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[XFS] implement generic xfs_btree_lookup

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From: Dave Chinner <dgc@sgi.com>

[hch: split out from bigger patch and minor adaptions]

SGI-PV: 985583

SGI-Modid: xfs-linux-melb:xfs-kern:32192a

Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
Signed-off-by: Bill O'Donnell <billodo@sgi.com>
Signed-off-by: David Chinner <david@fromorbit.com>
This commit is contained in:
Christoph Hellwig 2008-10-30 16:56:09 +11:00 committed by Lachlan McIlroy
parent 8df4da4a0a
commit fe033cc848
12 changed files with 487 additions and 735 deletions
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48
fs/xfs/xfs_alloc.c
View File

@ -89,6 +89,54 @@ STATIC int xfs_alloc_ag_vextent_small(xfs_alloc_arg_t *,
* Internal functions.
*/
/*
* Lookup the record equal to [bno, len] in the btree given by cur.
*/
STATIC int /* error */
xfs_alloc_lookup_eq(
struct xfs_btree_cur *cur, /* btree cursor */
xfs_agblock_t bno, /* starting block of extent */
xfs_extlen_t len, /* length of extent */
int *stat) /* success/failure */
{
cur->bc_rec.a.ar_startblock = bno;
cur->bc_rec.a.ar_blockcount = len;
return xfs_btree_lookup(cur, XFS_LOOKUP_EQ, stat);
}
/*
* Lookup the first record greater than or equal to [bno, len]
* in the btree given by cur.
*/
STATIC int /* error */
xfs_alloc_lookup_ge(
struct xfs_btree_cur *cur, /* btree cursor */
xfs_agblock_t bno, /* starting block of extent */
xfs_extlen_t len, /* length of extent */
int *stat) /* success/failure */
{
cur->bc_rec.a.ar_startblock = bno;
cur->bc_rec.a.ar_blockcount = len;
return xfs_btree_lookup(cur, XFS_LOOKUP_GE, stat);
}
/*
* Lookup the first record less than or equal to [bno, len]
* in the btree given by cur.
*/
STATIC int /* error */
xfs_alloc_lookup_le(
struct xfs_btree_cur *cur, /* btree cursor */
xfs_agblock_t bno, /* starting block of extent */
xfs_extlen_t len, /* length of extent */
int *stat) /* success/failure */
{
cur->bc_rec.a.ar_startblock = bno;
cur->bc_rec.a.ar_blockcount = len;
return xfs_btree_lookup(cur, XFS_LOOKUP_LE, stat);
}
/*
* Compute aligned version of the found extent.
* Takes alignment and min length into account.

312
fs/xfs/xfs_alloc_btree.c
View File

@ -937,223 +937,6 @@ xfs_alloc_log_recs(
xfs_trans_log_buf(cur->bc_tp, bp, first, last);
}
/*
* Lookup the record. The cursor is made to point to it, based on dir.
* Return 0 if can't find any such record, 1 for success.
*/
STATIC int /* error */
xfs_alloc_lookup(
xfs_btree_cur_t *cur, /* btree cursor */
xfs_lookup_t dir, /* <=, ==, or >= */
int *stat) /* success/failure */
{
xfs_agblock_t agbno; /* a.g. relative btree block number */
xfs_agnumber_t agno; /* allocation group number */
xfs_alloc_block_t *block=NULL; /* current btree block */
int diff; /* difference for the current key */
int error; /* error return value */
int keyno=0; /* current key number */
int level; /* level in the btree */
xfs_mount_t *mp; /* file system mount point */
XFS_STATS_INC(xs_abt_lookup);
/*
* Get the allocation group header, and the root block number.
*/
mp = cur->bc_mp;
{
xfs_agf_t *agf; /* a.g. freespace header */
agf = XFS_BUF_TO_AGF(cur->bc_private.a.agbp);
agno = be32_to_cpu(agf->agf_seqno);
agbno = be32_to_cpu(agf->agf_roots[cur->bc_btnum]);
}
/*
* Iterate over each level in the btree, starting at the root.
* For each level above the leaves, find the key we need, based
* on the lookup record, then follow the corresponding block
* pointer down to the next level.
*/
for (level = cur->bc_nlevels - 1, diff = 1; level >= 0; level--) {
xfs_buf_t *bp; /* buffer pointer for btree block */
xfs_daddr_t d; /* disk address of btree block */
/*
* Get the disk address we're looking for.
*/
d = XFS_AGB_TO_DADDR(mp, agno, agbno);
/*
* If the old buffer at this level is for a different block,
* throw it away, otherwise just use it.
*/
bp = cur->bc_bufs[level];
if (bp && XFS_BUF_ADDR(bp) != d)
bp = NULL;
if (!bp) {
/*
* Need to get a new buffer. Read it, then
* set it in the cursor, releasing the old one.
*/
if ((error = xfs_btree_read_bufs(mp, cur->bc_tp, agno,
agbno, 0, &bp, XFS_ALLOC_BTREE_REF)))
return error;
xfs_btree_setbuf(cur, level, bp);
/*
* Point to the btree block, now that we have the buffer
*/
block = XFS_BUF_TO_ALLOC_BLOCK(bp);
if ((error = xfs_btree_check_sblock(cur, block, level,
bp)))
return error;
} else
block = XFS_BUF_TO_ALLOC_BLOCK(bp);
/*
* If we already had a key match at a higher level, we know
* we need to use the first entry in this block.
*/
if (diff == 0)
keyno = 1;
/*
* Otherwise we need to search this block. Do a binary search.
*/
else {
int high; /* high entry number */
xfs_alloc_key_t *kkbase=NULL;/* base of keys in block */
xfs_alloc_rec_t *krbase=NULL;/* base of records in block */
int low; /* low entry number */
/*
* Get a pointer to keys or records.
*/
if (level > 0)
kkbase = XFS_ALLOC_KEY_ADDR(block, 1, cur);
else
krbase = XFS_ALLOC_REC_ADDR(block, 1, cur);
/*
* Set low and high entry numbers, 1-based.
*/
low = 1;
if (!(high = be16_to_cpu(block->bb_numrecs))) {
/*
* If the block is empty, the tree must
* be an empty leaf.
*/
ASSERT(level == 0 && cur->bc_nlevels == 1);
cur->bc_ptrs[0] = dir != XFS_LOOKUP_LE;
*stat = 0;
return 0;
}
/*
* Binary search the block.
*/
while (low <= high) {
xfs_extlen_t blockcount; /* key value */
xfs_agblock_t startblock; /* key value */
XFS_STATS_INC(xs_abt_compare);
/*
* keyno is average of low and high.
*/
keyno = (low + high) >> 1;
/*
* Get startblock & blockcount.
*/
if (level > 0) {
xfs_alloc_key_t *kkp;
kkp = kkbase + keyno - 1;
startblock = be32_to_cpu(kkp->ar_startblock);
blockcount = be32_to_cpu(kkp->ar_blockcount);
} else {
xfs_alloc_rec_t *krp;
krp = krbase + keyno - 1;
startblock = be32_to_cpu(krp->ar_startblock);
blockcount = be32_to_cpu(krp->ar_blockcount);
}
/*
* Compute difference to get next direction.
*/
if (cur->bc_btnum == XFS_BTNUM_BNO)
diff = (int)startblock -
(int)cur->bc_rec.a.ar_startblock;
else if (!(diff = (int)blockcount -
(int)cur->bc_rec.a.ar_blockcount))
diff = (int)startblock -
(int)cur->bc_rec.a.ar_startblock;
/*
* Less than, move right.
*/
if (diff < 0)
low = keyno + 1;
/*
* Greater than, move left.
*/
else if (diff > 0)
high = keyno - 1;
/*
* Equal, we're done.
*/
else
break;
}
}
/*
* If there are more levels, set up for the next level
* by getting the block number and filling in the cursor.
*/
if (level > 0) {
/*
* If we moved left, need the previous key number,
* unless there isn't one.
*/
if (diff > 0 && --keyno < 1)
keyno = 1;
agbno = be32_to_cpu(*XFS_ALLOC_PTR_ADDR(block, keyno, cur));
#ifdef DEBUG
if ((error = xfs_btree_check_sptr(cur, agbno, level)))
return error;
#endif
cur->bc_ptrs[level] = keyno;
}
}
/*
* Done with the search.
* See if we need to adjust the results.
*/
if (dir != XFS_LOOKUP_LE && diff < 0) {
keyno++;
/*
* If ge search and we went off the end of the block, but it's
* not the last block, we're in the wrong block.
*/
if (dir == XFS_LOOKUP_GE &&
keyno > be16_to_cpu(block->bb_numrecs) &&
be32_to_cpu(block->bb_rightsib) != NULLAGBLOCK) {
int i;
cur->bc_ptrs[0] = keyno;
if ((error = xfs_btree_increment(cur, 0, &i)))
return error;
XFS_WANT_CORRUPTED_RETURN(i == 1);
*stat = 1;
return 0;
}
}
else if (dir == XFS_LOOKUP_LE && diff > 0)
keyno--;
cur->bc_ptrs[0] = keyno;
/*
* Return if we succeeded or not.
*/
if (keyno == 0 || keyno > be16_to_cpu(block->bb_numrecs))
*stat = 0;
else
*stat = ((dir != XFS_LOOKUP_EQ) || (diff == 0));
return 0;
}
/*
* Move 1 record left from cur/level if possible.
* Update cur to reflect the new path.
@ -1918,53 +1701,6 @@ xfs_alloc_insert(
return 0;
}
/*
* Lookup the record equal to [bno, len] in the btree given by cur.
*/
int /* error */
xfs_alloc_lookup_eq(
xfs_btree_cur_t *cur, /* btree cursor */
xfs_agblock_t bno, /* starting block of extent */
xfs_extlen_t len, /* length of extent */
int *stat) /* success/failure */
{
cur->bc_rec.a.ar_startblock = bno;
cur->bc_rec.a.ar_blockcount = len;
return xfs_alloc_lookup(cur, XFS_LOOKUP_EQ, stat);
}
/*
* Lookup the first record greater than or equal to [bno, len]
* in the btree given by cur.
*/
int /* error */
xfs_alloc_lookup_ge(
xfs_btree_cur_t *cur, /* btree cursor */
xfs_agblock_t bno, /* starting block of extent */
xfs_extlen_t len, /* length of extent */
int *stat) /* success/failure */
{
cur->bc_rec.a.ar_startblock = bno;
cur->bc_rec.a.ar_blockcount = len;
return xfs_alloc_lookup(cur, XFS_LOOKUP_GE, stat);
}
/*
* Lookup the first record less than or equal to [bno, len]
* in the btree given by cur.
*/
int /* error */
xfs_alloc_lookup_le(
xfs_btree_cur_t *cur, /* btree cursor */
xfs_agblock_t bno, /* starting block of extent */
xfs_extlen_t len, /* length of extent */
int *stat) /* success/failure */
{
cur->bc_rec.a.ar_startblock = bno;
cur->bc_rec.a.ar_blockcount = len;
return xfs_alloc_lookup(cur, XFS_LOOKUP_LE, stat);
}
/*
* Update the record referred to by cur, to the value given by [bno, len].
* This either works (return 0) or gets an EFSCORRUPTED error.
@ -2052,6 +1788,51 @@ xfs_allocbt_get_maxrecs(
return cur->bc_mp->m_alloc_mxr[level != 0];
}
STATIC void
xfs_allocbt_init_key_from_rec(
union xfs_btree_key *key,
union xfs_btree_rec *rec)
{
ASSERT(rec->alloc.ar_startblock != 0);
key->alloc.ar_startblock = rec->alloc.ar_startblock;
key->alloc.ar_blockcount = rec->alloc.ar_blockcount;
}
STATIC void
xfs_allocbt_init_ptr_from_cur(
struct xfs_btree_cur *cur,
union xfs_btree_ptr *ptr)
{
struct xfs_agf *agf = XFS_BUF_TO_AGF(cur->bc_private.a.agbp);
ASSERT(cur->bc_private.a.agno == be32_to_cpu(agf->agf_seqno));
ASSERT(agf->agf_roots[cur->bc_btnum] != 0);
ptr->s = agf->agf_roots[cur->bc_btnum];
}
STATIC __int64_t
xfs_allocbt_key_diff(
struct xfs_btree_cur *cur,
union xfs_btree_key *key)
{
xfs_alloc_rec_incore_t *rec = &cur->bc_rec.a;
xfs_alloc_key_t *kp = &key->alloc;
__int64_t diff;
if (cur->bc_btnum == XFS_BTNUM_BNO) {
return (__int64_t)be32_to_cpu(kp->ar_startblock) -
rec->ar_startblock;
}
diff = (__int64_t)be32_to_cpu(kp->ar_blockcount) - rec->ar_blockcount;
if (diff)
return diff;
return (__int64_t)be32_to_cpu(kp->ar_startblock) - rec->ar_startblock;
}
#ifdef XFS_BTREE_TRACE
ktrace_t *xfs_allocbt_trace_buf;
@ -2124,6 +1905,9 @@ static const struct xfs_btree_ops xfs_allocbt_ops = {
.dup_cursor = xfs_allocbt_dup_cursor,
.get_maxrecs = xfs_allocbt_get_maxrecs,
.init_key_from_rec = xfs_allocbt_init_key_from_rec,
.init_ptr_from_cur = xfs_allocbt_init_ptr_from_cur,
.key_diff = xfs_allocbt_key_diff,
#ifdef XFS_BTREE_TRACE
.trace_enter = xfs_allocbt_trace_enter,

20
fs/xfs/xfs_alloc_btree.h
View File

@ -113,26 +113,6 @@ extern int xfs_alloc_get_rec(struct xfs_btree_cur *cur, xfs_agblock_t *bno,
*/
extern int xfs_alloc_insert(struct xfs_btree_cur *cur, int *stat);
/*
* Lookup the record equal to [bno, len] in the btree given by cur.
*/
extern int xfs_alloc_lookup_eq(struct xfs_btree_cur *cur, xfs_agblock_t bno,
xfs_extlen_t len, int *stat);
/*
* Lookup the first record greater than or equal to [bno, len]
* in the btree given by cur.
*/
extern int xfs_alloc_lookup_ge(struct xfs_btree_cur *cur, xfs_agblock_t bno,
xfs_extlen_t len, int *stat);
/*
* Lookup the first record less than or equal to [bno, len]
* in the btree given by cur.
*/
extern int xfs_alloc_lookup_le(struct xfs_btree_cur *cur, xfs_agblock_t bno,
xfs_extlen_t len, int *stat);
/*
* Update the record referred to by cur, to the value given by [bno, len].
* This either works (return 0) or gets an EFSCORRUPTED error.

29
fs/xfs/xfs_bmap.c
View File

@ -402,6 +402,35 @@ xfs_bmap_disk_count_leaves(
* Bmap internal routines.
*/
STATIC int /* error */
xfs_bmbt_lookup_eq(
struct xfs_btree_cur *cur,
xfs_fileoff_t off,
xfs_fsblock_t bno,
xfs_filblks_t len,
int *stat) /* success/failure */
{
cur->bc_rec.b.br_startoff = off;
cur->bc_rec.b.br_startblock = bno;
cur->bc_rec.b.br_blockcount = len;
return xfs_btree_lookup(cur, XFS_LOOKUP_EQ, stat);
}
STATIC int /* error */
xfs_bmbt_lookup_ge(
struct xfs_btree_cur *cur,
xfs_fileoff_t off,
xfs_fsblock_t bno,
xfs_filblks_t len,
int *stat) /* success/failure */
{
cur->bc_rec.b.br_startoff = off;
cur->bc_rec.b.br_startblock = bno;
cur->bc_rec.b.br_blockcount = len;
return xfs_btree_lookup(cur, XFS_LOOKUP_GE, stat);
}
/*
* Called from xfs_bmap_add_attrfork to handle btree format files.
*/

197
fs/xfs/xfs_bmap_btree.c
View File

@ -812,146 +812,6 @@ xfs_bmbt_log_ptrs(
XFS_BMBT_TRACE_CURSOR(cur, EXIT);
}
/*
* Lookup the record. The cursor is made to point to it, based on dir.
*/
STATIC int /* error */
xfs_bmbt_lookup(
xfs_btree_cur_t *cur,
xfs_lookup_t dir,
int *stat) /* success/failure */
{
xfs_bmbt_block_t *block=NULL;
xfs_buf_t *bp;
xfs_daddr_t d;
xfs_sfiloff_t diff;
int error; /* error return value */
xfs_fsblock_t fsbno=0;
int high;
int i;
int keyno=0;
xfs_bmbt_key_t *kkbase=NULL;
xfs_bmbt_key_t *kkp;
xfs_bmbt_rec_t *krbase=NULL;
xfs_bmbt_rec_t *krp;
int level;
int low;
xfs_mount_t *mp;
xfs_bmbt_ptr_t *pp;
xfs_bmbt_irec_t *rp;
xfs_fileoff_t startoff;
xfs_trans_t *tp;
XFS_STATS_INC(xs_bmbt_lookup);
XFS_BMBT_TRACE_CURSOR(cur, ENTRY);
XFS_BMBT_TRACE_ARGI(cur, (int)dir);
tp = cur->bc_tp;
mp = cur->bc_mp;
rp = &cur->bc_rec.b;
for (level = cur->bc_nlevels - 1, diff = 1; level >= 0; level--) {
if (level < cur->bc_nlevels - 1) {
d = XFS_FSB_TO_DADDR(mp, fsbno);
bp = cur->bc_bufs[level];
if (bp && XFS_BUF_ADDR(bp) != d)
bp = NULL;
if (!bp) {
if ((error = xfs_btree_read_bufl(mp, tp, fsbno,
0, &bp, XFS_BMAP_BTREE_REF))) {
XFS_BMBT_TRACE_CURSOR(cur, ERROR);
return error;
}
xfs_btree_setbuf(cur, level, bp);
block = XFS_BUF_TO_BMBT_BLOCK(bp);
if ((error = xfs_btree_check_lblock(cur, block,
level, bp))) {
XFS_BMBT_TRACE_CURSOR(cur, ERROR);
return error;
}
} else
block = XFS_BUF_TO_BMBT_BLOCK(bp);
} else
block = xfs_bmbt_get_block(cur, level, &bp);
if (diff == 0)
keyno = 1;
else {
if (level > 0)
kkbase = XFS_BMAP_KEY_IADDR(block, 1, cur);
else
krbase = XFS_BMAP_REC_IADDR(block, 1, cur);
low = 1;
if (!(high = be16_to_cpu(block->bb_numrecs))) {
ASSERT(level == 0);
cur->bc_ptrs[0] = dir != XFS_LOOKUP_LE;
XFS_BMBT_TRACE_CURSOR(cur, EXIT);
*stat = 0;
return 0;
}
while (low <= high) {
XFS_STATS_INC(xs_bmbt_compare);
keyno = (low + high) >> 1;
if (level > 0) {
kkp = kkbase + keyno - 1;
startoff = be64_to_cpu(kkp->br_startoff);
} else {
krp = krbase + keyno - 1;
startoff = xfs_bmbt_disk_get_startoff(krp);
}
diff = (xfs_sfiloff_t)
(startoff - rp->br_startoff);
if (diff < 0)
low = keyno + 1;
else if (diff > 0)
high = keyno - 1;
else
break;
}
}
if (level > 0) {
if (diff > 0 && --keyno < 1)
keyno = 1;
pp = XFS_BMAP_PTR_IADDR(block, keyno, cur);
fsbno = be64_to_cpu(*pp);
#ifdef DEBUG
if ((error = xfs_btree_check_lptr(cur, fsbno, level))) {
XFS_BMBT_TRACE_CURSOR(cur, ERROR);
return error;
}
#endif
cur->bc_ptrs[level] = keyno;
}
}
if (dir != XFS_LOOKUP_LE && diff < 0) {
keyno++;
/*
* If ge search and we went off the end of the block, but it's
* not the last block, we're in the wrong block.
*/
if (dir == XFS_LOOKUP_GE && keyno > be16_to_cpu(block->bb_numrecs) &&
be64_to_cpu(block->bb_rightsib) != NULLDFSBNO) {
cur->bc_ptrs[0] = keyno;
if ((error = xfs_btree_increment(cur, 0, &i))) {
XFS_BMBT_TRACE_CURSOR(cur, ERROR);
return error;
}
XFS_WANT_CORRUPTED_RETURN(i == 1);
XFS_BMBT_TRACE_CURSOR(cur, EXIT);
*stat = 1;
return 0;
}
}
else if (dir == XFS_LOOKUP_LE && diff > 0)
keyno--;
cur->bc_ptrs[0] = keyno;
if (keyno == 0 || keyno > be16_to_cpu(block->bb_numrecs)) {
XFS_BMBT_TRACE_CURSOR(cur, EXIT);
*stat = 0;
} else {
XFS_BMBT_TRACE_CURSOR(cur, EXIT);
*stat = ((dir != XFS_LOOKUP_EQ) || (diff == 0));
}
return 0;
}
/*
* Move 1 record left from cur/level if possible.
* Update cur to reflect the new path.
@ -1809,34 +1669,6 @@ xfs_bmbt_log_recs(
XFS_BMBT_TRACE_CURSOR(cur, EXIT);
}
int /* error */
xfs_bmbt_lookup_eq(
xfs_btree_cur_t *cur,
xfs_fileoff_t off,
xfs_fsblock_t bno,
xfs_filblks_t len,
int *stat) /* success/failure */
{
cur->bc_rec.b.br_startoff = off;
cur->bc_rec.b.br_startblock = bno;
cur->bc_rec.b.br_blockcount = len;
return xfs_bmbt_lookup(cur, XFS_LOOKUP_EQ, stat);
}
int /* error */
xfs_bmbt_lookup_ge(
xfs_btree_cur_t *cur,
xfs_fileoff_t off,
xfs_fsblock_t bno,
xfs_filblks_t len,
int *stat) /* success/failure */
{
cur->bc_rec.b.br_startoff = off;
cur->bc_rec.b.br_startblock = bno;
cur->bc_rec.b.br_blockcount = len;
return xfs_bmbt_lookup(cur, XFS_LOOKUP_GE, stat);
}
/*
* Give the bmap btree a new root block. Copy the old broot contents
* down into a real block and make the broot point to it.
@ -2269,6 +2101,32 @@ xfs_bmbt_get_maxrecs(
return XFS_BMAP_BLOCK_IMAXRECS(level, cur);
}
STATIC void
xfs_bmbt_init_key_from_rec(
union xfs_btree_key *key,
union xfs_btree_rec *rec)
{
key->bmbt.br_startoff =
cpu_to_be64(xfs_bmbt_disk_get_startoff(&rec->bmbt));
}
STATIC void
xfs_bmbt_init_ptr_from_cur(
struct xfs_btree_cur *cur,
union xfs_btree_ptr *ptr)
{
ptr->l = 0;
}
STATIC __int64_t
xfs_bmbt_key_diff(
struct xfs_btree_cur *cur,
union xfs_btree_key *key)
{
return (__int64_t)be64_to_cpu(key->bmbt.br_startoff) -
cur->bc_rec.b.br_startoff;
}
#ifdef XFS_BTREE_TRACE
ktrace_t *xfs_bmbt_trace_buf;
@ -2360,6 +2218,9 @@ static const struct xfs_btree_ops xfs_bmbt_ops = {
.dup_cursor = xfs_bmbt_dup_cursor,
.get_maxrecs = xfs_bmbt_get_maxrecs,
.init_key_from_rec = xfs_bmbt_init_key_from_rec,
.init_ptr_from_cur = xfs_bmbt_init_ptr_from_cur,
.key_diff = xfs_bmbt_key_diff,
#ifdef XFS_BTREE_TRACE
.trace_enter = xfs_bmbt_trace_enter,

4
fs/xfs/xfs_bmap_btree.h
View File

@ -254,10 +254,6 @@ extern int xfs_bmbt_insert(struct xfs_btree_cur *, int *);
extern void xfs_bmbt_log_block(struct xfs_btree_cur *, struct xfs_buf *, int);
extern void xfs_bmbt_log_recs(struct xfs_btree_cur *, struct xfs_buf *, int,
int);
extern int xfs_bmbt_lookup_eq(struct xfs_btree_cur *, xfs_fileoff_t,
xfs_fsblock_t, xfs_filblks_t, int *);
extern int xfs_bmbt_lookup_ge(struct xfs_btree_cur *, xfs_fileoff_t,
xfs_fsblock_t, xfs_filblks_t, int *);
/*
* Give the bmap btree a new root block. Copy the old broot contents

219
fs/xfs/xfs_btree.c
View File

@ -1270,3 +1270,222 @@ error0:
return error;
}
STATIC int
xfs_btree_lookup_get_block(
struct xfs_btree_cur *cur, /* btree cursor */
int level, /* level in the btree */
union xfs_btree_ptr *pp, /* ptr to btree block */
struct xfs_btree_block **blkp) /* return btree block */
{
struct xfs_buf *bp; /* buffer pointer for btree block */
int error = 0;
/* special case the root block if in an inode */
if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
(level == cur->bc_nlevels - 1)) {
*blkp = xfs_btree_get_iroot(cur);
return 0;
}
/*
* If the old buffer at this level for the disk address we are
* looking for re-use it.
*
* Otherwise throw it away and get a new one.
*/
bp = cur->bc_bufs[level];
if (bp && XFS_BUF_ADDR(bp) == xfs_btree_ptr_to_daddr(cur, pp)) {
*blkp = XFS_BUF_TO_BLOCK(bp);
return 0;
}
error = xfs_btree_read_buf_block(cur, pp, level, 0, blkp, &bp);
if (error)
return error;
xfs_btree_setbuf(cur, level, bp);
return 0;
}
/*
* Get current search key. For level 0 we don't actually have a key
* structure so we make one up from the record. For all other levels
* we just return the right key.
*/
STATIC union xfs_btree_key *
xfs_lookup_get_search_key(
struct xfs_btree_cur *cur,
int level,
int keyno,
struct xfs_btree_block *block,
union xfs_btree_key *kp)
{
if (level == 0) {
cur->bc_ops->init_key_from_rec(kp,
xfs_btree_rec_addr(cur, keyno, block));
return kp;
}
return xfs_btree_key_addr(cur, keyno, block);
}
/*
* Lookup the record. The cursor is made to point to it, based on dir.
* Return 0 if can't find any such record, 1 for success.
*/
int /* error */
xfs_btree_lookup(
struct xfs_btree_cur *cur, /* btree cursor */
xfs_lookup_t dir, /* <=, ==, or >= */
int *stat) /* success/failure */
{
struct xfs_btree_block *block; /* current btree block */
__int64_t diff; /* difference for the current key */
int error; /* error return value */
int keyno; /* current key number */
int level; /* level in the btree */
union xfs_btree_ptr *pp; /* ptr to btree block */
union xfs_btree_ptr ptr; /* ptr to btree block */
XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
XFS_BTREE_TRACE_ARGI(cur, dir);
XFS_BTREE_STATS_INC(cur, lookup);
block = NULL;
keyno = 0;
/* initialise start pointer from cursor */
cur->bc_ops->init_ptr_from_cur(cur, &ptr);
pp = &ptr;
/*
* Iterate over each level in the btree, starting at the root.
* For each level above the leaves, find the key we need, based
* on the lookup record, then follow the corresponding block
* pointer down to the next level.
*/
for (level = cur->bc_nlevels - 1, diff = 1; level >= 0; level--) {
/* Get the block we need to do the lookup on. */
error = xfs_btree_lookup_get_block(cur, level, pp, &block);
if (error)
goto error0;
if (diff == 0) {
/*
* If we already had a key match at a higher level, we
* know we need to use the first entry in this block.
*/
keyno = 1;
} else {
/* Otherwise search this block. Do a binary search. */
int high; /* high entry number */
int low; /* low entry number */
/* Set low and high entry numbers, 1-based. */
low = 1;
high = xfs_btree_get_numrecs(block);
if (!high) {
/* Block is empty, must be an empty leaf. */
ASSERT(level == 0 && cur->bc_nlevels == 1);
cur->bc_ptrs[0] = dir != XFS_LOOKUP_LE;
XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
*stat = 0;
return 0;
}
/* Binary search the block. */
while (low <= high) {
union xfs_btree_key key;
union xfs_btree_key *kp;
XFS_BTREE_STATS_INC(cur, compare);
/* keyno is average of low and high. */
keyno = (low + high) >> 1;
/* Get current search key */
kp = xfs_lookup_get_search_key(cur, level,
keyno, block, &key);
/*
* Compute difference to get next direction:
* - less than, move right
* - greater than, move left
* - equal, we're done
*/
diff = cur->bc_ops->key_diff(cur, kp);
if (diff < 0)
low = keyno + 1;
else if (diff > 0)
high = keyno - 1;
else
break;
}
}
/*
* If there are more levels, set up for the next level
* by getting the block number and filling in the cursor.
*/
if (level > 0) {
/*
* If we moved left, need the previous key number,
* unless there isn't one.
*/
if (diff > 0 && --keyno < 1)
keyno = 1;
pp = xfs_btree_ptr_addr(cur, keyno, block);
#ifdef DEBUG
error = xfs_btree_check_ptr(cur, pp, 0, level);
if (error)
goto error0;
#endif
cur->bc_ptrs[level] = keyno;
}
}
/* Done with the search. See if we need to adjust the results. */
if (dir != XFS_LOOKUP_LE && diff < 0) {
keyno++;
/*
* If ge search and we went off the end of the block, but it's
* not the last block, we're in the wrong block.
*/
xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_RIGHTSIB);
if (dir == XFS_LOOKUP_GE &&
keyno > xfs_btree_get_numrecs(block) &&
!xfs_btree_ptr_is_null(cur, &ptr)) {
int i;
cur->bc_ptrs[0] = keyno;
error = xfs_btree_increment(cur, 0, &i);
if (error)
goto error0;
XFS_WANT_CORRUPTED_RETURN(i == 1);
XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
*stat = 1;
return 0;
}
} else if (dir == XFS_LOOKUP_LE && diff > 0)
keyno--;
cur->bc_ptrs[0] = keyno;
/* Return if we succeeded or not. */
if (keyno == 0 || keyno > xfs_btree_get_numrecs(block))
*stat = 0;
else if (dir != XFS_LOOKUP_EQ || diff == 0)
*stat = 1;
else
*stat = 0;
XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
return 0;
error0:
XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
return error;
}

11
fs/xfs/xfs_btree.h
View File

@ -190,6 +190,16 @@ struct xfs_btree_ops {
/* records in block/level */
int (*get_maxrecs)(struct xfs_btree_cur *cur, int level);
/* init values of btree structures */
void (*init_key_from_rec)(union xfs_btree_key *key,
union xfs_btree_rec *rec);
void (*init_ptr_from_cur)(struct xfs_btree_cur *cur,
union xfs_btree_ptr *ptr);
/* difference between key value and cursor value */
__int64_t (*key_diff)(struct xfs_btree_cur *cur,
union xfs_btree_key *key);
/* btree tracing */
#ifdef XFS_BTREE_TRACE
void (*trace_enter)(struct xfs_btree_cur *, const char *,
@ -507,6 +517,7 @@ xfs_btree_setbuf(
*/
int xfs_btree_increment(struct xfs_btree_cur *, int, int *);
int xfs_btree_decrement(struct xfs_btree_cur *, int, int *);
int xfs_btree_lookup(struct xfs_btree_cur *, xfs_lookup_t, int *);
/*
* Helpers.

53
fs/xfs/xfs_ialloc.c
View File

@ -118,6 +118,59 @@ xfs_ialloc_cluster_alignment(
return 1;
}
/*
* Lookup the record equal to ino in the btree given by cur.
*/
STATIC int /* error */
xfs_inobt_lookup_eq(
struct xfs_btree_cur *cur, /* btree cursor */
xfs_agino_t ino, /* starting inode of chunk */
__int32_t fcnt, /* free inode count */
xfs_inofree_t free, /* free inode mask */
int *stat) /* success/failure */
{
cur->bc_rec.i.ir_startino = ino;
cur->bc_rec.i.ir_freecount = fcnt;
cur->bc_rec.i.ir_free = free;
return xfs_btree_lookup(cur, XFS_LOOKUP_EQ, stat);
}
/*
* Lookup the first record greater than or equal to ino
* in the btree given by cur.
*/
int /* error */
xfs_inobt_lookup_ge(
struct xfs_btree_cur *cur, /* btree cursor */
xfs_agino_t ino, /* starting inode of chunk */
__int32_t fcnt, /* free inode count */
xfs_inofree_t free, /* free inode mask */
int *stat) /* success/failure */
{
cur->bc_rec.i.ir_startino = ino;
cur->bc_rec.i.ir_freecount = fcnt;
cur->bc_rec.i.ir_free = free;
return xfs_btree_lookup(cur, XFS_LOOKUP_GE, stat);
}
/*
* Lookup the first record less than or equal to ino
* in the btree given by cur.
*/
int /* error */
xfs_inobt_lookup_le(
struct xfs_btree_cur *cur, /* btree cursor */
xfs_agino_t ino, /* starting inode of chunk */
__int32_t fcnt, /* free inode count */
xfs_inofree_t free, /* free inode mask */
int *stat) /* success/failure */
{
cur->bc_rec.i.ir_startino = ino;
cur->bc_rec.i.ir_freecount = fcnt;
cur->bc_rec.i.ir_free = free;
return xfs_btree_lookup(cur, XFS_LOOKUP_LE, stat);
}
/*
* Allocate new inodes in the allocation group specified by agbp.
* Return 0 for success, else error code.

15
fs/xfs/xfs_ialloc.h
View File

@ -154,6 +154,21 @@ xfs_ialloc_pagi_init(
struct xfs_trans *tp, /* transaction pointer */
xfs_agnumber_t agno); /* allocation group number */
/*
* Lookup the first record greater than or equal to ino
* in the btree given by cur.
*/
int xfs_inobt_lookup_ge(struct xfs_btree_cur *cur, xfs_agino_t ino,
__int32_t fcnt, xfs_inofree_t free, int *stat);
/*
* Lookup the first record less than or equal to ino
* in the btree given by cur.
*/
int xfs_inobt_lookup_le(struct xfs_btree_cur *cur, xfs_agino_t ino,
__int32_t fcnt, xfs_inofree_t free, int *stat);
#endif /* __KERNEL__ */
#endif /* __XFS_IALLOC_H__ */

294
fs/xfs/xfs_ialloc_btree.c
View File

@ -828,212 +828,6 @@ xfs_inobt_log_recs(
xfs_trans_log_buf(cur->bc_tp, bp, first, last);
}
/*
* Lookup the record. The cursor is made to point to it, based on dir.
* Return 0 if can't find any such record, 1 for success.
*/
STATIC int /* error */
xfs_inobt_lookup(
xfs_btree_cur_t *cur, /* btree cursor */
xfs_lookup_t dir, /* <=, ==, or >= */
int *stat) /* success/failure */
{
xfs_agblock_t agbno; /* a.g. relative btree block number */
xfs_agnumber_t agno; /* allocation group number */
xfs_inobt_block_t *block=NULL; /* current btree block */
__int64_t diff; /* difference for the current key */
int error; /* error return value */
int keyno=0; /* current key number */
int level; /* level in the btree */
xfs_mount_t *mp; /* file system mount point */
/*
* Get the allocation group header, and the root block number.
*/
mp = cur->bc_mp;
{
xfs_agi_t *agi; /* a.g. inode header */
agi = XFS_BUF_TO_AGI(cur->bc_private.a.agbp);
agno = be32_to_cpu(agi->agi_seqno);
agbno = be32_to_cpu(agi->agi_root);
}
/*
* Iterate over each level in the btree, starting at the root.
* For each level above the leaves, find the key we need, based
* on the lookup record, then follow the corresponding block
* pointer down to the next level.
*/
for (level = cur->bc_nlevels - 1, diff = 1; level >= 0; level--) {
xfs_buf_t *bp; /* buffer pointer for btree block */
xfs_daddr_t d; /* disk address of btree block */
/*
* Get the disk address we're looking for.
*/
d = XFS_AGB_TO_DADDR(mp, agno, agbno);
/*
* If the old buffer at this level is for a different block,
* throw it away, otherwise just use it.
*/
bp = cur->bc_bufs[level];
if (bp && XFS_BUF_ADDR(bp) != d)
bp = NULL;
if (!bp) {
/*
* Need to get a new buffer. Read it, then
* set it in the cursor, releasing the old one.
*/
if ((error = xfs_btree_read_bufs(mp, cur->bc_tp,
agno, agbno, 0, &bp, XFS_INO_BTREE_REF)))
return error;
xfs_btree_setbuf(cur, level, bp);
/*
* Point to the btree block, now that we have the buffer
*/
block = XFS_BUF_TO_INOBT_BLOCK(bp);
if ((error = xfs_btree_check_sblock(cur, block, level,
bp)))
return error;
} else
block = XFS_BUF_TO_INOBT_BLOCK(bp);
/*
* If we already had a key match at a higher level, we know
* we need to use the first entry in this block.
*/
if (diff == 0)
keyno = 1;
/*
* Otherwise we need to search this block. Do a binary search.
*/
else {
int high; /* high entry number */
xfs_inobt_key_t *kkbase=NULL;/* base of keys in block */
xfs_inobt_rec_t *krbase=NULL;/* base of records in block */
int low; /* low entry number */
/*
* Get a pointer to keys or records.
*/
if (level > 0)
kkbase = XFS_INOBT_KEY_ADDR(block, 1, cur);
else
krbase = XFS_INOBT_REC_ADDR(block, 1, cur);
/*
* Set low and high entry numbers, 1-based.
*/
low = 1;
if (!(high = be16_to_cpu(block->bb_numrecs))) {
/*
* If the block is empty, the tree must
* be an empty leaf.
*/
ASSERT(level == 0 && cur->bc_nlevels == 1);
cur->bc_ptrs[0] = dir != XFS_LOOKUP_LE;
*stat = 0;
return 0;
}
/*
* Binary search the block.
*/
while (low <= high) {
xfs_agino_t startino; /* key value */
/*
* keyno is average of low and high.
*/
keyno = (low + high) >> 1;
/*
* Get startino.
*/
if (level > 0) {
xfs_inobt_key_t *kkp;
kkp = kkbase + keyno - 1;
startino = be32_to_cpu(kkp->ir_startino);
} else {
xfs_inobt_rec_t *krp;
krp = krbase + keyno - 1;
startino = be32_to_cpu(krp->ir_startino);
}
/*
* Compute difference to get next direction.
*/
diff = (__int64_t)
startino - cur->bc_rec.i.ir_startino;
/*
* Less than, move right.
*/
if (diff < 0)
low = keyno + 1;
/*
* Greater than, move left.
*/
else if (diff > 0)
high = keyno - 1;
/*
* Equal, we're done.
*/
else
break;
}
}
/*
* If there are more levels, set up for the next level
* by getting the block number and filling in the cursor.
*/
if (level > 0) {
/*
* If we moved left, need the previous key number,
* unless there isn't one.
*/
if (diff > 0 && --keyno < 1)
keyno = 1;
agbno = be32_to_cpu(*XFS_INOBT_PTR_ADDR(block, keyno, cur));
#ifdef DEBUG
if ((error = xfs_btree_check_sptr(cur, agbno, level)))
return error;
#endif
cur->bc_ptrs[level] = keyno;
}
}
/*
* Done with the search.
* See if we need to adjust the results.
*/
if (dir != XFS_LOOKUP_LE && diff < 0) {
keyno++;
/*
* If ge search and we went off the end of the block, but it's
* not the last block, we're in the wrong block.
*/
if (dir == XFS_LOOKUP_GE &&
keyno > be16_to_cpu(block->bb_numrecs) &&
be32_to_cpu(block->bb_rightsib) != NULLAGBLOCK) {
int i;
cur->bc_ptrs[0] = keyno;
if ((error = xfs_btree_increment(cur, 0, &i)))
return error;
ASSERT(i == 1);
*stat = 1;
return 0;
}
}
else if (dir == XFS_LOOKUP_LE && diff > 0)
keyno--;
cur->bc_ptrs[0] = keyno;
/*
* Return if we succeeded or not.
*/
if (keyno == 0 || keyno > be16_to_cpu(block->bb_numrecs))
*stat = 0;
else
*stat = ((dir != XFS_LOOKUP_EQ) || (diff == 0));
return 0;
}
/*
* Move 1 record left from cur/level if possible.
* Update cur to reflect the new path.
@ -1797,59 +1591,6 @@ xfs_inobt_insert(
return 0;
}
/*
* Lookup the record equal to ino in the btree given by cur.
*/
int /* error */
xfs_inobt_lookup_eq(
xfs_btree_cur_t *cur, /* btree cursor */
xfs_agino_t ino, /* starting inode of chunk */
__int32_t fcnt, /* free inode count */
xfs_inofree_t free, /* free inode mask */
int *stat) /* success/failure */
{
cur->bc_rec.i.ir_startino = ino;
cur->bc_rec.i.ir_freecount = fcnt;
cur->bc_rec.i.ir_free = free;
return xfs_inobt_lookup(cur, XFS_LOOKUP_EQ, stat);
}
/*
* Lookup the first record greater than or equal to ino
* in the btree given by cur.
*/
int /* error */
xfs_inobt_lookup_ge(
xfs_btree_cur_t *cur, /* btree cursor */
xfs_agino_t ino, /* starting inode of chunk */
__int32_t fcnt, /* free inode count */
xfs_inofree_t free, /* free inode mask */
int *stat) /* success/failure */
{
cur->bc_rec.i.ir_startino = ino;
cur->bc_rec.i.ir_freecount = fcnt;
cur->bc_rec.i.ir_free = free;
return xfs_inobt_lookup(cur, XFS_LOOKUP_GE, stat);
}
/*
* Lookup the first record less than or equal to ino
* in the btree given by cur.
*/
int /* error */
xfs_inobt_lookup_le(
xfs_btree_cur_t *cur, /* btree cursor */
xfs_agino_t ino, /* starting inode of chunk */
__int32_t fcnt, /* free inode count */
xfs_inofree_t free, /* free inode mask */
int *stat) /* success/failure */
{
cur->bc_rec.i.ir_startino = ino;
cur->bc_rec.i.ir_freecount = fcnt;
cur->bc_rec.i.ir_free = free;
return xfs_inobt_lookup(cur, XFS_LOOKUP_LE, stat);
}
/*
* Update the record referred to by cur, to the value given
* by [ino, fcnt, free].
@ -1918,6 +1659,38 @@ xfs_inobt_get_maxrecs(
return cur->bc_mp->m_inobt_mxr[level != 0];
}
STATIC void
xfs_inobt_init_key_from_rec(
union xfs_btree_key *key,
union xfs_btree_rec *rec)
{
key->inobt.ir_startino = rec->inobt.ir_startino;
}
/*
* intial value of ptr for lookup
*/
STATIC void
xfs_inobt_init_ptr_from_cur(
struct xfs_btree_cur *cur,
union xfs_btree_ptr *ptr)
{
struct xfs_agi *agi = XFS_BUF_TO_AGI(cur->bc_private.a.agbp);
ASSERT(cur->bc_private.a.agno == be32_to_cpu(agi->agi_seqno));
ptr->s = agi->agi_root;
}
STATIC __int64_t
xfs_inobt_key_diff(
struct xfs_btree_cur *cur,
union xfs_btree_key *key)
{
return (__int64_t)be32_to_cpu(key->inobt.ir_startino) -
cur->bc_rec.i.ir_startino;
}
#ifdef XFS_BTREE_TRACE
ktrace_t *xfs_inobt_trace_buf;
@ -1990,6 +1763,9 @@ static const struct xfs_btree_ops xfs_inobt_ops = {
.dup_cursor = xfs_inobt_dup_cursor,
.get_maxrecs = xfs_inobt_get_maxrecs,
.init_key_from_rec = xfs_inobt_init_key_from_rec,
.init_ptr_from_cur = xfs_inobt_init_ptr_from_cur,
.key_diff = xfs_inobt_key_diff,
#ifdef XFS_BTREE_TRACE
.trace_enter = xfs_inobt_trace_enter,

20
fs/xfs/xfs_ialloc_btree.h
View File

@ -135,26 +135,6 @@ extern int xfs_inobt_get_rec(struct xfs_btree_cur *cur, xfs_agino_t *ino,
*/
extern int xfs_inobt_insert(struct xfs_btree_cur *cur, int *stat);
/*
* Lookup the record equal to ino in the btree given by cur.
*/
extern int xfs_inobt_lookup_eq(struct xfs_btree_cur *cur, xfs_agino_t ino,
__int32_t fcnt, xfs_inofree_t free, int *stat);
/*
* Lookup the first record greater than or equal to ino
* in the btree given by cur.
*/
extern int xfs_inobt_lookup_ge(struct xfs_btree_cur *cur, xfs_agino_t ino,
__int32_t fcnt, xfs_inofree_t free, int *stat);
/*
* Lookup the first record less than or equal to ino
* in the btree given by cur.
*/
extern int xfs_inobt_lookup_le(struct xfs_btree_cur *cur, xfs_agino_t ino,
__int32_t fcnt, xfs_inofree_t free, int *stat);
/*
* Update the record referred to by cur, to the value given
* by [ino, fcnt, free].