[PATCH 008/119] xfs: separate freelist fixing into a separate helper

Darrick J. Wong
2016-06-17T01:18:51Z

From: Dave Chinner <david@fromorbit.com>

Break up xfs_free_extent() into a helper that fixes the freelist.
This helper will be used subsequently to ensure the freelist during
deferred rmap processing.

Signed-off-by: Dave Chinner <david@fromorbit.com>
[darrick: refactor to put this at the head of the patchset]
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
---
fs/xfs/libxfs/xfs_alloc.c | 82 +++++++++++++++++++++++++++++----------------
fs/xfs/libxfs/xfs_alloc.h | 2 +
2 files changed, 55 insertions(+), 29 deletions(-)

diff --git a/fs/xfs/libxfs/xfs_alloc.c b/fs/xfs/libxfs/xfs_alloc.c
index 58bdca7..1c76a0e 100644
--- a/fs/xfs/libxfs/xfs_alloc.c
+++ b/fs/xfs/libxfs/xfs_alloc.c
@@ -2660,55 +2660,79 @@ error0:
return error;
}

-/*
- * Free an extent.
- * Just break up the extent address and hand off to xfs_free_ag_extent
- * after fixing up the freelist.
- */
-int /* error */
-xfs_free_extent(
- xfs_trans_t *tp, /* transaction pointer */
- xfs_fsblock_t bno, /* starting block number of extent */
- xfs_extlen_t len) /* length of extent */
+/* Ensure that the freelist is at full capacity. */
+int
+xfs_free_extent_fix_freelist(
+ struct xfs_trans *tp,
+ xfs_agnumber_t agno,
+ struct xfs_buf **agbp)
{
- xfs_alloc_arg_t args;
- int error;
+ xfs_alloc_arg_t args;
+ int error;

- ASSERT(len != 0);
memset(&args, 0, sizeof(xfs_alloc_arg_t));
args.tp = tp;
args.mp = tp->t_mountp;
+ args.agno = agno;

/*
* validate that the block number is legal - the enables us to detect
* and handle a silent filesystem corruption rather than crashing.
*/
- args.agno = XFS_FSB_TO_AGNO(args.mp, bno);
if (args.agno >= args.mp->m_sb.sb_agcount)
return -EFSCORRUPTED;

- args.agbno = XFS_FSB_TO_AGBNO(args.mp, bno);
- if (args.agbno >= args.mp->m_sb.sb_agblocks)
- return -EFSCORRUPTED;
-
args.pag = xfs_perag_get(args.mp, args.agno);
ASSERT(args.pag);

error = xfs_alloc_fix_freelist(&args, XFS_ALLOC_FLAG_FREEING);
if (error)
- goto error0;
+ goto out;
+
+ *agbp = args.agbp;
+out:
+ xfs_perag_put(args.pag);
+ return error;
+}
+
+/*
+ * Free an extent.
+ * Just break up the extent address and hand off to xfs_free_ag_extent
+ * after fixing up the freelist.
+ */
+int /* error */
+xfs_free_extent(
+ struct xfs_trans *tp, /* transaction pointer */
+ xfs_fsblock_t bno, /* starting block number of extent */
+ xfs_extlen_t len) /* length of extent */
+{
+ struct xfs_mount *mp = tp->t_mountp;
+ struct xfs_buf *agbp;
+ xfs_agnumber_t agno = XFS_FSB_TO_AGNO(mp, bno);
+ xfs_agblock_t agbno = XFS_FSB_TO_AGBNO(mp, bno);
+ int error;
+
+ ASSERT(len != 0);
+
+ error = xfs_free_extent_fix_freelist(tp, agno, &agbp);
+ if (error)
+ return error;
+
+ XFS_WANT_CORRUPTED_GOTO(mp, agbno < mp->m_sb.sb_agblocks, err);

/* validate the extent size is legal now we have the agf locked */
- if (args.agbno + len >
- be32_to_cpu(XFS_BUF_TO_AGF(args.agbp)->agf_length)) {
- error = -EFSCORRUPTED;
- goto error0;
- }
+ XFS_WANT_CORRUPTED_GOTO(mp,
+ agbno + len <= be32_to_cpu(XFS_BUF_TO_AGF(agbp)->agf_length),
+ err);

- error = xfs_free_ag_extent(tp, args.agbp, args.agno, args.agbno, len, 0);
- if (!error)
- xfs_extent_busy_insert(tp, args.agno, args.agbno, len, 0);
-error0:
- xfs_perag_put(args.pag);
+ error = xfs_free_ag_extent(tp, agbp, agno, agbno, len, 0);
+ if (error)
+ goto err;
+
+ xfs_extent_busy_insert(tp, agno, agbno, len, 0);
+ return 0;
+
+err:
+ xfs_trans_brelse(tp, agbp);
return error;
}
diff --git a/fs/xfs/libxfs/xfs_alloc.h b/fs/xfs/libxfs/xfs_alloc.h
index 92a66ba..cf268b2 100644
--- a/fs/xfs/libxfs/xfs_alloc.h
+++ b/fs/xfs/libxfs/xfs_alloc.h
@@ -229,5 +229,7 @@ xfs_alloc_get_rec(
int xfs_read_agf(struct xfs_mount *mp, struct xfs_trans *tp,
xfs_agnumber_t agno, int flags, struct xfs_buf **bpp);
int xfs_alloc_fix_freelist(struct xfs_alloc_arg *args, int flags);
+int xfs_free_extent_fix_freelist(struct xfs_trans *tp, xfs_agnumber_t agno,
+ struct xfs_buf **agbp);

#endif /* __XFS_ALLOC_H__ */