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xfs: verify btree blocks as they are read from disk
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Add an btree block verify callback function and pass it into the
buffer read functions. Because each different btree block type
requires different verification, add a function to the ops structure
that is called from the generic code.

Also, propagate the verification callback functions through the
readahead functions, and into the external bmap and bulkstat inode
readahead code that uses the generic btree buffer read functions.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Phil White <pwhite@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
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Dave Chinner authored and Ben Myers committed Nov 16, 2012
1 parent af133e8 commit 3d3e6f6
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Showing 10 changed files with 230 additions and 61 deletions.
61 changes: 61 additions & 0 deletions fs/xfs/xfs_alloc_btree.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -272,6 +272,66 @@ xfs_allocbt_key_diff(
return (__int64_t)be32_to_cpu(kp->ar_startblock) - rec->ar_startblock;
}

void
xfs_allocbt_read_verify(
struct xfs_buf *bp)
{
struct xfs_mount *mp = bp->b_target->bt_mount;
struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp);
struct xfs_perag *pag = bp->b_pag;
unsigned int level;
int sblock_ok; /* block passes checks */

/*
* magic number and level verification
*
* During growfs operations, we can't verify the exact level as the
* perag is not fully initialised and hence not attached to the buffer.
* In this case, check against the maximum tree depth.
*/
level = be16_to_cpu(block->bb_level);
switch (block->bb_magic) {
case cpu_to_be32(XFS_ABTB_MAGIC):
if (pag)
sblock_ok = level < pag->pagf_levels[XFS_BTNUM_BNOi];
else
sblock_ok = level < mp->m_ag_maxlevels;
break;
case cpu_to_be32(XFS_ABTC_MAGIC):
if (pag)
sblock_ok = level < pag->pagf_levels[XFS_BTNUM_CNTi];
else
sblock_ok = level < mp->m_ag_maxlevels;
break;
default:
sblock_ok = 0;
break;
}

/* numrecs verification */
sblock_ok = sblock_ok &&
be16_to_cpu(block->bb_numrecs) <= mp->m_alloc_mxr[level != 0];

/* sibling pointer verification */
sblock_ok = sblock_ok &&
(block->bb_u.s.bb_leftsib == cpu_to_be32(NULLAGBLOCK) ||
be32_to_cpu(block->bb_u.s.bb_leftsib) < mp->m_sb.sb_agblocks) &&
block->bb_u.s.bb_leftsib &&
(block->bb_u.s.bb_rightsib == cpu_to_be32(NULLAGBLOCK) ||
be32_to_cpu(block->bb_u.s.bb_rightsib) < mp->m_sb.sb_agblocks) &&
block->bb_u.s.bb_rightsib;

if (!sblock_ok) {
trace_xfs_btree_corrupt(bp, _RET_IP_);
XFS_CORRUPTION_ERROR("xfs_allocbt_read_verify",
XFS_ERRLEVEL_LOW, mp, block);
xfs_buf_ioerror(bp, EFSCORRUPTED);
}

bp->b_iodone = NULL;
xfs_buf_ioend(bp, 0);
}

#ifdef DEBUG
STATIC int
xfs_allocbt_keys_inorder(
Expand Down Expand Up @@ -327,6 +387,7 @@ static const struct xfs_btree_ops xfs_allocbt_ops = {
.init_rec_from_cur = xfs_allocbt_init_rec_from_cur,
.init_ptr_from_cur = xfs_allocbt_init_ptr_from_cur,
.key_diff = xfs_allocbt_key_diff,
.read_verify = xfs_allocbt_read_verify,
#ifdef DEBUG
.keys_inorder = xfs_allocbt_keys_inorder,
.recs_inorder = xfs_allocbt_recs_inorder,
Expand Down
60 changes: 36 additions & 24 deletions fs/xfs/xfs_bmap.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -2662,8 +2662,9 @@ xfs_bmap_btree_to_extents(
if ((error = xfs_btree_check_lptr(cur, cbno, 1)))
return error;
#endif
if ((error = xfs_btree_read_bufl(mp, tp, cbno, 0, &cbp,
XFS_BMAP_BTREE_REF)))
error = xfs_btree_read_bufl(mp, tp, cbno, 0, &cbp, XFS_BMAP_BTREE_REF,
xfs_bmbt_read_verify);
if (error)
return error;
cblock = XFS_BUF_TO_BLOCK(cbp);
if ((error = xfs_btree_check_block(cur, cblock, 0, cbp)))
Expand Down Expand Up @@ -4078,8 +4079,9 @@ xfs_bmap_read_extents(
* pointer (leftmost) at each level.
*/
while (level-- > 0) {
if ((error = xfs_btree_read_bufl(mp, tp, bno, 0, &bp,
XFS_BMAP_BTREE_REF)))
error = xfs_btree_read_bufl(mp, tp, bno, 0, &bp,
XFS_BMAP_BTREE_REF, xfs_bmbt_read_verify);
if (error)
return error;
block = XFS_BUF_TO_BLOCK(bp);
XFS_WANT_CORRUPTED_GOTO(
Expand Down Expand Up @@ -4124,7 +4126,8 @@ xfs_bmap_read_extents(
*/
nextbno = be64_to_cpu(block->bb_u.l.bb_rightsib);
if (nextbno != NULLFSBLOCK)
xfs_btree_reada_bufl(mp, nextbno, 1);
xfs_btree_reada_bufl(mp, nextbno, 1,
xfs_bmbt_read_verify);
/*
* Copy records into the extent records.
*/
Expand Down Expand Up @@ -4156,8 +4159,9 @@ xfs_bmap_read_extents(
*/
if (bno == NULLFSBLOCK)
break;
if ((error = xfs_btree_read_bufl(mp, tp, bno, 0, &bp,
XFS_BMAP_BTREE_REF)))
error = xfs_btree_read_bufl(mp, tp, bno, 0, &bp,
XFS_BMAP_BTREE_REF, xfs_bmbt_read_verify);
if (error)
return error;
block = XFS_BUF_TO_BLOCK(bp);
}
Expand Down Expand Up @@ -5868,15 +5872,16 @@ xfs_bmap_check_leaf_extents(
*/
while (level-- > 0) {
/* See if buf is in cur first */
bp_release = 0;
bp = xfs_bmap_get_bp(cur, XFS_FSB_TO_DADDR(mp, bno));
if (bp) {
bp_release = 0;
} else {
if (!bp) {
bp_release = 1;
error = xfs_btree_read_bufl(mp, NULL, bno, 0, &bp,
XFS_BMAP_BTREE_REF,
xfs_bmbt_read_verify);
if (error)
goto error_norelse;
}
if (!bp && (error = xfs_btree_read_bufl(mp, NULL, bno, 0, &bp,
XFS_BMAP_BTREE_REF)))
goto error_norelse;
block = XFS_BUF_TO_BLOCK(bp);
XFS_WANT_CORRUPTED_GOTO(
xfs_bmap_sanity_check(mp, bp, level),
Expand Down Expand Up @@ -5953,15 +5958,16 @@ xfs_bmap_check_leaf_extents(
if (bno == NULLFSBLOCK)
break;

bp_release = 0;
bp = xfs_bmap_get_bp(cur, XFS_FSB_TO_DADDR(mp, bno));
if (bp) {
bp_release = 0;
} else {
if (!bp) {
bp_release = 1;
error = xfs_btree_read_bufl(mp, NULL, bno, 0, &bp,
XFS_BMAP_BTREE_REF,
xfs_bmbt_read_verify);
if (error)
goto error_norelse;
}
if (!bp && (error = xfs_btree_read_bufl(mp, NULL, bno, 0, &bp,
XFS_BMAP_BTREE_REF)))
goto error_norelse;
block = XFS_BUF_TO_BLOCK(bp);
}
if (bp_release) {
Expand Down Expand Up @@ -6052,7 +6058,9 @@ xfs_bmap_count_tree(
struct xfs_btree_block *block, *nextblock;
int numrecs;

if ((error = xfs_btree_read_bufl(mp, tp, bno, 0, &bp, XFS_BMAP_BTREE_REF)))
error = xfs_btree_read_bufl(mp, tp, bno, 0, &bp, XFS_BMAP_BTREE_REF,
xfs_bmbt_read_verify);
if (error)
return error;
*count += 1;
block = XFS_BUF_TO_BLOCK(bp);
Expand All @@ -6061,8 +6069,10 @@ xfs_bmap_count_tree(
/* Not at node above leaves, count this level of nodes */
nextbno = be64_to_cpu(block->bb_u.l.bb_rightsib);
while (nextbno != NULLFSBLOCK) {
if ((error = xfs_btree_read_bufl(mp, tp, nextbno,
0, &nbp, XFS_BMAP_BTREE_REF)))
error = xfs_btree_read_bufl(mp, tp, nextbno, 0, &nbp,
XFS_BMAP_BTREE_REF,
xfs_bmbt_read_verify);
if (error)
return error;
*count += 1;
nextblock = XFS_BUF_TO_BLOCK(nbp);
Expand Down Expand Up @@ -6091,8 +6101,10 @@ xfs_bmap_count_tree(
if (nextbno == NULLFSBLOCK)
break;
bno = nextbno;
if ((error = xfs_btree_read_bufl(mp, tp, bno, 0, &bp,
XFS_BMAP_BTREE_REF)))
error = xfs_btree_read_bufl(mp, tp, bno, 0, &bp,
XFS_BMAP_BTREE_REF,
xfs_bmbt_read_verify);
if (error)
return error;
*count += 1;
block = XFS_BUF_TO_BLOCK(bp);
Expand Down
47 changes: 47 additions & 0 deletions fs/xfs/xfs_bmap_btree.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -36,6 +36,7 @@
#include "xfs_bmap.h"
#include "xfs_error.h"
#include "xfs_quota.h"
#include "xfs_trace.h"

/*
* Determine the extent state.
Expand Down Expand Up @@ -707,6 +708,51 @@ xfs_bmbt_key_diff(
cur->bc_rec.b.br_startoff;
}

void
xfs_bmbt_read_verify(
struct xfs_buf *bp)
{
struct xfs_mount *mp = bp->b_target->bt_mount;
struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp);
unsigned int level;
int lblock_ok; /* block passes checks */

/* magic number and level verification.
*
* We don't know waht fork we belong to, so just verify that the level
* is less than the maximum of the two. Later checks will be more
* precise.
*/
level = be16_to_cpu(block->bb_level);
lblock_ok = block->bb_magic == cpu_to_be32(XFS_BMAP_MAGIC) &&
level < max(mp->m_bm_maxlevels[0], mp->m_bm_maxlevels[1]);

/* numrecs verification */
lblock_ok = lblock_ok &&
be16_to_cpu(block->bb_numrecs) <= mp->m_bmap_dmxr[level != 0];

/* sibling pointer verification */
lblock_ok = lblock_ok &&
block->bb_u.l.bb_leftsib &&
(block->bb_u.l.bb_leftsib == cpu_to_be64(NULLDFSBNO) ||
XFS_FSB_SANITY_CHECK(mp,
be64_to_cpu(block->bb_u.l.bb_leftsib))) &&
block->bb_u.l.bb_rightsib &&
(block->bb_u.l.bb_rightsib == cpu_to_be64(NULLDFSBNO) ||
XFS_FSB_SANITY_CHECK(mp,
be64_to_cpu(block->bb_u.l.bb_rightsib)));

if (!lblock_ok) {
trace_xfs_btree_corrupt(bp, _RET_IP_);
XFS_CORRUPTION_ERROR("xfs_bmbt_read_verify",
XFS_ERRLEVEL_LOW, mp, block);
xfs_buf_ioerror(bp, EFSCORRUPTED);
}

bp->b_iodone = NULL;
xfs_buf_ioend(bp, 0);
}

#ifdef DEBUG
STATIC int
xfs_bmbt_keys_inorder(
Expand Down Expand Up @@ -746,6 +792,7 @@ static const struct xfs_btree_ops xfs_bmbt_ops = {
.init_rec_from_cur = xfs_bmbt_init_rec_from_cur,
.init_ptr_from_cur = xfs_bmbt_init_ptr_from_cur,
.key_diff = xfs_bmbt_key_diff,
.read_verify = xfs_bmbt_read_verify,
#ifdef DEBUG
.keys_inorder = xfs_bmbt_keys_inorder,
.recs_inorder = xfs_bmbt_recs_inorder,
Expand Down
1 change: 1 addition & 0 deletions fs/xfs/xfs_bmap_btree.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -232,6 +232,7 @@ extern void xfs_bmbt_to_bmdr(struct xfs_mount *, struct xfs_btree_block *, int,
extern int xfs_bmbt_get_maxrecs(struct xfs_btree_cur *, int level);
extern int xfs_bmdr_maxrecs(struct xfs_mount *, int blocklen, int leaf);
extern int xfs_bmbt_maxrecs(struct xfs_mount *, int blocklen, int leaf);
extern void xfs_bmbt_read_verify(struct xfs_buf *bp);

extern struct xfs_btree_cur *xfs_bmbt_init_cursor(struct xfs_mount *,
struct xfs_trans *, struct xfs_inode *, int);
Expand Down
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