diff options
| -rw-r--r-- | fs/xfs/xfs_alloc.h | 16 | ||||
| -rw-r--r-- | fs/xfs/xfs_bmap.c | 18 |
2 files changed, 26 insertions, 8 deletions
diff --git a/fs/xfs/xfs_alloc.h b/fs/xfs/xfs_alloc.h index 0ab56b32c7eb..d0b3bc72005b 100644 --- a/fs/xfs/xfs_alloc.h +++ b/fs/xfs/xfs_alloc.h @@ -75,6 +75,22 @@ typedef unsigned int xfs_alloctype_t; #define XFS_ALLOC_SET_ASIDE(mp) (4 + ((mp)->m_sb.sb_agcount * 4)) /* + * When deciding how much space to allocate out of an AG, we limit the + * allocation maximum size to the size the AG. However, we cannot use all the + * blocks in the AG - some are permanently used by metadata. These + * blocks are generally: + * - the AG superblock, AGF, AGI and AGFL + * - the AGF (bno and cnt) and AGI btree root blocks + * - 4 blocks on the AGFL according to XFS_ALLOC_SET_ASIDE() limits + * + * The AG headers are sector sized, so the amount of space they take up is + * dependent on filesystem geometry. The others are all single blocks. + */ +#define XFS_ALLOC_AG_MAX_USABLE(mp) \ + ((mp)->m_sb.sb_agblocks - XFS_BB_TO_FSB(mp, XFS_FSS_TO_BB(mp, 4)) - 7) + + +/* * Argument structure for xfs_alloc routines. * This is turned into a structure to avoid having 20 arguments passed * down several levels of the stack. diff --git a/fs/xfs/xfs_bmap.c b/fs/xfs/xfs_bmap.c index 4111cd3966c7..f3a3768189bb 100644 --- a/fs/xfs/xfs_bmap.c +++ b/fs/xfs/xfs_bmap.c @@ -2430,7 +2430,7 @@ xfs_bmap_btalloc_nullfb( startag = ag = 0; pag = xfs_perag_get(mp, ag); - while (*blen < ap->alen) { + while (*blen < args->maxlen) { if (!pag->pagf_init) { error = xfs_alloc_pagf_init(mp, args->tp, ag, XFS_ALLOC_FLAG_TRYLOCK); @@ -2452,7 +2452,7 @@ xfs_bmap_btalloc_nullfb( notinit = 1; if (xfs_inode_is_filestream(ap->ip)) { - if (*blen >= ap->alen) + if (*blen >= args->maxlen) break; if (ap->userdata) { @@ -2498,14 +2498,14 @@ xfs_bmap_btalloc_nullfb( * If the best seen length is less than the request * length, use the best as the minimum. */ - else if (*blen < ap->alen) + else if (*blen < args->maxlen) args->minlen = *blen; /* - * Otherwise we've seen an extent as big as alen, + * Otherwise we've seen an extent as big as maxlen, * use that as the minimum. */ else - args->minlen = ap->alen; + args->minlen = args->maxlen; /* * set the failure fallback case to look in the selected @@ -2573,7 +2573,9 @@ xfs_bmap_btalloc( args.tp = ap->tp; args.mp = mp; args.fsbno = ap->rval; - args.maxlen = MIN(ap->alen, mp->m_sb.sb_agblocks); + + /* Trim the allocation back to the maximum an AG can fit. */ + args.maxlen = MIN(ap->alen, XFS_ALLOC_AG_MAX_USABLE(mp)); args.firstblock = ap->firstblock; blen = 0; if (nullfb) { @@ -2621,7 +2623,7 @@ xfs_bmap_btalloc( /* * Adjust for alignment */ - if (blen > args.alignment && blen <= ap->alen) + if (blen > args.alignment && blen <= args.maxlen) args.minlen = blen - args.alignment; args.minalignslop = 0; } else { @@ -2640,7 +2642,7 @@ xfs_bmap_btalloc( * of minlen+alignment+slop doesn't go up * between the calls. */ - if (blen > mp->m_dalign && blen <= ap->alen) + if (blen > mp->m_dalign && blen <= args.maxlen) nextminlen = blen - mp->m_dalign; else nextminlen = args.minlen; |