// SPDX-License-Identifier: GPL-2.0-or-later /* * Copyright (C) International Business Machines Corp., 2000-2004 */ #include <linux/fs.h> #include <linux/quotaops.h> #include "jfs_incore.h" #include "jfs_inode.h" #include "jfs_superblock.h" #include "jfs_dmap.h" #include "jfs_extent.h" #include "jfs_debug.h" /* * forward references */ static int extBalloc(struct inode *, s64, s64 *, s64 *); static s64 extRoundDown(s64 nb); #define DPD(a) (printk("(a): %d\n",(a))) #define DPC(a) (printk("(a): %c\n",(a))) #define DPL1(a) \ { \ if ((a) >> 32) \ printk("(a): %x%08x ",(a)); \ else \ printk("(a): %x ",(a) << 32); \ } #define DPL(a) \ { \ if ((a) >> 32) \ printk("(a): %x%08x\n",(a)); \ else \ printk("(a): %x\n",(a) << 32); \ } #define DPD1(a) (printk("(a): %d ",(a))) #define DPX(a) (printk("(a): %08x\n",(a))) #define DPX1(a) (printk("(a): %08x ",(a))) #define DPS(a) (printk("%s\n",(a))) #define DPE(a) (printk("\nENTERING: %s\n",(a))) #define DPE1(a) (printk("\nENTERING: %s",(a))) #define DPS1(a) (printk(" %s ",(a))) /* * NAME: extAlloc() * * FUNCTION: allocate an extent for a specified page range within a * file. * * PARAMETERS: * ip - the inode of the file. * xlen - requested extent length. * pno - the starting page number with the file. * xp - pointer to an xad. on entry, xad describes an * extent that is used as an allocation hint if the * xaddr of the xad is non-zero. on successful exit, * the xad describes the newly allocated extent. * abnr - bool indicating whether the newly allocated extent * should be marked as allocated but not recorded. * * RETURN VALUES: * 0 - success * -EIO - i/o error. * -ENOSPC - insufficient disk resources. */ int extAlloc(struct inode *ip, s64 xlen, s64 pno, xad_t * xp, bool abnr) { struct jfs_sb_info *sbi = JFS_SBI(ip->i_sb); s64 nxlen, nxaddr, xoff, hint, xaddr = 0; int rc; int xflag; if (isReadOnly(ip)) { jfs_error(ip->i_sb, "read-only filesystem\n"); return -EIO; } /* This blocks if we are low on resources */ txBeginAnon(ip->i_sb); /* Avoid race with jfs_commit_inode() */ mutex_lock(&JFS_IP(ip)->commit_mutex); /* validate extent length */ if (xlen > MAXXLEN) xlen = MAXXLEN; /* get the page's starting extent offset */ xoff = pno << sbi->l2nbperpage; /* check if an allocation hint was provided */ if ((hint = addressXAD(xp))) { /* get the size of the extent described by the hint */ nxlen = lengthXAD(xp); /* check if the hint is for the portion of the file * immediately previous to the current allocation * request and if hint extent has the same abnr * value as the current request. if so, we can * extend the hint extent to include the current * extent if we can allocate the blocks immediately * following the hint extent. */ if (offsetXAD(xp) + nxlen == xoff && abnr == ((xp->flag & XAD_NOTRECORDED) ? true : false)) xaddr = hint + nxlen; /* adjust the hint to the last block of the extent */ hint += (nxlen - 1); } /* allocate the disk blocks for the extent. initially, extBalloc() * will try to allocate disk blocks for the requested size (xlen). * if this fails (xlen contiguous free blocks not available), it'll * try to allocate a smaller number of blocks (producing a smaller * extent), with this smaller number of blocks consisting of the * requested number of blocks rounded down to the next smaller * power of 2 number (i.e. 16 -> 8). it'll continue to round down * and retry the allocation until the number of blocks to allocate * is smaller than the number of blocks per page. */ nxlen = xlen; if ((rc = extBalloc(ip, hint ? hint : INOHINT(ip), &nxlen, &nxaddr))) { mutex_unlock(&JFS_IP(ip)->commit_mutex); return (rc); } /* Allocate blocks to quota. */ rc = dquot_alloc_block(ip, nxlen); if (rc) { dbFree(ip, nxaddr, (s64) nxlen); mutex_unlock(&JFS_IP(ip)->commit_mutex); return rc; } /* determine the value of the extent flag */ xflag = abnr ? XAD_NOTRECORDED : 0; /* if we can extend the hint extent to cover the current request, * extend it. otherwise, insert a new extent to * cover the current request. */ if (xaddr && xaddr == nxaddr) rc = xtExtend(0, ip, xoff, (int) nxlen, 0); else rc = xtInsert(0, ip, xflag, xoff, (int) nxlen, &nxaddr, 0); /* if the extend or insert failed, * free the newly allocated blocks and return the error. */ if (rc) { dbFree(ip, nxaddr, nxlen); dquot_free_block(ip, nxlen); mutex_unlock(&JFS_IP(ip)->commit_mutex); return (rc); } /* set the results of the extent allocation */ XADaddress(xp, nxaddr); XADlength(xp, nxlen); XADoffset(xp, xoff); xp->flag = xflag; mark_inode_dirty(ip); mutex_unlock(&JFS_IP(ip)->commit_mutex); /* * COMMIT_SyncList flags an anonymous tlock on page that is on * sync list. * We need to commit the inode to get the page written to the disk. */ if (test_and_clear_cflag(COMMIT_Synclist,ip)) jfs_commit_inode(ip, 0); return (0); } /* * NAME: extHint() * * FUNCTION: produce an extent allocation hint for a file offset. * * PARAMETERS: * ip - the inode of the file. * offset - file offset for which the hint is needed. * xp - pointer to the xad that is to be filled in with * the hint. * * RETURN VALUES: * 0 - success * -EIO - i/o error. */ int extHint(struct inode *ip, s64 offset, xad_t * xp) { struct super_block *sb = ip->i_sb; int nbperpage = JFS_SBI(sb)->nbperpage; s64 prev; int rc = 0; s64 xaddr; int xlen; int xflag; /* init the hint as "no hint provided" */ XADaddress(xp, 0); /* determine the starting extent offset of the page previous * to the page containing the offset. */ prev = ((offset & ~POFFSET) >> JFS_SBI(sb)->l2bsize) - nbperpage; /* if the offset is in the first page of the file, no hint provided. */ if (prev < 0) goto out; rc = xtLookup(ip, prev, nbperpage, &xflag, &xaddr, &xlen, 0); if ((rc == 0) && xlen) { if (xlen != nbperpage) { jfs_error(ip->i_sb, "corrupt xtree\n"); rc = -EIO; } XADaddress(xp, xaddr); XADlength(xp, xlen); XADoffset(xp, prev); /* * only preserve the abnr flag within the xad flags * of the returned hint. */ xp->flag = xflag & XAD_NOTRECORDED; } else rc = 0; out: return (rc); } /* * NAME: extRecord() * * FUNCTION: change a page with a file from not recorded to recorded. * * PARAMETERS: * ip - inode of the file. * cp - cbuf of the file page. * * RETURN VALUES: * 0 - success * -EIO - i/o error. * -ENOSPC - insufficient disk resources. */ int extRecord(struct inode *ip, xad_t * xp) { int rc; if (isReadOnly(ip)) { jfs_error(ip->i_sb, "read-only filesystem\n"); return -EIO; } txBeginAnon(ip->i_sb); mutex_lock(&JFS_IP(ip)->commit_mutex); /* update the extent */ rc = xtUpdate(0, ip, xp); mutex_unlock(&JFS_IP(ip)->commit_mutex); return rc; } /* * NAME: extBalloc() * * FUNCTION: allocate disk blocks to form an extent. * * initially, we will try to allocate disk blocks for the * requested size (nblocks). if this fails (nblocks * contiguous free blocks not available), we'll try to allocate * a smaller number of blocks (producing a smaller extent), with * this smaller number of blocks consisting of the requested * number of blocks rounded down to the next smaller power of 2 * number (i.e. 16 -> 8). we'll continue to round down and * retry the allocation until the number of blocks to allocate * is smaller than the number of blocks per page. * * PARAMETERS: * ip - the inode of the file. * hint - disk block number to be used as an allocation hint. * *nblocks - pointer to an s64 value. on entry, this value specifies * the desired number of block to be allocated. on successful * exit, this value is set to the number of blocks actually * allocated. * blkno - pointer to a block address that is filled in on successful * return with the starting block number of the newly * allocated block range. * * RETURN VALUES: * 0 - success * -EIO - i/o error. * -ENOSPC - insufficient disk resources. */ static int extBalloc(struct inode *ip, s64 hint, s64 * nblocks, s64 * blkno) { struct jfs_inode_info *ji = JFS_IP(ip); struct jfs_sb_info *sbi = JFS_SBI(ip->i_sb); s64 nb, nblks, daddr, max; int rc, nbperpage = sbi->nbperpage; struct bmap *bmp = sbi->bmap; int ag; /* get the number of blocks to initially attempt to allocate. * we'll first try the number of blocks requested unless this * number is greater than the maximum number of contiguous free * blocks in the map. in that case, we'll start off with the * maximum free. */ /* give up if no space left */ if (bmp->db_maxfreebud == -1) return -ENOSPC; max = (s64) 1 << bmp->db_maxfreebud; if (*nblocks >= max && *nblocks > nbperpage) nb = nblks = (max > nbperpage) ? max : nbperpage; else nb = nblks = *nblocks; /* try to allocate blocks */ while ((rc = dbAlloc(ip, hint, nb, &daddr)) != 0) { /* if something other than an out of space error, * stop and return this error. */ if (rc != -ENOSPC) return (rc); /* decrease the allocation request size */ nb = min(nblks, extRoundDown(nb)); /* give up if we cannot cover a page */ if (nb < nbperpage) return (rc); } *nblocks = nb; *blkno = daddr; if (S_ISREG(ip->i_mode) && (ji->fileset == FILESYSTEM_I)) { ag = BLKTOAG(daddr, sbi); spin_lock_irq(&ji->ag_lock); if (ji->active_ag == -1) { atomic_inc(&bmp->db_active[ag]); ji->active_ag = ag; } else if (ji->active_ag != ag) { atomic_dec(&bmp->db_active[ji->active_ag]); atomic_inc(&bmp->db_active[ag]); ji->active_ag = ag; } spin_unlock_irq(&ji->ag_lock); } return (0); } /* * NAME: extRoundDown() * * FUNCTION: round down a specified number of blocks to the next * smallest power of 2 number. * * PARAMETERS: * nb - the inode of the file. * * RETURN VALUES: * next smallest power of 2 number. */ static s64 extRoundDown(s64 nb) { int i; u64 m, k; for (i = 0, m = (u64) 1 << 63; i < 64; i++, m >>= 1) { if (m & nb) break; } i = 63 - i; k = (u64) 1 << i; k = ((k - 1) & nb) ? k : k >> 1; return (k); }
