diff options
Diffstat (limited to 'ANDROID_3.4.5/fs/xfs/xfs_alloc.c')
| -rw-r--r-- | ANDROID_3.4.5/fs/xfs/xfs_alloc.c | 3074 |
1 files changed, 0 insertions, 3074 deletions
diff --git a/ANDROID_3.4.5/fs/xfs/xfs_alloc.c b/ANDROID_3.4.5/fs/xfs/xfs_alloc.c deleted file mode 100644 index 0f0df275..00000000 --- a/ANDROID_3.4.5/fs/xfs/xfs_alloc.c +++ /dev/null @@ -1,3074 +0,0 @@ -/* - * 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" - -struct workqueue_struct *xfs_alloc_wq; - -#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_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 *); -STATIC void xfs_alloc_busy_trim(struct xfs_alloc_arg *, - xfs_agblock_t, xfs_extlen_t, xfs_agblock_t *, xfs_extlen_t *); - -/* - * 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. - */ -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. - */ -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. - */ -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_alloc_arg_t *args, /* allocation argument structure */ - xfs_agblock_t foundbno, /* starting block in found extent */ - xfs_extlen_t foundlen, /* length in found extent */ - xfs_agblock_t *resbno, /* result block number */ - xfs_extlen_t *reslen) /* result length */ -{ - xfs_agblock_t bno; - xfs_extlen_t len; - - /* Trim busy sections out of found extent */ - xfs_alloc_busy_trim(args, foundbno, foundlen, &bno, &len); - - if (args->alignment > 1 && len >= args->minlen) { - xfs_agblock_t aligned_bno = roundup(bno, args->alignment); - xfs_extlen_t diff = aligned_bno - bno; - - *resbno = aligned_bno; - *reslen = diff >= len ? 0 : len - diff; - } else { - *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) - - 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(!xfs_buf_geterror(bp)); - xfs_buf_set_ref(bp, XFS_AGFL_REF); - *bpp = bp; - return 0; -} - -STATIC int -xfs_alloc_update_counters( - struct xfs_trans *tp, - struct xfs_perag *pag, - struct xfs_buf *agbp, - long len) -{ - struct xfs_agf *agf = XFS_BUF_TO_AGF(agbp); - - pag->pagf_freeblks += len; - be32_add_cpu(&agf->agf_freeblks, len); - - xfs_trans_agblocks_delta(tp, len); - if (unlikely(be32_to_cpu(agf->agf_freeblks) > - be32_to_cpu(agf->agf_length))) - return EFSCORRUPTED; - - xfs_alloc_log_agf(tp, agbp, XFS_AGF_FREEBLKS); - 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 || args->agbno == NULLAGBLOCK) - return error; - - ASSERT(args->len >= args->minlen); - ASSERT(args->len <= args->maxlen); - ASSERT(!args->wasfromfl || !args->isfl); - ASSERT(args->agbno % args->alignment == 0); - - if (!args->wasfromfl) { - error = xfs_alloc_update_counters(args->tp, args->pag, - args->agbp, - -((long)(args->len))); - if (error) - return error; - - ASSERT(!xfs_alloc_busy_search(args->mp, 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, - -((long)(args->len))); - } - - XFS_STATS_INC(xs_allocx); - XFS_STATS_ADD(xs_allocb, args->len); - return error; -} - -/* - * 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 */ - int error; - xfs_agblock_t fbno; /* start block of found extent */ - xfs_extlen_t flen; /* length of found extent */ - xfs_agblock_t tbno; /* start block of trimmed extent */ - xfs_extlen_t tlen; /* length of trimmed extent */ - xfs_agblock_t tend; /* end block of trimmed extent */ - int i; /* success/failure of operation */ - - 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. - */ - error = xfs_alloc_lookup_le(bno_cur, args->agbno, args->minlen, &i); - if (error) - goto error0; - if (!i) - goto not_found; - - /* - * Grab the freespace record. - */ - error = xfs_alloc_get_rec(bno_cur, &fbno, &flen, &i); - if (error) - goto error0; - XFS_WANT_CORRUPTED_GOTO(i == 1, error0); - ASSERT(fbno <= args->agbno); - - /* - * Check for overlapping busy extents. - */ - xfs_alloc_busy_trim(args, fbno, flen, &tbno, &tlen); - - /* - * Give up if the start of the extent is busy, or the freespace isn't - * long enough for the minimum request. - */ - if (tbno > args->agbno) - goto not_found; - if (tlen < args->minlen) - goto not_found; - tend = tbno + tlen; - if (tend < args->agbno + args->minlen) - goto not_found; - - /* - * End of extent will be smaller of the freespace end and the - * maximal requested end. - * - * Fix the length according to mod and prod if given. - */ - args->len = XFS_AGBLOCK_MIN(tend, args->agbno + args->maxlen) - - args->agbno; - xfs_alloc_fix_len(args); - if (!xfs_alloc_fix_minleft(args)) - goto not_found; - - ASSERT(args->agbno + args->len <= tend); - - /* - * We are allocating agbno for args->len - * 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)); - error = xfs_alloc_fixup_trees(cnt_cur, bno_cur, fbno, flen, args->agbno, - args->len, XFSA_FIXUP_BNO_OK); - if (error) { - 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); - - args->wasfromfl = 0; - trace_xfs_alloc_exact_done(args); - return 0; - -not_found: - /* Didn't find it, return null. */ - xfs_btree_del_cursor(bno_cur, XFS_BTREE_NOERROR); - args->agbno = NULLAGBLOCK; - trace_xfs_alloc_exact_notfound(args); - return 0; - -error0: - xfs_btree_del_cursor(bno_cur, XFS_BTREE_ERROR); - trace_xfs_alloc_exact_error(args); - return error; -} - -/* - * Search the btree in a given direction via the search cursor and compare - * the records found against the good extent we've already found. - */ -STATIC int -xfs_alloc_find_best_extent( - struct xfs_alloc_arg *args, /* allocation argument structure */ - struct xfs_btree_cur **gcur, /* good cursor */ - struct xfs_btree_cur **scur, /* searching cursor */ - xfs_agblock_t gdiff, /* difference for search comparison */ - xfs_agblock_t *sbno, /* extent found by search */ - xfs_extlen_t *slen, /* extent length */ - xfs_agblock_t *sbnoa, /* aligned extent found by search */ - xfs_extlen_t *slena, /* aligned extent length */ - int dir) /* 0 = search right, 1 = search left */ -{ - xfs_agblock_t new; - xfs_agblock_t sdiff; - int error; - int i; - - /* The good extent is perfect, no need to search. */ - if (!gdiff) - goto out_use_good; - - /* - * Look until we find a better one, run out of space or run off the end. - */ - do { - error = xfs_alloc_get_rec(*scur, sbno, slen, &i); - if (error) - goto error0; - XFS_WANT_CORRUPTED_GOTO(i == 1, error0); - xfs_alloc_compute_aligned(args, *sbno, *slen, sbnoa, slena); - - /* - * The good extent is closer than this one. - */ - if (!dir) { - if (*sbnoa >= args->agbno + gdiff) - goto out_use_good; - } else { - if (*sbnoa <= args->agbno - gdiff) - goto out_use_good; - } - - /* - * Same distance, compare length and pick the best. - */ - if (*slena >= args->minlen) { - args->len = XFS_EXTLEN_MIN(*slena, args->maxlen); - xfs_alloc_fix_len(args); - - sdiff = xfs_alloc_compute_diff(args->agbno, args->len, - args->alignment, *sbnoa, - *slena, &new); - - /* - * Choose closer size and invalidate other cursor. - */ - if (sdiff < gdiff) - goto out_use_search; - goto out_use_good; - } - - if (!dir) - error = xfs_btree_increment(*scur, 0, &i); - else - error = xfs_btree_decrement(*scur, 0, &i); - if (error) - goto error0; - } while (i); - -out_use_good: - xfs_btree_del_cursor(*scur, XFS_BTREE_NOERROR); - *scur = NULL; - return 0; - -out_use_search: - xfs_btree_del_cursor(*gcur, XFS_BTREE_NOERROR); - *gcur = NULL; - return 0; - -error0: - /* caller invalidates cursors */ - 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 */ - 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 */ - int forced = 0; -#if defined(DEBUG) && defined(__KERNEL__) - /* - * Randomly don't execute the first algorithm. - */ - int dofirst; /* set to do first algorithm */ - - dofirst = random32() & 1; -#endif - -restart: - bno_cur_lt = NULL; - bno_cur_gt = NULL; - ltlen = 0; - gtlena = 0; - ltlena = 0; - - /* - * 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); - - /* - * 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); - trace_xfs_alloc_near_noentry(args); - 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(args, ltbno, ltlen, - <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, ltbnoa, ltlena, <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); - ASSERT(ltbno + ltlen <= 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 <= ltbno + ltlen); - /* - * 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(args, ltbno, ltlen, - <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(args, gtbno, gtlen, - >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) { - if (ltlena >= args->minlen) { - /* - * Left side is good, look for a right side entry. - */ - args->len = XFS_EXTLEN_MIN(ltlena, args->maxlen); - xfs_alloc_fix_len(args); - ltdiff = xfs_alloc_compute_diff(args->agbno, args->len, - args->alignment, ltbnoa, ltlena, <new); - - error = xfs_alloc_find_best_extent(args, - &bno_cur_lt, &bno_cur_gt, - ltdiff, >bno, >len, - >bnoa, >lena, - 0 /* search right */); - } else { - ASSERT(gtlena >= args->minlen); - - /* - * Right side is good, look for a left side entry. - */ - args->len = XFS_EXTLEN_MIN(gtlena, args->maxlen); - xfs_alloc_fix_len(args); - gtdiff = xfs_alloc_compute_diff(args->agbno, args->len, - args->alignment, gtbnoa, gtlena, >new); - - error = xfs_alloc_find_best_extent(args, - &bno_cur_gt, &bno_cur_lt, - gtdiff, <bno, <len, - <bnoa, <lena, - 1 /* search left */); - } - - if (error) - goto error0; - } - - /* - * If we couldn't get anything, give up. - */ - if (bno_cur_lt == NULL && bno_cur_gt == NULL) { - if (!forced++) { - trace_xfs_alloc_near_busy(args); - xfs_log_force(args->mp, XFS_LOG_SYNC); - goto restart; - } - - 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. - */ - 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, - ltbnoa, ltlena, <new); - ASSERT(ltnew >= ltbno); - ASSERT(ltnew + rlen <= ltbnoa + ltlena); - 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 */ - int forced = 0; - -restart: - /* - * 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 or we have busy extents that we cannot allocate from, then - * we have to settle for a smaller extent. In the case that there are - * no large extents, this will return the last entry in the tree unless - * the tree is empty. In the case that there are only busy large - * extents, this will return the largest small extent unless there - * are no smaller extents available. - */ - if (!i || forced > 1) { - error = xfs_alloc_ag_vextent_small(args, cnt_cur, - &fbno, &flen, &i); - if (error) - 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); - xfs_alloc_compute_aligned(args, fbno, flen, &rbno, &rlen); - } else { - /* - * Search for a non-busy extent that is large enough. - * If we are at low space, don't check, or if we fall of - * the end of the btree, turn off the busy check and - * restart. - */ - for (;;) { - error = xfs_alloc_get_rec(cnt_cur, &fbno, &flen, &i); - if (error) - goto error0; - XFS_WANT_CORRUPTED_GOTO(i == 1, error0); - - xfs_alloc_compute_aligned(args, fbno, flen, - &rbno, &rlen); - - if (rlen >= args->maxlen) - break; - - error = xfs_btree_increment(cnt_cur, 0, &i); - if (error) - goto error0; - if (i == 0) { - /* - * Our only valid extents must have been busy. - * Make it unbusy by forcing the log out and - * retrying. If we've been here before, forcing - * the log isn't making the extents available, - * which means they have probably been freed in - * this transaction. In that case, we have to - * give up on them and we'll attempt a minlen - * allocation the next time around. - */ - xfs_btree_del_cursor(cnt_cur, - XFS_BTREE_NOERROR); - trace_xfs_alloc_size_busy(args); - if (!forced++) - xfs_log_force(args->mp, XFS_LOG_SYNC); - goto restart; - } - } - } - - /* - * 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. - */ - 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(args, fbno, flen, - &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; - if (rlen < args->minlen) { - if (!forced++) { - xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR); - trace_xfs_alloc_size_busy(args); - xfs_log_force(args->mp, XFS_LOG_SYNC); - goto restart; - } - goto out_nominleft; - } - xfs_alloc_fix_len(args); - - if (!xfs_alloc_fix_minleft(args)) - goto out_nominleft; - 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; - -out_nominleft: - xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR); - trace_xfs_alloc_size_nominleft(args); - args->agbno = NULLAGBLOCK; - return 0; -} - -/* - * 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) { - xfs_alloc_busy_reuse(args->mp, args->agno, fbno, 1, - args->userdata); - - 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 */ - xfs_perag_t *pag; /* per allocation group data */ - - 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. - */ - pag = xfs_perag_get(mp, agno); - error = xfs_alloc_update_counters(tp, pag, agbp, len); - xfs_perag_put(pag); - if (error) - goto error0; - - 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); - - 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; - - 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(!(*bpp)->b_error); - agf = XFS_BUF_TO_AGF(*bpp); - - /* - * Validate the magic number of the agf block. - */ - agf_ok = - agf->agf_magicnum == cpu_to_be32(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_ref(*bpp, 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(!(*bpp)->b_error); - - 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; -} - -static void -xfs_alloc_vextent_worker( - struct work_struct *work) -{ - struct xfs_alloc_arg *args = container_of(work, - struct xfs_alloc_arg, work); - unsigned long pflags; - - /* we are in a transaction context here */ - current_set_flags_nested(&pflags, PF_FSTRANS); - - args->result = __xfs_alloc_vextent(args); - complete(args->done); - - current_restore_flags_nested(&pflags, PF_FSTRANS); -} - - -int /* error */ -xfs_alloc_vextent( - xfs_alloc_arg_t *args) /* allocation argument structure */ -{ - DECLARE_COMPLETION_ONSTACK(done); - - args->done = &done; - INIT_WORK(&args->work, xfs_alloc_vextent_worker); - queue_work(xfs_alloc_wq, &args->work); - wait_for_completion(&done); - return args->result; -} - -/* - * 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; - - /* - * validate that the block number is legal - the enables us to detect - * and handle a silent filesystem corruption rather than crashing. - */ - args.agno = XFS_FSB_TO_AGNO(args.mp, bno); - if (args.agno >= args.mp->m_sb.sb_agcount) - return EFSCORRUPTED; - - args.agbno = XFS_FSB_TO_AGBNO(args.mp, bno); - if (args.agbno >= args.mp->m_sb.sb_agblocks) - return EFSCORRUPTED; - - args.pag = xfs_perag_get(args.mp, args.agno); - ASSERT(args.pag); - - error = xfs_alloc_fix_freelist(&args, XFS_ALLOC_FLAG_FREEING); - if (error) - goto error0; - - /* validate the extent size is legal now we have the agf locked */ - if (args.agbno + len > - be32_to_cpu(XFS_BUF_TO_AGF(args.agbp)->agf_length)) { - error = EFSCORRUPTED; - goto error0; - } - - error = xfs_free_ag_extent(tp, args.agbp, args.agno, args.agbno, len, 0); - if (!error) - xfs_alloc_busy_insert(tp, args.agno, args.agbno, len, 0); -error0: - xfs_perag_put(args.pag); - return error; -} - -void -xfs_alloc_busy_insert( - struct xfs_trans *tp, - xfs_agnumber_t agno, - xfs_agblock_t bno, - xfs_extlen_t len, - unsigned int flags) -{ - struct xfs_busy_extent *new; - struct xfs_busy_extent *busyp; - struct xfs_perag *pag; - struct rb_node **rbp; - struct rb_node *parent = NULL; - - 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_enomem(tp->t_mountp, agno, bno, len); - xfs_trans_set_sync(tp); - return; - } - - new->agno = agno; - new->bno = bno; - new->length = len; - INIT_LIST_HEAD(&new->list); - new->flags = flags; - - /* trace before insert to be able to see failed inserts */ - trace_xfs_alloc_busy(tp->t_mountp, agno, bno, len); - - pag = xfs_perag_get(tp->t_mountp, new->agno); - spin_lock(&pag->pagb_lock); - rbp = &pag->pagb_tree.rb_node; - while (*rbp) { - parent = *rbp; - busyp = rb_entry(parent, struct xfs_busy_extent, rb_node); - - if (new->bno < busyp->bno) { - rbp = &(*rbp)->rb_left; - ASSERT(new->bno + new->length <= busyp->bno); - } else if (new->bno > busyp->bno) { - rbp = &(*rbp)->rb_right; - ASSERT(bno >= busyp->bno + busyp->length); - } else { - ASSERT(0); - } - } - - 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); -} - -/* - * 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. - */ -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); - xfs_perag_put(pag); - return match; -} - -/* - * The found free extent [fbno, fend] overlaps part or all of the given busy - * extent. If the overlap covers the beginning, the end, or all of the busy - * extent, the overlapping portion can be made unbusy and used for the - * allocation. We can't split a busy extent because we can't modify a - * transaction/CIL context busy list, but we can update an entries block - * number or length. - * - * Returns true if the extent can safely be reused, or false if the search - * needs to be restarted. - */ -STATIC bool -xfs_alloc_busy_update_extent( - struct xfs_mount *mp, - struct xfs_perag *pag, - struct xfs_busy_extent *busyp, - xfs_agblock_t fbno, - xfs_extlen_t flen, - bool userdata) -{ - xfs_agblock_t fend = fbno + flen; - xfs_agblock_t bbno = busyp->bno; - xfs_agblock_t bend = bbno + busyp->length; - - /* - * This extent is currently being discarded. Give the thread - * performing the discard a chance to mark the extent unbusy - * and retry. - */ - if (busyp->flags & XFS_ALLOC_BUSY_DISCARDED) { - spin_unlock(&pag->pagb_lock); - delay(1); - spin_lock(&pag->pagb_lock); - return false; - } - - /* - * If there is a busy extent overlapping a user allocation, we have - * no choice but to force the log and retry the search. - * - * Fortunately this does not happen during normal operation, but - * only if the filesystem is very low on space and has to dip into - * the AGFL for normal allocations. - */ - if (userdata) - goto out_force_log; - - if (bbno < fbno && bend > fend) { - /* - * Case 1: - * bbno bend - * +BBBBBBBBBBBBBBBBB+ - * +---------+ - * fbno fend - */ - - /* - * We would have to split the busy extent to be able to track - * it correct, which we cannot do because we would have to - * modify the list of busy extents attached to the transaction - * or CIL context, which is immutable. - * - * Force out the log to clear the busy extent and retry the - * search. - */ - goto out_force_log; - } else if (bbno >= fbno && bend <= fend) { - /* - * Case 2: - * bbno bend - * +BBBBBBBBBBBBBBBBB+ - * +-----------------+ - * fbno fend - * - * Case 3: - * bbno bend - * +BBBBBBBBBBBBBBBBB+ - * +--------------------------+ - * fbno fend - * - * Case 4: - * bbno bend - * +BBBBBBBBBBBBBBBBB+ - * +--------------------------+ - * fbno fend - * - * Case 5: - * bbno bend - * +BBBBBBBBBBBBBBBBB+ - * +-----------------------------------+ - * fbno fend - * - */ - - /* - * The busy extent is fully covered by the extent we are - * allocating, and can simply be removed from the rbtree. - * However we cannot remove it from the immutable list - * tracking busy extents in the transaction or CIL context, - * so set the length to zero to mark it invalid. - * - * We also need to restart the busy extent search from the - * tree root, because erasing the node can rearrange the - * tree topology. - */ - rb_erase(&busyp->rb_node, &pag->pagb_tree); - busyp->length = 0; - return false; - } else if (fend < bend) { - /* - * Case 6: - * bbno bend - * +BBBBBBBBBBBBBBBBB+ - * +---------+ - * fbno fend - * - * Case 7: - * bbno bend - * +BBBBBBBBBBBBBBBBB+ - * +------------------+ - * fbno fend - * - */ - busyp->bno = fend; - } else if (bbno < fbno) { - /* - * Case 8: - * bbno bend - * +BBBBBBBBBBBBBBBBB+ - * +-------------+ - * fbno fend - * - * Case 9: - * bbno bend - * +BBBBBBBBBBBBBBBBB+ - * +----------------------+ - * fbno fend - */ - busyp->length = fbno - busyp->bno; - } else { - ASSERT(0); - } - - trace_xfs_alloc_busy_reuse(mp, pag->pag_agno, fbno, flen); - return true; - -out_force_log: - spin_unlock(&pag->pagb_lock); - xfs_log_force(mp, XFS_LOG_SYNC); - trace_xfs_alloc_busy_force(mp, pag->pag_agno, fbno, flen); - spin_lock(&pag->pagb_lock); - return false; -} - - -/* - * For a given extent [fbno, flen], make sure we can reuse it safely. - */ -void -xfs_alloc_busy_reuse( - struct xfs_mount *mp, - xfs_agnumber_t agno, - xfs_agblock_t fbno, - xfs_extlen_t flen, - bool userdata) -{ - struct xfs_perag *pag; - struct rb_node *rbp; - - ASSERT(flen > 0); - - pag = xfs_perag_get(mp, agno); - spin_lock(&pag->pagb_lock); -restart: - rbp = pag->pagb_tree.rb_node; - while (rbp) { - struct xfs_busy_extent *busyp = - rb_entry(rbp, struct xfs_busy_extent, rb_node); - xfs_agblock_t bbno = busyp->bno; - xfs_agblock_t bend = bbno + busyp->length; - - if (fbno + flen <= bbno) { - rbp = rbp->rb_left; - continue; - } else if (fbno >= bend) { - rbp = rbp->rb_right; - continue; - } - - if (!xfs_alloc_busy_update_extent(mp, pag, busyp, fbno, flen, - userdata)) - goto restart; - } - spin_unlock(&pag->pagb_lock); - xfs_perag_put(pag); -} - -/* - * For a given extent [fbno, flen], search the busy extent list to find a - * subset of the extent that is not busy. If *rlen is smaller than - * args->minlen no suitable extent could be found, and the higher level - * code needs to force out the log and retry the allocation. - */ -STATIC void -xfs_alloc_busy_trim( - struct xfs_alloc_arg *args, - xfs_agblock_t bno, - xfs_extlen_t len, - xfs_agblock_t *rbno, - xfs_extlen_t *rlen) -{ - xfs_agblock_t fbno; - xfs_extlen_t flen; - struct rb_node *rbp; - - ASSERT(len > 0); - - spin_lock(&args->pag->pagb_lock); -restart: - fbno = bno; - flen = len; - rbp = args->pag->pagb_tree.rb_node; - while (rbp && flen >= args->minlen) { - struct xfs_busy_extent *busyp = - rb_entry(rbp, struct xfs_busy_extent, rb_node); - xfs_agblock_t fend = fbno + flen; - xfs_agblock_t bbno = busyp->bno; - xfs_agblock_t bend = bbno + busyp->length; - - if (fend <= bbno) { - rbp = rbp->rb_left; - continue; - } else if (fbno >= bend) { - rbp = rbp->rb_right; - continue; - } - - /* - * If this is a metadata allocation, try to reuse the busy - * extent instead of trimming the allocation. - */ - if (!args->userdata && - !(busyp->flags & XFS_ALLOC_BUSY_DISCARDED)) { - if (!xfs_alloc_busy_update_extent(args->mp, args->pag, - busyp, fbno, flen, - false)) - goto restart; - continue; - } - - if (bbno <= fbno) { - /* start overlap */ - - /* - * Case 1: - * bbno bend - * +BBBBBBBBBBBBBBBBB+ - * +---------+ - * fbno fend - * - * Case 2: - * bbno bend - * +BBBBBBBBBBBBBBBBB+ - * +-------------+ - * fbno fend - * - * Case 3: - * bbno bend - * +BBBBBBBBBBBBBBBBB+ - * +-------------+ - * fbno fend - * - * Case 4: - * bbno bend - * +BBBBBBBBBBBBBBBBB+ - * +-----------------+ - * fbno fend - * - * No unbusy region in extent, return failure. - */ - if (fend <= bend) - goto fail; - - /* - * Case 5: - * bbno bend - * +BBBBBBBBBBBBBBBBB+ - * +----------------------+ - * fbno fend - * - * Case 6: - * bbno bend - * +BBBBBBBBBBBBBBBBB+ - * +--------------------------+ - * fbno fend - * - * Needs to be trimmed to: - * +-------+ - * fbno fend - */ - fbno = bend; - } else if (bend >= fend) { - /* end overlap */ - - /* - * Case 7: - * bbno bend - * +BBBBBBBBBBBBBBBBB+ - * +------------------+ - * fbno fend - * - * Case 8: - * bbno bend - * +BBBBBBBBBBBBBBBBB+ - * +--------------------------+ - * fbno fend - * - * Needs to be trimmed to: - * +-------+ - * fbno fend - */ - fend = bbno; - } else { - /* middle overlap */ - - /* - * Case 9: - * bbno bend - * +BBBBBBBBBBBBBBBBB+ - * +-----------------------------------+ - * fbno fend - * - * Can be trimmed to: - * +-------+ OR +-------+ - * fbno fend fbno fend - * - * Backward allocation leads to significant - * fragmentation of directories, which degrades - * directory performance, therefore we always want to - * choose the option that produces forward allocation - * patterns. - * Preferring the lower bno extent will make the next - * request use "fend" as the start of the next - * allocation; if the segment is no longer busy at - * that point, we'll get a contiguous allocation, but - * even if it is still busy, we will get a forward - * allocation. - * We try to avoid choosing the segment at "bend", - * because that can lead to the next allocation - * taking the segment at "fbno", which would be a - * backward allocation. We only use the segment at - * "fbno" if it is much larger than the current - * requested size, because in that case there's a - * good chance subsequent allocations will be - * contiguous. - */ - if (bbno - fbno >= args->maxlen) { - /* left candidate fits perfect */ - fend = bbno; - } else if (fend - bend >= args->maxlen * 4) { - /* right candidate has enough free space */ - fbno = bend; - } else if (bbno - fbno >= args->minlen) { - /* left candidate fits minimum requirement */ - fend = bbno; - } else { - goto fail; - } - } - - flen = fend - fbno; - } - spin_unlock(&args->pag->pagb_lock); - - if (fbno != bno || flen != len) { - trace_xfs_alloc_busy_trim(args->mp, args->agno, bno, len, - fbno, flen); - } - *rbno = fbno; - *rlen = flen; - return; -fail: - /* - * Return a zero extent length as failure indications. All callers - * re-check if the trimmed extent satisfies the minlen requirement. - */ - spin_unlock(&args->pag->pagb_lock); - trace_xfs_alloc_busy_trim(args->mp, args->agno, bno, len, fbno, 0); - *rbno = fbno; - *rlen = 0; -} - -static void -xfs_alloc_busy_clear_one( - struct xfs_mount *mp, - struct xfs_perag *pag, - struct xfs_busy_extent *busyp) -{ - if (busyp->length) { - trace_xfs_alloc_busy_clear(mp, busyp->agno, busyp->bno, - busyp->length); - rb_erase(&busyp->rb_node, &pag->pagb_tree); - } - - list_del_init(&busyp->list); - kmem_free(busyp); -} - -/* - * Remove all extents on the passed in list from the busy extents tree. - * If do_discard is set skip extents that need to be discarded, and mark - * these as undergoing a discard operation instead. - */ -void -xfs_alloc_busy_clear( - struct xfs_mount *mp, - struct list_head *list, - bool do_discard) -{ - struct xfs_busy_extent *busyp, *n; - struct xfs_perag *pag = NULL; - xfs_agnumber_t agno = NULLAGNUMBER; - - list_for_each_entry_safe(busyp, n, list, list) { - if (busyp->agno != agno) { - if (pag) { - spin_unlock(&pag->pagb_lock); - xfs_perag_put(pag); - } - pag = xfs_perag_get(mp, busyp->agno); - spin_lock(&pag->pagb_lock); - agno = busyp->agno; - } - - if (do_discard && busyp->length && - !(busyp->flags & XFS_ALLOC_BUSY_SKIP_DISCARD)) - busyp->flags = XFS_ALLOC_BUSY_DISCARDED; - else - xfs_alloc_busy_clear_one(mp, pag, busyp); - } - - if (pag) { - spin_unlock(&pag->pagb_lock); - xfs_perag_put(pag); - } -} - -/* - * Callback for list_sort to sort busy extents by the AG they reside in. - */ -int -xfs_busy_extent_ag_cmp( - void *priv, - struct list_head *a, - struct list_head *b) -{ - return container_of(a, struct xfs_busy_extent, list)->agno - - container_of(b, struct xfs_busy_extent, list)->agno; -} |