. This also helps document
the fact they are performing list insert and remove operations. No
functional code change.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
---
fs/xfs/xfs_inode.c | 92 ++++++++++++++++++++++++++++++----------------
1 file changed, 60 insertions(+), 32 deletions(-)

diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
index 2072bd25989a..f2f502b65691 100644
--- a/fs/xfs/xfs_inode.c
+++ b/fs/xfs/xfs_inode.c
@@ -2205,35 +2205,20 @@ xfs_iunlink_update_inode(
return error;
}

-/*
- * This is called when the inode's link count has gone to 0 or we are creating
- * a tmpfile via O_TMPFILE. The inode @ip must have nlink == 0.
- *
- * We place the on-disk inode on a list in the AGI. It will be pulled from this
- * list when the inode is freed.
- */
-STATIC int
-xfs_iunlink(
+static int
+xfs_iunlink_insert_inode(
struct xfs_trans *tp,
+ struct xfs_buf *agibp,
struct xfs_inode *ip)
{
struct xfs_mount *mp = tp->t_mountp;
struct xfs_agi *agi;
- struct xfs_buf *agibp;
xfs_agino_t next_agino;
- xfs_agnumber_t agno = XFS_INO_TO_AGNO(mp, ip->i_ino);
xfs_agino_t agino = XFS_INO_TO_AGINO(mp, ip->i_ino);
+ xfs_agnumber_t agno = XFS_INO_TO_AGNO(mp, ip->i_ino);
short bucket_index = agino % XFS_AGI_UNLINKED_BUCKETS;
int error;

- ASSERT(VFS_I(ip)->i_nlink == 0);
- ASSERT(VFS_I(ip)->i_mode != 0);
- trace_xfs_iunlink(ip);
-
- /* Get the agi buffer first. It ensures lock ordering on the list. */
- error = xfs_read_agi(mp, tp, agno, &agibp);
- if (error)
- return error;
agi = agibp->b_addr;

/*
@@ -2274,6 +2259,35 @@ xfs_iunlink(
return xfs_iunlink_update_bucket(tp, agno, agibp, bucket_index, agino);
}

+/*
+ * This is called when the inode's link count has gone to 0 or we are creating
+ * a tmpfile via O_TMPFILE. The inode @ip must have nlink == 0.
+ *
+ * We place the on-disk inode on a list in the AGI. It will be pulled from this
+ * list when the inode is freed.
+ */
+STATIC int
+xfs_iunlink(
+ struct xfs_trans *tp,
+ struct xfs_inode *ip)
+{
+ struct xfs_mount *mp = tp->t_mountp;
+ struct xfs_buf *agibp;
+ xfs_agnumber_t agno = XFS_INO_TO_AGNO(mp, ip->i_ino);
+ int error;
+
+ ASSERT(VFS_I(ip)->i_nlink == 0);
+ ASSERT(VFS_I(ip)->i_mode != 0);
+ trace_xfs_iunlink(ip);
+
+ /* Get the agi buffer first. It ensures lock ordering on the list. */
+ error = xfs_read_agi(mp, tp, agno, &agibp);
+ if (error)
+ return error;
+
+ return xfs_iunlink_insert_inode(tp, agibp, ip);
+}
+
/* Return the imap, dinode pointer, and buffer for an inode. */
STATIC int
xfs_iunlink_map_ino(
@@ -2388,32 +2402,23 @@ xfs_iunlink_map_prev(
return 0;
}

-/*
- * Pull the on-disk inode from the AGI unlinked list.
- */
-STATIC int
-xfs_iunlink_remove(
+static int
+xfs_iunlink_remove_inode(
struct xfs_trans *tp,
+ struct xfs_buf *agibp,
struct xfs_inode *ip)
{
struct xfs_mount *mp = tp->t_mountp;
struct xfs_agi *agi;
- struct xfs_buf *agibp;
struct xfs_buf *last_ibp;
struct xfs_dinode *last_dip = NULL;
- xfs_agnumber_t agno = XFS_INO_TO_AGNO(mp, ip->i_ino);
xfs_agino_t agino = XFS_INO_TO_AGINO(mp, ip->i_ino);
+ xfs_agnumber_t agno = XFS_INO_TO_AGNO(mp, ip->i_ino);
xfs_agino_t next_agino;
xfs_agino_t head_agino;
short bucket_index = agino % XFS_AGI_UNLINKED_BUCKETS;
int error;

- trace_xfs_iunlink_remove(ip);
-
- /* Get the agi buffer first. It ensures lock ordering on the list. */
- error = xfs_read_agi(mp, tp, agno, &agibp);
- if (error)
- return error;
agi = agibp->b_addr;

/*
@@ -2482,6 +2487,29 @@ xfs_iunlink_remove(
next_agino);
}

+/*
+ * Pull the on-disk inode from the AGI unlinked list.
+ */
+STATIC int
+xfs_iunlink_remove(
+ struct xfs_trans *tp,
+ struct xfs_inode *ip)
+{
+ struct xfs_mount *mp = tp->t_mountp;
+ struct xfs_buf *agibp;
+ xfs_agnumber_t agno = XFS_INO_TO_AGNO(mp, ip->i_ino);
+ int error;
+
+ trace_xfs_iunlink_remove(ip);
+
+ /* Get the agi buffer first. It ensures lock ordering on the list. */
+ error = xfs_read_agi(mp, tp, agno, &agibp);
+ if (error)
+ return error;
+
+ return xfs_iunlink_remove_inode(tp, agibp, ip);
+}
+
/*
* Look up the inode number specified and if it is not already marked XFS_ISTALE
* mark it stale. We should only find clean inodes in this lookup that aren't
--
2.26.2.761.g0e0b3e54be