Both function contain the same basic loop over all AGs. Merge the two
by creating three passes in the loop instead of duplicating the code.
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
fs/xfs/xfs_ialloc.c | 179 +++++++++++++++-------------------------------------
1 file changed, 55 insertions(+), 124 deletions(-)
Index: xfs/fs/xfs/xfs_ialloc.c
===================================================================
--- xfs.orig/fs/xfs/xfs_ialloc.c 2012-07-02 12:25:24.365774992 +0200
+++ xfs/fs/xfs/xfs_ialloc.c 2012-07-02 12:26:14.325774734 +0200
@@ -439,114 +439,6 @@ 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_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_agnumber_t agcount; /* number of ag's in the filesystem */
- xfs_agnumber_t agno; /* current ag number */
- int flags; /* alloc buffer locking flags */
- xfs_extlen_t ineed; /* blocks needed for inode allocation */
- xfs_extlen_t longest = 0; /* longest extent available */
- xfs_mount_t *mp; /* mount point structure */
- 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
- * (and they won't fit in the inode, but that's hard to figure out).
- */
- needspace = S_ISDIR(mode) || S_ISREG(mode) || S_ISLNK(mode);
- mp = tp->t_mountp;
- agcount = mp->m_maxagi;
- if (S_ISDIR(mode))
- pagno = xfs_ialloc_next_ag(mp);
- else {
- pagno = XFS_INO_TO_AGNO(mp, parent);
- 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.
- * Instead, we include whether there is a need to allocate inodes
- * to mean that blocks must be allocated for them,
- * if none are currently free.
- */
- agno = pagno;
- 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) {
- error = xfs_ialloc_pagi_init(mp, tp, agno);
- if (error)
- goto nextag;
- }
-
- if (pag->pagi_freecount) {
- xfs_perag_put(pag);
- return agno;
- }
-
- if (!okalloc)
- goto nextag;
-
- if (!pag->pagf_init) {
- error = xfs_alloc_pagf_init(mp, tp, agno, flags);
- if (error)
- goto nextag;
- }
-
- /*
- * 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;
- }
-nextag:
- xfs_perag_put(pag);
- /*
- * No point in iterating over the rest, if we're shutting
- * down.
- */
- if (XFS_FORCED_SHUTDOWN(mp))
- return NULLAGNUMBER;
- agno++;
- if (agno >= agcount)
- agno = 0;
- if (agno == pagno) {
- if (flags == 0)
- return NULLAGNUMBER;
- flags = 0;
- }
- }
-}
-
-/*
* Try to retrieve the next record to the left/right from the current one.
*/
STATIC int
@@ -901,10 +793,10 @@ xfs_dialloc(
struct xfs_buf *agbp;
xfs_agnumber_t agno;
int error;
- int ialloced;
int noroom = 0;
xfs_agnumber_t start_agno;
struct xfs_perag *pag;
+ int pass;
if (*IO_agbp) {
/*
@@ -917,16 +809,6 @@ xfs_dialloc(
}
/*
- * We do not have an agbp, so select an initial allocation
- * group for inode allocation.
- */
- start_agno = xfs_ialloc_ag_select(tp, parent, mode, okalloc);
- if (start_agno == NULLAGNUMBER) {
- *inop = NULLFSINO;
- return 0;
- }
-
- /*
* If we have already hit the ceiling of inode blocks then clear
* okalloc so we scan all available agi structures for a free
* inode.
@@ -938,12 +820,31 @@ xfs_dialloc(
}
/*
- * Loop until we find an allocation group that either has free inodes
- * or in which we can allocate some inodes. Iterate through the
- * allocation groups upward, wrapping at the end.
+ * For directories start with a new allocation groups, for other file
+ * types aim to find an inode close to the parent.
*/
+ if (S_ISDIR(mode)) {
+ start_agno = xfs_ialloc_next_ag(mp);
+ ASSERT(start_agno < mp->m_maxagi);
+ } else {
+ start_agno = XFS_INO_TO_AGNO(mp, parent);
+ if (start_agno >= mp->m_maxagi)
+ start_agno = 0;
+ }
+
+ /*
+ * Loop through allocation groups, looking for one with a little
+ * free space in it. Note we don't look for free inodes, exactly.
+ * Instead, we include whether there is a need to allocate inodes
+ * to mean that blocks must be allocated for them, if none are
+ * currently free.
+ */
+ *inop = NULLFSINO;
agno = start_agno;
+ pass = 0;
for (;;) {
+ int ialloced;
+
pag = xfs_perag_get(mp, agno);
if (!pag->pagi_inodeok) {
xfs_ialloc_next_ag(mp);
@@ -980,6 +881,33 @@ xfs_dialloc(
goto nextag;
}
+ if (!pag->pagf_init) {
+ int flags = pass ? 0 : XFS_ALLOC_FLAG_TRYLOCK;
+
+ error = xfs_alloc_pagf_init(mp, tp, agno, flags);
+ if (error)
+ goto out_error;
+ }
+
+ if (pass < 2) {
+ /*
+ * Is there enough free space for the file plus a block
+ * of inodes?
+ */
+ xfs_extlen_t longest = pag->pagf_longest;
+ int needspace =
+ S_ISDIR(mode) || S_ISREG(mode) || S_ISLNK(mode);
+
+ if (!longest)
+ longest = pag->pagf_flcount > 0;
+
+ if (pag->pagf_freeblks <
+ XFS_IALLOC_BLOCKS(mp) + needspace)
+ goto nextag;
+ if (longest < XFS_IALLOC_BLOCKS(mp))
+ goto nextag;
+ }
+
error = xfs_ialloc_ag_alloc(tp, agbp, &ialloced);
if (error) {
xfs_trans_brelse(tp, agbp);
@@ -1012,8 +940,11 @@ nextag:
if (++agno == mp->m_sb.sb_agcount)
agno = 0;
if (agno == start_agno) {
- *inop = NULLFSINO;
- return noroom ? ENOSPC : 0;
+ if (pass == 2) {
+ *inop = NULLFSINO;
+ return noroom ? ENOSPC : 0;
+ }
+ pass++;
}
}
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