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linux-next/fs/xfs/libxfs/xfs_da_btree.c
Darrick J. Wong 9676b54e6e xfs: make xfs_trans_get_buf_map return an error code 
Convert xfs_trans_get_buf_map() to return numeric error codes like most
everywhere else in xfs.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2020-01-26 14:32:26 -08:00

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// 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_bit.h"
#include "xfs_mount.h"
#include "xfs_inode.h"
#include "xfs_dir2.h"
#include "xfs_dir2_priv.h"
#include "xfs_trans.h"
#include "xfs_bmap.h"
#include "xfs_attr_leaf.h"
#include "xfs_error.h"
#include "xfs_trace.h"
#include "xfs_buf_item.h"
#include "xfs_log.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_da3_root_split(xfs_da_state_t *state,
xfs_da_state_blk_t *existing_root,
xfs_da_state_blk_t *new_child);
STATIC int xfs_da3_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_da3_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_da3_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_da3_root_join(xfs_da_state_t *state,
xfs_da_state_blk_t *root_blk);
STATIC int xfs_da3_node_toosmall(xfs_da_state_t *state, int *retval);
STATIC void xfs_da3_node_remove(xfs_da_state_t *state,
xfs_da_state_blk_t *drop_blk);
STATIC void xfs_da3_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 int xfs_da3_blk_unlink(xfs_da_state_t *state,
xfs_da_state_blk_t *drop_blk,
xfs_da_state_blk_t *save_blk);
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_cache_free(xfs_da_state_zone, state);
}
static inline int xfs_dabuf_nfsb(struct xfs_mount *mp, int whichfork)
{
if (whichfork == XFS_DATA_FORK)
return mp->m_dir_geo->fsbcount;
return mp->m_attr_geo->fsbcount;
}
void
xfs_da3_node_hdr_from_disk(
struct xfs_mount *mp,
struct xfs_da3_icnode_hdr *to,
struct xfs_da_intnode *from)
{
if (xfs_sb_version_hascrc(&mp->m_sb)) {
struct xfs_da3_intnode *from3 = (struct xfs_da3_intnode *)from;
to->forw = be32_to_cpu(from3->hdr.info.hdr.forw);
to->back = be32_to_cpu(from3->hdr.info.hdr.back);
to->magic = be16_to_cpu(from3->hdr.info.hdr.magic);
to->count = be16_to_cpu(from3->hdr.__count);
to->level = be16_to_cpu(from3->hdr.__level);
to->btree = from3->__btree;
ASSERT(to->magic == XFS_DA3_NODE_MAGIC);
} else {
to->forw = be32_to_cpu(from->hdr.info.forw);
to->back = be32_to_cpu(from->hdr.info.back);
to->magic = be16_to_cpu(from->hdr.info.magic);
to->count = be16_to_cpu(from->hdr.__count);
to->level = be16_to_cpu(from->hdr.__level);
to->btree = from->__btree;
ASSERT(to->magic == XFS_DA_NODE_MAGIC);
}
}
void
xfs_da3_node_hdr_to_disk(
struct xfs_mount *mp,
struct xfs_da_intnode *to,
struct xfs_da3_icnode_hdr *from)
{
if (xfs_sb_version_hascrc(&mp->m_sb)) {
struct xfs_da3_intnode *to3 = (struct xfs_da3_intnode *)to;
ASSERT(from->magic == XFS_DA3_NODE_MAGIC);
to3->hdr.info.hdr.forw = cpu_to_be32(from->forw);
to3->hdr.info.hdr.back = cpu_to_be32(from->back);
to3->hdr.info.hdr.magic = cpu_to_be16(from->magic);
to3->hdr.__count = cpu_to_be16(from->count);
to3->hdr.__level = cpu_to_be16(from->level);
} else {
ASSERT(from->magic == XFS_DA_NODE_MAGIC);
to->hdr.info.forw = cpu_to_be32(from->forw);
to->hdr.info.back = cpu_to_be32(from->back);
to->hdr.info.magic = cpu_to_be16(from->magic);
to->hdr.__count = cpu_to_be16(from->count);
to->hdr.__level = cpu_to_be16(from->level);
}
}
/*
* Verify an xfs_da3_blkinfo structure. Note that the da3 fields are only
* accessible on v5 filesystems. This header format is common across da node,
* attr leaf and dir leaf blocks.
*/
xfs_failaddr_t
xfs_da3_blkinfo_verify(
struct xfs_buf *bp,
struct xfs_da3_blkinfo *hdr3)
{
struct xfs_mount *mp = bp->b_mount;
struct xfs_da_blkinfo *hdr = &hdr3->hdr;
if (!xfs_verify_magic16(bp, hdr->magic))
return __this_address;
if (xfs_sb_version_hascrc(&mp->m_sb)) {
if (!uuid_equal(&hdr3->uuid, &mp->m_sb.sb_meta_uuid))
return __this_address;
if (be64_to_cpu(hdr3->blkno) != bp->b_bn)
return __this_address;
if (!xfs_log_check_lsn(mp, be64_to_cpu(hdr3->lsn)))
return __this_address;
}
return NULL;
}
static xfs_failaddr_t
xfs_da3_node_verify(
struct xfs_buf *bp)
{
struct xfs_mount *mp = bp->b_mount;
struct xfs_da_intnode *hdr = bp->b_addr;
struct xfs_da3_icnode_hdr ichdr;
xfs_failaddr_t fa;
xfs_da3_node_hdr_from_disk(mp, &ichdr, hdr);
fa = xfs_da3_blkinfo_verify(bp, bp->b_addr);
if (fa)
return fa;
if (ichdr.level == 0)
return __this_address;
if (ichdr.level > XFS_DA_NODE_MAXDEPTH)
return __this_address;
if (ichdr.count == 0)
return __this_address;
/*
* we don't know if the node is for and attribute or directory tree,
* so only fail if the count is outside both bounds
*/
if (ichdr.count > mp->m_dir_geo->node_ents &&
ichdr.count > mp->m_attr_geo->node_ents)
return __this_address;
/* XXX: hash order check? */
return NULL;
}
static void
xfs_da3_node_write_verify(
struct xfs_buf *bp)
{
struct xfs_mount *mp = bp->b_mount;
struct xfs_buf_log_item *bip = bp->b_log_item;
struct xfs_da3_node_hdr *hdr3 = bp->b_addr;
xfs_failaddr_t fa;
fa = xfs_da3_node_verify(bp);
if (fa) {
xfs_verifier_error(bp, -EFSCORRUPTED, fa);
return;
}
if (!xfs_sb_version_hascrc(&mp->m_sb))
return;
if (bip)
hdr3->info.lsn = cpu_to_be64(bip->bli_item.li_lsn);
xfs_buf_update_cksum(bp, XFS_DA3_NODE_CRC_OFF);
}
/*
* leaf/node format detection on trees is sketchy, so a node read can be done on
* leaf level blocks when detection identifies the tree as a node format tree
* incorrectly. In this case, we need to swap the verifier to match the correct
* format of the block being read.
*/
static void
xfs_da3_node_read_verify(
struct xfs_buf *bp)
{
struct xfs_da_blkinfo *info = bp->b_addr;
xfs_failaddr_t fa;
switch (be16_to_cpu(info->magic)) {
case XFS_DA3_NODE_MAGIC:
if (!xfs_buf_verify_cksum(bp, XFS_DA3_NODE_CRC_OFF)) {
xfs_verifier_error(bp, -EFSBADCRC,
__this_address);
break;
}
/* fall through */
case XFS_DA_NODE_MAGIC:
fa = xfs_da3_node_verify(bp);
if (fa)
xfs_verifier_error(bp, -EFSCORRUPTED, fa);
return;
case XFS_ATTR_LEAF_MAGIC:
case XFS_ATTR3_LEAF_MAGIC:
bp->b_ops = &xfs_attr3_leaf_buf_ops;
bp->b_ops->verify_read(bp);
return;
case XFS_DIR2_LEAFN_MAGIC:
case XFS_DIR3_LEAFN_MAGIC:
bp->b_ops = &xfs_dir3_leafn_buf_ops;
bp->b_ops->verify_read(bp);
return;
default:
xfs_verifier_error(bp, -EFSCORRUPTED, __this_address);
break;
}
}
/* Verify the structure of a da3 block. */
static xfs_failaddr_t
xfs_da3_node_verify_struct(
struct xfs_buf *bp)
{
struct xfs_da_blkinfo *info = bp->b_addr;
switch (be16_to_cpu(info->magic)) {
case XFS_DA3_NODE_MAGIC:
case XFS_DA_NODE_MAGIC:
return xfs_da3_node_verify(bp);
case XFS_ATTR_LEAF_MAGIC:
case XFS_ATTR3_LEAF_MAGIC:
bp->b_ops = &xfs_attr3_leaf_buf_ops;
return bp->b_ops->verify_struct(bp);
case XFS_DIR2_LEAFN_MAGIC:
case XFS_DIR3_LEAFN_MAGIC:
bp->b_ops = &xfs_dir3_leafn_buf_ops;
return bp->b_ops->verify_struct(bp);
default:
return __this_address;
}
}
const struct xfs_buf_ops xfs_da3_node_buf_ops = {
.name = "xfs_da3_node",
.magic16 = { cpu_to_be16(XFS_DA_NODE_MAGIC),
cpu_to_be16(XFS_DA3_NODE_MAGIC) },
.verify_read = xfs_da3_node_read_verify,
.verify_write = xfs_da3_node_write_verify,
.verify_struct = xfs_da3_node_verify_struct,
};
static int
xfs_da3_node_set_type(
struct xfs_trans *tp,
struct xfs_buf *bp)
{
struct xfs_da_blkinfo *info = bp->b_addr;
switch (be16_to_cpu(info->magic)) {
case XFS_DA_NODE_MAGIC:
case XFS_DA3_NODE_MAGIC:
xfs_trans_buf_set_type(tp, bp, XFS_BLFT_DA_NODE_BUF);
return 0;
case XFS_ATTR_LEAF_MAGIC:
case XFS_ATTR3_LEAF_MAGIC:
xfs_trans_buf_set_type(tp, bp, XFS_BLFT_ATTR_LEAF_BUF);
return 0;
case XFS_DIR2_LEAFN_MAGIC:
case XFS_DIR3_LEAFN_MAGIC:
xfs_trans_buf_set_type(tp, bp, XFS_BLFT_DIR_LEAFN_BUF);
return 0;
default:
XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, tp->t_mountp,
info, sizeof(*info));
xfs_trans_brelse(tp, bp);
return -EFSCORRUPTED;
}
}
int
xfs_da3_node_read(
struct xfs_trans *tp,
struct xfs_inode *dp,
xfs_dablk_t bno,
struct xfs_buf **bpp,
int whichfork)
{
int error;
error = xfs_da_read_buf(tp, dp, bno, 0, bpp, whichfork,
&xfs_da3_node_buf_ops);
if (error || !*bpp || !tp)
return error;
return xfs_da3_node_set_type(tp, *bpp);
}
int
xfs_da3_node_read_mapped(
struct xfs_trans *tp,
struct xfs_inode *dp,
xfs_daddr_t mappedbno,
struct xfs_buf **bpp,
int whichfork)
{
struct xfs_mount *mp = dp->i_mount;
int error;
error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp, mappedbno,
XFS_FSB_TO_BB(mp, xfs_dabuf_nfsb(mp, whichfork)), 0,
bpp, &xfs_da3_node_buf_ops);
if (error || !*bpp)
return error;
if (whichfork == XFS_ATTR_FORK)
xfs_buf_set_ref(*bpp, XFS_ATTR_BTREE_REF);
else
xfs_buf_set_ref(*bpp, XFS_DIR_BTREE_REF);
if (!tp)
return 0;
return xfs_da3_node_set_type(tp, *bpp);
}
/*========================================================================
* Routines used for growing the Btree.
*========================================================================*/
/*
* Create the initial contents of an intermediate node.
*/
int
xfs_da3_node_create(
struct xfs_da_args *args,
xfs_dablk_t blkno,
int level,
struct xfs_buf **bpp,
int whichfork)
{
struct xfs_da_intnode *node;
struct xfs_trans *tp = args->trans;
struct xfs_mount *mp = tp->t_mountp;
struct xfs_da3_icnode_hdr ichdr = {0};
struct xfs_buf *bp;
int error;
struct xfs_inode *dp = args->dp;
trace_xfs_da_node_create(args);
ASSERT(level <= XFS_DA_NODE_MAXDEPTH);
error = xfs_da_get_buf(tp, dp, blkno, &bp, whichfork);
if (error)
return error;
bp->b_ops = &xfs_da3_node_buf_ops;
xfs_trans_buf_set_type(tp, bp, XFS_BLFT_DA_NODE_BUF);
node = bp->b_addr;
if (xfs_sb_version_hascrc(&mp->m_sb)) {
struct xfs_da3_node_hdr *hdr3 = bp->b_addr;
memset(hdr3, 0, sizeof(struct xfs_da3_node_hdr));
ichdr.magic = XFS_DA3_NODE_MAGIC;
hdr3->info.blkno = cpu_to_be64(bp->b_bn);
hdr3->info.owner = cpu_to_be64(args->dp->i_ino);
uuid_copy(&hdr3->info.uuid, &mp->m_sb.sb_meta_uuid);
} else {
ichdr.magic = XFS_DA_NODE_MAGIC;
}
ichdr.level = level;
xfs_da3_node_hdr_to_disk(dp->i_mount, node, &ichdr);
xfs_trans_log_buf(tp, bp,
XFS_DA_LOGRANGE(node, &node->hdr, args->geo->node_hdr_size));
*bpp = bp;
return 0;
}
/*
* Split a leaf node, rebalance, then possibly split
* intermediate nodes, rebalance, etc.
*/
int /* error */
xfs_da3_split(
struct xfs_da_state *state)
{
struct xfs_da_state_blk *oldblk;
struct xfs_da_state_blk *newblk;
struct xfs_da_state_blk *addblk;
struct xfs_da_intnode *node;
int max;
int action = 0;
int error;
int 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_attr3_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. The new
* extrablk will be consumed by xfs_da3_node_split if
* the node is split.
*/
state->extravalid = 1;
if (state->inleaf) {
state->extraafter = 0; /* before newblk */
trace_xfs_attr_leaf_split_before(state->args);
error = xfs_attr3_leaf_split(state, oldblk,
&state->extrablk);
} else {
state->extraafter = 1; /* after newblk */
trace_xfs_attr_leaf_split_after(state->args);
error = xfs_attr3_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_da3_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_da3_fixhashpath(state, &state->path);
}
if (!addblk)
return 0;
/*
* xfs_da3_node_split() should have consumed any extra blocks we added
* during a double leaf split in the attr fork. This is guaranteed as
* we can't be here if the attr fork only has a single leaf block.
*/
ASSERT(state->extravalid == 0 ||
state->path.blk[max].magic == XFS_DIR2_LEAFN_MAGIC);
/*
* Split the root node.
*/
ASSERT(state->path.active == 0);
oldblk = &state->path.blk[0];
error = xfs_da3_root_split(state, oldblk, addblk);
if (error)
goto out;
/*
* Update pointers to the node which used to be block 0 and just got
* bumped because of the addition of a new root node. Note that the
* original block 0 could be at any position in the list of blocks in
* the tree.
*
* Note: the magic numbers and sibling pointers are in the same physical
* place for both v2 and v3 headers (by design). Hence it doesn't matter
* which version of the xfs_da_intnode structure we use here as the
* result will be the same using either structure.
*/
node = oldblk->bp->b_addr;
if (node->hdr.info.forw) {
if (be32_to_cpu(node->hdr.info.forw) != addblk->blkno) {
xfs_buf_corruption_error(oldblk->bp);
error = -EFSCORRUPTED;
goto out;
}
node = addblk->bp->b_addr;
node->hdr.info.back = cpu_to_be32(oldblk->blkno);
xfs_trans_log_buf(state->args->trans, addblk->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) {
xfs_buf_corruption_error(oldblk->bp);
error = -EFSCORRUPTED;
goto out;
}
node = addblk->bp->b_addr;
node->hdr.info.forw = cpu_to_be32(oldblk->blkno);
xfs_trans_log_buf(state->args->trans, addblk->bp,
XFS_DA_LOGRANGE(node, &node->hdr.info,
sizeof(node->hdr.info)));
}
out:
addblk->bp = NULL;
return error;
}
/*
* 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_da3_root_split(
struct xfs_da_state *state,
struct xfs_da_state_blk *blk1,
struct xfs_da_state_blk *blk2)
{
struct xfs_da_intnode *node;
struct xfs_da_intnode *oldroot;
struct xfs_da_node_entry *btree;
struct xfs_da3_icnode_hdr nodehdr;
struct xfs_da_args *args;
struct xfs_buf *bp;
struct xfs_inode *dp;
struct xfs_trans *tp;
struct xfs_dir2_leaf *leaf;
xfs_dablk_t blkno;
int level;
int error;
int size;
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;
error = xfs_da_grow_inode(args, &blkno);
if (error)
return error;
dp = args->dp;
tp = args->trans;
error = xfs_da_get_buf(tp, dp, blkno, &bp, args->whichfork);
if (error)
return error;
node = bp->b_addr;
oldroot = blk1->bp->b_addr;
if (oldroot->hdr.info.magic == cpu_to_be16(XFS_DA_NODE_MAGIC) ||
oldroot->hdr.info.magic == cpu_to_be16(XFS_DA3_NODE_MAGIC)) {
struct xfs_da3_icnode_hdr icnodehdr;
xfs_da3_node_hdr_from_disk(dp->i_mount, &icnodehdr, oldroot);
btree = icnodehdr.btree;
size = (int)((char *)&btree[icnodehdr.count] - (char *)oldroot);
level = icnodehdr.level;
/*
* we are about to copy oldroot to bp, so set up the type
* of bp while we know exactly what it will be.
*/
xfs_trans_buf_set_type(tp, bp, XFS_BLFT_DA_NODE_BUF);
} else {
struct xfs_dir3_icleaf_hdr leafhdr;
leaf = (xfs_dir2_leaf_t *)oldroot;
xfs_dir2_leaf_hdr_from_disk(dp->i_mount, &leafhdr, leaf);
ASSERT(leafhdr.magic == XFS_DIR2_LEAFN_MAGIC ||
leafhdr.magic == XFS_DIR3_LEAFN_MAGIC);
size = (int)((char *)&leafhdr.ents[leafhdr.count] -
(char *)leaf);
level = 0;
/*
* we are about to copy oldroot to bp, so set up the type
* of bp while we know exactly what it will be.
*/
xfs_trans_buf_set_type(tp, bp, XFS_BLFT_DIR_LEAFN_BUF);
}
/*
* we can copy most of the information in the node from one block to
* another, but for CRC enabled headers we have to make sure that the
* block specific identifiers are kept intact. We update the buffer
* directly for this.
*/
memcpy(node, oldroot, size);
if (oldroot->hdr.info.magic == cpu_to_be16(XFS_DA3_NODE_MAGIC) ||
oldroot->hdr.info.magic == cpu_to_be16(XFS_DIR3_LEAFN_MAGIC)) {
struct xfs_da3_intnode *node3 = (struct xfs_da3_intnode *)node;
node3->hdr.info.blkno = cpu_to_be64(bp->b_bn);
}
xfs_trans_log_buf(tp, bp, 0, size - 1);
bp->b_ops = blk1->bp->b_ops;
xfs_trans_buf_copy_type(bp, blk1->bp);
blk1->bp = bp;
blk1->blkno = blkno;
/*
* Set up the new root node.
*/
error = xfs_da3_node_create(args,
(args->whichfork == XFS_DATA_FORK) ? args->geo->leafblk : 0,
level + 1, &bp, args->whichfork);
if (error)
return error;
node = bp->b_addr;
xfs_da3_node_hdr_from_disk(dp->i_mount, &nodehdr, node);
btree = nodehdr.btree;
btree[0].hashval = cpu_to_be32(blk1->hashval);
btree[0].before = cpu_to_be32(blk1->blkno);
btree[1].hashval = cpu_to_be32(blk2->hashval);
btree[1].before = cpu_to_be32(blk2->blkno);
nodehdr.count = 2;
xfs_da3_node_hdr_to_disk(dp->i_mount, node, &nodehdr);
#ifdef DEBUG
if (oldroot->hdr.info.magic == cpu_to_be16(XFS_DIR2_LEAFN_MAGIC) ||
oldroot->hdr.info.magic == cpu_to_be16(XFS_DIR3_LEAFN_MAGIC)) {
ASSERT(blk1->blkno >= args->geo->leafblk &&
blk1->blkno < args->geo->freeblk);
ASSERT(blk2->blkno >= args->geo->leafblk &&
blk2->blkno < args->geo->freeblk);
}
#endif
/* Header is already logged by xfs_da_node_create */
xfs_trans_log_buf(tp, bp,
XFS_DA_LOGRANGE(node, btree, sizeof(xfs_da_node_entry_t) * 2));
return 0;
}
/*
* Split the node, rebalance, then add the new entry.
*/
STATIC int /* error */
xfs_da3_node_split(
struct xfs_da_state *state,
struct xfs_da_state_blk *oldblk,
struct xfs_da_state_blk *newblk,
struct xfs_da_state_blk *addblk,
int treelevel,
int *result)
{
struct xfs_da_intnode *node;
struct xfs_da3_icnode_hdr nodehdr;
xfs_dablk_t blkno;
int newcount;
int error;
int useextra;
struct xfs_inode *dp = state->args->dp;
trace_xfs_da_node_split(state->args);
node = oldblk->bp->b_addr;
xfs_da3_node_hdr_from_disk(dp->i_mount, &nodehdr, node);
/*
* 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 (nodehdr.count + newcount > state->args->geo->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_da3_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_da3_node_rebalance(state, oldblk, newblk);
error = xfs_da3_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_da3_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;
xfs_da3_node_hdr_from_disk(dp->i_mount, &nodehdr, node);
if (oldblk->index <= nodehdr.count) {
oldblk->index++;
xfs_da3_node_add(state, oldblk, addblk);
if (useextra) {
if (state->extraafter)
oldblk->index++;
xfs_da3_node_add(state, oldblk, &state->extrablk);
state->extravalid = 0;
}
} else {
newblk->index++;
xfs_da3_node_add(state, newblk, addblk);
if (useextra) {
if (state->extraafter)
newblk->index++;
xfs_da3_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_da3_node_rebalance(
struct xfs_da_state *state,
struct xfs_da_state_blk *blk1,
struct xfs_da_state_blk *blk2)
{
struct xfs_da_intnode *node1;
struct xfs_da_intnode *node2;
struct xfs_da_intnode *tmpnode;
struct xfs_da_node_entry *btree1;
struct xfs_da_node_entry *btree2;
struct xfs_da_node_entry *btree_s;
struct xfs_da_node_entry *btree_d;
struct xfs_da3_icnode_hdr nodehdr1;
struct xfs_da3_icnode_hdr nodehdr2;
struct xfs_trans *tp;
int count;
int tmp;
int swap = 0;
struct xfs_inode *dp = state->args->dp;
trace_xfs_da_node_rebalance(state->args);
node1 = blk1->bp->b_addr;
node2 = blk2->bp->b_addr;
xfs_da3_node_hdr_from_disk(dp->i_mount, &nodehdr1, node1);
xfs_da3_node_hdr_from_disk(dp->i_mount, &nodehdr2, node2);
btree1 = nodehdr1.btree;
btree2 = nodehdr2.btree;
/*
* Figure out how many entries need to move, and in which direction.
* Swap the nodes around if that makes it simpler.
*/
if (nodehdr1.count > 0 && nodehdr2.count > 0 &&
((be32_to_cpu(btree2[0].hashval) < be32_to_cpu(btree1[0].hashval)) ||
(be32_to_cpu(btree2[nodehdr2.count - 1].hashval) <
be32_to_cpu(btree1[nodehdr1.count - 1].hashval)))) {
tmpnode = node1;
node1 = node2;
node2 = tmpnode;
xfs_da3_node_hdr_from_disk(dp->i_mount, &nodehdr1, node1);
xfs_da3_node_hdr_from_disk(dp->i_mount, &nodehdr2, node2);
btree1 = nodehdr1.btree;
btree2 = nodehdr2.btree;
swap = 1;
}
count = (nodehdr1.count - nodehdr2.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.
*/
tmp = nodehdr2.count;
if (tmp > 0) {
tmp *= (uint)sizeof(xfs_da_node_entry_t);
btree_s = &btree2[0];
btree_d = &btree2[count];
memmove(btree_d, btree_s, tmp);
}
/*
* Move the req'd B-tree elements from high in node1 to
* low in node2.
*/
nodehdr2.count += count;
tmp = count * (uint)sizeof(xfs_da_node_entry_t);
btree_s = &btree1[nodehdr1.count - count];
btree_d = &btree2[0];
memcpy(btree_d, btree_s, tmp);
nodehdr1.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 = &btree2[0];
btree_d = &btree1[nodehdr1.count];
memcpy(btree_d, btree_s, tmp);
nodehdr1.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 = nodehdr2.count - count;
tmp *= (uint)sizeof(xfs_da_node_entry_t);
btree_s = &btree2[count];
btree_d = &btree2[0];
memmove(btree_d, btree_s, tmp);
nodehdr2.count -= count;
}
/*
* Log header of node 1 and all current bits of node 2.
*/
xfs_da3_node_hdr_to_disk(dp->i_mount, node1, &nodehdr1);
xfs_trans_log_buf(tp, blk1->bp,
XFS_DA_LOGRANGE(node1, &node1->hdr,
state->args->geo->node_hdr_size));
xfs_da3_node_hdr_to_disk(dp->i_mount, node2, &nodehdr2);
xfs_trans_log_buf(tp, blk2->bp,
XFS_DA_LOGRANGE(node2, &node2->hdr,
state->args->geo->node_hdr_size +
(sizeof(btree2[0]) * nodehdr2.count)));
/*
* Record the last hashval from each block for upward propagation.
* (note: don't use the swapped node pointers)
*/
if (swap) {
node1 = blk1->bp->b_addr;
node2 = blk2->bp->b_addr;
xfs_da3_node_hdr_from_disk(dp->i_mount, &nodehdr1, node1);
xfs_da3_node_hdr_from_disk(dp->i_mount, &nodehdr2, node2);
btree1 = nodehdr1.btree;
btree2 = nodehdr2.btree;
}
blk1->hashval = be32_to_cpu(btree1[nodehdr1.count - 1].hashval);
blk2->hashval = be32_to_cpu(btree2[nodehdr2.count - 1].hashval);
/*
* Adjust the expected index for insertion.
*/
if (blk1->index >= nodehdr1.count) {
blk2->index = blk1->index - nodehdr1.count;
blk1->index = nodehdr1.count + 1; /* make it invalid */
}
}
/*
* Add a new entry to an intermediate node.
*/
STATIC void
xfs_da3_node_add(
struct xfs_da_state *state,
struct xfs_da_state_blk *oldblk,
struct xfs_da_state_blk *newblk)
{
struct xfs_da_intnode *node;
struct xfs_da3_icnode_hdr nodehdr;
struct xfs_da_node_entry *btree;
int tmp;
struct xfs_inode *dp = state->args->dp;
trace_xfs_da_node_add(state->args);
node = oldblk->bp->b_addr;
xfs_da3_node_hdr_from_disk(dp->i_mount, &nodehdr, node);
btree = nodehdr.btree;
ASSERT(oldblk->index >= 0 && oldblk->index <= nodehdr.count);
ASSERT(newblk->blkno != 0);
if (state->args->whichfork == XFS_DATA_FORK)
ASSERT(newblk->blkno >= state->args->geo->leafblk &&
newblk->blkno < state->args->geo->freeblk);
/*
* We may need to make some room before we insert the new node.
*/
tmp = 0;
if (oldblk->index < nodehdr.count) {
tmp = (nodehdr.count - oldblk->index) * (uint)sizeof(*btree);
memmove(&btree[oldblk->index + 1], &btree[oldblk->index], tmp);
}
btree[oldblk->index].hashval = cpu_to_be32(newblk->hashval);
btree[oldblk->index].before = cpu_to_be32(newblk->blkno);
xfs_trans_log_buf(state->args->trans, oldblk->bp,
XFS_DA_LOGRANGE(node, &btree[oldblk->index],
tmp + sizeof(*btree)));
nodehdr.count += 1;
xfs_da3_node_hdr_to_disk(dp->i_mount, node, &nodehdr);
xfs_trans_log_buf(state->args->trans, oldblk->bp,
XFS_DA_LOGRANGE(node, &node->hdr,
state->args->geo->node_hdr_size));
/*
* Copy the last hash value from the oldblk to propagate upwards.
*/
oldblk->hashval = be32_to_cpu(btree[nodehdr.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_da3_join(
struct xfs_da_state *state)
{
struct xfs_da_state_blk *drop_blk;
struct xfs_da_state_blk *save_blk;
int action = 0;
int error;
trace_xfs_da_join(state->args);
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_attr3_leaf_toosmall(state, &action);
if (error)
return error;
if (action == 0)
return 0;
xfs_attr3_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_da3_node_remove(state, drop_blk);
xfs_da3_fixhashpath(state, &state->path);
error = xfs_da3_node_toosmall(state, &action);
if (error)
return error;
if (action == 0)
return 0;
xfs_da3_node_unbalance(state, drop_blk, save_blk);
break;
}
xfs_da3_fixhashpath(state, &state->altpath);
error = xfs_da3_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_da3_node_remove(state, drop_blk);
xfs_da3_fixhashpath(state, &state->path);
error = xfs_da3_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_DIR3_LEAFN_MAGIC) ||
magic == cpu_to_be16(XFS_ATTR_LEAF_MAGIC) ||
magic == cpu_to_be16(XFS_ATTR3_LEAF_MAGIC));
} else {
ASSERT(magic == cpu_to_be16(XFS_DA_NODE_MAGIC) ||
magic == cpu_to_be16(XFS_DA3_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_da3_root_join(
struct xfs_da_state *state,
struct xfs_da_state_blk *root_blk)
{
struct xfs_da_intnode *oldroot;
struct xfs_da_args *args;
xfs_dablk_t child;
struct xfs_buf *bp;
struct xfs_da3_icnode_hdr oldroothdr;
int error;
struct xfs_inode *dp = state->args->dp;
trace_xfs_da_root_join(state->args);
ASSERT(root_blk->magic == XFS_DA_NODE_MAGIC);
args = state->args;
oldroot = root_blk->bp->b_addr;
xfs_da3_node_hdr_from_disk(dp->i_mount, &oldroothdr, oldroot);
ASSERT(oldroothdr.forw == 0);
ASSERT(oldroothdr.back == 0);
/*
* If the root has more than one child, then don't do anything.
*/
if (oldroothdr.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(oldroothdr.btree[0].before);
ASSERT(child != 0);
error = xfs_da3_node_read(args->trans, dp, child, &bp, args->whichfork);
if (error)
return error;
xfs_da_blkinfo_onlychild_validate(bp->b_addr, oldroothdr.level);
/*
* This could be copying a leaf back into the root block in the case of
* there only being a single leaf block left in the tree. Hence we have
* to update the b_ops pointer as well to match the buffer type change
* that could occur. For dir3 blocks we also need to update the block
* number in the buffer header.
*/
memcpy(root_blk->bp->b_addr, bp->b_addr, args->geo->blksize);
root_blk->bp->b_ops = bp->b_ops;
xfs_trans_buf_copy_type(root_blk->bp, bp);
if (oldroothdr.magic == XFS_DA3_NODE_MAGIC) {
struct xfs_da3_blkinfo *da3 = root_blk->bp->b_addr;
da3->blkno = cpu_to_be64(root_blk->bp->b_bn);
}
xfs_trans_log_buf(args->trans, root_blk->bp, 0,
args->geo->blksize - 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_da3_node_toosmall(
struct xfs_da_state *state,
int *action)
{
struct xfs_da_intnode *node;
struct xfs_da_state_blk *blk;
struct xfs_da_blkinfo *info;
xfs_dablk_t blkno;
struct xfs_buf *bp;
struct xfs_da3_icnode_hdr nodehdr;
int count;
int forward;
int error;
int retval;
int i;
struct xfs_inode *dp = state->args->dp;
trace_xfs_da_node_toosmall(state->args);
/*
* 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;
node = (xfs_da_intnode_t *)info;
xfs_da3_node_hdr_from_disk(dp->i_mount, &nodehdr, node);
if (nodehdr.count > (state->args->geo->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 (nodehdr.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_da3_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.
*/
count = state->args->geo->node_ents;
count -= state->args->geo->node_ents >> 2;
count -= nodehdr.count;
/* start with smaller blk num */
forward = nodehdr.forw < nodehdr.back;
for (i = 0; i < 2; forward = !forward, i++) {
struct xfs_da3_icnode_hdr thdr;
if (forward)
blkno = nodehdr.forw;
else
blkno = nodehdr.back;
if (blkno == 0)
continue;
error = xfs_da3_node_read(state->args->trans, dp, blkno, &bp,
state->args->whichfork);
if (error)
return error;
node = bp->b_addr;
xfs_da3_node_hdr_from_disk(dp->i_mount, &thdr, node);
xfs_trans_brelse(state->args->trans, bp);
if (count - thdr.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_da3_path_shift(state, &state->altpath, forward,
0, &retval);
} else {
error = xfs_da3_path_shift(state, &state->path, forward,
0, &retval);
}
if (error)
return error;
if (retval) {
*action = 0;
return 0;
}
*action = 1;
return 0;
}
/*
* Pick up the last hashvalue from an intermediate node.
*/
STATIC uint
xfs_da3_node_lasthash(
struct xfs_inode *dp,
struct xfs_buf *bp,
int *count)
{
struct xfs_da3_icnode_hdr nodehdr;
xfs_da3_node_hdr_from_disk(dp->i_mount, &nodehdr, bp->b_addr);
if (count)
*count = nodehdr.count;
if (!nodehdr.count)
return 0;
return be32_to_cpu(nodehdr.btree[nodehdr.count - 1].hashval);
}
/*
* Walk back up the tree adjusting hash values as necessary,
* when we stop making changes, return.
*/
void
xfs_da3_fixhashpath(
struct xfs_da_state *state,
struct xfs_da_state_path *path)
{
struct xfs_da_state_blk *blk;
struct xfs_da_intnode *node;
struct xfs_da_node_entry *btree;
xfs_dahash_t lasthash=0;
int level;
int count;
struct xfs_inode *dp = state->args->dp;
trace_xfs_da_fixhashpath(state->args);
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_leaf_lasthash(dp, blk->bp, &count);
if (count == 0)
return;
break;
case XFS_DA_NODE_MAGIC:
lasthash = xfs_da3_node_lasthash(dp, blk->bp, &count);
if (count == 0)
return;
break;
}
for (blk--, level--; level >= 0; blk--, level--) {
struct xfs_da3_icnode_hdr nodehdr;
node = blk->bp->b_addr;
xfs_da3_node_hdr_from_disk(dp->i_mount, &nodehdr, node);
btree = nodehdr.btree;
if (be32_to_cpu(btree[blk->index].hashval) == lasthash)
break;
blk->hashval = lasthash;
btree[blk->index].hashval = cpu_to_be32(lasthash);
xfs_trans_log_buf(state->args->trans, blk->bp,
XFS_DA_LOGRANGE(node, &btree[blk->index],
sizeof(*btree)));
lasthash = be32_to_cpu(btree[nodehdr.count - 1].hashval);
}
}
/*
* Remove an entry from an intermediate node.
*/
STATIC void
xfs_da3_node_remove(
struct xfs_da_state *state,
struct xfs_da_state_blk *drop_blk)
{
struct xfs_da_intnode *node;
struct xfs_da3_icnode_hdr nodehdr;
struct xfs_da_node_entry *btree;
int index;
int tmp;
struct xfs_inode *dp = state->args->dp;
trace_xfs_da_node_remove(state->args);
node = drop_blk->bp->b_addr;
xfs_da3_node_hdr_from_disk(dp->i_mount, &nodehdr, node);
ASSERT(drop_blk->index < nodehdr.count);
ASSERT(drop_blk->index >= 0);
/*
* Copy over the offending entry, or just zero it out.
*/
index = drop_blk->index;
btree = nodehdr.btree;
if (index < nodehdr.count - 1) {
tmp = nodehdr.count - index - 1;
tmp *= (uint)sizeof(xfs_da_node_entry_t);
memmove(&btree[index], &btree[index + 1], tmp);
xfs_trans_log_buf(state->args->trans, drop_blk->bp,
XFS_DA_LOGRANGE(node, &btree[index], tmp));
index = nodehdr.count - 1;
}
memset(&btree[index], 0, sizeof(xfs_da_node_entry_t));
xfs_trans_log_buf(state->args->trans, drop_blk->bp,
XFS_DA_LOGRANGE(node, &btree[index], sizeof(btree[index])));
nodehdr.count -= 1;
xfs_da3_node_hdr_to_disk(dp->i_mount, node, &nodehdr);
xfs_trans_log_buf(state->args->trans, drop_blk->bp,
XFS_DA_LOGRANGE(node, &node->hdr, state->args->geo->node_hdr_size));
/*
* Copy the last hash value from the block to propagate upwards.
*/
drop_blk->hashval = be32_to_cpu(btree[index - 1].hashval);
}
/*
* Unbalance the elements between two intermediate nodes,
* move all Btree elements from one node into another.
*/
STATIC void
xfs_da3_node_unbalance(
struct xfs_da_state *state,
struct xfs_da_state_blk *drop_blk,
struct xfs_da_state_blk *save_blk)
{
struct xfs_da_intnode *drop_node;
struct xfs_da_intnode *save_node;
struct xfs_da_node_entry *drop_btree;
struct xfs_da_node_entry *save_btree;
struct xfs_da3_icnode_hdr drop_hdr;
struct xfs_da3_icnode_hdr save_hdr;
struct xfs_trans *tp;
int sindex;
int tmp;
struct xfs_inode *dp = state->args->dp;
trace_xfs_da_node_unbalance(state->args);
drop_node = drop_blk->bp->b_addr;
save_node = save_blk->bp->b_addr;
xfs_da3_node_hdr_from_disk(dp->i_mount, &drop_hdr, drop_node);
xfs_da3_node_hdr_from_disk(dp->i_mount, &save_hdr, save_node);
drop_btree = drop_hdr.btree;
save_btree = save_hdr.btree;
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_btree[0].hashval) <
be32_to_cpu(save_btree[0].hashval)) ||
(be32_to_cpu(drop_btree[drop_hdr.count - 1].hashval) <
be32_to_cpu(save_btree[save_hdr.count - 1].hashval))) {
/* XXX: check this - is memmove dst correct? */
tmp = save_hdr.count * sizeof(xfs_da_node_entry_t);
memmove(&save_btree[drop_hdr.count], &save_btree[0], tmp);
sindex = 0;
xfs_trans_log_buf(tp, save_blk->bp,
XFS_DA_LOGRANGE(save_node, &save_btree[0],
(save_hdr.count + drop_hdr.count) *
sizeof(xfs_da_node_entry_t)));
} else {
sindex = save_hdr.count;
xfs_trans_log_buf(tp, save_blk->bp,
XFS_DA_LOGRANGE(save_node, &save_btree[sindex],
drop_hdr.count * sizeof(xfs_da_node_entry_t)));
}
/*
* Move all the B-tree elements from drop_blk to save_blk.
*/
tmp = drop_hdr.count * (uint)sizeof(xfs_da_node_entry_t);
memcpy(&save_btree[sindex], &drop_btree[0], tmp);
save_hdr.count += drop_hdr.count;
xfs_da3_node_hdr_to_disk(dp->i_mount, save_node, &save_hdr);
xfs_trans_log_buf(tp, save_blk->bp,
XFS_DA_LOGRANGE(save_node, &save_node->hdr,
state->args->geo->node_hdr_size));
/*
* Save the last hashval in the remaining block for upward propagation.
*/
save_blk->hashval = be32_to_cpu(save_btree[save_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_da3_node_lookup_int(
struct xfs_da_state *state,
int *result)
{
struct xfs_da_state_blk *blk;
struct xfs_da_blkinfo *curr;
struct xfs_da_intnode *node;
struct xfs_da_node_entry *btree;
struct xfs_da3_icnode_hdr nodehdr;
struct xfs_da_args *args;
xfs_dablk_t blkno;
xfs_dahash_t hashval;
xfs_dahash_t btreehashval;
int probe;
int span;
int max;
int error;
int retval;
unsigned int expected_level = 0;
uint16_t magic;
struct xfs_inode *dp = state->args->dp;
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->geo->leafblk;
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_da3_node_read(args->trans, args->dp, blkno,
&blk->bp, args->whichfork);
if (error) {
blk->blkno = 0;
state->path.active--;
return error;
}
curr = blk->bp->b_addr;
magic = be16_to_cpu(curr->magic);
if (magic == XFS_ATTR_LEAF_MAGIC ||
magic == XFS_ATTR3_LEAF_MAGIC) {
blk->magic = XFS_ATTR_LEAF_MAGIC;
blk->hashval = xfs_attr_leaf_lasthash(blk->bp, NULL);
break;
}
if (magic == XFS_DIR2_LEAFN_MAGIC ||
magic == XFS_DIR3_LEAFN_MAGIC) {
blk->magic = XFS_DIR2_LEAFN_MAGIC;
blk->hashval = xfs_dir2_leaf_lasthash(args->dp,
blk->bp, NULL);
break;
}
if (magic != XFS_DA_NODE_MAGIC && magic != XFS_DA3_NODE_MAGIC) {
xfs_buf_corruption_error(blk->bp);
return -EFSCORRUPTED;
}
blk->magic = XFS_DA_NODE_MAGIC;
/*
* Search an intermediate node for a match.
*/
node = blk->bp->b_addr;
xfs_da3_node_hdr_from_disk(dp->i_mount, &nodehdr, node);
btree = nodehdr.btree;
/* Tree taller than we can handle; bail out! */
if (nodehdr.level >= XFS_DA_NODE_MAXDEPTH) {
xfs_buf_corruption_error(blk->bp);
return -EFSCORRUPTED;
}
/* Check the level from the root. */
if (blkno == args->geo->leafblk)
expected_level = nodehdr.level - 1;
else if (expected_level != nodehdr.level) {
xfs_buf_corruption_error(blk->bp);
return -EFSCORRUPTED;
} else
expected_level--;
max = nodehdr.count;
blk->hashval = be32_to_cpu(btree[max - 1].hashval);
/*
* Binary search. (note: small blocks will skip loop)
*/
probe = span = max / 2;
hashval = args->hashval;
while (span > 4) {
span /= 2;
btreehashval = be32_to_cpu(btree[probe].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[probe].hashval) == hashval));
/*
* Since we may have duplicate hashval's, find the first
* matching hashval in the node.
*/
while (probe > 0 &&
be32_to_cpu(btree[probe].hashval) >= hashval) {
probe--;
}
while (probe < max &&
be32_to_cpu(btree[probe].hashval) < hashval) {
probe++;
}
/*
* Pick the right block to descend on.
*/
if (probe == max) {
blk->index = max - 1;
blkno = be32_to_cpu(btree[max - 1].before);
} else {
blk->index = probe;
blkno = be32_to_cpu(btree[probe].before);
}
/* We can't point back to the root. */
if (XFS_IS_CORRUPT(dp->i_mount, blkno == args->geo->leafblk))
return -EFSCORRUPTED;
}
if (XFS_IS_CORRUPT(dp->i_mount, expected_level != 0))
return -EFSCORRUPTED;
/*
* 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_attr3_leaf_lookup_int(blk->bp, args);
blk->index = args->index;
args->blkno = blk->blkno;
} else {
ASSERT(0);
return -EFSCORRUPTED;
}
if (((retval == -ENOENT) || (retval == -ENOATTR)) &&
(blk->hashval == args->hashval)) {
error = xfs_da3_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 = -ENOATTR;
}
}
break;
}
*result = retval;
return 0;
}
/*========================================================================
* Utility routines.
*========================================================================*/
/*
* Compare two intermediate nodes for "order".
*/
STATIC int
xfs_da3_node_order(
struct xfs_inode *dp,
struct xfs_buf *node1_bp,
struct xfs_buf *node2_bp)
{
struct xfs_da_intnode *node1;
struct xfs_da_intnode *node2;
struct xfs_da_node_entry *btree1;
struct xfs_da_node_entry *btree2;
struct xfs_da3_icnode_hdr node1hdr;
struct xfs_da3_icnode_hdr node2hdr;
node1 = node1_bp->b_addr;
node2 = node2_bp->b_addr;
xfs_da3_node_hdr_from_disk(dp->i_mount, &node1hdr, node1);
xfs_da3_node_hdr_from_disk(dp->i_mount, &node2hdr, node2);
btree1 = node1hdr.btree;
btree2 = node2hdr.btree;
if (node1hdr.count > 0 && node2hdr.count > 0 &&
((be32_to_cpu(btree2[0].hashval) < be32_to_cpu(btree1[0].hashval)) ||
(be32_to_cpu(btree2[node2hdr.count - 1].hashval) <
be32_to_cpu(btree1[node1hdr.count - 1].hashval)))) {
return 1;
}
return 0;
}
/*
* Link a new block into a doubly linked list of blocks (of whatever type).
*/
int /* error */
xfs_da3_blk_link(
struct xfs_da_state *state,
struct xfs_da_state_blk *old_blk,
struct xfs_da_state_blk *new_blk)
{
struct xfs_da_blkinfo *old_info;
struct xfs_da_blkinfo *new_info;
struct xfs_da_blkinfo *tmp_info;
struct xfs_da_args *args;
struct xfs_buf *bp;
int before = 0;
int error;
struct xfs_inode *dp = state->args->dp;
/*
* 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);
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(dp, old_blk->bp, new_blk->bp);
break;
case XFS_DA_NODE_MAGIC:
before = xfs_da3_node_order(dp, 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_da3_node_read(args->trans, dp,
be32_to_cpu(old_info->back),
&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->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_da3_node_read(args->trans, dp,
be32_to_cpu(old_info->forw),
&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;
}
/*
* Unlink a block from a doubly linked list of blocks.
*/
STATIC int /* error */
xfs_da3_blk_unlink(
struct xfs_da_state *state,
struct xfs_da_state_blk *drop_blk,
struct xfs_da_state_blk *save_blk)
{
struct xfs_da_blkinfo *drop_info;
struct xfs_da_blkinfo *save_info;
struct xfs_da_blkinfo *tmp_info;
struct xfs_da_args *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 == 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_da3_node_read(args->trans, args->dp,
be32_to_cpu(drop_info->back),
&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_da3_node_read(args->trans, args->dp,
be32_to_cpu(drop_info->forw),
&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_da3_path_shift(
struct xfs_da_state *state,
struct xfs_da_state_path *path,
int forward,
int release,
int *result)
{
struct xfs_da_state_blk *blk;
struct xfs_da_blkinfo *info;
struct xfs_da_args *args;
struct xfs_da_node_entry *btree;
struct xfs_da3_icnode_hdr nodehdr;
struct xfs_buf *bp;
xfs_dablk_t blkno = 0;
int level;
int error;
struct xfs_inode *dp = state->args->dp;
trace_xfs_da_path_shift(state->args);
/*
* 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--) {
xfs_da3_node_hdr_from_disk(dp->i_mount, &nodehdr,
blk->bp->b_addr);
if (forward && (blk->index < nodehdr.count - 1)) {
blk->index++;
blkno = be32_to_cpu(nodehdr.btree[blk->index].before);
break;
} else if (!forward && (blk->index > 0)) {
blk->index--;
blkno = be32_to_cpu(nodehdr.btree[blk->index].before);
break;
}
}
if (level < 0) {
*result = -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++) {
/*
* Read the next child block into a local buffer.
*/
error = xfs_da3_node_read(args->trans, dp, blkno, &bp,
args->whichfork);
if (error)
return error;
/*
* Release the old block (if it's dirty, the trans doesn't
* actually let go) and swap the local buffer into the path
* structure. This ensures failure of the above read doesn't set
* a NULL buffer in an active slot in the path.
*/
if (release)
xfs_trans_brelse(args->trans, blk->bp);
blk->blkno = blkno;
blk->bp = bp;
info = blk->bp->b_addr;
ASSERT(info->magic == cpu_to_be16(XFS_DA_NODE_MAGIC) ||
info->magic == cpu_to_be16(XFS_DA3_NODE_MAGIC) ||
info->magic == cpu_to_be16(XFS_DIR2_LEAFN_MAGIC) ||
info->magic == cpu_to_be16(XFS_DIR3_LEAFN_MAGIC) ||
info->magic == cpu_to_be16(XFS_ATTR_LEAF_MAGIC) ||
info->magic == cpu_to_be16(XFS_ATTR3_LEAF_MAGIC));
/*
* Note: we flatten the magic number to a single type so we
* don't have to compare against crc/non-crc types elsewhere.
*/
switch (be16_to_cpu(info->magic)) {
case XFS_DA_NODE_MAGIC:
case XFS_DA3_NODE_MAGIC:
blk->magic = XFS_DA_NODE_MAGIC;
xfs_da3_node_hdr_from_disk(dp->i_mount, &nodehdr,
bp->b_addr);
btree = nodehdr.btree;
blk->hashval = be32_to_cpu(btree[nodehdr.count - 1].hashval);
if (forward)
blk->index = 0;
else
blk->index = nodehdr.count - 1;
blkno = be32_to_cpu(btree[blk->index].before);
break;
case XFS_ATTR_LEAF_MAGIC:
case XFS_ATTR3_LEAF_MAGIC:
blk->magic = XFS_ATTR_LEAF_MAGIC;
ASSERT(level == path->active-1);
blk->index = 0;
blk->hashval = xfs_attr_leaf_lasthash(blk->bp, NULL);
break;
case XFS_DIR2_LEAFN_MAGIC:
case XFS_DIR3_LEAFN_MAGIC:
blk->magic = XFS_DIR2_LEAFN_MAGIC;
ASSERT(level == path->active-1);
blk->index = 0;
blk->hashval = xfs_dir2_leaf_lasthash(args->dp,
blk->bp, NULL);
break;
default:
ASSERT(0);
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;
}
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_rfsblock_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;
error = xfs_bmapi_write(tp, dp, *bno, count,
xfs_bmapi_aflag(w)|XFS_BMAPI_METADATA|XFS_BMAPI_CONTIG,
args->total, &map, &nmap);
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, 0);
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->total, &mapp[mapi], &nmap);
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 = -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 error;
trace_xfs_da_grow_inode(args);
bno = args->geo->leafblk;
error = xfs_da_grow_inode_int(args, &bno, args->geo->fsbcount);
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_da3_swap_lastblock(
struct xfs_da_args *args,
xfs_dablk_t *dead_blknop,
struct xfs_buf **dead_bufp)
{
struct xfs_da_blkinfo *dead_info;
struct xfs_da_blkinfo *sib_info;
struct xfs_da_intnode *par_node;
struct xfs_da_intnode *dead_node;
struct xfs_dir2_leaf *dead_leaf2;
struct xfs_da_node_entry *btree;
struct xfs_da3_icnode_hdr par_hdr;
struct xfs_inode *dp;
struct xfs_trans *tp;
struct xfs_mount *mp;
struct xfs_buf *dead_buf;
struct xfs_buf *last_buf;
struct xfs_buf *sib_buf;
struct xfs_buf *par_buf;
xfs_dahash_t dead_hash;
xfs_fileoff_t lastoff;
xfs_dablk_t dead_blkno;
xfs_dablk_t last_blkno;
xfs_dablk_t sib_blkno;
xfs_dablk_t par_blkno;
int error;
int w;
int entno;
int level;
int dead_level;
trace_xfs_da_swap_lastblock(args);
dead_buf = *dead_bufp;
dead_blkno = *dead_blknop;
tp = args->trans;
dp = args->dp;
w = args->whichfork;
ASSERT(w == XFS_DATA_FORK);
mp = dp->i_mount;
lastoff = args->geo->freeblk;
error = xfs_bmap_last_before(tp, dp, &lastoff, w);
if (error)
return error;
if (XFS_IS_CORRUPT(mp, lastoff == 0))
return -EFSCORRUPTED;
/*
* Read the last block in the btree space.
*/
last_blkno = (xfs_dablk_t)lastoff - args->geo->fsbcount;
error = xfs_da3_node_read(tp, dp, last_blkno, &last_buf, w);
if (error)
return error;
/*
* Copy the last block into the dead buffer and log it.
*/
memcpy(dead_buf->b_addr, last_buf->b_addr, args->geo->blksize);
xfs_trans_log_buf(tp, dead_buf, 0, args->geo->blksize - 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_info->magic == cpu_to_be16(XFS_DIR3_LEAFN_MAGIC)) {
struct xfs_dir3_icleaf_hdr leafhdr;
struct xfs_dir2_leaf_entry *ents;
dead_leaf2 = (xfs_dir2_leaf_t *)dead_info;
xfs_dir2_leaf_hdr_from_disk(dp->i_mount, &leafhdr,
dead_leaf2);
ents = leafhdr.ents;
dead_level = 0;
dead_hash = be32_to_cpu(ents[leafhdr.count - 1].hashval);
} else {
struct xfs_da3_icnode_hdr deadhdr;
dead_node = (xfs_da_intnode_t *)dead_info;
xfs_da3_node_hdr_from_disk(dp->i_mount, &deadhdr, dead_node);
btree = deadhdr.btree;
dead_level = deadhdr.level;
dead_hash = be32_to_cpu(btree[deadhdr.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))) {
error = xfs_da3_node_read(tp, dp, sib_blkno, &sib_buf, w);
if (error)
goto done;
sib_info = sib_buf->b_addr;
if (XFS_IS_CORRUPT(mp,
be32_to_cpu(sib_info->forw) != last_blkno ||
sib_info->magic != dead_info->magic)) {
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))) {
error = xfs_da3_node_read(tp, dp, sib_blkno, &sib_buf, w);
if (error)
goto done;
sib_info = sib_buf->b_addr;
if (XFS_IS_CORRUPT(mp,
be32_to_cpu(sib_info->back) != last_blkno ||
sib_info->magic != dead_info->magic)) {
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 = args->geo->leafblk;
level = -1;
/*
* Walk down the tree looking for the parent of the moved block.
*/
for (;;) {
error = xfs_da3_node_read(tp, dp, par_blkno, &par_buf, w);
if (error)
goto done;
par_node = par_buf->b_addr;
xfs_da3_node_hdr_from_disk(dp->i_mount, &par_hdr, par_node);
if (XFS_IS_CORRUPT(mp,
level >= 0 && level != par_hdr.level + 1)) {
error = -EFSCORRUPTED;
goto done;
}
level = par_hdr.level;
btree = par_hdr.btree;
for (entno = 0;
entno < par_hdr.count &&
be32_to_cpu(btree[entno].hashval) < dead_hash;
entno++)
continue;
if (XFS_IS_CORRUPT(mp, entno == par_hdr.count)) {
error = -EFSCORRUPTED;
goto done;
}
par_blkno = be32_to_cpu(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 < par_hdr.count &&
be32_to_cpu(btree[entno].before) != last_blkno;
entno++)
continue;
if (entno < par_hdr.count)
break;
par_blkno = par_hdr.forw;
xfs_trans_brelse(tp, par_buf);
par_buf = NULL;
if (XFS_IS_CORRUPT(mp, par_blkno == 0)) {
error = -EFSCORRUPTED;
goto done;
}
error = xfs_da3_node_read(tp, dp, par_blkno, &par_buf, w);
if (error)
goto done;
par_node = par_buf->b_addr;
xfs_da3_node_hdr_from_disk(dp->i_mount, &par_hdr, par_node);
if (XFS_IS_CORRUPT(mp, par_hdr.level != level)) {
error = -EFSCORRUPTED;
goto done;
}
btree = par_hdr.btree;
entno = 0;
}
/*
* Update the parent entry pointing to the moved block.
*/
btree[entno].before = cpu_to_be32(dead_blkno);
xfs_trans_log_buf(tp, par_buf,
XFS_DA_LOGRANGE(par_node, &btree[entno].before,
sizeof(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(
struct xfs_da_args *args,
xfs_dablk_t dead_blkno,
struct xfs_buf *dead_buf)
{
struct xfs_inode *dp;
int done, error, w, count;
struct xfs_trans *tp;
trace_xfs_da_shrink_inode(args);
dp = args->dp;
w = args->whichfork;
tp = args->trans;
count = args->geo->fsbcount;
for (;;) {
/*
* Remove extents. If we get ENOSPC for a dir we have to move
* the last block to the place we want to kill.
*/
error = xfs_bunmapi(tp, dp, dead_blkno, count,
xfs_bmapi_aflag(w), 0, &done);
if (error == -ENOSPC) {
if (w != XFS_DATA_FORK)
break;
error = xfs_da3_swap_lastblock(args, &dead_blkno,
&dead_buf);
if (error)
break;
} else {
break;
}
}
xfs_trans_binval(tp, dead_buf);
return error;
}
static int
xfs_dabuf_map(
struct xfs_inode *dp,
xfs_dablk_t bno,
unsigned int flags,
int whichfork,
struct xfs_buf_map **mapp,
int *nmaps)
{
struct xfs_mount *mp = dp->i_mount;
int nfsb = xfs_dabuf_nfsb(mp, whichfork);
struct xfs_bmbt_irec irec, *irecs = &irec;
struct xfs_buf_map *map = *mapp;
xfs_fileoff_t off = bno;
int error = 0, nirecs, i;
if (nfsb > 1)
irecs = kmem_zalloc(sizeof(irec) * nfsb, KM_NOFS);
nirecs = nfsb;
error = xfs_bmapi_read(dp, bno, nfsb, irecs, &nirecs,
xfs_bmapi_aflag(whichfork));
if (error)
goto out_free_irecs;
/*
* Use the caller provided map for the single map case, else allocate a
* larger one that needs to be free by the caller.
*/
if (nirecs > 1) {
map = kmem_zalloc(nirecs * sizeof(struct xfs_buf_map), KM_NOFS);
if (!map)
goto out_free_irecs;
*mapp = map;
}
for (i = 0; i < nirecs; i++) {
if (irecs[i].br_startblock == HOLESTARTBLOCK ||
irecs[i].br_startblock == DELAYSTARTBLOCK)
goto invalid_mapping;
if (off != irecs[i].br_startoff)
goto invalid_mapping;
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);
off += irecs[i].br_blockcount;
}
if (off != bno + nfsb)
goto invalid_mapping;
*nmaps = nirecs;
out_free_irecs:
if (irecs != &irec)
kmem_free(irecs);
return error;
invalid_mapping:
/* Caller ok with no mapping. */
if (XFS_IS_CORRUPT(mp, !(flags & XFS_DABUF_MAP_HOLE_OK))) {
error = -EFSCORRUPTED;
if (xfs_error_level >= XFS_ERRLEVEL_LOW) {
xfs_alert(mp, "%s: bno %u inode %llu",
__func__, bno, dp->i_ino);
for (i = 0; i < nirecs; i++) {
xfs_alert(mp,
"[%02d] br_startoff %lld br_startblock %lld br_blockcount %lld br_state %d",
i, irecs[i].br_startoff,
irecs[i].br_startblock,
irecs[i].br_blockcount,
irecs[i].br_state);
}
}
} else {
*nmaps = 0;
}
goto out_free_irecs;
}
/*
* Get a buffer for the dir/attr block.
*/
int
xfs_da_get_buf(
struct xfs_trans *tp,
struct xfs_inode *dp,
xfs_dablk_t bno,
struct xfs_buf **bpp,
int whichfork)
{
struct xfs_mount *mp = dp->i_mount;
struct xfs_buf *bp;
struct xfs_buf_map map, *mapp = &map;
int nmap = 1;
int error;
*bpp = NULL;
error = xfs_dabuf_map(dp, bno, 0, whichfork, &mapp, &nmap);
if (error || nmap == 0)
goto out_free;
error = xfs_trans_get_buf_map(tp, mp->m_ddev_targp, mapp, nmap, 0, &bp);
if (error)
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 *tp,
struct xfs_inode *dp,
xfs_dablk_t bno,
unsigned int flags,
struct xfs_buf **bpp,
int whichfork,
const struct xfs_buf_ops *ops)
{
struct xfs_mount *mp = dp->i_mount;
struct xfs_buf *bp;
struct xfs_buf_map map, *mapp = &map;
int nmap = 1;
int error;
*bpp = NULL;
error = xfs_dabuf_map(dp, bno, flags, whichfork, &mapp, &nmap);
if (error || !nmap)
goto out_free;
error = xfs_trans_read_buf_map(mp, tp, mp->m_ddev_targp, mapp, nmap, 0,
&bp, ops);
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);
*bpp = bp;
out_free:
if (mapp != &map)
kmem_free(mapp);
return error;
}
/*
* Readahead the dir/attr block.
*/
int
xfs_da_reada_buf(
struct xfs_inode *dp,
xfs_dablk_t bno,
unsigned int flags,
int whichfork,
const struct xfs_buf_ops *ops)
{
struct xfs_buf_map map;
struct xfs_buf_map *mapp;
int nmap;
int error;
mapp = &map;
nmap = 1;
error = xfs_dabuf_map(dp, bno, flags, whichfork, &mapp, &nmap);
if (error || !nmap)
goto out_free;
xfs_buf_readahead_map(dp->i_mount->m_ddev_targp, mapp, nmap, ops);
out_free:
if (mapp != &map)
kmem_free(mapp);
return error;
}
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