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linuxdebug/fs/jfs/jfs_xtree.c

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null pointer error
2024-07-16 15:50:57 +02:00
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright (C) International Business Machines Corp., 2000-2005
*/
/*
* jfs_xtree.c: extent allocation descriptor B+-tree manager
*/
#include <linux/fs.h>
#include <linux/module.h>
#include <linux/quotaops.h>
#include <linux/seq_file.h>
#include "jfs_incore.h"
#include "jfs_filsys.h"
#include "jfs_metapage.h"
#include "jfs_dmap.h"
#include "jfs_dinode.h"
#include "jfs_superblock.h"
#include "jfs_debug.h"
/*
* xtree local flag
*/
#define XT_INSERT 0x00000001
/*
* xtree key/entry comparison: extent offset
*
* return:
* -1: k < start of extent
* 0: start_of_extent <= k <= end_of_extent
* 1: k > end_of_extent
*/
#define XT_CMP(CMP, K, X, OFFSET64)\
{\
OFFSET64 = offsetXAD(X);\
(CMP) = ((K) >= OFFSET64 + lengthXAD(X)) ? 1 :\
((K) < OFFSET64) ? -1 : 0;\
}
/* write a xad entry */
#define XT_PUTENTRY(XAD, FLAG, OFF, LEN, ADDR)\
{\
(XAD)->flag = (FLAG);\
XADoffset((XAD), (OFF));\
XADlength((XAD), (LEN));\
XADaddress((XAD), (ADDR));\
}
#define XT_PAGE(IP, MP) BT_PAGE(IP, MP, xtpage_t, i_xtroot)
/* get page buffer for specified block address */
/* ToDo: Replace this ugly macro with a function */
#define XT_GETPAGE(IP, BN, MP, SIZE, P, RC) \
do { \
BT_GETPAGE(IP, BN, MP, xtpage_t, SIZE, P, RC, i_xtroot); \
if (!(RC)) { \
if ((le16_to_cpu((P)->header.nextindex) < XTENTRYSTART) || \
(le16_to_cpu((P)->header.nextindex) > \
le16_to_cpu((P)->header.maxentry)) || \
(le16_to_cpu((P)->header.maxentry) > \
(((BN) == 0) ? XTROOTMAXSLOT : PSIZE >> L2XTSLOTSIZE))) { \
jfs_error((IP)->i_sb, \
"XT_GETPAGE: xtree page corrupt\n"); \
BT_PUTPAGE(MP); \
MP = NULL; \
RC = -EIO; \
} \
} \
} while (0)
/* for consistency */
#define XT_PUTPAGE(MP) BT_PUTPAGE(MP)
#define XT_GETSEARCH(IP, LEAF, BN, MP, P, INDEX) \
BT_GETSEARCH(IP, LEAF, BN, MP, xtpage_t, P, INDEX, i_xtroot)
/* xtree entry parameter descriptor */
struct xtsplit {
struct metapage *mp;
s16 index;
u8 flag;
s64 off;
s64 addr;
int len;
struct pxdlist *pxdlist;
};
/*
* statistics
*/
#ifdef CONFIG_JFS_STATISTICS
static struct {
uint search;
uint fastSearch;
uint split;
} xtStat;
#endif
/*
* forward references
*/
static int xtSearch(struct inode *ip, s64 xoff, s64 *next, int *cmpp,
struct btstack * btstack, int flag);
static int xtSplitUp(tid_t tid,
struct inode *ip,
struct xtsplit * split, struct btstack * btstack);
static int xtSplitPage(tid_t tid, struct inode *ip, struct xtsplit * split,
struct metapage ** rmpp, s64 * rbnp);
static int xtSplitRoot(tid_t tid, struct inode *ip,
struct xtsplit * split, struct metapage ** rmpp);
/*
* xtLookup()
*
* function: map a single page into a physical extent;
*/
int xtLookup(struct inode *ip, s64 lstart,
s64 llen, int *pflag, s64 * paddr, s32 * plen, int no_check)
{
int rc = 0;
struct btstack btstack;
int cmp;
s64 bn;
struct metapage *mp;
xtpage_t *p;
int index;
xad_t *xad;
s64 next, size, xoff, xend;
int xlen;
s64 xaddr;
*paddr = 0;
*plen = llen;
if (!no_check) {
/* is lookup offset beyond eof ? */
size = ((u64) ip->i_size + (JFS_SBI(ip->i_sb)->bsize - 1)) >>
JFS_SBI(ip->i_sb)->l2bsize;
if (lstart >= size)
return 0;
}
/*
* search for the xad entry covering the logical extent
*/
//search:
if ((rc = xtSearch(ip, lstart, &next, &cmp, &btstack, 0))) {
jfs_err("xtLookup: xtSearch returned %d", rc);
return rc;
}
/*
* compute the physical extent covering logical extent
*
* N.B. search may have failed (e.g., hole in sparse file),
* and returned the index of the next entry.
*/
/* retrieve search result */
XT_GETSEARCH(ip, btstack.top, bn, mp, p, index);
/* is xad found covering start of logical extent ?
* lstart is a page start address,
* i.e., lstart cannot start in a hole;
*/
if (cmp) {
if (next)
*plen = min(next - lstart, llen);
goto out;
}
/*
* lxd covered by xad
*/
xad = &p->xad[index];
xoff = offsetXAD(xad);
xlen = lengthXAD(xad);
xend = xoff + xlen;
xaddr = addressXAD(xad);
/* initialize new pxd */
*pflag = xad->flag;
*paddr = xaddr + (lstart - xoff);
/* a page must be fully covered by an xad */
*plen = min(xend - lstart, llen);
out:
XT_PUTPAGE(mp);
return rc;
}
/*
* xtSearch()
*
* function: search for the xad entry covering specified offset.
*
* parameters:
* ip - file object;
* xoff - extent offset;
* nextp - address of next extent (if any) for search miss
* cmpp - comparison result:
* btstack - traverse stack;
* flag - search process flag (XT_INSERT);
*
* returns:
* btstack contains (bn, index) of search path traversed to the entry.
* *cmpp is set to result of comparison with the entry returned.
* the page containing the entry is pinned at exit.
*/
static int xtSearch(struct inode *ip, s64 xoff, s64 *nextp,
int *cmpp, struct btstack * btstack, int flag)
{
struct jfs_inode_info *jfs_ip = JFS_IP(ip);
int rc = 0;
int cmp = 1; /* init for empty page */
s64 bn; /* block number */
struct metapage *mp; /* page buffer */
xtpage_t *p; /* page */
xad_t *xad;
int base, index, lim, btindex;
struct btframe *btsp;
int nsplit = 0; /* number of pages to split */
s64 t64;
s64 next = 0;
INCREMENT(xtStat.search);
BT_CLR(btstack);
btstack->nsplit = 0;
/*
* search down tree from root:
*
* between two consecutive entries of <Ki, Pi> and <Kj, Pj> of
* internal page, child page Pi contains entry with k, Ki <= K < Kj.
*
* if entry with search key K is not found
* internal page search find the entry with largest key Ki
* less than K which point to the child page to search;
* leaf page search find the entry with smallest key Kj
* greater than K so that the returned index is the position of
* the entry to be shifted right for insertion of new entry.
* for empty tree, search key is greater than any key of the tree.
*
* by convention, root bn = 0.
*/
for (bn = 0;;) {
/* get/pin the page to search */
XT_GETPAGE(ip, bn, mp, PSIZE, p, rc);
if (rc)
return rc;
/* try sequential access heuristics with the previous
* access entry in target leaf page:
* once search narrowed down into the target leaf,
* key must either match an entry in the leaf or
* key entry does not exist in the tree;
*/
//fastSearch:
if ((jfs_ip->btorder & BT_SEQUENTIAL) &&
(p->header.flag & BT_LEAF) &&
(index = jfs_ip->btindex) <
le16_to_cpu(p->header.nextindex)) {
xad = &p->xad[index];
t64 = offsetXAD(xad);
if (xoff < t64 + lengthXAD(xad)) {
if (xoff >= t64) {
*cmpp = 0;
goto out;
}
/* stop sequential access heuristics */
goto binarySearch;
} else { /* (t64 + lengthXAD(xad)) <= xoff */
/* try next sequential entry */
index++;
if (index <
le16_to_cpu(p->header.nextindex)) {
xad++;
t64 = offsetXAD(xad);
if (xoff < t64 + lengthXAD(xad)) {
if (xoff >= t64) {
*cmpp = 0;
goto out;
}
/* miss: key falls between
* previous and this entry
*/
*cmpp = 1;
next = t64;
goto out;
}
/* (xoff >= t64 + lengthXAD(xad));
* matching entry may be further out:
* stop heuristic search
*/
/* stop sequential access heuristics */
goto binarySearch;
}
/* (index == p->header.nextindex);
* miss: key entry does not exist in
* the target leaf/tree
*/
*cmpp = 1;
goto out;
}
/*
* if hit, return index of the entry found, and
* if miss, where new entry with search key is
* to be inserted;
*/
out:
/* compute number of pages to split */
if (flag & XT_INSERT) {
if (p->header.nextindex == /* little-endian */
p->header.maxentry)
nsplit++;
else
nsplit = 0;
btstack->nsplit = nsplit;
}
/* save search result */
btsp = btstack->top;
btsp->bn = bn;
btsp->index = index;
btsp->mp = mp;
/* update sequential access heuristics */
jfs_ip->btindex = index;
if (nextp)
*nextp = next;
INCREMENT(xtStat.fastSearch);
return 0;
}
/* well, ... full search now */
binarySearch:
lim = le16_to_cpu(p->header.nextindex) - XTENTRYSTART;
/*
* binary search with search key K on the current page
*/
for (base = XTENTRYSTART; lim; lim >>= 1) {
index = base + (lim >> 1);
XT_CMP(cmp, xoff, &p->xad[index], t64);
if (cmp == 0) {
/*
* search hit
*/
/* search hit - leaf page:
* return the entry found
*/
if (p->header.flag & BT_LEAF) {
*cmpp = cmp;
/* compute number of pages to split */
if (flag & XT_INSERT) {
if (p->header.nextindex ==
p->header.maxentry)
nsplit++;
else
nsplit = 0;
btstack->nsplit = nsplit;
}
/* save search result */
btsp = btstack->top;
btsp->bn = bn;
btsp->index = index;
btsp->mp = mp;
/* init sequential access heuristics */
btindex = jfs_ip->btindex;
if (index == btindex ||
index == btindex + 1)
jfs_ip->btorder = BT_SEQUENTIAL;
else
jfs_ip->btorder = BT_RANDOM;
jfs_ip->btindex = index;
return 0;
}
/* search hit - internal page:
* descend/search its child page
*/
if (index < le16_to_cpu(p->header.nextindex)-1)
next = offsetXAD(&p->xad[index + 1]);
goto next;
}
if (cmp > 0) {
base = index + 1;
--lim;
}
}
/*
* search miss
*
* base is the smallest index with key (Kj) greater than
* search key (K) and may be zero or maxentry index.
*/
if (base < le16_to_cpu(p->header.nextindex))
next = offsetXAD(&p->xad[base]);
/*
* search miss - leaf page:
*
* return location of entry (base) where new entry with
* search key K is to be inserted.
*/
if (p->header.flag & BT_LEAF) {
*cmpp = cmp;
/* compute number of pages to split */
if (flag & XT_INSERT) {
if (p->header.nextindex ==
p->header.maxentry)
nsplit++;
else
nsplit = 0;
btstack->nsplit = nsplit;
}
/* save search result */
btsp = btstack->top;
btsp->bn = bn;
btsp->index = base;
btsp->mp = mp;
/* init sequential access heuristics */
btindex = jfs_ip->btindex;
if (base == btindex || base == btindex + 1)
jfs_ip->btorder = BT_SEQUENTIAL;
else
jfs_ip->btorder = BT_RANDOM;
jfs_ip->btindex = base;
if (nextp)
*nextp = next;
return 0;
}
/*
* search miss - non-leaf page:
*
* if base is non-zero, decrement base by one to get the parent
* entry of the child page to search.
*/
index = base ? base - 1 : base;
/*
* go down to child page
*/
next:
/* update number of pages to split */
if (p->header.nextindex == p->header.maxentry)
nsplit++;
else
nsplit = 0;
/* push (bn, index) of the parent page/entry */
if (BT_STACK_FULL(btstack)) {
jfs_error(ip->i_sb, "stack overrun!\n");
XT_PUTPAGE(mp);
return -EIO;
}
BT_PUSH(btstack, bn, index);
/* get the child page block number */
bn = addressXAD(&p->xad[index]);
/* unpin the parent page */
XT_PUTPAGE(mp);
}
}
/*
* xtInsert()
*
* function:
*
* parameter:
* tid - transaction id;
* ip - file object;
* xflag - extent flag (XAD_NOTRECORDED):
* xoff - extent offset;
* xlen - extent length;
* xaddrp - extent address pointer (in/out):
* if (*xaddrp)
* caller allocated data extent at *xaddrp;
* else
* allocate data extent and return its xaddr;
* flag -
*
* return:
*/
int xtInsert(tid_t tid, /* transaction id */
struct inode *ip, int xflag, s64 xoff, s32 xlen, s64 * xaddrp,
int flag)
{
int rc = 0;
s64 xaddr, hint;
struct metapage *mp; /* meta-page buffer */
xtpage_t *p; /* base B+-tree index page */
s64 bn;
int index, nextindex;
struct btstack btstack; /* traverse stack */
struct xtsplit split; /* split information */
xad_t *xad;
int cmp;
s64 next;
struct tlock *tlck;
struct xtlock *xtlck;
jfs_info("xtInsert: nxoff:0x%lx nxlen:0x%x", (ulong) xoff, xlen);
/*
* search for the entry location at which to insert:
*
* xtFastSearch() and xtSearch() both returns (leaf page
* pinned, index at which to insert).
* n.b. xtSearch() may return index of maxentry of
* the full page.
*/
if ((rc = xtSearch(ip, xoff, &next, &cmp, &btstack, XT_INSERT)))
return rc;
/* retrieve search result */
XT_GETSEARCH(ip, btstack.top, bn, mp, p, index);
/* This test must follow XT_GETSEARCH since mp must be valid if
* we branch to out: */
if ((cmp == 0) || (next && (xlen > next - xoff))) {
rc = -EEXIST;
goto out;
}
/*
* allocate data extent requested
*
* allocation hint: last xad
*/
if ((xaddr = *xaddrp) == 0) {
if (index > XTENTRYSTART) {
xad = &p->xad[index - 1];
hint = addressXAD(xad) + lengthXAD(xad) - 1;
} else
hint = 0;
if ((rc = dquot_alloc_block(ip, xlen)))
goto out;
if ((rc = dbAlloc(ip, hint, (s64) xlen, &xaddr))) {
dquot_free_block(ip, xlen);
goto out;
}
}
/*
* insert entry for new extent
*/
xflag |= XAD_NEW;
/*
* if the leaf page is full, split the page and
* propagate up the router entry for the new page from split
*
* The xtSplitUp() will insert the entry and unpin the leaf page.
*/
nextindex = le16_to_cpu(p->header.nextindex);
if (nextindex == le16_to_cpu(p->header.maxentry)) {
split.mp = mp;
split.index = index;
split.flag = xflag;
split.off = xoff;
split.len = xlen;
split.addr = xaddr;
split.pxdlist = NULL;
if ((rc = xtSplitUp(tid, ip, &split, &btstack))) {
/* undo data extent allocation */
if (*xaddrp == 0) {
dbFree(ip, xaddr, (s64) xlen);
dquot_free_block(ip, xlen);
}
return rc;
}
*xaddrp = xaddr;
return 0;
}
/*
* insert the new entry into the leaf page
*/
/*
* acquire a transaction lock on the leaf page;
*
* action: xad insertion/extension;
*/
BT_MARK_DIRTY(mp, ip);
/* if insert into middle, shift right remaining entries. */
if (index < nextindex)
memmove(&p->xad[index + 1], &p->xad[index],
(nextindex - index) * sizeof(xad_t));
/* insert the new entry: mark the entry NEW */
xad = &p->xad[index];
XT_PUTENTRY(xad, xflag, xoff, xlen, xaddr);
/* advance next available entry index */
le16_add_cpu(&p->header.nextindex, 1);
/* Don't log it if there are no links to the file */
if (!test_cflag(COMMIT_Nolink, ip)) {
tlck = txLock(tid, ip, mp, tlckXTREE | tlckGROW);
xtlck = (struct xtlock *) & tlck->lock;
xtlck->lwm.offset =
(xtlck->lwm.offset) ? min(index,
(int)xtlck->lwm.offset) : index;
xtlck->lwm.length =
le16_to_cpu(p->header.nextindex) - xtlck->lwm.offset;
}
*xaddrp = xaddr;
out:
/* unpin the leaf page */
XT_PUTPAGE(mp);
return rc;
}
/*
* xtSplitUp()
*
* function:
* split full pages as propagating insertion up the tree
*
* parameter:
* tid - transaction id;
* ip - file object;
* split - entry parameter descriptor;
* btstack - traverse stack from xtSearch()
*
* return:
*/
static int
xtSplitUp(tid_t tid,
struct inode *ip, struct xtsplit * split, struct btstack * btstack)
{
int rc = 0;
struct metapage *smp;
xtpage_t *sp; /* split page */
struct metapage *rmp;
s64 rbn; /* new right page block number */
struct metapage *rcmp;
xtpage_t *rcp; /* right child page */
s64 rcbn; /* right child page block number */
int skip; /* index of entry of insertion */
int nextindex; /* next available entry index of p */
struct btframe *parent; /* parent page entry on traverse stack */
xad_t *xad;
s64 xaddr;
int xlen;
int nsplit; /* number of pages split */
struct pxdlist pxdlist;
pxd_t *pxd;
struct tlock *tlck;
struct xtlock *xtlck;
smp = split->mp;
sp = XT_PAGE(ip, smp);
/* is inode xtree root extension/inline EA area free ? */
if ((sp->header.flag & BT_ROOT) && (!S_ISDIR(ip->i_mode)) &&
(le16_to_cpu(sp->header.maxentry) < XTROOTMAXSLOT) &&
(JFS_IP(ip)->mode2 & INLINEEA)) {
sp->header.maxentry = cpu_to_le16(XTROOTMAXSLOT);
JFS_IP(ip)->mode2 &= ~INLINEEA;
BT_MARK_DIRTY(smp, ip);
/*
* acquire a transaction lock on the leaf page;
*
* action: xad insertion/extension;
*/
/* if insert into middle, shift right remaining entries. */
skip = split->index;
nextindex = le16_to_cpu(sp->header.nextindex);
if (skip < nextindex)
memmove(&sp->xad[skip + 1], &sp->xad[skip],
(nextindex - skip) * sizeof(xad_t));
/* insert the new entry: mark the entry NEW */
xad = &sp->xad[skip];
XT_PUTENTRY(xad, split->flag, split->off, split->len,
split->addr);
/* advance next available entry index */
le16_add_cpu(&sp->header.nextindex, 1);
/* Don't log it if there are no links to the file */
if (!test_cflag(COMMIT_Nolink, ip)) {
tlck = txLock(tid, ip, smp, tlckXTREE | tlckGROW);
xtlck = (struct xtlock *) & tlck->lock;
xtlck->lwm.offset = (xtlck->lwm.offset) ?
min(skip, (int)xtlck->lwm.offset) : skip;
xtlck->lwm.length =
le16_to_cpu(sp->header.nextindex) -
xtlck->lwm.offset;
}
return 0;
}
/*
* allocate new index blocks to cover index page split(s)
*
* allocation hint: ?
*/
if (split->pxdlist == NULL) {
nsplit = btstack->nsplit;
split->pxdlist = &pxdlist;
pxdlist.maxnpxd = pxdlist.npxd = 0;
pxd = &pxdlist.pxd[0];
xlen = JFS_SBI(ip->i_sb)->nbperpage;
for (; nsplit > 0; nsplit--, pxd++) {
if ((rc = dbAlloc(ip, (s64) 0, (s64) xlen, &xaddr))
== 0) {
PXDaddress(pxd, xaddr);
PXDlength(pxd, xlen);
pxdlist.maxnpxd++;
continue;
}
/* undo allocation */
XT_PUTPAGE(smp);
return rc;
}
}
/*
* Split leaf page <sp> into <sp> and a new right page <rp>.
*
* The split routines insert the new entry into the leaf page,
* and acquire txLock as appropriate.
* return <rp> pinned and its block number <rpbn>.
*/
rc = (sp->header.flag & BT_ROOT) ?
xtSplitRoot(tid, ip, split, &rmp) :
xtSplitPage(tid, ip, split, &rmp, &rbn);
XT_PUTPAGE(smp);
if (rc)
return -EIO;
/*
* propagate up the router entry for the leaf page just split
*
* insert a router entry for the new page into the parent page,
* propagate the insert/split up the tree by walking back the stack
* of (bn of parent page, index of child page entry in parent page)
* that were traversed during the search for the page that split.
*
* the propagation of insert/split up the tree stops if the root
* splits or the page inserted into doesn't have to split to hold
* the new entry.
*
* the parent entry for the split page remains the same, and
* a new entry is inserted at its right with the first key and
* block number of the new right page.
*
* There are a maximum of 3 pages pinned at any time:
* right child, left parent and right parent (when the parent splits)
* to keep the child page pinned while working on the parent.
* make sure that all pins are released at exit.
*/
while ((parent = BT_POP(btstack)) != NULL) {
/* parent page specified by stack frame <parent> */
/* keep current child pages <rcp> pinned */
rcmp = rmp;
rcbn = rbn;
rcp = XT_PAGE(ip, rcmp);
/*
* insert router entry in parent for new right child page <rp>
*/
/* get/pin the parent page <sp> */
XT_GETPAGE(ip, parent->bn, smp, PSIZE, sp, rc);
if (rc) {
XT_PUTPAGE(rcmp);
return rc;
}
/*
* The new key entry goes ONE AFTER the index of parent entry,
* because the split was to the right.
*/
skip = parent->index + 1;
/*
* split or shift right remaining entries of the parent page
*/
nextindex = le16_to_cpu(sp->header.nextindex);
/*
* parent page is full - split the parent page
*/
if (nextindex == le16_to_cpu(sp->header.maxentry)) {
/* init for parent page split */
split->mp = smp;
split->index = skip; /* index at insert */
split->flag = XAD_NEW;
split->off = offsetXAD(&rcp->xad[XTENTRYSTART]);
split->len = JFS_SBI(ip->i_sb)->nbperpage;
split->addr = rcbn;
/* unpin previous right child page */
XT_PUTPAGE(rcmp);
/* The split routines insert the new entry,
* and acquire txLock as appropriate.
* return <rp> pinned and its block number <rpbn>.
*/
rc = (sp->header.flag & BT_ROOT) ?
xtSplitRoot(tid, ip, split, &rmp) :
xtSplitPage(tid, ip, split, &rmp, &rbn);
if (rc) {
XT_PUTPAGE(smp);
return rc;
}
XT_PUTPAGE(smp);
/* keep new child page <rp> pinned */
}
/*
* parent page is not full - insert in parent page
*/
else {
/*
* insert router entry in parent for the right child
* page from the first entry of the right child page:
*/
/*
* acquire a transaction lock on the parent page;
*
* action: router xad insertion;
*/
BT_MARK_DIRTY(smp, ip);
/*
* if insert into middle, shift right remaining entries
*/
if (skip < nextindex)
memmove(&sp->xad[skip + 1], &sp->xad[skip],
(nextindex -
skip) << L2XTSLOTSIZE);
/* insert the router entry */
xad = &sp->xad[skip];
XT_PUTENTRY(xad, XAD_NEW,
offsetXAD(&rcp->xad[XTENTRYSTART]),
JFS_SBI(ip->i_sb)->nbperpage, rcbn);
/* advance next available entry index. */
le16_add_cpu(&sp->header.nextindex, 1);
/* Don't log it if there are no links to the file */
if (!test_cflag(COMMIT_Nolink, ip)) {
tlck = txLock(tid, ip, smp,
tlckXTREE | tlckGROW);
xtlck = (struct xtlock *) & tlck->lock;
xtlck->lwm.offset = (xtlck->lwm.offset) ?
min(skip, (int)xtlck->lwm.offset) : skip;
xtlck->lwm.length =
le16_to_cpu(sp->header.nextindex) -
xtlck->lwm.offset;
}
/* unpin parent page */
XT_PUTPAGE(smp);
/* exit propagate up */
break;
}
}
/* unpin current right page */
XT_PUTPAGE(rmp);
return 0;
}
/*
* xtSplitPage()
*
* function:
* split a full non-root page into
* original/split/left page and new right page
* i.e., the original/split page remains as left page.
*
* parameter:
* int tid,
* struct inode *ip,
* struct xtsplit *split,
* struct metapage **rmpp,
* u64 *rbnp,
*
* return:
* Pointer to page in which to insert or NULL on error.
*/
static int
xtSplitPage(tid_t tid, struct inode *ip,
struct xtsplit * split, struct metapage ** rmpp, s64 * rbnp)
{
int rc = 0;
struct metapage *smp;
xtpage_t *sp;
struct metapage *rmp;
xtpage_t *rp; /* new right page allocated */
s64 rbn; /* new right page block number */
struct metapage *mp;
xtpage_t *p;
s64 nextbn;
int skip, maxentry, middle, righthalf, n;
xad_t *xad;
struct pxdlist *pxdlist;
pxd_t *pxd;
struct tlock *tlck;
struct xtlock *sxtlck = NULL, *rxtlck = NULL;
int quota_allocation = 0;
smp = split->mp;
sp = XT_PAGE(ip, smp);
INCREMENT(xtStat.split);
pxdlist = split->pxdlist;
pxd = &pxdlist->pxd[pxdlist->npxd];
pxdlist->npxd++;
rbn = addressPXD(pxd);
/* Allocate blocks to quota. */
rc = dquot_alloc_block(ip, lengthPXD(pxd));
if (rc)
goto clean_up;
quota_allocation += lengthPXD(pxd);
/*
* allocate the new right page for the split
*/
rmp = get_metapage(ip, rbn, PSIZE, 1);
if (rmp == NULL) {
rc = -EIO;
goto clean_up;
}
jfs_info("xtSplitPage: ip:0x%p smp:0x%p rmp:0x%p", ip, smp, rmp);
BT_MARK_DIRTY(rmp, ip);
/*
* action: new page;
*/
rp = (xtpage_t *) rmp->data;
rp->header.self = *pxd;
rp->header.flag = sp->header.flag & BT_TYPE;
rp->header.maxentry = sp->header.maxentry; /* little-endian */
rp->header.nextindex = cpu_to_le16(XTENTRYSTART);
BT_MARK_DIRTY(smp, ip);
/* Don't log it if there are no links to the file */
if (!test_cflag(COMMIT_Nolink, ip)) {
/*
* acquire a transaction lock on the new right page;
*/
tlck = txLock(tid, ip, rmp, tlckXTREE | tlckNEW);
rxtlck = (struct xtlock *) & tlck->lock;
rxtlck->lwm.offset = XTENTRYSTART;
/*
* acquire a transaction lock on the split page
*/
tlck = txLock(tid, ip, smp, tlckXTREE | tlckGROW);
sxtlck = (struct xtlock *) & tlck->lock;
}
/*
* initialize/update sibling pointers of <sp> and <rp>
*/
nextbn = le64_to_cpu(sp->header.next);
rp->header.next = cpu_to_le64(nextbn);
rp->header.prev = cpu_to_le64(addressPXD(&sp->header.self));
sp->header.next = cpu_to_le64(rbn);
skip = split->index;
/*
* sequential append at tail (after last entry of last page)
*
* if splitting the last page on a level because of appending
* a entry to it (skip is maxentry), it's likely that the access is
* sequential. adding an empty page on the side of the level is less
* work and can push the fill factor much higher than normal.
* if we're wrong it's no big deal - we will do the split the right
* way next time.
* (it may look like it's equally easy to do a similar hack for
* reverse sorted data, that is, split the tree left, but it's not.
* Be my guest.)
*/
if (nextbn == 0 && skip == le16_to_cpu(sp->header.maxentry)) {
/*
* acquire a transaction lock on the new/right page;
*
* action: xad insertion;
*/
/* insert entry at the first entry of the new right page */
xad = &rp->xad[XTENTRYSTART];
XT_PUTENTRY(xad, split->flag, split->off, split->len,
split->addr);
rp->header.nextindex = cpu_to_le16(XTENTRYSTART + 1);
if (!test_cflag(COMMIT_Nolink, ip)) {
/* rxtlck->lwm.offset = XTENTRYSTART; */
rxtlck->lwm.length = 1;
}
*rmpp = rmp;
*rbnp = rbn;
jfs_info("xtSplitPage: sp:0x%p rp:0x%p", sp, rp);
return 0;
}
/*
* non-sequential insert (at possibly middle page)
*/
/*
* update previous pointer of old next/right page of <sp>
*/
if (nextbn != 0) {
XT_GETPAGE(ip, nextbn, mp, PSIZE, p, rc);
if (rc) {
XT_PUTPAGE(rmp);
goto clean_up;
}
BT_MARK_DIRTY(mp, ip);
/*
* acquire a transaction lock on the next page;
*
* action:sibling pointer update;
*/
if (!test_cflag(COMMIT_Nolink, ip))
tlck = txLock(tid, ip, mp, tlckXTREE | tlckRELINK);
p->header.prev = cpu_to_le64(rbn);
/* sibling page may have been updated previously, or
* it may be updated later;
*/
XT_PUTPAGE(mp);
}
/*
* split the data between the split and new/right pages
*/
maxentry = le16_to_cpu(sp->header.maxentry);
middle = maxentry >> 1;
righthalf = maxentry - middle;
/*
* skip index in old split/left page - insert into left page:
*/
if (skip <= middle) {
/* move right half of split page to the new right page */
memmove(&rp->xad[XTENTRYSTART], &sp->xad[middle],
righthalf << L2XTSLOTSIZE);
/* shift right tail of left half to make room for new entry */
if (skip < middle)
memmove(&sp->xad[skip + 1], &sp->xad[skip],
(middle - skip) << L2XTSLOTSIZE);
/* insert new entry */
xad = &sp->xad[skip];
XT_PUTENTRY(xad, split->flag, split->off, split->len,
split->addr);
/* update page header */
sp->header.nextindex = cpu_to_le16(middle + 1);
if (!test_cflag(COMMIT_Nolink, ip)) {
sxtlck->lwm.offset = (sxtlck->lwm.offset) ?
min(skip, (int)sxtlck->lwm.offset) : skip;
}
rp->header.nextindex =
cpu_to_le16(XTENTRYSTART + righthalf);
}
/*
* skip index in new right page - insert into right page:
*/
else {
/* move left head of right half to right page */
n = skip - middle;
memmove(&rp->xad[XTENTRYSTART], &sp->xad[middle],
n << L2XTSLOTSIZE);
/* insert new entry */
n += XTENTRYSTART;
xad = &rp->xad[n];
XT_PUTENTRY(xad, split->flag, split->off, split->len,
split->addr);
/* move right tail of right half to right page */
if (skip < maxentry)
memmove(&rp->xad[n + 1], &sp->xad[skip],
(maxentry - skip) << L2XTSLOTSIZE);
/* update page header */
sp->header.nextindex = cpu_to_le16(middle);
if (!test_cflag(COMMIT_Nolink, ip)) {
sxtlck->lwm.offset = (sxtlck->lwm.offset) ?
min(middle, (int)sxtlck->lwm.offset) : middle;
}
rp->header.nextindex = cpu_to_le16(XTENTRYSTART +
righthalf + 1);
}
if (!test_cflag(COMMIT_Nolink, ip)) {
sxtlck->lwm.length = le16_to_cpu(sp->header.nextindex) -
sxtlck->lwm.offset;
/* rxtlck->lwm.offset = XTENTRYSTART; */
rxtlck->lwm.length = le16_to_cpu(rp->header.nextindex) -
XTENTRYSTART;
}
*rmpp = rmp;
*rbnp = rbn;
jfs_info("xtSplitPage: sp:0x%p rp:0x%p", sp, rp);
return rc;
clean_up:
/* Rollback quota allocation. */
if (quota_allocation)
dquot_free_block(ip, quota_allocation);
return (rc);
}
/*
* xtSplitRoot()
*
* function:
* split the full root page into original/root/split page and new
* right page
* i.e., root remains fixed in tree anchor (inode) and the root is
* copied to a single new right child page since root page <<
* non-root page, and the split root page contains a single entry
* for the new right child page.
*
* parameter:
* int tid,
* struct inode *ip,
* struct xtsplit *split,
* struct metapage **rmpp)
*
* return:
* Pointer to page in which to insert or NULL on error.
*/
static int
xtSplitRoot(tid_t tid,
struct inode *ip, struct xtsplit * split, struct metapage ** rmpp)
{
xtpage_t *sp;
struct metapage *rmp;
xtpage_t *rp;
s64 rbn;
int skip, nextindex;
xad_t *xad;
pxd_t *pxd;
struct pxdlist *pxdlist;
struct tlock *tlck;
struct xtlock *xtlck;
int rc;
sp = &JFS_IP(ip)->i_xtroot;
INCREMENT(xtStat.split);
/*
* allocate a single (right) child page
*/
pxdlist = split->pxdlist;
pxd = &pxdlist->pxd[pxdlist->npxd];
pxdlist->npxd++;
rbn = addressPXD(pxd);
rmp = get_metapage(ip, rbn, PSIZE, 1);
if (rmp == NULL)
return -EIO;
/* Allocate blocks to quota. */
rc = dquot_alloc_block(ip, lengthPXD(pxd));
if (rc) {
release_metapage(rmp);
return rc;
}
jfs_info("xtSplitRoot: ip:0x%p rmp:0x%p", ip, rmp);
/*
* acquire a transaction lock on the new right page;
*
* action: new page;
*/
BT_MARK_DIRTY(rmp, ip);
rp = (xtpage_t *) rmp->data;
rp->header.flag =
(sp->header.flag & BT_LEAF) ? BT_LEAF : BT_INTERNAL;
rp->header.self = *pxd;
rp->header.nextindex = cpu_to_le16(XTENTRYSTART);
rp->header.maxentry = cpu_to_le16(PSIZE >> L2XTSLOTSIZE);
/* initialize sibling pointers */
rp->header.next = 0;
rp->header.prev = 0;
/*
* copy the in-line root page into new right page extent
*/
nextindex = le16_to_cpu(sp->header.maxentry);
memmove(&rp->xad[XTENTRYSTART], &sp->xad[XTENTRYSTART],
(nextindex - XTENTRYSTART) << L2XTSLOTSIZE);
/*
* insert the new entry into the new right/child page
* (skip index in the new right page will not change)
*/
skip = split->index;
/* if insert into middle, shift right remaining entries */
if (skip != nextindex)
memmove(&rp->xad[skip + 1], &rp->xad[skip],
(nextindex - skip) * sizeof(xad_t));
xad = &rp->xad[skip];
XT_PUTENTRY(xad, split->flag, split->off, split->len, split->addr);
/* update page header */
rp->header.nextindex = cpu_to_le16(nextindex + 1);
if (!test_cflag(COMMIT_Nolink, ip)) {
tlck = txLock(tid, ip, rmp, tlckXTREE | tlckNEW);
xtlck = (struct xtlock *) & tlck->lock;
xtlck->lwm.offset = XTENTRYSTART;
xtlck->lwm.length = le16_to_cpu(rp->header.nextindex) -
XTENTRYSTART;
}
/*
* reset the root
*
* init root with the single entry for the new right page
* set the 1st entry offset to 0, which force the left-most key
* at any level of the tree to be less than any search key.
*/
/*
* acquire a transaction lock on the root page (in-memory inode);
*
* action: root split;
*/
BT_MARK_DIRTY(split->mp, ip);
xad = &sp->xad[XTENTRYSTART];
XT_PUTENTRY(xad, XAD_NEW, 0, JFS_SBI(ip->i_sb)->nbperpage, rbn);
/* update page header of root */
sp->header.flag &= ~BT_LEAF;
sp->header.flag |= BT_INTERNAL;
sp->header.nextindex = cpu_to_le16(XTENTRYSTART + 1);
if (!test_cflag(COMMIT_Nolink, ip)) {
tlck = txLock(tid, ip, split->mp, tlckXTREE | tlckGROW);
xtlck = (struct xtlock *) & tlck->lock;
xtlck->lwm.offset = XTENTRYSTART;
xtlck->lwm.length = 1;
}
*rmpp = rmp;
jfs_info("xtSplitRoot: sp:0x%p rp:0x%p", sp, rp);
return 0;
}
/*
* xtExtend()
*
* function: extend in-place;
*
* note: existing extent may or may not have been committed.
* caller is responsible for pager buffer cache update, and
* working block allocation map update;
* update pmap: alloc whole extended extent;
*/
int xtExtend(tid_t tid, /* transaction id */
struct inode *ip, s64 xoff, /* delta extent offset */
s32 xlen, /* delta extent length */
int flag)
{
int rc = 0;
int cmp;
struct metapage *mp; /* meta-page buffer */
xtpage_t *p; /* base B+-tree index page */
s64 bn;
int index, nextindex, len;
struct btstack btstack; /* traverse stack */
struct xtsplit split; /* split information */
xad_t *xad;
s64 xaddr;
struct tlock *tlck;
struct xtlock *xtlck = NULL;
jfs_info("xtExtend: nxoff:0x%lx nxlen:0x%x", (ulong) xoff, xlen);
/* there must exist extent to be extended */
if ((rc = xtSearch(ip, xoff - 1, NULL, &cmp, &btstack, XT_INSERT)))
return rc;
/* retrieve search result */
XT_GETSEARCH(ip, btstack.top, bn, mp, p, index);
if (cmp != 0) {
XT_PUTPAGE(mp);
jfs_error(ip->i_sb, "xtSearch did not find extent\n");
return -EIO;
}
/* extension must be contiguous */
xad = &p->xad[index];
if ((offsetXAD(xad) + lengthXAD(xad)) != xoff) {
XT_PUTPAGE(mp);
jfs_error(ip->i_sb, "extension is not contiguous\n");
return -EIO;
}
/*
* acquire a transaction lock on the leaf page;
*
* action: xad insertion/extension;
*/
BT_MARK_DIRTY(mp, ip);
if (!test_cflag(COMMIT_Nolink, ip)) {
tlck = txLock(tid, ip, mp, tlckXTREE | tlckGROW);
xtlck = (struct xtlock *) & tlck->lock;
}
/* extend will overflow extent ? */
xlen = lengthXAD(xad) + xlen;
if ((len = xlen - MAXXLEN) <= 0)
goto extendOld;
/*
* extent overflow: insert entry for new extent
*/
//insertNew:
xoff = offsetXAD(xad) + MAXXLEN;
xaddr = addressXAD(xad) + MAXXLEN;
nextindex = le16_to_cpu(p->header.nextindex);
/*
* if the leaf page is full, insert the new entry and
* propagate up the router entry for the new page from split
*
* The xtSplitUp() will insert the entry and unpin the leaf page.
*/
if (nextindex == le16_to_cpu(p->header.maxentry)) {
/* xtSpliUp() unpins leaf pages */
split.mp = mp;
split.index = index + 1;
split.flag = XAD_NEW;
split.off = xoff; /* split offset */
split.len = len;
split.addr = xaddr;
split.pxdlist = NULL;
if ((rc = xtSplitUp(tid, ip, &split, &btstack)))
return rc;
/* get back old page */
XT_GETPAGE(ip, bn, mp, PSIZE, p, rc);
if (rc)
return rc;
/*
* if leaf root has been split, original root has been
* copied to new child page, i.e., original entry now
* resides on the new child page;
*/
if (p->header.flag & BT_INTERNAL) {
ASSERT(p->header.nextindex ==
cpu_to_le16(XTENTRYSTART + 1));
xad = &p->xad[XTENTRYSTART];
bn = addressXAD(xad);
XT_PUTPAGE(mp);
/* get new child page */
XT_GETPAGE(ip, bn, mp, PSIZE, p, rc);
if (rc)
return rc;
BT_MARK_DIRTY(mp, ip);
if (!test_cflag(COMMIT_Nolink, ip)) {
tlck = txLock(tid, ip, mp, tlckXTREE|tlckGROW);
xtlck = (struct xtlock *) & tlck->lock;
}
}
}
/*
* insert the new entry into the leaf page
*/
else {
/* insert the new entry: mark the entry NEW */
xad = &p->xad[index + 1];
XT_PUTENTRY(xad, XAD_NEW, xoff, len, xaddr);
/* advance next available entry index */
le16_add_cpu(&p->header.nextindex, 1);
}
/* get back old entry */
xad = &p->xad[index];
xlen = MAXXLEN;
/*
* extend old extent
*/
extendOld:
XADlength(xad, xlen);
if (!(xad->flag & XAD_NEW))
xad->flag |= XAD_EXTENDED;
if (!test_cflag(COMMIT_Nolink, ip)) {
xtlck->lwm.offset =
(xtlck->lwm.offset) ? min(index,
(int)xtlck->lwm.offset) : index;
xtlck->lwm.length =
le16_to_cpu(p->header.nextindex) - xtlck->lwm.offset;
}
/* unpin the leaf page */
XT_PUTPAGE(mp);
return rc;
}
/*
* xtUpdate()
*
* function: update XAD;
*
* update extent for allocated_but_not_recorded or
* compressed extent;
*
* parameter:
* nxad - new XAD;
* logical extent of the specified XAD must be completely
* contained by an existing XAD;
*/
int xtUpdate(tid_t tid, struct inode *ip, xad_t * nxad)
{ /* new XAD */
int rc = 0;
int cmp;
struct metapage *mp; /* meta-page buffer */
xtpage_t *p; /* base B+-tree index page */
s64 bn;
int index0, index, newindex, nextindex;
struct btstack btstack; /* traverse stack */
struct xtsplit split; /* split information */
xad_t *xad, *lxad, *rxad;
int xflag;
s64 nxoff, xoff;
int nxlen, xlen, lxlen, rxlen;
s64 nxaddr, xaddr;
struct tlock *tlck;
struct xtlock *xtlck = NULL;
int newpage = 0;
/* there must exist extent to be tailgated */
nxoff = offsetXAD(nxad);
nxlen = lengthXAD(nxad);
nxaddr = addressXAD(nxad);
if ((rc = xtSearch(ip, nxoff, NULL, &cmp, &btstack, XT_INSERT)))
return rc;
/* retrieve search result */
XT_GETSEARCH(ip, btstack.top, bn, mp, p, index0);
if (cmp != 0) {
XT_PUTPAGE(mp);
jfs_error(ip->i_sb, "Could not find extent\n");
return -EIO;
}
BT_MARK_DIRTY(mp, ip);
/*
* acquire tlock of the leaf page containing original entry
*/
if (!test_cflag(COMMIT_Nolink, ip)) {
tlck = txLock(tid, ip, mp, tlckXTREE | tlckGROW);
xtlck = (struct xtlock *) & tlck->lock;
}
xad = &p->xad[index0];
xflag = xad->flag;
xoff = offsetXAD(xad);
xlen = lengthXAD(xad);
xaddr = addressXAD(xad);
/* nXAD must be completely contained within XAD */
if ((xoff > nxoff) ||
(nxoff + nxlen > xoff + xlen)) {
XT_PUTPAGE(mp);
jfs_error(ip->i_sb,
"nXAD in not completely contained within XAD\n");
return -EIO;
}
index = index0;
newindex = index + 1;
nextindex = le16_to_cpu(p->header.nextindex);
if (xoff < nxoff)
goto coalesceRight;
/*
* coalesce with left XAD
*/
/* is XAD first entry of page ? */
if (index == XTENTRYSTART)
goto replace;
/* is nXAD logically and physically contiguous with lXAD ? */
lxad = &p->xad[index - 1];
lxlen = lengthXAD(lxad);
if (!(lxad->flag & XAD_NOTRECORDED) &&
(nxoff == offsetXAD(lxad) + lxlen) &&
(nxaddr == addressXAD(lxad) + lxlen) &&
(lxlen + nxlen < MAXXLEN)) {
/* extend right lXAD */
index0 = index - 1;
XADlength(lxad, lxlen + nxlen);
/* If we just merged two extents together, need to make sure the
* right extent gets logged. If the left one is marked XAD_NEW,
* then we know it will be logged. Otherwise, mark as
* XAD_EXTENDED
*/
if (!(lxad->flag & XAD_NEW))
lxad->flag |= XAD_EXTENDED;
if (xlen > nxlen) {
/* truncate XAD */
XADoffset(xad, xoff + nxlen);
XADlength(xad, xlen - nxlen);
XADaddress(xad, xaddr + nxlen);
goto out;
} else { /* (xlen == nxlen) */
/* remove XAD */
if (index < nextindex - 1)
memmove(&p->xad[index], &p->xad[index + 1],
(nextindex - index -
1) << L2XTSLOTSIZE);
p->header.nextindex =
cpu_to_le16(le16_to_cpu(p->header.nextindex) -
1);
index = index0;
newindex = index + 1;
nextindex = le16_to_cpu(p->header.nextindex);
xoff = nxoff = offsetXAD(lxad);
xlen = nxlen = lxlen + nxlen;
xaddr = nxaddr = addressXAD(lxad);
goto coalesceRight;
}
}
/*
* replace XAD with nXAD
*/
replace: /* (nxoff == xoff) */
if (nxlen == xlen) {
/* replace XAD with nXAD:recorded */
*xad = *nxad;
xad->flag = xflag & ~XAD_NOTRECORDED;
goto coalesceRight;
} else /* (nxlen < xlen) */
goto updateLeft;
/*
* coalesce with right XAD
*/
coalesceRight: /* (xoff <= nxoff) */
/* is XAD last entry of page ? */
if (newindex == nextindex) {
if (xoff == nxoff)
goto out;
goto updateRight;
}
/* is nXAD logically and physically contiguous with rXAD ? */
rxad = &p->xad[index + 1];
rxlen = lengthXAD(rxad);
if (!(rxad->flag & XAD_NOTRECORDED) &&
(nxoff + nxlen == offsetXAD(rxad)) &&
(nxaddr + nxlen == addressXAD(rxad)) &&
(rxlen + nxlen < MAXXLEN)) {
/* extend left rXAD */
XADoffset(rxad, nxoff);
XADlength(rxad, rxlen + nxlen);
XADaddress(rxad, nxaddr);
/* If we just merged two extents together, need to make sure
* the left extent gets logged. If the right one is marked
* XAD_NEW, then we know it will be logged. Otherwise, mark as
* XAD_EXTENDED
*/
if (!(rxad->flag & XAD_NEW))
rxad->flag |= XAD_EXTENDED;
if (xlen > nxlen)
/* truncate XAD */
XADlength(xad, xlen - nxlen);
else { /* (xlen == nxlen) */
/* remove XAD */
memmove(&p->xad[index], &p->xad[index + 1],
(nextindex - index - 1) << L2XTSLOTSIZE);
p->header.nextindex =
cpu_to_le16(le16_to_cpu(p->header.nextindex) -
1);
}
goto out;
} else if (xoff == nxoff)
goto out;
if (xoff >= nxoff) {
XT_PUTPAGE(mp);
jfs_error(ip->i_sb, "xoff >= nxoff\n");
return -EIO;
}
/*
* split XAD into (lXAD, nXAD):
*
* |---nXAD--->
* --|----------XAD----------|--
* |-lXAD-|
*/
updateRight: /* (xoff < nxoff) */
/* truncate old XAD as lXAD:not_recorded */
xad = &p->xad[index];
XADlength(xad, nxoff - xoff);
/* insert nXAD:recorded */
if (nextindex == le16_to_cpu(p->header.maxentry)) {
/* xtSpliUp() unpins leaf pages */
split.mp = mp;
split.index = newindex;
split.flag = xflag & ~XAD_NOTRECORDED;
split.off = nxoff;
split.len = nxlen;
split.addr = nxaddr;
split.pxdlist = NULL;
if ((rc = xtSplitUp(tid, ip, &split, &btstack)))
return rc;
/* get back old page */
XT_GETPAGE(ip, bn, mp, PSIZE, p, rc);
if (rc)
return rc;
/*
* if leaf root has been split, original root has been
* copied to new child page, i.e., original entry now
* resides on the new child page;
*/
if (p->header.flag & BT_INTERNAL) {
ASSERT(p->header.nextindex ==
cpu_to_le16(XTENTRYSTART + 1));
xad = &p->xad[XTENTRYSTART];
bn = addressXAD(xad);
XT_PUTPAGE(mp);
/* get new child page */
XT_GETPAGE(ip, bn, mp, PSIZE, p, rc);
if (rc)
return rc;
BT_MARK_DIRTY(mp, ip);
if (!test_cflag(COMMIT_Nolink, ip)) {
tlck = txLock(tid, ip, mp, tlckXTREE|tlckGROW);
xtlck = (struct xtlock *) & tlck->lock;
}
} else {
/* is nXAD on new page ? */
if (newindex >
(le16_to_cpu(p->header.maxentry) >> 1)) {
newindex =
newindex -
le16_to_cpu(p->header.nextindex) +
XTENTRYSTART;
newpage = 1;
}
}
} else {
/* if insert into middle, shift right remaining entries */
if (newindex < nextindex)
memmove(&p->xad[newindex + 1], &p->xad[newindex],
(nextindex - newindex) << L2XTSLOTSIZE);
/* insert the entry */
xad = &p->xad[newindex];
*xad = *nxad;
xad->flag = xflag & ~XAD_NOTRECORDED;
/* advance next available entry index. */
p->header.nextindex =
cpu_to_le16(le16_to_cpu(p->header.nextindex) + 1);
}
/*
* does nXAD force 3-way split ?
*
* |---nXAD--->|
* --|----------XAD-------------|--
* |-lXAD-| |-rXAD -|
*/
if (nxoff + nxlen == xoff + xlen)
goto out;
/* reorient nXAD as XAD for further split XAD into (nXAD, rXAD) */
if (newpage) {
/* close out old page */
if (!test_cflag(COMMIT_Nolink, ip)) {
xtlck->lwm.offset = (xtlck->lwm.offset) ?
min(index0, (int)xtlck->lwm.offset) : index0;
xtlck->lwm.length =
le16_to_cpu(p->header.nextindex) -
xtlck->lwm.offset;
}
bn = le64_to_cpu(p->header.next);
XT_PUTPAGE(mp);
/* get new right page */
XT_GETPAGE(ip, bn, mp, PSIZE, p, rc);
if (rc)
return rc;
BT_MARK_DIRTY(mp, ip);
if (!test_cflag(COMMIT_Nolink, ip)) {
tlck = txLock(tid, ip, mp, tlckXTREE | tlckGROW);
xtlck = (struct xtlock *) & tlck->lock;
}
index0 = index = newindex;
} else
index++;
newindex = index + 1;
nextindex = le16_to_cpu(p->header.nextindex);
xlen = xlen - (nxoff - xoff);
xoff = nxoff;
xaddr = nxaddr;
/* recompute split pages */
if (nextindex == le16_to_cpu(p->header.maxentry)) {
XT_PUTPAGE(mp);
if ((rc = xtSearch(ip, nxoff, NULL, &cmp, &btstack, XT_INSERT)))
return rc;
/* retrieve search result */
XT_GETSEARCH(ip, btstack.top, bn, mp, p, index0);
if (cmp != 0) {
XT_PUTPAGE(mp);
jfs_error(ip->i_sb, "xtSearch failed\n");
return -EIO;
}
if (index0 != index) {
XT_PUTPAGE(mp);
jfs_error(ip->i_sb, "unexpected value of index\n");
return -EIO;
}
}
/*
* split XAD into (nXAD, rXAD)
*
* ---nXAD---|
* --|----------XAD----------|--
* |-rXAD-|
*/
updateLeft: /* (nxoff == xoff) && (nxlen < xlen) */
/* update old XAD with nXAD:recorded */
xad = &p->xad[index];
*xad = *nxad;
xad->flag = xflag & ~XAD_NOTRECORDED;
/* insert rXAD:not_recorded */
xoff = xoff + nxlen;
xlen = xlen - nxlen;
xaddr = xaddr + nxlen;
if (nextindex == le16_to_cpu(p->header.maxentry)) {
/*
printf("xtUpdate.updateLeft.split p:0x%p\n", p);
*/
/* xtSpliUp() unpins leaf pages */
split.mp = mp;
split.index = newindex;
split.flag = xflag;
split.off = xoff;
split.len = xlen;
split.addr = xaddr;
split.pxdlist = NULL;
if ((rc = xtSplitUp(tid, ip, &split, &btstack)))
return rc;
/* get back old page */
XT_GETPAGE(ip, bn, mp, PSIZE, p, rc);
if (rc)
return rc;
/*
* if leaf root has been split, original root has been
* copied to new child page, i.e., original entry now
* resides on the new child page;
*/
if (p->header.flag & BT_INTERNAL) {
ASSERT(p->header.nextindex ==
cpu_to_le16(XTENTRYSTART + 1));
xad = &p->xad[XTENTRYSTART];
bn = addressXAD(xad);
XT_PUTPAGE(mp);
/* get new child page */
XT_GETPAGE(ip, bn, mp, PSIZE, p, rc);
if (rc)
return rc;
BT_MARK_DIRTY(mp, ip);
if (!test_cflag(COMMIT_Nolink, ip)) {
tlck = txLock(tid, ip, mp, tlckXTREE|tlckGROW);
xtlck = (struct xtlock *) & tlck->lock;
}
}
} else {
/* if insert into middle, shift right remaining entries */
if (newindex < nextindex)
memmove(&p->xad[newindex + 1], &p->xad[newindex],
(nextindex - newindex) << L2XTSLOTSIZE);
/* insert the entry */
xad = &p->xad[newindex];
XT_PUTENTRY(xad, xflag, xoff, xlen, xaddr);
/* advance next available entry index. */
p->header.nextindex =
cpu_to_le16(le16_to_cpu(p->header.nextindex) + 1);
}
out:
if (!test_cflag(COMMIT_Nolink, ip)) {
xtlck->lwm.offset = (xtlck->lwm.offset) ?
min(index0, (int)xtlck->lwm.offset) : index0;
xtlck->lwm.length = le16_to_cpu(p->header.nextindex) -
xtlck->lwm.offset;
}
/* unpin the leaf page */
XT_PUTPAGE(mp);
return rc;
}
/*
* xtAppend()
*
* function: grow in append mode from contiguous region specified ;
*
* parameter:
* tid - transaction id;
* ip - file object;
* xflag - extent flag:
* xoff - extent offset;
* maxblocks - max extent length;
* xlen - extent length (in/out);
* xaddrp - extent address pointer (in/out):
* flag -
*
* return:
*/
int xtAppend(tid_t tid, /* transaction id */
struct inode *ip, int xflag, s64 xoff, s32 maxblocks,
s32 * xlenp, /* (in/out) */
s64 * xaddrp, /* (in/out) */
int flag)
{
int rc = 0;
struct metapage *mp; /* meta-page buffer */
xtpage_t *p; /* base B+-tree index page */
s64 bn, xaddr;
int index, nextindex;
struct btstack btstack; /* traverse stack */
struct xtsplit split; /* split information */
xad_t *xad;
int cmp;
struct tlock *tlck;
struct xtlock *xtlck;
int nsplit, nblocks, xlen;
struct pxdlist pxdlist;
pxd_t *pxd;
s64 next;
xaddr = *xaddrp;
xlen = *xlenp;
jfs_info("xtAppend: xoff:0x%lx maxblocks:%d xlen:%d xaddr:0x%lx",
(ulong) xoff, maxblocks, xlen, (ulong) xaddr);
/*
* search for the entry location at which to insert:
*
* xtFastSearch() and xtSearch() both returns (leaf page
* pinned, index at which to insert).
* n.b. xtSearch() may return index of maxentry of
* the full page.
*/
if ((rc = xtSearch(ip, xoff, &next, &cmp, &btstack, XT_INSERT)))
return rc;
/* retrieve search result */
XT_GETSEARCH(ip, btstack.top, bn, mp, p, index);
if (cmp == 0) {
rc = -EEXIST;
goto out;
}
if (next)
xlen = min(xlen, (int)(next - xoff));
//insert:
/*
* insert entry for new extent
*/
xflag |= XAD_NEW;
/*
* if the leaf page is full, split the page and
* propagate up the router entry for the new page from split
*
* The xtSplitUp() will insert the entry and unpin the leaf page.
*/
nextindex = le16_to_cpu(p->header.nextindex);
if (nextindex < le16_to_cpu(p->header.maxentry))
goto insertLeaf;
/*
* allocate new index blocks to cover index page split(s)
*/
nsplit = btstack.nsplit;
split.pxdlist = &pxdlist;
pxdlist.maxnpxd = pxdlist.npxd = 0;
pxd = &pxdlist.pxd[0];
nblocks = JFS_SBI(ip->i_sb)->nbperpage;
for (; nsplit > 0; nsplit--, pxd++, xaddr += nblocks, maxblocks -= nblocks) {
if ((rc = dbAllocBottomUp(ip, xaddr, (s64) nblocks)) == 0) {
PXDaddress(pxd, xaddr);
PXDlength(pxd, nblocks);
pxdlist.maxnpxd++;
continue;
}
/* undo allocation */
goto out;
}
xlen = min(xlen, maxblocks);
/*
* allocate data extent requested
*/
if ((rc = dbAllocBottomUp(ip, xaddr, (s64) xlen)))
goto out;
split.mp = mp;
split.index = index;
split.flag = xflag;
split.off = xoff;
split.len = xlen;
split.addr = xaddr;
if ((rc = xtSplitUp(tid, ip, &split, &btstack))) {
/* undo data extent allocation */
dbFree(ip, *xaddrp, (s64) * xlenp);
return rc;
}
*xaddrp = xaddr;
*xlenp = xlen;
return 0;
/*
* insert the new entry into the leaf page
*/
insertLeaf:
/*
* allocate data extent requested
*/
if ((rc = dbAllocBottomUp(ip, xaddr, (s64) xlen)))
goto out;
BT_MARK_DIRTY(mp, ip);
/*
* acquire a transaction lock on the leaf page;
*
* action: xad insertion/extension;
*/
tlck = txLock(tid, ip, mp, tlckXTREE | tlckGROW);
xtlck = (struct xtlock *) & tlck->lock;
/* insert the new entry: mark the entry NEW */
xad = &p->xad[index];
XT_PUTENTRY(xad, xflag, xoff, xlen, xaddr);
/* advance next available entry index */
le16_add_cpu(&p->header.nextindex, 1);
xtlck->lwm.offset =
(xtlck->lwm.offset) ? min(index,(int) xtlck->lwm.offset) : index;
xtlck->lwm.length = le16_to_cpu(p->header.nextindex) -
xtlck->lwm.offset;
*xaddrp = xaddr;
*xlenp = xlen;
out:
/* unpin the leaf page */
XT_PUTPAGE(mp);
return rc;
}
/*
* xtInitRoot()
*
* initialize file root (inline in inode)
*/
void xtInitRoot(tid_t tid, struct inode *ip)
{
xtpage_t *p;
/*
* acquire a transaction lock on the root
*
* action:
*/
txLock(tid, ip, (struct metapage *) &JFS_IP(ip)->bxflag,
tlckXTREE | tlckNEW);
p = &JFS_IP(ip)->i_xtroot;
p->header.flag = DXD_INDEX | BT_ROOT | BT_LEAF;
p->header.nextindex = cpu_to_le16(XTENTRYSTART);
if (S_ISDIR(ip->i_mode))
p->header.maxentry = cpu_to_le16(XTROOTINITSLOT_DIR);
else {
p->header.maxentry = cpu_to_le16(XTROOTINITSLOT);
ip->i_size = 0;
}
return;
}
/*
* We can run into a deadlock truncating a file with a large number of
* xtree pages (large fragmented file). A robust fix would entail a
* reservation system where we would reserve a number of metadata pages
* and tlocks which we would be guaranteed without a deadlock. Without
* this, a partial fix is to limit number of metadata pages we will lock
* in a single transaction. Currently we will truncate the file so that
* no more than 50 leaf pages will be locked. The caller of xtTruncate
* will be responsible for ensuring that the current transaction gets
* committed, and that subsequent transactions are created to truncate
* the file further if needed.
*/
#define MAX_TRUNCATE_LEAVES 50
/*
* xtTruncate()
*
* function:
* traverse for truncation logging backward bottom up;
* terminate at the last extent entry at the current subtree
* root page covering new down size.
* truncation may occur within the last extent entry.
*
* parameter:
* int tid,
* struct inode *ip,
* s64 newsize,
* int type) {PWMAP, PMAP, WMAP; DELETE, TRUNCATE}
*
* return:
*
* note:
* PWMAP:
* 1. truncate (non-COMMIT_NOLINK file)
* by jfs_truncate() or jfs_open(O_TRUNC):
* xtree is updated;
* 2. truncate index table of directory when last entry removed
* map update via tlock at commit time;
* PMAP:
* Call xtTruncate_pmap instead
* WMAP:
* 1. remove (free zero link count) on last reference release
* (pmap has been freed at commit zero link count);
* 2. truncate (COMMIT_NOLINK file, i.e., tmp file):
* xtree is updated;
* map update directly at truncation time;
*
* if (DELETE)
* no LOG_NOREDOPAGE is required (NOREDOFILE is sufficient);
* else if (TRUNCATE)
* must write LOG_NOREDOPAGE for deleted index page;
*
* pages may already have been tlocked by anonymous transactions
* during file growth (i.e., write) before truncation;
*
* except last truncated entry, deleted entries remains as is
* in the page (nextindex is updated) for other use
* (e.g., log/update allocation map): this avoid copying the page
* info but delay free of pages;
*
*/
s64 xtTruncate(tid_t tid, struct inode *ip, s64 newsize, int flag)
{
int rc = 0;
s64 teof;
struct metapage *mp;
xtpage_t *p;
s64 bn;
int index, nextindex;
xad_t *xad;
s64 xoff, xaddr;
int xlen, len, freexlen;
struct btstack btstack;
struct btframe *parent;
struct tblock *tblk = NULL;
struct tlock *tlck = NULL;
struct xtlock *xtlck = NULL;
struct xdlistlock xadlock; /* maplock for COMMIT_WMAP */
struct pxd_lock *pxdlock; /* maplock for COMMIT_WMAP */
s64 nfreed;
int freed, log;
int locked_leaves = 0;
/* save object truncation type */
if (tid) {
tblk = tid_to_tblock(tid);
tblk->xflag |= flag;
}
nfreed = 0;
flag &= COMMIT_MAP;
assert(flag != COMMIT_PMAP);
if (flag == COMMIT_PWMAP)
log = 1;
else {
log = 0;
xadlock.flag = mlckFREEXADLIST;
xadlock.index = 1;
}
/*
* if the newsize is not an integral number of pages,
* the file between newsize and next page boundary will
* be cleared.
* if truncating into a file hole, it will cause
* a full block to be allocated for the logical block.
*/
/*
* release page blocks of truncated region <teof, eof>
*
* free the data blocks from the leaf index blocks.
* delete the parent index entries corresponding to
* the freed child data/index blocks.
* free the index blocks themselves which aren't needed
* in new sized file.
*
* index blocks are updated only if the blocks are to be
* retained in the new sized file.
* if type is PMAP, the data and index pages are NOT
* freed, and the data and index blocks are NOT freed
* from working map.
* (this will allow continued access of data/index of
* temporary file (zerolink count file truncated to zero-length)).
*/
teof = (newsize + (JFS_SBI(ip->i_sb)->bsize - 1)) >>
JFS_SBI(ip->i_sb)->l2bsize;
/* clear stack */
BT_CLR(&btstack);
/*
* start with root
*
* root resides in the inode
*/
bn = 0;
/*
* first access of each page:
*/
getPage:
XT_GETPAGE(ip, bn, mp, PSIZE, p, rc);
if (rc)
return rc;
/* process entries backward from last index */
index = le16_to_cpu(p->header.nextindex) - 1;
/* Since this is the rightmost page at this level, and we may have
* already freed a page that was formerly to the right, let's make
* sure that the next pointer is zero.
*/
if (p->header.next) {
if (log)
/*
* Make sure this change to the header is logged.
* If we really truncate this leaf, the flag
* will be changed to tlckTRUNCATE
*/
tlck = txLock(tid, ip, mp, tlckXTREE|tlckGROW);
BT_MARK_DIRTY(mp, ip);
p->header.next = 0;
}
if (p->header.flag & BT_INTERNAL)
goto getChild;
/*
* leaf page
*/
freed = 0;
/* does region covered by leaf page precede Teof ? */
xad = &p->xad[index];
xoff = offsetXAD(xad);
xlen = lengthXAD(xad);
if (teof >= xoff + xlen) {
XT_PUTPAGE(mp);
goto getParent;
}
/* (re)acquire tlock of the leaf page */
if (log) {
if (++locked_leaves > MAX_TRUNCATE_LEAVES) {
/*
* We need to limit the size of the transaction
* to avoid exhausting pagecache & tlocks
*/
XT_PUTPAGE(mp);
newsize = (xoff + xlen) << JFS_SBI(ip->i_sb)->l2bsize;
goto getParent;
}
tlck = txLock(tid, ip, mp, tlckXTREE);
tlck->type = tlckXTREE | tlckTRUNCATE;
xtlck = (struct xtlock *) & tlck->lock;
xtlck->hwm.offset = le16_to_cpu(p->header.nextindex) - 1;
}
BT_MARK_DIRTY(mp, ip);
/*
* scan backward leaf page entries
*/
for (; index >= XTENTRYSTART; index--) {
xad = &p->xad[index];
xoff = offsetXAD(xad);
xlen = lengthXAD(xad);
xaddr = addressXAD(xad);
/*
* The "data" for a directory is indexed by the block
* device's address space. This metadata must be invalidated
* here
*/
if (S_ISDIR(ip->i_mode) && (teof == 0))
invalidate_xad_metapages(ip, *xad);
/*
* entry beyond eof: continue scan of current page
* xad
* ---|---=======------->
* eof
*/
if (teof < xoff) {
nfreed += xlen;
continue;
}
/*
* (xoff <= teof): last entry to be deleted from page;
* If other entries remain in page: keep and update the page.
*/
/*
* eof == entry_start: delete the entry
* xad
* -------|=======------->
* eof
*
*/
if (teof == xoff) {
nfreed += xlen;
if (index == XTENTRYSTART)
break;
nextindex = index;
}
/*
* eof within the entry: truncate the entry.
* xad
* -------===|===------->
* eof
*/
else if (teof < xoff + xlen) {
/* update truncated entry */
len = teof - xoff;
freexlen = xlen - len;
XADlength(xad, len);
/* save pxd of truncated extent in tlck */
xaddr += len;
if (log) { /* COMMIT_PWMAP */
xtlck->lwm.offset = (xtlck->lwm.offset) ?
min(index, (int)xtlck->lwm.offset) : index;
xtlck->lwm.length = index + 1 -
xtlck->lwm.offset;
xtlck->twm.offset = index;
pxdlock = (struct pxd_lock *) & xtlck->pxdlock;
pxdlock->flag = mlckFREEPXD;
PXDaddress(&pxdlock->pxd, xaddr);
PXDlength(&pxdlock->pxd, freexlen);
}
/* free truncated extent */
else { /* COMMIT_WMAP */
pxdlock = (struct pxd_lock *) & xadlock;
pxdlock->flag = mlckFREEPXD;
PXDaddress(&pxdlock->pxd, xaddr);
PXDlength(&pxdlock->pxd, freexlen);
txFreeMap(ip, pxdlock, NULL, COMMIT_WMAP);
/* reset map lock */
xadlock.flag = mlckFREEXADLIST;
}
/* current entry is new last entry; */
nextindex = index + 1;
nfreed += freexlen;
}
/*
* eof beyond the entry:
* xad
* -------=======---|--->
* eof
*/
else { /* (xoff + xlen < teof) */
nextindex = index + 1;
}
if (nextindex < le16_to_cpu(p->header.nextindex)) {
if (!log) { /* COMMIT_WAMP */
xadlock.xdlist = &p->xad[nextindex];
xadlock.count =
le16_to_cpu(p->header.nextindex) -
nextindex;
txFreeMap(ip, (struct maplock *) & xadlock,
NULL, COMMIT_WMAP);
}
p->header.nextindex = cpu_to_le16(nextindex);
}
XT_PUTPAGE(mp);
/* assert(freed == 0); */
goto getParent;
} /* end scan of leaf page entries */
freed = 1;
/*
* leaf page become empty: free the page if type != PMAP
*/
if (log) { /* COMMIT_PWMAP */
/* txCommit() with tlckFREE:
* free data extents covered by leaf [XTENTRYSTART:hwm);
* invalidate leaf if COMMIT_PWMAP;
* if (TRUNCATE), will write LOG_NOREDOPAGE;
*/
tlck->type = tlckXTREE | tlckFREE;
} else { /* COMMIT_WAMP */
/* free data extents covered by leaf */
xadlock.xdlist = &p->xad[XTENTRYSTART];
xadlock.count =
le16_to_cpu(p->header.nextindex) - XTENTRYSTART;
txFreeMap(ip, (struct maplock *) & xadlock, NULL, COMMIT_WMAP);
}
if (p->header.flag & BT_ROOT) {
p->header.flag &= ~BT_INTERNAL;
p->header.flag |= BT_LEAF;
p->header.nextindex = cpu_to_le16(XTENTRYSTART);
XT_PUTPAGE(mp); /* debug */
goto out;
} else {
if (log) { /* COMMIT_PWMAP */
/* page will be invalidated at tx completion
*/
XT_PUTPAGE(mp);
} else { /* COMMIT_WMAP */
if (mp->lid)
lid_to_tlock(mp->lid)->flag |= tlckFREELOCK;
/* invalidate empty leaf page */
discard_metapage(mp);
}
}
/*
* the leaf page become empty: delete the parent entry
* for the leaf page if the parent page is to be kept
* in the new sized file.
*/
/*
* go back up to the parent page
*/
getParent:
/* pop/restore parent entry for the current child page */
if ((parent = BT_POP(&btstack)) == NULL)
/* current page must have been root */
goto out;
/* get back the parent page */
bn = parent->bn;
XT_GETPAGE(ip, bn, mp, PSIZE, p, rc);
if (rc)
return rc;
index = parent->index;
/*
* child page was not empty:
*/
if (freed == 0) {
/* has any entry deleted from parent ? */
if (index < le16_to_cpu(p->header.nextindex) - 1) {
/* (re)acquire tlock on the parent page */
if (log) { /* COMMIT_PWMAP */
/* txCommit() with tlckTRUNCATE:
* free child extents covered by parent [);
*/
tlck = txLock(tid, ip, mp, tlckXTREE);
xtlck = (struct xtlock *) & tlck->lock;
if (!(tlck->type & tlckTRUNCATE)) {
xtlck->hwm.offset =
le16_to_cpu(p->header.
nextindex) - 1;
tlck->type =
tlckXTREE | tlckTRUNCATE;
}
} else { /* COMMIT_WMAP */
/* free child extents covered by parent */
xadlock.xdlist = &p->xad[index + 1];
xadlock.count =
le16_to_cpu(p->header.nextindex) -
index - 1;
txFreeMap(ip, (struct maplock *) & xadlock,
NULL, COMMIT_WMAP);
}
BT_MARK_DIRTY(mp, ip);
p->header.nextindex = cpu_to_le16(index + 1);
}
XT_PUTPAGE(mp);
goto getParent;
}
/*
* child page was empty:
*/
nfreed += lengthXAD(&p->xad[index]);
/*
* During working map update, child page's tlock must be handled
* before parent's. This is because the parent's tlock will cause
* the child's disk space to be marked available in the wmap, so
* it's important that the child page be released by that time.
*
* ToDo: tlocks should be on doubly-linked list, so we can
* quickly remove it and add it to the end.
*/
/*
* Move parent page's tlock to the end of the tid's tlock list
*/
if (log && mp->lid && (tblk->last != mp->lid) &&
lid_to_tlock(mp->lid)->tid) {
lid_t lid = mp->lid;
struct tlock *prev;
tlck = lid_to_tlock(lid);
if (tblk->next == lid)
tblk->next = tlck->next;
else {
for (prev = lid_to_tlock(tblk->next);
prev->next != lid;
prev = lid_to_tlock(prev->next)) {
assert(prev->next);
}
prev->next = tlck->next;
}
lid_to_tlock(tblk->last)->next = lid;
tlck->next = 0;
tblk->last = lid;
}
/*
* parent page become empty: free the page
*/
if (index == XTENTRYSTART) {
if (log) { /* COMMIT_PWMAP */
/* txCommit() with tlckFREE:
* free child extents covered by parent;
* invalidate parent if COMMIT_PWMAP;
*/
tlck = txLock(tid, ip, mp, tlckXTREE);
xtlck = (struct xtlock *) & tlck->lock;
xtlck->hwm.offset =
le16_to_cpu(p->header.nextindex) - 1;
tlck->type = tlckXTREE | tlckFREE;
} else { /* COMMIT_WMAP */
/* free child extents covered by parent */
xadlock.xdlist = &p->xad[XTENTRYSTART];
xadlock.count =
le16_to_cpu(p->header.nextindex) -
XTENTRYSTART;
txFreeMap(ip, (struct maplock *) & xadlock, NULL,
COMMIT_WMAP);
}
BT_MARK_DIRTY(mp, ip);
if (p->header.flag & BT_ROOT) {
p->header.flag &= ~BT_INTERNAL;
p->header.flag |= BT_LEAF;
p->header.nextindex = cpu_to_le16(XTENTRYSTART);
if (le16_to_cpu(p->header.maxentry) == XTROOTMAXSLOT) {
/*
* Shrink root down to allow inline
* EA (otherwise fsck complains)
*/
p->header.maxentry =
cpu_to_le16(XTROOTINITSLOT);
JFS_IP(ip)->mode2 |= INLINEEA;
}
XT_PUTPAGE(mp); /* debug */
goto out;
} else {
if (log) { /* COMMIT_PWMAP */
/* page will be invalidated at tx completion
*/
XT_PUTPAGE(mp);
} else { /* COMMIT_WMAP */
if (mp->lid)
lid_to_tlock(mp->lid)->flag |=
tlckFREELOCK;
/* invalidate parent page */
discard_metapage(mp);
}
/* parent has become empty and freed:
* go back up to its parent page
*/
/* freed = 1; */
goto getParent;
}
}
/*
* parent page still has entries for front region;
*/
else {
/* try truncate region covered by preceding entry
* (process backward)
*/
index--;
/* go back down to the child page corresponding
* to the entry
*/
goto getChild;
}
/*
* internal page: go down to child page of current entry
*/
getChild:
/* save current parent entry for the child page */
if (BT_STACK_FULL(&btstack)) {
jfs_error(ip->i_sb, "stack overrun!\n");
XT_PUTPAGE(mp);
return -EIO;
}
BT_PUSH(&btstack, bn, index);
/* get child page */
xad = &p->xad[index];
bn = addressXAD(xad);
/*
* first access of each internal entry:
*/
/* release parent page */
XT_PUTPAGE(mp);
/* process the child page */
goto getPage;
out:
/*
* update file resource stat
*/
/* set size
*/
if (S_ISDIR(ip->i_mode) && !newsize)
ip->i_size = 1; /* fsck hates zero-length directories */
else
ip->i_size = newsize;
/* update quota allocation to reflect freed blocks */
dquot_free_block(ip, nfreed);
/*
* free tlock of invalidated pages
*/
if (flag == COMMIT_WMAP)
txFreelock(ip);
return newsize;
}
/*
* xtTruncate_pmap()
*
* function:
* Perform truncate to zero length for deleted file, leaving the
* xtree and working map untouched. This allows the file to
* be accessed via open file handles, while the delete of the file
* is committed to disk.
*
* parameter:
* tid_t tid,
* struct inode *ip,
* s64 committed_size)
*
* return: new committed size
*
* note:
*
* To avoid deadlock by holding too many transaction locks, the
* truncation may be broken up into multiple transactions.
* The committed_size keeps track of part of the file has been
* freed from the pmaps.
*/
s64 xtTruncate_pmap(tid_t tid, struct inode *ip, s64 committed_size)
{
s64 bn;
struct btstack btstack;
int cmp;
int index;
int locked_leaves = 0;
struct metapage *mp;
xtpage_t *p;
struct btframe *parent;
int rc;
struct tblock *tblk;
struct tlock *tlck = NULL;
xad_t *xad;
int xlen;
s64 xoff;
struct xtlock *xtlck = NULL;
/* save object truncation type */
tblk = tid_to_tblock(tid);
tblk->xflag |= COMMIT_PMAP;
/* clear stack */
BT_CLR(&btstack);
if (committed_size) {
xoff = (committed_size >> JFS_SBI(ip->i_sb)->l2bsize) - 1;
rc = xtSearch(ip, xoff, NULL, &cmp, &btstack, 0);
if (rc)
return rc;
XT_GETSEARCH(ip, btstack.top, bn, mp, p, index);
if (cmp != 0) {
XT_PUTPAGE(mp);
jfs_error(ip->i_sb, "did not find extent\n");
return -EIO;
}
} else {
/*
* start with root
*
* root resides in the inode
*/
bn = 0;
/*
* first access of each page:
*/
getPage:
XT_GETPAGE(ip, bn, mp, PSIZE, p, rc);
if (rc)
return rc;
/* process entries backward from last index */
index = le16_to_cpu(p->header.nextindex) - 1;
if (p->header.flag & BT_INTERNAL)
goto getChild;
}
/*
* leaf page
*/
if (++locked_leaves > MAX_TRUNCATE_LEAVES) {
/*
* We need to limit the size of the transaction
* to avoid exhausting pagecache & tlocks
*/
xad = &p->xad[index];
xoff = offsetXAD(xad);
xlen = lengthXAD(xad);
XT_PUTPAGE(mp);
return (xoff + xlen) << JFS_SBI(ip->i_sb)->l2bsize;
}
tlck = txLock(tid, ip, mp, tlckXTREE);
tlck->type = tlckXTREE | tlckFREE;
xtlck = (struct xtlock *) & tlck->lock;
xtlck->hwm.offset = index;
XT_PUTPAGE(mp);
/*
* go back up to the parent page
*/
getParent:
/* pop/restore parent entry for the current child page */
if ((parent = BT_POP(&btstack)) == NULL)
/* current page must have been root */
goto out;
/* get back the parent page */
bn = parent->bn;
XT_GETPAGE(ip, bn, mp, PSIZE, p, rc);
if (rc)
return rc;
index = parent->index;
/*
* parent page become empty: free the page
*/
if (index == XTENTRYSTART) {
/* txCommit() with tlckFREE:
* free child extents covered by parent;
* invalidate parent if COMMIT_PWMAP;
*/
tlck = txLock(tid, ip, mp, tlckXTREE);
xtlck = (struct xtlock *) & tlck->lock;
xtlck->hwm.offset = le16_to_cpu(p->header.nextindex) - 1;
tlck->type = tlckXTREE | tlckFREE;
XT_PUTPAGE(mp);
if (p->header.flag & BT_ROOT) {
goto out;
} else {
goto getParent;
}
}
/*
* parent page still has entries for front region;
*/
else
index--;
/*
* internal page: go down to child page of current entry
*/
getChild:
/* save current parent entry for the child page */
if (BT_STACK_FULL(&btstack)) {
jfs_error(ip->i_sb, "stack overrun!\n");
XT_PUTPAGE(mp);
return -EIO;
}
BT_PUSH(&btstack, bn, index);
/* get child page */
xad = &p->xad[index];
bn = addressXAD(xad);
/*
* first access of each internal entry:
*/
/* release parent page */
XT_PUTPAGE(mp);
/* process the child page */
goto getPage;
out:
return 0;
}
#ifdef CONFIG_JFS_STATISTICS
int jfs_xtstat_proc_show(struct seq_file *m, void *v)
{
seq_printf(m,
"JFS Xtree statistics\n"
"====================\n"
"searches = %d\n"
"fast searches = %d\n"
"splits = %d\n",
xtStat.search,
xtStat.fastSearch,
xtStat.split);
return 0;
}
#endif