From: Brian Foster Date: Thu, 24 Apr 2014 06:00:53 +0000 (+1000) Subject: xfs: use and update the finobt on inode allocation X-Git-Tag: v3.16-rc1~46^2~6^2~5 X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=6dd8638e4e8764e0d6557fc62840a815a99c136d;p=linux-2.6-block.git xfs: use and update the finobt on inode allocation Replace xfs_dialloc_ag() with an implementation that looks for a record in the finobt. The finobt only tracks records with at least one free inode. This eliminates the need for the intra-ag scan in the original algorithm. Once the inode is allocated, update the finobt appropriately (possibly removing the record) as well as the inobt. Move the original xfs_dialloc_ag() algorithm to xfs_dialloc_ag_inobt() and fall back as such if finobt support is not enabled. Signed-off-by: Brian Foster Reviewed-by: Dave Chinner Signed-off-by: Dave Chinner --- diff --git a/fs/xfs/xfs_ialloc.c b/fs/xfs/xfs_ialloc.c index 203db98f0bc9..ab3540b675d5 100644 --- a/fs/xfs/xfs_ialloc.c +++ b/fs/xfs/xfs_ialloc.c @@ -722,13 +722,10 @@ xfs_ialloc_get_rec( } /* - * Allocate an inode. - * - * The caller selected an AG for us, and made sure that free inodes are - * available. + * Allocate an inode using the inobt-only algorithm. */ STATIC int -xfs_dialloc_ag( +xfs_dialloc_ag_inobt( struct xfs_trans *tp, struct xfs_buf *agbp, xfs_ino_t parent, @@ -986,6 +983,294 @@ error0: return error; } +/* + * Use the free inode btree to allocate an inode based on distance from the + * parent. Note that the provided cursor may be deleted and replaced. + */ +STATIC int +xfs_dialloc_ag_finobt_near( + xfs_agino_t pagino, + struct xfs_btree_cur **ocur, + struct xfs_inobt_rec_incore *rec) +{ + struct xfs_btree_cur *lcur = *ocur; /* left search cursor */ + struct xfs_btree_cur *rcur; /* right search cursor */ + struct xfs_inobt_rec_incore rrec; + int error; + int i, j; + + error = xfs_inobt_lookup(lcur, pagino, XFS_LOOKUP_LE, &i); + if (error) + return error; + + if (i == 1) { + error = xfs_inobt_get_rec(lcur, rec, &i); + if (error) + return error; + XFS_WANT_CORRUPTED_RETURN(i == 1); + + /* + * See if we've landed in the parent inode record. The finobt + * only tracks chunks with at least one free inode, so record + * existence is enough. + */ + if (pagino >= rec->ir_startino && + pagino < (rec->ir_startino + XFS_INODES_PER_CHUNK)) + return 0; + } + + error = xfs_btree_dup_cursor(lcur, &rcur); + if (error) + return error; + + error = xfs_inobt_lookup(rcur, pagino, XFS_LOOKUP_GE, &j); + if (error) + goto error_rcur; + if (j == 1) { + error = xfs_inobt_get_rec(rcur, &rrec, &j); + if (error) + goto error_rcur; + XFS_WANT_CORRUPTED_GOTO(j == 1, error_rcur); + } + + XFS_WANT_CORRUPTED_GOTO(i == 1 || j == 1, error_rcur); + if (i == 1 && j == 1) { + /* + * Both the left and right records are valid. Choose the closer + * inode chunk to the target. + */ + if ((pagino - rec->ir_startino + XFS_INODES_PER_CHUNK - 1) > + (rrec.ir_startino - pagino)) { + *rec = rrec; + xfs_btree_del_cursor(lcur, XFS_BTREE_NOERROR); + *ocur = rcur; + } else { + xfs_btree_del_cursor(rcur, XFS_BTREE_NOERROR); + } + } else if (j == 1) { + /* only the right record is valid */ + *rec = rrec; + xfs_btree_del_cursor(lcur, XFS_BTREE_NOERROR); + *ocur = rcur; + } else if (i == 1) { + /* only the left record is valid */ + xfs_btree_del_cursor(rcur, XFS_BTREE_NOERROR); + } + + return 0; + +error_rcur: + xfs_btree_del_cursor(rcur, XFS_BTREE_ERROR); + return error; +} + +/* + * Use the free inode btree to find a free inode based on a newino hint. If + * the hint is NULL, find the first free inode in the AG. + */ +STATIC int +xfs_dialloc_ag_finobt_newino( + struct xfs_agi *agi, + struct xfs_btree_cur *cur, + struct xfs_inobt_rec_incore *rec) +{ + int error; + int i; + + if (agi->agi_newino != cpu_to_be32(NULLAGINO)) { + error = xfs_inobt_lookup(cur, agi->agi_newino, XFS_LOOKUP_EQ, + &i); + if (error) + return error; + if (i == 1) { + error = xfs_inobt_get_rec(cur, rec, &i); + if (error) + return error; + XFS_WANT_CORRUPTED_RETURN(i == 1); + + return 0; + } + } + + /* + * Find the first inode available in the AG. + */ + error = xfs_inobt_lookup(cur, 0, XFS_LOOKUP_GE, &i); + if (error) + return error; + XFS_WANT_CORRUPTED_RETURN(i == 1); + + error = xfs_inobt_get_rec(cur, rec, &i); + if (error) + return error; + XFS_WANT_CORRUPTED_RETURN(i == 1); + + return 0; +} + +/* + * Update the inobt based on a modification made to the finobt. Also ensure that + * the records from both trees are equivalent post-modification. + */ +STATIC int +xfs_dialloc_ag_update_inobt( + struct xfs_btree_cur *cur, /* inobt cursor */ + struct xfs_inobt_rec_incore *frec, /* finobt record */ + int offset) /* inode offset */ +{ + struct xfs_inobt_rec_incore rec; + int error; + int i; + + error = xfs_inobt_lookup(cur, frec->ir_startino, XFS_LOOKUP_EQ, &i); + if (error) + return error; + XFS_WANT_CORRUPTED_RETURN(i == 1); + + error = xfs_inobt_get_rec(cur, &rec, &i); + if (error) + return error; + XFS_WANT_CORRUPTED_RETURN(i == 1); + ASSERT((XFS_AGINO_TO_OFFSET(cur->bc_mp, rec.ir_startino) % + XFS_INODES_PER_CHUNK) == 0); + + rec.ir_free &= ~XFS_INOBT_MASK(offset); + rec.ir_freecount--; + + XFS_WANT_CORRUPTED_RETURN((rec.ir_free == frec->ir_free) && + (rec.ir_freecount == frec->ir_freecount)); + + error = xfs_inobt_update(cur, &rec); + if (error) + return error; + + return 0; +} + +/* + * Allocate an inode using the free inode btree, if available. Otherwise, fall + * back to the inobt search algorithm. + * + * The caller selected an AG for us, and made sure that free inodes are + * available. + */ +STATIC int +xfs_dialloc_ag( + struct xfs_trans *tp, + struct xfs_buf *agbp, + xfs_ino_t parent, + xfs_ino_t *inop) +{ + 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; /* finobt cursor */ + struct xfs_btree_cur *icur; /* inobt cursor */ + struct xfs_inobt_rec_incore rec; + xfs_ino_t ino; + int error; + int offset; + int i; + + if (!xfs_sb_version_hasfinobt(&mp->m_sb)) + return xfs_dialloc_ag_inobt(tp, agbp, parent, inop); + + pag = xfs_perag_get(mp, agno); + + /* + * If pagino is 0 (this is the root inode allocation) use newino. + * This must work because we've just allocated some. + */ + if (!pagino) + pagino = be32_to_cpu(agi->agi_newino); + + cur = xfs_inobt_init_cursor(mp, tp, agbp, agno, XFS_BTNUM_FINO); + + error = xfs_check_agi_freecount(cur, agi); + if (error) + goto error_cur; + + /* + * The search algorithm depends on whether we're in the same AG as the + * parent. If so, find the closest available inode to the parent. If + * not, consider the agi hint or find the first free inode in the AG. + */ + if (agno == pagno) + error = xfs_dialloc_ag_finobt_near(pagino, &cur, &rec); + else + error = xfs_dialloc_ag_finobt_newino(agi, cur, &rec); + if (error) + goto error_cur; + + offset = xfs_lowbit64(rec.ir_free); + ASSERT(offset >= 0); + ASSERT(offset < XFS_INODES_PER_CHUNK); + ASSERT((XFS_AGINO_TO_OFFSET(mp, rec.ir_startino) % + XFS_INODES_PER_CHUNK) == 0); + ino = XFS_AGINO_TO_INO(mp, agno, rec.ir_startino + offset); + + /* + * Modify or remove the finobt record. + */ + rec.ir_free &= ~XFS_INOBT_MASK(offset); + rec.ir_freecount--; + if (rec.ir_freecount) + error = xfs_inobt_update(cur, &rec); + else + error = xfs_btree_delete(cur, &i); + if (error) + goto error_cur; + + /* + * The finobt has now been updated appropriately. We haven't updated the + * agi and superblock yet, so we can create an inobt cursor and validate + * the original freecount. If all is well, make the equivalent update to + * the inobt using the finobt record and offset information. + */ + icur = xfs_inobt_init_cursor(mp, tp, agbp, agno, XFS_BTNUM_INO); + + error = xfs_check_agi_freecount(icur, agi); + if (error) + goto error_icur; + + error = xfs_dialloc_ag_update_inobt(icur, &rec, offset); + if (error) + goto error_icur; + + /* + * Both trees have now been updated. We must update the perag and + * superblock before we can check the freecount for each btree. + */ + be32_add_cpu(&agi->agi_freecount, -1); + xfs_ialloc_log_agi(tp, agbp, XFS_AGI_FREECOUNT); + pag->pagi_freecount--; + + xfs_trans_mod_sb(tp, XFS_TRANS_SB_IFREE, -1); + + error = xfs_check_agi_freecount(icur, agi); + if (error) + goto error_icur; + error = xfs_check_agi_freecount(cur, agi); + if (error) + goto error_icur; + + xfs_btree_del_cursor(icur, XFS_BTREE_NOERROR); + xfs_btree_del_cursor(cur, XFS_BTREE_NOERROR); + xfs_perag_put(pag); + *inop = ino; + return 0; + +error_icur: + xfs_btree_del_cursor(icur, XFS_BTREE_ERROR); +error_cur: + xfs_btree_del_cursor(cur, XFS_BTREE_ERROR); + xfs_perag_put(pag); + return error; +} + /* * Allocate an inode on disk. *