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jfs: remove xtLookupList()
xtLookupList() was a more generalized version of xtLookup() with a nastier interface. Its only caller, extHint(), is actually better suited to using xtLookup() than xtLookupList(). This also lets us remove the definition of lxd_t, an obnoxious packed structure that was only used in-memory. Signed-off-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com>
This commit is contained in:
Dave Kleikamp
parent
da9c138e9e
commit
fec1878fe9
@ -362,11 +362,12 @@ exit:
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int extHint(struct inode *ip, s64 offset, xad_t * xp)
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{
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struct super_block *sb = ip->i_sb;
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struct xadlist xadl;
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struct lxdlist lxdl;
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lxd_t lxd;
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int nbperpage = JFS_SBI(sb)->nbperpage;
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s64 prev;
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int rc, nbperpage = JFS_SBI(sb)->nbperpage;
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int rc = 0;
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s64 xaddr;
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int xlen;
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int xflag;
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/* init the hint as "no hint provided" */
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XADaddress(xp, 0);
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@ -376,46 +377,30 @@ int extHint(struct inode *ip, s64 offset, xad_t * xp)
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*/
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prev = ((offset & ~POFFSET) >> JFS_SBI(sb)->l2bsize) - nbperpage;
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/* if the offsets in the first page of the file,
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* no hint provided.
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/* if the offset is in the first page of the file, no hint provided.
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*/
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if (prev < 0)
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return (0);
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goto out;
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/* prepare to lookup the previous page's extent info */
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lxdl.maxnlxd = 1;
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lxdl.nlxd = 1;
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lxdl.lxd = &lxd;
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LXDoffset(&lxd, prev)
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LXDlength(&lxd, nbperpage);
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rc = xtLookup(ip, prev, nbperpage, &xflag, &xaddr, &xlen, 0);
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xadl.maxnxad = 1;
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xadl.nxad = 0;
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xadl.xad = xp;
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if ((rc == 0) && xlen) {
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if (xlen != nbperpage) {
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jfs_error(ip->i_sb, "extHint: corrupt xtree");
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rc = -EIO;
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}
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XADaddress(xp, xaddr);
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XADlength(xp, xlen);
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/*
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* only preserve the abnr flag within the xad flags
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* of the returned hint.
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*/
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xp->flag = xflag & XAD_NOTRECORDED;
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} else
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rc = 0;
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/* perform the lookup */
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if ((rc = xtLookupList(ip, &lxdl, &xadl, 0)))
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return (rc);
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/* check if no extent exists for the previous page.
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* this is possible for sparse files.
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*/
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if (xadl.nxad == 0) {
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// assert(ISSPARSE(ip));
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return (0);
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}
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/* only preserve the abnr flag within the xad flags
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* of the returned hint.
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*/
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xp->flag &= XAD_NOTRECORDED;
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if(xadl.nxad != 1 || lengthXAD(xp) != nbperpage) {
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jfs_error(ip->i_sb, "extHint: corrupt xtree");
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return -EIO;
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}
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return (0);
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out:
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return (rc);
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}
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@ -57,35 +57,6 @@ struct timestruc_t {
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#define HIGHORDER 0x80000000u /* high order bit on */
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#define ONES 0xffffffffu /* all bit on */
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/*
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* logical xd (lxd)
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*/
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typedef struct {
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unsigned len:24;
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unsigned off1:8;
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u32 off2;
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} lxd_t;
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/* lxd_t field construction */
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#define LXDlength(lxd, length32) ( (lxd)->len = length32 )
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#define LXDoffset(lxd, offset64)\
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{\
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(lxd)->off1 = ((s64)offset64) >> 32;\
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(lxd)->off2 = (offset64) & 0xffffffff;\
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}
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/* lxd_t field extraction */
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#define lengthLXD(lxd) ( (lxd)->len )
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#define offsetLXD(lxd)\
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( ((s64)((lxd)->off1)) << 32 | (lxd)->off2 )
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/* lxd list */
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struct lxdlist {
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s16 maxnlxd;
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s16 nlxd;
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lxd_t *lxd;
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};
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/*
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* physical xd (pxd)
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*/
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@ -164,11 +164,8 @@ int xtLookup(struct inode *ip, s64 lstart,
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/* is lookup offset beyond eof ? */
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size = ((u64) ip->i_size + (JFS_SBI(ip->i_sb)->bsize - 1)) >>
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JFS_SBI(ip->i_sb)->l2bsize;
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if (lstart >= size) {
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jfs_err("xtLookup: lstart (0x%lx) >= size (0x%lx)",
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(ulong) lstart, (ulong) size);
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if (lstart >= size)
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return 0;
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}
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}
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/*
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@ -220,264 +217,6 @@ int xtLookup(struct inode *ip, s64 lstart,
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return rc;
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}
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/*
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* xtLookupList()
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*
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* function: map a single logical extent into a list of physical extent;
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*
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* parameter:
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* struct inode *ip,
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* struct lxdlist *lxdlist, lxd list (in)
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* struct xadlist *xadlist, xad list (in/out)
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* int flag)
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*
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* coverage of lxd by xad under assumption of
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* . lxd's are ordered and disjoint.
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* . xad's are ordered and disjoint.
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*
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* return:
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* 0: success
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*
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* note: a page being written (even a single byte) is backed fully,
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* except the last page which is only backed with blocks
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* required to cover the last byte;
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* the extent backing a page is fully contained within an xad;
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*/
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int xtLookupList(struct inode *ip, struct lxdlist * lxdlist,
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struct xadlist * xadlist, int flag)
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{
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int rc = 0;
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struct btstack btstack;
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int cmp;
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s64 bn;
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struct metapage *mp;
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xtpage_t *p;
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int index;
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lxd_t *lxd;
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xad_t *xad, *pxd;
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s64 size, lstart, lend, xstart, xend, pstart;
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s64 llen, xlen, plen;
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s64 xaddr, paddr;
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int nlxd, npxd, maxnpxd;
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npxd = xadlist->nxad = 0;
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maxnpxd = xadlist->maxnxad;
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pxd = xadlist->xad;
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nlxd = lxdlist->nlxd;
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lxd = lxdlist->lxd;
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lstart = offsetLXD(lxd);
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llen = lengthLXD(lxd);
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lend = lstart + llen;
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size = (ip->i_size + (JFS_SBI(ip->i_sb)->bsize - 1)) >>
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JFS_SBI(ip->i_sb)->l2bsize;
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/*
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* search for the xad entry covering the logical extent
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*/
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search:
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if (lstart >= size)
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return 0;
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if ((rc = xtSearch(ip, lstart, NULL, &cmp, &btstack, 0)))
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return rc;
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/*
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* compute the physical extent covering logical extent
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*
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* N.B. search may have failed (e.g., hole in sparse file),
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* and returned the index of the next entry.
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*/
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//map:
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/* retrieve search result */
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XT_GETSEARCH(ip, btstack.top, bn, mp, p, index);
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/* is xad on the next sibling page ? */
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if (index == le16_to_cpu(p->header.nextindex)) {
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if (p->header.flag & BT_ROOT)
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goto mapend;
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if ((bn = le64_to_cpu(p->header.next)) == 0)
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goto mapend;
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XT_PUTPAGE(mp);
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/* get next sibling page */
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XT_GETPAGE(ip, bn, mp, PSIZE, p, rc);
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if (rc)
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return rc;
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index = XTENTRYSTART;
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}
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xad = &p->xad[index];
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/*
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* is lxd covered by xad ?
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*/
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compare:
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xstart = offsetXAD(xad);
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xlen = lengthXAD(xad);
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xend = xstart + xlen;
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xaddr = addressXAD(xad);
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compare1:
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if (xstart < lstart)
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goto compare2;
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/* (lstart <= xstart) */
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/* lxd is NOT covered by xad */
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if (lend <= xstart) {
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/*
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* get next lxd
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*/
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if (--nlxd == 0)
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goto mapend;
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lxd++;
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lstart = offsetLXD(lxd);
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llen = lengthLXD(lxd);
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lend = lstart + llen;
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if (lstart >= size)
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goto mapend;
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/* compare with the current xad */
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goto compare1;
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}
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/* lxd is covered by xad */
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else { /* (xstart < lend) */
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/* initialize new pxd */
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pstart = xstart;
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plen = min(lend - xstart, xlen);
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paddr = xaddr;
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goto cover;
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}
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/* (xstart < lstart) */
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compare2:
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/* lxd is covered by xad */
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if (lstart < xend) {
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/* initialize new pxd */
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pstart = lstart;
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plen = min(xend - lstart, llen);
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paddr = xaddr + (lstart - xstart);
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goto cover;
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}
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/* lxd is NOT covered by xad */
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else { /* (xend <= lstart) */
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/*
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* get next xad
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*
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* linear search next xad covering lxd on
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* the current xad page, and then tree search
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*/
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if (index == le16_to_cpu(p->header.nextindex) - 1) {
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if (p->header.flag & BT_ROOT)
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goto mapend;
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XT_PUTPAGE(mp);
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goto search;
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} else {
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index++;
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xad++;
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/* compare with new xad */
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goto compare;
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}
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}
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/*
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* lxd is covered by xad and a new pxd has been initialized
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* (lstart <= xstart < lend) or (xstart < lstart < xend)
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*/
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cover:
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/* finalize pxd corresponding to current xad */
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XT_PUTENTRY(pxd, xad->flag, pstart, plen, paddr);
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if (++npxd >= maxnpxd)
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goto mapend;
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pxd++;
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/*
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* lxd is fully covered by xad
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*/
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if (lend <= xend) {
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/*
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* get next lxd
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*/
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if (--nlxd == 0)
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goto mapend;
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lxd++;
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lstart = offsetLXD(lxd);
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llen = lengthLXD(lxd);
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lend = lstart + llen;
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if (lstart >= size)
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goto mapend;
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/*
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* test for old xad covering new lxd
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* (old xstart < new lstart)
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*/
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goto compare2;
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}
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/*
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* lxd is partially covered by xad
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*/
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else { /* (xend < lend) */
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/*
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* get next xad
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*
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* linear search next xad covering lxd on
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* the current xad page, and then next xad page search
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*/
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if (index == le16_to_cpu(p->header.nextindex) - 1) {
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if (p->header.flag & BT_ROOT)
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goto mapend;
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if ((bn = le64_to_cpu(p->header.next)) == 0)
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goto mapend;
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XT_PUTPAGE(mp);
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/* get next sibling page */
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XT_GETPAGE(ip, bn, mp, PSIZE, p, rc);
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if (rc)
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return rc;
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index = XTENTRYSTART;
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xad = &p->xad[index];
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} else {
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index++;
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xad++;
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}
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/*
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* test for new xad covering old lxd
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* (old lstart < new xstart)
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*/
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goto compare;
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}
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mapend:
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xadlist->nxad = npxd;
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//out:
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XT_PUTPAGE(mp);
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return rc;
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}
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/*
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* xtSearch()
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*
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@ -110,8 +110,6 @@ typedef union {
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*/
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extern int xtLookup(struct inode *ip, s64 lstart, s64 llen,
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int *pflag, s64 * paddr, int *plen, int flag);
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extern int xtLookupList(struct inode *ip, struct lxdlist * lxdlist,
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struct xadlist * xadlist, int flag);
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extern void xtInitRoot(tid_t tid, struct inode *ip);
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extern int xtInsert(tid_t tid, struct inode *ip,
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int xflag, s64 xoff, int xlen, s64 * xaddrp, int flag);
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