linux_dsm_epyc7002/fs/xfs/xfs_attr_remote.c
Dave Chinner 8275cdd0e7 xfs: remote attribute overwrite causes transaction overrun
Commit e461fcb ("xfs: remote attribute lookups require the value
length") passes the remote attribute length in the xfs_da_args
structure on lookup so that CRC calculations and validity checking
can be performed correctly by related code. This, unfortunately has
the side effect of changing the args->valuelen parameter in cases
where it shouldn't.

That is, when we replace a remote attribute, the incoming
replacement stores the value and length in args->value and
args->valuelen, but then the lookup which finds the existing remote
attribute overwrites args->valuelen with the length of the remote
attribute being replaced. Hence when we go to create the new
attribute, we create it of the size of the existing remote
attribute, not the size it is supposed to be. When the new attribute
is much smaller than the old attribute, this results in a
transaction overrun and an ASSERT() failure on a debug kernel:

XFS: Assertion failed: tp->t_blk_res_used <= tp->t_blk_res, file: fs/xfs/xfs_trans.c, line: 331

Fix this by keeping the remote attribute value length separate to
the attribute value length in the xfs_da_args structure. The enables
us to pass the length of the remote attribute to be removed without
overwriting the new attribute's length.

Also, ensure that when we save remote block contexts for a later
rename we zero the original state variables so that we don't confuse
the state of the attribute to be removes with the state of the new
attribute that we just added. [Spotted by Brain Foster.]

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2014-05-06 07:37:31 +10:00

627 lines
15 KiB
C

/*
* Copyright (c) 2000-2005 Silicon Graphics, Inc.
* Copyright (c) 2013 Red Hat, Inc.
* All Rights Reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it would be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#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_sb.h"
#include "xfs_ag.h"
#include "xfs_mount.h"
#include "xfs_da_format.h"
#include "xfs_da_btree.h"
#include "xfs_inode.h"
#include "xfs_alloc.h"
#include "xfs_trans.h"
#include "xfs_inode_item.h"
#include "xfs_bmap.h"
#include "xfs_bmap_util.h"
#include "xfs_attr.h"
#include "xfs_attr_leaf.h"
#include "xfs_attr_remote.h"
#include "xfs_trans_space.h"
#include "xfs_trace.h"
#include "xfs_cksum.h"
#include "xfs_buf_item.h"
#include "xfs_error.h"
#define ATTR_RMTVALUE_MAPSIZE 1 /* # of map entries at once */
/*
* Each contiguous block has a header, so it is not just a simple attribute
* length to FSB conversion.
*/
int
xfs_attr3_rmt_blocks(
struct xfs_mount *mp,
int attrlen)
{
if (xfs_sb_version_hascrc(&mp->m_sb)) {
int buflen = XFS_ATTR3_RMT_BUF_SPACE(mp, mp->m_sb.sb_blocksize);
return (attrlen + buflen - 1) / buflen;
}
return XFS_B_TO_FSB(mp, attrlen);
}
/*
* Checking of the remote attribute header is split into two parts. The verifier
* does CRC, location and bounds checking, the unpacking function checks the
* attribute parameters and owner.
*/
static bool
xfs_attr3_rmt_hdr_ok(
struct xfs_mount *mp,
void *ptr,
xfs_ino_t ino,
uint32_t offset,
uint32_t size,
xfs_daddr_t bno)
{
struct xfs_attr3_rmt_hdr *rmt = ptr;
if (bno != be64_to_cpu(rmt->rm_blkno))
return false;
if (offset != be32_to_cpu(rmt->rm_offset))
return false;
if (size != be32_to_cpu(rmt->rm_bytes))
return false;
if (ino != be64_to_cpu(rmt->rm_owner))
return false;
/* ok */
return true;
}
static bool
xfs_attr3_rmt_verify(
struct xfs_mount *mp,
void *ptr,
int fsbsize,
xfs_daddr_t bno)
{
struct xfs_attr3_rmt_hdr *rmt = ptr;
if (!xfs_sb_version_hascrc(&mp->m_sb))
return false;
if (rmt->rm_magic != cpu_to_be32(XFS_ATTR3_RMT_MAGIC))
return false;
if (!uuid_equal(&rmt->rm_uuid, &mp->m_sb.sb_uuid))
return false;
if (be64_to_cpu(rmt->rm_blkno) != bno)
return false;
if (be32_to_cpu(rmt->rm_bytes) > fsbsize - sizeof(*rmt))
return false;
if (be32_to_cpu(rmt->rm_offset) +
be32_to_cpu(rmt->rm_bytes) > XATTR_SIZE_MAX)
return false;
if (rmt->rm_owner == 0)
return false;
return true;
}
static void
xfs_attr3_rmt_read_verify(
struct xfs_buf *bp)
{
struct xfs_mount *mp = bp->b_target->bt_mount;
char *ptr;
int len;
xfs_daddr_t bno;
/* no verification of non-crc buffers */
if (!xfs_sb_version_hascrc(&mp->m_sb))
return;
ptr = bp->b_addr;
bno = bp->b_bn;
len = BBTOB(bp->b_length);
ASSERT(len >= XFS_LBSIZE(mp));
while (len > 0) {
if (!xfs_verify_cksum(ptr, XFS_LBSIZE(mp),
XFS_ATTR3_RMT_CRC_OFF)) {
xfs_buf_ioerror(bp, EFSBADCRC);
break;
}
if (!xfs_attr3_rmt_verify(mp, ptr, XFS_LBSIZE(mp), bno)) {
xfs_buf_ioerror(bp, EFSCORRUPTED);
break;
}
len -= XFS_LBSIZE(mp);
ptr += XFS_LBSIZE(mp);
bno += mp->m_bsize;
}
if (bp->b_error)
xfs_verifier_error(bp);
else
ASSERT(len == 0);
}
static void
xfs_attr3_rmt_write_verify(
struct xfs_buf *bp)
{
struct xfs_mount *mp = bp->b_target->bt_mount;
struct xfs_buf_log_item *bip = bp->b_fspriv;
char *ptr;
int len;
xfs_daddr_t bno;
/* no verification of non-crc buffers */
if (!xfs_sb_version_hascrc(&mp->m_sb))
return;
ptr = bp->b_addr;
bno = bp->b_bn;
len = BBTOB(bp->b_length);
ASSERT(len >= XFS_LBSIZE(mp));
while (len > 0) {
if (!xfs_attr3_rmt_verify(mp, ptr, XFS_LBSIZE(mp), bno)) {
xfs_buf_ioerror(bp, EFSCORRUPTED);
xfs_verifier_error(bp);
return;
}
if (bip) {
struct xfs_attr3_rmt_hdr *rmt;
rmt = (struct xfs_attr3_rmt_hdr *)ptr;
rmt->rm_lsn = cpu_to_be64(bip->bli_item.li_lsn);
}
xfs_update_cksum(ptr, XFS_LBSIZE(mp), XFS_ATTR3_RMT_CRC_OFF);
len -= XFS_LBSIZE(mp);
ptr += XFS_LBSIZE(mp);
bno += mp->m_bsize;
}
ASSERT(len == 0);
}
const struct xfs_buf_ops xfs_attr3_rmt_buf_ops = {
.verify_read = xfs_attr3_rmt_read_verify,
.verify_write = xfs_attr3_rmt_write_verify,
};
STATIC int
xfs_attr3_rmt_hdr_set(
struct xfs_mount *mp,
void *ptr,
xfs_ino_t ino,
uint32_t offset,
uint32_t size,
xfs_daddr_t bno)
{
struct xfs_attr3_rmt_hdr *rmt = ptr;
if (!xfs_sb_version_hascrc(&mp->m_sb))
return 0;
rmt->rm_magic = cpu_to_be32(XFS_ATTR3_RMT_MAGIC);
rmt->rm_offset = cpu_to_be32(offset);
rmt->rm_bytes = cpu_to_be32(size);
uuid_copy(&rmt->rm_uuid, &mp->m_sb.sb_uuid);
rmt->rm_owner = cpu_to_be64(ino);
rmt->rm_blkno = cpu_to_be64(bno);
return sizeof(struct xfs_attr3_rmt_hdr);
}
/*
* Helper functions to copy attribute data in and out of the one disk extents
*/
STATIC int
xfs_attr_rmtval_copyout(
struct xfs_mount *mp,
struct xfs_buf *bp,
xfs_ino_t ino,
int *offset,
int *valuelen,
__uint8_t **dst)
{
char *src = bp->b_addr;
xfs_daddr_t bno = bp->b_bn;
int len = BBTOB(bp->b_length);
ASSERT(len >= XFS_LBSIZE(mp));
while (len > 0 && *valuelen > 0) {
int hdr_size = 0;
int byte_cnt = XFS_ATTR3_RMT_BUF_SPACE(mp, XFS_LBSIZE(mp));
byte_cnt = min(*valuelen, byte_cnt);
if (xfs_sb_version_hascrc(&mp->m_sb)) {
if (!xfs_attr3_rmt_hdr_ok(mp, src, ino, *offset,
byte_cnt, bno)) {
xfs_alert(mp,
"remote attribute header mismatch bno/off/len/owner (0x%llx/0x%x/Ox%x/0x%llx)",
bno, *offset, byte_cnt, ino);
return EFSCORRUPTED;
}
hdr_size = sizeof(struct xfs_attr3_rmt_hdr);
}
memcpy(*dst, src + hdr_size, byte_cnt);
/* roll buffer forwards */
len -= XFS_LBSIZE(mp);
src += XFS_LBSIZE(mp);
bno += mp->m_bsize;
/* roll attribute data forwards */
*valuelen -= byte_cnt;
*dst += byte_cnt;
*offset += byte_cnt;
}
return 0;
}
STATIC void
xfs_attr_rmtval_copyin(
struct xfs_mount *mp,
struct xfs_buf *bp,
xfs_ino_t ino,
int *offset,
int *valuelen,
__uint8_t **src)
{
char *dst = bp->b_addr;
xfs_daddr_t bno = bp->b_bn;
int len = BBTOB(bp->b_length);
ASSERT(len >= XFS_LBSIZE(mp));
while (len > 0 && *valuelen > 0) {
int hdr_size;
int byte_cnt = XFS_ATTR3_RMT_BUF_SPACE(mp, XFS_LBSIZE(mp));
byte_cnt = min(*valuelen, byte_cnt);
hdr_size = xfs_attr3_rmt_hdr_set(mp, dst, ino, *offset,
byte_cnt, bno);
memcpy(dst + hdr_size, *src, byte_cnt);
/*
* If this is the last block, zero the remainder of it.
* Check that we are actually the last block, too.
*/
if (byte_cnt + hdr_size < XFS_LBSIZE(mp)) {
ASSERT(*valuelen - byte_cnt == 0);
ASSERT(len == XFS_LBSIZE(mp));
memset(dst + hdr_size + byte_cnt, 0,
XFS_LBSIZE(mp) - hdr_size - byte_cnt);
}
/* roll buffer forwards */
len -= XFS_LBSIZE(mp);
dst += XFS_LBSIZE(mp);
bno += mp->m_bsize;
/* roll attribute data forwards */
*valuelen -= byte_cnt;
*src += byte_cnt;
*offset += byte_cnt;
}
}
/*
* Read the value associated with an attribute from the out-of-line buffer
* that we stored it in.
*/
int
xfs_attr_rmtval_get(
struct xfs_da_args *args)
{
struct xfs_bmbt_irec map[ATTR_RMTVALUE_MAPSIZE];
struct xfs_mount *mp = args->dp->i_mount;
struct xfs_buf *bp;
xfs_dablk_t lblkno = args->rmtblkno;
__uint8_t *dst = args->value;
int valuelen;
int nmap;
int error;
int blkcnt = args->rmtblkcnt;
int i;
int offset = 0;
trace_xfs_attr_rmtval_get(args);
ASSERT(!(args->flags & ATTR_KERNOVAL));
ASSERT(args->rmtvaluelen == args->valuelen);
valuelen = args->rmtvaluelen;
while (valuelen > 0) {
nmap = ATTR_RMTVALUE_MAPSIZE;
error = xfs_bmapi_read(args->dp, (xfs_fileoff_t)lblkno,
blkcnt, map, &nmap,
XFS_BMAPI_ATTRFORK);
if (error)
return error;
ASSERT(nmap >= 1);
for (i = 0; (i < nmap) && (valuelen > 0); i++) {
xfs_daddr_t dblkno;
int dblkcnt;
ASSERT((map[i].br_startblock != DELAYSTARTBLOCK) &&
(map[i].br_startblock != HOLESTARTBLOCK));
dblkno = XFS_FSB_TO_DADDR(mp, map[i].br_startblock);
dblkcnt = XFS_FSB_TO_BB(mp, map[i].br_blockcount);
error = xfs_trans_read_buf(mp, NULL, mp->m_ddev_targp,
dblkno, dblkcnt, 0, &bp,
&xfs_attr3_rmt_buf_ops);
if (error)
return error;
error = xfs_attr_rmtval_copyout(mp, bp, args->dp->i_ino,
&offset, &valuelen,
&dst);
xfs_buf_relse(bp);
if (error)
return error;
/* roll attribute extent map forwards */
lblkno += map[i].br_blockcount;
blkcnt -= map[i].br_blockcount;
}
}
ASSERT(valuelen == 0);
return 0;
}
/*
* Write the value associated with an attribute into the out-of-line buffer
* that we have defined for it.
*/
int
xfs_attr_rmtval_set(
struct xfs_da_args *args)
{
struct xfs_inode *dp = args->dp;
struct xfs_mount *mp = dp->i_mount;
struct xfs_bmbt_irec map;
xfs_dablk_t lblkno;
xfs_fileoff_t lfileoff = 0;
__uint8_t *src = args->value;
int blkcnt;
int valuelen;
int nmap;
int error;
int offset = 0;
trace_xfs_attr_rmtval_set(args);
/*
* Find a "hole" in the attribute address space large enough for
* us to drop the new attribute's value into. Because CRC enable
* attributes have headers, we can't just do a straight byte to FSB
* conversion and have to take the header space into account.
*/
blkcnt = xfs_attr3_rmt_blocks(mp, args->rmtvaluelen);
error = xfs_bmap_first_unused(args->trans, args->dp, blkcnt, &lfileoff,
XFS_ATTR_FORK);
if (error)
return error;
args->rmtblkno = lblkno = (xfs_dablk_t)lfileoff;
args->rmtblkcnt = blkcnt;
/*
* Roll through the "value", allocating blocks on disk as required.
*/
while (blkcnt > 0) {
int committed;
/*
* Allocate a single extent, up to the size of the value.
*/
xfs_bmap_init(args->flist, args->firstblock);
nmap = 1;
error = xfs_bmapi_write(args->trans, dp, (xfs_fileoff_t)lblkno,
blkcnt,
XFS_BMAPI_ATTRFORK | XFS_BMAPI_METADATA,
args->firstblock, args->total, &map, &nmap,
args->flist);
if (!error) {
error = xfs_bmap_finish(&args->trans, args->flist,
&committed);
}
if (error) {
ASSERT(committed);
args->trans = NULL;
xfs_bmap_cancel(args->flist);
return(error);
}
/*
* bmap_finish() may have committed the last trans and started
* a new one. We need the inode to be in all transactions.
*/
if (committed)
xfs_trans_ijoin(args->trans, dp, 0);
ASSERT(nmap == 1);
ASSERT((map.br_startblock != DELAYSTARTBLOCK) &&
(map.br_startblock != HOLESTARTBLOCK));
lblkno += map.br_blockcount;
blkcnt -= map.br_blockcount;
/*
* Start the next trans in the chain.
*/
error = xfs_trans_roll(&args->trans, dp);
if (error)
return (error);
}
/*
* Roll through the "value", copying the attribute value to the
* already-allocated blocks. Blocks are written synchronously
* so that we can know they are all on disk before we turn off
* the INCOMPLETE flag.
*/
lblkno = args->rmtblkno;
blkcnt = args->rmtblkcnt;
valuelen = args->rmtvaluelen;
while (valuelen > 0) {
struct xfs_buf *bp;
xfs_daddr_t dblkno;
int dblkcnt;
ASSERT(blkcnt > 0);
xfs_bmap_init(args->flist, args->firstblock);
nmap = 1;
error = xfs_bmapi_read(dp, (xfs_fileoff_t)lblkno,
blkcnt, &map, &nmap,
XFS_BMAPI_ATTRFORK);
if (error)
return(error);
ASSERT(nmap == 1);
ASSERT((map.br_startblock != DELAYSTARTBLOCK) &&
(map.br_startblock != HOLESTARTBLOCK));
dblkno = XFS_FSB_TO_DADDR(mp, map.br_startblock),
dblkcnt = XFS_FSB_TO_BB(mp, map.br_blockcount);
bp = xfs_buf_get(mp->m_ddev_targp, dblkno, dblkcnt, 0);
if (!bp)
return ENOMEM;
bp->b_ops = &xfs_attr3_rmt_buf_ops;
xfs_attr_rmtval_copyin(mp, bp, args->dp->i_ino, &offset,
&valuelen, &src);
error = xfs_bwrite(bp); /* GROT: NOTE: synchronous write */
xfs_buf_relse(bp);
if (error)
return error;
/* roll attribute extent map forwards */
lblkno += map.br_blockcount;
blkcnt -= map.br_blockcount;
}
ASSERT(valuelen == 0);
return 0;
}
/*
* Remove the value associated with an attribute by deleting the
* out-of-line buffer that it is stored on.
*/
int
xfs_attr_rmtval_remove(
struct xfs_da_args *args)
{
struct xfs_mount *mp = args->dp->i_mount;
xfs_dablk_t lblkno;
int blkcnt;
int error;
int done;
trace_xfs_attr_rmtval_remove(args);
/*
* Roll through the "value", invalidating the attribute value's blocks.
*/
lblkno = args->rmtblkno;
blkcnt = args->rmtblkcnt;
while (blkcnt > 0) {
struct xfs_bmbt_irec map;
struct xfs_buf *bp;
xfs_daddr_t dblkno;
int dblkcnt;
int nmap;
/*
* Try to remember where we decided to put the value.
*/
nmap = 1;
error = xfs_bmapi_read(args->dp, (xfs_fileoff_t)lblkno,
blkcnt, &map, &nmap, XFS_BMAPI_ATTRFORK);
if (error)
return(error);
ASSERT(nmap == 1);
ASSERT((map.br_startblock != DELAYSTARTBLOCK) &&
(map.br_startblock != HOLESTARTBLOCK));
dblkno = XFS_FSB_TO_DADDR(mp, map.br_startblock),
dblkcnt = XFS_FSB_TO_BB(mp, map.br_blockcount);
/*
* If the "remote" value is in the cache, remove it.
*/
bp = xfs_incore(mp->m_ddev_targp, dblkno, dblkcnt, XBF_TRYLOCK);
if (bp) {
xfs_buf_stale(bp);
xfs_buf_relse(bp);
bp = NULL;
}
lblkno += map.br_blockcount;
blkcnt -= map.br_blockcount;
}
/*
* Keep de-allocating extents until the remote-value region is gone.
*/
lblkno = args->rmtblkno;
blkcnt = args->rmtblkcnt;
done = 0;
while (!done) {
int committed;
xfs_bmap_init(args->flist, args->firstblock);
error = xfs_bunmapi(args->trans, args->dp, lblkno, blkcnt,
XFS_BMAPI_ATTRFORK | XFS_BMAPI_METADATA,
1, args->firstblock, args->flist,
&done);
if (!error) {
error = xfs_bmap_finish(&args->trans, args->flist,
&committed);
}
if (error) {
ASSERT(committed);
args->trans = NULL;
xfs_bmap_cancel(args->flist);
return error;
}
/*
* bmap_finish() may have committed the last trans and started
* a new one. We need the inode to be in all transactions.
*/
if (committed)
xfs_trans_ijoin(args->trans, args->dp, 0);
/*
* Close out trans and start the next one in the chain.
*/
error = xfs_trans_roll(&args->trans, args->dp);
if (error)
return (error);
}
return(0);
}