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authorDave Chinner <david@fromorbit.com>2015-06-23 08:48:43 +1000
committerDave Chinner <david@fromorbit.com>2015-06-23 08:48:43 +1000
commit3d238b7e0efc2d9dde7513298ef32da289a6a0f4 (patch)
treee427366b478ecc974a4fc2a341a75f6c0114b012 /fs/xfs/libxfs/xfs_alloc.c
parent4ea79766168b64766d6c9fcdaa9fab83a6cfebcf (diff)
parent496817b4befced99dff6f23997723bf0962d56b0 (diff)
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Merge branch 'xfs-freelist-cleanup' into for-next
Diffstat (limited to 'fs/xfs/libxfs/xfs_alloc.c')
-rw-r--r--fs/xfs/libxfs/xfs_alloc.c239
1 files changed, 132 insertions, 107 deletions
diff --git a/fs/xfs/libxfs/xfs_alloc.c b/fs/xfs/libxfs/xfs_alloc.c
index bc78ac08e72e..f9e9ffe6fb46 100644
--- a/fs/xfs/libxfs/xfs_alloc.c
+++ b/fs/xfs/libxfs/xfs_alloc.c
@@ -1857,11 +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;
@@ -1870,131 +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;
@@ -2003,21 +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
@@ -2026,9 +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.
@@ -2037,12 +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;
}
/*