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[PATCH] JFS: Don't allocate extents that overlap existing extents
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Modify xtSearch so that it returns the next allocated block when the
requested block is unmapped.  This can be used to make sure we don't
create a new extent that overlaps the next one.

Signed-off-by: Dave Kleikamp <shaggy@austin.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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Dave Kleikamp authored and Linus Torvalds committed May 3, 2005
1 parent 1c62782 commit 6628465
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Showing 3 changed files with 46 additions and 25 deletions.
6 changes: 3 additions & 3 deletions fs/jfs/inode.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -178,7 +178,7 @@ jfs_get_blocks(struct inode *ip, sector_t lblock, unsigned long max_blocks,
xad_t xad;
s64 xaddr;
int xflag;
s32 xlen;
s32 xlen = max_blocks;

/*
* Take appropriate lock on inode
Expand All @@ -190,7 +190,7 @@ jfs_get_blocks(struct inode *ip, sector_t lblock, unsigned long max_blocks,

if (((lblock64 << ip->i_sb->s_blocksize_bits) < ip->i_size) &&
(!xtLookup(ip, lblock64, max_blocks, &xflag, &xaddr, &xlen, 0)) &&
xlen) {
xaddr) {
if (xflag & XAD_NOTRECORDED) {
if (!create)
/*
Expand Down Expand Up @@ -229,7 +229,7 @@ jfs_get_blocks(struct inode *ip, sector_t lblock, unsigned long max_blocks,
#ifdef _JFS_4K
if ((rc = extHint(ip, lblock64 << ip->i_sb->s_blocksize_bits, &xad)))
goto unlock;
rc = extAlloc(ip, max_blocks, lblock64, &xad, FALSE);
rc = extAlloc(ip, xlen, lblock64, &xad, FALSE);
if (rc)
goto unlock;

Expand Down
4 changes: 2 additions & 2 deletions fs/jfs/jfs_dtree.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -212,7 +212,7 @@ static struct metapage *read_index_page(struct inode *inode, s64 blkno)
s32 xlen;

rc = xtLookup(inode, blkno, 1, &xflag, &xaddr, &xlen, 1);
if (rc || (xlen == 0))
if (rc || (xaddr == 0))
return NULL;

return read_metapage(inode, xaddr, PSIZE, 1);
Expand All @@ -231,7 +231,7 @@ static struct metapage *get_index_page(struct inode *inode, s64 blkno)
s32 xlen;

rc = xtLookup(inode, blkno, 1, &xflag, &xaddr, &xlen, 1);
if (rc || (xlen == 0))
if (rc || (xaddr == 0))
return NULL;

return get_metapage(inode, xaddr, PSIZE, 1);
Expand Down
61 changes: 41 additions & 20 deletions fs/jfs/jfs_xtree.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -111,8 +111,8 @@ static struct {
/*
* forward references
*/
static int xtSearch(struct inode *ip,
s64 xoff, int *cmpp, struct btstack * btstack, int flag);
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,
Expand Down Expand Up @@ -159,11 +159,12 @@ int xtLookup(struct inode *ip, s64 lstart,
xtpage_t *p;
int index;
xad_t *xad;
s64 size, xoff, xend;
s64 next, size, xoff, xend;
int xlen;
s64 xaddr;

*plen = 0;
*paddr = 0;
*plen = llen;

if (!no_check) {
/* is lookup offset beyond eof ? */
Expand All @@ -180,7 +181,7 @@ int xtLookup(struct inode *ip, s64 lstart,
* search for the xad entry covering the logical extent
*/
//search:
if ((rc = xtSearch(ip, lstart, &cmp, &btstack, 0))) {
if ((rc = xtSearch(ip, lstart, &next, &cmp, &btstack, 0))) {
jfs_err("xtLookup: xtSearch returned %d", rc);
return rc;
}
Expand All @@ -198,8 +199,11 @@ int xtLookup(struct inode *ip, s64 lstart,
* lstart is a page start address,
* i.e., lstart cannot start in a hole;
*/
if (cmp)
if (cmp) {
if (next)
*plen = min(next - lstart, llen);
goto out;
}

/*
* lxd covered by xad
Expand Down Expand Up @@ -284,7 +288,7 @@ int xtLookupList(struct inode *ip, struct lxdlist * lxdlist,
if (lstart >= size)
return 0;

if ((rc = xtSearch(ip, lstart, &cmp, &btstack, 0)))
if ((rc = xtSearch(ip, lstart, NULL, &cmp, &btstack, 0)))
return rc;

/*
Expand Down Expand Up @@ -488,6 +492,7 @@ int xtLookupList(struct inode *ip, struct lxdlist * lxdlist,
* 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);
Expand All @@ -497,7 +502,7 @@ int xtLookupList(struct inode *ip, struct lxdlist * lxdlist,
* *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, /* offset of extent */
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);
Expand All @@ -511,6 +516,7 @@ static int xtSearch(struct inode *ip, s64 xoff, /* offset of extent */
struct btframe *btsp;
int nsplit = 0; /* number of pages to split */
s64 t64;
s64 next = 0;

INCREMENT(xtStat.search);

Expand Down Expand Up @@ -579,6 +585,7 @@ static int xtSearch(struct inode *ip, s64 xoff, /* offset of extent */
* previous and this entry
*/
*cmpp = 1;
next = t64;
goto out;
}

Expand Down Expand Up @@ -623,6 +630,9 @@ static int xtSearch(struct inode *ip, s64 xoff, /* offset of extent */
/* update sequential access heuristics */
jfs_ip->btindex = index;

if (nextp)
*nextp = next;

INCREMENT(xtStat.fastSearch);
return 0;
}
Expand Down Expand Up @@ -675,10 +685,11 @@ static int xtSearch(struct inode *ip, s64 xoff, /* offset of extent */

return 0;
}

/* search hit - internal page:
* descend/search its child page
*/
if (index < p->header.nextindex - 1)
next = offsetXAD(&p->xad[index + 1]);
goto next;
}

Expand All @@ -694,6 +705,8 @@ static int xtSearch(struct inode *ip, s64 xoff, /* offset of extent */
* base is the smallest index with key (Kj) greater than
* search key (K) and may be zero or maxentry index.
*/
if (base < p->header.nextindex)
next = offsetXAD(&p->xad[base]);
/*
* search miss - leaf page:
*
Expand Down Expand Up @@ -727,6 +740,9 @@ static int xtSearch(struct inode *ip, s64 xoff, /* offset of extent */
jfs_ip->btorder = BT_RANDOM;
jfs_ip->btindex = base;

if (nextp)
*nextp = next;

return 0;
}

Expand Down Expand Up @@ -793,6 +809,7 @@ int xtInsert(tid_t tid, /* transaction id */
struct xtsplit split; /* split information */
xad_t *xad;
int cmp;
s64 next;
struct tlock *tlck;
struct xtlock *xtlck;

Expand All @@ -806,15 +823,15 @@ int xtInsert(tid_t tid, /* transaction id */
* n.b. xtSearch() may return index of maxentry of
* the full page.
*/
if ((rc = xtSearch(ip, xoff, &cmp, &btstack, XT_INSERT)))
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) {
if ((cmp == 0) || (next && (xlen > next - xoff))) {
rc = -EEXIST;
goto out;
}
Expand Down Expand Up @@ -1626,7 +1643,7 @@ int xtExtend(tid_t tid, /* transaction id */
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, &cmp, &btstack, XT_INSERT)))
if ((rc = xtSearch(ip, xoff - 1, NULL, &cmp, &btstack, XT_INSERT)))
return rc;

/* retrieve search result */
Expand Down Expand Up @@ -1794,7 +1811,7 @@ printf("xtTailgate: nxoff:0x%lx nxlen:0x%x nxaddr:0x%lx\n",
*/

/* there must exist extent to be tailgated */
if ((rc = xtSearch(ip, xoff, &cmp, &btstack, XT_INSERT)))
if ((rc = xtSearch(ip, xoff, NULL, &cmp, &btstack, XT_INSERT)))
return rc;

/* retrieve search result */
Expand Down Expand Up @@ -1977,7 +1994,7 @@ int xtUpdate(tid_t tid, struct inode *ip, xad_t * nxad)
nxlen = lengthXAD(nxad);
nxaddr = addressXAD(nxad);

if ((rc = xtSearch(ip, nxoff, &cmp, &btstack, XT_INSERT)))
if ((rc = xtSearch(ip, nxoff, NULL, &cmp, &btstack, XT_INSERT)))
return rc;

/* retrieve search result */
Expand Down Expand Up @@ -2291,7 +2308,7 @@ int xtUpdate(tid_t tid, struct inode *ip, xad_t * nxad)
if (nextindex == le16_to_cpu(p->header.maxentry)) {
XT_PUTPAGE(mp);

if ((rc = xtSearch(ip, nxoff, &cmp, &btstack, XT_INSERT)))
if ((rc = xtSearch(ip, nxoff, NULL, &cmp, &btstack, XT_INSERT)))
return rc;

/* retrieve search result */
Expand Down Expand Up @@ -2438,6 +2455,7 @@ int xtAppend(tid_t tid, /* transaction id */
int nsplit, nblocks, xlen;
struct pxdlist pxdlist;
pxd_t *pxd;
s64 next;

xaddr = *xaddrp;
xlen = *xlenp;
Expand All @@ -2452,7 +2470,7 @@ int xtAppend(tid_t tid, /* transaction id */
* n.b. xtSearch() may return index of maxentry of
* the full page.
*/
if ((rc = xtSearch(ip, xoff, &cmp, &btstack, XT_INSERT)))
if ((rc = xtSearch(ip, xoff, &next, &cmp, &btstack, XT_INSERT)))
return rc;

/* retrieve search result */
Expand All @@ -2462,6 +2480,9 @@ int xtAppend(tid_t tid, /* transaction id */
rc = -EEXIST;
goto out;
}

if (next)
xlen = min(xlen, (int)(next - xoff));
//insert:
/*
* insert entry for new extent
Expand Down Expand Up @@ -2600,7 +2621,7 @@ int xtDelete(tid_t tid, struct inode *ip, s64 xoff, s32 xlen, int flag)
/*
* find the matching entry; xtSearch() pins the page
*/
if ((rc = xtSearch(ip, xoff, &cmp, &btstack, 0)))
if ((rc = xtSearch(ip, xoff, NULL, &cmp, &btstack, 0)))
return rc;

XT_GETSEARCH(ip, btstack.top, bn, mp, p, index);
Expand Down Expand Up @@ -2852,7 +2873,7 @@ xtRelocate(tid_t tid, struct inode * ip, xad_t * oxad, /* old XAD */
*/
if (xtype == DATAEXT) {
/* search in leaf entry */
rc = xtSearch(ip, xoff, &cmp, &btstack, 0);
rc = xtSearch(ip, xoff, NULL, &cmp, &btstack, 0);
if (rc)
return rc;

Expand Down Expand Up @@ -2958,7 +2979,7 @@ xtRelocate(tid_t tid, struct inode * ip, xad_t * oxad, /* old XAD */
}

/* get back parent page */
if ((rc = xtSearch(ip, xoff, &cmp, &btstack, 0)))
if ((rc = xtSearch(ip, xoff, NULL, &cmp, &btstack, 0)))
return rc;

XT_GETSEARCH(ip, btstack.top, bn, pmp, pp, index);
Expand Down Expand Up @@ -3991,7 +4012,7 @@ s64 xtTruncate_pmap(tid_t tid, struct inode *ip, s64 committed_size)

if (committed_size) {
xoff = (committed_size >> JFS_SBI(ip->i_sb)->l2bsize) - 1;
rc = xtSearch(ip, xoff, &cmp, &btstack, 0);
rc = xtSearch(ip, xoff, NULL, &cmp, &btstack, 0);
if (rc)
return rc;

Expand Down

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