Loop over the in-core perag structures and prefer using pagi_freecount over
going out to the AGI buffer where possible.
Reviewed-by: Dave Chinner <dchinner@xxxxxxxxxx>
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
fs/xfs/xfs_ialloc.c | 95 ++++++++++++++++++++++++----------------------------
1 file changed, 44 insertions(+), 51 deletions(-)
Index: xfs/fs/xfs/xfs_ialloc.c
===================================================================
--- xfs.orig/fs/xfs/xfs_ialloc.c 2012-07-02 12:24:18.305775386 +0200
+++ xfs/fs/xfs/xfs_ialloc.c 2012-07-02 12:24:50.605775194 +0200
@@ -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;
/*
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