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linux/fs/jfs/jfs_xtree.c
Dave Kleikamp e471e5942c fs/jfs: Remove dead code 
Since the JFS code was first added to Linux, there has been code hidden
in ifdefs  for some potential future features such as defragmentation
and supporting block sizes other than 4KB. There has been no ongoing
development on JFS for many years, so it's past time to remove this dead
code from the source.

Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com>
2022-04-25 14:00:33 -05:00

2917 lines
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// 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
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