| /* |
| * 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_mount.h" |
| #include "xfs_bmap_btree.h" |
| #include "xfs_alloc_btree.h" |
| #include "xfs_ialloc_btree.h" |
| #include "xfs_dinode.h" |
| #include "xfs_inode.h" |
| #include "xfs_btree.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 int |
| xfs_alloc_busy_search(struct xfs_mount *mp, 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 and mark the |
| * transaction as synchronous if blocks are found. This |
| * avoids the need to block due to a synchronous log |
| * force to ensure correct ordering as the synchronous |
| * transaction will guarantee that for us. |
| */ |
| if (xfs_alloc_busy_search(args->mp, args->agno, |
| args->agbno, args->len)) |
| xfs_trans_set_sync(args->tp); |
| } |
| 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 */ |
| |
| pag = xfs_perag_get(mp, agno); |
| pag->pagf_freeblks += len; |
| xfs_perag_put(pag); |
| |
| agf = XFS_BUF_TO_AGF(agbp); |
| be32_add_cpu(&agf->agf_freeblks, len); |
| xfs_trans_agblocks_delta(tp, 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_busy_insert(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 */ |
| 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) { |
| ASSERT(flags & XFS_ALLOC_FLAG_TRYLOCK); |
| ASSERT(!(flags & XFS_ALLOC_FLAG_FREEING)); |
| args->agbp = NULL; |
| return 0; |
| } |
| } else |
| agbp = NULL; |
| |
| /* |
| * If this is a metadata preferred 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 & XFS_ALLOC_FLAG_TRYLOCK)) { |
| ASSERT(!(flags & XFS_ALLOC_FLAG_FREEING)); |
| args->agbp = NULL; |
| return 0; |
| } |
| |
| if (!(flags & XFS_ALLOC_FLAG_FREEING)) { |
| /* |
| * If it looks like there isn't a long enough extent, or enough |
| * total blocks, reject it. |
| */ |
| need = XFS_MIN_FREELIST_PAG(pag, mp); |
| longest = xfs_alloc_longest_free_extent(mp, pag); |
| if ((args->minlen + args->alignment + args->minalignslop - 1) > |
| longest || |
| ((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) { |
| ASSERT(flags & XFS_ALLOC_FLAG_TRYLOCK); |
| ASSERT(!(flags & XFS_ALLOC_FLAG_FREEING)); |
| 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); |
| /* |
| * If there isn't enough total or single-extent, reject it. |
| */ |
| if (!(flags & XFS_ALLOC_FLAG_FREEING)) { |
| delta = need > be32_to_cpu(agf->agf_flcount) ? |
| (need - be32_to_cpu(agf->agf_flcount)) : 0; |
| longest = be32_to_cpu(agf->agf_longest); |
| longest = (longest > delta) ? (longest - delta) : |
| (be32_to_cpu(agf->agf_flcount) > 0 || longest > 0); |
| if ((args->minlen + args->alignment + args->minalignslop - 1) > |
| longest || |
| ((int)(be32_to_cpu(agf->agf_freeblks) + |
| be32_to_cpu(agf->agf_flcount) - need - args->total) < |
| (int)args->minleft)) { |
| xfs_trans_brelse(tp, agbp); |
| args->agbp = NULL; |
| return 0; |
| } |
| } |
| /* |
| * Make the freelist shorter if it's too long. |
| */ |
| while (be32_to_cpu(agf->agf_flcount) > need) { |
| xfs_buf_t *bp; |
| |
| error = xfs_alloc_get_freelist(tp, agbp, &bno, 0); |
| if (error) |
| 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 (be32_to_cpu(agf->agf_flcount) < need) { |
| targs.agbno = 0; |
| targs.maxlen = need - be32_to_cpu(agf->agf_flcount); |
| /* |
| * Allocate as many blocks as possible at once. |
| */ |
| if ((error = xfs_alloc_ag_vextent(&targs))) { |
| xfs_trans_brelse(tp, agflbp); |
| 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) { |
| if (flags & XFS_ALLOC_FLAG_FREEING) |
| break; |
| xfs_trans_brelse(tp, agflbp); |
| args->agbp = NULL; |
| return 0; |
| } |
| /* |
| * Put each allocated block on the list. |
| */ |
| for (bno = targs.agbno; bno < targs.agbno + targs.len; bno++) { |
| error = xfs_alloc_put_freelist(tp, agbp, |
| agflbp, bno, 0); |
| if (error) |
| return error; |
| } |
| } |
| xfs_trans_brelse(tp, agflbp); |
| 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 */ |
| int btreeblk) /* destination is a AGF btree */ |
| { |
| 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; |
| int logflags; |
| 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, |
| be32_to_cpu(agf->agf_seqno), &agflbp))) |
| return error; |
| agfl = XFS_BUF_TO_AGFL(agflbp); |
| /* |
| * Get the block number and update the data structures. |
| */ |
| bno = be32_to_cpu(agfl->agfl_bno[be32_to_cpu(agf->agf_flfirst)]); |
| be32_add_cpu(&agf->agf_flfirst, 1); |
| xfs_trans_brelse(tp, agflbp); |
| if (be32_to_cpu(agf->agf_flfirst) == XFS_AGFL_SIZE(mp)) |
| agf->agf_flfirst = 0; |
| |
| pag = xfs_perag_get(mp, be32_to_cpu(agf->agf_seqno)); |
| be32_add_cpu(&agf->agf_flcount, -1); |
| xfs_trans_agflist_delta(tp, -1); |
| pag->pagf_flcount--; |
| xfs_perag_put(pag); |
| |
| logflags = XFS_AGF_FLFIRST | XFS_AGF_FLCOUNT; |
| if (btreeblk) { |
| be32_add_cpu(&agf->agf_btreeblks, 1); |
| pag->pagf_btreeblks++; |
| logflags |= XFS_AGF_BTREEBLKS; |
| } |
| |
| xfs_alloc_log_agf(tp, agbp, logflags); |
| *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 before this transaction. |
| * |
| * We do this by setting the current transaction to a sync transaction |
| * which guarantees that the freeing transaction is on disk before this |
| * transaction. This is done instead of a synchronous log force here so |
| * that we don't sit and wait with the AGF locked in the transaction |
| * during the log force. |
| */ |
| if (xfs_alloc_busy_search(mp, be32_to_cpu(agf->agf_seqno), bno, 1)) |
| xfs_trans_set_sync(tp); |
| 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), |
| offsetof(xfs_agf_t, agf_btreeblks), |
| sizeof(xfs_agf_t) |
| }; |
| |
| trace_xfs_agf(tp->t_mountp, XFS_BUF_TO_AGF(bp), fields, _RET_IP_); |
| |
| 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 */ |
| int btreeblk) /* block came from a AGF btree */ |
| { |
| xfs_agf_t *agf; /* a.g. freespace structure */ |
| xfs_agfl_t *agfl; /* a.g. free block array */ |
| __be32 *blockp;/* pointer to array entry */ |
| int error; |
| int logflags; |
| 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, |
| be32_to_cpu(agf->agf_seqno), &agflbp))) |
| return error; |
| agfl = XFS_BUF_TO_AGFL(agflbp); |
| be32_add_cpu(&agf->agf_fllast, 1); |
| if (be32_to_cpu(agf->agf_fllast) == XFS_AGFL_SIZE(mp)) |
| agf->agf_fllast = 0; |
| |
| pag = xfs_perag_get(mp, be32_to_cpu(agf->agf_seqno)); |
| be32_add_cpu(&agf->agf_flcount, 1); |
| xfs_trans_agflist_delta(tp, 1); |
| pag->pagf_flcount++; |
| |
| logflags = XFS_AGF_FLLAST | XFS_AGF_FLCOUNT; |
| if (btreeblk) { |
| be32_add_cpu(&agf->agf_btreeblks, -1); |
| pag->pagf_btreeblks--; |
| logflags |= XFS_AGF_BTREEBLKS; |
| } |
| xfs_perag_put(pag); |
| |
| xfs_alloc_log_agf(tp, agbp, logflags); |
| |
| ASSERT(be32_to_cpu(agf->agf_flcount) <= XFS_AGFL_SIZE(mp)); |
| blockp = &agfl->agfl_bno[be32_to_cpu(agf->agf_fllast)]; |
| *blockp = cpu_to_be32(bno); |
| xfs_alloc_log_agf(tp, agbp, logflags); |
| 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_read_agf( |
| struct xfs_mount *mp, /* mount point structure */ |
| struct xfs_trans *tp, /* transaction pointer */ |
| xfs_agnumber_t agno, /* allocation group number */ |
| int flags, /* XFS_BUF_ */ |
| struct xfs_buf **bpp) /* buffer for the ag freelist header */ |
| { |
| struct xfs_agf *agf; /* ag freelist header */ |
| int agf_ok; /* set if agf is consistent */ |
| 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, bpp); |
| if (error) |
| return error; |
| if (!*bpp) |
| return 0; |
| |
| ASSERT(!XFS_BUF_GETERROR(*bpp)); |
| agf = XFS_BUF_TO_AGF(*bpp); |
| |
| /* |
| * Validate the magic number of the agf block. |
| */ |
| agf_ok = |
| be32_to_cpu(agf->agf_magicnum) == XFS_AGF_MAGIC && |
| XFS_AGF_GOOD_VERSION(be32_to_cpu(agf->agf_versionnum)) && |
| be32_to_cpu(agf->agf_freeblks) <= be32_to_cpu(agf->agf_length) && |
| be32_to_cpu(agf->agf_flfirst) < XFS_AGFL_SIZE(mp) && |
| be32_to_cpu(agf->agf_fllast) < XFS_AGFL_SIZE(mp) && |
| be32_to_cpu(agf->agf_flcount) <= XFS_AGFL_SIZE(mp) && |
| be32_to_cpu(agf->agf_seqno) == agno; |
| if (xfs_sb_version_haslazysbcount(&mp->m_sb)) |
| agf_ok = agf_ok && be32_to_cpu(agf->agf_btreeblks) <= |
| be32_to_cpu(agf->agf_length); |
| 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, *bpp); |
| return XFS_ERROR(EFSCORRUPTED); |
| } |
| XFS_BUF_SET_VTYPE_REF(*bpp, B_FS_AGF, XFS_AGF_REF); |
| return 0; |
| } |
| |
| /* |
| * Read in the allocation group header (free/alloc section). |
| */ |
| int /* error */ |
| xfs_alloc_read_agf( |
| struct xfs_mount *mp, /* mount point structure */ |
| struct xfs_trans *tp, /* transaction pointer */ |
| xfs_agnumber_t agno, /* allocation group number */ |
| int flags, /* XFS_ALLOC_FLAG_... */ |
| struct xfs_buf **bpp) /* buffer for the ag freelist header */ |
| { |
| struct xfs_agf *agf; /* ag freelist header */ |
| struct xfs_perag *pag; /* per allocation group data */ |
| int error; |
| |
| ASSERT(agno != NULLAGNUMBER); |
| |
| error = xfs_read_agf(mp, tp, agno, |
| (flags & XFS_ALLOC_FLAG_TRYLOCK) ? XBF_TRYLOCK : 0, |
| bpp); |
| if (error) |
| return error; |
| if (!*bpp) |
| return 0; |
| ASSERT(!XFS_BUF_GETERROR(*bpp)); |
| |
| agf = XFS_BUF_TO_AGF(*bpp); |
| pag = xfs_perag_get(mp, agno); |
| if (!pag->pagf_init) { |
| pag->pagf_freeblks = be32_to_cpu(agf->agf_freeblks); |
| pag->pagf_btreeblks = be32_to_cpu(agf->agf_btreeblks); |
| pag->pagf_flcount = be32_to_cpu(agf->agf_flcount); |
| pag->pagf_longest = be32_to_cpu(agf->agf_longest); |
| pag->pagf_levels[XFS_BTNUM_BNOi] = |
| be32_to_cpu(agf->agf_levels[XFS_BTNUM_BNOi]); |
| pag->pagf_levels[XFS_BTNUM_CNTi] = |
| be32_to_cpu(agf->agf_levels[XFS_BTNUM_CNTi]); |
| spin_lock_init(&pag->pagb_lock); |
| pag->pagb_count = 0; |
| pag->pagb_tree = RB_ROOT; |
| pag->pagf_init = 1; |
| } |
| #ifdef DEBUG |
| else if (!XFS_FORCED_SHUTDOWN(mp)) { |
| ASSERT(pag->pagf_freeblks == be32_to_cpu(agf->agf_freeblks)); |
| ASSERT(pag->pagf_btreeblks == be32_to_cpu(agf->agf_btreeblks)); |
| ASSERT(pag->pagf_flcount == be32_to_cpu(agf->agf_flcount)); |
| ASSERT(pag->pagf_longest == be32_to_cpu(agf->agf_longest)); |
| ASSERT(pag->pagf_levels[XFS_BTNUM_BNOi] == |
| be32_to_cpu(agf->agf_levels[XFS_BTNUM_BNOi])); |
| ASSERT(pag->pagf_levels[XFS_BTNUM_CNTi] == |
| be32_to_cpu(agf->agf_levels[XFS_BTNUM_CNTi])); |
| } |
| #endif |
| xfs_perag_put(pag); |
| 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 */ |
| 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_xfs_alloc_vextent_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); |
| args->pag = xfs_perag_get(mp, args->agno); |
| args->minleft = 0; |
| error = xfs_alloc_fix_freelist(args, 0); |
| args->minleft = minleft; |
| if (error) { |
| trace_xfs_alloc_vextent_nofix(args); |
| goto error0; |
| } |
| if (!args->agbp) { |
| trace_xfs_alloc_vextent_noagbp(args); |
| break; |
| } |
| args->agbno = XFS_FSB_TO_AGBNO(mp, args->fsbno); |
| if ((error = xfs_alloc_ag_vextent(args))) |
| goto error0; |
| 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. |
| */ |
| for (;;) { |
| args->pag = xfs_perag_get(mp, args->agno); |
| if (no_min) args->minleft = 0; |
| error = xfs_alloc_fix_freelist(args, flags); |
| args->minleft = minleft; |
| if (error) { |
| trace_xfs_alloc_vextent_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_xfs_alloc_vextent_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; |
| /* |
| * For the first allocation, we can try any AG to get |
| * space. However, if we already have allocated a |
| * block, we don't want to try AGs whose number is below |
| * sagno. Otherwise, we may end up with out-of-order |
| * locking of AGF, which might cause deadlock. |
| */ |
| if (++(args->agno) == mp->m_sb.sb_agcount) { |
| if (args->firstblock != NULLFSBLOCK) |
| args->agno = sagno; |
| else |
| 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_xfs_alloc_vextent_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; |
| } |
| } |
| } |
| xfs_perag_put(args->pag); |
| } |
| 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 |
| } |
| xfs_perag_put(args->pag); |
| return 0; |
| error0: |
| xfs_perag_put(args->pag); |
| 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 */ |
| { |
| xfs_alloc_arg_t args; |
| int error; |
| |
| ASSERT(len != 0); |
| memset(&args, 0, sizeof(xfs_alloc_arg_t)); |
| 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.pag = xfs_perag_get(args.mp, args.agno); |
| if ((error = xfs_alloc_fix_freelist(&args, XFS_ALLOC_FLAG_FREEING))) |
| goto error0; |
| #ifdef DEBUG |
| ASSERT(args.agbp != NULL); |
| ASSERT((args.agbno + len) <= |
| be32_to_cpu(XFS_BUF_TO_AGF(args.agbp)->agf_length)); |
| #endif |
| error = xfs_free_ag_extent(tp, args.agbp, args.agno, args.agbno, len, 0); |
| error0: |
| xfs_perag_put(args.pag); |
| return error; |
| } |
| |
| |
| /* |
| * AG Busy list management |
| * The busy list contains block ranges that have been freed but whose |
| * transactions 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_busy_insert - add to the per-ag busy list |
| * xfs_alloc_busy_clear - remove an item from the per-ag busy list |
| * xfs_alloc_busy_search - search for a busy extent |
| */ |
| |
| /* |
| * Insert a new extent into the busy tree. |
| * |
| * The busy extent tree is indexed by the start block of the busy extent. |
| * there can be multiple overlapping ranges in the busy extent tree but only |
| * ever one entry at a given start block. The reason for this is that |
| * multi-block extents can be freed, then smaller chunks of that extent |
| * allocated and freed again before the first transaction commit is on disk. |
| * If the exact same start block is freed a second time, we have to wait for |
| * that busy extent to pass out of the tree before the new extent is inserted. |
| * There are two main cases we have to handle here. |
| * |
| * The first case is a transaction that triggers a "free - allocate - free" |
| * cycle. This can occur during btree manipulations as a btree block is freed |
| * to the freelist, then allocated from the free list, then freed again. In |
| * this case, the second extxpnet free is what triggers the duplicate and as |
| * such the transaction IDs should match. Because the extent was allocated in |
| * this transaction, the transaction must be marked as synchronous. This is |
| * true for all cases where the free/alloc/free occurs in the one transaction, |
| * hence the addition of the ASSERT(tp->t_flags & XFS_TRANS_SYNC) to this case. |
| * This serves to catch violations of the second case quite effectively. |
| * |
| * The second case is where the free/alloc/free occur in different |
| * transactions. In this case, the thread freeing the extent the second time |
| * can't mark the extent busy immediately because it is already tracked in a |
| * transaction that may be committing. When the log commit for the existing |
| * busy extent completes, the busy extent will be removed from the tree. If we |
| * allow the second busy insert to continue using that busy extent structure, |
| * it can be freed before this transaction is safely in the log. Hence our |
| * only option in this case is to force the log to remove the existing busy |
| * extent from the list before we insert the new one with the current |
| * transaction ID. |
| * |
| * The problem we are trying to avoid in the free-alloc-free in separate |
| * transactions is most easily described with a timeline: |
| * |
| * Thread 1 Thread 2 Thread 3 xfslogd |
| * xact alloc |
| * free X |
| * mark busy |
| * commit xact |
| * free xact |
| * xact alloc |
| * alloc X |
| * busy search |
| * mark xact sync |
| * commit xact |
| * free xact |
| * force log |
| * checkpoint starts |
| * .... |
| * xact alloc |
| * free X |
| * mark busy |
| * finds match |
| * *** KABOOM! *** |
| * .... |
| * log IO completes |
| * unbusy X |
| * checkpoint completes |
| * |
| * By issuing a log force in thread 3 @ "KABOOM", the thread will block until |
| * the checkpoint completes, and the busy extent it matched will have been |
| * removed from the tree when it is woken. Hence it can then continue safely. |
| * |
| * However, to ensure this matching process is robust, we need to use the |
| * transaction ID for identifying transaction, as delayed logging results in |
| * the busy extent and transaction lifecycles being different. i.e. the busy |
| * extent is active for a lot longer than the transaction. Hence the |
| * transaction structure can be freed and reallocated, then mark the same |
| * extent busy again in the new transaction. In this case the new transaction |
| * will have a different tid but can have the same address, and hence we need |
| * to check against the tid. |
| * |
| * Future: for delayed logging, we could avoid the log force if the extent was |
| * first freed in the current checkpoint sequence. This, however, requires the |
| * ability to pin the current checkpoint in memory until this transaction |
| * commits to ensure that both the original free and the current one combine |
| * logically into the one checkpoint. If the checkpoint sequences are |
| * different, however, we still need to wait on a log force. |
| */ |
| void |
| xfs_alloc_busy_insert( |
| struct xfs_trans *tp, |
| xfs_agnumber_t agno, |
| xfs_agblock_t bno, |
| xfs_extlen_t len) |
| { |
| struct xfs_busy_extent *new; |
| struct xfs_busy_extent *busyp; |
| struct xfs_perag *pag; |
| struct rb_node **rbp; |
| struct rb_node *parent; |
| int match; |
| |
| |
| new = kmem_zalloc(sizeof(struct xfs_busy_extent), KM_MAYFAIL); |
| if (!new) { |
| /* |
| * No Memory! 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. |
| */ |
| trace_xfs_alloc_busy(tp, agno, bno, len, 1); |
| xfs_trans_set_sync(tp); |
| return; |
| } |
| |
| new->agno = agno; |
| new->bno = bno; |
| new->length = len; |
| new->tid = xfs_log_get_trans_ident(tp); |
| |
| INIT_LIST_HEAD(&new->list); |
| |
| /* trace before insert to be able to see failed inserts */ |
| trace_xfs_alloc_busy(tp, agno, bno, len, 0); |
| |
| pag = xfs_perag_get(tp->t_mountp, new->agno); |
| restart: |
| spin_lock(&pag->pagb_lock); |
| rbp = &pag->pagb_tree.rb_node; |
| parent = NULL; |
| busyp = NULL; |
| match = 0; |
| while (*rbp && match >= 0) { |
| parent = *rbp; |
| busyp = rb_entry(parent, struct xfs_busy_extent, rb_node); |
| |
| if (new->bno < busyp->bno) { |
| /* may overlap, but exact start block is lower */ |
| rbp = &(*rbp)->rb_left; |
| if (new->bno + new->length > busyp->bno) |
| match = busyp->tid == new->tid ? 1 : -1; |
| } else if (new->bno > busyp->bno) { |
| /* may overlap, but exact start block is higher */ |
| rbp = &(*rbp)->rb_right; |
| if (bno < busyp->bno + busyp->length) |
| match = busyp->tid == new->tid ? 1 : -1; |
| } else { |
| match = busyp->tid == new->tid ? 1 : -1; |
| break; |
| } |
| } |
| if (match < 0) { |
| /* overlap marked busy in different transaction */ |
| spin_unlock(&pag->pagb_lock); |
| xfs_log_force(tp->t_mountp, XFS_LOG_SYNC); |
| goto restart; |
| } |
| if (match > 0) { |
| /* |
| * overlap marked busy in same transaction. Update if exact |
| * start block match, otherwise combine the busy extents into |
| * a single range. |
| */ |
| if (busyp->bno == new->bno) { |
| busyp->length = max(busyp->length, new->length); |
| spin_unlock(&pag->pagb_lock); |
| ASSERT(tp->t_flags & XFS_TRANS_SYNC); |
| xfs_perag_put(pag); |
| kmem_free(new); |
| return; |
| } |
| rb_erase(&busyp->rb_node, &pag->pagb_tree); |
| new->length = max(busyp->bno + busyp->length, |
| new->bno + new->length) - |
| min(busyp->bno, new->bno); |
| new->bno = min(busyp->bno, new->bno); |
| } else |
| busyp = NULL; |
| |
| rb_link_node(&new->rb_node, parent, rbp); |
| rb_insert_color(&new->rb_node, &pag->pagb_tree); |
| |
| list_add(&new->list, &tp->t_busy); |
| spin_unlock(&pag->pagb_lock); |
| xfs_perag_put(pag); |
| kmem_free(busyp); |
| } |
| |
| /* |
| * Search for a busy extent within the range of the extent we are about to |
| * allocate. You need to be holding the busy extent tree lock when calling |
| * xfs_alloc_busy_search(). This function returns 0 for no overlapping busy |
| * extent, -1 for an overlapping but not exact busy extent, and 1 for an exact |
| * match. This is done so that a non-zero return indicates an overlap that |
| * will require a synchronous transaction, but it can still be |
| * used to distinguish between a partial or exact match. |
| */ |
| static int |
| xfs_alloc_busy_search( |
| struct xfs_mount *mp, |
| xfs_agnumber_t agno, |
| xfs_agblock_t bno, |
| xfs_extlen_t len) |
| { |
| struct xfs_perag *pag; |
| struct rb_node *rbp; |
| struct xfs_busy_extent *busyp; |
| int match = 0; |
| |
| pag = xfs_perag_get(mp, agno); |
| spin_lock(&pag->pagb_lock); |
| |
| rbp = pag->pagb_tree.rb_node; |
| |
| /* find closest start bno overlap */ |
| while (rbp) { |
| busyp = rb_entry(rbp, struct xfs_busy_extent, rb_node); |
| if (bno < busyp->bno) { |
| /* may overlap, but exact start block is lower */ |
| if (bno + len > busyp->bno) |
| match = -1; |
| rbp = rbp->rb_left; |
| } else if (bno > busyp->bno) { |
| /* may overlap, but exact start block is higher */ |
| if (bno < busyp->bno + busyp->length) |
| match = -1; |
| rbp = rbp->rb_right; |
| } else { |
| /* bno matches busyp, length determines exact match */ |
| match = (busyp->length == len) ? 1 : -1; |
| break; |
| } |
| } |
| spin_unlock(&pag->pagb_lock); |
| trace_xfs_alloc_busysearch(mp, agno, bno, len, !!match); |
| xfs_perag_put(pag); |
| return match; |
| } |
| |
| void |
| xfs_alloc_busy_clear( |
| struct xfs_mount *mp, |
| struct xfs_busy_extent *busyp) |
| { |
| struct xfs_perag *pag; |
| |
| trace_xfs_alloc_unbusy(mp, busyp->agno, busyp->bno, |
| busyp->length); |
| |
| ASSERT(xfs_alloc_busy_search(mp, busyp->agno, busyp->bno, |
| busyp->length) == 1); |
| |
| list_del_init(&busyp->list); |
| |
| pag = xfs_perag_get(mp, busyp->agno); |
| spin_lock(&pag->pagb_lock); |
| rb_erase(&busyp->rb_node, &pag->pagb_tree); |
| spin_unlock(&pag->pagb_lock); |
| xfs_perag_put(pag); |
| |
| kmem_free(busyp); |
| } |