linux-brain/fs/xfs/libxfs/xfs_bmap_btree.c
Darrick J. Wong b521c89027 xfs: fix sign handling problem in xfs_bmbt_diff_two_keys
In xfs_bmbt_diff_two_keys, we perform a signed int64_t subtraction with
two unsigned 64-bit quantities.  If the second quantity is actually the
"maximum" key (all ones) as used in _query_all, the subtraction
effectively becomes addition of two positive numbers and the function
returns incorrect results.  Fix this with explicit comparisons of the
unsigned values.  Nobody needs this now, but the online repair patches
will need this to work properly.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2019-08-28 08:31:01 -07:00

662 lines
17 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (c) 2000-2003,2005 Silicon Graphics, Inc.
* All Rights Reserved.
*/
#include "xfs.h"
#include "xfs_fs.h"
#include "xfs_shared.h"
#include "xfs_format.h"
#include "xfs_log_format.h"
#include "xfs_trans_resv.h"
#include "xfs_bit.h"
#include "xfs_mount.h"
#include "xfs_inode.h"
#include "xfs_trans.h"
#include "xfs_alloc.h"
#include "xfs_btree.h"
#include "xfs_bmap_btree.h"
#include "xfs_bmap.h"
#include "xfs_error.h"
#include "xfs_quota.h"
#include "xfs_trace.h"
#include "xfs_rmap.h"
/*
* Convert on-disk form of btree root to in-memory form.
*/
void
xfs_bmdr_to_bmbt(
struct xfs_inode *ip,
xfs_bmdr_block_t *dblock,
int dblocklen,
struct xfs_btree_block *rblock,
int rblocklen)
{
struct xfs_mount *mp = ip->i_mount;
int dmxr;
xfs_bmbt_key_t *fkp;
__be64 *fpp;
xfs_bmbt_key_t *tkp;
__be64 *tpp;
xfs_btree_init_block_int(mp, rblock, XFS_BUF_DADDR_NULL,
XFS_BTNUM_BMAP, 0, 0, ip->i_ino,
XFS_BTREE_LONG_PTRS);
rblock->bb_level = dblock->bb_level;
ASSERT(be16_to_cpu(rblock->bb_level) > 0);
rblock->bb_numrecs = dblock->bb_numrecs;
dmxr = xfs_bmdr_maxrecs(dblocklen, 0);
fkp = XFS_BMDR_KEY_ADDR(dblock, 1);
tkp = XFS_BMBT_KEY_ADDR(mp, rblock, 1);
fpp = XFS_BMDR_PTR_ADDR(dblock, 1, dmxr);
tpp = XFS_BMAP_BROOT_PTR_ADDR(mp, rblock, 1, rblocklen);
dmxr = be16_to_cpu(dblock->bb_numrecs);
memcpy(tkp, fkp, sizeof(*fkp) * dmxr);
memcpy(tpp, fpp, sizeof(*fpp) * dmxr);
}
void
xfs_bmbt_disk_get_all(
struct xfs_bmbt_rec *rec,
struct xfs_bmbt_irec *irec)
{
uint64_t l0 = get_unaligned_be64(&rec->l0);
uint64_t l1 = get_unaligned_be64(&rec->l1);
irec->br_startoff = (l0 & xfs_mask64lo(64 - BMBT_EXNTFLAG_BITLEN)) >> 9;
irec->br_startblock = ((l0 & xfs_mask64lo(9)) << 43) | (l1 >> 21);
irec->br_blockcount = l1 & xfs_mask64lo(21);
if (l0 >> (64 - BMBT_EXNTFLAG_BITLEN))
irec->br_state = XFS_EXT_UNWRITTEN;
else
irec->br_state = XFS_EXT_NORM;
}
/*
* Extract the blockcount field from an on disk bmap extent record.
*/
xfs_filblks_t
xfs_bmbt_disk_get_blockcount(
xfs_bmbt_rec_t *r)
{
return (xfs_filblks_t)(be64_to_cpu(r->l1) & xfs_mask64lo(21));
}
/*
* Extract the startoff field from a disk format bmap extent record.
*/
xfs_fileoff_t
xfs_bmbt_disk_get_startoff(
xfs_bmbt_rec_t *r)
{
return ((xfs_fileoff_t)be64_to_cpu(r->l0) &
xfs_mask64lo(64 - BMBT_EXNTFLAG_BITLEN)) >> 9;
}
/*
* Set all the fields in a bmap extent record from the uncompressed form.
*/
void
xfs_bmbt_disk_set_all(
struct xfs_bmbt_rec *r,
struct xfs_bmbt_irec *s)
{
int extent_flag = (s->br_state != XFS_EXT_NORM);
ASSERT(s->br_state == XFS_EXT_NORM || s->br_state == XFS_EXT_UNWRITTEN);
ASSERT(!(s->br_startoff & xfs_mask64hi(64-BMBT_STARTOFF_BITLEN)));
ASSERT(!(s->br_blockcount & xfs_mask64hi(64-BMBT_BLOCKCOUNT_BITLEN)));
ASSERT(!(s->br_startblock & xfs_mask64hi(64-BMBT_STARTBLOCK_BITLEN)));
put_unaligned_be64(
((xfs_bmbt_rec_base_t)extent_flag << 63) |
((xfs_bmbt_rec_base_t)s->br_startoff << 9) |
((xfs_bmbt_rec_base_t)s->br_startblock >> 43), &r->l0);
put_unaligned_be64(
((xfs_bmbt_rec_base_t)s->br_startblock << 21) |
((xfs_bmbt_rec_base_t)s->br_blockcount &
(xfs_bmbt_rec_base_t)xfs_mask64lo(21)), &r->l1);
}
/*
* Convert in-memory form of btree root to on-disk form.
*/
void
xfs_bmbt_to_bmdr(
struct xfs_mount *mp,
struct xfs_btree_block *rblock,
int rblocklen,
xfs_bmdr_block_t *dblock,
int dblocklen)
{
int dmxr;
xfs_bmbt_key_t *fkp;
__be64 *fpp;
xfs_bmbt_key_t *tkp;
__be64 *tpp;
if (xfs_sb_version_hascrc(&mp->m_sb)) {
ASSERT(rblock->bb_magic == cpu_to_be32(XFS_BMAP_CRC_MAGIC));
ASSERT(uuid_equal(&rblock->bb_u.l.bb_uuid,
&mp->m_sb.sb_meta_uuid));
ASSERT(rblock->bb_u.l.bb_blkno ==
cpu_to_be64(XFS_BUF_DADDR_NULL));
} else
ASSERT(rblock->bb_magic == cpu_to_be32(XFS_BMAP_MAGIC));
ASSERT(rblock->bb_u.l.bb_leftsib == cpu_to_be64(NULLFSBLOCK));
ASSERT(rblock->bb_u.l.bb_rightsib == cpu_to_be64(NULLFSBLOCK));
ASSERT(rblock->bb_level != 0);
dblock->bb_level = rblock->bb_level;
dblock->bb_numrecs = rblock->bb_numrecs;
dmxr = xfs_bmdr_maxrecs(dblocklen, 0);
fkp = XFS_BMBT_KEY_ADDR(mp, rblock, 1);
tkp = XFS_BMDR_KEY_ADDR(dblock, 1);
fpp = XFS_BMAP_BROOT_PTR_ADDR(mp, rblock, 1, rblocklen);
tpp = XFS_BMDR_PTR_ADDR(dblock, 1, dmxr);
dmxr = be16_to_cpu(dblock->bb_numrecs);
memcpy(tkp, fkp, sizeof(*fkp) * dmxr);
memcpy(tpp, fpp, sizeof(*fpp) * dmxr);
}
STATIC struct xfs_btree_cur *
xfs_bmbt_dup_cursor(
struct xfs_btree_cur *cur)
{
struct xfs_btree_cur *new;
new = xfs_bmbt_init_cursor(cur->bc_mp, cur->bc_tp,
cur->bc_private.b.ip, cur->bc_private.b.whichfork);
/*
* Copy the firstblock, dfops, and flags values,
* since init cursor doesn't get them.
*/
new->bc_private.b.flags = cur->bc_private.b.flags;
return new;
}
STATIC void
xfs_bmbt_update_cursor(
struct xfs_btree_cur *src,
struct xfs_btree_cur *dst)
{
ASSERT((dst->bc_tp->t_firstblock != NULLFSBLOCK) ||
(dst->bc_private.b.ip->i_d.di_flags & XFS_DIFLAG_REALTIME));
dst->bc_private.b.allocated += src->bc_private.b.allocated;
dst->bc_tp->t_firstblock = src->bc_tp->t_firstblock;
src->bc_private.b.allocated = 0;
}
STATIC int
xfs_bmbt_alloc_block(
struct xfs_btree_cur *cur,
union xfs_btree_ptr *start,
union xfs_btree_ptr *new,
int *stat)
{
xfs_alloc_arg_t args; /* block allocation args */
int error; /* error return value */
memset(&args, 0, sizeof(args));
args.tp = cur->bc_tp;
args.mp = cur->bc_mp;
args.fsbno = cur->bc_tp->t_firstblock;
xfs_rmap_ino_bmbt_owner(&args.oinfo, cur->bc_private.b.ip->i_ino,
cur->bc_private.b.whichfork);
if (args.fsbno == NULLFSBLOCK) {
args.fsbno = be64_to_cpu(start->l);
args.type = XFS_ALLOCTYPE_START_BNO;
/*
* Make sure there is sufficient room left in the AG to
* complete a full tree split for an extent insert. If
* we are converting the middle part of an extent then
* we may need space for two tree splits.
*
* We are relying on the caller to make the correct block
* reservation for this operation to succeed. If the
* reservation amount is insufficient then we may fail a
* block allocation here and corrupt the filesystem.
*/
args.minleft = args.tp->t_blk_res;
} else if (cur->bc_tp->t_flags & XFS_TRANS_LOWMODE) {
args.type = XFS_ALLOCTYPE_START_BNO;
} else {
args.type = XFS_ALLOCTYPE_NEAR_BNO;
}
args.minlen = args.maxlen = args.prod = 1;
args.wasdel = cur->bc_private.b.flags & XFS_BTCUR_BPRV_WASDEL;
if (!args.wasdel && args.tp->t_blk_res == 0) {
error = -ENOSPC;
goto error0;
}
error = xfs_alloc_vextent(&args);
if (error)
goto error0;
if (args.fsbno == NULLFSBLOCK && args.minleft) {
/*
* Could not find an AG with enough free space to satisfy
* a full btree split. Try again and if
* successful activate the lowspace algorithm.
*/
args.fsbno = 0;
args.type = XFS_ALLOCTYPE_FIRST_AG;
error = xfs_alloc_vextent(&args);
if (error)
goto error0;
cur->bc_tp->t_flags |= XFS_TRANS_LOWMODE;
}
if (WARN_ON_ONCE(args.fsbno == NULLFSBLOCK)) {
*stat = 0;
return 0;
}
ASSERT(args.len == 1);
cur->bc_tp->t_firstblock = args.fsbno;
cur->bc_private.b.allocated++;
cur->bc_private.b.ip->i_d.di_nblocks++;
xfs_trans_log_inode(args.tp, cur->bc_private.b.ip, XFS_ILOG_CORE);
xfs_trans_mod_dquot_byino(args.tp, cur->bc_private.b.ip,
XFS_TRANS_DQ_BCOUNT, 1L);
new->l = cpu_to_be64(args.fsbno);
*stat = 1;
return 0;
error0:
return error;
}
STATIC int
xfs_bmbt_free_block(
struct xfs_btree_cur *cur,
struct xfs_buf *bp)
{
struct xfs_mount *mp = cur->bc_mp;
struct xfs_inode *ip = cur->bc_private.b.ip;
struct xfs_trans *tp = cur->bc_tp;
xfs_fsblock_t fsbno = XFS_DADDR_TO_FSB(mp, XFS_BUF_ADDR(bp));
struct xfs_owner_info oinfo;
xfs_rmap_ino_bmbt_owner(&oinfo, ip->i_ino, cur->bc_private.b.whichfork);
xfs_bmap_add_free(cur->bc_tp, fsbno, 1, &oinfo);
ip->i_d.di_nblocks--;
xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
xfs_trans_mod_dquot_byino(tp, ip, XFS_TRANS_DQ_BCOUNT, -1L);
return 0;
}
STATIC int
xfs_bmbt_get_minrecs(
struct xfs_btree_cur *cur,
int level)
{
if (level == cur->bc_nlevels - 1) {
struct xfs_ifork *ifp;
ifp = XFS_IFORK_PTR(cur->bc_private.b.ip,
cur->bc_private.b.whichfork);
return xfs_bmbt_maxrecs(cur->bc_mp,
ifp->if_broot_bytes, level == 0) / 2;
}
return cur->bc_mp->m_bmap_dmnr[level != 0];
}
int
xfs_bmbt_get_maxrecs(
struct xfs_btree_cur *cur,
int level)
{
if (level == cur->bc_nlevels - 1) {
struct xfs_ifork *ifp;
ifp = XFS_IFORK_PTR(cur->bc_private.b.ip,
cur->bc_private.b.whichfork);
return xfs_bmbt_maxrecs(cur->bc_mp,
ifp->if_broot_bytes, level == 0);
}
return cur->bc_mp->m_bmap_dmxr[level != 0];
}
/*
* Get the maximum records we could store in the on-disk format.
*
* For non-root nodes this is equivalent to xfs_bmbt_get_maxrecs, but
* for the root node this checks the available space in the dinode fork
* so that we can resize the in-memory buffer to match it. After a
* resize to the maximum size this function returns the same value
* as xfs_bmbt_get_maxrecs for the root node, too.
*/
STATIC int
xfs_bmbt_get_dmaxrecs(
struct xfs_btree_cur *cur,
int level)
{
if (level != cur->bc_nlevels - 1)
return cur->bc_mp->m_bmap_dmxr[level != 0];
return xfs_bmdr_maxrecs(cur->bc_private.b.forksize, level == 0);
}
STATIC void
xfs_bmbt_init_key_from_rec(
union xfs_btree_key *key,
union xfs_btree_rec *rec)
{
key->bmbt.br_startoff =
cpu_to_be64(xfs_bmbt_disk_get_startoff(&rec->bmbt));
}
STATIC void
xfs_bmbt_init_high_key_from_rec(
union xfs_btree_key *key,
union xfs_btree_rec *rec)
{
key->bmbt.br_startoff = cpu_to_be64(
xfs_bmbt_disk_get_startoff(&rec->bmbt) +
xfs_bmbt_disk_get_blockcount(&rec->bmbt) - 1);
}
STATIC void
xfs_bmbt_init_rec_from_cur(
struct xfs_btree_cur *cur,
union xfs_btree_rec *rec)
{
xfs_bmbt_disk_set_all(&rec->bmbt, &cur->bc_rec.b);
}
STATIC void
xfs_bmbt_init_ptr_from_cur(
struct xfs_btree_cur *cur,
union xfs_btree_ptr *ptr)
{
ptr->l = 0;
}
STATIC int64_t
xfs_bmbt_key_diff(
struct xfs_btree_cur *cur,
union xfs_btree_key *key)
{
return (int64_t)be64_to_cpu(key->bmbt.br_startoff) -
cur->bc_rec.b.br_startoff;
}
STATIC int64_t
xfs_bmbt_diff_two_keys(
struct xfs_btree_cur *cur,
union xfs_btree_key *k1,
union xfs_btree_key *k2)
{
uint64_t a = be64_to_cpu(k1->bmbt.br_startoff);
uint64_t b = be64_to_cpu(k2->bmbt.br_startoff);
/*
* Note: This routine previously casted a and b to int64 and subtracted
* them to generate a result. This lead to problems if b was the
* "maximum" key value (all ones) being signed incorrectly, hence this
* somewhat less efficient version.
*/
if (a > b)
return 1;
if (b > a)
return -1;
return 0;
}
static xfs_failaddr_t
xfs_bmbt_verify(
struct xfs_buf *bp)
{
struct xfs_mount *mp = bp->b_mount;
struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp);
xfs_failaddr_t fa;
unsigned int level;
if (!xfs_verify_magic(bp, block->bb_magic))
return __this_address;
if (xfs_sb_version_hascrc(&mp->m_sb)) {
/*
* XXX: need a better way of verifying the owner here. Right now
* just make sure there has been one set.
*/
fa = xfs_btree_lblock_v5hdr_verify(bp, XFS_RMAP_OWN_UNKNOWN);
if (fa)
return fa;
}
/*
* numrecs and level verification.
*
* We don't know what 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);
if (level > max(mp->m_bm_maxlevels[0], mp->m_bm_maxlevels[1]))
return __this_address;
return xfs_btree_lblock_verify(bp, mp->m_bmap_dmxr[level != 0]);
}
static void
xfs_bmbt_read_verify(
struct xfs_buf *bp)
{
xfs_failaddr_t fa;
if (!xfs_btree_lblock_verify_crc(bp))
xfs_verifier_error(bp, -EFSBADCRC, __this_address);
else {
fa = xfs_bmbt_verify(bp);
if (fa)
xfs_verifier_error(bp, -EFSCORRUPTED, fa);
}
if (bp->b_error)
trace_xfs_btree_corrupt(bp, _RET_IP_);
}
static void
xfs_bmbt_write_verify(
struct xfs_buf *bp)
{
xfs_failaddr_t fa;
fa = xfs_bmbt_verify(bp);
if (fa) {
trace_xfs_btree_corrupt(bp, _RET_IP_);
xfs_verifier_error(bp, -EFSCORRUPTED, fa);
return;
}
xfs_btree_lblock_calc_crc(bp);
}
const struct xfs_buf_ops xfs_bmbt_buf_ops = {
.name = "xfs_bmbt",
.magic = { cpu_to_be32(XFS_BMAP_MAGIC),
cpu_to_be32(XFS_BMAP_CRC_MAGIC) },
.verify_read = xfs_bmbt_read_verify,
.verify_write = xfs_bmbt_write_verify,
.verify_struct = xfs_bmbt_verify,
};
STATIC int
xfs_bmbt_keys_inorder(
struct xfs_btree_cur *cur,
union xfs_btree_key *k1,
union xfs_btree_key *k2)
{
return be64_to_cpu(k1->bmbt.br_startoff) <
be64_to_cpu(k2->bmbt.br_startoff);
}
STATIC int
xfs_bmbt_recs_inorder(
struct xfs_btree_cur *cur,
union xfs_btree_rec *r1,
union xfs_btree_rec *r2)
{
return xfs_bmbt_disk_get_startoff(&r1->bmbt) +
xfs_bmbt_disk_get_blockcount(&r1->bmbt) <=
xfs_bmbt_disk_get_startoff(&r2->bmbt);
}
static const struct xfs_btree_ops xfs_bmbt_ops = {
.rec_len = sizeof(xfs_bmbt_rec_t),
.key_len = sizeof(xfs_bmbt_key_t),
.dup_cursor = xfs_bmbt_dup_cursor,
.update_cursor = xfs_bmbt_update_cursor,
.alloc_block = xfs_bmbt_alloc_block,
.free_block = xfs_bmbt_free_block,
.get_maxrecs = xfs_bmbt_get_maxrecs,
.get_minrecs = xfs_bmbt_get_minrecs,
.get_dmaxrecs = xfs_bmbt_get_dmaxrecs,
.init_key_from_rec = xfs_bmbt_init_key_from_rec,
.init_high_key_from_rec = xfs_bmbt_init_high_key_from_rec,
.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,
.diff_two_keys = xfs_bmbt_diff_two_keys,
.buf_ops = &xfs_bmbt_buf_ops,
.keys_inorder = xfs_bmbt_keys_inorder,
.recs_inorder = xfs_bmbt_recs_inorder,
};
/*
* Allocate a new bmap btree cursor.
*/
struct xfs_btree_cur * /* new bmap btree cursor */
xfs_bmbt_init_cursor(
struct xfs_mount *mp, /* file system mount point */
struct xfs_trans *tp, /* transaction pointer */
struct xfs_inode *ip, /* inode owning the btree */
int whichfork) /* data or attr fork */
{
struct xfs_ifork *ifp = XFS_IFORK_PTR(ip, whichfork);
struct xfs_btree_cur *cur;
ASSERT(whichfork != XFS_COW_FORK);
cur = kmem_zone_zalloc(xfs_btree_cur_zone, KM_NOFS);
cur->bc_tp = tp;
cur->bc_mp = mp;
cur->bc_nlevels = be16_to_cpu(ifp->if_broot->bb_level) + 1;
cur->bc_btnum = XFS_BTNUM_BMAP;
cur->bc_blocklog = mp->m_sb.sb_blocklog;
cur->bc_statoff = XFS_STATS_CALC_INDEX(xs_bmbt_2);
cur->bc_ops = &xfs_bmbt_ops;
cur->bc_flags = XFS_BTREE_LONG_PTRS | XFS_BTREE_ROOT_IN_INODE;
if (xfs_sb_version_hascrc(&mp->m_sb))
cur->bc_flags |= XFS_BTREE_CRC_BLOCKS;
cur->bc_private.b.forksize = XFS_IFORK_SIZE(ip, whichfork);
cur->bc_private.b.ip = ip;
cur->bc_private.b.allocated = 0;
cur->bc_private.b.flags = 0;
cur->bc_private.b.whichfork = whichfork;
return cur;
}
/*
* Calculate number of records in a bmap btree block.
*/
int
xfs_bmbt_maxrecs(
struct xfs_mount *mp,
int blocklen,
int leaf)
{
blocklen -= XFS_BMBT_BLOCK_LEN(mp);
if (leaf)
return blocklen / sizeof(xfs_bmbt_rec_t);
return blocklen / (sizeof(xfs_bmbt_key_t) + sizeof(xfs_bmbt_ptr_t));
}
/*
* Calculate number of records in a bmap btree inode root.
*/
int
xfs_bmdr_maxrecs(
int blocklen,
int leaf)
{
blocklen -= sizeof(xfs_bmdr_block_t);
if (leaf)
return blocklen / sizeof(xfs_bmdr_rec_t);
return blocklen / (sizeof(xfs_bmdr_key_t) + sizeof(xfs_bmdr_ptr_t));
}
/*
* Change the owner of a btree format fork fo the inode passed in. Change it to
* the owner of that is passed in so that we can change owners before or after
* we switch forks between inodes. The operation that the caller is doing will
* determine whether is needs to change owner before or after the switch.
*
* For demand paged transactional modification, the fork switch should be done
* after reading in all the blocks, modifying them and pinning them in the
* transaction. For modification when the buffers are already pinned in memory,
* the fork switch can be done before changing the owner as we won't need to
* validate the owner until the btree buffers are unpinned and writes can occur
* again.
*
* For recovery based ownership change, there is no transactional context and
* so a buffer list must be supplied so that we can record the buffers that we
* modified for the caller to issue IO on.
*/
int
xfs_bmbt_change_owner(
struct xfs_trans *tp,
struct xfs_inode *ip,
int whichfork,
xfs_ino_t new_owner,
struct list_head *buffer_list)
{
struct xfs_btree_cur *cur;
int error;
ASSERT(tp || buffer_list);
ASSERT(!(tp && buffer_list));
if (whichfork == XFS_DATA_FORK)
ASSERT(ip->i_d.di_format == XFS_DINODE_FMT_BTREE);
else
ASSERT(ip->i_d.di_aformat == XFS_DINODE_FMT_BTREE);
cur = xfs_bmbt_init_cursor(ip->i_mount, tp, ip, whichfork);
if (!cur)
return -ENOMEM;
cur->bc_private.b.flags |= XFS_BTCUR_BPRV_INVALID_OWNER;
error = xfs_btree_change_owner(cur, new_owner, buffer_list);
xfs_btree_del_cursor(cur, error);
return error;
}
/* Calculate the bmap btree size for some records. */
unsigned long long
xfs_bmbt_calc_size(
struct xfs_mount *mp,
unsigned long long len)
{
return xfs_btree_calc_size(mp->m_bmap_dmnr, len);
}