linux/fs/xfs/xfs_attr_list.c
Brian Foster 2f66124154 xfs: pass attr geometry to attr leaf header conversion functions
The firstused field of the xfs_attr3_leaf_hdr structure is subject to an
overflow when fs blocksize is 64k. In preparation to handle this
overflow in the header conversion functions, pass the attribute geometry
to the functions that convert the in-core structure to and from the
on-disk structure.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2015-04-13 11:26:02 +10:00

654 lines
16 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_format.h"
#include "xfs_log_format.h"
#include "xfs_trans_resv.h"
#include "xfs_bit.h"
#include "xfs_mount.h"
#include "xfs_da_format.h"
#include "xfs_da_btree.h"
#include "xfs_inode.h"
#include "xfs_trans.h"
#include "xfs_inode_item.h"
#include "xfs_bmap.h"
#include "xfs_attr.h"
#include "xfs_attr_sf.h"
#include "xfs_attr_remote.h"
#include "xfs_attr_leaf.h"
#include "xfs_error.h"
#include "xfs_trace.h"
#include "xfs_buf_item.h"
#include "xfs_cksum.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.
*/
int
xfs_attr_shortform_list(xfs_attr_list_context_t *context)
{
attrlist_cursor_kern_t *cursor;
xfs_attr_sf_sort_t *sbuf, *sbp;
xfs_attr_shortform_t *sf;
xfs_attr_sf_entry_t *sfe;
xfs_inode_t *dp;
int sbsize, nsbuf, count, i;
int error;
ASSERT(context != NULL);
dp = context->dp;
ASSERT(dp != NULL);
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;
cursor = context->cursor;
ASSERT(cursor != NULL);
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++) {
error = context->put_listent(context,
sfe->flags,
sfe->nameval,
(int)sfe->namelen,
(int)sfe->valuelen,
&sfe->nameval[sfe->namelen]);
/*
* Either search callback finished early or
* didn't fit it all in the buffer after all.
*/
if (context->seen_enough)
break;
if (error)
return error;
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_SLEEP | 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);
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) {
kmem_free(sbuf);
return 0;
}
/*
* Loop putting entries into the user buffer.
*/
for ( ; i < nsbuf; i++, sbp++) {
if (cursor->hashval != sbp->hash) {
cursor->hashval = sbp->hash;
cursor->offset = 0;
}
error = context->put_listent(context,
sbp->flags,
sbp->name,
sbp->namelen,
sbp->valuelen,
&sbp->name[sbp->namelen]);
if (error)
return error;
if (context->seen_enough)
break;
cursor->offset++;
}
kmem_free(sbuf);
return 0;
}
STATIC int
xfs_attr_node_list(xfs_attr_list_context_t *context)
{
attrlist_cursor_kern_t *cursor;
xfs_attr_leafblock_t *leaf;
xfs_da_intnode_t *node;
struct xfs_attr3_icleaf_hdr leafhdr;
struct xfs_da3_icnode_hdr nodehdr;
struct xfs_da_node_entry *btree;
int error, i;
struct xfs_buf *bp;
struct xfs_inode *dp = context->dp;
struct xfs_mount *mp = dp->i_mount;
trace_xfs_attr_node_list(context);
cursor = context->cursor;
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(NULL, dp, cursor->blkno, -1,
&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(NULL, 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(NULL, bp);
bp = NULL;
} else if (cursor->hashval <= be32_to_cpu(
entries[0].hashval)) {
trace_xfs_attr_list_wrong_blk(context);
xfs_trans_brelse(NULL, bp);
bp = NULL;
}
break;
default:
trace_xfs_attr_list_wrong_blk(context);
xfs_trans_brelse(NULL, 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) {
cursor->blkno = 0;
for (;;) {
__uint16_t magic;
error = xfs_da3_node_read(NULL, dp,
cursor->blkno, -1, &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("xfs_attr_node_list(3)",
XFS_ERRLEVEL_LOW,
context->dp->i_mount,
node);
xfs_trans_brelse(NULL, bp);
return -EFSCORRUPTED;
}
dp->d_ops->node_hdr_from_disk(&nodehdr, node);
btree = dp->d_ops->node_tree_p(node);
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;
}
}
if (i == nodehdr.count) {
xfs_trans_brelse(NULL, bp);
return 0;
}
xfs_trans_brelse(NULL, bp);
}
}
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) {
xfs_trans_brelse(NULL, bp);
return error;
}
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(NULL, bp);
error = xfs_attr3_leaf_read(NULL, dp, cursor->blkno, -1, &bp);
if (error)
return error;
}
xfs_trans_brelse(NULL, bp);
return 0;
}
/*
* 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 attrlist_cursor_kern *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 retval;
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 = context->cursor;
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.
*/
retval = 0;
for (; i < ichdr.count; entry++, i++) {
if (be32_to_cpu(entry->hashval) != cursor->hashval) {
cursor->hashval = be32_to_cpu(entry->hashval);
cursor->offset = 0;
}
if (entry->flags & XFS_ATTR_INCOMPLETE)
continue; /* skip incomplete entries */
if (entry->flags & XFS_ATTR_LOCAL) {
xfs_attr_leaf_name_local_t *name_loc =
xfs_attr3_leaf_name_local(leaf, i);
retval = context->put_listent(context,
entry->flags,
name_loc->nameval,
(int)name_loc->namelen,
be16_to_cpu(name_loc->valuelen),
&name_loc->nameval[name_loc->namelen]);
if (retval)
return retval;
} else {
xfs_attr_leaf_name_remote_t *name_rmt =
xfs_attr3_leaf_name_remote(leaf, i);
int valuelen = be32_to_cpu(name_rmt->valuelen);
if (context->put_value) {
xfs_da_args_t args;
memset((char *)&args, 0, sizeof(args));
args.geo = context->dp->i_mount->m_attr_geo;
args.dp = context->dp;
args.whichfork = XFS_ATTR_FORK;
args.valuelen = valuelen;
args.rmtvaluelen = valuelen;
args.value = kmem_alloc(valuelen, KM_SLEEP | KM_NOFS);
args.rmtblkno = be32_to_cpu(name_rmt->valueblk);
args.rmtblkcnt = xfs_attr3_rmt_blocks(
args.dp->i_mount, valuelen);
retval = xfs_attr_rmtval_get(&args);
if (retval)
return retval;
retval = context->put_listent(context,
entry->flags,
name_rmt->name,
(int)name_rmt->namelen,
valuelen,
args.value);
kmem_free(args.value);
} else {
retval = context->put_listent(context,
entry->flags,
name_rmt->name,
(int)name_rmt->namelen,
valuelen,
NULL);
}
if (retval)
return retval;
}
if (context->seen_enough)
break;
cursor->offset++;
}
trace_xfs_attr_list_leaf_end(context);
return retval;
}
/*
* Copy out attribute entries for attr_list(), for leaf attribute lists.
*/
STATIC int
xfs_attr_leaf_list(xfs_attr_list_context_t *context)
{
int error;
struct xfs_buf *bp;
trace_xfs_attr_leaf_list(context);
context->cursor->blkno = 0;
error = xfs_attr3_leaf_read(NULL, context->dp, 0, -1, &bp);
if (error)
return error;
error = xfs_attr3_leaf_list_int(bp, context);
xfs_trans_brelse(NULL, bp);
return error;
}
int
xfs_attr_list_int(
xfs_attr_list_context_t *context)
{
int error;
xfs_inode_t *dp = context->dp;
uint lock_mode;
XFS_STATS_INC(xs_attr_list);
if (XFS_FORCED_SHUTDOWN(dp->i_mount))
return -EIO;
/*
* Decide on what work routines to call based on the inode size.
*/
lock_mode = xfs_ilock_attr_map_shared(dp);
if (!xfs_inode_hasattr(dp)) {
error = 0;
} else if (dp->i_d.di_aformat == XFS_DINODE_FMT_LOCAL) {
error = xfs_attr_shortform_list(context);
} else if (xfs_bmap_one_block(dp, XFS_ATTR_FORK)) {
error = xfs_attr_leaf_list(context);
} else {
error = xfs_attr_node_list(context);
}
xfs_iunlock(dp, lock_mode);
return error;
}
#define ATTR_ENTBASESIZE /* minimum bytes used by an attr */ \
(((struct attrlist_ent *) 0)->a_name - (char *) 0)
#define ATTR_ENTSIZE(namelen) /* actual bytes used by an attr */ \
((ATTR_ENTBASESIZE + (namelen) + 1 + sizeof(u_int32_t)-1) \
& ~(sizeof(u_int32_t)-1))
/*
* Format an attribute and copy it out to the user's buffer.
* Take care to check values and protect against them changing later,
* we may be reading them directly out of a user buffer.
*/
STATIC int
xfs_attr_put_listent(
xfs_attr_list_context_t *context,
int flags,
unsigned char *name,
int namelen,
int valuelen,
unsigned char *value)
{
struct attrlist *alist = (struct attrlist *)context->alist;
attrlist_ent_t *aep;
int arraytop;
ASSERT(!(context->flags & ATTR_KERNOVAL));
ASSERT(context->count >= 0);
ASSERT(context->count < (ATTR_MAX_VALUELEN/8));
ASSERT(context->firstu >= sizeof(*alist));
ASSERT(context->firstu <= context->bufsize);
/*
* Only list entries in the right namespace.
*/
if (((context->flags & ATTR_SECURE) == 0) !=
((flags & XFS_ATTR_SECURE) == 0))
return 0;
if (((context->flags & ATTR_ROOT) == 0) !=
((flags & XFS_ATTR_ROOT) == 0))
return 0;
arraytop = sizeof(*alist) +
context->count * sizeof(alist->al_offset[0]);
context->firstu -= ATTR_ENTSIZE(namelen);
if (context->firstu < arraytop) {
trace_xfs_attr_list_full(context);
alist->al_more = 1;
context->seen_enough = 1;
return 1;
}
aep = (attrlist_ent_t *)&context->alist[context->firstu];
aep->a_valuelen = valuelen;
memcpy(aep->a_name, name, namelen);
aep->a_name[namelen] = 0;
alist->al_offset[context->count++] = context->firstu;
alist->al_count = context->count;
trace_xfs_attr_list_add(context);
return 0;
}
/*
* Generate a list of extended attribute names and optionally
* also value lengths. Positive return value follows the XFS
* convention of being an error, zero or negative return code
* is the length of the buffer returned (negated), indicating
* success.
*/
int
xfs_attr_list(
xfs_inode_t *dp,
char *buffer,
int bufsize,
int flags,
attrlist_cursor_kern_t *cursor)
{
xfs_attr_list_context_t context;
struct attrlist *alist;
int error;
/*
* Validate the cursor.
*/
if (cursor->pad1 || cursor->pad2)
return -EINVAL;
if ((cursor->initted == 0) &&
(cursor->hashval || cursor->blkno || cursor->offset))
return -EINVAL;
/*
* Check for a properly aligned buffer.
*/
if (((long)buffer) & (sizeof(int)-1))
return -EFAULT;
if (flags & ATTR_KERNOVAL)
bufsize = 0;
/*
* Initialize the output buffer.
*/
memset(&context, 0, sizeof(context));
context.dp = dp;
context.cursor = cursor;
context.resynch = 1;
context.flags = flags;
context.alist = buffer;
context.bufsize = (bufsize & ~(sizeof(int)-1)); /* align */
context.firstu = context.bufsize;
context.put_listent = xfs_attr_put_listent;
alist = (struct attrlist *)context.alist;
alist->al_count = 0;
alist->al_more = 0;
alist->al_offset[0] = context.bufsize;
error = xfs_attr_list_int(&context);
ASSERT(error <= 0);
return error;
}