diff options
Diffstat (limited to 'fs/jfs/jfs_extent.c')
| -rw-r--r-- | fs/jfs/jfs_extent.c | 651 |
1 files changed, 651 insertions, 0 deletions
diff --git a/fs/jfs/jfs_extent.c b/fs/jfs/jfs_extent.c new file mode 100644 index 00000000..e5fe8506 --- /dev/null +++ b/fs/jfs/jfs_extent.c @@ -0,0 +1,651 @@ +/* + * Copyright (C) International Business Machines Corp., 2000-2004 + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See + * the GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +#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 *); +#ifdef _NOTYET +static int extBrealloc(struct inode *, s64, s64, s64 *, s64 *); +#endif +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; + + /* 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 disk. + */ + if (test_and_clear_cflag(COMMIT_Synclist,ip)) + jfs_commit_inode(ip, 0); + + return (0); +} + + +#ifdef _NOTYET +/* + * NAME: extRealloc() + * + * FUNCTION: extend the allocation of a file extent containing a + * partial back last page. + * + * PARAMETERS: + * ip - the inode of the file. + * cp - cbuf for the partial backed last page. + * xlen - request size of the resulting extent. + * xp - pointer to an xad. 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 extRealloc(struct inode *ip, s64 nxlen, xad_t * xp, bool abnr) +{ + struct super_block *sb = ip->i_sb; + s64 xaddr, xlen, nxaddr, delta, xoff; + s64 ntail, nextend, ninsert; + int rc, nbperpage = JFS_SBI(sb)->nbperpage; + int xflag; + + /* This blocks if we are low on resources */ + txBeginAnon(ip->i_sb); + + mutex_lock(&JFS_IP(ip)->commit_mutex); + /* validate extent length */ + if (nxlen > MAXXLEN) + nxlen = MAXXLEN; + + /* get the extend (partial) page's disk block address and + * number of blocks. + */ + xaddr = addressXAD(xp); + xlen = lengthXAD(xp); + xoff = offsetXAD(xp); + + /* if the extend page is abnr and if the request is for + * the extent to be allocated and recorded, + * make the page allocated and recorded. + */ + if ((xp->flag & XAD_NOTRECORDED) && !abnr) { + xp->flag = 0; + if ((rc = xtUpdate(0, ip, xp))) + goto exit; + } + + /* try to allocated the request number of blocks for the + * extent. dbRealloc() first tries to satisfy the request + * by extending the allocation in place. otherwise, it will + * try to allocate a new set of blocks large enough for the + * request. in satisfying a request, dbReAlloc() may allocate + * less than what was request but will always allocate enough + * space as to satisfy the extend page. + */ + if ((rc = extBrealloc(ip, xaddr, xlen, &nxlen, &nxaddr))) + goto exit; + + /* Allocat 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; + } + + delta = nxlen - xlen; + + /* check if the extend page is not abnr but the request is abnr + * and the allocated disk space is for more than one page. if this + * is the case, there is a miss match of abnr between the extend page + * and the one or more pages following the extend page. as a result, + * two extents will have to be manipulated. the first will be that + * of the extent of the extend page and will be manipulated thru + * an xtExtend() or an xtTailgate(), depending upon whether the + * disk allocation occurred as an inplace extension. the second + * extent will be manipulated (created) through an xtInsert() and + * will be for the pages following the extend page. + */ + if (abnr && (!(xp->flag & XAD_NOTRECORDED)) && (nxlen > nbperpage)) { + ntail = nbperpage; + nextend = ntail - xlen; + ninsert = nxlen - nbperpage; + + xflag = XAD_NOTRECORDED; + } else { + ntail = nxlen; + nextend = delta; + ninsert = 0; + + xflag = xp->flag; + } + + /* if we were able to extend the disk allocation in place, + * extend the extent. otherwise, move the extent to a + * new disk location. + */ + if (xaddr == nxaddr) { + /* extend the extent */ + if ((rc = xtExtend(0, ip, xoff + xlen, (int) nextend, 0))) { + dbFree(ip, xaddr + xlen, delta); + dquot_free_block(ip, nxlen); + goto exit; + } + } else { + /* + * move the extent to a new location: + * + * xtTailgate() accounts for relocated tail extent; + */ + if ((rc = xtTailgate(0, ip, xoff, (int) ntail, nxaddr, 0))) { + dbFree(ip, nxaddr, nxlen); + dquot_free_block(ip, nxlen); + goto exit; + } + } + + + /* check if we need to also insert a new extent */ + if (ninsert) { + /* perform the insert. if it fails, free the blocks + * to be inserted and make it appear that we only did + * the xtExtend() or xtTailgate() above. + */ + xaddr = nxaddr + ntail; + if (xtInsert (0, ip, xflag, xoff + ntail, (int) ninsert, + &xaddr, 0)) { + dbFree(ip, xaddr, (s64) ninsert); + delta = nextend; + nxlen = ntail; + xflag = 0; + } + } + + /* set the return results */ + XADaddress(xp, nxaddr); + XADlength(xp, nxlen); + XADoffset(xp, xoff); + xp->flag = xflag; + + mark_inode_dirty(ip); +exit: + mutex_unlock(&JFS_IP(ip)->commit_mutex); + return (rc); +} +#endif /* _NOTYET */ + + +/* + * 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, "extHint: corrupt xtree"); + 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; + + 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; +} + + +#ifdef _NOTYET +/* + * NAME: extFill() + * + * FUNCTION: allocate disk space for a file page that represents + * a file hole. + * + * PARAMETERS: + * ip - the inode of the file. + * cp - cbuf of the file page represent the hole. + * + * RETURN VALUES: + * 0 - success + * -EIO - i/o error. + * -ENOSPC - insufficient disk resources. + */ +int extFill(struct inode *ip, xad_t * xp) +{ + int rc, nbperpage = JFS_SBI(ip->i_sb)->nbperpage; + s64 blkno = offsetXAD(xp) >> ip->i_blkbits; + +// assert(ISSPARSE(ip)); + + /* initialize the extent allocation hint */ + XADaddress(xp, 0); + + /* allocate an extent to fill the hole */ + if ((rc = extAlloc(ip, nbperpage, blkno, xp, false))) + return (rc); + + assert(lengthPXD(xp) == nbperpage); + + return (0); +} +#endif /* _NOTYET */ + + +/* + * 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. + */ + 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); +} + + +#ifdef _NOTYET +/* + * NAME: extBrealloc() + * + * FUNCTION: attempt to extend an extent's allocation. + * + * Initially, we will try to extend the extent's allocation + * in place. If this fails, we'll try to move the extent + * to a new set of blocks. If moving the extent, we initially + * will try to allocate disk blocks for the requested size + * (newnblks). if this fails (new 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. + * blkno - starting block number of the extents current allocation. + * nblks - number of blocks within the extents current allocation. + * newnblks - pointer to a s64 value. on entry, this value is the + * the new desired extent size (number of blocks). on + * successful exit, this value is set to the extent's actual + * new size (new number of blocks). + * newblkno - the starting block number of the extents new allocation. + * + * RETURN VALUES: + * 0 - success + * -EIO - i/o error. + * -ENOSPC - insufficient disk resources. + */ +static int +extBrealloc(struct inode *ip, + s64 blkno, s64 nblks, s64 * newnblks, s64 * newblkno) +{ + int rc; + + /* try to extend in place */ + if ((rc = dbExtend(ip, blkno, nblks, *newnblks - nblks)) == 0) { + *newblkno = blkno; + return (0); + } else { + if (rc != -ENOSPC) + return (rc); + } + + /* in place extension not possible. + * try to move the extent to a new set of blocks. + */ + return (extBalloc(ip, blkno, newnblks, newblkno)); +} +#endif /* _NOTYET */ + + +/* + * 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); +} |