linux/fs/xfs/xfs_attr_list.c
Darrick J. Wong 8d57c21600 xfs: add a function to deal with corrupt buffers post-verifiers
Add a helper function to get rid of buffers that we have decided are
corrupt after the verifiers have run.  This function is intended to
handle metadata checks that can't happen in the verifiers, such as
inter-block relationship checking.  Note that we now mark the buffer
stale so that it will not end up on any LRU and will be purged on
release.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2020-03-12 07:58:12 -07:00

540 lines
13 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (c) 2000-2005 Silicon Graphics, Inc.
* Copyright (c) 2013 Red Hat, 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_mount.h"
#include "xfs_da_format.h"
#include "xfs_inode.h"
#include "xfs_trans.h"
#include "xfs_bmap.h"
#include "xfs_attr.h"
#include "xfs_attr_sf.h"
#include "xfs_attr_leaf.h"
#include "xfs_error.h"
#include "xfs_trace.h"
#include "xfs_dir2.h"
STATIC int
xfs_attr_shortform_compare(const void *a, const void *b)
{
xfs_attr_sf_sort_t *sa, *sb;
sa = (xfs_attr_sf_sort_t *)a;
sb = (xfs_attr_sf_sort_t *)b;
if (sa->hash < sb->hash) {
return -1;
} else if (sa->hash > sb->hash) {
return 1;
} else {
return sa->entno - sb->entno;
}
}
#define XFS_ISRESET_CURSOR(cursor) \
(!((cursor)->initted) && !((cursor)->hashval) && \
!((cursor)->blkno) && !((cursor)->offset))
/*
* Copy out entries of shortform attribute lists for attr_list().
* Shortform attribute lists are not stored in hashval sorted order.
* If the output buffer is not large enough to hold them all, then we
* we have to calculate each entries' hashvalue and sort them before
* we can begin returning them to the user.
*/
static int
xfs_attr_shortform_list(
struct xfs_attr_list_context *context)
{
struct xfs_attrlist_cursor_kern *cursor = &context->cursor;
struct xfs_inode *dp = context->dp;
struct xfs_attr_sf_sort *sbuf, *sbp;
struct xfs_attr_shortform *sf;
struct xfs_attr_sf_entry *sfe;
int sbsize, nsbuf, count, i;
int error = 0;
ASSERT(dp->i_afp != NULL);
sf = (xfs_attr_shortform_t *)dp->i_afp->if_u1.if_data;
ASSERT(sf != NULL);
if (!sf->hdr.count)
return 0;
trace_xfs_attr_list_sf(context);
/*
* If the buffer is large enough and the cursor is at the start,
* do not bother with sorting since we will return everything in
* one buffer and another call using the cursor won't need to be
* made.
* Note the generous fudge factor of 16 overhead bytes per entry.
* If bufsize is zero then put_listent must be a search function
* and can just scan through what we have.
*/
if (context->bufsize == 0 ||
(XFS_ISRESET_CURSOR(cursor) &&
(dp->i_afp->if_bytes + sf->hdr.count * 16) < context->bufsize)) {
for (i = 0, sfe = &sf->list[0]; i < sf->hdr.count; i++) {
if (XFS_IS_CORRUPT(context->dp->i_mount,
!xfs_attr_namecheck(sfe->nameval,
sfe->namelen)))
return -EFSCORRUPTED;
context->put_listent(context,
sfe->flags,
sfe->nameval,
(int)sfe->namelen,
(int)sfe->valuelen);
/*
* Either search callback finished early or
* didn't fit it all in the buffer after all.
*/
if (context->seen_enough)
break;
sfe = XFS_ATTR_SF_NEXTENTRY(sfe);
}
trace_xfs_attr_list_sf_all(context);
return 0;
}
/* do no more for a search callback */
if (context->bufsize == 0)
return 0;
/*
* It didn't all fit, so we have to sort everything on hashval.
*/
sbsize = sf->hdr.count * sizeof(*sbuf);
sbp = sbuf = kmem_alloc(sbsize, KM_NOFS);
/*
* Scan the attribute list for the rest of the entries, storing
* the relevant info from only those that match into a buffer.
*/
nsbuf = 0;
for (i = 0, sfe = &sf->list[0]; i < sf->hdr.count; i++) {
if (unlikely(
((char *)sfe < (char *)sf) ||
((char *)sfe >= ((char *)sf + dp->i_afp->if_bytes)))) {
XFS_CORRUPTION_ERROR("xfs_attr_shortform_list",
XFS_ERRLEVEL_LOW,
context->dp->i_mount, sfe,
sizeof(*sfe));
kmem_free(sbuf);
return -EFSCORRUPTED;
}
sbp->entno = i;
sbp->hash = xfs_da_hashname(sfe->nameval, sfe->namelen);
sbp->name = sfe->nameval;
sbp->namelen = sfe->namelen;
/* These are bytes, and both on-disk, don't endian-flip */
sbp->valuelen = sfe->valuelen;
sbp->flags = sfe->flags;
sfe = XFS_ATTR_SF_NEXTENTRY(sfe);
sbp++;
nsbuf++;
}
/*
* Sort the entries on hash then entno.
*/
xfs_sort(sbuf, nsbuf, sizeof(*sbuf), xfs_attr_shortform_compare);
/*
* Re-find our place IN THE SORTED LIST.
*/
count = 0;
cursor->initted = 1;
cursor->blkno = 0;
for (sbp = sbuf, i = 0; i < nsbuf; i++, sbp++) {
if (sbp->hash == cursor->hashval) {
if (cursor->offset == count) {
break;
}
count++;
} else if (sbp->hash > cursor->hashval) {
break;
}
}
if (i == nsbuf)
goto out;
/*
* Loop putting entries into the user buffer.
*/
for ( ; i < nsbuf; i++, sbp++) {
if (cursor->hashval != sbp->hash) {
cursor->hashval = sbp->hash;
cursor->offset = 0;
}
if (XFS_IS_CORRUPT(context->dp->i_mount,
!xfs_attr_namecheck(sbp->name,
sbp->namelen))) {
error = -EFSCORRUPTED;
goto out;
}
context->put_listent(context,
sbp->flags,
sbp->name,
sbp->namelen,
sbp->valuelen);
if (context->seen_enough)
break;
cursor->offset++;
}
out:
kmem_free(sbuf);
return error;
}
/*
* We didn't find the block & hash mentioned in the cursor state, so
* walk down the attr btree looking for the hash.
*/
STATIC int
xfs_attr_node_list_lookup(
struct xfs_attr_list_context *context,
struct xfs_attrlist_cursor_kern *cursor,
struct xfs_buf **pbp)
{
struct xfs_da3_icnode_hdr nodehdr;
struct xfs_da_intnode *node;
struct xfs_da_node_entry *btree;
struct xfs_inode *dp = context->dp;
struct xfs_mount *mp = dp->i_mount;
struct xfs_trans *tp = context->tp;
struct xfs_buf *bp;
int i;
int error = 0;
unsigned int expected_level = 0;
uint16_t magic;
ASSERT(*pbp == NULL);
cursor->blkno = 0;
for (;;) {
error = xfs_da3_node_read(tp, dp, cursor->blkno, &bp,
XFS_ATTR_FORK);
if (error)
return error;
node = bp->b_addr;
magic = be16_to_cpu(node->hdr.info.magic);
if (magic == XFS_ATTR_LEAF_MAGIC ||
magic == XFS_ATTR3_LEAF_MAGIC)
break;
if (magic != XFS_DA_NODE_MAGIC &&
magic != XFS_DA3_NODE_MAGIC) {
XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp,
node, sizeof(*node));
goto out_corruptbuf;
}
xfs_da3_node_hdr_from_disk(mp, &nodehdr, node);
/* Tree taller than we can handle; bail out! */
if (nodehdr.level >= XFS_DA_NODE_MAXDEPTH)
goto out_corruptbuf;
/* Check the level from the root node. */
if (cursor->blkno == 0)
expected_level = nodehdr.level - 1;
else if (expected_level != nodehdr.level)
goto out_corruptbuf;
else
expected_level--;
btree = nodehdr.btree;
for (i = 0; i < nodehdr.count; btree++, i++) {
if (cursor->hashval <= be32_to_cpu(btree->hashval)) {
cursor->blkno = be32_to_cpu(btree->before);
trace_xfs_attr_list_node_descend(context,
btree);
break;
}
}
xfs_trans_brelse(tp, bp);
if (i == nodehdr.count)
return 0;
/* We can't point back to the root. */
if (XFS_IS_CORRUPT(mp, cursor->blkno == 0))
return -EFSCORRUPTED;
}
if (expected_level != 0)
goto out_corruptbuf;
*pbp = bp;
return 0;
out_corruptbuf:
xfs_buf_mark_corrupt(bp);
xfs_trans_brelse(tp, bp);
return -EFSCORRUPTED;
}
STATIC int
xfs_attr_node_list(
struct xfs_attr_list_context *context)
{
struct xfs_attrlist_cursor_kern *cursor = &context->cursor;
struct xfs_attr3_icleaf_hdr leafhdr;
struct xfs_attr_leafblock *leaf;
struct xfs_da_intnode *node;
struct xfs_buf *bp;
struct xfs_inode *dp = context->dp;
struct xfs_mount *mp = dp->i_mount;
int error = 0;
trace_xfs_attr_node_list(context);
cursor->initted = 1;
/*
* Do all sorts of validation on the passed-in cursor structure.
* If anything is amiss, ignore the cursor and look up the hashval
* starting from the btree root.
*/
bp = NULL;
if (cursor->blkno > 0) {
error = xfs_da3_node_read(context->tp, dp, cursor->blkno, &bp,
XFS_ATTR_FORK);
if ((error != 0) && (error != -EFSCORRUPTED))
return error;
if (bp) {
struct xfs_attr_leaf_entry *entries;
node = bp->b_addr;
switch (be16_to_cpu(node->hdr.info.magic)) {
case XFS_DA_NODE_MAGIC:
case XFS_DA3_NODE_MAGIC:
trace_xfs_attr_list_wrong_blk(context);
xfs_trans_brelse(context->tp, bp);
bp = NULL;
break;
case XFS_ATTR_LEAF_MAGIC:
case XFS_ATTR3_LEAF_MAGIC:
leaf = bp->b_addr;
xfs_attr3_leaf_hdr_from_disk(mp->m_attr_geo,
&leafhdr, leaf);
entries = xfs_attr3_leaf_entryp(leaf);
if (cursor->hashval > be32_to_cpu(
entries[leafhdr.count - 1].hashval)) {
trace_xfs_attr_list_wrong_blk(context);
xfs_trans_brelse(context->tp, bp);
bp = NULL;
} else if (cursor->hashval <= be32_to_cpu(
entries[0].hashval)) {
trace_xfs_attr_list_wrong_blk(context);
xfs_trans_brelse(context->tp, bp);
bp = NULL;
}
break;
default:
trace_xfs_attr_list_wrong_blk(context);
xfs_trans_brelse(context->tp, bp);
bp = NULL;
}
}
}
/*
* We did not find what we expected given the cursor's contents,
* so we start from the top and work down based on the hash value.
* Note that start of node block is same as start of leaf block.
*/
if (bp == NULL) {
error = xfs_attr_node_list_lookup(context, cursor, &bp);
if (error || !bp)
return error;
}
ASSERT(bp != NULL);
/*
* Roll upward through the blocks, processing each leaf block in
* order. As long as there is space in the result buffer, keep
* adding the information.
*/
for (;;) {
leaf = bp->b_addr;
error = xfs_attr3_leaf_list_int(bp, context);
if (error)
break;
xfs_attr3_leaf_hdr_from_disk(mp->m_attr_geo, &leafhdr, leaf);
if (context->seen_enough || leafhdr.forw == 0)
break;
cursor->blkno = leafhdr.forw;
xfs_trans_brelse(context->tp, bp);
error = xfs_attr3_leaf_read(context->tp, dp, cursor->blkno,
&bp);
if (error)
return error;
}
xfs_trans_brelse(context->tp, bp);
return error;
}
/*
* Copy out attribute list entries for attr_list(), for leaf attribute lists.
*/
int
xfs_attr3_leaf_list_int(
struct xfs_buf *bp,
struct xfs_attr_list_context *context)
{
struct xfs_attrlist_cursor_kern *cursor = &context->cursor;
struct xfs_attr_leafblock *leaf;
struct xfs_attr3_icleaf_hdr ichdr;
struct xfs_attr_leaf_entry *entries;
struct xfs_attr_leaf_entry *entry;
int i;
struct xfs_mount *mp = context->dp->i_mount;
trace_xfs_attr_list_leaf(context);
leaf = bp->b_addr;
xfs_attr3_leaf_hdr_from_disk(mp->m_attr_geo, &ichdr, leaf);
entries = xfs_attr3_leaf_entryp(leaf);
cursor->initted = 1;
/*
* Re-find our place in the leaf block if this is a new syscall.
*/
if (context->resynch) {
entry = &entries[0];
for (i = 0; i < ichdr.count; entry++, i++) {
if (be32_to_cpu(entry->hashval) == cursor->hashval) {
if (cursor->offset == context->dupcnt) {
context->dupcnt = 0;
break;
}
context->dupcnt++;
} else if (be32_to_cpu(entry->hashval) >
cursor->hashval) {
context->dupcnt = 0;
break;
}
}
if (i == ichdr.count) {
trace_xfs_attr_list_notfound(context);
return 0;
}
} else {
entry = &entries[0];
i = 0;
}
context->resynch = 0;
/*
* We have found our place, start copying out the new attributes.
*/
for (; i < ichdr.count; entry++, i++) {
char *name;
int namelen, valuelen;
if (be32_to_cpu(entry->hashval) != cursor->hashval) {
cursor->hashval = be32_to_cpu(entry->hashval);
cursor->offset = 0;
}
if ((entry->flags & XFS_ATTR_INCOMPLETE) &&
!context->allow_incomplete)
continue;
if (entry->flags & XFS_ATTR_LOCAL) {
xfs_attr_leaf_name_local_t *name_loc;
name_loc = xfs_attr3_leaf_name_local(leaf, i);
name = name_loc->nameval;
namelen = name_loc->namelen;
valuelen = be16_to_cpu(name_loc->valuelen);
} else {
xfs_attr_leaf_name_remote_t *name_rmt;
name_rmt = xfs_attr3_leaf_name_remote(leaf, i);
name = name_rmt->name;
namelen = name_rmt->namelen;
valuelen = be32_to_cpu(name_rmt->valuelen);
}
if (XFS_IS_CORRUPT(context->dp->i_mount,
!xfs_attr_namecheck(name, namelen)))
return -EFSCORRUPTED;
context->put_listent(context, entry->flags,
name, namelen, valuelen);
if (context->seen_enough)
break;
cursor->offset++;
}
trace_xfs_attr_list_leaf_end(context);
return 0;
}
/*
* Copy out attribute entries for attr_list(), for leaf attribute lists.
*/
STATIC int
xfs_attr_leaf_list(
struct xfs_attr_list_context *context)
{
struct xfs_buf *bp;
int error;
trace_xfs_attr_leaf_list(context);
context->cursor.blkno = 0;
error = xfs_attr3_leaf_read(context->tp, context->dp, 0, &bp);
if (error)
return error;
error = xfs_attr3_leaf_list_int(bp, context);
xfs_trans_brelse(context->tp, bp);
return error;
}
int
xfs_attr_list_ilocked(
struct xfs_attr_list_context *context)
{
struct xfs_inode *dp = context->dp;
ASSERT(xfs_isilocked(dp, XFS_ILOCK_SHARED | XFS_ILOCK_EXCL));
/*
* Decide on what work routines to call based on the inode size.
*/
if (!xfs_inode_hasattr(dp))
return 0;
else if (dp->i_d.di_aformat == XFS_DINODE_FMT_LOCAL)
return xfs_attr_shortform_list(context);
else if (xfs_bmap_one_block(dp, XFS_ATTR_FORK))
return xfs_attr_leaf_list(context);
return xfs_attr_node_list(context);
}
int
xfs_attr_list(
struct xfs_attr_list_context *context)
{
struct xfs_inode *dp = context->dp;
uint lock_mode;
int error;
XFS_STATS_INC(dp->i_mount, xs_attr_list);
if (XFS_FORCED_SHUTDOWN(dp->i_mount))
return -EIO;
lock_mode = xfs_ilock_attr_map_shared(dp);
error = xfs_attr_list_ilocked(context);
xfs_iunlock(dp, lock_mode);
return error;
}