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linux/fs/xfs/xfs_alloc.c
David Chinner 92821e2ba4 [XFS] Lazy Superblock Counters 
When we have a couple of hundred transactions on the fly at once, they all
typically modify the on disk superblock in some way.
create/unclink/mkdir/rmdir modify inode counts, allocation/freeing modify
free block counts.

When these counts are modified in a transaction, they must eventually lock
the superblock buffer and apply the mods. The buffer then remains locked
until the transaction is committed into the incore log buffer. The result
of this is that with enough transactions on the fly the incore superblock
buffer becomes a bottleneck.

The result of contention on the incore superblock buffer is that
transaction rates fall - the more pressure that is put on the superblock
buffer, the slower things go.

The key to removing the contention is to not require the superblock fields
in question to be locked. We do that by not marking the superblock dirty
in the transaction. IOWs, we modify the incore superblock but do not
modify the cached superblock buffer. In short, we do not log superblock
modifications to critical fields in the superblock on every transaction.
In fact we only do it just before we write the superblock to disk every
sync period or just before unmount.

This creates an interesting problem - if we don't log or write out the
fields in every transaction, then how do the values get recovered after a
crash? the answer is simple - we keep enough duplicate, logged information
in other structures that we can reconstruct the correct count after log
recovery has been performed.

It is the AGF and AGI structures that contain the duplicate information;
after recovery, we walk every AGI and AGF and sum their individual
counters to get the correct value, and we do a transaction into the log to
correct them. An optimisation of this is that if we have a clean unmount
record, we know the value in the superblock is correct, so we can avoid
the summation walk under normal conditions and so mount/recovery times do
not change under normal operation.

One wrinkle that was discovered during development was that the blocks
used in the freespace btrees are never accounted for in the AGF counters.
This was once a valid optimisation to make; when the filesystem is full,
the free space btrees are empty and consume no space. Hence when it
matters, the "accounting" is correct. But that means the when we do the
AGF summations, we would not have a correct count and xfs_check would
complain. Hence a new counter was added to track the number of blocks used
by the free space btrees. This is an *on-disk format change*.

As a result of this, lazy superblock counters are a mkfs option and at the
moment on linux there is no way to convert an old filesystem. This is
possible - xfs_db can be used to twiddle the right bits and then
xfs_repair will do the format conversion for you. Similarly, you can
convert backwards as well. At some point we'll add functionality to
xfs_admin to do the bit twiddling easily....

SGI-PV: 964999
SGI-Modid: xfs-linux-melb:xfs-kern:28652a

Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Tim Shimmin <tes@sgi.com>
2007-07-14 15:28:50 +10:00

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/*
* Copyright (c) 2000-2002,2005 Silicon Graphics, Inc.
* All Rights Reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it would be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "xfs.h"
#include "xfs_fs.h"
#include "xfs_types.h"
#include "xfs_bit.h"
#include "xfs_log.h"
#include "xfs_inum.h"
#include "xfs_trans.h"
#include "xfs_sb.h"
#include "xfs_ag.h"
#include "xfs_dir2.h"
#include "xfs_dmapi.h"
#include "xfs_mount.h"
#include "xfs_bmap_btree.h"
#include "xfs_alloc_btree.h"
#include "xfs_ialloc_btree.h"
#include "xfs_dir2_sf.h"
#include "xfs_attr_sf.h"
#include "xfs_dinode.h"
#include "xfs_inode.h"
#include "xfs_btree.h"
#include "xfs_ialloc.h"
#include "xfs_alloc.h"
#include "xfs_error.h"
#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_search_busy(xfs_trans_t *tp,
xfs_agnumber_t agno,
xfs_agblock_t bno,
xfs_extlen_t len);
#if defined(XFS_ALLOC_TRACE)
ktrace_t *xfs_alloc_trace_buf;
#define TRACE_ALLOC(s,a) \
xfs_alloc_trace_alloc(fname, s, a, __LINE__)
#define TRACE_FREE(s,a,b,x,f) \
xfs_alloc_trace_free(fname, s, mp, a, b, x, f, __LINE__)
#define TRACE_MODAGF(s,a,f) \
xfs_alloc_trace_modagf(fname, s, mp, a, f, __LINE__)
#define TRACE_BUSY(fname,s,ag,agb,l,sl,tp) \
xfs_alloc_trace_busy(fname, s, mp, ag, agb, l, sl, tp, XFS_ALLOC_KTRACE_BUSY, __LINE__)
#define TRACE_UNBUSY(fname,s,ag,sl,tp) \
xfs_alloc_trace_busy(fname, s, mp, ag, -1, -1, sl, tp, XFS_ALLOC_KTRACE_UNBUSY, __LINE__)
#define TRACE_BUSYSEARCH(fname,s,ag,agb,l,sl,tp) \
xfs_alloc_trace_busy(fname, s, mp, ag, agb, l, sl, tp, XFS_ALLOC_KTRACE_BUSYSEARCH, __LINE__)
#else
#define TRACE_ALLOC(s,a)
#define TRACE_FREE(s,a,b,x,f)
#define TRACE_MODAGF(s,a,f)
#define TRACE_BUSY(s,a,ag,agb,l,sl,tp)
#define TRACE_UNBUSY(fname,s,ag,sl,tp)
#define TRACE_BUSYSEARCH(fname,s,ag,agb,l,sl,tp)
#endif /* XFS_ALLOC_TRACE */
/*
* Prototypes for per-ag allocation routines
*/
STATIC int xfs_alloc_ag_vextent_exact(xfs_alloc_arg_t *);
STATIC int xfs_alloc_ag_vextent_near(xfs_alloc_arg_t *);
STATIC int xfs_alloc_ag_vextent_size(xfs_alloc_arg_t *);
STATIC int xfs_alloc_ag_vextent_small(xfs_alloc_arg_t *,
xfs_btree_cur_t *, xfs_agblock_t *, xfs_extlen_t *, int *);
/*
* Internal functions.
*/
/*
* Compute aligned version of the found extent.
* Takes alignment and min length into account.
*/
STATIC int /* success (>= minlen) */
xfs_alloc_compute_aligned(
xfs_agblock_t foundbno, /* starting block in found extent */
xfs_extlen_t foundlen, /* length in found extent */
xfs_extlen_t alignment, /* alignment for allocation */
xfs_extlen_t minlen, /* minimum length for allocation */
xfs_agblock_t *resbno, /* result block number */
xfs_extlen_t *reslen) /* result length */
{
xfs_agblock_t bno;
xfs_extlen_t diff;
xfs_extlen_t len;
if (alignment > 1 && foundlen >= minlen) {
bno = roundup(foundbno, alignment);
diff = bno - foundbno;
len = diff >= foundlen ? 0 : foundlen - diff;
} else {
bno = foundbno;
len = foundlen;
}
*resbno = bno;
*reslen = len;
return len >= minlen;
}
/*
* Compute best start block and diff for "near" allocations.
* freelen >= wantlen already checked by caller.
*/
STATIC xfs_extlen_t /* difference value (absolute) */
xfs_alloc_compute_diff(
xfs_agblock_t wantbno, /* target starting block */
xfs_extlen_t wantlen, /* target length */
xfs_extlen_t alignment, /* target alignment */
xfs_agblock_t freebno, /* freespace's starting block */
xfs_extlen_t freelen, /* freespace's length */
xfs_agblock_t *newbnop) /* result: best start block from free */
{
xfs_agblock_t freeend; /* end of freespace extent */
xfs_agblock_t newbno1; /* return block number */
xfs_agblock_t newbno2; /* other new block number */
xfs_extlen_t newlen1=0; /* length with newbno1 */
xfs_extlen_t newlen2=0; /* length with newbno2 */
xfs_agblock_t wantend; /* end of target extent */
ASSERT(freelen >= wantlen);
freeend = freebno + freelen;
wantend = wantbno + wantlen;
if (freebno >= wantbno) {
if ((newbno1 = roundup(freebno, alignment)) >= freeend)
newbno1 = NULLAGBLOCK;
} else if (freeend >= wantend && alignment > 1) {
newbno1 = roundup(wantbno, alignment);
newbno2 = newbno1 - alignment;
if (newbno1 >= freeend)
newbno1 = NULLAGBLOCK;
else
newlen1 = XFS_EXTLEN_MIN(wantlen, freeend - newbno1);
if (newbno2 < freebno)
newbno2 = NULLAGBLOCK;
else
newlen2 = XFS_EXTLEN_MIN(wantlen, freeend - newbno2);
if (newbno1 != NULLAGBLOCK && newbno2 != NULLAGBLOCK) {
if (newlen1 < newlen2 ||
(newlen1 == newlen2 &&
XFS_ABSDIFF(newbno1, wantbno) >
XFS_ABSDIFF(newbno2, wantbno)))
newbno1 = newbno2;
} else if (newbno2 != NULLAGBLOCK)
newbno1 = newbno2;
} else if (freeend >= wantend) {
newbno1 = wantbno;
} else if (alignment > 1) {
newbno1 = roundup(freeend - wantlen, alignment);
if (newbno1 > freeend - wantlen &&
newbno1 - alignment >= freebno)
newbno1 -= alignment;
else if (newbno1 >= freeend)
newbno1 = NULLAGBLOCK;
} else
newbno1 = freeend - wantlen;
*newbnop = newbno1;
return newbno1 == NULLAGBLOCK ? 0 : XFS_ABSDIFF(newbno1, wantbno);
}
/*
* Fix up the length, based on mod and prod.
* len should be k * prod + mod for some k.
* If len is too small it is returned unchanged.
* If len hits maxlen it is left alone.
*/
STATIC void
xfs_alloc_fix_len(
xfs_alloc_arg_t *args) /* allocation argument structure */
{
xfs_extlen_t k;
xfs_extlen_t rlen;
ASSERT(args->mod < args->prod);
rlen = args->len;
ASSERT(rlen >= args->minlen);
ASSERT(rlen <= args->maxlen);
if (args->prod <= 1 || rlen < args->mod || rlen == args->maxlen ||
(args->mod == 0 && rlen < args->prod))
return;
k = rlen % args->prod;
if (k == args->mod)
return;
if (k > args->mod) {
if ((int)(rlen = rlen - k - args->mod) < (int)args->minlen)
return;
} else {
if ((int)(rlen = rlen - args->prod - (args->mod - k)) <
(int)args->minlen)
return;
}
ASSERT(rlen >= args->minlen);
ASSERT(rlen <= args->maxlen);
args->len = rlen;
}
/*
* Fix up length if there is too little space left in the a.g.
* Return 1 if ok, 0 if too little, should give up.
*/
STATIC int
xfs_alloc_fix_minleft(
xfs_alloc_arg_t *args) /* allocation argument structure */
{
xfs_agf_t *agf; /* a.g. freelist header */
int diff; /* free space difference */
if (args->minleft == 0)
return 1;
agf = XFS_BUF_TO_AGF(args->agbp);
diff = be32_to_cpu(agf->agf_freeblks)
+ be32_to_cpu(agf->agf_flcount)
- args->len - args->minleft;
if (diff >= 0)
return 1;
args->len += diff; /* shrink the allocated space */
if (args->len >= args->minlen)
return 1;
args->agbno = NULLAGBLOCK;
return 0;
}
/*
* Update the two btrees, logically removing from freespace the extent
* starting at rbno, rlen blocks. The extent is contained within the
* actual (current) free extent fbno for flen blocks.
* Flags are passed in indicating whether the cursors are set to the
* relevant records.
*/
STATIC int /* error code */
xfs_alloc_fixup_trees(
xfs_btree_cur_t *cnt_cur, /* cursor for by-size btree */
xfs_btree_cur_t *bno_cur, /* cursor for by-block btree */
xfs_agblock_t fbno, /* starting block of free extent */
xfs_extlen_t flen, /* length of free extent */
xfs_agblock_t rbno, /* starting block of returned extent */
xfs_extlen_t rlen, /* length of returned extent */
int flags) /* flags, XFSA_FIXUP_... */
{
int error; /* error code */
int i; /* operation results */
xfs_agblock_t nfbno1; /* first new free startblock */
xfs_agblock_t nfbno2; /* second new free startblock */
xfs_extlen_t nflen1=0; /* first new free length */
xfs_extlen_t nflen2=0; /* second new free length */
/*
* Look up the record in the by-size tree if necessary.
*/
if (flags & XFSA_FIXUP_CNT_OK) {
#ifdef DEBUG
if ((error = xfs_alloc_get_rec(cnt_cur, &nfbno1, &nflen1, &i)))
return error;
XFS_WANT_CORRUPTED_RETURN(
i == 1 && nfbno1 == fbno && nflen1 == flen);
#endif
} else {
if ((error = xfs_alloc_lookup_eq(cnt_cur, fbno, flen, &i)))
return error;
XFS_WANT_CORRUPTED_RETURN(i == 1);
}
/*
* Look up the record in the by-block tree if necessary.
*/
if (flags & XFSA_FIXUP_BNO_OK) {
#ifdef DEBUG
if ((error = xfs_alloc_get_rec(bno_cur, &nfbno1, &nflen1, &i)))
return error;
XFS_WANT_CORRUPTED_RETURN(
i == 1 && nfbno1 == fbno && nflen1 == flen);
#endif
} else {
if ((error = xfs_alloc_lookup_eq(bno_cur, fbno, flen, &i)))
return error;
XFS_WANT_CORRUPTED_RETURN(i == 1);
}
#ifdef DEBUG
{
xfs_alloc_block_t *bnoblock;
xfs_alloc_block_t *cntblock;
if (bno_cur->bc_nlevels == 1 &&
cnt_cur->bc_nlevels == 1) {
bnoblock = XFS_BUF_TO_ALLOC_BLOCK(bno_cur->bc_bufs[0]);
cntblock = XFS_BUF_TO_ALLOC_BLOCK(cnt_cur->bc_bufs[0]);
XFS_WANT_CORRUPTED_RETURN(
be16_to_cpu(bnoblock->bb_numrecs) ==
be16_to_cpu(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_alloc_delete(cnt_cur, &i)))
return error;
XFS_WANT_CORRUPTED_RETURN(i == 1);
/*
* Add new by-size btree entry(s).
*/
if (nfbno1 != NULLAGBLOCK) {
if ((error = xfs_alloc_lookup_eq(cnt_cur, nfbno1, nflen1, &i)))
return error;
XFS_WANT_CORRUPTED_RETURN(i == 0);
if ((error = xfs_alloc_insert(cnt_cur, &i)))
return error;
XFS_WANT_CORRUPTED_RETURN(i == 1);
}
if (nfbno2 != NULLAGBLOCK) {
if ((error = xfs_alloc_lookup_eq(cnt_cur, nfbno2, nflen2, &i)))
return error;
XFS_WANT_CORRUPTED_RETURN(i == 0);
if ((error = xfs_alloc_insert(cnt_cur, &i)))
return error;
XFS_WANT_CORRUPTED_RETURN(i == 1);
}
/*
* Fix up the by-block btree entry(s).
*/
if (nfbno1 == NULLAGBLOCK) {
/*
* No remaining freespace, just delete the by-block tree entry.
*/
if ((error = xfs_alloc_delete(bno_cur, &i)))
return error;
XFS_WANT_CORRUPTED_RETURN(i == 1);
} else {
/*
* Update the by-block entry to start later|be shorter.
*/
if ((error = xfs_alloc_update(bno_cur, nfbno1, nflen1)))
return error;
}
if (nfbno2 != NULLAGBLOCK) {
/*
* 2 resulting free entries, need to add one.
*/
if ((error = xfs_alloc_lookup_eq(bno_cur, nfbno2, nflen2, &i)))
return error;
XFS_WANT_CORRUPTED_RETURN(i == 0);
if ((error = xfs_alloc_insert(bno_cur, &i)))
return error;
XFS_WANT_CORRUPTED_RETURN(i == 1);
}
return 0;
}
/*
* Read in the allocation group free block array.
*/
STATIC int /* error */
xfs_alloc_read_agfl(
xfs_mount_t *mp, /* mount point structure */
xfs_trans_t *tp, /* transaction pointer */
xfs_agnumber_t agno, /* allocation group number */
xfs_buf_t **bpp) /* buffer for the ag free block array */
{
xfs_buf_t *bp; /* return value */
int error;
ASSERT(agno != NULLAGNUMBER);
error = xfs_trans_read_buf(
mp, tp, mp->m_ddev_targp,
XFS_AG_DADDR(mp, agno, XFS_AGFL_DADDR(mp)),
XFS_FSS_TO_BB(mp, 1), 0, &bp);
if (error)
return error;
ASSERT(bp);
ASSERT(!XFS_BUF_GETERROR(bp));
XFS_BUF_SET_VTYPE_REF(bp, B_FS_AGFL, XFS_AGFL_REF);
*bpp = bp;
return 0;
}
#if defined(XFS_ALLOC_TRACE)
/*
* Add an allocation trace entry for an alloc call.
*/
STATIC void
xfs_alloc_trace_alloc(
char *name, /* function tag string */
char *str, /* additional string */
xfs_alloc_arg_t *args, /* allocation argument structure */
int line) /* source line number */
{
ktrace_enter(xfs_alloc_trace_buf,
(void *)(__psint_t)(XFS_ALLOC_KTRACE_ALLOC | (line << 16)),
(void *)name,
(void *)str,
(void *)args->mp,
(void *)(__psunsigned_t)args->agno,
(void *)(__psunsigned_t)args->agbno,
(void *)(__psunsigned_t)args->minlen,
(void *)(__psunsigned_t)args->maxlen,
(void *)(__psunsigned_t)args->mod,
(void *)(__psunsigned_t)args->prod,
(void *)(__psunsigned_t)args->minleft,
(void *)(__psunsigned_t)args->total,
(void *)(__psunsigned_t)args->alignment,
(void *)(__psunsigned_t)args->len,
(void *)((((__psint_t)args->type) << 16) |
(__psint_t)args->otype),
(void *)(__psint_t)((args->wasdel << 3) |
(args->wasfromfl << 2) |
(args->isfl << 1) |
(args->userdata << 0)));
}
/*
* Add an allocation trace entry for a free call.
*/
STATIC void
xfs_alloc_trace_free(
char *name, /* function tag string */
char *str, /* additional string */
xfs_mount_t *mp, /* file system mount point */
xfs_agnumber_t agno, /* allocation group number */
xfs_agblock_t agbno, /* a.g. relative block number */
xfs_extlen_t len, /* length of extent */
int isfl, /* set if is freelist allocation/free */
int line) /* source line number */
{
ktrace_enter(xfs_alloc_trace_buf,
(void *)(__psint_t)(XFS_ALLOC_KTRACE_FREE | (line << 16)),
(void *)name,
(void *)str,
(void *)mp,
(void *)(__psunsigned_t)agno,
(void *)(__psunsigned_t)agbno,
(void *)(__psunsigned_t)len,
(void *)(__psint_t)isfl,
NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL);
}
/*
* Add an allocation trace entry for modifying an agf.
*/
STATIC void
xfs_alloc_trace_modagf(
char *name, /* function tag string */
char *str, /* additional string */
xfs_mount_t *mp, /* file system mount point */
xfs_agf_t *agf, /* new agf value */
int flags, /* logging flags for agf */
int line) /* source line number */
{
ktrace_enter(xfs_alloc_trace_buf,
(void *)(__psint_t)(XFS_ALLOC_KTRACE_MODAGF | (line << 16)),
(void *)name,
(void *)str,
(void *)mp,
(void *)(__psint_t)flags,
(void *)(__psunsigned_t)be32_to_cpu(agf->agf_seqno),
(void *)(__psunsigned_t)be32_to_cpu(agf->agf_length),
(void *)(__psunsigned_t)be32_to_cpu(agf->agf_roots[XFS_BTNUM_BNO]),
(void *)(__psunsigned_t)be32_to_cpu(agf->agf_roots[XFS_BTNUM_CNT]),
(void *)(__psunsigned_t)be32_to_cpu(agf->agf_levels[XFS_BTNUM_BNO]),
(void *)(__psunsigned_t)be32_to_cpu(agf->agf_levels[XFS_BTNUM_CNT]),
(void *)(__psunsigned_t)be32_to_cpu(agf->agf_flfirst),
(void *)(__psunsigned_t)be32_to_cpu(agf->agf_fllast),
(void *)(__psunsigned_t)be32_to_cpu(agf->agf_flcount),
(void *)(__psunsigned_t)be32_to_cpu(agf->agf_freeblks),
(void *)(__psunsigned_t)be32_to_cpu(agf->agf_longest));
}
STATIC void
xfs_alloc_trace_busy(
char *name, /* function tag string */
char *str, /* additional string */
xfs_mount_t *mp, /* file system mount point */
xfs_agnumber_t agno, /* allocation group number */
xfs_agblock_t agbno, /* a.g. relative block number */
xfs_extlen_t len, /* length of extent */
int slot, /* perag Busy slot */
xfs_trans_t *tp,
int trtype, /* type: add, delete, search */
int line) /* source line number */
{
ktrace_enter(xfs_alloc_trace_buf,
(void *)(__psint_t)(trtype | (line << 16)),
(void *)name,
(void *)str,
(void *)mp,
(void *)(__psunsigned_t)agno,
(void *)(__psunsigned_t)agbno,
(void *)(__psunsigned_t)len,
(void *)(__psint_t)slot,
(void *)tp,
NULL, NULL, NULL, NULL, NULL, NULL, NULL);
}
#endif /* XFS_ALLOC_TRACE */
/*
* Allocation group level functions.
*/
/*
* Allocate a variable extent in the allocation group agno.
* Type and bno are used to determine where in the allocation group the
* extent will start.
* Extent's length (returned in *len) will be between minlen and maxlen,
* and of the form k * prod + mod unless there's nothing that large.
* Return the starting a.g. block, or NULLAGBLOCK if we can't do it.
*/
STATIC int /* error */
xfs_alloc_ag_vextent(
xfs_alloc_arg_t *args) /* argument structure for allocation */
{
int error=0;
#ifdef XFS_ALLOC_TRACE
static char fname[] = "xfs_alloc_ag_vextent";
#endif
ASSERT(args->minlen > 0);
ASSERT(args->maxlen > 0);
ASSERT(args->minlen <= args->maxlen);
ASSERT(args->mod < args->prod);
ASSERT(args->alignment > 0);
/*
* Branch to correct routine based on the type.
*/
args->wasfromfl = 0;
switch (args->type) {
case XFS_ALLOCTYPE_THIS_AG:
error = xfs_alloc_ag_vextent_size(args);
break;
case XFS_ALLOCTYPE_NEAR_BNO:
error = xfs_alloc_ag_vextent_near(args);
break;
case XFS_ALLOCTYPE_THIS_BNO:
error = xfs_alloc_ag_vextent_exact(args);
break;
default:
ASSERT(0);
/* NOTREACHED */
}
if (error)
return error;
/*
* If the allocation worked, need to change the agf structure
* (and log it), and the superblock.
*/
if (args->agbno != NULLAGBLOCK) {
xfs_agf_t *agf; /* allocation group freelist header */
#ifdef XFS_ALLOC_TRACE
xfs_mount_t *mp = args->mp;
#endif
long slen = (long)args->len;
ASSERT(args->len >= args->minlen && args->len <= args->maxlen);
ASSERT(!(args->wasfromfl) || !args->isfl);
ASSERT(args->agbno % args->alignment == 0);
if (!(args->wasfromfl)) {
agf = XFS_BUF_TO_AGF(args->agbp);
be32_add(&agf->agf_freeblks, -(args->len));
xfs_trans_agblocks_delta(args->tp,
-((long)(args->len)));
args->pag->pagf_freeblks -= args->len;
ASSERT(be32_to_cpu(agf->agf_freeblks) <=
be32_to_cpu(agf->agf_length));
TRACE_MODAGF(NULL, agf, XFS_AGF_FREEBLKS);
xfs_alloc_log_agf(args->tp, args->agbp,
XFS_AGF_FREEBLKS);
/* search the busylist for these blocks */
xfs_alloc_search_busy(args->tp, args->agno,
args->agbno, args->len);
}
if (!args->isfl)
xfs_trans_mod_sb(args->tp,
args->wasdel ? XFS_TRANS_SB_RES_FDBLOCKS :
XFS_TRANS_SB_FDBLOCKS, -slen);
XFS_STATS_INC(xs_allocx);
XFS_STATS_ADD(xs_allocb, args->len);
}
return 0;
}
/*
* Allocate a variable extent at exactly agno/bno.
* Extent's length (returned in *len) will be between minlen and maxlen,
* and of the form k * prod + mod unless there's nothing that large.
* Return the starting a.g. block (bno), or NULLAGBLOCK if we can't do it.
*/
STATIC int /* error */
xfs_alloc_ag_vextent_exact(
xfs_alloc_arg_t *args) /* allocation argument structure */
{
xfs_btree_cur_t *bno_cur;/* by block-number btree cursor */
xfs_btree_cur_t *cnt_cur;/* by count btree cursor */
xfs_agblock_t end; /* end of allocated extent */
int error;
xfs_agblock_t fbno; /* start block of found extent */
xfs_agblock_t fend; /* end block of found extent */
xfs_extlen_t flen; /* length of found extent */
#ifdef XFS_ALLOC_TRACE
static char fname[] = "xfs_alloc_ag_vextent_exact";
#endif
int i; /* success/failure of operation */
xfs_agblock_t maxend; /* end of maximal extent */
xfs_agblock_t minend; /* end of minimal extent */
xfs_extlen_t rlen; /* length of returned extent */
ASSERT(args->alignment == 1);
/*
* Allocate/initialize a cursor for the by-number freespace btree.
*/
bno_cur = xfs_btree_init_cursor(args->mp, args->tp, args->agbp,
args->agno, XFS_BTNUM_BNO, NULL, 0);
/*
* Lookup bno and minlen in the btree (minlen is irrelevant, really).
* Look for the closest free block <= bno, it must contain bno
* if any free block does.
*/
if ((error = xfs_alloc_lookup_le(bno_cur, args->agbno, args->minlen, &i)))
goto error0;
if (!i) {
/*
* Didn't find it, return null.
*/
xfs_btree_del_cursor(bno_cur, XFS_BTREE_NOERROR);
args->agbno = NULLAGBLOCK;
return 0;
}
/*
* Grab the freespace record.
*/
if ((error = xfs_alloc_get_rec(bno_cur, &fbno, &flen, &i)))
goto error0;
XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
ASSERT(fbno <= args->agbno);
minend = args->agbno + args->minlen;
maxend = args->agbno + args->maxlen;
fend = fbno + flen;
/*
* Give up if the freespace isn't long enough for the minimum request.
*/
if (fend < minend) {
xfs_btree_del_cursor(bno_cur, XFS_BTREE_NOERROR);
args->agbno = NULLAGBLOCK;
return 0;
}
/*
* End of extent will be smaller of the freespace end and the
* maximal requested end.
*/
end = XFS_AGBLOCK_MIN(fend, maxend);
/*
* Fix the length according to mod and prod if given.
*/
args->len = end - args->agbno;
xfs_alloc_fix_len(args);
if (!xfs_alloc_fix_minleft(args)) {
xfs_btree_del_cursor(bno_cur, XFS_BTREE_NOERROR);
return 0;
}
rlen = args->len;
ASSERT(args->agbno + rlen <= fend);
end = args->agbno + rlen;
/*
* We are allocating agbno for rlen [agbno .. end]
* Allocate/initialize a cursor for the by-size btree.
*/
cnt_cur = xfs_btree_init_cursor(args->mp, args->tp, args->agbp,
args->agno, XFS_BTNUM_CNT, NULL, 0);
ASSERT(args->agbno + args->len <=
be32_to_cpu(XFS_BUF_TO_AGF(args->agbp)->agf_length));
if ((error = xfs_alloc_fixup_trees(cnt_cur, bno_cur, fbno, flen,
args->agbno, args->len, XFSA_FIXUP_BNO_OK))) {
xfs_btree_del_cursor(cnt_cur, XFS_BTREE_ERROR);
goto error0;
}
xfs_btree_del_cursor(bno_cur, XFS_BTREE_NOERROR);
xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
TRACE_ALLOC("normal", args);
args->wasfromfl = 0;
return 0;
error0:
xfs_btree_del_cursor(bno_cur, XFS_BTREE_ERROR);
TRACE_ALLOC("error", args);
return error;
}
/*
* Allocate a variable extent near bno in the allocation group agno.
* Extent's length (returned in len) will be between minlen and maxlen,
* and of the form k * prod + mod unless there's nothing that large.
* Return the starting a.g. block, or NULLAGBLOCK if we can't do it.
*/
STATIC int /* error */
xfs_alloc_ag_vextent_near(
xfs_alloc_arg_t *args) /* allocation argument structure */
{
xfs_btree_cur_t *bno_cur_gt; /* cursor for bno btree, right side */
xfs_btree_cur_t *bno_cur_lt; /* cursor for bno btree, left side */
xfs_btree_cur_t *cnt_cur; /* cursor for count btree */
#ifdef XFS_ALLOC_TRACE
static char fname[] = "xfs_alloc_ag_vextent_near";
#endif
xfs_agblock_t gtbno; /* start bno of right side entry */
xfs_agblock_t gtbnoa; /* aligned ... */
xfs_extlen_t gtdiff; /* difference to right side entry */
xfs_extlen_t gtlen; /* length of right side entry */
xfs_extlen_t gtlena; /* aligned ... */
xfs_agblock_t gtnew; /* useful start bno of right side */
int error; /* error code */
int i; /* result code, temporary */
int j; /* result code, temporary */
xfs_agblock_t ltbno; /* start bno of left side entry */
xfs_agblock_t ltbnoa; /* aligned ... */
xfs_extlen_t ltdiff; /* difference to left side entry */
/*REFERENCED*/
xfs_agblock_t ltend; /* end bno of left side entry */
xfs_extlen_t ltlen; /* length of left side entry */
xfs_extlen_t ltlena; /* aligned ... */
xfs_agblock_t ltnew; /* useful start bno of left side */
xfs_extlen_t rlen; /* length of returned extent */
#if defined(DEBUG) && defined(__KERNEL__)
/*
* Randomly don't execute the first algorithm.
*/
int dofirst; /* set to do first algorithm */
dofirst = random32() & 1;
#endif
/*
* Get a cursor for the by-size btree.
*/
cnt_cur = xfs_btree_init_cursor(args->mp, args->tp, args->agbp,
args->agno, XFS_BTNUM_CNT, NULL, 0);
ltlen = 0;
bno_cur_lt = bno_cur_gt = NULL;
/*
* See if there are any free extents as big as maxlen.
*/
if ((error = xfs_alloc_lookup_ge(cnt_cur, 0, args->maxlen, &i)))
goto error0;
/*
* If none, then pick up the last entry in the tree unless the
* tree is empty.
*/
if (!i) {
if ((error = xfs_alloc_ag_vextent_small(args, cnt_cur, &ltbno,
&ltlen, &i)))
goto error0;
if (i == 0 || ltlen == 0) {
xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
return 0;
}
ASSERT(i == 1);
}
args->wasfromfl = 0;
/*
* First algorithm.
* If the requested extent is large wrt the freespaces available
* in this a.g., then the cursor will be pointing to a btree entry
* near the right edge of the tree. If it's in the last btree leaf
* block, then we just examine all the entries in that block
* that are big enough, and pick the best one.
* This is written as a while loop so we can break out of it,
* but we never loop back to the top.
*/
while (xfs_btree_islastblock(cnt_cur, 0)) {
xfs_extlen_t bdiff;
int besti=0;
xfs_extlen_t blen=0;
xfs_agblock_t bnew=0;
#if defined(DEBUG) && defined(__KERNEL__)
if (!dofirst)
break;
#endif
/*
* Start from the entry that lookup found, sequence through
* all larger free blocks. If we're actually pointing at a
* record smaller than maxlen, go to the start of this block,
* and skip all those smaller than minlen.
*/
if (ltlen || args->alignment > 1) {
cnt_cur->bc_ptrs[0] = 1;
do {
if ((error = xfs_alloc_get_rec(cnt_cur, &ltbno,
&ltlen, &i)))
goto error0;
XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
if (ltlen >= args->minlen)
break;
if ((error = xfs_alloc_increment(cnt_cur, 0, &i)))
goto error0;
} while (i);
ASSERT(ltlen >= args->minlen);
if (!i)
break;
}
i = cnt_cur->bc_ptrs[0];
for (j = 1, blen = 0, bdiff = 0;
!error && j && (blen < args->maxlen || bdiff > 0);
error = xfs_alloc_increment(cnt_cur, 0, &j)) {
/*
* For each entry, decide if it's better than
* the previous best entry.
*/
if ((error = xfs_alloc_get_rec(cnt_cur, &ltbno, &ltlen, &i)))
goto error0;
XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
if (!xfs_alloc_compute_aligned(ltbno, ltlen,
args->alignment, args->minlen,
&ltbnoa, &ltlena))
continue;
args->len = XFS_EXTLEN_MIN(ltlena, args->maxlen);
xfs_alloc_fix_len(args);
ASSERT(args->len >= args->minlen);
if (args->len < blen)
continue;
ltdiff = xfs_alloc_compute_diff(args->agbno, args->len,
args->alignment, ltbno, ltlen, &ltnew);
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, &ltbno, &ltlen, &i)))
goto error0;
XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
ltend = ltbno + ltlen;
ASSERT(ltend <= be32_to_cpu(XFS_BUF_TO_AGF(args->agbp)->agf_length));
args->len = blen;
if (!xfs_alloc_fix_minleft(args)) {
xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
TRACE_ALLOC("nominleft", args);
return 0;
}
blen = args->len;
/*
* We are allocating starting at bnew for blen blocks.
*/
args->agbno = bnew;
ASSERT(bnew >= ltbno);
ASSERT(bnew + blen <= ltend);
/*
* Set up a cursor for the by-bno tree.
*/
bno_cur_lt = xfs_btree_init_cursor(args->mp, args->tp,
args->agbp, args->agno, XFS_BTNUM_BNO, NULL, 0);
/*
* Fix up the btree entries.
*/
if ((error = xfs_alloc_fixup_trees(cnt_cur, bno_cur_lt, ltbno,
ltlen, bnew, blen, XFSA_FIXUP_CNT_OK)))
goto error0;
xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
xfs_btree_del_cursor(bno_cur_lt, XFS_BTREE_NOERROR);
TRACE_ALLOC("first", args);
return 0;
}
/*
* Second algorithm.
* Search in the by-bno tree to the left and to the right
* simultaneously, until in each case we find a space big enough,
* or run into the edge of the tree. When we run into the edge,
* we deallocate that cursor.
* If both searches succeed, we compare the two spaces and pick
* the better one.
* With alignment, it's possible for both to fail; the upper
* level algorithm that picks allocation groups for allocations
* is not supposed to do this.
*/
/*
* Allocate and initialize the cursor for the leftward search.
*/
bno_cur_lt = xfs_btree_init_cursor(args->mp, args->tp, args->agbp,
args->agno, XFS_BTNUM_BNO, NULL, 0);
/*
* Lookup <= bno to find the leftward search's starting point.
*/
if ((error = xfs_alloc_lookup_le(bno_cur_lt, args->agbno, args->maxlen, &i)))
goto error0;
if (!i) {
/*
* Didn't find anything; use this cursor for the rightward
* search.
*/
bno_cur_gt = bno_cur_lt;
bno_cur_lt = NULL;
}
/*
* Found something. Duplicate the cursor for the rightward search.
*/
else if ((error = xfs_btree_dup_cursor(bno_cur_lt, &bno_cur_gt)))
goto error0;
/*
* Increment the cursor, so we will point at the entry just right
* of the leftward entry if any, or to the leftmost entry.
*/
if ((error = xfs_alloc_increment(bno_cur_gt, 0, &i)))
goto error0;
if (!i) {
/*
* It failed, there are no rightward entries.
*/
xfs_btree_del_cursor(bno_cur_gt, XFS_BTREE_NOERROR);
bno_cur_gt = NULL;
}
/*
* Loop going left with the leftward cursor, right with the
* rightward cursor, until either both directions give up or
* we find an entry at least as big as minlen.
*/
do {
if (bno_cur_lt) {
if ((error = xfs_alloc_get_rec(bno_cur_lt, &ltbno, &ltlen, &i)))
goto error0;
XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
if (xfs_alloc_compute_aligned(ltbno, ltlen,
args->alignment, args->minlen,
&ltbnoa, &ltlena))
break;
if ((error = xfs_alloc_decrement(bno_cur_lt, 0, &i)))
goto error0;
if (!i) {
xfs_btree_del_cursor(bno_cur_lt,
XFS_BTREE_NOERROR);
bno_cur_lt = NULL;
}
}
if (bno_cur_gt) {
if ((error = xfs_alloc_get_rec(bno_cur_gt, &gtbno, &gtlen, &i)))
goto error0;
XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
if (xfs_alloc_compute_aligned(gtbno, gtlen,
args->alignment, args->minlen,
&gtbnoa, &gtlena))
break;
if ((error = xfs_alloc_increment(bno_cur_gt, 0, &i)))
goto error0;
if (!i) {
xfs_btree_del_cursor(bno_cur_gt,
XFS_BTREE_NOERROR);
bno_cur_gt = NULL;
}
}
} while (bno_cur_lt || bno_cur_gt);
/*
* Got both cursors still active, need to find better entry.
*/
if (bno_cur_lt && bno_cur_gt) {
/*
* Left side is long enough, look for a right side entry.
*/
if (ltlena >= args->minlen) {
/*
* Fix up the length.
*/
args->len = XFS_EXTLEN_MIN(ltlena, args->maxlen);
xfs_alloc_fix_len(args);
rlen = args->len;
ltdiff = xfs_alloc_compute_diff(args->agbno, rlen,
args->alignment, ltbno, ltlen, &ltnew);
/*
* Not perfect.
*/
if (ltdiff) {
/*
* Look until we find a better one, run out of
* space, or run off the end.
*/
while (bno_cur_lt && bno_cur_gt) {
if ((error = xfs_alloc_get_rec(
bno_cur_gt, &gtbno,
&gtlen, &i)))
goto error0;
XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
xfs_alloc_compute_aligned(gtbno, gtlen,
args->alignment, args->minlen,
&gtbnoa, &gtlena);
/*
* The left one is clearly better.
*/
if (gtbnoa >= args->agbno + ltdiff) {
xfs_btree_del_cursor(
bno_cur_gt,
XFS_BTREE_NOERROR);
bno_cur_gt = NULL;
break;
}
/*
* If we reach a big enough entry,
* compare the two and pick the best.
*/
if (gtlena >= args->minlen) {
args->len =
XFS_EXTLEN_MIN(gtlena,
args->maxlen);
xfs_alloc_fix_len(args);
rlen = args->len;
gtdiff = xfs_alloc_compute_diff(
args->agbno, rlen,
args->alignment,
gtbno, gtlen, &gtnew);
/*
* Right side is better.
*/
if (gtdiff < ltdiff) {
xfs_btree_del_cursor(
bno_cur_lt,
XFS_BTREE_NOERROR);
bno_cur_lt = NULL;
}
/*
* Left side is better.
*/
else {
xfs_btree_del_cursor(
bno_cur_gt,
XFS_BTREE_NOERROR);
bno_cur_gt = NULL;
}
break;
}
/*
* Fell off the right end.
*/
if ((error = xfs_alloc_increment(
bno_cur_gt, 0, &i)))
goto error0;
if (!i) {
xfs_btree_del_cursor(
bno_cur_gt,
XFS_BTREE_NOERROR);
bno_cur_gt = NULL;
break;
}
}
}
/*
* The left side is perfect, trash the right side.
*/
else {
xfs_btree_del_cursor(bno_cur_gt,
XFS_BTREE_NOERROR);
bno_cur_gt = NULL;
}
}
/*
* It's the right side that was found first, look left.
*/
else {
/*
* Fix up the length.
*/
args->len = XFS_EXTLEN_MIN(gtlena, args->maxlen);
xfs_alloc_fix_len(args);
rlen = args->len;
gtdiff = xfs_alloc_compute_diff(args->agbno, rlen,
args->alignment, gtbno, gtlen, &gtnew);
/*
* Right side entry isn't perfect.
*/
if (gtdiff) {
/*
* Look until we find a better one, run out of
* space, or run off the end.
*/
while (bno_cur_lt && bno_cur_gt) {
if ((error = xfs_alloc_get_rec(
bno_cur_lt, &ltbno,
&ltlen, &i)))
goto error0;
XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
xfs_alloc_compute_aligned(ltbno, ltlen,
args->alignment, args->minlen,
&ltbnoa, &ltlena);
/*
* The right one is clearly better.
*/
if (ltbnoa <= args->agbno - gtdiff) {
xfs_btree_del_cursor(
bno_cur_lt,
XFS_BTREE_NOERROR);
bno_cur_lt = NULL;
break;
}
/*
* If we reach a big enough entry,
* compare the two and pick the best.
*/
if (ltlena >= args->minlen) {
args->len = XFS_EXTLEN_MIN(
ltlena, args->maxlen);
xfs_alloc_fix_len(args);
rlen = args->len;
ltdiff = xfs_alloc_compute_diff(
args->agbno, rlen,
args->alignment,
ltbno, ltlen, &ltnew);
/*
* Left side is better.
*/
if (ltdiff < gtdiff) {
xfs_btree_del_cursor(
bno_cur_gt,
XFS_BTREE_NOERROR);
bno_cur_gt = NULL;
}
/*
* Right side is better.
*/
else {
xfs_btree_del_cursor(
bno_cur_lt,
XFS_BTREE_NOERROR);
bno_cur_lt = NULL;
}
break;
}
/*
* Fell off the left end.
*/
if ((error = xfs_alloc_decrement(
bno_cur_lt, 0, &i)))
goto error0;
if (!i) {
xfs_btree_del_cursor(bno_cur_lt,
XFS_BTREE_NOERROR);
bno_cur_lt = NULL;
break;
}
}
}
/*
* The right side is perfect, trash the left side.
*/
else {
xfs_btree_del_cursor(bno_cur_lt,
XFS_BTREE_NOERROR);
bno_cur_lt = NULL;
}
}
}
/*
* If we couldn't get anything, give up.
*/
if (bno_cur_lt == NULL && bno_cur_gt == NULL) {
TRACE_ALLOC("neither", args);
args->agbno = NULLAGBLOCK;
return 0;
}
/*
* At this point we have selected a freespace entry, either to the
* left or to the right. If it's on the right, copy all the
* useful variables to the "left" set so we only have one
* copy of this code.
*/
if (bno_cur_gt) {
bno_cur_lt = bno_cur_gt;
bno_cur_gt = NULL;
ltbno = gtbno;
ltbnoa = gtbnoa;
ltlen = gtlen;
ltlena = gtlena;
j = 1;
} else
j = 0;
/*
* Fix up the length and compute the useful address.
*/
ltend = ltbno + ltlen;
args->len = XFS_EXTLEN_MIN(ltlena, args->maxlen);
xfs_alloc_fix_len(args);
if (!xfs_alloc_fix_minleft(args)) {
TRACE_ALLOC("nominleft", args);
xfs_btree_del_cursor(bno_cur_lt, XFS_BTREE_NOERROR);
xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
return 0;
}
rlen = args->len;
(void)xfs_alloc_compute_diff(args->agbno, rlen, args->alignment, ltbno,
ltlen, &ltnew);
ASSERT(ltnew >= ltbno);
ASSERT(ltnew + rlen <= ltend);
ASSERT(ltnew + rlen <= be32_to_cpu(XFS_BUF_TO_AGF(args->agbp)->agf_length));
args->agbno = ltnew;
if ((error = xfs_alloc_fixup_trees(cnt_cur, bno_cur_lt, ltbno, ltlen,
ltnew, rlen, XFSA_FIXUP_BNO_OK)))
goto error0;
TRACE_ALLOC(j ? "gt" : "lt", args);
xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
xfs_btree_del_cursor(bno_cur_lt, XFS_BTREE_NOERROR);
return 0;
error0:
TRACE_ALLOC("error", args);
if (cnt_cur != NULL)
xfs_btree_del_cursor(cnt_cur, XFS_BTREE_ERROR);
if (bno_cur_lt != NULL)
xfs_btree_del_cursor(bno_cur_lt, XFS_BTREE_ERROR);
if (bno_cur_gt != NULL)
xfs_btree_del_cursor(bno_cur_gt, XFS_BTREE_ERROR);
return error;
}
/*
* Allocate a variable extent anywhere in the allocation group agno.
* Extent's length (returned in len) will be between minlen and maxlen,
* and of the form k * prod + mod unless there's nothing that large.
* Return the starting a.g. block, or NULLAGBLOCK if we can't do it.
*/
STATIC int /* error */
xfs_alloc_ag_vextent_size(
xfs_alloc_arg_t *args) /* allocation argument structure */
{
xfs_btree_cur_t *bno_cur; /* cursor for bno btree */
xfs_btree_cur_t *cnt_cur; /* cursor for cnt btree */
int error; /* error result */
xfs_agblock_t fbno; /* start of found freespace */
xfs_extlen_t flen; /* length of found freespace */
#ifdef XFS_ALLOC_TRACE
static char fname[] = "xfs_alloc_ag_vextent_size";
#endif
int i; /* temp status variable */
xfs_agblock_t rbno; /* returned block number */
xfs_extlen_t rlen; /* length of returned extent */
/*
* Allocate and initialize a cursor for the by-size btree.
*/
cnt_cur = xfs_btree_init_cursor(args->mp, args->tp, args->agbp,
args->agno, XFS_BTNUM_CNT, NULL, 0);
bno_cur = NULL;
/*
* Look for an entry >= maxlen+alignment-1 blocks.
*/
if ((error = xfs_alloc_lookup_ge(cnt_cur, 0,
args->maxlen + args->alignment - 1, &i)))
goto error0;
/*
* If none, then pick up the last entry in the tree unless the
* tree is empty.
*/
if (!i) {
if ((error = xfs_alloc_ag_vextent_small(args, cnt_cur, &fbno,
&flen, &i)))
goto error0;
if (i == 0 || flen == 0) {
xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
TRACE_ALLOC("noentry", args);
return 0;
}
ASSERT(i == 1);
}
/*
* There's a freespace as big as maxlen+alignment-1, get it.
*/
else {
if ((error = xfs_alloc_get_rec(cnt_cur, &fbno, &flen, &i)))
goto error0;
XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
}
/*
* In the first case above, we got the last entry in the
* by-size btree. Now we check to see if the space hits maxlen
* once aligned; if not, we search left for something better.
* This can't happen in the second case above.
*/
xfs_alloc_compute_aligned(fbno, flen, args->alignment, args->minlen,
&rbno, &rlen);
rlen = XFS_EXTLEN_MIN(args->maxlen, rlen);
XFS_WANT_CORRUPTED_GOTO(rlen == 0 ||
(rlen <= flen && rbno + rlen <= fbno + flen), error0);
if (rlen < args->maxlen) {
xfs_agblock_t bestfbno;
xfs_extlen_t bestflen;
xfs_agblock_t bestrbno;
xfs_extlen_t bestrlen;
bestrlen = rlen;
bestrbno = rbno;
bestflen = flen;
bestfbno = fbno;
for (;;) {
if ((error = xfs_alloc_decrement(cnt_cur, 0, &i)))
goto error0;
if (i == 0)
break;
if ((error = xfs_alloc_get_rec(cnt_cur, &fbno, &flen,
&i)))
goto error0;
XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
if (flen < bestrlen)
break;
xfs_alloc_compute_aligned(fbno, flen, args->alignment,
args->minlen, &rbno, &rlen);
rlen = XFS_EXTLEN_MIN(args->maxlen, rlen);
XFS_WANT_CORRUPTED_GOTO(rlen == 0 ||
(rlen <= flen && rbno + rlen <= fbno + flen),
error0);
if (rlen > bestrlen) {
bestrlen = rlen;
bestrbno = rbno;
bestflen = flen;
bestfbno = fbno;
if (rlen == args->maxlen)
break;
}
}
if ((error = xfs_alloc_lookup_eq(cnt_cur, bestfbno, bestflen,
&i)))
goto error0;
XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
rlen = bestrlen;
rbno = bestrbno;
flen = bestflen;
fbno = bestfbno;
}
args->wasfromfl = 0;
/*
* Fix up the length.
*/
args->len = rlen;
xfs_alloc_fix_len(args);
if (rlen < args->minlen || !xfs_alloc_fix_minleft(args)) {
xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
TRACE_ALLOC("nominleft", args);
args->agbno = NULLAGBLOCK;
return 0;
}
rlen = args->len;
XFS_WANT_CORRUPTED_GOTO(rlen <= flen, error0);
/*
* Allocate and initialize a cursor for the by-block tree.
*/
bno_cur = xfs_btree_init_cursor(args->mp, args->tp, args->agbp,
args->agno, XFS_BTNUM_BNO, NULL, 0);
if ((error = xfs_alloc_fixup_trees(cnt_cur, bno_cur, fbno, flen,
rbno, rlen, XFSA_FIXUP_CNT_OK)))
goto error0;
xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
xfs_btree_del_cursor(bno_cur, XFS_BTREE_NOERROR);
cnt_cur = bno_cur = NULL;
args->len = rlen;
args->agbno = rbno;
XFS_WANT_CORRUPTED_GOTO(
args->agbno + args->len <=
be32_to_cpu(XFS_BUF_TO_AGF(args->agbp)->agf_length),
error0);
TRACE_ALLOC("normal", args);
return 0;
error0:
TRACE_ALLOC("error", args);
if (cnt_cur)
xfs_btree_del_cursor(cnt_cur, XFS_BTREE_ERROR);
if (bno_cur)
xfs_btree_del_cursor(bno_cur, XFS_BTREE_ERROR);
return error;
}
/*
* Deal with the case where only small freespaces remain.
* Either return the contents of the last freespace record,
* or allocate space from the freelist if there is nothing in the tree.
*/
STATIC int /* error */
xfs_alloc_ag_vextent_small(
xfs_alloc_arg_t *args, /* allocation argument structure */
xfs_btree_cur_t *ccur, /* by-size cursor */
xfs_agblock_t *fbnop, /* result block number */
xfs_extlen_t *flenp, /* result length */
int *stat) /* status: 0-freelist, 1-normal/none */
{
int error;
xfs_agblock_t fbno;
xfs_extlen_t flen;
#ifdef XFS_ALLOC_TRACE
static char fname[] = "xfs_alloc_ag_vextent_small";
#endif
int i;
if ((error = xfs_alloc_decrement(ccur, 0, &i)))
goto error0;
if (i) {
if ((error = xfs_alloc_get_rec(ccur, &fbno, &flen, &i)))
goto error0;
XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
}
/*
* Nothing in the btree, try the freelist. Make sure
* to respect minleft even when pulling from the
* freelist.
*/
else if (args->minlen == 1 && args->alignment == 1 && !args->isfl &&
(be32_to_cpu(XFS_BUF_TO_AGF(args->agbp)->agf_flcount)
> args->minleft)) {
error = xfs_alloc_get_freelist(args->tp, args->agbp, &fbno, 0);
if (error)
goto error0;
if (fbno != NULLAGBLOCK) {
if (args->userdata) {
xfs_buf_t *bp;
bp = xfs_btree_get_bufs(args->mp, args->tp,
args->agno, fbno, 0);
xfs_trans_binval(args->tp, bp);
}
args->len = 1;
args->agbno = fbno;
XFS_WANT_CORRUPTED_GOTO(
args->agbno + args->len <=
be32_to_cpu(XFS_BUF_TO_AGF(args->agbp)->agf_length),
error0);
args->wasfromfl = 1;
TRACE_ALLOC("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_ALLOC("notenough", args);
flen = 0;
}
*fbnop = fbno;
*flenp = flen;
*stat = 1;
TRACE_ALLOC("normal", args);
return 0;
error0:
TRACE_ALLOC("error", args);
return error;
}
/*
* Free the extent starting at agno/bno for length.
*/
STATIC int /* error */
xfs_free_ag_extent(
xfs_trans_t *tp, /* transaction pointer */
xfs_buf_t *agbp, /* buffer for a.g. freelist header */
xfs_agnumber_t agno, /* allocation group number */
xfs_agblock_t bno, /* starting block number */
xfs_extlen_t len, /* length of extent */
int isfl) /* set if is freelist blocks - no sb acctg */
{
xfs_btree_cur_t *bno_cur; /* cursor for by-block btree */
xfs_btree_cur_t *cnt_cur; /* cursor for by-size btree */
int error; /* error return value */
#ifdef XFS_ALLOC_TRACE
static char fname[] = "xfs_free_ag_extent";
#endif
xfs_agblock_t gtbno; /* start of right neighbor block */
xfs_extlen_t gtlen; /* length of right neighbor block */
int haveleft; /* have a left neighbor block */
int haveright; /* have a right neighbor block */
int i; /* temp, result code */
xfs_agblock_t ltbno; /* start of left neighbor block */
xfs_extlen_t ltlen; /* length of left neighbor block */
xfs_mount_t *mp; /* mount point struct for filesystem */
xfs_agblock_t nbno; /* new starting block of freespace */
xfs_extlen_t nlen; /* new length of freespace */
mp = tp->t_mountp;
/*
* Allocate and initialize a cursor for the by-block btree.
*/
bno_cur = xfs_btree_init_cursor(mp, tp, agbp, agno, XFS_BTNUM_BNO, NULL,
0);
cnt_cur = NULL;
/*
* Look for a neighboring block on the left (lower block numbers)
* that is contiguous with this space.
*/
if ((error = xfs_alloc_lookup_le(bno_cur, bno, len, &haveleft)))
goto error0;
if (haveleft) {
/*
* There is a block to our left.
*/
if ((error = xfs_alloc_get_rec(bno_cur, &ltbno, &ltlen, &i)))
goto error0;
XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
/*
* It's not contiguous, though.
*/
if (ltbno + ltlen < bno)
haveleft = 0;
else {
/*
* If this failure happens the request to free this
* space was invalid, it's (partly) already free.
* Very bad.
*/
XFS_WANT_CORRUPTED_GOTO(ltbno + ltlen <= bno, error0);
}
}
/*
* Look for a neighboring block on the right (higher block numbers)
* that is contiguous with this space.
*/
if ((error = xfs_alloc_increment(bno_cur, 0, &haveright)))
goto error0;
if (haveright) {
/*
* There is a block to our right.
*/
if ((error = xfs_alloc_get_rec(bno_cur, &gtbno, &gtlen, &i)))
goto error0;
XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
/*
* It's not contiguous, though.
*/
if (bno + len < gtbno)
haveright = 0;
else {
/*
* If this failure happens the request to free this
* space was invalid, it's (partly) already free.
* Very bad.
*/
XFS_WANT_CORRUPTED_GOTO(gtbno >= bno + len, error0);
}
}
/*
* Now allocate and initialize a cursor for the by-size tree.
*/
cnt_cur = xfs_btree_init_cursor(mp, tp, agbp, agno, XFS_BTNUM_CNT, NULL,
0);
/*
* Have both left and right contiguous neighbors.
* Merge all three into a single free block.
*/
if (haveleft && haveright) {
/*
* Delete the old by-size entry on the left.
*/
if ((error = xfs_alloc_lookup_eq(cnt_cur, ltbno, ltlen, &i)))
goto error0;
XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
if ((error = xfs_alloc_delete(cnt_cur, &i)))
goto error0;
XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
/*
* Delete the old by-size entry on the right.
*/
if ((error = xfs_alloc_lookup_eq(cnt_cur, gtbno, gtlen, &i)))
goto error0;
XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
if ((error = xfs_alloc_delete(cnt_cur, &i)))
goto error0;
XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
/*
* Delete the old by-block entry for the right block.
*/
if ((error = xfs_alloc_delete(bno_cur, &i)))
goto error0;
XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
/*
* Move the by-block cursor back to the left neighbor.
*/
if ((error = xfs_alloc_decrement(bno_cur, 0, &i)))
goto error0;
XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
#ifdef DEBUG
/*
* Check that this is the right record: delete didn't
* mangle the cursor.
*/
{
xfs_agblock_t xxbno;
xfs_extlen_t xxlen;
if ((error = xfs_alloc_get_rec(bno_cur, &xxbno, &xxlen,
&i)))
goto error0;
XFS_WANT_CORRUPTED_GOTO(
i == 1 && xxbno == ltbno && xxlen == ltlen,
error0);
}
#endif
/*
* Update remaining by-block entry to the new, joined block.
*/
nbno = ltbno;
nlen = len + ltlen + gtlen;
if ((error = xfs_alloc_update(bno_cur, nbno, nlen)))
goto error0;
}
/*
* Have only a left contiguous neighbor.
* Merge it together with the new freespace.
*/
else if (haveleft) {
/*
* Delete the old by-size entry on the left.
*/
if ((error = xfs_alloc_lookup_eq(cnt_cur, ltbno, ltlen, &i)))
goto error0;
XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
if ((error = xfs_alloc_delete(cnt_cur, &i)))
goto error0;
XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
/*
* Back up the by-block cursor to the left neighbor, and
* update its length.
*/
if ((error = xfs_alloc_decrement(bno_cur, 0, &i)))
goto error0;
XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
nbno = ltbno;
nlen = len + ltlen;
if ((error = xfs_alloc_update(bno_cur, nbno, nlen)))
goto error0;
}
/*
* Have only a right contiguous neighbor.
* Merge it together with the new freespace.
*/
else if (haveright) {
/*
* Delete the old by-size entry on the right.
*/
if ((error = xfs_alloc_lookup_eq(cnt_cur, gtbno, gtlen, &i)))
goto error0;
XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
if ((error = xfs_alloc_delete(cnt_cur, &i)))
goto error0;
XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
/*
* Update the starting block and length of the right
* neighbor in the by-block tree.
*/
nbno = bno;
nlen = len + gtlen;
if ((error = xfs_alloc_update(bno_cur, nbno, nlen)))
goto error0;
}
/*
* No contiguous neighbors.
* Insert the new freespace into the by-block tree.
*/
else {
nbno = bno;
nlen = len;
if ((error = xfs_alloc_insert(bno_cur, &i)))
goto error0;
XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
}
xfs_btree_del_cursor(bno_cur, XFS_BTREE_NOERROR);
bno_cur = NULL;
/*
* In all cases we need to insert the new freespace in the by-size tree.
*/
if ((error = xfs_alloc_lookup_eq(cnt_cur, nbno, nlen, &i)))
goto error0;
XFS_WANT_CORRUPTED_GOTO(i == 0, error0);
if ((error = xfs_alloc_insert(cnt_cur, &i)))
goto error0;
XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
cnt_cur = NULL;
/*
* Update the freespace totals in the ag and superblock.
*/
{
xfs_agf_t *agf;
xfs_perag_t *pag; /* per allocation group data */
agf = XFS_BUF_TO_AGF(agbp);
pag = &mp->m_perag[agno];
be32_add(&agf->agf_freeblks, len);
xfs_trans_agblocks_delta(tp, len);
pag->pagf_freeblks += len;
XFS_WANT_CORRUPTED_GOTO(
be32_to_cpu(agf->agf_freeblks) <=
be32_to_cpu(agf->agf_length),
error0);
TRACE_MODAGF(NULL, agf, XFS_AGF_FREEBLKS);
xfs_alloc_log_agf(tp, agbp, XFS_AGF_FREEBLKS);
if (!isfl)
xfs_trans_mod_sb(tp, XFS_TRANS_SB_FDBLOCKS, (long)len);
XFS_STATS_INC(xs_freex);
XFS_STATS_ADD(xs_freeb, len);
}
TRACE_FREE(haveleft ?
(haveright ? "both" : "left") :
(haveright ? "right" : "none"),
agno, bno, len, isfl);
/*
* Since blocks move to the free list without the coordination
* used in xfs_bmap_finish, we can't allow block to be available
* for reallocation and non-transaction writing (user data)
* until we know that the transaction that moved it to the free
* list is permanently on disk. We track the blocks by declaring
* these blocks as "busy"; the busy list is maintained on a per-ag
* basis and each transaction records which entries should be removed
* when the iclog commits to disk. If a busy block is allocated,
* the iclog is pushed up to the LSN that freed the block.
*/
xfs_alloc_mark_busy(tp, agno, bno, len);
return 0;
error0:
TRACE_FREE("error", agno, bno, len, isfl);
if (bno_cur)
xfs_btree_del_cursor(bno_cur, XFS_BTREE_ERROR);
if (cnt_cur)
xfs_btree_del_cursor(cnt_cur, XFS_BTREE_ERROR);
return error;
}
/*
* Visible (exported) allocation/free functions.
* Some of these are used just by xfs_alloc_btree.c and this file.
*/
/*
* Compute and fill in value of m_ag_maxlevels.
*/
void
xfs_alloc_compute_maxlevels(
xfs_mount_t *mp) /* file system mount structure */
{
int level;
uint maxblocks;
uint maxleafents;
int minleafrecs;
int minnoderecs;
maxleafents = (mp->m_sb.sb_agblocks + 1) / 2;
minleafrecs = mp->m_alloc_mnr[0];
minnoderecs = mp->m_alloc_mnr[1];
maxblocks = (maxleafents + minleafrecs - 1) / minleafrecs;
for (level = 1; maxblocks > 1; level++)
maxblocks = (maxblocks + minnoderecs - 1) / minnoderecs;
mp->m_ag_maxlevels = level;
}
/*
* Decide whether to use this allocation group for this allocation.
* If so, fix up the btree freelist's size.
*/
STATIC int /* error */
xfs_alloc_fix_freelist(
xfs_alloc_arg_t *args, /* allocation argument structure */
int flags) /* XFS_ALLOC_FLAG_... */
{
xfs_buf_t *agbp; /* agf buffer pointer */
xfs_agf_t *agf; /* a.g. freespace structure pointer */
xfs_buf_t *agflbp;/* agfl buffer pointer */
xfs_agblock_t bno; /* freelist block */
xfs_extlen_t delta; /* new blocks needed in freelist */
int error; /* error result code */
xfs_extlen_t longest;/* longest extent in allocation group */
xfs_mount_t *mp; /* file system mount point structure */
xfs_extlen_t need; /* total blocks needed in freelist */
xfs_perag_t *pag; /* per-ag information structure */
xfs_alloc_arg_t targs; /* local allocation arguments */
xfs_trans_t *tp; /* transaction pointer */
mp = args->mp;
pag = args->pag;
tp = args->tp;
if (!pag->pagf_init) {
if ((error = xfs_alloc_read_agf(mp, tp, args->agno, flags,
&agbp)))
return error;
if (!pag->pagf_init) {
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)) {
need = XFS_MIN_FREELIST_PAG(pag, mp);
delta = need > pag->pagf_flcount ? need - pag->pagf_flcount : 0;
/*
* If it looks like there isn't a long enough extent, or enough
* total blocks, reject it.
*/
longest = (pag->pagf_longest > delta) ?
(pag->pagf_longest - delta) :
(pag->pagf_flcount > 0 || pag->pagf_longest > 0);
if ((args->minlen + args->alignment + args->minalignslop - 1) >
longest ||
((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;
#ifdef XFS_ALLOC_TRACE
static char fname[] = "xfs_alloc_get_freelist";
#endif
xfs_mount_t *mp; /* mount structure */
xfs_perag_t *pag; /* per allocation group data */
agf = XFS_BUF_TO_AGF(agbp);
/*
* Freelist is empty, give up.
*/
if (!agf->agf_flcount) {
*bnop = NULLAGBLOCK;
return 0;
}
/*
* Read the array of free blocks.
*/
mp = tp->t_mountp;
if ((error = xfs_alloc_read_agfl(mp, tp,
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(&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 = &mp->m_perag[be32_to_cpu(agf->agf_seqno)];
be32_add(&agf->agf_flcount, -1);
xfs_trans_agflist_delta(tp, -1);
pag->pagf_flcount--;
logflags = XFS_AGF_FLFIRST | XFS_AGF_FLCOUNT;
if (btreeblk) {
be32_add(&agf->agf_btreeblks, 1);
pag->pagf_btreeblks++;
logflags |= XFS_AGF_BTREEBLKS;
}
TRACE_MODAGF(NULL, agf, logflags);
xfs_alloc_log_agf(tp, agbp, logflags);
*bnop = bno;
/*
* As blocks are freed, they are added to the per-ag busy list
* and remain there until the freeing transaction is committed to
* disk. Now that we have allocated blocks, this list must be
* searched to see if a block is being reused. If one is, then
* the freeing transaction must be pushed to disk NOW by forcing
* to disk all iclogs up that transaction's LSN.
*/
xfs_alloc_search_busy(tp, be32_to_cpu(agf->agf_seqno), bno, 1);
return 0;
}
/*
* Log the given fields from the agf structure.
*/
void
xfs_alloc_log_agf(
xfs_trans_t *tp, /* transaction pointer */
xfs_buf_t *bp, /* buffer for a.g. freelist header */
int fields) /* mask of fields to be logged (XFS_AGF_...) */
{
int first; /* first byte offset */
int last; /* last byte offset */
static const short offsets[] = {
offsetof(xfs_agf_t, agf_magicnum),
offsetof(xfs_agf_t, agf_versionnum),
offsetof(xfs_agf_t, agf_seqno),
offsetof(xfs_agf_t, agf_length),
offsetof(xfs_agf_t, agf_roots[0]),
offsetof(xfs_agf_t, agf_levels[0]),
offsetof(xfs_agf_t, agf_flfirst),
offsetof(xfs_agf_t, agf_fllast),
offsetof(xfs_agf_t, agf_flcount),
offsetof(xfs_agf_t, agf_freeblks),
offsetof(xfs_agf_t, agf_longest),
offsetof(xfs_agf_t, agf_btreeblks),
sizeof(xfs_agf_t)
};
xfs_btree_offsets(fields, offsets, XFS_AGF_NUM_BITS, &first, &last);
xfs_trans_log_buf(tp, bp, (uint)first, (uint)last);
}
/*
* Interface for inode allocation to force the pag data to be initialized.
*/
int /* error */
xfs_alloc_pagf_init(
xfs_mount_t *mp, /* file system mount structure */
xfs_trans_t *tp, /* transaction pointer */
xfs_agnumber_t agno, /* allocation group number */
int flags) /* XFS_ALLOC_FLAGS_... */
{
xfs_buf_t *bp;
int error;
if ((error = xfs_alloc_read_agf(mp, tp, agno, flags, &bp)))
return error;
if (bp)
xfs_trans_brelse(tp, bp);
return 0;
}
/*
* Put the block on the freelist for the allocation group.
*/
int /* error */
xfs_alloc_put_freelist(
xfs_trans_t *tp, /* transaction pointer */
xfs_buf_t *agbp, /* buffer for a.g. freelist header */
xfs_buf_t *agflbp,/* buffer for a.g. free block array */
xfs_agblock_t bno, /* block being freed */
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;
#ifdef XFS_ALLOC_TRACE
static char fname[] = "xfs_alloc_put_freelist";
#endif
xfs_mount_t *mp; /* mount structure */
xfs_perag_t *pag; /* per allocation group data */
agf = XFS_BUF_TO_AGF(agbp);
mp = tp->t_mountp;
if (!agflbp && (error = xfs_alloc_read_agfl(mp, tp,
be32_to_cpu(agf->agf_seqno), &agflbp)))
return error;
agfl = XFS_BUF_TO_AGFL(agflbp);
be32_add(&agf->agf_fllast, 1);
if (be32_to_cpu(agf->agf_fllast) == XFS_AGFL_SIZE(mp))
agf->agf_fllast = 0;
pag = &mp->m_perag[be32_to_cpu(agf->agf_seqno)];
be32_add(&agf->agf_flcount, 1);
xfs_trans_agflist_delta(tp, 1);
pag->pagf_flcount++;
logflags = XFS_AGF_FLLAST | XFS_AGF_FLCOUNT;
if (btreeblk) {
be32_add(&agf->agf_btreeblks, -1);
pag->pagf_btreeblks--;
logflags |= XFS_AGF_BTREEBLKS;
}
TRACE_MODAGF(NULL, agf, logflags);
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);
TRACE_MODAGF(NULL, agf, logflags);
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_alloc_read_agf(
xfs_mount_t *mp, /* mount point structure */
xfs_trans_t *tp, /* transaction pointer */
xfs_agnumber_t agno, /* allocation group number */
int flags, /* XFS_ALLOC_FLAG_... */
xfs_buf_t **bpp) /* buffer for the ag freelist header */
{
xfs_agf_t *agf; /* ag freelist header */
int agf_ok; /* set if agf is consistent */
xfs_buf_t *bp; /* return value */
xfs_perag_t *pag; /* per allocation group data */
int error;
ASSERT(agno != NULLAGNUMBER);
error = xfs_trans_read_buf(
mp, tp, mp->m_ddev_targp,
XFS_AG_DADDR(mp, agno, XFS_AGF_DADDR(mp)),
XFS_FSS_TO_BB(mp, 1),
(flags & XFS_ALLOC_FLAG_TRYLOCK) ? XFS_BUF_TRYLOCK : 0U,
&bp);
if (error)
return error;
ASSERT(!bp || !XFS_BUF_GETERROR(bp));
if (!bp) {
*bpp = NULL;
return 0;
}
/*
* Validate the magic number of the agf block.
*/
agf = XFS_BUF_TO_AGF(bp);
agf_ok =
be32_to_cpu(agf->agf_magicnum) == XFS_AGF_MAGIC &&
XFS_AGF_GOOD_VERSION(be32_to_cpu(agf->agf_versionnum)) &&
be32_to_cpu(agf->agf_freeblks) <= be32_to_cpu(agf->agf_length) &&
be32_to_cpu(agf->agf_flfirst) < XFS_AGFL_SIZE(mp) &&
be32_to_cpu(agf->agf_fllast) < XFS_AGFL_SIZE(mp) &&
be32_to_cpu(agf->agf_flcount) <= XFS_AGFL_SIZE(mp);
if (unlikely(XFS_TEST_ERROR(!agf_ok, mp, XFS_ERRTAG_ALLOC_READ_AGF,
XFS_RANDOM_ALLOC_READ_AGF))) {
XFS_CORRUPTION_ERROR("xfs_alloc_read_agf",
XFS_ERRLEVEL_LOW, mp, agf);
xfs_trans_brelse(tp, bp);
return XFS_ERROR(EFSCORRUPTED);
}
pag = &mp->m_perag[agno];
if (!pag->pagf_init) {
pag->pagf_freeblks = 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]);
spinlock_init(&pag->pagb_lock, "xfspagb");
pag->pagb_list = kmem_zalloc(XFS_PAGB_NUM_SLOTS *
sizeof(xfs_perag_busy_t), KM_SLEEP);
pag->pagf_init = 1;
}
#ifdef DEBUG
else if (!XFS_FORCED_SHUTDOWN(mp)) {
ASSERT(pag->pagf_freeblks == be32_to_cpu(agf->agf_freeblks));
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_BUF_SET_VTYPE_REF(bp, B_FS_AGF, XFS_AGF_REF);
*bpp = bp;
return 0;
}
/*
* Allocate an extent (variable-size).
* Depending on the allocation type, we either look in a single allocation
* group or loop over the allocation groups to find the result.
*/
int /* error */
xfs_alloc_vextent(
xfs_alloc_arg_t *args) /* allocation argument structure */
{
xfs_agblock_t agsize; /* allocation group size */
int error;
int flags; /* XFS_ALLOC_FLAG_... locking flags */
#ifdef XFS_ALLOC_TRACE
static char fname[] = "xfs_alloc_vextent";
#endif
xfs_extlen_t minleft;/* minimum left value, temp copy */
xfs_mount_t *mp; /* mount structure pointer */
xfs_agnumber_t sagno; /* starting allocation group number */
xfs_alloctype_t type; /* input allocation type */
int bump_rotor = 0;
int no_min = 0;
xfs_agnumber_t rotorstep = xfs_rotorstep; /* inode32 agf stepper */
mp = args->mp;
type = args->otype = args->type;
args->agbno = NULLAGBLOCK;
/*
* Just fix this up, for the case where the last a.g. is shorter
* (or there's only one a.g.) and the caller couldn't easily figure
* that out (xfs_bmap_alloc).
*/
agsize = mp->m_sb.sb_agblocks;
if (args->maxlen > agsize)
args->maxlen = agsize;
if (args->alignment == 0)
args->alignment = 1;
ASSERT(XFS_FSB_TO_AGNO(mp, args->fsbno) < mp->m_sb.sb_agcount);
ASSERT(XFS_FSB_TO_AGBNO(mp, args->fsbno) < agsize);
ASSERT(args->minlen <= args->maxlen);
ASSERT(args->minlen <= agsize);
ASSERT(args->mod < args->prod);
if (XFS_FSB_TO_AGNO(mp, args->fsbno) >= mp->m_sb.sb_agcount ||
XFS_FSB_TO_AGBNO(mp, args->fsbno) >= agsize ||
args->minlen > args->maxlen || args->minlen > agsize ||
args->mod >= args->prod) {
args->fsbno = NULLFSBLOCK;
TRACE_ALLOC("badargs", args);
return 0;
}
minleft = args->minleft;
switch (type) {
case XFS_ALLOCTYPE_THIS_AG:
case XFS_ALLOCTYPE_NEAR_BNO:
case XFS_ALLOCTYPE_THIS_BNO:
/*
* These three force us into a single a.g.
*/
args->agno = XFS_FSB_TO_AGNO(mp, args->fsbno);
down_read(&mp->m_peraglock);
args->pag = &mp->m_perag[args->agno];
args->minleft = 0;
error = xfs_alloc_fix_freelist(args, 0);
args->minleft = minleft;
if (error) {
TRACE_ALLOC("nofix", args);
goto error0;
}
if (!args->agbp) {
up_read(&mp->m_peraglock);
TRACE_ALLOC("noagbp", args);
break;
}
args->agbno = XFS_FSB_TO_AGBNO(mp, args->fsbno);
if ((error = xfs_alloc_ag_vextent(args)))
goto error0;
up_read(&mp->m_peraglock);
break;
case XFS_ALLOCTYPE_START_BNO:
/*
* Try near allocation first, then anywhere-in-ag after
* the first a.g. fails.
*/
if ((args->userdata == XFS_ALLOC_INITIAL_USER_DATA) &&
(mp->m_flags & XFS_MOUNT_32BITINODES)) {
args->fsbno = XFS_AGB_TO_FSB(mp,
((mp->m_agfrotor / rotorstep) %
mp->m_sb.sb_agcount), 0);
bump_rotor = 1;
}
args->agbno = XFS_FSB_TO_AGBNO(mp, args->fsbno);
args->type = XFS_ALLOCTYPE_NEAR_BNO;
/* FALLTHROUGH */
case XFS_ALLOCTYPE_ANY_AG:
case XFS_ALLOCTYPE_START_AG:
case XFS_ALLOCTYPE_FIRST_AG:
/*
* Rotate through the allocation groups looking for a winner.
*/
if (type == XFS_ALLOCTYPE_ANY_AG) {
/*
* Start with the last place we left off.
*/
args->agno = sagno = (mp->m_agfrotor / rotorstep) %
mp->m_sb.sb_agcount;
args->type = XFS_ALLOCTYPE_THIS_AG;
flags = XFS_ALLOC_FLAG_TRYLOCK;
} else if (type == XFS_ALLOCTYPE_FIRST_AG) {
/*
* Start with allocation group given by bno.
*/
args->agno = XFS_FSB_TO_AGNO(mp, args->fsbno);
args->type = XFS_ALLOCTYPE_THIS_AG;
sagno = 0;
flags = 0;
} else {
if (type == XFS_ALLOCTYPE_START_AG)
args->type = XFS_ALLOCTYPE_THIS_AG;
/*
* Start with the given allocation group.
*/
args->agno = sagno = XFS_FSB_TO_AGNO(mp, args->fsbno);
flags = XFS_ALLOC_FLAG_TRYLOCK;
}
/*
* Loop over allocation groups twice; first time with
* trylock set, second time without.
*/
down_read(&mp->m_peraglock);
for (;;) {
args->pag = &mp->m_perag[args->agno];
if (no_min) args->minleft = 0;
error = xfs_alloc_fix_freelist(args, flags);
args->minleft = minleft;
if (error) {
TRACE_ALLOC("nofix", args);
goto error0;
}
/*
* If we get a buffer back then the allocation will fly.
*/
if (args->agbp) {
if ((error = xfs_alloc_ag_vextent(args)))
goto error0;
break;
}
TRACE_ALLOC("loopfailed", args);
/*
* Didn't work, figure out the next iteration.
*/
if (args->agno == sagno &&
type == XFS_ALLOCTYPE_START_BNO)
args->type = XFS_ALLOCTYPE_THIS_AG;
/*
* 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_ALLOC("allfailed", args);
break;
}
if (flags == 0) {
no_min = 1;
} else {
flags = 0;
if (type == XFS_ALLOCTYPE_START_BNO) {
args->agbno = XFS_FSB_TO_AGBNO(mp,
args->fsbno);
args->type = XFS_ALLOCTYPE_NEAR_BNO;
}
}
}
}
up_read(&mp->m_peraglock);
if (bump_rotor || (type == XFS_ALLOCTYPE_ANY_AG)) {
if (args->agno == sagno)
mp->m_agfrotor = (mp->m_agfrotor + 1) %
(mp->m_sb.sb_agcount * rotorstep);
else
mp->m_agfrotor = (args->agno * rotorstep + 1) %
(mp->m_sb.sb_agcount * rotorstep);
}
break;
default:
ASSERT(0);
/* NOTREACHED */
}
if (args->agbno == NULLAGBLOCK)
args->fsbno = NULLFSBLOCK;
else {
args->fsbno = XFS_AGB_TO_FSB(mp, args->agno, args->agbno);
#ifdef DEBUG
ASSERT(args->len >= args->minlen);
ASSERT(args->len <= args->maxlen);
ASSERT(args->agbno % args->alignment == 0);
XFS_AG_CHECK_DADDR(mp, XFS_FSB_TO_DADDR(mp, args->fsbno),
args->len);
#endif
}
return 0;
error0:
up_read(&mp->m_peraglock);
return error;
}
/*
* Free an extent.
* Just break up the extent address and hand off to xfs_free_ag_extent
* after fixing up the freelist.
*/
int /* error */
xfs_free_extent(
xfs_trans_t *tp, /* transaction pointer */
xfs_fsblock_t bno, /* starting block number of extent */
xfs_extlen_t len) /* length of extent */
{
xfs_alloc_arg_t args;
int error;
ASSERT(len != 0);
memset(&args, 0, sizeof(xfs_alloc_arg_t));
args.tp = tp;
args.mp = tp->t_mountp;
args.agno = XFS_FSB_TO_AGNO(args.mp, bno);
ASSERT(args.agno < args.mp->m_sb.sb_agcount);
args.agbno = XFS_FSB_TO_AGBNO(args.mp, bno);
down_read(&args.mp->m_peraglock);
args.pag = &args.mp->m_perag[args.agno];
if ((error = xfs_alloc_fix_freelist(&args, XFS_ALLOC_FLAG_FREEING)))
goto error0;
#ifdef DEBUG
ASSERT(args.agbp != NULL);
ASSERT((args.agbno + len) <=
be32_to_cpu(XFS_BUF_TO_AGF(args.agbp)->agf_length));
#endif
error = xfs_free_ag_extent(tp, args.agbp, args.agno, args.agbno, len, 0);
error0:
up_read(&args.mp->m_peraglock);
return error;
}
/*
* AG Busy list management
* The busy list contains block ranges that have been freed but whose
* transactions have not yet hit disk. If any block listed in a busy
* list is reused, the transaction that freed it must be forced to disk
* before continuing to use the block.
*
* xfs_alloc_mark_busy - add to the per-ag busy list
* xfs_alloc_clear_busy - remove an item from the per-ag busy list
*/
void
xfs_alloc_mark_busy(xfs_trans_t *tp,
xfs_agnumber_t agno,
xfs_agblock_t bno,
xfs_extlen_t len)
{
xfs_mount_t *mp;
xfs_perag_busy_t *bsy;
int n;
SPLDECL(s);
mp = tp->t_mountp;
s = mutex_spinlock(&mp->m_perag[agno].pagb_lock);
/* search pagb_list for an open slot */
for (bsy = mp->m_perag[agno].pagb_list, n = 0;
n < XFS_PAGB_NUM_SLOTS;
bsy++, n++) {
if (bsy->busy_tp == NULL) {
break;
}
}
if (n < XFS_PAGB_NUM_SLOTS) {
bsy = &mp->m_perag[agno].pagb_list[n];
mp->m_perag[agno].pagb_count++;
TRACE_BUSY("xfs_alloc_mark_busy", "got", agno, bno, len, n, tp);
bsy->busy_start = bno;
bsy->busy_length = len;
bsy->busy_tp = tp;
xfs_trans_add_busy(tp, agno, n);
} else {
TRACE_BUSY("xfs_alloc_mark_busy", "FULL", agno, bno, len, -1, tp);
/*
* The busy list is full! Since it is now not possible to
* track the free block, make this a synchronous transaction
* to insure that the block is not reused before this
* transaction commits.
*/
xfs_trans_set_sync(tp);
}
mutex_spinunlock(&mp->m_perag[agno].pagb_lock, s);
}
void
xfs_alloc_clear_busy(xfs_trans_t *tp,
xfs_agnumber_t agno,
int idx)
{
xfs_mount_t *mp;
xfs_perag_busy_t *list;
SPLDECL(s);
mp = tp->t_mountp;
s = mutex_spinlock(&mp->m_perag[agno].pagb_lock);
list = mp->m_perag[agno].pagb_list;
ASSERT(idx < XFS_PAGB_NUM_SLOTS);
if (list[idx].busy_tp == tp) {
TRACE_UNBUSY("xfs_alloc_clear_busy", "found", agno, idx, tp);
list[idx].busy_tp = NULL;
mp->m_perag[agno].pagb_count--;
} else {
TRACE_UNBUSY("xfs_alloc_clear_busy", "missing", agno, idx, tp);
}
mutex_spinunlock(&mp->m_perag[agno].pagb_lock, s);
}
/*
* returns non-zero if any of (agno,bno):len is in a busy list
*/
STATIC int
xfs_alloc_search_busy(xfs_trans_t *tp,
xfs_agnumber_t agno,
xfs_agblock_t bno,
xfs_extlen_t len)
{
xfs_mount_t *mp;
xfs_perag_busy_t *bsy;
int n;
xfs_agblock_t uend, bend;
xfs_lsn_t lsn;
int cnt;
SPLDECL(s);
mp = tp->t_mountp;
s = mutex_spinlock(&mp->m_perag[agno].pagb_lock);
cnt = mp->m_perag[agno].pagb_count;
uend = bno + len - 1;
/* search pagb_list for this slot, skipping open slots */
for (bsy = mp->m_perag[agno].pagb_list, n = 0;
cnt; bsy++, n++) {
/*
* (start1,length1) within (start2, length2)
*/
if (bsy->busy_tp != NULL) {
bend = bsy->busy_start + bsy->busy_length - 1;
if ((bno > bend) ||
(uend < bsy->busy_start)) {
cnt--;
} else {
TRACE_BUSYSEARCH("xfs_alloc_search_busy",
"found1", agno, bno, len, n,
tp);
break;
}
}
}
/*
* If a block was found, force the log through the LSN of the
* transaction that freed the block
*/
if (cnt) {
TRACE_BUSYSEARCH("xfs_alloc_search_busy", "found", agno, bno, len, n, tp);
lsn = bsy->busy_tp->t_commit_lsn;
mutex_spinunlock(&mp->m_perag[agno].pagb_lock, s);
xfs_log_force(mp, lsn, XFS_LOG_FORCE|XFS_LOG_SYNC);
} else {
TRACE_BUSYSEARCH("xfs_alloc_search_busy", "not-found", agno, bno, len, n, tp);
n = -1;
mutex_spinunlock(&mp->m_perag[agno].pagb_lock, s);
}
return n;
}
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