diff options
Diffstat (limited to 'fs/xfs/xfs_alloc.c')
| -rw-r--r-- | fs/xfs/xfs_alloc.c | 2623 |
1 files changed, 2623 insertions, 0 deletions
diff --git a/fs/xfs/xfs_alloc.c b/fs/xfs/xfs_alloc.c new file mode 100644 index 000000000000..36603db10fe9 --- /dev/null +++ b/fs/xfs/xfs_alloc.c @@ -0,0 +1,2623 @@ +/* + * 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, NULL, 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, NULL, 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. + */ + int dofirst; /* set to do first algorithm */ + + 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, NULL, 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, NULL, 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, NULL, 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 = NULL; + } + /* + * 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, NULL, 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, NULL, 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, NULL, + 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, NULL, + 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 (!agf->agf_flcount) { + *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)) + agf->agf_flfirst = 0; + 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)) + agf->agf_fllast = 0; + 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; + xfs_agnumber_t rotorstep = xfs_rotorstep; /* inode32 agf stepper */ + + 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 / rotorstep) % + mp->m_sb.sb_agcount), 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 / rotorstep) % + mp->m_sb.sb_agcount; + 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)) { + if (args->agno == sagno) + mp->m_agfrotor = (mp->m_agfrotor + 1) % + (mp->m_sb.sb_agcount * rotorstep); + else + mp->m_agfrotor = (args->agno * rotorstep + 1) % + (mp->m_sb.sb_agcount * rotorstep); + } + 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; +} |