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Diffstat (limited to 'fs/xfs/scrub/repair.c')
-rw-r--r--fs/xfs/scrub/repair.c128
1 files changed, 103 insertions, 25 deletions
diff --git a/fs/xfs/scrub/repair.c b/fs/xfs/scrub/repair.c
index 9f08dd9bf1d5..4fc0a5ea7673 100644
--- a/fs/xfs/scrub/repair.c
+++ b/fs/xfs/scrub/repair.c
@@ -29,6 +29,8 @@
#include "xfs_ag_resv.h"
#include "xfs_trans_space.h"
#include "xfs_quota.h"
+#include "xfs_attr.h"
+#include "xfs_reflink.h"
#include "scrub/xfs_scrub.h"
#include "scrub/scrub.h"
#include "scrub/common.h"
@@ -692,13 +694,14 @@ xrep_findroot_block(
struct xrep_find_ag_btree *fab,
uint64_t owner,
xfs_agblock_t agbno,
- bool *found_it)
+ bool *done_with_block)
{
struct xfs_mount *mp = ri->sc->mp;
struct xfs_buf *bp;
struct xfs_btree_block *btblock;
xfs_daddr_t daddr;
- int error;
+ int block_level;
+ int error = 0;
daddr = XFS_AGB_TO_DADDR(mp, ri->sc->sa.agno, agbno);
@@ -717,36 +720,111 @@ xrep_findroot_block(
return error;
}
+ /*
+ * Read the buffer into memory so that we can see if it's a match for
+ * our btree type. We have no clue if it is beforehand, and we want to
+ * avoid xfs_trans_read_buf's behavior of dumping the DONE state (which
+ * will cause needless disk reads in subsequent calls to this function)
+ * and logging metadata verifier failures.
+ *
+ * Therefore, pass in NULL buffer ops. If the buffer was already in
+ * memory from some other caller it will already have b_ops assigned.
+ * If it was in memory from a previous unsuccessful findroot_block
+ * call, the buffer won't have b_ops but it should be clean and ready
+ * for us to try to verify if the read call succeeds. The same applies
+ * if the buffer wasn't in memory at all.
+ *
+ * Note: If we never match a btree type with this buffer, it will be
+ * left in memory with NULL b_ops. This shouldn't be a problem unless
+ * the buffer gets written.
+ */
error = xfs_trans_read_buf(mp, ri->sc->tp, mp->m_ddev_targp, daddr,
mp->m_bsize, 0, &bp, NULL);
if (error)
return error;
- /*
- * Does this look like a block matching our fs and higher than any
- * other block we've found so far? If so, reattach buffer verifiers
- * so the AIL won't complain if the buffer is also dirty.
- */
+ /* Ensure the block magic matches the btree type we're looking for. */
btblock = XFS_BUF_TO_BLOCK(bp);
if (be32_to_cpu(btblock->bb_magic) != fab->magic)
goto out;
- if (xfs_sb_version_hascrc(&mp->m_sb) &&
- !uuid_equal(&btblock->bb_u.s.bb_uuid, &mp->m_sb.sb_meta_uuid))
- goto out;
- bp->b_ops = fab->buf_ops;
- /* Ignore this block if it's lower in the tree than we've seen. */
- if (fab->root != NULLAGBLOCK &&
- xfs_btree_get_level(btblock) < fab->height)
- goto out;
+ /*
+ * If the buffer already has ops applied and they're not the ones for
+ * this btree type, we know this block doesn't match the btree and we
+ * can bail out.
+ *
+ * If the buffer ops match ours, someone else has already validated
+ * the block for us, so we can move on to checking if this is a root
+ * block candidate.
+ *
+ * If the buffer does not have ops, nobody has successfully validated
+ * the contents and the buffer cannot be dirty. If the magic, uuid,
+ * and structure match this btree type then we'll move on to checking
+ * if it's a root block candidate. If there is no match, bail out.
+ */
+ if (bp->b_ops) {
+ if (bp->b_ops != fab->buf_ops)
+ goto out;
+ } else {
+ ASSERT(!xfs_trans_buf_is_dirty(bp));
+ if (!uuid_equal(&btblock->bb_u.s.bb_uuid,
+ &mp->m_sb.sb_meta_uuid))
+ goto out;
+ fab->buf_ops->verify_read(bp);
+ if (bp->b_error) {
+ bp->b_error = 0;
+ goto out;
+ }
- /* Make sure we pass the verifiers. */
- bp->b_ops->verify_read(bp);
- if (bp->b_error)
+ /*
+ * Some read verifiers will (re)set b_ops, so we must be
+ * careful not to blow away any such assignment.
+ */
+ if (!bp->b_ops)
+ bp->b_ops = fab->buf_ops;
+ }
+
+ /*
+ * This block passes the magic/uuid and verifier tests for this btree
+ * type. We don't need the caller to try the other tree types.
+ */
+ *done_with_block = true;
+
+ /*
+ * Compare this btree block's level to the height of the current
+ * candidate root block.
+ *
+ * If the level matches the root we found previously, throw away both
+ * blocks because there can't be two candidate roots.
+ *
+ * If level is lower in the tree than the root we found previously,
+ * ignore this block.
+ */
+ block_level = xfs_btree_get_level(btblock);
+ if (block_level + 1 == fab->height) {
+ fab->root = NULLAGBLOCK;
goto out;
- fab->root = agbno;
- fab->height = xfs_btree_get_level(btblock) + 1;
- *found_it = true;
+ } else if (block_level < fab->height) {
+ goto out;
+ }
+
+ /*
+ * This is the highest block in the tree that we've found so far.
+ * Update the btree height to reflect what we've learned from this
+ * block.
+ */
+ fab->height = block_level + 1;
+
+ /*
+ * If this block doesn't have sibling pointers, then it's the new root
+ * block candidate. Otherwise, the root will be found farther up the
+ * tree.
+ */
+ if (btblock->bb_u.s.bb_leftsib == cpu_to_be32(NULLAGBLOCK) &&
+ btblock->bb_u.s.bb_rightsib == cpu_to_be32(NULLAGBLOCK))
+ fab->root = agbno;
+ else
+ fab->root = NULLAGBLOCK;
trace_xrep_findroot_block(mp, ri->sc->sa.agno, agbno,
be32_to_cpu(btblock->bb_magic), fab->height - 1);
@@ -768,7 +846,7 @@ xrep_findroot_rmap(
struct xrep_findroot *ri = priv;
struct xrep_find_ag_btree *fab;
xfs_agblock_t b;
- bool found_it;
+ bool done;
int error = 0;
/* Ignore anything that isn't AG metadata. */
@@ -777,16 +855,16 @@ xrep_findroot_rmap(
/* Otherwise scan each block + btree type. */
for (b = 0; b < rec->rm_blockcount; b++) {
- found_it = false;
+ done = false;
for (fab = ri->btree_info; fab->buf_ops; fab++) {
if (rec->rm_owner != fab->rmap_owner)
continue;
error = xrep_findroot_block(ri, fab,
rec->rm_owner, rec->rm_startblock + b,
- &found_it);
+ &done);
if (error)
return error;
- if (found_it)
+ if (done)
break;
}
}