leandrof/linux
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

xfs: repair the AGFL

Browse Source 
Repair the AGFL from the rmap data.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
This commit is contained in:
Darrick J. Wong
2018-08-09 22:43:02 -07:00
parent f9ed6debca
commit 0e93d3f43e
5 changed files with 380 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files

92
fs/xfs/scrub/bitmap.c
View File

@@ -9,6 +9,7 @@
#include "xfs_format.h"
#include "xfs_trans_resv.h"
#include "xfs_mount.h"
#include "xfs_btree.h"
#include "scrub/xfs_scrub.h"
#include "scrub/scrub.h"
#include "scrub/common.h"
@@ -209,3 +210,94 @@ out:
}
#undef LEFT_ALIGNED
#undef RIGHT_ALIGNED
/*
* Record all btree blocks seen while iterating all records of a btree.
*
* We know that the btree query_all function starts at the left edge and walks
* towards the right edge of the tree. Therefore, we know that we can walk up
* the btree cursor towards the root; if the pointer for a given level points
* to the first record/key in that block, we haven't seen this block before;
* and therefore we need to remember that we saw this block in the btree.
*
* So if our btree is:
*
* 4
* / | \
* 1 2 3
*
* Pretend for this example that each leaf block has 100 btree records. For
* the first btree record, we'll observe that bc_ptrs[0] == 1, so we record
* that we saw block 1. Then we observe that bc_ptrs[1] == 1, so we record
* block 4. The list is [1, 4].
*
* For the second btree record, we see that bc_ptrs[0] == 2, so we exit the
* loop. The list remains [1, 4].
*
* For the 101st btree record, we've moved onto leaf block 2. Now
* bc_ptrs[0] == 1 again, so we record that we saw block 2. We see that
* bc_ptrs[1] == 2, so we exit the loop. The list is now [1, 4, 2].
*
* For the 102nd record, bc_ptrs[0] == 2, so we continue.
*
* For the 201st record, we've moved on to leaf block 3. bc_ptrs[0] == 1, so
* we add 3 to the list. Now it is [1, 4, 2, 3].
*
* For the 300th record we just exit, with the list being [1, 4, 2, 3].
*/
/*
* Record all the buffers pointed to by the btree cursor. Callers already
* engaged in a btree walk should call this function to capture the list of
* blocks going from the leaf towards the root.
*/
int
xfs_bitmap_set_btcur_path(
struct xfs_bitmap *bitmap,
struct xfs_btree_cur *cur)
{
struct xfs_buf *bp;
xfs_fsblock_t fsb;
int i;
int error;
for (i = 0; i < cur->bc_nlevels && cur->bc_ptrs[i] == 1; i++) {
xfs_btree_get_block(cur, i, &bp);
if (!bp)
continue;
fsb = XFS_DADDR_TO_FSB(cur->bc_mp, bp->b_bn);
error = xfs_bitmap_set(bitmap, fsb, 1);
if (error)
return error;
}
return 0;
}
/* Collect a btree's block in the bitmap. */
STATIC int
xfs_bitmap_collect_btblock(
struct xfs_btree_cur *cur,
int level,
void *priv)
{
struct xfs_bitmap *bitmap = priv;
struct xfs_buf *bp;
xfs_fsblock_t fsbno;
xfs_btree_get_block(cur, level, &bp);
if (!bp)
return 0;
fsbno = XFS_DADDR_TO_FSB(cur->bc_mp, bp->b_bn);
return xfs_bitmap_set(bitmap, fsbno, 1);
}
/* Walk the btree and mark the bitmap wherever a btree block is found. */
int
xfs_bitmap_set_btblocks(
struct xfs_bitmap *bitmap,
struct xfs_btree_cur *cur)
{
return xfs_btree_visit_blocks(cur, xfs_bitmap_collect_btblock, bitmap);
}