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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-09-08 01:01:14 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-09-08 01:01:14 -0300
commite5fd91f1ef340da553f7a79da9540c3db711c937 (patch)
treeb11842027dc6641da63f4bcc524f8678263304a3 /fs/xfs/libxfs/xfs_alloc.c
parent2a9b0348e685a63d97486f6749622b61e9e3292f (diff)
Linux-libre 4.2-gnu
Diffstat (limited to 'fs/xfs/libxfs/xfs_alloc.c')
-rw-r--r--fs/xfs/libxfs/xfs_alloc.c281
1 files changed, 169 insertions, 112 deletions
diff --git a/fs/xfs/libxfs/xfs_alloc.c b/fs/xfs/libxfs/xfs_alloc.c
index 516162be1..f9e9ffe6f 100644
--- a/fs/xfs/libxfs/xfs_alloc.c
+++ b/fs/xfs/libxfs/xfs_alloc.c
@@ -149,13 +149,27 @@ xfs_alloc_compute_aligned(
{
xfs_agblock_t bno;
xfs_extlen_t len;
+ xfs_extlen_t diff;
/* Trim busy sections out of found extent */
xfs_extent_busy_trim(args, foundbno, foundlen, &bno, &len);
+ /*
+ * If we have a largish extent that happens to start before min_agbno,
+ * see if we can shift it into range...
+ */
+ if (bno < args->min_agbno && bno + len > args->min_agbno) {
+ diff = args->min_agbno - bno;
+ if (len > diff) {
+ bno += diff;
+ len -= diff;
+ }
+ }
+
if (args->alignment > 1 && len >= args->minlen) {
xfs_agblock_t aligned_bno = roundup(bno, args->alignment);
- xfs_extlen_t diff = aligned_bno - bno;
+
+ diff = aligned_bno - bno;
*resbno = aligned_bno;
*reslen = diff >= len ? 0 : len - diff;
@@ -795,9 +809,13 @@ xfs_alloc_find_best_extent(
* The good extent is closer than this one.
*/
if (!dir) {
+ if (*sbnoa > args->max_agbno)
+ goto out_use_good;
if (*sbnoa >= args->agbno + gdiff)
goto out_use_good;
} else {
+ if (*sbnoa < args->min_agbno)
+ goto out_use_good;
if (*sbnoa <= args->agbno - gdiff)
goto out_use_good;
}
@@ -884,6 +902,17 @@ xfs_alloc_ag_vextent_near(
dofirst = prandom_u32() & 1;
#endif
+ /* handle unitialized agbno range so caller doesn't have to */
+ if (!args->min_agbno && !args->max_agbno)
+ args->max_agbno = args->mp->m_sb.sb_agblocks - 1;
+ ASSERT(args->min_agbno <= args->max_agbno);
+
+ /* clamp agbno to the range if it's outside */
+ if (args->agbno < args->min_agbno)
+ args->agbno = args->min_agbno;
+ if (args->agbno > args->max_agbno)
+ args->agbno = args->max_agbno;
+
restart:
bno_cur_lt = NULL;
bno_cur_gt = NULL;
@@ -976,6 +1005,8 @@ restart:
&ltbnoa, &ltlena);
if (ltlena < args->minlen)
continue;
+ if (ltbnoa < args->min_agbno || ltbnoa > args->max_agbno)
+ continue;
args->len = XFS_EXTLEN_MIN(ltlena, args->maxlen);
xfs_alloc_fix_len(args);
ASSERT(args->len >= args->minlen);
@@ -1096,11 +1127,11 @@ restart:
XFS_WANT_CORRUPTED_GOTO(args->mp, i == 1, error0);
xfs_alloc_compute_aligned(args, ltbno, ltlen,
&ltbnoa, &ltlena);
- if (ltlena >= args->minlen)
+ if (ltlena >= args->minlen && ltbnoa >= args->min_agbno)
break;
if ((error = xfs_btree_decrement(bno_cur_lt, 0, &i)))
goto error0;
- if (!i) {
+ if (!i || ltbnoa < args->min_agbno) {
xfs_btree_del_cursor(bno_cur_lt,
XFS_BTREE_NOERROR);
bno_cur_lt = NULL;
@@ -1112,11 +1143,11 @@ restart:
XFS_WANT_CORRUPTED_GOTO(args->mp, i == 1, error0);
xfs_alloc_compute_aligned(args, gtbno, gtlen,
&gtbnoa, &gtlena);
- if (gtlena >= args->minlen)
+ if (gtlena >= args->minlen && gtbnoa <= args->max_agbno)
break;
if ((error = xfs_btree_increment(bno_cur_gt, 0, &i)))
goto error0;
- if (!i) {
+ if (!i || gtbnoa > args->max_agbno) {
xfs_btree_del_cursor(bno_cur_gt,
XFS_BTREE_NOERROR);
bno_cur_gt = NULL;
@@ -1216,6 +1247,7 @@ restart:
ASSERT(ltnew >= ltbno);
ASSERT(ltnew + rlen <= ltbnoa + ltlena);
ASSERT(ltnew + rlen <= be32_to_cpu(XFS_BUF_TO_AGF(args->agbp)->agf_length));
+ ASSERT(ltnew >= args->min_agbno && ltnew <= args->max_agbno);
args->agbno = ltnew;
if ((error = xfs_alloc_fixup_trees(cnt_cur, bno_cur_lt, ltbno, ltlen,
@@ -1825,11 +1857,11 @@ xfs_alloc_compute_maxlevels(
xfs_extlen_t
xfs_alloc_longest_free_extent(
struct xfs_mount *mp,
- struct xfs_perag *pag)
+ struct xfs_perag *pag,
+ xfs_extlen_t need)
{
- xfs_extlen_t need, delta = 0;
+ xfs_extlen_t delta = 0;
- need = XFS_MIN_FREELIST_PAG(pag, mp);
if (need > pag->pagf_flcount)
delta = need - pag->pagf_flcount;
@@ -1838,131 +1870,150 @@ xfs_alloc_longest_free_extent(
return pag->pagf_flcount > 0 || pag->pagf_longest > 0;
}
+unsigned int
+xfs_alloc_min_freelist(
+ struct xfs_mount *mp,
+ struct xfs_perag *pag)
+{
+ unsigned int min_free;
+
+ /* space needed by-bno freespace btree */
+ min_free = min_t(unsigned int, pag->pagf_levels[XFS_BTNUM_BNOi] + 1,
+ mp->m_ag_maxlevels);
+ /* space needed by-size freespace btree */
+ min_free += min_t(unsigned int, pag->pagf_levels[XFS_BTNUM_CNTi] + 1,
+ mp->m_ag_maxlevels);
+
+ return min_free;
+}
+
+/*
+ * Check if the operation we are fixing up the freelist for should go ahead or
+ * not. If we are freeing blocks, we always allow it, otherwise the allocation
+ * is dependent on whether the size and shape of free space available will
+ * permit the requested allocation to take place.
+ */
+static bool
+xfs_alloc_space_available(
+ struct xfs_alloc_arg *args,
+ xfs_extlen_t min_free,
+ int flags)
+{
+ struct xfs_perag *pag = args->pag;
+ xfs_extlen_t longest;
+ int available;
+
+ if (flags & XFS_ALLOC_FLAG_FREEING)
+ return true;
+
+ /* do we have enough contiguous free space for the allocation? */
+ longest = xfs_alloc_longest_free_extent(args->mp, pag, min_free);
+ if ((args->minlen + args->alignment + args->minalignslop - 1) > longest)
+ return false;
+
+ /* do have enough free space remaining for the allocation? */
+ available = (int)(pag->pagf_freeblks + pag->pagf_flcount -
+ min_free - args->total);
+ if (available < (int)args->minleft)
+ return false;
+
+ return true;
+}
+
/*
* 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_... */
+ struct xfs_alloc_arg *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;
+ struct xfs_mount *mp = args->mp;
+ struct xfs_perag *pag = args->pag;
+ struct xfs_trans *tp = args->tp;
+ struct xfs_buf *agbp = NULL;
+ struct xfs_buf *agflbp = NULL;
+ struct xfs_alloc_arg targs; /* local allocation arguments */
+ xfs_agblock_t bno; /* freelist block */
+ xfs_extlen_t need; /* total blocks needed in freelist */
+ int error;
- pag = args->pag;
- tp = args->tp;
if (!pag->pagf_init) {
- if ((error = xfs_alloc_read_agf(mp, tp, args->agno, flags,
- &agbp)))
- return error;
+ error = xfs_alloc_read_agf(mp, tp, args->agno, flags, &agbp);
+ if (error)
+ goto out_no_agbp;
if (!pag->pagf_init) {
ASSERT(flags & XFS_ALLOC_FLAG_TRYLOCK);
ASSERT(!(flags & XFS_ALLOC_FLAG_FREEING));
- args->agbp = NULL;
- return 0;
+ goto out_agbp_relse;
}
- } 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 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;
+ goto out_agbp_relse;
}
- 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;
- }
- }
+ need = xfs_alloc_min_freelist(mp, pag);
+ if (!xfs_alloc_space_available(args, need, flags))
+ goto out_agbp_relse;
/*
* 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) {
+ if (!agbp) {
+ error = xfs_alloc_read_agf(mp, tp, args->agno, flags, &agbp);
+ if (error)
+ goto out_no_agbp;
+ if (!agbp) {
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;
+ goto out_no_agbp;
}
}
+
+ /* If there isn't enough total space or single-extent, reject it. */
+ need = xfs_alloc_min_freelist(mp, pag);
+ if (!xfs_alloc_space_available(args, need, flags))
+ goto out_agbp_relse;
+
/*
* Make the freelist shorter if it's too long.
+ *
+ * Note that from this point onwards, we will always release the agf and
+ * agfl buffers on error. This handles the case where we error out and
+ * the buffers are clean or may not have been joined to the transaction
+ * and hence need to be released manually. If they have been joined to
+ * the transaction, then xfs_trans_brelse() will handle them
+ * appropriately based on the recursion count and dirty state of the
+ * buffer.
+ *
+ * XXX (dgc): When we have lots of free space, does this buy us
+ * anything other than extra overhead when we need to put more blocks
+ * back on the free list? Maybe we should only do this when space is
+ * getting low or the AGFL is more than half full?
*/
- while (be32_to_cpu(agf->agf_flcount) > need) {
- xfs_buf_t *bp;
+ while (pag->pagf_flcount > need) {
+ struct xfs_buf *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;
+ goto out_agbp_relse;
+ error = xfs_free_ag_extent(tp, agbp, args->agno, bno, 1, 1);
+ if (error)
+ goto out_agbp_relse;
bp = xfs_btree_get_bufs(mp, tp, args->agno, bno, 0);
xfs_trans_binval(tp, bp);
}
- /*
- * Initialize the args structure.
- */
+
memset(&targs, 0, sizeof(targs));
targs.tp = tp;
targs.mp = mp;
@@ -1971,21 +2022,20 @@ xfs_alloc_fix_freelist(
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) {
+ error = xfs_alloc_read_agfl(mp, tp, targs.agno, &agflbp);
+ if (error)
+ goto out_agbp_relse;
+
+ /* Make the freelist longer if it's too short. */
+ while (pag->pagf_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;
- }
+ targs.maxlen = need - pag->pagf_flcount;
+
+ /* Allocate as many blocks as possible at once. */
+ error = xfs_alloc_ag_vextent(&targs);
+ if (error)
+ goto out_agflbp_relse;
+
/*
* Stop if we run out. Won't happen if callers are obeying
* the restrictions correctly. Can happen for free calls
@@ -1994,9 +2044,7 @@ xfs_alloc_fix_freelist(
if (targs.agbno == NULLAGBLOCK) {
if (flags & XFS_ALLOC_FLAG_FREEING)
break;
- xfs_trans_brelse(tp, agflbp);
- args->agbp = NULL;
- return 0;
+ goto out_agflbp_relse;
}
/*
* Put each allocated block on the list.
@@ -2005,12 +2053,21 @@ xfs_alloc_fix_freelist(
error = xfs_alloc_put_freelist(tp, agbp,
agflbp, bno, 0);
if (error)
- return error;
+ goto out_agflbp_relse;
}
}
xfs_trans_brelse(tp, agflbp);
args->agbp = agbp;
return 0;
+
+out_agflbp_relse:
+ xfs_trans_brelse(tp, agflbp);
+out_agbp_relse:
+ if (agbp)
+ xfs_trans_brelse(tp, agbp);
+out_no_agbp:
+ args->agbp = NULL;
+ return error;
}
/*