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WSL2-Linux-Kernel/fs/xfs/xfs_da_btree.c

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62 KiB
C
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/*
* Copyright (c) 2000-2005 Silicon Graphics, 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_types.h"
#include "xfs_bit.h"
#include "xfs_log.h"
#include "xfs_trans.h"
#include "xfs_sb.h"
#include "xfs_ag.h"
#include "xfs_mount.h"
#include "xfs_da_btree.h"
#include "xfs_bmap_btree.h"
#include "xfs_dir2.h"
#include "xfs_dir2_format.h"
#include "xfs_dir2_priv.h"
#include "xfs_dinode.h"
#include "xfs_inode.h"
#include "xfs_inode_item.h"
#include "xfs_alloc.h"
#include "xfs_bmap.h"
#include "xfs_attr.h"
#include "xfs_attr_leaf.h"
#include "xfs_error.h"
#include "xfs_trace.h"
/*
* xfs_da_btree.c
*
* Routines to implement directories as Btrees of hashed names.
*/
/*========================================================================
* Function prototypes for the kernel.
*========================================================================*/
/*
* Routines used for growing the Btree.
*/
STATIC int xfs_da_root_split(xfs_da_state_t *state,
xfs_da_state_blk_t *existing_root,
xfs_da_state_blk_t *new_child);
STATIC int xfs_da_node_split(xfs_da_state_t *state,
xfs_da_state_blk_t *existing_blk,
xfs_da_state_blk_t *split_blk,
xfs_da_state_blk_t *blk_to_add,
int treelevel,
int *result);
STATIC void xfs_da_node_rebalance(xfs_da_state_t *state,
xfs_da_state_blk_t *node_blk_1,
xfs_da_state_blk_t *node_blk_2);
STATIC void xfs_da_node_add(xfs_da_state_t *state,
xfs_da_state_blk_t *old_node_blk,
xfs_da_state_blk_t *new_node_blk);
/*
* Routines used for shrinking the Btree.
*/
STATIC int xfs_da_root_join(xfs_da_state_t *state,
xfs_da_state_blk_t *root_blk);
STATIC int xfs_da_node_toosmall(xfs_da_state_t *state, int *retval);
STATIC void xfs_da_node_remove(xfs_da_state_t *state,
xfs_da_state_blk_t *drop_blk);
STATIC void xfs_da_node_unbalance(xfs_da_state_t *state,
xfs_da_state_blk_t *src_node_blk,
xfs_da_state_blk_t *dst_node_blk);
/*
* Utility routines.
*/
STATIC uint xfs_da_node_lasthash(struct xfs_buf *bp, int *count);
STATIC int xfs_da_node_order(struct xfs_buf *node1_bp,
struct xfs_buf *node2_bp);
STATIC int xfs_da_blk_unlink(xfs_da_state_t *state,
xfs_da_state_blk_t *drop_blk,
xfs_da_state_blk_t *save_blk);
STATIC void xfs_da_state_kill_altpath(xfs_da_state_t *state);
/*========================================================================
* Routines used for growing the Btree.
*========================================================================*/
/*
* Create the initial contents of an intermediate node.
*/
int
xfs_da_node_create(xfs_da_args_t *args, xfs_dablk_t blkno, int level,
struct xfs_buf **bpp, int whichfork)
{
xfs_da_intnode_t *node;
struct xfs_buf *bp;
int error;
xfs_trans_t *tp;
trace_xfs_da_node_create(args);
tp = args->trans;
error = xfs_da_get_buf(tp, args->dp, blkno, -1, &bp, whichfork);
if (error)
return(error);
ASSERT(bp != NULL);
node = bp->b_addr;
node->hdr.info.forw = 0;
node->hdr.info.back = 0;
node->hdr.info.magic = cpu_to_be16(XFS_DA_NODE_MAGIC);
node->hdr.info.pad = 0;
node->hdr.count = 0;
node->hdr.level = cpu_to_be16(level);
xfs_trans_log_buf(tp, bp,
XFS_DA_LOGRANGE(node, &node->hdr, sizeof(node->hdr)));
*bpp = bp;
return(0);
}
/*
* Split a leaf node, rebalance, then possibly split
* intermediate nodes, rebalance, etc.
*/
int /* error */
xfs_da_split(xfs_da_state_t *state)
{
xfs_da_state_blk_t *oldblk, *newblk, *addblk;
xfs_da_intnode_t *node;
struct xfs_buf *bp;
int max, action, error, i;
trace_xfs_da_split(state->args);
/*
* Walk back up the tree splitting/inserting/adjusting as necessary.
* If we need to insert and there isn't room, split the node, then
* decide which fragment to insert the new block from below into.
* Note that we may split the root this way, but we need more fixup.
*/
max = state->path.active - 1;
ASSERT((max >= 0) && (max < XFS_DA_NODE_MAXDEPTH));
ASSERT(state->path.blk[max].magic == XFS_ATTR_LEAF_MAGIC ||
state->path.blk[max].magic == XFS_DIR2_LEAFN_MAGIC);
addblk = &state->path.blk[max]; /* initial dummy value */
for (i = max; (i >= 0) && addblk; state->path.active--, i--) {
oldblk = &state->path.blk[i];
newblk = &state->altpath.blk[i];
/*
* If a leaf node then
* Allocate a new leaf node, then rebalance across them.
* else if an intermediate node then
* We split on the last layer, must we split the node?
*/
switch (oldblk->magic) {
case XFS_ATTR_LEAF_MAGIC:
error = xfs_attr_leaf_split(state, oldblk, newblk);
if ((error != 0) && (error != ENOSPC)) {
return(error); /* GROT: attr is inconsistent */
}
if (!error) {
addblk = newblk;
break;
}
/*
* Entry wouldn't fit, split the leaf again.
*/
state->extravalid = 1;
if (state->inleaf) {
state->extraafter = 0; /* before newblk */
trace_xfs_attr_leaf_split_before(state->args);
error = xfs_attr_leaf_split(state, oldblk,
&state->extrablk);
} else {
state->extraafter = 1; /* after newblk */
trace_xfs_attr_leaf_split_after(state->args);
error = xfs_attr_leaf_split(state, newblk,
&state->extrablk);
}
if (error)
return(error); /* GROT: attr inconsistent */
addblk = newblk;
break;
case XFS_DIR2_LEAFN_MAGIC:
error = xfs_dir2_leafn_split(state, oldblk, newblk);
if (error)
return error;
addblk = newblk;
break;
case XFS_DA_NODE_MAGIC:
error = xfs_da_node_split(state, oldblk, newblk, addblk,
max - i, &action);
addblk->bp = NULL;
if (error)
return(error); /* GROT: dir is inconsistent */
/*
* Record the newly split block for the next time thru?
*/
if (action)
addblk = newblk;
else
addblk = NULL;
break;
}
/*
* Update the btree to show the new hashval for this child.
*/
xfs_da_fixhashpath(state, &state->path);
}
if (!addblk)
return(0);
/*
* Split the root node.
*/
ASSERT(state->path.active == 0);
oldblk = &state->path.blk[0];
error = xfs_da_root_split(state, oldblk, addblk);
if (error) {
addblk->bp = NULL;
return(error); /* GROT: dir is inconsistent */
}
/*
* Update pointers to the node which used to be block 0 and
* just got bumped because of the addition of a new root node.
* There might be three blocks involved if a double split occurred,
* and the original block 0 could be at any position in the list.
*/
node = oldblk->bp->b_addr;
if (node->hdr.info.forw) {
if (be32_to_cpu(node->hdr.info.forw) == addblk->blkno) {
bp = addblk->bp;
} else {
ASSERT(state->extravalid);
bp = state->extrablk.bp;
}
node = bp->b_addr;
node->hdr.info.back = cpu_to_be32(oldblk->blkno);
xfs_trans_log_buf(state->args->trans, bp,
XFS_DA_LOGRANGE(node, &node->hdr.info,
sizeof(node->hdr.info)));
}
node = oldblk->bp->b_addr;
if (node->hdr.info.back) {
if (be32_to_cpu(node->hdr.info.back) == addblk->blkno) {
bp = addblk->bp;
} else {
ASSERT(state->extravalid);
bp = state->extrablk.bp;
}
node = bp->b_addr;
node->hdr.info.forw = cpu_to_be32(oldblk->blkno);
xfs_trans_log_buf(state->args->trans, bp,
XFS_DA_LOGRANGE(node, &node->hdr.info,
sizeof(node->hdr.info)));
}
addblk->bp = NULL;
return(0);
}
/*
* Split the root. We have to create a new root and point to the two
* parts (the split old root) that we just created. Copy block zero to
* the EOF, extending the inode in process.
*/
STATIC int /* error */
xfs_da_root_split(xfs_da_state_t *state, xfs_da_state_blk_t *blk1,
xfs_da_state_blk_t *blk2)
{
xfs_da_intnode_t *node, *oldroot;
xfs_da_args_t *args;
xfs_dablk_t blkno;
struct xfs_buf *bp;
int error, size;
xfs_inode_t *dp;
xfs_trans_t *tp;
xfs_mount_t *mp;
xfs_dir2_leaf_t *leaf;
trace_xfs_da_root_split(state->args);
/*
* Copy the existing (incorrect) block from the root node position
* to a free space somewhere.
*/
args = state->args;
ASSERT(args != NULL);
error = xfs_da_grow_inode(args, &blkno);
if (error)
return(error);
dp = args->dp;
tp = args->trans;
mp = state->mp;
error = xfs_da_get_buf(tp, dp, blkno, -1, &bp, args->whichfork);
if (error)
return(error);
ASSERT(bp != NULL);
node = bp->b_addr;
oldroot = blk1->bp->b_addr;
if (oldroot->hdr.info.magic == cpu_to_be16(XFS_DA_NODE_MAGIC)) {
size = (int)((char *)&oldroot->btree[be16_to_cpu(oldroot->hdr.count)] -
(char *)oldroot);
} else {
ASSERT(oldroot->hdr.info.magic == cpu_to_be16(XFS_DIR2_LEAFN_MAGIC));
leaf = (xfs_dir2_leaf_t *)oldroot;
size = (int)((char *)&leaf->ents[be16_to_cpu(leaf->hdr.count)] -
(char *)leaf);
}
memcpy(node, oldroot, size);
xfs_trans_log_buf(tp, bp, 0, size - 1);
blk1->bp = bp;
blk1->blkno = blkno;
/*
* Set up the new root node.
*/
error = xfs_da_node_create(args,
(args->whichfork == XFS_DATA_FORK) ? mp->m_dirleafblk : 0,
be16_to_cpu(node->hdr.level) + 1, &bp, args->whichfork);
if (error)
return(error);
node = bp->b_addr;
node->btree[0].hashval = cpu_to_be32(blk1->hashval);
node->btree[0].before = cpu_to_be32(blk1->blkno);
node->btree[1].hashval = cpu_to_be32(blk2->hashval);
node->btree[1].before = cpu_to_be32(blk2->blkno);
node->hdr.count = cpu_to_be16(2);
#ifdef DEBUG
if (oldroot->hdr.info.magic == cpu_to_be16(XFS_DIR2_LEAFN_MAGIC)) {
ASSERT(blk1->blkno >= mp->m_dirleafblk &&
blk1->blkno < mp->m_dirfreeblk);
ASSERT(blk2->blkno >= mp->m_dirleafblk &&
blk2->blkno < mp->m_dirfreeblk);
}
#endif
/* Header is already logged by xfs_da_node_create */
xfs_trans_log_buf(tp, bp,
XFS_DA_LOGRANGE(node, node->btree,
sizeof(xfs_da_node_entry_t) * 2));
return(0);
}
/*
* Split the node, rebalance, then add the new entry.
*/
STATIC int /* error */
xfs_da_node_split(xfs_da_state_t *state, xfs_da_state_blk_t *oldblk,
xfs_da_state_blk_t *newblk,
xfs_da_state_blk_t *addblk,
int treelevel, int *result)
{
xfs_da_intnode_t *node;
xfs_dablk_t blkno;
int newcount, error;
int useextra;
trace_xfs_da_node_split(state->args);
node = oldblk->bp->b_addr;
ASSERT(node->hdr.info.magic == cpu_to_be16(XFS_DA_NODE_MAGIC));
/*
* With V2 dirs the extra block is data or freespace.
*/
useextra = state->extravalid && state->args->whichfork == XFS_ATTR_FORK;
newcount = 1 + useextra;
/*
* Do we have to split the node?
*/
if ((be16_to_cpu(node->hdr.count) + newcount) > state->node_ents) {
/*
* Allocate a new node, add to the doubly linked chain of
* nodes, then move some of our excess entries into it.
*/
error = xfs_da_grow_inode(state->args, &blkno);
if (error)
return(error); /* GROT: dir is inconsistent */
error = xfs_da_node_create(state->args, blkno, treelevel,
&newblk->bp, state->args->whichfork);
if (error)
return(error); /* GROT: dir is inconsistent */
newblk->blkno = blkno;
newblk->magic = XFS_DA_NODE_MAGIC;
xfs_da_node_rebalance(state, oldblk, newblk);
error = xfs_da_blk_link(state, oldblk, newblk);
if (error)
return(error);
*result = 1;
} else {
*result = 0;
}
/*
* Insert the new entry(s) into the correct block
* (updating last hashval in the process).
*
* xfs_da_node_add() inserts BEFORE the given index,
* and as a result of using node_lookup_int() we always
* point to a valid entry (not after one), but a split
* operation always results in a new block whose hashvals
* FOLLOW the current block.
*
* If we had double-split op below us, then add the extra block too.
*/
node = oldblk->bp->b_addr;
if (oldblk->index <= be16_to_cpu(node->hdr.count)) {
oldblk->index++;
xfs_da_node_add(state, oldblk, addblk);
if (useextra) {
if (state->extraafter)
oldblk->index++;
xfs_da_node_add(state, oldblk, &state->extrablk);
state->extravalid = 0;
}
} else {
newblk->index++;
xfs_da_node_add(state, newblk, addblk);
if (useextra) {
if (state->extraafter)
newblk->index++;
xfs_da_node_add(state, newblk, &state->extrablk);
state->extravalid = 0;
}
}
return(0);
}
/*
* Balance the btree elements between two intermediate nodes,
* usually one full and one empty.
*
* NOTE: if blk2 is empty, then it will get the upper half of blk1.
*/
STATIC void
xfs_da_node_rebalance(xfs_da_state_t *state, xfs_da_state_blk_t *blk1,
xfs_da_state_blk_t *blk2)
{
xfs_da_intnode_t *node1, *node2, *tmpnode;
xfs_da_node_entry_t *btree_s, *btree_d;
int count, tmp;
xfs_trans_t *tp;
trace_xfs_da_node_rebalance(state->args);
node1 = blk1->bp->b_addr;
node2 = blk2->bp->b_addr;
/*
* Figure out how many entries need to move, and in which direction.
* Swap the nodes around if that makes it simpler.
*/
if ((be16_to_cpu(node1->hdr.count) > 0) && (be16_to_cpu(node2->hdr.count) > 0) &&
((be32_to_cpu(node2->btree[0].hashval) < be32_to_cpu(node1->btree[0].hashval)) ||
(be32_to_cpu(node2->btree[be16_to_cpu(node2->hdr.count)-1].hashval) <
be32_to_cpu(node1->btree[be16_to_cpu(node1->hdr.count)-1].hashval)))) {
tmpnode = node1;
node1 = node2;
node2 = tmpnode;
}
ASSERT(node1->hdr.info.magic == cpu_to_be16(XFS_DA_NODE_MAGIC));
ASSERT(node2->hdr.info.magic == cpu_to_be16(XFS_DA_NODE_MAGIC));
count = (be16_to_cpu(node1->hdr.count) - be16_to_cpu(node2->hdr.count)) / 2;
if (count == 0)
return;
tp = state->args->trans;
/*
* Two cases: high-to-low and low-to-high.
*/
if (count > 0) {
/*
* Move elements in node2 up to make a hole.
*/
if ((tmp = be16_to_cpu(node2->hdr.count)) > 0) {
tmp *= (uint)sizeof(xfs_da_node_entry_t);
btree_s = &node2->btree[0];
btree_d = &node2->btree[count];
memmove(btree_d, btree_s, tmp);
}
/*
* Move the req'd B-tree elements from high in node1 to
* low in node2.
*/
be16_add_cpu(&node2->hdr.count, count);
tmp = count * (uint)sizeof(xfs_da_node_entry_t);
btree_s = &node1->btree[be16_to_cpu(node1->hdr.count) - count];
btree_d = &node2->btree[0];
memcpy(btree_d, btree_s, tmp);
be16_add_cpu(&node1->hdr.count, -count);
} else {
/*
* Move the req'd B-tree elements from low in node2 to
* high in node1.
*/
count = -count;
tmp = count * (uint)sizeof(xfs_da_node_entry_t);
btree_s = &node2->btree[0];
btree_d = &node1->btree[be16_to_cpu(node1->hdr.count)];
memcpy(btree_d, btree_s, tmp);
be16_add_cpu(&node1->hdr.count, count);
xfs_trans_log_buf(tp, blk1->bp,
XFS_DA_LOGRANGE(node1, btree_d, tmp));
/*
* Move elements in node2 down to fill the hole.
*/
tmp = be16_to_cpu(node2->hdr.count) - count;
tmp *= (uint)sizeof(xfs_da_node_entry_t);
btree_s = &node2->btree[count];
btree_d = &node2->btree[0];
memmove(btree_d, btree_s, tmp);
be16_add_cpu(&node2->hdr.count, -count);
}
/*
* Log header of node 1 and all current bits of node 2.
*/
xfs_trans_log_buf(tp, blk1->bp,
XFS_DA_LOGRANGE(node1, &node1->hdr, sizeof(node1->hdr)));
xfs_trans_log_buf(tp, blk2->bp,
XFS_DA_LOGRANGE(node2, &node2->hdr,
sizeof(node2->hdr) +
sizeof(node2->btree[0]) * be16_to_cpu(node2->hdr.count)));
/*
* Record the last hashval from each block for upward propagation.
* (note: don't use the swapped node pointers)
*/
node1 = blk1->bp->b_addr;
node2 = blk2->bp->b_addr;
blk1->hashval = be32_to_cpu(node1->btree[be16_to_cpu(node1->hdr.count)-1].hashval);
blk2->hashval = be32_to_cpu(node2->btree[be16_to_cpu(node2->hdr.count)-1].hashval);
/*
* Adjust the expected index for insertion.
*/
if (blk1->index >= be16_to_cpu(node1->hdr.count)) {
blk2->index = blk1->index - be16_to_cpu(node1->hdr.count);
blk1->index = be16_to_cpu(node1->hdr.count) + 1; /* make it invalid */
}
}
/*
* Add a new entry to an intermediate node.
*/
STATIC void
xfs_da_node_add(xfs_da_state_t *state, xfs_da_state_blk_t *oldblk,
xfs_da_state_blk_t *newblk)
{
xfs_da_intnode_t *node;
xfs_da_node_entry_t *btree;
int tmp;
trace_xfs_da_node_add(state->args);
node = oldblk->bp->b_addr;
ASSERT(node->hdr.info.magic == cpu_to_be16(XFS_DA_NODE_MAGIC));
ASSERT((oldblk->index >= 0) && (oldblk->index <= be16_to_cpu(node->hdr.count)));
ASSERT(newblk->blkno != 0);
if (state->args->whichfork == XFS_DATA_FORK)
ASSERT(newblk->blkno >= state->mp->m_dirleafblk &&
newblk->blkno < state->mp->m_dirfreeblk);
/*
* We may need to make some room before we insert the new node.
*/
tmp = 0;
btree = &node->btree[ oldblk->index ];
if (oldblk->index < be16_to_cpu(node->hdr.count)) {
tmp = (be16_to_cpu(node->hdr.count) - oldblk->index) * (uint)sizeof(*btree);
memmove(btree + 1, btree, tmp);
}
btree->hashval = cpu_to_be32(newblk->hashval);
btree->before = cpu_to_be32(newblk->blkno);
xfs_trans_log_buf(state->args->trans, oldblk->bp,
XFS_DA_LOGRANGE(node, btree, tmp + sizeof(*btree)));
be16_add_cpu(&node->hdr.count, 1);
xfs_trans_log_buf(state->args->trans, oldblk->bp,
XFS_DA_LOGRANGE(node, &node->hdr, sizeof(node->hdr)));
/*
* Copy the last hash value from the oldblk to propagate upwards.
*/
oldblk->hashval = be32_to_cpu(node->btree[be16_to_cpu(node->hdr.count)-1 ].hashval);
}
/*========================================================================
* Routines used for shrinking the Btree.
*========================================================================*/
/*
* Deallocate an empty leaf node, remove it from its parent,
* possibly deallocating that block, etc...
*/
int
xfs_da_join(xfs_da_state_t *state)
{
xfs_da_state_blk_t *drop_blk, *save_blk;
int action, error;
trace_xfs_da_join(state->args);
action = 0;
drop_blk = &state->path.blk[ state->path.active-1 ];
save_blk = &state->altpath.blk[ state->path.active-1 ];
ASSERT(state->path.blk[0].magic == XFS_DA_NODE_MAGIC);
ASSERT(drop_blk->magic == XFS_ATTR_LEAF_MAGIC ||
drop_blk->magic == XFS_DIR2_LEAFN_MAGIC);
/*
* Walk back up the tree joining/deallocating as necessary.
* When we stop dropping blocks, break out.
*/
for ( ; state->path.active >= 2; drop_blk--, save_blk--,
state->path.active--) {
/*
* See if we can combine the block with a neighbor.
* (action == 0) => no options, just leave
* (action == 1) => coalesce, then unlink
* (action == 2) => block empty, unlink it
*/
switch (drop_blk->magic) {
case XFS_ATTR_LEAF_MAGIC:
error = xfs_attr_leaf_toosmall(state, &action);
if (error)
return(error);
if (action == 0)
return(0);
xfs_attr_leaf_unbalance(state, drop_blk, save_blk);
break;
case XFS_DIR2_LEAFN_MAGIC:
error = xfs_dir2_leafn_toosmall(state, &action);
if (error)
return error;
if (action == 0)
return 0;
xfs_dir2_leafn_unbalance(state, drop_blk, save_blk);
break;
case XFS_DA_NODE_MAGIC:
/*
* Remove the offending node, fixup hashvals,
* check for a toosmall neighbor.
*/
xfs_da_node_remove(state, drop_blk);
xfs_da_fixhashpath(state, &state->path);
error = xfs_da_node_toosmall(state, &action);
if (error)
return(error);
if (action == 0)
return 0;
xfs_da_node_unbalance(state, drop_blk, save_blk);
break;
}
xfs_da_fixhashpath(state, &state->altpath);
error = xfs_da_blk_unlink(state, drop_blk, save_blk);
xfs_da_state_kill_altpath(state);
if (error)
return(error);
error = xfs_da_shrink_inode(state->args, drop_blk->blkno,
drop_blk->bp);
drop_blk->bp = NULL;
if (error)
return(error);
}
/*
* We joined all the way to the top. If it turns out that
* we only have one entry in the root, make the child block
* the new root.
*/
xfs_da_node_remove(state, drop_blk);
xfs_da_fixhashpath(state, &state->path);
error = xfs_da_root_join(state, &state->path.blk[0]);
return(error);
}
#ifdef DEBUG
static void
xfs_da_blkinfo_onlychild_validate(struct xfs_da_blkinfo *blkinfo, __u16 level)
{
__be16 magic = blkinfo->magic;
if (level == 1) {
ASSERT(magic == cpu_to_be16(XFS_DIR2_LEAFN_MAGIC) ||
magic == cpu_to_be16(XFS_ATTR_LEAF_MAGIC));
} else
ASSERT(magic == cpu_to_be16(XFS_DA_NODE_MAGIC));
ASSERT(!blkinfo->forw);
ASSERT(!blkinfo->back);
}
#else /* !DEBUG */
#define xfs_da_blkinfo_onlychild_validate(blkinfo, level)
#endif /* !DEBUG */
/*
* We have only one entry in the root. Copy the only remaining child of
* the old root to block 0 as the new root node.
*/
STATIC int
xfs_da_root_join(xfs_da_state_t *state, xfs_da_state_blk_t *root_blk)
{
xfs_da_intnode_t *oldroot;
xfs_da_args_t *args;
xfs_dablk_t child;
struct xfs_buf *bp;
int error;
trace_xfs_da_root_join(state->args);
args = state->args;
ASSERT(args != NULL);
ASSERT(root_blk->magic == XFS_DA_NODE_MAGIC);
oldroot = root_blk->bp->b_addr;
ASSERT(oldroot->hdr.info.magic == cpu_to_be16(XFS_DA_NODE_MAGIC));
ASSERT(!oldroot->hdr.info.forw);
ASSERT(!oldroot->hdr.info.back);
/*
* If the root has more than one child, then don't do anything.
*/
if (be16_to_cpu(oldroot->hdr.count) > 1)
return(0);
/*
* Read in the (only) child block, then copy those bytes into
* the root block's buffer and free the original child block.
*/
child = be32_to_cpu(oldroot->btree[0].before);
ASSERT(child != 0);
error = xfs_da_read_buf(args->trans, args->dp, child, -1, &bp,
args->whichfork);
if (error)
return(error);
ASSERT(bp != NULL);
xfs_da_blkinfo_onlychild_validate(bp->b_addr,
be16_to_cpu(oldroot->hdr.level));
memcpy(root_blk->bp->b_addr, bp->b_addr, state->blocksize);
xfs_trans_log_buf(args->trans, root_blk->bp, 0, state->blocksize - 1);
error = xfs_da_shrink_inode(args, child, bp);
return(error);
}
/*
* Check a node block and its neighbors to see if the block should be
* collapsed into one or the other neighbor. Always keep the block
* with the smaller block number.
* If the current block is over 50% full, don't try to join it, return 0.
* If the block is empty, fill in the state structure and return 2.
* If it can be collapsed, fill in the state structure and return 1.
* If nothing can be done, return 0.
*/
STATIC int
xfs_da_node_toosmall(xfs_da_state_t *state, int *action)
{
xfs_da_intnode_t *node;
xfs_da_state_blk_t *blk;
xfs_da_blkinfo_t *info;
int count, forward, error, retval, i;
xfs_dablk_t blkno;
struct xfs_buf *bp;
/*
* Check for the degenerate case of the block being over 50% full.
* If so, it's not worth even looking to see if we might be able
* to coalesce with a sibling.
*/
blk = &state->path.blk[ state->path.active-1 ];
info = blk->bp->b_addr;
ASSERT(info->magic == cpu_to_be16(XFS_DA_NODE_MAGIC));
node = (xfs_da_intnode_t *)info;
count = be16_to_cpu(node->hdr.count);
if (count > (state->node_ents >> 1)) {
*action = 0; /* blk over 50%, don't try to join */
return(0); /* blk over 50%, don't try to join */
}
/*
* Check for the degenerate case of the block being empty.
* If the block is empty, we'll simply delete it, no need to
* coalesce it with a sibling block. We choose (arbitrarily)
* to merge with the forward block unless it is NULL.
*/
if (count == 0) {
/*
* Make altpath point to the block we want to keep and
* path point to the block we want to drop (this one).
*/
forward = (info->forw != 0);
memcpy(&state->altpath, &state->path, sizeof(state->path));
error = xfs_da_path_shift(state, &state->altpath, forward,
0, &retval);
if (error)
return(error);
if (retval) {
*action = 0;
} else {
*action = 2;
}
return(0);
}
/*
* Examine each sibling block to see if we can coalesce with
* at least 25% free space to spare. We need to figure out
* whether to merge with the forward or the backward block.
* We prefer coalescing with the lower numbered sibling so as
* to shrink a directory over time.
*/
/* start with smaller blk num */
forward = (be32_to_cpu(info->forw) < be32_to_cpu(info->back));
for (i = 0; i < 2; forward = !forward, i++) {
if (forward)
blkno = be32_to_cpu(info->forw);
else
blkno = be32_to_cpu(info->back);
if (blkno == 0)
continue;
error = xfs_da_read_buf(state->args->trans, state->args->dp,
blkno, -1, &bp, state->args->whichfork);
if (error)
return(error);
ASSERT(bp != NULL);
node = (xfs_da_intnode_t *)info;
count = state->node_ents;
count -= state->node_ents >> 2;
count -= be16_to_cpu(node->hdr.count);
node = bp->b_addr;
ASSERT(node->hdr.info.magic == cpu_to_be16(XFS_DA_NODE_MAGIC));
count -= be16_to_cpu(node->hdr.count);
xfs_trans_brelse(state->args->trans, bp);
if (count >= 0)
break; /* fits with at least 25% to spare */
}
if (i >= 2) {
*action = 0;
return(0);
}
/*
* Make altpath point to the block we want to keep (the lower
* numbered block) and path point to the block we want to drop.
*/
memcpy(&state->altpath, &state->path, sizeof(state->path));
if (blkno < blk->blkno) {
error = xfs_da_path_shift(state, &state->altpath, forward,
0, &retval);
if (error) {
return(error);
}
if (retval) {
*action = 0;
return(0);
}
} else {
error = xfs_da_path_shift(state, &state->path, forward,
0, &retval);
if (error) {
return(error);
}
if (retval) {
*action = 0;
return(0);
}
}
*action = 1;
return(0);
}
/*
* Walk back up the tree adjusting hash values as necessary,
* when we stop making changes, return.
*/
void
xfs_da_fixhashpath(xfs_da_state_t *state, xfs_da_state_path_t *path)
{
xfs_da_state_blk_t *blk;
xfs_da_intnode_t *node;
xfs_da_node_entry_t *btree;
xfs_dahash_t lasthash=0;
int level, count;
level = path->active-1;
blk = &path->blk[ level ];
switch (blk->magic) {
case XFS_ATTR_LEAF_MAGIC:
lasthash = xfs_attr_leaf_lasthash(blk->bp, &count);
if (count == 0)
return;
break;
case XFS_DIR2_LEAFN_MAGIC:
lasthash = xfs_dir2_leafn_lasthash(blk->bp, &count);
if (count == 0)
return;
break;
case XFS_DA_NODE_MAGIC:
lasthash = xfs_da_node_lasthash(blk->bp, &count);
if (count == 0)
return;
break;
}
for (blk--, level--; level >= 0; blk--, level--) {
node = blk->bp->b_addr;
ASSERT(node->hdr.info.magic == cpu_to_be16(XFS_DA_NODE_MAGIC));
btree = &node->btree[ blk->index ];
if (be32_to_cpu(btree->hashval) == lasthash)
break;
blk->hashval = lasthash;
btree->hashval = cpu_to_be32(lasthash);
xfs_trans_log_buf(state->args->trans, blk->bp,
XFS_DA_LOGRANGE(node, btree, sizeof(*btree)));
lasthash = be32_to_cpu(node->btree[be16_to_cpu(node->hdr.count)-1].hashval);
}
}
/*
* Remove an entry from an intermediate node.
*/
STATIC void
xfs_da_node_remove(xfs_da_state_t *state, xfs_da_state_blk_t *drop_blk)
{
xfs_da_intnode_t *node;
xfs_da_node_entry_t *btree;
int tmp;
trace_xfs_da_node_remove(state->args);
node = drop_blk->bp->b_addr;
ASSERT(drop_blk->index < be16_to_cpu(node->hdr.count));
ASSERT(drop_blk->index >= 0);
/*
* Copy over the offending entry, or just zero it out.
*/
btree = &node->btree[drop_blk->index];
if (drop_blk->index < (be16_to_cpu(node->hdr.count)-1)) {
tmp = be16_to_cpu(node->hdr.count) - drop_blk->index - 1;
tmp *= (uint)sizeof(xfs_da_node_entry_t);
memmove(btree, btree + 1, tmp);
xfs_trans_log_buf(state->args->trans, drop_blk->bp,
XFS_DA_LOGRANGE(node, btree, tmp));
btree = &node->btree[be16_to_cpu(node->hdr.count)-1];
}
memset((char *)btree, 0, sizeof(xfs_da_node_entry_t));
xfs_trans_log_buf(state->args->trans, drop_blk->bp,
XFS_DA_LOGRANGE(node, btree, sizeof(*btree)));
be16_add_cpu(&node->hdr.count, -1);
xfs_trans_log_buf(state->args->trans, drop_blk->bp,
XFS_DA_LOGRANGE(node, &node->hdr, sizeof(node->hdr)));
/*
* Copy the last hash value from the block to propagate upwards.
*/
btree--;
drop_blk->hashval = be32_to_cpu(btree->hashval);
}
/*
* Unbalance the btree elements between two intermediate nodes,
* move all Btree elements from one node into another.
*/
STATIC void
xfs_da_node_unbalance(xfs_da_state_t *state, xfs_da_state_blk_t *drop_blk,
xfs_da_state_blk_t *save_blk)
{
xfs_da_intnode_t *drop_node, *save_node;
xfs_da_node_entry_t *btree;
int tmp;
xfs_trans_t *tp;
trace_xfs_da_node_unbalance(state->args);
drop_node = drop_blk->bp->b_addr;
save_node = save_blk->bp->b_addr;
ASSERT(drop_node->hdr.info.magic == cpu_to_be16(XFS_DA_NODE_MAGIC));
ASSERT(save_node->hdr.info.magic == cpu_to_be16(XFS_DA_NODE_MAGIC));
tp = state->args->trans;
/*
* If the dying block has lower hashvals, then move all the
* elements in the remaining block up to make a hole.
*/
if ((be32_to_cpu(drop_node->btree[0].hashval) < be32_to_cpu(save_node->btree[ 0 ].hashval)) ||
(be32_to_cpu(drop_node->btree[be16_to_cpu(drop_node->hdr.count)-1].hashval) <
be32_to_cpu(save_node->btree[be16_to_cpu(save_node->hdr.count)-1].hashval)))
{
btree = &save_node->btree[be16_to_cpu(drop_node->hdr.count)];
tmp = be16_to_cpu(save_node->hdr.count) * (uint)sizeof(xfs_da_node_entry_t);
memmove(btree, &save_node->btree[0], tmp);
btree = &save_node->btree[0];
xfs_trans_log_buf(tp, save_blk->bp,
XFS_DA_LOGRANGE(save_node, btree,
(be16_to_cpu(save_node->hdr.count) + be16_to_cpu(drop_node->hdr.count)) *
sizeof(xfs_da_node_entry_t)));
} else {
btree = &save_node->btree[be16_to_cpu(save_node->hdr.count)];
xfs_trans_log_buf(tp, save_blk->bp,
XFS_DA_LOGRANGE(save_node, btree,
be16_to_cpu(drop_node->hdr.count) *
sizeof(xfs_da_node_entry_t)));
}
/*
* Move all the B-tree elements from drop_blk to save_blk.
*/
tmp = be16_to_cpu(drop_node->hdr.count) * (uint)sizeof(xfs_da_node_entry_t);
memcpy(btree, &drop_node->btree[0], tmp);
be16_add_cpu(&save_node->hdr.count, be16_to_cpu(drop_node->hdr.count));
xfs_trans_log_buf(tp, save_blk->bp,
XFS_DA_LOGRANGE(save_node, &save_node->hdr,
sizeof(save_node->hdr)));
/*
* Save the last hashval in the remaining block for upward propagation.
*/
save_blk->hashval = be32_to_cpu(save_node->btree[be16_to_cpu(save_node->hdr.count)-1].hashval);
}
/*========================================================================
* Routines used for finding things in the Btree.
*========================================================================*/
/*
* Walk down the Btree looking for a particular filename, filling
* in the state structure as we go.
*
* We will set the state structure to point to each of the elements
* in each of the nodes where either the hashval is or should be.
*
* We support duplicate hashval's so for each entry in the current
* node that could contain the desired hashval, descend. This is a
* pruned depth-first tree search.
*/
int /* error */
xfs_da_node_lookup_int(xfs_da_state_t *state, int *result)
{
xfs_da_state_blk_t *blk;
xfs_da_blkinfo_t *curr;
xfs_da_intnode_t *node;
xfs_da_node_entry_t *btree;
xfs_dablk_t blkno;
int probe, span, max, error, retval;
xfs_dahash_t hashval, btreehashval;
xfs_da_args_t *args;
args = state->args;
/*
* Descend thru the B-tree searching each level for the right
* node to use, until the right hashval is found.
*/
blkno = (args->whichfork == XFS_DATA_FORK)? state->mp->m_dirleafblk : 0;
for (blk = &state->path.blk[0], state->path.active = 1;
state->path.active <= XFS_DA_NODE_MAXDEPTH;
blk++, state->path.active++) {
/*
* Read the next node down in the tree.
*/
blk->blkno = blkno;
error = xfs_da_read_buf(args->trans, args->dp, blkno,
-1, &blk->bp, args->whichfork);
if (error) {
blk->blkno = 0;
state->path.active--;
return(error);
}
curr = blk->bp->b_addr;
blk->magic = be16_to_cpu(curr->magic);
ASSERT(blk->magic == XFS_DA_NODE_MAGIC ||
blk->magic == XFS_DIR2_LEAFN_MAGIC ||
blk->magic == XFS_ATTR_LEAF_MAGIC);
/*
* Search an intermediate node for a match.
*/
if (blk->magic == XFS_DA_NODE_MAGIC) {
node = blk->bp->b_addr;
max = be16_to_cpu(node->hdr.count);
blk->hashval = be32_to_cpu(node->btree[max-1].hashval);
/*
* Binary search. (note: small blocks will skip loop)
*/
probe = span = max / 2;
hashval = args->hashval;
for (btree = &node->btree[probe]; span > 4;
btree = &node->btree[probe]) {
span /= 2;
btreehashval = be32_to_cpu(btree->hashval);
if (btreehashval < hashval)
probe += span;
else if (btreehashval > hashval)
probe -= span;
else
break;
}
ASSERT((probe >= 0) && (probe < max));
ASSERT((span <= 4) || (be32_to_cpu(btree->hashval) == hashval));
/*
* Since we may have duplicate hashval's, find the first
* matching hashval in the node.
*/
while ((probe > 0) && (be32_to_cpu(btree->hashval) >= hashval)) {
btree--;
probe--;
}
while ((probe < max) && (be32_to_cpu(btree->hashval) < hashval)) {
btree++;
probe++;
}
/*
* Pick the right block to descend on.
*/
if (probe == max) {
blk->index = max-1;
blkno = be32_to_cpu(node->btree[max-1].before);
} else {
blk->index = probe;
blkno = be32_to_cpu(btree->before);
}
} else if (blk->magic == XFS_ATTR_LEAF_MAGIC) {
blk->hashval = xfs_attr_leaf_lasthash(blk->bp, NULL);
break;
} else if (blk->magic == XFS_DIR2_LEAFN_MAGIC) {
blk->hashval = xfs_dir2_leafn_lasthash(blk->bp, NULL);
break;
}
}
/*
* A leaf block that ends in the hashval that we are interested in
* (final hashval == search hashval) means that the next block may
* contain more entries with the same hashval, shift upward to the
* next leaf and keep searching.
*/
for (;;) {
if (blk->magic == XFS_DIR2_LEAFN_MAGIC) {
retval = xfs_dir2_leafn_lookup_int(blk->bp, args,
&blk->index, state);
} else if (blk->magic == XFS_ATTR_LEAF_MAGIC) {
retval = xfs_attr_leaf_lookup_int(blk->bp, args);
blk->index = args->index;
args->blkno = blk->blkno;
} else {
ASSERT(0);
return XFS_ERROR(EFSCORRUPTED);
}
if (((retval == ENOENT) || (retval == ENOATTR)) &&
(blk->hashval == args->hashval)) {
error = xfs_da_path_shift(state, &state->path, 1, 1,
&retval);
if (error)
return(error);
if (retval == 0) {
continue;
} else if (blk->magic == XFS_ATTR_LEAF_MAGIC) {
/* path_shift() gives ENOENT */
retval = XFS_ERROR(ENOATTR);
}
}
break;
}
*result = retval;
return(0);
}
/*========================================================================
* Utility routines.
*========================================================================*/
/*
* Link a new block into a doubly linked list of blocks (of whatever type).
*/
int /* error */
xfs_da_blk_link(xfs_da_state_t *state, xfs_da_state_blk_t *old_blk,
xfs_da_state_blk_t *new_blk)
{
xfs_da_blkinfo_t *old_info, *new_info, *tmp_info;
xfs_da_args_t *args;
int before=0, error;
struct xfs_buf *bp;
/*
* Set up environment.
*/
args = state->args;
ASSERT(args != NULL);
old_info = old_blk->bp->b_addr;
new_info = new_blk->bp->b_addr;
ASSERT(old_blk->magic == XFS_DA_NODE_MAGIC ||
old_blk->magic == XFS_DIR2_LEAFN_MAGIC ||
old_blk->magic == XFS_ATTR_LEAF_MAGIC);
ASSERT(old_blk->magic == be16_to_cpu(old_info->magic));
ASSERT(new_blk->magic == be16_to_cpu(new_info->magic));
ASSERT(old_blk->magic == new_blk->magic);
switch (old_blk->magic) {
case XFS_ATTR_LEAF_MAGIC:
before = xfs_attr_leaf_order(old_blk->bp, new_blk->bp);
break;
case XFS_DIR2_LEAFN_MAGIC:
before = xfs_dir2_leafn_order(old_blk->bp, new_blk->bp);
break;
case XFS_DA_NODE_MAGIC:
before = xfs_da_node_order(old_blk->bp, new_blk->bp);
break;
}
/*
* Link blocks in appropriate order.
*/
if (before) {
/*
* Link new block in before existing block.
*/
trace_xfs_da_link_before(args);
new_info->forw = cpu_to_be32(old_blk->blkno);
new_info->back = old_info->back;
if (old_info->back) {
error = xfs_da_read_buf(args->trans, args->dp,
be32_to_cpu(old_info->back),
-1, &bp, args->whichfork);
if (error)
return(error);
ASSERT(bp != NULL);
tmp_info = bp->b_addr;
ASSERT(be16_to_cpu(tmp_info->magic) == be16_to_cpu(old_info->magic));
ASSERT(be32_to_cpu(tmp_info->forw) == old_blk->blkno);
tmp_info->forw = cpu_to_be32(new_blk->blkno);
xfs_trans_log_buf(args->trans, bp, 0, sizeof(*tmp_info)-1);
}
old_info->back = cpu_to_be32(new_blk->blkno);
} else {
/*
* Link new block in after existing block.
*/
trace_xfs_da_link_after(args);
new_info->forw = old_info->forw;
new_info->back = cpu_to_be32(old_blk->blkno);
if (old_info->forw) {
error = xfs_da_read_buf(args->trans, args->dp,
be32_to_cpu(old_info->forw),
-1, &bp, args->whichfork);
if (error)
return(error);
ASSERT(bp != NULL);
tmp_info = bp->b_addr;
ASSERT(tmp_info->magic == old_info->magic);
ASSERT(be32_to_cpu(tmp_info->back) == old_blk->blkno);
tmp_info->back = cpu_to_be32(new_blk->blkno);
xfs_trans_log_buf(args->trans, bp, 0, sizeof(*tmp_info)-1);
}
old_info->forw = cpu_to_be32(new_blk->blkno);
}
xfs_trans_log_buf(args->trans, old_blk->bp, 0, sizeof(*tmp_info) - 1);
xfs_trans_log_buf(args->trans, new_blk->bp, 0, sizeof(*tmp_info) - 1);
return(0);
}
/*
* Compare two intermediate nodes for "order".
*/
STATIC int
xfs_da_node_order(
struct xfs_buf *node1_bp,
struct xfs_buf *node2_bp)
{
xfs_da_intnode_t *node1, *node2;
node1 = node1_bp->b_addr;
node2 = node2_bp->b_addr;
ASSERT(node1->hdr.info.magic == cpu_to_be16(XFS_DA_NODE_MAGIC) &&
node2->hdr.info.magic == cpu_to_be16(XFS_DA_NODE_MAGIC));
if ((be16_to_cpu(node1->hdr.count) > 0) && (be16_to_cpu(node2->hdr.count) > 0) &&
((be32_to_cpu(node2->btree[0].hashval) <
be32_to_cpu(node1->btree[0].hashval)) ||
(be32_to_cpu(node2->btree[be16_to_cpu(node2->hdr.count)-1].hashval) <
be32_to_cpu(node1->btree[be16_to_cpu(node1->hdr.count)-1].hashval)))) {
return(1);
}
return(0);
}
/*
* Pick up the last hashvalue from an intermediate node.
*/
STATIC uint
xfs_da_node_lasthash(
struct xfs_buf *bp,
int *count)
{
xfs_da_intnode_t *node;
node = bp->b_addr;
ASSERT(node->hdr.info.magic == cpu_to_be16(XFS_DA_NODE_MAGIC));
if (count)
*count = be16_to_cpu(node->hdr.count);
if (!node->hdr.count)
return(0);
return be32_to_cpu(node->btree[be16_to_cpu(node->hdr.count)-1].hashval);
}
/*
* Unlink a block from a doubly linked list of blocks.
*/
STATIC int /* error */
xfs_da_blk_unlink(xfs_da_state_t *state, xfs_da_state_blk_t *drop_blk,
xfs_da_state_blk_t *save_blk)
{
xfs_da_blkinfo_t *drop_info, *save_info, *tmp_info;
xfs_da_args_t *args;
struct xfs_buf *bp;
int error;
/*
* Set up environment.
*/
args = state->args;
ASSERT(args != NULL);
save_info = save_blk->bp->b_addr;
drop_info = drop_blk->bp->b_addr;
ASSERT(save_blk->magic == XFS_DA_NODE_MAGIC ||
save_blk->magic == XFS_DIR2_LEAFN_MAGIC ||
save_blk->magic == XFS_ATTR_LEAF_MAGIC);
ASSERT(save_blk->magic == be16_to_cpu(save_info->magic));
ASSERT(drop_blk->magic == be16_to_cpu(drop_info->magic));
ASSERT(save_blk->magic == drop_blk->magic);
ASSERT((be32_to_cpu(save_info->forw) == drop_blk->blkno) ||
(be32_to_cpu(save_info->back) == drop_blk->blkno));
ASSERT((be32_to_cpu(drop_info->forw) == save_blk->blkno) ||
(be32_to_cpu(drop_info->back) == save_blk->blkno));
/*
* Unlink the leaf block from the doubly linked chain of leaves.
*/
if (be32_to_cpu(save_info->back) == drop_blk->blkno) {
trace_xfs_da_unlink_back(args);
save_info->back = drop_info->back;
if (drop_info->back) {
error = xfs_da_read_buf(args->trans, args->dp,
be32_to_cpu(drop_info->back),
-1, &bp, args->whichfork);
if (error)
return(error);
ASSERT(bp != NULL);
tmp_info = bp->b_addr;
ASSERT(tmp_info->magic == save_info->magic);
ASSERT(be32_to_cpu(tmp_info->forw) == drop_blk->blkno);
tmp_info->forw = cpu_to_be32(save_blk->blkno);
xfs_trans_log_buf(args->trans, bp, 0,
sizeof(*tmp_info) - 1);
}
} else {
trace_xfs_da_unlink_forward(args);
save_info->forw = drop_info->forw;
if (drop_info->forw) {
error = xfs_da_read_buf(args->trans, args->dp,
be32_to_cpu(drop_info->forw),
-1, &bp, args->whichfork);
if (error)
return(error);
ASSERT(bp != NULL);
tmp_info = bp->b_addr;
ASSERT(tmp_info->magic == save_info->magic);
ASSERT(be32_to_cpu(tmp_info->back) == drop_blk->blkno);
tmp_info->back = cpu_to_be32(save_blk->blkno);
xfs_trans_log_buf(args->trans, bp, 0,
sizeof(*tmp_info) - 1);
}
}
xfs_trans_log_buf(args->trans, save_blk->bp, 0, sizeof(*save_info) - 1);
return(0);
}
/*
* Move a path "forward" or "!forward" one block at the current level.
*
* This routine will adjust a "path" to point to the next block
* "forward" (higher hashvalues) or "!forward" (lower hashvals) in the
* Btree, including updating pointers to the intermediate nodes between
* the new bottom and the root.
*/
int /* error */
xfs_da_path_shift(xfs_da_state_t *state, xfs_da_state_path_t *path,
int forward, int release, int *result)
{
xfs_da_state_blk_t *blk;
xfs_da_blkinfo_t *info;
xfs_da_intnode_t *node;
xfs_da_args_t *args;
xfs_dablk_t blkno=0;
int level, error;
/*
* Roll up the Btree looking for the first block where our
* current index is not at the edge of the block. Note that
* we skip the bottom layer because we want the sibling block.
*/
args = state->args;
ASSERT(args != NULL);
ASSERT(path != NULL);
ASSERT((path->active > 0) && (path->active < XFS_DA_NODE_MAXDEPTH));
level = (path->active-1) - 1; /* skip bottom layer in path */
for (blk = &path->blk[level]; level >= 0; blk--, level--) {
ASSERT(blk->bp != NULL);
node = blk->bp->b_addr;
ASSERT(node->hdr.info.magic == cpu_to_be16(XFS_DA_NODE_MAGIC));
if (forward && (blk->index < be16_to_cpu(node->hdr.count)-1)) {
blk->index++;
blkno = be32_to_cpu(node->btree[blk->index].before);
break;
} else if (!forward && (blk->index > 0)) {
blk->index--;
blkno = be32_to_cpu(node->btree[blk->index].before);
break;
}
}
if (level < 0) {
*result = XFS_ERROR(ENOENT); /* we're out of our tree */
ASSERT(args->op_flags & XFS_DA_OP_OKNOENT);
return(0);
}
/*
* Roll down the edge of the subtree until we reach the
* same depth we were at originally.
*/
for (blk++, level++; level < path->active; blk++, level++) {
/*
* Release the old block.
* (if it's dirty, trans won't actually let go)
*/
if (release)
xfs_trans_brelse(args->trans, blk->bp);
/*
* Read the next child block.
*/
blk->blkno = blkno;
error = xfs_da_read_buf(args->trans, args->dp, blkno, -1,
&blk->bp, args->whichfork);
if (error)
return(error);
ASSERT(blk->bp != NULL);
info = blk->bp->b_addr;
ASSERT(info->magic == cpu_to_be16(XFS_DA_NODE_MAGIC) ||
info->magic == cpu_to_be16(XFS_DIR2_LEAFN_MAGIC) ||
info->magic == cpu_to_be16(XFS_ATTR_LEAF_MAGIC));
blk->magic = be16_to_cpu(info->magic);
if (blk->magic == XFS_DA_NODE_MAGIC) {
node = (xfs_da_intnode_t *)info;
blk->hashval = be32_to_cpu(node->btree[be16_to_cpu(node->hdr.count)-1].hashval);
if (forward)
blk->index = 0;
else
blk->index = be16_to_cpu(node->hdr.count)-1;
blkno = be32_to_cpu(node->btree[blk->index].before);
} else {
ASSERT(level == path->active-1);
blk->index = 0;
switch(blk->magic) {
case XFS_ATTR_LEAF_MAGIC:
blk->hashval = xfs_attr_leaf_lasthash(blk->bp,
NULL);
break;
case XFS_DIR2_LEAFN_MAGIC:
blk->hashval = xfs_dir2_leafn_lasthash(blk->bp,
NULL);
break;
default:
ASSERT(blk->magic == XFS_ATTR_LEAF_MAGIC ||
blk->magic == XFS_DIR2_LEAFN_MAGIC);
break;
}
}
}
*result = 0;
return(0);
}
/*========================================================================
* Utility routines.
*========================================================================*/
/*
* Implement a simple hash on a character string.
* Rotate the hash value by 7 bits, then XOR each character in.
* This is implemented with some source-level loop unrolling.
*/
xfs_dahash_t
xfs_da_hashname(const __uint8_t *name, int namelen)
{
xfs_dahash_t hash;
/*
* Do four characters at a time as long as we can.
*/
for (hash = 0; namelen >= 4; namelen -= 4, name += 4)
hash = (name[0] << 21) ^ (name[1] << 14) ^ (name[2] << 7) ^
(name[3] << 0) ^ rol32(hash, 7 * 4);
/*
* Now do the rest of the characters.
*/
switch (namelen) {
case 3:
return (name[0] << 14) ^ (name[1] << 7) ^ (name[2] << 0) ^
rol32(hash, 7 * 3);
case 2:
return (name[0] << 7) ^ (name[1] << 0) ^ rol32(hash, 7 * 2);
case 1:
return (name[0] << 0) ^ rol32(hash, 7 * 1);
default: /* case 0: */
return hash;
}
}
enum xfs_dacmp
xfs_da_compname(
struct xfs_da_args *args,
const unsigned char *name,
int len)
{
return (args->namelen == len && memcmp(args->name, name, len) == 0) ?
XFS_CMP_EXACT : XFS_CMP_DIFFERENT;
}
static xfs_dahash_t
xfs_default_hashname(
struct xfs_name *name)
{
return xfs_da_hashname(name->name, name->len);
}
const struct xfs_nameops xfs_default_nameops = {
.hashname = xfs_default_hashname,
.compname = xfs_da_compname
};
int
xfs_da_grow_inode_int(
struct xfs_da_args *args,
xfs_fileoff_t *bno,
int count)
{
struct xfs_trans *tp = args->trans;
struct xfs_inode *dp = args->dp;
int w = args->whichfork;
xfs_drfsbno_t nblks = dp->i_d.di_nblocks;
struct xfs_bmbt_irec map, *mapp;
int nmap, error, got, i, mapi;
/*
* Find a spot in the file space to put the new block.
*/
error = xfs_bmap_first_unused(tp, dp, count, bno, w);
if (error)
return error;
/*
* Try mapping it in one filesystem block.
*/
nmap = 1;
ASSERT(args->firstblock != NULL);
error = xfs_bmapi_write(tp, dp, *bno, count,
xfs_bmapi_aflag(w)|XFS_BMAPI_METADATA|XFS_BMAPI_CONTIG,
args->firstblock, args->total, &map, &nmap,
args->flist);
if (error)
return error;
ASSERT(nmap <= 1);
if (nmap == 1) {
mapp = &map;
mapi = 1;
} else if (nmap == 0 && count > 1) {
xfs_fileoff_t b;
int c;
/*
* If we didn't get it and the block might work if fragmented,
* try without the CONTIG flag. Loop until we get it all.
*/
mapp = kmem_alloc(sizeof(*mapp) * count, KM_SLEEP);
for (b = *bno, mapi = 0; b < *bno + count; ) {
nmap = MIN(XFS_BMAP_MAX_NMAP, count);
c = (int)(*bno + count - b);
error = xfs_bmapi_write(tp, dp, b, c,
xfs_bmapi_aflag(w)|XFS_BMAPI_METADATA,
args->firstblock, args->total,
&mapp[mapi], &nmap, args->flist);
if (error)
goto out_free_map;
if (nmap < 1)
break;
mapi += nmap;
b = mapp[mapi - 1].br_startoff +
mapp[mapi - 1].br_blockcount;
}
} else {
mapi = 0;
mapp = NULL;
}
/*
* Count the blocks we got, make sure it matches the total.
*/
for (i = 0, got = 0; i < mapi; i++)
got += mapp[i].br_blockcount;
if (got != count || mapp[0].br_startoff != *bno ||
mapp[mapi - 1].br_startoff + mapp[mapi - 1].br_blockcount !=
*bno + count) {
error = XFS_ERROR(ENOSPC);
goto out_free_map;
}
/* account for newly allocated blocks in reserved blocks total */
args->total -= dp->i_d.di_nblocks - nblks;
out_free_map:
if (mapp != &map)
kmem_free(mapp);
return error;
}
/*
* Add a block to the btree ahead of the file.
* Return the new block number to the caller.
*/
int
xfs_da_grow_inode(
struct xfs_da_args *args,
xfs_dablk_t *new_blkno)
{
xfs_fileoff_t bno;
int count;
int error;
trace_xfs_da_grow_inode(args);
if (args->whichfork == XFS_DATA_FORK) {
bno = args->dp->i_mount->m_dirleafblk;
count = args->dp->i_mount->m_dirblkfsbs;
} else {
bno = 0;
count = 1;
}
error = xfs_da_grow_inode_int(args, &bno, count);
if (!error)
*new_blkno = (xfs_dablk_t)bno;
return error;
}
/*
* Ick. We need to always be able to remove a btree block, even
* if there's no space reservation because the filesystem is full.
* This is called if xfs_bunmapi on a btree block fails due to ENOSPC.
* It swaps the target block with the last block in the file. The
* last block in the file can always be removed since it can't cause
* a bmap btree split to do that.
*/
STATIC int
xfs_da_swap_lastblock(
xfs_da_args_t *args,
xfs_dablk_t *dead_blknop,
struct xfs_buf **dead_bufp)
{
xfs_dablk_t dead_blkno, last_blkno, sib_blkno, par_blkno;
struct xfs_buf *dead_buf, *last_buf, *sib_buf, *par_buf;
xfs_fileoff_t lastoff;
xfs_inode_t *ip;
xfs_trans_t *tp;
xfs_mount_t *mp;
int error, w, entno, level, dead_level;
xfs_da_blkinfo_t *dead_info, *sib_info;
xfs_da_intnode_t *par_node, *dead_node;
xfs_dir2_leaf_t *dead_leaf2;
xfs_dahash_t dead_hash;
trace_xfs_da_swap_lastblock(args);
dead_buf = *dead_bufp;
dead_blkno = *dead_blknop;
tp = args->trans;
ip = args->dp;
w = args->whichfork;
ASSERT(w == XFS_DATA_FORK);
mp = ip->i_mount;
lastoff = mp->m_dirfreeblk;
error = xfs_bmap_last_before(tp, ip, &lastoff, w);
if (error)
return error;
if (unlikely(lastoff == 0)) {
XFS_ERROR_REPORT("xfs_da_swap_lastblock(1)", XFS_ERRLEVEL_LOW,
mp);
return XFS_ERROR(EFSCORRUPTED);
}
/*
* Read the last block in the btree space.
*/
last_blkno = (xfs_dablk_t)lastoff - mp->m_dirblkfsbs;
if ((error = xfs_da_read_buf(tp, ip, last_blkno, -1, &last_buf, w)))
return error;
/*
* Copy the last block into the dead buffer and log it.
*/
memcpy(dead_buf->b_addr, last_buf->b_addr, mp->m_dirblksize);
xfs_trans_log_buf(tp, dead_buf, 0, mp->m_dirblksize - 1);
dead_info = dead_buf->b_addr;
/*
* Get values from the moved block.
*/
if (dead_info->magic == cpu_to_be16(XFS_DIR2_LEAFN_MAGIC)) {
dead_leaf2 = (xfs_dir2_leaf_t *)dead_info;
dead_level = 0;
dead_hash = be32_to_cpu(dead_leaf2->ents[be16_to_cpu(dead_leaf2->hdr.count) - 1].hashval);
} else {
ASSERT(dead_info->magic == cpu_to_be16(XFS_DA_NODE_MAGIC));
dead_node = (xfs_da_intnode_t *)dead_info;
dead_level = be16_to_cpu(dead_node->hdr.level);
dead_hash = be32_to_cpu(dead_node->btree[be16_to_cpu(dead_node->hdr.count) - 1].hashval);
}
sib_buf = par_buf = NULL;
/*
* If the moved block has a left sibling, fix up the pointers.
*/
if ((sib_blkno = be32_to_cpu(dead_info->back))) {
if ((error = xfs_da_read_buf(tp, ip, sib_blkno, -1, &sib_buf, w)))
goto done;
sib_info = sib_buf->b_addr;
if (unlikely(
be32_to_cpu(sib_info->forw) != last_blkno ||
sib_info->magic != dead_info->magic)) {
XFS_ERROR_REPORT("xfs_da_swap_lastblock(2)",
XFS_ERRLEVEL_LOW, mp);
error = XFS_ERROR(EFSCORRUPTED);
goto done;
}
sib_info->forw = cpu_to_be32(dead_blkno);
xfs_trans_log_buf(tp, sib_buf,
XFS_DA_LOGRANGE(sib_info, &sib_info->forw,
sizeof(sib_info->forw)));
sib_buf = NULL;
}
/*
* If the moved block has a right sibling, fix up the pointers.
*/
if ((sib_blkno = be32_to_cpu(dead_info->forw))) {
if ((error = xfs_da_read_buf(tp, ip, sib_blkno, -1, &sib_buf, w)))
goto done;
sib_info = sib_buf->b_addr;
if (unlikely(
be32_to_cpu(sib_info->back) != last_blkno ||
sib_info->magic != dead_info->magic)) {
XFS_ERROR_REPORT("xfs_da_swap_lastblock(3)",
XFS_ERRLEVEL_LOW, mp);
error = XFS_ERROR(EFSCORRUPTED);
goto done;
}
sib_info->back = cpu_to_be32(dead_blkno);
xfs_trans_log_buf(tp, sib_buf,
XFS_DA_LOGRANGE(sib_info, &sib_info->back,
sizeof(sib_info->back)));
sib_buf = NULL;
}
par_blkno = mp->m_dirleafblk;
level = -1;
/*
* Walk down the tree looking for the parent of the moved block.
*/
for (;;) {
if ((error = xfs_da_read_buf(tp, ip, par_blkno, -1, &par_buf, w)))
goto done;
par_node = par_buf->b_addr;
if (unlikely(par_node->hdr.info.magic !=
cpu_to_be16(XFS_DA_NODE_MAGIC) ||
(level >= 0 && level != be16_to_cpu(par_node->hdr.level) + 1))) {
XFS_ERROR_REPORT("xfs_da_swap_lastblock(4)",
XFS_ERRLEVEL_LOW, mp);
error = XFS_ERROR(EFSCORRUPTED);
goto done;
}
level = be16_to_cpu(par_node->hdr.level);
for (entno = 0;
entno < be16_to_cpu(par_node->hdr.count) &&
be32_to_cpu(par_node->btree[entno].hashval) < dead_hash;
entno++)
continue;
if (unlikely(entno == be16_to_cpu(par_node->hdr.count))) {
XFS_ERROR_REPORT("xfs_da_swap_lastblock(5)",
XFS_ERRLEVEL_LOW, mp);
error = XFS_ERROR(EFSCORRUPTED);
goto done;
}
par_blkno = be32_to_cpu(par_node->btree[entno].before);
if (level == dead_level + 1)
break;
xfs_trans_brelse(tp, par_buf);
par_buf = NULL;
}
/*
* We're in the right parent block.
* Look for the right entry.
*/
for (;;) {
for (;
entno < be16_to_cpu(par_node->hdr.count) &&
be32_to_cpu(par_node->btree[entno].before) != last_blkno;
entno++)
continue;
if (entno < be16_to_cpu(par_node->hdr.count))
break;
par_blkno = be32_to_cpu(par_node->hdr.info.forw);
xfs_trans_brelse(tp, par_buf);
par_buf = NULL;
if (unlikely(par_blkno == 0)) {
XFS_ERROR_REPORT("xfs_da_swap_lastblock(6)",
XFS_ERRLEVEL_LOW, mp);
error = XFS_ERROR(EFSCORRUPTED);
goto done;
}
if ((error = xfs_da_read_buf(tp, ip, par_blkno, -1, &par_buf, w)))
goto done;
par_node = par_buf->b_addr;
if (unlikely(
be16_to_cpu(par_node->hdr.level) != level ||
par_node->hdr.info.magic != cpu_to_be16(XFS_DA_NODE_MAGIC))) {
XFS_ERROR_REPORT("xfs_da_swap_lastblock(7)",
XFS_ERRLEVEL_LOW, mp);
error = XFS_ERROR(EFSCORRUPTED);
goto done;
}
entno = 0;
}
/*
* Update the parent entry pointing to the moved block.
*/
par_node->btree[entno].before = cpu_to_be32(dead_blkno);
xfs_trans_log_buf(tp, par_buf,
XFS_DA_LOGRANGE(par_node, &par_node->btree[entno].before,
sizeof(par_node->btree[entno].before)));
*dead_blknop = last_blkno;
*dead_bufp = last_buf;
return 0;
done:
if (par_buf)
xfs_trans_brelse(tp, par_buf);
if (sib_buf)
xfs_trans_brelse(tp, sib_buf);
xfs_trans_brelse(tp, last_buf);
return error;
}
/*
* Remove a btree block from a directory or attribute.
*/
int
xfs_da_shrink_inode(
xfs_da_args_t *args,
xfs_dablk_t dead_blkno,
struct xfs_buf *dead_buf)
{
xfs_inode_t *dp;
int done, error, w, count;
xfs_trans_t *tp;
xfs_mount_t *mp;
trace_xfs_da_shrink_inode(args);
dp = args->dp;
w = args->whichfork;
tp = args->trans;
mp = dp->i_mount;
if (w == XFS_DATA_FORK)
count = mp->m_dirblkfsbs;
else
count = 1;
for (;;) {
/*
* Remove extents. If we get ENOSPC for a dir we have to move
* the last block to the place we want to kill.
*/
if ((error = xfs_bunmapi(tp, dp, dead_blkno, count,
xfs_bmapi_aflag(w)|XFS_BMAPI_METADATA,
0, args->firstblock, args->flist,
&done)) == ENOSPC) {
if (w != XFS_DATA_FORK)
break;
if ((error = xfs_da_swap_lastblock(args, &dead_blkno,
&dead_buf)))
break;
} else {
break;
}
}
xfs_trans_binval(tp, dead_buf);
return error;
}
/*
* See if the mapping(s) for this btree block are valid, i.e.
* don't contain holes, are logically contiguous, and cover the whole range.
*/
STATIC int
xfs_da_map_covers_blocks(
int nmap,
xfs_bmbt_irec_t *mapp,
xfs_dablk_t bno,
int count)
{
int i;
xfs_fileoff_t off;
for (i = 0, off = bno; i < nmap; i++) {
if (mapp[i].br_startblock == HOLESTARTBLOCK ||
mapp[i].br_startblock == DELAYSTARTBLOCK) {
return 0;
}
if (off != mapp[i].br_startoff) {
return 0;
}
off += mapp[i].br_blockcount;
}
return off == bno + count;
}
/*
* Convert a struct xfs_bmbt_irec to a struct xfs_buf_map.
*
* For the single map case, it is assumed that the caller has provided a pointer
* to a valid xfs_buf_map. For the multiple map case, this function will
* allocate the xfs_buf_map to hold all the maps and replace the caller's single
* map pointer with the allocated map.
*/
static int
xfs_buf_map_from_irec(
struct xfs_mount *mp,
struct xfs_buf_map **mapp,
unsigned int *nmaps,
struct xfs_bmbt_irec *irecs,
unsigned int nirecs)
{
struct xfs_buf_map *map;
int i;
ASSERT(*nmaps == 1);
ASSERT(nirecs >= 1);
if (nirecs > 1) {
map = kmem_zalloc(nirecs * sizeof(struct xfs_buf_map), KM_SLEEP);
if (!map)
return ENOMEM;
*mapp = map;
}
*nmaps = nirecs;
map = *mapp;
for (i = 0; i < *nmaps; i++) {
ASSERT(irecs[i].br_startblock != DELAYSTARTBLOCK &&
irecs[i].br_startblock != HOLESTARTBLOCK);
map[i].bm_bn = XFS_FSB_TO_DADDR(mp, irecs[i].br_startblock);
map[i].bm_len = XFS_FSB_TO_BB(mp, irecs[i].br_blockcount);
}
return 0;
}
/*
* Map the block we are given ready for reading. There are three possible return
* values:
* -1 - will be returned if we land in a hole and mappedbno == -2 so the
* caller knows not to execute a subsequent read.
* 0 - if we mapped the block successfully
* >0 - positive error number if there was an error.
*/
static int
xfs_dabuf_map(
struct xfs_trans *trans,
struct xfs_inode *dp,
xfs_dablk_t bno,
xfs_daddr_t mappedbno,
int whichfork,
struct xfs_buf_map **map,
int *nmaps)
{
struct xfs_mount *mp = dp->i_mount;
int nfsb;
int error = 0;
struct xfs_bmbt_irec irec;
struct xfs_bmbt_irec *irecs = &irec;
int nirecs;
ASSERT(map && *map);
ASSERT(*nmaps == 1);
nfsb = (whichfork == XFS_DATA_FORK) ? mp->m_dirblkfsbs : 1;
/*
* Caller doesn't have a mapping. -2 means don't complain
* if we land in a hole.
*/
if (mappedbno == -1 || mappedbno == -2) {
/*
* Optimize the one-block case.
*/
if (nfsb != 1)
irecs = kmem_zalloc(sizeof(irec) * nfsb, KM_SLEEP);
nirecs = nfsb;
error = xfs_bmapi_read(dp, (xfs_fileoff_t)bno, nfsb, irecs,
&nirecs, xfs_bmapi_aflag(whichfork));
if (error)
goto out;
} else {
irecs->br_startblock = XFS_DADDR_TO_FSB(mp, mappedbno);
irecs->br_startoff = (xfs_fileoff_t)bno;
irecs->br_blockcount = nfsb;
irecs->br_state = 0;
nirecs = 1;
}
if (!xfs_da_map_covers_blocks(nirecs, irecs, bno, nfsb)) {
error = mappedbno == -2 ? -1 : XFS_ERROR(EFSCORRUPTED);
if (unlikely(error == EFSCORRUPTED)) {
if (xfs_error_level >= XFS_ERRLEVEL_LOW) {
int i;
xfs_alert(mp, "%s: bno %lld dir: inode %lld",
__func__, (long long)bno,
(long long)dp->i_ino);
for (i = 0; i < *nmaps; i++) {
xfs_alert(mp,
"[%02d] br_startoff %lld br_startblock %lld br_blockcount %lld br_state %d",
i,
(long long)irecs[i].br_startoff,
(long long)irecs[i].br_startblock,
(long long)irecs[i].br_blockcount,
irecs[i].br_state);
}
}
XFS_ERROR_REPORT("xfs_da_do_buf(1)",
XFS_ERRLEVEL_LOW, mp);
}
goto out;
}
error = xfs_buf_map_from_irec(mp, map, nmaps, irecs, nirecs);
out:
if (irecs != &irec)
kmem_free(irecs);
return error;
}
/*
* Get a buffer for the dir/attr block.
*/
int
xfs_da_get_buf(
struct xfs_trans *trans,
struct xfs_inode *dp,
xfs_dablk_t bno,
xfs_daddr_t mappedbno,
struct xfs_buf **bpp,
int whichfork)
{
struct xfs_buf *bp;
struct xfs_buf_map map;
struct xfs_buf_map *mapp;
int nmap;
int error;
*bpp = NULL;
mapp = &map;
nmap = 1;
error = xfs_dabuf_map(trans, dp, bno, mappedbno, whichfork,
&mapp, &nmap);
if (error) {
/* mapping a hole is not an error, but we don't continue */
if (error == -1)
error = 0;
goto out_free;
}
bp = xfs_trans_get_buf_map(trans, dp->i_mount->m_ddev_targp,
mapp, nmap, 0);
error = bp ? bp->b_error : XFS_ERROR(EIO);
if (error) {
xfs_trans_brelse(trans, bp);
goto out_free;
}
*bpp = bp;
out_free:
if (mapp != &map)
kmem_free(mapp);
return error;
}
/*
* Get a buffer for the dir/attr block, fill in the contents.
*/
int
xfs_da_read_buf(
struct xfs_trans *trans,
struct xfs_inode *dp,
xfs_dablk_t bno,
xfs_daddr_t mappedbno,
struct xfs_buf **bpp,
int whichfork)
{
struct xfs_buf *bp;
struct xfs_buf_map map;
struct xfs_buf_map *mapp;
int nmap;
int error;
*bpp = NULL;
mapp = &map;
nmap = 1;
error = xfs_dabuf_map(trans, dp, bno, mappedbno, whichfork,
&mapp, &nmap);
if (error) {
/* mapping a hole is not an error, but we don't continue */
if (error == -1)
error = 0;
goto out_free;
}
error = xfs_trans_read_buf_map(dp->i_mount, trans,
dp->i_mount->m_ddev_targp,
mapp, nmap, 0, &bp);
if (error)
goto out_free;
if (whichfork == XFS_ATTR_FORK)
xfs_buf_set_ref(bp, XFS_ATTR_BTREE_REF);
else
xfs_buf_set_ref(bp, XFS_DIR_BTREE_REF);
/*
* This verification code will be moved to a CRC verification callback
* function so just leave it here unchanged until then.
*/
{
xfs_dir2_data_hdr_t *hdr = bp->b_addr;
xfs_dir2_free_t *free = bp->b_addr;
xfs_da_blkinfo_t *info = bp->b_addr;
uint magic, magic1;
struct xfs_mount *mp = dp->i_mount;
magic = be16_to_cpu(info->magic);
magic1 = be32_to_cpu(hdr->magic);
if (unlikely(
XFS_TEST_ERROR((magic != XFS_DA_NODE_MAGIC) &&
(magic != XFS_ATTR_LEAF_MAGIC) &&
(magic != XFS_DIR2_LEAF1_MAGIC) &&
(magic != XFS_DIR2_LEAFN_MAGIC) &&
(magic1 != XFS_DIR2_BLOCK_MAGIC) &&
(magic1 != XFS_DIR2_DATA_MAGIC) &&
(free->hdr.magic != cpu_to_be32(XFS_DIR2_FREE_MAGIC)),
mp, XFS_ERRTAG_DA_READ_BUF,
XFS_RANDOM_DA_READ_BUF))) {
trace_xfs_da_btree_corrupt(bp, _RET_IP_);
XFS_CORRUPTION_ERROR("xfs_da_do_buf(2)",
XFS_ERRLEVEL_LOW, mp, info);
error = XFS_ERROR(EFSCORRUPTED);
xfs_trans_brelse(trans, bp);
goto out_free;
}
}
*bpp = bp;
out_free:
if (mapp != &map)
kmem_free(mapp);
return error;
}
/*
* Readahead the dir/attr block.
*/
xfs_daddr_t
xfs_da_reada_buf(
struct xfs_trans *trans,
struct xfs_inode *dp,
xfs_dablk_t bno,
int whichfork)
{
xfs_daddr_t mappedbno = -1;
struct xfs_buf_map map;
struct xfs_buf_map *mapp;
int nmap;
int error;
mapp = &map;
nmap = 1;
error = xfs_dabuf_map(trans, dp, bno, -1, whichfork,
&mapp, &nmap);
if (error) {
/* mapping a hole is not an error, but we don't continue */
if (error == -1)
error = 0;
goto out_free;
}
mappedbno = mapp[0].bm_bn;
xfs_buf_readahead_map(dp->i_mount->m_ddev_targp, mapp, nmap);
out_free:
if (mapp != &map)
kmem_free(mapp);
if (error)
return -1;
return mappedbno;
}
kmem_zone_t *xfs_da_state_zone; /* anchor for state struct zone */
/*
* Allocate a dir-state structure.
* We don't put them on the stack since they're large.
*/
xfs_da_state_t *
xfs_da_state_alloc(void)
{
return kmem_zone_zalloc(xfs_da_state_zone, KM_NOFS);
}
/*
* Kill the altpath contents of a da-state structure.
*/
STATIC void
xfs_da_state_kill_altpath(xfs_da_state_t *state)
{
int i;
for (i = 0; i < state->altpath.active; i++)
state->altpath.blk[i].bp = NULL;
state->altpath.active = 0;
}
/*
* Free a da-state structure.
*/
void
xfs_da_state_free(xfs_da_state_t *state)
{
xfs_da_state_kill_altpath(state);
#ifdef DEBUG
memset((char *)state, 0, sizeof(*state));
#endif /* DEBUG */
kmem_zone_free(xfs_da_state_zone, state);
}
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