[XFS] factor out xfs_read_agi helper
Add a helper to read the AGI header and perform basic verification.
Based on hunks from a larger patch from Dave Chinner.
(First sent on Juli 23rd)
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <david@fromorbit.com>
Signed-off-by: Niv Sardi <xaiki@sgi.com>
diff --git a/fs/xfs/xfs_ialloc.c b/fs/xfs/xfs_ialloc.c
index c8a56c52..efb65fe 100644
--- a/fs/xfs/xfs_ialloc.c
+++ b/fs/xfs/xfs_ialloc.c
@@ -1462,70 +1462,95 @@
xfs_trans_log_buf(tp, bp, first, last);
}
+#ifdef DEBUG
+STATIC void
+xfs_check_agi_unlinked(
+ struct xfs_agi *agi)
+{
+ int i;
+
+ for (i = 0; i < XFS_AGI_UNLINKED_BUCKETS; i++)
+ ASSERT(agi->agi_unlinked[i]);
+}
+#else
+#define xfs_check_agi_unlinked(agi)
+#endif
+
/*
* Read in the allocation group header (inode allocation section)
*/
int
-xfs_ialloc_read_agi(
- xfs_mount_t *mp, /* file system mount structure */
- xfs_trans_t *tp, /* transaction pointer */
- xfs_agnumber_t agno, /* allocation group number */
- xfs_buf_t **bpp) /* allocation group hdr buf */
+xfs_read_agi(
+ struct xfs_mount *mp, /* file system mount structure */
+ struct xfs_trans *tp, /* transaction pointer */
+ xfs_agnumber_t agno, /* allocation group number */
+ struct xfs_buf **bpp) /* allocation group hdr buf */
{
- xfs_agi_t *agi; /* allocation group header */
- int agi_ok; /* agi is consistent */
- xfs_buf_t *bp; /* allocation group hdr buf */
- xfs_perag_t *pag; /* per allocation group data */
- int error;
+ struct xfs_agi *agi; /* allocation group header */
+ int agi_ok; /* agi is consistent */
+ int error;
ASSERT(agno != NULLAGNUMBER);
- error = xfs_trans_read_buf(
- mp, tp, mp->m_ddev_targp,
+
+ error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp,
XFS_AG_DADDR(mp, agno, XFS_AGI_DADDR(mp)),
- XFS_FSS_TO_BB(mp, 1), 0, &bp);
+ XFS_FSS_TO_BB(mp, 1), 0, bpp);
if (error)
return error;
- ASSERT(bp && !XFS_BUF_GETERROR(bp));
+
+ ASSERT(*bpp && !XFS_BUF_GETERROR(*bpp));
+ agi = XFS_BUF_TO_AGI(*bpp);
/*
* Validate the magic number of the agi block.
*/
- agi = XFS_BUF_TO_AGI(bp);
- agi_ok =
- be32_to_cpu(agi->agi_magicnum) == XFS_AGI_MAGIC &&
- XFS_AGI_GOOD_VERSION(be32_to_cpu(agi->agi_versionnum));
+ agi_ok = be32_to_cpu(agi->agi_magicnum) == XFS_AGI_MAGIC &&
+ XFS_AGI_GOOD_VERSION(be32_to_cpu(agi->agi_versionnum)) &&
+ be32_to_cpu(agi->agi_seqno) == agno;
if (unlikely(XFS_TEST_ERROR(!agi_ok, mp, XFS_ERRTAG_IALLOC_READ_AGI,
XFS_RANDOM_IALLOC_READ_AGI))) {
- XFS_CORRUPTION_ERROR("xfs_ialloc_read_agi", XFS_ERRLEVEL_LOW,
+ XFS_CORRUPTION_ERROR("xfs_read_agi", XFS_ERRLEVEL_LOW,
mp, agi);
- xfs_trans_brelse(tp, bp);
+ xfs_trans_brelse(tp, *bpp);
return XFS_ERROR(EFSCORRUPTED);
}
+
+ XFS_BUF_SET_VTYPE_REF(*bpp, B_FS_AGI, XFS_AGI_REF);
+
+ xfs_check_agi_unlinked(agi);
+ return 0;
+}
+
+int
+xfs_ialloc_read_agi(
+ struct xfs_mount *mp, /* file system mount structure */
+ struct xfs_trans *tp, /* transaction pointer */
+ xfs_agnumber_t agno, /* allocation group number */
+ struct xfs_buf **bpp) /* allocation group hdr buf */
+{
+ struct xfs_agi *agi; /* allocation group header */
+ struct xfs_perag *pag; /* per allocation group data */
+ int error;
+
+ error = xfs_read_agi(mp, tp, agno, bpp);
+ if (error)
+ return error;
+
+ agi = XFS_BUF_TO_AGI(*bpp);
pag = &mp->m_perag[agno];
+
if (!pag->pagi_init) {
pag->pagi_freecount = be32_to_cpu(agi->agi_freecount);
pag->pagi_count = be32_to_cpu(agi->agi_count);
pag->pagi_init = 1;
- } else {
- /*
- * It's possible for these to be out of sync if
- * we are in the middle of a forced shutdown.
- */
- ASSERT(pag->pagi_freecount == be32_to_cpu(agi->agi_freecount) ||
- XFS_FORCED_SHUTDOWN(mp));
}
-#ifdef DEBUG
- {
- int i;
-
- for (i = 0; i < XFS_AGI_UNLINKED_BUCKETS; i++)
- ASSERT(agi->agi_unlinked[i]);
- }
-#endif
-
- XFS_BUF_SET_VTYPE_REF(bp, B_FS_AGI, XFS_AGI_REF);
- *bpp = bp;
+ /*
+ * It's possible for these to be out of sync if
+ * we are in the middle of a forced shutdown.
+ */
+ ASSERT(pag->pagi_freecount == be32_to_cpu(agi->agi_freecount) ||
+ XFS_FORCED_SHUTDOWN(mp));
return 0;
}
