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 | 145 ++++++++++++++++++++++++++++++++++++++--------------
1 file changed, 106 insertions(+), 39 deletions(-)
diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
index f23f13f0f2e6..8af5f4e989ac 100644
--- a/fs/xfs/xfs_inode.c
+++ b/fs/xfs/xfs_inode.c
@@ -2066,6 +2066,105 @@ xfs_iunlink(
return error;
}
+/* Return the imap, dinode pointer, and buffer for an inode. */
+STATIC int
+xfs_iunlink_map_ino(
+ struct xfs_trans *tp,
+ xfs_ino_t ino,
+ 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, 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, 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 @ino, @imap, @dipp, and @bpp.
+ *
+ * @tp, @pag, @head_agino, and @target_agino are input parameters.
+ * @ino, @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,
+ struct xfs_perag *pag,
+ xfs_agino_t head_agino,
+ xfs_agino_t target_agino,
+ xfs_ino_t *ino,
+ struct xfs_imap *imap,
+ struct xfs_dinode **dipp,
+ struct xfs_buf **bpp)
+{
+ struct xfs_mount *mp = tp->t_mountp;
+ struct xfs_buf *last_ibp = NULL;
+ struct xfs_dinode *last_dip;
+ xfs_ino_t next_ino = NULLFSINO;
+ 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 (last_ibp)
+ xfs_trans_brelse(tp, last_ibp);
+
+ next_ino = XFS_AGINO_TO_INO(mp, pag->pag_agno, next_agino);
+ error = xfs_iunlink_map_ino(tp, next_ino, imap, &last_dip,
+ &last_ibp);
+ if (error)
+ return error;
+
+ unlinked_agino = be32_to_cpu(last_dip->di_next_unlinked);
+ /*
+ * Make sure this pointer is valid and isn't an obvious
+ * infinite loop.
+ */
+ if (!xfs_verify_agino(mp, pag->pag_agno, unlinked_agino) ||
+ next_agino == unlinked_agino) {
+ XFS_CORRUPTION_ERROR(__func__,
+ XFS_ERRLEVEL_LOW, mp,
+ last_dip, sizeof(*last_dip));
+ error = -EFSCORRUPTED;
+ return error;
+ }
+ next_agino = unlinked_agino;
+ }
+
+ /* Should never happen, but don't return garbage. */
+ if (next_ino == NULLFSINO)
+ return -EFSCORRUPTED;
+
+ *ino = next_ino;
+ *dipp = last_dip;
+ *bpp = last_ibp;
+ return 0;
+}
+
/*
* Pull the on-disk inode from the AGI unlinked list.
*/
@@ -2080,7 +2179,7 @@ xfs_iunlink_remove(
struct xfs_buf *last_ibp;
struct xfs_dinode *last_dip = NULL;
struct xfs_perag *pag;
- xfs_ino_t next_ino;
+ xfs_ino_t prev_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;
@@ -2125,43 +2224,11 @@ xfs_iunlink_remove(
} else {
struct xfs_imap imap;
- /*
- * 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);
- goto out;
- }
-
- 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);
- goto out;
- }
-
- 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));
- error = -EFSCORRUPTED;
- goto out;
- }
- }
+ /* We need to search the list for the inode being freed. */
+ error = xfs_iunlink_map_prev(tp, pag, next_agino, agino,
+ &prev_ino, &imap, &last_dip, &last_ibp);
+ if (error)
+ goto out;
/*
* Now last_ibp points to the buffer previous to us on the
@@ -2174,7 +2241,7 @@ xfs_iunlink_remove(
/* Point the previous inode on the list to the next inode. */
xfs_iunlink_update_dinode(tp, agno, last_ibp, last_dip, &imap,
- next_ino, next_agino);
+ prev_ino, next_agino);
}
pag->pagi_unlinked_count--;
out:
