File: [Development] / xfs-linux-nodel / xfs_alloc.c (download)
Revision 1.96.1.1, Thu Sep 26 00:14:53 1996 UTC (21 years, 1 month ago) by kayuri
Changes since 1.96: +2 -2
lines
Fixed a bug in xfs_alloc_ag_vextent_near() where we were not setting
agbno to NULLAGBLOCK which would lead us to believe that the allocation
succeeded when it had infact failed.
|
#ident "$Revision: 1.97 $"
/*
* Free space allocation for XFS.
*/
#ifdef SIM
#define _KERNEL 1
#endif
#include <sys/param.h>
#include <sys/sysinfo.h>
#include <sys/buf.h>
#include <sys/ksa.h>
#include <sys/debug.h>
#ifdef SIM
#undef _KERNEL
#endif
#include <sys/vnode.h>
#include <sys/ktrace.h>
#include <sys/kmem.h>
#include <sys/errno.h>
#include <sys/uuid.h>
#include <stddef.h>
#ifdef SIM
#include <stdlib.h>
#include <bstring.h>
#else
#include <sys/systm.h>
#endif
#include "xfs_macros.h"
#include "xfs_types.h"
#include "xfs_inum.h"
#include "xfs_log.h"
#include "xfs_trans.h"
#include "xfs_sb.h"
#include "xfs_ag.h"
#include "xfs_mount.h"
#include "xfs_alloc_btree.h"
#include "xfs_bmap_btree.h"
#include "xfs_ialloc_btree.h"
#include "xfs_btree.h"
#include "xfs_ialloc.h"
#include "xfs_alloc.h"
#include "xfs_bit.h"
#include "xfs_error.h"
#ifdef SIM
#include "sim.h"
#endif
#if defined(DEBUG) && !defined(SIM)
/*
* Allocation tracing.
*/
ktrace_t *xfs_alloc_trace_buf;
#endif
#define XFS_ABSDIFF(a,b) (((a) <= (b)) ? ((b) - (a)) : ((a) - (b)))
/*
* Prototypes for internal functions.
*/
/*
* Compute aligned version of the found extent.
* Takes alignment and min length into account.
*/
STATIC int /* success (>= minlen) */
xfs_alloc_compute_aligned(
xfs_agblock_t foundbno, /* starting block in found extent */
xfs_extlen_t foundlen, /* length in found extent */
xfs_extlen_t alignment, /* alignment for allocation */
xfs_extlen_t minlen, /* minimum length for allocation */
xfs_agblock_t *resbno, /* result block number */
xfs_extlen_t *reslen); /* result length */
/*
* Compute best start block and diff for "near" allocations.
* freelen >= wantlen already checked by caller.
*/
STATIC xfs_extlen_t /* difference value (absolute) */
xfs_alloc_compute_diff(
xfs_agblock_t wantbno, /* target starting block */
xfs_extlen_t wantlen, /* target length */
xfs_extlen_t alignment, /* target alignment */
xfs_agblock_t freebno, /* freespace's starting block */
xfs_extlen_t freelen, /* freespace's length */
xfs_agblock_t *newbnop); /* result: best start block from free */
/*
* Fix up the length, based on mod and prod.
* len should be k * prod + mod for some k.
* If len is too small it is returned unchanged.
* If len hits maxlen it is left alone.
*/
STATIC void
xfs_alloc_fix_len(
xfs_alloc_arg_t *args); /* allocation argument structure */
/*
* Fix up length if there is too little space left in the a.g.
* Return 1 if ok, 0 if too little, should give up.
*/
STATIC int
xfs_alloc_fix_minleft(
xfs_alloc_arg_t *args); /* allocation argument structure */
/*
* Update the two btrees, logically removing from freespace the extent
* starting at rbno, rlen blocks. The extent is contained within the
* actual (current) free extent fbno for flen blocks.
* Flags are passed in indicating whether the cursors are set to the
* relevant records.
*/
STATIC int /* error code */
xfs_alloc_fixup_trees(
xfs_btree_cur_t *cnt_cur, /* cursor for by-size btree */
xfs_btree_cur_t *bno_cur, /* cursor for by-block btree */
xfs_agblock_t fbno, /* starting block of free extent */
xfs_extlen_t flen, /* length of free extent */
xfs_agblock_t rbno, /* starting block of returned extent */
xfs_extlen_t rlen, /* length of returned extent */
int flags, /* flags, XFSA_FIXUP_... */
int *stat); /* success code, 1=ok, 0=failed */
#define XFSA_FIXUP_BNO_OK 1
#define XFSA_FIXUP_CNT_OK 2
/*
* Read in the allocation group free block array.
*/
STATIC int /* error */
xfs_alloc_read_agfl(
xfs_mount_t *mp, /* mount point structure */
xfs_trans_t *tp, /* transaction pointer */
xfs_agnumber_t agno, /* allocation group number */
buf_t **bpp); /* buffer for the ag free block array */
#if defined(XFS_ALLOC_TRACE)
/*
* Add an allocation trace entry for an alloc call.
*/
STATIC void
xfs_alloc_trace_alloc(
char *name, /* function tag string */
char *str, /* additional string */
xfs_alloc_arg_t *args); /* allocation argument structure */
/*
* Add an allocation trace entry for a free call.
*/
STATIC void
xfs_alloc_trace_free(
char *name, /* function tag string */
char *str, /* additional string */
xfs_mount_t *mp, /* file system mount point */
xfs_agnumber_t agno, /* allocation group number */
xfs_agblock_t agbno, /* a.g. relative block number */
xfs_extlen_t len, /* length of extent */
int isfl); /* set if is freelist allocation/free */
/*
* Add an allocation trace entry for modifying an agf.
*/
STATIC void
xfs_alloc_trace_modagf(
char *name, /* function tag string */
char *str, /* additional string */
xfs_mount_t *mp, /* file system mount point */
xfs_agf_t *agf, /* new agf value */
int flags); /* logging flags for agf */
#else
#define xfs_alloc_trace_alloc(n,s,a)
#define xfs_alloc_trace_free(n,s,a,b,c,d,e)
#define xfs_alloc_trace_modagf(n,s,a,b,c)
#endif /* XFS_ALLOC_TRACE */
/*
* Prototypes for per-ag allocation routines
*/
/*
* Allocate a variable extent in the allocation group agno.
* Type and bno are used to determine where in the allocation group the
* extent will start.
* Extent's length (returned in len) will be between minlen and maxlen,
* and of the form k * prod + mod unless there's nothing that large.
* Return the starting a.g. block, or NULLAGBLOCK if we can't do it.
*/
STATIC int /* error */
xfs_alloc_ag_vextent(
xfs_alloc_arg_t *args); /* allocation argument structure */
#if 0
/*
* Allocate a variable extent at exactly agno/bno.
* Extent's length (returned in *len) will be between minlen and maxlen,
* and of the form k * prod + mod unless there's nothing that large.
* Return the starting a.g. block (bno), or NULLAGBLOCK if we can't do it.
*/
STATIC int /* error */
xfs_alloc_ag_vextent_exact(
xfs_alloc_arg_t *args); /* allocation argument structure */
#endif
/*
* Allocate a variable extent near bno in the allocation group agno.
* Extent's length (returned in *len) will be between minlen and maxlen,
* and of the form k * prod + mod unless there's nothing that large.
* Return the starting a.g. block, or NULLAGBLOCK if we can't do it.
*/
STATIC int /* error */
xfs_alloc_ag_vextent_near(
xfs_alloc_arg_t *args); /* allocation argument structure */
/*
* Allocate a variable extent anywhere in the allocation group agno.
* Extent's length (returned in *len) will be between minlen and maxlen,
* and of the form k * prod + mod unless there's nothing that large.
* Return the starting a.g. block, or NULLAGBLOCK if we can't do it.
*/
STATIC int /* error */
xfs_alloc_ag_vextent_size(
xfs_alloc_arg_t *args); /* allocation argument structure */
/*
* Deal with the case where only small freespaces remain.
* Either return the contents of the last freespace record,
* or allocate space from the freelist if there is nothing in the tree.
*/
STATIC int /* error */
xfs_alloc_ag_vextent_small(
xfs_alloc_arg_t *args, /* allocation argument structure */
xfs_btree_cur_t *ccur, /* by-size cursor */
xfs_agblock_t *fbnop, /* result block number */
xfs_extlen_t *flenp, /* result length */
int *stat); /* status: 0-freelist, 1-normal/none */
/*
* Free the extent starting at agno/bno for length.
*/
STATIC int /* error */
xfs_free_ag_extent(
xfs_trans_t *tp, /* transaction pointer */
buf_t *agbp, /* buffer for a.g. freelist header */
xfs_agnumber_t agno, /* allocation group number */
xfs_agblock_t bno, /* starting block number */
xfs_extlen_t len, /* length of extent */
int isfl); /* set if is freelist blocks - no sb acctg */
/*
* Internal functions.
*/
/*
* Compute aligned version of the found extent.
* Takes alignment and min length into account.
*/
STATIC int /* success (>= minlen) */
xfs_alloc_compute_aligned(
xfs_agblock_t foundbno, /* starting block in found extent */
xfs_extlen_t foundlen, /* length in found extent */
xfs_extlen_t alignment, /* alignment for allocation */
xfs_extlen_t minlen, /* minimum length for allocation */
xfs_agblock_t *resbno, /* result block number */
xfs_extlen_t *reslen) /* result length */
{
xfs_agblock_t bno;
xfs_extlen_t diff;
xfs_extlen_t len;
if (alignment > 1 && foundlen >= minlen) {
bno = roundup(foundbno, alignment);
diff = bno - foundbno;
len = diff >= foundlen ? 0 : foundlen - diff;
} else {
bno = foundbno;
len = foundlen;
}
*resbno = bno;
*reslen = len;
return len >= minlen;
}
/*
* Compute best start block and diff for "near" allocations.
* freelen >= wantlen already checked by caller.
*/
STATIC xfs_extlen_t /* difference value (absolute) */
xfs_alloc_compute_diff(
xfs_agblock_t wantbno, /* target starting block */
xfs_extlen_t wantlen, /* target length */
xfs_extlen_t alignment, /* target alignment */
xfs_agblock_t freebno, /* freespace's starting block */
xfs_extlen_t freelen, /* freespace's length */
xfs_agblock_t *newbnop) /* result: best start block from free */
{
xfs_agblock_t freeend; /* end of freespace extent */
xfs_agblock_t newbno1; /* return block number */
xfs_agblock_t newbno2; /* other new block number */
xfs_extlen_t newlen1; /* length with newbno1 */
xfs_extlen_t newlen2; /* length with newbno2 */
xfs_agblock_t wantend; /* end of target extent */
ASSERT(freelen >= wantlen);
freeend = freebno + freelen;
wantend = wantbno + wantlen;
if (freebno >= wantbno) {
if ((newbno1 = roundup(freebno, alignment)) >= freeend)
newbno1 = NULLAGBLOCK;
} else if (freeend >= wantend && alignment > 1) {
newbno1 = roundup(wantbno, alignment);
newbno2 = newbno1 - alignment;
if (newbno1 >= freeend)
newbno1 = NULLAGBLOCK;
else
newlen1 = XFS_EXTLEN_MIN(wantlen, freeend - newbno1);
if (newbno2 < freebno)
newbno2 = NULLAGBLOCK;
else
newlen2 = XFS_EXTLEN_MIN(wantlen, freeend - newbno2);
if (newbno1 != NULLAGBLOCK && newbno2 != NULLAGBLOCK) {
if (newlen1 < newlen2 ||
(newlen1 == newlen2 &&
XFS_ABSDIFF(newbno1, wantbno) >
XFS_ABSDIFF(newbno2, wantbno)))
newbno1 = newbno2;
} else if (newbno2 != NULLAGBLOCK)
newbno1 = newbno2;
} else if (freeend >= wantend) {
newbno1 = wantbno;
} else if (alignment > 1) {
newbno1 = roundup(freeend - wantlen, alignment);
if (newbno1 > freeend - wantlen &&
newbno1 - alignment >= freebno)
newbno1 -= alignment;
else if (newbno1 >= freeend)
newbno1 = NULLAGBLOCK;
} else
newbno1 = freeend - wantlen;
*newbnop = newbno1;
return newbno1 == NULLAGBLOCK ? 0 : XFS_ABSDIFF(newbno1, wantbno);
}
/*
* Fix up the length, based on mod and prod.
* len should be k * prod + mod for some k.
* If len is too small it is returned unchanged.
* If len hits maxlen it is left alone.
*/
STATIC void
xfs_alloc_fix_len(
xfs_alloc_arg_t *args) /* allocation argument structure */
{
xfs_extlen_t k;
xfs_extlen_t rlen;
ASSERT(args->mod < args->prod);
rlen = args->len;
ASSERT(rlen >= args->minlen);
ASSERT(rlen <= args->maxlen);
if (args->prod <= 1 || rlen < args->mod || rlen == args->maxlen ||
(args->mod == 0 && rlen < args->prod))
return;
k = rlen % args->prod;
if (k == args->mod)
return;
if (k > args->mod) {
if ((int)(rlen = rlen - k - args->mod) < (int)args->minlen)
return;
} else {
if ((int)(rlen = rlen - args->prod - (args->mod - k)) <
(int)args->minlen)
return;
}
ASSERT(rlen >= args->minlen);
ASSERT(rlen <= args->maxlen);
args->len = rlen;
}
/*
* Fix up length if there is too little space left in the a.g.
* Return 1 if ok, 0 if too little, should give up.
*/
STATIC int
xfs_alloc_fix_minleft(
xfs_alloc_arg_t *args) /* allocation argument structure */
{
xfs_agf_t *agf; /* a.g. freelist header */
int diff; /* free space difference */
if (args->minleft == 0)
return 1;
agf = XFS_BUF_TO_AGF(args->agbp);
diff = agf->agf_freeblks + agf->agf_flcount - args->len - args->minleft;
if (diff >= 0)
return 1;
args->len += diff; /* shrink the allocated space */
if (args->len >= args->minlen)
return 1;
args->agbno = NULLAGBLOCK;
return 0;
}
/*
* Update the two btrees, logically removing from freespace the extent
* starting at rbno, rlen blocks. The extent is contained within the
* actual (current) free extent fbno for flen blocks.
* Flags are passed in indicating whether the cursors are set to the
* relevant records.
*/
STATIC int /* error code */
xfs_alloc_fixup_trees(
xfs_btree_cur_t *cnt_cur, /* cursor for by-size btree */
xfs_btree_cur_t *bno_cur, /* cursor for by-block btree */
xfs_agblock_t fbno, /* starting block of free extent */
xfs_extlen_t flen, /* length of free extent */
xfs_agblock_t rbno, /* starting block of returned extent */
xfs_extlen_t rlen, /* length of returned extent */
int flags, /* flags, XFSA_FIXUP_... */
int *stat) /* success code, 1=ok, 0=failed */
{
int error; /* error code */
int i; /* operation results */
xfs_agblock_t nfbno1; /* first new free startblock */
xfs_agblock_t nfbno2; /* second new free startblock */
xfs_extlen_t nflen1; /* first new free length */
xfs_extlen_t nflen2; /* second new free length */
#define WANT(x) do { ASSERT(x); if (!(x)) { *stat = 0; return 0; }} while (0)
/*
* Look up the record in the by-size tree if necessary.
*/
if (flags & XFSA_FIXUP_CNT_OK) {
#ifdef DEBUG
i = xfs_alloc_get_rec(cnt_cur, &nfbno1, &nflen1);
ASSERT(i == 1);
ASSERT(nfbno1 == fbno);
ASSERT(nflen1 == flen);
#endif
} else {
if (error = xfs_alloc_lookup_eq(cnt_cur, fbno, flen, &i))
return error;
WANT(i == 1);
}
/*
* Look up the record in the by-block tree if necessary.
*/
if (flags & XFSA_FIXUP_BNO_OK) {
#ifdef DEBUG
i = xfs_alloc_get_rec(bno_cur, &nfbno1, &nflen1);
ASSERT(i == 1);
ASSERT(nfbno1 == fbno);
ASSERT(nflen1 == flen);
#endif
} else {
if (error = xfs_alloc_lookup_eq(bno_cur, fbno, flen, &i))
return error;
WANT(i == 1);
}
#ifdef DEBUG
{
xfs_alloc_block_t *bnoblock;
xfs_alloc_block_t *cntblock;
if (bno_cur->bc_nlevels == 1 &&
cnt_cur->bc_nlevels == 1) {
bnoblock = XFS_BUF_TO_ALLOC_BLOCK(bno_cur->bc_bufs[0]);
cntblock = XFS_BUF_TO_ALLOC_BLOCK(cnt_cur->bc_bufs[0]);
ASSERT(bnoblock->bb_numrecs == cntblock->bb_numrecs);
}
}
#endif
/*
* Deal with all four cases: the allocated record is contained
* within the freespace record, so we can have new freespace
* at either (or both) end, or no freespace remaining.
*/
if (rbno == fbno && rlen == flen)
nfbno1 = nfbno2 = NULLAGBLOCK;
else if (rbno == fbno) {
nfbno1 = rbno + rlen;
nflen1 = flen - rlen;
nfbno2 = NULLAGBLOCK;
} else if (rbno + rlen == fbno + flen) {
nfbno1 = fbno;
nflen1 = flen - rlen;
nfbno2 = NULLAGBLOCK;
} else {
nfbno1 = fbno;
nflen1 = rbno - fbno;
nfbno2 = rbno + rlen;
nflen2 = (fbno + flen) - nfbno2;
}
/*
* Delete the entry from the by-size btree.
*/
if (error = xfs_alloc_delete(cnt_cur, &i))
return error;
WANT(i == 1);
/*
* Add new by-size btree entry(s).
*/
if (nfbno1 != NULLAGBLOCK) {
if (error = xfs_alloc_lookup_eq(cnt_cur, nfbno1, nflen1, &i))
return error;
WANT(i == 0);
if (error = xfs_alloc_insert(cnt_cur, &i))
return error;
WANT(i == 1);
}
if (nfbno2 != NULLAGBLOCK) {
if (error = xfs_alloc_lookup_eq(cnt_cur, nfbno2, nflen2, &i))
return error;
WANT(i == 0);
if (error = xfs_alloc_insert(cnt_cur, &i))
return error;
WANT(i == 1);
}
/*
* Fix up the by-block btree entry(s).
*/
if (nfbno1 == NULLAGBLOCK) {
/*
* No remaining freespace, just delete the by-block tree entry.
*/
if (error = xfs_alloc_delete(bno_cur, &i))
return error;
WANT(i == 1);
} else {
/*
* Update the by-block entry to start later|be shorter.
*/
i = xfs_alloc_update(bno_cur, nfbno1, nflen1);
WANT(i == 1);
}
if (nfbno2 != NULLAGBLOCK) {
/*
* 2 resulting free entries, need to add one.
*/
if (error = xfs_alloc_lookup_eq(bno_cur, nfbno2, nflen2, &i))
return error;
WANT(i == 0);
if (error = xfs_alloc_insert(bno_cur, &i))
return error;
WANT(i == 1);
}
*stat = 1;
return 0;
#undef WANT
}
/*
* Read in the allocation group free block array.
*/
STATIC int /* error */
xfs_alloc_read_agfl(
xfs_mount_t *mp, /* mount point structure */
xfs_trans_t *tp, /* transaction pointer */
xfs_agnumber_t agno, /* allocation group number */
buf_t **bpp) /* buffer for the ag free block array */
{
buf_t *bp; /* return value */
daddr_t d; /* disk block address */
int error;
ASSERT(agno != NULLAGNUMBER);
d = XFS_AG_DADDR(mp, agno, XFS_AGFL_DADDR);
error = xfs_trans_read_buf(tp, mp->m_dev, d, 1, 0, &bp);
if (error) {
return error;
}
ASSERT(bp);
ASSERT(!geterror(bp));
bp->b_ref = XFS_AGFL_REF;
*bpp = bp;
return 0;
}
#if defined(XFS_ALLOC_TRACE)
/*
* Add an allocation trace entry for an alloc call.
*/
STATIC void
xfs_alloc_trace_alloc(
char *name, /* function tag string */
char *str, /* additional string */
xfs_alloc_arg_t *args) /* allocation argument structure */
{
ktrace_enter(xfs_alloc_trace_buf,
(void *)(__psint_t)XFS_ALLOC_KTRACE_ALLOC,
(void *)name,
(void *)str,
(void *)args->mp,
(void *)(__psunsigned_t)args->agno,
(void *)(__psunsigned_t)args->agbno,
(void *)(__psunsigned_t)args->minlen,
(void *)(__psunsigned_t)args->maxlen,
(void *)(__psunsigned_t)args->mod,
(void *)(__psunsigned_t)args->prod,
(void *)(__psunsigned_t)args->minleft,
(void *)(__psunsigned_t)args->total,
(void *)(__psunsigned_t)args->alignment,
(void *)(__psunsigned_t)args->len,
(void *)((((__psint_t)args->type) << 16) |
(__psint_t)args->otype),
(void *)(__psint_t)((args->wasdel << 3) |
(args->wasfromfl << 2) |
(args->isfl << 1) |
(args->userdata << 0)));
}
/*
* Add an allocation trace entry for a free call.
*/
STATIC void
xfs_alloc_trace_free(
char *name, /* function tag string */
char *str, /* additional string */
xfs_mount_t *mp, /* file system mount point */
xfs_agnumber_t agno, /* allocation group number */
xfs_agblock_t agbno, /* a.g. relative block number */
xfs_extlen_t len, /* length of extent */
int isfl) /* set if is freelist allocation/free */
{
ktrace_enter(xfs_alloc_trace_buf,
(void *)(__psint_t)XFS_ALLOC_KTRACE_FREE,
(void *)name,
(void *)str,
(void *)mp,
(void *)(__psunsigned_t)agno,
(void *)(__psunsigned_t)agbno,
(void *)(__psunsigned_t)len,
(void *)(__psint_t)isfl,
NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL);
}
/*
* Add an allocation trace entry for modifying an agf.
*/
STATIC void
xfs_alloc_trace_modagf(
char *name, /* function tag string */
char *str, /* additional string */
xfs_mount_t *mp, /* file system mount point */
xfs_agf_t *agf, /* new agf value */
int flags) /* logging flags for agf */
{
ktrace_enter(xfs_alloc_trace_buf,
(void *)(__psint_t)XFS_ALLOC_KTRACE_MODAGF,
(void *)name,
(void *)str,
(void *)mp,
(void *)(__psint_t)flags,
(void *)(__psunsigned_t)agf->agf_seqno,
(void *)(__psunsigned_t)agf->agf_length,
(void *)(__psunsigned_t)agf->agf_roots[XFS_BTNUM_BNO],
(void *)(__psunsigned_t)agf->agf_roots[XFS_BTNUM_CNT],
(void *)(__psunsigned_t)agf->agf_levels[XFS_BTNUM_BNO],
(void *)(__psunsigned_t)agf->agf_levels[XFS_BTNUM_CNT],
(void *)(__psunsigned_t)agf->agf_flfirst,
(void *)(__psunsigned_t)agf->agf_fllast,
(void *)(__psunsigned_t)agf->agf_flcount,
(void *)(__psunsigned_t)agf->agf_freeblks,
(void *)(__psunsigned_t)agf->agf_longest);
}
#endif /* XFS_ALLOC_TRACE */
/*
* Allocation group level functions.
*/
/*
* Allocate a variable extent in the allocation group agno.
* Type and bno are used to determine where in the allocation group the
* extent will start.
* Extent's length (returned in *len) will be between minlen and maxlen,
* and of the form k * prod + mod unless there's nothing that large.
* Return the starting a.g. block, or NULLAGBLOCK if we can't do it.
*/
STATIC int /* error */
xfs_alloc_ag_vextent(
xfs_alloc_arg_t *args) /* argument structure for allocation */
{
int error;
ASSERT(args->minlen > 0);
ASSERT(args->maxlen > 0);
ASSERT(args->minlen <= args->maxlen);
ASSERT(args->mod < args->prod);
ASSERT(args->alignment > 0);
/*
* Branch to correct routine based on the type.
*/
args->wasfromfl = 0;
switch (args->type) {
case XFS_ALLOCTYPE_THIS_AG:
error = xfs_alloc_ag_vextent_size(args);
break;
case XFS_ALLOCTYPE_NEAR_BNO:
error = xfs_alloc_ag_vextent_near(args);
break;
#if 0
case XFS_ALLOCTYPE_THIS_BNO:
error = xfs_alloc_ag_vextent_exact(args);
break;
#endif
default:
ASSERT(0);
/* NOTREACHED */
}
if (error) {
return error;
}
/*
* If the allocation worked, need to change the agf structure
* (and log it), and the superblock.
*/
if (args->agbno != NULLAGBLOCK) {
xfs_agf_t *agf; /* allocation group freelist header */
long slen = (long)args->len;
ASSERT(args->len >= args->minlen && args->len <= args->maxlen);
ASSERT(!(args->wasfromfl) || !args->isfl);
ASSERT(args->agbno % args->alignment == 0);
if (!(args->wasfromfl)) {
agf = XFS_BUF_TO_AGF(args->agbp);
agf->agf_freeblks -= args->len;
xfs_trans_agblocks_delta(args->tp,
-((long)(args->len)));
args->pag->pagf_freeblks -= args->len;
ASSERT(agf->agf_freeblks <= agf->agf_length);
xfs_alloc_trace_modagf("xfs_alloc_ag_vextent", NULL,
args->mp, agf, XFS_AGF_FREEBLKS);
xfs_alloc_log_agf(args->tp, args->agbp,
XFS_AGF_FREEBLKS);
}
if (!args->isfl)
xfs_trans_mod_sb(args->tp,
args->wasdel ? XFS_TRANS_SB_RES_FDBLOCKS :
XFS_TRANS_SB_FDBLOCKS, -slen);
XFSSTATS.xs_allocx++;
XFSSTATS.xs_allocb += args->len;
}
return 0;
}
#if 0
/*
* Allocate a variable extent at exactly agno/bno.
* Extent's length (returned in *len) will be between minlen and maxlen,
* and of the form k * prod + mod unless there's nothing that large.
* Return the starting a.g. block (bno), or NULLAGBLOCK if we can't do it.
*/
STATIC int /* error */
xfs_alloc_ag_vextent_exact(
xfs_alloc_arg_t *args) /* allocation argument structure */
{
xfs_btree_cur_t *bno_cur;/* by block-number btree cursor */
xfs_btree_cur_t *cnt_cur;/* by count btree cursor */
xfs_agblock_t end; /* end of allocated extent */
int error;
xfs_agblock_t fbno; /* start block of found extent */
xfs_agblock_t fend; /* end block of found extent */
xfs_extlen_t flen; /* length of found extent */
#ifdef XFS_ALLOC_TRACE
static char fname[] = "xfs_alloc_ag_vextent_exact";
#endif
int i; /* success/failure of operation */
xfs_agblock_t maxend; /* end of maximal extent */
xfs_agblock_t minend; /* end of minimal extent */
xfs_extlen_t rlen; /* length of returned extent */
ASSERT(args->alignment == 1);
/*
* Allocate/initialize a cursor for the by-number freespace btree.
*/
bno_cur = xfs_btree_init_cursor(args->mp, args->tp, args->agbp,
args->agno, XFS_BTNUM_BNO, 0, 0);
/*
* Lookup bno and minlen in the btree (minlen is irrelevant, really).
* Look for the closest free block <= bno, it must contain bno
* if any free block does.
*/
error = xfs_alloc_lookup_le(bno_cur, args->agbno, args->minlen, &i);
if (error) {
return error;
}
if (!i) {
/*
* Didn't find it, return null.
*/
xfs_btree_del_cursor(bno_cur, XFS_BTREE_NOERROR);
args->agbno = NULLAGBLOCK;
return 0;
}
/*
* Grab the freespace record.
*/
xfs_alloc_get_rec(bno_cur, &fbno, &flen);
ASSERT(fbno <= args->agbno);
minend = args->agbno + args->minlen;
maxend = args->agbno + args->maxlen;
fend = fbno + flen;
/*
* Give up if the freespace isn't long enough for the minimum request.
*/
if (fend < minend) {
xfs_btree_del_cursor(bno_cur, XFS_BTREE_NOERROR);
args->agbno = NULLAGBLOCK;
return 0;
}
/*
* End of extent will be smaller of the freespace end and the
* maximal requested end.
*/
end = XFS_AGBLOCK_MIN(fend, maxend);
/*
* Fix the length according to mod and prod if given.
*/
args->len = end - args->agbno;
xfs_alloc_fix_len(args);
if (!xfs_alloc_fix_minleft(args)) {
xfs_btree_del_cursor(bno_cur, XFS_BTREE_NOERROR);
return 0;
}
rlen = args->len;
ASSERT(args->agbno + rlen <= fend);
end = args->agbno + rlen;
/*
* We are allocating agbno for rlen [agbno .. end)
* Allocate/initialize a cursor for the by-size btree.
*/
cnt_cur = xfs_btree_init_cursor(args->mp, args->tp, args->agbp,
args->agno, XFS_BTNUM_CNT, 0, 0);
/*
* Look up the previously found extent.
*/
error = xfs_alloc_lookup_eq(cnt_cur, fbno, flen, &i);
if (error) {
xfs_btree_del_cursor(bno_cur, XFS_BTREE_ERROR);
xfs_btree_del_cursor(cnt_cur, XFS_BTREE_ERROR);
return error;
}
ASSERT(i == 1);
/*
* Delete the extent from the by-size btree.
*/
error = xfs_alloc_delete(cnt_cur, &i);
if (error) {
xfs_btree_del_cursor(bno_cur, XFS_BTREE_ERROR);
xfs_btree_del_cursor(cnt_cur, XFS_BTREE_ERROR);
return error;
}
/*
* If the found freespace starts left of the allocation, add back the
* leftover freespace to the by-size btree.
*/
if (fbno < args->agbno) {
error = xfs_alloc_lookup_eq(cnt_cur, fbno,
args->agbno - fbno, &i);
if (error) {
xfs_btree_del_cursor(bno_cur, XFS_BTREE_ERROR);
xfs_btree_del_cursor(cnt_cur, XFS_BTREE_ERROR);
return error;
}
error = xfs_alloc_insert(cnt_cur, &i);
if (error) {
xfs_btree_del_cursor(bno_cur, XFS_BTREE_ERROR);
xfs_btree_del_cursor(cnt_cur, XFS_BTREE_ERROR);
return error;
}
}
/*
* If the found freespace ends right of the allocation, add back the
* leftover freespace to the by-size btree.
*/
if (fend > end) {
error = xfs_alloc_lookup_eq(cnt_cur, end, fend - end, &i);
if (error) {
xfs_btree_del_cursor(bno_cur, XFS_BTREE_ERROR);
xfs_btree_del_cursor(cnt_cur, XFS_BTREE_ERROR);
return error;
}
error = xfs_alloc_insert(cnt_cur, &i);
if (error) {
xfs_btree_del_cursor(bno_cur, XFS_BTREE_ERROR);
xfs_btree_del_cursor(cnt_cur, XFS_BTREE_ERROR);
return error;
}
}
xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
/*
* If the found freespace matches the allocation, just delete it
* from the by-bno btree.
*/
if (fbno == args->agbno && fend == end) {
error = xfs_alloc_delete(bno_cur, &i);
if (error) {
xfs_btree_del_cursor(bno_cur, XFS_BTREE_ERROR);
return error;
}
}
/*
* If the found freespace starts at the same block but is longer,
* just update the by-bno btree entry to be shorter.
*/
else if (fbno == args->agbno)
xfs_alloc_update(bno_cur, end, fend - end);
else {
/*
* If the found freespace starts left of the allocation,
* update the length of that by-bno entry.
*/
xfs_alloc_update(bno_cur, fbno, args->agbno - fbno);
/*
* ... and if the found freespace ends right of the
* allocation, add another btree entry with the leftover space.
*/
if (fend > end) {
error = xfs_alloc_lookup_eq(bno_cur, end,
fend - end, &i);
if (error) {
xfs_btree_del_cursor(bno_cur,
XFS_BTREE_ERROR);
return error;
}
error = xfs_alloc_insert(bno_cur, &i);
if (error) {
xfs_btree_del_cursor(bno_cur,
XFS_BTREE_ERROR);
return error;
}
}
}
xfs_btree_del_cursor(bno_cur, XFS_BTREE_NOERROR);
args->len = rlen;
ASSERT(args->agbno + args->len <=
XFS_BUF_TO_AGF(args->agbp)->agf_length);
xfs_alloc_trace_alloc(fname, NULL, args);
args->wasfromfl = 0;
return 0;
}
#endif
/*
* Allocate a variable extent near bno in the allocation group agno.
* Extent's length (returned in len) will be between minlen and maxlen,
* and of the form k * prod + mod unless there's nothing that large.
* Return the starting a.g. block, or NULLAGBLOCK if we can't do it.
*/
STATIC int /* error */
xfs_alloc_ag_vextent_near(
xfs_alloc_arg_t *args) /* allocation argument structure */
{
xfs_btree_cur_t *bno_cur_gt; /* cursor for bno btree, right side */
xfs_btree_cur_t *bno_cur_lt; /* cursor for bno btree, left side */
xfs_btree_cur_t *cnt_cur; /* cursor for count btree */
#ifdef XFS_ALLOC_TRACE
static char fname[] = "xfs_alloc_ag_vextent_near";
#endif
xfs_agblock_t gtbno; /* start bno of right side entry */
xfs_agblock_t gtbnoa; /* aligned ... */
xfs_extlen_t gtdiff; /* difference to right side entry */
xfs_extlen_t gtlen; /* length of right side entry */
xfs_extlen_t gtlena; /* aligned ... */
xfs_agblock_t gtnew; /* useful start bno of right side */
int error; /* error code */
int i; /* result code, temporary */
int j; /* result code, temporary */
xfs_agblock_t ltbno; /* start bno of left side entry */
xfs_agblock_t ltbnoa; /* aligned ... */
xfs_extlen_t ltdiff; /* difference to left side entry */
/*REFERENCED*/
xfs_agblock_t ltend; /* end bno of left side entry */
xfs_extlen_t ltlen; /* length of left side entry */
xfs_extlen_t ltlena; /* aligned ... */
xfs_agblock_t ltnew; /* useful start bno of left side */
xfs_extlen_t rlen; /* length of returned extent */
#if defined(DEBUG) && !defined(SIM)
/*
* Randomly don't execute the first algorithm.
*/
static int seed; /* randomizing seed value */
int dofirst; /* set to do first algorithm */
timespec_t now; /* current time */
extern ulong_t random(void);
if (!seed) {
nanotime(&now);
seed = (int)now.tv_sec ^ (int)now.tv_nsec;
}
dofirst = random() & 1;
#endif
/*
* Get a cursor for the by-size btree.
*/
cnt_cur = xfs_btree_init_cursor(args->mp, args->tp, args->agbp,
args->agno, XFS_BTNUM_CNT, 0, 0);
ltlen = 0;
/*
* See if there are any free extents as big as maxlen.
*/
if (error = xfs_alloc_lookup_ge(cnt_cur, 0, args->maxlen, &i))
goto error0;
/*
* If none, then pick up the last entry in the tree unless the
* tree is empty.
*/
if (!i) {
if (error = xfs_alloc_ag_vextent_small(args, cnt_cur, <bno,
<len, &i))
goto error0;
if (i == 0 || ltlen == 0) {
xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
return 0;
}
ASSERT(i == 1);
}
args->wasfromfl = 0;
/*
* First algorithm.
* If the requested extent is large wrt the freespaces available
* in this a.g., then the cursor will be pointing to a btree entry
* near the right edge of the tree. If it's in the last btree leaf
* block, then we just examine all the entries in that block
* that are big enough, and pick the best one.
* This is written as a while loop so we can break out of it,
* but we never loop back to the top.
*/
while (xfs_btree_islastblock(cnt_cur, 0)) {
xfs_extlen_t bdiff;
int besti;
xfs_extlen_t blen;
xfs_agblock_t bnew;
#if defined(DEBUG) && !defined(SIM)
if (!dofirst)
break;
#endif
/*
* Start from the entry that lookup found, sequence through
* all larger free blocks. If we're actually pointing at a
* record smaller than maxlen, go to the start of this block,
* and skip all those smaller than minlen.
*/
if (ltlen || args->alignment > 1) {
cnt_cur->bc_ptrs[0] = 1;
do {
xfs_alloc_get_rec(cnt_cur, <bno, <len);
if (ltlen >= args->minlen)
break;
if (error = xfs_alloc_increment(cnt_cur, 0, &i))
goto error0;
} while (i);
ASSERT(ltlen >= args->minlen);
if (!i)
break;
}
i = cnt_cur->bc_ptrs[0];
for (j = 1, blen = 0, bdiff = 0;
!error && j && (blen < args->maxlen || bdiff > 0);
error = xfs_alloc_increment(cnt_cur, 0, &j)) {
/*
* For each entry, decide if it's better than
* the previous best entry.
*/
xfs_alloc_get_rec(cnt_cur, <bno, <len);
if (!xfs_alloc_compute_aligned(ltbno, ltlen,
args->alignment, args->minlen,
<bnoa, <lena))
continue;
args->len = XFS_EXTLEN_MIN(ltlena, args->maxlen);
xfs_alloc_fix_len(args);
ASSERT(args->len >= args->minlen);
if (args->len < blen)
continue;
ltdiff = xfs_alloc_compute_diff(args->agbno, args->len,
args->alignment, ltbno, ltlen, <new);
if (ltnew != NULLAGBLOCK &&
(args->len > blen || ltdiff < bdiff)) {
bdiff = ltdiff;
bnew = ltnew;
blen = args->len;
besti = cnt_cur->bc_ptrs[0];
}
}
/*
* It didn't work. We COULD be in a case where
* there's a good record somewhere, so try again.
*/
if (blen == 0)
break;
/*
* Point at the best entry, and retrieve it again.
*/
cnt_cur->bc_ptrs[0] = besti;
xfs_alloc_get_rec(cnt_cur, <bno, <len);
ltend = ltbno + ltlen;
ASSERT(ltend <= XFS_BUF_TO_AGF(args->agbp)->agf_length);
args->len = blen;
if (!xfs_alloc_fix_minleft(args)) {
xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
return 0;
}
blen = args->len;
/*
* We are allocating starting at bnew for blen blocks.
*/
args->agbno = bnew;
ASSERT(bnew >= ltbno);
ASSERT(bnew + blen <= ltend);
/*
* Set up a cursor for the by-bno tree.
*/
bno_cur_lt = xfs_btree_init_cursor(args->mp, args->tp,
args->agbp, args->agno, XFS_BTNUM_BNO, 0, 0);
/*
* Fix up the btree entries.
*/
if (error = xfs_alloc_fixup_trees(cnt_cur, bno_cur_lt, ltbno,
ltlen, bnew, blen, XFSA_FIXUP_CNT_OK, &i))
goto error1;
ASSERT(i == 1);
xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
xfs_btree_del_cursor(bno_cur_lt, XFS_BTREE_NOERROR);
xfs_alloc_trace_alloc(fname, "first", args);
return 0;
}
/*
* Second algorithm.
* Search in the by-bno tree to the left and to the right
* simultaneously, until in each case we find a space big enough,
* or run into the edge of the tree. When we run into the edge,
* we deallocate that cursor.
* If both searches succeed, we compare the two spaces and pick
* the better one.
* With alignment, it's possible for both to fail; the upper
* level algorithm that picks allocation groups for allocations
* is not supposed to do this.
*/
/*
* Allocate and initialize the cursor for the leftward search.
*/
bno_cur_lt = xfs_btree_init_cursor(args->mp, args->tp, args->agbp,
args->agno, XFS_BTNUM_BNO, 0, 0);
/*
* Lookup <= bno to find the leftward search's starting point.
*/
if (error = xfs_alloc_lookup_le(bno_cur_lt, args->agbno,
args->maxlen, &i))
goto error1;
if (!i) {
/*
* Didn't find anything; use this cursor for the rightward
* search.
*/
bno_cur_gt = bno_cur_lt;
bno_cur_lt = 0;
}
/*
* Found something. Duplicate the cursor for the rightward search.
*/
else
bno_cur_gt = xfs_btree_dup_cursor(bno_cur_lt);
/*
* Increment the cursor, so we will point at the entry just right
* of the leftward entry if any, or to the leftmost entry.
*/
if (error = xfs_alloc_increment(bno_cur_gt, 0, &i))
goto error2;
if (!i) {
/*
* It failed, there are no rightward entries.
*/
xfs_btree_del_cursor(bno_cur_gt, XFS_BTREE_NOERROR);
bno_cur_gt = 0;
}
/*
* Loop going left with the leftward cursor, right with the
* rightward cursor, until either both directions give up or
* we find an entry at least as big as minlen.
*/
do {
if (bno_cur_lt) {
xfs_alloc_get_rec(bno_cur_lt, <bno, <len);
if (xfs_alloc_compute_aligned(ltbno, ltlen,
args->alignment, args->minlen,
<bnoa, <lena))
break;
if (error = xfs_alloc_decrement(bno_cur_lt, 0, &i))
goto error2;
if (!i) {
xfs_btree_del_cursor(bno_cur_lt,
XFS_BTREE_NOERROR);
bno_cur_lt = 0;
}
}
if (bno_cur_gt) {
xfs_alloc_get_rec(bno_cur_gt, >bno, >len);
if (xfs_alloc_compute_aligned(gtbno, gtlen,
args->alignment, args->minlen,
>bnoa, >lena))
break;
if (error = xfs_alloc_increment(bno_cur_gt, 0, &i))
goto error2;
if (!i) {
xfs_btree_del_cursor(bno_cur_gt,
XFS_BTREE_NOERROR);
bno_cur_gt = 0;
}
}
} while (bno_cur_lt || bno_cur_gt);
/*
* Got both cursors still active, need to find better entry.
*/
if (bno_cur_lt && bno_cur_gt) {
/*
* Left side is long enough, look for a right side entry.
*/
if (ltlena >= args->minlen) {
/*
* Fix up the length.
*/
args->len = XFS_EXTLEN_MIN(ltlena, args->maxlen);
xfs_alloc_fix_len(args);
rlen = args->len;
ltdiff = xfs_alloc_compute_diff(args->agbno, rlen,
args->alignment, ltbno, ltlen, <new);
/*
* Not perfect.
*/
if (ltdiff) {
/*
* Look until we find a better one, run out of
* space, or run off the end.
*/
while (bno_cur_lt && bno_cur_gt) {
xfs_alloc_get_rec(bno_cur_gt, >bno,
>len);
xfs_alloc_compute_aligned(gtbno, gtlen,
args->alignment, args->minlen,
>bnoa, >lena);
/*
* The left one is clearly better.
*/
if (gtbnoa >= args->agbno + ltdiff) {
xfs_btree_del_cursor(
bno_cur_gt,
XFS_BTREE_NOERROR);
bno_cur_gt = 0;
break;
}
/*
* If we reach a big enough entry,
* compare the two and pick the best.
*/
if (gtlena >= args->minlen) {
args->len =
XFS_EXTLEN_MIN(gtlena,
args->maxlen);
xfs_alloc_fix_len(args);
rlen = args->len;
gtdiff = xfs_alloc_compute_diff(
args->agbno, rlen,
args->alignment,
gtbno, gtlen, >new);
/*
* Right side is better.
*/
if (gtdiff < ltdiff) {
xfs_btree_del_cursor(
bno_cur_lt,
XFS_BTREE_NOERROR);
bno_cur_lt = 0;
}
/*
* Left side is better.
*/
else {
xfs_btree_del_cursor(
bno_cur_gt,
XFS_BTREE_NOERROR);
bno_cur_gt = 0;
}
break;
}
/*
* Fell off the right end.
*/
if (error = xfs_alloc_increment(
bno_cur_gt, 0, &i))
goto error2;
if (!i) {
xfs_btree_del_cursor(
bno_cur_gt,
XFS_BTREE_NOERROR);
bno_cur_gt = 0;
break;
}
}
}
/*
* The left side is perfect, trash the right side.
*/
else {
xfs_btree_del_cursor(bno_cur_gt,
XFS_BTREE_NOERROR);
bno_cur_gt = 0;
}
}
/*
* It's the right side that was found first, look left.
*/
else {
/*
* Fix up the length.
*/
args->len = XFS_EXTLEN_MIN(gtlena, args->maxlen);
xfs_alloc_fix_len(args);
rlen = args->len;
gtdiff = xfs_alloc_compute_diff(args->agbno, rlen,
args->alignment, gtbno, gtlen, >new);
/*
* Right side entry isn't perfect.
*/
if (gtdiff) {
/*
* Look until we find a better one, run out of
* space, or run off the end.
*/
while (bno_cur_lt && bno_cur_gt) {
xfs_alloc_get_rec(bno_cur_lt, <bno,
<len);
xfs_alloc_compute_aligned(ltbno, ltlen,
args->alignment, args->minlen,
<bnoa, <lena);
/*
* The right one is clearly better.
*/
if (ltbnoa <= args->agbno - gtdiff) {
xfs_btree_del_cursor(
bno_cur_lt,
XFS_BTREE_NOERROR);
bno_cur_lt = 0;
break;
}
/*
* If we reach a big enough entry,
* compare the two and pick the best.
*/
if (ltlena >= args->minlen) {
args->len = XFS_EXTLEN_MIN(
ltlena, args->maxlen);
xfs_alloc_fix_len(args);
rlen = args->len;
ltdiff = xfs_alloc_compute_diff(
args->agbno, rlen,
args->alignment,
ltbno, ltlen, <new);
/*
* Left side is better.
*/
if (ltdiff < gtdiff) {
xfs_btree_del_cursor(
bno_cur_gt,
XFS_BTREE_NOERROR);
bno_cur_gt = 0;
}
/*
* Right side is better.
*/
else {
xfs_btree_del_cursor(
bno_cur_lt,
XFS_BTREE_NOERROR);
bno_cur_lt = 0;
}
break;
}
/*
* Fell off the left end.
*/
if (error = xfs_alloc_decrement(
bno_cur_lt, 0, &i))
goto error2;
if (!i) {
xfs_btree_del_cursor(bno_cur_lt,
XFS_BTREE_NOERROR);
bno_cur_lt = 0;
break;
}
}
}
/*
* The right side is perfect, trash the left side.
*/
else {
xfs_btree_del_cursor(bno_cur_lt,
XFS_BTREE_NOERROR);
bno_cur_lt = 0;
}
}
}
/*
* If we couldn't get anything, give up.
*/
if (bno_cur_lt == NULL && bno_cur_gt == NULL) {
xfs_alloc_trace_alloc(fname, "neither", args);
args->agbno = NULLAGBLOCK;
return 0;
}
/*
* At this point we have selected a freespace entry, either to the
* left or to the right. If it's on the right, copy all the
* useful variables to the "left" set so we only have one
* copy of this code.
*/
if (bno_cur_gt) {
bno_cur_lt = bno_cur_gt;
bno_cur_gt = NULL;
ltbno = gtbno;
ltbnoa = gtbnoa;
ltlen = gtlen;
ltlena = gtlena;
j = 1;
} else
j = 0;
/*
* Fix up the length and compute the useful address.
*/
ltend = ltbno + ltlen;
args->len = XFS_EXTLEN_MIN(ltlena, args->maxlen);
xfs_alloc_fix_len(args);
if (!xfs_alloc_fix_minleft(args)) {
xfs_btree_del_cursor(bno_cur_lt, XFS_BTREE_NOERROR);
xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
return 0;
}
rlen = args->len;
(void)xfs_alloc_compute_diff(args->agbno, rlen, args->alignment, ltbno,
ltlen, <new);
ASSERT(ltnew >= ltbno);
ASSERT(ltnew + rlen <= ltend);
ASSERT(ltnew + rlen <= XFS_BUF_TO_AGF(args->agbp)->agf_length);
args->agbno = ltnew;
if (error = xfs_alloc_fixup_trees(cnt_cur, bno_cur_lt, ltbno, ltlen,
ltnew, rlen, XFSA_FIXUP_BNO_OK, &i))
goto error1;
ASSERT(i == 1);
xfs_alloc_trace_alloc(fname, j ? "gt" : "lt", args);
xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
xfs_btree_del_cursor(bno_cur_lt, XFS_BTREE_NOERROR);
return 0;
error0:
xfs_alloc_trace_alloc(fname, "error0", args);
xfs_btree_del_cursor(cnt_cur, XFS_BTREE_ERROR);
return error;
error1:
xfs_alloc_trace_alloc(fname, "error1", args);
xfs_btree_del_cursor(cnt_cur, XFS_BTREE_ERROR);
xfs_btree_del_cursor(bno_cur_lt, XFS_BTREE_ERROR);
return error;
error2:
xfs_alloc_trace_alloc(fname, "error2", args);
xfs_btree_del_cursor(cnt_cur, XFS_BTREE_ERROR);
if (bno_cur_lt != NULL) {
xfs_btree_del_cursor(bno_cur_lt, XFS_BTREE_ERROR);
}
if (bno_cur_gt != NULL) {
xfs_btree_del_cursor(bno_cur_gt, XFS_BTREE_ERROR);
}
return error;
}
/*
* Allocate a variable extent anywhere in the allocation group agno.
* Extent's length (returned in len) will be between minlen and maxlen,
* and of the form k * prod + mod unless there's nothing that large.
* Return the starting a.g. block, or NULLAGBLOCK if we can't do it.
*/
STATIC int /* error */
xfs_alloc_ag_vextent_size(
xfs_alloc_arg_t *args) /* allocation argument structure */
{
xfs_btree_cur_t *bno_cur; /* cursor for bno btree */
xfs_btree_cur_t *cnt_cur; /* cursor for cnt btree */
int error; /* error result */
xfs_agblock_t fbno; /* start of found freespace */
xfs_extlen_t flen; /* length of found freespace */
#ifdef XFS_ALLOC_TRACE
static char fname[] = "xfs_alloc_ag_vextent_size";
#endif
int i; /* temp status variable */
xfs_agblock_t rbno; /* returned block number */
xfs_extlen_t rlen; /* length of returned extent */
/*
* Allocate and initialize a cursor for the by-size btree.
*/
cnt_cur = xfs_btree_init_cursor(args->mp, args->tp, args->agbp,
args->agno, XFS_BTNUM_CNT, 0, 0);
/*
* Look for an entry >= maxlen+alignment-1 blocks.
*/
if (error = xfs_alloc_lookup_ge(cnt_cur, 0,
args->maxlen + args->alignment - 1, &i))
goto error0;
/*
* If none, then pick up the last entry in the tree unless the
* tree is empty.
*/
if (!i) {
if (error = xfs_alloc_ag_vextent_small(args, cnt_cur, &fbno,
&flen, &i))
goto error0;
if (i == 0 || flen == 0) {
xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
return 0;
}
ASSERT(i == 1);
}
/*
* There's a freespace as big as maxlen+alignment-1, get it.
*/
else {
i = xfs_alloc_get_rec(cnt_cur, &fbno, &flen);
ASSERT(i == 1);
}
/*
* In the first case above, we got the last entry in the
* by-size btree. Now we check to see if the space hits maxlen
* once aligned; if not, we search left for something better.
* This can't happen in the second case above.
*/
xfs_alloc_compute_aligned(fbno, flen, args->alignment, args->minlen,
&rbno, &rlen);
rlen = XFS_EXTLEN_MIN(args->maxlen, rlen);
ASSERT(rlen <= flen);
ASSERT(rbno + rlen <= fbno + flen);
if (rlen < args->maxlen) {
xfs_agblock_t bestfbno;
xfs_extlen_t bestflen;
xfs_agblock_t bestrbno;
xfs_extlen_t bestrlen;
bestrlen = rlen;
bestrbno = rbno;
bestflen = flen;
bestfbno = fbno;
for (;;) {
if (error = xfs_alloc_decrement(cnt_cur, 0, &i))
goto error0;
if (i == 0)
break;
i = xfs_alloc_get_rec(cnt_cur, &fbno, &flen);
ASSERT(i == 1);
if (flen < bestrlen)
break;
xfs_alloc_compute_aligned(fbno, flen, args->alignment,
args->minlen, &rbno, &rlen);
rlen = XFS_EXTLEN_MIN(args->maxlen, rlen);
ASSERT(rlen <= flen);
ASSERT(rbno + rlen <= fbno + flen);
if (rlen > bestrlen) {
bestrlen = rlen;
bestrbno = rbno;
bestflen = flen;
bestfbno = fbno;
if (rlen == args->maxlen)
break;
}
}
if (error = xfs_alloc_lookup_eq(cnt_cur, bestfbno,
bestflen, &i))
goto error0;
ASSERT(i == 1);
rlen = bestrlen;
rbno = bestrbno;
flen = bestflen;
fbno = bestfbno;
}
args->wasfromfl = 0;
/*
* Fix up the length.
*/
args->len = rlen;
xfs_alloc_fix_len(args);
if (rlen < args->minlen || !xfs_alloc_fix_minleft(args)) {
xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
xfs_alloc_trace_alloc(fname, "nominleft", args);
return 0;
}
rlen = args->len;
ASSERT(rlen <= flen);
/*
* Allocate and initialize a cursor for the by-block tree.
*/
bno_cur = xfs_btree_init_cursor(args->mp, args->tp, args->agbp,
args->agno, XFS_BTNUM_BNO, 0, 0);
if (error = xfs_alloc_fixup_trees(cnt_cur, bno_cur, fbno, flen,
rbno, rlen, XFSA_FIXUP_CNT_OK, &i))
goto error1;
ASSERT(i == 1);
xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
xfs_btree_del_cursor(bno_cur, XFS_BTREE_NOERROR);
args->len = rlen;
args->agbno = rbno;
ASSERT(args->agbno + args->len <=
XFS_BUF_TO_AGF(args->agbp)->agf_length);
xfs_alloc_trace_alloc(fname, "normal", args);
return 0;
error0:
xfs_btree_del_cursor(cnt_cur, XFS_BTREE_ERROR);
xfs_alloc_trace_alloc(fname, "error0", args);
return error;
error1:
xfs_btree_del_cursor(cnt_cur, XFS_BTREE_ERROR);
xfs_btree_del_cursor(bno_cur, XFS_BTREE_ERROR);
xfs_alloc_trace_alloc(fname, "error1", args);
return error;
}
/*
* Deal with the case where only small freespaces remain.
* Either return the contents of the last freespace record,
* or allocate space from the freelist if there is nothing in the tree.
*/
STATIC int /* error */
xfs_alloc_ag_vextent_small(
xfs_alloc_arg_t *args, /* allocation argument structure */
xfs_btree_cur_t *ccur, /* by-size cursor */
xfs_agblock_t *fbnop, /* result block number */
xfs_extlen_t *flenp, /* result length */
int *stat) /* status: 0-freelist, 1-normal/none */
{
int error;
xfs_agblock_t fbno;
xfs_extlen_t flen;
#ifdef XFS_ALLOC_TRACE
static char fname[] = "xfs_alloc_ag_vextent_small";
#endif
int i;
if (error = xfs_alloc_decrement(ccur, 0, &i))
return error;
if (i) {
i = xfs_alloc_get_rec(ccur, &fbno, &flen);
ASSERT(i == 1);
}
/*
* Nothing in the btree, try the freelist. Make sure
* to respect minleft even when pulling from the
* freelist.
*/
else if (args->minlen == 1 && args->alignment == 1 &&
!args->isfl &&
(XFS_BUF_TO_AGF(args->agbp)->agf_flcount > args->minleft)) {
if (error = xfs_alloc_get_freelist(args->tp, args->agbp,
&fbno))
return error;
if (fbno != NULLAGBLOCK) {
if (args->userdata) {
buf_t *bp;
if (error = xfs_btree_read_bufs(args->mp,
args->tp, args->agno, fbno,
0, &bp))
return error;
xfs_trans_binval(args->tp, bp);
/*
* Since blocks move to the free list without
* the coordination used in xfs_bmap_finish,
* we can't allow the user to write to the
* block until we know that the transaction
* that moved it to the free list is
* permanently on disk. The only way to
* ensure that is to make this transaction
* synchronous.
*/
xfs_trans_set_sync(args->tp);
}
args->len = 1;
args->agbno = fbno;
ASSERT(args->agbno + args->len <=
XFS_BUF_TO_AGF(args->agbp)->agf_length);
args->wasfromfl = 1;
xfs_alloc_trace_alloc(fname, "freelist", args);
*stat = 0;
return 0;
}
/*
* Nothing in the freelist.
*/
else
flen = 0;
}
/*
* Can't allocate from the freelist for some reason.
*/
else
flen = 0;
/*
* Can't do the allocation, give up.
*/
if (flen < args->minlen) {
args->agbno = NULLAGBLOCK;
xfs_alloc_trace_alloc(fname, "notenough", args);
flen = 0;
}
*fbnop = fbno;
*flenp = flen;
*stat = 1;
return 0;
}
/*
* Free the extent starting at agno/bno for length.
*/
STATIC int /* error */
xfs_free_ag_extent(
xfs_trans_t *tp, /* transaction pointer */
buf_t *agbp, /* buffer for a.g. freelist header */
xfs_agnumber_t agno, /* allocation group number */
xfs_agblock_t bno, /* starting block number */
xfs_extlen_t len, /* length of extent */
int isfl) /* set if is freelist blocks - no sb acctg */
{
xfs_btree_cur_t *bno_cur; /* cursor for by-block btree */
xfs_btree_cur_t *cnt_cur; /* cursor for by-size btree */
int error;
#ifdef XFS_ALLOC_TRACE
static char fname[] = "xfs_free_ag_extent";
#endif
xfs_agblock_t gtbno; /* start of right neighbor block */
xfs_extlen_t gtlen; /* length of right neighbor block */
int haveleft; /* have a left neighbor block */
int haveright; /* have a right neighbor block */
int i; /* temp, result code */
xfs_agblock_t ltbno; /* start of left neighbor block */
xfs_extlen_t ltlen; /* length of left neighbor block */
xfs_mount_t *mp; /* mount point struct for filesystem */
xfs_agblock_t nbno; /* new starting block of freespace */
xfs_extlen_t nlen; /* new length of freespace */
mp = tp->t_mountp;
/*
* Allocate and initialize a cursor for the by-block btree.
*/
bno_cur = xfs_btree_init_cursor(mp, tp, agbp, agno, XFS_BTNUM_BNO, 0,
0);
/*
* Look for a neighboring block on the left (lower block numbers)
* that is contiguous with this space.
*/
if (error = xfs_alloc_lookup_le(bno_cur, bno, len, &haveleft))
goto error0;
if (haveleft) {
/*
* There is a block to our left.
*/
xfs_alloc_get_rec(bno_cur, <bno, <len);
/*
* It's not contiguous, though.
*/
if (ltbno + ltlen < bno)
haveleft = 0;
/*
* If this happens the request to free this space was
* invalid, it's (partly) already free.
*/
else if (ltbno + ltlen > bno) {
ASSERT(0);
xfs_btree_del_cursor(bno_cur, XFS_BTREE_NOERROR);
return 0;
}
}
/*
* Look for a neighboring block on the right (higher block numbers)
* that is contiguous with this space.
*/
if (error = xfs_alloc_increment(bno_cur, 0, &haveright))
goto error0;
if (haveright) {
/*
* There is a block to our right.
*/
xfs_alloc_get_rec(bno_cur, >bno, >len);
/*
* It's not contiguous, though.
*/
if (bno + len < gtbno)
haveright = 0;
/*
* If this happens the request to free this space was
* invalid, it's (partly) already free.
*/
else if (gtbno < bno + len) {
ASSERT(0);
xfs_btree_del_cursor(bno_cur, XFS_BTREE_NOERROR);
return 0;
}
}
/*
* Now allocate and initialize a cursor for the by-size tree.
*/
cnt_cur = xfs_btree_init_cursor(mp, tp, agbp, agno, XFS_BTNUM_CNT, 0,
0);
/*
* Have both left and right contiguous neighbors.
* Merge all three into a single free block.
*/
if (haveleft && haveright) {
/*
* Delete the old by-size entry on the left.
*/
if (error = xfs_alloc_lookup_eq(cnt_cur, ltbno, ltlen, &i))
goto error1;
ASSERT(i == 1);
if (error = xfs_alloc_delete(cnt_cur, &i))
goto error1;
/*
* Delete the old by-size entry on the right.
*/
if (error = xfs_alloc_lookup_eq(cnt_cur, gtbno, gtlen, &i))
goto error1;
ASSERT(i == 1);
if (error = xfs_alloc_delete(cnt_cur, &i))
goto error1;
/*
* Delete the old by-block entry for the right block.
*/
if (error = xfs_alloc_delete(bno_cur, &i))
goto error1;
/*
* Move the by-block cursor back to the left neighbor.
*/
if (error = xfs_alloc_decrement(bno_cur, 0, &i))
goto error1;
#ifdef DEBUG
/*
* Check that this is the right record: delete didn't
* mangle the cursor.
*/
{
xfs_agblock_t xxbno;
xfs_extlen_t xxlen;
xfs_alloc_get_rec(bno_cur, &xxbno, &xxlen);
ASSERT(xxbno == ltbno);
ASSERT(xxlen == ltlen);
}
#endif
/*
* Update remaining by-block entry to the new, joined block.
*/
nbno = ltbno;
nlen = len + ltlen + gtlen;
xfs_alloc_update(bno_cur, nbno, nlen);
}
/*
* Have only a left contiguous neighbor.
* Merge it together with the new freespace.
*/
else if (haveleft) {
/*
* Delete the old by-size entry on the left.
*/
if (error = xfs_alloc_lookup_eq(cnt_cur, ltbno, ltlen, &i))
goto error1;
ASSERT(i == 1);
if (error = xfs_alloc_delete(cnt_cur, &i))
goto error1;
/*
* Back up the by-block cursor to the left neighbor, and
* update its length.
*/
if (error = xfs_alloc_decrement(bno_cur, 0, &i))
goto error1;
nbno = ltbno;
nlen = len + ltlen;
xfs_alloc_update(bno_cur, nbno, nlen);
}
/*
* Have only a right contiguous neighbor.
* Merge it together with the new freespace.
*/
else if (haveright) {
/*
* Delete the old by-size entry on the right.
*/
if (error = xfs_alloc_lookup_eq(cnt_cur, gtbno, gtlen, &i))
goto error1;
ASSERT(i == 1);
if (error = xfs_alloc_delete(cnt_cur, &i))
goto error1;
/*
* Update the starting block and length of the right
* neighbor in the by-block tree.
*/
nbno = bno;
nlen = len + gtlen;
xfs_alloc_update(bno_cur, nbno, nlen);
}
/*
* No contiguous neighbors.
* Insert the new freespace into the by-block tree.
*/
else {
nbno = bno;
nlen = len;
if (error = xfs_alloc_insert(bno_cur, &i))
goto error1;
}
xfs_btree_del_cursor(bno_cur, XFS_BTREE_NOERROR);
/*
* In all cases we need to insert the new freespace in the by-size tree.
*/
if (error = xfs_alloc_lookup_eq(cnt_cur, nbno, nlen, &i))
goto error1;
if (error = xfs_alloc_insert(cnt_cur, &i))
goto error1;
xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
/*
* Update the freespace totals in the ag and superblock.
*/
{
xfs_agf_t *agf;
xfs_perag_t *pag; /* per allocation group data */
agf = XFS_BUF_TO_AGF(agbp);
pag = &mp->m_perag[agno];
agf->agf_freeblks += len;
xfs_trans_agblocks_delta(tp, len);
pag->pagf_freeblks += len;
ASSERT(agf->agf_freeblks <= agf->agf_length);
xfs_alloc_trace_modagf(fname, NULL, mp, agf, XFS_AGF_FREEBLKS);
xfs_alloc_log_agf(tp, agbp, XFS_AGF_FREEBLKS);
if (!isfl)
xfs_trans_mod_sb(tp, XFS_TRANS_SB_FDBLOCKS, (long)len);
XFSSTATS.xs_freex++;
XFSSTATS.xs_freeb += len;
}
xfs_alloc_trace_free(fname,
haveleft ?
(haveright ? "both" : "left") :
(haveright ? "right" : "none"),
mp, agno, bno, len, isfl);
return 0;
error0:
xfs_btree_del_cursor(bno_cur, XFS_BTREE_ERROR);
xfs_alloc_trace_free(fname, "error0", mp, agno, bno, len, isfl);
return error;
error1:
xfs_btree_del_cursor(bno_cur, XFS_BTREE_ERROR);
xfs_btree_del_cursor(cnt_cur, XFS_BTREE_ERROR);
xfs_alloc_trace_free(fname, "error1", mp, agno, bno, len, isfl);
return error;
}
/*
* Visible (exported) allocation/free functions.
* Some of these are used just by xfs_alloc_btree.c and this file.
*/
/*
* Compute and fill in value of m_ag_maxlevels.
*/
void
xfs_alloc_compute_maxlevels(
xfs_mount_t *mp) /* file system mount structure */
{
int level;
uint maxblocks;
uint maxleafents;
int minleafrecs;
int minnoderecs;
maxleafents = (mp->m_sb.sb_agblocks + 1) / 2;
minleafrecs = mp->m_alloc_mnr[0];
minnoderecs = mp->m_alloc_mnr[1];
maxblocks = (maxleafents + minleafrecs - 1) / minleafrecs;
for (level = 1; maxblocks > 1; level++)
maxblocks = (maxblocks + minnoderecs - 1) / minnoderecs;
mp->m_ag_maxlevels = level;
}
/*
* Decide whether to use this allocation group for this allocation.
* If so, fix up the btree freelist's size.
* This is external so mkfs can call it, too.
*/
int /* error */
xfs_alloc_fix_freelist(
xfs_alloc_arg_t *args, /* allocation argument structure */
int flags) /* XFS_ALLOC_FLAG_... */
{
buf_t *agbp; /* agf buffer pointer */
xfs_agf_t *agf; /* a.g. freespace structure pointer */
buf_t *agflbp;/* agfl buffer pointer */
xfs_agblock_t bno; /* freelist block */
int error; /* error result code */
xfs_extlen_t longest;/* longest extent in allocation group */
xfs_mount_t *mp; /* file system mount point structure */
xfs_extlen_t need; /* total blocks needed */
xfs_perag_t *pag; /* per-ag information structure */
xfs_alloc_arg_t targs; /* local allocation arguments */
xfs_trans_t *tp; /* transaction pointer */
mp = args->mp;
pag = args->pag;
tp = args->tp;
if (!pag->pagf_init) {
error = xfs_alloc_read_agf(mp, tp, args->agno, flags, &agbp);
if (error) {
return error;
}
if (!pag->pagf_init) {
args->agbp = NULL;
return 0;
}
} else
agbp = NULL;
need = XFS_MIN_FREELIST_PAG(pag, mp);
/*
* If it looks like there isn't a long enough extent, or enough
* total blocks, reject it.
*/
longest = (pag->pagf_longest > need) ?
(pag->pagf_longest - need) :
(pag->pagf_flcount > 0 || pag->pagf_longest > 0);
if (args->minlen + args->alignment - 1 > longest ||
(args->minleft &&
(int)(pag->pagf_freeblks + pag->pagf_flcount -
need - args->total) <
(int)args->minleft)) {
if (agbp)
xfs_trans_brelse(tp, agbp);
args->agbp = NULL;
return 0;
}
/*
* Get the a.g. freespace buffer.
* Can fail if we're not blocking on locks, and it's held.
*/
if (agbp == NULL) {
error = xfs_alloc_read_agf(mp, tp, args->agno, flags, &agbp);
if (error) {
return error;
}
if (agbp == NULL) {
args->agbp = NULL;
return 0;
}
}
/*
* Figure out how many blocks we should have in the freelist.
*/
agf = XFS_BUF_TO_AGF(agbp);
ASSERT(agf->agf_magicnum == XFS_AGF_MAGIC);
ASSERT(agf->agf_freeblks <= agf->agf_length);
ASSERT(agf->agf_flfirst < XFS_AGFL_SIZE);
ASSERT(agf->agf_fllast < XFS_AGFL_SIZE);
ASSERT(agf->agf_flcount <= XFS_AGFL_SIZE);
need = XFS_MIN_FREELIST(agf, mp);
/*
* If there isn't enough total or single-extent, reject it.
*/
longest = (agf->agf_longest > need) ?
(agf->agf_longest - need) :
(agf->agf_flcount > 0 || agf->agf_longest > 0);
if (args->minlen + args->alignment - 1 > longest ||
(args->minleft &&
(int)(agf->agf_freeblks + agf->agf_flcount - need - args->total) <
(int)args->minleft)) {
xfs_trans_brelse(tp, agbp);
args->agbp = NULL;
return 0;
}
/*
* Make the freelist shorter if it's too long.
*/
while (agf->agf_flcount > need) {
buf_t *bp;
error = xfs_alloc_get_freelist(tp, agbp, &bno);
if (error) {
return error;
}
error = xfs_free_ag_extent(tp, agbp, args->agno, bno, 1, 1);
if (error) {
return error;
}
error = xfs_btree_read_bufs(mp, tp, args->agno, bno, 0, &bp);
if (error) {
return error;
}
xfs_trans_binval(tp, bp);
/*
* Since blocks move to the free list without
* the coordination used in xfs_bmap_finish,
* we can't allow block to be available for reallocation
* and non-transaction writing (user data)
* until we know that the transaction
* that moved it to the free list is
* permanently on disk. The only way to
* ensure that is to make this transaction
* synchronous.
*/
xfs_trans_set_sync(tp);
}
/*
* Initialize the args structure.
*/
targs.tp = tp;
targs.mp = mp;
targs.agbp = agbp;
targs.agno = args->agno;
targs.mod = targs.minleft = targs.wasdel = targs.userdata = 0;
targs.alignment = targs.minlen = targs.prod = targs.isfl = 1;
targs.type = XFS_ALLOCTYPE_THIS_AG;
targs.pag = pag;
error = xfs_alloc_read_agfl(mp, tp, targs.agno, &agflbp);
if (error) {
return error;
}
/*
* Make the freelist longer if it's too short.
*/
while (agf->agf_flcount < need) {
targs.agbno = 0;
targs.maxlen = need - agf->agf_flcount;
/*
* Allocate as many blocks as possible at once.
*/
error = xfs_alloc_ag_vextent(&targs);
if (error) {
return error;
}
/*
* Stop if we run out. Won't happen if callers are obeying
* the restrictions correctly. Can happen for free calls
* on a completely full ag.
*/
if (targs.agbno == NULLAGBLOCK)
break;
/*
* Put each allocated block on the list.
*/
for (bno = targs.agbno; bno < targs.agbno + targs.len; bno++) {
error = xfs_alloc_put_freelist(tp, agbp, agflbp, bno);
if (error) {
return error;
}
}
}
args->agbp = agbp;
return 0;
}
/*
* Get a block from the freelist.
* Returns with the buffer for the block gotten.
*/
int /* error */
xfs_alloc_get_freelist(
xfs_trans_t *tp, /* transaction pointer */
buf_t *agbp, /* buffer containing the agf structure */
xfs_agblock_t *bnop) /* block address retrieved from freelist */
{
xfs_agf_t *agf; /* a.g. freespace structure */
xfs_agfl_t *agfl; /* a.g. freelist structure */
buf_t *agflbp;/* buffer for a.g. freelist structure */
xfs_agblock_t bno; /* block number returned */
int error;
#ifdef XFS_ALLOC_TRACE
static char fname[] = "xfs_alloc_get_freelist";
#endif
xfs_perag_t *pag; /* per allocation group data */
agf = XFS_BUF_TO_AGF(agbp);
/*
* Freelist is empty, give up.
*/
if (agf->agf_flcount == 0) {
*bnop = NULLAGBLOCK;
return 0;
}
/*
* Read the array of free blocks.
*/
error = xfs_alloc_read_agfl(tp->t_mountp, tp, agf->agf_seqno,
&agflbp);
if (error) {
return error;
}
agfl = XFS_BUF_TO_AGFL(agflbp);
/*
* Get the block number and update the data structures.
*/
bno = agfl->agfl_bno[agf->agf_flfirst++];
xfs_trans_brelse(tp, agflbp);
if (agf->agf_flfirst == XFS_AGFL_SIZE)
agf->agf_flfirst = 0;
pag = &tp->t_mountp->m_perag[agf->agf_seqno];
agf->agf_flcount--;
xfs_trans_agflist_delta(tp, -1);
pag->pagf_flcount--;
xfs_alloc_trace_modagf(fname, NULL, tp->t_mountp, agf,
XFS_AGF_FLFIRST | XFS_AGF_FLCOUNT);
xfs_alloc_log_agf(tp, agbp, XFS_AGF_FLFIRST | XFS_AGF_FLCOUNT);
*bnop = bno;
return 0;
}
/*
* Log the given fields from the agf structure.
*/
void
xfs_alloc_log_agf(
xfs_trans_t *tp, /* transaction pointer */
buf_t *bp, /* buffer for a.g. freelist header */
int fields) /* mask of fields to be logged (XFS_AGF_...) */
{
int first; /* first byte offset */
int last; /* last byte offset */
static const short offsets[] = {
offsetof(xfs_agf_t, agf_magicnum),
offsetof(xfs_agf_t, agf_versionnum),
offsetof(xfs_agf_t, agf_seqno),
offsetof(xfs_agf_t, agf_length),
offsetof(xfs_agf_t, agf_roots[0]),
offsetof(xfs_agf_t, agf_levels[0]),
offsetof(xfs_agf_t, agf_flfirst),
offsetof(xfs_agf_t, agf_fllast),
offsetof(xfs_agf_t, agf_flcount),
offsetof(xfs_agf_t, agf_freeblks),
offsetof(xfs_agf_t, agf_longest),
sizeof(xfs_agf_t)
};
xfs_btree_offsets(fields, offsets, XFS_AGF_NUM_BITS, &first, &last);
xfs_trans_log_buf(tp, bp, (uint)first, (uint)last);
}
/*
* Interface for inode allocation to force the pag data to be initialized.
*/
int /* error */
xfs_alloc_pagf_init(
xfs_mount_t *mp, /* file system mount structure */
xfs_trans_t *tp, /* transaction pointer */
xfs_agnumber_t agno, /* allocation group number */
int flags) /* XFS_ALLOC_FLAGS_... */
{
buf_t *bp;
int error;
error = xfs_alloc_read_agf(mp, tp, agno, flags, &bp);
if (error) {
return error;
}
if (bp) {
xfs_trans_brelse(tp, bp);
}
return 0;
}
/*
* Put the block on the freelist for the allocation group.
*/
int /* error */
xfs_alloc_put_freelist(
xfs_trans_t *tp, /* transaction pointer */
buf_t *agbp, /* buffer for a.g. freelist header */
buf_t *agflbp,/* buffer for a.g. free block array */
xfs_agblock_t bno) /* block being freed */
{
xfs_agf_t *agf; /* a.g. freespace structure */
xfs_agfl_t *agfl; /* a.g. free block array */
xfs_agblock_t *blockp;/* pointer to array entry */
int error;
#ifdef XFS_ALLOC_TRACE
static char fname[] = "xfs_alloc_put_freelist";
#endif
xfs_perag_t *pag; /* per allocation group data */
agf = XFS_BUF_TO_AGF(agbp);
if (!agflbp) {
error = xfs_alloc_read_agfl(tp->t_mountp, tp,
agf->agf_seqno, &agflbp);
if (error) {
return error;
}
}
agfl = XFS_BUF_TO_AGFL(agflbp);
if (++agf->agf_fllast == XFS_AGFL_SIZE)
agf->agf_fllast = 0;
pag = &tp->t_mountp->m_perag[agf->agf_seqno];
agf->agf_flcount++;
xfs_trans_agflist_delta(tp, 1);
pag->pagf_flcount++;
ASSERT(agf->agf_flcount <= XFS_AGFL_SIZE);
blockp = &agfl->agfl_bno[agf->agf_fllast];
*blockp = bno;
xfs_alloc_trace_modagf(fname, NULL, tp->t_mountp, agf,
XFS_AGF_FLLAST | XFS_AGF_FLCOUNT);
xfs_alloc_log_agf(tp, agbp, XFS_AGF_FLLAST | XFS_AGF_FLCOUNT);
xfs_trans_log_buf(tp, agflbp, (caddr_t)blockp - (caddr_t)agfl,
(caddr_t)blockp - (caddr_t)agfl + sizeof(*blockp) - 1);
return 0;
}
/*
* Read in the allocation group header (free/alloc section).
*/
int /* error */
xfs_alloc_read_agf(
xfs_mount_t *mp, /* mount point structure */
xfs_trans_t *tp, /* transaction pointer */
xfs_agnumber_t agno, /* allocation group number */
int flags, /* XFS_ALLOC_FLAG_... */
buf_t **bpp) /* buffer for the ag freelist header */
{
xfs_agf_t *agf; /* ag freelist header */
buf_t *bp; /* return value */
daddr_t d; /* disk block address */
int error;
xfs_perag_t *pag; /* per allocation group data */
ASSERT(agno != NULLAGNUMBER);
d = XFS_AG_DADDR(mp, agno, XFS_AGF_DADDR);
error = xfs_trans_read_buf(tp, mp->m_dev, d, 1,
(flags & XFS_ALLOC_FLAG_TRYLOCK) ? BUF_TRYLOCK : 0U, &bp);
if (error) {
return error;
}
ASSERT(!bp || !geterror(bp));
if (!bp) {
*bpp = NULL;
return 0;
}
/*
* Validate the magic number of the agf block.
*/
agf = XFS_BUF_TO_AGF(bp);
if ((agf->agf_magicnum != XFS_AGF_MAGIC) ||
!XFS_AGF_GOOD_VERSION(agf->agf_versionnum)) {
bp->b_flags |= B_ERROR;
xfs_trans_brelse(tp, bp);
return XFS_ERROR(EIO);
}
pag = &mp->m_perag[agno];
if (!pag->pagf_init) {
pag->pagf_freeblks = agf->agf_freeblks;
pag->pagf_flcount = agf->agf_flcount;
pag->pagf_longest = agf->agf_longest;
pag->pagf_levels[XFS_BTNUM_BNOi] =
agf->agf_levels[XFS_BTNUM_BNOi];
pag->pagf_levels[XFS_BTNUM_CNTi] =
agf->agf_levels[XFS_BTNUM_CNTi];
pag->pagf_init = 1;
} else {
ASSERT(pag->pagf_freeblks == agf->agf_freeblks);
ASSERT(pag->pagf_flcount == agf->agf_flcount);
ASSERT(pag->pagf_longest == agf->agf_longest);
ASSERT(pag->pagf_levels[XFS_BTNUM_BNOi] ==
agf->agf_levels[XFS_BTNUM_BNOi]);
ASSERT(pag->pagf_levels[XFS_BTNUM_CNTi] ==
agf->agf_levels[XFS_BTNUM_CNTi]);
}
bp->b_ref = XFS_AGF_REF;
*bpp = bp;
return 0;
}
/*
* Allocate an extent (variable-size).
* Depending on the allocation type, we either look in a single allocation
* group or loop over the allocation groups to find the result.
*/
int /* error */
xfs_alloc_vextent(
xfs_alloc_arg_t *args) /* allocation argument structure */
{
xfs_agblock_t agsize; /* allocation group size */
int error;
int flags; /* XFS_ALLOC_FLAG_... locking flags */
#ifdef XFS_ALLOC_TRACE
static char fname[] = "xfs_alloc_vextent";
#endif
xfs_extlen_t minleft;/* minimum left value, temp copy */
xfs_mount_t *mp; /* mount structure pointer */
xfs_agnumber_t sagno; /* starting allocation group number */
xfs_alloctype_t type; /* input allocation type */
mp = args->mp;
type = args->otype = args->type;
args->agbno = NULLAGBLOCK;
/*
* Just fix this up, for the case where the last a.g. is shorter
* (or there's only one a.g.) and the caller couldn't easily figure
* that out (xfs_bmap_alloc).
*/
agsize = mp->m_sb.sb_agblocks;
if (args->maxlen > agsize)
args->maxlen = agsize;
if (args->alignment == 0)
args->alignment = 1;
ASSERT(XFS_FSB_TO_AGNO(mp, args->fsbno) < mp->m_sb.sb_agcount);
ASSERT(XFS_FSB_TO_AGBNO(mp, args->fsbno) < agsize);
ASSERT(args->minlen <= args->maxlen);
ASSERT(args->minlen <= agsize);
ASSERT(args->mod < args->prod);
if (XFS_FSB_TO_AGNO(mp, args->fsbno) >= mp->m_sb.sb_agcount ||
XFS_FSB_TO_AGBNO(mp, args->fsbno) >= agsize ||
args->minlen > args->maxlen || args->minlen > agsize ||
args->mod >= args->prod) {
args->fsbno = NULLFSBLOCK;
xfs_alloc_trace_alloc(fname, "badargs", args);
return 0;
}
switch (type) {
case XFS_ALLOCTYPE_THIS_AG:
case XFS_ALLOCTYPE_NEAR_BNO:
#if 0
case XFS_ALLOCTYPE_THIS_BNO:
#endif
/*
* These three force us into a single a.g.
*/
args->agno = XFS_FSB_TO_AGNO(mp, args->fsbno);
mrlock(&mp->m_peraglock, MR_ACCESS, PINOD);
args->pag = &mp->m_perag[args->agno];
minleft = args->minleft;
args->minleft = 0;
error = xfs_alloc_fix_freelist(args, 0);
args->minleft = minleft;
if (error) {
goto error0;
}
if (!args->agbp) {
mrunlock(&mp->m_peraglock);
break;
}
args->agbno = XFS_FSB_TO_AGBNO(mp, args->fsbno);
error = xfs_alloc_ag_vextent(args);
if (error) {
goto error0;
}
mrunlock(&mp->m_peraglock);
break;
case XFS_ALLOCTYPE_START_BNO:
/*
* Try near allocation first, then anywhere-in-ag after
* the first a.g. fails.
*/
args->agbno = XFS_FSB_TO_AGBNO(mp, args->fsbno);
args->type = XFS_ALLOCTYPE_NEAR_BNO;
/* FALLTHROUGH */
case XFS_ALLOCTYPE_ANY_AG:
case XFS_ALLOCTYPE_START_AG:
case XFS_ALLOCTYPE_FIRST_AG:
/*
* Rotate through the allocation groups looking for a winner.
*/
if (type == XFS_ALLOCTYPE_ANY_AG) {
/*
* Start with the last place we left off.
*/
args->agno = sagno = mp->m_agfrotor;
args->type = XFS_ALLOCTYPE_THIS_AG;
flags = XFS_ALLOC_FLAG_TRYLOCK;
} else if (type == XFS_ALLOCTYPE_FIRST_AG) {
/*
* Start with allocation group given by bno.
*/
args->agno = XFS_FSB_TO_AGNO(mp, args->fsbno);
args->type = XFS_ALLOCTYPE_THIS_AG;
sagno = 0;
flags = 0;
} else {
if (type == XFS_ALLOCTYPE_START_AG)
args->type = XFS_ALLOCTYPE_THIS_AG;
/*
* Start with the given allocation group.
*/
args->agno = sagno = XFS_FSB_TO_AGNO(mp, args->fsbno);
flags = XFS_ALLOC_FLAG_TRYLOCK;
}
/*
* Loop over allocation groups twice; first time with
* trylock set, second time without.
*/
for (;;) {
mrlock(&mp->m_peraglock, MR_ACCESS, PINOD);
args->pag = &mp->m_perag[args->agno];
error = xfs_alloc_fix_freelist(args, flags);
if (error) {
goto error0;
}
/*
* If we get a buffer back then the allocation will fly.
*/
if (args->agbp) {
error = xfs_alloc_ag_vextent(args);
if (error) {
goto error0;
}
mrunlock(&mp->m_peraglock);
break;
}
mrunlock(&mp->m_peraglock);
xfs_alloc_trace_alloc(fname, "loopfailed", args);
/*
* Didn't work, figure out the next iteration.
*/
if (args->agno == sagno &&
type == XFS_ALLOCTYPE_START_BNO)
args->type = XFS_ALLOCTYPE_THIS_AG;
if (++(args->agno) == mp->m_sb.sb_agcount)
args->agno = 0;
/*
* Reached the starting a.g., must either be done
* or switch to non-trylock mode.
*/
if (args->agno == sagno) {
if (flags == 0) {
args->agbno = NULLAGBLOCK;
xfs_alloc_trace_alloc(fname,
"allfailed", args);
break;
}
flags = 0;
if (type == XFS_ALLOCTYPE_START_BNO) {
args->agbno = XFS_FSB_TO_AGBNO(mp,
args->fsbno);
args->type = XFS_ALLOCTYPE_NEAR_BNO;
}
}
}
mp->m_agfrotor = (args->agno + 1) % mp->m_sb.sb_agcount;
break;
default:
ASSERT(0);
/* NOTREACHED */
}
if (args->agbno == NULLAGBLOCK)
args->fsbno = NULLFSBLOCK;
else {
args->fsbno = XFS_AGB_TO_FSB(mp, args->agno, args->agbno);
#ifdef DEBUG
ASSERT(args->len >= args->minlen);
ASSERT(args->len <= args->maxlen);
ASSERT(args->agbno % args->alignment == 0);
XFS_AG_CHECK_DADDR(mp, XFS_FSB_TO_DADDR(mp, args->fsbno),
args->len);
#endif
}
return 0;
error0:
mrunlock(&mp->m_peraglock);
return error;
}
/*
* Free an extent.
* Just break up the extent address and hand off to xfs_free_ag_extent
* after fixing up the freelist.
*/
int /* error */
xfs_free_extent(
xfs_trans_t *tp, /* transaction pointer */
xfs_fsblock_t bno, /* starting block number of extent */
xfs_extlen_t len) /* length of extent */
{
#ifdef DEBUG
xfs_agf_t *agf; /* a.g. freespace header */
#endif
xfs_alloc_arg_t args; /* allocation argument structure */
int error;
ASSERT(len != 0);
args.tp = tp;
args.mp = tp->t_mountp;
args.agno = XFS_FSB_TO_AGNO(args.mp, bno);
ASSERT(args.agno < args.mp->m_sb.sb_agcount);
args.agbno = XFS_FSB_TO_AGBNO(args.mp, bno);
args.alignment = 1;
args.minlen = args.minleft = 0;
mrlock(&args.mp->m_peraglock, MR_ACCESS, PINOD);
args.pag = &args.mp->m_perag[args.agno];
if (error = xfs_alloc_fix_freelist(&args, 0))
goto error0;
#ifdef DEBUG
ASSERT(args.agbp != NULL);
agf = XFS_BUF_TO_AGF(args.agbp);
ASSERT(args.agbno + len <= agf->agf_length);
#endif
error = xfs_free_ag_extent(tp, args.agbp, args.agno, args.agbno,
len, 0);
error0:
mrunlock(&args.mp->m_peraglock);
return error;
}
![[BACK]](/icons/back.gif){kind=icon}
Return to xfs_alloc.c CVS log ![[TXT]](/icons/text.gif){kind=icon}
![[DIR]](/icons/dir.gif){kind=icon}
Up to [Development] / xfs-linux-nodel