spin_lock(&mp->m_agirotor_lock);
agno = mp->m_agirotor;
- if (++mp->m_agirotor == mp->m_maxagi)
+ if (++mp->m_agirotor >= mp->m_maxagi)
mp->m_agirotor = 0;
spin_unlock(&mp->m_agirotor_lock);
* 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 */
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
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.
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);
/*
* 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;
}
}
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;
+ xfs_agnumber_t start_agno;
struct xfs_perag *pag;
if (*IO_agbp) {
* 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) {
+ start_agno = xfs_ialloc_ag_select(tp, parent, mode, okalloc);
+ if (start_agno == NULLAGNUMBER) {
*inop = NULLFSINO;
return 0;
}
- agi = XFS_BUF_TO_AGI(agbp);
-
- mp = tp->t_mountp;
- agno = be32_to_cpu(agi->agi_seqno);
- tagno = agno;
/*
* If we have already hit the ceiling of inode blocks then clear
* okalloc so we scan all available agi structures for a free
* inode.
*/
-
if (mp->m_maxicount &&
mp->m_sb.sb_icount + XFS_IALLOC_INODES(mp) > mp->m_maxicount) {
noroom = 1;
* or in which we can allocate some inodes. Iterate through the
* allocation groups upward, wrapping at the end.
*/
- while (!agi->agi_freecount) {
- /*
- * Don't do anything if we're not supposed to allocate
- * any blocks, just go on to the next ag.
- */
- if (okalloc) {
- /*
- * Try to allocate some new inodes in the allocation
- * group.
- */
- if ((error = xfs_ialloc_ag_alloc(tp, agbp, &ialloced))) {
- xfs_trans_brelse(tp, agbp);
- if (error == ENOSPC) {
- *inop = NULLFSINO;
- return 0;
- } else
- return error;
- }
- if (ialloced) {
- /*
- * We successfully allocated some inodes, return
- * the current context to the caller so that it
- * can commit the current transaction and call
- * us again where we left off.
- */
- ASSERT(be32_to_cpu(agi->agi_freecount) > 0);
- *IO_agbp = agbp;
- *inop = NULLFSINO;
- return 0;
- }
+ agno = start_agno;
+ 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 out_error;
}
+
/*
- * If it failed, give up on this ag.
+ * Do a first racy fast path check if this AG is usable.
*/
- xfs_trans_brelse(tp, agbp);
+ if (!pag->pagi_freecount && !okalloc)
+ goto nextag;
+
/*
- * Go on to the next ag: get its ag header.
+ * Then read in the AGI buffer and recheck with the AGI buffer
+ * lock held.
*/
-nextag:
- if (++tagno == mp->m_sb.sb_agcount)
- tagno = 0;
- if (tagno == agno) {
+ error = xfs_ialloc_read_agi(mp, tp, agno, &agbp);
+ if (error)
+ goto out_error;
+
+ if (pag->pagi_freecount) {
+ xfs_perag_put(pag);
+ goto out_alloc;
+ }
+
+ if (!okalloc)
+ goto nextag_relse_buffer;
+
+
+ error = xfs_ialloc_ag_alloc(tp, agbp, &ialloced);
+ if (error) {
+ xfs_trans_brelse(tp, agbp);
+
+ if (error != ENOSPC)
+ goto out_error;
+
+ xfs_perag_put(pag);
*inop = NULLFSINO;
- return noroom ? ENOSPC : 0;
+ return 0;
}
- pag = xfs_perag_get(mp, tagno);
- if (pag->pagi_inodeok == 0) {
+
+ if (ialloced) {
+ /*
+ * We successfully allocated some inodes, return
+ * the current context to the caller so that it
+ * can commit the current transaction and call
+ * us again where we left off.
+ */
+ ASSERT(pag->pagi_freecount > 0);
xfs_perag_put(pag);
- goto nextag;
+
+ *IO_agbp = agbp;
+ *inop = NULLFSINO;
+ return 0;
}
- error = xfs_ialloc_read_agi(mp, tp, tagno, &agbp);
+
+nextag_relse_buffer:
+ xfs_trans_brelse(tp, agbp);
+nextag:
xfs_perag_put(pag);
- if (error)
- goto nextag;
- agi = XFS_BUF_TO_AGI(agbp);
- ASSERT(agi->agi_magicnum == cpu_to_be32(XFS_AGI_MAGIC));
+ if (++agno == mp->m_sb.sb_agcount)
+ agno = 0;
+ if (agno == start_agno) {
+ *inop = NULLFSINO;
+ return noroom ? ENOSPC : 0;
+ }
}
out_alloc:
*IO_agbp = NULL;
return xfs_dialloc_ag(tp, agbp, parent, inop);
+out_error:
+ xfs_perag_put(pag);
+ return XFS_ERROR(error);
}
/*
projects / deliverable / linux.git / blobdiff