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author | Christoph Hellwig <hch@infradead.org> | 2012-07-04 10:54:49 -0400 |
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committer | Ben Myers <bpm@sgi.com> | 2012-07-29 16:08:13 -0500 |
commit | 55d6af64cb8bf8c7e9a84b254d2c3479be8c067c (patch) | |
tree | 81aa38aee76d5133e12485ee7f47a5309582fac3 | |
parent | 4bb61069d2019dea2a7e4e0f4432101f03a9b820 (diff) | |
download | linux-3.10-55d6af64cb8bf8c7e9a84b254d2c3479be8c067c.tar.gz linux-3.10-55d6af64cb8bf8c7e9a84b254d2c3479be8c067c.tar.bz2 linux-3.10-55d6af64cb8bf8c7e9a84b254d2c3479be8c067c.zip |
xfs: refactor xfs_ialloc_ag_select
Loop over the in-core perag structures and prefer using pagi_freecount over
going out to the AGI buffer where possible.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
-rw-r--r-- | fs/xfs/xfs_ialloc.c | 95 |
1 files changed, 44 insertions, 51 deletions
diff --git a/fs/xfs/xfs_ialloc.c b/fs/xfs/xfs_ialloc.c index 7aa8a02b793..ecb9f22a7f3 100644 --- a/fs/xfs/xfs_ialloc.c +++ b/fs/xfs/xfs_ialloc.c @@ -442,14 +442,13 @@ xfs_ialloc_next_ag( * Select an allocation group to look for a free inode in, based on the parent * inode and then mode. Return the allocation group buffer. */ -STATIC xfs_buf_t * /* allocation group buffer */ +STATIC xfs_agnumber_t xfs_ialloc_ag_select( xfs_trans_t *tp, /* transaction pointer */ xfs_ino_t parent, /* parent directory inode number */ umode_t mode, /* bits set to indicate file type */ int okalloc) /* ok to allocate more space */ { - xfs_buf_t *agbp; /* allocation group header buffer */ xfs_agnumber_t agcount; /* number of ag's in the filesystem */ xfs_agnumber_t agno; /* current ag number */ int flags; /* alloc buffer locking flags */ @@ -459,6 +458,7 @@ xfs_ialloc_ag_select( int needspace; /* file mode implies space allocated */ xfs_perag_t *pag; /* per allocation group data */ xfs_agnumber_t pagno; /* parent (starting) ag number */ + int error; /* * Files of these types need at least one block if length > 0 @@ -474,7 +474,9 @@ xfs_ialloc_ag_select( if (pagno >= agcount) pagno = 0; } + ASSERT(pagno < agcount); + /* * Loop through allocation groups, looking for one with a little * free space in it. Note we don't look for free inodes, exactly. @@ -486,51 +488,45 @@ xfs_ialloc_ag_select( flags = XFS_ALLOC_FLAG_TRYLOCK; for (;;) { pag = xfs_perag_get(mp, agno); + if (!pag->pagi_inodeok) { + xfs_ialloc_next_ag(mp); + goto nextag; + } + if (!pag->pagi_init) { - if (xfs_ialloc_read_agi(mp, tp, agno, &agbp)) { - agbp = NULL; + error = xfs_ialloc_pagi_init(mp, tp, agno); + if (error) goto nextag; - } - } else - agbp = NULL; + } - if (!pag->pagi_inodeok) { - xfs_ialloc_next_ag(mp); - goto unlock_nextag; + if (pag->pagi_freecount) { + xfs_perag_put(pag); + return agno; } - /* - * Is there enough free space for the file plus a block - * of inodes (if we need to allocate some)? - */ - ineed = pag->pagi_freecount ? 0 : XFS_IALLOC_BLOCKS(mp); - if (ineed && !pag->pagf_init) { - if (agbp == NULL && - xfs_ialloc_read_agi(mp, tp, agno, &agbp)) { - agbp = NULL; + if (!okalloc) + goto nextag; + + if (!pag->pagf_init) { + error = xfs_alloc_pagf_init(mp, tp, agno, flags); + if (error) goto nextag; - } - (void)xfs_alloc_pagf_init(mp, tp, agno, flags); } - if (!ineed || pag->pagf_init) { - if (ineed && !(longest = pag->pagf_longest)) - longest = pag->pagf_flcount > 0; - if (!ineed || - (pag->pagf_freeblks >= needspace + ineed && - longest >= ineed && - okalloc)) { - if (agbp == NULL && - xfs_ialloc_read_agi(mp, tp, agno, &agbp)) { - agbp = NULL; - goto nextag; - } - xfs_perag_put(pag); - return agbp; - } + + /* + * Is there enough free space for the file plus a block of + * inodes? (if we need to allocate some)? + */ + ineed = XFS_IALLOC_BLOCKS(mp); + longest = pag->pagf_longest; + if (!longest) + longest = pag->pagf_flcount > 0; + + if (pag->pagf_freeblks >= needspace + ineed && + longest >= ineed) { + xfs_perag_put(pag); + return agno; } -unlock_nextag: - if (agbp) - xfs_trans_brelse(tp, agbp); nextag: xfs_perag_put(pag); /* @@ -538,13 +534,13 @@ nextag: * down. */ if (XFS_FORCED_SHUTDOWN(mp)) - return NULL; + return NULLAGNUMBER; agno++; if (agno >= agcount) agno = 0; if (agno == pagno) { if (flags == 0) - return NULL; + return NULLAGNUMBER; flags = 0; } } @@ -901,13 +897,13 @@ xfs_dialloc( struct xfs_buf **IO_agbp, xfs_ino_t *inop) { + struct xfs_mount *mp = tp->t_mountp; struct xfs_buf *agbp; xfs_agnumber_t agno; struct xfs_agi *agi; int error; int ialloced; int noroom = 0; - struct xfs_mount *mp; xfs_agnumber_t tagno; struct xfs_perag *pag; @@ -925,20 +921,17 @@ xfs_dialloc( * We do not have an agbp, so select an initial allocation * group for inode allocation. */ - agbp = xfs_ialloc_ag_select(tp, parent, mode, okalloc); - - /* - * Couldn't find an allocation group satisfying the - * criteria, give up. - */ - if (!agbp) { + agno = xfs_ialloc_ag_select(tp, parent, mode, okalloc); + if (agno == NULLAGNUMBER) { *inop = NULLFSINO; return 0; } + + error = xfs_ialloc_read_agi(mp, tp, agno, &agbp); + if (error) + return XFS_ERROR(error); agi = XFS_BUF_TO_AGI(agbp); - mp = tp->t_mountp; - agno = be32_to_cpu(agi->agi_seqno); tagno = agno; /* |