From c467c049e7e6e8b8fe9f38b13b20a4cf7e03f36b Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Mon, 15 Feb 2010 23:34:42 +0000 Subject: [PATCH] xfs: split xfs_bmap_btalloc Split out the nullfb case into a separate function to reduce the stack footprint and make the code more readable. Signed-off-by: Christoph Hellwig Reviewed-by: Dave Chinner Signed-off-by: Alex Elder --- fs/xfs/xfs_bmap.c | 220 +++++++++++++++++++++++++--------------------- 1 file changed, 119 insertions(+), 101 deletions(-) diff --git a/fs/xfs/xfs_bmap.c b/fs/xfs/xfs_bmap.c index 1869fb973819..5c11e4d17010 100644 --- a/fs/xfs/xfs_bmap.c +++ b/fs/xfs/xfs_bmap.c @@ -2549,6 +2549,121 @@ xfs_bmap_rtalloc( return 0; } +STATIC int +xfs_bmap_btalloc_nullfb( + struct xfs_bmalloca *ap, + struct xfs_alloc_arg *args, + xfs_extlen_t *blen) +{ + struct xfs_mount *mp = ap->ip->i_mount; + struct xfs_perag *pag; + xfs_agnumber_t ag, startag; + int notinit = 0; + int error; + + if (ap->userdata && xfs_inode_is_filestream(ap->ip)) + args->type = XFS_ALLOCTYPE_NEAR_BNO; + else + args->type = XFS_ALLOCTYPE_START_BNO; + args->total = ap->total; + + /* + * Search for an allocation group with a single extent large enough + * for the request. If one isn't found, then adjust the minimum + * allocation size to the largest space found. + */ + startag = ag = XFS_FSB_TO_AGNO(mp, args->fsbno); + if (startag == NULLAGNUMBER) + startag = ag = 0; + + pag = xfs_perag_get(mp, ag); + while (*blen < ap->alen) { + if (!pag->pagf_init) { + error = xfs_alloc_pagf_init(mp, args->tp, ag, + XFS_ALLOC_FLAG_TRYLOCK); + if (error) { + xfs_perag_put(pag); + return error; + } + } + + /* + * See xfs_alloc_fix_freelist... + */ + if (pag->pagf_init) { + xfs_extlen_t longest; + longest = xfs_alloc_longest_free_extent(mp, pag); + if (*blen < longest) + *blen = longest; + } else + notinit = 1; + + if (xfs_inode_is_filestream(ap->ip)) { + if (*blen >= ap->alen) + break; + + if (ap->userdata) { + /* + * If startag is an invalid AG, we've + * come here once before and + * xfs_filestream_new_ag picked the + * best currently available. + * + * Don't continue looping, since we + * could loop forever. + */ + if (startag == NULLAGNUMBER) + break; + + error = xfs_filestream_new_ag(ap, &ag); + xfs_perag_put(pag); + if (error) + return error; + + /* loop again to set 'blen'*/ + startag = NULLAGNUMBER; + pag = xfs_perag_get(mp, ag); + continue; + } + } + if (++ag == mp->m_sb.sb_agcount) + ag = 0; + if (ag == startag) + break; + xfs_perag_put(pag); + pag = xfs_perag_get(mp, ag); + } + xfs_perag_put(pag); + + /* + * Since the above loop did a BUF_TRYLOCK, it is + * possible that there is space for this request. + */ + if (notinit || *blen < ap->minlen) + args->minlen = ap->minlen; + /* + * If the best seen length is less than the request + * length, use the best as the minimum. + */ + else if (*blen < ap->alen) + args->minlen = *blen; + /* + * Otherwise we've seen an extent as big as alen, + * use that as the minimum. + */ + else + args->minlen = ap->alen; + + /* + * set the failure fallback case to look in the selected + * AG as the stream may have moved. + */ + if (xfs_inode_is_filestream(ap->ip)) + ap->rval = args->fsbno = XFS_AGB_TO_FSB(mp, ag, 0); + + return 0; +} + STATIC int xfs_bmap_btalloc( xfs_bmalloca_t *ap) /* bmap alloc argument struct */ @@ -2556,16 +2671,13 @@ xfs_bmap_btalloc( xfs_mount_t *mp; /* mount point structure */ xfs_alloctype_t atype = 0; /* type for allocation routines */ xfs_extlen_t align; /* minimum allocation alignment */ - xfs_agnumber_t ag; xfs_agnumber_t fb_agno; /* ag number of ap->firstblock */ - xfs_agnumber_t startag; + xfs_agnumber_t ag; xfs_alloc_arg_t args; xfs_extlen_t blen; xfs_extlen_t nextminlen = 0; - xfs_perag_t *pag; int nullfb; /* true if ap->firstblock isn't set */ int isaligned; - int notinit; int tryagain; int error; @@ -2612,103 +2724,9 @@ xfs_bmap_btalloc( args.firstblock = ap->firstblock; blen = 0; if (nullfb) { - if (ap->userdata && xfs_inode_is_filestream(ap->ip)) - args.type = XFS_ALLOCTYPE_NEAR_BNO; - else - args.type = XFS_ALLOCTYPE_START_BNO; - args.total = ap->total; - - /* - * Search for an allocation group with a single extent - * large enough for the request. - * - * If one isn't found, then adjust the minimum allocation - * size to the largest space found. - */ - startag = ag = XFS_FSB_TO_AGNO(mp, args.fsbno); - if (startag == NULLAGNUMBER) - startag = ag = 0; - notinit = 0; - pag = xfs_perag_get(mp, ag); - while (blen < ap->alen) { - if (!pag->pagf_init && - (error = xfs_alloc_pagf_init(mp, args.tp, - ag, XFS_ALLOC_FLAG_TRYLOCK))) { - xfs_perag_put(pag); - return error; - } - /* - * See xfs_alloc_fix_freelist... - */ - if (pag->pagf_init) { - xfs_extlen_t longest; - longest = xfs_alloc_longest_free_extent(mp, pag); - if (blen < longest) - blen = longest; - } else - notinit = 1; - - if (xfs_inode_is_filestream(ap->ip)) { - if (blen >= ap->alen) - break; - - if (ap->userdata) { - /* - * If startag is an invalid AG, we've - * come here once before and - * xfs_filestream_new_ag picked the - * best currently available. - * - * Don't continue looping, since we - * could loop forever. - */ - if (startag == NULLAGNUMBER) - break; - - error = xfs_filestream_new_ag(ap, &ag); - xfs_perag_put(pag); - if (error) - return error; - - /* loop again to set 'blen'*/ - startag = NULLAGNUMBER; - pag = xfs_perag_get(mp, ag); - continue; - } - } - if (++ag == mp->m_sb.sb_agcount) - ag = 0; - if (ag == startag) - break; - xfs_perag_put(pag); - pag = xfs_perag_get(mp, ag); - } - xfs_perag_put(pag); - /* - * Since the above loop did a BUF_TRYLOCK, it is - * possible that there is space for this request. - */ - if (notinit || blen < ap->minlen) - args.minlen = ap->minlen; - /* - * If the best seen length is less than the request - * length, use the best as the minimum. - */ - else if (blen < ap->alen) - args.minlen = blen; - /* - * Otherwise we've seen an extent as big as alen, - * use that as the minimum. - */ - else - args.minlen = ap->alen; - - /* - * set the failure fallback case to look in the selected - * AG as the stream may have moved. - */ - if (xfs_inode_is_filestream(ap->ip)) - ap->rval = args.fsbno = XFS_AGB_TO_FSB(mp, ag, 0); + error = xfs_bmap_btalloc_nullfb(ap, &args, &blen); + if (error) + return error; } else if (ap->low) { if (xfs_inode_is_filestream(ap->ip)) args.type = XFS_ALLOCTYPE_FIRST_AG;