File: [Development] / xfs-linux / xfs_alloc.c (download)
Revision 1.92, Thu Jun 13 01:35:15 1996 UTC (21 years, 4 months ago) by doucette
Branch: MAIN
Changes since 1.91: +5 -3
lines
Fix bug in xfs_alloc_compute_diff where we ended up tossing alignment
blocks off the end of the extent, thus fragmenting the extent.
This was noticed in simulation (mkfs) because the simulation
btree insert was broken (due to bad ovbcopy).
|
#ident "$Revision: 1.88 $"
/*
* 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 */
#ifndef SIM
/*
* 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 */
#endif /* !SIM */
/*
* 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);
}
/*
* 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 */
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);
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;
}
#ifndef SIM
/*
* 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;
}
#endif /* !SIM */
/*
* 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;
}
#ifdef SIM
ASSERT(agf->agf_flcount <= need);
#else
/*
* 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);
}
#endif /* SIM */
/*
* 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;
}
ASSERT(args->agbno != NULLAGBLOCK);
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;
}
#ifndef SIM
/*
* 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;
}
#endif /* !SIM */
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