zte's code,first commit
Change-Id: I9a04da59e459a9bc0d67f101f700d9d7dc8d681b
diff --git a/ap/os/linux/linux-3.4.x/fs/xfs/xfs_alloc.c b/ap/os/linux/linux-3.4.x/fs/xfs/xfs_alloc.c
new file mode 100644
index 0000000..0f0df27
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/fs/xfs/xfs_alloc.c
@@ -0,0 +1,3074 @@
+/*
+ * 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;
+}