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4082 lines
111 KiB
4082 lines
111 KiB
// SPDX-License-Identifier: GPL-2.0-or-later |
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/* |
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* Copyright (C) International Business Machines Corp., 2000-2004 |
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* Portions Copyright (C) Tino Reichardt, 2012 |
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*/ |
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|
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#include <linux/fs.h> |
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#include <linux/slab.h> |
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#include "jfs_incore.h" |
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#include "jfs_superblock.h" |
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#include "jfs_dmap.h" |
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#include "jfs_imap.h" |
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#include "jfs_lock.h" |
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#include "jfs_metapage.h" |
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#include "jfs_debug.h" |
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#include "jfs_discard.h" |
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|
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/* |
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* SERIALIZATION of the Block Allocation Map. |
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* |
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* the working state of the block allocation map is accessed in |
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* two directions: |
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* |
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* 1) allocation and free requests that start at the dmap |
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* level and move up through the dmap control pages (i.e. |
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* the vast majority of requests). |
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* |
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* 2) allocation requests that start at dmap control page |
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* level and work down towards the dmaps. |
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* |
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* the serialization scheme used here is as follows. |
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* |
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* requests which start at the bottom are serialized against each |
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* other through buffers and each requests holds onto its buffers |
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* as it works it way up from a single dmap to the required level |
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* of dmap control page. |
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* requests that start at the top are serialized against each other |
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* and request that start from the bottom by the multiple read/single |
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* write inode lock of the bmap inode. requests starting at the top |
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* take this lock in write mode while request starting at the bottom |
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* take the lock in read mode. a single top-down request may proceed |
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* exclusively while multiple bottoms-up requests may proceed |
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* simultaneously (under the protection of busy buffers). |
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* |
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* in addition to information found in dmaps and dmap control pages, |
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* the working state of the block allocation map also includes read/ |
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* write information maintained in the bmap descriptor (i.e. total |
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* free block count, allocation group level free block counts). |
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* a single exclusive lock (BMAP_LOCK) is used to guard this information |
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* in the face of multiple-bottoms up requests. |
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* (lock ordering: IREAD_LOCK, BMAP_LOCK); |
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* |
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* accesses to the persistent state of the block allocation map (limited |
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* to the persistent bitmaps in dmaps) is guarded by (busy) buffers. |
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*/ |
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|
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#define BMAP_LOCK_INIT(bmp) mutex_init(&bmp->db_bmaplock) |
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#define BMAP_LOCK(bmp) mutex_lock(&bmp->db_bmaplock) |
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#define BMAP_UNLOCK(bmp) mutex_unlock(&bmp->db_bmaplock) |
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|
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/* |
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* forward references |
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*/ |
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static void dbAllocBits(struct bmap * bmp, struct dmap * dp, s64 blkno, |
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int nblocks); |
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static void dbSplit(dmtree_t * tp, int leafno, int splitsz, int newval); |
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static int dbBackSplit(dmtree_t * tp, int leafno); |
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static int dbJoin(dmtree_t * tp, int leafno, int newval); |
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static void dbAdjTree(dmtree_t * tp, int leafno, int newval); |
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static int dbAdjCtl(struct bmap * bmp, s64 blkno, int newval, int alloc, |
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int level); |
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static int dbAllocAny(struct bmap * bmp, s64 nblocks, int l2nb, s64 * results); |
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static int dbAllocNext(struct bmap * bmp, struct dmap * dp, s64 blkno, |
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int nblocks); |
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static int dbAllocNear(struct bmap * bmp, struct dmap * dp, s64 blkno, |
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int nblocks, |
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int l2nb, s64 * results); |
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static int dbAllocDmap(struct bmap * bmp, struct dmap * dp, s64 blkno, |
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int nblocks); |
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static int dbAllocDmapLev(struct bmap * bmp, struct dmap * dp, int nblocks, |
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int l2nb, |
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s64 * results); |
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static int dbAllocAG(struct bmap * bmp, int agno, s64 nblocks, int l2nb, |
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s64 * results); |
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static int dbAllocCtl(struct bmap * bmp, s64 nblocks, int l2nb, s64 blkno, |
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s64 * results); |
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static int dbExtend(struct inode *ip, s64 blkno, s64 nblocks, s64 addnblocks); |
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static int dbFindBits(u32 word, int l2nb); |
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static int dbFindCtl(struct bmap * bmp, int l2nb, int level, s64 * blkno); |
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static int dbFindLeaf(dmtree_t * tp, int l2nb, int *leafidx); |
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static int dbFreeBits(struct bmap * bmp, struct dmap * dp, s64 blkno, |
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int nblocks); |
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static int dbFreeDmap(struct bmap * bmp, struct dmap * dp, s64 blkno, |
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int nblocks); |
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static int dbMaxBud(u8 * cp); |
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static int blkstol2(s64 nb); |
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|
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static int cntlz(u32 value); |
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static int cnttz(u32 word); |
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static int dbAllocDmapBU(struct bmap * bmp, struct dmap * dp, s64 blkno, |
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int nblocks); |
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static int dbInitDmap(struct dmap * dp, s64 blkno, int nblocks); |
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static int dbInitDmapTree(struct dmap * dp); |
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static int dbInitTree(struct dmaptree * dtp); |
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static int dbInitDmapCtl(struct dmapctl * dcp, int level, int i); |
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static int dbGetL2AGSize(s64 nblocks); |
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|
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/* |
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* buddy table |
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* |
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* table used for determining buddy sizes within characters of |
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* dmap bitmap words. the characters themselves serve as indexes |
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* into the table, with the table elements yielding the maximum |
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* binary buddy of free bits within the character. |
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*/ |
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static const s8 budtab[256] = { |
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3, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, |
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2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, |
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2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, |
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2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, |
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2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, |
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2, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, |
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2, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, |
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2, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, |
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2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, |
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2, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, |
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2, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, |
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2, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, |
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2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, |
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2, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, |
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2, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, |
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2, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, -1 |
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}; |
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/* |
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* NAME: dbMount() |
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* |
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* FUNCTION: initializate the block allocation map. |
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* |
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* memory is allocated for the in-core bmap descriptor and |
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* the in-core descriptor is initialized from disk. |
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* |
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* PARAMETERS: |
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* ipbmap - pointer to in-core inode for the block map. |
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* |
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* RETURN VALUES: |
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* 0 - success |
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* -ENOMEM - insufficient memory |
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* -EIO - i/o error |
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*/ |
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int dbMount(struct inode *ipbmap) |
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{ |
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struct bmap *bmp; |
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struct dbmap_disk *dbmp_le; |
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struct metapage *mp; |
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int i; |
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|
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/* |
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* allocate/initialize the in-memory bmap descriptor |
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*/ |
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/* allocate memory for the in-memory bmap descriptor */ |
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bmp = kmalloc(sizeof(struct bmap), GFP_KERNEL); |
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if (bmp == NULL) |
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return -ENOMEM; |
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/* read the on-disk bmap descriptor. */ |
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mp = read_metapage(ipbmap, |
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BMAPBLKNO << JFS_SBI(ipbmap->i_sb)->l2nbperpage, |
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PSIZE, 0); |
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if (mp == NULL) { |
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kfree(bmp); |
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return -EIO; |
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} |
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|
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/* copy the on-disk bmap descriptor to its in-memory version. */ |
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dbmp_le = (struct dbmap_disk *) mp->data; |
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bmp->db_mapsize = le64_to_cpu(dbmp_le->dn_mapsize); |
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bmp->db_nfree = le64_to_cpu(dbmp_le->dn_nfree); |
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bmp->db_l2nbperpage = le32_to_cpu(dbmp_le->dn_l2nbperpage); |
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bmp->db_numag = le32_to_cpu(dbmp_le->dn_numag); |
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bmp->db_maxlevel = le32_to_cpu(dbmp_le->dn_maxlevel); |
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bmp->db_maxag = le32_to_cpu(dbmp_le->dn_maxag); |
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bmp->db_agpref = le32_to_cpu(dbmp_le->dn_agpref); |
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bmp->db_aglevel = le32_to_cpu(dbmp_le->dn_aglevel); |
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bmp->db_agheight = le32_to_cpu(dbmp_le->dn_agheight); |
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bmp->db_agwidth = le32_to_cpu(dbmp_le->dn_agwidth); |
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bmp->db_agstart = le32_to_cpu(dbmp_le->dn_agstart); |
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bmp->db_agl2size = le32_to_cpu(dbmp_le->dn_agl2size); |
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for (i = 0; i < MAXAG; i++) |
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bmp->db_agfree[i] = le64_to_cpu(dbmp_le->dn_agfree[i]); |
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bmp->db_agsize = le64_to_cpu(dbmp_le->dn_agsize); |
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bmp->db_maxfreebud = dbmp_le->dn_maxfreebud; |
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/* release the buffer. */ |
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release_metapage(mp); |
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/* bind the bmap inode and the bmap descriptor to each other. */ |
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bmp->db_ipbmap = ipbmap; |
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JFS_SBI(ipbmap->i_sb)->bmap = bmp; |
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memset(bmp->db_active, 0, sizeof(bmp->db_active)); |
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/* |
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* allocate/initialize the bmap lock |
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*/ |
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BMAP_LOCK_INIT(bmp); |
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return (0); |
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} |
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/* |
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* NAME: dbUnmount() |
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* |
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* FUNCTION: terminate the block allocation map in preparation for |
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* file system unmount. |
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* |
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* the in-core bmap descriptor is written to disk and |
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* the memory for this descriptor is freed. |
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* |
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* PARAMETERS: |
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* ipbmap - pointer to in-core inode for the block map. |
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* |
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* RETURN VALUES: |
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* 0 - success |
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* -EIO - i/o error |
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*/ |
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int dbUnmount(struct inode *ipbmap, int mounterror) |
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{ |
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struct bmap *bmp = JFS_SBI(ipbmap->i_sb)->bmap; |
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if (!(mounterror || isReadOnly(ipbmap))) |
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dbSync(ipbmap); |
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/* |
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* Invalidate the page cache buffers |
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*/ |
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truncate_inode_pages(ipbmap->i_mapping, 0); |
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/* free the memory for the in-memory bmap. */ |
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kfree(bmp); |
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return (0); |
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} |
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/* |
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* dbSync() |
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*/ |
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int dbSync(struct inode *ipbmap) |
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{ |
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struct dbmap_disk *dbmp_le; |
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struct bmap *bmp = JFS_SBI(ipbmap->i_sb)->bmap; |
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struct metapage *mp; |
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int i; |
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/* |
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* write bmap global control page |
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*/ |
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/* get the buffer for the on-disk bmap descriptor. */ |
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mp = read_metapage(ipbmap, |
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BMAPBLKNO << JFS_SBI(ipbmap->i_sb)->l2nbperpage, |
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PSIZE, 0); |
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if (mp == NULL) { |
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jfs_err("dbSync: read_metapage failed!"); |
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return -EIO; |
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} |
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/* copy the in-memory version of the bmap to the on-disk version */ |
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dbmp_le = (struct dbmap_disk *) mp->data; |
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dbmp_le->dn_mapsize = cpu_to_le64(bmp->db_mapsize); |
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dbmp_le->dn_nfree = cpu_to_le64(bmp->db_nfree); |
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dbmp_le->dn_l2nbperpage = cpu_to_le32(bmp->db_l2nbperpage); |
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dbmp_le->dn_numag = cpu_to_le32(bmp->db_numag); |
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dbmp_le->dn_maxlevel = cpu_to_le32(bmp->db_maxlevel); |
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dbmp_le->dn_maxag = cpu_to_le32(bmp->db_maxag); |
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dbmp_le->dn_agpref = cpu_to_le32(bmp->db_agpref); |
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dbmp_le->dn_aglevel = cpu_to_le32(bmp->db_aglevel); |
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dbmp_le->dn_agheight = cpu_to_le32(bmp->db_agheight); |
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dbmp_le->dn_agwidth = cpu_to_le32(bmp->db_agwidth); |
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dbmp_le->dn_agstart = cpu_to_le32(bmp->db_agstart); |
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dbmp_le->dn_agl2size = cpu_to_le32(bmp->db_agl2size); |
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for (i = 0; i < MAXAG; i++) |
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dbmp_le->dn_agfree[i] = cpu_to_le64(bmp->db_agfree[i]); |
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dbmp_le->dn_agsize = cpu_to_le64(bmp->db_agsize); |
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dbmp_le->dn_maxfreebud = bmp->db_maxfreebud; |
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/* write the buffer */ |
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write_metapage(mp); |
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|
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/* |
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* write out dirty pages of bmap |
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*/ |
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filemap_write_and_wait(ipbmap->i_mapping); |
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diWriteSpecial(ipbmap, 0); |
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return (0); |
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} |
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/* |
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* NAME: dbFree() |
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* |
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* FUNCTION: free the specified block range from the working block |
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* allocation map. |
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* |
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* the blocks will be free from the working map one dmap |
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* at a time. |
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* |
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* PARAMETERS: |
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* ip - pointer to in-core inode; |
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* blkno - starting block number to be freed. |
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* nblocks - number of blocks to be freed. |
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* |
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* RETURN VALUES: |
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* 0 - success |
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* -EIO - i/o error |
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*/ |
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int dbFree(struct inode *ip, s64 blkno, s64 nblocks) |
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{ |
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struct metapage *mp; |
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struct dmap *dp; |
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int nb, rc; |
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s64 lblkno, rem; |
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struct inode *ipbmap = JFS_SBI(ip->i_sb)->ipbmap; |
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struct bmap *bmp = JFS_SBI(ip->i_sb)->bmap; |
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struct super_block *sb = ipbmap->i_sb; |
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IREAD_LOCK(ipbmap, RDWRLOCK_DMAP); |
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|
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/* block to be freed better be within the mapsize. */ |
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if (unlikely((blkno == 0) || (blkno + nblocks > bmp->db_mapsize))) { |
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IREAD_UNLOCK(ipbmap); |
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printk(KERN_ERR "blkno = %Lx, nblocks = %Lx\n", |
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(unsigned long long) blkno, |
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(unsigned long long) nblocks); |
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jfs_error(ip->i_sb, "block to be freed is outside the map\n"); |
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return -EIO; |
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} |
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|
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/** |
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* TRIM the blocks, when mounted with discard option |
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*/ |
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if (JFS_SBI(sb)->flag & JFS_DISCARD) |
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if (JFS_SBI(sb)->minblks_trim <= nblocks) |
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jfs_issue_discard(ipbmap, blkno, nblocks); |
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|
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/* |
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* free the blocks a dmap at a time. |
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*/ |
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mp = NULL; |
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for (rem = nblocks; rem > 0; rem -= nb, blkno += nb) { |
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/* release previous dmap if any */ |
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if (mp) { |
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write_metapage(mp); |
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} |
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|
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/* get the buffer for the current dmap. */ |
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lblkno = BLKTODMAP(blkno, bmp->db_l2nbperpage); |
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mp = read_metapage(ipbmap, lblkno, PSIZE, 0); |
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if (mp == NULL) { |
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IREAD_UNLOCK(ipbmap); |
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return -EIO; |
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} |
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dp = (struct dmap *) mp->data; |
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|
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/* determine the number of blocks to be freed from |
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* this dmap. |
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*/ |
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nb = min(rem, BPERDMAP - (blkno & (BPERDMAP - 1))); |
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|
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/* free the blocks. */ |
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if ((rc = dbFreeDmap(bmp, dp, blkno, nb))) { |
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jfs_error(ip->i_sb, "error in block map\n"); |
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release_metapage(mp); |
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IREAD_UNLOCK(ipbmap); |
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return (rc); |
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} |
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} |
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|
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/* write the last buffer. */ |
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write_metapage(mp); |
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|
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IREAD_UNLOCK(ipbmap); |
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|
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return (0); |
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} |
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|
|
|
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/* |
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* NAME: dbUpdatePMap() |
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* |
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* FUNCTION: update the allocation state (free or allocate) of the |
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* specified block range in the persistent block allocation map. |
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* |
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* the blocks will be updated in the persistent map one |
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* dmap at a time. |
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* |
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* PARAMETERS: |
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* ipbmap - pointer to in-core inode for the block map. |
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* free - 'true' if block range is to be freed from the persistent |
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* map; 'false' if it is to be allocated. |
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* blkno - starting block number of the range. |
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* nblocks - number of contiguous blocks in the range. |
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* tblk - transaction block; |
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* |
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* RETURN VALUES: |
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* 0 - success |
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* -EIO - i/o error |
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*/ |
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int |
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dbUpdatePMap(struct inode *ipbmap, |
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int free, s64 blkno, s64 nblocks, struct tblock * tblk) |
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{ |
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int nblks, dbitno, wbitno, rbits; |
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int word, nbits, nwords; |
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struct bmap *bmp = JFS_SBI(ipbmap->i_sb)->bmap; |
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s64 lblkno, rem, lastlblkno; |
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u32 mask; |
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struct dmap *dp; |
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struct metapage *mp; |
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struct jfs_log *log; |
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int lsn, difft, diffp; |
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unsigned long flags; |
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|
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/* the blocks better be within the mapsize. */ |
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if (blkno + nblocks > bmp->db_mapsize) { |
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printk(KERN_ERR "blkno = %Lx, nblocks = %Lx\n", |
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(unsigned long long) blkno, |
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(unsigned long long) nblocks); |
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jfs_error(ipbmap->i_sb, "blocks are outside the map\n"); |
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return -EIO; |
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} |
|
|
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/* compute delta of transaction lsn from log syncpt */ |
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lsn = tblk->lsn; |
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log = (struct jfs_log *) JFS_SBI(tblk->sb)->log; |
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logdiff(difft, lsn, log); |
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|
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/* |
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* update the block state a dmap at a time. |
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*/ |
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mp = NULL; |
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lastlblkno = 0; |
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for (rem = nblocks; rem > 0; rem -= nblks, blkno += nblks) { |
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/* get the buffer for the current dmap. */ |
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lblkno = BLKTODMAP(blkno, bmp->db_l2nbperpage); |
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if (lblkno != lastlblkno) { |
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if (mp) { |
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write_metapage(mp); |
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} |
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|
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mp = read_metapage(bmp->db_ipbmap, lblkno, PSIZE, |
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0); |
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if (mp == NULL) |
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return -EIO; |
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metapage_wait_for_io(mp); |
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} |
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dp = (struct dmap *) mp->data; |
|
|
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/* determine the bit number and word within the dmap of |
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* the starting block. also determine how many blocks |
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* are to be updated within this dmap. |
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*/ |
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dbitno = blkno & (BPERDMAP - 1); |
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word = dbitno >> L2DBWORD; |
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nblks = min(rem, (s64)BPERDMAP - dbitno); |
|
|
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/* update the bits of the dmap words. the first and last |
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* words may only have a subset of their bits updated. if |
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* this is the case, we'll work against that word (i.e. |
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* partial first and/or last) only in a single pass. a |
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* single pass will also be used to update all words that |
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* are to have all their bits updated. |
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*/ |
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for (rbits = nblks; rbits > 0; |
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rbits -= nbits, dbitno += nbits) { |
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/* determine the bit number within the word and |
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* the number of bits within the word. |
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*/ |
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wbitno = dbitno & (DBWORD - 1); |
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nbits = min(rbits, DBWORD - wbitno); |
|
|
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/* check if only part of the word is to be updated. */ |
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if (nbits < DBWORD) { |
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/* update (free or allocate) the bits |
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* in this word. |
|
*/ |
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mask = |
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(ONES << (DBWORD - nbits) >> wbitno); |
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if (free) |
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dp->pmap[word] &= |
|
cpu_to_le32(~mask); |
|
else |
|
dp->pmap[word] |= |
|
cpu_to_le32(mask); |
|
|
|
word += 1; |
|
} else { |
|
/* one or more words are to have all |
|
* their bits updated. determine how |
|
* many words and how many bits. |
|
*/ |
|
nwords = rbits >> L2DBWORD; |
|
nbits = nwords << L2DBWORD; |
|
|
|
/* update (free or allocate) the bits |
|
* in these words. |
|
*/ |
|
if (free) |
|
memset(&dp->pmap[word], 0, |
|
nwords * 4); |
|
else |
|
memset(&dp->pmap[word], (int) ONES, |
|
nwords * 4); |
|
|
|
word += nwords; |
|
} |
|
} |
|
|
|
/* |
|
* update dmap lsn |
|
*/ |
|
if (lblkno == lastlblkno) |
|
continue; |
|
|
|
lastlblkno = lblkno; |
|
|
|
LOGSYNC_LOCK(log, flags); |
|
if (mp->lsn != 0) { |
|
/* inherit older/smaller lsn */ |
|
logdiff(diffp, mp->lsn, log); |
|
if (difft < diffp) { |
|
mp->lsn = lsn; |
|
|
|
/* move bp after tblock in logsync list */ |
|
list_move(&mp->synclist, &tblk->synclist); |
|
} |
|
|
|
/* inherit younger/larger clsn */ |
|
logdiff(difft, tblk->clsn, log); |
|
logdiff(diffp, mp->clsn, log); |
|
if (difft > diffp) |
|
mp->clsn = tblk->clsn; |
|
} else { |
|
mp->log = log; |
|
mp->lsn = lsn; |
|
|
|
/* insert bp after tblock in logsync list */ |
|
log->count++; |
|
list_add(&mp->synclist, &tblk->synclist); |
|
|
|
mp->clsn = tblk->clsn; |
|
} |
|
LOGSYNC_UNLOCK(log, flags); |
|
} |
|
|
|
/* write the last buffer. */ |
|
if (mp) { |
|
write_metapage(mp); |
|
} |
|
|
|
return (0); |
|
} |
|
|
|
|
|
/* |
|
* NAME: dbNextAG() |
|
* |
|
* FUNCTION: find the preferred allocation group for new allocations. |
|
* |
|
* Within the allocation groups, we maintain a preferred |
|
* allocation group which consists of a group with at least |
|
* average free space. It is the preferred group that we target |
|
* new inode allocation towards. The tie-in between inode |
|
* allocation and block allocation occurs as we allocate the |
|
* first (data) block of an inode and specify the inode (block) |
|
* as the allocation hint for this block. |
|
* |
|
* We try to avoid having more than one open file growing in |
|
* an allocation group, as this will lead to fragmentation. |
|
* This differs from the old OS/2 method of trying to keep |
|
* empty ags around for large allocations. |
|
* |
|
* PARAMETERS: |
|
* ipbmap - pointer to in-core inode for the block map. |
|
* |
|
* RETURN VALUES: |
|
* the preferred allocation group number. |
|
*/ |
|
int dbNextAG(struct inode *ipbmap) |
|
{ |
|
s64 avgfree; |
|
int agpref; |
|
s64 hwm = 0; |
|
int i; |
|
int next_best = -1; |
|
struct bmap *bmp = JFS_SBI(ipbmap->i_sb)->bmap; |
|
|
|
BMAP_LOCK(bmp); |
|
|
|
/* determine the average number of free blocks within the ags. */ |
|
avgfree = (u32)bmp->db_nfree / bmp->db_numag; |
|
|
|
/* |
|
* if the current preferred ag does not have an active allocator |
|
* and has at least average freespace, return it |
|
*/ |
|
agpref = bmp->db_agpref; |
|
if ((atomic_read(&bmp->db_active[agpref]) == 0) && |
|
(bmp->db_agfree[agpref] >= avgfree)) |
|
goto unlock; |
|
|
|
/* From the last preferred ag, find the next one with at least |
|
* average free space. |
|
*/ |
|
for (i = 0 ; i < bmp->db_numag; i++, agpref++) { |
|
if (agpref == bmp->db_numag) |
|
agpref = 0; |
|
|
|
if (atomic_read(&bmp->db_active[agpref])) |
|
/* open file is currently growing in this ag */ |
|
continue; |
|
if (bmp->db_agfree[agpref] >= avgfree) { |
|
/* Return this one */ |
|
bmp->db_agpref = agpref; |
|
goto unlock; |
|
} else if (bmp->db_agfree[agpref] > hwm) { |
|
/* Less than avg. freespace, but best so far */ |
|
hwm = bmp->db_agfree[agpref]; |
|
next_best = agpref; |
|
} |
|
} |
|
|
|
/* |
|
* If no inactive ag was found with average freespace, use the |
|
* next best |
|
*/ |
|
if (next_best != -1) |
|
bmp->db_agpref = next_best; |
|
/* else leave db_agpref unchanged */ |
|
unlock: |
|
BMAP_UNLOCK(bmp); |
|
|
|
/* return the preferred group. |
|
*/ |
|
return (bmp->db_agpref); |
|
} |
|
|
|
/* |
|
* NAME: dbAlloc() |
|
* |
|
* FUNCTION: attempt to allocate a specified number of contiguous free |
|
* blocks from the working allocation block map. |
|
* |
|
* the block allocation policy uses hints and a multi-step |
|
* approach. |
|
* |
|
* for allocation requests smaller than the number of blocks |
|
* per dmap, we first try to allocate the new blocks |
|
* immediately following the hint. if these blocks are not |
|
* available, we try to allocate blocks near the hint. if |
|
* no blocks near the hint are available, we next try to |
|
* allocate within the same dmap as contains the hint. |
|
* |
|
* if no blocks are available in the dmap or the allocation |
|
* request is larger than the dmap size, we try to allocate |
|
* within the same allocation group as contains the hint. if |
|
* this does not succeed, we finally try to allocate anywhere |
|
* within the aggregate. |
|
* |
|
* we also try to allocate anywhere within the aggregate |
|
* for allocation requests larger than the allocation group |
|
* size or requests that specify no hint value. |
|
* |
|
* PARAMETERS: |
|
* ip - pointer to in-core inode; |
|
* hint - allocation hint. |
|
* nblocks - number of contiguous blocks in the range. |
|
* results - on successful return, set to the starting block number |
|
* of the newly allocated contiguous range. |
|
* |
|
* RETURN VALUES: |
|
* 0 - success |
|
* -ENOSPC - insufficient disk resources |
|
* -EIO - i/o error |
|
*/ |
|
int dbAlloc(struct inode *ip, s64 hint, s64 nblocks, s64 * results) |
|
{ |
|
int rc, agno; |
|
struct inode *ipbmap = JFS_SBI(ip->i_sb)->ipbmap; |
|
struct bmap *bmp; |
|
struct metapage *mp; |
|
s64 lblkno, blkno; |
|
struct dmap *dp; |
|
int l2nb; |
|
s64 mapSize; |
|
int writers; |
|
|
|
/* assert that nblocks is valid */ |
|
assert(nblocks > 0); |
|
|
|
/* get the log2 number of blocks to be allocated. |
|
* if the number of blocks is not a log2 multiple, |
|
* it will be rounded up to the next log2 multiple. |
|
*/ |
|
l2nb = BLKSTOL2(nblocks); |
|
|
|
bmp = JFS_SBI(ip->i_sb)->bmap; |
|
|
|
mapSize = bmp->db_mapsize; |
|
|
|
/* the hint should be within the map */ |
|
if (hint >= mapSize) { |
|
jfs_error(ip->i_sb, "the hint is outside the map\n"); |
|
return -EIO; |
|
} |
|
|
|
/* if the number of blocks to be allocated is greater than the |
|
* allocation group size, try to allocate anywhere. |
|
*/ |
|
if (l2nb > bmp->db_agl2size) { |
|
IWRITE_LOCK(ipbmap, RDWRLOCK_DMAP); |
|
|
|
rc = dbAllocAny(bmp, nblocks, l2nb, results); |
|
|
|
goto write_unlock; |
|
} |
|
|
|
/* |
|
* If no hint, let dbNextAG recommend an allocation group |
|
*/ |
|
if (hint == 0) |
|
goto pref_ag; |
|
|
|
/* we would like to allocate close to the hint. adjust the |
|
* hint to the block following the hint since the allocators |
|
* will start looking for free space starting at this point. |
|
*/ |
|
blkno = hint + 1; |
|
|
|
if (blkno >= bmp->db_mapsize) |
|
goto pref_ag; |
|
|
|
agno = blkno >> bmp->db_agl2size; |
|
|
|
/* check if blkno crosses over into a new allocation group. |
|
* if so, check if we should allow allocations within this |
|
* allocation group. |
|
*/ |
|
if ((blkno & (bmp->db_agsize - 1)) == 0) |
|
/* check if the AG is currently being written to. |
|
* if so, call dbNextAG() to find a non-busy |
|
* AG with sufficient free space. |
|
*/ |
|
if (atomic_read(&bmp->db_active[agno])) |
|
goto pref_ag; |
|
|
|
/* check if the allocation request size can be satisfied from a |
|
* single dmap. if so, try to allocate from the dmap containing |
|
* the hint using a tiered strategy. |
|
*/ |
|
if (nblocks <= BPERDMAP) { |
|
IREAD_LOCK(ipbmap, RDWRLOCK_DMAP); |
|
|
|
/* get the buffer for the dmap containing the hint. |
|
*/ |
|
rc = -EIO; |
|
lblkno = BLKTODMAP(blkno, bmp->db_l2nbperpage); |
|
mp = read_metapage(ipbmap, lblkno, PSIZE, 0); |
|
if (mp == NULL) |
|
goto read_unlock; |
|
|
|
dp = (struct dmap *) mp->data; |
|
|
|
/* first, try to satisfy the allocation request with the |
|
* blocks beginning at the hint. |
|
*/ |
|
if ((rc = dbAllocNext(bmp, dp, blkno, (int) nblocks)) |
|
!= -ENOSPC) { |
|
if (rc == 0) { |
|
*results = blkno; |
|
mark_metapage_dirty(mp); |
|
} |
|
|
|
release_metapage(mp); |
|
goto read_unlock; |
|
} |
|
|
|
writers = atomic_read(&bmp->db_active[agno]); |
|
if ((writers > 1) || |
|
((writers == 1) && (JFS_IP(ip)->active_ag != agno))) { |
|
/* |
|
* Someone else is writing in this allocation |
|
* group. To avoid fragmenting, try another ag |
|
*/ |
|
release_metapage(mp); |
|
IREAD_UNLOCK(ipbmap); |
|
goto pref_ag; |
|
} |
|
|
|
/* next, try to satisfy the allocation request with blocks |
|
* near the hint. |
|
*/ |
|
if ((rc = |
|
dbAllocNear(bmp, dp, blkno, (int) nblocks, l2nb, results)) |
|
!= -ENOSPC) { |
|
if (rc == 0) |
|
mark_metapage_dirty(mp); |
|
|
|
release_metapage(mp); |
|
goto read_unlock; |
|
} |
|
|
|
/* try to satisfy the allocation request with blocks within |
|
* the same dmap as the hint. |
|
*/ |
|
if ((rc = dbAllocDmapLev(bmp, dp, (int) nblocks, l2nb, results)) |
|
!= -ENOSPC) { |
|
if (rc == 0) |
|
mark_metapage_dirty(mp); |
|
|
|
release_metapage(mp); |
|
goto read_unlock; |
|
} |
|
|
|
release_metapage(mp); |
|
IREAD_UNLOCK(ipbmap); |
|
} |
|
|
|
/* try to satisfy the allocation request with blocks within |
|
* the same allocation group as the hint. |
|
*/ |
|
IWRITE_LOCK(ipbmap, RDWRLOCK_DMAP); |
|
if ((rc = dbAllocAG(bmp, agno, nblocks, l2nb, results)) != -ENOSPC) |
|
goto write_unlock; |
|
|
|
IWRITE_UNLOCK(ipbmap); |
|
|
|
|
|
pref_ag: |
|
/* |
|
* Let dbNextAG recommend a preferred allocation group |
|
*/ |
|
agno = dbNextAG(ipbmap); |
|
IWRITE_LOCK(ipbmap, RDWRLOCK_DMAP); |
|
|
|
/* Try to allocate within this allocation group. if that fails, try to |
|
* allocate anywhere in the map. |
|
*/ |
|
if ((rc = dbAllocAG(bmp, agno, nblocks, l2nb, results)) == -ENOSPC) |
|
rc = dbAllocAny(bmp, nblocks, l2nb, results); |
|
|
|
write_unlock: |
|
IWRITE_UNLOCK(ipbmap); |
|
|
|
return (rc); |
|
|
|
read_unlock: |
|
IREAD_UNLOCK(ipbmap); |
|
|
|
return (rc); |
|
} |
|
|
|
#ifdef _NOTYET |
|
/* |
|
* NAME: dbAllocExact() |
|
* |
|
* FUNCTION: try to allocate the requested extent; |
|
* |
|
* PARAMETERS: |
|
* ip - pointer to in-core inode; |
|
* blkno - extent address; |
|
* nblocks - extent length; |
|
* |
|
* RETURN VALUES: |
|
* 0 - success |
|
* -ENOSPC - insufficient disk resources |
|
* -EIO - i/o error |
|
*/ |
|
int dbAllocExact(struct inode *ip, s64 blkno, int nblocks) |
|
{ |
|
int rc; |
|
struct inode *ipbmap = JFS_SBI(ip->i_sb)->ipbmap; |
|
struct bmap *bmp = JFS_SBI(ip->i_sb)->bmap; |
|
struct dmap *dp; |
|
s64 lblkno; |
|
struct metapage *mp; |
|
|
|
IREAD_LOCK(ipbmap, RDWRLOCK_DMAP); |
|
|
|
/* |
|
* validate extent request: |
|
* |
|
* note: defragfs policy: |
|
* max 64 blocks will be moved. |
|
* allocation request size must be satisfied from a single dmap. |
|
*/ |
|
if (nblocks <= 0 || nblocks > BPERDMAP || blkno >= bmp->db_mapsize) { |
|
IREAD_UNLOCK(ipbmap); |
|
return -EINVAL; |
|
} |
|
|
|
if (nblocks > ((s64) 1 << bmp->db_maxfreebud)) { |
|
/* the free space is no longer available */ |
|
IREAD_UNLOCK(ipbmap); |
|
return -ENOSPC; |
|
} |
|
|
|
/* read in the dmap covering the extent */ |
|
lblkno = BLKTODMAP(blkno, bmp->db_l2nbperpage); |
|
mp = read_metapage(ipbmap, lblkno, PSIZE, 0); |
|
if (mp == NULL) { |
|
IREAD_UNLOCK(ipbmap); |
|
return -EIO; |
|
} |
|
dp = (struct dmap *) mp->data; |
|
|
|
/* try to allocate the requested extent */ |
|
rc = dbAllocNext(bmp, dp, blkno, nblocks); |
|
|
|
IREAD_UNLOCK(ipbmap); |
|
|
|
if (rc == 0) |
|
mark_metapage_dirty(mp); |
|
|
|
release_metapage(mp); |
|
|
|
return (rc); |
|
} |
|
#endif /* _NOTYET */ |
|
|
|
/* |
|
* NAME: dbReAlloc() |
|
* |
|
* FUNCTION: attempt to extend a current allocation by a specified |
|
* number of blocks. |
|
* |
|
* this routine attempts to satisfy the allocation request |
|
* by first trying to extend the existing allocation in |
|
* place by allocating the additional blocks as the blocks |
|
* immediately following the current allocation. if these |
|
* blocks are not available, this routine will attempt to |
|
* allocate a new set of contiguous blocks large enough |
|
* to cover the existing allocation plus the additional |
|
* number of blocks required. |
|
* |
|
* PARAMETERS: |
|
* ip - pointer to in-core inode requiring allocation. |
|
* blkno - starting block of the current allocation. |
|
* nblocks - number of contiguous blocks within the current |
|
* allocation. |
|
* addnblocks - number of blocks to add to the allocation. |
|
* results - on successful return, set to the starting block number |
|
* of the existing allocation if the existing allocation |
|
* was extended in place or to a newly allocated contiguous |
|
* range if the existing allocation could not be extended |
|
* in place. |
|
* |
|
* RETURN VALUES: |
|
* 0 - success |
|
* -ENOSPC - insufficient disk resources |
|
* -EIO - i/o error |
|
*/ |
|
int |
|
dbReAlloc(struct inode *ip, |
|
s64 blkno, s64 nblocks, s64 addnblocks, s64 * results) |
|
{ |
|
int rc; |
|
|
|
/* try to extend the allocation in place. |
|
*/ |
|
if ((rc = dbExtend(ip, blkno, nblocks, addnblocks)) == 0) { |
|
*results = blkno; |
|
return (0); |
|
} else { |
|
if (rc != -ENOSPC) |
|
return (rc); |
|
} |
|
|
|
/* could not extend the allocation in place, so allocate a |
|
* new set of blocks for the entire request (i.e. try to get |
|
* a range of contiguous blocks large enough to cover the |
|
* existing allocation plus the additional blocks.) |
|
*/ |
|
return (dbAlloc |
|
(ip, blkno + nblocks - 1, addnblocks + nblocks, results)); |
|
} |
|
|
|
|
|
/* |
|
* NAME: dbExtend() |
|
* |
|
* FUNCTION: attempt to extend a current allocation by a specified |
|
* number of blocks. |
|
* |
|
* this routine attempts to satisfy the allocation request |
|
* by first trying to extend the existing allocation in |
|
* place by allocating the additional blocks as the blocks |
|
* immediately following the current allocation. |
|
* |
|
* PARAMETERS: |
|
* ip - pointer to in-core inode requiring allocation. |
|
* blkno - starting block of the current allocation. |
|
* nblocks - number of contiguous blocks within the current |
|
* allocation. |
|
* addnblocks - number of blocks to add to the allocation. |
|
* |
|
* RETURN VALUES: |
|
* 0 - success |
|
* -ENOSPC - insufficient disk resources |
|
* -EIO - i/o error |
|
*/ |
|
static int dbExtend(struct inode *ip, s64 blkno, s64 nblocks, s64 addnblocks) |
|
{ |
|
struct jfs_sb_info *sbi = JFS_SBI(ip->i_sb); |
|
s64 lblkno, lastblkno, extblkno; |
|
uint rel_block; |
|
struct metapage *mp; |
|
struct dmap *dp; |
|
int rc; |
|
struct inode *ipbmap = sbi->ipbmap; |
|
struct bmap *bmp; |
|
|
|
/* |
|
* We don't want a non-aligned extent to cross a page boundary |
|
*/ |
|
if (((rel_block = blkno & (sbi->nbperpage - 1))) && |
|
(rel_block + nblocks + addnblocks > sbi->nbperpage)) |
|
return -ENOSPC; |
|
|
|
/* get the last block of the current allocation */ |
|
lastblkno = blkno + nblocks - 1; |
|
|
|
/* determine the block number of the block following |
|
* the existing allocation. |
|
*/ |
|
extblkno = lastblkno + 1; |
|
|
|
IREAD_LOCK(ipbmap, RDWRLOCK_DMAP); |
|
|
|
/* better be within the file system */ |
|
bmp = sbi->bmap; |
|
if (lastblkno < 0 || lastblkno >= bmp->db_mapsize) { |
|
IREAD_UNLOCK(ipbmap); |
|
jfs_error(ip->i_sb, "the block is outside the filesystem\n"); |
|
return -EIO; |
|
} |
|
|
|
/* we'll attempt to extend the current allocation in place by |
|
* allocating the additional blocks as the blocks immediately |
|
* following the current allocation. we only try to extend the |
|
* current allocation in place if the number of additional blocks |
|
* can fit into a dmap, the last block of the current allocation |
|
* is not the last block of the file system, and the start of the |
|
* inplace extension is not on an allocation group boundary. |
|
*/ |
|
if (addnblocks > BPERDMAP || extblkno >= bmp->db_mapsize || |
|
(extblkno & (bmp->db_agsize - 1)) == 0) { |
|
IREAD_UNLOCK(ipbmap); |
|
return -ENOSPC; |
|
} |
|
|
|
/* get the buffer for the dmap containing the first block |
|
* of the extension. |
|
*/ |
|
lblkno = BLKTODMAP(extblkno, bmp->db_l2nbperpage); |
|
mp = read_metapage(ipbmap, lblkno, PSIZE, 0); |
|
if (mp == NULL) { |
|
IREAD_UNLOCK(ipbmap); |
|
return -EIO; |
|
} |
|
|
|
dp = (struct dmap *) mp->data; |
|
|
|
/* try to allocate the blocks immediately following the |
|
* current allocation. |
|
*/ |
|
rc = dbAllocNext(bmp, dp, extblkno, (int) addnblocks); |
|
|
|
IREAD_UNLOCK(ipbmap); |
|
|
|
/* were we successful ? */ |
|
if (rc == 0) |
|
write_metapage(mp); |
|
else |
|
/* we were not successful */ |
|
release_metapage(mp); |
|
|
|
return (rc); |
|
} |
|
|
|
|
|
/* |
|
* NAME: dbAllocNext() |
|
* |
|
* FUNCTION: attempt to allocate the blocks of the specified block |
|
* range within a dmap. |
|
* |
|
* PARAMETERS: |
|
* bmp - pointer to bmap descriptor |
|
* dp - pointer to dmap. |
|
* blkno - starting block number of the range. |
|
* nblocks - number of contiguous free blocks of the range. |
|
* |
|
* RETURN VALUES: |
|
* 0 - success |
|
* -ENOSPC - insufficient disk resources |
|
* -EIO - i/o error |
|
* |
|
* serialization: IREAD_LOCK(ipbmap) held on entry/exit; |
|
*/ |
|
static int dbAllocNext(struct bmap * bmp, struct dmap * dp, s64 blkno, |
|
int nblocks) |
|
{ |
|
int dbitno, word, rembits, nb, nwords, wbitno, nw; |
|
int l2size; |
|
s8 *leaf; |
|
u32 mask; |
|
|
|
if (dp->tree.leafidx != cpu_to_le32(LEAFIND)) { |
|
jfs_error(bmp->db_ipbmap->i_sb, "Corrupt dmap page\n"); |
|
return -EIO; |
|
} |
|
|
|
/* pick up a pointer to the leaves of the dmap tree. |
|
*/ |
|
leaf = dp->tree.stree + le32_to_cpu(dp->tree.leafidx); |
|
|
|
/* determine the bit number and word within the dmap of the |
|
* starting block. |
|
*/ |
|
dbitno = blkno & (BPERDMAP - 1); |
|
word = dbitno >> L2DBWORD; |
|
|
|
/* check if the specified block range is contained within |
|
* this dmap. |
|
*/ |
|
if (dbitno + nblocks > BPERDMAP) |
|
return -ENOSPC; |
|
|
|
/* check if the starting leaf indicates that anything |
|
* is free. |
|
*/ |
|
if (leaf[word] == NOFREE) |
|
return -ENOSPC; |
|
|
|
/* check the dmaps words corresponding to block range to see |
|
* if the block range is free. not all bits of the first and |
|
* last words may be contained within the block range. if this |
|
* is the case, we'll work against those words (i.e. partial first |
|
* and/or last) on an individual basis (a single pass) and examine |
|
* the actual bits to determine if they are free. a single pass |
|
* will be used for all dmap words fully contained within the |
|
* specified range. within this pass, the leaves of the dmap |
|
* tree will be examined to determine if the blocks are free. a |
|
* single leaf may describe the free space of multiple dmap |
|
* words, so we may visit only a subset of the actual leaves |
|
* corresponding to the dmap words of the block range. |
|
*/ |
|
for (rembits = nblocks; rembits > 0; rembits -= nb, dbitno += nb) { |
|
/* determine the bit number within the word and |
|
* the number of bits within the word. |
|
*/ |
|
wbitno = dbitno & (DBWORD - 1); |
|
nb = min(rembits, DBWORD - wbitno); |
|
|
|
/* check if only part of the word is to be examined. |
|
*/ |
|
if (nb < DBWORD) { |
|
/* check if the bits are free. |
|
*/ |
|
mask = (ONES << (DBWORD - nb) >> wbitno); |
|
if ((mask & ~le32_to_cpu(dp->wmap[word])) != mask) |
|
return -ENOSPC; |
|
|
|
word += 1; |
|
} else { |
|
/* one or more dmap words are fully contained |
|
* within the block range. determine how many |
|
* words and how many bits. |
|
*/ |
|
nwords = rembits >> L2DBWORD; |
|
nb = nwords << L2DBWORD; |
|
|
|
/* now examine the appropriate leaves to determine |
|
* if the blocks are free. |
|
*/ |
|
while (nwords > 0) { |
|
/* does the leaf describe any free space ? |
|
*/ |
|
if (leaf[word] < BUDMIN) |
|
return -ENOSPC; |
|
|
|
/* determine the l2 number of bits provided |
|
* by this leaf. |
|
*/ |
|
l2size = |
|
min_t(int, leaf[word], NLSTOL2BSZ(nwords)); |
|
|
|
/* determine how many words were handled. |
|
*/ |
|
nw = BUDSIZE(l2size, BUDMIN); |
|
|
|
nwords -= nw; |
|
word += nw; |
|
} |
|
} |
|
} |
|
|
|
/* allocate the blocks. |
|
*/ |
|
return (dbAllocDmap(bmp, dp, blkno, nblocks)); |
|
} |
|
|
|
|
|
/* |
|
* NAME: dbAllocNear() |
|
* |
|
* FUNCTION: attempt to allocate a number of contiguous free blocks near |
|
* a specified block (hint) within a dmap. |
|
* |
|
* starting with the dmap leaf that covers the hint, we'll |
|
* check the next four contiguous leaves for sufficient free |
|
* space. if sufficient free space is found, we'll allocate |
|
* the desired free space. |
|
* |
|
* PARAMETERS: |
|
* bmp - pointer to bmap descriptor |
|
* dp - pointer to dmap. |
|
* blkno - block number to allocate near. |
|
* nblocks - actual number of contiguous free blocks desired. |
|
* l2nb - log2 number of contiguous free blocks desired. |
|
* results - on successful return, set to the starting block number |
|
* of the newly allocated range. |
|
* |
|
* RETURN VALUES: |
|
* 0 - success |
|
* -ENOSPC - insufficient disk resources |
|
* -EIO - i/o error |
|
* |
|
* serialization: IREAD_LOCK(ipbmap) held on entry/exit; |
|
*/ |
|
static int |
|
dbAllocNear(struct bmap * bmp, |
|
struct dmap * dp, s64 blkno, int nblocks, int l2nb, s64 * results) |
|
{ |
|
int word, lword, rc; |
|
s8 *leaf; |
|
|
|
if (dp->tree.leafidx != cpu_to_le32(LEAFIND)) { |
|
jfs_error(bmp->db_ipbmap->i_sb, "Corrupt dmap page\n"); |
|
return -EIO; |
|
} |
|
|
|
leaf = dp->tree.stree + le32_to_cpu(dp->tree.leafidx); |
|
|
|
/* determine the word within the dmap that holds the hint |
|
* (i.e. blkno). also, determine the last word in the dmap |
|
* that we'll include in our examination. |
|
*/ |
|
word = (blkno & (BPERDMAP - 1)) >> L2DBWORD; |
|
lword = min(word + 4, LPERDMAP); |
|
|
|
/* examine the leaves for sufficient free space. |
|
*/ |
|
for (; word < lword; word++) { |
|
/* does the leaf describe sufficient free space ? |
|
*/ |
|
if (leaf[word] < l2nb) |
|
continue; |
|
|
|
/* determine the block number within the file system |
|
* of the first block described by this dmap word. |
|
*/ |
|
blkno = le64_to_cpu(dp->start) + (word << L2DBWORD); |
|
|
|
/* if not all bits of the dmap word are free, get the |
|
* starting bit number within the dmap word of the required |
|
* string of free bits and adjust the block number with the |
|
* value. |
|
*/ |
|
if (leaf[word] < BUDMIN) |
|
blkno += |
|
dbFindBits(le32_to_cpu(dp->wmap[word]), l2nb); |
|
|
|
/* allocate the blocks. |
|
*/ |
|
if ((rc = dbAllocDmap(bmp, dp, blkno, nblocks)) == 0) |
|
*results = blkno; |
|
|
|
return (rc); |
|
} |
|
|
|
return -ENOSPC; |
|
} |
|
|
|
|
|
/* |
|
* NAME: dbAllocAG() |
|
* |
|
* FUNCTION: attempt to allocate the specified number of contiguous |
|
* free blocks within the specified allocation group. |
|
* |
|
* unless the allocation group size is equal to the number |
|
* of blocks per dmap, the dmap control pages will be used to |
|
* find the required free space, if available. we start the |
|
* search at the highest dmap control page level which |
|
* distinctly describes the allocation group's free space |
|
* (i.e. the highest level at which the allocation group's |
|
* free space is not mixed in with that of any other group). |
|
* in addition, we start the search within this level at a |
|
* height of the dmapctl dmtree at which the nodes distinctly |
|
* describe the allocation group's free space. at this height, |
|
* the allocation group's free space may be represented by 1 |
|
* or two sub-trees, depending on the allocation group size. |
|
* we search the top nodes of these subtrees left to right for |
|
* sufficient free space. if sufficient free space is found, |
|
* the subtree is searched to find the leftmost leaf that |
|
* has free space. once we have made it to the leaf, we |
|
* move the search to the next lower level dmap control page |
|
* corresponding to this leaf. we continue down the dmap control |
|
* pages until we find the dmap that contains or starts the |
|
* sufficient free space and we allocate at this dmap. |
|
* |
|
* if the allocation group size is equal to the dmap size, |
|
* we'll start at the dmap corresponding to the allocation |
|
* group and attempt the allocation at this level. |
|
* |
|
* the dmap control page search is also not performed if the |
|
* allocation group is completely free and we go to the first |
|
* dmap of the allocation group to do the allocation. this is |
|
* done because the allocation group may be part (not the first |
|
* part) of a larger binary buddy system, causing the dmap |
|
* control pages to indicate no free space (NOFREE) within |
|
* the allocation group. |
|
* |
|
* PARAMETERS: |
|
* bmp - pointer to bmap descriptor |
|
* agno - allocation group number. |
|
* nblocks - actual number of contiguous free blocks desired. |
|
* l2nb - log2 number of contiguous free blocks desired. |
|
* results - on successful return, set to the starting block number |
|
* of the newly allocated range. |
|
* |
|
* RETURN VALUES: |
|
* 0 - success |
|
* -ENOSPC - insufficient disk resources |
|
* -EIO - i/o error |
|
* |
|
* note: IWRITE_LOCK(ipmap) held on entry/exit; |
|
*/ |
|
static int |
|
dbAllocAG(struct bmap * bmp, int agno, s64 nblocks, int l2nb, s64 * results) |
|
{ |
|
struct metapage *mp; |
|
struct dmapctl *dcp; |
|
int rc, ti, i, k, m, n, agperlev; |
|
s64 blkno, lblkno; |
|
int budmin; |
|
|
|
/* allocation request should not be for more than the |
|
* allocation group size. |
|
*/ |
|
if (l2nb > bmp->db_agl2size) { |
|
jfs_error(bmp->db_ipbmap->i_sb, |
|
"allocation request is larger than the allocation group size\n"); |
|
return -EIO; |
|
} |
|
|
|
/* determine the starting block number of the allocation |
|
* group. |
|
*/ |
|
blkno = (s64) agno << bmp->db_agl2size; |
|
|
|
/* check if the allocation group size is the minimum allocation |
|
* group size or if the allocation group is completely free. if |
|
* the allocation group size is the minimum size of BPERDMAP (i.e. |
|
* 1 dmap), there is no need to search the dmap control page (below) |
|
* that fully describes the allocation group since the allocation |
|
* group is already fully described by a dmap. in this case, we |
|
* just call dbAllocCtl() to search the dmap tree and allocate the |
|
* required space if available. |
|
* |
|
* if the allocation group is completely free, dbAllocCtl() is |
|
* also called to allocate the required space. this is done for |
|
* two reasons. first, it makes no sense searching the dmap control |
|
* pages for free space when we know that free space exists. second, |
|
* the dmap control pages may indicate that the allocation group |
|
* has no free space if the allocation group is part (not the first |
|
* part) of a larger binary buddy system. |
|
*/ |
|
if (bmp->db_agsize == BPERDMAP |
|
|| bmp->db_agfree[agno] == bmp->db_agsize) { |
|
rc = dbAllocCtl(bmp, nblocks, l2nb, blkno, results); |
|
if ((rc == -ENOSPC) && |
|
(bmp->db_agfree[agno] == bmp->db_agsize)) { |
|
printk(KERN_ERR "blkno = %Lx, blocks = %Lx\n", |
|
(unsigned long long) blkno, |
|
(unsigned long long) nblocks); |
|
jfs_error(bmp->db_ipbmap->i_sb, |
|
"dbAllocCtl failed in free AG\n"); |
|
} |
|
return (rc); |
|
} |
|
|
|
/* the buffer for the dmap control page that fully describes the |
|
* allocation group. |
|
*/ |
|
lblkno = BLKTOCTL(blkno, bmp->db_l2nbperpage, bmp->db_aglevel); |
|
mp = read_metapage(bmp->db_ipbmap, lblkno, PSIZE, 0); |
|
if (mp == NULL) |
|
return -EIO; |
|
dcp = (struct dmapctl *) mp->data; |
|
budmin = dcp->budmin; |
|
|
|
if (dcp->leafidx != cpu_to_le32(CTLLEAFIND)) { |
|
jfs_error(bmp->db_ipbmap->i_sb, "Corrupt dmapctl page\n"); |
|
release_metapage(mp); |
|
return -EIO; |
|
} |
|
|
|
/* search the subtree(s) of the dmap control page that describes |
|
* the allocation group, looking for sufficient free space. to begin, |
|
* determine how many allocation groups are represented in a dmap |
|
* control page at the control page level (i.e. L0, L1, L2) that |
|
* fully describes an allocation group. next, determine the starting |
|
* tree index of this allocation group within the control page. |
|
*/ |
|
agperlev = |
|
(1 << (L2LPERCTL - (bmp->db_agheight << 1))) / bmp->db_agwidth; |
|
ti = bmp->db_agstart + bmp->db_agwidth * (agno & (agperlev - 1)); |
|
|
|
/* dmap control page trees fan-out by 4 and a single allocation |
|
* group may be described by 1 or 2 subtrees within the ag level |
|
* dmap control page, depending upon the ag size. examine the ag's |
|
* subtrees for sufficient free space, starting with the leftmost |
|
* subtree. |
|
*/ |
|
for (i = 0; i < bmp->db_agwidth; i++, ti++) { |
|
/* is there sufficient free space ? |
|
*/ |
|
if (l2nb > dcp->stree[ti]) |
|
continue; |
|
|
|
/* sufficient free space found in a subtree. now search down |
|
* the subtree to find the leftmost leaf that describes this |
|
* free space. |
|
*/ |
|
for (k = bmp->db_agheight; k > 0; k--) { |
|
for (n = 0, m = (ti << 2) + 1; n < 4; n++) { |
|
if (l2nb <= dcp->stree[m + n]) { |
|
ti = m + n; |
|
break; |
|
} |
|
} |
|
if (n == 4) { |
|
jfs_error(bmp->db_ipbmap->i_sb, |
|
"failed descending stree\n"); |
|
release_metapage(mp); |
|
return -EIO; |
|
} |
|
} |
|
|
|
/* determine the block number within the file system |
|
* that corresponds to this leaf. |
|
*/ |
|
if (bmp->db_aglevel == 2) |
|
blkno = 0; |
|
else if (bmp->db_aglevel == 1) |
|
blkno &= ~(MAXL1SIZE - 1); |
|
else /* bmp->db_aglevel == 0 */ |
|
blkno &= ~(MAXL0SIZE - 1); |
|
|
|
blkno += |
|
((s64) (ti - le32_to_cpu(dcp->leafidx))) << budmin; |
|
|
|
/* release the buffer in preparation for going down |
|
* the next level of dmap control pages. |
|
*/ |
|
release_metapage(mp); |
|
|
|
/* check if we need to continue to search down the lower |
|
* level dmap control pages. we need to if the number of |
|
* blocks required is less than maximum number of blocks |
|
* described at the next lower level. |
|
*/ |
|
if (l2nb < budmin) { |
|
|
|
/* search the lower level dmap control pages to get |
|
* the starting block number of the dmap that |
|
* contains or starts off the free space. |
|
*/ |
|
if ((rc = |
|
dbFindCtl(bmp, l2nb, bmp->db_aglevel - 1, |
|
&blkno))) { |
|
if (rc == -ENOSPC) { |
|
jfs_error(bmp->db_ipbmap->i_sb, |
|
"control page inconsistent\n"); |
|
return -EIO; |
|
} |
|
return (rc); |
|
} |
|
} |
|
|
|
/* allocate the blocks. |
|
*/ |
|
rc = dbAllocCtl(bmp, nblocks, l2nb, blkno, results); |
|
if (rc == -ENOSPC) { |
|
jfs_error(bmp->db_ipbmap->i_sb, |
|
"unable to allocate blocks\n"); |
|
rc = -EIO; |
|
} |
|
return (rc); |
|
} |
|
|
|
/* no space in the allocation group. release the buffer and |
|
* return -ENOSPC. |
|
*/ |
|
release_metapage(mp); |
|
|
|
return -ENOSPC; |
|
} |
|
|
|
|
|
/* |
|
* NAME: dbAllocAny() |
|
* |
|
* FUNCTION: attempt to allocate the specified number of contiguous |
|
* free blocks anywhere in the file system. |
|
* |
|
* dbAllocAny() attempts to find the sufficient free space by |
|
* searching down the dmap control pages, starting with the |
|
* highest level (i.e. L0, L1, L2) control page. if free space |
|
* large enough to satisfy the desired free space is found, the |
|
* desired free space is allocated. |
|
* |
|
* PARAMETERS: |
|
* bmp - pointer to bmap descriptor |
|
* nblocks - actual number of contiguous free blocks desired. |
|
* l2nb - log2 number of contiguous free blocks desired. |
|
* results - on successful return, set to the starting block number |
|
* of the newly allocated range. |
|
* |
|
* RETURN VALUES: |
|
* 0 - success |
|
* -ENOSPC - insufficient disk resources |
|
* -EIO - i/o error |
|
* |
|
* serialization: IWRITE_LOCK(ipbmap) held on entry/exit; |
|
*/ |
|
static int dbAllocAny(struct bmap * bmp, s64 nblocks, int l2nb, s64 * results) |
|
{ |
|
int rc; |
|
s64 blkno = 0; |
|
|
|
/* starting with the top level dmap control page, search |
|
* down the dmap control levels for sufficient free space. |
|
* if free space is found, dbFindCtl() returns the starting |
|
* block number of the dmap that contains or starts off the |
|
* range of free space. |
|
*/ |
|
if ((rc = dbFindCtl(bmp, l2nb, bmp->db_maxlevel, &blkno))) |
|
return (rc); |
|
|
|
/* allocate the blocks. |
|
*/ |
|
rc = dbAllocCtl(bmp, nblocks, l2nb, blkno, results); |
|
if (rc == -ENOSPC) { |
|
jfs_error(bmp->db_ipbmap->i_sb, "unable to allocate blocks\n"); |
|
return -EIO; |
|
} |
|
return (rc); |
|
} |
|
|
|
|
|
/* |
|
* NAME: dbDiscardAG() |
|
* |
|
* FUNCTION: attempt to discard (TRIM) all free blocks of specific AG |
|
* |
|
* algorithm: |
|
* 1) allocate blocks, as large as possible and save them |
|
* while holding IWRITE_LOCK on ipbmap |
|
* 2) trim all these saved block/length values |
|
* 3) mark the blocks free again |
|
* |
|
* benefit: |
|
* - we work only on one ag at some time, minimizing how long we |
|
* need to lock ipbmap |
|
* - reading / writing the fs is possible most time, even on |
|
* trimming |
|
* |
|
* downside: |
|
* - we write two times to the dmapctl and dmap pages |
|
* - but for me, this seems the best way, better ideas? |
|
* /TR 2012 |
|
* |
|
* PARAMETERS: |
|
* ip - pointer to in-core inode |
|
* agno - ag to trim |
|
* minlen - minimum value of contiguous blocks |
|
* |
|
* RETURN VALUES: |
|
* s64 - actual number of blocks trimmed |
|
*/ |
|
s64 dbDiscardAG(struct inode *ip, int agno, s64 minlen) |
|
{ |
|
struct inode *ipbmap = JFS_SBI(ip->i_sb)->ipbmap; |
|
struct bmap *bmp = JFS_SBI(ip->i_sb)->bmap; |
|
s64 nblocks, blkno; |
|
u64 trimmed = 0; |
|
int rc, l2nb; |
|
struct super_block *sb = ipbmap->i_sb; |
|
|
|
struct range2trim { |
|
u64 blkno; |
|
u64 nblocks; |
|
} *totrim, *tt; |
|
|
|
/* max blkno / nblocks pairs to trim */ |
|
int count = 0, range_cnt; |
|
u64 max_ranges; |
|
|
|
/* prevent others from writing new stuff here, while trimming */ |
|
IWRITE_LOCK(ipbmap, RDWRLOCK_DMAP); |
|
|
|
nblocks = bmp->db_agfree[agno]; |
|
max_ranges = nblocks; |
|
do_div(max_ranges, minlen); |
|
range_cnt = min_t(u64, max_ranges + 1, 32 * 1024); |
|
totrim = kmalloc_array(range_cnt, sizeof(struct range2trim), GFP_NOFS); |
|
if (totrim == NULL) { |
|
jfs_error(bmp->db_ipbmap->i_sb, "no memory for trim array\n"); |
|
IWRITE_UNLOCK(ipbmap); |
|
return 0; |
|
} |
|
|
|
tt = totrim; |
|
while (nblocks >= minlen) { |
|
l2nb = BLKSTOL2(nblocks); |
|
|
|
/* 0 = okay, -EIO = fatal, -ENOSPC -> try smaller block */ |
|
rc = dbAllocAG(bmp, agno, nblocks, l2nb, &blkno); |
|
if (rc == 0) { |
|
tt->blkno = blkno; |
|
tt->nblocks = nblocks; |
|
tt++; count++; |
|
|
|
/* the whole ag is free, trim now */ |
|
if (bmp->db_agfree[agno] == 0) |
|
break; |
|
|
|
/* give a hint for the next while */ |
|
nblocks = bmp->db_agfree[agno]; |
|
continue; |
|
} else if (rc == -ENOSPC) { |
|
/* search for next smaller log2 block */ |
|
l2nb = BLKSTOL2(nblocks) - 1; |
|
nblocks = 1LL << l2nb; |
|
} else { |
|
/* Trim any already allocated blocks */ |
|
jfs_error(bmp->db_ipbmap->i_sb, "-EIO\n"); |
|
break; |
|
} |
|
|
|
/* check, if our trim array is full */ |
|
if (unlikely(count >= range_cnt - 1)) |
|
break; |
|
} |
|
IWRITE_UNLOCK(ipbmap); |
|
|
|
tt->nblocks = 0; /* mark the current end */ |
|
for (tt = totrim; tt->nblocks != 0; tt++) { |
|
/* when mounted with online discard, dbFree() will |
|
* call jfs_issue_discard() itself */ |
|
if (!(JFS_SBI(sb)->flag & JFS_DISCARD)) |
|
jfs_issue_discard(ip, tt->blkno, tt->nblocks); |
|
dbFree(ip, tt->blkno, tt->nblocks); |
|
trimmed += tt->nblocks; |
|
} |
|
kfree(totrim); |
|
|
|
return trimmed; |
|
} |
|
|
|
/* |
|
* NAME: dbFindCtl() |
|
* |
|
* FUNCTION: starting at a specified dmap control page level and block |
|
* number, search down the dmap control levels for a range of |
|
* contiguous free blocks large enough to satisfy an allocation |
|
* request for the specified number of free blocks. |
|
* |
|
* if sufficient contiguous free blocks are found, this routine |
|
* returns the starting block number within a dmap page that |
|
* contains or starts a range of contiqious free blocks that |
|
* is sufficient in size. |
|
* |
|
* PARAMETERS: |
|
* bmp - pointer to bmap descriptor |
|
* level - starting dmap control page level. |
|
* l2nb - log2 number of contiguous free blocks desired. |
|
* *blkno - on entry, starting block number for conducting the search. |
|
* on successful return, the first block within a dmap page |
|
* that contains or starts a range of contiguous free blocks. |
|
* |
|
* RETURN VALUES: |
|
* 0 - success |
|
* -ENOSPC - insufficient disk resources |
|
* -EIO - i/o error |
|
* |
|
* serialization: IWRITE_LOCK(ipbmap) held on entry/exit; |
|
*/ |
|
static int dbFindCtl(struct bmap * bmp, int l2nb, int level, s64 * blkno) |
|
{ |
|
int rc, leafidx, lev; |
|
s64 b, lblkno; |
|
struct dmapctl *dcp; |
|
int budmin; |
|
struct metapage *mp; |
|
|
|
/* starting at the specified dmap control page level and block |
|
* number, search down the dmap control levels for the starting |
|
* block number of a dmap page that contains or starts off |
|
* sufficient free blocks. |
|
*/ |
|
for (lev = level, b = *blkno; lev >= 0; lev--) { |
|
/* get the buffer of the dmap control page for the block |
|
* number and level (i.e. L0, L1, L2). |
|
*/ |
|
lblkno = BLKTOCTL(b, bmp->db_l2nbperpage, lev); |
|
mp = read_metapage(bmp->db_ipbmap, lblkno, PSIZE, 0); |
|
if (mp == NULL) |
|
return -EIO; |
|
dcp = (struct dmapctl *) mp->data; |
|
budmin = dcp->budmin; |
|
|
|
if (dcp->leafidx != cpu_to_le32(CTLLEAFIND)) { |
|
jfs_error(bmp->db_ipbmap->i_sb, |
|
"Corrupt dmapctl page\n"); |
|
release_metapage(mp); |
|
return -EIO; |
|
} |
|
|
|
/* search the tree within the dmap control page for |
|
* sufficient free space. if sufficient free space is found, |
|
* dbFindLeaf() returns the index of the leaf at which |
|
* free space was found. |
|
*/ |
|
rc = dbFindLeaf((dmtree_t *) dcp, l2nb, &leafidx); |
|
|
|
/* release the buffer. |
|
*/ |
|
release_metapage(mp); |
|
|
|
/* space found ? |
|
*/ |
|
if (rc) { |
|
if (lev != level) { |
|
jfs_error(bmp->db_ipbmap->i_sb, |
|
"dmap inconsistent\n"); |
|
return -EIO; |
|
} |
|
return -ENOSPC; |
|
} |
|
|
|
/* adjust the block number to reflect the location within |
|
* the dmap control page (i.e. the leaf) at which free |
|
* space was found. |
|
*/ |
|
b += (((s64) leafidx) << budmin); |
|
|
|
/* we stop the search at this dmap control page level if |
|
* the number of blocks required is greater than or equal |
|
* to the maximum number of blocks described at the next |
|
* (lower) level. |
|
*/ |
|
if (l2nb >= budmin) |
|
break; |
|
} |
|
|
|
*blkno = b; |
|
return (0); |
|
} |
|
|
|
|
|
/* |
|
* NAME: dbAllocCtl() |
|
* |
|
* FUNCTION: attempt to allocate a specified number of contiguous |
|
* blocks starting within a specific dmap. |
|
* |
|
* this routine is called by higher level routines that search |
|
* the dmap control pages above the actual dmaps for contiguous |
|
* free space. the result of successful searches by these |
|
* routines are the starting block numbers within dmaps, with |
|
* the dmaps themselves containing the desired contiguous free |
|
* space or starting a contiguous free space of desired size |
|
* that is made up of the blocks of one or more dmaps. these |
|
* calls should not fail due to insufficent resources. |
|
* |
|
* this routine is called in some cases where it is not known |
|
* whether it will fail due to insufficient resources. more |
|
* specifically, this occurs when allocating from an allocation |
|
* group whose size is equal to the number of blocks per dmap. |
|
* in this case, the dmap control pages are not examined prior |
|
* to calling this routine (to save pathlength) and the call |
|
* might fail. |
|
* |
|
* for a request size that fits within a dmap, this routine relies |
|
* upon the dmap's dmtree to find the requested contiguous free |
|
* space. for request sizes that are larger than a dmap, the |
|
* requested free space will start at the first block of the |
|
* first dmap (i.e. blkno). |
|
* |
|
* PARAMETERS: |
|
* bmp - pointer to bmap descriptor |
|
* nblocks - actual number of contiguous free blocks to allocate. |
|
* l2nb - log2 number of contiguous free blocks to allocate. |
|
* blkno - starting block number of the dmap to start the allocation |
|
* from. |
|
* results - on successful return, set to the starting block number |
|
* of the newly allocated range. |
|
* |
|
* RETURN VALUES: |
|
* 0 - success |
|
* -ENOSPC - insufficient disk resources |
|
* -EIO - i/o error |
|
* |
|
* serialization: IWRITE_LOCK(ipbmap) held on entry/exit; |
|
*/ |
|
static int |
|
dbAllocCtl(struct bmap * bmp, s64 nblocks, int l2nb, s64 blkno, s64 * results) |
|
{ |
|
int rc, nb; |
|
s64 b, lblkno, n; |
|
struct metapage *mp; |
|
struct dmap *dp; |
|
|
|
/* check if the allocation request is confined to a single dmap. |
|
*/ |
|
if (l2nb <= L2BPERDMAP) { |
|
/* get the buffer for the dmap. |
|
*/ |
|
lblkno = BLKTODMAP(blkno, bmp->db_l2nbperpage); |
|
mp = read_metapage(bmp->db_ipbmap, lblkno, PSIZE, 0); |
|
if (mp == NULL) |
|
return -EIO; |
|
dp = (struct dmap *) mp->data; |
|
|
|
/* try to allocate the blocks. |
|
*/ |
|
rc = dbAllocDmapLev(bmp, dp, (int) nblocks, l2nb, results); |
|
if (rc == 0) |
|
mark_metapage_dirty(mp); |
|
|
|
release_metapage(mp); |
|
|
|
return (rc); |
|
} |
|
|
|
/* allocation request involving multiple dmaps. it must start on |
|
* a dmap boundary. |
|
*/ |
|
assert((blkno & (BPERDMAP - 1)) == 0); |
|
|
|
/* allocate the blocks dmap by dmap. |
|
*/ |
|
for (n = nblocks, b = blkno; n > 0; n -= nb, b += nb) { |
|
/* get the buffer for the dmap. |
|
*/ |
|
lblkno = BLKTODMAP(b, bmp->db_l2nbperpage); |
|
mp = read_metapage(bmp->db_ipbmap, lblkno, PSIZE, 0); |
|
if (mp == NULL) { |
|
rc = -EIO; |
|
goto backout; |
|
} |
|
dp = (struct dmap *) mp->data; |
|
|
|
/* the dmap better be all free. |
|
*/ |
|
if (dp->tree.stree[ROOT] != L2BPERDMAP) { |
|
release_metapage(mp); |
|
jfs_error(bmp->db_ipbmap->i_sb, |
|
"the dmap is not all free\n"); |
|
rc = -EIO; |
|
goto backout; |
|
} |
|
|
|
/* determine how many blocks to allocate from this dmap. |
|
*/ |
|
nb = min_t(s64, n, BPERDMAP); |
|
|
|
/* allocate the blocks from the dmap. |
|
*/ |
|
if ((rc = dbAllocDmap(bmp, dp, b, nb))) { |
|
release_metapage(mp); |
|
goto backout; |
|
} |
|
|
|
/* write the buffer. |
|
*/ |
|
write_metapage(mp); |
|
} |
|
|
|
/* set the results (starting block number) and return. |
|
*/ |
|
*results = blkno; |
|
return (0); |
|
|
|
/* something failed in handling an allocation request involving |
|
* multiple dmaps. we'll try to clean up by backing out any |
|
* allocation that has already happened for this request. if |
|
* we fail in backing out the allocation, we'll mark the file |
|
* system to indicate that blocks have been leaked. |
|
*/ |
|
backout: |
|
|
|
/* try to backout the allocations dmap by dmap. |
|
*/ |
|
for (n = nblocks - n, b = blkno; n > 0; |
|
n -= BPERDMAP, b += BPERDMAP) { |
|
/* get the buffer for this dmap. |
|
*/ |
|
lblkno = BLKTODMAP(b, bmp->db_l2nbperpage); |
|
mp = read_metapage(bmp->db_ipbmap, lblkno, PSIZE, 0); |
|
if (mp == NULL) { |
|
/* could not back out. mark the file system |
|
* to indicate that we have leaked blocks. |
|
*/ |
|
jfs_error(bmp->db_ipbmap->i_sb, |
|
"I/O Error: Block Leakage\n"); |
|
continue; |
|
} |
|
dp = (struct dmap *) mp->data; |
|
|
|
/* free the blocks is this dmap. |
|
*/ |
|
if (dbFreeDmap(bmp, dp, b, BPERDMAP)) { |
|
/* could not back out. mark the file system |
|
* to indicate that we have leaked blocks. |
|
*/ |
|
release_metapage(mp); |
|
jfs_error(bmp->db_ipbmap->i_sb, "Block Leakage\n"); |
|
continue; |
|
} |
|
|
|
/* write the buffer. |
|
*/ |
|
write_metapage(mp); |
|
} |
|
|
|
return (rc); |
|
} |
|
|
|
|
|
/* |
|
* NAME: dbAllocDmapLev() |
|
* |
|
* FUNCTION: attempt to allocate a specified number of contiguous blocks |
|
* from a specified dmap. |
|
* |
|
* this routine checks if the contiguous blocks are available. |
|
* if so, nblocks of blocks are allocated; otherwise, ENOSPC is |
|
* returned. |
|
* |
|
* PARAMETERS: |
|
* mp - pointer to bmap descriptor |
|
* dp - pointer to dmap to attempt to allocate blocks from. |
|
* l2nb - log2 number of contiguous block desired. |
|
* nblocks - actual number of contiguous block desired. |
|
* results - on successful return, set to the starting block number |
|
* of the newly allocated range. |
|
* |
|
* RETURN VALUES: |
|
* 0 - success |
|
* -ENOSPC - insufficient disk resources |
|
* -EIO - i/o error |
|
* |
|
* serialization: IREAD_LOCK(ipbmap), e.g., from dbAlloc(), or |
|
* IWRITE_LOCK(ipbmap), e.g., dbAllocCtl(), held on entry/exit; |
|
*/ |
|
static int |
|
dbAllocDmapLev(struct bmap * bmp, |
|
struct dmap * dp, int nblocks, int l2nb, s64 * results) |
|
{ |
|
s64 blkno; |
|
int leafidx, rc; |
|
|
|
/* can't be more than a dmaps worth of blocks */ |
|
assert(l2nb <= L2BPERDMAP); |
|
|
|
/* search the tree within the dmap page for sufficient |
|
* free space. if sufficient free space is found, dbFindLeaf() |
|
* returns the index of the leaf at which free space was found. |
|
*/ |
|
if (dbFindLeaf((dmtree_t *) & dp->tree, l2nb, &leafidx)) |
|
return -ENOSPC; |
|
|
|
/* determine the block number within the file system corresponding |
|
* to the leaf at which free space was found. |
|
*/ |
|
blkno = le64_to_cpu(dp->start) + (leafidx << L2DBWORD); |
|
|
|
/* if not all bits of the dmap word are free, get the starting |
|
* bit number within the dmap word of the required string of free |
|
* bits and adjust the block number with this value. |
|
*/ |
|
if (dp->tree.stree[leafidx + LEAFIND] < BUDMIN) |
|
blkno += dbFindBits(le32_to_cpu(dp->wmap[leafidx]), l2nb); |
|
|
|
/* allocate the blocks */ |
|
if ((rc = dbAllocDmap(bmp, dp, blkno, nblocks)) == 0) |
|
*results = blkno; |
|
|
|
return (rc); |
|
} |
|
|
|
|
|
/* |
|
* NAME: dbAllocDmap() |
|
* |
|
* FUNCTION: adjust the disk allocation map to reflect the allocation |
|
* of a specified block range within a dmap. |
|
* |
|
* this routine allocates the specified blocks from the dmap |
|
* through a call to dbAllocBits(). if the allocation of the |
|
* block range causes the maximum string of free blocks within |
|
* the dmap to change (i.e. the value of the root of the dmap's |
|
* dmtree), this routine will cause this change to be reflected |
|
* up through the appropriate levels of the dmap control pages |
|
* by a call to dbAdjCtl() for the L0 dmap control page that |
|
* covers this dmap. |
|
* |
|
* PARAMETERS: |
|
* bmp - pointer to bmap descriptor |
|
* dp - pointer to dmap to allocate the block range from. |
|
* blkno - starting block number of the block to be allocated. |
|
* nblocks - number of blocks to be allocated. |
|
* |
|
* RETURN VALUES: |
|
* 0 - success |
|
* -EIO - i/o error |
|
* |
|
* serialization: IREAD_LOCK(ipbmap) or IWRITE_LOCK(ipbmap) held on entry/exit; |
|
*/ |
|
static int dbAllocDmap(struct bmap * bmp, struct dmap * dp, s64 blkno, |
|
int nblocks) |
|
{ |
|
s8 oldroot; |
|
int rc; |
|
|
|
/* save the current value of the root (i.e. maximum free string) |
|
* of the dmap tree. |
|
*/ |
|
oldroot = dp->tree.stree[ROOT]; |
|
|
|
/* allocate the specified (blocks) bits */ |
|
dbAllocBits(bmp, dp, blkno, nblocks); |
|
|
|
/* if the root has not changed, done. */ |
|
if (dp->tree.stree[ROOT] == oldroot) |
|
return (0); |
|
|
|
/* root changed. bubble the change up to the dmap control pages. |
|
* if the adjustment of the upper level control pages fails, |
|
* backout the bit allocation (thus making everything consistent). |
|
*/ |
|
if ((rc = dbAdjCtl(bmp, blkno, dp->tree.stree[ROOT], 1, 0))) |
|
dbFreeBits(bmp, dp, blkno, nblocks); |
|
|
|
return (rc); |
|
} |
|
|
|
|
|
/* |
|
* NAME: dbFreeDmap() |
|
* |
|
* FUNCTION: adjust the disk allocation map to reflect the allocation |
|
* of a specified block range within a dmap. |
|
* |
|
* this routine frees the specified blocks from the dmap through |
|
* a call to dbFreeBits(). if the deallocation of the block range |
|
* causes the maximum string of free blocks within the dmap to |
|
* change (i.e. the value of the root of the dmap's dmtree), this |
|
* routine will cause this change to be reflected up through the |
|
* appropriate levels of the dmap control pages by a call to |
|
* dbAdjCtl() for the L0 dmap control page that covers this dmap. |
|
* |
|
* PARAMETERS: |
|
* bmp - pointer to bmap descriptor |
|
* dp - pointer to dmap to free the block range from. |
|
* blkno - starting block number of the block to be freed. |
|
* nblocks - number of blocks to be freed. |
|
* |
|
* RETURN VALUES: |
|
* 0 - success |
|
* -EIO - i/o error |
|
* |
|
* serialization: IREAD_LOCK(ipbmap) or IWRITE_LOCK(ipbmap) held on entry/exit; |
|
*/ |
|
static int dbFreeDmap(struct bmap * bmp, struct dmap * dp, s64 blkno, |
|
int nblocks) |
|
{ |
|
s8 oldroot; |
|
int rc = 0, word; |
|
|
|
/* save the current value of the root (i.e. maximum free string) |
|
* of the dmap tree. |
|
*/ |
|
oldroot = dp->tree.stree[ROOT]; |
|
|
|
/* free the specified (blocks) bits */ |
|
rc = dbFreeBits(bmp, dp, blkno, nblocks); |
|
|
|
/* if error or the root has not changed, done. */ |
|
if (rc || (dp->tree.stree[ROOT] == oldroot)) |
|
return (rc); |
|
|
|
/* root changed. bubble the change up to the dmap control pages. |
|
* if the adjustment of the upper level control pages fails, |
|
* backout the deallocation. |
|
*/ |
|
if ((rc = dbAdjCtl(bmp, blkno, dp->tree.stree[ROOT], 0, 0))) { |
|
word = (blkno & (BPERDMAP - 1)) >> L2DBWORD; |
|
|
|
/* as part of backing out the deallocation, we will have |
|
* to back split the dmap tree if the deallocation caused |
|
* the freed blocks to become part of a larger binary buddy |
|
* system. |
|
*/ |
|
if (dp->tree.stree[word] == NOFREE) |
|
dbBackSplit((dmtree_t *) & dp->tree, word); |
|
|
|
dbAllocBits(bmp, dp, blkno, nblocks); |
|
} |
|
|
|
return (rc); |
|
} |
|
|
|
|
|
/* |
|
* NAME: dbAllocBits() |
|
* |
|
* FUNCTION: allocate a specified block range from a dmap. |
|
* |
|
* this routine updates the dmap to reflect the working |
|
* state allocation of the specified block range. it directly |
|
* updates the bits of the working map and causes the adjustment |
|
* of the binary buddy system described by the dmap's dmtree |
|
* leaves to reflect the bits allocated. it also causes the |
|
* dmap's dmtree, as a whole, to reflect the allocated range. |
|
* |
|
* PARAMETERS: |
|
* bmp - pointer to bmap descriptor |
|
* dp - pointer to dmap to allocate bits from. |
|
* blkno - starting block number of the bits to be allocated. |
|
* nblocks - number of bits to be allocated. |
|
* |
|
* RETURN VALUES: none |
|
* |
|
* serialization: IREAD_LOCK(ipbmap) or IWRITE_LOCK(ipbmap) held on entry/exit; |
|
*/ |
|
static void dbAllocBits(struct bmap * bmp, struct dmap * dp, s64 blkno, |
|
int nblocks) |
|
{ |
|
int dbitno, word, rembits, nb, nwords, wbitno, nw, agno; |
|
dmtree_t *tp = (dmtree_t *) & dp->tree; |
|
int size; |
|
s8 *leaf; |
|
|
|
/* pick up a pointer to the leaves of the dmap tree */ |
|
leaf = dp->tree.stree + LEAFIND; |
|
|
|
/* determine the bit number and word within the dmap of the |
|
* starting block. |
|
*/ |
|
dbitno = blkno & (BPERDMAP - 1); |
|
word = dbitno >> L2DBWORD; |
|
|
|
/* block range better be within the dmap */ |
|
assert(dbitno + nblocks <= BPERDMAP); |
|
|
|
/* allocate the bits of the dmap's words corresponding to the block |
|
* range. not all bits of the first and last words may be contained |
|
* within the block range. if this is the case, we'll work against |
|
* those words (i.e. partial first and/or last) on an individual basis |
|
* (a single pass), allocating the bits of interest by hand and |
|
* updating the leaf corresponding to the dmap word. a single pass |
|
* will be used for all dmap words fully contained within the |
|
* specified range. within this pass, the bits of all fully contained |
|
* dmap words will be marked as free in a single shot and the leaves |
|
* will be updated. a single leaf may describe the free space of |
|
* multiple dmap words, so we may update only a subset of the actual |
|
* leaves corresponding to the dmap words of the block range. |
|
*/ |
|
for (rembits = nblocks; rembits > 0; rembits -= nb, dbitno += nb) { |
|
/* determine the bit number within the word and |
|
* the number of bits within the word. |
|
*/ |
|
wbitno = dbitno & (DBWORD - 1); |
|
nb = min(rembits, DBWORD - wbitno); |
|
|
|
/* check if only part of a word is to be allocated. |
|
*/ |
|
if (nb < DBWORD) { |
|
/* allocate (set to 1) the appropriate bits within |
|
* this dmap word. |
|
*/ |
|
dp->wmap[word] |= cpu_to_le32(ONES << (DBWORD - nb) |
|
>> wbitno); |
|
|
|
/* update the leaf for this dmap word. in addition |
|
* to setting the leaf value to the binary buddy max |
|
* of the updated dmap word, dbSplit() will split |
|
* the binary system of the leaves if need be. |
|
*/ |
|
dbSplit(tp, word, BUDMIN, |
|
dbMaxBud((u8 *) & dp->wmap[word])); |
|
|
|
word += 1; |
|
} else { |
|
/* one or more dmap words are fully contained |
|
* within the block range. determine how many |
|
* words and allocate (set to 1) the bits of these |
|
* words. |
|
*/ |
|
nwords = rembits >> L2DBWORD; |
|
memset(&dp->wmap[word], (int) ONES, nwords * 4); |
|
|
|
/* determine how many bits. |
|
*/ |
|
nb = nwords << L2DBWORD; |
|
|
|
/* now update the appropriate leaves to reflect |
|
* the allocated words. |
|
*/ |
|
for (; nwords > 0; nwords -= nw) { |
|
if (leaf[word] < BUDMIN) { |
|
jfs_error(bmp->db_ipbmap->i_sb, |
|
"leaf page corrupt\n"); |
|
break; |
|
} |
|
|
|
/* determine what the leaf value should be |
|
* updated to as the minimum of the l2 number |
|
* of bits being allocated and the l2 number |
|
* of bits currently described by this leaf. |
|
*/ |
|
size = min_t(int, leaf[word], |
|
NLSTOL2BSZ(nwords)); |
|
|
|
/* update the leaf to reflect the allocation. |
|
* in addition to setting the leaf value to |
|
* NOFREE, dbSplit() will split the binary |
|
* system of the leaves to reflect the current |
|
* allocation (size). |
|
*/ |
|
dbSplit(tp, word, size, NOFREE); |
|
|
|
/* get the number of dmap words handled */ |
|
nw = BUDSIZE(size, BUDMIN); |
|
word += nw; |
|
} |
|
} |
|
} |
|
|
|
/* update the free count for this dmap */ |
|
le32_add_cpu(&dp->nfree, -nblocks); |
|
|
|
BMAP_LOCK(bmp); |
|
|
|
/* if this allocation group is completely free, |
|
* update the maximum allocation group number if this allocation |
|
* group is the new max. |
|
*/ |
|
agno = blkno >> bmp->db_agl2size; |
|
if (agno > bmp->db_maxag) |
|
bmp->db_maxag = agno; |
|
|
|
/* update the free count for the allocation group and map */ |
|
bmp->db_agfree[agno] -= nblocks; |
|
bmp->db_nfree -= nblocks; |
|
|
|
BMAP_UNLOCK(bmp); |
|
} |
|
|
|
|
|
/* |
|
* NAME: dbFreeBits() |
|
* |
|
* FUNCTION: free a specified block range from a dmap. |
|
* |
|
* this routine updates the dmap to reflect the working |
|
* state allocation of the specified block range. it directly |
|
* updates the bits of the working map and causes the adjustment |
|
* of the binary buddy system described by the dmap's dmtree |
|
* leaves to reflect the bits freed. it also causes the dmap's |
|
* dmtree, as a whole, to reflect the deallocated range. |
|
* |
|
* PARAMETERS: |
|
* bmp - pointer to bmap descriptor |
|
* dp - pointer to dmap to free bits from. |
|
* blkno - starting block number of the bits to be freed. |
|
* nblocks - number of bits to be freed. |
|
* |
|
* RETURN VALUES: 0 for success |
|
* |
|
* serialization: IREAD_LOCK(ipbmap) or IWRITE_LOCK(ipbmap) held on entry/exit; |
|
*/ |
|
static int dbFreeBits(struct bmap * bmp, struct dmap * dp, s64 blkno, |
|
int nblocks) |
|
{ |
|
int dbitno, word, rembits, nb, nwords, wbitno, nw, agno; |
|
dmtree_t *tp = (dmtree_t *) & dp->tree; |
|
int rc = 0; |
|
int size; |
|
|
|
/* determine the bit number and word within the dmap of the |
|
* starting block. |
|
*/ |
|
dbitno = blkno & (BPERDMAP - 1); |
|
word = dbitno >> L2DBWORD; |
|
|
|
/* block range better be within the dmap. |
|
*/ |
|
assert(dbitno + nblocks <= BPERDMAP); |
|
|
|
/* free the bits of the dmaps words corresponding to the block range. |
|
* not all bits of the first and last words may be contained within |
|
* the block range. if this is the case, we'll work against those |
|
* words (i.e. partial first and/or last) on an individual basis |
|
* (a single pass), freeing the bits of interest by hand and updating |
|
* the leaf corresponding to the dmap word. a single pass will be used |
|
* for all dmap words fully contained within the specified range. |
|
* within this pass, the bits of all fully contained dmap words will |
|
* be marked as free in a single shot and the leaves will be updated. a |
|
* single leaf may describe the free space of multiple dmap words, |
|
* so we may update only a subset of the actual leaves corresponding |
|
* to the dmap words of the block range. |
|
* |
|
* dbJoin() is used to update leaf values and will join the binary |
|
* buddy system of the leaves if the new leaf values indicate this |
|
* should be done. |
|
*/ |
|
for (rembits = nblocks; rembits > 0; rembits -= nb, dbitno += nb) { |
|
/* determine the bit number within the word and |
|
* the number of bits within the word. |
|
*/ |
|
wbitno = dbitno & (DBWORD - 1); |
|
nb = min(rembits, DBWORD - wbitno); |
|
|
|
/* check if only part of a word is to be freed. |
|
*/ |
|
if (nb < DBWORD) { |
|
/* free (zero) the appropriate bits within this |
|
* dmap word. |
|
*/ |
|
dp->wmap[word] &= |
|
cpu_to_le32(~(ONES << (DBWORD - nb) |
|
>> wbitno)); |
|
|
|
/* update the leaf for this dmap word. |
|
*/ |
|
rc = dbJoin(tp, word, |
|
dbMaxBud((u8 *) & dp->wmap[word])); |
|
if (rc) |
|
return rc; |
|
|
|
word += 1; |
|
} else { |
|
/* one or more dmap words are fully contained |
|
* within the block range. determine how many |
|
* words and free (zero) the bits of these words. |
|
*/ |
|
nwords = rembits >> L2DBWORD; |
|
memset(&dp->wmap[word], 0, nwords * 4); |
|
|
|
/* determine how many bits. |
|
*/ |
|
nb = nwords << L2DBWORD; |
|
|
|
/* now update the appropriate leaves to reflect |
|
* the freed words. |
|
*/ |
|
for (; nwords > 0; nwords -= nw) { |
|
/* determine what the leaf value should be |
|
* updated to as the minimum of the l2 number |
|
* of bits being freed and the l2 (max) number |
|
* of bits that can be described by this leaf. |
|
*/ |
|
size = |
|
min(LITOL2BSZ |
|
(word, L2LPERDMAP, BUDMIN), |
|
NLSTOL2BSZ(nwords)); |
|
|
|
/* update the leaf. |
|
*/ |
|
rc = dbJoin(tp, word, size); |
|
if (rc) |
|
return rc; |
|
|
|
/* get the number of dmap words handled. |
|
*/ |
|
nw = BUDSIZE(size, BUDMIN); |
|
word += nw; |
|
} |
|
} |
|
} |
|
|
|
/* update the free count for this dmap. |
|
*/ |
|
le32_add_cpu(&dp->nfree, nblocks); |
|
|
|
BMAP_LOCK(bmp); |
|
|
|
/* update the free count for the allocation group and |
|
* map. |
|
*/ |
|
agno = blkno >> bmp->db_agl2size; |
|
bmp->db_nfree += nblocks; |
|
bmp->db_agfree[agno] += nblocks; |
|
|
|
/* check if this allocation group is not completely free and |
|
* if it is currently the maximum (rightmost) allocation group. |
|
* if so, establish the new maximum allocation group number by |
|
* searching left for the first allocation group with allocation. |
|
*/ |
|
if ((bmp->db_agfree[agno] == bmp->db_agsize && agno == bmp->db_maxag) || |
|
(agno == bmp->db_numag - 1 && |
|
bmp->db_agfree[agno] == (bmp-> db_mapsize & (BPERDMAP - 1)))) { |
|
while (bmp->db_maxag > 0) { |
|
bmp->db_maxag -= 1; |
|
if (bmp->db_agfree[bmp->db_maxag] != |
|
bmp->db_agsize) |
|
break; |
|
} |
|
|
|
/* re-establish the allocation group preference if the |
|
* current preference is right of the maximum allocation |
|
* group. |
|
*/ |
|
if (bmp->db_agpref > bmp->db_maxag) |
|
bmp->db_agpref = bmp->db_maxag; |
|
} |
|
|
|
BMAP_UNLOCK(bmp); |
|
|
|
return 0; |
|
} |
|
|
|
|
|
/* |
|
* NAME: dbAdjCtl() |
|
* |
|
* FUNCTION: adjust a dmap control page at a specified level to reflect |
|
* the change in a lower level dmap or dmap control page's |
|
* maximum string of free blocks (i.e. a change in the root |
|
* of the lower level object's dmtree) due to the allocation |
|
* or deallocation of a range of blocks with a single dmap. |
|
* |
|
* on entry, this routine is provided with the new value of |
|
* the lower level dmap or dmap control page root and the |
|
* starting block number of the block range whose allocation |
|
* or deallocation resulted in the root change. this range |
|
* is respresented by a single leaf of the current dmapctl |
|
* and the leaf will be updated with this value, possibly |
|
* causing a binary buddy system within the leaves to be |
|
* split or joined. the update may also cause the dmapctl's |
|
* dmtree to be updated. |
|
* |
|
* if the adjustment of the dmap control page, itself, causes its |
|
* root to change, this change will be bubbled up to the next dmap |
|
* control level by a recursive call to this routine, specifying |
|
* the new root value and the next dmap control page level to |
|
* be adjusted. |
|
* PARAMETERS: |
|
* bmp - pointer to bmap descriptor |
|
* blkno - the first block of a block range within a dmap. it is |
|
* the allocation or deallocation of this block range that |
|
* requires the dmap control page to be adjusted. |
|
* newval - the new value of the lower level dmap or dmap control |
|
* page root. |
|
* alloc - 'true' if adjustment is due to an allocation. |
|
* level - current level of dmap control page (i.e. L0, L1, L2) to |
|
* be adjusted. |
|
* |
|
* RETURN VALUES: |
|
* 0 - success |
|
* -EIO - i/o error |
|
* |
|
* serialization: IREAD_LOCK(ipbmap) or IWRITE_LOCK(ipbmap) held on entry/exit; |
|
*/ |
|
static int |
|
dbAdjCtl(struct bmap * bmp, s64 blkno, int newval, int alloc, int level) |
|
{ |
|
struct metapage *mp; |
|
s8 oldroot; |
|
int oldval; |
|
s64 lblkno; |
|
struct dmapctl *dcp; |
|
int rc, leafno, ti; |
|
|
|
/* get the buffer for the dmap control page for the specified |
|
* block number and control page level. |
|
*/ |
|
lblkno = BLKTOCTL(blkno, bmp->db_l2nbperpage, level); |
|
mp = read_metapage(bmp->db_ipbmap, lblkno, PSIZE, 0); |
|
if (mp == NULL) |
|
return -EIO; |
|
dcp = (struct dmapctl *) mp->data; |
|
|
|
if (dcp->leafidx != cpu_to_le32(CTLLEAFIND)) { |
|
jfs_error(bmp->db_ipbmap->i_sb, "Corrupt dmapctl page\n"); |
|
release_metapage(mp); |
|
return -EIO; |
|
} |
|
|
|
/* determine the leaf number corresponding to the block and |
|
* the index within the dmap control tree. |
|
*/ |
|
leafno = BLKTOCTLLEAF(blkno, dcp->budmin); |
|
ti = leafno + le32_to_cpu(dcp->leafidx); |
|
|
|
/* save the current leaf value and the current root level (i.e. |
|
* maximum l2 free string described by this dmapctl). |
|
*/ |
|
oldval = dcp->stree[ti]; |
|
oldroot = dcp->stree[ROOT]; |
|
|
|
/* check if this is a control page update for an allocation. |
|
* if so, update the leaf to reflect the new leaf value using |
|
* dbSplit(); otherwise (deallocation), use dbJoin() to update |
|
* the leaf with the new value. in addition to updating the |
|
* leaf, dbSplit() will also split the binary buddy system of |
|
* the leaves, if required, and bubble new values within the |
|
* dmapctl tree, if required. similarly, dbJoin() will join |
|
* the binary buddy system of leaves and bubble new values up |
|
* the dmapctl tree as required by the new leaf value. |
|
*/ |
|
if (alloc) { |
|
/* check if we are in the middle of a binary buddy |
|
* system. this happens when we are performing the |
|
* first allocation out of an allocation group that |
|
* is part (not the first part) of a larger binary |
|
* buddy system. if we are in the middle, back split |
|
* the system prior to calling dbSplit() which assumes |
|
* that it is at the front of a binary buddy system. |
|
*/ |
|
if (oldval == NOFREE) { |
|
rc = dbBackSplit((dmtree_t *) dcp, leafno); |
|
if (rc) { |
|
release_metapage(mp); |
|
return rc; |
|
} |
|
oldval = dcp->stree[ti]; |
|
} |
|
dbSplit((dmtree_t *) dcp, leafno, dcp->budmin, newval); |
|
} else { |
|
rc = dbJoin((dmtree_t *) dcp, leafno, newval); |
|
if (rc) { |
|
release_metapage(mp); |
|
return rc; |
|
} |
|
} |
|
|
|
/* check if the root of the current dmap control page changed due |
|
* to the update and if the current dmap control page is not at |
|
* the current top level (i.e. L0, L1, L2) of the map. if so (i.e. |
|
* root changed and this is not the top level), call this routine |
|
* again (recursion) for the next higher level of the mapping to |
|
* reflect the change in root for the current dmap control page. |
|
*/ |
|
if (dcp->stree[ROOT] != oldroot) { |
|
/* are we below the top level of the map. if so, |
|
* bubble the root up to the next higher level. |
|
*/ |
|
if (level < bmp->db_maxlevel) { |
|
/* bubble up the new root of this dmap control page to |
|
* the next level. |
|
*/ |
|
if ((rc = |
|
dbAdjCtl(bmp, blkno, dcp->stree[ROOT], alloc, |
|
level + 1))) { |
|
/* something went wrong in bubbling up the new |
|
* root value, so backout the changes to the |
|
* current dmap control page. |
|
*/ |
|
if (alloc) { |
|
dbJoin((dmtree_t *) dcp, leafno, |
|
oldval); |
|
} else { |
|
/* the dbJoin() above might have |
|
* caused a larger binary buddy system |
|
* to form and we may now be in the |
|
* middle of it. if this is the case, |
|
* back split the buddies. |
|
*/ |
|
if (dcp->stree[ti] == NOFREE) |
|
dbBackSplit((dmtree_t *) |
|
dcp, leafno); |
|
dbSplit((dmtree_t *) dcp, leafno, |
|
dcp->budmin, oldval); |
|
} |
|
|
|
/* release the buffer and return the error. |
|
*/ |
|
release_metapage(mp); |
|
return (rc); |
|
} |
|
} else { |
|
/* we're at the top level of the map. update |
|
* the bmap control page to reflect the size |
|
* of the maximum free buddy system. |
|
*/ |
|
assert(level == bmp->db_maxlevel); |
|
if (bmp->db_maxfreebud != oldroot) { |
|
jfs_error(bmp->db_ipbmap->i_sb, |
|
"the maximum free buddy is not the old root\n"); |
|
} |
|
bmp->db_maxfreebud = dcp->stree[ROOT]; |
|
} |
|
} |
|
|
|
/* write the buffer. |
|
*/ |
|
write_metapage(mp); |
|
|
|
return (0); |
|
} |
|
|
|
|
|
/* |
|
* NAME: dbSplit() |
|
* |
|
* FUNCTION: update the leaf of a dmtree with a new value, splitting |
|
* the leaf from the binary buddy system of the dmtree's |
|
* leaves, as required. |
|
* |
|
* PARAMETERS: |
|
* tp - pointer to the tree containing the leaf. |
|
* leafno - the number of the leaf to be updated. |
|
* splitsz - the size the binary buddy system starting at the leaf |
|
* must be split to, specified as the log2 number of blocks. |
|
* newval - the new value for the leaf. |
|
* |
|
* RETURN VALUES: none |
|
* |
|
* serialization: IREAD_LOCK(ipbmap) or IWRITE_LOCK(ipbmap) held on entry/exit; |
|
*/ |
|
static void dbSplit(dmtree_t * tp, int leafno, int splitsz, int newval) |
|
{ |
|
int budsz; |
|
int cursz; |
|
s8 *leaf = tp->dmt_stree + le32_to_cpu(tp->dmt_leafidx); |
|
|
|
/* check if the leaf needs to be split. |
|
*/ |
|
if (leaf[leafno] > tp->dmt_budmin) { |
|
/* the split occurs by cutting the buddy system in half |
|
* at the specified leaf until we reach the specified |
|
* size. pick up the starting split size (current size |
|
* - 1 in l2) and the corresponding buddy size. |
|
*/ |
|
cursz = leaf[leafno] - 1; |
|
budsz = BUDSIZE(cursz, tp->dmt_budmin); |
|
|
|
/* split until we reach the specified size. |
|
*/ |
|
while (cursz >= splitsz) { |
|
/* update the buddy's leaf with its new value. |
|
*/ |
|
dbAdjTree(tp, leafno ^ budsz, cursz); |
|
|
|
/* on to the next size and buddy. |
|
*/ |
|
cursz -= 1; |
|
budsz >>= 1; |
|
} |
|
} |
|
|
|
/* adjust the dmap tree to reflect the specified leaf's new |
|
* value. |
|
*/ |
|
dbAdjTree(tp, leafno, newval); |
|
} |
|
|
|
|
|
/* |
|
* NAME: dbBackSplit() |
|
* |
|
* FUNCTION: back split the binary buddy system of dmtree leaves |
|
* that hold a specified leaf until the specified leaf |
|
* starts its own binary buddy system. |
|
* |
|
* the allocators typically perform allocations at the start |
|
* of binary buddy systems and dbSplit() is used to accomplish |
|
* any required splits. in some cases, however, allocation |
|
* may occur in the middle of a binary system and requires a |
|
* back split, with the split proceeding out from the middle of |
|
* the system (less efficient) rather than the start of the |
|
* system (more efficient). the cases in which a back split |
|
* is required are rare and are limited to the first allocation |
|
* within an allocation group which is a part (not first part) |
|
* of a larger binary buddy system and a few exception cases |
|
* in which a previous join operation must be backed out. |
|
* |
|
* PARAMETERS: |
|
* tp - pointer to the tree containing the leaf. |
|
* leafno - the number of the leaf to be updated. |
|
* |
|
* RETURN VALUES: none |
|
* |
|
* serialization: IREAD_LOCK(ipbmap) or IWRITE_LOCK(ipbmap) held on entry/exit; |
|
*/ |
|
static int dbBackSplit(dmtree_t * tp, int leafno) |
|
{ |
|
int budsz, bud, w, bsz, size; |
|
int cursz; |
|
s8 *leaf = tp->dmt_stree + le32_to_cpu(tp->dmt_leafidx); |
|
|
|
/* leaf should be part (not first part) of a binary |
|
* buddy system. |
|
*/ |
|
assert(leaf[leafno] == NOFREE); |
|
|
|
/* the back split is accomplished by iteratively finding the leaf |
|
* that starts the buddy system that contains the specified leaf and |
|
* splitting that system in two. this iteration continues until |
|
* the specified leaf becomes the start of a buddy system. |
|
* |
|
* determine maximum possible l2 size for the specified leaf. |
|
*/ |
|
size = |
|
LITOL2BSZ(leafno, le32_to_cpu(tp->dmt_l2nleafs), |
|
tp->dmt_budmin); |
|
|
|
/* determine the number of leaves covered by this size. this |
|
* is the buddy size that we will start with as we search for |
|
* the buddy system that contains the specified leaf. |
|
*/ |
|
budsz = BUDSIZE(size, tp->dmt_budmin); |
|
|
|
/* back split. |
|
*/ |
|
while (leaf[leafno] == NOFREE) { |
|
/* find the leftmost buddy leaf. |
|
*/ |
|
for (w = leafno, bsz = budsz;; bsz <<= 1, |
|
w = (w < bud) ? w : bud) { |
|
if (bsz >= le32_to_cpu(tp->dmt_nleafs)) { |
|
jfs_err("JFS: block map error in dbBackSplit"); |
|
return -EIO; |
|
} |
|
|
|
/* determine the buddy. |
|
*/ |
|
bud = w ^ bsz; |
|
|
|
/* check if this buddy is the start of the system. |
|
*/ |
|
if (leaf[bud] != NOFREE) { |
|
/* split the leaf at the start of the |
|
* system in two. |
|
*/ |
|
cursz = leaf[bud] - 1; |
|
dbSplit(tp, bud, cursz, cursz); |
|
break; |
|
} |
|
} |
|
} |
|
|
|
if (leaf[leafno] != size) { |
|
jfs_err("JFS: wrong leaf value in dbBackSplit"); |
|
return -EIO; |
|
} |
|
return 0; |
|
} |
|
|
|
|
|
/* |
|
* NAME: dbJoin() |
|
* |
|
* FUNCTION: update the leaf of a dmtree with a new value, joining |
|
* the leaf with other leaves of the dmtree into a multi-leaf |
|
* binary buddy system, as required. |
|
* |
|
* PARAMETERS: |
|
* tp - pointer to the tree containing the leaf. |
|
* leafno - the number of the leaf to be updated. |
|
* newval - the new value for the leaf. |
|
* |
|
* RETURN VALUES: none |
|
*/ |
|
static int dbJoin(dmtree_t * tp, int leafno, int newval) |
|
{ |
|
int budsz, buddy; |
|
s8 *leaf; |
|
|
|
/* can the new leaf value require a join with other leaves ? |
|
*/ |
|
if (newval >= tp->dmt_budmin) { |
|
/* pickup a pointer to the leaves of the tree. |
|
*/ |
|
leaf = tp->dmt_stree + le32_to_cpu(tp->dmt_leafidx); |
|
|
|
/* try to join the specified leaf into a large binary |
|
* buddy system. the join proceeds by attempting to join |
|
* the specified leafno with its buddy (leaf) at new value. |
|
* if the join occurs, we attempt to join the left leaf |
|
* of the joined buddies with its buddy at new value + 1. |
|
* we continue to join until we find a buddy that cannot be |
|
* joined (does not have a value equal to the size of the |
|
* last join) or until all leaves have been joined into a |
|
* single system. |
|
* |
|
* get the buddy size (number of words covered) of |
|
* the new value. |
|
*/ |
|
budsz = BUDSIZE(newval, tp->dmt_budmin); |
|
|
|
/* try to join. |
|
*/ |
|
while (budsz < le32_to_cpu(tp->dmt_nleafs)) { |
|
/* get the buddy leaf. |
|
*/ |
|
buddy = leafno ^ budsz; |
|
|
|
/* if the leaf's new value is greater than its |
|
* buddy's value, we join no more. |
|
*/ |
|
if (newval > leaf[buddy]) |
|
break; |
|
|
|
/* It shouldn't be less */ |
|
if (newval < leaf[buddy]) |
|
return -EIO; |
|
|
|
/* check which (leafno or buddy) is the left buddy. |
|
* the left buddy gets to claim the blocks resulting |
|
* from the join while the right gets to claim none. |
|
* the left buddy is also eligible to participate in |
|
* a join at the next higher level while the right |
|
* is not. |
|
* |
|
*/ |
|
if (leafno < buddy) { |
|
/* leafno is the left buddy. |
|
*/ |
|
dbAdjTree(tp, buddy, NOFREE); |
|
} else { |
|
/* buddy is the left buddy and becomes |
|
* leafno. |
|
*/ |
|
dbAdjTree(tp, leafno, NOFREE); |
|
leafno = buddy; |
|
} |
|
|
|
/* on to try the next join. |
|
*/ |
|
newval += 1; |
|
budsz <<= 1; |
|
} |
|
} |
|
|
|
/* update the leaf value. |
|
*/ |
|
dbAdjTree(tp, leafno, newval); |
|
|
|
return 0; |
|
} |
|
|
|
|
|
/* |
|
* NAME: dbAdjTree() |
|
* |
|
* FUNCTION: update a leaf of a dmtree with a new value, adjusting |
|
* the dmtree, as required, to reflect the new leaf value. |
|
* the combination of any buddies must already be done before |
|
* this is called. |
|
* |
|
* PARAMETERS: |
|
* tp - pointer to the tree to be adjusted. |
|
* leafno - the number of the leaf to be updated. |
|
* newval - the new value for the leaf. |
|
* |
|
* RETURN VALUES: none |
|
*/ |
|
static void dbAdjTree(dmtree_t * tp, int leafno, int newval) |
|
{ |
|
int lp, pp, k; |
|
int max; |
|
|
|
/* pick up the index of the leaf for this leafno. |
|
*/ |
|
lp = leafno + le32_to_cpu(tp->dmt_leafidx); |
|
|
|
/* is the current value the same as the old value ? if so, |
|
* there is nothing to do. |
|
*/ |
|
if (tp->dmt_stree[lp] == newval) |
|
return; |
|
|
|
/* set the new value. |
|
*/ |
|
tp->dmt_stree[lp] = newval; |
|
|
|
/* bubble the new value up the tree as required. |
|
*/ |
|
for (k = 0; k < le32_to_cpu(tp->dmt_height); k++) { |
|
/* get the index of the first leaf of the 4 leaf |
|
* group containing the specified leaf (leafno). |
|
*/ |
|
lp = ((lp - 1) & ~0x03) + 1; |
|
|
|
/* get the index of the parent of this 4 leaf group. |
|
*/ |
|
pp = (lp - 1) >> 2; |
|
|
|
/* determine the maximum of the 4 leaves. |
|
*/ |
|
max = TREEMAX(&tp->dmt_stree[lp]); |
|
|
|
/* if the maximum of the 4 is the same as the |
|
* parent's value, we're done. |
|
*/ |
|
if (tp->dmt_stree[pp] == max) |
|
break; |
|
|
|
/* parent gets new value. |
|
*/ |
|
tp->dmt_stree[pp] = max; |
|
|
|
/* parent becomes leaf for next go-round. |
|
*/ |
|
lp = pp; |
|
} |
|
} |
|
|
|
|
|
/* |
|
* NAME: dbFindLeaf() |
|
* |
|
* FUNCTION: search a dmtree_t for sufficient free blocks, returning |
|
* the index of a leaf describing the free blocks if |
|
* sufficient free blocks are found. |
|
* |
|
* the search starts at the top of the dmtree_t tree and |
|
* proceeds down the tree to the leftmost leaf with sufficient |
|
* free space. |
|
* |
|
* PARAMETERS: |
|
* tp - pointer to the tree to be searched. |
|
* l2nb - log2 number of free blocks to search for. |
|
* leafidx - return pointer to be set to the index of the leaf |
|
* describing at least l2nb free blocks if sufficient |
|
* free blocks are found. |
|
* |
|
* RETURN VALUES: |
|
* 0 - success |
|
* -ENOSPC - insufficient free blocks. |
|
*/ |
|
static int dbFindLeaf(dmtree_t * tp, int l2nb, int *leafidx) |
|
{ |
|
int ti, n = 0, k, x = 0; |
|
|
|
/* first check the root of the tree to see if there is |
|
* sufficient free space. |
|
*/ |
|
if (l2nb > tp->dmt_stree[ROOT]) |
|
return -ENOSPC; |
|
|
|
/* sufficient free space available. now search down the tree |
|
* starting at the next level for the leftmost leaf that |
|
* describes sufficient free space. |
|
*/ |
|
for (k = le32_to_cpu(tp->dmt_height), ti = 1; |
|
k > 0; k--, ti = ((ti + n) << 2) + 1) { |
|
/* search the four nodes at this level, starting from |
|
* the left. |
|
*/ |
|
for (x = ti, n = 0; n < 4; n++) { |
|
/* sufficient free space found. move to the next |
|
* level (or quit if this is the last level). |
|
*/ |
|
if (l2nb <= tp->dmt_stree[x + n]) |
|
break; |
|
} |
|
|
|
/* better have found something since the higher |
|
* levels of the tree said it was here. |
|
*/ |
|
assert(n < 4); |
|
} |
|
|
|
/* set the return to the leftmost leaf describing sufficient |
|
* free space. |
|
*/ |
|
*leafidx = x + n - le32_to_cpu(tp->dmt_leafidx); |
|
|
|
return (0); |
|
} |
|
|
|
|
|
/* |
|
* NAME: dbFindBits() |
|
* |
|
* FUNCTION: find a specified number of binary buddy free bits within a |
|
* dmap bitmap word value. |
|
* |
|
* this routine searches the bitmap value for (1 << l2nb) free |
|
* bits at (1 << l2nb) alignments within the value. |
|
* |
|
* PARAMETERS: |
|
* word - dmap bitmap word value. |
|
* l2nb - number of free bits specified as a log2 number. |
|
* |
|
* RETURN VALUES: |
|
* starting bit number of free bits. |
|
*/ |
|
static int dbFindBits(u32 word, int l2nb) |
|
{ |
|
int bitno, nb; |
|
u32 mask; |
|
|
|
/* get the number of bits. |
|
*/ |
|
nb = 1 << l2nb; |
|
assert(nb <= DBWORD); |
|
|
|
/* complement the word so we can use a mask (i.e. 0s represent |
|
* free bits) and compute the mask. |
|
*/ |
|
word = ~word; |
|
mask = ONES << (DBWORD - nb); |
|
|
|
/* scan the word for nb free bits at nb alignments. |
|
*/ |
|
for (bitno = 0; mask != 0; bitno += nb, mask >>= nb) { |
|
if ((mask & word) == mask) |
|
break; |
|
} |
|
|
|
ASSERT(bitno < 32); |
|
|
|
/* return the bit number. |
|
*/ |
|
return (bitno); |
|
} |
|
|
|
|
|
/* |
|
* NAME: dbMaxBud(u8 *cp) |
|
* |
|
* FUNCTION: determine the largest binary buddy string of free |
|
* bits within 32-bits of the map. |
|
* |
|
* PARAMETERS: |
|
* cp - pointer to the 32-bit value. |
|
* |
|
* RETURN VALUES: |
|
* largest binary buddy of free bits within a dmap word. |
|
*/ |
|
static int dbMaxBud(u8 * cp) |
|
{ |
|
signed char tmp1, tmp2; |
|
|
|
/* check if the wmap word is all free. if so, the |
|
* free buddy size is BUDMIN. |
|
*/ |
|
if (*((uint *) cp) == 0) |
|
return (BUDMIN); |
|
|
|
/* check if the wmap word is half free. if so, the |
|
* free buddy size is BUDMIN-1. |
|
*/ |
|
if (*((u16 *) cp) == 0 || *((u16 *) cp + 1) == 0) |
|
return (BUDMIN - 1); |
|
|
|
/* not all free or half free. determine the free buddy |
|
* size thru table lookup using quarters of the wmap word. |
|
*/ |
|
tmp1 = max(budtab[cp[2]], budtab[cp[3]]); |
|
tmp2 = max(budtab[cp[0]], budtab[cp[1]]); |
|
return (max(tmp1, tmp2)); |
|
} |
|
|
|
|
|
/* |
|
* NAME: cnttz(uint word) |
|
* |
|
* FUNCTION: determine the number of trailing zeros within a 32-bit |
|
* value. |
|
* |
|
* PARAMETERS: |
|
* value - 32-bit value to be examined. |
|
* |
|
* RETURN VALUES: |
|
* count of trailing zeros |
|
*/ |
|
static int cnttz(u32 word) |
|
{ |
|
int n; |
|
|
|
for (n = 0; n < 32; n++, word >>= 1) { |
|
if (word & 0x01) |
|
break; |
|
} |
|
|
|
return (n); |
|
} |
|
|
|
|
|
/* |
|
* NAME: cntlz(u32 value) |
|
* |
|
* FUNCTION: determine the number of leading zeros within a 32-bit |
|
* value. |
|
* |
|
* PARAMETERS: |
|
* value - 32-bit value to be examined. |
|
* |
|
* RETURN VALUES: |
|
* count of leading zeros |
|
*/ |
|
static int cntlz(u32 value) |
|
{ |
|
int n; |
|
|
|
for (n = 0; n < 32; n++, value <<= 1) { |
|
if (value & HIGHORDER) |
|
break; |
|
} |
|
return (n); |
|
} |
|
|
|
|
|
/* |
|
* NAME: blkstol2(s64 nb) |
|
* |
|
* FUNCTION: convert a block count to its log2 value. if the block |
|
* count is not a l2 multiple, it is rounded up to the next |
|
* larger l2 multiple. |
|
* |
|
* PARAMETERS: |
|
* nb - number of blocks |
|
* |
|
* RETURN VALUES: |
|
* log2 number of blocks |
|
*/ |
|
static int blkstol2(s64 nb) |
|
{ |
|
int l2nb; |
|
s64 mask; /* meant to be signed */ |
|
|
|
mask = (s64) 1 << (64 - 1); |
|
|
|
/* count the leading bits. |
|
*/ |
|
for (l2nb = 0; l2nb < 64; l2nb++, mask >>= 1) { |
|
/* leading bit found. |
|
*/ |
|
if (nb & mask) { |
|
/* determine the l2 value. |
|
*/ |
|
l2nb = (64 - 1) - l2nb; |
|
|
|
/* check if we need to round up. |
|
*/ |
|
if (~mask & nb) |
|
l2nb++; |
|
|
|
return (l2nb); |
|
} |
|
} |
|
assert(0); |
|
return 0; /* fix compiler warning */ |
|
} |
|
|
|
|
|
/* |
|
* NAME: dbAllocBottomUp() |
|
* |
|
* FUNCTION: alloc the specified block range from the working block |
|
* allocation map. |
|
* |
|
* the blocks will be alloc from the working map one dmap |
|
* at a time. |
|
* |
|
* PARAMETERS: |
|
* ip - pointer to in-core inode; |
|
* blkno - starting block number to be freed. |
|
* nblocks - number of blocks to be freed. |
|
* |
|
* RETURN VALUES: |
|
* 0 - success |
|
* -EIO - i/o error |
|
*/ |
|
int dbAllocBottomUp(struct inode *ip, s64 blkno, s64 nblocks) |
|
{ |
|
struct metapage *mp; |
|
struct dmap *dp; |
|
int nb, rc; |
|
s64 lblkno, rem; |
|
struct inode *ipbmap = JFS_SBI(ip->i_sb)->ipbmap; |
|
struct bmap *bmp = JFS_SBI(ip->i_sb)->bmap; |
|
|
|
IREAD_LOCK(ipbmap, RDWRLOCK_DMAP); |
|
|
|
/* block to be allocated better be within the mapsize. */ |
|
ASSERT(nblocks <= bmp->db_mapsize - blkno); |
|
|
|
/* |
|
* allocate the blocks a dmap at a time. |
|
*/ |
|
mp = NULL; |
|
for (rem = nblocks; rem > 0; rem -= nb, blkno += nb) { |
|
/* release previous dmap if any */ |
|
if (mp) { |
|
write_metapage(mp); |
|
} |
|
|
|
/* get the buffer for the current dmap. */ |
|
lblkno = BLKTODMAP(blkno, bmp->db_l2nbperpage); |
|
mp = read_metapage(ipbmap, lblkno, PSIZE, 0); |
|
if (mp == NULL) { |
|
IREAD_UNLOCK(ipbmap); |
|
return -EIO; |
|
} |
|
dp = (struct dmap *) mp->data; |
|
|
|
/* determine the number of blocks to be allocated from |
|
* this dmap. |
|
*/ |
|
nb = min(rem, BPERDMAP - (blkno & (BPERDMAP - 1))); |
|
|
|
/* allocate the blocks. */ |
|
if ((rc = dbAllocDmapBU(bmp, dp, blkno, nb))) { |
|
release_metapage(mp); |
|
IREAD_UNLOCK(ipbmap); |
|
return (rc); |
|
} |
|
} |
|
|
|
/* write the last buffer. */ |
|
write_metapage(mp); |
|
|
|
IREAD_UNLOCK(ipbmap); |
|
|
|
return (0); |
|
} |
|
|
|
|
|
static int dbAllocDmapBU(struct bmap * bmp, struct dmap * dp, s64 blkno, |
|
int nblocks) |
|
{ |
|
int rc; |
|
int dbitno, word, rembits, nb, nwords, wbitno, agno; |
|
s8 oldroot; |
|
struct dmaptree *tp = (struct dmaptree *) & dp->tree; |
|
|
|
/* save the current value of the root (i.e. maximum free string) |
|
* of the dmap tree. |
|
*/ |
|
oldroot = tp->stree[ROOT]; |
|
|
|
/* determine the bit number and word within the dmap of the |
|
* starting block. |
|
*/ |
|
dbitno = blkno & (BPERDMAP - 1); |
|
word = dbitno >> L2DBWORD; |
|
|
|
/* block range better be within the dmap */ |
|
assert(dbitno + nblocks <= BPERDMAP); |
|
|
|
/* allocate the bits of the dmap's words corresponding to the block |
|
* range. not all bits of the first and last words may be contained |
|
* within the block range. if this is the case, we'll work against |
|
* those words (i.e. partial first and/or last) on an individual basis |
|
* (a single pass), allocating the bits of interest by hand and |
|
* updating the leaf corresponding to the dmap word. a single pass |
|
* will be used for all dmap words fully contained within the |
|
* specified range. within this pass, the bits of all fully contained |
|
* dmap words will be marked as free in a single shot and the leaves |
|
* will be updated. a single leaf may describe the free space of |
|
* multiple dmap words, so we may update only a subset of the actual |
|
* leaves corresponding to the dmap words of the block range. |
|
*/ |
|
for (rembits = nblocks; rembits > 0; rembits -= nb, dbitno += nb) { |
|
/* determine the bit number within the word and |
|
* the number of bits within the word. |
|
*/ |
|
wbitno = dbitno & (DBWORD - 1); |
|
nb = min(rembits, DBWORD - wbitno); |
|
|
|
/* check if only part of a word is to be allocated. |
|
*/ |
|
if (nb < DBWORD) { |
|
/* allocate (set to 1) the appropriate bits within |
|
* this dmap word. |
|
*/ |
|
dp->wmap[word] |= cpu_to_le32(ONES << (DBWORD - nb) |
|
>> wbitno); |
|
|
|
word++; |
|
} else { |
|
/* one or more dmap words are fully contained |
|
* within the block range. determine how many |
|
* words and allocate (set to 1) the bits of these |
|
* words. |
|
*/ |
|
nwords = rembits >> L2DBWORD; |
|
memset(&dp->wmap[word], (int) ONES, nwords * 4); |
|
|
|
/* determine how many bits */ |
|
nb = nwords << L2DBWORD; |
|
word += nwords; |
|
} |
|
} |
|
|
|
/* update the free count for this dmap */ |
|
le32_add_cpu(&dp->nfree, -nblocks); |
|
|
|
/* reconstruct summary tree */ |
|
dbInitDmapTree(dp); |
|
|
|
BMAP_LOCK(bmp); |
|
|
|
/* if this allocation group is completely free, |
|
* update the highest active allocation group number |
|
* if this allocation group is the new max. |
|
*/ |
|
agno = blkno >> bmp->db_agl2size; |
|
if (agno > bmp->db_maxag) |
|
bmp->db_maxag = agno; |
|
|
|
/* update the free count for the allocation group and map */ |
|
bmp->db_agfree[agno] -= nblocks; |
|
bmp->db_nfree -= nblocks; |
|
|
|
BMAP_UNLOCK(bmp); |
|
|
|
/* if the root has not changed, done. */ |
|
if (tp->stree[ROOT] == oldroot) |
|
return (0); |
|
|
|
/* root changed. bubble the change up to the dmap control pages. |
|
* if the adjustment of the upper level control pages fails, |
|
* backout the bit allocation (thus making everything consistent). |
|
*/ |
|
if ((rc = dbAdjCtl(bmp, blkno, tp->stree[ROOT], 1, 0))) |
|
dbFreeBits(bmp, dp, blkno, nblocks); |
|
|
|
return (rc); |
|
} |
|
|
|
|
|
/* |
|
* NAME: dbExtendFS() |
|
* |
|
* FUNCTION: extend bmap from blkno for nblocks; |
|
* dbExtendFS() updates bmap ready for dbAllocBottomUp(); |
|
* |
|
* L2 |
|
* | |
|
* L1---------------------------------L1 |
|
* | | |
|
* L0---------L0---------L0 L0---------L0---------L0 |
|
* | | | | | | |
|
* d0,...,dn d0,...,dn d0,...,dn d0,...,dn d0,...,dn d0,.,dm; |
|
* L2L1L0d0,...,dnL0d0,...,dnL0d0,...,dnL1L0d0,...,dnL0d0,...,dnL0d0,..dm |
|
* |
|
* <---old---><----------------------------extend-----------------------> |
|
*/ |
|
int dbExtendFS(struct inode *ipbmap, s64 blkno, s64 nblocks) |
|
{ |
|
struct jfs_sb_info *sbi = JFS_SBI(ipbmap->i_sb); |
|
int nbperpage = sbi->nbperpage; |
|
int i, i0 = true, j, j0 = true, k, n; |
|
s64 newsize; |
|
s64 p; |
|
struct metapage *mp, *l2mp, *l1mp = NULL, *l0mp = NULL; |
|
struct dmapctl *l2dcp, *l1dcp, *l0dcp; |
|
struct dmap *dp; |
|
s8 *l0leaf, *l1leaf, *l2leaf; |
|
struct bmap *bmp = sbi->bmap; |
|
int agno, l2agsize, oldl2agsize; |
|
s64 ag_rem; |
|
|
|
newsize = blkno + nblocks; |
|
|
|
jfs_info("dbExtendFS: blkno:%Ld nblocks:%Ld newsize:%Ld", |
|
(long long) blkno, (long long) nblocks, (long long) newsize); |
|
|
|
/* |
|
* initialize bmap control page. |
|
* |
|
* all the data in bmap control page should exclude |
|
* the mkfs hidden dmap page. |
|
*/ |
|
|
|
/* update mapsize */ |
|
bmp->db_mapsize = newsize; |
|
bmp->db_maxlevel = BMAPSZTOLEV(bmp->db_mapsize); |
|
|
|
/* compute new AG size */ |
|
l2agsize = dbGetL2AGSize(newsize); |
|
oldl2agsize = bmp->db_agl2size; |
|
|
|
bmp->db_agl2size = l2agsize; |
|
bmp->db_agsize = 1 << l2agsize; |
|
|
|
/* compute new number of AG */ |
|
agno = bmp->db_numag; |
|
bmp->db_numag = newsize >> l2agsize; |
|
bmp->db_numag += ((u32) newsize % (u32) bmp->db_agsize) ? 1 : 0; |
|
|
|
/* |
|
* reconfigure db_agfree[] |
|
* from old AG configuration to new AG configuration; |
|
* |
|
* coalesce contiguous k (newAGSize/oldAGSize) AGs; |
|
* i.e., (AGi, ..., AGj) where i = k*n and j = k*(n+1) - 1 to AGn; |
|
* note: new AG size = old AG size * (2**x). |
|
*/ |
|
if (l2agsize == oldl2agsize) |
|
goto extend; |
|
k = 1 << (l2agsize - oldl2agsize); |
|
ag_rem = bmp->db_agfree[0]; /* save agfree[0] */ |
|
for (i = 0, n = 0; i < agno; n++) { |
|
bmp->db_agfree[n] = 0; /* init collection point */ |
|
|
|
/* coalesce contiguous k AGs; */ |
|
for (j = 0; j < k && i < agno; j++, i++) { |
|
/* merge AGi to AGn */ |
|
bmp->db_agfree[n] += bmp->db_agfree[i]; |
|
} |
|
} |
|
bmp->db_agfree[0] += ag_rem; /* restore agfree[0] */ |
|
|
|
for (; n < MAXAG; n++) |
|
bmp->db_agfree[n] = 0; |
|
|
|
/* |
|
* update highest active ag number |
|
*/ |
|
|
|
bmp->db_maxag = bmp->db_maxag / k; |
|
|
|
/* |
|
* extend bmap |
|
* |
|
* update bit maps and corresponding level control pages; |
|
* global control page db_nfree, db_agfree[agno], db_maxfreebud; |
|
*/ |
|
extend: |
|
/* get L2 page */ |
|
p = BMAPBLKNO + nbperpage; /* L2 page */ |
|
l2mp = read_metapage(ipbmap, p, PSIZE, 0); |
|
if (!l2mp) { |
|
jfs_error(ipbmap->i_sb, "L2 page could not be read\n"); |
|
return -EIO; |
|
} |
|
l2dcp = (struct dmapctl *) l2mp->data; |
|
|
|
/* compute start L1 */ |
|
k = blkno >> L2MAXL1SIZE; |
|
l2leaf = l2dcp->stree + CTLLEAFIND + k; |
|
p = BLKTOL1(blkno, sbi->l2nbperpage); /* L1 page */ |
|
|
|
/* |
|
* extend each L1 in L2 |
|
*/ |
|
for (; k < LPERCTL; k++, p += nbperpage) { |
|
/* get L1 page */ |
|
if (j0) { |
|
/* read in L1 page: (blkno & (MAXL1SIZE - 1)) */ |
|
l1mp = read_metapage(ipbmap, p, PSIZE, 0); |
|
if (l1mp == NULL) |
|
goto errout; |
|
l1dcp = (struct dmapctl *) l1mp->data; |
|
|
|
/* compute start L0 */ |
|
j = (blkno & (MAXL1SIZE - 1)) >> L2MAXL0SIZE; |
|
l1leaf = l1dcp->stree + CTLLEAFIND + j; |
|
p = BLKTOL0(blkno, sbi->l2nbperpage); |
|
j0 = false; |
|
} else { |
|
/* assign/init L1 page */ |
|
l1mp = get_metapage(ipbmap, p, PSIZE, 0); |
|
if (l1mp == NULL) |
|
goto errout; |
|
|
|
l1dcp = (struct dmapctl *) l1mp->data; |
|
|
|
/* compute start L0 */ |
|
j = 0; |
|
l1leaf = l1dcp->stree + CTLLEAFIND; |
|
p += nbperpage; /* 1st L0 of L1.k */ |
|
} |
|
|
|
/* |
|
* extend each L0 in L1 |
|
*/ |
|
for (; j < LPERCTL; j++) { |
|
/* get L0 page */ |
|
if (i0) { |
|
/* read in L0 page: (blkno & (MAXL0SIZE - 1)) */ |
|
|
|
l0mp = read_metapage(ipbmap, p, PSIZE, 0); |
|
if (l0mp == NULL) |
|
goto errout; |
|
l0dcp = (struct dmapctl *) l0mp->data; |
|
|
|
/* compute start dmap */ |
|
i = (blkno & (MAXL0SIZE - 1)) >> |
|
L2BPERDMAP; |
|
l0leaf = l0dcp->stree + CTLLEAFIND + i; |
|
p = BLKTODMAP(blkno, |
|
sbi->l2nbperpage); |
|
i0 = false; |
|
} else { |
|
/* assign/init L0 page */ |
|
l0mp = get_metapage(ipbmap, p, PSIZE, 0); |
|
if (l0mp == NULL) |
|
goto errout; |
|
|
|
l0dcp = (struct dmapctl *) l0mp->data; |
|
|
|
/* compute start dmap */ |
|
i = 0; |
|
l0leaf = l0dcp->stree + CTLLEAFIND; |
|
p += nbperpage; /* 1st dmap of L0.j */ |
|
} |
|
|
|
/* |
|
* extend each dmap in L0 |
|
*/ |
|
for (; i < LPERCTL; i++) { |
|
/* |
|
* reconstruct the dmap page, and |
|
* initialize corresponding parent L0 leaf |
|
*/ |
|
if ((n = blkno & (BPERDMAP - 1))) { |
|
/* read in dmap page: */ |
|
mp = read_metapage(ipbmap, p, |
|
PSIZE, 0); |
|
if (mp == NULL) |
|
goto errout; |
|
n = min(nblocks, (s64)BPERDMAP - n); |
|
} else { |
|
/* assign/init dmap page */ |
|
mp = read_metapage(ipbmap, p, |
|
PSIZE, 0); |
|
if (mp == NULL) |
|
goto errout; |
|
|
|
n = min_t(s64, nblocks, BPERDMAP); |
|
} |
|
|
|
dp = (struct dmap *) mp->data; |
|
*l0leaf = dbInitDmap(dp, blkno, n); |
|
|
|
bmp->db_nfree += n; |
|
agno = le64_to_cpu(dp->start) >> l2agsize; |
|
bmp->db_agfree[agno] += n; |
|
|
|
write_metapage(mp); |
|
|
|
l0leaf++; |
|
p += nbperpage; |
|
|
|
blkno += n; |
|
nblocks -= n; |
|
if (nblocks == 0) |
|
break; |
|
} /* for each dmap in a L0 */ |
|
|
|
/* |
|
* build current L0 page from its leaves, and |
|
* initialize corresponding parent L1 leaf |
|
*/ |
|
*l1leaf = dbInitDmapCtl(l0dcp, 0, ++i); |
|
write_metapage(l0mp); |
|
l0mp = NULL; |
|
|
|
if (nblocks) |
|
l1leaf++; /* continue for next L0 */ |
|
else { |
|
/* more than 1 L0 ? */ |
|
if (j > 0) |
|
break; /* build L1 page */ |
|
else { |
|
/* summarize in global bmap page */ |
|
bmp->db_maxfreebud = *l1leaf; |
|
release_metapage(l1mp); |
|
release_metapage(l2mp); |
|
goto finalize; |
|
} |
|
} |
|
} /* for each L0 in a L1 */ |
|
|
|
/* |
|
* build current L1 page from its leaves, and |
|
* initialize corresponding parent L2 leaf |
|
*/ |
|
*l2leaf = dbInitDmapCtl(l1dcp, 1, ++j); |
|
write_metapage(l1mp); |
|
l1mp = NULL; |
|
|
|
if (nblocks) |
|
l2leaf++; /* continue for next L1 */ |
|
else { |
|
/* more than 1 L1 ? */ |
|
if (k > 0) |
|
break; /* build L2 page */ |
|
else { |
|
/* summarize in global bmap page */ |
|
bmp->db_maxfreebud = *l2leaf; |
|
release_metapage(l2mp); |
|
goto finalize; |
|
} |
|
} |
|
} /* for each L1 in a L2 */ |
|
|
|
jfs_error(ipbmap->i_sb, "function has not returned as expected\n"); |
|
errout: |
|
if (l0mp) |
|
release_metapage(l0mp); |
|
if (l1mp) |
|
release_metapage(l1mp); |
|
release_metapage(l2mp); |
|
return -EIO; |
|
|
|
/* |
|
* finalize bmap control page |
|
*/ |
|
finalize: |
|
|
|
return 0; |
|
} |
|
|
|
|
|
/* |
|
* dbFinalizeBmap() |
|
*/ |
|
void dbFinalizeBmap(struct inode *ipbmap) |
|
{ |
|
struct bmap *bmp = JFS_SBI(ipbmap->i_sb)->bmap; |
|
int actags, inactags, l2nl; |
|
s64 ag_rem, actfree, inactfree, avgfree; |
|
int i, n; |
|
|
|
/* |
|
* finalize bmap control page |
|
*/ |
|
//finalize: |
|
/* |
|
* compute db_agpref: preferred ag to allocate from |
|
* (the leftmost ag with average free space in it); |
|
*/ |
|
//agpref: |
|
/* get the number of active ags and inacitve ags */ |
|
actags = bmp->db_maxag + 1; |
|
inactags = bmp->db_numag - actags; |
|
ag_rem = bmp->db_mapsize & (bmp->db_agsize - 1); /* ??? */ |
|
|
|
/* determine how many blocks are in the inactive allocation |
|
* groups. in doing this, we must account for the fact that |
|
* the rightmost group might be a partial group (i.e. file |
|
* system size is not a multiple of the group size). |
|
*/ |
|
inactfree = (inactags && ag_rem) ? |
|
((inactags - 1) << bmp->db_agl2size) + ag_rem |
|
: inactags << bmp->db_agl2size; |
|
|
|
/* determine how many free blocks are in the active |
|
* allocation groups plus the average number of free blocks |
|
* within the active ags. |
|
*/ |
|
actfree = bmp->db_nfree - inactfree; |
|
avgfree = (u32) actfree / (u32) actags; |
|
|
|
/* if the preferred allocation group has not average free space. |
|
* re-establish the preferred group as the leftmost |
|
* group with average free space. |
|
*/ |
|
if (bmp->db_agfree[bmp->db_agpref] < avgfree) { |
|
for (bmp->db_agpref = 0; bmp->db_agpref < actags; |
|
bmp->db_agpref++) { |
|
if (bmp->db_agfree[bmp->db_agpref] >= avgfree) |
|
break; |
|
} |
|
if (bmp->db_agpref >= bmp->db_numag) { |
|
jfs_error(ipbmap->i_sb, |
|
"cannot find ag with average freespace\n"); |
|
} |
|
} |
|
|
|
/* |
|
* compute db_aglevel, db_agheight, db_width, db_agstart: |
|
* an ag is covered in aglevel dmapctl summary tree, |
|
* at agheight level height (from leaf) with agwidth number of nodes |
|
* each, which starts at agstart index node of the smmary tree node |
|
* array; |
|
*/ |
|
bmp->db_aglevel = BMAPSZTOLEV(bmp->db_agsize); |
|
l2nl = |
|
bmp->db_agl2size - (L2BPERDMAP + bmp->db_aglevel * L2LPERCTL); |
|
bmp->db_agheight = l2nl >> 1; |
|
bmp->db_agwidth = 1 << (l2nl - (bmp->db_agheight << 1)); |
|
for (i = 5 - bmp->db_agheight, bmp->db_agstart = 0, n = 1; i > 0; |
|
i--) { |
|
bmp->db_agstart += n; |
|
n <<= 2; |
|
} |
|
|
|
} |
|
|
|
|
|
/* |
|
* NAME: dbInitDmap()/ujfs_idmap_page() |
|
* |
|
* FUNCTION: initialize working/persistent bitmap of the dmap page |
|
* for the specified number of blocks: |
|
* |
|
* at entry, the bitmaps had been initialized as free (ZEROS); |
|
* The number of blocks will only account for the actually |
|
* existing blocks. Blocks which don't actually exist in |
|
* the aggregate will be marked as allocated (ONES); |
|
* |
|
* PARAMETERS: |
|
* dp - pointer to page of map |
|
* nblocks - number of blocks this page |
|
* |
|
* RETURNS: NONE |
|
*/ |
|
static int dbInitDmap(struct dmap * dp, s64 Blkno, int nblocks) |
|
{ |
|
int blkno, w, b, r, nw, nb, i; |
|
|
|
/* starting block number within the dmap */ |
|
blkno = Blkno & (BPERDMAP - 1); |
|
|
|
if (blkno == 0) { |
|
dp->nblocks = dp->nfree = cpu_to_le32(nblocks); |
|
dp->start = cpu_to_le64(Blkno); |
|
|
|
if (nblocks == BPERDMAP) { |
|
memset(&dp->wmap[0], 0, LPERDMAP * 4); |
|
memset(&dp->pmap[0], 0, LPERDMAP * 4); |
|
goto initTree; |
|
} |
|
} else { |
|
le32_add_cpu(&dp->nblocks, nblocks); |
|
le32_add_cpu(&dp->nfree, nblocks); |
|
} |
|
|
|
/* word number containing start block number */ |
|
w = blkno >> L2DBWORD; |
|
|
|
/* |
|
* free the bits corresponding to the block range (ZEROS): |
|
* note: not all bits of the first and last words may be contained |
|
* within the block range. |
|
*/ |
|
for (r = nblocks; r > 0; r -= nb, blkno += nb) { |
|
/* number of bits preceding range to be freed in the word */ |
|
b = blkno & (DBWORD - 1); |
|
/* number of bits to free in the word */ |
|
nb = min(r, DBWORD - b); |
|
|
|
/* is partial word to be freed ? */ |
|
if (nb < DBWORD) { |
|
/* free (set to 0) from the bitmap word */ |
|
dp->wmap[w] &= cpu_to_le32(~(ONES << (DBWORD - nb) |
|
>> b)); |
|
dp->pmap[w] &= cpu_to_le32(~(ONES << (DBWORD - nb) |
|
>> b)); |
|
|
|
/* skip the word freed */ |
|
w++; |
|
} else { |
|
/* free (set to 0) contiguous bitmap words */ |
|
nw = r >> L2DBWORD; |
|
memset(&dp->wmap[w], 0, nw * 4); |
|
memset(&dp->pmap[w], 0, nw * 4); |
|
|
|
/* skip the words freed */ |
|
nb = nw << L2DBWORD; |
|
w += nw; |
|
} |
|
} |
|
|
|
/* |
|
* mark bits following the range to be freed (non-existing |
|
* blocks) as allocated (ONES) |
|
*/ |
|
|
|
if (blkno == BPERDMAP) |
|
goto initTree; |
|
|
|
/* the first word beyond the end of existing blocks */ |
|
w = blkno >> L2DBWORD; |
|
|
|
/* does nblocks fall on a 32-bit boundary ? */ |
|
b = blkno & (DBWORD - 1); |
|
if (b) { |
|
/* mark a partial word allocated */ |
|
dp->wmap[w] = dp->pmap[w] = cpu_to_le32(ONES >> b); |
|
w++; |
|
} |
|
|
|
/* set the rest of the words in the page to allocated (ONES) */ |
|
for (i = w; i < LPERDMAP; i++) |
|
dp->pmap[i] = dp->wmap[i] = cpu_to_le32(ONES); |
|
|
|
/* |
|
* init tree |
|
*/ |
|
initTree: |
|
return (dbInitDmapTree(dp)); |
|
} |
|
|
|
|
|
/* |
|
* NAME: dbInitDmapTree()/ujfs_complete_dmap() |
|
* |
|
* FUNCTION: initialize summary tree of the specified dmap: |
|
* |
|
* at entry, bitmap of the dmap has been initialized; |
|
* |
|
* PARAMETERS: |
|
* dp - dmap to complete |
|
* blkno - starting block number for this dmap |
|
* treemax - will be filled in with max free for this dmap |
|
* |
|
* RETURNS: max free string at the root of the tree |
|
*/ |
|
static int dbInitDmapTree(struct dmap * dp) |
|
{ |
|
struct dmaptree *tp; |
|
s8 *cp; |
|
int i; |
|
|
|
/* init fixed info of tree */ |
|
tp = &dp->tree; |
|
tp->nleafs = cpu_to_le32(LPERDMAP); |
|
tp->l2nleafs = cpu_to_le32(L2LPERDMAP); |
|
tp->leafidx = cpu_to_le32(LEAFIND); |
|
tp->height = cpu_to_le32(4); |
|
tp->budmin = BUDMIN; |
|
|
|
/* init each leaf from corresponding wmap word: |
|
* note: leaf is set to NOFREE(-1) if all blocks of corresponding |
|
* bitmap word are allocated. |
|
*/ |
|
cp = tp->stree + le32_to_cpu(tp->leafidx); |
|
for (i = 0; i < LPERDMAP; i++) |
|
*cp++ = dbMaxBud((u8 *) & dp->wmap[i]); |
|
|
|
/* build the dmap's binary buddy summary tree */ |
|
return (dbInitTree(tp)); |
|
} |
|
|
|
|
|
/* |
|
* NAME: dbInitTree()/ujfs_adjtree() |
|
* |
|
* FUNCTION: initialize binary buddy summary tree of a dmap or dmapctl. |
|
* |
|
* at entry, the leaves of the tree has been initialized |
|
* from corresponding bitmap word or root of summary tree |
|
* of the child control page; |
|
* configure binary buddy system at the leaf level, then |
|
* bubble up the values of the leaf nodes up the tree. |
|
* |
|
* PARAMETERS: |
|
* cp - Pointer to the root of the tree |
|
* l2leaves- Number of leaf nodes as a power of 2 |
|
* l2min - Number of blocks that can be covered by a leaf |
|
* as a power of 2 |
|
* |
|
* RETURNS: max free string at the root of the tree |
|
*/ |
|
static int dbInitTree(struct dmaptree * dtp) |
|
{ |
|
int l2max, l2free, bsize, nextb, i; |
|
int child, parent, nparent; |
|
s8 *tp, *cp, *cp1; |
|
|
|
tp = dtp->stree; |
|
|
|
/* Determine the maximum free string possible for the leaves */ |
|
l2max = le32_to_cpu(dtp->l2nleafs) + dtp->budmin; |
|
|
|
/* |
|
* configure the leaf levevl into binary buddy system |
|
* |
|
* Try to combine buddies starting with a buddy size of 1 |
|
* (i.e. two leaves). At a buddy size of 1 two buddy leaves |
|
* can be combined if both buddies have a maximum free of l2min; |
|
* the combination will result in the left-most buddy leaf having |
|
* a maximum free of l2min+1. |
|
* After processing all buddies for a given size, process buddies |
|
* at the next higher buddy size (i.e. current size * 2) and |
|
* the next maximum free (current free + 1). |
|
* This continues until the maximum possible buddy combination |
|
* yields maximum free. |
|
*/ |
|
for (l2free = dtp->budmin, bsize = 1; l2free < l2max; |
|
l2free++, bsize = nextb) { |
|
/* get next buddy size == current buddy pair size */ |
|
nextb = bsize << 1; |
|
|
|
/* scan each adjacent buddy pair at current buddy size */ |
|
for (i = 0, cp = tp + le32_to_cpu(dtp->leafidx); |
|
i < le32_to_cpu(dtp->nleafs); |
|
i += nextb, cp += nextb) { |
|
/* coalesce if both adjacent buddies are max free */ |
|
if (*cp == l2free && *(cp + bsize) == l2free) { |
|
*cp = l2free + 1; /* left take right */ |
|
*(cp + bsize) = -1; /* right give left */ |
|
} |
|
} |
|
} |
|
|
|
/* |
|
* bubble summary information of leaves up the tree. |
|
* |
|
* Starting at the leaf node level, the four nodes described by |
|
* the higher level parent node are compared for a maximum free and |
|
* this maximum becomes the value of the parent node. |
|
* when all lower level nodes are processed in this fashion then |
|
* move up to the next level (parent becomes a lower level node) and |
|
* continue the process for that level. |
|
*/ |
|
for (child = le32_to_cpu(dtp->leafidx), |
|
nparent = le32_to_cpu(dtp->nleafs) >> 2; |
|
nparent > 0; nparent >>= 2, child = parent) { |
|
/* get index of 1st node of parent level */ |
|
parent = (child - 1) >> 2; |
|
|
|
/* set the value of the parent node as the maximum |
|
* of the four nodes of the current level. |
|
*/ |
|
for (i = 0, cp = tp + child, cp1 = tp + parent; |
|
i < nparent; i++, cp += 4, cp1++) |
|
*cp1 = TREEMAX(cp); |
|
} |
|
|
|
return (*tp); |
|
} |
|
|
|
|
|
/* |
|
* dbInitDmapCtl() |
|
* |
|
* function: initialize dmapctl page |
|
*/ |
|
static int dbInitDmapCtl(struct dmapctl * dcp, int level, int i) |
|
{ /* start leaf index not covered by range */ |
|
s8 *cp; |
|
|
|
dcp->nleafs = cpu_to_le32(LPERCTL); |
|
dcp->l2nleafs = cpu_to_le32(L2LPERCTL); |
|
dcp->leafidx = cpu_to_le32(CTLLEAFIND); |
|
dcp->height = cpu_to_le32(5); |
|
dcp->budmin = L2BPERDMAP + L2LPERCTL * level; |
|
|
|
/* |
|
* initialize the leaves of current level that were not covered |
|
* by the specified input block range (i.e. the leaves have no |
|
* low level dmapctl or dmap). |
|
*/ |
|
cp = &dcp->stree[CTLLEAFIND + i]; |
|
for (; i < LPERCTL; i++) |
|
*cp++ = NOFREE; |
|
|
|
/* build the dmap's binary buddy summary tree */ |
|
return (dbInitTree((struct dmaptree *) dcp)); |
|
} |
|
|
|
|
|
/* |
|
* NAME: dbGetL2AGSize()/ujfs_getagl2size() |
|
* |
|
* FUNCTION: Determine log2(allocation group size) from aggregate size |
|
* |
|
* PARAMETERS: |
|
* nblocks - Number of blocks in aggregate |
|
* |
|
* RETURNS: log2(allocation group size) in aggregate blocks |
|
*/ |
|
static int dbGetL2AGSize(s64 nblocks) |
|
{ |
|
s64 sz; |
|
s64 m; |
|
int l2sz; |
|
|
|
if (nblocks < BPERDMAP * MAXAG) |
|
return (L2BPERDMAP); |
|
|
|
/* round up aggregate size to power of 2 */ |
|
m = ((u64) 1 << (64 - 1)); |
|
for (l2sz = 64; l2sz >= 0; l2sz--, m >>= 1) { |
|
if (m & nblocks) |
|
break; |
|
} |
|
|
|
sz = (s64) 1 << l2sz; |
|
if (sz < nblocks) |
|
l2sz += 1; |
|
|
|
/* agsize = roundupSize/max_number_of_ag */ |
|
return (l2sz - L2MAXAG); |
|
} |
|
|
|
|
|
/* |
|
* NAME: dbMapFileSizeToMapSize() |
|
* |
|
* FUNCTION: compute number of blocks the block allocation map file |
|
* can cover from the map file size; |
|
* |
|
* RETURNS: Number of blocks which can be covered by this block map file; |
|
*/ |
|
|
|
/* |
|
* maximum number of map pages at each level including control pages |
|
*/ |
|
#define MAXL0PAGES (1 + LPERCTL) |
|
#define MAXL1PAGES (1 + LPERCTL * MAXL0PAGES) |
|
|
|
/* |
|
* convert number of map pages to the zero origin top dmapctl level |
|
*/ |
|
#define BMAPPGTOLEV(npages) \ |
|
(((npages) <= 3 + MAXL0PAGES) ? 0 : \ |
|
((npages) <= 2 + MAXL1PAGES) ? 1 : 2) |
|
|
|
s64 dbMapFileSizeToMapSize(struct inode * ipbmap) |
|
{ |
|
struct super_block *sb = ipbmap->i_sb; |
|
s64 nblocks; |
|
s64 npages, ndmaps; |
|
int level, i; |
|
int complete, factor; |
|
|
|
nblocks = ipbmap->i_size >> JFS_SBI(sb)->l2bsize; |
|
npages = nblocks >> JFS_SBI(sb)->l2nbperpage; |
|
level = BMAPPGTOLEV(npages); |
|
|
|
/* At each level, accumulate the number of dmap pages covered by |
|
* the number of full child levels below it; |
|
* repeat for the last incomplete child level. |
|
*/ |
|
ndmaps = 0; |
|
npages--; /* skip the first global control page */ |
|
/* skip higher level control pages above top level covered by map */ |
|
npages -= (2 - level); |
|
npages--; /* skip top level's control page */ |
|
for (i = level; i >= 0; i--) { |
|
factor = |
|
(i == 2) ? MAXL1PAGES : ((i == 1) ? MAXL0PAGES : 1); |
|
complete = (u32) npages / factor; |
|
ndmaps += complete * ((i == 2) ? LPERCTL * LPERCTL : |
|
((i == 1) ? LPERCTL : 1)); |
|
|
|
/* pages in last/incomplete child */ |
|
npages = (u32) npages % factor; |
|
/* skip incomplete child's level control page */ |
|
npages--; |
|
} |
|
|
|
/* convert the number of dmaps into the number of blocks |
|
* which can be covered by the dmaps; |
|
*/ |
|
nblocks = ndmaps << L2BPERDMAP; |
|
|
|
return (nblocks); |
|
}
|
|
|