From: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
There's a loop that searches an unlinked bucket list to find the inode
that points to a given inode. Hoist this into a separate function;
later we'll use our iunlink backref cache to bypass the slow list
operation. No functional changes.
Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
---
fs/xfs/xfs_inode.c | 135 +++++++++++++++++++++++++++++++++++++---------------
1 file changed, 96 insertions(+), 39 deletions(-)
diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
index eb51fa33f91a..161d8da459aa 100644
--- a/fs/xfs/xfs_inode.c
+++ b/fs/xfs/xfs_inode.c
@@ -2082,6 +2082,96 @@ xfs_iunlink(
return xfs_iunlink_update_bucket(tp, agno, agibp, bucket_index, agino);
}
+/* Return the imap, dinode pointer, and buffer for an inode. */
+STATIC int
+xfs_iunlink_map_ino(
+ struct xfs_trans *tp,
+ xfs_agnumber_t agno,
+ xfs_agino_t agino,
+ struct xfs_imap *imap,
+ struct xfs_dinode **dipp,
+ struct xfs_buf **bpp)
+{
+ struct xfs_mount *mp = tp->t_mountp;
+ int error;
+
+ imap->im_blkno = 0;
+ error = xfs_imap(mp, tp, XFS_AGINO_TO_INO(mp, agno, agino), imap, 0);
+ if (error) {
+ xfs_warn(mp, "%s: xfs_imap returned error %d.",
+ __func__, error);
+ return error;
+ }
+
+ error = xfs_imap_to_bp(mp, tp, imap, dipp, bpp, 0, 0);
+ if (error) {
+ xfs_warn(mp, "%s: xfs_imap_to_bp returned error %d.",
+ __func__, error);
+ return error;
+ }
+
+ return 0;
+}
+
+/*
+ * Walk the unlinked chain from @head_agino until we find the inode that
+ * points to @target_agino. Return the inode number, map, dinode pointer,
+ * and inode cluster buffer of that inode as @agino, @imap, @dipp, and @bpp.
+ *
+ * @tp, @pag, @head_agino, and @target_agino are input parameters.
+ * @agino, @imap, @dipp, and @bpp are all output parameters.
+ *
+ * Do not call this function if @target_agino is the head of the list.
+ */
+STATIC int
+xfs_iunlink_map_prev(
+ struct xfs_trans *tp,
+ xfs_agnumber_t agno,
+ xfs_agino_t head_agino,
+ xfs_agino_t target_agino,
+ xfs_agino_t *agino,
+ struct xfs_imap *imap,
+ struct xfs_dinode **dipp,
+ struct xfs_buf **bpp)
+{
+ struct xfs_mount *mp = tp->t_mountp;
+ xfs_agino_t next_agino;
+ int error;
+
+ ASSERT(head_agino != target_agino);
+
+ next_agino = head_agino;
+ while (next_agino != target_agino) {
+ xfs_agino_t unlinked_agino;
+
+ if (*bpp)
+ xfs_trans_brelse(tp, *bpp);
+
+ *agino = next_agino;
+ error = xfs_iunlink_map_ino(tp, agno, next_agino, imap, dipp,
+ bpp);
+ if (error)
+ return error;
+
+ unlinked_agino = be32_to_cpu((*dipp)->di_next_unlinked);
+ /*
+ * Make sure this pointer is valid and isn't an obvious
+ * infinite loop.
+ */
+ if (!xfs_verify_agino(mp, agno, unlinked_agino) ||
+ next_agino == unlinked_agino) {
+ XFS_CORRUPTION_ERROR(__func__,
+ XFS_ERRLEVEL_LOW, mp,
+ *dipp, sizeof(**dipp));
+ error = -EFSCORRUPTED;
+ return error;
+ }
+ next_agino = unlinked_agino;
+ }
+
+ return 0;
+}
+
/*
* Pull the on-disk inode from the AGI unlinked list.
*/
@@ -2093,9 +2183,8 @@ xfs_iunlink_remove(
struct xfs_mount *mp = tp->t_mountp;
struct xfs_agi *agi;
struct xfs_buf *agibp;
- struct xfs_buf *last_ibp;
+ struct xfs_buf *last_ibp = NULL;
struct xfs_dinode *last_dip = NULL;
- xfs_ino_t next_ino;
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_agino_t next_agino;
@@ -2138,43 +2227,11 @@ xfs_iunlink_remove(
struct xfs_imap imap;
xfs_agino_t prev_agino;
- /*
- * We need to search the list for the inode being freed.
- */
- last_ibp = NULL;
- while (next_agino != agino) {
- if (last_ibp)
- xfs_trans_brelse(tp, last_ibp);
-
- imap.im_blkno = 0;
- next_ino = XFS_AGINO_TO_INO(mp, agno, next_agino);
-
- error = xfs_imap(mp, tp, next_ino, &imap, 0);
- if (error) {
- xfs_warn(mp,
- "%s: xfs_imap returned error %d.",
- __func__, error);
- return error;
- }
-
- error = xfs_imap_to_bp(mp, tp, &imap, &last_dip,
- &last_ibp, 0, 0);
- if (error) {
- xfs_warn(mp,
- "%s: xfs_imap_to_bp returned error %d.",
- __func__, error);
- return error;
- }
-
- prev_agino = next_agino;
- next_agino = be32_to_cpu(last_dip->di_next_unlinked);
- if (!xfs_verify_agino(mp, agno, next_agino)) {
- XFS_CORRUPTION_ERROR(__func__,
- XFS_ERRLEVEL_LOW, mp,
- last_dip, sizeof(*last_dip));
- return -EFSCORRUPTED;
- }
- }
+ /* We need to search the list for the inode being freed. */
+ error = xfs_iunlink_map_prev(tp, agno, next_agino, agino,
+ &prev_agino, &imap, &last_dip, &last_ibp);
+ if (error)
+ return error;
/*
* Now last_ibp points to the buffer previous to us on the
