patch-2.4.25 linux-2.4.25/fs/xfs/xfs_alloc.c
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- Lines: 2620
- Date:
2004-02-18 05:36:32.000000000 -0800
- Orig file:
linux-2.4.24/fs/xfs/xfs_alloc.c
- Orig date:
1969-12-31 16:00:00.000000000 -0800
diff -urN linux-2.4.24/fs/xfs/xfs_alloc.c linux-2.4.25/fs/xfs/xfs_alloc.c
@@ -0,0 +1,2619 @@
+/*
+ * Copyright (c) 2000-2002 Silicon Graphics, Inc. All Rights Reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it would be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * Further, this software is distributed without any warranty that it is
+ * free of the rightful claim of any third person regarding infringement
+ * or the like. Any license provided herein, whether implied or
+ * otherwise, applies only to this software file. Patent licenses, if
+ * any, provided herein do not apply to combinations of this program with
+ * other software, or any other product whatsoever.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write the Free Software Foundation, Inc., 59
+ * Temple Place - Suite 330, Boston MA 02111-1307, USA.
+ *
+ * Contact information: Silicon Graphics, Inc., 1600 Amphitheatre Pkwy,
+ * Mountain View, CA 94043, or:
+ *
+ * http://www.sgi.com
+ *
+ * For further information regarding this notice, see:
+ *
+ * http://oss.sgi.com/projects/GenInfo/SGIGPLNoticeExplan/
+ */
+
+/*
+ * Free space allocation for XFS.
+ */
+#include "xfs.h"
+#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_dir.h"
+#include "xfs_dmapi.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"
+
+
+#define XFS_ABSDIFF(a,b) (((a) <= (b)) ? ((b) - (a)) : ((a) - (b)))
+
+#define XFSA_FIXUP_BNO_OK 1
+#define XFSA_FIXUP_CNT_OK 2
+
+int
+xfs_alloc_search_busy(xfs_trans_t *tp,
+ xfs_agnumber_t agno,
+ xfs_agblock_t bno,
+ xfs_extlen_t len);
+
+#if defined(XFS_ALLOC_TRACE)
+ktrace_t *xfs_alloc_trace_buf;
+
+#define TRACE_ALLOC(s,a) \
+ xfs_alloc_trace_alloc(fname, s, a, __LINE__)
+#define TRACE_FREE(s,a,b,x,f) \
+ xfs_alloc_trace_free(fname, s, mp, a, b, x, f, __LINE__)
+#define TRACE_MODAGF(s,a,f) \
+ xfs_alloc_trace_modagf(fname, s, mp, a, f, __LINE__)
+#define TRACE_BUSY(fname,s,ag,agb,l,sl,tp) \
+ xfs_alloc_trace_busy(fname, s, mp, ag, agb, l, sl, tp, XFS_ALLOC_KTRACE_BUSY, __LINE__)
+#define TRACE_UNBUSY(fname,s,ag,sl,tp) \
+ xfs_alloc_trace_busy(fname, s, mp, ag, -1, -1, sl, tp, XFS_ALLOC_KTRACE_UNBUSY, __LINE__)
+#define TRACE_BUSYSEARCH(fname,s,ag,agb,l,sl,tp) \
+ xfs_alloc_trace_busy(fname, s, mp, ag, agb, l, sl, tp, XFS_ALLOC_KTRACE_BUSYSEARCH, __LINE__)
+#else
+#define TRACE_ALLOC(s,a)
+#define TRACE_FREE(s,a,b,x,f)
+#define TRACE_MODAGF(s,a,f)
+#define TRACE_BUSY(s,a,ag,agb,l,sl,tp)
+#define TRACE_UNBUSY(fname,s,ag,sl,tp)
+#define TRACE_BUSYSEARCH(fname,s,ag,agb,l,sl,tp)
+#endif /* XFS_ALLOC_TRACE */
+
+/*
+ * Prototypes for per-ag allocation routines
+ */
+
+STATIC int xfs_alloc_ag_vextent_exact(xfs_alloc_arg_t *);
+STATIC int xfs_alloc_ag_vextent_near(xfs_alloc_arg_t *);
+STATIC int xfs_alloc_ag_vextent_size(xfs_alloc_arg_t *);
+STATIC int xfs_alloc_ag_vextent_small(xfs_alloc_arg_t *,
+ xfs_btree_cur_t *, xfs_agblock_t *, xfs_extlen_t *, int *);
+
+/*
+ * 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=0; /* length with newbno1 */
+ xfs_extlen_t newlen2=0; /* 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 = INT_GET(agf->agf_freeblks, ARCH_CONVERT)
+ + INT_GET(agf->agf_flcount, ARCH_CONVERT)
+ - 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 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=0; /* first new free length */
+ xfs_extlen_t nflen2=0; /* second new free length */
+
+ /*
+ * Look up the record in the by-size tree if necessary.
+ */
+ if (flags & XFSA_FIXUP_CNT_OK) {
+#ifdef DEBUG
+ if ((error = xfs_alloc_get_rec(cnt_cur, &nfbno1, &nflen1, &i)))
+ return error;
+ XFS_WANT_CORRUPTED_RETURN(
+ i == 1 && nfbno1 == fbno && nflen1 == flen);
+#endif
+ } else {
+ if ((error = xfs_alloc_lookup_eq(cnt_cur, fbno, flen, &i)))
+ return error;
+ XFS_WANT_CORRUPTED_RETURN(i == 1);
+ }
+ /*
+ * Look up the record in the by-block tree if necessary.
+ */
+ if (flags & XFSA_FIXUP_BNO_OK) {
+#ifdef DEBUG
+ if ((error = xfs_alloc_get_rec(bno_cur, &nfbno1, &nflen1, &i)))
+ return error;
+ XFS_WANT_CORRUPTED_RETURN(
+ i == 1 && nfbno1 == fbno && nflen1 == flen);
+#endif
+ } else {
+ if ((error = xfs_alloc_lookup_eq(bno_cur, fbno, flen, &i)))
+ return error;
+ XFS_WANT_CORRUPTED_RETURN(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]);
+ XFS_WANT_CORRUPTED_RETURN(
+ INT_GET(bnoblock->bb_numrecs, ARCH_CONVERT) == INT_GET(cntblock->bb_numrecs, ARCH_CONVERT));
+ }
+ }
+#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;
+ XFS_WANT_CORRUPTED_RETURN(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;
+ XFS_WANT_CORRUPTED_RETURN(i == 0);
+ if ((error = xfs_alloc_insert(cnt_cur, &i)))
+ return error;
+ XFS_WANT_CORRUPTED_RETURN(i == 1);
+ }
+ if (nfbno2 != NULLAGBLOCK) {
+ if ((error = xfs_alloc_lookup_eq(cnt_cur, nfbno2, nflen2, &i)))
+ return error;
+ XFS_WANT_CORRUPTED_RETURN(i == 0);
+ if ((error = xfs_alloc_insert(cnt_cur, &i)))
+ return error;
+ XFS_WANT_CORRUPTED_RETURN(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;
+ XFS_WANT_CORRUPTED_RETURN(i == 1);
+ } else {
+ /*
+ * Update the by-block entry to start later|be shorter.
+ */
+ if ((error = xfs_alloc_update(bno_cur, nfbno1, nflen1)))
+ return error;
+ }
+ if (nfbno2 != NULLAGBLOCK) {
+ /*
+ * 2 resulting free entries, need to add one.
+ */
+ if ((error = xfs_alloc_lookup_eq(bno_cur, nfbno2, nflen2, &i)))
+ return error;
+ XFS_WANT_CORRUPTED_RETURN(i == 0);
+ if ((error = xfs_alloc_insert(bno_cur, &i)))
+ return error;
+ XFS_WANT_CORRUPTED_RETURN(i == 1);
+ }
+ return 0;
+}
+
+/*
+ * 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 */
+ xfs_buf_t **bpp) /* buffer for the ag free block array */
+{
+ xfs_buf_t *bp; /* return value */
+ int error;
+
+ ASSERT(agno != NULLAGNUMBER);
+ error = xfs_trans_read_buf(
+ mp, tp, mp->m_ddev_targp,
+ XFS_AG_DADDR(mp, agno, XFS_AGFL_DADDR(mp)),
+ XFS_FSS_TO_BB(mp, 1), 0, &bp);
+ if (error)
+ return error;
+ ASSERT(bp);
+ ASSERT(!XFS_BUF_GETERROR(bp));
+ XFS_BUF_SET_VTYPE_REF(bp, B_FS_AGFL, 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 */
+ int line) /* source line number */
+{
+ ktrace_enter(xfs_alloc_trace_buf,
+ (void *)(__psint_t)(XFS_ALLOC_KTRACE_ALLOC | (line << 16)),
+ (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 */
+ int line) /* source line number */
+{
+ ktrace_enter(xfs_alloc_trace_buf,
+ (void *)(__psint_t)(XFS_ALLOC_KTRACE_FREE | (line << 16)),
+ (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 */
+ int line) /* source line number */
+{
+ ktrace_enter(xfs_alloc_trace_buf,
+ (void *)(__psint_t)(XFS_ALLOC_KTRACE_MODAGF | (line << 16)),
+ (void *)name,
+ (void *)str,
+ (void *)mp,
+ (void *)(__psint_t)flags,
+ (void *)(__psunsigned_t)INT_GET(agf->agf_seqno, ARCH_CONVERT),
+ (void *)(__psunsigned_t)INT_GET(agf->agf_length, ARCH_CONVERT),
+ (void *)(__psunsigned_t)INT_GET(agf->agf_roots[XFS_BTNUM_BNO],
+ ARCH_CONVERT),
+ (void *)(__psunsigned_t)INT_GET(agf->agf_roots[XFS_BTNUM_CNT],
+ ARCH_CONVERT),
+ (void *)(__psunsigned_t)INT_GET(agf->agf_levels[XFS_BTNUM_BNO],
+ ARCH_CONVERT),
+ (void *)(__psunsigned_t)INT_GET(agf->agf_levels[XFS_BTNUM_CNT],
+ ARCH_CONVERT),
+ (void *)(__psunsigned_t)INT_GET(agf->agf_flfirst, ARCH_CONVERT),
+ (void *)(__psunsigned_t)INT_GET(agf->agf_fllast, ARCH_CONVERT),
+ (void *)(__psunsigned_t)INT_GET(agf->agf_flcount, ARCH_CONVERT),
+ (void *)(__psunsigned_t)INT_GET(agf->agf_freeblks, ARCH_CONVERT),
+ (void *)(__psunsigned_t)INT_GET(agf->agf_longest, ARCH_CONVERT));
+}
+
+STATIC void
+xfs_alloc_trace_busy(
+ char *name, /* function tag string */
+ char *str, /* additional string */
+ xfs_mount_t *mp, /* file system mount poing */
+ xfs_agnumber_t agno, /* allocation group number */
+ xfs_agblock_t agbno, /* a.g. relative block number */
+ xfs_extlen_t len, /* length of extent */
+ int slot, /* perag Busy slot */
+ xfs_trans_t *tp,
+ int trtype, /* type: add, delete, search */
+ int line) /* source line number */
+{
+ ktrace_enter(xfs_alloc_trace_buf,
+ (void *)(__psint_t)(trtype | (line << 16)),
+ (void *)name,
+ (void *)str,
+ (void *)mp,
+ (void *)(__psunsigned_t)agno,
+ (void *)(__psunsigned_t)agbno,
+ (void *)(__psunsigned_t)len,
+ (void *)(__psint_t)slot,
+ (void *)tp,
+ NULL, NULL, NULL, NULL, NULL, NULL, NULL);
+}
+#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=0;
+#ifdef XFS_ALLOC_TRACE
+ static char fname[] = "xfs_alloc_ag_vextent";
+#endif
+
+ 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;
+ case XFS_ALLOCTYPE_THIS_BNO:
+ error = xfs_alloc_ag_vextent_exact(args);
+ break;
+ 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 */
+#ifdef XFS_ALLOC_TRACE
+ xfs_mount_t *mp = args->mp;
+#endif
+ 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);
+ INT_MOD(agf->agf_freeblks, ARCH_CONVERT, -(args->len));
+ xfs_trans_agblocks_delta(args->tp,
+ -((long)(args->len)));
+ args->pag->pagf_freeblks -= args->len;
+ ASSERT(INT_GET(agf->agf_freeblks, ARCH_CONVERT)
+ <= INT_GET(agf->agf_length, ARCH_CONVERT));
+ TRACE_MODAGF(NULL, agf, XFS_AGF_FREEBLKS);
+ xfs_alloc_log_agf(args->tp, args->agbp,
+ XFS_AGF_FREEBLKS);
+ /* search the busylist for these blocks */
+ xfs_alloc_search_busy(args->tp, args->agno,
+ args->agbno, args->len);
+ }
+ if (!args->isfl)
+ xfs_trans_mod_sb(args->tp,
+ args->wasdel ? XFS_TRANS_SB_RES_FDBLOCKS :
+ XFS_TRANS_SB_FDBLOCKS, -slen);
+ XFS_STATS_INC(xs_allocx);
+ XFS_STATS_ADD(xs_allocb, args->len);
+ }
+ return 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.
+ */
+ if ((error = xfs_alloc_lookup_le(bno_cur, args->agbno, args->minlen, &i)))
+ goto error0;
+ 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.
+ */
+ if ((error = xfs_alloc_get_rec(bno_cur, &fbno, &flen, &i)))
+ goto error0;
+ XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
+ 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);
+ ASSERT(args->agbno + args->len <=
+ INT_GET(XFS_BUF_TO_AGF(args->agbp)->agf_length,
+ ARCH_CONVERT));
+ if ((error = xfs_alloc_fixup_trees(cnt_cur, bno_cur, fbno, flen,
+ args->agbno, args->len, XFSA_FIXUP_BNO_OK))) {
+ xfs_btree_del_cursor(cnt_cur, XFS_BTREE_ERROR);
+ goto error0;
+ }
+ xfs_btree_del_cursor(bno_cur, XFS_BTREE_NOERROR);
+ xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
+ TRACE_ALLOC("normal", args);
+ args->wasfromfl = 0;
+ return 0;
+
+error0:
+ xfs_btree_del_cursor(bno_cur, XFS_BTREE_ERROR);
+ TRACE_ALLOC("error", args);
+ return error;
+}
+
+/*
+ * 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(__KERNEL__)
+ /*
+ * 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 */
+
+ 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;
+ bno_cur_lt = bno_cur_gt = NULL;
+ /*
+ * 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=0;
+ xfs_extlen_t blen=0;
+ xfs_agblock_t bnew=0;
+
+#if defined(DEBUG) && defined(__KERNEL__)
+ 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 {
+ if ((error = xfs_alloc_get_rec(cnt_cur, <bno,
+ <len, &i)))
+ goto error0;
+ XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
+ 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.
+ */
+ if ((error = xfs_alloc_get_rec(cnt_cur, <bno, <len, &i)))
+ goto error0;
+ XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
+ 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;
+ if ((error = xfs_alloc_get_rec(cnt_cur, <bno, <len, &i)))
+ goto error0;
+ XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
+ ltend = ltbno + ltlen;
+ ASSERT(ltend <= INT_GET(XFS_BUF_TO_AGF(args->agbp)->agf_length,
+ ARCH_CONVERT));
+ args->len = blen;
+ if (!xfs_alloc_fix_minleft(args)) {
+ xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
+ TRACE_ALLOC("nominleft", args);
+ 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)))
+ goto error0;
+ xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
+ xfs_btree_del_cursor(bno_cur_lt, XFS_BTREE_NOERROR);
+ TRACE_ALLOC("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 error0;
+ 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 if ((error = xfs_btree_dup_cursor(bno_cur_lt, &bno_cur_gt)))
+ goto error0;
+ /*
+ * 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 error0;
+ if (!i) {
+ /*
+ * It failed, there are no rightward entries.
+ */
+ xfs_btree_del_cursor(bno_cur_gt, XFS_BTREE_NOERROR);
+ bno_cur_gt = NULL;
+ }
+ /*
+ * 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) {
+ if ((error = xfs_alloc_get_rec(bno_cur_lt, <bno, <len, &i)))
+ goto error0;
+ XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
+ 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 error0;
+ if (!i) {
+ xfs_btree_del_cursor(bno_cur_lt,
+ XFS_BTREE_NOERROR);
+ bno_cur_lt = NULL;
+ }
+ }
+ if (bno_cur_gt) {
+ if ((error = xfs_alloc_get_rec(bno_cur_gt, >bno, >len, &i)))
+ goto error0;
+ XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
+ 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 error0;
+ if (!i) {
+ xfs_btree_del_cursor(bno_cur_gt,
+ XFS_BTREE_NOERROR);
+ bno_cur_gt = NULL;
+ }
+ }
+ } 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) {
+ if ((error = xfs_alloc_get_rec(
+ bno_cur_gt, >bno,
+ >len, &i)))
+ goto error0;
+ XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
+ 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 = NULL;
+ 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 = NULL;
+ }
+ /*
+ * Left side is better.
+ */
+ else {
+ xfs_btree_del_cursor(
+ bno_cur_gt,
+ XFS_BTREE_NOERROR);
+ bno_cur_gt = NULL;
+ }
+ break;
+ }
+ /*
+ * Fell off the right end.
+ */
+ if ((error = xfs_alloc_increment(
+ bno_cur_gt, 0, &i)))
+ goto error0;
+ if (!i) {
+ xfs_btree_del_cursor(
+ bno_cur_gt,
+ XFS_BTREE_NOERROR);
+ bno_cur_gt = NULL;
+ break;
+ }
+ }
+ }
+ /*
+ * The left side is perfect, trash the right side.
+ */
+ else {
+ xfs_btree_del_cursor(bno_cur_gt,
+ XFS_BTREE_NOERROR);
+ bno_cur_gt = NULL;
+ }
+ }
+ /*
+ * 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) {
+ if ((error = xfs_alloc_get_rec(
+ bno_cur_lt, <bno,
+ <len, &i)))
+ goto error0;
+ XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
+ 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 = NULL;
+ 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 = NULL;
+ }
+ /*
+ * Right side is better.
+ */
+ else {
+ xfs_btree_del_cursor(
+ bno_cur_lt,
+ XFS_BTREE_NOERROR);
+ bno_cur_lt = NULL;
+ }
+ break;
+ }
+ /*
+ * Fell off the left end.
+ */
+ if ((error = xfs_alloc_decrement(
+ bno_cur_lt, 0, &i)))
+ goto error0;
+ if (!i) {
+ xfs_btree_del_cursor(bno_cur_lt,
+ XFS_BTREE_NOERROR);
+ bno_cur_lt = NULL;
+ break;
+ }
+ }
+ }
+ /*
+ * The right side is perfect, trash the left side.
+ */
+ else {
+ xfs_btree_del_cursor(bno_cur_lt,
+ XFS_BTREE_NOERROR);
+ bno_cur_lt = NULL;
+ }
+ }
+ }
+ /*
+ * If we couldn't get anything, give up.
+ */
+ if (bno_cur_lt == NULL && bno_cur_gt == NULL) {
+ TRACE_ALLOC("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)) {
+ TRACE_ALLOC("nominleft", 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 <= INT_GET(XFS_BUF_TO_AGF(args->agbp)->agf_length,
+ ARCH_CONVERT));
+ args->agbno = ltnew;
+ if ((error = xfs_alloc_fixup_trees(cnt_cur, bno_cur_lt, ltbno, ltlen,
+ ltnew, rlen, XFSA_FIXUP_BNO_OK)))
+ goto error0;
+ TRACE_ALLOC(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:
+ TRACE_ALLOC("error", args);
+ if (cnt_cur != NULL)
+ 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);
+ bno_cur = NULL;
+ /*
+ * 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);
+ TRACE_ALLOC("noentry", args);
+ return 0;
+ }
+ ASSERT(i == 1);
+ }
+ /*
+ * There's a freespace as big as maxlen+alignment-1, get it.
+ */
+ else {
+ if ((error = xfs_alloc_get_rec(cnt_cur, &fbno, &flen, &i)))
+ goto error0;
+ XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
+ }
+ /*
+ * 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);
+ XFS_WANT_CORRUPTED_GOTO(rlen == 0 ||
+ (rlen <= flen && rbno + rlen <= fbno + flen), error0);
+ 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;
+ if ((error = xfs_alloc_get_rec(cnt_cur, &fbno, &flen,
+ &i)))
+ goto error0;
+ XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
+ if (flen < bestrlen)
+ break;
+ xfs_alloc_compute_aligned(fbno, flen, args->alignment,
+ args->minlen, &rbno, &rlen);
+ rlen = XFS_EXTLEN_MIN(args->maxlen, rlen);
+ XFS_WANT_CORRUPTED_GOTO(rlen == 0 ||
+ (rlen <= flen && rbno + rlen <= fbno + flen),
+ error0);
+ 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;
+ XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
+ 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);
+ TRACE_ALLOC("nominleft", args);
+ args->agbno = NULLAGBLOCK;
+ return 0;
+ }
+ rlen = args->len;
+ XFS_WANT_CORRUPTED_GOTO(rlen <= flen, error0);
+ /*
+ * 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)))
+ goto error0;
+ xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
+ xfs_btree_del_cursor(bno_cur, XFS_BTREE_NOERROR);
+ cnt_cur = bno_cur = NULL;
+ args->len = rlen;
+ args->agbno = rbno;
+ XFS_WANT_CORRUPTED_GOTO(
+ args->agbno + args->len <=
+ INT_GET(XFS_BUF_TO_AGF(args->agbp)->agf_length,
+ ARCH_CONVERT),
+ error0);
+ TRACE_ALLOC("normal", args);
+ return 0;
+
+error0:
+ TRACE_ALLOC("error", args);
+ if (cnt_cur)
+ xfs_btree_del_cursor(cnt_cur, XFS_BTREE_ERROR);
+ if (bno_cur)
+ xfs_btree_del_cursor(bno_cur, XFS_BTREE_ERROR);
+ 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)))
+ goto error0;
+ if (i) {
+ if ((error = xfs_alloc_get_rec(ccur, &fbno, &flen, &i)))
+ goto error0;
+ XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
+ }
+ /*
+ * 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 &&
+ (INT_GET(XFS_BUF_TO_AGF(args->agbp)->agf_flcount,
+ ARCH_CONVERT) > args->minleft)) {
+ if ((error = xfs_alloc_get_freelist(args->tp, args->agbp, &fbno)))
+ goto error0;
+ if (fbno != NULLAGBLOCK) {
+ if (args->userdata) {
+ xfs_buf_t *bp;
+
+ bp = xfs_btree_get_bufs(args->mp, args->tp,
+ args->agno, fbno, 0);
+ xfs_trans_binval(args->tp, bp);
+ }
+ args->len = 1;
+ args->agbno = fbno;
+ XFS_WANT_CORRUPTED_GOTO(
+ args->agbno + args->len <=
+ INT_GET(XFS_BUF_TO_AGF(args->agbp)->agf_length,
+ ARCH_CONVERT),
+ error0);
+ args->wasfromfl = 1;
+ TRACE_ALLOC("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;
+ TRACE_ALLOC("notenough", args);
+ flen = 0;
+ }
+ *fbnop = fbno;
+ *flenp = flen;
+ *stat = 1;
+ TRACE_ALLOC("normal", args);
+ return 0;
+
+error0:
+ TRACE_ALLOC("error", args);
+ return error;
+}
+
+/*
+ * Free the extent starting at agno/bno for length.
+ */
+STATIC int /* error */
+xfs_free_ag_extent(
+ xfs_trans_t *tp, /* transaction pointer */
+ xfs_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; /* error return value */
+#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);
+ cnt_cur = NULL;
+ /*
+ * 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.
+ */
+ if ((error = xfs_alloc_get_rec(bno_cur, <bno, <len, &i)))
+ goto error0;
+ XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
+ /*
+ * It's not contiguous, though.
+ */
+ if (ltbno + ltlen < bno)
+ haveleft = 0;
+ else {
+ /*
+ * If this failure happens the request to free this
+ * space was invalid, it's (partly) already free.
+ * Very bad.
+ */
+ XFS_WANT_CORRUPTED_GOTO(ltbno + ltlen <= bno, error0);
+ }
+ }
+ /*
+ * 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.
+ */
+ if ((error = xfs_alloc_get_rec(bno_cur, >bno, >len, &i)))
+ goto error0;
+ XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
+ /*
+ * It's not contiguous, though.
+ */
+ if (bno + len < gtbno)
+ haveright = 0;
+ else {
+ /*
+ * If this failure happens the request to free this
+ * space was invalid, it's (partly) already free.
+ * Very bad.
+ */
+ XFS_WANT_CORRUPTED_GOTO(gtbno >= bno + len, error0);
+ }
+ }
+ /*
+ * 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 error0;
+ XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
+ if ((error = xfs_alloc_delete(cnt_cur, &i)))
+ goto error0;
+ XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
+ /*
+ * Delete the old by-size entry on the right.
+ */
+ if ((error = xfs_alloc_lookup_eq(cnt_cur, gtbno, gtlen, &i)))
+ goto error0;
+ XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
+ if ((error = xfs_alloc_delete(cnt_cur, &i)))
+ goto error0;
+ XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
+ /*
+ * Delete the old by-block entry for the right block.
+ */
+ if ((error = xfs_alloc_delete(bno_cur, &i)))
+ goto error0;
+ XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
+ /*
+ * Move the by-block cursor back to the left neighbor.
+ */
+ if ((error = xfs_alloc_decrement(bno_cur, 0, &i)))
+ goto error0;
+ XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
+#ifdef DEBUG
+ /*
+ * Check that this is the right record: delete didn't
+ * mangle the cursor.
+ */
+ {
+ xfs_agblock_t xxbno;
+ xfs_extlen_t xxlen;
+
+ if ((error = xfs_alloc_get_rec(bno_cur, &xxbno, &xxlen,
+ &i)))
+ goto error0;
+ XFS_WANT_CORRUPTED_GOTO(
+ i == 1 && xxbno == ltbno && xxlen == ltlen,
+ error0);
+ }
+#endif
+ /*
+ * Update remaining by-block entry to the new, joined block.
+ */
+ nbno = ltbno;
+ nlen = len + ltlen + gtlen;
+ if ((error = xfs_alloc_update(bno_cur, nbno, nlen)))
+ goto error0;
+ }
+ /*
+ * 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 error0;
+ XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
+ if ((error = xfs_alloc_delete(cnt_cur, &i)))
+ goto error0;
+ XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
+ /*
+ * Back up the by-block cursor to the left neighbor, and
+ * update its length.
+ */
+ if ((error = xfs_alloc_decrement(bno_cur, 0, &i)))
+ goto error0;
+ XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
+ nbno = ltbno;
+ nlen = len + ltlen;
+ if ((error = xfs_alloc_update(bno_cur, nbno, nlen)))
+ goto error0;
+ }
+ /*
+ * 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 error0;
+ XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
+ if ((error = xfs_alloc_delete(cnt_cur, &i)))
+ goto error0;
+ XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
+ /*
+ * Update the starting block and length of the right
+ * neighbor in the by-block tree.
+ */
+ nbno = bno;
+ nlen = len + gtlen;
+ if ((error = xfs_alloc_update(bno_cur, nbno, nlen)))
+ goto error0;
+ }
+ /*
+ * 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 error0;
+ XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
+ }
+ xfs_btree_del_cursor(bno_cur, XFS_BTREE_NOERROR);
+ bno_cur = NULL;
+ /*
+ * 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 error0;
+ XFS_WANT_CORRUPTED_GOTO(i == 0, error0);
+ if ((error = xfs_alloc_insert(cnt_cur, &i)))
+ goto error0;
+ XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
+ xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
+ cnt_cur = NULL;
+ /*
+ * 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];
+ INT_MOD(agf->agf_freeblks, ARCH_CONVERT, len);
+ xfs_trans_agblocks_delta(tp, len);
+ pag->pagf_freeblks += len;
+ XFS_WANT_CORRUPTED_GOTO(
+ INT_GET(agf->agf_freeblks, ARCH_CONVERT)
+ <= INT_GET(agf->agf_length, ARCH_CONVERT),
+ error0);
+ TRACE_MODAGF(NULL, 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);
+ XFS_STATS_INC(xs_freex);
+ XFS_STATS_ADD(xs_freeb, len);
+ }
+ TRACE_FREE(haveleft ?
+ (haveright ? "both" : "left") :
+ (haveright ? "right" : "none"),
+ agno, bno, len, isfl);
+
+ /*
+ * 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. We track the blocks by declaring
+ * these blocks as "busy"; the busy list is maintained on a per-ag
+ * basis and each transaction records which entries should be removed
+ * when the iclog commits to disk. If a busy block is allocated,
+ * the iclog is pushed up to the LSN that freed the block.
+ */
+ xfs_alloc_mark_busy(tp, agno, bno, len);
+ return 0;
+
+ error0:
+ TRACE_FREE("error", agno, bno, len, isfl);
+ if (bno_cur)
+ xfs_btree_del_cursor(bno_cur, XFS_BTREE_ERROR);
+ if (cnt_cur)
+ xfs_btree_del_cursor(cnt_cur, XFS_BTREE_ERROR);
+ 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.
+ */
+STATIC int /* error */
+xfs_alloc_fix_freelist(
+ xfs_alloc_arg_t *args, /* allocation argument structure */
+ int flags) /* XFS_ALLOC_FLAG_... */
+{
+ xfs_buf_t *agbp; /* agf buffer pointer */
+ xfs_agf_t *agf; /* a.g. freespace structure pointer */
+ xfs_buf_t *agflbp;/* agfl buffer pointer */
+ xfs_agblock_t bno; /* freelist block */
+ xfs_extlen_t delta; /* new blocks needed in freelist */
+ 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 in freelist */
+ 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) {
+ if ((error = xfs_alloc_read_agf(mp, tp, args->agno, flags,
+ &agbp)))
+ return error;
+ if (!pag->pagf_init) {
+ args->agbp = NULL;
+ return 0;
+ }
+ } else
+ agbp = NULL;
+
+ /* If this is a metadata prefered pag and we are user data
+ * then try somewhere else if we are not being asked to
+ * try harder at this point
+ */
+ if (pag->pagf_metadata && args->userdata && flags) {
+ args->agbp = NULL;
+ return 0;
+ }
+
+ need = XFS_MIN_FREELIST_PAG(pag, mp);
+ delta = need > pag->pagf_flcount ? need - pag->pagf_flcount : 0;
+ /*
+ * If it looks like there isn't a long enough extent, or enough
+ * total blocks, reject it.
+ */
+ longest = (pag->pagf_longest > delta) ?
+ (pag->pagf_longest - delta) :
+ (pag->pagf_flcount > 0 || pag->pagf_longest > 0);
+ if (args->minlen + args->alignment + args->minalignslop - 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) {
+ if ((error = xfs_alloc_read_agf(mp, tp, args->agno, flags,
+ &agbp)))
+ 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);
+ need = XFS_MIN_FREELIST(agf, mp);
+ delta = need > INT_GET(agf->agf_flcount, ARCH_CONVERT) ?
+ (need - INT_GET(agf->agf_flcount, ARCH_CONVERT)) : 0;
+ /*
+ * If there isn't enough total or single-extent, reject it.
+ */
+ longest = INT_GET(agf->agf_longest, ARCH_CONVERT);
+ longest = (longest > delta) ? (longest - delta) :
+ (INT_GET(agf->agf_flcount, ARCH_CONVERT) > 0 || longest > 0);
+ if (args->minlen + args->alignment + args->minalignslop - 1 > longest ||
+ (args->minleft &&
+ (int)(INT_GET(agf->agf_freeblks, ARCH_CONVERT) +
+ INT_GET(agf->agf_flcount, ARCH_CONVERT) - 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 (INT_GET(agf->agf_flcount, ARCH_CONVERT) > need) {
+ xfs_buf_t *bp;
+
+ if ((error = xfs_alloc_get_freelist(tp, agbp, &bno)))
+ return error;
+ if ((error = xfs_free_ag_extent(tp, agbp, args->agno, bno, 1, 1)))
+ return error;
+ bp = xfs_btree_get_bufs(mp, tp, args->agno, bno, 0);
+ xfs_trans_binval(tp, bp);
+ }
+ /*
+ * 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 =
+ targs.minalignslop = 0;
+ targs.alignment = targs.minlen = targs.prod = targs.isfl = 1;
+ targs.type = XFS_ALLOCTYPE_THIS_AG;
+ targs.pag = pag;
+ if ((error = xfs_alloc_read_agfl(mp, tp, targs.agno, &agflbp)))
+ return error;
+ /*
+ * Make the freelist longer if it's too short.
+ */
+ while (INT_GET(agf->agf_flcount, ARCH_CONVERT) < need) {
+ targs.agbno = 0;
+ targs.maxlen = need - INT_GET(agf->agf_flcount, ARCH_CONVERT);
+ /*
+ * Allocate as many blocks as possible at once.
+ */
+ if ((error = xfs_alloc_ag_vextent(&targs)))
+ 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++) {
+ if ((error = xfs_alloc_put_freelist(tp, agbp, agflbp,
+ bno)))
+ 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 */
+ xfs_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 */
+ xfs_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_mount_t *mp; /* mount structure */
+ xfs_perag_t *pag; /* per allocation group data */
+
+ agf = XFS_BUF_TO_AGF(agbp);
+ /*
+ * Freelist is empty, give up.
+ */
+ if (INT_ISZERO(agf->agf_flcount, ARCH_CONVERT)) {
+ *bnop = NULLAGBLOCK;
+ return 0;
+ }
+ /*
+ * Read the array of free blocks.
+ */
+ mp = tp->t_mountp;
+ if ((error = xfs_alloc_read_agfl(mp, tp,
+ INT_GET(agf->agf_seqno, ARCH_CONVERT), &agflbp)))
+ return error;
+ agfl = XFS_BUF_TO_AGFL(agflbp);
+ /*
+ * Get the block number and update the data structures.
+ */
+ bno = INT_GET(agfl->agfl_bno[INT_GET(agf->agf_flfirst, ARCH_CONVERT)], ARCH_CONVERT);
+ INT_MOD(agf->agf_flfirst, ARCH_CONVERT, 1);
+ xfs_trans_brelse(tp, agflbp);
+ if (INT_GET(agf->agf_flfirst, ARCH_CONVERT) == XFS_AGFL_SIZE(mp))
+ INT_ZERO(agf->agf_flfirst, ARCH_CONVERT);
+ pag = &mp->m_perag[INT_GET(agf->agf_seqno, ARCH_CONVERT)];
+ INT_MOD(agf->agf_flcount, ARCH_CONVERT, -1);
+ xfs_trans_agflist_delta(tp, -1);
+ pag->pagf_flcount--;
+ TRACE_MODAGF(NULL, agf, XFS_AGF_FLFIRST | XFS_AGF_FLCOUNT);
+ xfs_alloc_log_agf(tp, agbp, XFS_AGF_FLFIRST | XFS_AGF_FLCOUNT);
+ *bnop = bno;
+
+ /*
+ * As blocks are freed, they are added to the per-ag busy list
+ * and remain there until the freeing transaction is committed to
+ * disk. Now that we have allocated blocks, this list must be
+ * searched to see if a block is being reused. If one is, then
+ * the freeing transaction must be pushed to disk NOW by forcing
+ * to disk all iclogs up that transaction's LSN.
+ */
+ xfs_alloc_search_busy(tp, INT_GET(agf->agf_seqno, ARCH_CONVERT), bno, 1);
+ return 0;
+}
+
+/*
+ * Log the given fields from the agf structure.
+ */
+void
+xfs_alloc_log_agf(
+ xfs_trans_t *tp, /* transaction pointer */
+ xfs_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_... */
+{
+ xfs_buf_t *bp;
+ int error;
+
+ if ((error = xfs_alloc_read_agf(mp, tp, agno, flags, &bp)))
+ 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 */
+ xfs_buf_t *agbp, /* buffer for a.g. freelist header */
+ xfs_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_mount_t *mp; /* mount structure */
+ xfs_perag_t *pag; /* per allocation group data */
+
+ agf = XFS_BUF_TO_AGF(agbp);
+ mp = tp->t_mountp;
+
+ if (!agflbp && (error = xfs_alloc_read_agfl(mp, tp,
+ INT_GET(agf->agf_seqno, ARCH_CONVERT), &agflbp)))
+ return error;
+ agfl = XFS_BUF_TO_AGFL(agflbp);
+ INT_MOD(agf->agf_fllast, ARCH_CONVERT, 1);
+ if (INT_GET(agf->agf_fllast, ARCH_CONVERT) == XFS_AGFL_SIZE(mp))
+ INT_ZERO(agf->agf_fllast, ARCH_CONVERT);
+ pag = &mp->m_perag[INT_GET(agf->agf_seqno, ARCH_CONVERT)];
+ INT_MOD(agf->agf_flcount, ARCH_CONVERT, 1);
+ xfs_trans_agflist_delta(tp, 1);
+ pag->pagf_flcount++;
+ ASSERT(INT_GET(agf->agf_flcount, ARCH_CONVERT) <= XFS_AGFL_SIZE(mp));
+ blockp = &agfl->agfl_bno[INT_GET(agf->agf_fllast, ARCH_CONVERT)];
+ INT_SET(*blockp, ARCH_CONVERT, bno);
+ TRACE_MODAGF(NULL, 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,
+ (int)((xfs_caddr_t)blockp - (xfs_caddr_t)agfl),
+ (int)((xfs_caddr_t)blockp - (xfs_caddr_t)agfl +
+ sizeof(xfs_agblock_t) - 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_... */
+ xfs_buf_t **bpp) /* buffer for the ag freelist header */
+{
+ xfs_agf_t *agf; /* ag freelist header */
+ int agf_ok; /* set if agf is consistent */
+ xfs_buf_t *bp; /* return value */
+ xfs_perag_t *pag; /* per allocation group data */
+ int error;
+
+ ASSERT(agno != NULLAGNUMBER);
+ error = xfs_trans_read_buf(
+ mp, tp, mp->m_ddev_targp,
+ XFS_AG_DADDR(mp, agno, XFS_AGF_DADDR(mp)),
+ XFS_FSS_TO_BB(mp, 1),
+ (flags & XFS_ALLOC_FLAG_TRYLOCK) ? XFS_BUF_TRYLOCK : 0U,
+ &bp);
+ if (error)
+ return error;
+ ASSERT(!bp || !XFS_BUF_GETERROR(bp));
+ if (!bp) {
+ *bpp = NULL;
+ return 0;
+ }
+ /*
+ * Validate the magic number of the agf block.
+ */
+ agf = XFS_BUF_TO_AGF(bp);
+ agf_ok =
+ INT_GET(agf->agf_magicnum, ARCH_CONVERT) == XFS_AGF_MAGIC &&
+ XFS_AGF_GOOD_VERSION(
+ INT_GET(agf->agf_versionnum, ARCH_CONVERT)) &&
+ INT_GET(agf->agf_freeblks, ARCH_CONVERT) <=
+ INT_GET(agf->agf_length, ARCH_CONVERT) &&
+ INT_GET(agf->agf_flfirst, ARCH_CONVERT) < XFS_AGFL_SIZE(mp) &&
+ INT_GET(agf->agf_fllast, ARCH_CONVERT) < XFS_AGFL_SIZE(mp) &&
+ INT_GET(agf->agf_flcount, ARCH_CONVERT) <= XFS_AGFL_SIZE(mp);
+ if (unlikely(XFS_TEST_ERROR(!agf_ok, mp, XFS_ERRTAG_ALLOC_READ_AGF,
+ XFS_RANDOM_ALLOC_READ_AGF))) {
+ XFS_CORRUPTION_ERROR("xfs_alloc_read_agf",
+ XFS_ERRLEVEL_LOW, mp, agf);
+ xfs_trans_brelse(tp, bp);
+ return XFS_ERROR(EFSCORRUPTED);
+ }
+ pag = &mp->m_perag[agno];
+ if (!pag->pagf_init) {
+ pag->pagf_freeblks = INT_GET(agf->agf_freeblks, ARCH_CONVERT);
+ pag->pagf_flcount = INT_GET(agf->agf_flcount, ARCH_CONVERT);
+ pag->pagf_longest = INT_GET(agf->agf_longest, ARCH_CONVERT);
+ pag->pagf_levels[XFS_BTNUM_BNOi] =
+ INT_GET(agf->agf_levels[XFS_BTNUM_BNOi], ARCH_CONVERT);
+ pag->pagf_levels[XFS_BTNUM_CNTi] =
+ INT_GET(agf->agf_levels[XFS_BTNUM_CNTi], ARCH_CONVERT);
+ spinlock_init(&pag->pagb_lock, "xfspagb");
+ pag->pagb_list = kmem_zalloc(XFS_PAGB_NUM_SLOTS *
+ sizeof(xfs_perag_busy_t), KM_SLEEP);
+ pag->pagf_init = 1;
+ }
+#ifdef DEBUG
+ else if (!XFS_FORCED_SHUTDOWN(mp)) {
+ ASSERT(pag->pagf_freeblks == INT_GET(agf->agf_freeblks, ARCH_CONVERT));
+ ASSERT(pag->pagf_flcount == INT_GET(agf->agf_flcount, ARCH_CONVERT));
+ ASSERT(pag->pagf_longest == INT_GET(agf->agf_longest, ARCH_CONVERT));
+ ASSERT(pag->pagf_levels[XFS_BTNUM_BNOi] ==
+ INT_GET(agf->agf_levels[XFS_BTNUM_BNOi], ARCH_CONVERT));
+ ASSERT(pag->pagf_levels[XFS_BTNUM_CNTi] ==
+ INT_GET(agf->agf_levels[XFS_BTNUM_CNTi], ARCH_CONVERT));
+ }
+#endif
+ XFS_BUF_SET_VTYPE_REF(bp, B_FS_AGF, 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 */
+ int bump_rotor = 0;
+ int no_min = 0;
+
+ 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;
+ TRACE_ALLOC("badargs", args);
+ return 0;
+ }
+ minleft = args->minleft;
+
+ switch (type) {
+ case XFS_ALLOCTYPE_THIS_AG:
+ case XFS_ALLOCTYPE_NEAR_BNO:
+ case XFS_ALLOCTYPE_THIS_BNO:
+ /*
+ * These three force us into a single a.g.
+ */
+ args->agno = XFS_FSB_TO_AGNO(mp, args->fsbno);
+ down_read(&mp->m_peraglock);
+ args->pag = &mp->m_perag[args->agno];
+ args->minleft = 0;
+ error = xfs_alloc_fix_freelist(args, 0);
+ args->minleft = minleft;
+ if (error) {
+ TRACE_ALLOC("nofix", args);
+ goto error0;
+ }
+ if (!args->agbp) {
+ up_read(&mp->m_peraglock);
+ TRACE_ALLOC("noagbp", args);
+ break;
+ }
+ args->agbno = XFS_FSB_TO_AGBNO(mp, args->fsbno);
+ if ((error = xfs_alloc_ag_vextent(args)))
+ goto error0;
+ up_read(&mp->m_peraglock);
+ break;
+ case XFS_ALLOCTYPE_START_BNO:
+ /*
+ * Try near allocation first, then anywhere-in-ag after
+ * the first a.g. fails.
+ */
+ if ((args->userdata == XFS_ALLOC_INITIAL_USER_DATA) &&
+ (mp->m_flags & XFS_MOUNT_32BITINODES)) {
+ args->fsbno = XFS_AGB_TO_FSB(mp, mp->m_agfrotor, 0);
+ bump_rotor = 1;
+ }
+ 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.
+ */
+ down_read(&mp->m_peraglock);
+ for (;;) {
+ args->pag = &mp->m_perag[args->agno];
+ if (no_min) args->minleft = 0;
+ error = xfs_alloc_fix_freelist(args, flags);
+ args->minleft = minleft;
+ if (error) {
+ TRACE_ALLOC("nofix", args);
+ goto error0;
+ }
+ /*
+ * If we get a buffer back then the allocation will fly.
+ */
+ if (args->agbp) {
+ if ((error = xfs_alloc_ag_vextent(args)))
+ goto error0;
+ break;
+ }
+ TRACE_ALLOC("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 (no_min == 1) {
+ args->agbno = NULLAGBLOCK;
+ TRACE_ALLOC("allfailed", args);
+ break;
+ }
+ if (flags == 0) {
+ no_min = 1;
+ } else {
+ flags = 0;
+ if (type == XFS_ALLOCTYPE_START_BNO) {
+ args->agbno = XFS_FSB_TO_AGBNO(mp,
+ args->fsbno);
+ args->type = XFS_ALLOCTYPE_NEAR_BNO;
+ }
+ }
+ }
+ }
+ up_read(&mp->m_peraglock);
+ if (bump_rotor || (type == XFS_ALLOCTYPE_ANY_AG))
+ 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:
+ up_read(&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 = args.minalignslop = 0;
+ down_read(&args.mp->m_peraglock);
+ 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 <= INT_GET(agf->agf_length, ARCH_CONVERT));
+#endif
+ error = xfs_free_ag_extent(tp, args.agbp, args.agno, args.agbno,
+ len, 0);
+error0:
+ up_read(&args.mp->m_peraglock);
+ return error;
+}
+
+
+/*
+ * AG Busy list management
+ * The busy list contains block ranges that have been freed but whose
+ * transacations have not yet hit disk. If any block listed in a busy
+ * list is reused, the transaction that freed it must be forced to disk
+ * before continuing to use the block.
+ *
+ * xfs_alloc_mark_busy - add to the per-ag busy list
+ * xfs_alloc_clear_busy - remove an item from the per-ag busy list
+ */
+void
+xfs_alloc_mark_busy(xfs_trans_t *tp,
+ xfs_agnumber_t agno,
+ xfs_agblock_t bno,
+ xfs_extlen_t len)
+{
+ xfs_mount_t *mp;
+ xfs_perag_busy_t *bsy;
+ int n;
+ SPLDECL(s);
+
+ mp = tp->t_mountp;
+ s = mutex_spinlock(&mp->m_perag[agno].pagb_lock);
+
+ /* search pagb_list for an open slot */
+ for (bsy = mp->m_perag[agno].pagb_list, n = 0;
+ n < XFS_PAGB_NUM_SLOTS;
+ bsy++, n++) {
+ if (bsy->busy_tp == NULL) {
+ break;
+ }
+ }
+
+ if (n < XFS_PAGB_NUM_SLOTS) {
+ bsy = &mp->m_perag[agno].pagb_list[n];
+ mp->m_perag[agno].pagb_count++;
+ TRACE_BUSY("xfs_alloc_mark_busy", "got", agno, bno, len, n, tp);
+ bsy->busy_start = bno;
+ bsy->busy_length = len;
+ bsy->busy_tp = tp;
+ xfs_trans_add_busy(tp, agno, n);
+ } else {
+ TRACE_BUSY("xfs_alloc_mark_busy", "FULL", agno, bno, len, -1, tp);
+ /*
+ * The busy list is full! Since it is now not possible to
+ * track the free block, make this a synchronous transaction
+ * to insure that the block is not reused before this
+ * transaction commits.
+ */
+ xfs_trans_set_sync(tp);
+ }
+
+ mutex_spinunlock(&mp->m_perag[agno].pagb_lock, s);
+}
+
+void
+xfs_alloc_clear_busy(xfs_trans_t *tp,
+ xfs_agnumber_t agno,
+ int idx)
+{
+ xfs_mount_t *mp;
+ xfs_perag_busy_t *list;
+ SPLDECL(s);
+
+ mp = tp->t_mountp;
+
+ s = mutex_spinlock(&mp->m_perag[agno].pagb_lock);
+ list = mp->m_perag[agno].pagb_list;
+
+ ASSERT(idx < XFS_PAGB_NUM_SLOTS);
+ if (list[idx].busy_tp == tp) {
+ TRACE_UNBUSY("xfs_alloc_clear_busy", "found", agno, idx, tp);
+ list[idx].busy_tp = NULL;
+ mp->m_perag[agno].pagb_count--;
+ } else {
+ TRACE_UNBUSY("xfs_alloc_clear_busy", "missing", agno, idx, tp);
+ }
+
+ mutex_spinunlock(&mp->m_perag[agno].pagb_lock, s);
+}
+
+
+/*
+ * returns non-zero if any of (agno,bno):len is in a busy list
+ */
+int
+xfs_alloc_search_busy(xfs_trans_t *tp,
+ xfs_agnumber_t agno,
+ xfs_agblock_t bno,
+ xfs_extlen_t len)
+{
+ xfs_mount_t *mp;
+ xfs_perag_busy_t *bsy;
+ int n;
+ xfs_agblock_t uend, bend;
+ xfs_lsn_t lsn;
+ int cnt;
+ SPLDECL(s);
+
+ mp = tp->t_mountp;
+
+ s = mutex_spinlock(&mp->m_perag[agno].pagb_lock);
+ cnt = mp->m_perag[agno].pagb_count;
+
+ uend = bno + len - 1;
+
+ /* search pagb_list for this slot, skipping open slots */
+ for (bsy = mp->m_perag[agno].pagb_list, n = 0;
+ cnt; bsy++, n++) {
+
+ /*
+ * (start1,length1) within (start2, length2)
+ */
+ if (bsy->busy_tp != NULL) {
+ bend = bsy->busy_start + bsy->busy_length - 1;
+ if ((bno > bend) ||
+ (uend < bsy->busy_start)) {
+ cnt--;
+ } else {
+ TRACE_BUSYSEARCH("xfs_alloc_search_busy",
+ "found1", agno, bno, len, n,
+ tp);
+ break;
+ }
+ }
+ }
+
+ /*
+ * If a block was found, force the log through the LSN of the
+ * transaction that freed the block
+ */
+ if (cnt) {
+ TRACE_BUSYSEARCH("xfs_alloc_search_busy", "found", agno, bno, len, n, tp);
+ lsn = bsy->busy_tp->t_commit_lsn;
+ mutex_spinunlock(&mp->m_perag[agno].pagb_lock, s);
+ xfs_log_force(mp, lsn, XFS_LOG_FORCE|XFS_LOG_SYNC);
+ } else {
+ TRACE_BUSYSEARCH("xfs_alloc_search_busy", "not-found", agno, bno, len, n, tp);
+ n = -1;
+ mutex_spinunlock(&mp->m_perag[agno].pagb_lock, s);
+ }
+
+ return n;
+}
FUNET's LINUX-ADM group, linux-adm@nic.funet.fi
TCL-scripts by Sam Shen (who was at: slshen@lbl.gov)