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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
commit57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch)
tree5e910f0e82173f4ef4f51111366a3f1299037a7b /fs/jfs/jfs_dmap.h
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+/*
+ * Copyright (C) International Business Machines Corp., 2000-2002
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
+ * the GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+#ifndef _H_JFS_DMAP
+#define _H_JFS_DMAP
+
+#include "jfs_txnmgr.h"
+
+#define BMAPVERSION 1 /* version number */
+#define TREESIZE (256+64+16+4+1) /* size of a dmap tree */
+#define LEAFIND (64+16+4+1) /* index of 1st leaf of a dmap tree */
+#define LPERDMAP 256 /* num leaves per dmap tree */
+#define L2LPERDMAP 8 /* l2 number of leaves per dmap tree */
+#define DBWORD 32 /* # of blks covered by a map word */
+#define L2DBWORD 5 /* l2 # of blks covered by a mword */
+#define BUDMIN L2DBWORD /* max free string in a map word */
+#define BPERDMAP (LPERDMAP * DBWORD) /* num of blks per dmap */
+#define L2BPERDMAP 13 /* l2 num of blks per dmap */
+#define CTLTREESIZE (1024+256+64+16+4+1) /* size of a dmapctl tree */
+#define CTLLEAFIND (256+64+16+4+1) /* idx of 1st leaf of a dmapctl tree */
+#define LPERCTL 1024 /* num of leaves per dmapctl tree */
+#define L2LPERCTL 10 /* l2 num of leaves per dmapctl tree */
+#define ROOT 0 /* index of the root of a tree */
+#define NOFREE ((s8) -1) /* no blocks free */
+#define MAXAG 128 /* max number of allocation groups */
+#define L2MAXAG 7 /* l2 max num of AG */
+#define L2MINAGSZ 25 /* l2 of minimum AG size in bytes */
+#define BMAPBLKNO 0 /* lblkno of bmap within the map */
+
+/*
+ * maximum l2 number of disk blocks at the various dmapctl levels.
+ */
+#define L2MAXL0SIZE (L2BPERDMAP + 1 * L2LPERCTL)
+#define L2MAXL1SIZE (L2BPERDMAP + 2 * L2LPERCTL)
+#define L2MAXL2SIZE (L2BPERDMAP + 3 * L2LPERCTL)
+
+/*
+ * maximum number of disk blocks at the various dmapctl levels.
+ */
+#define MAXL0SIZE ((s64)1 << L2MAXL0SIZE)
+#define MAXL1SIZE ((s64)1 << L2MAXL1SIZE)
+#define MAXL2SIZE ((s64)1 << L2MAXL2SIZE)
+
+#define MAXMAPSIZE MAXL2SIZE /* maximum aggregate map size */
+
+/*
+ * determine the maximum free string for four (lower level) nodes
+ * of the tree.
+ */
+static inline signed char TREEMAX(signed char *cp)
+{
+ signed char tmp1, tmp2;
+
+ tmp1 = max(*(cp+2), *(cp+3));
+ tmp2 = max(*(cp), *(cp+1));
+
+ return max(tmp1, tmp2);
+}
+
+/*
+ * convert disk block number to the logical block number of the dmap
+ * describing the disk block. s is the log2(number of logical blocks per page)
+ *
+ * The calculation figures out how many logical pages are in front of the dmap.
+ * - the number of dmaps preceding it
+ * - the number of L0 pages preceding its L0 page
+ * - the number of L1 pages preceding its L1 page
+ * - 3 is added to account for the L2, L1, and L0 page for this dmap
+ * - 1 is added to account for the control page of the map.
+ */
+#define BLKTODMAP(b,s) \
+ ((((b) >> 13) + ((b) >> 23) + ((b) >> 33) + 3 + 1) << (s))
+
+/*
+ * convert disk block number to the logical block number of the LEVEL 0
+ * dmapctl describing the disk block. s is the log2(number of logical blocks
+ * per page)
+ *
+ * The calculation figures out how many logical pages are in front of the L0.
+ * - the number of dmap pages preceding it
+ * - the number of L0 pages preceding it
+ * - the number of L1 pages preceding its L1 page
+ * - 2 is added to account for the L2, and L1 page for this L0
+ * - 1 is added to account for the control page of the map.
+ */
+#define BLKTOL0(b,s) \
+ (((((b) >> 23) << 10) + ((b) >> 23) + ((b) >> 33) + 2 + 1) << (s))
+
+/*
+ * convert disk block number to the logical block number of the LEVEL 1
+ * dmapctl describing the disk block. s is the log2(number of logical blocks
+ * per page)
+ *
+ * The calculation figures out how many logical pages are in front of the L1.
+ * - the number of dmap pages preceding it
+ * - the number of L0 pages preceding it
+ * - the number of L1 pages preceding it
+ * - 1 is added to account for the L2 page
+ * - 1 is added to account for the control page of the map.
+ */
+#define BLKTOL1(b,s) \
+ (((((b) >> 33) << 20) + (((b) >> 33) << 10) + ((b) >> 33) + 1 + 1) << (s))
+
+/*
+ * convert disk block number to the logical block number of the dmapctl
+ * at the specified level which describes the disk block.
+ */
+#define BLKTOCTL(b,s,l) \
+ (((l) == 2) ? 1 : ((l) == 1) ? BLKTOL1((b),(s)) : BLKTOL0((b),(s)))
+
+/*
+ * convert aggregate map size to the zero origin dmapctl level of the
+ * top dmapctl.
+ */
+#define BMAPSZTOLEV(size) \
+ (((size) <= MAXL0SIZE) ? 0 : ((size) <= MAXL1SIZE) ? 1 : 2)
+
+/* convert disk block number to allocation group number.
+ */
+#define BLKTOAG(b,sbi) ((b) >> ((sbi)->bmap->db_agl2size))
+
+/* convert allocation group number to starting disk block
+ * number.
+ */
+#define AGTOBLK(a,ip) \
+ ((s64)(a) << (JFS_SBI((ip)->i_sb)->bmap->db_agl2size))
+
+/*
+ * dmap summary tree
+ *
+ * dmaptree must be consistent with dmapctl.
+ */
+struct dmaptree {
+ __le32 nleafs; /* 4: number of tree leafs */
+ __le32 l2nleafs; /* 4: l2 number of tree leafs */
+ __le32 leafidx; /* 4: index of first tree leaf */
+ __le32 height; /* 4: height of the tree */
+ s8 budmin; /* 1: min l2 tree leaf value to combine */
+ s8 stree[TREESIZE]; /* TREESIZE: tree */
+ u8 pad[2]; /* 2: pad to word boundary */
+}; /* - 360 - */
+
+/*
+ * dmap page per 8K blocks bitmap
+ */
+struct dmap {
+ __le32 nblocks; /* 4: num blks covered by this dmap */
+ __le32 nfree; /* 4: num of free blks in this dmap */
+ __le64 start; /* 8: starting blkno for this dmap */
+ struct dmaptree tree; /* 360: dmap tree */
+ u8 pad[1672]; /* 1672: pad to 2048 bytes */
+ __le32 wmap[LPERDMAP]; /* 1024: bits of the working map */
+ __le32 pmap[LPERDMAP]; /* 1024: bits of the persistent map */
+}; /* - 4096 - */
+
+/*
+ * disk map control page per level.
+ *
+ * dmapctl must be consistent with dmaptree.
+ */
+struct dmapctl {
+ __le32 nleafs; /* 4: number of tree leafs */
+ __le32 l2nleafs; /* 4: l2 number of tree leafs */
+ __le32 leafidx; /* 4: index of the first tree leaf */
+ __le32 height; /* 4: height of tree */
+ s8 budmin; /* 1: minimum l2 tree leaf value */
+ s8 stree[CTLTREESIZE]; /* CTLTREESIZE: dmapctl tree */
+ u8 pad[2714]; /* 2714: pad to 4096 */
+}; /* - 4096 - */
+
+/*
+ * common definition for dmaptree within dmap and dmapctl
+ */
+typedef union dmtree {
+ struct dmaptree t1;
+ struct dmapctl t2;
+} dmtree_t;
+
+/* macros for accessing fields within dmtree */
+#define dmt_nleafs t1.nleafs
+#define dmt_l2nleafs t1.l2nleafs
+#define dmt_leafidx t1.leafidx
+#define dmt_height t1.height
+#define dmt_budmin t1.budmin
+#define dmt_stree t1.stree
+
+/*
+ * on-disk aggregate disk allocation map descriptor.
+ */
+struct dbmap_disk {
+ __le64 dn_mapsize; /* 8: number of blocks in aggregate */
+ __le64 dn_nfree; /* 8: num free blks in aggregate map */
+ __le32 dn_l2nbperpage; /* 4: number of blks per page */
+ __le32 dn_numag; /* 4: total number of ags */
+ __le32 dn_maxlevel; /* 4: number of active ags */
+ __le32 dn_maxag; /* 4: max active alloc group number */
+ __le32 dn_agpref; /* 4: preferred alloc group (hint) */
+ __le32 dn_aglevel; /* 4: dmapctl level holding the AG */
+ __le32 dn_agheight; /* 4: height in dmapctl of the AG */
+ __le32 dn_agwidth; /* 4: width in dmapctl of the AG */
+ __le32 dn_agstart; /* 4: start tree index at AG height */
+ __le32 dn_agl2size; /* 4: l2 num of blks per alloc group */
+ __le64 dn_agfree[MAXAG];/* 8*MAXAG: per AG free count */
+ __le64 dn_agsize; /* 8: num of blks per alloc group */
+ s8 dn_maxfreebud; /* 1: max free buddy system */
+ u8 pad[3007]; /* 3007: pad to 4096 */
+}; /* - 4096 - */
+
+struct dbmap {
+ s64 dn_mapsize; /* number of blocks in aggregate */
+ s64 dn_nfree; /* num free blks in aggregate map */
+ int dn_l2nbperpage; /* number of blks per page */
+ int dn_numag; /* total number of ags */
+ int dn_maxlevel; /* number of active ags */
+ int dn_maxag; /* max active alloc group number */
+ int dn_agpref; /* preferred alloc group (hint) */
+ int dn_aglevel; /* dmapctl level holding the AG */
+ int dn_agheight; /* height in dmapctl of the AG */
+ int dn_agwidth; /* width in dmapctl of the AG */
+ int dn_agstart; /* start tree index at AG height */
+ int dn_agl2size; /* l2 num of blks per alloc group */
+ s64 dn_agfree[MAXAG]; /* per AG free count */
+ s64 dn_agsize; /* num of blks per alloc group */
+ signed char dn_maxfreebud; /* max free buddy system */
+}; /* - 4096 - */
+/*
+ * in-memory aggregate disk allocation map descriptor.
+ */
+struct bmap {
+ struct dbmap db_bmap; /* on-disk aggregate map descriptor */
+ struct inode *db_ipbmap; /* ptr to aggregate map incore inode */
+ struct mutex db_bmaplock; /* aggregate map lock */
+ atomic_t db_active[MAXAG]; /* count of active, open files in AG */
+ u32 *db_DBmap;
+};
+
+/* macros for accessing fields within in-memory aggregate map descriptor */
+#define db_mapsize db_bmap.dn_mapsize
+#define db_nfree db_bmap.dn_nfree
+#define db_agfree db_bmap.dn_agfree
+#define db_agsize db_bmap.dn_agsize
+#define db_agl2size db_bmap.dn_agl2size
+#define db_agwidth db_bmap.dn_agwidth
+#define db_agheight db_bmap.dn_agheight
+#define db_agstart db_bmap.dn_agstart
+#define db_numag db_bmap.dn_numag
+#define db_maxlevel db_bmap.dn_maxlevel
+#define db_aglevel db_bmap.dn_aglevel
+#define db_agpref db_bmap.dn_agpref
+#define db_maxag db_bmap.dn_maxag
+#define db_maxfreebud db_bmap.dn_maxfreebud
+#define db_l2nbperpage db_bmap.dn_l2nbperpage
+
+/*
+ * macros for various conversions needed by the allocators.
+ * blkstol2(), cntlz(), and cnttz() are operating system dependent functions.
+ */
+/* convert number of blocks to log2 number of blocks, rounding up to
+ * the next log2 value if blocks is not a l2 multiple.
+ */
+#define BLKSTOL2(d) (blkstol2(d))
+
+/* convert number of leafs to log2 leaf value */
+#define NLSTOL2BSZ(n) (31 - cntlz((n)) + BUDMIN)
+
+/* convert leaf index to log2 leaf value */
+#define LITOL2BSZ(n,m,b) ((((n) == 0) ? (m) : cnttz((n))) + (b))
+
+/* convert a block number to a dmap control leaf index */
+#define BLKTOCTLLEAF(b,m) \
+ (((b) & (((s64)1 << ((m) + L2LPERCTL)) - 1)) >> (m))
+
+/* convert log2 leaf value to buddy size */
+#define BUDSIZE(s,m) (1 << ((s) - (m)))
+
+/*
+ * external references.
+ */
+extern int dbMount(struct inode *ipbmap);
+
+extern int dbUnmount(struct inode *ipbmap, int mounterror);
+
+extern int dbFree(struct inode *ipbmap, s64 blkno, s64 nblocks);
+
+extern int dbUpdatePMap(struct inode *ipbmap,
+ int free, s64 blkno, s64 nblocks, struct tblock * tblk);
+
+extern int dbNextAG(struct inode *ipbmap);
+
+extern int dbAlloc(struct inode *ipbmap, s64 hint, s64 nblocks, s64 * results);
+
+extern int dbReAlloc(struct inode *ipbmap,
+ s64 blkno, s64 nblocks, s64 addnblocks, s64 * results);
+
+extern int dbSync(struct inode *ipbmap);
+extern int dbAllocBottomUp(struct inode *ip, s64 blkno, s64 nblocks);
+extern int dbExtendFS(struct inode *ipbmap, s64 blkno, s64 nblocks);
+extern void dbFinalizeBmap(struct inode *ipbmap);
+extern s64 dbMapFileSizeToMapSize(struct inode *ipbmap);
+extern s64 dbDiscardAG(struct inode *ip, int agno, s64 minlen);
+
+#endif /* _H_JFS_DMAP */