/linux-2.6.33/kernel/linux-2.6.33/fs/xfs/xfs_alloc.c
C | 2603 lines | 1813 code | 129 blank | 661 comment | 461 complexity | b4fb12d2c36e8ce1ccae689878f96e90 MD5 | raw file
Possible License(s): GPL-2.0, LGPL-2.0, AGPL-1.0
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- /*
- * Copyright (c) 2000-2002,2005 Silicon Graphics, Inc.
- * All Rights Reserved.
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms 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. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write the Free Software Foundation,
- * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
- */
- #include "xfs.h"
- #include "xfs_fs.h"
- #include "xfs_types.h"
- #include "xfs_bit.h"
- #include "xfs_log.h"
- #include "xfs_inum.h"
- #include "xfs_trans.h"
- #include "xfs_sb.h"
- #include "xfs_ag.h"
- #include "xfs_dir2.h"
- #include "xfs_dmapi.h"
- #include "xfs_mount.h"
- #include "xfs_bmap_btree.h"
- #include "xfs_alloc_btree.h"
- #include "xfs_ialloc_btree.h"
- #include "xfs_dir2_sf.h"
- #include "xfs_attr_sf.h"
- #include "xfs_dinode.h"
- #include "xfs_inode.h"
- #include "xfs_btree.h"
- #include "xfs_ialloc.h"
- #include "xfs_alloc.h"
- #include "xfs_error.h"
- #include "xfs_trace.h"
- #define XFS_ABSDIFF(a,b) (((a) <= (b)) ? ((b) - (a)) : ((a) - (b)))
- #define XFSA_FIXUP_BNO_OK 1
- #define XFSA_FIXUP_CNT_OK 2
- STATIC void
- xfs_alloc_search_busy(xfs_trans_t *tp,
- xfs_agnumber_t agno,
- xfs_agblock_t bno,
- xfs_extlen_t len);
- /*
- * 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.
- */
- /*
- * Lookup the record equal to [bno, len] in the btree given by cur.
- */
- STATIC int /* error */
- xfs_alloc_lookup_eq(
- struct xfs_btree_cur *cur, /* btree cursor */
- xfs_agblock_t bno, /* starting block of extent */
- xfs_extlen_t len, /* length of extent */
- int *stat) /* success/failure */
- {
- cur->bc_rec.a.ar_startblock = bno;
- cur->bc_rec.a.ar_blockcount = len;
- return xfs_btree_lookup(cur, XFS_LOOKUP_EQ, stat);
- }
- /*
- * Lookup the first record greater than or equal to [bno, len]
- * in the btree given by cur.
- */
- STATIC int /* error */
- xfs_alloc_lookup_ge(
- struct xfs_btree_cur *cur, /* btree cursor */
- xfs_agblock_t bno, /* starting block of extent */
- xfs_extlen_t len, /* length of extent */
- int *stat) /* success/failure */
- {
- cur->bc_rec.a.ar_startblock = bno;
- cur->bc_rec.a.ar_blockcount = len;
- return xfs_btree_lookup(cur, XFS_LOOKUP_GE, stat);
- }
- /*
- * Lookup the first record less than or equal to [bno, len]
- * in the btree given by cur.
- */
- STATIC int /* error */
- xfs_alloc_lookup_le(
- struct xfs_btree_cur *cur, /* btree cursor */
- xfs_agblock_t bno, /* starting block of extent */
- xfs_extlen_t len, /* length of extent */
- int *stat) /* success/failure */
- {
- cur->bc_rec.a.ar_startblock = bno;
- cur->bc_rec.a.ar_blockcount = len;
- return xfs_btree_lookup(cur, XFS_LOOKUP_LE, stat);
- }
- /*
- * Update the record referred to by cur to the value given
- * by [bno, len].
- * This either works (return 0) or gets an EFSCORRUPTED error.
- */
- STATIC int /* error */
- xfs_alloc_update(
- struct xfs_btree_cur *cur, /* btree cursor */
- xfs_agblock_t bno, /* starting block of extent */
- xfs_extlen_t len) /* length of extent */
- {
- union xfs_btree_rec rec;
- rec.alloc.ar_startblock = cpu_to_be32(bno);
- rec.alloc.ar_blockcount = cpu_to_be32(len);
- return xfs_btree_update(cur, &rec);
- }
- /*
- * Get the data from the pointed-to record.
- */
- STATIC int /* error */
- xfs_alloc_get_rec(
- struct xfs_btree_cur *cur, /* btree cursor */
- xfs_agblock_t *bno, /* output: starting block of extent */
- xfs_extlen_t *len, /* output: length of extent */
- int *stat) /* output: success/failure */
- {
- union xfs_btree_rec *rec;
- int error;
- error = xfs_btree_get_rec(cur, &rec, stat);
- if (!error && *stat == 1) {
- *bno = be32_to_cpu(rec->alloc.ar_startblock);
- *len = be32_to_cpu(rec->alloc.ar_blockcount);
- }
- return error;
- }
- /*
- * Compute aligned version of the found extent.
- * Takes alignment and min length into account.
- */
- STATIC void
- 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;
- }
- /*
- * 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 = be32_to_cpu(agf->agf_freeblks)
- + be32_to_cpu(agf->agf_flcount)
- - args->len - args->minleft;
- if (diff >= 0)
- return 1;
- args->len += diff; /* shrink the allocated space */
- if (args->len >= args->minlen)
- return 1;
- args->agbno = NULLAGBLOCK;
- return 0;
- }
- /*
- * Update the two btrees, logically removing from freespace the extent
- * starting at rbno, rlen blocks. The extent is contained within the
- * actual (current) free extent fbno for flen blocks.
- * Flags are passed in indicating whether the cursors are set to the
- * relevant records.
- */
- STATIC int /* error code */
- xfs_alloc_fixup_trees(
- xfs_btree_cur_t *cnt_cur, /* cursor for by-size btree */
- xfs_btree_cur_t *bno_cur, /* cursor for by-block btree */
- xfs_agblock_t fbno, /* starting block of free extent */
- xfs_extlen_t flen, /* length of free extent */
- xfs_agblock_t rbno, /* starting block of returned extent */
- xfs_extlen_t rlen, /* length of returned extent */
- int flags) /* flags, XFSA_FIXUP_... */
- {
- int 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
- if (bno_cur->bc_nlevels == 1 && cnt_cur->bc_nlevels == 1) {
- struct xfs_btree_block *bnoblock;
- struct xfs_btree_block *cntblock;
- bnoblock = XFS_BUF_TO_BLOCK(bno_cur->bc_bufs[0]);
- cntblock = XFS_BUF_TO_BLOCK(cnt_cur->bc_bufs[0]);
- XFS_WANT_CORRUPTED_RETURN(
- bnoblock->bb_numrecs == cntblock->bb_numrecs);
- }
- #endif
- /*
- * Deal with all four cases: the allocated record is contained
- * within the freespace record, so we can have new freespace
- * at either (or both) end, or no freespace remaining.
- */
- if (rbno == fbno && rlen == flen)
- nfbno1 = nfbno2 = NULLAGBLOCK;
- else if (rbno == fbno) {
- nfbno1 = rbno + rlen;
- nflen1 = flen - rlen;
- nfbno2 = NULLAGBLOCK;
- } else if (rbno + rlen == fbno + flen) {
- nfbno1 = fbno;
- nflen1 = flen - rlen;
- nfbno2 = NULLAGBLOCK;
- } else {
- nfbno1 = fbno;
- nflen1 = rbno - fbno;
- nfbno2 = rbno + rlen;
- nflen2 = (fbno + flen) - nfbno2;
- }
- /*
- * Delete the entry from the by-size btree.
- */
- if ((error = xfs_btree_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_btree_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_btree_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_btree_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_btree_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;
- }
- /*
- * 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;
- 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 */
- 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);
- be32_add_cpu(&agf->agf_freeblks, -(args->len));
- xfs_trans_agblocks_delta(args->tp,
- -((long)(args->len)));
- args->pag->pagf_freeblks -= args->len;
- ASSERT(be32_to_cpu(agf->agf_freeblks) <=
- be32_to_cpu(agf->agf_length));
- 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 */
- 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_allocbt_init_cursor(args->mp, args->tp, args->agbp,
- args->agno, XFS_BTNUM_BNO);
- /*
- * 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_allocbt_init_cursor(args->mp, args->tp, args->agbp,
- args->agno, XFS_BTNUM_CNT);
- ASSERT(args->agbno + args->len <=
- be32_to_cpu(XFS_BUF_TO_AGF(args->agbp)->agf_length));
- 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_xfs_alloc_exact_done(args);
- args->wasfromfl = 0;
- return 0;
- error0:
- xfs_btree_del_cursor(bno_cur, XFS_BTREE_ERROR);
- trace_xfs_alloc_exact_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 */
- 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 = random32() & 1;
- #endif
- /*
- * Get a cursor for the by-size btree.
- */
- cnt_cur = xfs_allocbt_init_cursor(args->mp, args->tp, args->agbp,
- args->agno, XFS_BTNUM_CNT);
- 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_btree_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_btree_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);
- xfs_alloc_compute_aligned(ltbno, ltlen, args->alignment,
- args->minlen, <bnoa, <lena);
- if (ltlena < args->minlen)
- 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 <= be32_to_cpu(XFS_BUF_TO_AGF(args->agbp)->agf_length));
- args->len = blen;
- if (!xfs_alloc_fix_minleft(args)) {
- xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
- trace_xfs_alloc_near_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_allocbt_init_cursor(args->mp, args->tp,
- args->agbp, args->agno, XFS_BTNUM_BNO);
- /*
- * 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_xfs_alloc_near_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_allocbt_init_cursor(args->mp, args->tp, args->agbp,
- args->agno, XFS_BTNUM_BNO);
- /*
- * 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_btree_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);
- xfs_alloc_compute_aligned(ltbno, ltlen, args->alignment,
- args->minlen, <bnoa, <lena);
- if (ltlena >= args->minlen)
- break;
- if ((error = xfs_btree_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);
- xfs_alloc_compute_aligned(gtbno, gtlen, args->alignment,
- args->minlen, >bnoa, >lena);
- if (gtlena >= args->minlen)
- break;
- if ((error = xfs_btree_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_btree_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_btree_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_xfs_alloc_size_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_xfs_alloc_near_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 <= be32_to_cpu(XFS_BUF_TO_AGF(args->agbp)->agf_length));
- args->agbno = ltnew;
- if ((error = xfs_alloc_fixup_trees(cnt_cur, bno_cur_lt, ltbno, ltlen,
- ltnew, rlen, XFSA_FIXUP_BNO_OK)))
- goto error0;
- if (j)
- trace_xfs_alloc_near_greater(args);
- else
- trace_xfs_alloc_near_lesser(args);
- xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
- xfs_btree_del_cursor(bno_cur_lt, XFS_BTREE_NOERROR);
- return 0;
- error0:
- trace_xfs_alloc_near_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 */
- 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_allocbt_init_cursor(args->mp, args->tp, args->agbp,
- args->agno, XFS_BTNUM_CNT);
- 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_xfs_alloc_size_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_btree_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_xfs_alloc_size_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_allocbt_init_cursor(args->mp, args->tp, args->agbp,
- args->agno, XFS_BTNUM_BNO);
- 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 <=
- be32_to_cpu(XFS_BUF_TO_AGF(args->agbp)->agf_length),
- error0);
- trace_xfs_alloc_size_done(args);
- return 0;
- error0:
- trace_xfs_alloc_size_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;
- int i;
- if ((error = xfs_btree_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 &&
- (be32_to_cpu(XFS_BUF_TO_AGF(args->agbp)->agf_flcount)
- > args->minleft)) {
- error = xfs_alloc_get_freelist(args->tp, args->agbp, &fbno, 0);
- if (error)
- 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 <=
- be32_to_cpu(XFS_BUF_TO_AGF(args->agbp)->agf_length),
- error0);
- args->wasfromfl = 1;
- trace_xfs_alloc_small_freelist(args);
- *stat = 0;
- return 0;
- }
- /*
- * Nothing in the freelist.
- */
- else
- flen = 0;
- }
- /*
- * Can't allocate from the freelist for some reason.
- */
- else {
- fbno = NULLAGBLOCK;
- flen = 0;
- }
- /*
- * Can't do the allocation, give up.
- */
- if (flen < args->minlen) {
- args->agbno = NULLAGBLOCK;
- trace_xfs_alloc_small_notenough(args);
- flen = 0;
- }
- *fbnop = fbno;
- *flenp = flen;
- *stat = 1;
- trace_xfs_alloc_small_done(args);
- return 0;
- error0:
- trace_xfs_alloc_small_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 */
- 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_allocbt_init_cursor(mp, tp, agbp, agno, XFS_BTNUM_BNO);
- 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_btree_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_allocbt_init_cursor(mp, tp, agbp, agno, XFS_BTNUM_CNT);
- /*
- * 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_btree_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_btree_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_btree_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_btree_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_btree_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_btree_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_btree_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_btree_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_btree_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];
- be32_add_cpu(&agf->agf_freeblks, len);
- xfs_trans_agblocks_delta(tp, len);
- pag->pagf_freeblks += len;
- XFS_WANT_CORRUPTED_GOTO(
- be32_to_cpu(agf->agf_freeblks) <=
- be32_to_cpu(agf->agf_length),
- error0);
- 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_xfs_free_extent(mp, agno, bno, len, isfl, haveleft, haveright);
- /*
- * 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_xfs_free_extent(mp, agno, bno, len, isfl, -1, -1);
- 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;
- }
- /*
- * Find the length of the longest extent in an AG.
- */
- xfs_extlen_t
- xfs_alloc_longest_free_extent(
- struct xfs_mount *mp,
- struct xfs_perag *pag)
- {
- xfs_extlen_t need, delta = 0;
- need = XFS_MIN_FREELIST_PAG(pag, mp);
- if (need > pag->pagf_flcount)
- delta = need - pag->pagf_flcount;
- if (pag->pagf_longest > delta)
- return pag->pagf_longest - delta;
- return pag->pagf_flcount > 0 || pag->pagf_longest > 0;
- }
- /*
- * 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 *…
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