xfs_attr_list.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 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;
if (dp->i_afp->if_format == XFS_DINODE_FMT_LOCAL)
return xfs_attr_shortform_list(context);
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;
}