--- /dev/null
+/*
+ * Copyright (C) International Business Machines Corp., 2000-2005
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
+ * the GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+/*
+ * 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);
+
+#ifdef _STILL_TO_PORT
+static int xtDeleteUp(tid_t tid, struct inode *ip, struct metapage * fmp,
+ xtpage_t * fp, struct btstack * btstack);
+
+static int xtSearchNode(struct inode *ip,
+ xad_t * xad,
+ int *cmpp, struct btstack * btstack, int flag);
+
+static int xtRelink(tid_t tid, struct inode *ip, xtpage_t * fp);
+#endif /* _STILL_TO_PORT */
+
+/*
+ * 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;
+}
+
+#ifdef _NOTYET
+/*
+ * xtTailgate()
+ *
+ * function: split existing 'tail' extent
+ * (split offset >= start offset of tail extent), and
+ * relocate and extend the split tail half;
+ *
+ * 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: free old split tail extent, alloc new extent;
+ */
+int xtTailgate(tid_t tid, /* transaction id */
+ struct inode *ip, s64 xoff, /* split/new extent offset */
+ s32 xlen, /* new extent length */
+ s64 xaddr, /* new extent address */
+ 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, llen, rlen;
+ struct btstack btstack; /* traverse stack */
+ struct xtsplit split; /* split information */
+ xad_t *xad;
+ struct tlock *tlck;
+ struct xtlock *xtlck = 0;
+ struct tlock *mtlck;
+ struct maplock *pxdlock;
+
+/*
+printf("xtTailgate: nxoff:0x%lx nxlen:0x%x nxaddr:0x%lx\n",
+ (ulong)xoff, xlen, (ulong)xaddr);
+*/
+
+ /* there must exist extent to be tailgated */
+ if ((rc = xtSearch(ip, xoff, 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, "couldn't find extent\n");
+ return -EIO;
+ }
+
+ /* entry found must be last entry */
+ nextindex = le16_to_cpu(p->header.nextindex);
+ if (index != nextindex - 1) {
+ XT_PUTPAGE(mp);
+ jfs_error(ip->i_sb, "the entry found is not the last entry\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;
+ }
+
+ /* completely replace extent ? */
+ xad = &p->xad[index];
+/*
+printf("xtTailgate: xoff:0x%lx xlen:0x%x xaddr:0x%lx\n",
+ (ulong)offsetXAD(xad), lengthXAD(xad), (ulong)addressXAD(xad));
+*/
+ if ((llen = xoff - offsetXAD(xad)) == 0)
+ goto updateOld;
+
+ /*
+ * partially replace extent: insert entry for new extent
+ */
+//insertNew:
+ /*
+ * 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 = 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;
+ }
+ }
+ }
+ /*
+ * 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, xlen, xaddr);
+
+ /* advance next available entry index */
+ le16_add_cpu(&p->header.nextindex, 1);
+ }
+
+ /* get back old XAD */
+ xad = &p->xad[index];
+
+ /*
+ * truncate/relocate old extent at split offset
+ */
+ updateOld:
+ /* update dmap for old/committed/truncated extent */
+ rlen = lengthXAD(xad) - llen;
+ if (!(xad->flag & XAD_NEW)) {
+ /* free from PWMAP at commit */
+ if (!test_cflag(COMMIT_Nolink, ip)) {
+ mtlck = txMaplock(tid, ip, tlckMAP);
+ pxdlock = (struct maplock *) & mtlck->lock;
+ pxdlock->flag = mlckFREEPXD;
+ PXDaddress(&pxdlock->pxd, addressXAD(xad) + llen);
+ PXDlength(&pxdlock->pxd, rlen);
+ pxdlock->index = 1;
+ }
+ } else
+ /* free from WMAP */
+ dbFree(ip, addressXAD(xad) + llen, (s64) rlen);
+
+ if (llen)
+ /* truncate */
+ XADlength(xad, llen);
+ else
+ /* replace */
+ XT_PUTENTRY(xad, XAD_NEW, xoff, xlen, xaddr);
+
+ 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;
+}
+#endif /* _NOTYET */
+
+/*
+ * 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);
+
+#ifdef _JFS_WIP_NOCOALESCE
+ if (xoff < nxoff)
+ goto updateRight;
+
+ /*
+ * replace XAD with nXAD
+ */
+ replace: /* (nxoff == xoff) */
+ if (nxlen == xlen) {
+ /* replace XAD with nXAD:recorded */
+ *xad = *nxad;
+ xad->flag = xflag & ~XAD_NOTRECORDED;
+
+ goto out;
+ } else /* (nxlen < xlen) */
+ goto updateLeft;
+#endif /* _JFS_WIP_NOCOALESCE */
+
+/* #ifdef _JFS_WIP_COALESCE */
+ if (xoff < nxoff)
+ goto coalesceRight;
+
+ /*
+ * coalesce with left XAD
+ */
+//coalesceLeft: /* (xoff == nxoff) */
+ /* 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;
+ }
+/* #endif _JFS_WIP_COALESCE */
+
+ /*
+ * 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;
+}
+#ifdef _STILL_TO_PORT
+
+/* - TBD for defragmentaion/reorganization -
+ *
+ * xtDelete()
+ *
+ * function:
+ * delete the entry with the specified key.
+ *
+ * N.B.: whole extent of the entry is assumed to be deleted.
+ *
+ * parameter:
+ *
+ * return:
+ * ENOENT: if the entry is not found.
+ *
+ * exception:
+ */
+int xtDelete(tid_t tid, struct inode *ip, s64 xoff, s32 xlen, int flag)
+{
+ int rc = 0;
+ struct btstack btstack;
+ int cmp;
+ s64 bn;
+ struct metapage *mp;
+ xtpage_t *p;
+ int index, nextindex;
+ struct tlock *tlck;
+ struct xtlock *xtlck;
+
+ /*
+ * find the matching entry; xtSearch() pins the page
+ */
+ if ((rc = xtSearch(ip, xoff, NULL, &cmp, &btstack, 0)))
+ return rc;
+
+ XT_GETSEARCH(ip, btstack.top, bn, mp, p, index);
+ if (cmp) {
+ /* unpin the leaf page */
+ XT_PUTPAGE(mp);
+ return -ENOENT;
+ }
+
+ /*
+ * delete the entry from the leaf page
+ */
+ nextindex = le16_to_cpu(p->header.nextindex);
+ le16_add_cpu(&p->header.nextindex, -1);
+
+ /*
+ * if the leaf page bocome empty, free the page
+ */
+ if (p->header.nextindex == cpu_to_le16(XTENTRYSTART))
+ return (xtDeleteUp(tid, ip, mp, p, &btstack));
+
+ BT_MARK_DIRTY(mp, ip);
+ /*
+ * acquire a transaction lock on the leaf page;
+ *
+ * action:xad deletion;
+ */
+ tlck = txLock(tid, ip, mp, tlckXTREE);
+ xtlck = (struct xtlock *) & tlck->lock;
+ xtlck->lwm.offset =
+ (xtlck->lwm.offset) ? min(index, xtlck->lwm.offset) : index;
+
+ /* if delete from middle, shift left/compact the remaining entries */
+ if (index < nextindex - 1)
+ memmove(&p->xad[index], &p->xad[index + 1],
+ (nextindex - index - 1) * sizeof(xad_t));
+
+ XT_PUTPAGE(mp);
+
+ return 0;
+}
+
+
+/* - TBD for defragmentaion/reorganization -
+ *
+ * xtDeleteUp()
+ *
+ * function:
+ * free empty pages as propagating deletion up the tree
+ *
+ * parameter:
+ *
+ * return:
+ */
+static int
+xtDeleteUp(tid_t tid, struct inode *ip,
+ struct metapage * fmp, xtpage_t * fp, struct btstack * btstack)
+{
+ int rc = 0;
+ struct metapage *mp;
+ xtpage_t *p;
+ int index, nextindex;
+ s64 xaddr;
+ int xlen;
+ struct btframe *parent;
+ struct tlock *tlck;
+ struct xtlock *xtlck;
+
+ /*
+ * keep root leaf page which has become empty
+ */
+ if (fp->header.flag & BT_ROOT) {
+ /* keep the root page */
+ fp->header.flag &= ~BT_INTERNAL;
+ fp->header.flag |= BT_LEAF;
+ fp->header.nextindex = cpu_to_le16(XTENTRYSTART);
+
+ /* XT_PUTPAGE(fmp); */
+
+ return 0;
+ }
+
+ /*
+ * free non-root leaf page
+ */
+ if ((rc = xtRelink(tid, ip, fp))) {
+ XT_PUTPAGE(fmp);
+ return rc;
+ }
+
+ xaddr = addressPXD(&fp->header.self);
+ xlen = lengthPXD(&fp->header.self);
+ /* free the page extent */
+ dbFree(ip, xaddr, (s64) xlen);
+
+ /* free the buffer page */
+ discard_metapage(fmp);
+
+ /*
+ * propagate page deletion up the index tree
+ *
+ * If the delete from the parent page makes it empty,
+ * continue all the way up the tree.
+ * stop if the root page is reached (which is never deleted) or
+ * if the entry deletion does not empty the page.
+ */
+ while ((parent = BT_POP(btstack)) != NULL) {
+ /* get/pin the parent page <sp> */
+ XT_GETPAGE(ip, parent->bn, mp, PSIZE, p, rc);
+ if (rc)
+ return rc;
+
+ index = parent->index;
+
+ /* delete the entry for the freed child page from parent.
+ */
+ nextindex = le16_to_cpu(p->header.nextindex);
+
+ /*
+ * the parent has the single entry being deleted:
+ * free the parent page which has become empty.
+ */
+ if (nextindex == 1) {
+ if (p->header.flag & BT_ROOT) {
+ /* keep the root page */
+ p->header.flag &= ~BT_INTERNAL;
+ p->header.flag |= BT_LEAF;
+ p->header.nextindex =
+ cpu_to_le16(XTENTRYSTART);
+
+ /* XT_PUTPAGE(mp); */
+
+ break;
+ } else {
+ /* free the parent page */
+ if ((rc = xtRelink(tid, ip, p)))
+ return rc;
+
+ xaddr = addressPXD(&p->header.self);
+ /* free the page extent */
+ dbFree(ip, xaddr,
+ (s64) JFS_SBI(ip->i_sb)->nbperpage);
+
+ /* unpin/free the buffer page */
+ discard_metapage(mp);
+
+ /* propagate up */
+ continue;
+ }
+ }
+ /*
+ * the parent has other entries remaining:
+ * delete the router entry from the parent page.
+ */
+ else {
+ BT_MARK_DIRTY(mp, ip);
+ /*
+ * acquire a transaction lock on the leaf page;
+ *
+ * action:xad deletion;
+ */
+ tlck = txLock(tid, ip, mp, tlckXTREE);
+ xtlck = (struct xtlock *) & tlck->lock;
+ xtlck->lwm.offset =
+ (xtlck->lwm.offset) ? min(index,
+ xtlck->lwm.
+ offset) : index;
+
+ /* if delete from middle,
+ * shift left/compact the remaining entries in the page
+ */
+ if (index < nextindex - 1)
+ memmove(&p->xad[index], &p->xad[index + 1],
+ (nextindex - index -
+ 1) << L2XTSLOTSIZE);
+
+ le16_add_cpu(&p->header.nextindex, -1);
+ jfs_info("xtDeleteUp(entry): 0x%lx[%d]",
+ (ulong) parent->bn, index);
+ }
+
+ /* unpin the parent page */
+ XT_PUTPAGE(mp);
+
+ /* exit propagation up */
+ break;
+ }
+
+ return 0;
+}
+
+
+/*
+ * NAME: xtRelocate()
+ *
+ * FUNCTION: relocate xtpage or data extent of regular file;
+ * This function is mainly used by defragfs utility.
+ *
+ * NOTE: This routine does not have the logic to handle
+ * uncommitted allocated extent. The caller should call
+ * txCommit() to commit all the allocation before call
+ * this routine.
+ */
+int
+xtRelocate(tid_t tid, struct inode * ip, xad_t * oxad, /* old XAD */
+ s64 nxaddr, /* new xaddr */
+ int xtype)
+{ /* extent type: XTPAGE or DATAEXT */
+ int rc = 0;
+ struct tblock *tblk;
+ struct tlock *tlck;
+ struct xtlock *xtlck;
+ struct metapage *mp, *pmp, *lmp, *rmp; /* meta-page buffer */
+ xtpage_t *p, *pp, *rp, *lp; /* base B+-tree index page */
+ xad_t *xad;
+ pxd_t *pxd;
+ s64 xoff, xsize;
+ int xlen;
+ s64 oxaddr, sxaddr, dxaddr, nextbn, prevbn;
+ cbuf_t *cp;
+ s64 offset, nbytes, nbrd, pno;
+ int nb, npages, nblks;
+ s64 bn;
+ int cmp;
+ int index;
+ struct pxd_lock *pxdlock;
+ struct btstack btstack; /* traverse stack */
+
+ xtype = xtype & EXTENT_TYPE;
+
+ xoff = offsetXAD(oxad);
+ oxaddr = addressXAD(oxad);
+ xlen = lengthXAD(oxad);
+
+ /* validate extent offset */
+ offset = xoff << JFS_SBI(ip->i_sb)->l2bsize;
+ if (offset >= ip->i_size)
+ return -ESTALE; /* stale extent */
+
+ jfs_info("xtRelocate: xtype:%d xoff:0x%lx xlen:0x%x xaddr:0x%lx:0x%lx",
+ xtype, (ulong) xoff, xlen, (ulong) oxaddr, (ulong) nxaddr);
+
+ /*
+ * 1. get and validate the parent xtpage/xad entry
+ * covering the source extent to be relocated;
+ */
+ if (xtype == DATAEXT) {
+ /* search in leaf entry */
+ rc = xtSearch(ip, xoff, NULL, &cmp, &btstack, 0);
+ if (rc)
+ return rc;
+
+ /* retrieve search result */
+ XT_GETSEARCH(ip, btstack.top, bn, pmp, pp, index);
+
+ if (cmp) {
+ XT_PUTPAGE(pmp);
+ return -ESTALE;
+ }
+
+ /* validate for exact match with a single entry */
+ xad = &pp->xad[index];
+ if (addressXAD(xad) != oxaddr || lengthXAD(xad) != xlen) {
+ XT_PUTPAGE(pmp);
+ return -ESTALE;
+ }
+ } else { /* (xtype == XTPAGE) */
+
+ /* search in internal entry */
+ rc = xtSearchNode(ip, oxad, &cmp, &btstack, 0);
+ if (rc)
+ return rc;
+
+ /* retrieve search result */
+ XT_GETSEARCH(ip, btstack.top, bn, pmp, pp, index);
+
+ if (cmp) {
+ XT_PUTPAGE(pmp);
+ return -ESTALE;
+ }
+
+ /* xtSearchNode() validated for exact match with a single entry
+ */
+ xad = &pp->xad[index];
+ }
+ jfs_info("xtRelocate: parent xad entry validated.");
+
+ /*
+ * 2. relocate the extent
+ */
+ if (xtype == DATAEXT) {
+ /* if the extent is allocated-but-not-recorded
+ * there is no real data to be moved in this extent,
+ */
+ if (xad->flag & XAD_NOTRECORDED)
+ goto out;
+ else
+ /* release xtpage for cmRead()/xtLookup() */
+ XT_PUTPAGE(pmp);
+
+ /*
+ * cmRelocate()
+ *
+ * copy target data pages to be relocated;
+ *
+ * data extent must start at page boundary and
+ * multiple of page size (except the last data extent);
+ * read in each page of the source data extent into cbuf,
+ * update the cbuf extent descriptor of the page to be
+ * homeward bound to new dst data extent
+ * copy the data from the old extent to new extent.
+ * copy is essential for compressed files to avoid problems
+ * that can arise if there was a change in compression
+ * algorithms.
+ * it is a good strategy because it may disrupt cache
+ * policy to keep the pages in memory afterwards.
+ */
+ offset = xoff << JFS_SBI(ip->i_sb)->l2bsize;
+ assert((offset & CM_OFFSET) == 0);
+ nbytes = xlen << JFS_SBI(ip->i_sb)->l2bsize;
+ pno = offset >> CM_L2BSIZE;
+ npages = (nbytes + (CM_BSIZE - 1)) >> CM_L2BSIZE;
+/*
+ npages = ((offset + nbytes - 1) >> CM_L2BSIZE) -
+ (offset >> CM_L2BSIZE) + 1;
+*/
+ sxaddr = oxaddr;
+ dxaddr = nxaddr;
+
+ /* process the request one cache buffer at a time */
+ for (nbrd = 0; nbrd < nbytes; nbrd += nb,
+ offset += nb, pno++, npages--) {
+ /* compute page size */
+ nb = min(nbytes - nbrd, CM_BSIZE);
+
+ /* get the cache buffer of the page */
+ if (rc = cmRead(ip, offset, npages, &cp))
+ break;
+
+ assert(addressPXD(&cp->cm_pxd) == sxaddr);
+ assert(!cp->cm_modified);
+
+ /* bind buffer with the new extent address */
+ nblks = nb >> JFS_IP(ip->i_sb)->l2bsize;
+ cmSetXD(ip, cp, pno, dxaddr, nblks);
+
+ /* release the cbuf, mark it as modified */
+ cmPut(cp, true);
+
+ dxaddr += nblks;
+ sxaddr += nblks;
+ }
+
+ /* get back parent page */
+ if ((rc = xtSearch(ip, xoff, NULL, &cmp, &btstack, 0)))
+ return rc;
+
+ XT_GETSEARCH(ip, btstack.top, bn, pmp, pp, index);
+ jfs_info("xtRelocate: target data extent relocated.");
+ } else { /* (xtype == XTPAGE) */
+
+ /*
+ * read in the target xtpage from the source extent;
+ */
+ XT_GETPAGE(ip, oxaddr, mp, PSIZE, p, rc);
+ if (rc) {
+ XT_PUTPAGE(pmp);
+ return rc;
+ }
+
+ /*
+ * read in sibling pages if any to update sibling pointers;
+ */
+ rmp = NULL;
+ if (p->header.next) {
+ nextbn = le64_to_cpu(p->header.next);
+ XT_GETPAGE(ip, nextbn, rmp, PSIZE, rp, rc);
+ if (rc) {
+ XT_PUTPAGE(pmp);
+ XT_PUTPAGE(mp);
+ return (rc);
+ }
+ }
+
+ lmp = NULL;
+ if (p->header.prev) {
+ prevbn = le64_to_cpu(p->header.prev);
+ XT_GETPAGE(ip, prevbn, lmp, PSIZE, lp, rc);
+ if (rc) {
+ XT_PUTPAGE(pmp);
+ XT_PUTPAGE(mp);
+ if (rmp)
+ XT_PUTPAGE(rmp);
+ return (rc);
+ }
+ }
+
+ /* at this point, all xtpages to be updated are in memory */
+
+ /*
+ * update sibling pointers of sibling xtpages if any;
+ */
+ if (lmp) {
+ BT_MARK_DIRTY(lmp, ip);
+ tlck = txLock(tid, ip, lmp, tlckXTREE | tlckRELINK);
+ lp->header.next = cpu_to_le64(nxaddr);
+ XT_PUTPAGE(lmp);
+ }
+
+ if (rmp) {
+ BT_MARK_DIRTY(rmp, ip);
+ tlck = txLock(tid, ip, rmp, tlckXTREE | tlckRELINK);
+ rp->header.prev = cpu_to_le64(nxaddr);
+ XT_PUTPAGE(rmp);
+ }
+
+ /*
+ * update the target xtpage to be relocated
+ *
+ * update the self address of the target page
+ * and write to destination extent;
+ * redo image covers the whole xtpage since it is new page
+ * to the destination extent;
+ * update of bmap for the free of source extent
+ * of the target xtpage itself:
+ * update of bmap for the allocation of destination extent
+ * of the target xtpage itself:
+ * update of bmap for the extents covered by xad entries in
+ * the target xtpage is not necessary since they are not
+ * updated;
+ * if not committed before this relocation,
+ * target page may contain XAD_NEW entries which must
+ * be scanned for bmap update (logredo() always
+ * scan xtpage REDOPAGE image for bmap update);
+ * if committed before this relocation (tlckRELOCATE),
+ * scan may be skipped by commit() and logredo();
+ */
+ BT_MARK_DIRTY(mp, ip);
+ /* tlckNEW init xtlck->lwm.offset = XTENTRYSTART; */
+ tlck = txLock(tid, ip, mp, tlckXTREE | tlckNEW);
+ xtlck = (struct xtlock *) & tlck->lock;
+
+ /* update the self address in the xtpage header */
+ pxd = &p->header.self;
+ PXDaddress(pxd, nxaddr);
+
+ /* linelock for the after image of the whole page */
+ xtlck->lwm.length =
+ le16_to_cpu(p->header.nextindex) - xtlck->lwm.offset;
+
+ /* update the buffer extent descriptor of target xtpage */
+ xsize = xlen << JFS_SBI(ip->i_sb)->l2bsize;
+ bmSetXD(mp, nxaddr, xsize);
+
+ /* unpin the target page to new homeward bound */
+ XT_PUTPAGE(mp);
+ jfs_info("xtRelocate: target xtpage relocated.");
+ }
+
+ /*
+ * 3. acquire maplock for the source extent to be freed;
+ *
+ * acquire a maplock saving the src relocated extent address;
+ * to free of the extent at commit time;
+ */
+ out:
+ /* if DATAEXT relocation, write a LOG_UPDATEMAP record for
+ * free PXD of the source data extent (logredo() will update
+ * bmap for free of source data extent), and update bmap for
+ * free of the source data extent;
+ */
+ if (xtype == DATAEXT)
+ tlck = txMaplock(tid, ip, tlckMAP);
+ /* if XTPAGE relocation, write a LOG_NOREDOPAGE record
+ * for the source xtpage (logredo() will init NoRedoPage
+ * filter and will also update bmap for free of the source
+ * xtpage), and update bmap for free of the source xtpage;
+ * N.B. We use tlckMAP instead of tlkcXTREE because there
+ * is no buffer associated with this lock since the buffer
+ * has been redirected to the target location.
+ */
+ else /* (xtype == XTPAGE) */
+ tlck = txMaplock(tid, ip, tlckMAP | tlckRELOCATE);
+
+ pxdlock = (struct pxd_lock *) & tlck->lock;
+ pxdlock->flag = mlckFREEPXD;
+ PXDaddress(&pxdlock->pxd, oxaddr);
+ PXDlength(&pxdlock->pxd, xlen);
+ pxdlock->index = 1;
+
+ /*
+ * 4. update the parent xad entry for relocation;
+ *
+ * acquire tlck for the parent entry with XAD_NEW as entry
+ * update which will write LOG_REDOPAGE and update bmap for
+ * allocation of XAD_NEW destination extent;
+ */
+ jfs_info("xtRelocate: update parent xad entry.");
+ BT_MARK_DIRTY(pmp, ip);
+ tlck = txLock(tid, ip, pmp, tlckXTREE | tlckGROW);
+ xtlck = (struct xtlock *) & tlck->lock;
+
+ /* update the XAD with the new destination extent; */
+ xad = &pp->xad[index];
+ xad->flag |= XAD_NEW;
+ XADaddress(xad, nxaddr);
+
+ xtlck->lwm.offset = min(index, xtlck->lwm.offset);
+ xtlck->lwm.length = le16_to_cpu(pp->header.nextindex) -
+ xtlck->lwm.offset;
+
+ /* unpin the parent xtpage */
+ XT_PUTPAGE(pmp);
+
+ return rc;
+}
+
+
+/*
+ * xtSearchNode()
+ *
+ * function: search for the internal xad entry covering specified extent.
+ * This function is mainly used by defragfs utility.
+ *
+ * parameters:
+ * ip - file object;
+ * xad - extent to find;
+ * cmpp - comparison result:
+ * btstack - traverse stack;
+ * flag - search process flag;
+ *
+ * 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 xtSearchNode(struct inode *ip, xad_t * xad, /* required XAD entry */
+ int *cmpp, struct btstack * btstack, int flag)
+{
+ int rc = 0;
+ s64 xoff, xaddr;
+ int xlen;
+ int cmp = 1; /* init for empty page */
+ s64 bn; /* block number */
+ struct metapage *mp; /* meta-page buffer */
+ xtpage_t *p; /* page */
+ int base, index, lim;
+ struct btframe *btsp;
+ s64 t64;
+
+ BT_CLR(btstack);
+
+ xoff = offsetXAD(xad);
+ xlen = lengthXAD(xad);
+ xaddr = addressXAD(xad);
+
+ /*
+ * 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;
+ if (p->header.flag & BT_LEAF) {
+ XT_PUTPAGE(mp);
+ return -ESTALE;
+ }
+
+ 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
+ *
+ * verify for exact match;
+ */
+ if (xaddr == addressXAD(&p->xad[index]) &&
+ xoff == offsetXAD(&p->xad[index])) {
+ *cmpp = cmp;
+
+ /* save search result */
+ btsp = btstack->top;
+ btsp->bn = bn;
+ btsp->index = index;
+ btsp->mp = mp;
+
+ return 0;
+ }
+
+ /* descend/search its child page */
+ goto next;
+ }
+
+ if (cmp > 0) {
+ base = index + 1;
+ --lim;
+ }
+ }
+
+ /*
+ * search miss - non-leaf page:
+ *
+ * base is the smallest index with key (Kj) greater than
+ * search key (K) and may be zero or maxentry index.
+ * 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:
+ /* get the child page block number */
+ bn = addressXAD(&p->xad[index]);
+
+ /* unpin the parent page */
+ XT_PUTPAGE(mp);
+ }
+}
+
+
+/*
+ * xtRelink()
+ *
+ * function:
+ * link around a freed page.
+ *
+ * Parameter:
+ * int tid,
+ * struct inode *ip,
+ * xtpage_t *p)
+ *
+ * returns:
+ */
+static int xtRelink(tid_t tid, struct inode *ip, xtpage_t * p)
+{
+ int rc = 0;
+ struct metapage *mp;
+ s64 nextbn, prevbn;
+ struct tlock *tlck;
+
+ nextbn = le64_to_cpu(p->header.next);
+ prevbn = le64_to_cpu(p->header.prev);
+
+ /* update prev pointer of the next page */
+ if (nextbn != 0) {
+ XT_GETPAGE(ip, nextbn, mp, PSIZE, p, rc);
+ if (rc)
+ return rc;
+
+ /*
+ * acquire a transaction lock on the page;
+ *
+ * action: update prev pointer;
+ */
+ BT_MARK_DIRTY(mp, ip);
+ tlck = txLock(tid, ip, mp, tlckXTREE | tlckRELINK);
+
+ /* the page may already have been tlock'd */
+
+ p->header.prev = cpu_to_le64(prevbn);
+
+ XT_PUTPAGE(mp);
+ }
+
+ /* update next pointer of the previous page */
+ if (prevbn != 0) {
+ XT_GETPAGE(ip, prevbn, mp, PSIZE, p, rc);
+ if (rc)
+ return rc;
+
+ /*
+ * acquire a transaction lock on the page;
+ *
+ * action: update next pointer;
+ */
+ BT_MARK_DIRTY(mp, ip);
+ tlck = txLock(tid, ip, mp, tlckXTREE | tlckRELINK);
+
+ /* the page may already have been tlock'd */
+
+ p->header.next = le64_to_cpu(nextbn);
+
+ XT_PUTPAGE(mp);
+ }
+
+ return 0;
+}
+#endif /* _STILL_TO_PORT */
+
+
+/*
+ * 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
+ * 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
+static 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;
+}
+
+static int jfs_xtstat_proc_open(struct inode *inode, struct file *file)
+{
+ return single_open(file, jfs_xtstat_proc_show, NULL);
+}
+
+const struct file_operations jfs_xtstat_proc_fops = {
+ .owner = THIS_MODULE,
+ .open = jfs_xtstat_proc_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = single_release,
+};
+#endif
Code Review / kvmfornfv.git / blobdiff