From f2ecc5e453134a13c3b2b0f2cac52ab2d5c540d7 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Wed, 4 Jul 2012 10:54:46 -0400 Subject: [PATCH] xfs: split xfs_dialloc Move the actual allocation once we have selected an allocation group into a separate helper, and make xfs_dialloc a wrapper around it. Signed-off-by: Christoph Hellwig Reviewed-by: Dave Chinner Reviewed-by: Ben Myers Signed-off-by: Ben Myers --- fs/xfs/xfs_ialloc.c | 349 ++++++++++++++++++++++---------------------- 1 file changed, 174 insertions(+), 175 deletions(-) diff --git a/fs/xfs/xfs_ialloc.c b/fs/xfs/xfs_ialloc.c index 30b816d1f7e0..a124b9f88aae 100644 --- a/fs/xfs/xfs_ialloc.c +++ b/fs/xfs/xfs_ialloc.c @@ -607,188 +607,35 @@ xfs_ialloc_get_rec( } /* - * Visible inode allocation functions. - */ - -/* - * Allocate an inode on disk. - * Mode is used to tell whether the new inode will need space, and whether - * it is a directory. + * Allocate an inode. * - * The arguments IO_agbp and alloc_done are defined to work within - * the constraint of one allocation per transaction. - * xfs_dialloc() is designed to be called twice if it has to do an - * allocation to make more free inodes. On the first call, - * IO_agbp should be set to NULL. If an inode is available, - * i.e., xfs_dialloc() did not need to do an allocation, an inode - * number is returned. In this case, IO_agbp would be set to the - * current ag_buf and alloc_done set to false. - * If an allocation needed to be done, xfs_dialloc would return - * the current ag_buf in IO_agbp and set alloc_done to true. - * The caller should then commit the current transaction, allocate a new - * transaction, and call xfs_dialloc() again, passing in the previous - * value of IO_agbp. IO_agbp should be held across the transactions. - * Since the agbp is locked across the two calls, the second call is - * guaranteed to have a free inode available. - * - * Once we successfully pick an inode its number is returned and the - * on-disk data structures are updated. The inode itself is not read - * in, since doing so would break ordering constraints with xfs_reclaim. + * The caller selected an AG for us, and made sure that free inodes are + * available. */ -int -xfs_dialloc( - xfs_trans_t *tp, /* transaction pointer */ - xfs_ino_t parent, /* parent inode (directory) */ - umode_t mode, /* mode bits for new inode */ - int okalloc, /* ok to allocate more space */ - xfs_buf_t **IO_agbp, /* in/out ag header's buffer */ - boolean_t *alloc_done, /* true if we needed to replenish - inode freelist */ - xfs_ino_t *inop) /* inode number allocated */ +STATIC int +xfs_dialloc_ag( + struct xfs_trans *tp, + struct xfs_buf *agbp, + xfs_ino_t parent, + xfs_ino_t *inop) { - xfs_agnumber_t agcount; /* number of allocation groups */ - xfs_buf_t *agbp; /* allocation group header's buffer */ - xfs_agnumber_t agno; /* allocation group number */ - xfs_agi_t *agi; /* allocation group header structure */ - xfs_btree_cur_t *cur; /* inode allocation btree cursor */ - int error; /* error return value */ - int i; /* result code */ - int ialloced; /* inode allocation status */ - int noroom = 0; /* no space for inode blk allocation */ - xfs_ino_t ino; /* fs-relative inode to be returned */ - /* REFERENCED */ - int j; /* result code */ - xfs_mount_t *mp; /* file system mount structure */ - int offset; /* index of inode in chunk */ - xfs_agino_t pagino; /* parent's AG relative inode # */ - xfs_agnumber_t pagno; /* parent's AG number */ - xfs_inobt_rec_incore_t rec; /* inode allocation record */ - xfs_agnumber_t tagno; /* testing allocation group number */ - xfs_btree_cur_t *tcur; /* temp cursor */ - xfs_inobt_rec_incore_t trec; /* temp inode allocation record */ - struct xfs_perag *pag; - - - if (*IO_agbp == NULL) { - /* - * 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) { - *inop = NULLFSINO; - return 0; - } - agi = XFS_BUF_TO_AGI(agbp); - ASSERT(agi->agi_magicnum == cpu_to_be32(XFS_AGI_MAGIC)); - } else { - /* - * Continue where we left off before. In this case, we - * know that the allocation group has free inodes. - */ - agbp = *IO_agbp; - agi = XFS_BUF_TO_AGI(agbp); - ASSERT(agi->agi_magicnum == cpu_to_be32(XFS_AGI_MAGIC)); - ASSERT(be32_to_cpu(agi->agi_freecount) > 0); - } - mp = tp->t_mountp; - agcount = mp->m_sb.sb_agcount; - agno = be32_to_cpu(agi->agi_seqno); - tagno = agno; - pagno = XFS_INO_TO_AGNO(mp, parent); - pagino = XFS_INO_TO_AGINO(mp, parent); - - /* - * 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; - okalloc = 0; - } + struct xfs_mount *mp = tp->t_mountp; + struct xfs_agi *agi = XFS_BUF_TO_AGI(agbp); + xfs_agnumber_t agno = be32_to_cpu(agi->agi_seqno); + xfs_agnumber_t pagno = XFS_INO_TO_AGNO(mp, parent); + xfs_agino_t pagino = XFS_INO_TO_AGINO(mp, parent); + struct xfs_perag *pag; + struct xfs_btree_cur *cur, *tcur; + struct xfs_inobt_rec_incore rec, trec; + xfs_ino_t ino; + int error; + int offset; + int i, j; - /* - * 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. - */ - *alloc_done = B_FALSE; - 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); - *alloc_done = B_TRUE; - *IO_agbp = agbp; - *inop = NULLFSINO; - return 0; - } - } - /* - * If it failed, give up on this ag. - */ - xfs_trans_brelse(tp, agbp); - /* - * Go on to the next ag: get its ag header. - */ -nextag: - if (++tagno == agcount) - tagno = 0; - if (tagno == agno) { - *inop = NULLFSINO; - return noroom ? ENOSPC : 0; - } - pag = xfs_perag_get(mp, tagno); - if (pag->pagi_inodeok == 0) { - xfs_perag_put(pag); - goto nextag; - } - error = xfs_ialloc_read_agi(mp, tp, tagno, &agbp); - xfs_perag_put(pag); - if (error) - goto nextag; - agi = XFS_BUF_TO_AGI(agbp); - ASSERT(agi->agi_magicnum == cpu_to_be32(XFS_AGI_MAGIC)); - } - /* - * Here with an allocation group that has a free inode. - * Reset agno since we may have chosen a new ag in the - * loop above. - */ - agno = tagno; - *IO_agbp = NULL; pag = xfs_perag_get(mp, agno); restart_pagno: - cur = xfs_inobt_init_cursor(mp, tp, agbp, be32_to_cpu(agi->agi_seqno)); + cur = xfs_inobt_init_cursor(mp, tp, agbp, agno); /* * If pagino is 0 (this is the root inode allocation) use newino. * This must work because we've just allocated some. @@ -1020,6 +867,158 @@ error0: return error; } +/* + * Allocate an inode on disk. + * + * Mode is used to tell whether the new inode will need space, and whether it + * is a directory. + * + * This function is designed to be called twice if it has to do an allocation + * to make more free inodes. On the first call, *IO_agbp should be set to NULL. + * If an inode is available without having to performn an allocation, an inode + * number is returned. In this case, *IO_agbp would be NULL. If an allocation + * needes to be done, xfs_dialloc would return the current AGI buffer in + * *IO_agbp. The caller should then commit the current transaction, allocate a + * new transaction, and call xfs_dialloc() again, passing in the previous value + * of *IO_agbp. IO_agbp should be held across the transactions. Since the AGI + * buffer is locked across the two calls, the second call is guaranteed to have + * a free inode available. + * + * Once we successfully pick an inode its number is returned and the on-disk + * data structures are updated. The inode itself is not read in, since doing so + * would break ordering constraints with xfs_reclaim. + */ +int +xfs_dialloc( + struct xfs_trans *tp, + xfs_ino_t parent, + umode_t mode, + int okalloc, + struct xfs_buf **IO_agbp, + boolean_t *alloc_done, + xfs_ino_t *inop) +{ + 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; + + if (*IO_agbp == NULL) { + /* + * 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) { + *inop = NULLFSINO; + return 0; + } + agi = XFS_BUF_TO_AGI(agbp); + ASSERT(agi->agi_magicnum == cpu_to_be32(XFS_AGI_MAGIC)); + } else { + /* + * Continue where we left off before. In this case, we + * know that the allocation group has free inodes. + */ + agbp = *IO_agbp; + agi = XFS_BUF_TO_AGI(agbp); + ASSERT(agi->agi_magicnum == cpu_to_be32(XFS_AGI_MAGIC)); + ASSERT(be32_to_cpu(agi->agi_freecount) > 0); + } + 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; + okalloc = 0; + } + + /* + * 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. + */ + *alloc_done = B_FALSE; + 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); + *alloc_done = B_TRUE; + *IO_agbp = agbp; + *inop = NULLFSINO; + return 0; + } + } + /* + * If it failed, give up on this ag. + */ + xfs_trans_brelse(tp, agbp); + /* + * Go on to the next ag: get its ag header. + */ +nextag: + if (++tagno == mp->m_sb.sb_agcount) + tagno = 0; + if (tagno == agno) { + *inop = NULLFSINO; + return noroom ? ENOSPC : 0; + } + pag = xfs_perag_get(mp, tagno); + if (pag->pagi_inodeok == 0) { + xfs_perag_put(pag); + goto nextag; + } + error = xfs_ialloc_read_agi(mp, tp, tagno, &agbp); + xfs_perag_put(pag); + if (error) + goto nextag; + agi = XFS_BUF_TO_AGI(agbp); + ASSERT(agi->agi_magicnum == cpu_to_be32(XFS_AGI_MAGIC)); + } + + *IO_agbp = NULL; + return xfs_dialloc_ag(tp, agbp, parent, inop); +} + /* * Free disk inode. Carefully avoids touching the incore inode, all * manipulations incore are the caller's responsibility. -- 2.34.1